Contracting and Reporting Conservatism around a Change in Fiduciary Duties*

We exploit an influential 1991 Delaware court ruling to examine simultaneously two types of conservatism that play important roles in resolving creditor–owner agency conflicts: contracting conservatism and reporting conservatism. The ruling expanded managerial fiduciary duties in favor of creditors for Delaware-incorporated firms in the vicinity of insolvency. In those firms, following the ruling, debt contracts are less likely to include conservative adjustments to accounting numbers used for covenant compliance (i.e., contracting conservatism decreases), while public financial reporting becomes more conservative (i.e., reporting conservatism increases). The decrease in contracting conservatism is concentrated in firms that exhibit a greater increase in reporting conservatism, suggesting that reporting conservatism is more cost-effective in resolving agency conflicts. In addition, the substitution effect is more pronounced in firms facing greater business uncertainty and firms with greater board independence.     

一种新型电磁式导引器

介绍一种以负阻抗L－C振荡为基本环节的电磁式导引器，分析了其工作原理，给出了实验线路框图及位移特性。     

小城镇经济辐射区研究--以重庆为例

本文以重庆为例,分析了小城镇经济辐射区范围的形成受行政范围、自然条件、人口规模、城镇用地规模、经济结构、经济规模、交通和市场等八个主要因素的影响,指出小城镇经济辐射能力弱、辐射范围小是欠发达地区普遍存在的现实问题,并在此基础上提出了相关建议.     

加强基础设施建设,提升中心城区的辐射带动能力

在新型城镇化进程中,加强中心城区的基础设施建设、提升中心城区的承载能力、发挥中心城区的辐射带动作用十分重要。本文在分析了黄河三角洲地区中心城市基础设施建设存在不足的基础上,提出了加强中心城区基础设施建设的看法与建议,旨在为全面提升该区域的城镇化水平提供参考。     

Climate,diseases, and the origins of corruption

It has been commonly observed that tropical countries tend to suffer from intense corruption and underdevelopment. This study provides an explanation for this long-standing disparity across the world based on variation in the intensity of ultraviolet radiation (UV-R). The central hypothesis is that UV-R is positively associated with the (historical) prevalence of eye diseases, which significantly shortens work-life expectancy as a skilled worker. This helps shape the worldwide distribution of corruption by affecting the incumbents' window of opportunity. Using data for up to 139 countries, I consistently find empirical support for the positive relationship between UV-R and corruption. The main findings withstand accounting for numerous alternative explanations for international differences in corruption levels. Employing individual-level data from the World Values Survey, I document suggestive evidence that exposure to UV-R is linked to surveyed respondents' tolerance towards corrupt activities. Furthermore, a subnational analysis for China lends credence to the cross-country evidence.     

浅析电力网中的电磁干扰

随着科学技术的迅速发展,大量新技术新材料的应用,电力系统的容量和电压都有很大的提高,出现了盲流高压输电、晶闸管的广泛应用、电力机车、电弧炉等整流设备的发展,大量电子类家用电器的广泛使用,使电力网中谐波污染变得相当严重。二次设备的微型化、数字化、电子化增加了二次设备对暂态干扰的敏感性,使暂态干扰和高频辐射干扰问题日益突出。所以,供电网络中的电磁兼容问题必须高度重视,认真对待,否则,将对电力网造成严重后果。     

介质涂层金属圆柱体有限元法电磁散射特性的分析

本文以有限元方法(FEM)为基础,结合边界积分方程(BIM)这一开域边界条件的混合有限元算法实现对目标散射特性问题的分析。本文以一个介质涂敷金属圆柱为例应用有限元/边界积分方程法(FEM-BIM)实现计算结果,并与精确结果进行对比,吻合很好。     

皖江城市带城市经济联系与中心城市辐射范围分析

分析经济区内城市间经济联系不仅有利于引导城市的空间发展,而且有利于空间经济的合理组织。以皖江城市带为例,引入克鲁格曼指数、建成区面积、人口素质权重系数等指标修正了以往的引力模型,并利用城市间的日发车班次数据对修正模型进行了检验。在此基础上,利用修正模型确定了各城市的主要对外联系方向及联系强度,采用断裂点公式计算了中心城市的吸引范围。结果表明:①皖江城市带内各城市对外经济联系强度差异较大;②各城市的主要联系方向呈现中心城市指向性和地域相邻指向性特征;③合肥和芜湖为皖江城市带的两个经济中心城市,它们的对外吸引范围较为狭小。     

大垂直口径天线俯仰波束赋形设计

给出了一种大垂直口径天线俯仰波束的优化设计过程。大垂直口径天线由10个辐射阵元 构成,可以看成为一个阵列。为使天线的辐射波束达到给定的波束要求,提出了一种改进 的遗传算法及其目标函数模型,对各辐射阵元的馈电幅度和相位同时进行优化。计算结果显 示,天线能够产生满足设计要求的俯仰波束。通过全波电磁仿真软件HFSS进行了验证,仿真 结果与计算结果吻合,证明了所提方法的有效性和实用性。     

非均匀微带线电磁脉冲耦合特性分析

针对电磁脉冲与非均匀微带线的耦合问题,基于时域有限差分法和卷积完全匹配层 ,研究了不同弯曲和不同斜切角非均匀微带线的电磁脉冲耦合特性,并对耦合机理进行了讨 论。仿真结果表明：由于结构的非均匀性,微带线不同端口的耦合系数相差较大;电磁脉冲 入射方向对耦合系数具有重要影响,不同方向耦合系数相差约60 dB;微带线拐角斜切 对降低 电磁耦合效果不明显。所得结论对提高微带电路和电子系统抗强电磁脉冲打击能力具有重要 意义。