Results 91 to 100 of about 31,003 (237)

Participation Disenchants: How Online Political Participation Decreases Online Political Efficacy in China

open access: yesRegulation &Governance, EarlyView.
ABSTRACT Existing literature largely agrees that authoritarian regimes establish channels for political participation to gather valuable information on citizens' anti‐regime sentiments and policy preferences and to supervise lower‐level bureaucrats and firms.
Anton Bogs
wiley   +1 more source

Embracing the politics of transformation: Policy action as “battle‐settlement events”

open access: yesReview of Policy Research, EarlyView.
Abstract Societal transformations for addressing climate change are intensely contested and at risk of resistance and backlash to ambitious policy action. But they are frequently modeled through heuristics such as S‐curves which abstract from such conflicts, assuming increasing returns to scale as a driver of transformations.
James Patterson, Matthew Paterson
wiley   +1 more source

几种天然高分子泡沫体的组成、结构与力学性能 [PDF]

open access: bronze, 2007
才 王   +3 more
openalex   +1 more source

Preparation and performance of fine-diameter SiC-based ceramic fiber [PDF]

open access: yes, 2017
连续细直径的碳化硅(SiC)纤维由于其高强度、耐高温、抗氧化等性能被用来做陶瓷基复合材料增强纤维。为了提高先驱体转化法制备的碳化硅纤维的性能,本文采用硼改性的聚钛碳硅烷,经过熔融纺丝,氧化交联,热解与烧结,制备含钛硼的碳化硅纤维。系统地研究了硼改性的聚钛碳硅烷高分子先驱体的结构及其纺丝性能,高分子纤维的氧化交联以及碳化硅纤维力学性能与吸波性能。 首先,采用液态聚硅烷、钛酸丁酯、硼酸丁酯反应合成含钛硼的高分子,然后将其与聚碳硅烷(PCS)混合制备了不同钛硼含量的硼改性聚钛碳硅烷 ...
王波伟
core  

On a branching route: The spectrum of path dependence in policy research

open access: yesReview of Policy Research, EarlyView.
Abstract This article describes the evolution of discussions around the concept of path dependence, which has established itself as an explanatory framework in various academic disciplines, including policy research. It outlines the diversity of conceptual ideas, presents efforts at specification that have expanded the range of possible interpretations
Jürgen Beyer
wiley   +1 more source

钢侧撑韧性斜撑构材之行为与应用(Ⅰ)

open access: yesJianzhu Gangjiegou Jinzhan, 2005
韧性斜撑构材由主受力组件与侧撑组件组成,主受力组件承担轴力而侧撑组件则在防止主受力组件受压挫屈,由于主受力组件不挫屈,因此能充分发挥材料之强度与韧性,成为一高强度且具高消能容量之斜撑构材。以韧性斜撑构材作为同心斜撑构架中之斜撑构材,此同心斜撑构架即称之为韧性同心斜撑构架,此种构架具有稳定之迟滞行为与高韧性之特性,为一优良之耐震结构系统。本文叙述韧性斜撑构材与韧性同心斜撑构架之力学与耐震行为,并根据其力学与耐震行为提出建议之设计方法。本文为第一部分。
陈正诚
doaj  

The preparation of silk fibroin scaffolds with designable properties and the study of cell-scaffolds interaction [PDF]

open access: yes, 2017
组织类型包括骨、肌肉、神经组织等,针对不同组织损伤修,对支架性质(如力学性能、表面形貌、孔隙结构等)的要求有着很大的区别。丝素蛋白因其良好的生物相容性和优异的力学性能,在组织工程领域应用广泛。丝素蛋白还具有极强的可设计性,可以通过不同制备方法制成多种形式的支架材料(如水凝胶、多孔海绵、膜、无纺布等),且丝素蛋白支架的蛋白构象、力学性能、降解速率等性质都具有很高的可调节性。因此,本文以丝素蛋白为原材料来设计并制备性质可调控的丝素蛋白支架材料,并研究材料性质对细胞行为的影响。 在形貌可设计丝素蛋白膜研究中 ...
卢岳
core  

A new beef: An analysis of discourse coalitions in the nascent cellular agriculture policy subsystem

open access: yesReview of Policy Research, EarlyView.
Abstract A robust approach to examining the nature and influence of coalitions in the policy process is the Advocacy Coalition Framework (ACF), which is especially useful to study policy issues fraught with scientific and technical controversy. Yet, important gaps exist in ACF literature regarding nascent policy subsystems. Consequently, there is scant
Nikki Nadeau, Ramiro Berardo
wiley   +1 more source

一种新型的不饱和聚酯酰胺合成及力学性能研究 [PDF]

open access: bronze, 2008
永平 艾   +4 more
openalex   +1 more source

Theoritical investigations of phase stability, elastic and thermodynamic properties of γ’ phase in Co-X (X:Al, V) based superalloys [PDF]

open access: yes, 2016
Ni基高温合金是航空航天领域应用最广的高温材料。随着国防科技的发展,新一代的航空航天飞机对发动机涡轮叶片材料的承温能力提出更高的要求。然而Ni基高温合金受熔点的限制,其服役温度很难进一步提高。寻找下一代高温合金成为国内外研究机构的关注焦点。最近,研究者们陆续在Co-Al基和Co-V基合金中发现与Ni3Al类似的γ’析出强化相,由此掀起了新型钴基高温合金的研究热潮。作为新型Co基高温合金中的关键强化相,γ’相的结构稳定性和弹性性质直接决定了Co基高温合金的综合力学性能 ...
邓斌
core  

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