空气源热泵机组供暖季节的能耗分析

利用负荷频率法对空气源热泵机组供暖季节的能耗进行分析，指出影响其能源利用系数的因素。     

秋收季节稻草燃烧粒子大气脱水醣类成分与粒径分布研究

以台湾中南部水稻作物区域为目标,探讨秋收稻草燃烧烟尘大气脱水醣类粒径分布成分特征;以改良离子层析仪解析3种大气悬浮粒子(PM2.5、PM10、总悬浮颗粒(TSP))大气脱水醣类成分浓度(左旋葡萄糖、甘露聚糖)与粒径分布,并探讨稻草燃烧对大气粒子的贡献率。结果显示,稻草燃烧期间大气(乡村/市郊)两种粒子(PM2.5与TSP)左旋葡萄糖浓度均大幅上升,两种粒子收成燃烧期间较非收成季节升高约5.5倍(较收成季节背景PM2.5与总悬浮颗粒分别高1.21倍与1.40倍)严重影响区域空气质量。市郊含左旋葡萄糖粒子分布以PM2.5细微粒为主(占TSP81%以上);乡村左旋葡萄糖粒径分布较广,PM2.5粒子占TSP56%左右,粗大粒子(PM>10)占总悬浮颗粒的35%。此外,结果显示稻草生物质燃烧对区域PM2.5粒子平均贡献率为12%,市郊稍高于乡村(乡村、市郊平均贡献率分别为10.5%、13.0%),显现稻草生物质燃烧对台湾中南部空气质量有严重影响。     

Stress-Strain State and Energy Fluxes in a Plate Containing a Stationary Crack under Impulsive Loading

We study the stress-strain state and energy fluxes in a continuous infinite plate and in a plate containing a stationary crack of finite length under impulsive loading. For this purpose, we develop a model of formation of the zone of elevated stresses and the zone of unloading as well as a numerical procedure for the evaluation of their parameters. We deduce analytic expressions for the quantitative analysis of the stress-strain state and energy fluxes in the plate near the tip of the stationary crack under arbitrary impulsive loading. The theoretical results are compared with the experimental data on the initiation of main cracks in plane specimens made of solid polymers. We formulate a quantitative criterion for the difference between the dynamic and quasistatic loading of a crack and show that the dynamic and static fracture processes can be described within the framework of a single approach.     

等离子体浸没离子注入(PIII)过程中初始离子阵鞘层尺度内各物理量的时空演化

等离子体浸没离子注入(PIII)是用于材料表面改性的一种较新的、廉价的、非视线的技术.靶体被浸没在等离子体中,等离子体中的离子在靶体负脉冲偏压的作用下注入靶体而实现材料的表面改性.为了描述等离子体浸没离子注入过程,我们引用了一维粒子模型(PIC)对其进行了数值模拟,该模型通过求解空间电势的Poisson方程,电子的Bolzmann分布以及离子在网格中受力运动的Newton运动方程来完成.本文重点研究了一个初始离子阵鞘层内电势、离子浓度、离子注入靶体的速度和动能以及离子流密度的时空演化规律.     

Investigation on Some Machinability Aspects of Inconel 825 During Dry Turning

In the current study, attempt has been made to investigate the influence of cutting speed (Vc) (51, 84, and 124 m/min) on various machining characteristics like chip morphology, chip thickness ratio, tool wear, surface, and sub-surface integrity during dry turning of Inconel 825. Comparable study was carried out using uncoated and commercially available chemical vapor deposition multilayer coated (TiN/TiCN/Al₂O₃/ZrCN) cemented carbide (ISO P30 grade) insert. Chip morphology consists of chip forms obtained at different cutting conditions. Serrated chips were observed when machining Inconel 825 with both types of tool with more serration in case of uncoated insert. The chip thickness ratio increased as cutting speed was increased. Use of multilayer coated tool also resulted in increase in chip thickness ratio. Rake and flank surfaces were examined with scanning electron microscope and optical microscope. Abrasion, adhesion, and diffusion wears were found to be dominating tool wear mechanism during dry machining of Inconel 825. The beneficial effect of coated tool over its uncoated counterpart was most prominent during machining at high cutting speed (Vc = 124 m/min). The surface and sub-surface integrity obtained with coated tool were superior to that while machining Inconel 825 with uncoated tool.     

Energy Release Channels During Destruction of Impurity-Helium Condensates

Injection of an impurity-helium gas jet passed through a radiofrequency discharge into a volume of superfluid helium leads to the growth of nanoclusters of impurity species which form impurity-helium condensates (IHCs). IHCs are porous materials with very low impurity density (～10²⁰ cm^?3). High average concentrations of stabilized free radicals can be achieved on the large total surface (～100 m²/cm³) of impurity nanoclusters. Warming of the IHCs leads to the destruction of the samples and formation of excited atoms and molecules as a consequence of the recombination of stabilized free radicals. We studied the influence of the nitrogen content in neon-helium and krypton-helium gas mixtures on the thermoluminescence spectra accompanying the destruction of the IHC samples, which were formed by using these gas mixtures. The energy release channels in the IHC samples were revealed from analysis of the thermoluminescence spectra.     

Mass-Spectrometric Study of the Temperature Variation in the Dimer-to-Monomer Ratio in the Free-Surface Vaporization Fluxes from Alkali Halide Single Crystals

A mass-spectrometric method is used to investigate the kinetics of the vaporization of LiF (970–1070 K), NaCl (722–889 K), KCl (780–900 K), KBr (724–918 K), and CsI (656–838 K) single crystals. A dimer-to-monomer ratio, J_D/J_M, in the fluxes vaporizing from free surfaces of these crystals are calculated, using the currents of M⁺, MX⁺, and M₂X⁺ ions formed via electron impact ionization of the molecules MX and M₂X₂ (M is the alkali atom; X is the halogen). It is found that the dimer-to-monomer ratio increases with temperature at a continually increasing rate in the LiF and NaCl cases. In the KCl, KBr, and CsI cases, this rate passes through a maximum. Such a specific temperature variation in J_D/J_M is discussed through the analysis of proposed mechanisms of dimer formation in light of the terrace–ledge–kink and surface charge models.     

扇贝真空冷冻干燥过程中变温变压工艺的研究

以栉孔扇贝闭壳肌为实验材料,在冻干过程中采用两次变温和一次变压的过程参数调节法进行冻干实验,结果表明:第一次变温时的物料中心温度对冻干样品的复水率和能耗是有影响的,当物料中心温度为1℃时进行第一次变温调节,样品的复水率和复水速度最快,品质最好,且干燥能耗也最少.     

空调列车运行时环境温度的曲线拟合

传统的列车空调负荷计算方法是将列车作为静物处理，它不能反映外部环境温度随时间和空间的不同而变化这一特点。本文综合考虑了列车运行时外部环境温度的动态变化，利用傅立叶级数进行曲线拟合，得出了列车运行时环境温度随运行时间变化的关系式，为今后掌握列车运行时环境参数的变化规律提供了理论参考，同时也给工程应用及空调设计带来许多方便。     

Energy Balance of a Semicrystalline Polymer During Local Plastic Deformation

Abstract: This paper, in a first part, presents the characteristics of a new experimental set‐up using digital image correlation (DIC) and infrared thermography (IRT). In a second part, the kinematical data, obtained by DIC, are used to track the material surface element temperature variations deduced from thermal images. They are then combined to construct the local energy balance. To illustrate the interest of such an approach, the paper then describes the calorimetric effects accompanying the propagation of necking in a plasticised PolyAmide 11. A thermodynamic analysis of cyclic loading finally aims to show the existence of an entropic elastic effect generally associated with rubber‐like materials.     

干燥地区蒸发冷却空调系统运行效果及能耗分析

介绍了蒸发冷却空调系统的形式,并进行了简单的分类.提出蒸发冷却空调系统分别从冷源侧、输配侧、末端侧的耗电量计算方法.通过对新疆某医院采用空气—水蒸发冷却空调系统和干燥地区某机场配餐中心采用全空气蒸发冷却空调系统的室内温湿度及整体耗电量实测数据对比分析,来评价蒸发冷却空调系统的运行效果及能耗,得出实测的室内平均温度均为2...     

Sources of Fluxes of Energy, Heat, and Diffusion Heat in a Bipolar Semiconductor: Influence of Nonequilibrium Charge Carriers

The equations of energy balance, heat balance, and diffusion heat balance are obtained for a bipolar semiconductor. The roles of nonequilibrium charge carriers and the recombination in the heat transport are established. The expressions for the sources of energy fluxes, heat fluxes, and diffusion heat fluxes are discussed. Both radiative and nonradiative recombinations are studied.     

干湿变化对多壁碳纳米管/水泥砂浆压阻效应的影响

通过四次烘干和三次吸湿试验,考察了湿度变化对多壁碳纳米管复合水泥砂浆(MWCNTs/CM)的电阻和压阻效应的影响,并与素水泥砂浆(CM)进行对比。结果表明:在试件湿度较大时,烘干和吸湿对MWCNTs/CM和CM电阻的影响较小,而当试件湿度较低时(第三次烘干及第一次吸湿后,湿度变化比低于1%时),电阻随着湿度的降低突然增加,并且湿度变化对CM电阻的影响程度显著高于MWCNTs/CM。同样,当试件湿度较大时,烘干和吸湿对MWCNTs/CM和CM压阻效应的影响较小,当试件湿度较低时(在第三次烘干后),CM和MWCNTs/CM的压阻效应显著增强,并且湿度变化对CM压阻效应的影响显著高于MWCNTs/CM。研究还表明,在湿度变化量大致相同时,吸湿过程中CM和MWCNTs/CM达到渗流阈值附近时压阻效应高于烘干过程。最后,初步探讨了MWCNTs/CM压阻效应随湿度变化的作用机理,给出了MWCNTs/CM压阻效应随湿度变化的等效电路模型。     

Temperature of Thin Natural Leather During Its Drying Through Pasting on a Dry Smooth Surface

Journal of Engineering Physics and Thermophysics - An account is given of the results of solving the differential equation of unsteady-state heat conduction with constant thermophysical...     

Variation in Creep Rupture of γ′ Strengthened Superalloys with Stacking Fault Energy of Matrices

The correlation between the creep rupturebehaviour and the stacking fault energy of matricesof γ′strengthened superalloys has been studied dur-ing constant load creep.At high temperature andintermediate stress,the creep rupture time andstrain strongly depend on the stacking fault energyof matrices rather than the creep friction stress,butat higher stress,the role of grain boundary carbidesbecomes more obvious.However,in the considerably extensive stressrange investigated here,the mean creep rate is apower function of the stacking fault energy ofmatrices and the power index decreases with in-creasing initial applied stress.Particularly,at inter-mediate stresses the product of this index and theinitial applied stress compensated by the shearmodulus is same for two series of superalloys.Hence,this product may be a criterion predictingthat the matrix deformation controls high tempera-ture creep rupture.