排序方式: 共有34条查询结果,搜索用时 93 毫秒
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蓄积于社会经济系统中的钢是社会物质财富的重要组成部分,充分利用蓄积于社会经济系统中的钢能够有效解决一系列资源与环境问题。基于钢的社会流动和蓄积过程,构建钢社会蓄积动态物质流分析模型,考察中国、美国和日本工业化进程中的钢社会蓄积水平及其演变趋势,结果表明中、美、日三国具有相似的钢社会蓄积历程:在完成工业化以前,钢社会蓄积呈现出从缓慢增长到快速增长再到迅速增长的阶段性特征;美、日进入后工业化阶段后,人均钢存量先后达到11t/人左右的饱和水平,经济增长与钢消费趋于解耦。钢的社会蓄积与工业化进程有着内在的联系,不同的工业化程度对应不同的钢社会蓄积水平。根据美、日经验,中国人均钢存量仍会进一步增长,并于后工业化阶段达到饱和。然而,由于中国人口数量大,达到与美、日相当的人均钢存量还需要消耗大量的资源,并会带来环境污染问题。因此,在新时代中国特色社会主义建设中,中国应走新型工业化道路,通过技术创新、供给侧结构性改革以及生活方式转变,努力降低人均钢存量的饱和水平。 相似文献
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对农村连锁超市饱和度进行准确判断,是零售企业向农村市场扩张,实现农村零售网点合理布局的依据。文章运用农村连锁超市饱和指数法,明确了超市零售设施规模对农村超市扩张决策的影响关系;并进一步运用农村连锁超市的凯莉动态相对指标法,确定了农村连锁超市企业市场份额的最高增速点X0和最高市场份额点X1。 相似文献
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The performance of firms depends not just on the structure of the industries in which they compete but also on their relative positioning within those industries, in terms of operating within particular niches. We propose that demand for these niches depends endogenously on the historical ecology of the products offered: Niches become saturated—reduced in their ability to support products—as a large number of previous offerings allows the audience to satisfy its desire for products of a particular type. Analyzing the survival rates of television series aired in the United States from 1946 to 2003, we found that the survival rates of future entrants fell with the extensiveness of recent offerings in the niche, and that the negative association between crowding and survival also weakened with this saturation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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井间示踪剂技术在油田开发中的应用 总被引:6,自引:0,他引:6
介绍了油田开发中几种常用的井间示踪剂技术原理、特点及在油田的应用效果和发展趋势,阐述了井间示踪剂技术的多种用途。通过示踪剂技术可以分析油田的水驱规律,了解断层的封闭状况,验证油水井的连通情况,计算注水井在平面上各个方向的渗流速度以及油井的水淹方向,确定区块的剩余油分布等,对于进一步认识油藏的非均质性、注入水沿裂缝窜流的规律、注水方案调整以及调剖堵剂用量的确定起到了积极的指导作用,为油田的油水井调整、工艺技术措施和综合治理提供了可靠的科学依据。 相似文献
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Extant literature has documented the direct effects of both sound frequency and color saturation on the perceived size of products. However, the cross-modal interaction effect of the two on size perception is yet unknown. Through three studies, this paper proposes that the effect of sound frequency on the perceived size of product is moderated by that product's own color saturation, and this further had downstream effects on consumers’ product preference and purchase when they possess predetermined product usage goals toward bigger/smaller sizes. Study 1 found behavioral evidence that only when the color of the product is in high saturation can the sound frequency significantly influence the perceived size of the product, with low (vs. high) frequency leading to larger (vs. smaller) perceived size. When the product's color is in low saturation, the effect of sound frequency on perceived size disappears. Study 2 adopted the event-related potential technique and found that high (vs. low) saturation elicited higher arousal (mirrored by P300 amplitudes). Sound frequency is first moderated by color saturation and was then mediated by arousal to affect the perceived product size. The above results were also replicated in the field (Study 3). Theoretical and practical implications are discussed. 相似文献
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This paper uses a monetary model of exchange market pressure to examine the impact of monetary policy on the Nepalese exchange rate. Using a recently developed estimation technique, impulse indicator saturation, along with general-to-specific modeling, we find that a contractionary monetary policy results in easing of pressure on the exchange rate. The robustness of the results is confirmed using misspecification tests. 相似文献
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本文对微机型保护装置在冶金企业的相关问题进行总结,结合微机保护在华菱钢铁应用中所表现出的影响安全运行的问题,提出影响微机保护在冶金电网运行的主要因素和解决措施。通过对解决措施的具体分析认为,微机保护在冶金企业应用与在电网应用有其不同的特殊性,保护生产厂与冶金企业应共同探讨提高微机保护的可靠性。 相似文献
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本文针对边底水发育的齐家油田高含水期剩余油分布复杂、直井开发底水锥进较快的实际,加强剩余油分布规律认识,通过油藏数值模拟和计算边底水油藏水驱前缘,搞清了底水锥进和边水舌进状况,提出了水平井挖潜零散剩余油治理对策。 相似文献
10.
Klaus Fiedler 《Environmental and Resource Economics》1997,9(3):309-321
Based on the classical biological Monod model a so called double-limited self-purification model working in an aggregate water
resource is constructed. From this model we derive a stationary selfpurification function and three conditions for ecological
sustainable development. 相似文献