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1.
论构建我国资源安全保障的法律体系   总被引:1,自引:0,他引:1  
曾文革  王海志 《生态环境》2006,15(1):190-193
资源安全是国家安全的重要组成部分,建构资源安全保障的法律体系具有十分重要的意义。文章从我国资源安全保障立法的现状出发,指出我国资源安全保障法律体系的指导思想是可持续发展观和科学的资源安全观,我国资源安全法律保障体系的整体框架应当包括保护自然资源系统的法律法规、合理开发战略性资源的法律法规、适度消费与高效利用资源的法律法规、利用国际市场与规避贸易风险的资源安全的法律法规、协调资源供给利用与净化资源安全管理的法律法规,并且我国资源安全保障具体法律制度应当从上述方面加以构建和完善。此外,构建我国资源安全法律保障具体制度还应当制定资源安全预警制度、资源安全押金制度、采取积极的资源安全激励措施等相关配套法律法规,从而保障我国资源安全保障法律的体系的完整与有效实施。  相似文献   

2.
利用岩石类型资料1092个数据,肝癌死亡调查资料1544例,研究了肝癌死亡率与人群生存区的岩石类型(岩浆岩、变质岩、碳酸盐岩、碎屑岩、红色碎屑岩、第四系松散岩)的相关性。在此基础上,综合评价了与肝癌有相关性的岩石类型对肝癌的产生和发展的影响。  相似文献   

3.
This paper investigates the views of citizens of the Province of Larnaka in Cyprus regarding solutions to combat the problem of water shortage in the area in which they live in. The research was carried out in 2008–2009 and used simple random sampling involving 426 individuals. According to the citizens, the most important solutions to the problem of water shortage are, in order of importance, desalination of seawater; less prodigal use of water; reduction of water losses from the transport network; construction of water dams; and reforestation of non-vegetated areas. These were followed by the construction of lake dams on agricultural land; installation of a water recycling system; construction of trenches in surfaces with steep slopes; protection and creation of agricultural evergreen plantations; use of seawater in pools; use of liquid urban waste for irrigation purposes; and construction of water tanks in houses to take advantage of rainwater. Less accepted solutions were deep tillage of arable land along contour lines; construction of terraces; rangeland management; and transporting water in tankers.  相似文献   

4.
The possible causes of diel vertical migrations of planktonic animals   总被引:2,自引:0,他引:2  
Experimental measurements of the sinking velocity of anaesthetized planktonic animals carried out in the first half of this century prove that the downward migration of planktonic populations may be entirely attributed to passive sinking. This conclusion, along with data from voluminous literature devoted to circadian rhythms, supports the supposition that diel vertical migration is the result of an innate alternation of phases of high and low activity. During the phase of low locomotory activity, a passive sinking of an organism of negative buoyancy takes place; during the phase of high activity, the same organism actively climbs to the surface using the well-known mechanisms of space orientation. This hypothesis offers an explanation both of the usual course of diel migration and various deviations from this course, some of which are mentioned here. If the above considerations are correct, and if we admit that one of the trends of the evolution of pelagic organisms is directed towards the reduction of energy expenditure for the maintenance of the body in a suspended state, i.e. towards neutral buoyancy, the conclusion may be drawn that diel vertical migrations are not the result of adaptation to the planktonic mode of life.  相似文献   

5.
80年代以来,由于酸雨的发生及其对农业生产和生态环境的危害,土壤酸化问题再次成为土壤化学研究的热点.铝离子的土壤化学行为是土壤酸化的根本原因,而铝的吸附是给离子的土壤化学行为的重要方面.因此.研究铝的吸附有助于提示土壤酸化的本质,为防治土壤酸化提供有益的信息.本文综述了近30年来铝离子吸附的研究进展.其中包括吸附性铝离子的形态;铝的吸附表面;阴离子对铝吸附的影响;铝吸附的机理;铝的吸附对土壤性质的影响等.  相似文献   

6.
The problems of the asymptotic behavior of age-dependent population models with interior and spatial structures are considered. It is proved that the existence and uniqueness of the stable state and its exact form is founded for general linear models. Problems on the speed of convergence to stable state and transitional effects are investigated. Methods of solving two special classes of nonlinear models (separate models and models of the Gurtin-MacCami type) are suggested. A model of forest stand dynamics on the basis of conception of layer-mosaic characteristics of the spatial-temporal structure of stands is examined as an example of the application of given results.  相似文献   

7.
Adverse effects of diesel oil on microanatomical structure of the alimentary canal of O. nilotica were studied using SEM observations. The study revealed irregular arrangement of the stratified epithelial cells along with fragmentation of the normal concentric pattem of microridges of the same cells in buccopharynx and oesophagus. The excessive secretion of mucus of buccopharynx and oesophagus were the salient changes caused by diesel oil pollution. The destruction and degeneration of the mucosal folds of stomach and intestine along with their epithelial cells exhibited a concrete hyperactivity resulting in abundant' secretion of mucus over the microridges of the epithelial cells. In the intestinal region the columnar epithelial cells showed tumefaction and microvilli of the plasma membrane of epithelial cells get heavily damaged. Disarray of the microridges of epithelial cells, excessive secretions of mucus formation of even cell sheet were the most conspicuous changes in rectum. It was concluded that chronic exposure of diesel oil may hamper the absorption of the nutrients through alimentary canal resulting into ill-growth and production of the fish.  相似文献   

8.
水分亏缺时氮磷营养对春小麦幼苗抗逆性的影响   总被引:8,自引:0,他引:8  
在盆栽条件下研究了水分亏缺时,氮、磷营养对春小麦幼苗渗透物质及相关保护酶活性的影响.结果表明:水分胁迫使春小麦幼苗叶片游离脯氨酸、可溶性糖含量增加,RWC降低,POD、CAT活性增强.随着水分亏缺加剧,氮营养相应地提高了幼苗叶片脯氨酸、可溶性糖含量以及POD、CAT活性;磷营养仅能提高叶片脯氨酸含量以及POD活性,但使其可溶性糖含量以及CAT活性维持在较低水平上.施肥使叶片RWC降低.春小麦的抗逆性指标之间存在相关性,特别是小麦幼苗叶片POD活性与游离脯氨酸累积量之间有极显著正相关关系,其决定系数r^2为0.7472.图1表2参12  相似文献   

9.
In the anomuran Clibanarius olivaceous Henderson, the cuticle of the cephalic and thoracic regions is calcified, while that of the abdominal region is uncalcified. Histochemical observations have been made on the possible enzymes involved in the process of calcification of cuticle. The calcified regions show the presence of enzymes such as phosphorylase, alkaline phosphatase and carbonic anhydrase. The possible role of phosphorylase in calcification may be production of phosphoric esters, which form the required substrate for alkaline phosphatase. The latter appear to be associated with the production of phosphate ions from phosphoric esters. The carbonic anhydrase may be associated with the production of carbonate ions. The suggestion that these enzymes are involved in the process of calcification is further supported by experimental evidence of inhibition of the action of enzymes by enzyme inhibitors. The inhibition of enzymes leads to reduction in the amount of calcium added to the cuticle.This paper formed part of a thesis approved for the award of Ph. D. degree of the University of Madras.  相似文献   

10.
近年来,血吸虫病在我国又有回升的势头,采用植物灭螺进而消灭血吸虫病是控制血吸虫病蔓延的有效方法.实验研究了一种新型灭螺植物——天南星(ArisaemaerubescertsSchott)的灭螺效果和机理.采用天南星植物水浸液用于灭螺(Oncomlaniahupensis)实验,并检测天南星处理后钉螺肝脏生理生化指标的变化.结果显示,天南星全株均具有较强的灭螺效果,其中块茎灭螺效果最好:0.1%块茎水浸液处理3天后钉螺死亡率达88.4%,5天后达100%;天南星不同部位的灭螺效果为:块茎>叶>茎.天南星块茎水浸液处理钉螺后,随处理浓度的增加和处理时间的延长,钉螺肝脏丙二醛(MDA)含量显著升高,而过氧化物酶(POD)和超氧化物歧化酶(SOD)活性显著降低.天南星水浸液可引起钉螺肝细胞的过氧化损伤,导致其抗氧化能力下降,从而降低了其代谢和解毒功能.研究结果表明,天南星是一种具有良好灭螺效果的植物,可成为构建植物群落生态工程灭螺林新的物种资源.  相似文献   

11.
本文在对信宜县山区农业气候资源进行深入研究分析的基础上,根据各种蔬菜的生物学特性,提出了信宜县山区露地种植反季节蔬菜的适宜海拔高度和栽培措施,为广东省山区合理利用垂直气候资源,发展反季节蔬菜生产提供了科学依据。  相似文献   

12.
首先介绍了分子生物学技术在微生物多样性及微生物生态研究中应用的理论基础,以及在此基础上引入的分子生物学技术如:PCR、DNA杂交技术在分子层面上来研究微生物遗传多样性,并结合已有工作积累展望了分子微生物生态研究的发展前景.图2参20  相似文献   

13.
B.M. Dolgonosov 《Ecological modelling》2010,221(13-14):1702-1709
Macroevolution of the biological and human world systems in the aspect of time-dependence of their sizes is studied. These systems are considered as ‘civilizations’, which are defined here in a generalized sense as the systems having memory and producing knowledge (vital information) necessary for survival. Sizes of three types of memory – genetic, neural, and external – are estimated. Dominating one of them leads to the development of an appropriate type of civilization. The rise and development of the genetic memory was accompanied with the formation of the biota (which can be tractable as a biological civilization) and a hyperbolic growth of its biodiversity. The prevailing development of the neural memory in one of the taxa of biota led to the rise of the human civilization and to a hyperbolic growth of its population. The development of the external memory will probably lead to the extraction of a taxon (probably, a pool of countries) from the human world community, with a hyperbolic growth of the taxon's memory and fund of knowledge but without a pronounced growth of its population.  相似文献   

14.
When discussing strategies for realising an environmental friendly agricultural production, there are methods for quantifying environmental effects which do not originate in agricultural contexts. For instance, the methodology of Life Cycle Assessment is mainly developed from analyses of industrial production lines and products. Substance flow analyses in agriculture contain a complete analysis of agriculturally caused substance and energy flows, to which certain environmental effects are assigned, and also an assessment of these effects. For the provision of production means, balancing agricultural production procedures includes the extraction of energy sources and mineral resources from their reservoirs. The growth phase of the crops regarded (cereals, sugar beet, rape) is described depending on the nutrients nitrogen, phophor, potassium and calcium. The nitrogen flux within the system plant-soil-atmosphere is recorded referring to its temporal dynamic. In the framework of this study, selected environmental effects of agricultural production procedures of winter wheat are calculated regarding different conditions of locations and are supplemented by declining scenario simulations. Essential features of the structure of the substance flow net, which is implemented for the calculation and which can be used completely or as for single modules for further studies, are explained. Basing on selected categories of effectiveness, ecological optimisation potentials of varying agricultural provision of production means and procedures are estimated within the whole context of provision. Thereby, the effects of a reduced employment of fertilisers, of a change as for the kind of fertiliser and of the region of origin of the N-fertiliser, as well as variations concerning mechanical work in the fields are outlined for the cultivation of winter wheat.  相似文献   

15.
H. Caspers 《Marine Biology》1984,79(3):229-236
The relationship between the phase of the moon and the emergence of the epitokous segments of the palolo worm Eunice viridis Gray has been known to the natives of the Samoan Islands for centuries. They predict the date and time of day when the emergence occurs so that they can be ready to catch the worms. This phenomenon is one of the best known examples of lunar periodicity. It was first described scientifically at the end of the last century. My own investigations concern the occurrence of the worms in the reef, in which they gnaw long tunnels through the massive blocks of coral limestone at levels characterized by the occurrence of symbiotic algae. Apparently the algae are the main sources of nutrition for the worms. The casting off of the epitokous segments occurs at the third quarter of the moon in October or November. An analysis of known dates on which the swarms of worms have appeared permitted a precise method of prediction to be formulated. The causality of this periodicity is discussed.  相似文献   

16.
初春苦草腐解过程中营养盐释放过程及规律   总被引:4,自引:0,他引:4  
采用室内模拟方法研究初春温度条件下苦草在腐解过程中碳、氮和磷的释放过程,研究沉水植物衰亡过程中营养盐的释放规律.结果表明,在初春温度条件下,苦草迅速腐解,向水体释放大量碳、氮和磷.随着时间的推移,苦草向水体释放的磷大部分沉积进入底泥,而氮则是部分沉积进入底泥,部分以气体形式移出水体.苦草腐烂分解产生的厌氧条件和大量有机碳的供给促进了水体反硝化作用并加快氮素移出水体.较大的生物残留量会引起水体缺氧,同时产生大量营养盐,导致水质严重恶化,因此需要适时收割水生植物来控制水体残留生物量.  相似文献   

17.
长春城市绿地植物群落生态脆弱度分析   总被引:4,自引:0,他引:4  
以北方寒地城市长春市为例,提出城市绿地植物群落生态脆弱度计算方法,对长春城市各类绿地进行了详细的植物群落生态脆弱度分析,分别论述了景观效果、绿地结构、绿地养护及人工干扰与生态脆弱度的关系,指出建立科学合理的复合群落绿地是从根本上降低城市绿地生态脆弱度的唯一出路。  相似文献   

18.
The high speed supernatant fraction of a homogenate of Squalus acanthias L. liver catalyses the oxidation of oleyl alcohol to oleic acid by an NAD-dependent process. Reduction of fatty acid to fatty alcohol could not be demonstrated. Liver lipids of S. acanthias contain about 60 and 40% of triglycerides and diacyl glyceryl ethers, respectively, with only traces of wax esters. Serum lipids contain 28, 15 and 26% of triglycerides, diacyl glyceryl ethers and wax esters, respectively. Cell-free fractions of S. acanthias liver catalyse the formation of wax esters by an ATP1-dependent process. The bulk of wax ester synthesis occurs in the high-speed supernatant fraction of liver. The rate of formation of the ester bond in wax esters is comparable to the rate of synthesis of ester bonds in triglycerides, and greatly exceeds the rate of formation of the ether bond in diacyl glyceryl ethers. Results are discussed in terms of possible factors controlling the levels of neutral lipids in S. acanthias.  相似文献   

19.
We have reviewed the development, background and valuation history of ecosystem services in China and abroad, and highlight the importance of ecosystem services and the necessity of their valuation at various temporal and spatial scales. Through critical review of the literature, we have elucidated disadvantages in studies of ecosystem services in China, including the lack of a definite purpose for the valuation of ecosystem services, improper emphasis of valuation studies, stifled application of the contingent valuation method, weak power of research panels in the field, and the absence of the participation of government officials. In addition, we discuss some case studies from Western countries which tracked changes in the total economic value (TEV) of ecosystem services across different states of ecological disturbance and evaluated changes in the TEV under different management regimes. These studies may be useful in guiding future research in China. In essence, there are three major aspects involved in the valuation of ecosystem services: improving accuracy of valuation, association of results of valuation with policy and management decisions, and transfer of payments for ecosystem services. We suggest three priorities for future research in China: to develop an ecosystem service valuation model, to enhance the relevance of valuation studies to policy development, and to reward the protectors of ecosystem services.  相似文献   

20.
海岸带岩土动力学特征的差异是影响海岸侵蚀过程与方向的重要因素之一。南海北大陆海岸带主要由花岗岩风化边坡组成。通过对该海岸带的北东翼及西南翼典型花岗岩风化壳剖面的黏土矿物及风化指标研究发现,两者存在不均一性:横向上,北东翼黏土矿物主要以高岭石、伊利石为主;西南翼黏土矿物主要以高岭石、伊利石和绿泥石为主,两翼均未见较明显的蒙脱石。相同层位比较,西南翼黏土矿物总量高于北东翼。垂向上,自地表到深部,北东翼黏土矿物组合及总量无明显的分层性,而西南翼则呈明显的分层性且地表含量明显高于深部。海岸带的风化作用也存在明显的不均一性:表现为横向上,北东翼海岸带风化程度要稍弱于西南翼;垂向上,北东翼化学风化指标n(Al2O3)/n(SiO2),n(Fe2O3+Al2O3)/n(SiO2),n(TiO2)/n(Al2O3)、CIA在风化壳中呈无规律变化,而西南翼则呈明显的分层性,这种分层基本与表土层、红土层及砂土层成一定的对应关系。从化学可蚀性指标来看,由南海北大陆海岸带花岗岩风化壳演化而成的土壤均为强抗蚀性,但相同层位比较,北东翼可蚀性要稍弱于西南翼剖面。研究认为,组成南海北大陆海岸带的花岗岩风化壳之黏土矿物与风化作用的不均一性可很大程度影响海岸带的可蚀性。  相似文献   

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