Results 121 to 130 of about 1,283,545 (238)
, 2009 以歧化松香胺为原料,合成了歧化松香胺Sch iff碱配体,配体进一步与氯化镍反应制得了歧化松香胺Sch iff碱-镍配合物,并用红外、紫外、元素分析、摩尔电导等测试技术进行了表征。考察了歧化松香胺Sch iff碱-镍配合物对枞酸氧化反应的催化性能,探讨了溶剂、H2O2浓度、反应温度及反应时间等因素对反应的影响。结果表明,配合物对枞酸的氧化聚合具有较好的催化性能,枞酸的转化率可达100%。Disproportionated rosin amine Schiff base was synthesized ...
盘鹏慧 +4 more
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Resource Substitution: Local Governments' Issue Attention and Policy Reinvention
Policy Studies Journal, EarlyView.ABSTRACT Research on policy reinvention, where a government modifies rather than replicates policy innovations introduced by other governments, has progressed significantly, but how it is influenced by the government's issue attention has not been thoroughly examined.
Yingxin Zhang, Yixue Yao, Kaifeng Yang
wiley +1 more source
, 2018 无机非金属氮化碳材料由于电子结构独特、不含金属、化学性质稳定且具有一定的可见光响应等,在能源和材料领域的地位日益突出,具有越来越广阔的研究和应用前景。基于氮化碳材料的二维层状结构和性质特征及其相关应用,本文采用密度泛函理论超软赝势方法,对氮化碳前驱体(melon)、氮氢缺陷前驱体以及石墨相氮化碳(g-C3N4)晶体及其表面结构、能带以及功函数等进行了研究,分析了二维氮化碳材料的物化性质与微观结构的关系。结果表明:Melon为直接带隙半导体,随着结构中氢键的减少 ...
韩清珍, 温浩
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Leveraging an Unhappiness Lens for Smarter Policies
Policy Studies Journal, EarlyView.ABSTRACT Traditional policy research has largely focused on enhancing happiness or well‐being, privileging positive outcomes as the primary metric of success. We argue that a systematic focus on the drivers of unhappiness—rather than solely on happiness—offers a complementary analytical framework that can uncover hidden societal deficits and broaden ...
Marine Coupaud +2 more
wiley +1 more source
, 2010 研究了磷钨杂多酸盐反应控制相转移催化H2O2直接氧化苯乙烯制环氧苯乙烷的反应,考察了溶剂、H2O2用量、催化剂用量、反应温度、时间、苯乙烯浓度等因素对反应的影响。获得的适宜的反应条件为：乙酸乙酯为溶剂,n（苯乙烯）∶n（H2O2）∶n（催化剂）=300∶300∶1,反应温度60℃,反应时间6h,反应液中苯乙烯质量分数为10%。在该条件下,苯乙烯的转化率为85.5%,环氧苯乙烷的选择性为84.9%。催化剂可过滤回收 ...
李军 +4 more
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Facets of Crises: How Problem Indicators and Public Perceptions Affect Policy Change
Policy Studies Journal, EarlyView.ABSTRACT Crises are widely acknowledged as catalysts for policy change. Yet, our understanding of the policy effects of crises remains limited. Why do only some crises lead to major changes, while significant policy changes also occur during seemingly non‐crisis periods?
Constantin Kaplaner +6 more
wiley +1 more source
, 2010 在前面我们知道了为什么可能运用加卸载响应比方法做地震预测，加卸载响应比方法不仅有坚实的理论基础，而且为实验室试验、数值计算以及过去的震例检测所证实。那么，在实际运用中，它真的有效吗？ 尹祥础课题组将它用于地震中期预测已经取得了较好的效果，他们成功地预测过一些国内的地震，还成功地预测过一些国外的地震(美国，日本，土耳其等)。下面来看一些用加卸载响应比LURR预报地震成功的实例。 中国大陆： 早在1980年代后期,尹祥础课题组就用加卸载响应比方法对中外逾百个震例,从有感地震的4级～8 ...
尚嘉兰
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, 2016 介绍了先进树脂基复合材料的基本特性,讨论了其在不同地面武器机动装备上的应用情况与发展现状,剖析了其在低成本制造技术、结构一体化集成技术等方面亟待解决的问题。同时 ...
齐文 +5 more
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Regional News, Regional Bias? Evidence From Media Discourses and Welfare Decisions in Germany
Policy Studies Journal, EarlyView.ABSTRACT How do media representations of immigrants shape their treatment by street‐level bureaucrats? Despite a uniform federal legal framework, decision‐making varies substantially across local welfare offices. Though prior research links national news reporting and policy implementation, little is known about how regional variation in news reporting
Stefanie Rueß
wiley +1 more source
, 2011 近些年,流程模拟技术在提取冶金工业领域的应用越来越广泛,而流程模拟软件则为模拟技术的应用提供有力的工具。本文对目前成功应用于提取冶金过程模拟的商业化软件进行了分析与讨论,包括热化学数据软件、选矿模拟软件及冶金过程流程模拟软件,阐述了这些软件在提取冶金过程中的应用进展 ...
王丽娜, 宋静, 齐涛, 曲景奎
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