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41.
本文总结了近年来国内外文献ZrV2O7研究进展,讨论了常用的合成方法以及负热膨胀的机理。并介绍了ZrV2O7复合陶瓷的研制与应用,指出了负热膨胀材料ZrV2O7潜在的应用领域,并对其发展趋势和应用前景进行了预测。 相似文献
42.
由于 Na2 CO3/Al2 O3吸收剂的活性成分 Na2 CO3与 CO2反应活性较低,选用 TiO2作为掺杂剂,采用浸渍法将其添加到 Na2 CO3/Al2 O3吸收剂中进行改性,研制一种新型具有高反应活性的钠基固体吸收剂。利用小型流化床反应器进行了14次循环脱碳/再生试验,并对吸收剂进行了 XRD 和氮吸附表征。结果表明:掺杂 TiO2后,吸收剂与 CO2的反应速率加快,特别是在碳酸化反应的前10 min 内;反应前后除 TiO2外无其他含 Ti 化合物生成;碳酸化反应产物为 NaHCO3和 Na5 H3(CO3)4;14次循环反应后吸收剂仍保持稳定的微观结构。采用 XPS 和 FTIR 分析了 TiO2对 Na2 CO3/Al2 O3吸收剂脱碳特性的改性机理。 相似文献
43.
奥康纳在经典短篇小说《好人难寻》中,通过塑造几个无名、无声、愚昧、伪善的女性受害者形象,呈现了一个人性扭曲、信仰缺失、道德堕落的危机重重的美国南方社会,表达了她对现代社会精神危机的高度关注和深刻思考。 相似文献
44.
党的十八大以来,世情、国情发生了重大变化,国内外形势严峻复杂,中国特色社会主义的发展面临的机遇与挑战相互交织.文章运用马克思主义基本原理,从国内、国外两个视角出发,系统梳理十八大以来中国共产党对社会基本矛盾、社会主要矛盾、外部矛盾的理论内涵、发展特征、三重逻辑的科学认识及相应的应对策略,总结其中的理论与实践经验,从而阐... 相似文献
45.
Knowledge production and scientific research have become increasingly more collaborative and international, particularly in pharmaceuticals. We analyze this tendency in general and tie formation in international research networks on the country level in particular. Based on a unique dataset of scientific publications related to pharmaceutical research and applying social network analysis, we find that both the number of countries and their connectivity increase in almost all disease group specific networks. The cores of the networks consist of high income OECD countries and remain rather stable over time. Using network regression techniques to analyze the network dynamics our results indicate that accumulative advantages based on connectedness and multi-connectivity are positively related to changes in the countries’ collaboration intensity whereas various indicators on similarity between countries do not allow for unambiguous conclusions. 相似文献
46.
This paper examines the sources of Europe's lagging business R&D performance relative to the US, particularly the role played by missing young leading innovators in high technology intensive sectors in Europe. It investigates through econometric analysis differences in the rates of return to R&D of European and US large R&D firms. It finds that, while in the US, young firms succeed in realizing significantly higher rates of return to R&D as compared to their older counterparts, including in high-tech sectors, European firms fail to generate significant rates of return, even if they are Yollies and even if they are in high-tech sectors. These findings can at least partly explain why Europe has less R&D intensive young leading innovators in high technology intensive sectors. 相似文献
47.
(International) R&D collaboration and SMEs: The effectiveness of targeted public R&D support schemes
This study analyses the impact and effectiveness of targeted public support for R&D investment at the firm level. We test whether the policy design aiming at incentivizing (international) collaboration and R&D in SMEs achieves input as well as output additionality. Our results show that the targeted public subsidies trigger R&D spending, especially so in internationally collaborating SMEs. We further evaluate the different impact of privately financed and publicly induced R&D investment on innovation performance. The results confirm that the publicly induced R&D is productive as it translates into marketable product innovations. While both types of R&D investments trigger significant output effects, the effect of policy-induced R&D investment on sales from market novelties is highest for international collaborators as well as for SMEs. 相似文献
48.
International knowledge spillovers, especially through multinational companies (MNCs), have recently been a major topic of academic and management debate. However, most studies treat MNC subsidiaries as relatively passive actors. We challenge this assumption by investigating the drivers of knowledge protection intensity of MNC subsidiaries. We argue that knowledge protection intensity is determined by MNC subsidiary mandates and by opportunities and risks originating from the host region. We hypothesize that not just competence-creating but also competence-exploiting mandates increase knowledge protection intensity. In addition, technological cluster regions in the host country can be expected to provide opportunities for knowledge sourcing and MNC subsidiaries may be willing to protect knowledge less intensively to participate in cluster networks. We test our hypotheses using a dataset of 694 observations of 631 MNC subsidiaries in Germany and develop recommendations for research, managers and policy makers. 相似文献
49.
含钒的化合物能够有效地催化H2O2,因此可作为多元Fenton-like催化剂中的有效组份之一,Fe2V4O13中存在Fe(Ⅲ)和V(V)同时和协同活化H2O2的可能性。通过液相合成法制备了Fe2V4O13,并对其对AOⅡ的催化活性进行了研究,研究表明,Fe2V4O13是一种新型高效稳定的多相Fenton-like催化剂。 相似文献
50.
采用O*NET工作分析系统中的工作技能、工作风格和工作价值观问卷对660名高校体育教师进行调查,研究表明:高校体育教师O*NET工作技能问卷包含专业技能、认知技能和社会技能,工作风格问卷包含关系导向、事业导向和创新导向,工作价值观问卷包括工作条件、自我实现、独立自主和环境支持,各因子均具有良好的内部一致性信度;O*NET问卷所包含的因子在任务完成情况、学生体育成绩、学生比赛成绩和教学研究成果四个方面对高校体育教师的工作绩效起到正向预测作用;高校体育教师的教龄能显著正向预测学生比赛成绩和教学研究成果两方面的工作绩效,职称高的体育教师取得高工作绩效的可能性大于职称低的。 相似文献