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排序方式: 共有1609条查询结果,搜索用时 31 毫秒
111.
We show a Lagrange-type duality theorem for a DC programming problem, which is a generalization of previous results by J.-E. Martínez-Legaz, M. Volle [5] and Y. Fujiwara, D. Kuroiwa [1] when all constraint functions are real-valued. To the purpose, we decompose the DC programming problem into certain infinite convex programming problems. 相似文献
112.
从技术的角度论证了用于钢轨及辙叉线上焊补用高频逆变焊机的性能 ,经铁道部产品质量检测中心的测试 ,各项主要技术指标均已达到国外同类产品的水平 .对辙叉焊补后的金相实验证明该方法科学合理 ;有关焊补工艺 ,大量现场实验说明取得了相当满意的结果 . 相似文献
113.
Hua Zhang Jian YangHuizhou Liu Shuming Wang 《Physica C: Superconductivity and its Applications》2010,470(22):1998-2001
This paper reports CeO2/YSZ/Y2O3 buffer layers deposited on biaxially textured NiW substrates by DC reactive sputtering in a reel-to-reel system. The effect of partial pressure of water vapor (PH2O) on surface morphology and orientation of the Y2O3 films was examined. The obtained CeO2/YSZ/Y2O3 buffer layers exhibit a highly biaxial texture, with in- and out-of-plane FWHM values respectively in the range of 6.0–7.0° and 4.5–5.5°. Crystallographic consistency of CeO2/YSZ/Y2O3 along meter length is excellent. Atomic force microscope observation (AFM) reveals a smooth, continuous and crack-free surface with a Root-mean-square roughness (RMS) lower than 10 nm. 相似文献
114.
Nanocrystalline cobalt ferrites with nominal composition CoCrxFe2−xO4 ranging from x=0.0 to 0.5 with step increment of 0.25 were prepared by sol–gel auto combustion and chemical co-precipitation techniques. A comparative study of structural, electrical and magnetic properties of these ferrites has been measured using different characterization techniques. Structural and micro-structural studies were measured using X-ray diffraction, Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy and atomic force microscopy. Crystallite sizes of the series are within the range of 12–29±2 nm. Lattice parameters decrease by increasing Cr3+ concentration. FTIR confirms the presence of two lattice absorption bands. DC electrical resistivity increases to a value of ∼1010 Ω-cm with increase in Cr3+ concentration, but the most significant increase is in samples prepared by sol–gel combustion. Dielectric properties have been measured as a function of frequency at room temperature. Dielectric loss decreases to 0.1037 and 0.0108 at 5 MHz for chemical co-precipitation and sol–gel combustion, respectively. Impedance measurements further helped in analyzing the electrical properties and to separate the grain and grain boundary resistance effects using a complex impedance analysis. Magnetic parameters were studied using a vibrating sample magnetometer in the applied field of 10 kOe. The saturation magnetization decreased from 63 to 10.8 emu/gm with increase in Cr3+ concentration. 相似文献
115.
116.
柴油机电子调速器配机模拟试验装置的研制 总被引:4,自引:0,他引:4
简要介绍了柴油机电子调速器配机模拟试验装置的基本工作原理及其系统的设计。采用数字计算机仿真技术,研制了一柴油机电子调速器配机模拟试验装置。试验结果表明,该装置能较逼真地模拟电子调速器与柴油机配机的工作情况,并能方便地测取电子调速器的主要性能参数。 相似文献
117.
《Composite Interfaces》2013,20(3):167-178
In this study, a modified binary polymer blend made up of polycarbonate and polystyrene blend has been prepared by loading of aluminum oxide (Al2O3) as a dopant. The role of alumina with polymer blend system was addressed in view of interfacing criteria. The filler concentration of modified blend was taken as 5, 10, and 15%. The morphological, thermal, and electrical properties were characterized by various techniques. Optical microscopy confirms the homogenous dispersion of Al2O3 in blend. The presence of alumina was detected by subatomic level using atomic force microscope (both two and three dimensional approach). The differential scanning calorimetric thermographs demonstrate decreasing softing point as function of alumina loading. The dielectric properties such as dielectric constant, loss, and electrical modulus were studied under DC bias. The effect of DC bias exhibits significant changes at low amount of Al2O3. The dielectric polarization supports Maxwell Wagner (MW) theory due to low frequency response. 15% Al2O3 gives the highest dielectric constant (ε′) value (3.5?×?105) at 10 Hz. The polymer modified blend with Al2O3 may be used as a one of the best dielectric medium. 相似文献
118.
介绍了全数字直流调速装置SIMOREGK6RA24在高炉探尺系统中的运用,该系统具有控制精度高,组态方便,调试简单,故障率低等优点。 相似文献
119.
CNMARC与DC的相互转换 总被引:2,自引:0,他引:2
杨小云 《科技情报开发与经济》2005,15(11):262-263
CNMARC在规范中文文献数字资源的管理中,起到了十分重要的作用,但随着书目资料与网页的合并,CNMARC的不足和DC明显的优势便显现出来,所以CNMARC和DC的相互转换成为必然。对DC与CNMARC相互转换的研究进展情况及转换方式进行了概述。 相似文献
120.
H. Tuy 《Journal of Optimization Theory and Applications》2003,118(1):201-216
We discuss global optimality conditions and cutting plane algorithms for DC optimization. The discussion is motivated by certain incorrect results that have appeared recently in the literature on these topics. Incidentally, we investigate the relation of the Tikhonov reciprocity theorem to the optimality conditions for general nonconvex global optimization problems and show how the outer-approximation scheme developed earlier for DC programming can be used to solve a wider class of problems. 相似文献