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1.
湖南生态经济系统的能值分析及其可持续性评估   总被引:1,自引:0,他引:1  
运用能值分析理论和方法,对湖南省1999~2006年的能值投入率、净能值产出率、环境负载率、能值货币比率、能值使用强度、人均能值使用量、电力能值比率、人口承载力、基于能值分析的可持续发展指数、废弃物能值比率等10个指标及其变化趋势进行定量分析,并与其它国家和地区的相关指标进行比较研究.研究结果表明:(1)湖南社会经济水平虽然不断上升,但目前整体上较落后,处于我国各省市的中游水平,湖南发展经济和提高人民生活水平的道路还很长.(2)湖南还属于资源输出型的生态经济区域,需要尽快改变这种状况.(3)湖南资源环境压力较大,应控制耗能产品、环境污染产品出口,努力发展水电,适度抑制人口增长,遵循功率最大化原则,提升生态经济系统的可持续发展能力.  相似文献   

2.
为分析K型偏心支撑框架在低周往复荷载作用下的抗震性能,通过模型试验及仿真试验研究了K型偏心支撑框架的滞回性能、刚度退化现象以及在循环荷载作用下的能量耗散机理.结果表明K型偏心支撑框架在弹性阶段刚度大,在塑性阶段耗能能力强;不同的耗能梁段长度对结构各层的耗能能力有很大的影响,耗能梁段不宜过短也不宜过长;当耗能梁段出现剪切屈服后,刚度出现明显的退化现象,仿真试验验证了试验剪切型梁段的屈服现象.K型偏心支撑框架具有良好的滞回性能和耗能性能,分析结果可供工程设计和相关研究参考.  相似文献   

3.
人地关系对用地效益的影响广泛而深刻,“压力-状态-响应(Pressure-State—Response,PSR)”框架能很好地揭示出土地利用中人地相互作用的链式关系。据此,构建相应的评价指标体系,应用主成分分析的方法,以南京市2002~2006年土地利用数据为研究对象构建矩阵,对南京市近5年土地利用程度进行分析评价。研究结果表明:(1)近5年来,南京市土地利用程度呈不断加强,由最初的低度利用,到中度集约利用再到集约利用;(2)土地利用程度与经济发展水平呈正相关,相关系数达0.922;(3)南京市土地利用程度仍有提升空间。本研究为南京市城市土地资源管理提供理论依据和科学指导,并为发达地区城市土地集约利用评价与动态分析提供借鉴。  相似文献   

4.
基于能值分析方法,对1990~2011年间河南省生态经济系统的能源和自然资源利用状况、投入与产出、环境承栽量和可持续发展指数等进行综合分析与评价。结果表明:1990~2011年河南省生态经济系统总能值输入呈递增趋势,从1990年的1.61×10~(23)sej增至2011年的7.46×10~(23)sej,其中不可更新资源能值投入由1.51×10~(23)sej增至6.91×10~(23)sej,占能值总投入中的比重约94%;人均能值和能值密度分别从1.86×10~(15)sej上升至7.94×10~(15)sej,0.97×10~(23)sej·m~(-2)上升至4.47×10~(12)sej-m~(-2);环境承栽量从14.27上升到66.85,能值投资率从0.004上升到0.08;可持续发展指数呈显著降低趋势,从19.30下降至0.19。从整体上说明河南省生态经济系统正处于不可持续性的消费型发展阶段。  相似文献   

5.
氧化酪蛋白对小鼠组织抗氧化能力及血液肽组成的影响   总被引:1,自引:0,他引:1  
目的研究酪蛋白经过加热氧化和脂质过氧化物MDA氧化后,对小鼠体内氧化还原状态及小鼠血液中肽组成的影响。方法酪蛋白经100℃加热(0、30、60、90min)和丙二醛(MDA)氧化(MDA终浓度0、0.2、20、200mmol/L)处理,测定其羰基、巯基含量及表面疏水性的变化。小鼠分为四组,分别灌胃生理盐水、正常酪蛋白、加热90rain、MDA氧化酪蛋白,测定0、30、60、90、120、160min血液中自由基水平,并采用HPLC-MS分析灌胃后120min小鼠血浆肽组分的变化,测定小鼠的肝脏、空肠、十二指肠组织抗氧化能力指标(总抗氧化能力T—AOC、丙二醛MDA、还原型谷胱甘肽GSH)。结果酪蛋白经过两种氧化处理,羰基含量均随氧化程度呈显著上升,巯基含量呈下降趋势。加热氧化后酪蛋白表面疏水性比正常酪蛋白低,而MDA氧化导致疏水性上升。小鼠血液中自由基最高峰出现在灌胃后160min。灌胃两种方式处理的酪蛋白,血液中自由基的含量均显著高于灌胃正常酪蛋白组(P〈0.05),肝脏、空肠、十二指肠还原型谷胱甘肽(GSH)含量和总抗氧化能力(T-AOC)均低于正常酪蛋白组,丙二醛(MDA)含量显著提高(P〈0.05)。HPLC—MS分析显示,灌胃MDA氧化酪蛋白组血液中肽组成与对照组不同,出现c7H15N4O含羰基类的物质:结论氧化会导致酪蛋白理化性质的改变,摄入氧化酪蛋白引起机体的氧化应激,降低组织抗氧化能力。  相似文献   

6.
以安徽省为例,选取工业废水、废气、固体废物等9项指标,采用主成分分析评价方法对污染综合指数进行评价。借鉴STIRPAT模型,采用偏最小二乘回归方法,对城镇化边际污染效应进行测度,并通过引入城镇化水平二次项,对城镇化与污染综合指数间是否契合库兹涅茨曲线进行探索。结果表明:1安徽省污染指数由2000年的42.95升至2012年的62.27,年均提升3.14%;2城镇化演进对环境污染具有显著的正向效应,其边际弹性系数为0.072732;3城镇化水平与污染综合指数间不存在倒U型EKC曲线关系,而表现为单调递增同向演化规律。基于研究结果,从优化产业结构,依靠科技进步实现转型发展,强化环境管理等方面提出了对策,为管理层制定协调城镇化与生态环境的政策提供参考,并为省域尺度的同类研究提供借鉴。  相似文献   

7.
吉林省白城市2002~2007年洪水资源利用实践为研究背景和实例,基于熵值权向量和多目标多级模糊优选理论,构建了洪水资源利用综合效益评价的多层次半结构性指标体系及动态连续评价模型.以2002年为对比基准年,采用了2种权重进行综合评价,分析评价结果可知洪水资源利用量和其产生的效益、综合评价值和对比增量之间存在着密切的正相关关系.在连续评价的6年中,2003年综合效益最优,其产生的效益评价增量为82.8%,最差的为2004年,其增量为18.2%.不仅对每年洪水资源利用效益进行了综合评价和等级确定,而且对6年进行了连续评价和前后增量对比,实现了评价的延续性和准确性.分析认为,洪水资源利用的经济、生态环境效益突出,社会效益也十分显著,加大利用量可以提高综合效益,并会对该区域的可持续发展起到积极的推动作用,同时动态连续评价的实现为进一步开发利用洪水资源提供了坚实的理论基础和技术支撑.  相似文献   

8.
根据区域经济学及产业经济学的理论,分析了湖南省有色金属产业的发展现状,建立了有色金属产业竞争力评价指标体系,运用主成分分析法将湖南与中部五省进行评价和比较。结论是湖南省有色金属产业竞争力属于中等偏上水平,总的经济效益偏低。提出了有效提升湖南省有色金属产业竞争力的政策建议.  相似文献   

9.
遴选经济、社会和生态三方面评价指标构建城市土地利用综合效益评价体系,运用功效系数法分层计量宁波市2002~2013年土地利用效益,并与其他五个同类城市对比。结果表明:12002~2013年宁波市城市土地利用综合效益呈逐年递增趋势,但与同类城市相比仍较低,土地利用水平有较大提升潜力;2城市土地利用综合效益与城市发展程度、产业结构及布局有一定关系,宁波第三产业有待进一步挖潜;3宁波土地利用综合效益的变化与经济、社会、生态的发展变化呈现不同步性。  相似文献   

10.
目的 研究表皮生长因子受体(epidermal growth factor receptor,EGFR)在不同转移潜能乳腺癌细胞中的表达,并探讨其在乳腺癌侵袭转移过程中的作用. 方法 利用人工基质膜侵袭实验获得高、低转移潜能乳腺癌细胞亚系,四甲基偶氮唑盐(MTT)法检测两系细胞生长曲线和倍增时间,流式细胞仪检测两系细胞周期,transwell侵袭小室模型比较两系的迁移能力.应用逆转录聚合酶链反应(RT-PCR)和免疫印迹(Western Blot)检测EGFR在两系细胞中的表达. 结果 利用transwell小室成功筛选出高、低转移潜能乳腺癌细胞亚系;它们的体外生长速度、倍增时间、细胞周期和侵袭力具有明显差异;RT-PCR和Western Blot均显示在高转移潜能乳腺癌细胞中EGFR在基因和蛋白水平的表达均显著高于低转移乳腺癌细胞. 结论 EGFR的过表达与乳腺癌细胞侵袭能力显著性相关,EGFR在乳腺癌侵袭过程中发挥了重要的作用.  相似文献   

11.
This paper puts forward the hypothesis that the distinctive features of quantum statistics are exclusively determined by the nature of the properties it describes. In particular, all statistically relevant properties of identical quantum particles in many-particle systems are conjectured to be irreducible, ‘inherent’ properties only belonging to the whole system. This allows one to explain quantum statistics without endorsing the ‘Received View’ that particles are non-individuals, or postulating that quantum systems obey peculiar probability distributions, or assuming that there are primitive restrictions on the range of states accessible to such systems. With this, the need for an unambiguously metaphysical explanation of certain physical facts is acknowledged and satisfied.  相似文献   

12.
Summary It was found that some ciliates,Stentor, Spirostomum andBlepharisma, which can contract rapidly like the stalks of Vorticellidae, have Ca2+-binding proteins that are very similar to spasmins, in the immunological sense. The presence of spasmins in other Protozoa and in some Metazoa was also investigated.  相似文献   

13.
A part of the gene coding for a halophilic serine protease from a halophilic archaeumHaloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus:Halobacterium, Haloarcula, Haloferax, andHalococcus.  相似文献   

14.
Summary Recent data on the immunologication of regulatory peptides and related propeptide sequences in endocrine cells and tumours of the gastrointestinal tract pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory beenrevised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptidesare the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, -MSH and CLIP (corticotropoin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenalin-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.  相似文献   

15.
Cognition wars     
In what kinds of physical systems can cognition be realized? There are currently competing answers among scientists and theorists of cognition. There are many plant scientists who maintain that cognition can be realized in plants. There are biological scientists who maintain that cognition is materially realized in bacteria. In this paper, I will present the basis for such claims and evaluate them and discuss the future for theories of the metaphysical basis of cognition in the cognitive sciences.  相似文献   

16.
Summary In vitro and in vivo data on the benzimidazoline compound indicate anthelmintic potential when introduced directly into the abomasum.  相似文献   

17.
Summary Monarch butterflies sequester cardenolides from their larval host plants in the milkweed genusAsclepias for use in defense against predation. Of 108Asclepias species in North America, monarchs are known to feed as larvae on 27. Research on 11 of these has shown that monarchs sequester cardenolides most effectively, to an asymptote of approximately 350 g/0.1 g dry butterfly, from plants with intermediate cardenolide contents rather than from those with very high or very low cardenolide contents. SinceAsclepias host plant species are distributed widely in space and time across the continent, monarchs exploit them by migration between breeding and overwintering areas. After overwintering in central Mexico, spring migrants east of the Rocky Mountains exploit three predominantAsclepias species in the southern USA that have moderately high cardenolide contents. Monarchs sequester cardenolides very effectively from these species. First generation butterflies are thus well protected against predators and continue the migration north. Across the northern USA and southern Canada most summer breeding occurs on a fourthAsclepias species and in autumn most of these monarchs migrate back to Mexican overwintering sites. The ecological implications of this cycle of cardenolide sequestration for the evolution of monarch migration are discussed.  相似文献   

18.
It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.  相似文献   

19.
The fate of environmental pollutants — the various isotopes of elements, and inorganic or organic compounds — is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them.  相似文献   

20.
What is the relationship between observations, predictions, texts, and instruments in ancient astrology? By distinguishing between two distinct kinds of observation claim in astrological texts, I show on the one hand the rhetorical and theoretical importance of each kind of observation claim to ancient astrological traditions, and on the other hand how practices of ancient astrology break from observation once astronomical phenomena become reliably predictable. We thus see a shift in practice from observationally derived predictions to a reliance on textual and instrumental authority, even though the rhetoric of ancient astrology still tries to maintain an emphasis on observation.  相似文献   

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