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Characterizing the coseismic slip behaviors of earthquakes could offer a better understanding of regional crustal deformation and future seismic potential assessments. On 18 December 2023, an Mw 6.0 earthquake occurred on the Lajishan–Jishishan fault system (LJFS) in the northeastern Tibetan Plateau, causing serious damage and casualties. The seismogenic fault hosting this earthquake is not well constrained, as no surface rupture was identified in the field. To address this issue, in this study, we use Interferometric Synthetic Aperture Radar (InSAR) data to investigate the coseismic surface deformation of this earthquake and invert both ascending and descending line-of-sight observations to probe the seismogenic fault and its slip characteristics. The InSAR observations show up to ~6 cm surface uplift caused by the Jishishan earthquake, which is consistent with the thrust-dominated focal mechanism. A Bayesian-based dislocation modeling indicates that two fault models, with eastern and western dip orientations, could reasonably fit the InSAR observations. By calculating the coseismic Coulomb failure stress changes (∆CFS) induced by both fault models, we find that the east-dipping fault scenario could reasonably explain the aftershock distributions under the framework of stress triggering, while the west-dipping fault scenario produced a negative ∆CFS in the region of dense aftershocks. Integrating regional geological structures, we suggest that the seismogenic fault of the Jishishan earthquake, which strikes NNE with a dip of 56° to the east, may be either the Jishishan western margin fault or a secondary buried branch. The optimal finite-fault slip modeling shows that the coseismic slip was dominated by reverse slip and confined to a depth range between ~5 and 15 km. The released seismic moment is 1.61 × 1018 N·m, which is equivalent to an Mw 6.07 earthquake. While the Jishishan earthquake ruptured a fault segment of approximately 20 km, it only released a small part of the seismic moment that was accumulated along the 220 km long Lajishan–Jishishan fault system. The remaining segments of the Lajishan–Jishishan fault system still have the capability to generate moderate-to-large earthquakes in the future. [ABSTRACT FROM AUTHOR]

Oblique convergence across the northern Qilian Shan is accommodated by sub‐parallel strike‐slip and thrust faults that ruptured simultaneously in the Mw 8 Gulang earthquake in 1927. We investigate the kinematics of fault loading in the northern Qilian Shan and provide insights into the conditions necessary for generating multi‐fault earthquakes. We perform Bayesian inversions for the geometry and creep rate on the fault network. We infer that all of the thrust faults are locked north of the Qilian‐Haiyuan strike‐slip fault and are accumulating elastic strain. Multi‐fault earthquakes may occurr in this fault system because the faults are simultaneously loaded by the same source of deformation and are linked together by locked fault segments. The interseismic velocity field alone can not contain the location or activity of individual faults visible in the geomorphology, therefore the short‐term geodetic measurements may not reliably indicate the long‐term behavior of the fault system. Plain Language Summary: This study aims to understand the earthquake hazard in the northern Qilian region of China. We use measurements of ground deformation between earthquakes to infer how the faults are being loaded in the region. We find that the ground deformation can be explained by a simple model with a single, slowly creeping fault at depth that loads all of the overlying faults. Large earthquakes that were caused by slip on many different faults at the same time have occurred in this region before. We suggest these so‐called "multi‐fault" earthquakes may occur because all of the faults are being simultaneously loaded by the same source of stress. Key Points: Oblique convergence in the northern Qilian Shan is accommodated by sub‐parallel thrust and strike‐slip faultingThe short‐term geodetic measurements do not constrain the thrust fault kinematics in the northern Qilian Shan over geological timescalesMulti‐fault earthquakes may be common in the region as all of the shallow thrust faults are linked together by locked fault segments [ABSTRACT FROM AUTHOR]

Walking and running at different speeds are common in daily life. This study investigated 6 degrees of freedom (DOF) kinematics of normal knees of Chinese during walking and running. Forty healthy participants were investigated in 4 conditions: comfortable walking, normal walking, slow running and ordinary running. The range of motion (ROM) and peak values in 6 DOF kinematics were analysed. As the speed increased, a general increase in flexion, lateral and proximal translations occurred. Significant increases of ROM in flexion/extension, axial rotation and medial/lateral translations were observed. The ROM of adduction/abduction, anterior/posterior and proximal/distal translations were greatest during normal walking. The maximum and minimum flexion/extension, maximum internal rotation and tibial lateral translations increased with the increase of speed. The maximum and minimum tibial proximal translations in running were found being greater than walking. A phenomenon between walking and running was observed: both tibial proximal/distal and medial/lateral translations increased when changed from walking to running. Non-linear transition exists in 6 DOF kinematics during walking to running. Discoveries in this study may have potential clinical values to serve as references of normal walking and running in the management of knee injury and knee rehabilitation. [ABSTRACT FROM AUTHOR]

The structural connectivity and kinematic relationship between the Altyn Tagh sinistral strike‐slip fault (ATF) and Qilian Shan fold‐and‐thrust belt along the north Tibetan margin east of 96°E is an important question for tectonicists interested in the evolving active deformation field of Central Asia and associated earthquake hazards of China's Hexi Corridor region. New results from a detailed 130‐km‐long N‐S magnetotelluric (MT) survey from the Qilian Shan to Beishan elucidates the locations and down‐dip orientations of major faults. Importantly, the results indicate that the Heishan‐Jinta'Nanshan fault system roots steeply into the lower crust, is unconnected to the Qilian Shan thrust wedge, and has reactivated the margin of the North China Craton and an older, regional ductile shear belt. The structurally linked ATF‐Heishan‐Jinta'Nanshan system defines a fundamental kinematic boundary in central Asia between the NE directed Qilian Shan thrust belt to the south and the eastwardly extruding Beishan‐Alxa Block to the north. Plain Language Summary: In this study, we present results of a comprehensive electrical resistivity survey conducted in the western Hexi Corridor region of China. The survey reveals significant sub‐surface faults and crustal boundaries, providing insights into the crustal structure between northernmost Tibet (Qilian Shan) and the Beishan. We document how the strike‐slip crustal boundary known as the Altyn Tagh Fault (ATF)‐Heishan‐Jinta'Nanshan system is steep and spatially unconnected to the Qilian Shan east of 98°E. It separates crustal blocks with contrasting motion histories; the southern block experiences compressional deformation, whereas the northern block accommodates extensional and transtensional deformation. Furthermore, the northeast trending ATF bends and converges into the more east‐west‐oriented Heishan‐Jinta'Nanshan system. We propose that this is a result of the Heishan‐Jinta'Nanshan system reactivating an older ductile shear belt and a mechanically weak boundary along the northwestern margin of the Precambrian North China Craton. Our study confirms the significance of inherited crustal structures in localizing continental interior reactivation and associated earthquake hazards. Key Points: A new detailed 3D resistivity model from Northern Tibet to the Southern Beishan clarifies the crustal structure in the NW Hexi CorridorThe Heishan fault system penetrates steeply to the lower crust and is unconnected to the Qilian Shan thrust wedgeCrustal thickening and mountain uplift in Qilian Shan is kinematically separated from eastward Beishan‐Alxa Block extrusion further north [ABSTRACT FROM AUTHOR]

This study compared performance strategies and sub-technique selection in cross-country skate skiing sprint races, specifically individual time-trial (ITT) and head-to-head (H2H) formats. Fourteen male cross-country skiers from the Chinese national team participated in the FIS-sanctioned sprint race day. GNSS and heart rate sensors recorded positioning, skiing speeds, heart rate, sub-technique usage, and skiing kinematics. Statistical parametric mapping (SPM) was used to determine the course positions (clusters) where instantaneous skiing speed was significantly associated with section time. One-way analyses of variance were used to examine differences between the ITT and H2H. H2H race speeds were 2.4 ± 0.2% faster than the ITT race (p < 0.05).Variations in sub-technique and skiing kinematics were observed between race formats, indicating different strategies and tactics employed by athletes. SPM identified specific clusters (primarily uphill) where the fastest athlete gained significant time over the slowest. The greatest time gains were associated with higher G3 sub-technique usage and longer G3 cycle length on steep uphill terrain (9–13% gradients). Integrating SPM analyses and sub-technique assessments can help optimise performance and tactics in sprint races. This study enhances our understanding of cross-country skiing dynamics and performance variations among elite competitors. [ABSTRACT FROM AUTHOR]

Geomorphological and sedimentological characteristics are key evidences for understanding the emplacement mechanisms of rock avalanches. Based on remote sensing, photogrammetry, and field surveys, the depositional characteristics of the Alasu rock avalanche (ARA) in southern Tianshan, China, were investigated in detail. It is reached that the ARA has a detached rock mass volume of ~ 93 × 106 m3 and propagated 3874 m on rugged terrain with a drop height of 1030 m. Large rock blocks (95,598 rock blocks with sizes ≥ 0.5 m) are widely distributed on the deposit surface. There is no decreasing trend in block size with travel distance for these rock blocks, while jigsaw and sibling structures of megablocks commonly occur in the carapace facies. The size and structural features of megablocks demonstrate that the carapace facies underwent a passive emplacement process with low degrees of fragmentation and disturbance. Furthermore, a series of surficial landforms, including irregular platforms, minor scarps, lateral levees, run-ups, ridges, and troughs, are preserved in the rock avalanche deposit. The most remarkable features are the large, subparallel, curved longitudinal ridges with continuous directional variations and three run-up traces. Extensions of these ridges indicate that the avalanche mass experienced a continuous extension-dominated process in emplacement due to its momentum transfer effect and high energy propagation. These observations and analyses may elucidate the emplacement mechanisms of rock avalanches in rugged landscapes. [ABSTRACT FROM AUTHOR]

Purpose: Para‐alpine sit skiers face unique challenges in balance control due to their disabilities and the use of sit skis. This study assessed their multi‐joint coordination before and after slackline training. Methods: Nine alpine sit skiers (6 M/3 F; 27 ± 8 years; height: 168.3 ± 6.0 cm; body mass: 55.4 ± 6.9 kg) with different disabilities (LW10‐LW12) volunteered for the experiment. All subjects performed slackline training for 5 weeks (20 sessions). Joint kinematics were captured by vision‐based markerless motion analysis. Root mean square (RMS) amplitude, mean velocity and mean power frequency (MPF) were evaluated. Results: After training, performance improved significantly with an increase in balance time (1041%, p = 0.002), and a decrease in joint angular velocities and RMS amplitude of the sit ski foot (p < 0.05). Joint synergies were developed through in‐ or anti‐phase movements between joint pairs, particularly involving the hip joints (continuous relative phase angles ~0° or 180°, p < 0.001). Multi‐joint coordination shifted from large‐RMS amplitude of elbows to low‐MPF large‐RMS amplitude of the hip and shoulders (p < 0.05), with a significant increase of hip weighting (77.61%, p = 0.031) in the principal component analysis. The coordination was maintained with the change of slackline tension (p < 0.05). Athletes with severe trunk disabilities (LW10) had shorter balance time and poorer coordination than athletes with full trunk functions (LW12). Conclusions: Our findings showed the development of joint coordination involving better control of the hip and sit skis during the challenging slackline training task. [ABSTRACT FROM AUTHOR]

As a part of the Columbia supercontinent, the North China craton is an ideal object for studying the evolution of supercontinent assembly and the mechanism of orogenesis in the Paleoproterozoic. The Jiao-Liao-Ji belt, located in the eastern part of the North China craton, provides important clues for our understanding of Paleoproterozoic orogenic processes. A series of Paleoproterozoic granitic gneiss domes is preserved in the Liaodong segment of the Jiao-Liao-Ji belt. These domes are cored by the Liaoji granitic gneisses (emplaced at 2250-2150 Ma) and mantled by metamorphosed volcanic-sedimentary rocks (deposited at 2200-1940 Ma). Combining multiple lines of evidence from mesostructures and microstructures, kinematics, magnetic fabrics, and crystallographic fabrics, we suggest that the granitic gneiss domes reflect inhomogeneous shearing of the middle to lower crust during Paleoproterozoic orogenic processes. Intensive layer-paralleling shearing characterized subhorizontal flow during nearly E-W--oriented compression. As a hot orogen formed in the Paleoproterozoic, the orogenic deformation in the Jiao-Liao-Ji belt was characterized by extensive doming due to dominant subhorizontal flow and subsidiary vertical flow in the middle to lower crust. [ABSTRACT FROM AUTHOR]

The Xieliupo landslide is a typical large-scale active landslide in Zhouqu, China, in the Pingding-Huama fault zone that has slid eight times since the beginning of the twentieth century. The landslide has caused catastrophic environmental, economic, and life losses in the area. In this study, combining the geomorphological field surveys, Unmanned Aerial Vehicle (UAV) mapping, interpretation of optical images, InSAR, and Cosi-Corr (Co-registration of Optically Sensed Images and Correlation) monitoring analysis, we conducted insights into the deformation kinematics of large Xieliupo landslide. The Xieliupo landslide has the characteristics of graded sub-activity with eight secondary landslides. The secondary landslides I and II in the upper parts are loess slide-flow with a moving pattern of creep–rip–push on the condition of steep gradient and the triggering of intense precipitation. The middle part was divided into two sides by a relatively stable ridge, where the loess rotational landslides III and collapse VI in the northern side are controlled by low-lying terrain in the valley, and the landslides IV and V are moderately active under the influence of steep gradient and compression from the landslides I and II. The secondary landslides VII and VIII in the toe are relatively slightly active with a gentle slope gradient influenced by road construction and Bailong River erosion. Time-series InSAR deformation from 2015 to 2020 revealed a close positive correlation between accelerating displacements and increasing precipitation. The deformation response characteristics of cascade collapse retreat and fluctuating acceleration of the Xieliupo landslide to heavy rainfall were revealed. The seismic activity is one probable factor contributing to the reactivated displacement of Xieliupo landslide. Notably, the intense rainfall on August 13, 2020, triggered the maximum displacement of 5.93 m in a sliding direction of 319° (NW) at secondary landslide II. This study significantly provides new insight into the deformation characteristics and kinematics of Xieliupo and reference for catastrophic landslide hazard mitigation. The proposed technique strategy can be used for analyzing similar large complex landslides in other mountainous regions. [ABSTRACT FROM AUTHOR]

Background: Long-term nursing home (NH) care helps NH residents with their daily activities and improves their quality of life, but negatively affects their independent physical activities and increases the risk of dangerous events. Dangerous events in the elderly usually occur in the conversion of walking periods when forward striding has already happened, but the body has not yet entered a completely steady walking. Objectives: Compare the gait characteristics in Chinese long-term NH residents and community-living elderly during the walking Transitional Period (TP) and Stabilization Period (SP). Methods: 32 long-term NH residents and 33 age- and sex-matched community-living elderly were recruited. The 30-Second Chair Stand Test (30-s CST), Timed Up and Go Test (TUGT), and Modified Falls Efficacy Scale (MFES) were used to assess their body function. The Xsens MVN BIOMECH system was used to collect and analyze the gait parameters of participants. Results: Compared to community-living elderly, NH residents had fewer numbers of 30-s CST, took more time to complete TUGT, and lower MEFS scores. NH residents showed slower gait speed (P < 0.001), less peak hip flexion (P = 0.022) and extension (P = 0.003), knee internal rotation (P = 0.023), and ankle plantarflexion (P = 0.001) and internal rotation (P = 0.007) angles during walking. When walking progressed from TP to SP, NH residents showed increased ankle dorsiflexion (P < 0.001), decreased hip internal rotation (P < 0.001), and community-living elderly had increased hip extension (P = 0.005) angles. Conclusions: Chinese long-term NH residents had reduced lower extremities strength and postural balance, and higher fear of falling compared to community-living elderly. Their walking performance also showed high fall risk. Besides, long-term NH residents adopted a distal strategy to propel the body forward, which may be a compensatory measure to compensate for inadequate proximal joint control from forward walking to stable walking, and long-term NH residents have reduced postural stability during this process. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the effects of stroke rate and sex on trunk and shoulder kinematics of Olympic athletes during rowing on an ergometer. Fifty-eight participants (31 females and 27 males) from the Chinese National Rowing Team were recruited. Trunk (i.e., the pelvis, lumbar and thoracic spine) and shoulder kinematics were measured using an inertial measurement unit system for three stroke rates (18, 26, and 32 strokes/min). Range of motion and angles at the catch and finish were assessed using mixed model ANOVA and correlation analyses with rowing power. Range of motion increased significantly at higher rates for both female and male athletes. This may be a strategy used by athletes when dealing with higher demand for power during training, because a greater range of motion with a longer stroke length could reduce the demand for force generation and possibly delay fatigue. Female rowers exhibited greater range of motion in the lumbar spine, thorax and shoulders than males due to more extended positions at the finish. The sex-related kinematic differences may be attributed to differences in body size, muscle strength and endurance. Practitioners are recommended to consider these factors when developing rowing techniques and providing training suggestions. [ABSTRACT FROM AUTHOR]

Background and objectives: Alzheimer's disease (AD) has an insidious onset, the early stages are easily overlooked, and there are no reliable, rapid, and inexpensive ancillary detection methods. This study analyzes the differences in handwriting kinematic characteristics between AD patients and normal elderly people to model handwriting characteristics. The aim is to investigate whether handwriting analysis has a promising future in AD auxiliary screening or even auxiliary diagnosis and to provide a basis for developing a handwriting-based diagnostic tool. Materials and methods: Thirty-four AD patients (15 males, 77.15 ± 1.796 years) and 45 healthy controls (20 males, 74.78 ± 2.193 years) were recruited. Participants performed four writing tasks with digital dot-matrix pens which simultaneously captured their handwriting as they wrote. The writing tasks consisted of two graphics tasks and two textual tasks. The two graphics tasks are connecting fixed dots (task 1) and copying intersecting pentagons (task 2), and the two textual tasks are dictating three words (task 3) and copying a sentence (task 4). The data were analyzed by using Student's t-test and Mann-Whitney U test to obtain statistically significant handwriting characteristics. Moreover, seven classification algorithms, such as eXtreme Gradient Boosting (XGB) and Logistic Regression (LR) were used to build classification models. Finally, the Receiver Operating Characteristic (ROC) curve, accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Area Under Curve (AUC) were used to assess whether writing scores and kinematics parameters are diagnostic. Results: Kinematic analysis showed statistically significant differences between the AD and controlled groups for most parameters (p < 0.05, p < 0.01). The results found that patients with AD showed slower writing speed, tremendous writing pressure, and poorer writing stability. We built statistically significant features into a classification model, among which the model built by XGB was the most effective with a maximum accuracy of 96.55%. The handwriting characteristics also achieved good diagnostic value in the ROC analysis. Task 2 had a better classification effect than task 1. ROC curve analysis showed that the best threshold value was 0.084, accuracy = 96.30%, sensitivity = 100%, specificity = 93.41%, PPV = 92.21%, NPV = 100%, and AUC = 0.991. Task 4 had a better classification effect than task 3. ROC curve analysis showed that the best threshold value was 0.597, accuracy = 96.55%, sensitivity = 94.20%, specificity = 98.37%, PPV = 97.81%, NPV = 95.63%, and AUC = 0.994. Conclusion: This study's results prove that handwriting characteristic analysis is promising in auxiliary AD screening or AD diagnosis. [ABSTRACT FROM AUTHOR]

Treadmill training is useful for racewalking training; however, it may affect gait characteristics and lead to non-legal techniques. The aim of this study was to determine the kinematic differences between treadmill and overground conditions during racewalking at different speeds. Twenty-two elite racewalkers participated in this study. They racewalked under treadmill and overground conditions at high and medium speeds. A 12-camera motion analysis system was used to record the racewalking trials. Significant condition by speed interactions were detected in step frequency and pelvis rotation angle; step frequency decreased while pelvis rotation angle increased from overground to treadmill conditions at high speed. Compared to overground conditions, racewalkers decreased the ankle dorsiflexion angle at heel strike and increased hip flexion, shoulder hyperextension, and elbow flexion angles at heel strike and hip and shoulder extension angles at toe-off under treadmill conditions. Compared to medium speed, racewalkers decreased the contact time, hip flexion, and shoulder hyperextension at heel strike, and ankle plantarflexion and shoulder extension angles at toe-off, and increased flight time, step length, and elbow flexion angle at heel strike at high speed. Several kinematic differences during racewalking were detected between treadmill and overground conditions, with more differences detected at high speed, indicating that treadmill racewalking, especially at high speed, has different gait characteristics. However, no differences were detected in flight time and knee angle under treadmill conditions compared to overground conditions, indicating that racewalking on a treadmill does not increase the risk of disqualification. [ABSTRACT FROM AUTHOR]

Background: Measurement of knee laxity after anterior cruciate ligament (ACL) injury is crucial for appropriate treatment and rehabilitation decision-making. This study examined the potential of a new digital arthrometer (Ligs, Innomotion, Shanghai, China) to quantify anterior tibial translation (ATT) in patients with ACL injuries and in healthy subjects. Methods: A total of 60 participants included 30 subjects with single-leg ACL injuries and 30 healthy subjects included as controls. The lower leg was immobilized. The thruster is positioned posterior to the lower leg and parallel to the tibial tuberosity in the sagittal plane. The load is applied vertically to the tibia under a dynamic load of 0–150 N, with continuous displacement recorded. The intrarater and interrater reliability will be examined. ATT and side-to-side differences (SSD) between the control and ACL injury groups were compared. Receiver operating characteristic (ROC) curves were analyzed, and the area under the curve (AUC) was calculated to determine the diagnostic accuracy of the Ligs. Results: The interrater ICC was 0.909 and the intrarater ICC was 0.943. Significant differences in the SSD were observed between the control and ACL injury groups (for all P < 0.05), with the largest effect size (ES = 1.12) at 80 N. When comparing ATT at different loads between injured and healthy sides in the ACL injury group, displacement was statistically significant at different loads. At a load of 150 N, the AUC was the maximum (0.857) and the sensitivity and specificity were 0.87 and 0.73, respectively. Conclusions: A digital arthrometer can be used as a quantitative instrument to quantify knee laxity. Quantitative measurement of ATT and SSD under controlled loading can be an objective and effective tool for clinical practice. [ABSTRACT FROM AUTHOR]

Rock glaciers are typical periglacial landforms with tongue or lobate morphological shapes and characterized by the distinct front, lateral margins, and often by ridge-and-furrow surface topography textures as well as kinematic characteristics, widely distributed in alpine environments. Multitemporal Synthetic aperture radar interferometry (MT-InSAR), is a remote sensing technique with demonstrated effectiveness for detecting landform kinematics. However, its application to rock glaciers is challenged by temporal decorrelation and atmospheric phase noises due to complex topography and snow cover. We designed a quadtree segmentation and parallel computing-based MT-InSAR method to improve the quality and efficiency of deformation measurement of rock glaciers. We applied the method to a rock glacier inventory of the Nyainqêntanglha Range, China, derived from high-resolution Gaofen-2 images, to quantify the activity rate of each rock glacier. Results showed that 32.1% (6,389) of the identified rock glaciers exhibited slope-parallel deformation rates exceeding 100 mm/y. The activities of the rock glaciers exhibited strong correlations with their distance to glaciers, precipitation, freeze–thaw magnitude, and permafrost occurrence probability. The results demonstrate the effectiveness of the developed segmentation-parallel MT-InSAR method for monitoring rock glacier deformation over a large region. [ABSTRACT FROM AUTHOR]

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Natural ester insulating oil not only has a biodegradation rate of almost 100% but also meets the carbon emission requirements of China’s “Carbon Peak and Carbon Neutrality” and the “European Green Deal” proposed by the European Union. It is considered to be a good substitute for mineral insulating oil. However, due to its higher kinematic viscosity than traditional mineral oil in low-temperature environments, it limits the safety promotion and application of transformers in cold regions. First, we design an experiment to test the kinematic viscosity and density of natural ester insulating oil. Under extremely harsh experimental conditions, we measure key experimental data such as kinematic viscosity. Second, the structure of the four main triglyceride molecules is optimized, and the molecular dynamics (MD) simulation technology is used to establish an MD model that can predict the kinematic viscosity of natural ester insulating oil (−20 °C to 20 °C). Finally, the model is further simplified by the free volume theory to better predict the kinematic viscosity of natural ester insulating oil. This study makes up for the lack of laboratory low-temperature testing of the kinematic viscosity of natural ester insulating oil and provides a convenient and reliable tool for predicting the kinematic viscosity of natural ester insulating oil. It can not only predict the natural ester insulating oil mixed in various proportions but also predict the kinematic viscosity of a certain natural ester molecule. Furthermore, it also provides a guiding direction for the improvement of low-temperature kinematic viscosity of natural ester insulating oil, as well as a strong reference for predicting other properties of other substances. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the difference of kinematic skill characteristics between the Chinese and world elite female discus athletes. We used the methods of literature, three-dimensional video analysis, and mathematical statistics to compare and analyze the differences of some kinematic parameters between the three Chinese female discus athletes and four world female discus athletes. The result shows that the speed of discus release of the Chinese elite female discus athletes is lower (p < 0.05) than that of the world elite female discus athletes. Compared to the world elite female discus athletes, the height of release is higher (p < 0.05). But there was no significant difference in the angle of release (p > 0.05), rotation rhythm (p > 0.05), and discus speed increment (p > 0.05) in different stages during the throwing procedure from double support stage to delivery stage. The results may provide reference for the special technique training of the Chinese female discus throwers, so as to improve the discus throwing level of Chinese women. [ABSTRACT FROM AUTHOR]

BACKGROUND: Proprioception is essential for the normal movement of knee joints. How proprioception training affects the postoperative knee functional recovery after anterior cruciate ligament (ACL) reconstruction remains unknown. OBJECTIVE: This study investigated the effect of proprioception training on the knee joint kinematics of patients after ACL reconstruction (ACLR). METHODS: The randomized controlled study was performed at the Department of Orthopaedics and Traumatology of Guangdong Provincial People's Hospital between December 2019 and April 2021. Forty-five patients who underwent ACLR were randomly divided into a proprioception group (n = 23) and a control group (n = 22). The patients were randomly divided into an experimental group and a control group according to whether the final digits of their ID numbers were odd or even. All patients followed a common postoperative rehabilitation program. The outcome measures included the patients Lysholm scores, hop distances, and knee kinematics during unanticipated jump-cut maneuvering measured at different follow-up times. Knee joint kinematics were described as the positional and orientational changes of the femur relative to the tibia. RESULTS: After surgery, the proprioception group did not exhibit significantly higher hop distances than the control group at the 6-month (114.8 ± 19.0 vs. 105.9 ± 20.7 cm, p = 0.137, 95% CI: - 3.13 to 22.03 cm) and 1-year follow-ups (143.1 ± 19.3 vs. 133.9 ± 26.2 cm, p = 0.216, 95% CI: - 5.57 to 23.87 cm). For knee joint kinematics, the members of the proprioception training group exhibited significantly reduced knee abduction (valgus) angles and external rotation and significantly increased knee flexion compared to those in the common training group. CONCLUSIONS: The results suggested that proprioceptive rehabilitation training enhances knee joint functional performance and shows altered knee joint kinematics in ACL-reconstructed populations during unanticipated jump-cut maneuvering compared with the common rehabilitation training. [ABSTRACT FROM AUTHOR]

Background: Axial disturbances are the most disabling symptoms of Parkinson's disease (PD). Kinect-based objective measures could extract motion characteristics with high reliability and validity. Purpose: The present research aimed to quantify the therapy-response of axial motor symptoms to daily medication regimen and to explore the correlates of the improvement rate (IR) of axial motor symptoms based on a Kinect camera. Materials and methods: We enrolled 44 patients with PD and 21 healthy controls. All 65 participants performed the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III and the Kinect-based kinematic evaluation to assess arising from a chair, gait, posture, and postural stability before and after medication. Spearman's correlation analysis and multiple linear regression model were performed to explore the relationships between motor feature IR and clinical data. Results: All the features arising from a chair (P = 0.001), stride length (P = 0.001), velocity (P < 0.001), the height of foot lift (P < 0.001), and turning time (P = 0.001) improved significantly after a daily drug regimen in patients with PD. In addition, the anterior trunk flexion (lumbar level) exhibited significant improvement (P = 0.004). The IR of the axial motor symptoms score was significantly correlated with the IRs of kinematic features for gait velocity, stride length, foot lift height, and sitting speed (rs = 0.345, P = 0.022; rs = 0.382, P = 0.010; rs = 0.314, P = 0.038; rs = 0.518, P < 0.001, respectively). A multivariable regression analysis showed that the improvement in axial motor symptoms was associated with the IR of gait velocity only (β = 0.593, 95% CI = 0.023-1.164, P = 0.042). Conclusion: Axial symptoms were not completely drug-resistant, and some kinematic features can be improved after the daily medication regimen of patients with PD. [ABSTRACT FROM AUTHOR]

The debate on the role of vertical versus horizontal tectonism in Archean cratons is intimately linked to the initiation of plate tectonics. The dome-and-keel architecture has been considered as a consequence of vertical tectonism. Although such a structural pattern is documented in some Mesoarchean and older cratons, such as the Kaapvaal and Pilbara cratons, whether it also occurs in Neoarchean cratons is poorly constrained. Determining the kinematics, structural evolution, and the timing of these structures is crucial in understanding how the tectonic behavior operated during the evolution of the early Earth. The North China Craton, especially its eastern part, is a Neoarchean continental block and preserves typical greenstone- granite rock assemblages. Detailed structural mapping reveals that the Anziling area (east China) is characterized by a typical dome structure without significant reworking by later deformation. The dome is in tectonic contact with a supracrustal rock assemblage that is now the dip-slip Shuangshanzi ductile shear zone. In the supracrustal rocks, compositional layers are folded into upright isoclinal folds. Meanwhile, along the shear zone, foliation varies from NNW to SW with sub-vertical dip. Mineral stretching lineations indicate a sinistral shear sense with a slightly oblique-slip component in the north, but show NWW-directed and SW-directed steep dip-slip shear in the west and south, respectively. Kinematic indicators imply that the granitic dome formed through a vertically upward movement accompanied by an uneven clockwise rotation. The supracrustal rocks sank downwards to form the regional keel structure. Structural data suggests that the Anziling area is a typical dome-and-keel structure. U-Pb zircon dating on pre-, syn-, and post-tectonic dykes indicate that the dome-and-keel structure formed at 2530-2500 Ma, and was intimately related to the emplacement of tonalite-trondhjemite-granodiorite granitoids. New data from this study suggest that until the late Neoarchean, the vertical tectonism was still a dominant tectonic regime that was operating in the eastern North China Craton. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) injury can lead to changes in tibiofemoral kinematics during gait, but the detailed short-term kinematic changes after ACL injury are still unknown. Purpose: To measure tibiofemoral kinematics during gait in ACL-deficient (ACLD) knees over time after ACL injury. Study Design: Controlled laboratory study. Methods: The authors categorized 76 patients with unilateral ACLD knees into 4 groups based on the time from injury: <3 months (group 1), 3 to 6 months (group 2), >6 to 12 months (group 3), and >12 months (group 4). The controls were 20 participants with ACL-intact knees. Changes in the knee kinematics and range of motion during gait were compared among ACLD groups and those with ACL-intact knees. Results: Compared with controls, the range of motion of flexion in group 1 was significantly lower (6°; P =.033), and the mean knee flexion was significantly increased (0.7°-3.4°) in groups 1 to 4 (all P ≤.004). There was more internal tibial rotation (2.9°-4.3°) in group 1 and 2, and more anterior tibial translation (4.3 mm) in group 1 during the stance or swing phases than in controls (P ≤.049 for all). The mean internal tibial rotation and anterior tibial translation significantly decreased from group 1 to group 4 (P <.001 for both). Compared with controls, the mean medial tibial translation was significantly greater (1.2-2.5 mm) in all groups, and more medial tibial translations (2.4-3.7 mm) were observed during the stance phase in groups 1, 3, and 4 (P ≤.047 for all). Conclusion: ACLD knees displayed a motion impairment walking strategy within 3 months, and a higher-flexion walking strategy increased with time after injury. Excessive anterior translation and internal rotation of the tibia tended to return to normal, while excessive medial translation of the tibia increased in ACLD knees after 6 months postinjury. These results may provide new insight into the compensatory mechanisms and risk factors for premature osteoarthritis in ACLD knees. [ABSTRACT FROM AUTHOR]

The North China Craton (NCC) is an important tectonic element in China, which is characterized by intense seismic activity and complex tectonic setting. Thus quantifying its deformation is essential for studying the tectonic processes and deformation mechanisms in this region. Here we use a combination of dense GPS data sets to analyze the crustal movement and present updated estimates of fault motions based on elastic block models. We uncover spatial variations in deformation patterns, indicating that different mechanisms may dominate the tectonic processes for different parts of the NCC. In the western part, the rifts around the Ordos block manifest strike‐slip and extensional deformation, and the strike‐slip motion is more significant than the extensional component; whereas in the east, the Tanlu fault experiences right‐lateral and shortening slips, consistent with the features from historical seismic activity and regional tectonics. Our analysis indicates that the deformation in the eastern NCC is principally influenced by the Pacific subduction, whereas the deformation in the western NCC is mainly related to the India‐Eurasia collision. Moreover, our estimate of motion along the Tanlu fault supports a relatively long seismic interval of ∼10 ka, comparable to those inferred from recent paleoseismic research on this fault and other slow‐slip faults in the NCC. Our study indicates that the faults in the NCC even with very slow motions may still have the potential to produce strong earthquakes. Thus seismic risks across these slow‐slip faults cannot be ignored and should not be determined solely based on the rate of fault motions. Plain Language Summary: North China is situated at the eastern part of the Chinese continent, which is characterized by intense seismic activity and dense population. Numerous strong earthquakes have occurred in this region that caused huge casualties during the past decades. Thus quantifying the fault slip rates is essential for understanding the deformation regimes and seismic risk assessments in this region. Here we use dense space‐geodetic measurements to analyze the crustal movement and fault motion in the study area. We reveal that the fault motion derived in our study exhibits distinct features of deformation from west to east of the region, implying that different regimes may dominate the tectonic processes in different parts of North China. Moreover, our analysis suggests that the faults even with very slow motions in this region may still have the potential to produce strong earthquakes. Thus, seismic hazards across these slow‐slip faults cannot be ignored and should not be determined solely based on the rate of fault motions. Key Points: We use dense GPS measurements and elastic block models to quantify the faulting kinematics and slip partitioning in North ChinaWe find spatial variations of kinematics, implying that different regimes may dominate tectonic processes for different parts of North ChinaSeismic risks along slow‐slip faults cannot be ignored and should not be determined solely based on the rate of fault motions in North China [ABSTRACT FROM AUTHOR]

Knowledge of kinematics is crucial for understanding landslide mechanisms and assessing hazards. However, characterizing landslide kinematics is often challenging because landslides are sudden events with spatial and temporal coverage. Combining field investigations and remote sensing, the present study reveals the kinematic features, evolution processes, and triggering mechanism of a translational debris slide (the Tonghua landslide) that occurred on August 8 of 2017 in Sichuan Province, China. Based on digital orthophoto maps and digital elevation models derived from unmanned aerial vehicle photogrammetry, 3 years of post-failure kinematics were surveyed in detail. The landslide body experienced moderate-velocity (1.19–3.98 m/d) to slow-velocity (33.2–205.5 mm/d) sliding, eventually entering a period of very-slow-velocity (0.1–1.0 mm/d) sliding. A long-term pre-failure creeping process in the source area of the landslide was detected by interpreting interferometric synthetic aperture radar data and satellite images. At the front part of the source area, the observed deformation velocity was 15–25 mm/year between November 7, 2014 and July 30, 2017. Additionally, the source area of the landslide was found to be located on a hollow slope within a cirque catchment of ~ 67,500 m2. This complicated topographic feature promoted groundwater infiltration and long-term slope creeping; indeed, the 2008 Wenchuan earthquake may have aggravated surface cracking and soil weakening. Long-term creep of the slope caused cracking, saturation, and deformation of the soil body. Finally, seismic effects caused by tunnel blasting triggered sliding of the deformed soils. [ABSTRACT FROM AUTHOR]

While the morphology and evolution of the quadrate among early birds and through the evolutionary origin of birds is not well known, we add to knowledge about that past diversity through description of the morphology of the quadrate in the unusually elongate skull of the Cretaceous enantiornithine bird Longipteryx chaoyangensis. The lateral and caudal surfaces of the quadrate are well exposed in two specimens revealing morphologies typical of early birds and their dinosaurian close relatives like a small otic head and two mandibular condyles. However, both skeletons exhibit quadrates with a unique, enlarged lateral crest that has not been previously described among Mesozoic birds. It is possible that the rostral surface of this lateral expansion served as the origination site for enlarged jaw musculature in a manner similar to the enlarged subcapitular tubercle in extant galloanserine birds. The caudally concave surface of the quadrate likely reflects some aspect of cranial pneumaticity, with its shape and position reminiscent of quadrates found in close non‐avialan maniraptoran relatives. It is possible that this lateral crest has a wider distribution among enantiornithines and other early birds and that the crest has been misidentified as the orbital process in some more damaged specimens. In addition, the enlarged lateral mandibular condyle (relative to the medial condyle) differs from the condition typically reported among enantiornithines and could indicate a difference in jaw function or mechanics in this bird with an elongated rostrum, or simply misinterpretations of morphology. Further examination of the quadrate in temporally early and phylogenetically stemward birds, along with their close outgroups, could greatly impact the study of several different aspects of bird biology including assessment of phylogenetic relationships, interpretation of the function and kinematics of the skull, reconstruction of foraging paleoecology, and evolution of skull morphological diversity among Mesozoic birds. [ABSTRACT FROM AUTHOR]

In the abandoned mine area with Karst landform in China, soils are few and thin but rocks are common, traditional planting hole diggers are unequal to work in rocks for vegetation restoration. A reamer bit with variable lateral drilling radius was designed based on the PDC (polycrystalline diamond compact) bit technology and metamorphic mechanism. Two lateral camber blades with PDC teeth were installed inside the bit body, a screw mechanism was employed as the actuation and a spatial double triangle mechanism was taken for the transmission. The curve of the camber blade was specially defined thus the reaming load was decentralized to 85.7% teeth on the blade. The kinematics of the lateral reamer bit was analysed, the mapping models from the actuation to the reaming radius and speed were established. Concrete samples were reamed indoors from 240mm to 407mm in diameter, the reaming cutting load and time length were measured and analysed. The lateral reamer bit was approved with the experiment results, this study provided equipment support for digging the planting hole in rocky abandoned mine areas and also expanded the PDC bit application. [ABSTRACT FROM AUTHOR]

The relationship between the North and South China blocks, particularly their spatial- temporal framework and evolutionary history, has been widely debated. We conducted a comprehensive study of the structural geometry and kinematics of the thrust belts in the intersection zone between the Dabashan and eastern Sichuan Basin based on seismic data, drilling data, field investigation data, and zircon and apatite (U-Th)/He thermochronology data. These data sets provide important insights into the relationship between the North and South China blocks during the post-orogenic process. Due to the detachments, the strata of the eastern Sichuan Basin can be divided into four structural intervals characterized by duplex structures and fault-related fold structures. Balanced restoration indicates the vertical differences are represented by the shortening ratio of the upper structural interval of ~6%, that of the middle ~10%, and that of the lower ~7%. Besides, the shortening ratios indicate an increasing tendency of the deformation intensity from the west to the east. The (U-Th)/ He dating results suggest two age ranges, i.e., from 180 Ma to 130 Ma and from 50 Ma to 20 Ma, respectively. These age data sets also imply a younger tendency westward. The intersection zone may have experienced the following stages since the late Mesozoic era: (1) the stable continental sedimentation stage from the Late Triassic to the Late Jurassic epochs; (2) the continuous thrust stage from the Late Jurassic to the early Paleogene epochs, which is associated with the subduction of the Paleo-Pacific Ocean; and (3) the uplift and denudation stage as a whole caused by the uplift of the Tibetan Plateau since the Paleogene period. [ABSTRACT FROM AUTHOR]

The strength of tectonic deformation in tectonically complex regions, particularly multi-stage superimposed tectonic regions, can have a significant impact on shale gas preservation conditions. However, differential tectonic deformation has still not been quantitatively constrained, and its impact on the preservation conditions of shale gas is thus poorly understood in the northern Guizhou Province, southwest China. This study investigates the differential preservation conditions of marine shale gas in four eroded synclines (including Shixi, Daozhen, Zhongguan, and Fuyan Synclines) of the northern Guizhou Province. Interpretation of structures in field outcrops, geometry and kinematic analysis, and typical gas reservoir anatomy are combined to quantitatively explore the effect of superimposed deformation on the preservation conditions of shale gas. According to a set of new structural and kinematic constraints, the Riedel shear model for strike-slip faults is firstly conducted in the eroded synclines in the northern Guizhou Province, which innovatively established a linkage between detailed structural analysis and evaluation of shale-gas preservation conditions. We demonstrate that superimposing of deformations plays a role in differential accumulation in eroded synclines. The results indicate that (1) fault strike in the Shixi Syncline is more concentrated than Zhongguan and Fuyan Synclines, whereas fault strikes in the Zhongguan and Fuyan Synclines are more scattered. There is only one direction of maximum principal stress (σ 1) in the Shixi and Daozhen Synclines. There are two maximum principal stress directions (σ 1) in the Zhongguan and Fuyan Synclines. The Zhongguan and the Fuyan Synclines have tensional environments, whereas the Shixi and the Daozhen Syncline have compressional settings; (2) the formation dip angle, distance to a class II fracture, average detachment layer thickness, intensity of superimposed modifications, and interlimb angle may be positively correlated with gas content; (3) the progressive transformation pattern is established. These findings lay the foundation for the future research on the differential preservation mechanism of eroded synclines and may be useful for enhancing research on worldwide strike-slip faults controlling hydrocarbon accumulation. • Riedel shear model first adopted on shale-gas preservation in complex structure zone. • Superimposed deformation was clarified by new structural and kinematic constraints. • Differential shale-gas conceptual accumulation model on eroded synclines is built. • Strike-slip stepwise transformation model for shale-gas accumulation first stressed. [ABSTRACT FROM AUTHOR]

This study determined the acute changes in kinematics and kinetics when an additional load equivalent to 5% body mass was attached to the torso during change of direction (COD). In this within-subject repeated measures study, 14 male soccer players (age: 18.29 ± 0.32 years) volunteered to participate. Subjects performed COD under two conditions in randomized order: (1) no WR, and (2) with WR. No significant differences between the loaded and unloaded conditions in actual COD angle, approach speed, braking time, propulsive time, contact time, COD completion time (all p > 0.05, ES = 0.05–0.11), and all measured kinematic parameters (all p > 0.05, ES = 0–0.18). Nonetheless, ankle plantar/dorsi flexion ROM had possibly small increase in the loaded condition (ES = 0.24). Kinetics analysis has shown that the loaded condition was likely to have small increase in relative peak vertical propulsive ground reaction force (GRF, p = 0.11, ES = 0.41), and possible small increases in relative peak braking GRF (vertical: p = 0.21, ES = 0.42; total: p = 0.22, ES = 0.38), relative peak total propulsive GRF (p = 0.24, ES = 0.26), and relative braking impulse (horizontal, vertical, and total; p = 0.27–0.41, ES = 0.26–0.28). WR did not significantly change the acute movement techniques, meanwhile induced small increases in important kinetic stimuli for potential adaptation in COD. [ABSTRACT FROM AUTHOR]

The present study provided a preliminary investigation on the kinetic and fragmentation characteristics of the Xuzha rock avalanche, a ridge-top rock avalanche located in the southeast of the Tibetan Plateau, China. Field investigation revealed that the Xuzha rock avalanche originated from a steep slope and caused the tributary of the Jinsha River dammed, showing an extreme high mobility. The vertical profile of avalanche debris showed that it experienced intensive fragmentation during transport. To back-analyze its kinetic and fragmentation processes, the discrete element modeling was conducted. Simulation results suggested that the Xuzha rock avalanche lasted about 80 s and had a maximum velocity of ~ 73 m/s, about 1.5 times the highest average velocity (48 m/s). The travel distance and the thickness of the deposits matched well with the field observations. Notable features including the preservation of the original positional order and the inverse vertical grading of avalanche debris obtained from the simulation were consistent with the field observations. The statistical results of fragments showed that the fragment size distributions could be described by Weibull distribution. In general, with the landslide propagation, the size of fragments gradually decreased and the fragment size distribution became narrower. Further, dynamic fragmentation continuously occurred with the landslide propagation, generating an abundance of fine-grain particles which behaved as interstitial granular fluids between coarse particles. Finally, we inferred that dynamic rock fragmentation and fine particle fluidization were the reasonable explanations for the high mobility of the Xuzha rock avalanche. [ABSTRACT FROM AUTHOR]

In recent years, car to bicycle collisions take place more and more frequently, which have attracted the attention of some organizations and engineers. They are trying to make some rules for cars to realize better bicyclist protection, including defining new head impact location area and head impact velocity in pedestrian protection tests. However, car to E-bicycle collisions occur more than car to bicycle collisions in China. Therefore, vehicle to E-bicycle collisions should be researched to define appropriate head impact location area and head impact velocity in pedestrian protection tests for cars in Chinese market. In this article, the head kinematics of E-bicycle riders in car to E-bicycle side collisions are studied. First, through analyzing data from China In-Depth Accident Study Database (which conducts field investigation, analysis, and research on traffic accidents in China), some representative conditions and key parameters in car to E-bicycle collisions are extracted. Second, a condition of car to E-bicycle side collision from above analysis is simulated. Third, an experiment according to the above condition is performed and the finite element models in the above simulation are validated. Then, a series of conditions are simulated by using the validated models, and some factors affecting head impact locations and head impact velocities in car to E-bicycle side collisions are studied. Finally, some factors that affect the head kinematics of E-bicycle riders in car to E-bicycle collisions are identified and some results of head movement in these collisions are concluded, such as head impact locations and head impact velocities. [ABSTRACT FROM AUTHOR]

Qinghai-Tibet Plateau is one of the regions with the strongest crustal tectonic movement in the world due to its special continental tectonic location. There are many large active faults in the block and its surrounding areas, which are prone to strong earthquakes. The area is also a natural test site for studying the mechanism of plate tectonic movement in the continent. Global Positioning System(GPS)is widely used in the study of crustal deformation monitoring due to its high temporal and spatial resolution, wide coverage, and high observation accuracy. The high-resolution GPS crustal movement velocity field obtainedby China crustal movement observation network(CMONOC-Ⅰ)and China continental tectonic environment monitoring network(CMONOC-Ⅱ), has clearly revealed the crustal tectonic movement and deformation of Qinghai-Tibet Plateau in the past 20 years. The research progress of current crustal movement and deformation characteristics of Qinghai-Tibet Plateau was systematically summarized based on GPS monitoring data, and the GPS data sources, and high-precision data processing methods and strategies for monitoring the crustal movement of Qinghai-Tibet Plateau were reviewed. The influence of different reference data on the processing results of GPS velocity field was discussed, and the current analysis models for crustal movement and deformation of Qinghai-Tibet Plateau were comprehensively explained from kinematics and dynamics. The current tectonic movement and deformation characteristics were deeply analyzed from both the shallow and deep of Qinghai-Tibet Plateau based on the calculations of integrated model. From the perspective of tectonic dynamic mechanism of plate movement, the current regional dynamics background of Qinghai-Tibet Plateau and the uplift mechanism of the mount Qomolangma region under its influence were interpreted in detail. Finally, the results of crustal movement and deformation of Qinghai-Tibet Plateau using GPS technology were summarized, and the important development trend of crustal deformation monitoring of Qinghai-Tibet Plateau in the future was also prospected. [ABSTRACT FROM AUTHOR]

The formation and dynamic process analysis of the rockslide avalanche in mountainous areas are one of the consequences of the catastrophic accident. Such loose accumulation in upslope may saturate partially or completely when the stability of their accumulation dam is distributed or affected by rainfall. We present a case study with respect to the southern Wuyi Mountain located in eastern China, where the wet and rainy climate has led to dozens of similar rockslide hazards. The purpose of this paper was to analyse the mechanism and dynamic characteristics of the rockslide influenced by the same geological conditions and to predict the outburst susceptibility of similar landslides in the future. Detail field surveys, 3D laser scanning, and high-density electrical methods were used to collect the geotechnical information of the complex landslide, to identify the discontinuity between the landslide material and the bedrock, and to investigate the deformation characterization and dynamic process of the rockslide. Based on remote sensing interpretation and field investigation of the deformation process of a landslide in different times and different parts, the background, mechanism, and cause of the landslide were demonstrated. The landslide is controlled by the characteristics of the geological structure, including collapse, circular sliding, plane sliding, and debris flow. In addition, there are rock avalanches on the rear edge of the slope subjected to the combined action of rainfall and gravity. Moreover, there are some resistance anomaly areas of the aquifer and soil between 2 and 50 m where the resistivity is less than 120 ohm-m, and they were deduced to be full of water, confirming a "bathtub" type structure. The mechanism of the catastrophic landslide was a combination of the upper pushing deformation induced by rainfall line uplift and rotational; due to the ancient landslide reactivation in the transposition area, the velocity of the rockslide reached 40.11 m/s. [ABSTRACT FROM AUTHOR]

Decreasing deformation rates across the southern Tianshan have led to different seismogenic mechanisms and different proposed models to explain the orogen-scale fault kinematics. In this study, we focus on the segmentation of the Kepingtage fault by studying variations in the total offset and shortening rates of the Kepingtage fault along the southern front of the Tianshan. We used fault scarp mapping and trench excavations to assess fault segmentation and deformation on the Kepingtage fault. Our results indicate there are different shortening rates on the western (2.5–2.7 mm/year) versus the eastern segments (~ 0.3 mm/year), which are separated by the Piqiang tear fault. The decrease in shortening rates is not gradual; instead, it decreases sharply from west to east at the Piqiang fault. These segmentation boundaries are also supported by geodetic data and balanced structural restorations. Our data support a model where strike-slip faults accommodate step-changes in the deformation rates and the earthquake risks from west to east across the Tianshan. [ABSTRACT FROM AUTHOR]

At 8:40 p.m. (Beijing time) on July 23, 2019, a large landslide occurred at Jichang, a village in Shuicheng, Guizhou Province, China, resulting in 42 deaths, 9 missing people, and 21 buildings buried. Field investigation and unmanned aerial vehicle (UAV) photography allow us to characterize this slope failure and analyze its process and causes. Initially, the materials detached from the mountainside and slid over from the slope. Then, the sliding materials partly accumulated in the middle and upper parts of the slope which were blocked by a convex terrain. The rest turned into a high-speed debris flow, divided by the stable block, and descended along two existing gullies at high velocity, and finally decelerating and accumulating. Based on the high-resolution post-sliding DEM data, the original topography of the study area was reconstructed to estimate the volume of the landslide that was about 1,500,000 m3. Based on a first-order evaluation of the landslide kinematics, the whole sliding process of this event lasted about 60 s, the maximum speed was about 25 m/s, and the average speed was 16.6 m/s, indicating a typical high-speed long-runout debris flow. Analysis suggests that continuous heavy rainfall was the dominant factor to trigger this landslide, and the loose weathered regolith and special local topography were the basic intrinsic factors for this event. [ABSTRACT FROM AUTHOR]

On July 23, 2019, a large-scale landslide occurred in Jichang town, Shuicheng County, Liupanshui City, Guizhou Province in China. The landslide, which moved along two gullies, resulted in strong punching-shear, induced scarping on vegetation and large destruction of houses, and finally formed a deposit with a volume of 2 × 106 m3. This research aims to understand the effect of topography on landslide kinematics. To achieve this aim, a detailed field investigation was first carried out with an unmanned aerial vehicle (UAV) aerial photography survey, resident interviews, and field sampling. The rainfall analysis indicates the effective rainfall within 7 days before landslides was 70.14 mm which exceeded the rainfall threshold of 54.3 mm in this region, which finally triggered the landslide. Traditional soil mechanic tests were then performed to identify the soil properties of the source material. Combined with numerical simulation using the nonlinear shallow water equation, the whole process of landslides was divided into four stages: instability stage, acceleration stage, transformation stage, and impact and accumulation stage. The simulations results show the landslide block slid with a low velocity of 8 m/s for about 100 m. Then, Froude number of landslide increases from 2 to 3 when passing the high and steep terrain, indicating that landslide change to inertial dominated with potential same Froude behavior of classic debris flow. The rupture mass slid with the peak velocity of 23 m/s and diverged in two gullies and ran out for about 600 m. The maximum velocity is 23 m/s in east gully while only 15 m/s in west gully. Compared with deep and incised valleys in the west, shallow and straight valley in the east decreases the deposit depth and further increases the velocity of landslide material with increased runout distance. This research may provide a fast flow path of back analyzing geo-hazards on complex terrain and serve as a basis for future research on long runout landslides. [ABSTRACT FROM AUTHOR]

In view of the problems existed of sugarcane harvester in China, the paper analyzes the types and characteristics of the existing sugarcane collection mechanism. A new type of three degree of freedom sugarcane harvester hybrid drive collection mechanism was designed in three dimensions. The geometric model of the new configuration related components and the overall assembly was established. And imported into the ADAMS simulation software. After the simulation, the working point and the force curve of the component node were output and analyzed. In order to obtain the motion law of the new three-degree-of-freedom stacking mechanism, verify the correctness of the theoretical model, and provide reference for the in-depth research and prototype trial production of the stacking mechanism in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Side-step cutting is the most common offensive technique in the field of sports that greatly increases the risk of knee injury. However, the biomechanical performance strategies and the characteristics of lower limb joint load during the side-step cutting are not very clear. OBJECTIVE: To carry out the biomechanics test of the side-step cutting in lower limb movement strategy among college female basketball and football players, and to analyze the kinematics and dynamics parameters of the lower limbs, providing an important reference for athletes and trainers to prevent lower limb injuries, especially cruciate ligament injury. METHODS: Twelve female football and basketball players coming from a university were selected as the experimental subjects. The kinematics and dynamics parameters of the side-step cutting were acquired synchronously by using the three-dimensional dynamometer and the motion image shooting system. The relevant data were processed and analyzed by SPSS 21.0 software. The study protocol was approved by Tianjin University of Sports in China. RESULTS AND CONCLUSION: (1) Football players had greater ankle metatarsal flexion angle and hip abduction angle, maximum ankle valgus angle, knee flexion and rotation angle with knee flexion and rotation angle changes. {2) Football players had greater peak ankle rotation and hip adduction moment, while basketball players had larger plantar flexion moment. (3} Basketball players have smaller first and second peak values of forward and backward partial braking force, the first peak value of vertical partial braking force and larger peak value of forward and backward partial pushing force. In the process of side-step cutting, football players are accustomed to stop in a sudden way with their forefeet touching, thus producing higher ground reaction force and increasing knee flexion angle to buffer, while having greater ankle valgus angle and knee rotation angle. Basketball players have smaller knee flexion angle in the process of side-step cutting. A smaller angle is not conducive to the lower limb joint to buffer the ground reaction force, and then increases the risk of anterior cruciate ligament injury. [ABSTRACT FROM AUTHOR]

Global Positioning System (GPS) satellite tracking loss always occurs under challenging observation conditions such as poor satellite visibility, high receiver velocity and so on. The announcement of China's BeiDou Navigation Satellite System (BDS) regional service in 2012 has, on one hand, provided a new standalone positioning system and, on the other hand, augmented GPS under challenging observation conditions. This paper carries out BDS/GPS relative kinematic positioning with poor satellite visibility and high receiver velocity including an under-foliage pedestrian positioning at the speed of ∼5 km h−1, a city urban vehicle positioning at the speed of ∼30 km h−1, and an open-sky air vehicle positioning at the speed of ∼130 km h−1. Numerical results reveal that the standalone system cannot always provide reliable kinematic positioning solution in challenging observation environments. Instead, BDS/GPS combined system can provide better kinematic performance, i.e. 94.2% solution with 0.251 m precision (1-sigma) for the under-foliage pedestrian scenario and 97.0% solution with 0.151 m precision (1-sigma) for the city-urban vehicle scenario. As for the high receiver velocity case, both BDS and GPS can provide cm-level kinematic positioning precisions from the perspective of aerial photogrammetry. The BDS/GPS combined system cannot further improve the positioning availability and precision too much. [ABSTRACT FROM AUTHOR]

The dynamic evolution in an overriding plate remains a controversial issue. Cretaceous structures in the western Liaoning (WL) region of the eastern North China Craton (NCC), an overriding plate bordering the Pacific Ocean, provide insights into the dynamic evolution related to Paleo-Pacific Plate subduction. We present structural and fault-slip data from the Jurassic–Cretaceous basins in the WL region, together with previously published isotopic ages, to constrain structural and stress field evolution during the Cretaceous. These data reveal four phases of deformation in the WL region: tectonic shortening (D1) at 137–136 Ma, extension (D2) during 136–97 Ma, another shortening (D3) at the beginning of the Late Cretaceous, and relatively weak extension (D4) during the Late Cretaceous. Inversions of the measured fault-slip data yield NW–SE compression during D1, NW–SE extension during D2, NNW–SSE compression during D3, and N–S extension during D4. Deformation phases D1 and D3 correspond to shortening events B and C of the Yanshan Movement, whereas D2 corresponds to the peak destruction of the NCC in a back-arc extensional setting. The structural evolution indicates that the back-arc extension (D2) of the Early Cretaceous started immediately after the brief shortening event D1 and ended with another shortening event D3. Subsequently, the back-arc region underwent weak extension (D4) during the Late Cretaceous. A slab-driven model could account for the tectonic evolution in the eastern NCC. Periodic changes in the kinematics of the subducting Paleo-Pacific Plate are responsible for the alternation of the back-arc extension and compression in the overriding plate. [ABSTRACT FROM AUTHOR]

North China, one of the most populated regions in the world, is exposed to elevated seismic hazards and has experienced multiple M ≥ 8 earthquakes in the past 1,000 years. The recent 1976 Ms 7.8 Tangshan earthquake constitutes a vivid reminder of the tectonic activity. Yet, the tectonic origin of the regional seismic unrest remains poorly understood. Here, we use geodetic data to construct a kinematic model encompassing the North China Block (NCB) and its neighboring Amurian Block (AB) and the South China Block (SCB) to illuminate the link between lithospheric strain accumulation and seismic activity. Our analysis illuminates two east-west oriented left-lateral shear zones that decouple the AB from the NCB, the latter representing a collage of the North China Plain (NCP) and the Ordos Block (OB). Bookshelf faulting slices the NCP through a series of NNE-trending right-lateral and conjugate WNW-trending left-lateral shear zones. These shear zones drive historical and instrumental seismic activities. The NCB serves as a mechanical bridge accommodating the relative motion of the surrounding mobile tectonic units. In the far field, Pacific subduction at the Japan Trench, extrusion of the Tibetan plateau, and retreat at the Ryukyu trench cause internal strain within the NCB, leading to the frequent occurrences of destructive earthquakes. • The North China serves as a mechanical bridge linking the neighboring plates. • Primary sinistral shear zones decouple the Amurian Block and North China Block. • A secondary sinistral shear zone transects the North China Plain. • Dextral shear zones in the North China Plain are distributed in a bookshelf mode. • The shear zones broadly delineate recent instrumented seismicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Early Cretaceous marine transgressive cycle in NE China resulted from the subduction of the Paleo-Pacific Plate. • The Cretaceous Jixi Basin suffered initial back-arc extension, regional back-arc extension and block-continent collision. • Study on basin tectonics and geochronology could clarify conflicts of endemic transgressions and global sea-level changes. The occurrence of abundant marine fossils from non-marine basins in NE China indicated a distinctive Early Cretaceous phase of marine transgressions along the NW Pacific margin. Such a transgression has not only profoundly shaped the regional climate and terrestrial ecosystem, exerting a critical influence on rise-radiation-extinction of the world-famous terrestrial Jehol Biota, but also significantly facilitated the accumulations of hydrocarbon source rocks in NE China. In light of a joint study on marine and non-marine fossils and newly reported high-precision geochronological data, the timing of the transgression had been constrained as the late Early Cretaceous, puzzlingly disagreeing with coeval global sea-level changes. Employing seismic reflections, drill-holes and well-exposed outcrops, this study achieves structural architecture and kinematics of the Jixi basin (in eastern Heilongjiang), west of the Paleo-Pacific subduction accretionary prisms, and firstly affords subduction-related tectonic origins for the transgressive cycle. Based on tectonic events constrained by this study, transgressive initiation (Barremian to early Aptian Didao Formation), climax (middle Aptian to early Albian Chengzihe Formation) and termination (latest Albian to Cenomanian Houshigou Formation) correlate with initial back-arc extension, regional back-arc extension and block-continent collision linked to the subduction of the Paleo-Pacific Plate, respectively. Utilizing the delicate anatomy of tectonic responses to subduction and block accretion tectonics along the NW Pacific margin, we throw light on enigmatic dynamics for the transgressive cycle, offering new insights into the conflicts of endemic transgressions and global sea-level changes. [ABSTRACT FROM AUTHOR]

The North Liuleng Shan Fault (NLSF) is one of the major active faults in the northern Shanxi Graben System (SGS) in North China. Although the fault has been investigated extensively in terms of late Quaternary activity, its active deformation pattern is still poorly characterized. In this study, we conducted a morphometric analysis of the fault using various geomorphic indices to assess the along-strike relative uplift rates, which include basin relief, slope, mountain front sinuosity (S mf), hypsometric integral (HI) and curves, valley floor width-to-height ratio (V f), asymmetry factor (A f), basin elongation ratio (R e), and normalized channel steepness indices (k sn). Our findings indicate that the central portion of the fault has experienced higher relative uplift rates than the southwestern and northeastern portions, as demonstrated by higher basin-averaged slopes and k sn values, and lower V f , R e , and S mf values. This spatial distribution pattern of relative uplift rates appears to correlate well with along-strike changes in the fault geometry and kinematics of the NLSF. We interpret the EW-striking, central portion of the NLSF as a releasing bend formed by the NE-striking, right-stepping, en-echelon southwestern and northeastern portions of the fault system, which are characterized by right-lateral oblique slip. Furthermore, the northeastward increase in HI values along with the regional basin evolution history suggest that the NLSF likely propagated from southwest to northeast. We propose that the southwestern portion of the fault most probably initiated earlier and that the central and northeastern portions formed later as extensional structures at the termini of the fault zone. Our findings contribute to a better understanding of the tectonics and genesis of the basin-and-range geomorphology in the northern SGS. • The relative uplift rate is highest in the central portion of the North Liuleng Shan Fault. • Oblique-slip releasing bend model explains the deformation along the North Liuleng Shan Fault. • The North Liuleng Shan Fault propagated gradually from southwest to northeast. [ABSTRACT FROM AUTHOR]

Previous studies have proposed that the Eastern Tibetan Plateau underwent ∼E–W oblique crustal shortening, due to the eastward extrusion of the plateau since ∼5–2 Ma to present. However, the effects of the oblique thrusting on the three-dimensional (3D) fold morphology and kinematics in the front of the Longmen Shan fold-and-thrust belt are still poorly understood. We use 3D seismic data to produce five 3D geometric models and compare our results with structural models of the Yanjinggou anticline in the Longmen Shan fold-and-thrust belt, to investigate the effects of oblique thrusting on 3D fold evolution. The results show that regional oblique thrusting occurred within the LMS fold-and-thrust belt, resulting in rotation and a curved structural morphology, and suggest that this process may be applicable globally to both small- and regional-scale structures, as well as larger-scale orogenic belts in obliquely convergent settings. • The effects of oblique thrusting on 3D fold geometry and kinematics are investigated. • The Yanjinggou anticline developed as a trishear fault-propagation fold with 1.2 km shortening. • The Yanjinggou anticline was affected by oblique thrusting at an angle of 55°. Three-dimensional (3D) subsurface seismic data acquisition and modeling are rarely undertaken; consequently, the complex effects of oblique thrusting on the 3D morphology and kinematics of folds are still poorly understood. We use 3D seismic data to produce five 3D geometric models and compare our results with structural models of the Yanjinggou anticline in the Longmen Shan fold-and-thrust belt, to investigate the effects of oblique thrusting on 3D fold evolution. 3D geometric modeling results reveal that oblique thrusting may cause fold asymmetry, vertical axis rotation, and a curved fold axis. 3D seismic interpretations and structural modeling suggest that the Yanjinggou anticline developed as a trishear fault-propagation fold and experienced a maximum shortening amount of 1.2 ± 0.1 km. The 3D structural and geometric models are consistent with paleomagnetic results, suggesting that the anticline was affected by oblique thrusting at an angle of 55° above a listric thrust fault with three fault ramps (19°, 30°, and 40°), causing the fold to rotate and develop a curved morphology. The integrated method used in this study to investigate the effects of oblique thrusting on 3D fold morphology and kinematics can be applied to regional oblique thrusting in the Longmen Shan and other fold-and-thrust belts worldwide. [ABSTRACT FROM AUTHOR]

Permafrost distributed in northeast China is the only high-altitude permafrost in China. The deformation monitoring over this permafrost region is of great importance to local climate change and ecological environments. This study focuses on the deformation monitoring of high-latitude permafrost in northeast China with time series InSAR technique. The spatial distribution characteristics, the annual deformation rates and the temporal deformation evolutions of permafrost could be retrieved from multi-temporal InSAR processing with Sentinel-1 TOPS datasets. This work concludes that time series InSAR technique could help to retrieve a comprehensive and reliable permafrost deformation, while a long time-series of displacements facilitated to better understand permafrost kinematics. [ABSTRACT FROM AUTHOR]

The ca. 2.54-2.51 Ga Dengfeng greenstone belt in the southern section of the Central orogenic belt of the North China craton consists of structurally juxtaposed slices of meta-ultramafic, metamafic, and felsic igneous rocks, metasedimentary rocks, including minor banded iron formation. The complex was metamorphosed to greenschist to amphibolite facies at ca. 2.5 Ga and intruded by ca. 2.50-2.42 Ga mafic and felsic plutons/dikes. Detailed field mapping and structural analyses show that the different lithostructural units, including a metamafic-dominant unit and a metasedimentary-dominant unit, are in tectonic contact, with complex thrust imbrication and multiple brittle and ductile deformation. The metasedimentary-dominant unit consists of coherent schist-metabasalt sequences, metaturbidites, and chaotic mélanges that are characterized by typical duplex structures and block-in-matrix fabrics, closely resembling the lithostratigraphy and structural patterns of Phanerozoic accretionary complexes. Together with distinctive and diagnostic geochemical signatures of metabasalts, sanukitoid-like metadiorite, and syntectonic adakitic sills/dikes, we interpret the Dengfeng greenstone belt as Neoarchean forearc and accretionary complexes consisting of dismembered forearc crustal sheets in the west and accreted oceanic plate stratigraphy in the east that were structurally imbricated at a convergent plate margin. The kinematic indicators and the spatial configurations of different tectonic units suggest a near-southwest-dipping intra-oceanic subduction zone beneath the arc in the Central orogenic belt, which later evolved into an arc-continent collision with the Eastern block. The accreted arc and accretionary prism are unconformably overlain by a clastic sedimentary wedge, the lower part of which has a maximum depositional age of ca. 2.45 Ga and is interpreted as a foreland basin sequence related to this collision. Documentation of the Neoarchean Dengfeng forearc and accretionary complexes demonstrates that ca. 2.5 Ga intra-oceanic subduction, oceanic plate stratigraphy accretion, and arc-continent collisional events occurred in the southern section of the Central orogenic belt of the North China craton. The accretion of the 2.54-2.51 Ga arc to the continental margin of the Eastern block marks an early episode of mountain building in the Central orogenic belt, which played an important role in the lateral growth of the North China craton. [ABSTRACT FROM AUTHOR]

Based on classical mechanics and the law of energy conservation, we present a model for predicting landslide sliding distance. We conceptualize landslide movement as the movement of a mass point and divide the sliding surface into two sections—an upper sliding surface where the slip is accelerating, and a lower section where deceleration occurs. Energy dissipation and landslide deformation during the sliding process are also considered as we constructed a coefficient of energy dissipation η and a factor of length ratio. Furthermore, different types of landslides which correspond to the energy dissipation coefficient η and L ratio are explored. The established sliding distance prediction model is verified using two cases—the Chonghetang landslide and the Zaoshugou #2 landslide, both in Lanzhou, China. The sliding surface parameters are derived using Bishop's method. The predicted landslide distances are quite close to the field measurements (error levels are 1.9% for the Chonghetang landslide and − 6.6% for the Zaoshugou #2 landslide). We conclude that our model provides an easy and widely applicable method for predicting loess landslide sliding distance. [ABSTRACT FROM AUTHOR]

Abstract The Wuhai Basin is located in the northwestern corner of the Ordos Block. Analyzing the geometry, along with the kinematic and dynamic characteristics of the boundary fault, the Zhuozishan West Piedmont Fault (ZWPF), will elucidate the regional tectonic environment and guide earthquake prevention and disaster reduction projects. Six representative sites were selected for topographic measurements, from the northern, middle and southern parts. Displacements of the ZWPF were calculated by measuring the top surface elevation of a widely distributed lacustrine layer in the footwall from outcrops at each site, and from boreholes in the hanging wall. The vertical slip rate of the ZWPF was then calculated based on the displacement and age of the lacustrine layer. Three to four normal fault-controlled terraces have developed on the footwall of the ZWPF, and the top surface of the lacustrine layer is at 1092–1132 m elevation. Data from boreholes showed that the top surface of the lacustrine layer is at an elevation of 1042–1063 m in the hanging wall. Vertical slip rates since 70 ka were estimated as 0.5 ± 0.2 to 1.0 ± 0.2 mm/a. The highest rate of vertical slip was observed at Fenghuang Ridge, in the central part of the fault system, and decreased to the south. In the northern Wuhai Basin, normal faulting still controls the piedmont landscape. However, NW-SE trending reverse faults and secondary folding have resulted from dextral strike-slip movement of the fault. The Wuhai Basin developed as a dextral-tensional negative flower structure. This study indicates that stress conditions of the northwestern margin of the Ordos Block include NE–SW compression and NW–SE extension, and an S-shaped rift zone has dominated the scale, structure, and evolution of the Yinchuan, Wuhai, and Hetao Basins, along with the active mode of faulting in these basins. Highlights • Vertical slip rates between 0.5 ± 0.2 and 1.0 ± 0.2 mm/a were calculated for the ZWPF. • The ZWPF has a larger strike-slip rate, resulting in development of reverse faults. • The Wuhai Basin has developed a dextral- tensional negative flower structure. • Stress conditions and S-shaped distribution dominate the development of basins. [ABSTRACT FROM AUTHOR]

The Tan–Lu Fault Zone (TLFZ) is the largest continental‐scale strike‐slip fault zone in East China. It experienced a complex Meso‐Cenozoic deformation and controlled the development and evolution of the Bohai Bay Basin (BBB). Though its Mesozoic sinistral and Cenozoic dextral motions have been well documented, its strike‐slip transition history and mechanism from sinistral to dextral motions in the Early Paleogene remain poorly understood. To investigate these issues, we made a thorough analysis on the fault geometry and kinematics as well as the response of depocentre in the Early Paleogene of the sags adjacent to the TLFZ across the southeast BBB. The results show that the WNW‐/NW‐, E‐W‐, and ENE‐/NE‐trending extensional faults developed in the Early Paleogene of those sags share almost the same geometrical and kinematic features. Such features indicate that the TLFZ is sinistral in Ek3‐Ek2 depositional stage, extension dominated in Ek1 depositional stage, and dextral in Es4L depositional stage. Such strike‐slip transition of the TLFZ is a comprehensive effect of the plate events around the Eurasian Plate. The NNW‐directed subduction of the Pacific to the Eurasian plates triggers the sinistral motion of the TLFZ during 65–55 Ma, but this sinistral motion is terminated by the far‐field effect of the NNE‐directed India–Eurasia collision initiating at 55 Ma. Then, the kinematic adjustment of the Pacific Plate from NNW to WNW breaks the stress balance exerted on the TLFZ by the subduction of the Pacific to Eurasian plates and the India–Eurasia collision and makes it turn into dextral motion gradually during 48–42 Ma. [ABSTRACT FROM AUTHOR]

Considerable post-breakup extensional deformation is recorded in the continental margins of the South China Sea (SCS). To recognize the nature and origin of the significant deformation during the syn-spreading stage (32-15.5 Ma) in the SCS, we comprehensively analyzed the geometry and kinematics of the faults and contemporaneous magmas in the Baiyun sag, northern margin of the SCS, using high-resolution regional three-dimensional seismic data. The kinematic analyses indicate that the faults in the Baiyun sag are recently formed following the onset of seafloor spreading in the SCS. The faults exhibit multiple episodes of growth history, with three active episodes, 32-29, 23.8-21 and 18.5-16.5 Ma, separated by periods of inactivity. Four volcanic groups comprising 98 volcanic mounds have been identified and described, located separately in the northwestern, the central, the southeastern and the northern slope areas. The occurrence of multiple palaeo-seafloors, complemented by the biostratigraphic and K-Ar dating data, reveals multiple extrusive events of the syn-spreading magmas in the Baiyun sag, with three active periods of 23.8-21, 18.5-17.5 and 17.5-16.5 Ma. This study confirms that the normal faulting has a shared genetic origin with the contemporaneous magmatism during the syn-spreading stage in the deep-offshore Baiyun sag, northern margin of the SCS. The episodic fault growth and magmatic extrusive events reveal that the Baiyun sag has undergone at least three episodic tectonic events during the syn-spreading stage, which evolved in response to the multi-stage seafloor spreading of the SCS. [ABSTRACT FROM AUTHOR]