南水北调东线工程泵站自动化系统设计与应用

本文简述了东线工程在整个南水北调工程建设中的重要作用和意义,介绍了南水北调东线工程泵站自动化系统的设计原则、系统组成、系统结构和系统功能,以及在金湖站的成功应用,系统具有技术先进、运行稳定可靠、使用灵活方便、便于维护等技术特点,并在此基础上,对泵站自动化系统的未来发展趋势做了展望。     

世界先进水平大型纸厂将在江苏建成──介绍金东纸业(江苏)有限公司2台大型纸机

位于江苏镇江大港的金东纸业（江苏）有限公司即将建成２台世界级全化浆铜版纸及印刷纸纸机。２台纸机均由ＶｏｉｔｈＳｕｌｚｅｒ提供;纸幅９７ｍ,车速１５００ｍ／ｍｉｎ。其中１台配以Ｖａｌｍｅｔ新一代Ｏｐｔｉ系列涂布机、超级压光机等完成设备。该文介绍其主要设备的特征、功能和效果。     

Bioaccessibility of provitamin A carotenoids in bananas (Musa spp.) and derived dishes in African countries

Bananas and plantains (Musa spp.) constitute an important component of the diet in Africa. Substantial levels of provitamin A carotenoids (pVACs) in Musa fruit have been reported, but the bioaccessibility of these pVACs remains unknown. In this study, we used an in vitro digestion model to assess the bioaccessibility (i.e. the transfer into micelles) of pVACs from boiled bananas and derived dishes using the Eastern Democratic Republic of Congo as a study context. In particular, the effect of different food ingredients added to boiled bananas on pVAC’s bioaccessibility was studied. The bioaccessibility of all-trans β-carotene ranged from 10% to 32%, depending on the food recipes, and was modified, particularly when pVACs-rich ingredients (palm oil/amaranth) were added. Efficiency of micellarization of all-trans β-carotene was similar to that of all-trans α-carotene and depended on the cultivar (Musilongo, plantain type, 16%; Vulambya, East African cooking type, 28%), while that of the 13-cis isomer was higher (21–33.5%). Taking into account bioaccessibility, the estimated vitamin A activity was significantly different across the different Musa-based dishes tested. Results are discussed in terms of recommendations to help reduce vitamin A deficiency in Musa-dependent African communities.     

华东地区某大坝坝基水质特征及防渗帷幕性状评价

大坝运行后水环境发生剧变,库水中水质特征变化可导致坝基地下侵蚀性的加强,侵蚀大坝及坝基帷幕等结构,使坝基帷幕防渗材料逐渐流失,以致帷幕防渗效果大大降低,从而造成坝基帷幕防渗性能的衰减。因此,需要对运行多年后的大坝防渗帷幕性状评价进行评价。以华东地区某水电站重力坝为例,对坝前、坝体、坝基等点位进行水样采集分析,研究不同点位水样的pH值、水化学成分及胶状析出物等水质特征,详细论证大坝坝基帷幕防渗性状,判定帷幕总体防渗性状完好,局部存在薄弱部位。     

Do African Economies Grow Similarly?

Abstract

This paper examines economic growth in 52 African countries for 1961–2016 and seeks to find if there is common growth. As all African countries have their particular features, concerning climate, harvest, industry, size, politics, and infrastructure, and more, it seems best to rely on a non-parametric method. Dynamic Time Warping is such a convenient method, also as it allows leads and lags across countries to vary over time, and as it can easily be incorporated into a clustering technique. Five clusters are found, two of which concern Equatorial Guinea and Botswana, and the three other clusters have common growth rates of about 0, 2 and 4 over more than five decades.     

The impact of weather fluctuations and climate shocks on farmers’ welfare: insights from rural Ethiopia

ABSTRACT

This paper examines the welfare effect of inter- and intra-seasonal weather shocks using a nationally representative dataset. Results show that both rainfall and maximum temperature variability appear to exert a negative impact on the considered outcomes. Higher between-years average of rainfall implies an increase in income. This impact is nonlinear when the shock is computed over shorter reference periods and is higher in the upper tail of the income distribution. Moreover, small levels of rainfall variability have a positive effect on income, but only up to a certain threshold, after which the effect becomes negative. There is a nonlinear relationship between welfare outcomes and the first two moments of the maximum temperature distribution. Agricultural extension services, access to rural credit and use of sustainable land management practices (SLM) are crucial to mitigating the negative welfare effects.     

基于TPSC技术的短路电流限制器在华东电网中的应用研究

基于TPSC技术的短路电流限制器作为一种新型FACTS设备,不仅能够有效地抑制短路电流,而且具有不改变电网正常情况下的有功、无功和电压分布的优点。对基于TPSC的短路电流限制器在华东电网中的应用进行了全面的研究,探讨了华东电网的短路电流水平、限制器的布点和抑制短路电流效果、限制器安装后系统的暂态稳定性等问题,并进行了限制器基本原理的电磁暂态过程仿真。