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911.
转型时期江苏省区域经济差异的分析与检验 总被引:6,自引:0,他引:6
王启仿 《中国人口.资源与环境》2004,14(3):75-79
区域经济差异一直是理论研究的热点问题,但不同的研究者对区域经济差异的研究时常会得出不同的结论,这往往是由于没有区分经济指标中的生计指标与产出指标所引起的。本文以不变价格实证分析了改革开放以来,江苏省13个行政区域间人均生计指标与产出指标的差异和相对差异的变迁趋势,并对“地区差异变动之悖论”进行了实证检验。 相似文献
912.
论自然资源的合理开发与环境管理 总被引:2,自引:0,他引:2
肖笃宁 《中国人口.资源与环境》1993,13(3):11-14
本文论述了自然资源开发建设项目的分类,区域资源综合开发的指导原则,自然资源开发与环境影响评价以及生态监测等内容,建议资源主管部门、开发建设单位与环保部门,齐抓共管寓保护于开发之中,使二者协调进行。 相似文献
913.
Zekai Sen Abüsselam Altunkaynak 《Journal of the American Water Resources Association》2004,40(5):1189-1196
ABSTRACT: Almost all of the existing solutions of aquifer test analysis assume constant discharge rate boundary conditions. In many actual pumping tests, constant discharge cannot be maintained. This paper presents a general solution for an aquifer test with variable discharge. The exact solution of drawdown distribution around an infinitesimally small diameter well in a uniform, horizontal, extensive, homogeneous, and isotropic confined aquifer is presented when the discharge changes with time during the aquifer test period. A general equation for the type curves resulting from any discharge variability is given, and its application for the exponential changes is presented in detail. A simple straight line procedure is proposed for field applications by considering late time drawdown data. The consideration of constant discharge leads to overestimation of transmissivity but storativity is underestimated. Practical application of the discharge variability is illustrated by a field example. 相似文献
914.
915.
浅论区域开发环境影响评价的指标体系 总被引:3,自引:0,他引:3
论述了区域开发环境影响评价应建立能反映环境可持续性和跨边界性的指标体系,提出了建立该指标体系的原则与方法。 相似文献
916.
本文运用区域规划的基本原则,分析了当前区域规划工作的状况和特点,指出了规划工作和宏观调控的现实意义,并提出了加强规划工作的建议. 相似文献
917.
ABSTRACT: A generalized skew map for Louisiana streams was developed using data from Louisiana, Mississippi, Arkansas, and Texas with 20 or more years of annual flood records. A comparison between the newly developed Louisiana Generalized Skew Map (LGSM) and the generalized skew map recommended by the U.S. Water Resources Council (WRCGSM) was performed. The mean square error for the LGSM was 16 percent less than that of WRCGSM in direct application of the two maps. Performance of the new map was compared with the WRCGSM and with a regional analysis procedure through its application to the Log Pearson Type 3 (LP3) distribution. Two-thirds of the stations tested had lower standardized root mean square deviations (SRMSD) by a narrow margin using the skew coefficients obtained from LGSM instead of WRCGSM. The regional analysis also performed as well as the LGSM in terms of SRMSD. Thus, it was concluded that both LGSM and the regional analysis provide a more reliable tool for flood frequency analysis for Louisiana streams with short annual flood records. 相似文献
918.
M. Zemamou A. Toumi K. Mrigua Y. Lahlou M. Aggour 《International Journal of Green Energy》2020,17(11):652-665
ABSTRACT Advanced wind turbine designs and technologies have been evolved to take advantage of wind energy. Despite the significant progress already attained, the need for a dependable wind energy converter particularly devoted to small-scale applications remains a challenging issue. Due to its design simplicity, Savonius wind turbine is the most suitable candidate for such applications. It operates at low wind speed, with the necessary starting capacity and insensitivity to wind directions. Moreover, in the literature related to wind energy, the Savonius rotor is known for its low performance compared to other types of wind turbines. In this paper, we present a study into the utilization of Bézier curves and transient computational fluid dynamics (CFD) to optimize the conventional Savonius blade design. The k-ω SST turbulence model is employed to perform a series of CFD simulations in order to assess the power coefficient of each generated design. A validation of optimization results using the Taguchi method was carried out. The comparative analysis of the torque and power coefficients shows a significant increase in the power coefficient (Cp). The optimal Cp is 0.35 and is 29% higher than the conventional Savoniu wind turbine (SWT). Subsequently, the effectiveness of the innovative geometry is proved by improved pressure and velocity distributions around blades of novel design. 相似文献
919.
William Whipple 《Journal of the American Water Resources Association》1978,14(6):1449-1456
ABSTRACT: A few years ago, many water quality administrators were convinced that large regional sewerage systems, consisting of one large treatment plant and long trunk sewers extending out to various communities, represented the only efficient and economical means of assuring water quality control. In communities favoring rapid development, the provision of sewer service and encouragement of development of new centers along the trunk sewers offered an additional advantage. More recently quite different points of view are arising in certain areas. In parts of New Jersey strong environmental and community resistance has arisen to proposed central plant-trunk sewer systems. The facilitation of new development along the trunk sewers is viewed as a menace by townships not wanting intensive development of these areas. The diversion of effluent flows to trunk sewers rather than septic tanks would dry up the streams which water quality programs are supposed to protect. Both sides to the controversy have mobilized engineering, environmental, economic, and legal expertise and some critical policy issues have developed. Reconsideration of regional sewerage management and particularly trunk sewer policy is required. The decision as to extent of sewerage service areas involves complex and sensitive planning issues. Because of potential conflicts of interest, such decisions should not be left to staffs of sewerage authorities and their design engineers. 相似文献
920.
Robert B. McKusick Richard M. Adams J. Herbert Snyder 《Journal of the American Water Resources Association》1977,13(3):489-498
ABSTRACT: This paper evolved from a concern that water resource administrators and planners do not have a consistent definition of the value of goods and services of outputs from projects and programs. A more flexible approach to planning and evaluation is presented that recognizes the interaction of production and consumption through the use of commodity demand curves. Use of the concept of consumer surplus permits measurement of the differential impacts on producers' and consumers' welfare. Quadratic programming is suggested as a consistent means of quantifying these differential impacts. 相似文献