圆筒仓滑模带钢桁架梁预就位施工技术应用

结合实际工程情况介绍滑模带钢桁架梁预就位施工新技术,由于筒仓直径大,高度高,钢桁架梁重量大,安装场地狭小,给安装钢桁架梁带来很多困难,通过筒仓滑模提升系统将仓顶的钢桁架梁带至需要安装的高度并进行安装就位,安全可靠,就位精确,缩短了施工工期,又降低施工费用。     

一类线性切换系统的鲁棒跟踪控制

文章研究了线性切换系统的鲁棒跟踪控制,并提出可解性的充分条件。设计切换控制规则使得切换线性系统满足加权H∞参考模型,并采用平均驻留时间法和Lyapunov函数来处理稳定性分析和控制器设计。通过使用线性矩阵不等式,控制器设计问题可以得到很好的解决。     

保护气预热装置的改进设计

在汽车工业减重、节能的大趋势下,对汽车板材处理的要求也相应提高。镀锌退火炉中板温均匀性是影响汽车板镀锌层的一大因素,为了进一步控制板温均匀性,减少退火时炉温的波动,设计并改进保护气预热装置,以达到提高汽车板镀锌质量的目的。     

向心训练与离心训练对大鼠腓肠肌H反射的影响

目的:探讨不同运动方式对大鼠神经肌肉系统H反射的影响.方法:选择72只SD大鼠随机分为向心组、离心组和对照组,3组各24只,其中向心组在4°的动物跑台上进行向心训练,离心组在-14°的动物跑台上进行离心训练,对照组不参加训练,训练8周后对大鼠右侧腓肠肌进行肌电图测试,采集H反射的主要指标.结果:离心组的Mmax波值显著高于对照组和向心组;离心组的Hmax波值显著高于对照组.3组之间的Hmax/Mmax值并不存在显著性差异;离心组Mmax波和Hmax波出现的时间要显著迟于向心组.结论:不同运动方式对大鼠H反射产生不同程度的影响,特别是离心训练后大鼠神经肌肉适应性得到改善.     

我国体育人文社会学科领域学者学术影响力分析

学术影响力的评价指标是研究成果学术水平的重要标度。本研究从中国期刊网(CNKI)、中国社会科学引文索引(CSSCI)和《复印报刊资料.体育》这三种国内主流数据库中采集数据,对发文量、被引量、H指数、转载量、高频次被引论文和高频次被引论著等评价指标进行分析,研究体育人文社会学科领域学者学术影响力,并以文献计量学方法加以论证。研究结果揭示了我国体育人文社会学科的研究热点和方向,基本反映出学者学术影响力的分布状况,可为该学科的发展提供良好的信息资源支撑。     

不确定时滞相关广义系统的H_∞鲁棒控制

针对不确定时滞相关广义系统的H∞鲁棒控制问题进行研究,目的是设计线性无记忆状态反馈控制器,使得对闭环系统所有的允许的不确定性正则、无脉冲、稳定且具有满意的H∞性能.将时滞相关广义系统的新有界实引理以严格的不等式线性矩阵方法给出,这些都是通过引入新的Lyapunov-Krasovskii泛函,使用詹森不等式得出的.其次,在新的有界实引理的基础上给出了(不确定)时滞相关广义系统的(鲁棒)控制器存在的充分条件.所得出的结果都以严格的线性矩阵不等式形式表示并且都是时滞相关的,未涉及系统矩阵的分解.最后,通过数值算例说明了该方法具有较小的保守性和有效性.     

What hampers innovation? Revealed barriers versus deterring barriers

Innovating firms are likely to face several challenges and experience different types of barriers. In this paper we argue that it is necessary to distinguish between two kinds of barriers to innovation. The first corresponds to what we describe as revealed barriers and reflects the degree of difficulty of the innovation process and the learning experience consequent on the firm engaging in innovation activity. The second type of impediment, which we label deterring barriers, encompasses the obstacles that prevent firms from committing to innovation. We use data from the 4th UK Community Innovation Survey (CIS4) to investigate the relationship between firms’ engagement in innovation and their assessment of the barriers to innovation. We show that the relationship is curvilinear in the case of costs and market barriers. These results have important implications for innovation policy and innovation management.     

Knowledge spillovers and firm performance in the high-technology industrial cluster

This paper attempts to empirically investigate the mechanisms underlying growth in Hsinchu high-tech clusters. We emphasize knowledge spillovers as one of the potential factors contributing to agglomeration benefits. This paper sheds light on the impact of external and internal spillovers on firm performance in Hsinchu high-tech clusters. The empirical results provide supporting evidence that the external R&D spillover is statistically significant in explaining net sales of firms in Hsinchu high-tech clusters.     

Do R&D subsidies affect SMEs’ access to external financing?

Many countries spend sizeable sums of public money on R&D grants to alleviate debt and equity gaps for small firms’ innovation projects. In making such awards, knowledgeable government officials may certify firms to private financiers. Using a unique Belgian dataset of 1107 approved requests and a control group of denied requests for a specific type of R&D grant, we examine the impact of subsidies on small firms’ access to external equity, short term and long term debt financing. We find that obtaining an R&D subsidy provides a positive signal about SME quality and results in better access to long-term debt.     

The temporal trajectories of innovative search: Insights from public hospital services

This article explores the temporal trajectories of innovative search. Drawing on conceptual ideas from the behavioural theory of the firm, it proposes that the level of temporal persistence in organisations’ innovative search activities is affected by four key factors. These include (i) the mode of innovative search as well as organisations’ (ii) strategic aspirations, (iii) slack resources and (iv) performance feedback. This conceptual model is tested in the context of public hospital services in England. Results from dynamic panel data analyses reveal stronger temporal persistence in science- than in practice-based innovative search activities. Findings also suggest that specialist hospitals relying on a continuous stream of new products, services and processes to meet their strategic aspirations are better positioned to sustain science-based innovative search activities than their generalist counterparts. Similarly, results uncover a positive association between the availability of financial slack and hospitals’ ability to continuously engage in superior levels of science-based innovative search. Contrary to theoretical expectations, however, positive performance feedback does not appear to have any persistence-enhancing effect.