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Abstract Earthquakes in the Taiwan region have caused significant economic losses. We develop a model to assess seismic economic losses in the Taiwan region using the records of economic losses caused by historical earthquakes. Unlike existing models, we introduce Gross National Income Per Capita (GNIPC) as a parameter that responds to the influence of socio-economic development. The results show that our model can accurately estimate the earthquake economic losses in Taiwan region. The difference between the results of this model and those of existing models is evident, indicating differences between the Taiwan region and mainland China regarding geological background, seismic tectonics, and social resistance to earthquakes. The prediction results also imply that the society significantly underestimates the seismic economic losses in the Taiwan region. Our model can help the Taiwan region in disaster prevention and preparedness, contingency planning, allocation of relief resources, and post-disaster socio-economic recovery.

Cement-based materials are essential components of engineered barrier systems in geological disposal facilities for both hazardous and radioactive waste. This review provides a comprehensive examination of the application of cement-based materials in various aspects of geological disposal. Specifically, it details the use of cement paste backfill for mine tailings, which has shown a reduction in permeability by 95 %, and cementitious grouts for ground stabilization, achieving a compressive strength increase of 20 %. Shotcrete applications for rock support demonstrate enhanced adhesion properties, with a 30 % improvement in bond strength. Cementitious matrices for low- and intermediate-level waste immobilization have been optimized to reduce leachability by 40 %. Concrete containers for high-level waste and spent fuel are discussed, highlighting their ability to maintain structural integrity under high radiation and thermal loads for over 100 years. Cement-based seals for repository closure are also examined, with a focus on their self-sealing properties and long-term durability. The long-term performance of these engineered barriers is influenced by deterioration processes such as physical, chemical, and biological degradation. This review discusses optimization strategies, including the development of alternative binder systems that reduce CO₂ emissions by 30 %, the incorporation of nanoengineered cements that enhance mechanical properties by 25 %, the use of smart additives that provide real-time monitoring capabilities, and the creation of multifunctional composites that combine strength and self-healing properties. Future research directions are highlighted, emphasizing the need for advanced predictive models, innovative material formulations, and integrated monitoring technologies to ensure the long-term safety and performance of geological disposal systems.

Abstract The recent high death tolls caused by large earthquakes are a further indication that earthquakes remain one of the most destructive natural hazards in the world and can seriously threaten the achievement of disaster reduction goals. To effectively reduce the existing seismic risk, the limited available mitigation resources should be allocated to areas with the most severe potential risk. However, identifying localized concentrations of risk requires detailed studies. Here, we propose a strategy to delineate regional high seismic risk zone at a fine resolution and with high confidence. We demonstrate this strategy by using the seismic hazard and loss estimation results for earthquake scenarios with a magnitude of Mw 7.5 for the Jiaocheng fault of the Shanxi Rift System, China. Our analyses reveal that the delineated zone accounts for only ~7% of the regional land area but for ~85% of the total financial loss. We recommend prioritizing seismic risk mitigation measures in such high-risk zones, especially for densely populated cities in seismically active areas, to better meet the disaster risk reduction targets in the Sendai Framework.

Abstract In this paper, a multi-fault tolerant controller considering actuator saturation is proposed. Based on the adaptive dynamic programming(ADP) algorithm, the fault tolerant control of the reconfigurable manipulator with sensor and actuator faults are carried out. Firstly, combined with the state space expression, the nonlinear transformation of sensor fault is performed by adopting the differential homeomorphism principle. An improved cost function is constructed based on the fault estimation function obtained by the fault observer, and combined with hyperbolic tangent function to deal with input constraint problem. Then, an evaluation neural network (NN) is established and the Hamilton–Jacobi–Bellman (HJB) equation is solved by online strategy iterative algorithm. Furthermore, based on Lyapunov theorem, the stability of reconfigurable manipulator systems with multi-fault are proved. Lastly, the simulation studies are used to certify the effectiveness of the presented fault tolerant control (FTC) scheme.

The island mining face in coal mines often encounters stress concentration and significant air leakage, elevating the risk of rock burst and spontaneous combustion of residual coal in the goaf. This study centers on the investigation of the 9305 island mining face within a mine situated in Shandong Province, China. Leveraging the features of coal spontaneous combustion and data from microseismic and gas monitoring throughout the mining process, a novel method for calculating safe mining speeds under compound disasters is introduced. The safe mining speed of the 9305 island mining face is stratified, and a prevention and control technology integrating long distance directional drilling for impact-spontaneous combustion compound disasters is proposed. Findings suggest that to mitigate spontaneous combustion of residual coal, considering the seam's spontaneous combustion tendency, the safe mining speed should exceed 3.7 m per day. Accounting for the distribution of microseismic events during coal seam extraction, the safe mining speed is maintained below 4.8 m per day in the unprotected mining area and capped at 8 m per day in the protected zone. Through a comprehensive analysis considering coal seam spontaneous combustion tendency, impact tendency, and time to coal seam oxidation to critical temperature, the safe mining speed for the island mining face ranges from 3.7 m per day to 4.8 m per day in the unprotected area and from 5.14 m per day to 8 m per day in the protected area. The proposed long distance directional drilling 'one hole, multiple purposes' scheme enables an integrated approach encompassing pressure relief before coal seam extraction, water injection during mining, and grouting post-mining. This method effectively prevents and controls the compound disasters of rock burst and coal spontaneous combustion, presenting innovative technical solutions for the safe extraction of coal resources.

Abstract This study provided a comprehensive understanding of the source process of the 1819 M 7.7 Kachchh Indian earthquake using physics‐based dynamic rupture modeling and strong ground motion simulations. We successfully simulated the spontaneous dynamic rupture along a curved non‐planar fault using the 3‐D curved‐grid finite‐difference method (CGFDM). The estimated earthquake magnitude is around 7.6, consistent with previous estimations. Our simulations accurately replicated macroscopic rupture patterns and surface deformation, showing agreement with observed data along the Allah Bund fault (ABF) with a maximum displacement ∼5.5 m at the Earth's surface. The maximum modeled coseismic slip on the fault was approximately 7.5 m. Notably, the ABF exhibited characteristics of a weak barrier (leaky barrier) at the bending part, allowing the rupture to propagate further. Despite limitations in surface deformation calculations, the modeled values aligned with the trend of surface fault slip, with a slight deviation in the epicenter toward the east compared to earlier studies. We observed a homogeneous principal stress oriented N25°E, consistent with the present day Indian plate motion. The estimated horizontal peak ground velocities (PGVh) and the maximum value of Intensity X+ aligns well with observations. Furthermore, conducting thorough case studies on significant earthquakes and potential seismic scenarios in stable continental regions is crucial. Such studies play a vital role in validating and improving dynamic rupture models. When combined with statistical methods, this research holds great promise for advancing seismic hazard assessments, earthquake engineering, and strategies for disaster management.

Abstract This study achieved the construction of earthquake disaster scenarios based on physics-based methods—from fault dynamic rupture to seismic wave propagation—and then population and economic loss estimations. The physics-based dynamic rupture and strong ground motion simulations can fully consider the three-dimensional complexity of physical parameters such as fault geometry, stress field, rock properties, and terrain. Quantitative analysis of multiple seismic disaster scenarios along the Qujiang Fault in western Yunnan Province in southwestern China based on different nucleation locations was achieved. The results indicate that the northwestern segment of the Qujiang Fault is expected to experience significantly higher levels of damage compared to the southeastern segment. Additionally, there are significant variations in human losses, even though the economic losses are similar across different scenarios. Dali Bai Autonomous Prefecture, Chuxiong Yi Autonomous Prefecture, Yuxi City, Honghe Hani and Yi Autonomous Prefecture, and Wenshan Zhuang and Miao Autonomous Prefecture were identified as at medium to high seismic risks, with Yuxi and Honghe being particularly vulnerable. Implementing targeted earthquake prevention measures in Yuxi and Honghe will significantly mitigate the potential risks posed by the Qujiang Fault. Notably, although the fault is within Yuxi, Honghe is likely to suffer the most severe damage. These findings emphasize the importance of considering rupture directivity and its influence on ground motion distribution when assessing seismic risk.

ObjectiveTo explore the feasibility of predicting the trend of measles epidemic using long short-term memory (LSTM) neural network model for conducting prevention and control of measles. MethodsThe data on 51 012 measles cases reported in Hebei province form 2004 through 2020 were collected from China Information System for Disease Control and Prevention. The LSTM neural network model was constructed and the optimal model was selected to predict the trend of measles epidemic in the province. Rooted mean squared error (RMSE) and mean absolute error (MAE) were used to evaluate the prediction of model established. ResultsThe annual number of measles cases reported in the province during the 17-year period were 950, 4 837, 7 953, 4 973, 2 273, 3 359, 14 457, 79, 38, 353, 5 365, 3 825, 1 825, 287, 241, 130, and 67, respectively, with a persistent decline since 2015. In addition, an obvious seasonality was observed in the incidence of measles. Using the collected data of 2017, the window length of 3 was determined for the constructed LSTM neural network model, with the RMSE of 17.288 and the MAE of 12.334, and the model was adopted to predict monthly number of measles cases from 2017 through 2020. The predicted monthly numbers of measles incidence were basically consistent with the number observed and the values of RMSE and MAE for years of 2017, 2019 and 2020 were all below 10, but the values for 2018 were slightly higher. ConclusionThe constructed LSTM neural network model in this study showed a good efficiency in predicting monthly measles incidence in Hebei province and the model could be used in the analysis on measles incidence trend and epidemic risk assessment.

Harvesting robots had difficulty extracting filament phenotypes for small, numerous filaments, heavy cross-obscuration, and similar phenotypic characteristics with organs. Robots experience difficulty in localizing under near-colored backgrounds and fuzzy contour features. It cannot accurately harvest filaments for robots. Therefore, a method for detecting and locating filament picking points based on an improved DeepLabv3+ algorithm is proposed in this study. A lightweight network structure, ShuffletNetV2, was used to replace the backbone network Xception of the traditional DeepLabv3+. Convolutional branches for 3 different sampling rates were added to extract information on the safflower features under the receptive field. Convolutional block attention was incorporated into feature extraction at the coding and decoding layers to solve the interference problem of the near-color background in the feature-fusion process. Then, using the region of interest of the safflower branch obtained by the improved DeepLabv3+, an algorithm for filament picking-point localization was designed based on barycenter projection. The tests demonstrated that this method was capable of accurately localizing the filament. The mean pixel accuracy and mean intersection over union of the improved DeepLabv3+ were 95.84% and 96.87%, respectively. The detection rate and weights file size required were superior to those of other algorithms. In the localization test, the depth-measurement distance between the depth camera and target safflower filament was 450 to 510 mm, which minimized the visual-localization error. The average localization and picking success rates were 92.50% and 90.83%, respectively. The results show that the proposed localization method offers a viable approach for accurate harvesting localization.

This study proposes a navigation system for the headland autonomous turning of a safflower picking robot. The proposed system includes binocular cameras, differential satellites, and inertial sensors. The method of extracting the headland boundary line combining the hue, saturation, and value-fixed threshold segmentation method and random sample consensus algorithm and planning the headland-turning trajectory of a robot based on the multiorder Bezier curve are used as control methods. In addition, a headland-turning tracking model of a safflower picking robot is designed, and a path-tracking control algorithm is developed. A field test verifies the performance of the designed headland-turning navigation system. The test results show that the accuracy of the judgment result regarding the existence of a headland is higher than 96%. In headland boundary detection, the angle deviation is less than 1.5˚, and the depth value error is less than 50 mm. The headland-turning path tracking test result shows that at a turning speed of 0.5 km/h, the average lateral deviation is 37 mm, and the turning time is 24.2 seconds. Compared to the 1 km/h, the turning speed of 0.5 km/h provides a better trajectory tracking effect, but the turning time is longer. The test results verify that this navigation system can accurately extract the headland boundary line and can successfully realise the headland-turning path tracking of a safflower picking robot. The results presented in this study can provide a useful reference for the autonomous navigation of a field robot.

Abstract We considered various non‐uniformities such as branch faults, rotation of stress field directions, and changes in tectonic environments to simulate the dynamic rupture process of the 6 February 2023 Mw 7.8 Kahramanmaraş earthquake in SE Türkiye. We utilized near‐fault waveform data, GNSS static displacements, and surface rupture to constrain the dynamic model. The results indicate that the high initial stress accumulated in the Kahramanmaraş‐Çelikhan seismic gap leads to the successful triggering of the East Anatolian Fault (EAF) and the supershear rupture in the northeast segment. Due to the complexity of fault geometry, the rupture speed along the southeastern segment of the EAF varied repeatedly between supershear and subshear, which contributed to the unexpectedly strong ground motion. Furthermore, the triggering of the EAF reminds us to be aware of the risk of seismic gaps on major faults being triggered by secondary faults, which is crucial to prevent significant disasters.

Abstract The 2016 Mw 5.9 Menyuan earthquake occurred near the Haiyuan fault system in the northeastern Tibetan plateau. Although some kinematic properties of this event have been investigated, more dynamic properties still need to be clarified. First, we use the empirical Green's function method to obtain this event's apparent source time functions (ASTFs), which present a bell shape with a duration of 3s and corresponding smooth spectra. We then conduct dynamic rupture simulations, which are well constrained by the seismic and geodetic observations, to explore more in‐depth source properties. The results show that the characteristics of ASTFs can be explained by the self‐arresting rupture model, which implies that the rupture propagation of this event may spontaneously terminate before reaching the barriers. This result suggests that the initial conditions when this earthquake nucleated may have controlled the rupture process. Our work contributes to understanding the stopping mechanism of some moderate earthquake ruptures.

Abstract We simulated the rupture dynamics and ground motion of the 1850 Xichang, China, earthquake on the Zemuhe fault, which consists of the Lijinbao segment, the Dajing segment, the Chechejie segment, and the Songxin segment, with the curved grid finite‐difference method, and compared the simulation results with the field observed data and written records inferred data. We focused on the rupture extent of this earthquake and the effects of the maximum principal stress azimuth and nucleation location on the rupture process and the corresponding damage distribution. Numerical simulation results suggest that the regional maximum principal stress orientation that surrounds the Zemuhe fault was approximately N55°W, which is identical with the azimuth from the stress relief experiment in the neighboring area. Our simulations further imply that the nucleation location is under Lanbiluo. The simulation of this preferred nucleation location model suggests that the rupture propagated through the entire Dajing segment and the Chechejie segment, and the rupture gradually arrested at shallow depths after it transferred to the Lijinbao segment and the Songxin segment. Moreover, the simulation suggests that the rupture on the Chechejie segment was initiated at the surface and then mainly propagated downward due to the free surface effect. In addition, the Xichang earthquake may have exhibited a low rupture velocity on the Dajing segment. Furthermore, our simulation results emphasize the importance of the stepover width in the earthquake dynamics.

Abstract In this paper, a human motion intention estimation-based decentralized robust interaction control method of modular robot manipulators (MRMs) is proposed under the situation of physical human–robot interaction (pHRI). Different from traditional interaction control scheme that depends on the biological signal and centralized control method, the decentralized robust interaction control is implemented that using only position measurements of each joint module in this investigation. Based on the harmonic drive compliance model, a novel torque-sensorless human motion intention estimation method is developed, which utilizes only the information of local dynamic position measurements. On this basis, the decentralized robust interaction control scheme is presented to achieve high performance of position tracking and ensure the security of interaction to create the ’safety’ interaction environment. The uniformly ultimately bounded (UUB) of the tracking error is proved by the Lyapunov theory. Finally, pHRI experiments confirm the effectiveness and advancement of the proposed method.

To investigate the deformation mechanisms of rock under hydrostatic stress, destructive experiments were conducted on sandstone under different levels of hydrostatic stress and stress Lode angles. The results reveal that the shape of the strength envelope on the π plane gradually changes from the shape of the Lade criterion to the shape of the Drucker-Prage criterion with an increase in hydrostatic stress. Normally, there exists a deviation between the strain and stress paths for porous rocks on the π plane, and the deviation decreases with an increase in stress Lode angle and hydrostatic stress. A rock failure hypothesis based on the rock porous structure was proposed to investigate the reasons for the abovementioned phenomena. It was found that the shear expansion in the minimum principal stress direction is the dominant factor affecting the Lode angle effect (LAE); the magnitude of the hydrostatic stress induces the variation of the porous structure and influences the shear expansion. Therefore, the hydrostatic stress state affects the LAE. The failure hypothesis proposed in this paper can clarify the hydrostatic stress effect, LAE, and the variation of the rock strength envelope shape.

The accurate acquisition of safflower filament information is the prerequisite for robotic picking operations. To detect safflower filaments accurately in different illumination, branch and leaf occlusion, and weather conditions, an improved Faster R-CNN model for filaments was proposed. Due to the characteristics of safflower filaments being dense and small in the safflower images, the model selected ResNeSt-101 with residual network structure as the backbone feature extraction network to enhance the expressive power of extracted features. Then, using Region of Interest (ROI) Align improved ROI Pooling to reduce the feature errors caused by double quantization. In addition, employing the partitioning around medoids (PAM) clustering was chosen to optimize the scale and number of initial anchors of the network to improve the detection accuracy of small-sized safflower filaments. The test results showed that the mean Average Precision (mAP) of the improved Faster R-CNN reached 91.49%. Comparing with Faster R-CNN, YOLOv3, YOLOv4, YOLOv5, and YOLOv6, the improved Faster R-CNN increased the mAP by 9.52%, 2.49%, 5.95%, 3.56%, and 1.47%, respectively. The mAP of safflower filaments detection was higher than 91% on a sunny, cloudy, and overcast day, in sunlight, backlight, branch and leaf occlusion, and dense occlusion. The improved Faster R-CNN can accurately realize the detection of safflower filaments in natural environments. It can provide technical support for the recognition of small-sized crops.

A model-free adaptive positioning control strategy for piezoelectric stick–slip actuators (PSSAs) with uncertain disturbance is proposed. The designed controller consists of a data-driven self-learning feedforward controller and a model-free adaptive feedback controller with a radial basis function neural network (RBFNN)-based observer. Unlike the traditional model-based control methods, the model-free adaptive control (MFAC) strategy avoids the complicated modeling process. First, the nonlinear system of the PSSA is dynamically linearized into a data model. Then, the model-free adaptive feedback controller based on a data model is designed to avoid the complicated modeling process and enhance the robustness of the control system. Simultaneously, the data-driven self-learning feedforward controller is improved to realize the high-precision control performance. Additionally, the convergence of the tracking error and the boundedness of the control output signal are proved. Finally, the experimentally obtained results illustrate the advantages and effectiveness of the developed control methodology on the bidirectional stick–slip piezoelectric actuator with coupled asymmetric flexure-hinge mechanisms. The positioning error through the proposed controller reaches 30 nm under the low-frequency condition and 200 nm under the high-frequency condition when the target position is set to 100 μm. In addition, the target position can be accurately tracked in less than 0.5 s in the presence of a 100 Hz frequency.

In the traditional integrity analysis of solid rocket motors, solid propellants failure and propellant-liner interface debonding were intentionally differentiated. This empirical distinction of failure regions based on the macroscopic phenomenon neglects their physical correlation, consequently increasing both experiment quantity and simulation complexity. Here, by experiments and simulations, propellant-liner interface debonding is shown to be induced by propellant breakage, i.e., the substrate failure. In experiments, interface debonding and propellants failure share the same cavitation and stringing processes in crack initiation, and the measured break strain of solid propellants and fracture energy of interface satisfy a similar temperature/strain-rate dependent shifting phenomenon. The finite element model can well predict both the strain field and the stress-strain response of interface debonding by using the parameters calibrated by tensile tests of solid propellants, verifying that interface debonding is induced by propellants breakage. Overall, failure envelopes of both propellants and interfaces satisfy a similar peak-position shifting phenomenon but different peak-value shifting phenomena. The time-temperature superposition of HTPB polymer binders induces the peak-position shift, and strain concentration and relaxation of propellants in the crack front induce the peak-value evolution. This study is promising to unify and simplify the solid propellants failure and interface debonding in the integrity analysis.

Lipid hormone is produced by highly differentiated endocrine cells and directly secretes into the blood circulation or tissue fluid to act as information transmission. It influences the physiological functions of the human body by controlling the metabolic processes of multiple tissue cells. Monitoring the levels of lipid hormone is of great importance for maintaining human health. The electrochemical sensor is considered as an ideal tool to detect lipid hormone owing to its advantages such as quick response, convenience and low economic costs. In recent 3 years, researchers have developed various electrochemical sensors for the detection of lipid hormone to improve their sensitivity or selectivity. The use of nanomaterials (such as carbon nanomaterials, precious metal and polymer) is a key research object and a breakthrough for improving the sensing performance of electrochemical sensors for detection of lipid hormone. This paper reviews and discusses the basic principle, nanomaterials, actuality and future development trend of electrochemical sensors for the detection of lipid hormone in the past 3 years.

In remote sensing images, small objects have too few discriminative features, are easily confused with background information, and are difficult to locate, leading to a degradation in detection accuracy when using general object detection networks for aerial images. To solve the above problems, we propose a remote sensing small object detection network based on the attention mechanism and multi-scale feature fusion, and name it AMMFN. Firstly, a detection head enhancement module (DHEM) was designed to strengthen the characterization of small object features through a combination of multi-scale feature fusion and attention mechanisms. Secondly, an attention mechanism based channel cascade (AMCC) module was designed to reduce the redundant information in the feature layer and protect small objects from information loss during feature fusion. Then, the Normalized Wasserstein Distance (NWD) was introduced and combined with Generalized Intersection over Union (GIoU) as the location regression loss function to improve the optimization weight of the model for small objects and the accuracy of the regression boxes. Finally, an object detection layer was added to improve the object feature extraction ability at different scales. Experimental results from the Unmanned Aerial Vehicles (UAV) dataset VisDrone2021 and the homemade dataset show that the AMMFN improves the APs values by 2.4% and 3.2%, respectively, compared with YOLOv5s, which represents an effective improvement in the detection accuracy of small objects.

Fracture characteristics at bedrock reservoirs in the Kunbei fault terrace belt in the southwest of Qaidam Basin, China, are investigated based on cores, thin sections, formation microscanner imaging, and production data. Results show that the weathered unit at the top of bedrocks is not an effective reservoir because of extremely low porosity. A semi-weathered unit is a potential reservoir, where formation water migrating along early effective fractures could form dissolution fractures and pores as primary storage space, and fractures can also act as seepage channels. Four fracture types can be identified from bedrock reservoirs, e.g., structural ones, diagenetic ones, weathering ones, and dissolution ones, while shear fractures related to faults are the most important ones. Fracture types and characteristics are different in granite and slate, e.g., high fracture density results in intensive dissolution in granite. Fracture density is closely related to tectonic stress. The bedrock reservoirs near fault zones and semi-weathered units are potential oil and gas exploration targets in the Kunbei fault terrace belt. Effective fractures govern dissolution behaviors as well as dominant seepage directions, which play a significant role in the development of bedrock reservoirs.

Epithelial-mesenchymal transition (EMT) plays a key role in embryonic development, wound healing and cancer. Here the authors develop an electrochemical sensor to detect EMT using E-cadherin antibody-quantum dot conjugates and a carbon nanotube-gold nanoparticle-modified electrode as a detection platform.

Abstract Stepover structures are widely distributed in natural fault systems. The jump distance is typically easier to identify than both the stepover location and the overlap distance because of the presence of lakes and sedimentary basins around the stepover. Using the curved grid finite‐difference method, we first conducted a 3D spontaneous dynamic rupture simulation of the 1833 Songming earthquake on a continuous model of the western Xiaojiang fault to estimate the regional stress azimuth. Then, we performed rupture process simulations with different stepover structure models on the western Xiaojiang fault to investigate the effects of the stepover location and overlap distance on the dynamic rupture process. In addition, we analyzed the fault strength ratio S and rupture velocity of the preferred fault models and discussed the occurrence of supershear rupture during the Songming event. Finally, we simulated the strong ground motion with the preferred fault models for the 1833 Songming earthquake. Our simulation results suggest that the optimal regional maximum principal stress azimuth during the Songming event was N20°W. Our simulations further reveal that the Qingshuihai stepover is located in the middle of Qingshuihai Lake, and the overlap distance is 6 km; in contrast, the location of the Yangzonghai stepover is located in the southern part of Yangzonghai Lake, and the overlap distance is not constrained. Furthermore, our numerical simulation indicates that the Songming earthquake exhibited supershear rupture; however, this supershear rupture is not sustained and is easily affected by the friction parameters and nucleation location.

To improve the stubble avoidance rate of no-till wheat seeders under the environment of corn stubble, the side-shift stubble avoidance system was developed in the present study based on deviation-perception fusion technology. Firstly, the amount of implement deviation compensation was accurately obtained by the information sensing system. Then, a fuzzy PID algorithm was proposed to optimize the performance of the control system. Finally, the simulation model of the control system was developed by Matlab/Simulink. The simulation results showed that the regulation time required for the system response curve to reach the steady state was 1.0 s, and the maximum overshoot was 8.2%. To verify the performance of the side-shift stubble avoidance system, an orthogonal test was conducted. The optimal combination of parameters was obtained, including the operation speed of 1.3 m/s, the hydraulic cylinder speed of 25 mm/s, and the straw mulch amount of 1.2 kg/m2. The field verification test was performed under the optimal parameters, showing the stubble avoidance rate was 90.6%, and the mean value of the sowing variation coefficient was 27.12%, which fully satisfied the requirements of stubble avoidance and sowing operation.

Natural fractures play an important role in the seepage system of Paleogene sandstone reservoirs at Nanpu Sag. Characteristics and formation mechanisms of natural fractures and stress-sensitivity permeability are comprehensively investigated and their impact on water injection is discussed based on core and log data (FMI and diplog data) as well as stress-sensitivity permeability measurement. Results show that high-angle shear fractures, including NE-SW strike fractures and NW-SE strike fractures, are widely developed in the study area, which were primarily developed during the late Paleogene and late Neogene. The present maximum horizontal principal stress is orientated at N60°–80°E, approximately parallel to the NE-SW fractures, contributing greatly to the seepage system at the early oilfield development stage. Fractures in the study area can be divided into three phases and are characterized by obvious stress-sensitivity permeability, which is closely related to fracture aperture and throat size. Since the fracture occurrence enhances stress sensitivity of permeability, it is necessary to regulate well pattern based on dynamic behaviors of fractured reservoirs at different development stages.

Molecularly imprinted polymer (MIP) is illustrated as an analogue of a natural biological antibody-antigen system. MIP is an appropriate substrate for electrochemical sensors owing to its binding sites, which match the functional groups and spatial structure of the target analytes. However, the irregular shapes and slow electron transfer rate of MIP limit the sensitivity and conductivity of electrochemical sensors. Nanomaterials, famous for their prominent electron transfer capacity and specific surface area, are increasingly employed in modifications of MIP sensors. Staying ahead of traditional electrochemical sensors, nanomaterials-based MIP sensors represent excellent sensing and recognition capability. This review intends to illustrate their advances over the past five years. Current limitations and development prospects are also discussed.

Carbon dioxide (CO 2 ) flooding is an effective method to enhance oil recovery in low-permeability reservoirs. Studying key geological factors controlling oil displacement efficiency is of great significance to the CO 2 injection scheme design in low-permeability reservoirs. Focusing on low-permeable H reservoir in Songliao Basin, China, this paper describes the contact and connection of sand bodies, natural fractures and high-permeability zones with core samples, log data and experiment firstly. After that, the impact of interaction of sand body connection, natural fracture and high-permeability zone on oil displacement efficiency is determined by using geological and dynamic data in CO 2 injection area. Results indicate that the connection of single sand bodies between injectors and producters wells primarily controls CO 2 flooding in low-permeability reservoirs. Furthermore, coupling of sand body connection, natural fractures and high-permeability zones is the key geological factor governing oil displacement efficiency of CO 2 injection in low-permeability reservoirs, where well or generally-connected sand bodies can improve the efficiency significantly. Meanwhile, the dominant seepage channels in other directions have no influence on producers, which is beneficial to improve CO 2 flooding efficiency.

Wood formation is a complicated process under the control of a large set of transcription factors. NAC transcription factors are considered “master switches” in this process. However, few NAC members have been cloned and characterized in Eucalyptus, which is one of the most economically important woody plants. Here, we reported an NAC transcription factor from Eucalyptus grandis, EgNAC141, which has no Arabidopsis orthologs associated with xylogenesis-related processes. EgNAC141 was predominantly expressed in lignin-rich tissues, such as the stem and xylem. Overexpression of EgNAC141 in Arabidopsis resulted in stronger lignification, larger xylem, and higher lignin content. The expression of lignin biosynthetic genes in transgenic plants was significantly higher compared with wild-type plants. The transient expression of EgNAC141 activated the expression of Arabidopsis lignin biosynthetic genes in a dual-luciferase assay. Overall, these results showed that EgNAC141 is a positive regulator of lignin biosynthesis and may help us understand the regulatory mechanism of wood formation.

Abstract We determine rupture kinematics of the 2020 Mw 6.7 Elazig, Turkey earthquake from joint inversion of interferometric synthetic aperture radar (InSAR) measurements, regional 1 Hz Global Navigation Satellite System (GNSS), strong motion, and teleseismic waveforms, and we also use dynamic modeling to assess the faulting properties to explain the observed kinematics. Our work shows that this event predominantly ruptured unilaterally toward the SW along the East Anatolian Fault Zone at a speed as slow as 2.0 km/s for ~20 s, and three main asperities are formed with a depth ranging from 20 km to the surface, but the surface rupture seems negligible. Besides, the dynamic model reveals an initial heterogeneous stress distribution with variations up to 30 MPa, which has been probably built up during the interseismic period. While this event does not seem to promote the failure of Pazarcık seismic gap, it remains elusive to evaluate the disturbed seismic potential between Elazig and Bingol regions.

Identification of typical vegetation succession types and their important influencing factors is an important prerequisite to implement differential vegetation and soil management after land abandonment on the Loess Plateau, China. However, there is no reported study specifically on the identification of vegetation types and their important factors as well as the thresholds of the important factors for classification of the vegetation types, based on the medium- to long-term succession of natural vegetation after cropland abandonment. We collected vegetation and soil data on the natural vegetation with the longest 60-year-old forest communities that developed after cropland abandonment and analyzed the data using two-way indicator species analysis, detrended correspondence analysis, direct canonical correspondence analysis and classification tree model. The vegetation communities were classified into five distinct vegetation types, including Artemisia scoparia, Lespedeza davurica and Stipa bungeana, Artemisia giraldii pamp, Sophora viciifolia, Quercus liaotungensis and Biota orientalis. The years after cropland abandonment and soil C/N were further identified as important factors determining the types of vegetation. Likewise, it was observed that most of the investigated soil nutrient variables and soil texture-related variables improved with the vegetation succession while soil water in the surface layers showed a decreasing trend. These findings may provide an ecological basis for site-specific management of vegetation types after cropland abandonment in the medium-long term on the Loess Plateau. Our results encourage further exploration of vegetation succession and their important factors based on longer periods of vegetation succession after cropland abandonment under more soil and climatic conditions on the mountainous areas as the Loess Plateau.

Spectral methods have previously been applied to analyze a multitude of vibration and acoustic problems due to their high computational efficiency. However, their application to interior structural acoustics systems has been limited to the analysis of a single plate coupled to a fluid-filled cavity. In this work, a general multidomain spectral approach is proposed for the eigenvalue and steady-state vibroacoustic analyses of interior structural-acoustic problems with discontinuous boundaries. The unified formulation is derived by means of a generalized variational principle in conjunction with the spectral discretization procedure. The established framework enables one to easily accommodate complex systems consisting of both a structure assembly and a built-up cavity with moderate geometric complexities and to effectively analyze vibroacoustic behaviors with sufficient accuracy at relatively high frequencies. Two practical examples are chosen to demonstrate the flexibility and efficiency of the proposed formulation: a built-up cavity backed by an assembly of multiple connected plates with arbitrary orientations and a thick irregular elastic solid coupled with a heavy acoustic medium. Comparison to finite element simulations and convergence studies for these two examples illustrate the considerable computational advantage of the method as compared to finite element procedures.

Objective: In China, Hib vaccine is a private-sector vaccine that is an option for parents to select to give to their children; it must be paid for out-of-pocket because it is not included in the government's Expanded Program on Immunization (EPI). We evaluated utilization patterns of Hib vaccine to provide evidence in support of development of a national Hib vaccination strategy. Methods: We obtained lists of children from immunization information systems (IIS) of counties or districts in 8 provinces of China. Using these lists, we selected 10 children at random from each birth cohort from 2008 through 2012. We obtained Hib vaccination dates from official vaccination certificates. The target sample size was 1,000 children. Results: We were able to obtain records for 978 subjects of the selected subjects; of these, 44.79% had received at least 1 dose of Hib vaccine, and 15.54%, 5.83%, 12.27%, and 11.15% had received one, two, three, and four doses, respectively. Per capita GDP was positively correlated with receipt of at least one dose of Hib vaccine. Among the 438 subjects who received Hib vaccine, 27% received 1 dose after 12 months of age; 15%, 7%, and 23% received one of three other patterns of Hib vaccination recommended by the World Health Organization (WHO) [a 3-dose primary series; 2 primary series doses and 1 booster; or 3 primary series doses and 1 booster]. The other 28% of subjects received patterns of Hib vaccination not recommended by WHO. Considering protection from Hib disease as receipt of a WHO-recommended Hib vaccine schedule, 29% of subjects could be considered protected after 12 months of age, 52% could be considered protected during infancy and beyond, and 19% could be considered to not have been protected adequately, despite being vaccinated. Conclusions: Coverage with Hib vaccine was low. There were significant differences between WHO recommendations and actual patterns of use of Hib vaccine, with half of vaccine recipients receiving no protection during infancy and one fifth receiving non-protective Hib vaccination patterns. Inclusion of Hib vaccine into China's EPI system, which provides vaccine at no charge to parents and makes specific vaccination schedule standards, has potential to make more effective use of Hib vaccine.

Subsoiling can break the compacted hardpan without turning or mixing soil layers. It has significant advantages in improving soil structure, promoting rainwater infiltration, and increasing air permeability of soil. The soil compacted hardpan will not be completely broken and more power consumption will be generated unless the desired tillage depth is obtained. However, due to uneven surface between and within each row of subsoiling shovel in the field, the existing adjustment methods, adjusting via the lifting device of the whole machine or a group of tillage components, cannot ensure each subsoiling shovel avoiding undesired tillage depth. Therefore, a tillage depth monitoring and control system for the independent adjustment of each subsoiling shovel was developed, and the methods of detecting, adjusting, displaying, and recording tillage depth were described. Field experiments were conducted to evaluate detecting accuracy, stability of tillage depth, transient response time, and advantages. The results showed that the value obtained by sensor differed from manual measurement at the speed of 3 km/h, 4 km/h, and 5 km/h averagely by 8.28%. The mean value of the coefficient of the tillage depth stability at three speeds were all greater than 94%. The mean transient response time was 0.6 s. The standard deviation of tillage depth obtained under system control was 38.31, which was less than the 51.52 obtained by only adjusting on the three-point suspension. The subsoiler equipped with this system was capable of obtaining a desired tillage depth of each subsoiling shovel in every second.

People’s health has been threatened by several common food hazards. Thus, it is very important to establish rapid and accurate methods to detect food hazards. In recent years, biosensors have inspired developments because of their specificity and sensitivity, short reaction time, low cost, small size and easy operation. Owing to their high precision and non-destructive characteristics, cell-based electrochemical detection methods can reflect the damage of food hazards to organisms better. In this review, the characteristics of electrochemical cell-based biosensors and their applications in the detection of common hazards in food are reviewed. The strategies of cell immobilization and 3D culture on electrodes are discussed. The current limitations and further development prospects of cell-based electrochemical biosensors are also evaluated.

Subsoiling has been acknowledged worldwide to break compacted hardpan, improve soil permeability and water storage capacity, and promote topsoil deepening and root growth. However, there exist certain factors which limit the wide in-field application of subsoiling machines. Of these factors, the main two are poor subsoiling quality and high energy consumption, especially the undesired tillage depth obtained in the field with cover crops. Based on the analysis of global adoption and benefits of subsoiling technology, and application status of subsoiling machines, this article reviewed the research methods, technical characteristics, and developing trends in five key aspects, including subsoiling shovel design, anti-drag technologies, technologies of tillage depth detection and control, and research on soil mechanical interaction. Combined with the research progress and application requirements of subsoiling machines across the globe, current problems and technical difficulties were analyzed and summarized. Aiming to solve these problems, improve subsoiling quality, and reduce energy consumption, this article proposed future directions for the development of subsoiling machines, including optimizing the soil model in computer simulation, strengthening research on the subsoiling mechanism and comprehensive effect, developing new tillage depth monitoring and control systems, and improving wear-resisting properties of subsoiling shovels.

Abstract Background Inhibition of nonsense-mediated mRNA decay (NMD) in tumor cells can suppress tumor growth through expressing new antigens whose mRNAs otherwise are degraded by NMD. Thus NMD inhibition is a promising approach for developing cancer therapies. Apparently, the success of this approach relies on the basal NMD activity in cancer cells. If NMD is already strongly inhibited in tumors, the approach would not work. Therefore, it is crucial to assess NMD activity in cancers to forecast the efficacy of NMD-inhibition based therapy. Methods Here we develop three metrics using RNA-seq data to measure NMD activity, and apply them to a dataset consisting of 72 lung cancer (adenocarcinoma) patients. Results We show that these metrics have good correlations, and that the NMD activities in adenocarcinoma samples vary among patients: some cancerous samples show significantly stronger NMD activities than the normal tissues while some others show the opposite pattern. The variation of NMD activities among these samples may be partly explained by the varying expression of NMD effectors. Conclusions In sum, NMD activity varies among lung cancerous samples, which forecasts varying efficacies of NMD-inhibition based therapy. The developed metrics can be further used in other cancer types to assess NMD activity.

ABSTRACT: Biodiversity plays a key role in human welfare by providing agricultural, economic, and health benefits. However, following the industrial revolution, the rapid expansion of the human population and subsequent economic activities have caused a dramatic loss in global biodiversity, resulting in significant disturbances to ecosystems and our own living conditions. Accordingly, the conservation of biodiversity has become one of the most important challenges for humanity. The vast numbers of plants, animals, and microorganisms, the enormous genetic diversity of these species and the different ecosystems to which these organisms belong are all part of a biologically diverse planet. A substantial proportion of the world’s biodiversity has been destroyed, this loss is a catastrophe for all living species, including humans. Fortunately, we are working to remedy the destruction of our ecosystems. Herein, we summarized the discovery and development of biodiversity as a field of study and discuss the importance of the genetic and metabolite diversity. We proposed potential solutions to the loss of biodiversity with the aim of facilitating further exploration and identification of biodiversity, contributing for human welfare through the conservation of human habitats.

Flavonoids have a variety of physiological activities such as anti-free radicals, regulating hormone levels, antibacterial factors, and anti-cancer factors, which are widely present in edible and medicinal plants. Real-time detection of flavonoids is a key step in the quality control of diverse matrices closely related to social, economic, and health issues. Traditional detection methods are time-consuming and require expensive equipment and complicated working conditions. Therefore, electrochemical sensors with high sensitivity and fast detection speed have aroused extensive research interest. Carbon nanomaterials are preferred material in improving the performance of electrochemical sensing. In this paper, we review the progress of electrochemical sensors based on carbon nanomaterials including carbon nanotubes, graphene, carbon and graphene quantum dots, mesoporous carbon, and carbon black for detecting flavonoids in food and drug homologous substances in the last four years. In addition, we look forward to the prospects and challenges of this research field.

Monitoring of marine polluted areas is an emergency task, where efficiency and low-power consumption are challenging for the recovery of marine monitoring equipment. Wireless sensor networks (WSNs) offer the potential for low-energy recovery of marine observation beacons. Reducing and balancing network energy consumption are major problems for this solution. This paper presents an energy-saving clustering algorithm for wireless sensor networks based on k-means algorithm and fuzzy logic system (KFNS). The algorithm is divided into three phases according to the different demands of each recovery phase. In the monitoring phase, a distributed method is used to select boundary nodes to reduce network energy consumption. The cluster routing phase solves the extreme imbalance of energy of nodes for clustering. In the recovery phase, the inter-node weights are obtained based on the fuzzy membership function. The Dijkstra algorithm is used to obtain the minimum weight path from the node to the base station, and the optimal recovery order of the nodes is obtained by using depth-first search (DFS). We compare the proposed algorithm with existing representative methods. Experimental results show that the algorithm has a longer life cycle and a more efficient recovery strategy.

With the development of nanomaterials and sensor technology, nanomaterials-based electrochemical immunosensors have been widely employed in various fields. Nanomaterials for electrode modification are emerging one after another in order to improve the performance of electrochemical immunosensors. When compared with traditional detection methods, electrochemical immunosensors have the advantages of simplicity, real-time analysis, high sensitivity, miniaturization, rapid detection time, and low cost. Here, we summarize recent developments in electrochemical immunosensors based on nanomaterials, including carbon nanomaterials, metal nanomaterials, and quantum dots. Additionally, we discuss research challenges and future prospects for this field of study.

Foodborne safety has become a global public health problem in both developed and developing countries. The rapid and precise monitoring and detection of foodborne pathogens has generated a strong interest by researchers in order to control and prevent human foodborne infections. Traditional methods for the detection of foodborne pathogens are often time-consuming, laborious, expensive, and unable to satisfy the demands of rapid food testing. Owing to the advantages of simplicity, real-time analysis, high sensitivity, miniaturization, rapid detection time, and low cost, electrochemical biosensing technology is more and more widely used in determination of foodborne pathogens. Here, we summarize recent developments in electrochemical biosensing technologies used to detect common foodborne pathogens. Additionally, we discuss research challenges and future prospects for this field of study.

Abstract Nonsense‐mediated mRNA decay (NMD) is a surveillance system that eliminates transcripts with premature termination codons. In this study, we show that mRNAs targeted by NMD are also suppressed at the translational level. The low translational efficiency (TE) is a consequence of multiple features acting in concert, including low translation initiation rate, mediated by 5′ secondary structure and by use of weak initiation sites, and low translation elongation speed, mediated by low codon usage bias. Despite low elongation rates, NMD transcripts show low ribosome density in the coding sequence, probably owing to low initiation rates, high abortion rates or rapid transit of the ribosome following initiation failure. The low TE is observed in the absence of NMD and is not explained by low transcript abundance. Translational inefficiency is flexible, such that NMD targets have increased TE upon starvation. We propose that the low TE predisposes to NMD and/or that it is part of a mechanism for regulation of NMD transcripts.

In this article, we study n-th order neutral nonlinear dynamic equation on time scales. We obtain sufficient conditions for the existence of non-oscillatory solutions by using fixed point theory.

Coal dust is one of the most serious issues in coal mines. The miners at an excavation face have a high potential for exposure to high concentrations of coal dust. The main method for removing coal dust is by ventilation. To better control the coal dust at the excavation face, it is important to understand the coal dust movement patterns and distribution characteristics. This paper used the computational fluid dynamics (CFD) approach to simulate coal dust movement under two different ventilation systems. The Eulerian-Lagrange method was used to study the gas‒solid two-phase fluid behavior. The coal dust concentration distributions under the two ventilation systems are presented and further compared. From the comparison results, it is found that a vortex ventilation system has better coal dust removal performance. This ventilation system is recommended for excavation for better coal dust control and miners’ health protection.

Over the past few decades, the coastal city of Shenzhen has been transformed from a small fishing village to a mega city as China’s first Special Economic Zone. The rapid economic development was matched by a sharp increase in the demand for usable land and coastal reclamation has been undertaken to create new land from the sea. However, it has been reported that subsidence occurred in land reclamation area and around subway tunnel area. Subsidence and the additional threat of coastal inundation from sea-level rise highlight the necessity of displacement monitoring in Shenzhen. The time Series InSAR technique is capable of detecting sub-centimeter displacement of the Earth’s surface over large areas. This study uses Envisat, COSMO-SkyMed, and Sentinel-1 datasets to determine the surface movements in Shenzhen from 2004 to 2010 and from 2013 to 2017. Subsidence observed can be attributable to both land reclamation and subway construction. Seasonal displacements are likely to be associated with precipitation. The influence of ocean tidal level changes on seasonal displacement is not strongly evident from the results and requires further investigations. In general, InSAR has proven its ability to provide accurate measurements of ground stability for the city of Shenzhen.

This article explores the applicability of the conventional wisdom that economic growth is paramount to environmental sustainability by examining ecotourism and nature-reserve sustainability in environmentally fragile poor regions. The discussion focuses on the Ordos Relict Gull Reserve in the Inner Mongolia region of China. The study evaluated reserve records of water and soil conditions and interpreted satellite images to identify lake-level and land-cover changes at the reserve. The Ordos Relict Gulls seem to have abandoned the reserve following ecotourism development and established new colonies in northern Shaanxi. We argue that ecotourism—especially ersatz ecotourism—in certain nature reserves is an unsustainable practice rooted in the conventional wisdom that economic development spurs environmental protection as suggested by the environmental Kuznets curve (EKC). The article concludes that environmental protection rather than economic growth is of vital importance in nature-society interactions in environmentally fragile poor areas. We call for prohibitions on tourism in such nature reserves to enhance sustainability.