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当前岩溶区隧道地下水涌水预测方法及理论都是当下难以攻克的难题,为了解决该问题,文章提出了复杂岩溶区域内隧道涌水预测方法。以广西郁江调水工程引水隧洞为例,基于我国岩溶地区隧道突(涌)水实例分析,从岩溶蓄水模式角度揭示岩溶区易发生涌水的构造机制,指出当前地质超前预报手段在涌水预报方面存在的问题。就岩溶地区隧道涌水量的预测理论研究现状,系统分析各预测方法的优缺点和适用条件。对不同含水地质构造的岩溶区进行划分,提出相应较合理的隧道涌水量预测方法,并结合工程实例验证其可行性。所得结论可为岩溶隧道涌水的预测研究提供借鉴。 相似文献
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结合沪蓉国道大水井隧道工程实例,根据该工程水文地质特点,文章选用三种不同的地下水动力学方法对隧道涌水量进行了计算分析。计算结果表明:在岩溶区进行涌水量预测,落合敏郎法及铁路规范经验公式计算的涌水量随渗透系数呈指数减少,非均值剖面二维流公式考虑到了岩溶的不均匀性,对计算区域进行了分区,计算的涌水量随渗透系数呈近线性减少。 相似文献
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从2种隧道涌水量计算方法的基本原理出发,讨论了其计算步骤、公式及适用条件。选择合适的计算方法预测涌水量,有助于预警和制定施工对策。以杭长铁路高岭隧道工程为例,采用水均衡法对隧道进行涌水量预测,然后对其涌水量进行评价和提出相应的工程建议,为工程的顺利实施提供了技术支持。 相似文献
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本文综合分析某段岩溶隧道水文地质情况,预测评估隧道涌突水量,有效遏制地质灾害,只有保证隧道安全施工,才能实现岩溶深长隧道的成功通行。研究结果表明:某隧道是比较典型的一种强岩溶隧道。隧道底层属于上白垩系罗镜滩组地表岩溶与石灰质砾岩发育,隧道内分布很多漏斗、洼地以及地下洞,大气降水通过漏斗与落水洞直接渗透至地下;分析岩溶水位、地质构造以及水系统发现,该隧道已经具备岩溶涌水条件,且隧道位于季节变动带和饱水带,所以隧道施工揭露溶洞概率相对较大,尤其是雨水较大时,很容易引发突泥或突水等地质灾害,隧道涌水存在突发性强、压力高以及水量大等特性,很容易引发重大事故;对比实际和预测的突水量、突水时间,预测的涌水量基本符合实际涌水量,说明预测的涌水量具有合理性。 相似文献
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煤矿开采过程中的工作面的涌水量预测是防治水工作的基础,为准确地预测纳林河二号煤矿31121工作面开采过程中的涌水量,通过对矿区水文地质条件的概化研究,结合数值模拟软件Visual Modflow,建立了数值模型预测涌水量,并与传统解析法计算的涌水量以及矿井实测涌水量进行对比分析,结果表明Visual Modflow软件预测涌水量较为接近实际涌水量,方法合理可靠且具有较强的操作性。 相似文献
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Hannes H Gissurarson 《Economic Affairs》1983,4(1):51-53
An Icelandic post-graduate student at Oxford outlines a method of preventing inflation that could be applied in other countries. 相似文献
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本文着重于讲解在高职院校数学教学中常出现的几种开放题,对它们的解法加以研究,归纳其一般思路、解法及其解答技巧,希望能有助于今后高职院校数学教学研究活动,供参考之用。 相似文献
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Michael Poole Glenville Jenkins 《International Journal of Human Resource Management》2013,24(6):841-856
In this paper, developments in human resource management in manufacturing in modern Britain based on a national sample are examined. The organization and role of human resource management, employee involvement, training and development, work practices and rewards are all targeted for an assessment of current practices. This is a prelude for a contrast between manufacturing and non-manufacturing. The conclusion is that the similarities between manufacturing and non-manufacturing substantially outweigh the differences. By inference, too, developments in human resource management practices are likely to reflect changes in the broader environment of businesses (and differences between companies) rather than being specific to the main industrial sectors. 相似文献
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《Spatial Economic Analysis》2013,8(4):441-461
Abstract Data on crop production are assembled for four provinces—Punjab, Sindh, North-West Frontier Province and Balochistan—for the period from 1980/81 to 2005/06 to examine inter-provincial differences in productivity growth rates. Propositions are put forward and examined to explain the superior productivity performance of Punjabi crop producers over those in Sindh and North-West Frontier Province, and the unusual productivity trends in Balochistan. The major factors relate to economic infrastructure and human capital. The impact of agricultural research is difficult to discern, and further work is required to assess the lagged effects of research expenditures on TFP growth. Explication des déséquilibres interprovinciaux dans l'augmentation de la productivité dans la production de cultures au Pakistan RÉSUMÉ On a rassemblé des données pour les quatre provinces suivantes: Penjab, Sindh, Khyber-Pakhtunkhwa, et Baloutchistan, pour la période 1980/81 à 2005/06, afin d'examiner les différences interprovinciales dans les taux d'expansion de la productivité. On présente et on examine des hypothèses pour expliquer le rendement supérieur des producteurs du Penjab par rapport à ceux du Sindh et du Khyber-Pakhtunkhwa, ainsi que les tendances de productivité inhabituelles du Baloutchistan. Les principaux facteurs se rapportent à l'infrastructure économique et au capital humain. L'impact de la recherche sur l'agriculture est difficile à établir, et des travaux supplémentaires seront nécessaires pour évaluer les effets décalés des frais de recherche sur l'expansion du TFP. Explicación de la desigualdad inter-provincial en el crecimiento de la productividad de la producción de cultivos en Pakistán EXTRACTO Se recopilan datos sobre la producción de cultivos de cuatro provincias: Punjab, Sindh, Provincia de la Frontera Norte-Oeste y Balochistan, durante el período de 1980/81 a 2005/06, para examinar las diferencias inter-provinciales en los índices de crecimiento de la productividad. Se plantean y examinan propuestas para explicar el mayor rendimiento de la productividad de los productores de cultivos Punjabi con respecto a los de Sindh y la Provincia de la Frontera Norte-Oeste, y las inusuales tendencias de la productividad de Balochistan. Los factores principales se relacionan con la infraestructura económica y el capital humano. El impacto de la investigación agrícola es difícil de discernir, y se requiere más trabajo para evaluar los efectos retrasados de los gastos de investigación en el crecimiento TFP. 相似文献
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西部外贸中小企业发展的战略选择 总被引:4,自引:0,他引:4
中小企业是西部地区外贸进出口的重要力量。据统计,2005年,西部地区中小企业的进出口额达156.03亿美元,占西部地区进出口总额的34.6%,同比增长37.5%,表现出强劲的发展势头,成为推动西部地区对外贸易发展的一支最具活力的力量。然而,与东部地区同类企业发展相比,由于受区域经济发展水平、思想观念、经营环境以及政策等多种因素的影响和制约,西部外贸中小企业的发展还明显滞后。 相似文献
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去年热播的电视剧《奋斗》有一个场景受到广泛关注,剧中那群青春偶像聚集在一个旧厂房改造成的LOFT里共同生活,这一方式成为众多年轻人向往的目标。而近期北京的LOFT小户型楼盘一经推出就受到热烈追捧,在冷清的楼市里点燃了"一把火"。"没错,我们的开发商就是受到《奋斗》的启示,才开发了这么一款LOFT产品。"美利山西区中心的小户型楼盘"LOFT精妆寓所"置业顾问李先生直言不讳地对记者表示。 相似文献
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Isabella Proeller 《Public Management Review》2013,15(1):7-29
Abstract The article explores which reform trends are expected to play a significant role in the further development of local government in European countries. Analysis is based on an adopted Delphi survey of (mainly academic) local government experts from thirty-two countries. Results include a list of trends structured by the perceived importance for the coming ten years. Redistributing responsibilities and duties across levels of government constitute the highest ratings out of all trends. Furthermore, results do not provide clear evidence to support a shift from public management to governance as has recently been proclaimed in academic debate and literature. Management topics continue to be of great importance. Last but not least, clusters extracted point to different reform groups, which highlight more reluctant or enthusiastic attitudes to the relevance of the suggested trends of the study. 相似文献
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Smith LS 《Hospital materiel management quarterly》1998,20(1):61-69
Materiel managers are faced with a shrinking world and changing work environment. The needs and expectations of the customer have shifted because of the increasing number of multicultural groups. These groups will continue to assert their right to culturally sensitive care. Materiel managers also need to learn to support and enhance the skills of a multicultural work force. One important tool for change will be technology. However, technology that brings the world closer together also creates new challenges for managers, who will have to deal with multicultural colleagues, buyers, sellers, and manufacturers of goods and services. 相似文献
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《Journal of econometrics》1986,31(1):93-118
Panel data based studies in econometrics use the analysis of covariance approach to control for various ‘individual effects’ by estimating coefficients from the ‘within’ dimension of the data. Often, however, the results are unsatisfactory, with ‘too low’ and insignificant coefficients. Errors of measurement in the independent variables whose relative importance gets magnified in the within dimension are then blamed for this outcome.Errors-in-variables models have not been used widely, in part because they seem to require extraneous information to be identified. We show how a variety of errors-in-variables models may be identifiable and estimable in panel data without the use of external instruments and apply it to a relatively simple but not uninteresting case: the estimation of ‘labor demand’ relationships, also known as the ‘short-run increasing returns to scale’ puzzle. 相似文献