Innovations and productivity: the shift during the 2008 crisis

This paper investigates how the recent crisis of 2008 changed relations between innovation and firm performance in Western Europe. We apply a structural framework of CDM modelling, which incorporates different stages of the knowledge creation process and takes into account the complex nature of innovations. The study is based on a balanced panel data of 420 listed manufacturing firms from the U.K., Germany and France. All the information is gathered from common sources, thereby reducing subjectivity, a typical problem in the field. We found, the crisis resulted in appreciable changes in the model. The most important evidence is enhancement of the role of firm resources in the post-recession period. We also reveal larger barriers for innovations, increased uncertainty and lower state dependence in R&D engagement, product creation and economic performance. These results could indicate the ‘cleaning effect’ of the crisis, which has worsened the business environment and enhanced competition.     

CDM-系列开窗导流式催化精馏模块在C4/C5醚化等反应中的工业应用

CDM-系列开窗导流式催化精馏模块具有优异的"催化反应"和"组分分离"双重功能,综合性能优于催化蒸馏组件CDP,是其升级换代产品。可应用于甲基叔丁基醚、轻汽油醚化、异丁烯叠合和叔丁醇脱水等工艺中,主要介绍CDM-系列开窗导流式催化精馏模块产品特点及在工业装置中的应用情况。     

预应力新技术在翠林大桥中的应用

翠林大桥为福建省厦漳高速公路上的重要桥梁，同时跨越翠林河和漳龙公路。桥型为五孔连续预应力混凝土箱梁桥，桥梁全长为２３５．４０ｍ，桥面全宽为２６．０ｍ，按汽车－超２０级、挂车－１２０荷载标准设计。本文着重介绍翠林大桥设计中国内首次应用的全断面同步张拉施工法、新型ＣＤＭ大吨位镦头锚体系，以及大直径（φ２２００ｍｍ）预应力混凝土空心管桩基础等新技术。     

金属板材中裂纹尖端区的损伤分析

从连续介质损伤力学的基本理论出发 ,研究了金属试件中裂纹尖端损伤区的发展和区内损伤的演变 .基于改进的Dugdale模型和已有的材料损伤率 ,计算了损伤区内的损伤分布和拉伸应力 ,讨论了损伤在整体材料破坏过程的作用 .结果表明 ,材料细观对宏观裂纹的起裂和扩展有很大的影响     

中国电力行业CDM潜力分析

构建了一种能够评估我国清洁发展机制(clean development mechanism,CDM)项目潜力的分析评价模型,该模型由两个主要模型"能源环境系统的综合评价模型"和"CDM项目潜力最优分析模型"组成。以此模型为基础,分析评价了我国电力行业CDM的实施潜力。结果表明,我国电力行业未来CDM项目的潜力巨大,且对节能的效果也非常显著。     

An adaptive ant colony optimization algorithm for constructing cognitive diagnosis tests

A critical issue in the applications of cognitive diagnosis models (CDMs) is how to construct a feasible test that achieves the optimal statistical performance for a given purpose. As it is hard to mathematically formulate the statistical performance of a CDM test based on the items used, exact algorithms are inapplicable to the problem. Existing test construction heuristics, however, suffer from either limited applicability or slow convergence. In order to efficiently approximate the optimal CDM test for different construction purposes, this paper proposes a novel test construction method based on ant colony optimization (ACO-TC). This method guides the test construction procedure with pheromone that represents previous construction experience and heuristic information that combines different item discrimination indices. Each test constructed is evaluated through simulation to ensure convergence towards the actual optimum. To further improve the search efficiency, an adaptation strategy is developed, which adjusts the design of heuristic information automatically according to the problem instance and the search stage. The effectiveness and efficiency of the proposed method is validated through a series of experiments with different conditions. Results show that compared with traditional test construction methods of CDMs, the proposed ACO-TC method can find a test with better statistical performance at a faster speed.     

CDM prediction of creep failure modes in thin and thick section Cr‐Mo‐V Butt‐welded pipes under combined internal pressure and end loads at temperatures in the range 540–620 °C

The paper examines the dependence of creep failure modes of butt‐welded pipes upon: temperatures in the range 540–620 °C; the ratio of axial to pressure loadings (loading condition); and, load levels which result in failure times in the region 2000–250 000 h. Continuum damage mechanics (CDM) analyses have been used to analyse two extreme geometries: thin section pipes (4.52 mm) and thick section steam pipes (46 mm) of the type found in power generation plant. The thick pipes have been selected to allow through‐thickness constraint to be developed. Two predominant modes of failure have been predicted: Fusion Boundary failure and Type IV failure. For the thin section pipes the modes of failure are not strongly dependent on applied loading levels, and loading condition, but are dependent on temperature: at 540 °C failure is in the Fusion Boundary and at 620 °C it is in the Type IV region. Failure mode in the thick pipes is dependent on temperature, and applied loading levels, but is essentially independent of loading condition. At 540 and 565 °C failure is in the Fusion Boundary; whereas at 575 °C, failure is in the Type IV region at higher applied stress levels, and in the Fusion Boundary at lower applied stress levels.     

基于模糊分析的CDM项目风险评估模拟研究

气候问题是国际关心的全球性问题。中国作为发展中的温室气体排放大国,高度重视气候问题,积极落实京都议定书的机制,采取了一系列相关政策和措施来应对气候问题,为全球的温室气体减排做出了巨大贡献。CDM项目开发更是得到国内许多企业的关注,但是人们在看到CDM项目丰厚利益的同时,也应该多关注其存在的风险。本文通过5部分对CDM项目风险进行研究,介绍了CDM的定义、基本程序、模糊聚类分析及三角模糊数层次分析方法理论,结合专家对CDM项目风险分析进行了模拟研究分类,比较出风险的重要程度。本文在CDM项目风险量化方面做了新的尝试,从而对CDM项目风险达到了一个系统的认识与了解。     

On the prediction of fatigue crack initiation in rolling/sliding contacts with provision for loading sequence effect

The principles of continuum damage mechanics are applied to predict the rolling/sliding contact fatigue crack initiation. The approach involves evaluating the subsurface stresses as well as the state of damage within the contact region. It is shown that the fatigue crack initiation life can be related to the scalar damage parameter D, which is a measure of micro-crack and voids density in the material. Comparison of the predicted results with the available experimental work shows good agreement. The effect of variable loading on the fatigue behavior of rolling contact with provision for non-linear damage evolution is also investigated.     

T/P91钢在高应力条件下蠕变行为的CDM模型模拟

通过对超临界火电机组用T/P91耐热钢的蠕变数据分析,探讨了T/P91钢在600℃下不同应力范围内的蠕变机制以及服役过程中的蠕变损伤.并使用基于材料物理本质建立的CDM(continuum damage mechanics)模型来模拟高应力范围内T/P91钢的蠕变曲线,将模拟结果与文献中的实验数据进行对比,表明模拟结果是可信的.