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.     

大数据时代下电子商务平台的探索和研究——以淘宝网为例

随着网络用户的日益增长,互联网记录着大量的用户个人信息和由智能终端产生的图片和信息,这些信息爆炸性的增长,并不断涌入网络海洋,产生海量的数据信息。在电子商务环境中大数据处理将会发展出更多强大和多元的功能。本文以淘宝网为例,分析研究如何合理利用数据,为企业的经营模式做出相应调整,并且在变化中不断进行企业新技术、新方法和新思路的探索。同时指出数据泄露的隐患,并给出相应建议。     

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.     

The untold story of commodity futures in China

We investigate the behavior of commodity futures risk premia in China. In the presence of retail-dominance and barriers-to-entry, the term structure and momentum premia remain persistent, whereas hedging pressure, skewness, volatility, and liquidity premia are distorted by time-varying margins and strict position limits. Furthermore, open interest, currency, and inflation premia are sensitive to institutional settings. The observed premia cannot be attributed to common risks, sentiment, transactions costs, or data-snooping, but are related to liquidity, anchoring, and regulation-induced limits-to-arbitrage. We highlight the distinctive features of Chinese futures markets and assess the challenges posed to theories of commodity risk premia.     

财政支出差异性对创业活动的激励效应分析

经济新常态下，创业是推动中国经济发展、改善民生的重要途径。创业过程的风险性、不确定性及正外部性需要政府给予积极支持。基于2007-2015年中国内地30个省市（除西藏外）数据，运用动态面板模型，考察地区财政支出和创业活动的关系。研究结果表明：财政支出规模对创业活动数量及创业活动质量具有滞后的积极作用；财政支出规模的滞后效应源于财政支出结构的滞后效应，不同财政支出结构对创业活动质量影响的差异较大；同时，创新是提升创业活动质量的重要手段。因此，政府应积极支持“大众创业、万众创新”，各地区财政创业扶持资金应该从规模和结构上进行调整，重点优化有利于创新的支出结构，为创业提供良好的公共环境。     

科学型企业商业模式:中国情境的复合案例研究

以中国企业为研究对象，运用复合案例研究方法分析与构建了科学型企业商业模式概念模型，分离出科学平台和价值平台两个独特要素，进而构建以科学平台-价值平台互动为核心的P2P商业模式运作模型，并根据不同类型科学型企业，分析模型的有效性、适用性以及模型在不同类型科学型企业中的共性与差异，最后总结出科学型企业商业模式特点及企业管理对策。     

Has Adoption of IFRS Increased Non–North American Institutional Investment in the Canadian Stock Markets?

We investigate whether non–North American (non‐NA) institutional investment in firms listed on the Canadian stock markets increased between the pre‐ and post‐IFRS adoption periods relative to such investment in firms listed on the U.S. stock markets. Prior to IFRS adoption, Canada had high‐quality financial reporting standards that were similar to the U.S. standards. As consequences of IFRS adoption, Canadian financial statements became more comparable with European and other IFRS country financial statements and less comparable with neighboring U.S. financial statements. Thus, a question of interest is whether the enhanced comparability with non‐NA companies was beneficial in terms of attracting non‐NA investment to Canadian companies versus U.S. companies. We find that there was no significant change in non‐NA institutional investment in Canadian firms relative to U.S. firms for the very largest (fifth quintile) and for smaller (first, second, and third quintiles) Canadian companies. However, intermediate‐sized Canadian companies in the fourth size quintile lost non‐NA institutional investment relative to their U.S. peer companies, suggesting that non‐NA investors cared more about comparability with U.S. peer companies than non‐NA peer companies for companies in this size quintile.