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针对采用线性无油直流压缩机的单门直冷式冷藏箱,试验分析蒸发器结霜对箱内温度波动幅度及开机率的影响,结果表明:蒸发器表面结霜会使箱内平均温度升高约1℃,蒸发器与箱内温度波动幅度均减小;调整至相同的箱内温度,蒸发器结霜可以使开机率降低0.9%~2.5%,从而降低系统能耗。 相似文献
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建立了某高速列车动力学模型及该列车一系悬挂阻尼三维结构原理图,基于该结构研究了列车一系悬挂阻尼常见的失效形式,并仿真分析了一系悬挂阻尼发生故障对车辆运行品质的影响。研究结果表明:一系悬挂阻尼常见故障主要由骨架密封磨损严重、O型圈老化严重、油液乳化等引起;当每辆车1个或每辆车2个一系悬挂阻尼发生故障,车辆横向及垂向平稳性受影响较小,其指标恶化率小于5%,但对舒适性有一定影响,舒适性指标恶化率最高可达15%;当车辆一系悬挂阻尼全部发生故障,其运行品质存在显著恶化,而舒适性恶化最为严重,其指标恶化率达186%。 相似文献
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基于Web的产品信息发布技术研究 总被引:1,自引:0,他引:1
与传统的产品宣传手段相比,基于Web的产品信息发布系统以其独有的优势正成为目前国内外企业推广产品的主要方式。阐述了基于Web的产品信息发布系统的概念和特点,对客户机/服务器模式和浏览器/服务器模式的优、缺点进行了比较。概述了XML、Flash、Cult3D和Viewpoint等网络产品信息发布相关技术的发展现状、特点及应用,对今后基于Web产品信息发布方式的方向进行了展望。 相似文献
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在各级政府质量奖的推动下,卓越绩效模式(PEM)在广东省大范围地推广开来.研究如何有效地为企业导入卓越绩效模式,在导入工作前期具有非常重要的意义.本文探讨了“创建标准化良好行为企业(GSP)”对导入PEM的基础性和支撑性作用,确立了以GSP为基础导入PEM的工作模式. 相似文献
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Zhiguo LiTianxing Niu Zhenjiang Zhang Guiying FengShuping Bi 《Thin solid films》2011,519(13):4225-4233
In this article we investigated the effect of solvents (CCl4, CH3CN, DMF, ethanol, ethanol-H2O and H2O) on self-assembly of Thioctic acid (TA) and Mercaptohexanol (MCH) on gold by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Electrochemical characteristics of TA and MCH self-assembled monolayers (SAMs) formed in different solvents were evaluated by inspecting the ions permeability (interfacial capacitance C and phase angle Ф1 Hz) and electron transfer capability (current density difference Δi and charge transfer resistance Rct). Experimental results indicated that the ability of solvents availing the ordering of SAMs was: for TA, CCl4 > ethanol > CH3CN > ethanol-H2O > DMF; for MCH, H2O > ethanol-H2O ≈ CCl4 > ethanol ≈ CH3CN > DMF. Through relating the C, Ф1 Hz, Δi and Rct of SAMs (TA and MCH) with parameters of solvent (polarity ETN, solubility parameter δ and octanol/water partition coefficients logPow), it was found that solvents with bigger logPow (smaller ETN and δ) availed the ordering of TA-SAMs but the effect of solvents on MCH self-assembly was complex and MCH-SAMs formed in H2O (the biggest ETN, δ and the smallest logPow) and CCl4 (the smallest ETN, δ and the biggest logPow) were more ordered than in other solvents. 相似文献
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通过对不同孔隙特征的加气充填混凝土试样沿发气方向进行切割和截面图像提取,采用Matlab对试样截面图像进行分析和统计计算,分别对各组试样的孔隙特征进行了表征;测试了试样各养护龄期的比强度、吸水率、体积膨胀率、冻融后的抗压强度损失率和质量损失率,以分析孔隙特征对加气充填混凝土力学性能和抗冻性的影响。结果表明:采用图像法对加气充填混凝土截面照片进行信息采集,通过Matlab的统计计算,可实现对该加气充填混凝土宏观孔和细观孔的信息提取与表征;大于5.00mm的孔隙占比越大,平均孔径差值c越大,反映出联通孔的相对数量越多,则试样的比强度越低,吸水率越大,体积膨胀率越小,抗冻性越差,反之,试样的比强度越高,吸水率越小,体积膨胀率越大,抗冻性越好;以两种细度混合的铝粉膏作为引气剂可以有效降低该加气充填混凝土连通孔的相对数量。 相似文献
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利用等离子体增强热丝化学气相沉积系统在沉积有过渡层Ta和催化剂层NiFe的Si衬底上制备出准直碳纳米管,并用扫描电子显微镜研究了它们的生长和结构,结果表明真空度对其生长和结构有较大的影响。当真空度为4000Pa和2000Pa时,准直碳纳米管较容易生长,并且真空度为2000Pa时生长的碳纳米管平均长度大于真空度为4000Pa时碳纳米管的平均长度。但真空度为667Pa时碳纳米管生长困难。根据热力学和辉光放电理论,分析了真空度对准直碳纳米管生长和结构的影响。 相似文献
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A. T. Chwang 《Journal of Engineering Mathematics》1981,15(1):49-63
Summary The effect of stratification of the fluid in the reservoir on hydrodynamic pressures on dams due to horizontal, harmonic ground accelerations has been analyzed. It has been found that both the zeroth-order solution, which corresponds to the constant-density solution, and the first-order solution have two components in the hydrodynamic pressure distribution, an in-phase component and an out-of-phase component which is 90° lagging. The out-of-phase components vanish in the absence of surface waves, and they become dominant when the wave-effect parameter C becomes large. The wave-effect parameter C is defined as 49-1, where g is the gravitational constant, the oscillation frequency and h the height of the fluid in the reservoir. The total horizontal force on a dam due to harmonic ground excitations has also been presented. 相似文献
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现代化的设备状态检测和故障诊断理论已经把设备的寿命预测作为一个重要的组成部分.随着科学技术的发展,设备运行状况的复杂化程度越来越明显,对于往复式空压机而言,这种信息的复杂性、不确定性程度反映更加强烈,传统的数学建模预报方法已不能满足设备的复杂化和现代化要求.提出一种基于RBF神经网络的振动信号在线预测模型,以空压机振动信号为基础,选取合适的特征参量,提高了性能预测精度,结果表明该模型是可行和有效的. 相似文献
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S. Shivakumara U. Manohar Y. Arthoba Naik T. V. Venkatesha 《Bulletin of Materials Science》2007,30(5):463-468
Electrodeposition of zinc on steel was obtained from acid chloride bath containing condensation products (CP) of 3,4,5-trimethoxy
benzaldehyde (TMB) and chitosan (CTN). The effect of bath constituents, pH, current density and temperature on the nature
of deposit was studied by Hull cell experiments. The bath composition and operating parameters were optimized. The adhesion,
ductility and corrosion resistance of the deposits were discussed. Throwing power and current efficiency values under different
plating conditions were measured. SEM photomicrographs of the deposit were taken to study the surface morphology. The inclusion
of addition agent in the deposit was investigated from IR spectrum of the scrapped deposit. The consumption of brightener
in the lab scale is 10 mLL−1 for 1000 amp-h. 相似文献