资源类型

期刊论文 17

年份

2021 1

2020 2

2017 2

2016 1

2015 1

2014 2

2012 1

2011 1

2010 1

2009 1

2007 1

2005 1

2001 1

展开 ︾

关键词

三轴转台 1

光刻机 1

光合产物 1

冬小麦 1

分配指数 1

可溶性糖 1

复合节流静压气浮导轨 1

多孔质 1

宏观静摩擦系数 1

小孔节流 1

局部最大小波系数；可靠特征点分配；目标跟踪；跟踪-学习-检测（TLD）；卡尔曼滤波器 1

工作点 1

干旱和复水 1

微分静摩擦系数 1

微牛纳牛静摩擦系数 1

微结构 1

气体静压轴承 1

热障涂层，稀土铌酸盐，置换，热导率，热膨胀系数，杨氏模量 1

空气动力稳定性 1

展开 ︾

检索范围：

排序： 展示方式：

Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 292-298 doi: 10.1007/s11709-009-0048-8

摘要： The aerodynamic interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in detail by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel test to study the effects on aerodynamic interferences of aerostatic coefficients of twin decks. The research results have shown that the drag coefficients of the leeward deck are much smaller than that of a single leeward deck. The drag coefficients of a windward deck decrease slightly compared with that of a single deck. The lift and torque coefficients of windward and leeward decks are also affected slightly by the aerodynamic interference of twin decks. And the aerodynamic interference effects on lift and torque coefficients of twin decks can be neglected.

关键词： twin decks     aerodynamic interference effects     aerostatic coefficients     wind tunnel test    

HTML PDF 收藏

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿（英文）》 2014年 第8卷 第1期   页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要： Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词： transimissity     HITEMP     HITRAN     Planck mean absorption coefficients    

HTML PDF 收藏

多孔质气体静压轴承在三轴转台设计中的应用

杜金名

《中国工程科学》 2005年 第7卷 第1期   页码 65-68

摘要：

气体静压轴承广泛应用于航空、航天、精密电子工业中。三轴转台是高精度的测试设备，用来对惯性系统和惯性元件进行检定、标定以及建立相应的误差模型，它的测试精度直接影响航空、航天等飞行器的控制和导航。转台的检测精度与回转轴的回转精度有密切关系。多孔质气体静压轴承同其他节流形式的轴承相比具有很高的承载能力、静态刚度以及很好的阻尼效应。文章对多孔质气体静压轴承进行了理论分析，并同气体静压小孔节流轴承的静态性能进行了比较，结果表明，此类轴承的承载能力明显优于小孔节流轴承。

关键词： 气体静压轴承     多孔质     小孔节流     三轴转台    

HTML PDF 收藏

微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年 第3卷 第8期   页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词： 微分静摩擦系数     微牛纳牛静摩擦系数     表观静摩擦系数     宏观静摩擦系数    

HTML PDF 收藏

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 190-194 doi: 10.1007/s11705-007-0035-3

摘要： The separations of olefin/paraffin, aromatic/aliphatic hydrocarbons or olefin isomers using ionic liquids instead of volatile solvents have interested many researchers. Activity coefficients γ at infinite dilution of a solute in ionic liquid are generally used in the selection of solvents for extraction or extractive distillation. In fact, the measurement of γ by gas-liquid chromatography is a speedy and cost-saving method. Activity coefficients at infinite dilution of hydrocarbon solutes, such as alkanes, hexenes, alkylbenzenes, styrene, in 1-allyl-3-methylimidazolium tetrafluoroborate ([AMIM][BF]) and 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM][PF6]), 1-isobutenyl-3-methylimidazolium tetrafluoroborate ([MPMIM][BF]) and [MPMIM][BF]-AgBF have been determined by gas-liquid chromatography using ionic liquids as stationary phase. The measurements were carried out at different temperatures from 298 to 318 K. The separating effects of these ionic liquids for alkanes/hexane, aliphatic hydrocarbons/benzene and hexene isomers have been discussed. The hydrophobic parameter, dipole element, frontier molecular orbital energy gap and hydration energy of these hydrocarbons were calculated with the PM3 semi-empirical quantum chemistry method. The quantitative relations among the computed structure parameters and activity coefficients at infinite dilution were also developed. The experimental activity coefficient data are consistent with the correlated and predicted results using QSPR models.

关键词： cost-saving     consistent     coefficient     measurement     separating    

HTML PDF 收藏

Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 397-405 doi: 10.1007/s11465-017-0415-4

摘要：

The inevitable deterioration of the lubrication conditions in a gearbox in service can change the tribological properties of the meshing teeth. In turn, such changes can significantly affect the dynamic responses and running status of gear systems. This paper investigates such an effect by utilizing virtual prototype technology to model and simulate the dynamics of a wind turbine gearbox system. The change in the lubrication conditions is modeled by the changes in the friction coefficients, thereby indicating that poor lubrication causes not only increased frictional losses but also significant changes in the dynamic responses. These results are further demonstrated by the mean and root mean square values calculated by the simulated responses under different friction coefficients. In addition, the spectrum exhibits significant changes in the first, second, and third harmonics of the meshing components. The findings and simulation method of this study provide theoretical bases for the development of accurate diagnostic techniques.

关键词： dynamic response     friction coefficient     wind loads     wind turbine gearbox    

HTML PDF 收藏

超大跨度斜拉桥空气静力和动力稳定性研究

张新军,孙海凌

《中国工程科学》 2014年 第16卷 第3期   页码 50-58

摘要：

随着斜拉桥跨度的持续增长，结构更趋于轻柔，风作用下的结构稳定性已成为超千米主跨斜拉桥设计和研究的重要问题。采用大跨度桥梁三维非线性空气静力和动力稳定性分析方法，对1400m主跨的超大跨度斜拉桥进行了空气静力和动力稳定性分析，并与同等主跨的悬索桥进行对比，从抗风性能角度探讨了斜拉桥在超千米主跨桥梁中的适用性。在此基础上，分别就主梁的高度和宽度、桥塔结构型式、桥塔高跨比、边主跨比、辅助墩设置、斜拉索锚固方式等结构设计参数对超大跨度斜拉桥空气静力和动力稳定性的影响进行了分析，指出了关键的设计参数及其合理取值。结果表明：与同等主跨的悬索桥相比，斜拉桥的结构刚度更大，空气静力和动力稳定性更好，适宜采用于超千米主跨的大跨度桥梁；超大跨度斜拉桥在增大主梁高度、减小梁宽、采用倒Y形桥塔并增大塔高、减小边跨长度、边跨设置辅助墩以及部分斜拉索地锚等情况下，都可以获得比较好的空气静力和动力稳定性。

关键词： 超大跨度斜拉桥     空气静力稳定性     空气动力稳定性     设计参数    

HTML PDF 收藏

光刻机小型复合节流静压气浮导轨微结构参数设计 Article

温众普,  吴剑威,  邢坤鹏,  张银,  李结安,  谭久彬

《工程（英文）》 2021年 第7卷 第2期   页码 226-237 doi: 10.1016/j.eng.2019.09.012

摘要：

在光刻机可变狭缝系统（VS）中，紧凑型复合节流静压气浮导轨是实现高精度、高加速度运动的首选结构。研究表明，导轨气浮工作面上加工浅腔、凹槽等微结构可以改善负载性能。然而，微结构微米级变化对导轨性能的影响尚不清晰。文中采用作者提出的网格自适应法，定量研究了微结构四个参数的影响，揭示了微结构变化对导轨负载性能的影响规律，并利用这些规律对微结构参数进行设计。设计方法的特点在于：通过调节浅腔参数，使承载力、刚度和转动刚度的工作点都统一起来。采用文中的设计流程和调整方法，可以在一定程度上缓解供气压力的限制和各项负载性能间的相互制约。实验结果表明，采用该方法所设计导轨的转动刚度达到2.14 × 104 Nm·rad–1，提高了69.8%。在ArF光刻机上的VS上对气浮导轨进行加速扫描实验，平均扫描加速度达到67.5 m·s–2，
达到了设计要求。

关键词： 光刻机     复合节流静压气浮导轨     微结构     工作点     转动刚度    

HTML PDF 收藏

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

《能源前沿（英文）》 2020年 第14卷 第2期   页码 383-399 doi: 10.1007/s11708-017-0505-3

摘要： Prediction of solar radiation has drawn increasing attention in the recent years. This is because of the lack of solar radiation measurement stations. In the present work, 14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters: extraterrestrial solar irradiance ( ), duration sunshine ( ) and daylight hours ( ). Since it has been observed that each model is adequate for some months of the year, one model cannot be used for the prediction of the whole year. Therefore, a smart hybrid system is proposed which selects, based on the intelligent rules, the most suitable prediction model of the 14 models listed in this study. For the test and evaluation of the proposed models, Tamanrasset city, which is located in the south of Algeria, is selected for this study. The meteorological data sets of five years (2000–2004) have been collected from the Algerian National Office of Meteorology (NOM), and two spatial databases. The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation, which offers an excellent measuring accuracy of values ranging from 93% to 97% in this location.

关键词： global solar radiation     statistical indicator     hybrid model     spatial database     correlation coefficients    

HTML PDF 收藏

Wind tunnel test study on the wind pressure coefficient of claddings of high-rise buildings

Yong QUAN, Yi LIANG, Fei WANG, Ming GU

《结构与土木工程前沿（英文）》 2011年 第5卷 第4期   页码 518-524 doi: 10.1007/s11709-011-0128-4

摘要： The area-averaged most unfavorable wind pressure coefficients (MUWPCs) on various regions of building surfaces and the influence of the side ratio and the terrain category were studied based on wind tunnel test data of scale models of typical high-rise buildings with rectangular cross-sections. The negative area-averaged MUWPCs in the middle-height edge areas generally increased with an increasing / side ratio. The area-averaged MUWPCs can be well fitted with a function of the average area reduced by the square of the building depth, . In addition, no unique pattern was found for the effect of the terrain category on the MUWPCs.

关键词： side ratio     area-averaged pressure coefficients     cladding     terrain category    

HTML PDF 收藏

CHARACTERISTICS OF SOIL QUALITY ATTRIBUTES UNDER DIFFERENT AGROECOSYSTEMS AND ITS IMPLICATIONS FOR AGRICULTURE IN THE CHOKE MOUNTAIN WATERSHED IN ETHIOPIA

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023502

摘要：

● Soil properties varied within coefficients of variation ranging from 7% to 169%.

关键词： agroecosystem     Choke Mountain watershed     coefficients of variation     Ethiopia     soil quality indicator    

HTML PDF 收藏

Local resistance of fluid flow across sudden contraction in small channels

Hang GUO, Ling WANG, Jian YU, Fang YE, Chongfang MA, Zhuo LI,

《能源前沿（英文）》 2010年 第4卷 第2期   页码 149-154 doi: 10.1007/s11708-009-0060-7

摘要： The pressure drop caused by flow area contraction in microchannels has been experimentally studied in this paper using the tiny gap pressure measurement method. The working fluid was deionized water at room temperature at near-atmospheric pressure. Three test sections with area ratios of 0.284 and 0.274 and at different tube diameter sizes were used. The experimental results show that the abrupt contraction coefficient decreases with the Reynolds number increasing, and it is much higher than that of conventional tubes in laminar flow. The widely-applied correlation =0.5(1−) could not predict the contraction coefficient of turbulent flow in the micro tubes. The decreases as the tube diameter increases. The transition from laminar to turbulent flow is not obvious when the diameter of the small tube is 0.32mm.

关键词： microchannels     pressure drop     abrupt contraction     loss coefficients    

HTML PDF 收藏

Multiphase redistribution differences of polycyclic aromatic hydrocarbons (PAHs) between two successive sediment suspensions

Rufeng LI,Chenghong FENG,Dongxin WANG,Baohua LI,Zhenyao SHEN

《环境科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 381-389 doi: 10.1007/s11783-015-0817-7

摘要： Successive sediment suspensions often happen in estuary, yet little research has probed into the difference in the release behaviors of organic compounds among different suspensions. This study took polycyclic aromatic hydrocarbons (PAHs) as typical organic contaminants and investigated the release behaviors between two successive suspensions with a particle entrainment simulator (PES). Results showed that successive sediment suspensions lowered the concentration of dissolved PAHs in the overlying water via facilitating the re-adsorption of dissolved PAHs onto the suspended particles. Fast-release and slow-release periods of PAHs were successively observed in the both suspensions. The concentration changes of dissolved PAHs in the second suspension were generally similar with but hysteretic to those in the first suspension. More vigorous desorption and re-absorption of PAHs were induced in the second suspension. Successive sediment suspensions obviously decreased the concentrations of mineral composition and organic matters in the overlying water, which significantly affects multiphase distribution of PAHs.

关键词： sediment suspension     PAHs     multiphase distribution     distribution coefficients    

HTML PDF 收藏

干旱和复水对冬小麦光合产物分配格局的影响

谷艳芳,丁圣彦,高志英,邢倩

《中国工程科学》 2012年 第14卷 第3期   页码 59-64

摘要：

于2005—2006年在中国科学院封丘农田生态实验站研究了不同水分处理下冬小麦光合产物分配格局及其动态。实验设全生育期干旱处理和充分供水处理以及干旱后拔节期、孕穗期、开花期复水处理。结果显示：不同生育期复水对冬小麦由于干旱胁迫引起的生物量下降有补偿作用；干旱和复水能改变器官水平上光合产物的分配格局；干旱胁迫引起叶、穗分配降低，并使茎、叶鞘和根分配指数上升；拔节期复水使叶光合产物分配指数增加、茎分配指数下降；孕穗期和开花期复水能提高光合产物在茎和穗中的分配；不同时期复水对干旱胁迫引起的产量下降均有不同程度的补偿作用，拔节期复水主要提高小麦单株穗数、孕穗期和开花期复水以提高千粒重为主。

关键词： 光合产物     分配指数     可溶性糖     冬小麦     干旱和复水    

HTML PDF 收藏

通过 B 位Ta置换对 AB O4型EuNbO4的热学和力学性质进行优化 Article

陈琳, 冯晶

《工程（英文）》 2020年 第6卷 第2期   页码 177-184 doi: 10.1016/j.eng.2019.12.006

摘要：

铁弹性的ABO4型RETaO4陶瓷和RENbO4陶瓷（RE表示稀土）是具有潜在应用价值的热障涂层（TBC）材料，研究人员正在对其进行大量研究。结果显示， RETaO4陶瓷的力学性质优于RENbO4陶瓷的力学性质。在本研究中，我们通过B位钽（Ta）置换对利用固相法（SSR）制备的EuNbO4陶瓷的热学和力学性质进行优化。我们使用X射线衍射（XRD）法和拉曼光谱技术对所制备的晶体结构进行确认，并利用扫描电子显微镜（SEM）对结构表面的微观形貌进行观察。结果表明，通过B位Ta置换可以有效提高EuNbO4陶瓷的杨氏模量和热膨胀系数（TEC），且其最大值分别为169 GPa和1.12×10−5 K−1（1200 ℃）； EuNbO4陶瓷的热导率被降低至1.52 W·K–1·m–1（700 ℃），且材料的抗热辐射能力得到了改善。我们建立了声子热扩散系数与温度之间的关系，用以通过消除热辐射效应来确定声子本征热导率。研究结果表明，通过B位Ta置换能够有效优化EuNbO4的热学和力学性质，从而使得此种材料在将来可成为一种高温结构陶瓷材料。

关键词： 热障涂层，稀土铌酸盐，置换，热导率，热膨胀系数，杨氏模量    

HTML PDF 收藏

标题 作者 时间 类型 操作

Experimental study of aerodynamic interference effects on aerostatic coefficients of twin deck bridges

Zhiwen LIU , Zhengqing CHEN , Gao LIU , Xinpeng SHAO ,

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

多孔质气体静压轴承在三轴转台设计中的应用

杜金名

期刊论文

微分和表观静摩擦系数的表式

王渭源

期刊论文

Measurement of activity coefficients at infinite dilution for hydrocarbons in imidazolium-based ionic

ZHU Jiqin, YU Yanmei, CHEN Jian, FEI Weiyang

期刊论文

Effect of friction coefficients on the dynamic response of gear systems

Lingli JIANG, Zhenyong DENG, Fengshou GU, Andrew D. BALL, Xuejun LI

期刊论文

超大跨度斜拉桥空气静力和动力稳定性研究

张新军,孙海凌

期刊论文

光刻机小型复合节流静压气浮导轨微结构参数设计

温众普,  吴剑威,  邢坤鹏,  张银,  李结安,  谭久彬

期刊论文

Smart model for accurate estimation of solar radiation

Lazhar ACHOUR, Malek BOUHARKAT, Ouarda ASSAS, Omar BEHAR

期刊论文

Wind tunnel test study on the wind pressure coefficient of claddings of high-rise buildings

Yong QUAN, Yi LIANG, Fei WANG, Ming GU

期刊论文

CHARACTERISTICS OF SOIL QUALITY ATTRIBUTES UNDER DIFFERENT AGROECOSYSTEMS AND ITS IMPLICATIONS FOR AGRICULTURE IN THE CHOKE MOUNTAIN WATERSHED IN ETHIOPIA

期刊论文

Local resistance of fluid flow across sudden contraction in small channels

Hang GUO, Ling WANG, Jian YU, Fang YE, Chongfang MA, Zhuo LI,

期刊论文

Multiphase redistribution differences of polycyclic aromatic hydrocarbons (PAHs) between two successive sediment suspensions

Rufeng LI,Chenghong FENG,Dongxin WANG,Baohua LI,Zhenyao SHEN

期刊论文

干旱和复水对冬小麦光合产物分配格局的影响

谷艳芳,丁圣彦,高志英,邢倩

期刊论文

通过 B 位Ta置换对 AB O4型EuNbO4的热学和力学性质进行优化

陈琳, 冯晶

期刊论文