爆破震动作用下新浇基础混凝土的安全震动速度研究

针对新浇筑混凝土的爆破震动控制,设法利用爆破地震波(Rayleigh波)作用下的新浇筑基础混凝土受力状态的理论分析和动力有限元计算,确定的新浇筑混凝土中的震动速度及动拉应变分布,并结合不同龄期下新浇筑混凝土的允许极限拉应变,从理论上确定新浇筑基础混凝土的安全震动速度及主要影响因素.理论分析结果和计算实例表明,新浇筑基础混凝土的允许震动速度值随基岩对新浇筑混凝土的基础约束程度的提高和随混凝土强度的降低而降低,我国现行采用的新浇筑大体积混凝土基础面上的质点安全震动速度值具有较大的安全储备.     

胶性材料在混凝土坝裂缝处理中的应用

介绍了观音阁坝被埋水下6年越冬停浇面水平裂缝采用“粘贴T1密封胶及表面粘三元乙丙后锚固”的处理方案。结果表明,利用胶性材料处理运行中的重力坝迎水面裂缝,技术可靠,方法简单,经济合理。     

牛头山水电站混凝土双曲拱坝设计和水库提前蓄水研究

牛头山水电站大坝为抛物线形混凝土双曲拱坝,最大坝高108.0 m,采用坝顶5孔开敞式溢洪道泄洪,挑流消能。为提前发挥水电站效益,在拱坝尚未完全封拱的情况下,通过计算分析,得出了水库可以下闸蓄水的结论。     

Changes in food provision in Russian households experiencing perestroika

The purpose of this article is to describe how households in Novgorod the Great, Russia, deal with food provision in everyday life. The study focuses on changes experienced in food provision and consumption in Russian society, in order to illustrate how households respond to the transformation towards a market economy. The study reflects women's perspective on food provision. Students from Novgorod the Great visited 105 households and asked the women in the household to answer a questionnaire. Results from the study show that in order to cope with changes in society related to economic reforms, Russian households had changed both their food consumption and food production patterns. There was no big difference between urban and rural households. Nearly all of the households were self‐sufficient in the provision of vegetables and potatoes. Many households had a ‘dacha’ (plot), where they produced most of what they needed. Among the changes experienced during recent years (i.e. during the end of the 1990s), a decade after perestroika was initiated, households mentioned the rise in food prices and the decrease of income. Households reported that they consumed less fruit and/or meat. Some households also mentioned that the quality of nourishment had decreased, thereby indicating lower general quality, lower nutrition value, or less healthy foodstuffs.     

The Impact of Institutional Differences on Derivatives Usage: a Comparative Study of US and Dutch Firms

This paper examines the influence of institutional differences on corporate risk management practices in the USA and the Netherlands. We compare results to surveys in each country using a strategy that corrects for differences over industry and size classes across the Dutch and US samples. We document several differences in the firms’ uses and attitudes towards derivatives and attempt to attribute them to the differences in the institutional environments between the USA and the Netherlands. We find that institutional differences appear to have an important impact on risk management practices and derivatives use across US and Dutch firms.     

Derivative activities and the risk of international banks: A market index and VaR approach

The results of a comparison of international banks using a three-factor multi-index model and a modified value-at-risk (VaR) analysis indicate that the use of options increases the interest rate beta for all banks, while both interest rate and currency swaps generally reduce risk. The results are the strongest and the most consistent for U.S. dealer banks, followed by European banks, and then Japanese banks. Furthermore, the evidence suggests that the VaR approach to risk management can effectively be used by both domestic as well as international banks, although the results appear to be somewhat sensitive to the regulatory environment in which the bank operates.     

高坝通航技术在水口工程的新发展

水口水电站坝高101m,航运过坝采用一线三级船闸和一线垂直升船机。水口升船机是当时国内已建和在建同类升船机中总体规模最大的升船机,也是我国第一座自行设计、制造、施工和安装的大型升船机。在塔楼结构动力分析和试验研究、塔楼滑框倒模施工、升船机整体模型试验研究、承船厢整体制造和浮运、船厢安全锁定装置和船厢对接密封装置试验研究、整机安装及联调试验等方面充分体现了水口升船机的建成是高坝通航技术的新发展。     

事业单位固定资产管理必须加强

加强事业单位资产管理，管好用好国有资产，保证资产的安全、完整，对促进事业单位发展意义重大。为此，必须从建立资产管理机构、建立全面预算控制制度，完善基础管理工作等入手，强化事业单位固定资产管理。     

Sources, uses, and forms of data in the new product development process

This paper presents qualitative and exploratory research investigating the role that managing knowledge and information plays in new product development (NPD). A set of 20 in-depth interviews uncovered eight basic types of information used throughout the NPD process and three general approaches to managing information needed in the NPD process. Although some exemplary companies seem to do an outstanding job of collecting and disseminating information, the majority of firms struggle. NPD process automation solutions tackle part of the problem, ignoring nonquantitative data forms and the full picture of information use throughout the entire development process.