检索结果-南通市图书馆

RISK-SENSITIVE FIXED-POINT SMOOTHING ESTIMATION FOR LINEAR DISCRETE-TIME SYSTEMS WITH MULTIPLE OUTPUT DELAYS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2013年第2期26卷 137-150页

作者： ZHAO Hongguo cui peng Postdoctoral Research Station of School of Mathematics Shandong University School of Information Science and Technology Taishan University School of Control Science and Engineering Shandong University

This paper investigates the risk-sensitive fixed-point smoothing estimation for hnear omcrete-time systems with multiple time-delay measurements. The problem considered can be converted into an optimization one in indefinite space. Then the risk-sensitive fixed-point smoother is obtained by solving the optimization problem via innovation analysis theory in indefinite space. Necessary and sufficient conditions guaranteeing the existence of the risk-sensitive smoother are also given when the risk-sensitive parameter is negative. Compared with the conventional approach, a significant advantage of presented approach is that it provides less computational cost.

关键词： Innovation Riccati equation risk-sensitive time-delay.

Variation operators for singular integrals and their commutators on weighted Morrey spaces and Sobolev spaces

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2022年第6期65卷 1267-1292页

作者： Feng Liu peng cui College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,we investigate the boundedness and compactness for variation operators of CalderónZygmund singular integrals and their commutators on weighted Morrey spaces and Sobolev *** be precise,letρ>2 and K be a standard Calderón-Zygmund *** by V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))(m≥1)theρ-variation operators of Calderón-Zygmund singular integrals and their m-th iterated commutators,*** assuming that V_(ρ)(T_(K))satisfies an a priori estimate,i.e.,the map V_(ρ)(T_(K)):L^(p0)(R^(n))→L^(p0)(R^(n))is bounded for some p0∈(1,∞),the bounds for V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))on weighted Morrey spaces and Sobolev spaces are ***,the compactness properties of V_(ρ)(T_(K,b)^(m))on weighted Lebesgue and Morrey spaces are also *** applications,the corresponding results for the Hilbert transform,the Hermite Riesz transform,Riesz transforms and rough singular integrals as well as their commutators on the above function spaces are presented.

关键词： variation operator Calderón-Zygmund singular integral commutator weighted Morrey space Sobolev space

Graphene quantum dots doped poly(vinyl alcohol)hybrid membranes for desalination via pervaporation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第11期63卷 226-234页

作者： Yunyun Wan Lulu Yao peng cui School of Chemistry and Chemical Engineering Hefei University of TechnologyChina Anhui Province Key Laboratory of Controllable Chemical Reaction&Materials Chemical Engineering Hefei230009China

Pervaporation desalination by highly hydrophilic materials such as poly(vinyl alcohol)(PVA)based separation membrane is a burgeoning technology of late ***,the improvement of membrane flux in pervaporation desalination has been a difficult ***,a novel hybrid membrane with doped graphene oxide quantum dots(GOQDs)which is rich in hydrophilic groups and small size into the matrix of PVA was prepared to improve the membrane *** membranes structures were described by field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM),Fourier transform infrared(FT-IR),differential scanning calorimetry(DSC),thermogravimetric analysis(TGA)and X-ray diffraction(XRD).And more,Water contact angle,swelling degree,and pervaporation properties were carried out to explore the effect of GOQDs in PVA *** addition,GOQDs content in the hybrid membrane,NaCl concentration,and feed temperature were investigated ***,the hydrogen bonds between PVA chains were weakened by the interaction between GOQDs and PVA ***,the hybrid membrane with optimized doped GOQDs content,200 mg·L^(-1),displays a high membrane flux of 17.09 kg·m^(-2)·h^(-1)and the salt rejection is consistently greater than 99.6%.

关键词： Pervaporation Desalination Graphene oxide quantum dots Poly(vinyl alcohol) Membranes

Optimization and Configuration of Control Parameters to Enhance Small-signal Stability of Hybrid LCC-MMC HVDC System

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 213-221页

作者： Chunyi Guo peng cui Chengyong Zhao School of Electrical Engineering North China Electric Power UniversityBeijing 102206China

This paper investigates the small-signal stability of the hybrid high-voltage direct current(HVDC)transmission *** system is composed of line commutated converter(LCC)as rectifier and modular multi-level converter(MMC)as inverter under weak AC grid ***,the impact of short-circuit ratio(SCR)at inverter side on the system stability is investigated by eigen-analysis,and the key control parameters which have major impact on the dominant mode are identified by the participation factor and sensitivity ***,considering the quadratic index and damping ratio characteristic,an objective function for evaluating the system stability is developed,and an optimization and configuration method for control parameters is presented by the utilization of Monte Carlo *** eigenvalue results and the electromagnetic transient(EMT)simulation results show that,with the optimized control parameters,the small-signal stability and the dynamic responses of the hybrid system are greatly improved,and the hybrid system can even operate under weak AC grid condition.

关键词： Hybrid high-voltage direct current(HVDC) line commutated converter(LCC) modular multi-level converter(MMC) optimization of control parameter

Depth-resolved numerical model of dam break mud flows with Herschel-Bulkley rheology

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2022年第4期19卷 1001-1017页

作者： TANG Jin-bo LIN peng-zhi cui peng State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of SciencesInstitute of Mountain Hazards and EnvironmentChinese Academy of Sciences and Ministry of Water ConservancyChengdu 610041China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Mud flows are common phenomena in mountainous areas,which can threaten human safety and cause property losses under certain extreme *** the dynamic characteristics of mud flows,especially in the vertical direction,is helpful for risk reduction and hazard *** this study,a 2D depth-resolved numerical model based on Herschel-Bulkley rheology was developed to study the vertical structures of unsteady mud flows with a *** numerical model was solved by the projection method,and the free surface of mud flows was captured through the VOF *** fully validate this new model,a series of laboratory experiments involving dam break mud flows were conducted,and the mud flow heights,bottom pressures and envelopes of mud residuum were *** numerical model proposed in this study was first validated by the steady-state solution for uniform flows of Herschel-Bulkley fluid on an inclined ***,the simulated and measured mud flow heights,bottom pressures at different x locations and envelopes with different bed slopes showed good ***,the numerical results for a Herschel-Bulkley fluid dam break flow were used to validate the proposed model,which further revealed good *** that,the scenarios in which mud flows impact on a structure were numerically studied,and the vertical profiles of the front velocity and impact pressure on the structure were analyzed and *** results show that a plug layer was formed in the mud flow under unsteady and nonuniform flow conditions,and the impact pressure on the structure was dominated by the dynamic *** addition,the vertical position with the maximum impact pressure acting on the structure was not at the bottom or the surface of the mud flows,and the normalized vertical position rose as the yield stress and consistency coefficient increase for Herschel-Bulkley fluids.

关键词： Mud flows Herschel-Bulkley rheology Depth-resolved model Numerical simulation Vertical profiles

An Empirical Formula for Suspended Sediment Delivery Ratio of Main River after Confluence of Debris flow

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2013年第2期10卷 326-336页

作者： ZHANG Jin-shan cui peng Key Laboratory of Mountain Hazard and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences

In order to calculate the suspended sediment discharge of the flood debris flows into the main river,a small scale flume test was designed to simulate the process of confluence of Jiangjia Ravine and Xiangjiang River in Yunnan province,*** test observation and data analysis,suspended sediment discharge of Debris flow after its entry into the main river was found to have a close relation with the bulk density,the confluence angle of the Debris flow and the main river,the ratio between per unit width discharge of Debris flow and main *** on the measured and simulated results,and statistical analysis,an empirical formula was proposed for the suspended SDR(Sediment Delivery Ratio) of the main river after the confluence of Debris *** with the observed results of Debris flow in 2009,the error between the data calculated by the empirical formula and the monitored data is only about 10%.

关键词： Debris flow Confluence SuspendedSediment Delivery Ratio (SDR) Jiangjia Ravine Xiaojiang River Model

Nonlinear Analysis of Bedload Transport Rate of Paroxysm Debris Flow

在线全文

学校读者我要写书评

暂无评论

四川大学学报（工程科学版） 2005年第S1期37卷 98-101页

作者： Wang, Xiekang Wang, Xianye cui, peng State Key Lab. of Hydraulics and Mountain River Eng. Sichuan Univ. Chengdu 610065 China Inst. of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

The evolution characteristics of bedload transport feature of paroxysm debris flow have been studied by means of both theory analysis and experimental *** analysis based on the flume experiment data of a sand pile model as well as a large amount of field data of debris flow clearly shown that the statistical distribu- tion for the main variable of the sand pile made of non-uniform sand (according the sand pile experiment,φ≥2.55) conform to the negative power law,that means the non-uniform sand syste...

关键词： paroxysm debris flow beclload transport rate self-organized criticality power law

Efficient Visible Electroluminescence from Porous Silicon Diodes Passivated by Carbon Films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第7期19卷 1013-1015页

作者： Li Hong-Jian, peng Jing-cui Department of Applied Physics Hu"nan University

By using n-butylamine as a carbon resource, carbon film is deposited on the p-n porous silicon (PS) surface with a radio-frequency glow discharge plasma system. Raman spectra and infrared reflection (IR) spectra of the carbon films indicate that there are amine-group and hydrogen atoms therein. The IR spectra of the passivated PS samples exhibit that the PS surfaces are mainly covered with Si-C, Si-N and Si-O bonds. Electroluminescence (EL) spectra show that the EL intensity of the passivated PS diodes increases greatly and the blueshift of the EL peak occurs compared with the diodes without treatment. Both of these are stable while the passivated diodes are exposed to the air indoors. The I-V characteristics reveal that the passivated diodes have a smaller series resistance and a lower onset voltage. The influence of the carbon film passivation on EL properties of PS has also been discussed. The results have proven that carbon film passivation is a good way to enhance the PS luminescent intensity and stability

关键词： Passivation

Energy and Charge Transfer from Guest to Host in Doped Organic Electroluminescent Devices

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第9期19卷 1356-1358页

作者： Li Hong-Jian, peng Jing-cui Department of Applied Physics Hu"nan University College of Physics Science and Technology Central South University

The luminescence properties of doped organic electroluminescent devices are explained by means of a Hamiltonian model. The results show that there is a corresponding relation between the amount of transferred charge and the change of the energy originating from charge transfer, and the relation can be influenced by dopant concentration. As the amount of transferred charge increases, the total energy decreases and the luminescence intensity increases. Therefore, we deduce that the energy transfer from guest to host may be derived from the charge transfer. For a given organic electroluminescent device, the maximum value of the conductivity can be observed in a specific dopant concentration. The calculated results show that the greater the transferred charges, the higher the conductivities in doped organic electroluminescent devices. The results agree basically with experimental results.

关键词： Charge transfer