半导体微波二极管国内外动态

本文主要介绍微波二极管的低噪声接收器件、微波发射器件和微波控制器件等研究状况以及它们的应用现状,另外,对这些器件的发展前景也作一概略展望.     

一种新的基于贝叶斯频谱估计的传输线长度测量方法

根据双臂电桥原理搭建出实验电路进行数据采集,再应用贝叶斯频谱估计算法对测得的数据进行分析,得出反射频率周期,然后根据反射原理推算出人工传输线的长度。由于在检测方法和分析方法上的改进,在传输线长度的测量精度上获得了很好的效果。在实验中,根据先验知识和理论得出一个特定的模型方程;在实际应用中如果能够找到一个合适的模型方程,那么就可以运用贝叶斯频谱估计方法进行分析,因此贝叶斯频谱估计算法有着非常广泛的实用价值。     

一种实现多位数直接开平方的算法

给出一种可精确计算七十五位数以下的数的平方的算法，解决了一般高级程序语言中没有直接精确计算位数较多的数的开平方函数问题。     

Corporate Governance Reforms: Redefined Expectations of Audit Committee Responsibilities and Effectiveness

Comprehensive regulatory changes brought on by recent corporate governance reforms have broadly redefined and re-emphasized the roles and responsibilities of all the participants in a public company’s financial reporting process. Most notably, these reforms have intensified scrutiny of corporate audit committees, whose role as protectors of investors’ interests now attracts substantially higher visibility and expectations. As a result, audit committees face the formidable challenge of effectively overseeing the company’s financial reporting process in a dramatically changed – and highly charged – corporate governance environment. This paper discusses the new expectations of audit committee responsibilities and effectiveness in the wake of corporate governance reforms, key challenges, “whistleblower” provisions and shortcomings, and provides some directions for future research.     

我国土地整理生态环境评价研究综述

改善土地利用的生态环境是土地整理的重要内容和目标。针对土地整理生态环境评价,国内很多学者从不同领域、学科视角开展了大量理论与实证研究,取得了丰硕的成果。本文主要从土地整理生态环境评价的理论研究、指标体系和评价方法研究等方面对近年来我国土地整理生态环境评价研究进行了梳理和总结,并针对目前存在的问题进行了思考和展望,以期为科学推进我国土地整理乃至农村土地整治工作提供借鉴。     

外国直接投资技术外溢理论研究综述

外国直接投资技术外溢是外国直接投资内含的人力资本、研发、管理经验等无形资本的非自愿性扩散。本文以时间为线索,概括叙述了20世纪60年代到90年代外国直接投资技术外溢理论的研究方法及主要观点,重点分析了21世纪以来外国直接投资技术外溢理论的最新研究进展,并客观评估了我国“以市场换技术”的战略效应,得出了几点启示。     

质量和包修期限的优化决策及其供应链绩效

文章从上下游互动的角度采用博弈论的理论方法分析研究了家电行业中包修期限承诺和质量提升努力对供应链整体绩效的影响及其最优的均衡结果。在质量提升努力和包修期限长短对市场需求和企业成本变化影响的定性定量分析的基础上分别建立了三个彼此相关的供应链策略互动的斯坦克伯格博弈模型,分别求出了制造商决策的最优质量水平、承诺包修期限和批发价格策略,以及零售商的最优价格策略,通过比较上述三种不同情形下企业利润的变化得到了一些可能有助于企业经营管理决策的建议。     

一种M-ary扩频信号的盲同步方法

针对通信侦察领域M-ary扩频信号的盲同步问题,根据M-ary扩频信号的结构特点及扩频码集元素间的相关特性,提出了一种扩频码长度和失步时间联合估计方法。该方法能够同时估计出M-ary扩频信号的扩频码长度及失步时间,且不受扩频码集类型的限制。仿真实验表明,该算法能在较低的信噪比条件下对三种不同码集的扩频信号进行估计,且算法的性能随着所使用数据的增多而提高。     

Bias-corrected estimates of reduction of post-surgery length of stay and corresponding cost savings through the widespread national implementation of fast-tracking after liver transplantation: a quasi-experimental study

Background: Fast-tracking is an approach adopted by Mayo Clinic in Florida’s (MCF) liver transplant (LT) program, which consists of early tracheal extubation and transfer of patients to surgical ward, eliminating a stay in the intensive care unit in select patients. Since adopting this approach in 2002, MCF has successfully fast-tracked 54.3% of patients undergoing LT.

Objectives: This study evaluated the reduction in post-operative length of stay (LOS) that resulted from the fast-tracking protocol and assessed the potential cost saving in the case of nationwide implementation.

Methods: A propensity score for fast-tracking was generated based on MCF liver transplant databases during 2011–2013. Various propensity score matching algorithms were used to form control groups from the United Network of Organ Sharing Standard Analysis and Research (STAR) file that had comparable demographic characteristics and health status to the treatment group identified in MCF. Multiple regression and matching estimators were employed for evaluation of the post-surgery LOS. The algorithm generated from the analysis was also applied to the STAR data to determine the proportion of patients in the US who could potentially be candidates for fast-tracking, and the potential savings.

Results: The effect of the fast-tracking on the post-transplant LOS was estimated at approximately from 2.5 (p-value?=?0.001) to 3.2 (p-value?Conclusion: The fast-track program was found to be effective in reducing post-transplant LOS, although the reduction appeared to be less than previously reported. Nationwide implementation of fast-tracking could result in substantial cost savings without compromising the patient outcome.     

天兴洲大桥江北铁路引桥施工便桥设计

在武汉天兴洲大桥铁路江北引桥滠口左线引桥1#桥施工中,为满足施工现场混凝土运输的需要．采取以下措施：8-9#墩处上游附近搭设施工便桥1座;便桥桥面板采用2500×1000×200mm钢筋混凝土槽型板;纵向主梁采用8片H600×200mm型钢横向排列,且每两片一组用1cm厚铜板进行抱箍：每墩采用2片36a工字钢做横抬梁;便桥基础采用铜管排桩基础。经对纵梁、横抬梁、桥面板及基础铜管桩受力进行分析．检算合格,经实践证明以上措施及方案安全可行。