检索结果-南通市图书馆

Exergy and exergoeconomic analyses for integration of aromatics separation with aromatics upgrading

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 2023年第2期17卷 183-193页

作者： dan zhang Minbo Yang Xiao Feng Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering&TechnologyXi’an Jiaotong UniversityXi’an 710049China

Methanol to aromatics produces multiple products,resulting in a limited selectivity of *** upgrading is an effective way to produce more valuable xylene product,and different feed ratios generate discrepant product *** work integrates the aromatics separation with toluene disproportionation,transalkylation of toluene and trimethylbenzene,and isomerization of xylene and *** and exergoeconomic analyses are conducted to give insights in the splitting ratios of benzene,toluene and heavy aromatics for aromatics ***,a detailed simulation model is developed in Aspen ***,300 splitting ratio sets of benzene and toluene for conversion are studied to investigate the process *** results indicate that there are different preferences for the splitting ratios of benzene and toluene in terms of exergy and exergoeconomic *** process generates lower total exergy destruction when the splitting ratio of toluene varies between 0.07 and 0.18,and that of benzene fluctuates between 0.55 and ***,the process presents lower total product unit cost with the splitting ratio of toluene less than 0.18 and that of benzene fluctuating between 0.44 and ***,it is found that distillation is the biggest contributor to the total exergy destruction,accounting for 94.97%.

关键词： aromatics separation and upgrading variant splitting ratios total exergy destruction total product unit cost

Novel Stability Criteria for Sampled-Data Systems With Variable Sampling Periods

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 257-262页

作者： Hanyong Shao Jianrong Zhao dan zhang Institute of Automation Qufu Normal University

This paper is concerned with a novel Lyapunovlike functional approach to the stability of sampled-data systems with variable sampling periods. The Lyapunov-like functional has four striking characters compared to usual ones. First, it is time-dependent. Second, it may be discontinuous. Third, not every term of it is required to be positive definite. Fourth, the Lyapunov functional includes not only the state and the sampled state but also the integral of the state. By using a recently reported inequality to estimate the derivative of this Lyapunov functional, a sampled-interval-dependent stability criterion with reduced conservatism is obtained. The stability criterion is further extended to sampled-data systems with polytopic uncertainties. Finally, three examples are given to illustrate the reduced conservatism of the stability criteria.

关键词： Lyapunov functional sampled-data systems sampling-interval-dependent stability

The Newton filtration and d-determination of bifurcation problems related to C^0 contact equivalence

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2006年第5期49卷 660-668页

作者： SU dan zhang Dunmu School of Mathematics and Statistics Wuhan University Wuhan 430072 China School of Mathematics and Statistics Wuhan University Wuhan 430072 China

In this paper, from the Newton filtration's point of view, we construct the singular Riemannian metric and use the method in singular theory to study the bifurcation problems, and give the sufficient condition of d-determination of bifurcation problems with respect to C0 contact equivalence. The special cases of the main result in this paper are the results of Sun Weizhi and Zou Jiancheng.

关键词： map germ, Newton filtration, singular Riemannian metric, C0 contact equivalence.

Immobilized Lentinus edodes residue as absorbent for the enhancement of cadmium adsorption performance

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2012年第4期6卷 498-508页

作者： Pei MA dan zhang Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Graduate University of Chinese Academy of Sciences Beijing 100049China Institute of Mountain Hazards and Environment Chinese Academy of Sciences and Ministry of Water ConservancyChengdu 610041China

To investigate the potential use of Lentinus edodes （L. edodes） residue for Cd^2＋ adsorption, poly alcohol Na alginate （PVA） was applied to immobilize it. The parameters including contact time, pH, adsorbent dosages, and coexisting metal ions were studied. The suitable pH for immobilized L. edodes was 4-7 wider than that for raw L. edodes （pH 6-7）. In the presence of Pb^2＋ concentration varying from 0 to 30mg.L^-1, the Cd^2＋ adsorption ratios declined by 6.71% and 47.45% for immobilized and raw L. edodes, respectively. While, with the coexisting ion Cu2＋ concentration varied from 0 to 30 mg.L^-1, the Cd^2＋ adsorption ratios declined by 12.97% and 50.56% for immobilized and raw L. edodes, respectively. The Cd^2＋ adsorption isotherms in singlemetal and dual-metal solutions were analyzed by using Langmuir, Freuxldlich, and Dubinin-Radushkevich models. The Cd^2＋ adsorption capacities （qm） in single-metal solution were 6.448 mg.L^-1 and 2.832 mg.L^-1 for immobilized and raw L. edodes, respectively. The qm of immobilized L. edodes were 1.850 mg Cd. gl in Cd^2＋＋ Pb^2＋ solution and 3.961mg Cd.g^-1 in Cd^2＋＋ Cu^2＋ solution, respectively. The Cd^2＋ adsorption processes subjected to both adsorbents follow pseudo-second-order model. Mechanism study showed the functional group of L. edodes was -OH, -NH, -CO, and PVA played an important role in metal adsorbing. Mining wastewater treatment test showed that PVA-SA-immobilized L. edodes was effective in mixed pollutant treatment even for wastewater containing metal ions in very low concentration.

关键词： competitive immobilization Lentinus edodes residue adsorption isotherm

Dendritic Cell Algorithm with Bayesian Optimization Hyperband for Signal Fusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第8期76卷 2317-2336页

作者： dan zhang Yu zhang Yiwen Liang School of Computer Science Wuhan UniversityWuhan430072China GNSS Research Center Wuhan UniversityWuhan430079China

The dendritic cell algorithm(DCA)is an excellent prototype for developing Machine Learning inspired by the function of the powerful natural immune *** many parameters increase complexity and lead to plenty of criticism in the signal fusion procedure of *** loss function of DCA is ambiguous due to its *** reduce the uncertainty,several researchers simplified the algorithm program;some introduced gradient descent to optimize parameters;some utilized searching methods to find the optimal parameter ***,these studies are either time-consuming or need to be revised in the case of non-convex *** overcome the problems,this study models the parameter optimization into a black-box optimization problem without knowing the information about its loss *** study hybridizes bayesian optimization hyperband(BOHB)with DCA to propose a novel DCA version,BHDCA,for accomplishing parameter optimization in the signal fusion *** BHDCA utilizes the bayesian optimization(BO)of BOHB to find promising parameter configurations and applies the hyperband of BOHB to allocate the suitable budget for each potential *** experimental results show that the proposed algorithm has significant advantages over the otherDCAexpansion algorithms in terms of signal fusion.

关键词： Dendritic cell algorithm signal fusion parameter optimization bayesian optimization hyperband

Effect of Phase Noise on the Stationary Entanglement of an Optomechanical System with Kerr Medium

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 2013年第2期30卷 143-146页

作者： zhang dan ZHENG Qiang School of Chemistry and Material Science Guizhou Normal UniversityGuiyang 550001 School of Mathematics and Computer Science Guizhou Normal UniversityGuiyang 550001

We theoretically investigate the effect of phase noise on the stationary entanglement of an optomechanical system,which has the additional Kerr medium in the *** are two kinds of interactions in the system,photon-mirror interaction and photon-photon *** find that the optomechanical entanglement can be suppressed by the phase noise of the pumping laser and Kerr interaction of *** also find that Kerr interaction can make the phase-noise-induced double peak of the stationary entanglement change to a single peak.

关键词： interaction. stationary interaction

Theoretical Analysis and Numerical Simulation of the Static and Dynamic Characteristics of Hydrostatic Guides Based on Progressive Mengen Flow Controller

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 Journal of Mechanical Engineering 2010年第6期23卷 709-716页

作者： GAO Dianrong ZHENG dan zhang Zuochao Key Laboratory of Heavy Machinery Fluid Power Transmission and Control of Hebei Province Yanshan University Qinhuangdao 066004 China

The oil film thickness of oil hydrostatic guide with constant pressure supply based on capillary restrictor is greatly affected by load, and this kind of hydrostatic guide is usually applied to the machine tools with moderate load. The static and dynamic characteristics of the guide have been studied by using some theoretical, numerical and experimental approaches, and some methods and measures have been proposed to improve its performances. The hydrostatic guide based on progressive mengen（PM） flow controller is especially suitable for the heavy numerical control（NC） machine tools. However, few literatures about the research on the static and dynamic characteristics of the hydrostatic guides based on PM flow controller are reported. In this paper, the formulae are derived for analyzing the static and dynamic characteristics of hydrostatic guides with rectangle pockets and PM flow controller according to the theory of hydrostatic bearing. On the basis of the analysis of hydrostatic bearing with circular pocket, some equations are derived for solving the static pressure, volume pressure and squeezing pressure which influence the dynamic characteristics of hydrostatic guides with rectangle pocket. The function and the influencing factors of three pressures are clarified. The formulae of amplitude-frequency characteristics and dynamic stiffness of the hydrostatic guide system are derived. With the help of software MATLAB, programs are coded with C＋＋ language to simulate numerically the static and dynamic characteristics of the hydrostatic guide based on PM flow controller. The simulation results indicate that the sensitive oil volume between the outlet of the PM flow controller and the guide pocket has the greatest influence on the characteristics of the guide, and it should be reduced as small as possible when the field working condition is met. Choosing the oil with a greater viscosity is also helpful in improving the dynamic performance of hydrostatic guides. The re

关键词： PM flow controller rectangle pocket static characteristics dynamic characteristics hydrostatic guides

Convergence performance comparisons of PID, MRAC, and PID ＋ MRAC hybrid controller

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2016年第2期11卷 213-217页

作者： dan zhang Bin WEI Department of Mechanical Engineering York University Toronto M3J 1P3 Canada Department of Automotive Mechanical and Manufacturing Engineering University of Ontario Institute of Tectmology Oshawa L1H 7K4 Canada

This study proposes a hybrid controller by combining a proportional-integral-derivative （PID） control and a model reference adaptive control （MRAC）, which named as PID ＋ MRAC controller. The convergence performances of the PID control, MRAC, and hybrid PID ＋ MRAC are also compared. Through the simulation in Matlab, the results show that the convergence speed and performance of the MRAC and the PID ＋MRAC controller are better than those of the PID controller. In addition, the convergence performance of the hybrid control is better than that of the MRAC control.

关键词： proportional-integral-derivative (PID) control,model reference adaptive control hybrid control conver-gence speed comparison

Variational quantum algorithms for scanning the complex spectrum of non-Hermitian systems

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 275-285页

作者： Xu-dan Xie Zheng-Yuan Xue dan-Bo zhang Key Laboratory of Atomic and Subatomic Structure and Quantum Control(Ministry of Education) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matterand School of PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials Guangdong–Hong Kong Joint Laboratory of Quantum Matterand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be ***,we propose a variational quantum algorithm for solving the non-Hermitian Hamiltonian by minimizing a type of energy variance,where zero variance can naturally determine the eigenvalues and the associated left and right ***,the energy is set as a parameter in the cost function and can be tuned to scan the whole spectrum efficiently by using a two-step optimization *** numerical simulations,we demonstrate the algorithm for preparing the left and right eigenstates,verifying the biorthogonal relations,as well as evaluating the *** also investigate the impact of quantum noise on our algorithm and show that its performance can be largely improved using error mitigation ***,our work suggests an avenue for solving non-Hermitian quantum many-body systems with variational quantum algorithms on near-term noisy quantum computers.

关键词： quantum algorithm non-Hermitian physics quantum manybody systems