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71.
以生态竞争力指标体系为研究对象,根据生态竞争力内涵、结构体系以及城市生态竞争力的特点,借鉴国内外相关研究成果,遵循生态竞争力指标体系构建的原则,创建城市生态竞争力指标体系。根据城市生态竞争力指标体系从环境、资源、经济、社会4个方面,对合肥市生态竞争力各项指标进行探讨。 相似文献
72.
A study was conducted to determine apparent digestibility coefficients for dry matter (ADMD), crude protein (ACPD) and gross energy (AED) of selected ingredients in diets for juvenile Penaeus setiferus . Ingredients tested were corn grain, cottonseed meal, crab meal, grain sorghum, meat and bone meal, menhaden fish meal, rice bran, rice grain, shrimp meal, soybean meal, squid liver powder, wheat flour, wheat gluten, wheat middlings and wheat shorts. ADMD coefficients of test ingredients ranged from 22% to 100% and appeared to be related to the fibre, ash and starch content of the ingredient. ACPD coefficients ranged from 58% to 100%. Plant protein supplements (soybean meal and cottonseed meal) were utilized as efficiently as, or better than, animal protein supplements (squid liver powder, menhaden fish meal, meat and bone meal, shrimp meal and crab meal). ACPD coefficients for meat and bone meal, shrimp meal and crab meal (58–59%) were significantly lower than those for menhaden fish meal (76%) and squid liver powder (82%). AED coefficients (44–100%) varied significantly among plant products of similar proximate composition. Corn grain and wheat flour were better utilized by P. setiferus than other high-starch energy supplements. Wheat gluten exhibited the highest ADMD, ACPD and AED coefficients of all ingredients tested. 相似文献
73.
The view that biodiversity-rich areas partially or largely managed by local residents, sometimes referred to as community-conserved areas (CCAs), can be effective in biological conservation has gained considerable ground over the past decade. In this paper, we review available scientific information on the conservation effectiveness of such areas globally. We compiled studies undertaken during the last 5 years (2004-2009) that use quantifiable ecological attributes to: (1) compare CCAs with strictly protected areas (SPAs); (2) compare CCAs with open-access ecosystems and (3) study trends in biological attributes of CCAs over time. We found that there were few consistent differences in diversity/species richness of flora or fauna protected under the two types of management or in deforestation rates. However, CCAs tend to harbour a species complement distinct from that of SPAs and show lowered abundances of monitored taxa that are of conservation importance. CCAs conserve biological values more effectively than open-access areas. Also, biological values tend to decline in CCAs over time. We conclude that CCAs could represent a significant improvement over open-access areas in terms of conservation effectiveness, yet fall short of the needs of comprehensive biological conservation. While extremely few studies have been undertaken in India, the trends seen largely concur with global ones. This review, based on a limited sample size, is only a beginning, and is expected to serve as an invitation for further research to address both the question of biological effectiveness of diverse forest governance regimes as well as the socio-economic, demographic and institutional reasons underlying these differences. 相似文献
74.
为了寻找一种能被广泛应用的马铃薯病毒鉴定技术 ,研究了指示植物的种类及其培育方法和利用指示植物鉴定病毒的方法。,结果表明 :指示植物可以广泛地应用于马铃薯的病毒鉴定中 相似文献
75.
植物病毒检测技术研究进展 总被引:2,自引:0,他引:2
介绍了常用植物病毒的检测方法,包括生物学检测法、电镜技术、血清学方法和分子生物学方法中一些较常用的病毒检测方法,同时对各种方法的优缺点进行了比较。 相似文献
76.
Summary A comparison is made between oribatid fauna (Acari, Oribatida) in the urban regions of West Berlin and forest areas. There are characteristic species compositions living in urban soils, in epilithic moss cushions or on the bark of trees. The urban environment obviously causes a change in the species pattern in these types of habitats and minimizes the number of species in central urban regions. The most important regional factors are probably relative aridity, air pollution and habitat isolation, showing a similar increasing tendency from sub-urban to central regions of West Berlin. The effects of air pollution (SO2) on moss-inhabiting oribatid mites are analysed in 13 sites of the urban district of West Berlin. The use of moss- and bark-dwelling mites as bioindicators of air pollution is discussed.Soil oribatids might be useful bioindicators of soil pollution in further research.Dedicated to the late Prof. Dr. M.S. Ghilarov 相似文献
77.
78.
番茄果实采后贮藏过程中的颜色动力学模型及其应用 总被引:14,自引:2,他引:14
研究了番茄采后成熟过程中果皮颜色的变化规律,发现色泽角(H°)、色泽比(a/b)和明度等主要颜色参数的变化均符合一级动力学模型,并由实验确定了各颜色模型的动力学参数:参考变化速率常数(Kref)和反应活化能(Eα)。在此基础上,设计了一个色泽角-时温预测器,能够预测和监控果实采后贮藏的品质变化。 相似文献
79.
80.
应用Merck RQflex 2型反射仪和硝酸根试纸条研究了氮肥施用数量和施用方式对宁夏银川平原复种大白菜产量和品质的影响,并探讨了大白菜硝酸盐与氮肥用量的相关性和速测指标。结果表明,大白菜的产量随施肥量的增加而增加,表现出线性——平台关系;施氮肥提高了大白菜产量和净菜率;关键需肥期进行追肥比传统的基肥加追肥具有显著的增产效果,且收获时体内硝酸盐水平降低;大白菜外叶叶柄硝酸盐含量随施氮量增加而显著增加,但随生育期延长而下降。复种大白菜最佳经济施氮量为572 kg/hm2,叶柄硝酸盐适宜含量为3 485.28 mg/kg。 相似文献