检索结果-南通市图书馆

The 16th Annual conference of hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-hong Kong Forum on Mechanics and Its Application 2012

作者： M.c.chan c.h.liu Department of Mechanical Engineering The University of Hong Kong

Large-eddy simulation(LES) equipped with the one-equation subgrid-scale model is employed to investigate the flows and turbulence over idealized two-dimensional(2D) street canyons in various thermal stratification *** prevailing wind,which is driven by a background pressure gradient above the building roof level,is perpendicular to the street axis representing the worst scenario of pollutant *** building-height-to-street-width(aspect) ratio is kept unity so the flows fall into the skimming flow *** boundaries are assigned to the domain inlet and outlet,and the spanwise extent,simulating the infinite horizontally homogenous building structures. The buoyancy force is modeled by Boussinesq approximation so incompressible flows at small Richardson number are assumed. In isothermal conditions over an aerodynamically smooth surface,it is well-known that the mean flows exhibit a logarithmic region(law of the wall).The conceptual model of logarithmic wind profile is also applicable to flows over homogenously rough surfaces,such as the idealized 2D street canyons in this study,in which the parameters,including the aerodynamic roughness height and the displacement height,are determined empirically as functions of the roughness configuration. however,in thermal stratification with the presence of buoyancy force(induced by the temperature difference between the urban fabrics and the prevailing wind),the mean wind profile deviates from its isothermal counterpart in which the extent of the logarithmic region depends on the Richardson *** slightly unstable stratification,the conventional law of the wall is modified by multiplying an empirical constant to the logarithmic term to account for the contributions from thermal stratification.A range of thermal stratification is tested by *** corresponding aerodynamic roughness height,displacement height,and empirical constant are obtained by regression to the LES *** is found that,with incre

关键词： Large-Eddy Simulation of Flows over Idealized Urban Roughness in Unstable Thermal Stratification

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

Theoretical research on electron capture in ion-atom and ion-molecule collisions at low energies

Theoretical research on electron capture in ion-atom and ion...

引用

第五届全国计算原子与分子物理学术会议

作者： c.h.liu J.G Wang R.K.Janev Institute of Modern Physics Chinese Academy of Sciences Data center for high Energy Density Matter Institute of Applied Physics and Computational Mathematics Macedonian Academy of Sciences and Arts

＜正＞Electron capture in ion-atom and ion-molecule collisions is a fundamental collision process in atomic physics related to its application in laboratory and astrophysical plasma environments by affecting the ionization balance and energy *** the applications for plasma research,the heavy particle collision processes may drive the fundamental interest in collision ***

关键词：

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

大气中点源重力波的求导法计算机模式

引用

中国科学（A辑） 1992年第5期23卷 530-540页

作者：庄洪春 c.h.liu M.c.Kelley 中国科学院空间科学与应用研究中心北京100080 美国伊利诺大学美国康乃尔大学

本文首先给出了等温大气中点源重力波的解析解.然后,在此基础上建立了水平等温分层大气中点源重力波的计算机模式.从而解决了在真实大气中对点源重力波传播的数值计算问题.对大气中点源声波的传播过程也可以借助本计算机模式进行数值计算.

关键词：大气重力波大气波动求导法

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The anode power supply for electron cyclotron resonance heating system on J-TEXT

The anode power supply for electron cyclotron resonance heat...

引用

第十八届全国等离子体科学技术会议

作者： c.h.liu D.h.Xia F.T.cui Z.J.Wang State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

The electron cyclotron resonance heating(EcRh) system with 60 Ghz/200 k W/0.5 s gyrotron donated by culham Science center is being developed on J-TEXT tokamak for plasma heating,current drive and MhD ***,an anode power supply(APS) has been rebuild and tested for the output power control of the gyrotron,which the input voltage is derived from an80 k V negative cathode power *** control strategy by controlling the grid voltage of the tetrode Th5186 is applied to get accurate anode climbing voltage,which the output voltage can be obtained from 0 to 30 k V with respect to cathode power *** characteristic of the APS,including control,protection,modulation,output waveform,were tested with the 100 k V/60 A negative cathode power supply,the dummy load and the EcRh control *** results indicating that the APS can meet the requirements of the EcRh system on J-TEXT.

关键词： J-TEXT EcRh APS Th5186 tetrode fiber isolation

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

食盐中微量碘的分析研究

引用

西北大学学报(自然科学版) 1957年第2期 103-106页

作者：刘致和贺春祺贾齐松

一引言碘是防御和治疗由缺碘而引起的各项病症的药剂,而食盐中的碘又是人们从食料中得到这一元素的经常来源,所以对于食盐中含碘量的分析研究是很重要的。因此,轻工业部盐务总局委托高等教育部将「食盐中含微量碘的分析研究」作为科学... 详细信息

一引言碘是防御和治疗由缺碘而引起的各项病症的药剂,而食盐中的碘又是人们从食料中得到这一元素的经常来源,所以对于食盐中含碘量的分析研究是很重要的。因此,轻工业部盐务总局委托高等教育部将「食盐中含微量碘的分析研究」作为科学研究专题,发给各校院研究,并指定西北大学,四川大学,福建师范学院和华东航空学院四校同时进行研究。

关键词：含碘量硫酸硫化合物分液漏斗微量碘食晚蒸溜用水冲洗

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

適於華北地區幾個抗銹小麥新品種的育成“農大36”“農大90”“農大183”“農大498”

引用

北京农业大学学报 1957年第2期 124-152页

作者：蔡旭張樹榛楊作民劉中宣王琳清丁壽康

一、引言我國國民經濟正在進一步發展和鞏固工業的標誌下蒸蒸日上,為了支援保證社會主義工業化建設的成就,對於發展糧食生產提出了互大的任務,根據全國農業發展綱要(草案)黄河以北地區每畝糧食作物產量要求在十二年内(1956-1962)逹到40... 详细信息

一、引言我國國民經濟正在進一步發展和鞏固工業的標誌下蒸蒸日上,為了支援保證社會主義工業化建設的成就,對於發展糧食生產提出了互大的任務,根據全國農業發展綱要(草案)黄河以北地區每畝糧食作物產量要求在十二年内(1956-1962)逹到400斤的水平。小麥是華北地區糧食作物中種植面積比重最大的一種,長時期來單位面積產量停留在百斤上下,而且歷年產量很不穩定。解放以来,由於生產關系的改變,勞動組織的加强,生產力的提高,單位面積產量有着顯著的增加,但是產量不穩定的情况依然嚴重。其原因概括的說来有兩種類型:一種是由於不良的外界環境條件所引起的,最常見的是春季的乾旱,從植株伸長初期起至抽穗開花期所出現的持續乾旱,引致植株莖稈矮小,分蘖多屬無效,穗部細小,籽粒因不正常的提前成熟而發育細小,因而產量顯著降低。1957年北京近郊的情形是最突出的

关键词：新品系蔡旭雄核抗锈性锈病育成抽穗期第二代水地抗寒性小穗数

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Experimental Research on a Feasible Building Insulation Material Based Reed in china

引用

Journal of Thermal Science 2025年第1期34卷 176-187页

作者： liu Tiantian PENG Yizhe liu Lifang cAI chenghan WANG Shuang LI hongqiang college of civil Engineering Hunan University college of civil Engineering Hunan University of Science and Technology School of Energy and Power Jiangsu University of Science and Technology National center for International Research collaboration in Building Safety and Environment (NcIRcBSE) Hunan University Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan University

The seemingly useless reeds are prepared as thermal insulation materials,which not only meet the requirements of environmental sustainability but also enhance the added value of reeds,creating new economic *** hydrophobicity of raw biomass surfaces leads to problems such as weak bonding strength and non-dense structure in the formed materials,as well as issues related to the residual insect infestations on the *** this study,reed straw was used as the raw material,and foamed geopolymer was used as the binder to prepare building insulation materials based *** improve the interfacial adhesion performance between reed straw and foamed geopolymer,a thermochemical modification method-thermal carbonization,was *** this study,the mechanical properties and hydraulic properties of the studied materials with different degrees of surface thermal modification were tested,especially the fire resistance performance,and weathering resistance performance rarely found in published *** the surface thermal modification condition of reed straw was 250℃（30 min）,the comprehensive performance of reed-based building insulation materials was the best,when the studied material density was 321.3 kg/m3;the compressive strength was 0.59 MPa;the thermal conductivity was 0.101 W/（m·K）;the ph was 11.27;the moisture absorption rate was 25.1%,and the compressive strength loss rate in wet-dry cycles was 18.5%.In addition,it had excellent fire resistance performance and weathering resistance *** new material can be widely used to improve the thermal insulation of traditional buildings and as sandwich filler in prefabricated buildings,such as preparing insulating walls.

关键词： building insulation material based reed fire resistance performance interface adhesion properties pre-treatment of reeds weathering resistance performance

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rational modulation of fluorophosphate cathode by anionic groups to reduce the polarization behavior for fast-charging sodium-ion batteries

引用

Journal of Energy chemistry 2025年第1期100卷 509-521页

作者： Xinyuan Wang Fan Zhang Xingyu Zhou Qian Wang changyu liu Yangyang liu hui Wang Xiaojie liu Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry & Materials Science Northwest University

Na3V2（PO4）2O2F （VP） is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific *** functional theory （DFT） and finite element simulations show that incorporating SO42-into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge ***,the average Na+diffusion coefficient of Na3V2（PO4）1.95（SO4）0.05O2F（VPS-1） is roughly double that of VP,leading to enhanced rate capability (80 c,75.5 mAh g-1) and cycling stability (111.0 mAh g-1capacity after 1000 cycles at 10 c current density) for ***-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 *** assembled VPS-1//SbSn/NPc full cell demonstrated stable cycling over 200 cycles at a high 5 c current,maintaining an average coulombic efficiency of 95.35%.

关键词： Anionic group modulation Polarization behavior Fast-charging Sodium-ion battery Fluorophosphate cathode

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Post-tunable salt gel electrolytes toward flexible supercapacitor switches

引用

Journal of Energy chemistry 2025年第1期100卷 114-124页

作者： hui Wang Shuang chen Xuming liu Qin Zhang Xin liu Polymeric and Soft Materials Laboratory School of Chemistry and Life Science and Advanced Institute of Materials Science Changchun University of Technology Polymeric and Soft Materials Laboratory School of Chemical Engineering and Advanced Institute of Materials Science Changchun University of Technology

convertible hydrogel supercapacitors have emerged as promising energy storage devices in switches,diodes, and transistors. however, inherent weaknesses in ionic conductivity, mechanical properties,and water retention of hydrogel electrolytes seriously hinder their development. Inspired by the hardness conversion of sea cucumber skin, a conductivity and mechanics dual-tunable salt gel electrolyte is successfully designed. The salt gel presents a reversible switching of conductors-insulators and a mechanical regulation between softness and hardness via the dissolution-crystallization transition of sodium acetate trihydrate（SAT）. Meanwhile, the salt gels spontaneously grow a layer of “armor” through saturated phase-change salt crystals effectively reducing water evaporation of hydrogel ***, this phase-change soft-rigid conversion strategy will expand the capabilities of gel-based flexible supercapacitors(area capacitance: 258.6 mF cm-2), and the capacitance retention rate could still reach 86.9% after 3000 cycles at high temperatures. Moreover, the salt gel supercapacitor is potentially used in over-heat alarm systems. It is anticipated that the strategy of conductivity and mechanics of dual-tunable salt gel would provide a new perspective on the development of energy storage devices,wearable electronics, and flexible robots.

关键词： capacitance

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Economic effect of china's carbon neutrality target under shared socioeconomic pathways

引用

Science china Earth Sciences 2025年第1期68卷 142-157页

作者： Zemiao liu Xianjin hUANG Xinxian QI School of Geography and Ocean Science Nanjing University Key Laboratory of carbon Neutrality and Territory Optimization Ministry of Natural Resources Frontiers Science center for critical Earth Material cycling Nanjing University

Economic feasibility is crucial for achieving the carbon neutrality target. however, current integrated assessments often underestimate the economic impacts of mitigation policies due to the lack of consideration of their economic benefits. This study integrates a warming-labour productivity model with a typical integrated assessment model using shared socioeconomic pathways. It simulates china's economic development and carbon emission levels under both baseline and carbon-neutral policy scenarios, evaluating the economic costs and benefits of emission reduction policies aimed at achieving carbon neutrality. These findings reveal the following:(1) The economic costs of emission reduction policies are projected to peak between 2050 and 2060, ranging from 0.41% to 9.37% of total GDP in the baseline scenario, primarily due to increased energy prices and R&D investments. These costs are expected to decline rapidly after 2070.(2) china's carbon-neutral policies will mitigate global warming, with the economic benefits of mitigation projected to reach 5.65% to 17.24% of china's total GDP by 2100.(3) Lowcarbon scenarios SSP1 and SSP4 could significantly reduce initial economic costs and advance the onset of net economic gains to 2060. This integrated assessment confirms that china's carbon neutrality target offers substantial net economic benefits in the long term. To minimize initial economic costs, efforts should focus on enhancing consumption-side transitions, upgrading lowcarbon technologies, and adopting new energy sources.

关键词： climate change china carbon neutrality Economic effects Policy

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：