检索结果-南通市图书馆

Efficient adjustment of product selectivity using controllable Pd nanoparticles in nitroarene hydrogenation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2020年第1期18卷 13-18页

作者： Jian Zhang liang wang Fang Chen Feng-Shou Xiao Key Laboratory of Applied Chemistry of Zhejiang Province and Department of Chemistry Zhejiang UniversityHangzhou 310028China

Product selectivity adjustment is a much-studied topic in mesoscience that is critical for industrial processes and strongly related to reaction intermediates formed by interactions between catalytic active sites and ***,we report efficient adjustment of the product selectivity in the hydrogenation of substituted nitroarenes via rational reaction intermediates achieved using controllable Pd *** nanoparticles fixed within zeolite Beta crystals(Pd@Beta)afforded rational Pd-NO2 interactions,in which the Pd nanoparticle-adsorbed substituted nitroarenes,such as nitrobenzaldehyde,were reasonably hydrogenated into the corresponding ***,for Pd nanoparticles supported on the external surfaces of zeolite beta crystals,various side products were obtained owing to the coexistence of Pd-NO2 and Pd-C=O *** Pd nanoparticles were artificially controlled in various positions in a fixed-bed reactor,the product selectivity was significantly *** results demonstrate the importance of molecular adsorption and diffusion processes in adjusting product selectivity in catalytic reactions.

关键词： Product selectivity Nitroarene hydrogenation Pd nanoparticles Zeolite crystals

Method for designing the optimal sealing depth in methane drainage boreholes to realize efficient drainage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2021年第6期8卷 1400-1410页

作者： Minghao Yi liang wang Congmeng Hao Qingquan Liu Zhenyang wang Key Laboratory of Coal Methane and Fire Control Ministry of EducationChina University of Mining and TechnologyXuzhou 221116JiangsuChina National Engineering Research Center for Coal Gas Control China University of Mining and TechnologyXuzhou 221116JiangsuChina School of Safety Engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina

The purpose of underground methane drainage technology is to prevent methane disasters and enable the efficient use of coal mine methane(CMM),and the sealing depth is a key factor that affects the performance of underground methane *** this work,the layouts of in-seam and crossing boreholes are considered to analyze the stress distribution and failure characteristics of roadway surrounding rock through a numerical simulation and field stress investigation to determine a reasonable sealing *** results show that the depths of the plastic and elastic zones in two experimental coal mines are 16 and 20 m *** sealing minimizes the air leakage through the fractures around the roadway when the sealing material covers the failure and plastic zones,and the field test results for CMM drainage at different sealing depths indicate that the CMM drainage efficiency increases with increasing sealing depth but does not change once the sealing depth exceeds the plastic ***,sealing in the high-permeability roadway surrounding rock does not have a strong influence on the borehole sealing *** these findings,a new CMM drainage system for key sealing in the low-permeability zone was developed that is effective for improving the CMM drainage efficiency and prolonging the high-concentration CMM drainage *** proposed approach offers a valuable quantitative analysis method for selecting the optimum sealing parameters for underground methane drainage,thereby improving considerably the drainage and utilization rates of CMM.

关键词： Coal mine methane Methane drainage Borehole sealing Mining safety Methane utilization

A UAV-Assisted V2X Network Architecture with Separated Data Transmission and Network Control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2023年第6期20卷 260-276页

作者： Xiao Ma liang wang Weijia Han Xijun wang Tingting Shang School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710119China School of Computer Science Shaanxi Normal UniversityXi’an 710119China School of Electronics and Information Technology Sun Yat-sen UniversityGuangzhou 510006China The Technical Quality Department of Hangzhou Hollysys Automation Co. Ltd.Xi’an BranchXi’an 710077China

With the explosive increasing number of connecting devices such as smart phones, vehicles,drones, and satellites in the wireless networks, how to manage and control such a huge number of networking nodes has become a great challenge. In this paper, we combine the advantages of centralized networks and distributed networks approaches for vehicular networks with the aid of Unmanned Aerial Vehicle(UAV), and propose a Center-controlled Multihop Wireless(CMW) networking scheme consisting of data transmission plane performed by vehicles and the network control plane implemented by the ***, we jointly explore the advantages of Medium Access Control(MAC) protocols in the link layer and routing schemes in the network layer to facilitate the multi-hop data transmission for the ground ***, the network control plane in the UAV can manage the whole network effectively via fully exploiting the acquired network topology information and traffic requests from each vehicle, and implements various kinds of control based on different traffic demands, which can enhance the networking flexibility and scalability significantly in vehicular *** results validate the advantages of the proposed scheme compared with existing methods.

关键词： V2X networks centralized network control network architecture UAV routing algorithm

Deep Q-Network Based Dynamic Trajectory Design for UAV-Aided Emergency Communications

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2020年第4期5卷 393-402页

作者： liang wang Kezhi wang Cunhua Pan Xiaomin Chen Nauman Aslam Department of Computer and Information Science Northumbria UniversityNewcastle upon TyneNE18STU.K School of Electronic Engineering and Computer Science Queen Mary University of LondonLondonE14NSU.K

In this paper,an unmanned aerial vehicle(UAV)-aided wireless emergence communication system is studied,where a UAV is deployed to support ground user equipments(UEs)for emergence *** aim to maximize the number of the UEs served,the fairness,and the overall uplink data rate via optimizing the trajectory of UAV and the transmission power of *** propose a deep Q-network(DQN)based algorithm,which involves the well-known deep neural network(DNN)and Q-learning,to solve the UAV trajectory ***,based on the optimized UAV trajectory,we further propose a successive convex approximation(SCA)based algorithm to tackle the power control problem for each *** simulations demonstrate that the proposed DQN based algorithm can achieve considerable performance gain over the existing benchmark algorithms in terms of fairness,the number of UEs served and overall uplink data rate via optimizing UAV’s trajectory and power optimization.

关键词： deep reinforcement learning deep Q-network(DQN) successive convex approximation(SCA) UAV power control

Collision-Free Path Planning with Kinematic Constraints in Urban Scenarios

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2021年第5期26卷 731-738页

作者： wang liang wang Bing wang Chunxiang Department of Automation Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China

In urban driving scenarios,owing to the presence of multiple static obstacles such as parked cars and roadblocks,planning a collision-free and smooth path remains a challenging *** addition,the path-planning problem is mostly non-convex,and contains multiple local ***,a method for combining a sampling-based method and an optimization-based method is proposed in this paper to generate a collision-free path with kinematic constraints for urban *** sampling-based method constructs a search graph to search for a seeding path for exploring a safe driving corridor,and the optimization-based method constructs a quadratic programming problem considering the desired state constraints,continuity constraints,driving corridor constraints,and kinematic constraints to perform path *** experimental results show that the proposed method is able to plan a collision-free and smooth path in real time when managing typical urban scenarios.

关键词： autonomous vehicle path planning dynamic searching quadratic programming

Adaptive Optimal Control of the Flapping Rule of a Fixed Flapping Plate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2009年第3期1卷 402-414页

作者： Chui-Jie Wu liang wang School of Aeronautics and Astronautics Dalian University of TechnologyDalian 116024China Research Center for Fluid Dynamics PLA University of Science and TechnologyNanjing 211101China

In this paper,with the use of the moving boundary computational fluid dynamics method,we developed a new real-time optimal control method which can be used to find the optimal flapping mode of a fixed flapping *** results show that there is a 54.0%increase in the thrust obtained by the unsteady optimal flapping *** addition,to reduce the cost of computation and to have a better understanding of the flapping rule,the maximum velocity at the end tip of the flapping plate is taken as the objective functional,with which the thrust is increased by 22.9%.

关键词： Flapping rule optimal control moving boundary CFD method

Restoring-force model of modified RAC columns with silica fume and hybrid fiber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2017年第11期24卷 2674-2684页

作者： YANG Tao wang She-liang LIU Wei School of Environmental and Chemical Engineering Xi’an Polytechnic UniversityXi’an 710048China School of Civil Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Academy of Building Research of Shaanxi Provincial Xi’an 710082China

In order to establish a restoring-force model for modified concrete columns with recycled aggregates concrete(RAC), cyclic loading tests were carried out on five concretes with RAC columns and ordinary concrete frame columns under the combined influence with different admixtures and admixtures ratios(silica fume and hybrid fiber). The expressions for characteristic nodes of the skeleton curve were given by the analysis and numerical regression of the test results. In addition, the hysteretic rules of the restoring-force model and the expression for unloading stiffness were presented. Finally, we summed up the complete calculation method of the hysteretic restoring force, whose results were in good agreement with experiment. The results demonstrated that the proposed model could simulate and reflect the corresponding hysteretic behaviors, and the calculation method can provide the theoretical basis for the engineering application.

关键词： modified RAC columns skeleton curve unloading stiffness hysteretic rule restoring-force model

High plastic Zr–Cu–Fe–Al–Nb bulk metallic glasses for biomedical applications

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 648-653页

作者： Shu-shen wang Yun-liang wang Yi-dong Wu Tan wang Xi-dong Hui State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

Four Zr–Cu–Fe–Al-based bulk metallic glasses（BMGs） with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr–Cu–Fe–Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson＇s ratio and low Young＇s and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316 L steel in phosphate buffer solution（PBS, pH 7.4）. The combination of the optimized composition with high deformation ability, low Young＇s modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.

关键词： metallic glasses biomedical materials mechanical properties corrosion resistance zirconium content niobium addition

Harnessing nanobodies to expand the recognition spectrumof plant NLRs for diverse pathogens

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

aBIOTECH 2023年第3期4卷 272-276页

作者： Ruyi wang Guo-liang wang Yuese Ning State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China Department of Plant Pathology The Ohio State UniversityColumbusOH 43210USA

The strategy to expand the recognition spectrum of plant nucleotide-binding domain leucine-richrepeat (NLR) proteins by modifying their recognition sequences is generally limited and oftenunsuccessful. Kourelis et al. introduced a groundbreaking approach for generating a customizedimmune receptor, called Pikobody. This method involves integrating a nanobody domain of a fluorescent protein (FP) into a plant NLR. Their research demonstrates that the resulting Pikobody successfully initiates an immune response against diverse pathogens when exposed to the corresponding FP.

关键词： NLR Pik Nanobody Fluorescent protein Immunity