中美高新技术产业全球价值链分工地位和竞争力研究

通过测算中美高新技术产业双边贸易规模及结构,探讨两国高新技术产业全球价值链分工地位与竞争力。研究结果表明：中国高新技术产业依附于全球价值链的加工和装配等低端环节,整体竞争力低于美国,但近年来有向价值链上游攀升的趋势;美国高新技术产业主导着全球价值链的研发和设计等高端环节。因此,应当继续提升自主创新能力,推进高水平对外开放,搭建国际技术交流平台,完善高新技术产业发展政策,助推中国高新技术产业实现价值链升级。     

高动态临近空间飞行器海上组网测控方案设计

为解决高动态临近空间飞行器海上测控对测量船数量需求较多、现有船队规模无法满足的难题,在分析测控需求特点的基础上,提出了一种基于测量船与临近空间飞艇组网测控的新模式。结合近中程、远程飞行试验分别进行了测控总体方案设计,并讨论了海上组网测控需要研究的关键技术。相关研究对我国后续开展高动态临近空间飞行器海上测控系统建设具有一定的参考价值。     

无源超高频抗金属标签天线设计方法综述

射频识别（RFID）技术的不断发展,对标签天线提出了更高的要求。普通标签天线直接应用于金属表面时,由于受到金属边界的影响,其性能会出现一定程度的下降。详细介绍了4种无源超高频抗金属标签天线的设计方法,包括调整天线与金属面的间距、采用吸波材料、引入高阻抗表面基板、采用平面倒F天线（PIFA）或微带天线结构,并分析了每种方法的优缺点及其对标签天线的阻抗匹配、带宽、尺寸、识别距离以及成本等方面的影响。微带贴片天线不仅具有低剖面、高方向性等优点,而且含有金属接地板,常用作抗金属标签天线的设计原型。在抗金属标签天线的设计与实际应用中,研究者可针对具体要求灵活运用这些设计方法。     

某黄河大桥薄壁空心墩液压爬模施工技术研究

本文结合某高速公路黄河特大桥X#墩的施工,介绍了液压爬模系统及爬模施工工艺在薄壁高墩建设中的应用,为今后高墩的施工积累经验。     

浅谈营盘山隧道岩溶处理

本文主要通过对营盘山大型溶洞施工组织顺序上的调整和对施工工艺工法顺序的处理方法调整及选择方面介绍,希望对类似的溶洞处理的施工有一定借鉴意义。     

高职院校学生实践能力评测系统的设计与实现

以高职院校学生实践能力评测为研究对象,提出由学校、企业和社会共同构建的评测指标体系,阐述评测方法,使用数据库和面向对象开发技术,介绍系统设计和实施的主要步骤,并针对系统应用中存在的问题提出改进意见.     

基于成本优化的制造业生产物流装配线排序问题分析

为了降低制造业的生产成本，提高收益，在分析生产物流配线闲置和超载成本的基础上，采用粒子群算法对其进行优化，并利用模糊自适应改进惯性权值，通过实证研究表明该方法实用，可操作性强，可以有效降低制造业生产物流成本，具有广泛的应用价值。     

The rise of Mexican entrepreneurial migration to the United States: A mixed‐embeddedness approach

Although many studies have analyzed the behavior of high‐skilled migration to the United States, few have focused on the escalating migration of Mexican entrepreneurs, and particularly on the determinants of this kind of high‐skilled migration. This article addresses this gap through a qualitative approach conforming to quantitative procedures, based on 20 in‐depth interviews applied to Mexican entrepreneurs working and/or living in the United States. Theoretically, a mixed‐embeddedness approach guides this research because it allows examining both the individual characteristics of Mexican entrepreneurs, and the influence of the home and host countries' institutional contexts on their business endeavors. Findings revealed Mexico's institutional weaknesses, such as insecurity, corruption, and bureaucracy, are important drivers of migration but so are the perception of a friendly U.S. fiscal system, the search for a better quality of life, and the appeal of a more transparent business environment.     

Does high‐speed rail connection really promote local economy? Evidence from China’s Yangtze River Delta

High‐speed rail (HSR) has led to a transportation revolution in China. This paper uses the county‐level panel data of China’s Yangtze River Delta to investigate the effect of HSR connection on local economy. To address the issue of endogenous HSR route placement, we use a straight‐line strategy to construct potential HSR connection variables as instrumental variables of the actual HSR connection. Both the difference‐in‐differences and instrumental variable methods show that HSR connection impedes local economy, especially in peripheral regions. The impediment effect is channeled through population reallocation from peripheral to core areas and the restructuring of industries.     

Perioperative inhaled corticosteroids treatment is associated with decreased length-of-stay and direct medical costs in high-respiratory-risk surgeries

Abstract

Aims: To examine the impact of perioperative inhaled corticosteroids (ICS) on length-of-stay (LOS) and costs among patients receiving high-respiratory-risk surgeries.

Methods: Adult patients who underwent high-respiratory-risk surgeries in 2015 were identified in the Tianjin Urban Employee Basic Medical Insurance database. Patients were grouped into ICS or non-ICS cohorts according to whether they received ICS during the perioperative period of the index hospitalization. Propensity Score Matching was performed to create matched pairs between two cohorts. The impact of perioperative ICS on LOS and direct medical costs was estimated by negative binomial model and generalized liner model.

Results: Eight hundred and twenty-one hospital stays with high-respiratory-risk were selected in the ICS cohort and another 821 stays in the non-ICS cohort were matched. The mean LOS was 13.0 (±0.3) days in the ICS cohort, which was significantly lower than the matched non-ICS cohort. Patients with thorax and ear-nose-throat surgeries had a significant decrease in LOS in the ICS cohort compared to the non-ICS cohort, with a mean decrease of 5.5 and 1.1?days, respectively. In adjusted analyses, perioperative ICS treatment was associated with shorter LOS, lower total, and respiratory-related costs (reductions of 10.1%, 7%, and 5.3%, respectively) after controlling for demographic, clinical, and hospital characteristics.

Limitations: Some respiratory risk factors such as living behavior and environment were unable to be captured and respiratory-related costs might be underestimated, limited by claim data. Lastly, caution should be taken when generalizing the results to other populations, as only patients with moderate-to-severe surgeries on the thorax and above were selected in this study.

Conclusions: Perioperative ICS treatment was associated with decreased LOS and lower costs for patients undergoing high-respiratory-risk surgeries in China.