三维涡流场基于有限元法的电磁位对

介绍了用有限元法解决三维涡流场问题时电磁位对的优选问题,分析了其适应情况和优缺点.对目前基于有限元法的三维涡流场数值分析方法的国内外现状作了综合评述.     

无波蕩器自由电子激光非线性分析

本文对低导引场无波荡器自由电子激光进行了非线性数值计算分析。结果表明,这种自由电子激光工作在毫米波段时,电子束在纵向及横向均有净动能交给信号波,具有很高的互作用效率(32％);而且,腔体长度较短,腔体直径较大,易于加工制作。     

具有复合周期磁场的电子回旋脉塞

本文从降低回旋脉塞中直流磁场的角度出发,利用线性伏拉索夫——麦克斯韦方程组,对通过静态复合周期磁场的弱相对论电子注与缓变圆波导中沿纵向作任意缓变的TE_(mn)模式之间的互作用机理,在理论上进行了详细的分析和讨论,导出了色散方程并作了数值计算。分析和计算表明,由于采用了静态复合周期磁场,其电子注与波互作用的不稳定性产生在电子回旋共振条件下,从而可以在不同的电子回旋空间谐波上工作而大大地降低直流磁场。     

粒子的镜象对称理论

本文证明了平均自旋和磁物同向,提出了恢复镜象对称的两个方案,并对它们进行了分析比较,发现它们是根本对立的,从而对CP联合反演提出了异议。     

Leukemia Attributable to Residential Magnetic Fields: Results from Analyses Allowing for Study Biases

Nearly every epidemiologic study of residential magnetic fields and childhood leukemia has exhibited a positive association. Nonetheless, because these studies suffer from various methodologic limitations and there is no known plausible mechanism of action, it remains uncertain as to how much, if any, of these associations are causal. Furthermore, because the observed associations are small and involve only the highest and most infrequent levels of exposure, it is believed that the public health impact of an effect would be small. We present some formal analyses of the impact of power-frequency residential magnetic-field exposure (as measured by attributable fractions), accounting for our uncertainties about study biases as well as uncertainties about exposure distribution. These analyses support the idea that the public health impact of residential fields is likely to be limited, but both no impact and a substantial impact remain possibilities in light of the available data.     

磁处理对豌豆幼苗生长及生理的效应

用磁感应强度为0．01T的磁场处理豌豆种子或用该磁场处理的水浸种显著促进豌豆幼苗的营养生长，增加干物质累积量，而用同样磁场处理的水浇灌胚根已经伸出的种子则显著抑制幼苗生长及干物质积累。     

直齿圆锥齿轮弧齿厚的计算

本文介绍利用球面渐开线方程计算圆锥齿轮背锥齿形弧齿厚的方法,并通过实例指出利用当量圆柱齿轮计算弧齿厚的理论误差。     

磁控RF-SIM卡的设计与实现

在非接触式手机移动支付日益盛行的背景下,结合智能卡、RFID、磁控等技术,提出一种磁控RF-SIM卡的设计和实现模式.该磁控RF-SIM卡由多芯片的硬件架构和多任务、多应用的卡操作系统软件架构组成.它为RF-SIM卡产品带来更大的竞争力,为推动手机移动支付的发展提供了有益的帮助.     

Value drivers of social businesses: A business model perspective

Hybrid organizational forms that combine commercial and welfare institutional logics play an increasingly important role in addressing the grand societal challenges we face today. Building on the literatures on hybrid organizations and social business models, we explore the characteristics of social businesses from a business model perspective. This study seeks to better understand the particularities and value drivers of hybrid social purpose in contrast to purely commercial business models. We follow a grounded theory approach and our findings are based on interview data from 17 social business firms. Building on social businesses' identified particularities, we propose four value drivers of social business models: 1) responsible efficiency, 2) impact complementarities, 3) shared values, and 4) integration novelties. We link our findings to the literature, contributing new insights into social businesses models and implications for practitioners.     

作业成本动因选择、合并与评价的系统方法构建

目前学术界关于作业成本动因选择与合并的研究,缺乏对动因留选与留选个数的探讨,而关于对成本动因选择合并的评价的研究未见。可以通过聚类分析建立模型,得到成本动因的相关类,再结合主成分分析指导留选动因的个数,最终确定留选动因,并首次建立评价动因选择与合并优劣性的主成分分析模型。实证分析表明,此系统方法更好地解决了成本动因选择与合并的问题,相同数据下该方法比矩阵理论与距离聚类分析结果更优,作业成本管理系统的复杂性与信息成本显著降低。本文为作业成本动因的选择与合并以及评价提供了一套系统方法。