检索结果-南通市图书馆

Energy modeling and optimization of building condenser water systems with all-variable speed pumps and tower fans:A case study

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第7期17卷 1085-1111页

作者： yong cao Chuang Wang Sheng Wang xiao Fu Xinguo Ming School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation Zhuhai 519070China GREE Electric Appliances Inc.of ZhuhaiZhuhai 519070China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Beijing Advanced Innovation Centerfor Future Urban Design Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The emergence of building condenser water systems with all-variable speed pumps and tower fans allows for increased efficiency and flexibility of chiller plants in partial load operation but also increases the control complexity of condenser water *** study aims to develop an integrated modeling technique for evaluating and optimizing the energy performance of such a condenser water *** proposed system model is based on the semi-physical semi-empirical chiller,pump,and cooling tower models,with capabilities of fully considering the hydraulic and thermal interactions in the condenser water loop,being solved analytically and much faster than iterative solvers and supporting the explicit optimization of the pump and tower fan frequency.A mathematical approach,based on the system model and constrained optimization technique,is subsequently established to evaluate the energy performance of a typical dual setpoint-based variable speed strategy and find its energy-saving potential and most efficient operation by jointly optimizing pumps and tower *** all-variable speed chiller plant from Wuhan,China,is used for a case study to validate the system model’s accuracy and explore its *** results showed that the system model can accurately simulate the condenser water system’s performance under various operating *** optimizing the frequencies of pumps and tower fans,the total system energy consumption can be reduced by 12%–13%compared to the fixed dual setpoint-based strategy with range and approach setpoints of 4℃and 2℃.In contrast,the energy-saving potential of optimizing the cooling tower sequencing is insignificant.A simple joint speed control method for optimizing the pumps and tower fans emerged,i.e.,the optimal pump and fan frequency are linearly correlated(if both are non-extremes)and depend on the chiller part load ratio only,irrespective of the ambient wet-bulb temperature and chilled water supply *** was also foun

关键词： all-variable speed chiller plant model-based optimization hydraulic and thermal coupling analytical solution dual setpoint-based variable speed control optimal joint speed control

Biomimetic transformation of gentiopicroside to erythrocentaurin

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 Chemical Letters 2009年第2期20卷 150-152页

作者： Cui Ling Wang Jian Li Liu Zhu Lan Liu Xin Sheng Li xiao yong cao School of Life Science Northwest University Xi'an 710069 China Department of Biology Shaanxi University of Technology Hanzhong 723001 China

Biomimetic transformation of gentiopicroside was carded out by β-glucosidase at pH 7.0 for 3 days at 37 ℃. Two products, erythrocentaurin and 5,6-dihydro-5-formyl-6-methyl-1H,3H-pyrano[3,4-c]pyran-1-one were isolate... 详细信息

关键词： Gentiopicroside Biomimetic transformation β-Glucosidase Erythrocentaurin 5,6-Dihydro-5-formyl-6-methyl-1H,3H-pyrano[3,4-c]pyran-1-one

Novel method for extraction of ship target with overlaps in SAR image via EM algorithm

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4期35卷 874-887页

作者： cao Rui WANG yong School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition can be *** addressing this issue,a method for extracting ship targets with overlaps via the expectation maximization(EM)algorithm is ***,the scatterers of ship targets are obtained via the target detection ***,the EM algorithm is applied to extract the scatterers of a single ship target with a single ***,a novel image amplitude estimation approach is pro-posed,with which the radar image of a single target with a sin-gle IPP can be *** proposed method can accom-plish IPP selection and targets separation in the image domain,which can improve the image quality and reserve the target information most *** of simulated and real mea-sured data demonstrate the effectiveness of the proposed method.

关键词： expectation maximization(EM)algorithm image processing imaging projection plane(IPP) overlapping ship tar-get synthetic aperture radar(SAR)

Experimental and Numerical Investigation of Non-synchronous Blade Vibration Excitation in a Transonic Axial Compressor

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 602-610页

作者： WANG Songbai WU Yadong CHEN yong cao Zhipeng School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240China AECC Sichuan Gas Turbine Establishment Chengdu610500China

The complex flow phenomenon of rotating instability(RI) and its induced non-synchronous vibration(NSV) have become a significant challenge as they continuously increase aerodynamic *** study aims to provide an understanding of the non-synchronous blade vibration phenomenon caused by the rotating instability of a transonic axial compressor *** this case,blade vibrations and non-synchronous excitation are captured by strain gauges and unsteady wall pressure transducer *** numerical simulations for a full-annulus configuration are used to obtain the non-synchronous flow *** results show that the first-stage rotor blade exhibits an NSV close to the first bending mode;NSV is accompanied by a sharp increase in pressure pulsation;amplitude can reach 20%,and unsteady aerodynamic frequency will lock in a structural mode frequency when the blade vibrates in a large-amplitude *** predicted NSV frequency aligns well with the experimental *** dominant mode of circumferential instability flow structure is approximately 47% of the number blades,and the cell size occupies 2-3 pitches in the circumferential *** full-annulus unsteady simulations demonstrate that the streamwise oscillation of the shedding and reattachment vortex structure is the main cause of NSV owing to the strong interaction between the tip leakage and separation vortices near the suction surface.

关键词： non-synchronous vibration transonic axial compressor rotor blade rotating instabilities unsteady flow

Bioinspired Closed-loop CPG-based Control of a Robotic Manta for Autonomous Swimming

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第1期21卷 177-191页

作者： Yiwei Hao yonghui cao Yingzhuo cao Xiong Mo Qiaogao Huang Lei Gong Guang Pan yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo 315103China Key Laboratory of Unmanned Underwater Vehicle Technology of Ministry of Industry and Information Technology Xi'an 710072China

Fish in nature exhibit a variety of swimming modes such as forward swimming,backward swimming,turning,pitching,etc.,enabling them to swim in complex scenes such as coral *** is still difficult for a robotic fish to swim autonomously in a confined area as a real ***,we develop an untethered robotic manta as an experimental platform,which consists of two flexible pectoral fins and a tail fin,with three infrared sensors installed on the front,left,and right sides of the head to sense the surrounding *** generate multiple swimming modes of the robotic manta and online switching of different modes,we design a closed-loop Central Pattern Generator(CPG)controller based on distance information and use a combination of phase difference and amplitude of the CPG model to achieve stable and rapid adjustment of yaw *** verify the autonomous swimming ability of the robotic manta in complex scenes,we design an experimental scenario with a concave *** experimental results show that the robotic manta can achieve forward swimming,backward swimming,in situ turning within the concave obstacle,and finally exit from the area safely while relying on the perception of external obstacles,which can provide insight into the autonomous exploration of complex scenes by the biomimetic robotic ***,the swimming ability of the robotic manta is verified by field tests.

关键词： Biomimetic robotic manta Central Pattern Generator Closed-loop control Backward swimming

Neuroprotective activity of two active chemical constituents from Tinospora hainanensis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

亚太热带医药杂志：英文版 2017年第2期10卷 108-113页

作者： Dao-Rui Yu Li-Ping Ji Tao Wang Xi-Nan Yi Guo-Hui Yi Tong He yong-xiao cao En-Wu Long Qi-Bing Liu Department of Pharmacology School of Pharmaceutical ScienceHainan Medical University Department of Pharmacology Xi’an Jiaotong University Health Science Center Research Center of Basic Medicine Hainan Medical University Department of Pharmacy Sichuan Provincial People’s Hospital

Objective:To determine the chemical structure of the new compound and investigate the protective effects of Tinosporaic acid A and B towards in-vitro ***:The structures of two new compounds were established by analyzing its 1D and 2D NMR spectra as well as *** neuroprotective effects with respect to the antioxidant properties were evaluated by radical scavenging tests and hydrogen peroxide-injured oxidative stress model in PC12 cell *** morphology of treated PC12 cells was observed by phase contrast ***-vitro MTT assay,lactate dehydrogenase activity assay and oxidative stress markers(intracellular ROS production,MDA level,and caspase-3 activity) were used to evaluate the protective effects against hydrogen peroxide induced cytotoxicity in PC12 ***:The two new compounds,named Tinosporaic acid A and B,were isolated and identified from the stem bark of Tinospora *** viability studies identified a representative concentration for each extract that was subsequently used to measure oxidative stress *** extracts were able to reverse the oxidative damage caused by hydrogen peroxide,thus promoting PC12 cells *** concentration of Tinosporaic acid A and B were 86.34 μg/mL and 22.06 μg/mL respectively,which is neuroprotective for EC_(50).The results indicated that both of them significantly attenuated hydrogen peroxide-induced ***:The two new compounds isolated from ethanol extracts of Tinospora hainanensis are the promising natural ones with neuroprotective activity and needed for further research.

关键词： Tinospora hainanensis Phytochemical analysis Neuroprotective activity NMR HRESIMS

Asymmetric reversible structural switching of a diene coordination polymer promoted by UV-visible light

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 536-541页

作者： yong Wang Qiaoqiao Zhang yong-yong cao Qi Liu Brendan F.Abrahams Jian-Ping Lang College of Chemistry Chemical Engineering and MaterialsSoochow UniversitySuzhou215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032China College of Biological Chemical Science and EngineeringJiaxing UniversityJiaxing314001China School of Chemistry University of MelbourneVictoria3010Australia

In natural and artificial systems,reversible reactions are commonly asymmetric with respect to the time scale and nature of the stimuli which drive the forward and backward *** applications for which switching behavior is required,it is desirable that the reversible reaction goes as close to symmetric as possible;however,such systems are ***,we report an example of ultraviolet(UV)-visible light-regulated asymmetric reversible structural switching involving a diene-based coordination polymer,CP1 and its monocyclobutane product,*** is possible to cycle at least ten times through a forward [2+2] photocycloaddition reaction and the reverse,photocleavage reaction.A single cycle can be completed within a few *** transformation is accompanied by fast and distinct fluorescence changes,arising from optimisation of the reaction *** functional theory calculations allow rationalisation of the asymmetric reversible transformation between CP1 and CP1a rather than between CP1 and its dicyclobutane product *** work provides a clear illustration of reversible structural switching which approaches symmetric behaviour with respect to reaction rate and *** insights gained from this work also assist in the design of fast,reversible switching materials.

关键词： asymmetrical reversible structural switching coordination polymer photocycloaddition UV-visible light-controlled fluorescence switching

Effect of Active–Passive Deformation on the Thrust by the Pectoral Fins of Bionic Manta Robot

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第2期21卷 718-728页

作者： Yang Lu Shaomin Meng Cheng Xing Yiwei Hao yonghui cao Guang Pan yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo315103China State Key Lab of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou310027China Zhejiang Key Laboratory of Advanced Manufacturing Technology School of Mechanical EngineeringZhejiang UniversityHangzhou310027China

Bionic manta underwater vehicles will play an essential role in future oceans and can perform tasks,such as long-duration reconnaissance and exploration,due to their efficient *** manta wings’deformation is evident during the swimming *** improve the propulsion performance of the unmanned submersible,the study of the deformation into the bionic pectoral fin is *** this research,we designed and fabricated a flexible bionic pectoral fin,which is based on the Fin Ray®effect with active and passive deformation(APD)*** APD fin was actively controlled by two servo motors and could be passively deformed to variable *** APD fin was moved at 0.5 Hz beat frequency,and the propulsive performance was experimentally verified of the bionic pectoral fins equipped with different extents of *** results showed that the pectoral fin with active–passive deformed capabilities could achieve similar natural biological deformation in the wingspan *** average thrust(T)under the optimal wingspan deformation is 61.5%higher than the traditional passive deformed pectoral *** obtained results shed light on the design and optimization of the bionic pectoral fins to improve the propulsive performance of unmanned underwater vehicles(UUV).

关键词： Manta ray Bionic pectoral fin Fin Ray®effect Active-passive deformation(APD)

A mixed-valence polyoxometalate-based 3D inorganic framework cathode material for high-efficiency rechargeable AZIBs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3677-3691页

作者： Qing Han Hao-Ran xiao Tao Zhou Bing-Chuan Li Liu Yang Ling-Ling Xie Xue-Jing Qiu Xian-yong Wu Li-Min Zhu xiao-Yu cao School of Chemistry and Chemical Engineering Henan University of TechnologyZhengzhou 450001China Key Laboratory of High Specific Energy Materials for Electrochemical Power Sources of Zhengzhou City Zhengzhou 450001China College of Materials Engineering Henan University of EngineeringZhengzhou450007China School of Environmental Engineering Henan University of TechnologyZhengzhou 450001China Department of Chemistry University of Puerto Rico-Rio Piedras CampusSan JuanPR 00925USA

The global trend towards new energy storage systems has stimulated the development of electrochemical energy storage *** these technologies,rechargeable aqueous zinc-ion batteries(AZIBs)have attracted considerable interest as a potential alternative to lithium-ion batteries(LIBs)due to their affordable cost,environmental compatibility and high safety *** this study,a high-quality electrode for AZIBs has been successfully developed using a dehydrated mixed-valence polyoxometalate-based three-dimensional(3D)inorganic framework material known as[H_6Mn_(3)V^Ⅳ_(15)V-^Ⅴ_(4O)_(46)(H_2O)_(12)](3D-MnVO).This innovative 3D-MnVO material is built from the alternate connections of{V_(19)O_(46)}"sphere-shaped"clusters andμ_(2)-{Mn(H_(2)O)_(4)}bridges,where each{V_(19)O_(46)}cluster is surrounded by three pairs of vertically distributed{Mn(H_(2)O)_(4)}units,thus resulting in the 3D interpenetrating grid-like network from the infinite[-{V_(19)O_(46)}-μ_(2)-Mn(H_(2)O)_(4)-{V_(19)O_(46)}]_∞chains in three mutually perpendicular *** 3D framework structure of 3D-MnVO possesses abundant oxygen vacancies,spacious and multi-level interconnected channels for ion transport,which facilitates the efficient intercalation/deintercalation of hydrated Zn^(2+)into the pores of the primary structure via the intercalation capacitance *** a result,the 3D-MnVO electrode exhibits excellent diffusion rates and minimal interfacial *** a current density of 0.1 A·g^(-1),the 3D-MnVO cathode delivers a commendable discharge capacity of170.5 mAh·g^(-1)with 81.6%capacity retention after100 charge/discharge ***,even at a high current density of 1.0 A·g^(-1),the 3D-MnVO electrode delivers a remarkable reversible capacity of198.9 mAh·g^(-1).Our research results provide valuable insights into the development of advanced polyoxometalate-based 3D inorganic framework electrode materials for high-performance rechargeable AZIBs.

关键词： Cathode Polyoxometalate 3D inorganic framework Zinc-ion batteries Energy storage mechanism