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Background and Purpose: The early prediction of local tumor progression-free survival (LTPFS) after radiofrequency ablation (RFA) for colorectal cancer (CRC) lung metastases has significant clinical importance. The application of radiomics in the prediction of tumor prognosis has been explored. This study aimed to construct a radiomics-based nomogram for predicting LTPFS after RFA in CRC patients with lung metastases. Methods: This study retrospectively analyzed 172 CRC patients with 401 lung metastases admitted to Department of Interventional Radiology, Fudan University Shanghai Cancer Center from August 2016 to January 2019. This study was reviewed by the medical ethics committee of Fudan University Shanghai Cancer Center (ethics number: 2402291-24). After augmentation of pre-ablation and immediate post-ablation computed tomography (CT) images, the target metastases and ablation regions were segmented manually to extract the radiomic features. Maximum relevance and minimum redundancy algorithm (MRMRA) and least absolute shrinkage and selection operator (LASSO) regression models were applied for feature selection. The clinical model, the radiomics model, and the fusion model were constructed based on the selected radiomic features and clinical variables screened by the multivariate analysis. The Harrell concordance index (C-index) and area under receiver operating characteristic (ROC) curves (AUC) were calculated to evaluate the prediction performance. Finally, the corresponding nomogram of the best model was drawn. Results: Among all the lung metastases, 102 (25.4%) had final recurrence, and 299 (74.6%) had complete response (CR). The median follow-up time was 21 months (95% CI: 19.466-22.534), and the LTPFS rates at 1, 2, and 3 years after RFA were 76.5% (95% CI: 72.0-80.4), 72.1% (95% CI: 66.6-76.9) and 69.9% (95% CI: 64.0-75.1). In both the training and test dataset, the fusion model based on the final 12 radiomic features through the LASSO regression and 4 clinical variables screened by multivariate analysis achieved the highest AUC values for LTPFS, with C-index values of 0.890 (95% CI: 0.854-0.927) and 0.843 (95% CI: 0.768-0.916), respectively. Conclusion: The fusion model based on radiomic features and clinical variables is feasible for predicting LTPFS after RFA of CRC patients with lung metastases, whose performance is superior to the single radiomic and clinical model. At the same time, the nomogram of the fusion model can intuitively predict the prognosis of CRC patients with lung metastases after RFA, thus assisting clinicians in developing individualized follow-up review plans for patients and adjusting treatment strategies flexibly.

Taking real-time and effective preventive maintenance measures on in-service roads can reduce traffic congestion, eliminate potential road safety hazards, and greatly reduce road maintenance costs. Therefore, based on the Persson friction theory, this study first determines the evaluation indicators for the anti slip ability of asphalt pavement. And based on vehicle dynamics and contact friction between tires and road surface, the anti-skid thresholds of road surfaces for different road conditions and vehicle models are solved through simulation. This study utilizes Python and neural network algorithms to establish a decision-making model for anti-slip recovery technology of asphalt pavement. The experiment shows that the model trained by Back Propagation neural network has high accuracy. The training accuracy of the model is stable at around 0.90, and the training loss value is around 0.34, which can be used for decision-making in anti slip recovery technology. When the speed is less than 60 km/h, the increase in the threshold of dynamic friction coefficient is significant. The maximum difference in growth rate is 47.9%. When the speed exceeds 60 km/h, the increase in the threshold of dynamic friction coefficient gradually slows down. Therefore, at lower speeds, it is more essential to consider the variable value of the dynamic friction coefficient. When the speed is high, more consideration needs to be given to its reference value. This study provides a scientific basis for ensuring that the anti slip ability of the road surface always meets the requirements of driving safety, and has important engineering practical value, economic and social benefits.

Abstract Aim Ischemic heart disease (IHD) represents a major cardiovascular condition heavily influenced by dietary factors. This study endeavors to assess the global, regional, and temporal impact of low-fiber diets on the burden of IHD. Method Leveraging data from the Global Burden of Disease (GBD) 2019 study, we analyzed the worldwide burden of IHD resulting from diet low in fiber using indices including death and disability-adjusted life years (DALY). This burden was further segmented based on variables including regions and countries. To track the evolution from 1990 to 2019, we utilized the Joinpoint regression model to estimate the temporal trend of IHD burden stemming from low-fiber diets. Results In 2019, a total of 348.85 thousand (95%UI: 147.57, 568.31) deaths and 7942.96 thousand (95%UI: 3373.58,12978.29) DALY (95% UI: 707.88, 1818) of IHD were attributed to diet low in fiber globally. These figures correspond to 3.82% of all IHD deaths and 4.36% of total IHD DALYs. The age-standardized death and DALY rates per 100,000 individuals were 4.48 (95% UI: 1.90,7.27) and 97.4(95%UI: 41.44, 158.88) respectively. However, significant regional disparities emerged in these age-standardized rates, with South Asia and Central Asia experiencing the highest rates. Between 1990 and 2019, we observed that most regions displayed a downward trend of the age-standardized DALY and death rate of IHD resulting from low-fiber diets, except for Central Sub-Saharan Africa and Southern Sub-Saharan Africa. Conclusion Our analysis underscores the substantial toll of IHD associated with low-fiber diets, particularly considering the significant regional variations. Therefore, it is imperative to sustain efforts to implement effective measures aimed at enhancing fiber intake worldwide, particularly in countries with lower socio-demographic indices.

On December 18, 2023, an Ms 6.2earthquake occurred in Jishishan County, Linxia Prefecture, Gansu Province, causing a large number of geological disasters and threatening people's lives and the safety of infrastructure. After the earthquake, Gansu and Qinghai provincial governments quickly deployed hundreds of geology professionals to carried out the investigation and verification geological disasters in the earthquake area. Based on the results of the earthquake geohazard investigation and verification, this paper analyses the characteristics, control factors and development trend of the earthquake-induced geohazards, and puts forward suggestions on disaster prevention and risk mitigation measures. Till December 23, a total of 2044 geohazards have been checked, including 78 new geohazards, 88 existing geohazards with intensified deformation due to earthquake, and 1 878 existing geohazards without obvious different from before. Most of new and intensified deforming geohazards are collapse, accounting for 67.5%, followed by landslide, accounting for 31.9%. Most of new and intensified deforming geohazards are small in scale, accounting for 84.9%, followed by medium, accounting for 10.8%. Disaster mode of new and intensified deforming geohazards are mostly small collapse threatening houses and roads. The co-seismic geohazards are densely distributed along the seismic fault, and the spatial density increases with the enhancement of earthquake intensity. Data from 206 groups of accelerate-meters within 50 km from the epicenter of the National Geological Safety Monitoring Network showed that the peak acceleration of the earthquake area was 30.4～1969.7 mg. and decayed logarithm with the increase of the distance from the epicenter. In addition, the surface deformation monitoring equipment also recorded the co-seismic displacement curve of a typical landslide. Analysis shows, earthquake put a deteriorate effect to rock and soil, which decreased their integration and strength. There is a magnificent geohazard after-effect of earthquake; collapse, landslide and debris flow will be much often than before. So the authors suggest: (1) update earthquake geohazard database as soon as possible, (2) work out targeted prevention and control measures for the geohazards with large potential danger, (3) conduct comprehensive remote sensing monitoring and research of earthquake-induced geohazard mechanism, (4) improve the meteorological early warning model and threshold. By all this efforts the risk of geohazards after earthquake will be reduced and controlled.

Objective The resurrections of ancient landslide deposits are one of the primary geological hazards in the Qinghai-Tibet Plateau and surrounding areas of China and pose significant safety threats to major transportation and water conservancy projects under construction in western China. Therefore, it is crucial to investigate the formation and evolution mechanism of ancient landslides and evaluate the stability of their deposits. This research can provide theoretical support for the early recognition and prevention of the resurrection of ancient landslide deposits. Methods The ancient landslide deposits in Jiangdingya, Zhouqu County, Gansu Province, have experienced local resurrection several times in the past decade, creating severe threats to the lives and property of local people by blocking the Bailong River. To determine the morphology and structural characteristics of the ancient Jiangdingya landslide deposits, this study utilized field investigations and unmanned aerial vehicle (UAV) tilt photography. Based on this, the evolution mechanism and dynamic process of the landslide were analysed, and the stability of the deposits was qualitatively evaluated using InSAR deformation data. Results The results show that the ancient landslide at Jiangdingya is a typical large-scale earthquake landslide, with its sliding body located in a downslope position in three directions, forming a multilevel stepped deposit shape. The dynamic process of an ancient landslide under seismic loads can be divided into several stages, including vibration and cracking in the upper-middle part, shearing and landslide initiation in the front edge locking segment, tearing and landslide acceleration in the rear edge, obstruction and landslide deceleration in the front edge, and stabilization. Conclusion Due to the overall downwards movement of the ancient landslide under seismic loads, there are a large number of intact rock masses in the upper deposits, which are relatively stable. However, the middle and lower deposits are mostly composed of weak structures such as fault fracture zones and fragmented rock masses, which have poor stability and are highly likely to resurrect in the future. This study provides important insights into the formation and evolution of ancient landslides and the evaluation of their stability, which can help prevent future landslides and protect local communities.

Abstract In vivo cardiac diffusion tensor imaging (cDTI) is a promising Magnetic Resonance Imaging (MRI) technique for evaluating the microstructure of myocardial tissue in living hearts, providing insights into cardiac function and enabling the development of innovative therapeutic strategies. However, the integration of cDTI into routine clinical practice poses challenging due to the technical obstacles involved in the acquisition, such as low signal-to-noise ratio and prolonged scanning times. In this study, we investigated and implemented three different types of deep learning-based MRI reconstruction models for cDTI reconstruction. We evaluated the performance of these models based on the reconstruction quality assessment, the diffusion tensor parameter assessment as well as the computational cost assessment. Our results indicate that the models discussed in this study can be applied for clinical use at an acceleration factor (AF) of $$\times 2$$ × 2 and $$\times 4$$ × 4 , with the D5C5 model showing superior fidelity for reconstruction and the SwinMR model providing higher perceptual scores. There is no statistical difference from the reference for all diffusion tensor parameters at AF $$\times 2$$ × 2 or most DT parameters at AF $$\times 4$$ × 4 , and the quality of most diffusion tensor parameter maps is visually acceptable. SwinMR is recommended as the optimal approach for reconstruction at AF $$\times 2$$ × 2 and AF $$\times 4$$ × 4 . However, we believe that the models discussed in this study are not yet ready for clinical use at a higher AF. At AF $$\times 8$$ × 8 , the performance of all models discussed remains limited, with only half of the diffusion tensor parameters being recovered to a level with no statistical difference from the reference. Some diffusion tensor parameter maps even provide wrong and misleading information.

The rock collapse disaster caused by the dangerous rock mass of slope is a geological disaster with strong sudden occurrence and destructive ability. The key to prevent and control the dangerous rock mass of slope is to delineate the influence range of the dangerous rock mass. In order to accurately assess the influence range of the dangerous rock mass of slope, improve the disaster prevention ability of the dangerous rock mass of slope and reduce the collapse threat, it is urgent to improve the calculation model of the influence range of the dangerous rock mass of slope. Based on the survey results of dangerous rock mass in Guangzhou, the types and slope shape characteristics of common dangerous rock mass in slope are summarized, and the physical and geometric model of the influence range of dangerous rock mass is established. The main factors affecting the collapse movement process, such as slope friction, block collision, bounce, fragmentation, properties of contact surface covering and coefficient of restitution, terrain conditions and earthquake, are comprehensively considered. The calculation model of collapse influence range of linear and curved slope under different slope conditions is established by generalized motion process elements, and the expansion coefficient of collapse influence range under earthquake conditions is obtained according to the influence of earthquake force on the kinetic energy of collapse body. On the basis of previous studies, this model further summarizes the geometric model of slope shape classification and formation, and calculates the calculation model of the maximum influence range of dangerous rock mass under common working conditions and different terrain conditions according to the movement process. After obtaining the slope height, slope and surface characteristics, the influence range of dangerous rock mass can be calculated according to this model. Through the verification and comparison of actual cases, the relative error of calculation results is small, and a certain safety distance can be reserved, which can be used for the evaluation of the influence range of dangerous rock mass in common slope slope, and provide a basis for the prevention and control of dangerous rock mass in slope.

Selective harmonic elimination pulse-width modulation (SHE-PWM) method has been widely used in various industrial multilevel converters befitting from low switching frequencies and precise elimination of low-order harmonics. Most of existing studies focus on accelerating calculation of switching angles or optimizing predictive neural networks. However, these offline methods cannot dynamically deal with the errors introduced by nonuniform dc sources of multilevel converters or biased placements of switching angles. This paper proposes an online adaptive SHE (OA-SHE) algorithm to compensate these errors. Errors caused by nonideal dc (NID) sources and leading-lagging placements (LLPs) are analyzed in detail. The error of output waveform is comprehensive result of NID sources and LLPs. By introducing feedback, the output waveform accuracy of multilevel converters can be increased greatly. Realization of the particle swarm optimization (PSO) with an embedded control system is presented to acquire good real-time performance. With the OA-SHE method, the value of particles has been higher than the initial value. High order harmonics, including 1st, 5th, 7th, 11th, and 13th components, are suppressed by the low-pass filter. Comparing to existing studies, this online algorithm does not need detailed model parameters and can be directly applied to practical applications achieving multi-objective optimization. Finally, both simulations and experiments are carried out to verify the effectiveness of this algorithm.

Abstract Infant‐type hemispheric glioma, a new subtype of pediatric high‐grade glioma, arises in the cerebral hemispheres. Despite better survival outcomes, the treatment of infant‐type hemispheric glioma is still facing challenges. Here, we reported a case of QKI‐ALK fusion, infant‐type hemispheric glioma with lung metastasis who achieved a complete clinical response after lorlatinib treatment. This typical case demonstrated the importance of appropriate molecularly targeted treatments in ALK‐fused tumors, and lorlatinib may serve as an effective complement to conventional chemotherapy and radiotherapy in primary glioma harboring ALK fusions and its metastasis.

Camera calibration will directly affect the accuracy and stability of the whole measurement system. According to the characteristics of circular array calibration plate, a camera calibration method based on circular array calibration plate is proposed in this paper. Firstly, subpixel edge detection algorithm is used for image preprocessing. Then, according to cross ratio invariance and geometric constraints, the projection point position of the center point is obtained. Finally, the calibration experiment was carried out. Experimental results show that under any illumination conditions, the average reprojection error of the center coordinates obtained by the improved calibration algorithm is less than 0.12 pixels, which is better than the traditional camera calibration algorithm.

On one hand, anti-slide shaft technology can overcome the problems of blocking the seepage and drainage path in the slope by traditional anti-slide piles. On the other hand, it can reduce the excavation quantities when the vertical drainage and anti slide structures are separately constructed. Besides, it can fully provide the hydration-heat dissipation surface to ensure the overall structure quality. It has been an important technology in modern landslide prevention engineering, and the novel one of geological disaster, hydrogeology and underground engineering in recent years. The anti-slide shaft technology involves hydrodynamic mechanics and solid mechanics, as well as hydrodynamic model, structural model, engineering geological model, etc. Besides, its promoted application is restricted by some problems, such as the lack of mature theoretical system, the relatively complex of this spatial structural combination, and the difficulty of the construction technology. Thus, it is necessary to carry out targeted current status summary research. Based on a large number of relevant documents, patents and practical engineering applications at home and abroad, we summarize the characteristics and classification of anti-slide shaft structure (anti-liquefaction pile, hollow anti-slide shaft, box anti-slide shaft, etc), and find that the anti-slide shaft structure are mostly pile-type or tie-type, forming a 3-D structure system with the combination characteristics of seepage, collection, drainage and anti-slide. This kind of seepage-collection-drainage structures usually include water permeable holes, radiant seepage holes and drainage pipes. The demonstration of typical application examples show that although the anti-slide shafts have the advantage of significant improvement on the stability, there is still a large optimization space from its extensive use and diversification. Thus, the current complex construction process, unclear mechanical properties and drainage characteristics, imperfect stability calculation theory, plane layout optimization method to be improved in anti-slide shaft technology are important scientific issues and research trend, which need to be paid attention in the future. The solutions of these scientific problems are not only beneficial to improving the mechanical and drainage theory, but also beneficial to improving the overall application level of anti-slide shaft technology.

A gaze control system for tracking Quasi-1D high-speed moving object is proposed, it can keep the object in the centre of the image within a certain range. Initially, the system structure is designed, and the tracking range of the system is expanded using a single saccade mirror. Then the model between the deflection angle of the saccade mirror and the pixel displacement is established. Finally, a frame-difference method based on image cropping is proposed to rapidly extract the moving object in the complex dynamic background. It feeds back the object position to the saccade mirror control system. The system adjusts the deflection angle of the saccade mirror in real time. Experimental results show that the system can satisfy the requirements of gaze control for tracking Quasi-1D high-speed moving object.

Rooftop photovoltaic system plays an important role in solar energy power generation especially in urban. In this paper, we present an assessment method for the PV power generation potential of rooftop in China. Using machine learning model processes the big data that consists of the gross domestic product, building footprint, road length and population, at a high geographic resolution of 10 km by 10 km. The result shows that the rooftop generation potential in China is 3.27×109 MWh annually, which is close to half of the total electricity generation of China mainland in 2020, and will contribute to 2.41×109 tons of CO2 emission reduction per year. The regional results are counted by provinces and cities, showing Shandong province is the one with highest potential of 0.275×109 MWh. On the whole, the western region covers a large area with sufficient solar radiation, while the eastern region has greater photovoltaic power generation potential because of its available roof resources. The development potential of first tier, new first tier and second tier cities is generally greater than that of third and fourth tier cities.

With the frequent occurrences of high-impact-low-probability (HILP) events such as typhoons, lightning strikes, and cyber attacks, people have the increasingly need of raising distribution network’s (DN) resilience. Deploying backup sources into the system can effectively improve the resilience of DNs. With the development of transportation electrification, the number of electric taxis (ETs) in urban transit is now growing. Besides, Vehicle-to-Grid (V2G) technology has also developed vigorously. Therefore, ETs can be dispatched to charging stations under unified command to feed power back to the grid when HILP events happen. To this end, we establish an optimization model for the post-event recovery of the DN using ETs. In this model, we combine the energy provided by V2G stations with the existing distributed generators and energy storage in the grid to restore the outage areas jointly. Topology reconfiguration technique and power flow balance of DN have also been fully considered in the modeling process. The whole grid is divided into several microgrids and powered by different sources. The multi-source multi-region power restoration method improves the stability of the DN restoration. It is easier to control the voltage and power quality. The method we proposed is tested on the modified IEEE 33-bus system. The simulation results verify the effectiveness and efficiency of our work.

Abundant natural gas resources are stored in the Lower Permian Qixia Formation of the Sichuan Basin. In recent years, great breakthrough for oil and gas exploration has been achieved in the Qixia Formation in the NW Sichuan Basin, and high-quality reservoirs mainly locate in dolomite strata. However, the origin of dolomites in the Qixia Formation is still unclear. Special zebra-textured dolomites were observed in the Qixia Formation from the cores of well ST 18. In this paper, a comparative study of the light and dark belts in the zebra texture was systematically carried out with petrological and geochemical methods. Results show that the light belt is mainly composed of medium to coarse crystalline saddle dolomites and its cathodoluminescence is bright red, while the dark zone is composed of medium to fine crystalline dolomites and its cathodoluminescence is dark red. The δ13C values in light and dark zones are within the δ13C range of contemporary seawater, while the δ18O values are more negative than those of contemporary seawater. It is then indicated that the dolomitization fluid was derived from seawater and the oxygen isotopes were fractionated by the affection of high temperature. The order degrees of dolomites in the light and dark zones are consistently high. It was speculated that the order degrees of dolomites in the light and dark zones had been matured to the same degree during the later burial stage. In addition, the occurrence of pyrite confirmed the involvement of hydrothermal fluids in the formation of dolomites. Therefore, the formation of zebra dolomites in well ST 18 mainly went through the following three stages: (1) Fluids dissolved and dolomitized primary limestones along tectonic fractures to form medium to fine crystalline dolomites in the dark zone; (2) Hot fluids precipitated to form medium to coarse crystalline saddle dolomites in the light zone; (3) The order degrees of dolomites in the dark and light zones had adjusted to the same degree in the later deep burial stage.

Hydrogel has been widely used in reservoir regulation for enhancing oil recovery, however, this process can experience negative influences on the properties and effects of the hydrogels. Therefore, developing novel hydrogels with excellent environmental responsiveness would improve the formation adaptability of hydrogels. In this study, novel polyvinyl polyamine hydrogels were synthesized by a ring-opening addition reaction between polyvinyl polyamines and polyethylene glycol glycidyl ether. The results of atomic force microscopy and transmission electron microscopy showed that the polyvinyl polyamine gel had a porous and irregular bulk structure and was endowed with water storage. With the temperature rising from 30 °C to 60 °C, the transmittance of diethylenetriamine hydrogel decreased from 84.3% to 18.8%, indicating that a phase transition had occurred. After the polyvinyl polyamine hydrogel with low initial viscosity was injected into the formation in the liquid phase, the increase of the reservoir temperature caused it to turn into an elastomer, thereby migrating to the depth of the reservoir and achieving effective plugging. Polyvinyl polyamine hydrogel could improve the profile of heterogeneous layers significantly by forcing subsequent fluids into the low permeability zone in the form of elastomers in the medium temperature reservoirs of 40–60 °C. The novel environmentally responsive polyvinyl polyamine hydrogels, capable of phase transformation with temperature, exhibited superior performance in recovering residual oil, which was beneficial for applications in reservoir profile control and oilfield development.

Abstract Background To evaluate the efficacy of the topical administration of immunosuppressants and corticosteroids in tapering doses in the management of patients with high-risk keratoplasty. Methods One hundred and six patients treated with topical immunosuppressants (50 eyes in the FK506 group and 56 eyes in the CsA group) and corticosteroid eye drops in tapering doses were enrolled in the study. The rates of rejection episodes, irreversible rejection, graft survival, and related influential factors were evaluated. Results The mean follow-up period was 48.1 ± 7.9 months (range, 36–60 months). The rates of rejection episodes and irreversible rejection were 14.0% and 6.00% in the FK506 group and 37.5% and 7.1% in the CsA group, respectively. Kaplan-Meier survival analysis demonstrated a significantly higher graft survival rate in the FK506 group (81.6%±5.3%, 71.1%±6.3%) compared with that in the CsA group (71.1%±6.3%, 57.5%±7.5%) at 3 and 5 years after surgery (P = 0.006). Multivariate logistic regression revealed that preoperative risk score ≥ 3 (P = 0.016) and endothelial immune rejection (P = 0.033) were risk factors associated with graft survival. Conclusions Topical administration of tacrolimus and corticosteroids in tapering doses is effective in decreasing the incidence of immune rejection in high-risk keratoplasty. Careful instruction of patients on the reasonable use of topical tacrolimus is critical to avoid immune rejection induced by sudden discontinuation of medication.

Abstract Visual inspection of photovoltaic modules using electroluminescence (EL) images is a common method of quality inspection. Because human inspection requires a lot of time, object detection algorithm to replace human inspection is a popular research direction in recent years. To solve the problem of low accuracy and slow speed in EL image detection, we propose a YOLO‐based object detection algorithm YOLO‐PV, which achieves 94.55% of AP (average precision) on the photovoltaic module EL image data set, and the interference speed exceeds 35 fps. The improvement of speed and accuracy benefits from the targeted design of the network architecture according to the characteristics of EL image. First, we weaken the backbone's ability to extract deep‐level information so that it can focus on extracting the low‐level defect information. Second, the PAN network is used for feature fusion in the Neck part. But, only the single‐size feature map output is retained, which significantly reduces the amount of calculation. Also, we analyze the impact of data enhancement methods on model overfitting and performance. Finally, we give effective data enhancement methods. The results show that the object detection algorithm in this paper can meet the requirements for high‐precision and real‐time processing on the PV module production line.

Abstract The osteogenic potential of bone marrow mesenchymal stem cells (BMSCs) declines dramatically with aging. By using a calvarial defect model, we showed that a senolytic cocktail (dasatinib+quercetin; D + Q) improved osteogenic capacity of aged BMSC both in vitro and in vivo. The study presented a model to assess strategies to improve bone-forming potential on aged BMSCs. D + Q might hold promise for improving BMSC function in aged populations.

Min County is an area with frequent debris flow in the south part of Gansu Province. In order to study the movement and accumulation characteristics of debris flow, the Malu River basin in Min County, Gansu Province, which was affected by serious debris flow on May 10, 2012, is selected as the research area. Six debris flow gullies in the basin are taken as the research object, which are taken as a whole. Considering the main river's scouring and carrying of debris flow deposits, FLO-2D is used to simulate the flow situation and different rainfall frequency of the main river before rainfall. According to the field investigation results, the debris flow simulation results under the condition of 2% rainfall frequency are compared to verify the accuracy of the model. Based on the simulation results, ArcGIS is used to carry out the risk assessment, identify the high-risk debris flow gully in the basin, delimit the high-risk residential area, and make statistics of the impacted area, so as to provide scientific basis for debris flow prevention and early warning.

The middle reach of the Taohe River in the southern part of Gansu Province is severely threatened by debris flow hazard. The Eryang River is an important branch of the Taohe River. On May 10, 2012, a large amount of debris flows was triggered by extreme heavy rainfall (with 1% frequency), resulting in serious losses of human life and property in Minxian County of Gansu Province. In order to recognize the hazard of debris flow in small watersheds, six key debris flow gullies in the Eryang watershed were selected as the research areas. The numerical simulation software FLO-2D was used to simulate the debris flow movement and accumulation characteristics of each debris flow gully under the actual “5·10” rainfall conditions, so as to reconstruct the "5·10" debris flow disaster scenario. Numerical simulation results show that the flow speed increased to the maximum after 15～30 minutes since the outburst. The flow lasted for about 3 hours. The speed in the moving section was very high, and decreased sharply at the gully-mouth, deposits accumulated in the river valley. According to the remote sensing and field investigation, the simulation results were compared with the actual situation. The comparison shows the simulation effect is good, and the deposition area, the discharge process, and the main damage area are well reconstructed by FLO-2D simulation. The same method and parameters are used to simulate the accumulation range, depth and velocity of debris flow under the precipitation of 2.0% and 0.2% frequencies, and the risk zoning map is produced by the simulation data. The potentially threatened houses and properties are also outlined. These provide references to the local government to control the debris risk. This work also provides a practical approach for the debris flow hazard assessment.

Abstract Although it is well-documented that invasion of invasive plants is promoted with allelopathic effects by inhibiting the growth and phenotypic performance of native plants, little is known conversely. In this study, the allelopathy effects of a native plant, Humulus scandens (Lour.) Merr., on a typical invasive species Alternanthera philoxeroides (Mart.) Griseb., was investigated by exposing A. philoxeroides seedlings to three chemical solvent extracts (i.e., petroleum ether extract (PE), ethyl acetate extract (EE), and n-butanol extract (NE) of H. scandens root (HR). The three chemical extracts inhibited the growth, stem length, node number, leaf number, leaf area, and root number, and increased malondialdehyde (MDA) content of A. philoxeroides seedlings, which indicated that the extracts inhibited the plant growth by damaging the membrane system of leaves. And the synthetical effect of allelopathy (SE) index indicated that EE had the greatest inhibition on the growth of A. philoxeroides. Fifty compounds were identified from the three extracts of HR using GC–MS analysis, among which 5 compounds (dibutyl phthalate, stigmasta-3,5-diene, 2,6-Di-tert-butylphenol campesterol, and neophytadiene) were identified from H. scandens root extracts for the first time. And n-hexadecanoic acid exists in all three extracts. The findings of the present study provide a novel method to potentially control the invasion of A. philoxeroides. However, field monitoring under natural conditions would be necessary to confirm in practice the results obtained with the bioassays.

Though two-dimensional (2D) nanocomposite materials have been attractive for flexible electrochromic (EC) devices, achieving both high performance and durability remains a challenge. Here, the authors report high-performance, environmentally stable 2D MXene/transition metal oxide-based EC devices.

In this study, a new low-speed control strategy based on active disturbance rejection control (ADRC) + fractional-order proportion integration differentiation (FOPID) is proposed to realize fast and accurate control of permanent magnet synchronous motor (PMSM) at low speed. First, a new nonlinear function with enhanced smoothness and continuity around the origin is designed. On the basis of the above nonlinear function, an improved extended state observer (ESO) is developed. Then, the parameters of ESO are adjusted online by the designed fuzzy rules. Considering the improved dynamic performance of the FOPID controller, the nonlinear state error feedback control law module of ADRC is replaced by FOPID to calculate the proportion, differential, and integral of the error signal. Finally, the simulation analysis of the new low-speed control system based on ADRC + FOPID is carried out. The results show that the proposed algorithm has faster response speed and better anti-interference ability in the low-speed control of PMSM than the traditional ADRC.

As an important building block for the synthesis of angiotensin-converting enzyme inhibitors, ethyl (R)-2-hydroxyl-4-phenylbutanoate [(R)-HPBE] has attracted increasing attention. The key to industrial biosynthesis of (R)-HPBE is a biocatalyst that efficiently reduces ethyl 2-oxo-4-phenylbutanoate (OPBE) with high R-enantioselectivity. This paper proposed a strategy for identifying key residues involved in enantioselectivity control based on per-residue free energy decomposition and sequence conservatism analysis. Using this strategy, 4 nonconservative sites with high energy contribution to binding of OPBE were chosen as engineering targets, generating variant Mu27 with 99% conversion and 98% (R) ee value at substrate loading of up to 500 ​mmol/L. MD simulations suggested the higher stability and formation probability of Mu27-OPBEproR prereaction state as key reasons for the excellent R-enantioselectivity of Mu27 towards OPBE. The success in this study provides a viable approach for rational design of alcohol dehydrogenases with high enantioselectivity towards unnatural substrates.

Impedance analysis is the leading method of solving the stability issues of grid-connected renewable energy generation systems. Taking the grid-connected system of direct drive permanent magnet synchronous generator (D-PMSG) as an example, the characteristics and application scope of the existing Nyquist stability criterion were analyzed. In order to make up for the deficiency of the existing impedance stability criterion, a quantitative stability criterion based on the fitting of fractional polynomial function of impedance characteristic was proposed, which applied port impedance characteristics of wind turbine derived or measured by equivalent fitting theory of fractional polynomial function. Within the fitting frequency band, the fractional polynomial was equivalent to original impedance characteristic. The oscillation frequency and the damping level of the given system were calculated by finding the zero point of fitting polynomial, which could analyze quantitatively the stability characteristics of the system. Finally, the correctness and effectiveness of the fractional polynomial fitting criterion were verified by theoretical analysis and time domain simulation.

Sustainable development of urban areas demands, among others, a holistic approach for identification and monitoring of environmental changes caused by human activities. In this study, the human-made impact on the geo-environment is studied through the application of the change detection study based on Principal Component Analysis on Landsat imageries and comparison of the digital elevation models taken at different times. The analysis is set up to identify and quantify the anthropogenic geomorphological changes in the loess landscape in Lanzhou city, Northwest China. Since 2002 Lanzhou has been undergoing a rapid economic development associated with construction boom. Due to limited flat building ground in the narrowed Yellow River Valley and subsequent expansion into the surrounding loess mountains, massive earthworks are conducted for reclamation of the suitable building ground. The results of the change detection analysis show that approximately 10% of the semi-natural study area corresponding to 35 km2 has been reshaped by leveling and terracing since 1994. In particular, the geomorphology was significantly changed in these and adjacent areas. For the single developing area Taipingyang, a moving volume of up to 57 million m3 was roughly estimated.

An improved active disturbance rejection control (ADRC) strategy is proposed for the control precision improvement of the trolley position and the pendulum angle of the linear inverted pendulum. First, a new nonlinear function with improved continuity and conductivity around the zero point is designed. On the basis of this new function, the control rates of the extended state observer (ESO) and the nonlinear state error feedback (NSEF) of the traditional ADRC controller are improved. Second, with the improved ESO, the various disturbances of the trolley position and the swing angle of the first-order linear inverted pendulum are expanded into two states. These two states are then observed in real time and linearly compensated. Third, with the improved control rate of the NSEF, the nonlinear integration method is adopted to nonlinearly combine the differential and the error differentials and subsequently provide high quality control to the system. Finally, simulation and experimental verification of the linear inverted pendulum control system based on the improved ADRC are conducted. Results show that the proposed control strategy has higher control precision and robustness than the double-closed-loop PID.

This paper proposes a new control strategy to the position control of the ball in the ball and beam system by adopting an active disturbance rejection control (ADRC). ADRC is composed of a tracking differentiator (TD), an extended state observer (ESO), a nonlinear state error feedback control law (NLSEF), and a disturbance compensation device (DCD). The ESO observes and tracks the position of the ball and the direct current (DC) servomotor in real time. The total disturbance of the system can be expanded and amplified, and can also be effectively compensated in real time to suppress interferences by the ESO. The procedures of research are as follows. First, the model of the ball and beam system, including the motion equation of the system and the DC servomotor, is established. Second, ADRC is designed and applied to the ball and beam system and the DC servomotor. Third, the control model of the ball and beam system is built on the basis of ADRC. Finally, the ball position of ADRC is simulated and verified. The results show that the ball and beam system based on ADRC exhibits better performance than the proportion integration differentiation controller.

Monitoring bodily pressure could provide valuable medical information for both doctors and patients. Long-term implantation of in vivo sensors is highly desirable in situations where perception reconstruction is needed. In particular, for fecal incontinence, artificial anal sphincters without perceptions could not remind patients when to defecate and even cause ischemic tissue necrosis due to uncontrolled clamping pressure. To address these issues, a novel self-packaging strain gauge sensor system is designed for in vivo perception reconstruction. In addition, long short-term memory (LSTM) networks, which show excellent performance in processing time series-related features and fitting properties, are used in this article to improve the prediction accuracy of the perception model. The proposed system has been tested and compared with the traditional linear regression (LR) approach using data from in vitro experiments. The results show that the Root-Mean-Square Error (RMSE) is reduced by more than 69%, which demonstrates that the prediction accuracy of the proposed LSTM model is higher than that of the LR model to reach a more accurate prediction of the amount of intestinal content. Furthermore, outcomes of in vivo experiments show that the robustness of the novel sensor system based on long short-term memory networks is verified through experiments with limited data.

Abstract In a Chinese prospective cohort, 500 patients with new‐onset type 2 diabetes (T2D) within 4.61 years and 500 matched healthy participants are selected as case and control groups, and randomized into discovery and validation sets to discover the metabolite changes before T2D onset and the related diabetogenic loci. A serum metabolomics analysis reveals that 81 metabolites changed significantly before T2D onset. Based on binary logistic regression, eight metabolites are defined as a biomarker panel for T2D prediction. Pipecolinic acid, carnitine C14:0, epinephrine and phosphatidylethanolamine 34:2 are first found associated with future T2D. The addition of the biomarker panel to the clinical markers (BMI, triglycerides, and fasting glucose) significantly improves the predictive ability in the discovery and validation sets, respectively. By associating metabolomics with genomics, a significant correlation (p