APM车辆冷却风机断路器跳开故障分析

自动旅客捷运系统APM作为一款全自动运行的城市轨道交通系统制式,具有全自动驾驶、高爬坡能力,线路灵活、平稳舒适等特点.APM车辆通常采用强迫风冷的方式对牵引系统进行冷却,以确保系统不会因为过温而造成故障.可以说冷却的正常运行对车辆能否安全运营起着关键作用.本文对APM车辆测试期间发生的风机断路器跳开故障进行了分析,并针对故障提出了解决措施.     

闽侯县闲置农地生态安全评价研究

[目的]根据闽侯县农用地闲置情况,结合当地社会经济及生态环境发展情况,深入分析闽侯县闲置农地的生态安全发展水平。[方法]建立闽侯县闲置农地生态安全评价指标体系,分别从农村垃圾处理点数量、财政支农资金、外部进入农村投资、农业生产总值、种粮补贴、自然灾害、农业技术水平、农村生物的多样性程度、农村家庭收入结构、农村生态补偿金额、农地的整理规模及环保支出占GDP比重共确定12个指标进行深入研究,运用普通最小二乘法对设计的多元线性回归模型进行回归,进一步对闽侯县闲置农地的生态安全水平进行评价。[结果]农村垃圾处理点数量、财政支农资金、种粮补贴、环保支出占GDP比重、生态补偿金额、生物多样性程度对闽侯县闲置农地生态安全水平起到促进作用,呈正相关趋势;自然灾害则与闲置农地生态安全水平呈负相关趋势。[结论]整体看来,闽侯县闲置农地的生态安全水平主要受到当地经济、环境及生态基础三大因素的影响。     

How will the Belt and Road initiative advance China’s exports?

We examined 2007, 2010, 2012, 2014, and 2016 data from 49 countries to determine changes wrought by China’s Belt and Road initiative; we also used panel data regarding the Maritime Silk and Inland Silk Roads to test initiative effects on Chinese exports. Post-initiative infrastructure expansion and logistics performance improvements led to positive effects on China’s exports. Additionally, legal-system similarities and inland borders with trade partners had a more positive effect on Chinese exports in the Inland Silk Road, while population and free trade agreements were found to have a more positive effect on the Maritime Silk Road.     

General Purpose Technologies and local knowledge accumulation — A study on MNC subunits and local innovation centers

This research looks into the innovative activities of subunits of large non-U.S firms in the U.S from 1969 to 1995, suggesting that the innovations in the subunits of multinational corporations are closely linked to their specializations in General Purpose Technologies (GPTs). GPTs enable recombining knowledge from different domains on an international scale, and that the specialization of innovations in GPT fields within a subunit is positively associated with the innovative capacity at large, along with the degree of technological diversification of that specific subunit. As firms expand geographically to tap into local innovation centers to develop new growth alternatives, specialization of GPTs in these firms actually facilitates further geographical dispersion of innovative activities across locations. Lastly, additional specializations of innovations in GPT fields within the host innovation centers does help in attracting innovation activities of firms from a wider range of industries.     

农机社会化服务采纳、禀赋差异与农村经济相对贫困缓解

进入以缓解相对贫困为重点的后扶贫时代，农村经济相对贫困问题仍不容忽视。农机社会化服务作为小农户与现代农业有机衔接的桥梁，对于推进乡村振兴战略和脱贫攻坚有序衔接具有重要作用。文章讨论的核心议题是农机社会化服务采纳如何缓解农村经济相对贫困，并尝试建立了“农机社会化服务采纳——禀赋差异缩小——农村经济相对贫困缓解”的理论分析框架。为此，文章首先对农机社会化服务采纳影响农村经济相对贫困的作用机制进行了理论分析，然后利用2750份河南省农户问卷调查数据，运用Logit模型，实证检验农机社会化服务采纳对农村经济相对贫困的影响，并通过替代核心自变量和变更样本的方法进行稳健性检验，运用PSM模型和IVProbit模型以及ERM模型进行内生性讨论，最后通过中介效应模型对其作用机制进行验证。结果表明，农机社会化服务采纳对农村经济相对贫困具有显著负向影响，缓解了农村经济相对贫困。考虑内生性后，结论仍具有稳健性。进一步的机制验证发现，农机社会化服务采纳通过缩小劳动力禀赋差异和技术禀赋差异，缓解农村经济相对贫困，劳动力禀赋差异缩小和技术禀赋差异缩小的中介效应占比分别为21.22%和7.36%。可见，应将完善农机社会化服务供需体系纳入农户相对贫困治理机制考虑范畴，引导农户从传统家庭化生产转向现代社会化生产，扩大农机社会化服务采纳范围；同时完善就业服务等相关配套体系以吸纳释放的弱劳动力，促进农户收入增长，缓解农村经济相对贫困。     

银行数据中心UPS架构规划

银行数据中心UPS动力系统在保障业务连续性方面具有举足轻重的作用,本文通过分析可靠性不同的7种UPS架构,结合UPS全生命周期的运营管理,兼顾稳定可靠、运营经济、维护方便,探讨了银行各级机构的UPS架构综合规划,并提出“混合型架构”的创新思路。混合型系统可用性能满足各方面的需要,使机房总体成本得到控制。     

气相色谱法测定蔬菜中对硫磷的残留量

本文建立了包菜中对硫磷残留量的气相色谱-火焰光度检测器(FPD)检测方法.样品用QuEChERS方法进行前处理后,采用外标法进行定量.对硫磷在80.0~1000μg·L-1范围中线性关系良好(r=0.9994),方法添加回收率为96.0%~111%,相对标准偏差RSD为2.5%~4.3%,方法的检出限为0.161μg·kg-1,能够满足蔬菜中对硫磷残留量的分析要求.     

Cost-effectiveness analysis of ramucirumab treatment for patients with hepatocellular carcinoma who progressed on sorafenib with α-fetoprotein concentrations of at least 400 ng/ml

Abstract

Objective: This study aimed to compare the cost-effectiveness of ramucirumab versus placebo for patients with hepatocellular carcinoma who progressed on sorafenib with α-fetoprotein concentrations (AFP) of at least 400?ng/ml in the United States.

Methods: A Markov model was constructed to assess the cost-effectiveness of ramucirumab. Health outcomes were measured as quality-adjusted life years (QALYs). With TreeAge software, the disease process was modeled as three health states: progression-free survival (PFS), progressive disease (PD), and death. Costs were extracted from the REACH-2 trial, and utility was derived from published literature. Incremental cost-effectiveness ratios (ICERs) were calculated to compare ramucirumab with placebo. Probabilistic sensitivity analyses were developed to examine the robustness of the results.

Results: In the base case analysis, ramucirumab therapy had a cost of $55,508.41 and generated 0.54 QALYs, while placebo therapy had a cost of $761.09 and generated 0.47 QALYs, leading to an additional $54,747.32 in costs and 0.07 QALYs. The ICER was $782,104.57 per QALY, which was much higher than the willingness-to-pay threshold of $100,000 per QALY. According to sensitivity analyses, the utility of PD in the two groups was the dominant parameter influencing the ICER.

Conclusion: Although ramucirumab was associated with prolonged survival for patients with advanced hepatocellular carcinoma who progressed on sorafenib treatment with an AFP of at least 400?ng/ml, it is not a cost-effective treatment from a United States payer perspective.     

Tariffs and formation of free trade agreements networks

This paper examines the formation of bilateral free trade agreements (FTAs) on the basis of country heterogeneity in the tariff level. We demonstrate that a country's unilateral incentive to form an FTA depends on the relative magnitudes of the (negative) market concession effect and the (positive) market expansion effect, both of which are determined by the tariff levels of the two FTA partner countries. Global welfare is maximised when all country pairs form FTAs. Two countries in equilibrium are more likely to form an FTA when their tariff gap is smaller or when their tariff levels are neither very high nor very low. This finding is robust to several extensions of the model. Our preliminary empirical analysis provides some evidence for the finding.     

Workplace incivility and work engagement: The mediating role of job insecurity and the moderating role of self-perceived employability

Drawing upon the job demand–resource model and the theory of existence, relatedness, and growth needs, we established and checked a model that connects workplace incivility to employee work engagement (i.e., vigor, dedication, and absorption) through job insecurity. Furthermore, we propose and test self-perceived employability as the boundary condition of this connection. The conclusions of two substudies with time-delay design provided evidence to support theoretical models. Specifically, the conclusions of both studies show that workplace incivility has negative impacts on work engagement (i.e., vigor, dedication, and absorption) through job insecurity. The results of Study 2 show that self-perceived employability not only weakens the negative influences of job insecurity on work engagement (i.e., vigor, dedication, and absorption) but also moderates the mediating roles of job insecurity in the relationships between workplace incivility and work engagement (i.e., vigor, dedication, and absorption). The theoretical and practical implications and limitations are discussed based on the conclusions of the two substudies.