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11.
董力 《水利经济》2018,36(1):5-7
分析了深化供给侧结构性改革背景下,推动质量变革、效率变革、动力变革对水利发展的新要求;从切实做好水利与国民经济的关系研究、积极开展水资源水生态的经济问题研究、着力加强水利行业政府和市场的关系研究等方面,探讨了新形势下水利经济研究的重点领域;明确提出加快推进水利经济研究特色智库建设,应整合优势资源、搭建宏观引领研究平台,坚持水利经济主线、积极培育特色品牌,以需求为导向、全面提升服务质量,深化学会改革、持续推进能力建设。  相似文献   
12.
Objective: This study was to determine if calcium fortification yields a higher price per serving in grocery store products. Researchers compared store brand to national brand grocery products in relation to cost in order to examine if calcium values were similar between store brand and national brand products. Methods: A total of 112 store brand and 211 national brand grocery products were collected from three low (national chain store), middle and high priced (Virginia and North Carolina regional store) grocery venues. Products were compared using price and calcium percentage per serving. ANOVA was used to determine between store brand and national brand for price per serving and calcium content, and between grocery venues. Results: National brand fortified products had a significantly lower mean price per serving when compared to national brand non-fortified products (p = 0.0002). There was no statistical difference between store brand fortified and non-fortified products (p = 0.9256). Low priced store brand products had the lowest mean price per serving ($0.34 ±0.24). Conclusions: This study found store brand products have similar calcium content as national brand products. Product cost was lower at low priced store compared to middle and high priced stores.  相似文献   
13.
This paper develops Area-wide Leading Inflation CyclE (ALICE) indicators with the aim to provide early signals for turning points in the euro area headline and core inflation cycles. The headline (core) ALICE leads the reference cycle by three (four) months and the lead times extend to five (nine) months based on longer-leading series. Both ALICE indicators signalled turning points in the inflation cycles ex post and also performed well in a simulated real-time exercise. Moreover, in particular the headline ALICE also appeared to be useful for quantitative forecasting of the direction and level of inflation.  相似文献   
14.
[目的]联合遥感和传统抽样方法的空间抽样技术是进行大区域农作物面积监测的有效手段。但传统抽样要求抽样单元间相互独立,并未考虑到区域农作物空间变异性的存在对农作物面积空间抽样效率是否有影响及其影响程度如何,从而限制了农作物面积监测的效率和精度。[方法]文章以吉林省德惠市为研究区,利用变异函数分别对10种抽样单元尺度内玉米和水稻种植面积的空间变异性进行定量评价。选择3种空间抽样方案(简单随机抽样、系统抽样、分层抽样),分别计算不同空间变异程度下的样本容量(n)、抽样相对误差(Re)和总体总值估计量的变异系数(CV(Y︿))作为空间抽样效率的评价指标,定量分析空间变异性对农作物面积空间抽样效率的影响,提出适宜空间变异农作物的空间抽样优化方案。[结果](1)玉米和水稻面积的空间变异性(反映为基台值C0+C)均随着抽样单元尺度的增加逐渐而减小,其中500m×500m和2 500m×2 500m抽样单元尺度下农作物面积的空间自相关程度相对最小。(2)相同抽样比下,农作物面积在3种抽样方法下的相对误差和变异系数均随着空间变异性的减小(抽样单元尺度增加)逐渐增大,其中玉米和水稻在分层抽样条件下的相对误差和变异系数具有相对最小值,分别限制在10%和20%以内,其次为系统抽样(Re<40%,CV(Y︿)<88%)和简单随机抽样(Re<50%,CV(Y︿)<75%)。 在抽样方法被选定的情况下,两种农作物的分层抽样相对误差变化率随着抽样比的增加迅速降低,当抽样比增至5%时,其相对误差和变异系数的变化率基本趋于稳定,继续增加抽样比来提高抽样精度的效果甚微。 在3 500m×3 500m抽样单元尺度内,按5%抽样比确定的样本容量对玉米和水稻面积进行分层抽样时,可达到95%的抽样精度(Re<5%)。 综合农作物在不同抽样单元尺度下的空间变异特征和空间抽样效率,基于2 500m×2 500m的抽样单元尺度和5%抽样比进行分层抽样的空间变异性农作物空间抽样方案是一种高精度、低成本、代表性强的空间抽样方案。[结论]该研究为区域农作物面积抽样调查方法的改善和抽样效率的提高提供技术支持和参考依据。  相似文献   
15.
常阿斌 《价值工程》2021,40(3):111-112
对一县城道路入口处的废置取土场37m高边坡进行治理,并根据取土场现状地貌设计假山、人工瀑布、绿化设计等进行景观提升改造,通过优化绿地空间格局,完善公园的游览系统、服务设施、植物群落等方面,有效改善入城口区域城市风貌,同时也为周边的社区居民提供日常休闲、娱乐、游览和康体活动的公共空间,并充分发挥其作为南部新城区域中心森林氧吧的生态作用,形成稳定的、可持续发展的城市绿色生态系统。  相似文献   
16.
This paper assesses the economic support for the creation of an Economic Community of West African States (ECOWAS) monetary union encompassing all its 15 members, an objective that was set more than 30 years ago. In line with previous empirical research, our conclusion is that the adoption of a common currency by the whole region is not recommended. This work takes a step forward and assesses alternative ways to reduce the current number of currencies in circulation in the Community. Based on our results, we suggest (i) the merging of the currencies of Guinea, Liberia and Sierra Leone into a single currency and (ii) the Gambia to join the West African Economic and Monetary Union (WAEMU).  相似文献   
17.
[目的]识别低山丘陵区高标准基本农田建设的限制性因素。[方法]基于GIS平台,运用AHP-熵权法,以重庆市高标准基本农田建设的6个典型项目区为例,从田块禀赋、设施配套、投入产出水平、社会经济水平及生态环境等5方面选取15项指标,识别低山丘陵区高标准基本农田建设的限制性因素。[结果](1)低山丘陵区高标准基本农田建设限制性因素依次存在中低山缓坡区丘陵宽谷区河谷平坝区的趋势,且不同微地貌条件下的限制性因素存在一定差异。(2)从项目区评价分值来看,河谷平坝区耕地质量分值最高,为高标准基本农田重点建设区域;丘陵宽谷区建设条件与耕地质量较好,是高标准基本农田建设次重点区域;而中低山缓坡区限制性因子较多,高标准基本农田建设适宜性较差。(3)文章研究的AHP-熵权法可以适用于其他地貌类型单元下高标准基本农田建设限制性因素识别研究。[结论]因地制宜,科学合理安排低山丘陵区微地貌类型下的高标准基本农田建设内容与整治任务。  相似文献   
18.
Abstract

The U.S. economy is addicted to the simulative impacts of household borrowing. Household debt has grown dramatically since the 1990s and has served to mitigate the detrimental effects of stagnant household wages. The accumulation of this debt has also had the macroeconomic impact of stimulating the economy, pushing it closer towards full employment. However does full employment stimulated by household indebtedness actually represent economic progress? It is argued that even the poorest citizen in a modern industrialized society is better off than a king of feudal Europe, yet in the United States such material prosperity is often tied to social insecurity thanks to debt. The growth of this debt has been enabled by a financial system that has evolved dramatically over the past forty years. The U.S. financial system’s primary role is no longer to finance investment but is rather a tool that enables a separation of ownership from use. Debt has fueled corporate profits which have enriched the shareholding class while at the same time the system has reduced the financial security of the majority of workers. This article crystalizes these issues by analyzing the differentials in financial circumstances faced by workers and shareholders in several major U.S. firms.  相似文献   
19.
We consider methods for estimating the means of survey variables in domains of a finite population, where sample sizes are too small to obtain reliable direct estimates. We construct generalized compositions from the direct and traditional design-based synthetic estimators and propose the methodology for evaluating their coefficients. This methodology measures similarities among sample elements and estimates of the domain means. We propose the compositions for two cases of auxiliary information: domain-level characteristics are available; true means of auxiliary variables are available for the estimation domains, and unit-level auxiliary vectors are known for the sample elements. In the simulation study, we show where the generalized compositions improve the traditional synthetic and composite estimators.  相似文献   
20.
High‐speed rail (HSR) has led to a transportation revolution in China. This paper uses the county‐level panel data of China’s Yangtze River Delta to investigate the effect of HSR connection on local economy. To address the issue of endogenous HSR route placement, we use a straight‐line strategy to construct potential HSR connection variables as instrumental variables of the actual HSR connection. Both the difference‐in‐differences and instrumental variable methods show that HSR connection impedes local economy, especially in peripheral regions. The impediment effect is channeled through population reallocation from peripheral to core areas and the restructuring of industries.  相似文献   
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