检索结果-南通市图书馆

Effect of Fluoride on the Ion-association of Calcium Phosphate and Crystallization of Hydroxyapatite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 831-838页

作者：宋昊月 cai Meng 袁萍邹朝勇 School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and the formation of ACP nanospheres in a buffer solution with constant ionic ***,the stability of ACP increased with increasing fluoride concentration,which was ascribed to the inhibitory effect of fluoride on the aggregation of ACP nanospheres and the nucleation of nanocrystals on the surface of ACP ***,fluoride could inhibit the lateral growth of HAP nanosheets and promote the formation of rod-like *** results further improve our understanding of the crystallization pathway of HAP crystals and the regulatory effects of fluoride.

关键词： crystallization amorphous calcium phosphate hydroxyapatite fluoride

Effect of operating conditions on the performance of riser reactor for oxidative coupling of methane Author links open overlay panel

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第8期91卷 235-248页

作者： Min cai Shuangzhu Kong Mengxi Liu Chunxi Lu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China

Oxidative coupling of methane(OCM)is characterized by high temperature and strong heat released.A riser reactor is designed for the OCM process to improve gas-solid contacting and heat *** work illustrates the effect of hydrodynamic conditions and feed gas composition on the performance of an OCM riser *** findings suggest that oxidative reactions predominantly occur within the acceleration zone and developed flow ***,at the low superficial gas velocity accompanied by a high solid circulating rate,the C_(2)yield initially increases in the acceleration zone,followed by a decrease in the developed flow zone and deceleration *** optimal operating conditions are a specific region corresponding to the solids holdup ranges from 0.015 to ***,the C_(2)yield can be elevated using an appropriate feed mixture.

关键词： Oxidative coupling of methane Riser Hydrodynamics Solids holdup

N-Heterocyclic carbene-catalyzed enantioselective(dynamic) kinetic resolutions and desymmetrizations

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

Science China Chemistry 2024年第2期67卷 482-511页

作者： Yi Zhang Hui cai Xiuhai Gan Zhichao Jin National Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityHuaxi DistrictGuiyang550025China

N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically *** content is organized according to the activation modes involved i... 详细信息

关键词： N-heterocyclic carbene kinetic resolution dynamic kinetic resolution desymmetrization organocatalysis

Heat Transfer and Flow Structure of a Turbine Blade's Air-cooled Leading Edge Considering Different Hole Shapes and Additional Flow Angles

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第4期33卷 1421-1442页

作者： QIN Runxuan ZHOU Xun WANG Songtao cai Le School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

A numerical study is conducted to elucidate the impact of hole shapes and additional flow angles on the flow structure of the coolant and temperature field in the leading edge area of the gas turbine *** typical hole shapes are considered for the GE-E3 *** impact of the additional flow angle(E)within each hole shape on the temperature field is *** results indicate that for the leading edge area and suction surface,the fan-shaped hole case performs best in decreasing temperatures,with a decrease of about 43 *** is mainly due to the fact that the fan-shaped hole has the maximum expansion in hole spanwise *** the pressure surface,the console hole case performs best in decreasing temperatures,with a maximum reduction of about 47.2 *** influence of E on the surface temperature at leading edge area varied between the different hole *** the cylinder hole and console hole,the E=-20°case has the lowest area-averaged *** both the fan-shaped hole and the 7-7-7 shaped hole are expansion holes,the pattern of variation of the leading edge area temperature with increasing E is similar for the fan-shaped hole case and 7-7-7 shaped hole *** E=20°case shows the lowest spanwise-averaged temperature near the hole outlet,and the E=-20°case shows the lowest spanwise-averaged temperature further downstream.

关键词： film cooling GE-E3 turbine rotor blade conjugate heat transfer leading edge

A reduced-order model for fast predicting ionized flows of hypersonic vehicles along flight trajectory

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 89-105页

作者： Jingchao ZHANG Chunsheng NIE Jinsheng cai Shucheng PAN School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing 100076China Institute of Extreme Mechanics Northwestern Polytechnical UniversityXi’an 710072China

An improved Reduced-Order Model(ROM)is proposed based on a flow-solution preprocessing operation and a fast sampling strategy to efficiently and accurately predict ionized hypersonic *** ROM is generated in low-dimensional space by performing the Proper Orthogonal Decomposition(POD)on snapshots and is coupled with the Radial Basis Function(RBF)to achieve fast prediction ***,due to the disparate scales in the ionized flow field,the conventional ROM usually generates spurious negative ***,this issue is addressed by performing flow-solution preprocessing in logarithmic space to improve the conventional ***,extra orthogonal polynomials are introduced in the RBF interpolation to achieve additional improvement of the prediction *** addition,to construct high-efficiency snapshots,a trajectory-constrained adaptive sampling strategy based on convex hull optimization is *** evaluate the performance of the proposed fast prediction method,two hypersonic vehicles with classic configurations,i.e.a wave-rider and a reentry capsule,are used to validate the proposed *** two cases show that the proposed fast prediction method has high accuracy near the vehicle surface and the free-stream region where the flow field is *** with the conventional ROM prediction,the prediction results are significantly improved by the proposed method around the discontinuities,*** shock wave and the ionized *** a result,the proposed fast prediction method reduces the error of the conventional ROM by at least 45%,with a speedup of approximately 2.0×105compared to the Computational Fluid Dynamic(CFD)*** test cases demonstrate that the method developed here is efficient and accurate for predicting ionized hypersonic flows.

关键词： Reduced-order model Radial basis function Constrained sampling Transfer function Fast flow prediction Ionized hypersonic flows

Heterointerface Engineering-Induced Oxygen Defects for the Manganese Dissolution Inhibition in Aqueous Zinc Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第3期7卷 112-122页

作者： Wentao Qu Yong cai Baohui Chen Ming Zhang Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics&Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China Engineering Research Center of Advanced Semiconductor Technology and Application of Ministry of Education&Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China Changsha Semiconductor Technology and Application Innovation Research Institute College of Semiconductors(College of Integrated Circuits)Hunan UniversityChangsha 410082China State Key Laboratory of Disaster Prevention&Reduction for Power Grid Transmission and Distribution Equipment(Hunan Electric Power Corporation Disaster Prevention and Reduction Center) Changsha 410007China

Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low ***,the manganese dissolution during the electrochemical reaction causes its electrochemical cycling stability to be *** this work,heterointerface engineering-induced oxygen defects are introduced into heterostructure MnO_(2)(δa-MnO_(2))by in situ electrochemical activation to inhibit manganese dissolution for aqueous zinc ion ***,the heterointerface between the disordered amorphous and the crystalline MnO_(2)ofδa-MnO_(2)is decisive for the formation of oxygen *** the experimental results indicate that the manganese dissolution ofδa-MnO_(2)is considerably inhibited during the charge/discharge *** analysis indicates that the oxygen defect regulates the electronic and band structure and the Mn-O bonding state of the electrode material,thereby promoting electron transport kinetics as well as inhibiting Mn ***,the capacity ofδa-MnO_(2)does not degrade after 100 cycles at a current density of 0.5 Ag^(-1)and also 91%capacity retention after 500cycles at 1 Ag^(-1).This study provides a promising insight into the development of high-performance manganese-based cathode materials through a facile and low-cost strategy.

关键词： electrochemical activation heterointerface manganese dissolution inhibition oxygen defects zinc ion batteries

Disentangling distinct Cu surface sites for electrocatalytic CO_(2)-to-CO and CO-to-C_(2+)conversion

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1047-1048页

作者： Kun Jiang Wen-Bin cai Interdisciplinary Science Research Centre School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Electrochemical CO_(2)reduction reaction(CO_(2)RR)is a promising strategy to curb anthropogenic carbon emissions,for which intermittent renewable electricity could be stored as chemical energy within carbon-based fuel... 详细信息

关键词： carbon Electrochemical surface

Low and high frequency transcutaneous electrical acupoint stimulation are differentiated by their effects on μ-opioid receptors in brain

在线全文

学校读者我要写书评

暂无评论

Low and high frequency transcutaneous electrical acupoint st...

Thyristor-inserted MMC Sub-module Topology with DC Fault Blocking Capability

中国神经科学学会第九届全国学术会议暨第五次会员代表大会

作者： Xiao-Hui XIANG~(1,3),Ying-Mao CHEN~2,Jin-Ming ZHANG~2,Jia-He TIAN~2,Ji-Sheng HAN~1,cai-lian cui~(1,*) 1 Neuroscience Research Institute and Department of Neurobiology,Peking University Health Science Center,Key Laboratory of Neuroscience,the Ministry of Education and Ministry of Public Health,Beijing 100191,China 2 Department of Nuclear Medicine,the Chinese PLA General Hospital,Beijing 100853,China 3 Department of Physiology and Pathophysiology,Medical College of Chinese People’s Armed Police Forces,Tianjin 300162,China

Objective Accumulated data show that the mechanisms of transcutaneous electrical acupoint stimulation (TEAS)analgesia involve the activation of endogenous opioid antinociceptive systems and theμ-opioid receptors (MORs)in the central nervous system(CNS).Positron emission tomography(PET)is the only real time in vivo method available today to study u-opioid receptor *** this study we investigated the different effects of low and high frequency TEAS on MOR binding potential of the brains in rhesus *** PET with C-carfentanil was performed three times randomly under TEAS of 0 Hz,2 Hz or 100 Hz respectively in each monkey separated by at least 2 *** was administered in the middle 30 min during the 95 min PET *** images were reconstructed in 3D OSEM *** distribution volume of three stages(before,during and after TEAS)were calculated using Logan plot with an online arterial radiocounting as input function and were analyzed using Statistical Parametric Mapping(SPM).Results 2 Hz TEAS evoked an increases in MOR binding potential in multiple pain and sensory processing brain regions including the dorsal cingulated cortex,caudate nucleus,putamen,temporal lobe, somatosensory cortex and amygdale during the TEAS compared with that of 0 Hz *** effect remained after TEAS in genual anterior cingulate cortex and temporal *** increase in MOR binding potential was found during and after the 100 Hz TEAS compared with 0 Hz *** The increases of u-opioid receptor binding potential in multiple pain and sensory processing brain regions may play a role in mediating the effect of low,but not high frequency TEAS.

关键词： μ-opioid receptor positron emission tomography transcutaneous electrical acupoint stimulation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第5期10卷 2221-2229页

作者： Cheng Peng Rui Li Xu cai Key Laboratory of Control of Power Transmission and Conversion Shanghai Jiao Tong UniversityMinistry of EducationShanghai Jiao Tong UniversityShanghai 200240China.

Modular multilevel converter(MMC)is increasingly being applied to high voltage direct current(HVDC)***,dc short circuit situations restrain the application of a conventional half bridge MMC *** this paper,a new sub-module topology with inserted thyristor can help the MMC system clear a dc side *** states and devices voltage stress of the proposed topology are analyzed and the conduction loss comparison between the proposed topology with several existing topologies with dc fault blocking capability is carried *** show the proposed topology is superior to other topologies in terms of conduction loss while using the same voltage rating ***,compared with traditional half bridge topology,only thyristors and diodes are added in the proposed ***,cost of the proposed topology can be lower than conventional hybrid MMC *** last,the fault blocking capability of the proposed topology is verified in the simulation.

关键词： Fault current limiting high voltage direct current(HVDC)transmission modular multilevel converter(MMC)