Validity of the equivalent-photon approximation for the production of massive spin-1 particles

We point out that the equivalent-photon approximation (EPA) for processes with massive spin-1 particles in the final state would have validity in a more restricted kinematic domain than for processes where it is commonly applied, viz., those with spin-1/2 or spin-0 particles in the final state. We obtain the criterion for the validity ofEPA for the two-photon production of a pair of charged, massive, point-like spin-1 particlesV ^±, each of massM and with a standard magnetic moment (κ=1). In a process in which one of the photons is real and the other virtual with four-momentumq, the condition for the validity ofEPA is |q ²|≪M ², in addition to the usual condition |q ²|≪W ²,W being theV ⁺ V ⁻ invariant mass. In a process in which both photons are virtual (with four-momentaq andq′), our condition is |q ²||q′²|W ⁴ ≪ 16M ⁸, in addition to |q ²| ≪M ², |q′²| ≪M ² and |q ²| ≪W ², |q′²| ≪W ². Even when these extra conditions permitting the use ofEPA are not fulfilled, convenient approximate expressions may still be obtained assuming merely |q ²| ≪W ² and |q′²| ≪W ². We also discuss how the extra conditions are altered when the vector bosons are incorporated in a spontaneously broken gauge theory. Examples ofW boson production in Weinberg-Salam model are considered for which the condition |q ²||q′²|W ⁴ ≪ 16M ⁸ is shown to be removed.     

磁泡研究有新突破——在磁畴壁上读取信息

本文报告了最新重要科技信息.利用外加磁场控制布洛赫畴壁(简记BL)可产生磁化矢量复杂扭转.其中能形成一些磁化方向垂直指向膜面的小区域.称为垂直布洛赫线(或VBL).利用这些成对的布洛赫线,可以制成存储密度极高的计算机存储器,因为信息是在布洛赫线内被编码寄存的,而不是在磁泡本身内.因此,极限信息密度可达到10~(10)bit/cm~2,从布洛赫线存储器中检索信息只需要约2/1000s、而目前检索信息要10s.     

薄膜定量分析中的Auger线型分析方法

采用Ａｕｇｅｒ线型分析方法－因子分析方法和已知组元强度的定量解谱技术，对电子束辅助Ｎ离子注入Ｓｉ和磁控溅射方法制备的ＴｉＮｘ薄膜的高分辨率俄歇电子能谱（ＡＥＳ），进行了定量分析。讨论了化学成分对ＡＥＳ线型的影响及线型分析技术的有效性和应用范围。     

Supply chain optimization of petroleum organization under uncertainty in market demands and prices

A multi-period stochastic planning model has been developed and implemented for a supply chain network of a petroleum organization operating in an oil producing country under uncertain market conditions. The proposed supply chain network consists of all activities related to crude oil production, processing and distribution. Uncertainties were introduced in market demands and prices. A deterministic optimization model was first developed and tested. The impact of uncertainty on the supply chain was studied by performing a sensitivity analysis in which ±20% deviations were introduced in market demands and prices of different commodities. A stochastic formulation was then proposed, which is based on the two-stage problem with finite number of realizations. The proposed stochastic programming approach proved to be quite effective in developing resilient production plans in light of high degree of uncertainty in market conditions. The anticipated production plans have a considerably lower expected value of perfect information (EVPI). The main conclusion of this study is that for an oil producing country with oil processing capabilities, the impact of economic uncertainties may be tolerated by an appropriate balance between crude exports and processing capacities.     

批量修改线宽方法的探讨

为解决计算机在绘图中很难调整线宽的问题，探索出了批量修改线宽的AutoLISP程序，以及在光栅打印机上设定笔宽和线型的方法。     

电力线载波通讯火灾报警网络系统的研究开发

研究开发一种以电力线载波通讯为基础的新型火灾报警网络系统，对网络系统结构、网络协议、逻辑组件和传输方式进行优化设计，分析了主要干扰因素对系统可靠性的影响以及技术对策。     

CA142 后轮罩应力应变分析

在解决大型复杂形状冲压件，尤其是汽车覆盖件的冲压生产技术问题时，圆网格方法已卓有成效。但对成形量小的浅拉延件，传统的圆网格法已不能满足要求。本文以ＣＡ１４２汽车后轮罩为对象，利用一种新的网格方法，计算了应变、应力等高线，分析了后轮罩出现冲压缺陷的原因。     

L—Fuzzy单位区间与L—Fuzzy实直线的连通性

本文主要讨论L-Fuzzy 单位区间I(L)和L-Fuzzy 实直线R(L)的连通性、证明了L-Fuzzy 单位区间I(L)和L-Fruzzy 实直线R(L)是连通的.     

对建筑工程产品及其生产特点的进一步认识

本文在建筑工程产品及其生产的技术经济特点传统观念的认识基础上，对其内容进行补充和变革，并提出了建筑工程产品经营、管理的特点，有利于建筑企业进一步适应市场竞争的要求；有利于建筑企业提高素质，加强生产经营管理。     

覆盖薄层介质平面导体上的表面波

本文根据Ｃｏｌｉｎ提出的等效传输线电路法对薄层介质覆盖平面导体的表面阻抗、表面波传输衰减与介质参数的关系进行分析，并提出乘积μｒμ＂ｒ可作为薄型吸波材料抑制表面波能力的品质因素