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211.
动物园中褐马鸡生理生化指标的研究 总被引:3,自引:0,他引:3
褐马鸡(Crosoptilonmantchuricun)是我国一类保护动物,世界濒危物种.建立自然保护区和动物园饲养是保护濒危动物的有效措施.因此,了解在不同生态环境中褐马鸡生理生化指标的变化对它的饲养、繁殖和疾病防治及其保护都具有一定的实际意义.迄... 相似文献
212.
水资源社会可再生性及其基本理论 总被引:4,自引:0,他引:4
水资源具有自然和社会可再生性。本文从水资源可再生的特性出发,提出水资源社会可再生性的涵义及其在水资源可再生系统中的地位,系统地分析了水资源社会可再生实现过程、其衡量指标及影响因素。基于我国水资源短缺形势,本文认为水资源社会再生利用是城市水资源有效利用的重要途径,是解决或缓解我国水资源短缺的重要手段,并给出提高水资源可再生性的建议。 相似文献
213.
Effect of Climatic Changes on Radial Increment and Age Structure Formation in High-Mountain Larch Forests of the Kuznetsk Ala Tau 总被引:1,自引:0,他引:1
The relationship between growth indices and renewal rates of the Siberian larch (Larix sibiricaLedeb.) stands that have grown at the timberline in the Kuznetsk Ala Tau mountains during the past 350 years was analyzed. The age generations of larch were formed in the 1640s, 1660s, 1680s, 1700s, 1720s, 1740s, 1760s–1770s, 1800s–1810s, 1850s, 1870s–1880s, 1900s, 1920s, and 1930s–1940s. It was shown that the formation of these age generations coincided with 10- to 30-year periods of increased growth of larch and improved temperature conditions in summer. 相似文献
214.
Asish Roy 《International Journal of Green Energy》2018,15(2):80-95
Wind is one of the fastest growing renewable energy resources in the electric power system. Availability of wind energy is volatile in nature due to the stochastic behavior of wind speed and non-linear variation of the wind power curve of wind turbine generator. Because of this impression and uncertainty, the availability estimation of wind power has become a challenging issue. In this paper, Markov Fuzzy Reward technique has been proposed for finding out the reliability of wind farm by assessing the availability of wind power. According to this technique, availability of the wind power has been estimated considering wind farm and demand both as a multi-state system. In addition to the availability, different reliability indices such as the number of absolute failures, mean time to deficiency, and probability of failures of a wind farm have been assessed in a time horizon, which can provide useful information for the power system planner at wind farm installing stage. A comparison of this study reveals the efficacy of the proposed Markov Fuzzy Reward approach over the conventional Markov Reward approach. 相似文献
215.
Scott T. Larned David B. Arscott Jochen Schmidt Jan C. Diettrich 《Journal of the American Water Resources Association》2010,46(3):541-553
Larned, Scott T., David B. Arscott, Jochen Schmidt, and Jan C. Diettrich, 2010. A Framework for Analyzing Longitudinal and Temporal Variation in River Flow and Developing Flow-Ecology Relationships. Journal of the American Water Resources Association (JAWRA) 46(3):541-553. DOI: 10.1111/j.1752-1688.2010.00433.x Abstract: We propose a framework for analyzing longitudinal flow variation and exploring its ecological consequences in four steps: (1) generating longitudinally continuous flow estimates; (2) computing indices that describe site-specific and longitudinal flow variation, including intermittence; (3) quantifying and visualizing longitudinal dynamics; (4) developing quantitative relationships between hydrological indices and ecological variables (flow-ecology relationships). We give examples of each step, using data from a New Zealand river and an empirical longitudinal flow model, ELFMOD. ELFMOD uses spot-gauging data and flow or proxy variable time series to estimate flow magnitude and state (flowing or dry) at user-defined intervals along river sections. Analyses of flow-ecology relationships for the New Zealand river indicated that fish and benthic and hyporheic invertebrate communities responded strongly to variation in mean annual flow permanence, flow duration, dry duration, drying frequency, inter-flood duration, and distances to flowing reaches. To put longitudinal flow variation into a broader context and guide future research, we propose a conceptual model that combines elements of two contrasting perspectives: rivers as longitudinal continua, and rivers as patch mosaics. In this conceptual model, hydrologically complex rivers are composed of linear sequences of nested hydrological gradients, which are bordered by hydrogeomorphic discontinuities, and which collectively generate hydrological dynamics at river-section scales. 相似文献
216.
217.
Faisal I. Khan Paul R. Amyotte 《Journal of Loss Prevention in the Process Industries》2005,18(4-6):310-326
This paper presents details of an integrated inherent safety index (I2SI). The conceptual framework of this index was presented at the 37th Annual Loss Prevention Symposium of the AIChE (2003) and published in Process Safety Progress (volume 23(2), 136–148, 2004). In addition to the framework, the current paper discusses additional features of the index such as the cost model and system design model, which were not presented or discussed earlier. I2SI is called an integrated index because the procedure considers the life cycle of the process with economic evaluation and hazard potential identification for each option. I2SI is comprised of sub-indices which account for hazard potential, inherent safety potential, and add-on control requirements. In addition to evaluating these respective characteristics, there are also indices that measure the economic potential of the option. To demonstrate the applicability and efficacy of I2SI, an application of the index to three acrylic acid production options is also discussed in the paper. 相似文献
218.
New emergy indices for sustainable development 总被引:4,自引:0,他引:4
The emergy indices for the evaluation of system‘ s sustainable development ability were studied. Results indicated that the emergy indices are simplified and merged, and a new emergy index for sustainable development(EISD) is deduced. Employing EISD, two cases areconducted. The first one is to compare three different dike-pond agro-ecological engineering modes, which are: melon-melon-cabbage-four domestic fishes (mode I ), melon-melon-cabbage-pig-four domestic fishes (mode H ) and melon-melon-cabbage-pig-four domestic fishes combined with Siniperca chuatsi B. ( mode Ⅲ ).The result is that the EISD of mode I is 0.53. Mode Ⅱ‘ s EISD is 5.26 times of mode I ,and mode Ⅲ‘s EISD is 6.83 times of mode I The second one is to evaluate the development of Zhongshan City, Pearl Delta, during 1996 to 2000.The result indicated that the EISD of Zhongshan had appreciably declined from 1996 to 1998, and quickly improved from 1998 to 2000, partly because of its environment protection and product construction. Both of the two cases studies showed that EISD can assessment the sustainable development ability more roundly, with the consideration of environmental impact and social-economic effect at the same time. 相似文献
219.
220.
Giuseppe Arbia Daniel A. Griffith Robert P. Haining 《Environmental and Ecological Statistics》2003,10(3):375-396
The collection of accurate and timely information on land use, crops, forest and vegetation are increasingly based on remote sensing spectral measurements produced by satellites. The most recent spacecrafts like the Earth Observing 1 (EO-1) produce a rich source of information being endowed with hyperspectral sensors that can provide up to 200 or more channels. In many instances such a multivariate signal has to be reduced to just one single value per pixel representing a particular characteristic of land. Linear combinations of bands are the general form of many indices. Since each individual image used to construct indices contains errors, when combined they produce a propagation of errors, a process that can distort a final output map. In this paper we measure the extent of error propagation when building linear vegetation indices. We consider three types of indices: the difference vegetation index (DVI), selected Kauth-Thomas indices (SBI, GVI and WET), and principal components, using benchmarking examples taken from the remote sensing literature. The main implication emerging from these examples is that the SBI and the first principal component are the indices more prone to error propagation. The formalization presented here allows a user to derive measures of error propagation in cases where technical characteristics of a sensor and physical characteristics of a landscape are known. These results can help a user to choose between alternative vegetation indices, and to associate a measure of reliability with such indices. 相似文献