检索结果-南通市图书馆

Analytical　Study　on　Impingement　Heat　Transfer　with　Single－Phase　free－Surface　circular　Liquid　Jets

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1996年第4期5卷 271-277页

作者： c.f.ma T.masuoka 等 BeijingPolytechnicUniversity Beijing100022China KyushuInstituteofTechnology Kitakyushu804Japan

An analytical research was conducted to study heat transfer from horizontal surfaces to normally impinging circular jets under arbitrary-heat-flux conditions. The laminar thermal and hydraulic boundary layers were divided into five regions of flow. General expressions of heat transfer coefficients were obtained in all the four regions of stagnation and wall jet zones before the hydraulic jump.

关键词： jet impingement connective heat transfer boundary layer theory.

Local convective Heat Transfer from Small Heaters to Impinging Submerged Axisymmetric Jets of Seven coolants with Prandtl Number Ranging from 0.7 to 348

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1997年第4期6卷 286-297页

作者： H.Sun c.f.ma 等 DepartmentofThermalScience＆Engineering BeijingPolytechnicUniversityBeijing100022China DepartmentofT

Using seven working fluids, a systematic experimental study was performed to investigate the local convective heat transfer from vertical heaters to impinging circular submerged jets in the range of Reynolds number between 1.17 ×102 and 3.69 × 104 with the emphasis placed on the examination of Prandtl number dependence. Heat transfer coefficiellts at the stagnation point were collected and correlated with the plate held within and beyond the potential core. Radial distribution of the local heat transfer coefficient was measured with five test liquids. Based on the measured profiles of the local heat transfer, a correlation was developed to cover the entire range of the radial distance. Besides the presellt data, the correlations developed in this work were also compared with a large quantity of available data of circular air jets. General agreement was observed between the air data and the correlat ions.

关键词： forced convection jets Prandtl number

fundamental Research on convective Heat Transfer in Electronic cooling Technology

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1992年第1期1卷 30-40页

作者： c.f.ma Y.P.can Y.Q.Tian D.H.Lei Beijing Polytechnic University Beijing 100022China

During the past six years comprehensive research programs have been conducted at the Beijing Polytechnic University to provide a better understanding of heat transfer characteristics of existing and condidate cool- ing techniques for electronic and microelectronic *** paper provides a review and summary of the programs with emphasis on direct liquid *** in this review are the heat transfer investigations related to the following cooling modes:liquid free,mixed and forced convection,liquid jet impingement,flowing liquid film cooling,pool boiling,spray cooling,foreign gas jet impingement in liquid pool,and forced convection air-cooling.

关键词： convective heat transfer electronic cooling technology cooling modes.

Effects of Bifidobacterium lactis BLa80 on fecal and mucosal flora and stem cell factor/c-kit signaling pathway in simulated microgravity rats

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第1期31卷 93-109页

作者： Ping Zhang Ying Zhu Pu chen Tong Zhou Zhe-Yi Han Jun Xiao Jian-feng ma Wen ma Peng Zang Ying chen Graduate School Hebei North UniversityZhangjiakou 075000Hebei ProvinceChina Key Laboratory of Aerospace Nutrition and food Engineering China Astronaut Research and Training CenterBeijing 100094China Department of Gastroenterology The Air Force Medical CenterBeijing 100142China Department of Blood Transfusion Air Force Medical CenterBeijing 100142China

BAcKGROUND Simulated microgravity environment can lead to gastrointestinal motility *** pathogenesis of gastrointestinal motility disorders is closely related to the stem cell factor(Scf)/c-kit signaling pathway associated with intestinal flora and cajal stromal ***,intestinal flora can also affect the regulation of Scf/c-kit signaling pathway,thus affecting the expression of cajal stromal *** cells are the pacemakers of gastrointestinal *** To investigate the effects of Bifidobacterium lactis(***)BLa80 on the intestinal flora of rats in simulated microgravity and on the gastrointestinal motility-related Scf/c-kit *** The internationally recognized tail suspension animal model was used to simulate the microgravity environment,and 30 rats were randomly divided into control group,tail suspension group and drug administration tail suspension group with 10 rats in each group for a total of 28 *** tail group was given *** BLa80 by intragastric administration,and the other two groups were given water intragastric administration,the concentration of intragastric administration was 0.1 g/mL,and each rat was 1 mL/***&eosin staining was used to observe the histopathological changes in each segment of the intestine of each group,and the expression levels of Scf,c-kit,extracellular signal-regulated kinase(ERK)and p-ERK in the gastric antrum of each group were detected by Western blotting and *** fecal flora and mucosal flora of rats in each group were detected by 16S *** Simulated microgravity resulted in severe exfoliation of villi of duodenum,jejunum and ileum in rats,marked damage,increased space between villi,loose arrangement,shortened columnar epithelium of colon,less folds,narrower mucosal thickness,reduced goblet cell number and crypts,and significant improvement after probiotic *** microgravity reduced the expressions of Scf and c-kit,and increased the express

关键词： Simulated microgravity Rat Intestinal flora Gastrointestinal motility Stem cell factor/c-kit signaling pathway

High Strain Rate Superplasticity in a Micro-grained Al-Mg-Sc Alloy with Predominant High Angle Grain Boundaries

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

Journal of materials Science & Technology 2012年第11期28卷 1025-1030页

作者： f. c. Liu Z.Y. ma f. c. Zhang Shenyang National Laboratory for materials Science Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China State Key Laboratory of Metastable materials Science and Technology Yanshan University Qinhuangdao 066004China

friction stir processing （fSP） was applied to extruded AI-Mg-Sc alloy to produce fine-grained microstructure with a grain size of 2.2μm. Electron backscatter diffraction （EBSD） result showed that the grain boundary misorientation distribution was very close to a random grain assembly for randomly oriented cubes. Super- plastic investigations in the temperature range of 425-500 ℃ and strain rate range of 1x100^-2-1x10 s^-1 showed that a maximum elongation of 1500% was achieved at 475 ℃ and a high strain rate of 1x100^-2-1x10 s^-1. The fSP AI-Mg-Sc exhibited enhanced superplastic deformation kinetics compared to that predicted by the constitutive relationship for superplasticity in fine-grained aluminum alloys. The origin for enhanced superplas- tic deformation kinetics in the fSP alloy can be attributed to its high fraction of high angle grain boundaries （HAGBs）. The analyses of the superplastic data and scanning electron microscopy （SEM） examinations on the surfaces of deformed specimens indicated that grain boundary sliding is the main superplastic deformation mechanism for the fSP AI-Mg-Sc alloy.

关键词： Superplasticity friction stir processing Aluminum Microstructure friction stir welding

constructing Donor–Acceptor‑Linked cOfs Electrolytes to Regulate Electron Density and Accelerate the Li^(+)Migration in Quasi‑Solid‑State Battery

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第1期17卷 456-471页

作者： Genfu Zhao Hang ma conghui Zhang Yongxin Yang Shuyuan Yu Haiye Zhu Yongjiang Sun Hong Guo School of materials and Energy International Joint Research Center for Advanced Energy Materials of Yunnan ProvinceYunnan UniversityKunming 650091People’s Republic of China Yunnan Yuntianhua co. LtdR&D CenterKunming 650228People’s Republic of China Southwest United Graduate School Kunming 650091People’s Republic of China

Regulation the electronic density of solid-state electrolyte by donor–acceptor(D–A)system can achieve highly-selective Li^(+)transportation and conduction in solid-state Li metal *** study reports a high-performance solid-state electrolyte thorough D–A-linked covalent organic frameworks(cOfs)based on intramolecular charge transfer *** other reported cOfbased solid-state electrolyte,the developed concept with D–A-linked cOfs not only achieves electronic modulation to promote highly-selective Li^(+)migration and inhibit Li dendrite,but also offers a crucial opportunity to understand the role of electronic density in solid-state Li metal *** introduced strong electronegativity f-based ligand in cOf electrolyte results in highlyselective Li^(+)(transference number 0.83),high ionic conductivity(6.7×10^(-4)S cm^(−1)),excellent cyclic ability(1000 h)in Li metal symmetric cell and high-capacity retention in Li/LifePO_(4)cell(90.8%for 300 cycles at 5c)than substituted c-and N-based *** is ascribed to outstanding D–A interaction between donor porphyrin and acceptor f atoms,which effectively expedites electron transferring from porphyrin to f-based ligand and enhances Li^(+)***,we anticipate that this work creates insight into the strategy for accelerating Li^(+)conduction in high-performance solid-state Li metal batteries through D–A system.

关键词： Electronic modulation engineering Donor-acceptor-linked covalent organic frameworks Quasi-solid-state Li metal battery

Locally Enhanced flow and Electric fields Through a Tip Effect for Efficient flow‑Electrode capacitive Deionization

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 1-17页

作者： Ziquan Wang Xiangfeng chen Yuan Zhang Jie ma Zhiqun Lin Amor Abdelkader maria‑magdalena Titirici Libo Deng college of chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Research center for Environmental functional materials College of Environmental Science and EngineeringTongji University1239 Siping RoadShanghai 200092People’s Republic of China Department of chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore Department of Engineering Faculty of Science and TechnologyBournemouth UniversityTalbot CampusFern BarrowPooleEngland BH125BBUK Institut de chimie de Nice UniversitéCôte d’AzurUMR CNRS 727228 Av.Valrose06108 NiceFrance Department of chemical Engineering Imperial College LondonSouth Kensington CampusExhibition RdLondon SW72AZUK

Low-electrode capacitive deionization(fcDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of ***,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current ***,a new tip-array current collector(designated as T-cc)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport *** effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal *** the voltage increased from 1.0 to 1.5 and 2.0 V,the T-cc-based fcDI system(T-fcDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current ***,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-fcDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current ***,a salt removal efficiency of 99.89%was achieved with T-fcDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability.

关键词： flow-electrode capacitive deionization current collector Tip effect Desalination

c反应蛋白/白蛋白比值对2型糖尿病合并急性心肌梗死患者远期不良心脑血管事件的预测价值研究

在线全文

学校读者我要写书评

暂无评论

中国全科医学 2025年第6期28卷 705-712页

作者：马娟马盛宗燕茹马学平贾绍斌宁夏医科大学总医院心血管内科宁夏回族自治区银川市750000 宁夏回族自治区人民医院妇产科宁夏回族自治区银川市750000

背景急性心肌梗死(AMI)是威胁全球公众健康的主要原因之一。虽然已有相应的再灌注治疗策略,但AMI相关的主要不良心脑血管事件(maccEs)仍然是全世界人口死亡的原因之一。尤其合并糖尿病的AMI患者,因冠状动脉病变复杂,病变程度严重,尽早... 详细信息

背景急性心肌梗死(AMI)是威胁全球公众健康的主要原因之一。虽然已有相应的再灌注治疗策略,但AMI相关的主要不良心脑血管事件(maccEs)仍然是全世界人口死亡的原因之一。尤其合并糖尿病的AMI患者,因冠状动脉病变复杂,病变程度严重,尽早发现和判断该部分患者远期预后相对困难,因此寻找相对简便、易获得的实验室指标,有利于为2型糖尿病(T2DM)合并AMI患者经皮冠状动脉介入(PcI)术后maccEs的预测提供依据。目的探讨血清c反应蛋白(cRP)/白蛋白(Alb)比值(cAR)对T2DM合并AMI患者PcI术后远期maccEs的预测价值。方法纳入2014—2019年就诊于宁夏医科大学总医院心血管内科1683例T2DM合并AMI患者为研究对象,收集患者的一般临床资料与检查结果。对所有患者进行电话或门诊随访,以全因死亡、非致死性心肌梗死、再发不稳定型心绞痛、非致死性脑卒中、新发心力衰竭或心力衰竭加重再入院、再次血运重建作为maccEs。根据患者随访期间是否发生maccEs分为maccEs组(508例)和非maccEs组(1175例)。采用单因素及多因素Logistic回归分析探讨T2DM合并AMI患者maccEs事件的影响因素。采用Kaplan-Meier法绘制患者的生存曲线,生存曲线的比较采用Log-rank检验。采用受试者工作特征(ROc)曲线分析cAR对T2DM合并AMI患者远期发生maccEs的预测效能,使用净重分类改善指标(NRI)和综合判别指数(IDI)评价cAR对T2DM合并AMI患者预后评估的改善效果。结果1683例患者中508例(30.18%)患者发生maccEs。多因素Logistic回归分析显示高血压病[OR(95%cI)=1.994(1.142~3.483)]、冠状动脉植入支架长度[OR(95%cI)=1.031(1.002~1.062)]、cRP[OR(95%cI)=0.950(0.915~0.986)]、Alb[OR(95%cI)=0.933(0.880~0.989)]及cAR[OR(95%cI)=5.582(1.705~18.277)]是T2DM合并AMI患者PcI术后发生maccEs的影响因素(PcAR中位表达水平(0.86),将患者分为cARcAR≥0.86组,Log-rank检验结果显示,cAR≥0.86组maccEs发生率高于cARc曲线显示cAR预测T2DM合并AMI患者发生maccEs的ROc曲线下面积为0.728(95%cI=0.702~0.754),最佳截断值为0.576,灵敏度为0.617,特异度为0.747。在基线模型基础上,与cRP、Alb相比,cAR能明显改善对患者发生maccEs的预测效果(NRI=0.377,IDI=0.166,c指数=0.690;PcAR是T2DM合并AMI患者PcI术后远期maccEs发生风险的有效预测指标。

关键词：心肌梗死糖尿病,2型主要不良心脑血管事件 c反应蛋白白蛋白预测

Synthesis and characterization of Mesoporous Alumina via a Reverse Precipitation Method

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2012年第6期28卷 572-576页

作者： Y.S.Wu J.ma f.Hu M.c.Li college of materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

Mesoporous aluminaΥ-AI203 with high specific surface area and large pore volume is prepared by using a facile reverse precipitation method from sodium aluminate and nitric acid. The effects of terminal pH value, aging time and thermal stability on the characterization of Υ-Al2Oa are studied by means of X-ray diffraction （XRD）, fourier transform infrared spectroscopy （fTIR）, Brunauer-Emmett-Teller （BET） method and scanning electron microscopy （SEM）. The results show that Υ-A1203 with better properties can be obtained by changing the preparation parameters. High BET surface area of 340 m2/g can be obtained by calcining at 500℃ for 4 h with large pore volume of 0.90 cm3/g and average pore size of 7.6 nm. After calcining at 1000°, the surface area is still 86 m2//g and the pore volume is 0.37 cm31/g.

关键词： Mesoporous alumina Reverse precipitation Thermal stability