检索结果-南通市图书馆

Study of a Waveguide CO2 Laser with Two Parallel Tubes

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

Chinese Journal of Lasers 1998年第1期 12-17页

作者： HUANG Yuangqing(Dept. of Sci. Instr. and Precision Mech. of Xiamen Univ.,Xiamen, 361005, China)received dec. 23 1996 revised ma.uscript received Apr. 22 1997

ＳｔｕｄｙｏｆａＷａｖｅｇｕｉｄｅＣＯ２ＬａｓｅｒｗｉｔｈＴｗｏＰａｒａｌｅｌＴｕｂｅｓＨＵＡＮＧＹｕａｎｇｑｉｎｇ（Ｄｅｐｔ．ｏｆＳｃｉ．Ｉｎｓｔｒ．ａｎｄＰｒｅｃｉｓｉｏｎＭｅｃｈ．ｏｆＸｉａｍｅｎＵｎｉｖ．，Ｘ... 详细信息

ＳｔｕｄｙｏｆａＷａｖｅｇｕｉｄｅＣＯ２ＬａｓｅｒｗｉｔｈＴｗｏＰａｒａｌｅｌＴｕｂｅｓＨＵＡＮＧＹｕａｎｇｑｉｎｇ（Ｄｅｐｔ．ｏｆＳｃｉ．Ｉｎｓｔｒ．ａｎｄＰｒｅｃｉｓｉｏｎＭｅｃｈ．ｏｆＸｉａｍｅｎＵｎｉｖ．，Ｘｉａｍｅｎ，３６１００５，Ｃｈｉｎ...

关键词： two parallel tubes waveguide CO2 laser single cathode double anode

Synthesis of Diethyl Oxalate by a Coupling-Regeneration Reaction of Carbon Monoxide

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

Journal of Energy Chemistry 2002年第Z1期 57-62页

作者： Fandong Meng,Genhui Xu,Baowei Wang,Xinbin ma1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 2. Luoyang Petrochemical Engineering Corporation, Luoyang 471003, China[ma.uscript received march 13, 2002 revised Apr

This article describes a process for the synthesis of diethyl oxalate by a coupling reaction of carbon monoxide, catalyzed by palladium in the presence of ethyl nitrite. The kinetics and mechanism of the coupling and regeneration reaction are also discussed. This paper presents the results of a scale-up test of the catalyst and the process based on an a priori computer simulation.

关键词： CO coupling diethyl oxalate kinetics and mechanism simulation scale-up test

Strange Quark Distribution and Corrections due to Shadowing and Isospin Symmetry Breaking

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

Chinese Physics Letters 1996年第9期13卷 648-651页

作者： ma Bo-qiang Institute of High Energy Physics Chinese Academy of SciencesBeijing 100039

The strange sea quarks distributions of nucleons obtained by two global analyses based on available structure function data of muon and neutrino deep inelastic scatterings are different from the strange sea quark distribution measured by the CCFR Collaboration from dimuon events in neutrino *** discuss possible contributions to this discrepancy from the nuclear shadowing in the deuteron and from the isospin symmetry breaking in the sea between the neutron and the proton.

关键词： scattering quark symmetry

Compensate Effect Under Time-Scale Transformation in Vaidya-Bonner Space-Time

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 Physics Letters 1996年第7期13卷 492-495页

作者： ma Yong ZHAO Zheng Department of Physics Chongqing Teachers CollegeChongqing 630047 Department of Physics Beijing Normal UniversityBeijing 100875

The Hawking effect in the Vaidya-Bonner space-time can be considered as a compensate effect of the scale transformation of coordinate *** gauge potential is the contraction of the affine *** is found that the rate of change of temperature can be obtained as the pure gauge potential of the compensate field,in addition to the Hawking temperature which was known from the stationary black holes.

关键词： gauge Transformation Vaidya

A cost-effectiveness assessment of the operational parameters of central HVAC systems during pandemics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2023年第5期16卷 667-682页

作者： Yufan Chang Zhengtao Ai Jinjun Ye Guochuan ma Department of Building Environment and Energy College of Civil EngineeringHunan UniversityChangshaHunanChina National Center for International Research Collaboration in Building Safety and Environment Hunan UniversityChangshaHunanChina China Southwest Architectural Design and Research Institute ChengduSichuanChina

The present study develops a cost-effectiveness assessment model to analyze the performance of major operational parameters of central HVAC systems in terms of airborne transmission risk,energy consumption,and medical and social cost.A typical multi-zone building model with a central HVAC system is built numerically,and the effect of outdoor air(OA)ratio(from 30%to 100%)and filtration level(MERV 13,MERV 16,and HEPA)are assessed under the conditions of five climate zones in *** with the baseline case with 30%OA and MERV 13 filtration,the airborne transmission risk in zones without infector is negligibly reduced with the increase in OA ratio and the upgrade of filtration level,owing to their slight modification on the equivalent ventilation rate of virus-free ***,depending on climate zone,a 10%increase in OA ratio results in 12.5%-78.6%and 0.1%-8.6%increase in heating and cooling energy consumption,respectively,while an upgrade of filtration level to MERV 16 and HEPA results in an increase of 0.08%-0.2%and 1.4%-2.6%,***,when compared to the use of 100%OA ratio and HEPA filtration,the application of 30%or 40%OA ratio and MERV 13 filtration would save annually an energy and facility related cost of$29.4 billion in China,though giving an increase of approximately$0.1 billion on medical and social cost from the increased number of confirmed *** study provides basic method and information for the formulation of cost-effective operational strategies of HVAC systems coping with the airborne transmission,especially in resource-limited regions.

关键词： outdoor air ratio filtration level airborne transmission risk energy consumption cost-effectiveness

(Nd_(0.9)Dy_(0.1))_(16)Co_(5)Fe_(70)Nb_(2)B_(7) PERmaNENT maGNETIC ALLOY AND BEHAVIOUR OF Nb

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 1996年第1期6卷 67-71页

作者： Pan Shuming Pan Feng ma Ruzhang General Research Institute of Non-ferrous Metals Beijing 100088 Beijing Tape Recorder Factory Beijing 100080 University of Science and Technology Beijing Beijing 100083

The magnetic properties of (Nd_(0.9)Dy_(0.1))_(16)Co_(5)Fe_(70)Nb_(2)B_(7) permanent magnetic alloy prepared by powder metallurgy are:Br=1.08T,_(1)H_(C)=1620kA/m,(BH)_(max)=208kJ/m^(3).The behaviour of Nb in this alloy was studied by joint methods of dynamic observation by high voltage electron microscope(HVEM)and Mossbauer *** Nb and Co substituting parts of Fe and adding a little Dy,practical magnetic alloy with excellent properties can be *** thermal stability of it is 80 ℃ higher than that of ternary Nd-Fe-13 *** study shows that adding Nb into Nd-Fe-B can make the intrinsic coercivity appear peak value at about Nb=2%(in mole fraction).Nb mainly enters into Nd-rich and B-rich phases,a little into Nd_(2)Fe_(14)B phase.

关键词： (Nd_(0.9)Dy_(0.1))_(16)Co_(5)Fe_(70)Nb_(2)B_(7) permanent magnetic alloy magnetic properties

Semi-unitary Transformation Induced Supersymmetric Partner Hulthen System

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 Physics Letters 1996年第7期13卷 485-488页

作者： ZHANG Jiu-an ma Gui-rong ZHANG Jian-zu Department of Physics Hebei Normal CollegeShijiazhuang 050091 Institute for Theoretical Physics East China University of Science and TechnologyShanghai 200237

The supersymmetric partner system of Hulthen system in the s state is obtained by using a semi-unitary *** physical foundation of applications of semi-unitary transformation to supersymmetric quantum mechanics is expl... 详细信息

关键词： unitary symmetric Transformation

Effect of Electric Field on the Electron-Surface Optical Phonon Scattering Rates in Quantum Wires

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 Physics Letters 1996年第4期13卷 297-300页

作者： CHANG Kai WANG Ruo-zhen ma Ben-kun Department of Physics Beijing Normal UniversityBeijing 100875

By using the variational method and the dielectric continuum model,we investigate the effect of electric Held on the intrasubband scattering rates of electron-surface optical *** results show that the scattering rates tend to increase with the electric field *** scattering rates become significant for wide quantum well wire and sufficiently high fields.

关键词： strength. Electron variational

Enhancing heavy gas capture in confined spaces through ventilation control technology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2024年第7期17卷 1161-1182页

作者： Tianqi Wang Angui Li Yuanqing ma Ying Zhang Haiguo Yin School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyNo.13 Yanta RDXi’anShaanxi710055China

Gas leakage accidents occur frequently in confined spaces,and heavy gases with a relative density greater than 1.15 among hazardous gases and greenhouse gases are commonly stored in confined ***,atmospheric pollutant emission standards are becoming more stringent,and it is essential to remove heavy gas after accidents while reducing emissions to the *** study proposes using a heavy gas collection tank(HGCT)to safeguard the internal environment and minimize emissions to the *** capture efficiencies applicable to heavy-gas environments under different ventilation strategies are *** research analyzes the impact of the exhaust rate,leakage rate,density of heavy gas,and air supply modes on the indoor concentration *** results demonstrate that the mass flow rate of heavy gas into the exhaust is positively correlated with the exhaust rate,but the gas from the exhaust system contains more *** exhaust rate should be greater than four times the space volume per hour;otherwise,heavy gas above 1000 ppm accumulates to a height of 0.67 m at ground ***,attachment ventilation as make-up air helps to reduce upstream heavy gas accumulation and reduces the extension of heavy gas along the room *** an HGCT with floor slope and attachment ventilation achieves an efficiency of 96.28%.This study provides valuable insights and references for preventing hazardous heavy gas leakage.

关键词： confined gases otherwise