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991.
常时微动测试在工程场地评价中的应用与发展 总被引:1,自引:0,他引:1
结合作者主持的上海中心大厦、2010年上海世博会中国国家馆等典型工程,在对常时微动测试发展历史及现状进行综合述评的基础上,详细介绍了常时微动测试的基本原理、现场测试、信号分析等内容,论述了常时微动测试技术在工程场地评价中的应用与发展,可以为相关的工程技术人员提供参考。 相似文献
992.
Nowadays, hydropneumatic transformer (short for HP transformer) is widely used as the main part of the power system of air‐powered vehicles to pump pressurized hydraulic oil from compressed air with a lower pressure. In this paper, the power system of a new kind of air‐powered vehicle is built using HP transformer as the pneumatic pressure boosting structure and hydraulic motor as the power unit. To set a foundation for the optimization of the power system, the dynamic characteristics are analyzed by building the mathematic model and setting up the experimental station. What is more, the affection of several key structure parameters is researched. Through experimental and simulation study, it can be concluded that, firstly, the mathematical model is proved to be effective; secondly, increasing the area ratio of the pistons would improve the output power as well as reduce the system efficiency, and we choose 6 for a balanced choice; thirdly, the output power and the system efficiency will rise with a larger oil discharge orifice; lastly, the increasing pressure of the input air will raise the power and meanwhile decrease the efficiency. In this system, the efficiency will remain above 30%. This research can be referred to in the design of the power system of air‐powered vehicle and the study on the optimization of the dynamic characteristics. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
993.
994.
This paper investigates the relationship between structure and electrochemical performance of reduced graphene oxide (RGO) prepared via heat treatment and chemical reduction method. Structure and morphology of RGO was characterized by means of Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction and Brunauer–Emmett–Teller. Electrochemical performance of RGO electrode supercapacitor was investigated in the organic electrolyte by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance. The results show heat treatment RGO has high graphitization degree, less surface oxygen‐containing groups, good charge–discharge efficiency and stable life cycle. The chemical reduced RGO has single‐graphene structure, high specific surface area, high specific capacitance and low internal resistance. The ascorbic acid reduction RGO exhibits good comprehensive electrochemical performance: Its specific capacitance was 220.7 F g?1, internal resistance was 3.0 Ω and charge–discharge efficiency was 97.0% after 2000 cycles of charging/discharging tests. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
995.
分析了Line Mixing(LM)以及Collision\|Induced Absorption(CIA)效应对中国全球二氧化碳监测科学实验卫星(TanSat)反演CO2所用的CO2的1.61、2.06 μm以及O2 0.76 μm 3个波段气体吸收的影响。LM效应对CO2的1.61、2.06 μm气体吸收截面的影响约2%,LM以及CIA效应对O2 0.76 μm波段的影响,在翼部达到75%,在中心区域约2%。LM效应使谱线线型变窄,使谱线中心吸收波数处吸收截面增大,翼部区域吸收截面减小。考虑LM以及CIA效应后,减小采用传统Voigt线型计算截面存在的结构性误差。分析了气体吸收截面以及LM效应随温度、气压的变化情况,LM效应在压强较大以及温度较低时对吸收截面影响较大。最后,在3个波段选择合理的气压、温度以及波数间隔,建立三维吸收截面查找表,在满足计算精度的同时节约时间,满足卫星大量观测反演的需要。 相似文献
996.
深层优质碎屑岩储层全生命周期分析方法论 总被引:1,自引:0,他引:1
油气勘探领域的深层是指沉积盆地中埋深在3 500~4 500 m及以深的地层。在含油气盆地的深层碎屑岩储层中,优质储层是重要的勘探目标。优质储层具有大量孔隙,其形成与沙或砂岩的沉积条件、埋藏方式、区域温压场、膏盐岩效应等多种因素有关。通过系统研究全球不同区域不同时代不同类型深层碎屑岩储层,提出优质深层碎屑岩储层的全生命周期研究方法,即从储层形成演变的全部时间出发,将深部储层的形成过程划分为早期剥蚀搬运沉积阶段、中期埋藏阶段、中期或/和晚期改造阶段,从全生命周期的尺度分阶段综合分析深层碎屑岩储层的形成及演化过程,推演在地质历史时期中的优质储层演化时序及发育阶段、分布位置。 相似文献
997.
Multibody System Dynamics - High dynamic non-cooperative space targets generally perform complex motions with large angular velocities, so capturing these targets directly may cause fracture damage... 相似文献
998.
Bi Xu Jackie Y. Cai Zongli XieLijing Wang Iko BurgarNiall Finn Zaisheng CaiLisa Wong 《Microporous and mesoporous materials》2012,148(1):152-158
The microstructures, physical properties and mechanical properties of the methyltrimethoxysilane (MTMS) derived aerogels, prepared at ambient pressure using an improved method reported in Part I, have been comprehensively characterised in this paper, as Part II. The study has revealed sophisticated pore structures and morphologies of the aerogels produced, and demonstrated the relationships between the key processing conditions and microstructures of the resultant aerogels. The results of the study also help to further understand the effect of microstructure changes on the macrostructure, volume shrinkage and performances of the aerogels, and provide a general guide on how to manipulate the processing conditions to produce monolithic MTMS based aerogels with desirable structure and properties by ambient pressure drying. 相似文献
999.
Exergy analysis is used as a tool to evaluate exergy losses in the steam-water jet injector so as to improve its overall performance.
What this article addresses here is mainly about a parametric study on the injector under various operating conditions, such
as different inlet water temperature, inlet steam pressure, pressure ratio, entrainment ratio and flowrate ratio. In addition,
the irreversible losses in the component parts of the two-stage injector were analyzed in detail. The results show that the
operating parameters have great effects on exergy efficiency of the injector. The average exergy efficiency of the two-stage
injector is 21% more than that of the single-stage one. Moreover, calculations based on experimental data indicate that the
highest exergy losses due to irreversibility occur in the first-stage mixing chamber. In light of this comparison, the exergy
losses occurring in the system are proportional to the exergy efficiency obtained by applying the system. 相似文献
1000.
Teng Xiao Weipan Cui Min Cai Wai Leung James W. Anderegg Joseph Shinar Ruth Shinar 《Organic Electronics》2013,14(1):267-272
We demonstrate the utility of a low-cost cesium iodide interlayer spun from an aqueous or 2-ethoxyethanol solution on ITO in inverted polymer solar cells of the structure ITO/CsI/P3HT:PCBM/MoO3/Al, where P3HT is poly(3-hexylthiophene) and PCBM is [6,6]-phenyl-C60-butyric acid methyl ester. The power conversion efficiency (PCE) of optimized cells was ~3.4%, comparable to that we obtained for inverted cells with Cs carbonate. The thickness of the CsI film was adjusted by varying the solution concentration. The concentration affected the surface morphology of P3HT:PCBM and the density of fractal-like aggregates (possibly related to the presence of Cs and film fabrication conditions) formed near the anode, as revealed by scanning electron microscopy. Auger analysis indicated a P3HT-rich surface. Optimization of the cells was achieved also by varying the thickness of the MoO3 and the drying/annealing conditions of the active layer, as was evident from the current–voltage characteristics, external quantum efficiency spectra, and PCE. The cells with the CsI interlayer were compared additionally to cells with CsCl or CsF interlayers (with a PCE of up to ~2.7%), which were inferior to the comparable cells with Cs2CO3 or CsI. The surface concentrations of Cs and the halide on ITO were monitored using X-ray photoelectron spectroscopy. The iodine level was low with the Cs:I ratio exceeding 8:1. In contrast, the Cs:Cl ratio was ~1.4:1 and the Cs:F ratio was ~1:1; the Cs2CO3 decomposed partially, as expected. Therefore, for CsI, as is the case for Cs2CO3 but not for CsF, Cs–O bonds are formed at the surface. Such bonds on ITO are important in modifying the ITO work function, improving the cell performance. The results indicate that spin coating solutions of the high polarity CsI is a promising and easy approach to introduce Cs–O on ITO in inverted structures for increased electron extraction from PCBM and possibly hole extraction from the P3HT-rich surface at the anode. 相似文献