三峡移民对库区经济的影响研究

三峡库区移民是一项投资大,移民人数多,影响地区广,持续时间长的巨大工程。通过对三峡库区移民几个阶段的投入产出分析,总结出三峡移民对库区经济发展的影响是非常巨大的。三峡移民应该走可持续发展的道路,我们既应该看到其对经济发展的短期影响,也要关注其对库区经济的长期影响,只有在深刻认识了三峡库区移民对经济所产生的影响之后,我们才能够寻找到可持续发展库区经济的有效措施,以做好三峡移民的后续工作。     

真空快速润麦工艺参数的试验研究

通过实验室试验,探索影响真空快速润麦的主要因素,对真空快速润麦工艺参数进行研究分析,为建设工业自动化生产线成套装备的设计提供技术支撑。     

外出从业经历、农地流转行为与农村劳动力转移——基于CHIP2013数据的实证分析

本文基于2013年中国家庭收入调查数据,采用倾向得分匹配(PSM)法和工具变量解决样本选择偏误和内生性问题,实证分析外出从业经历、农地流转行为对农村劳动力转移的影响;同时,运用中介效应模型研究农地流转行为在外出从业经历与农村劳动力转移之间的作用机制.研究结果表明,外出从业经历和农地流转行为对农村劳动力转移有显著的促进作...     

Immigration, In-Migration, Ethnicity and Entrepreneurship in the United Kingdom

This paper develops and tests hypotheses concerning the effect of migrant status and ethnicity on propensity to engage in entrepreneurship (defined as new business activity) at the individual level in the UK. The hypotheses are tested using bivariate analysis (Pearson tests of independence) and multivariate analysis (binary logistic regression). Bivariate analysis suggests that new business activity varies with migrant status and ethnicity. Multivariate analysis suggests that migration increases the odds of engaging in new business activity, that the independent effect of ethnicity is marginal, and that being a recent ethnic minority migrant decreases the odds, after controlling for other individual level factors. At the regional level, a preliminary analysis suggests that gross migration flow has a higher correlation with new business activity than other commonly used regional demographic or economic development measures.      

土石坝筑坝材料基本参数概率统计与相关分析

对９５个已建土石坝工程各种土料指标进行了概率统计分析，其结果可望为土石坝可靠性设计的参数取值提供参考，同时，以重粉质壤土为代表，研究了筑坝材料各指标间的相关性。     

铜街子工程坝基预裂控制爆破

本文介绍了在复杂地质条件下,通过反复试验、采用预裂爆破技术在玄武岩坝基进行各种坡面角度的全方位、大面积的生产性实践,并对预裂控制爆破提出了一些意见和具体施工方法.     

Vertical distribution of fauna in the bed sediment of three running water sites: Influence of physical and trophic factors

Relationships between invertebrates, substrate characteristics and trophic factors were investigated, with special emphasis on the hyporheic habitat, in order to characterize the functioning of different running waters ecosystems. Three contrasting study sites were chosen in catchments exhibiting different features: (1) a meandering reach of the Loire River in its alluvial floodplain, upstream of the ‘Bec d'Allier’; (2) a reach of the Galaure with a fairly developed riparian corridor, a small sinuous foothill river; and (3) a braided reach of the Drac, an alpine torrential stream. Each site was sampled once using the freezing-core technique with previous electro-positioning of the invertebrates. In each site, four 60 cm cores were extracted, each one from different morphodynamic units. In the Loire and Galaure rivers, most invertebrates are found in the first 15 cm of the sediment, with the exception of some particular taxa or morphodynamic units (riffle head). Conversely, in the Drac lotic units, maximum density of invertebrates occurs between 15 and 30 cm and more than 75 per cent of all organisms are found at a depth > 15 cm. The vertical distribution of organisms does not follow a uniform pattern in different streams. In the substrate, the vertical distribution of macroinvertebrates is very closely related to porosity in contrast with trophic parameters that always decrease with depth. The porosity is negatively correlated with the percentage of sand in the sediment and seems to be important in determining the vertical distribution of fauna, and should be integrated in a functional typology of running waters. The trophic parameters and the structure of invertebrate community with its dominant feeding groups allow discrimination of the different sites.     

广西暴雨统计参数稳定性分析

以广西设站较早、资料年限较长的 84个雨量站为例 ,对年最大 3d ,2 4h ,6h ,6 0min ,10min共 5种历时暴雨 ,通过对不同统计年限的暴雨频率统计参数分别进行分析比较 ,从而确定了各种历时的统计参数趋于稳定所需要的资料统计年限     

两岔河混凝土面板堆石坝碾压试验成果分析

混凝土面板砂卵石坝在我省为首次采用，为确定坝体填筑的各种参数，进行了现场碾压试验。碾压过程中，测定碾压层的填料级配、干密度、孔隙率、沉降量及渗透系数等参数。通过对取得参数的分析，确定选用的各种碾压参数。