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Journal of Energy Chemistry 2024年第10期97卷 68-78,I0003页

作者： Cheng He Jianglong ma Shen xi Wenxue Zhang State Key Laboratory for Mechanical Behavior of materials School of Materials Science and EngineeringXi'an Jiaotong UniversityXian 710049ShanxiChina School of materials Science and Engineering Chang'an UniversityXi'an 710064ShaanxiChina

Compared to single atom catalysts(SACs),the introduction of dual atom catalysts(DACs)has a significantly positive effect on improving the efficiency in the electrocatalytic nitrogen reduction reaction(NRR)which provides an environmental alternative to the Haber-Bosch ***,the research on the mechanism and strategy of designing bimetallic combinations for better performance is still in its early ***,based on"blocking and rebalance"mechanism,45 combinations of bimetallic pair dopedα-phosphorus carbide(TM_(A)TM_(B)@PC)are investigated as efficient NRR catalysts through density functional theory and machine learning *** a multi-step screening,the combinations of TiV,TiFe,MnMo,and FeW exhibit highly efficient catalytic performance with significantly lower limiting potentials(-0.17,-0.18,-0.14,and-0.30 V,respectively).Excitingly,the limiting potential for CrMo and CrW combinations is 0 V,which are considered to be extremely suitable for the NRR *** mechanism of"blocking and rebalance"is revealed by the exploration of charge transfer for phosphorus atoms in electron blocking ***,the descriptorφis proposed with machine learning,which provides design strategies and accurate prediction for finding efficient *** work not only offers promising catalysts TM_(A)TM_(B)@PC for NRR process but also provides design strategies by presenting the descriptorφ.

关键词： DACs Nitrogen reduction reaction 2D a-phosphorus carbide Inherent attributes machine learning

Strain engineering the D-band center for Janus MoSSe edge: Nitrogen fixation

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Journal of Energy Chemistry 2019年第6期28卷 155-159页

作者： xi Tang Zengxi Wei Quanhui Liu Jianmin ma School of Physics and Electronics Hunan UniversityChangsha 410082 HunanChina Institute of Advanced Electrochemical Energy Xi'an University of TechnologyXi'an 710048 ShaanxiChina

Nitrogen fixation is one of the most important and challenging process in production of ammonia at ambient temperature. We have first performed density function theory to propose the edge of Janus MoSSe(EJM) monolayer as a potential catalyst for nitrogen reduction reaction. Our results show that the superficial D-band centers play an important role in nitrogen fixation. The strain effects greatly alter the D-band center, and further change the interaction between the adsorbates and the surface of *** findings provide a new thought into designing transition-metal chalcogenide catalysts for nitrogen fixation.

关键词： Nitrogenfixation Electrocatalysis Janus MoSSe Strain engineering Density function theory

Attitude Control of Rigid Body with Inertia Uncertainty and Saturation Input

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Tsinghua Science and Technology 2017年第1期22卷 83-91页

作者： xi ma Fuchun Sun Hongbo Li Bing He Department of Computer Science and Technology Tsinghua UniversityState Key Lab of Intelligent Technology and Systemsand Tsinghua National Laboratory for Information Scienceand Technology (TNList) Department of Aerospace Engineering High-Tech Institute of Xi’an

In this paper, the attitude control problem of rigid body is addressed with considering inertia uncertainty,bounded time-varying disturbances, angular velocity-free measurement, and unknown non-symmetric saturation input. Using a mathematical transformation, the effects of bounded time-varying disturbances, uncertain inertia,and saturation input are combined as total disturbances. A novel finite-time observer is designed to estimate the unknown angular velocity and the total disturbances. For attitude control, an observer-based sliding-mode control protocol is proposed to force the system state convergence to the desired sliding-mode surface; the finite-time stability is guaranteed via Lyapunov theory analysis. Finally, a numerical simulation is presented to illustrate the effective performance of the proposed sliding-mode control protocol.

关键词： attitude control inertial uncertainty angular velocity-free measurement saturation input finite-time observer sliding-mode control

Protection of Metasequoia glyptostroboides Hu et Cheng in China

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Forestry Studies in China 2009年第4期11卷 249-257页

作者： WANG xi-qun GUO Bao-xiang Planning and Design Academy of Forest Products Industry State Forestry Administration Beijing 100010 P. R. China

Metasequoia （Metasequoia glyptostroboides Hu et Cheng） is an important but endangered tree species. In a sense, the course of protection of the metasequoia can be considered a miniature of the history of the protection of rare Chinese plants over the past 50 years. The approval and establishment of the National Class Nature Reserve for metasequoia is a milestone in this course. A thorough understanding of this course is beneficial to design the correct future protection plans and for taking effective measures. In this paper the entire protection course of metasequoia is reviewed, three detailed measures are proposed according to the present situation and existing problems and discussed as follows. 1） We should reinforce unceasingly the establishment of National Nature Reserves of metasequoia, put emphasis on the protection of the original natural mother trees （ONMTs） of metasequoia, design far- sighted projects to protect the ONMTs and strictly implement and enforce the regulations or laws regarding the protection of meta- sequoia. The establishment and functions of the organization should meet the demands of protecting the ONMTs and developing metasequoias. The budget should support and the quality of the personnel assigned to this task should satisfy the protection and de- velopment of the ONMTs. We should also promote the complete protection of the ONMTs at the same time and strengthen the pro- tection and restoration of the ONMTs and their ecosystem in the xiaohe valley, Lichuan County, Hubei Province, one of the natural concentration areas of ONMTs in the world. 2） A gene bank should be established for comprehensive protection of the genes of ex- isting original mother trees of metasequoia. 3） The key is to study the theoretical fundamentals of restoration and re-establishment of natural vegetation of metasequoia in the xiaohe valley to harmonize the relation among environmental departments, forestry sectors, academies of sciences and other educational or resea

关键词： Metasequoia glyptostroboides Hu et Cheng original mother trees protection course existing problems

Handmade tri-leaflet ePTFE conduits versus homografts for right ventricular outflow tract reconstruction

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World Journal of Pediatrics 2022年第3期18卷 206-213页

作者： Guan-xi Wang Feng-qun mao Kai ma Rui Liu Kun-Jing Pang Sen Zhang Yang Yang Ben-Qing Zhang Shou-Jun Li National Center for Cardiovascular Diseases Pediatric Cardiac CenterFuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeNo.167 Beilishi StreetXicheng DistrictBeijing 100037China Department of Echocardiography National Center for Cardiovascular DiseasesFuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeNo.167 Beilishi StreetXicheng DistrictBeijing 100037China Department of Pediatric Cardiac Surgery Fuwai HospitalChinese Academy of Medical SciencesPeking Union Medical College167 Beilishi RoadXicheng DistrictBeijing 100037China

Background This study aimed to investigate the performance of handmade tri-leaflet expanded polytetrafluoroethylene(ePTFE)conduits in the absence of a suitable *** Patients who underwent right ventricular outflow tract reconstruction with tri-leaflet ePTFE conduits or homografts between December 2016 and August 2020 were *** primary endpoint was the incidence of moderate or severe conduit stenosis(>36 mmHg)and/or moderate or severe *** secondary endpoint was the incidence of severe conduit stenosis(>64 mmHg)and/or severe *** There were 102 patients in the ePTFE group and 52 patients in the homograft *** median age was younger[34.5(interquartile range:20.8-62.8)vs.60.0(interquartile range:39.3-81.0)months,P=0.001]and the median weight was lower[13.5(10.0-19.0)vs.17.8(13.6-25.8)kg,P=0.003]in the ePTFE *** conduit size was smaller(17.9±2.2 vs.20.5±3.0 mm,Pmary endpoints(log rank,T3=0.33)and secondary endpoints(log rank,P=0.35).Multivariate analysis identified lower weight at surgery[P=0.01;hazard ratio:0.75;95%confidence interval(CI)0.59-0.94]and homograft conduit use(P=0.04;hazard ratio:8.43;95%CI 1.14—62.29)to be risk factors for moderate or severe conduit *** risk factors were found for moderate or severe conduit stenosis or conduit dysfunction on multivariate *** Handmade tri-leaflet ePTFE conduits showed acceptable early and midterm outcomes in the absence of a suitable homograft,but a longer follow-up is needed.

关键词： Expanded polytetrafluoroethylene conduit Homograft Right ventricular outflow tract reconstruction

PVSS:A Progressive Vehicle Search System for Video Surveillance Networks

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Journal of Computer Science & Technology 2019年第3期34卷 634-644页

作者： xin-Chen Liu Wu Liu Hua-Dong ma Shuang-qun Li Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China

This paper is focused on the task of searching for a specific vehicle that appears in the surveillance *** methods usually assume the vehicle images are well cropped from the surveillance videos,and then use visual attributes,like colors and types,or license plate numbers to match the target vehicle in the image ***,a complete vehicle search system should consider the problems of vehicle detection,representation,indexing,storage,matching,and so ***,it is very difficult for attribute-based search to accurately find the same vehicle due to intra-instance changes in different cameras and the extremely uncertain ***,the license plates may be mis-recognized in surveillance scenes due to the low resolution and *** this paper,a progressive vehicle search system,named as PVSS,is designed to solve the above *** is constituted of three modules:the crawler,the indexer,and the *** vehicle crawler aims to detect and track vehicles in surveillance videos and transfer the captured vehicle images,metadata and contextual information to the server or *** multi-grained attributes,such as the visual features and license plate fingerprints,are extracted and indexed by the vehicle *** last,a query triplet with an input vehicle image,the time range,and the spatial scope is taken as the input by the vehicle *** target vehicle will be searched in the database by a progressive *** experiments on the public dataset from a real surveillance net work validate the effec tiveness of PVSS.

关键词： multi-modal data analysis progressive search system vehicle search video surveillance network

A new benzophenone C-glycoside from Polygala telephioides Willd

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Chinese Chemical Letters 2010年第5期21卷 584-586页

作者： Ting Jun ma[a], xi Cheng Shi[b] Chang xi Jia[a] [a] Department of Food Science Beijing Agricultural College Beijing 102206 China [b] Research Insitute of Chemical Defense Beijing 100083 China

A new benzophenone C-glucoside,3’-C-[4-O-(5-hydroxyferuloyl)-β-D-glucopyranosyl]-2′,4′,6′-trihydroxy-3,4-dimethoxy-benzophenone, named telephenone D,was isolated from the whole plants of Polygala telephioides,and... 详细信息

关键词： Polygala telephioides Benzophenone C-glucoside Telephenone D

Rapid velocity reduction and drift potential assessment of off-nozzle pesticide droplets

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Chinese Journal of Chemical Engineering 2022年第6期35卷 243-254页

作者： Shidong Xue Jingkun Han xi xi Junyi Zhao Zhong Lan Rongfu Wen Xuehu ma Liaoning Key Laboratory of Clean Utilization of Chemical Resources Institute of Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China

The droplet velocity and diameter significantly affect both the spatial drift loss and the interfacial deposition behaviors, thus determining the ultimate utilization efficiency during pesticide *** the spatial velocity and diameter evolutions can reveal the mechanism of drift loss and guide to design regulation strategy. Here, we explored the spatial velocity distribution of droplets after leaving the nozzle by particle image velocimetry technology and particle tracking model, considering that the effect of nozzle configuration and the air velocity. It shows that all droplets decelerate rapidly with the velocity attenuation ratio ranging from 50% to 80% within the region of 200 mm below the *** spatial velocity evolution differences between droplets in crossflow are determined by the competition of vertical drag force and net gravity, and the drag force sharply increases as the droplet diameter decreases, especially for that smaller than 150 μm. Based on the spatial evolution differences of the droplet velocity and diameter, a functional adjuvant was added to the liquid for improving the diameter distribution. And the drift loss was significantly reduced due to the reduction of the proportion of easily drifting droplets.

关键词： Spray droplets Particle image velocimetry(PIV) Particle size distribution Multiphase flow Pesticide drift

Multipoint Heave Motion Prediction Method for Ships Based on the PSO-TGCN Model

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China Ocean Engineering 2023年第6期37卷 1022-1031页

作者： DING Shi-feng ma qun ZHOU Li HAN Sen DONG Wen-bo School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

During ship operations,frequent heave movements can pose significant challenges to the overall safety of the ship and completion of cargo *** existing heave compensation systems suffer from issues such as dead zones and control system time lags,which necessitate the development of reasonable prediction models for ship heave *** this paper,a novel model based on a time graph convolutional neural network algorithm and particle swarm optimization algorithm(PSO-TGCN)is proposed for the first time to predict the multipoint heave movements of ships under different sea *** enhance the dataset's suitability for training and reduce interference,various filter algorithms are employed to optimize the *** training process utilizes simulated heave data under different sea conditions and measured heave data from multiple *** results show that the PSO-TGCN model predicts the ship swaying motion in different sea states after 2 s with 84.7%accuracy,while predicting the swaying motion in three different *** performing a comparative study,it was also found that the present method achieves better performance that other popular *** model can provide technical support for intelligent ship control,improve the control accuracy of intelligent ships,and promote the development of intelligent ships.

关键词： ship motion prediction time delay multipoint forecast time-graph convolutional neural network particle swarm optimization

Influence of grain refinement on the corrosion behavior of metallic materials:A review

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International Journal of Minerals,Metallurgy and materials 2021年第7期28卷 1112-1126页

作者： Pan-jun Wang Ling-wei ma Xue-qun Cheng xiao-gang Li Institute of Advanced materials and Technology University of Science and Technology BeijingBeijing 100083China National materials Corrosion and Protection Scientific Data Center University of Science and Technology BeijingBeijing 100083China

Grain refinement can strengthen the mechanical properties of materials according to the classical Hall-Petch relationship but does not always result in better corrosion *** the past few decades,various techniques have been dedicated to refining grain,along with relevant studies on corrosion behavior,including general corrosion,pitting corrosion,and stress corrosion ***,the funda-mental consensus on how grain size influences corrosion behavior has not been *** paper reviews existing literature on the beneficial and detrimental effects of grain refinement on corrosion ***,the effects of microstructural changes(i.e.,grain boundary,dislo-cation,texture,residual stress,impurities,and second phase)resulting from grain refinement on corrosion behavior are *** grain re-finement not only has an impact on the corrosion performance,but also results in microstructural changes that have a non-negligible effect on corrosion behavior or even outweigh that of grain *** size is not the only factor affecting the corrosion behavior of metallic ma-terials;thus,the overall influence of microstructures on corrosion behavior should be understood.

关键词： corrosion behavior grain refinement microstructure high-temperature oxidation