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An online value iteration method for linear-quadratic mean field social control with unknown dynamics

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Science China(Information Sciences) 2024年第4期67卷 38-39页

作者： bing-Chang WANG Shumei LI Ying cao School of Control Science and Engineering Shandong University

Mean field(MF) models have been widely applied to economics, control theory, and other fields. Its prominent feature is that the individual influence on the overall population is negligible and the impact of the entire system to the single agent is significant and cannot be ignored. As a classical problem in control theory, linear quadratic(LQ) control for MF models has been widely investigated(e.g., [1, 2]).

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Prediction method of impeller performance and analysis of loss mechanism for mixed-flow pump

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Science China(Technological Sciences) 2012年第7期55卷 1988-1998页

作者： bing Hao TAN Lei cao ShuLiang LU Li State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Hydraulic Machinery Department China Institute of Water Resources and Hydropower ResearchBeijing 100038China

A loss model for the mixed-flow pump impellers was developed by summarizing a variety of loss calculation formulas *** internal flow field of the impeller was obtained by employing the iterative calculation for S 1 and S 2 stream surfaces to solve the continuity and motion equations of *** on the calculation method of the flow field and the loss model,it is achieved to predict the impeller performance of the mixed-flow pump and the performance curves of a mixed-flow pump model with adjustable *** with the test data,the loss model of the mixed-flow pump based on the iterative calculation can predict the impeller performance quickly and accurately,which has a high value on the engineering *** on the test verification,curves of various kinds of losses varied for the flow rate were analyzed under different blade *** addition,the mechanisms of various kinds of losses inside the mixed-flow pump impeller were discussed in-depth.

关键词： mixed-flow pump loss modeling iterative calculation performance prediction loss mechanism

Experimental study of the effect of blade tip clearance and blade angle error on the performance of mixed-flow pump

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Science China(Technological Sciences) 2013年第2期56卷 293-298页

作者： bing Hao cao ShuLiang HE ChengLian LU Li State Key Laboratory of Hydroscience and Engineering Tsinghua University Beifang Investigation Design & Research CO.Ltd Hydraulic Machinery Department China Institute of Water Resources and Hydropower Research

The hydraulic performance test of the mixed-flow pump has been carried out through selecting different blade tip clearances and various blade angle *** ratio of the mixed-flow pump efficiency reduction and the blade tip clearance variation(η/δ) varies with the flow rate coefficient revealing a parabolic *** empirical equation has been developed for the mixed-flow pump model by parabolic *** the same blade tip clearance variation δ,the mixed-flow pump efficiency reduction η increases rapidly as the flow rate *** any given flow rate,the efficiency,the head and the shaft power of the mixed-flow pump all decrease with the increase of the blade tip *** them,the efficiency reduction η varies approximately linearly with the blade tip clearance variation δ.When the angle of an individual blade of the mixed-flow pump has a deviation,the performance curves will move and *** curves have consistent change directions with the performance curves under the condition of all the blades rotated at the same time,but have smaller offset and lower range of *** an individual blade angle error changes to ±2°,the optimal efficiency of the mixed-flow pump will have no significant *** the individual blade angle error increases to ±4°,the optimal efficiency will decrease by 1%.

关键词： mixed-flow pump model test hydraulic performance blade tip clearance blade angle

Global Optimization Method for Linear Multiplicative Programming

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Acta Mathematicae Applicatae Sinica 2015年第2期31卷 325-334页

作者： Xue-gang ZHOU bing-yuan cao Kun WU School of Mathematics and Information Science Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Applied Mathematics Guangdong University of Finance School of Mathematical Science and Computing Technology Center South University

In this paper, a new global algorithm is presented to globally solve the linear multiplicative programming（LMP）. The problem（LMP） is firstly converted into an equivalent programming problem（LMP（H））by introducing p auxiliary variables. Then by exploiting structure of（LMP（H））, a linear relaxation programming（LP（H）） of（LMP（H）） is obtained with a problem（LMP） reduced to a sequence of linear programming problems. The algorithm is used to compute the lower bounds called the branch and bound search by solving linear relaxation programming problems（LP（H））. The proposed algorithm is proven that it is convergent to the global minimum through the solutions of a series of linear programming problems. Some examples are given to illustrate the feasibility of the proposed algorithm.

关键词： linear multiplicative programming global optimization linear programming branch and bound

Prediction and analysis of the potential risk of sudden oak death in China

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Journal of Forestry Research 2019年第6期30卷 2357-2366页

作者： Bo Xie Chunxiang cao Wei Chen bing Yu State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100101People’s Republic of China University of Chinese Academy of Sciences Beijing 100094People’s Republic of China School of Civil Engineering and Architecture Southwest Petroleum UniversityChengdu 610500People’s Republic of China

Sudden oak death(SOD)is one of the most rapid and destructive forest pathogens,which has caused the death of many host plants in Europe and *** are currently no cases in China where there are more host plants and a more suitable climate for this pathogen to ***,it is vital to discern the potential suitable habitat,quantify the risk levels,and monitor the potential high-risk *** this study,we modelled the potential invasion range and risk level of this pathogen at present and in future scenarios in China,using the least correlated components of all the environmental factors based on the Genetic Algorithm for Ruleset Production niche model and GIS *** results indicate that most areas in China are free from a potential SOD risk,and the majority of potential occurrence areas are concentrated in Southern China(Yunnan,Sichuan,Guizhou,Chongqing,Hunan,Fujian).The area of high and extremely high risk in 2050(RCP26,RCP45,RCP60,and RCP85)is larger than that at *** most susceptible area is Yunnan province with 80%of the area prone to SOD at extremely high risk in present and future *** results will be important for monitoring potential high-risk areas in the currently uninfected parts of China.

关键词： Phytophthora ramorum GARP Ecological niche models Suitable habitat Risk level

Fabrication of high-performance PVA/PAN composite pervaporation membranes crosslinked by PMDA for wastewater desalination

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Petroleum Science 2018年第1期15卷 146-156页

作者： Rui Zhang Xiaoying Xu bing cao Pei Li College of Materials Science and Engineering Beijing University of Chemical Technology

The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.

关键词： Pervaporation - Desalination Crosslinked PVA Composite membranes Wastewater treatment

Receptivity of plane Poiseuille flow to local micro-vibration disturbance on wall

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Water Science and Engineering 2015年第2期8卷 145-150页

作者： Wei-dong cao Qi-xiang Hu bing Liu Research Center of Fluid Machinery Engineering and Technology Jiangsu University

The receptivity of plane Poiseuille flow to local single-period micro-vibration disturbances with different phases at the top and bottom walls was investigated through direct numerical simulation of three-dimensional incompressible Navier-Stokes equations. Results show that the disturbance presents a symmetrical distribution in the spanwise direction when the micro-vibration on the wall ends, and the initial disturbance velocities and spatial distribution of the disturbance structure are different at the top and bottom walls. The disturbance＇s velocity, amplitude, and high- and low-speed streaks increase with time, and the amplitude of streamwise disturbance velocity is larger than those of spanwise and vertical disturbance velocities. However, no significant Tollmien-Schlichting wave was found in the flow field. The number of disturbance vortex cores gradually increases with the disturbance area. High-speed disturbance fluid concentrates near the wall and its normal velocity largely points to the wall, while low-speed disturbance fluid largely deviates from the wall. Furthermore, the streamwise velocity profiles near the top and bottom walls both become plump because of the existence of the disturbances, and the streamwise velocity profiles show a trend of evolving into turbulent velocity profiles. The shear stress near the wall increases significantly. The local micro-vibration disturbance on the wall in plane Poiseuille flow can induce the development of a structure similar to turbulent spots.

关键词： Poiseuille flow Disturbance Velocity profile Vortex High-and low-speed streaks

Analysis of load and adaptability of disc cutters during shield tunneling in soft-hard varied strata

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Frontiers of Structural and Civil Engineering 2023年第4期17卷 533-545页

作者： Fengwei yang Weilin SU Yi yang Zhiguo cao Yellow River Engineering Consulting Co. Ltd.Zhengzhou 450003China Key Laboratory of Water Management and Water Security for Yellow River Basin Ministry of Water ResourcesZhengzhou 450003China Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The disc cutters of shield machines exhibit unsatisfactory adaptability and performance during the soft–hard varied strata tunneling *** analyze the rotation state,cutting performance,and adaptability of disc cutters during shield tunneling in soft–hard varied strata,the Holmquist Johnson Cook and Federal Highway Administration constitutive models are introduced to numerically simulate the failure process of materials on the excavation face and to calculate the load of disc ***,the parameters of the models are modified based on laboratory disc cutter excavation test *** results of numerical calculation can reflect the load level and the behavior of the disc cutters during *** tangential loads of the disc cutters during the cutting of four typical soft-strata excavation face models are numerically calculated,thus providing reference values for the starting torque of the disc cutters.A greater penetration is suggested for soft-strata tunneling to allow the disc cutters to rotate smoothly and continuously as well as to guarantee a better cutting *** disc cutters in the center of the cutterhead should be specified with a lower starting torque to prevent uneven wear,rotation stagnation,cutterhead clogging,and other adverse phenomena.

关键词： shield tunneling disc cutter load laboratory excavation test numerical calculation soft-hard varied strata

Transcriptome Sequencing Reveals Astrocytes as a Therapeutic Target in Heat-Stroke

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Neuroscience Bulletin 2017年第6期33卷 627-640页

作者： bing Niu Tao Zhang Huaiqiang Hu bingzhen cao Department of Neurology General Hospital of Jinan Military Region Department of Neurology The 303rd Hospital of the People's Liberation Army

Heat-stroke is a serious form of hyperthermia with high mortality, and can induce severe central nervous system disorders. The neurovascular unit（NVU）, which consists of vascular cells, glial cells, and neurons, controls blood-brain barrier（BBB） permeability and cerebral blood flow, and maintains the proper functioning of neuronal circuits. However, the detailed function of each BBB component in heat-stroke remains unknown. In order to interpret alterations caused by heat stress, we performed transcriptome comparison of neuron and astrocyte primary cultures after heat treatment. Differentially-expressed genes were then selected and underwent Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Gene-act networks were also constructed, and the expression of pivotal genes was validated by quantitative PCR, as well as single-cell q PCR in heatstroke rats. Our work provides valuable information on the transcriptional changes in NVU cells after heat stress,reveals the diverse regulatory mechanisms of two of these cellular components, and shows that a cell-type-specificapproach may be a promising therapeutic strategy for heatstroke treatments.

关键词： Heat stroke RNA-seq Neuron Astrocyte Primary culture Single-cell qPCR