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91.
92.
目前物种的相对多度与种间关系的内部联系如何影响物种共存仍不清楚。为探讨植物群落物种间关系强度的多度不对称性及其对载畜率的响应,本研究以内蒙古短花针茅(Stipa breviflora)荒漠草原植物群落为对象,分析了对照、轻度、中度及重度放牧下群落物种的多度及其频率。结果表明:随载畜率的增大,物种数呈现出降低的趋势。不同载畜率下同分布指数CO均存在明显的多度依赖性;常见种(如短花针茅、无芒隐子草(Cleistogenes songorica)及刺穗藜(Chenopodum aristatum))对其他物种的作用强度普遍较强。不同载畜率下短花针茅对无芒隐子草及刺穗藜的作用强度均高于其二者对短花针茅的强度,表现出种间强度的不对称性。此外,放牧使得短花针茅对无芒隐子草的作用强度呈现出增大的趋势,使得无芒隐子草对短花针茅的作用强度呈现出降低的趋势。因此,物种间存在多度的不对称性,而放牧进一步造成其物种间作用强度的变化。 相似文献
93.
铁皮石斛在人工光型密闭式植物工厂的适宜光照强度 总被引:4,自引:0,他引:4
人工光型密闭式植物工厂适于高附加值植物尤其是珍贵药用植物的大规模/低成本化生产,其环境调控对珍贵药用植物的产量和质量有重要影响。笔者研究探索在控制温度、湿度、CO2浓度和光周期的条件下,光照强度对铁皮石斛(Dendrobium officinale)组培苗生长发育的影响,以期找到铁皮石斛组培阶段在人工光可控环境下的适宜光照环境。鲜重约300mg的铁皮石斛单腋芽作为外植体在温度24±1℃、湿度65±5%、光周期12h/d、及光期CO2浓度800±50μmol/mol的环境条件下,设置光照强度为37、68、92、120μmol/(m2·s)的4组试验区,并使用容积为380mL的方型聚碳酸酯组培容器在人工光型密闭式植物工厂中培育92d。组培容器的顶部留2个直径为10mm的圆孔覆盖高分子透气膜用来与容器外进行气体交换。铁皮石斛组培苗的生长发育和生理活性在光照强度为68μmol/(m2·s)时最佳,超过92μmol/(m2·s)时呈现明显的光抑制;多糖含量随着光照强度的增强而增加,超过92μmol/(m2·s)时呈下降趋势,但是68和92μmol/(m2·s)光照强度试验区的多糖含量没有显著性差异。因此,铁皮石斛组培苗在人工光型密闭式植物工厂内培育的适宜光照强度为60 ̄70μmol/(m2·s)。 相似文献
94.
95.
Discussion of the Application and Foreground of Falling Water Aeration with the Process of Sewage Treatment 下载免费PDF全文
The engineering design of sewage treatment plant for the Chongqing city, P. R. China is analyzed in this paper. Considering the situation of China and other projects, the characteristics of falling water reactor for the environment protection project and economy of investment is introduced ; the application and foreground of falling water aeration in the process of sewage treatment is discussed, such as Oxidation - ditch, SBR, and so on. The conclusion indicated that the falling water aeration can be designed and used as an independent aeration, and, it is an upgraded technology of sewage treatment which is adaptive for city water environment control in middle and small towns in China. The falling water aeration may reduce running cost of the sewage treatment plant, is adaptive for foothill and the mountainous areas, and reduces project investment and environments damage. 相似文献
96.
Under the background of the new rural construction in China, it is an important scientific question and an urgent social task to construct the harmonious society and to achieve the sustainable regional development on how to construct concentrative residence and manage the human habitat environment in the fast industrializing and typically urbanizing area. This paper analyzed the problems in the construction of the human habitat envi- ronment in the rural area of southern Jiangsu, discussed the methodologies of planning and design for rural con- centrative residence, researched the human habitat environment improvement technologies, and put forward the resolution of the recycling community for the rural inhabitation, which aimed at demonstrating the practicing in rapidly urbanizing regions. 相似文献
97.
98.
In this paper the inevitable trend of constructing open ecosystem in modern settlement environment was discussed through the history of the settlement environment and the characters of modern settlement environment.The ecological crisis,change of the modern life and the citizens' needs and the ecological system character show,that it is important for sustainable development of the settlement environment to construct open ecosystem.The construction of modern habitation and the city room embodies the concept of open ecosystem.Then,in construction and research of modern settlement,the ecological viewpoint and method should be applied. 相似文献
99.
TAN Wen-an 《保鲜与加工》2004,(12):73-77
By analyzing the process of enterprise information engineering construction and intra relationship among information system requirement, business process modeling, application system constructing and project management, one of 4 meta model composed of requirement engineering, process engineering, application system engineering and support engineering is proposed for enterprise information engineering. The developments and applications of the business processes and its application systems are integrated into the same development space and application space. Basing on this, a prototype system composed of requirement modeling environment, business process modeling environment, application system modeling environment, and support engineering environment has been designed and built, which is used for supporting enterprise information engineering constructing. It is valued for the enterprise information engineering construction in our country. 相似文献
100.
The thesis introduces the origin of demonstrate item on the city water environment quality improvement-tao-hua river water environment competitive administer, analyzes the current situation and cause of taohua river valley pollute and ecological destroy, and summarizes the gain and loss in projects which have taken place in the domestic city water environment competitive administer. On the base, a collectivity idea is put forward that it should stress recovering and rebuilding ecosystem on the item. Due to the water environment in taohua river is representative, if the item can be favorably carried out, it not only improves GuiLin water environment, makes people life advantage and expands city tour, but also produces important affects to the other domestic cities in the condition of using marketable economy means to improve city water environment quality. 相似文献