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1.
生态城市特征性指标的辨析及其应用   总被引:1,自引:0,他引:1  
生态城市是依据生态学原理提出的一类社会、经济、自然协调发展的城市.基于生态城市内涵建立的城市特征性指标对城市特征性要素的量化和评价,是将生态城市个性这一主观观念变为可操作性目标的主要途径.基于城市复合生态系统理论和生态城市"健康、安全和发展"内涵,探讨了生态城市特征性指标的辨析方法.以厦门为例构建了厦门生态城市特征性指标体系.评价结果揭示了厦门城市特有的生态环境和资源的总体状态为亚健康状态(0.69)、比较脆弱的中警状态(0.39)和一般持续的发展状态(0.63).与现实的分析调研结果相符.这表明生态城市特征性指标有助于研究者辨识和评价城市生态系统的特定复合特征,更有针对性地明确城市生态规划和建设的重点行动领域,从而为城市实施可持续发展战略提供决策依据.  相似文献   
2.
基于数字图像处理技术的金相分析研究   总被引:2,自引:0,他引:2  
姜蓬  蒋勇  邱榕  廖光煊 《火灾科学》2009,18(3):163-167
采用和改进了人际交互式图像分割算法Live-wire,对电气火灾中的典型火烧金相图和一次短路金相图进行处理,结合数字形态学操作,精确提取了两类金相图中的典型胞状晶和柱状晶结构;分析和讨论了多种结构描述子对晶格分类的作用,结果表明,离心率和晶格标记方差两个描述子能有效区分两类晶格结构;采用聚类分析和Fisher判别法,实现了对两类金相图的自动分类.  相似文献   
3.
This paper aims to reveal the heat transfer mechanism of low-temperature phase change material (PCM) and design PCM heat storage device in building heating environment. Firstly, low-temperature binary PCMs of lauric acid and stearic acid are prepared, and their thermal properties are investigated by DSC. Then, shell and tube latent heat thermal energy storage units are conducted, and heat transfer experiments are carried out to analyze the heat transfer mechanism of PCM. The results demonstrate that natural convection plays an important role in heat transfer process, and the heat storage efficiency of PCMs can be significantly enhanced by increasing the fin width and improving the inlet heat transfer fluid (HTF) temperature. Furthermore, some proposals are put forward to guide the design of PCM storage device in building heating environment.  相似文献   
4.
将活性污泥培养及驯化后接种于生物滴滤塔中,挂膜启动后处理模拟氯苯废气(简称氯苯废气),考察了生物滴滤塔在挂膜启动阶段及稳定运行阶段的性能。实验结果表明:接种41 d后生物滴滤塔成功挂膜,此时氯苯去除率稳定在90%以上;生物滴滤塔稳定运行阶段,随着进气中氯苯质量浓度由303.82 mg/m3逐渐增至1 489.05 mg/m3,氯苯去除率从85.1%降至70.1%。处理氯苯废气适宜的工艺条件为:空塔停留时间超过45 s,喷淋液流量31.8 mL/min,氯苯负荷23.97~128.01 g/(m3·h)。生物滴滤塔对喷淋液的酸性环境有较好的适应性,喷淋液pH的变化对氯苯去除率无显著影响。  相似文献   
5.
Abstract

Male corn earworm moths, Helicoverpa zea (Boddie), were captured in conical Texas pheromone traps (cone traps) and bucket traps baited with four different commercial lures manufactured by three different manufacturers. Because significant numbers were captured in bucket traps baited with some of the lures, and none with others, the volatile emissions from all of the lures were sampled and analyzed by gas Chromatographic methods. The numbers of males captured in two types of trap were compared with bait emissions in an endeavor to define a more effective lure for bucket traps. The lure from one manufacturer captured the same numbers of males in both trap types; one captured more in bucket traps than in cone traps, and another captured only a small number in bucket traps. The emission rate of all active compounds from each of the different lures was approximately linear for the duration of the assays. A gas‐liquid Chromatographic peak associated with a third compound, (Z)‐9‐tetradecenal, which reduces behavioral responses, was observed in the emissions from all lures evaluated. The effectiveness of the Hercon (Emmigsville, PA) lure in capturing males in both types of trap was associated with a lower emission of (Z)‐l 1‐hexadecenal, (Z)‐9‐hexadecenal and (Z)‐9‐tetradecenal than from the other lures.  相似文献   
6.
To optimally allocate resources between workers, reproductive females, and males, ant workers have to be able to identify the sex of larvae and raise them differently. The ability of workers to discriminate between the sexes in the brood was tested in colonies of queenless ponerine ants, Diacamma sp., from Japan. The ratio of male eggs in the egg pile was increased experimentally. This manipulation resulted in a corresponding increase in the ratio of adult males, suggesting that Diacamma workers do not raise the sexes differently. Received: 4 November 1997 / Accepted after revision: 14 March 1998  相似文献   
7.
丁蕾  蒋惠亮 《环境工程》2012,(Z2):289-292
为了研究废砂浆中碳化硅粉和硅粉的分离情况,选用混合模型对柱型水力旋流器多相流流场进行数值模拟。模拟结果表明:柱型水力旋流器的分离效率与入口速度、进口浓度等因素有关,并分析出一定条件下当主、次相的入口速度均为1.1m/s时颗粒分离效果较好,分离效率较高,实验检测分离性能较好,为进一步实验研究提供一定的指导。  相似文献   
8.
The prevalence of diversity training has not been matched by empirical research on its effectiveness. Among the most notable gaps are an absence of attention to its impact on discrimination and limited consideration of organizational‐level factors. Results from employee surveys across 395 healthcare organizations reveal an effect of the extent of diversity training in organizations on ethnic minorities' experiences of discrimination. In addition, the results demonstrate that the consequences of ethnic discrimination for individuals' job attitudes are influenced by organizational‐level phenomenon. These findings highlight the importance of attending to ethnic discrimination as an outcome of diversity training with implications for employee attitudes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
9.
Despite women's advancements in the workplace, gender inequality persists. We classify and test two frameworks used to explain gender differences in career success: unequal attributes and unequal effects. The unequal attributes framework suggests that gender is related to other attributes, which result in unequal career outcomes for men and women (i.e., a mediated effect). The unequal effects framework suggests that even when men and women share the same attribute or circumstances, they are rewarded differently, such that individual attributes have unequal effects on career outcomes for men and women (i.e., a moderated effect). We collected survey data from a gender‐balanced sample of 394 business school alumni. Using structural equation modeling to test the unequal attributes framework, we found that work hours, career orientation, having a nonemployed spouse, and working in a predominantly female job were unequal attributes that explained gender differences in career success. Using multigroup path analysis to examine unequal effects, we found that being agentic, married, having children at home, and working in a predominantly female workplace had unequal effects in relation to career success for men and women. We find support for both models across three categories of career success antecedents (i.e., personal, family, and job attributes).  相似文献   
10.
Reproductive isolation and speciation can result from female choice for particular males. Isolation can also result, however, from male mating preferences or from aggressive encounters which then influence mating decisions. In this study, we use laboratory discrimination trials to study the behavioral mechanisms of population discrimination in sagebrush lizards (Sceloporus graciosus). We specifically ask three questions about population-level discrimination: (1) Does it vary in strength in relation to the geographic distance between the populations? (2) Is it more apparent in inter- or intra-sexual interactions? (3) Does it take the form of attraction or avoidance? We ran 890 trials that tested the ability of male and female sagebrush lizards from one population to discriminate their own population from four other populations. In addition, we utilized both sequential and simultaneous-choice designs, which enabled us to distinguish between attraction and avoidance. We found that most population-level discrimination was exhibited by male lizards preferring to associate with particular types of females, as well as female avoidance of particular types of males. The strength and direction of both discriminations depended on the populations compared and on whether the tests were conducted as sequential- or simultaneous-choice tests, producing a complex relationship between geographic distance and behavioral discrimination. Our results suggest that there are roles for male attraction and female avoidance in population discrimination, reproductive isolation, and speciation.  相似文献   
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