凸极同步电机小信号运算电感的计算

小信号运算电感数值计算中的问题有:增量磁导率的使用,转子绕组的处理等。本文采用场路耦合法处理转子的阻尼绕组和励磁绕组,既合理地反映了转子的复杂回路,又避免了端部漏磁引起的修正。通过对采用不同磁导率计算的比较,得到了一些具有实际意义的结果。     

确定体效应二极管等效电路的一种新方法

文中以众所周知的体效应振荡器的等效电路模型为基础,采用曲线拟合的方法,利用测量得到的振荡频率和输出功率关于谐振腔长度的变化曲线,拟合出体效应管包括管座的等效电路参数。     

工程机械弹性轮胎特性的分析

本文分析了弹性轮胎的结构特点,从轮式工程机械的实际工况出发,建立了轮胎的数学模型。从而获得了表征轮胎力学性能的参数——等效弹性模量E_(?),并与实测结果进行了比较。该参数E_(?)具有物理意义明确,测试方便、准确,具有工程实用价值。     

亚太地区放射性个人剂量监测国际比对与思索

报告了参加亚太地区放射性个人剂量监测国际比对的结果,并提出了一些看法。     

A comparison of biological activities of a new soya biopeptide studied in an in vitro skin equivalent model and human volunteers

During aging, the epidermis and dermis become thin and an efficient anti-aging product should be able to stimulate the metabolism of senescent fibroblast and keratinocytes, in order to increase the quantity of extra-cellular matrix components such as collagen and glycosaminoglycans. A study performed in parallel on an in vitro skin equivalent model, and in vivo, with human volunteers, demonstrated the efficacy of one specific soya biopeptide for anti-aging properties. Such a biopeptide induces a significant increase of glycosaminoglycans synthesis in vitro and in vivo after a one-month treatment. We also showed that this new cosmetic ingredient is able to stimulate favourably the collagen synthesis in vitro and in vivo. This study provided the proof for anti-aging properties of a new soya biopeptide and also validated the skin equivalent model developed for this experimentation as an alternative method to animal or human testing for some cosmetic efficacy evaluations.     

The mathematical model of solidification latent heat under high cooling rate

Treatment of solidification latent heat is a key point in solidification simulation by the finite difference method. When latent heat is dealt with in a traditional method of equivalent latent heat, it was found that heat was increased when casting with a high cooling rate, and then the simulation result was distorted. In this paper, a new method is proposed to deal with solidification latent heat. Moreover, a mathematical model was suggested, in which the latent heat can be dealt with accurately under high or normal cooling rates. By contrasting the simulation results from this new method with the traditional one, it was indicated that this new model can obtain more accurate simulation results than the traditional model under high or normal cooling rates. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(2): 115–121, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20104     

Influence of geotechnical factors on gas flow experienced in a UK longwall coal mine panel

Methane drainage has become an integral part of modern coal mining operations when gas emissions cannot be practically dealt with using conventional ventilation methods alone. Boreholes are often drilled above and below the caving zone and connected to a drainage range located along the return gate. This paper describes the construction and analysis of the results obtained from the two- and three- dimensional geomechanical and gas flow models experienced around an active deep UK longwall coal production panel. The models constructed using the commercial FLAC codes were undertaken to provide information to the ventilation engineers at the mine on the likely gas sources and gas flow paths into the face line areas and gate roads. This information allows for the correct design of the orientation, length and support of the boreholes to maximise gas capture. The paper describes the method adopted to derive the relevant rock mass parameters and the laboratory tests conducted to obtain the stress-dependent permeability of coal measure rock strata. A functional relationship is proposed whereby the intrinsic bulk permeability of a sheared coal measure rock may be predicted from the confining stress. A detailed discussion of the geomechanical modelling methodology and the derivation of the strata permeabilities and gas flow modelling adopted is presented. The output of the models is described and used to interpret the major potential gas sources and pathway into the workings.     

利用注水井测试资料识别油层高渗透带

对于已进入高含水后期的水驱油田而言,控水是延长油田有效开发期,提高油田寿命的必由之路,而高含水后期水驱控水重点是针对导致注入水低效无效循环的高渗透带,因此必须开展高渗透带的识别,进而使水驱控水措施有的放矢,为高含水后期的水驱控水提供技术支撑。本文从高渗透带的基本特征出发,应用其在测井资料上的鲜明特征结合动静态等资料加以识别,并开展了应用,其效果表明应用测井资料识别高渗透带油层是可行的。     

Performance Requirements and Analysis of RF Receiver for PDMA Terminal

The performance requirements of a RF receiver for a packet division multiple access technology (PDMA) terminal and the corresponding calculations under the true PDMA signal excitations are presented in the paper. The output signal-to-noise power ratio, the reference receiving sensitivity, the maximum input RF power and the dynamic range, the out-of-channel selectivity and the third-order inter-modulation/cross-modulation characteristics are all analyzed for the PDMA terminal RF receiver in detail. And a feasible indirect method for obtaining the output noise power-spectrum-density of the terminal transmitter by measuring transceiver noise figure is also presented.     

闵20低渗透敏感性油藏注清水研究

敏感性油藏的注水一直是油田开发的一个难点.闵20油田就是一个敏感性中偏强的油田,先期投产的注水井注清水后,井口压力上升较快,注水效果差.本文通过流动实验对闵20油田进行了注入水配伍敏感因素分析及伤害预测,确定了在注水前及注水过程中采用1%TDG-15防膨液进行防膨的预处理方案;同时通过室内实验筛选了适合该区块的三防药剂;配合PEB清水精细过滤工艺提高注入水水质.这一系列措施实施后,闵20油田注水效果得到了明显的改善.