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Effect of Facet Displacement on Radiation Field and Its Application for Panel Adjustment of Large Reflector Antenna 被引量:3
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作者 Wei WANG Peiyuan LIAN +2 位作者 Shuxin ZHANG Binbin XIANG Qian XU 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第3期578-586,共9页
Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher sur... Large reflector antennas are widely used in radars, satellite communication, radio astronomy, and so on. The rapid developments in these fields have created demands for development of better performance and higher surface accuracy. However, low accuracy and low effi- ciency are the common disadvantages for traditional panel alignment and adjustment. In order to improve the surface accuracy of large reflector antenna, a new method is pre- sented to determinate panel adjustment values from far field pattern. Based on the method of Physical Optics (PO), the effect of panel facet displacement on radiation field value is derived. Then the linear system is constructed between panel adjustment vector and far field pattern. Using the method of Singular Value Decomposition (SVD), the adjustment value for all panel adjustors are obtained by solving the linear equations. An experiment is conducted on a 3.7 m reflector antenna with 12 segmented panels. The results of simulation and test are similar, which shows that the presented method is feasible. Moreover, thediscussion about validation shows that the method can be used for many cases of reflector shape. The proposed research provides the instruction to adjust surface panels efficiently and accurately. 展开更多
关键词 Reflector antennas Surface accuracy -Radiation field - Reflector antenna mechanical factors Electromechanical effects - Panel adjustment - Singularvalue decomposition (SVD)
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Quantifying Creep of Concrete Filled Steel Tubes 被引量:1
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作者 陈宝春 SHRESTHA K M 《Journal of Donghua University(English Edition)》 EI CAS 2010年第6期796-805,共10页
Using age adjusted effective modulus(AAEM)method,creep of concrete filled steel tube(CFST)member was formulated considering of creep coefficient and aging coefficient.Ten CFST specimens were tested including eight for... Using age adjusted effective modulus(AAEM)method,creep of concrete filled steel tube(CFST)member was formulated considering of creep coefficient and aging coefficient.Ten CFST specimens were tested including eight for creep and two for shrinkage.The experimental result was compared with the computed result using AAEM in which the creep coefficient was taken from calibration of ACI model based on experimental result on sealed concrete,and aging coefficient was supplied from relaxation test on sealed concrete specimen.Furthermore,the creep of CFST member was analyzed using author's own subroutine to input concrete properties through user programmable feature(UPF)in ANSYS software.Comparison was made on authors' own experimental database,some existing experimental results,and results from AAEM and numerical analysis.Finally,the conditions of applicability of AAEM method are put forward,and numerical approach to compute creep of CFST specimen is delineated. 展开更多
关键词 age adjusted effective modulus(AAEM) concrete filled steel tube(CFST) creep test user programmable feature(UPF) subroutine numerical analysis
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What Drives China’s Transformational Growth:Technology,Efficiency or Factor Cost?
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作者 何小钢 张宁 《China Economist》 2015年第5期4-18,共15页
With rising costs of capital, labor and energy, cost efficiency and cost management have become important questions confronting the next stage of China's economic growth. By building a parametric cost frontier model ... With rising costs of capital, labor and energy, cost efficiency and cost management have become important questions confronting the next stage of China's economic growth. By building a parametric cost frontier model using panel data, this paper investigates the drivers of economic growth transformation from a cost perspective. According to our research, among various effects triggering corporate cost variations and in addition to the expansion of production scale, the largest effect is from technological progress, followed by the effect of factor price adjustment and the effect of efficiency gains. Within the decomposition of factor price adjustment effect, the energy factor effect is the most significant. Furthermore, energy price fluctuations are likely to become major factors restricting saving-based growth. Further study reveals that both the ownership reform and opening up of SOEs are favorable to reducing the costs generated by inefficiency. This paper provides empirical evidence for the driving mechanism of saving-based growth transformation as well as empirical evidence to support to the further deepening of property rights and market-oriented reforms. 展开更多
关键词 growth transformation transformational growth technological progress effect factor price adjustment effect effect of efficiency gains
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Simple Raman scattering sensor integrated with a metallic planar optical waveguide: effective modulation via minor structural adjustment 被引量:1
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作者 陆炎 阚雪芬 +4 位作者 许田 方靖淮 王孟 殷澄 陈险峰 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第1期71-75,共5页
We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the di... We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized "hot spots." The observed excitation efficiency of the Raman signal is significantly enhanced,owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate(PMMA) thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm. 展开更多
关键词 Simple Raman scattering sensor integrated with a metallic planar optical waveguide effective modulation via minor structural adjustment
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What Are the Most Effective Adjustments To Ease Individual Income Tax Burdens?
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《Beijing Review》 2008年第52期46-47,共2页
The Chinese Government’s recent economic stimulus measures are attracting much attention because of its plan to increase people’s incomes and alleviate enterprises and residents’ economic burden.
关键词 In What Are the Most Effective adjustments To Ease Individual Income Tax Burdens
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