检索结果-南通市图书馆

Effects of atmospheric pressure on Developmental Characteristics and the Stability of Air Entraining Agent for Concrete

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 979-989页

作者：李立辉牛开民 TIAN Bo CHEN Xin FU Ziqian ZHU Xuwei School of Civil Engineering Chongqing Jiaotong UniversityChongqing 400074China Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China Research Institute of Highway Ministry of TransportBeijing 100088China

In order to ascertain the effects of atmospheric pressure on developmental characteristics and the stability of AEA(air-entraining agent)solution bubbles,AEA solution experiments and AEA solution bubble experiments were,respectively,conducted in Peking(50 m,101.2 kPa)and Lhasa(3,650 m,63.1 kPa).Surface tensions and inflection-point concentrations were tested based on AEA solutions,whilst developmental characteristics,thicknesses and elastic coefficients of liquid films were tested based on air bubbles of AEA *** study involved three types of AEAs,which were TM-O,226A,and *** experimental results show that initial sizes of TM-O,226A,and 226S are,respectively,increased by 43.5%,17.5%,and 3.8%.With the decrease of ambient pressure,the drainage rate and the drainage index of AEA solution bubbles *** experiments show that the liquid film thicknesses of all tested AEA solution bubbles are in micron *** the atmospheric pressure decreases from 101.2 to 63.1 kPa,the liquid film thicknesses of three types of AEA solutions decrease in various degrees;and film elasticities at critical thicknesses *** film of 226S solution bubbles is the most stable,presenting as a minimum thickness *** should be noted that elastic coefficient of liquid film only represents the level at critical thickness,thus it can not be applied as the only evaluating indicator of bubble *** a type of AEA,factors affecting the stability of its bubbles under low atmospheric pressure include initial bubbles size,liquid film thickness,liquid film elasticity,ambient temperature,etc.

关键词： air-entraining agent surface tension bubble size liquid film thickness liquid film elasticity atmospheric pressure

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

Dual-ionic imidazolium salts to promote synthesis of cyclic carbonates at atmospheric pressure

引用

Green Energy & Environment 2022年第6期7卷 1327-1339页

作者： Tengfei Wang Danning Zheng Beibei An Yi Liu Tiegang Ren HansÅgren Li Wang Jinglai Zhang Mårten S.G.Ahlquist Henan Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloys Henan UniversityKaifengHenan475004China Henan Engineering Research Center of Corrosion and Protection for Magnesium Alloys Henan UniversityKaifengHenan475004China College of Chemistry and Chemical Engineering Henan UniversityKaifengHenan475004China Department of Theoretical Chemistry&Biology School of BiotechnologyKTH Royal Institute of Technology10691 StockholmSweden

Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product *** can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen *** work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.

关键词： Dual-ionic imidazolium salts CO_(2)-Philic group New mechanism Room temperature atmospheric pressure

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

Effect of periodic wide atmospheric pressure change on CO emission in closed goaf

引用

International Journal of Coal Science & Technology 2023年第4期10卷 139-150页

作者： Zhuangzhuang Shao Bo Tan Ruili Hu Xiaozhen Song Yan Guo Tianze Li Shuhui Fu Chaohuan Chen Haiyan Wang School of Emergency Management and Safety Engineering China University of Mining and Technology(Beijing)Beijing 100083China Security Department University of International Business and EconomicsBeijing 100029China School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China

atmospheric pressure fuctuation is one of the most important factors afecting the climate environment and gas emission in the fre *** obtain the infuence rule of the surface atmospheric pressure change on the gas sampling and abnormal emission in the mine closed goaf,the No.1 coal mine in Dananhu was taken as the research *** Fourier transform and Fisher harmonic analysis and other statistical methods,the infuence of the periodic variation of atmospheric pressure on the gas leakage and outfow in the closed goaf was *** results showed that there were three atmospheric pressure periods of 15.2 d,1 d and 182.2 d,and the probability was greater than 95%.The time period with the highest number of atmospheric pressure peaks was 7:00–8:00,which accounted for 20.2%of total occurrence number in a *** the time periods with the highest number of atmospheric pressure trough were 2:00,15:00 and 16:00,accounting for 27.4%.The peak-to-trough transition time was mainly concentrated around 6 h,and the diurnal variation curve of atmospheric pressure was mainly *** atmospheric pressure change rate was mostly concentrated in 10–50 Pa/*** was determined that the distance that the gas sampling pipe was pre-laid into the inner side of the closed wall should be greater than 44.4 m,and the CO concentration and atmospheric pressure in the closed goaf were both periodic and negative with atmospheric *** research results have important guiding signifcance for the monitoring,early warning and environmental protection of the goaf.

关键词： atmospheric pressure Periodic variation Closed goaf CO emission Coal mine

来源：

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

atmospheric pressure Cold Argon/Oxygen Plasma Jet Assisted by Preionization of Syringe Needle Electrode

引用

Plasma Science and Technology 2010年第5期12卷 561-565页

作者：钱沐杨任春生王德真冯岩张家良 School of Physics and Optoelectronic Technology Dalian University of Technology

An atmospheric pressure nonequilibrium argon/oxygen plasma jet assisted by the preionization of syringe needle electrode discharge is reported. With the syringe needle plasma as its pre-ionization source, the hybrid barrier-jet was shown to generate uniform discharge with a lower breakdown voltage and a relatively low gas temperature varying from 390 K to 440 K, even when the vol.% oxygen in argon was up to 6%. Utilizing the actinometry method, the concentration of atomic oxygen was estimated to be about in an orders of magnitude of 10^17 cm^-3. The argon/oxygen plasma jet was then employed to clean out heat transfer oil, with a maximum cleaning rate of 0.1 mm/s achieved.

关键词： atmospheric pressure nonequilibrium Ar/02 plasma preionization actinometry concentration of atomic oxygen heat transfer oil

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

atmospheric pressure Radio Frequency Dielectric Barrier Discharges in Nitrogen/Argon

引用

Plasma Science and Technology 2013年第9期15卷 871-874页

作者：刘忠伟杨丽珍王正铎桑利军朱强李森 Laboratory of Plasma Physics and Materials Beijing Institute of Graphic Communication

This work reports the experimental results on the characteristics of radio frequency dielectric barrier N2/Ar discharges. Depending on the nitrogen content in the feed gas and the input power, the discharge can operate in two different modes： a homogeneous glow discharge and a constricted discharge. With increasing input power, the number of discharge columns increases. The discharge columns have starlike structures and exhibit symmetric self-organized arrangement. Optical emission spectroscopy was performed to estimate the plasma temperature. Spatially resolved gas temperature measurements, determined from NO emission rotational spectroscopy were taken across the 4.4 mm gap filled by the discharge. Gas temperature in the middle of the gas gap is lower than that close to the electrodes.

关键词： atmospheric pressure dielectric barrier discharge radio frequency discharge

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

atmospheric pressure-Aware Seamless 3-D Localization and Navigation for Mobile Internet Devices

引用

Tsinghua Science and Technology 2012年第2期17卷 172-178页

作者： Nengqiang He Jinhai Huo Yuhan Dong Yipeng Li Yang Yu Yong Ren Department of Electronic Engineering Tsinghua UniversityBeijing 100084China China Electronic System Engineering Corporation(CESEC) Beijing 100141China Department of Automation Tsinghua UniversityBeijing 100084China

This paper describes a seamless three-dimensional （3-D） localization and navigation system for smartphones. The smartphone includes an atmospheric pressure sensor to measure the user＇s altitude that is combined with the outdoor Global Positioning System （GPS） and indoor WiFi-APs localization systems in a seamless 3-D localization system. The smartphone software also provides seamless navigation services by updating map information for both indoor and outdoor locations through the mobile Internet. The indoor floor information calculated from the altitude information is used to project localization anchor nodes, e.g., WiFi-AP, on different floors onto the user＇s floor with an indoor 3-D localization algorithm using projection distances based on a Received Signal Strength （RSS） algorithm. Tests show that the 3-D method reduces systematic errors and achieves much higher accuracy than the traditional two-dimensional localization method.

关键词： 3-D localization and navigation atmospheric pressure mobile smartphone mobile Internet

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

Numerical study on an atmospheric pressure helium discharge propagating in a dielectric tube:influence of tube diameter

引用

Plasma Science and Technology 2018年第8期20卷 22-28页

作者：孙洲涛晏雯季龙飞毕振华宋颖刘东平 School of Physics and Materials Engineering Dalian Nationalities University

In this work, a two-dimensional numerical simulation of the discharge characteristics of helium plasma propagating inside a dielectric tube was performed. A trapezoidal ＋9 kV pulse lasting 400 ns was applied on a needle electrode set inside the dielectric tube to ignite the discharge. The discharges generated in the tubes with a variable or a constant inner diameter were *** focus of this study was on clarifying the effect of the tube diameter on the discharge structure and dynamics. The comparison of the discharge characteristics generated in dielectric tubes with different diameters was carried out. It was shown that the tube diameter plays a significant role in discharge behavior of plasma propagating in the dielectric tube.

关键词： atmospheric pressure helium discharges discharge front numerical simulation

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

Influence of Additive Gas on Electrical and Optical Characteristics of Non-equilibrium atmospheric pressure Argon Plasma Jet

引用

Plasma Science and Technology 2011年第5期13卷 575-582页

作者：费小猛 Shin-ichi KURODA Yuki KONDO Tamio MORI Katsuhiko HOSOI Department of Advanced Production Science and Technology Graduate School of EngineeringGunma University Cresur Corporation

Electrical and optical properties of an argon plasma jet were characterized. In particular, effects of an additive gas, namely nitrogen or oxygen, on these properties were studied in detail. The plasma jet was found to be of a glow-like discharge, which scarcely changed upon the injection of an additive gas, either directly or through a glass capillary. Optical emission spectroscopy characterization revealed that excited argon atoms were the predominant active species in this plasma jet. Metastable argon atoms were highly quenched, and N2（C3yIu） became the main energy carrier following nitrogen injection. When oxygen was added to the afterglow zone through a glass capillary, no significant quenching effect was observed and the number of oxygen atoms decreased with the increase in oxygen concentration. Finally, to demonstrate an application of this plasma jet, a high-density polyethylene surface was treated with argon, argon/nitrogen, and argon/oxygen plasmas.

关键词： atmospheric pressure Ar plasma jet additive gas discharge optical emission spectroscopy

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

Two-dimensional numerical study of an atmospheric pressure helium plasma jet with dual-power electrode

引用

Chinese Physics B 2015年第6期24卷 406-415页

作者：晏雯刘福成桑超峰王德真 Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Physics and Optoelectronic TechnologyDalian University of Technology College of Physics Science and Technology Hebei University

In this paper, the characteristics of an atmospheric pressure helium plasma jet generated by a dual-power electrode （DPE） configuration are investigated by using a two-dimensional fluid model. The effect of a needle electrode on the discharge is studied by comparing the results of the DPE configuration with those of the single ring electrode configuration. It is found that the existence of the needle leads to the generation of a helium plasma jet with a higher propagation velocity, higher species density, and larger discharge width. Furthermore, the influences of the needle radius and needle-to-ring discharge gap on the generation of a plasma jet are also studied. The simulation results indicate that the needle electrode has an evident influence on the plasma jet characteristics.

关键词： atmospheric pressure plasma jet dual-power electrodes fluid model

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

Study of Non-Thermal DC Arc Plasma of CH_4/Ar at atmospheric pressure Using Optical Emission Spectroscopy and Mass Spectrometry

引用

Plasma Science and Technology 2015年第9期17卷 743-748页

作者：廖梦然王毓吴涵峰李辉夏维东 Department of Thermal Science and Energy Engineering University of Science and Technology of China National Synchrotron Radiation Laboratory University of Science and Technology of China

Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and *** this work,plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmospheric-pressure DC arc discharge generator in CH_4/Ar were *** voltage-current characteristics were measured for different CH_4/Ar *** emission spectroscopy was employed to analyze the electron excitation temperature,gas temperature and electron density under various discharge *** hydrocarbon molecules produced in the CH4/Ar plasmas were detected with photoionization mass *** optical spectral results demonstrated that the electron excitation temperature was 0.4-1 eV,the gas temperature was 2800-4200 K and the electron density was in the range of（5-20）×10^15 cm^-*** mass spectrum indicated that a variety of unsaturated hydrocarbons（C2H4,C3H6,C6H6,etc.） and several highly unsaturated hydrocarbons（C4H2,C5H6,etc.） were produced in the non-thermal arc plasmas.

关键词： non-thermal plasma atmospheric pressure hydrocarbon methane argon,electrical characteristic optical emission spectra photoionization mass spectrometry

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

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：