基于多重交叉残差方法的空间目标旋转特性分析

针对传统的频谱分析和自相关函数反演周期时常出现虚假周期的问题，提出了多重交叉残差法处理空间旋转目标雷达散射截面(Radar Cross Section，RCS)的时间序列。以空间跟踪和监视系统(Space Tracking and Surveillance System,STSS)卫星为例，仿真了空间目标失稳旋转状态，对比了频谱分析、自相关函数和多重交叉残差3种方法的处理结果，发现当目标存在进动运动时多重交叉残差法抗干扰能力更强。在此基础上，进一步研究了不同章动角时多重交叉残差法对旋转周期的反演效果，结果表明章动角大小会影响旋转周期的反演准确度，且章动角达到一定数值后，卫星进动幅度过大导致RCS序列周期性模糊，无法用多重交叉残差法反演出旋转周期。     

舰载塔康天线波束空域扫描的耦合效应分析

针对舰载塔康(TACAN)天线安装架设位置特殊性需求,为解决天线阵列受到电扫描和机械扫描同时作用影响系统测角问题,建立了天线阵列接收信号的数学模型,分析了电扫描和机械扫描对天线阵列波束空域扫描的耦合效应,研究了耦合效应对舰载塔康系统测角性能的影响。理论推导和计算机仿真结果表明,天线接收信号受到阵元馈电频率、天线机械扫描速率以及阵列结构的共同影响,接收信号的周期性不再是馈电信号的频率,且其频谱发生了扩展。通过对机载天线接收信号进行有效滤波处理,可确保舰载塔康系统测角正常工作。     

输送机中心轴线标定及测量精度分析

通过对带式输送机安装中心轴线标定方法进行理论分析,推导出边长和角度实测的精度相关公式,同时输送机的施工安装工艺对测量标定中心轴线提出了较高的要求,为我们提出了在实际工作中的具体做法和应注意的几个问题。     

浅析工程资料在建筑工程预结算中的作用

编制工程预结算中一个重要的依据来源就是工程资料,它直接影响着此项编制工作的质量。文章对工程资料包含的几个方面进行分析,探讨了工程资料的重要性以及编制要求,供相关工程技术人员参考。     

基于DEFORM微型齿轮模具入模角分析及选用

对微型齿轮模具入模角挤压成形的影响进行有限元模拟,利用DEFORM软件模拟其成形过程中的金属流动充填规律和变形中应力应变、载荷特征,揭示了其微成形过程的变形机理,选择合理入模角实验,挤出形状良好的微型齿轮。     

大倾角综采工作面撤除工艺优化与应用

大倾角综采工作面设备快速撤除一直是煤矿生产的技术难题。本文针对刘庄煤矿121106俯采工作面撤除难题,通过合理优化工作面设备撤除整体路线以及撤除施工工艺,实现了工作面设备的安全快速撤除。     

Multimarket Contact and Rivalry over Knowledge‐based Resources

Research summary: Research shows that multimarket contact (MMC ) reduces rivalry involving downstream activities. Yet, studies showing that MMC can increase the threat of imitation suggest a need to better understand how MMC affects upstream rivalry over knowledge‐based resources. In this study, we argue that MMC increases rivalry over knowledge‐based resources since the deterrent threat of retaliation that typically leads to mutual forbearance in downstream activities will not be sufficient to restrain firms from protecting their knowledge from imitation in upstream activities. In support of these arguments we find that MMC increases the likelihood that a firm initiates patent litigation against a rival. This study suggests the relationship between MMC and rivalry may depend on the competitive domain and the type of resources over which firms are competing . Managerial Summary: How does market overlap or MMC affect rivalry between two competitors? Prior studies have largely found that an increase in market overlap decreases rivalry in less knowledge‐intensive context because of the deterrent threat of retaliation. However, in this paper, we argue that an increase in market overlap may not reduce rivalry in more knowledge‐intensive context because of heterogeneity in capabilities to protect knowledge. We find that a firm is more likely to initiate patent litigation against a rival as market overlap increases. Our findings suggest that the incentive to protect value across multiple product markets may surpass the motivation to cooperate with rivals and that managers should have a more nuanced view of how market overlap with competitors affects rivalry in more knowledge‐intensive contexts . Copyright © 2017 John Wiley & Sons, Ltd.     

Instrumental client relationship development among top-ranking service professionals

Informal client contact forms a crucial part of the daily routine of service professionals, in particular among top-ranking professionals working for consultancy and accountancy firms. In this paper, we investigate how 34 service professionals develop informal client contact, by studying their networking styles. Our study shows many similarities in informal client contact between two groups of service professionals grouped by gender, but we also found subtle differences in what we coin instrumental and expressive relations. Contrary to gender stereotypes, we found that female service professionals tended toward instrumental networking styles, using professionalism and distance and allowing the high quality of their work compensate for network deficits, contingent upon their clients’ gender. Male service professionals drew on expressive relations to develop emotional bonding with their male clients in particular, but nonetheless toward instrumental purposes. Our study contributes to service industries literature by theoretically and empirically establishing the different informal networking styles between top-ranking service professionals, and the role of emotional bonding in particular. In doing so, the paper helps to better understand the intricacies of informal client contact as a critical dimension of the professional services industry.     

出口欧盟食品接触材料风险分析

以2011年上半年欧盟食品和饲料快速预警系统（RASFF）对我国出口欧盟食品接触材料的通报情况为依据,总结通报涉及的产品种类、进口国家的风险特征和水平,分析风险来源,探讨应对措施,旨在发挥风险预警作用。     

混凝土管道铺设管基对覆土压力作用效果的影响

管道覆土对混凝土管作用的内力受铺设管基角β的影响,不同管基角其内力系数不同,同时管基角相同时,内力系数又是土压作用线与管道横截面纵轴线的夹角θ函数,即管周不同位置其受力不同。