浅谈刀具在数控加工中的作用及应用

本文叙述了刀具在数控加工中的重要意义;论述了在数控加工中应用刀具时,应注意的问题.     

一类椭圆-抛物耦合方程组弱解的衰减估计

该文研究在热效应影响下半导体模型,它归结为一个非线性椭圆-抛物耦合方程组初边值问题.考虑此半导体方程瞬态解和稳态解之间的关系,通过对解的一系列估计,给出了在一定条件下瞬态解与稳态解的一个衰减估计.     

InP衬底上电容和电阻的建模

在射频集成电路中，Inp衬底的高电阻率导致了低衬底损耗以及器件和电路性能的提高。该文提出了Inp衬底上MIM电容和电阻的简单而精确的等效电路模型。测量结果与等效电路的仿真结果拟合得非常好，从而证明该文提出的模型足以准确地描述Inp衬底上MIM电容和电阻的电磁场特性。另外，Inp和GaAs同属于Ⅲ-Ⅳ族化合物。它们具有相似的性质，因此，该文提出的模型同样适用于GaAs衬底上的电容和电阻。     

钢管初应力对钢管混凝土偏压构件承载力的影响

对有钢管初应力的钢管混凝土偏压构件承载力的影响因数进行了探讨,介绍了目前国内对该类构件承载力计算的两种方法,并将两种方法的计算结果进行了比较,分析了两者的计算误差,以进一步加深对钢管混凝土这一复杂结构的认识.     

乙烯-醋酸乙烯酯的结构与降凝性能的关系

用溶液聚合法合成了各种结构的乙烯-醋酸乙烯酯共聚物(EVA)降凝剂,考察了它们的结晶性质、溶解性质和降凝效果.由实验得到以下结论:EVA降凝剂的CH2链上只有远离极性基团的碳原子能够参与结晶.当参与结晶的碳原子数约等于原油中蜡的平均碳原子数的3/4时,EVA降凝剂的降凝效果最好.EVA降凝剂的相对分子质量分布的宽窄对降凝效果的影响不大,平均相对分子质量在1.2×104时降凝效果较好.     

BP神经网络技术在调剖效果预测中的应用研究

调剖效果预测是对调剖措施进行决策和方案优化设计的理论基础.通过对影响调剖效果的因素分析,建立了BP网络效果预测模型并对其进行优化改进.模型网络预测结果与实际生产效果对比分析表明,所建立的预测模型可靠.可利用BP网络模型进行调剖效果预测,并为调剖方案的优化设计提供科学决策依据.     

西峰白马区润湿反转剂驱模拟研究

西峰油田白马区长8油藏平均渗透率为0.77×10-3 μm2,属低渗透率油藏,储层岩石润湿性普遍存在中性-偏亲油性.为了提高原油采收率,针对该油藏条件开展了室内润湿反转剂驱实验和数值模拟研究,优选出适合该油藏的最佳驱油方案为:段塞尺寸为0.1倍孔隙体积,段塞组合为1 000 mg/L(0.05 PV) 200 mg/L(0.05 PV).应用润湿反转剂模型预测最佳驱油方案的原油采收率可以达到36.75%,与注水开发相比提高9%左右,润湿反转剂换油率达到538 t/t.可以认为低渗透油藏注润湿反转剂开发是可行的.     

提高油管漏磁检测设备性能的新方法

根据实际的漏磁检测设备相关参数,建立有限元仿真模型,确定了励磁线圈的形状和工作参数,获得最佳的信噪比.提出了在励磁线圈外面增加辅助磁路的措施来消除检测时的端部效应.通过在Hall探头两侧表面加装导磁块的方法,提高了探头对缺陷漏磁信号的轴向分量的检测能力.仿真数据同实验结果基本吻合,研究成果已经用在钢管漏磁检测设备的开发生产中.     

Investigation of the error in transferring the dimensions of the volt using a transportable stabilitron voltage standard

The results of an investigation of the characteristics of transportable voltage standards based on stabilitrons for the purpose of using them as standards of comparison when transferring the dimension of the unit of constant voltage in accordance with the State Standard GOST 8.027-2001 are presented. It is shown that, using the standard investigated, one can transfer the dimensions of the unit of voltage with an overall relative error of 5·10⁻⁸ for a voltage of both 1.018 V and 10 V. __________ Translated from Izmeritel'naya Tekhnika, No. 1, pp. 34–38, January, 2006.     

Preparation of Adrenochrome Hydrogel Patch, Gel, Ointment, and the Comparison of Their Blood Coagulating and Wound Healing Capability

The aim of this study is to make an effective blood coagulant and wound healing agent, which on its topical application on ruptured skin would help in instant coagulation of blood and ongoing healing of wound. The hydrogel has been prepared by mixing 28% w/v gelatin and 21% w/v PVA in distilled water, and heated to 40°C followed by addition of a blood coagulant at a lower temperature. Beeswax, alcohol, liquid paraffin, and adrenochrome were mixed, triturated, and heated accordingly to prepare adrenochrome ointment. Polyvinyl alcohol and glycerin were mixed and heated and the drug was added at a lower temperature, and stored at 4-5°C to form adrenochrome gel. Gelatin alone has cell adhesion property. Adrenochrome is a blood coagulant. Therefore, gelatin with adrenochrome in hydrogel has a synergistic effect in wound healing. To evaluate the efficacy of these three different formulations, incisions were made on the backs of three mice and simultaneously adrenochrome containing hydrogel patch, gel, and ointment were applied on the wound and observed at regular intervals for half an hour to examine the rate of blood coagulation and kept under observation for 2 days to study the rate of wound healing. The efficacy of all these three formulations was compared to appraise the most effective blood coagulating and wound healing agent.