检索结果-南通市图书馆

Universal synthesis of metallophthalocyanine covalent organic frameworks as ultra-sensitive multifaceted electrochemical sensor

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 2092-2101页

作者： Qi Liu Qiqi Sun yuming zhang Hao Li Wenmiao Chen yuexing zhang sirong yu Yanli Chen Jianzhuang Jiang School of Materials Science and Engineering China University of Petroleum(East China)Qingdao266580China Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials School of Chemistry and Biological EngineeringUniversity of Science and Technology BeijingBeijing100083China College of Chemistry and Chemical Engineering Dezhou UniversityDezhou253023China

The universal synthesis of highly stable covalent organic frameworks(COFs)for ultra-sensitive and multi-component electrochemical detection in different scenarios remains a great ***,a series of metallophthalocyanine-based twodimensional(2D)dioxin(DXI)-linked metalophthalocyanine(MPc)-n DXI-COFs(M=Ni,Zn;n=1,2)are afforded in high yield(80%-96%)by a facile trace-quinoline assisted one-pot condensation of tetracarbonitrile *** X-ray diffraction and electron microscopy investigations disclose their lamellar texture 2D network with AA stacking *** and calculation results elucidate that the 2DXI-linked MPc-2DXI-COFs provide the stronger built-in electronic field and more electrostatic/hydrogen bonding adsorption sites than DXI-linked MPc-DXI-COFs,and the lower electrode reaction Gibbs free energy and stronger adsorption of analytes at Ni Pc than Zn Pc unit,which grants Ni Pc-2DXI-COF excellent sensing properties for various analytes including neurotransmitters,organic pollutants,and heavy metal ions,with high sensitivity and low detection limit of 0.53 to 25.66 *** in binary and ternary systems and even in real-world conditions,simultaneous multi-component detection could be achieved.

关键词： covalent organic framework metallophthalocyanine 2D materials electrochemical sensors multi-component detection

同方期刊数据库

Real-time tracking of fast-moving object in occlusion scene

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第3期35卷 741-752页

作者： LI yuran LI Yichen zhang Monan yu Wenbin GUAN xinping Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Systems Control and Information Processing Ministry of Education of ChinaShanghai 200240China

Tracking the fast-moving object in occlusion situations is an important research topic in computer vision. Despite numerous notable contributions have been made in this field,few of them simultaneously incorporate both object's extrinsic features and intrinsic motion patterns into their methodologies,thereby restricting the potential for tracking accuracy improvement. In this paper, on the basis of efficient convolution operators(ECO) model, a speed-accuracy-balanced model is put forward. This model uses the simple correlation filter to track the object in real-time, and adopts the sophisticated deep-learning neural network to extract high-level features to train a more complex filter correcting the tracking mistakes, when the tracking state is judged to be poor. Furthermore, in the context of scenarios involving regular fast-moving, a motion model based on Kalman filter is designed which greatly promotes the tracking stability, because this motion model could predict the object's future location from its previous movement pattern. Additionally,instead of periodically updating our tracking model and training samples, a constrained condition for updating is proposed,which effectively mitigates contamination to the tracker from the background and undesirable samples avoiding model degradation when occlusion happens. From comprehensive experiments, our tracking model obtains better performance than ECO on object tracking benchmark 2015(OTB100), and improves the area under curve(AUC) by about 8% and 32% compared with ECO, in the scenarios of fast-moving and occlusion on our own collected dataset.

关键词： speed-accuracy balanced motion modeling constrained updater

Multi-Component Resource Recycling from Waste Light-Emitting Diode Under Hydrothermal Condition:Plastic Package Degradation,Speciation of Nano-TiO_(2),and Environmental Impact Assessment

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第8期39卷 253-261页

作者： Yongliang zhang Lu Zhan zhenming Xu School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Light emitting diodes(LEDs)have accounted for most of the lighting market as the technology matures and costs continue to *** a new type of e-waste,LED is a double-edged sword,as it contains not only precious and rare metals but also organic packaging *** previous studies,LED recycling focused on recovering precious and strategic metals while ignoring harmful substances such as organic packaging *** crushing and other traditional methods,hydrothermal treatment can provide an environment-friendly process for decomposing packaging *** work developed a closed reaction vessel,where the degradation rate of plastic polyphthalamide(PPA)was close to 100%,with nano-TiO_(2)encapsulated in plastic PPA being efficiently recovered,while metals contained in LED were also recycled ***,the role of water in plastic PPA degradation that has been overlooked in current studies was explored and speculated in detail in this *** impact assessment revealed that the proposed recycling route for waste LED could significantly reduce the overall environmental impact compared to the currently published *** the developed method could reduce more than half the impact of global ***,this research provides a theoretical basis and a promising method for recycling other plastic-packaged e-waste devices,such as integrated circuits.

关键词： Waste LED Hydrothermal treatment Recycling Plastic PPA degradation Packaging materials

Room-temperature ferroelectricity in van der Waals SnP_(2)S_(6)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 113-123页

作者： Chaowei he Jiantian zhang Li Gong Peng yu State Key Laboratory of Optoelectronic Materials and Technologies Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices Nanotechnology Research Center School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Instrumental Analysis and Research Center Sun Yat-sen UniversityGuangzhou 510275China

Two-dimensional(2D)ferroelectric materials,which possess electrically switchable spontaneous polarization and can be easily integrated with semiconductor technologies,is of utmost importance in the advancement of high-integration low-power *** the experimental discovery of certain 2D ferroelectric materials such as CuInP2S6 and In2Se3,achieving stable ferroelectricity at room temperature in these materials continues to present a significant ***,stable ferroelectric order at room temperature in the 2D limit is demonstrated in van der Waals SnP_(2)S_(6) atom layers,which can be fabricated via mechanical exfoliation of bulk SnP_(2)S_(6) *** polarization is observed in thin SnP_(2)S_(6) of~7 ***,a van der Waals ferroelectric field-effect transistor(Fe-FET)with ferroelectric SnP_(2)S_(6) as top-gate insulator and ptype WTe0.6Se1.4 as the channel was designed and fabricated successfully,which exhibits a clear clockwise hysteresis loop in transfer characteristics,demonstrating ferroelectric properties of SnP_(2)S_(6) atomic *** addition,a multilayer graphene/SnP_(2)S_(6)/multilayer graphene van der Waals vertical heterostructure phototransistor was also fabricated successfully,exhibiting improved optoelectronic performances with a responsivity(R)of 2.9 A/W and a detectivity(D)of 1.4×10^(12) *** results show that SnP_(2)S_(6) is a promising 2D ferroelectric material for ferroelectric-integrated low-power 2D devices.

关键词： two-dimensional ferroelectric materials ferroelectric fieldeffect transistors photodetectors

Semi-analytical solution for drained expansion analysis of a hollow cylinder of critical state soils

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 Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2326-2340页

作者： he Yang Jialiang zhang Haisui yu Peizhi Zhuang School of Qilu Transportation Shandong UniversityJinan250002China School of Civil Engineering University of LeedsLeedsLS29JTUK

The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material *** a result,this problem cannot be solved by the common self-similar-based similarity *** paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state *** stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic *** the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value *** solution is presented in a general form and thus can be useful for a wide range of *** the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil *** present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers.

关键词： Cavity expansion Drained analysis Boundary effect Critical state soil Non-self-similar Eulerian-Lagrangian approach

Dynamic Update Scheme of Spectrum Information Based on Spectrum Opportunity Incentive in the Database-Assisted Dynamic Spectrum Management

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 2024年第3期21卷 75-90页

作者： zhang yu Chen Yong he Panfeng Cai yueming Sixty-third Research Institute National University of Defense TechnologyNanjing 210007China College of Communications Engineering Army of Engineering UniversityNanjing 210007China

To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic update mechanism of SI based on spectrum opportunity incentive is established, in which spectrum users are encouraged to actively assist the database to update SI in real time. Secondly, the information update contribution(IUC) of spectrum opportunity is defined to describe the cost of accessing spectrum opportunity for heterogeneous spectrum users, and the profit of SI update obtained by the database from spectrum allocation. The process that the database determines the IUC of spectrum opportunity and spectrum user selects spectrum opportunity is mapped to a Hotelling model. Thirdly, the process of determining the IUC of spectrum opportunities is further modelled as a Stackelberg game by establishing multiple virtual spectrum resource providers(VSRPs) in the database. It is proved that there is a Nash Equilibrium in the game of determining the IUC of spectrum opportunities by VSRPs. Finally, an algorithm of determining the IUC based on a genetic algorithm is designed to achieve the optimal IUC. The-oretical analysis and simulation results show that the proposed method can quickly find the optimal solution of the IUC, and ensure that the spectrum resource provider can obtain the optimal profit of SI update.

关键词： database-assisted dynamic spectrum management Hotelling information updating contribution spectrum information updating Stackelberg

Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： yue Lu yu-quan zhang Zhong-wei he yuan Zheng College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the instability of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

Segregation of binary particles in gas-solid fluidized bed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2024年第6期18卷 113-121页

作者： Yaxiong yu Feng Lu Xuan he Fei Wei Chenxi zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China Ordos Laboratory Ordos 017010China Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China

Particle segregation and mixing behavior play a crucial role in industrial *** study investigates the saturated jetsam fraction,which indicates the maximum capacity of flotsam to entrain jetsam,in an initially separated binary fluidized bed with particle size *** to the value of saturated jetsam fraction,three distinct regimes-segregation,mixing,and an intermediate regime-are ***,intriguing relationships between the saturated jetsam fraction and superficial gas velocity are observed,exhibiting monotonic trends in both the segregation and mixing regimes,while a unique volcano-shaped curve in the intermediate ***,a comprehensive entrainment model based on two-fluid model elucidates the observed phenomena,emphasizing the significance of mixing behavior in fluidized layer on the saturated jetsam *** work offers potential insights for evaluating segregation in industrial applications.

关键词： fluidized bed segregation binary bubbles entrainment

Artificial Intelligence Based Multi-Scenario mmWave Channel Modeling for Intelligent High-Speed Train Communications

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 2024年第3期21卷 260-272页

作者： zhang Mengjiao Liu yu Huang Jie he Ruisi zhang Jingfan yu Chongyang Wang Chengxiang School of Microelectronics Shandong UniversityJinan 250101China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China The National Mobile Communications Research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 210096China The Purple Mountain Laboratories Nanjing 211111China

A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big *** corresponding artificial intelligence(AI)based HST channel modeling becomes a *** paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST ***,the ray tracing method verified by measurement data is applied to reconstruct four representative HST *** setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is ***,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario ***,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.

关键词： artificial intelligence channel characteristic prediction HST channel millimeter wave scenario classification