从某正样机的鉴定试验谈可靠性试验设计

介绍了在正样机定型质量控制过程中,强化鉴定试验可靠性设计方法研究。从编制鉴定试验大纲、方案评审、试验程序控制、试验数据分析、试验过程组织和技术能力提高等关键环节入手。确定正样机置信水平,得出正样机功能及主要性能满足战术技术指标要求。     

(Relative) autonomism,policy currents and the politics of mobilisation for food sovereignty in the United States: the case of Occupy the Farm*

Food sovereignty movements (FSMs) globally have sought to rearrange relations between land, power, state actions and societal forces outside the state, towards a new ideal of democratised, egalitarian and ecological food systems. The question of how best to reach this ideal has vexed movements and scholars alike, with many anti-capitalist theorists proposing that because of the historical dedication of states to maintaining unequal and unsustainable capitalist relations, change must be pursued outside and against the state rather than through it (i.e. through “autonomism”). Yet, analysis of FSMs globally shows that autonomism is relative, partial and best seen as an aspirational ideal rather than a fixed dogma. This paper deepens this insight by analysing a case within the United States where a local direct action group promoted food sovereignty by illegally occupying public land. The case shows how even apparently autonomist movements can through influence on state and societal actors contribute to state-based “policy currents” that flow in the direction of food sovereignty. This mutual codetermination by actors in and out of state institutions of the possibility and shape of “policy currents” renders state–society relations as important, even to those interested in (relative) autonomism. This paper thus leaves behind dichotomous interpretations of (and recommendations for) FSMs vis-à-vis autonomism, in order to unpack the influence (in thought) and impact (in action) of autonomist tendencies in food sovereignty construction.     

Evaluation of gas release rate through holes in pipelines

A mathematical model of an accidental gas release in a long transmission pipeline is presented in terms of computational fluid mechanics. It was found that the hole model is suitable for the release of gas through a small hole, while the pipe model is suitable for the gas release through a hole corresponding to the complete breaking of the pipe. In this paper, a new model was proposed for a hole that lies between both these situations. The results of the example show that when the initial inside pressure is higher than 1.5 MPA, the mass of gas released during the sonic flow is more than 90% of the total mass of gas released. The average release rate of the total release process could be substituted by the average release rate of the sonic flow, or by 30% of the initial release rate. This approximation would become more accurate with the increase in the initial inside pressure.     

Apoplastic ascorbate contributes to the differential ozone sensitivity in two varieties of winter wheat under fully open-air field conditions

We studied leaf apoplastic ascorbates in relation to ozone (O₃) sensitivity in two winter wheat (Triticum aestivum L.) varieties: Yangfumai 2 (Y2) and Yangmai 16 (Y16). The plants were exposed to elevated O₃ concentration 27% higher than the ambient O₃ concentration in a fully open-air field from tillering stage until final maturity. The less sensitive variety Y16 had higher concentration of reduced ascorbate in the apoplast and leaf tissue by 33.5% and 12.0%, respectively, than those in the more sensitive variety Y2, whereas no varietal difference was detected in the decline of reduced ascorbate concentration in response to elevated O₃. No effects of O₃ or variety were detected in either oxidized ascorbate or the redox state of ascorbate in the apoplast and leaf tissue. The lower ascorbate concentrations in both apoplast and leaf tissue should have contributed to the higher O₃ sensitivity in variety Y2.     

Improving our legacy: incorporation of adaptive management into state wildlife action plans

The loss of biodiversity is a mounting concern, but despite numerous attempts there are few large scale conservation efforts that have proven successful in reversing current declines. Given the challenge of biodiversity conservation, there is a need to develop strategic conservation plans that address species declines even with the inherent uncertainty in managing multiple species in complex environments. In 2002, the State Wildlife Grant program was initiated to fulfill this need, and while not explicitly outlined by Congress follows the fundamental premise of adaptive management, 'Learning by doing'. When action is necessary, but basic biological information and an understanding of appropriate management strategies are lacking, adaptive management enables managers to be proactive in spite of uncertainty. However, regardless of the strengths of adaptive management, the development of an effective adaptive management framework is challenging. In a review of 53 State Wildlife Action Plans, I found a keen awareness by planners that adaptive management was an effective method for addressing biodiversity conservation, but the development and incorporation of explicit adaptive management approaches within each plan remained elusive. Only ~25% of the plans included a framework for how adaptive management would be implemented at the project level within their state. There was, however, considerable support across plans for further development and implementation of adaptive management. By furthering the incorporation of adaptive management principles in conservation plans and explicitly outlining the decision making process, states will be poised to meet the pending challenges to biodiversity conservation.     

低压电器产品常见的湿热试验

介绍低压电器产品常见的湿热试验和相应试验参数,从而认识低压电器元器件和低压成套设备两大类产品湿热试验项目通常考核目的和意义,对低压电器实际检测的了解有更进一步的帮助。     

Changing governance structures and the environment: economy–environment relations at the local and regional scales

Two substantive bodies of research have developed in recent years, both of which have a focus upon local and regional scales. First, there has been the development of work on changing forms of local and regional governance. This has drawn on a range of theoretical perspectives, including notions of institutional capacity, urban regime theory and neo-regulationalist accounts. Second, a body of research has developed into environmental policy and sustainable development, but this has largely been normative and undertheorized. While these two bodies of literature have developed separately, we believe there is merit in bringing the insights from each together. A focus on local environmental policy helps to broaden our understanding of local governance and problems of after-Fordist regulation. Such a project also helps to illuminate problems in implementing policy on the environment and sustainability. The examination of changing local and regional forms of governance allows us to identify new state spaces, which may provide opportunities for the strategic insertion of environmental objectives into economic development policies. This paper seeks to theorize such environment–economy relations and emerging multi-scalar forms of environmental governance, drawing upon case study research work in six UK local authority areas. Copyright © 2002 John Wiley & Sons, Ltd.     

极端干湿循环作用下饱和泥浆红黏土的干缩裂隙发育特征

云贵高原红黏土常经历极端干湿循环过程,为研究极端干湿循环作用对红黏土干缩裂隙发育规律的影响,以昆明呈贡地区红黏土饱和泥浆样为研究对象,在室内进行5次干湿循环试验,通过监测红黏土质量和表面干缩裂隙的形成及其演化过程,分析了极端干湿循环作用对红黏土水分蒸发、干缩裂隙的形成及其演化、表面干缩裂隙网络结构形态的影响.结果 表明...     

我国若干湖泊水库的营养状态指数TSI_c及其与各参数的关系

基于我国２０多个湖泊水库的不同营养状态特征，首次得出了适用于我国若干湖泊的营养状态指数ＴＳＩｃ及其与各参数的关系，通过对这些湖泊的ＴＳＩｃ与ＴＳＩｍ值比较，指出ＴＳＩｃ比ＴＳＩｍ更适合于描述生物量与营养盐呈线性响应的我国这类湖泊的营养状态，此外还提出用相关加权法综合不同参数的营养状态指数，并用一个“综合”状态式来表示湖泊的营养状态。     

基于弱HSDI与强HSDI的区域可持续性评价——以中国环渤海地区为例

可持续性评价是可持续性科学研究的重要内容。在HDI和HSDI的基础上,构建对环境重视程度不同的弱HSDI与强HSDI评价指数,以中国环渤海地区为例,揭示区域2000-2015年可持续性基本状态与变化过程。结果表明：从基本状态来看,环渤海地区各市可持续性水平等级结构失衡,弱HSDI与强HSDI水平均呈两头小、中间大的纺锤形等级结构,但弱HSDI的等级结构失衡比强HSDI更严重,且弱、强HSDI空间格局差异较大;从变化过程来看,环渤海地区各市可持续发展步调不一致,弱HSDI与强HSDI均以显著增长趋势为主,但弱HSDI主要呈中高速增长,强HSDI主要呈中低速增长。结合评价结果,划分可持续性状态与过程矩阵,提出具有针对性的多元化策略,可为促进区域可持续发展提供决策参考。