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 共查询到20条相似文献,搜索用时 108 毫秒
1.
陈卫  付必谦 《兽类学报》1994,14(4):312-313
中华姬鼠种群生态的初步分析THEPRELIMINARYANALYSISONTHEPOPULATIONECOLOGYOFCHINESEFIELDMOUSE(APODEMUSDRACO)KeyWordsChineseFieldMouse(Apodemus...  相似文献   

2.
白鹤春迁林甸停歇地的生态研究   总被引:1,自引:0,他引:1  
李方满 《动物学研究》1998,19(1):38-38,52
白鹤春迁林甸停歇地的生态研究ECOLOGICALSTUDYONTHESIBRIANCRANESSPRINGMIGRATIONINLINDIANSTOPOVER关键词白鹤,迁徙KeywordsSibriancranes,Migration中图分类号Q...  相似文献   

3.
一种简单的分离提取水稻叶片中IAA,ABA和GAs的方法   总被引:1,自引:0,他引:1  
一种简单的分离提取水稻叶片中IAA,ABA和GAs的方法赵玉锦,王台,童哲(中国科学院植物研究所,100044)ASIMPLIFIEDMETHODFOREXTRACTIONOFENDOGENOUSIAA,ABAANDGAsFROMRICELEAVE¥...  相似文献   

4.
本文报导国人睾丸、附睾和输精管的NSE,AChE,ChE,ALP,ACP,5'-Nase,G-6-Pase,β-GA,β-GR,AP-M,ATPase和TPPase水解酶的组织化学活性、结果显示:睾丸曲细精管的ALP,5'-Nase和ATPase;睾丸间质细胞的NSE,ALP,ATPase和ACP;睾丸间质中的NSE,ALP和AT-Pasc;睾丸输出小管和附睾管上皮的NSE,ALP,ACP,5’-Nase,β-GA,β-GR,ATPase和Tppase;附睾头部间质中的NSE,AChE,ALP,和ATPase;输精管上皮细胞的ATPase的酶活性均呈强阳性或极强阳性。说明人类睾丸、附睾和输精管含有丰富的水解酶,尤其是附睾头部的输出小管、附睾管和头质均含有种类多活性高的水解酶,在精子的功能成熟上起了重要的作用,提示其可能作为生育与不育诊治中的重要指标。  相似文献   

5.
类别文献(篇数)专利(件数)AGENETICENGINEERINGANDFERMENTATIONA1NucleicAcidTechnology20574151A2Fermentation1326498BENGINEERINGB1BiochemicalEngineering432131CANALYSISC1SensorsandAnalysis11293DPHARMACEUTICALSD1....  相似文献   

6.
云南山茶科新种和新变种*闵天禄(中国科学院昆明植物研究所,昆明650204)NEWSPECIESANDVARIETIESOFTHEACEAEFROMYUNNANMingTienlu(KunmingInstituteofBotany,ChineseAc...  相似文献   

7.
CAMPTOTHECALOWREYANA,ANEWSPECIESOFANTI-CANCERHAPPYTREESShi-youLiArthurTempleColegeofForestry,StephenF.AustinStateUniversityn...  相似文献   

8.
新麦草的组织培养及染色体分析   总被引:4,自引:0,他引:4  
新麦草的组织培养及染色体分析孙震晓,夏光敏,陈惠民(山东大学生物系.济南250100)TISSUECULTUREANDCHROMOMEANALYSISOFPsATHYROSACHYSJUNCEA(FISCH.)NEVSKIsunZhen-xiao;x...  相似文献   

9.
社鼠消化道长度和重量的季节变化   总被引:10,自引:0,他引:10  
社鼠消化道长度和重量的季节变化SEASONALVARIATIONSINLENGTHANDWEIGHTOFDIGESTIVETRACTINRATTUSNIVIVENTERCONFUCIANUS关键词社鼠消化道形态季节动态KeywordsRatusniv...  相似文献   

10.
mRNA很可能携带三维遗传信息(英文)   总被引:1,自引:0,他引:1  
mRNA很可能携带三维遗传信息MESSENGERRNAPROBABLYCARRIESTHETHREE-DIMENSIONALGENETICINFORMATIONTheformingmechanismofthethree-dimensionalstru...  相似文献   

11.
生态网络中物质、能量流动的时间链分析   总被引:9,自引:1,他引:8  
韩博平 《生态学报》1995,15(2):163-168
本文以Markov过程理论为基础,利用转移矩阵对生态网络中物质、能量流动和随机行为进行的描述;将输入的物质、能量在生态网络中宏观分布随时间的变化定义为物质、能量流动的时间链,并给一般生态网络中物质、能量流动时间链的分析方法。两个稳态生态网络中物质、能量流动的时间链分析表明,时间链直观地反映了物质、能量在流动中流失或耗散的宏观行为,由于物质再循机普遍存在,使得物质流动的时间链与能量流动的时间链有着质  相似文献   

12.
物质、能量在生态网络中的总滞留时间(TRT)是反映物质、能量在生态网络中流动特征的一个整体指标.本文在分析生态网络中物质、能量滞留时间的基础上,给出了总滞留时间关于流动参量和状态参量的灵敏度解析形式.  相似文献   

13.
Neodymium is one of the most important enabling materials for next‐generation clean technologies, especially electric vehicles and wind turbines. As the world's largest producer of rare earth minerals, China dominates the global neodymium supply and a considerable amount of primary neodymium resources are from illegal mining. Many studies have been conducted on the material flow of neodymium in different regions, but few studies focus on China. In this study, a static material flow analysis of neodymium is conducted to quantitatively analyze the industrial chain structure of neodymium in China and to calculate the neodymium output from illegal mining. The results quantitatively depict the neodymium material flow of each stage of China's neodymium industrial chain in 2016, which indicates that 12.3–17.0 kt of primary neodymium resources were from illegal mining. On the basis of the results, reasonable conclusions can be drawn that the recycling of neodymium from end‐of‐life products provides an important opportunity to both reduce illegal rare earth mining and cope with increasing neodymium demand.  相似文献   

14.
This article characterizes the societal metabolism of the Colombian economy, identifying the main factors of natural resources use, overuse, or exhaustion. The environmental sustainability of a country depends to a large extent on the size of the economy compared to the available resource base. Material flow indicators provide an assessment of size or scale of economies. Direct material flow indicators are used to analyze the ecological dimension of economic activity in the period 1970–2007. Some resource extraction conflicts are briefly described in the light of material flow analysis. Foreign and domestic demand promotes increasing extraction and export of domestic natural resources. This is sometimes related to an irreversible deterioration of the local environment. The concept of “ecologically unequal exchange” with the rest of the world is analyzed in this context. Colombia has a large and growing negative physical trade balance, whereas per capita use of materials is still about half of the industrial countries’ average.  相似文献   

15.
To analyze and promote resource efficiency in urban areas, it is important to characterize urban metabolism and particularly, material flows. Material flow analysis (MFA) offers a means to capture the dynamism of cities and their activities. Urban‐scale MFAs have been conducted in many cities, usually employing variants of the Eurostat methodology. However, current methodologies generally reduce the study area into a “black box,” masking details of the complex processes within the city's metabolism. Therefore, besides the aggregated stocks and flows of materials, the movement of materials—often embedded in goods or commodities—should also be highlighted. Understanding the movement and dispersion of goods and commodities can allow for more detailed analysis of material flows. We highlight the potential benefits of using high‐resolution urban commodity flows in the context of understanding material resource use and opportunities for conservation. Through the use of geographic information systems and visualizations, we analyze two spatially explicit datasets: (1) commodity flow data in the United States, and (2) Global Positioning System‐based commercial vehicle (truck) driver activity data in Singapore. In the age of “big data,” we bring advancements in freight data collection to the field of urban metabolism, uncovering the secondary sourcing of materials that would otherwise have been masked in typical MFA studies. This brings us closer to a consumption‐based, finer‐resolution approach to MFA, which more effectively captures human activities and its impact on urban environments.  相似文献   

16.

Purpose

The aim of this research is to reveal the overall money flows and physical flows of the livestock and feed production supply chain in Thailand in order to analyze the resource use and cost and assess material use efficiency of the whole supply chain. Another aim is to evaluate the options to improve and evaluate trade-off between economic and environmental performance.

Methods

This research conducted material and monetary flow modeling using material flow analysis (MFA) and input output analysis (IOA). Data collected from the Thai Input-Output Tables 2005 were employed to develop the monetary flow model. Direct and indirect resource consumption (energy, water, and land use) and turnover along the supply chain were assessed using environmentally extended input-output analysis model (EEIOA). Scenario analysis with improvement options was applied to the model to evaluate the effectiveness of the improvement options.

Results and discussion

One third of energy and water consumption were from the animal farm itself. The rest were from feed production and upstream raw material production. Land use in the system was mainly from maize and paddy field. Feed conversion ratio improvement should play an important role in the strategy for resource efficiency and reduce environmental impact in the whole supply chain. Energy intensity reduction, the best option in overall energy reduction, is the policy that the government is pushing to be implemented in all sectors, and it can also easily be applied along with the other options. Therefore, it should be applied with the other options for improvement.

Conclusions

The results from monetary flow and physical material flow can visually show the holistic view of the Thai livestock production supply chain quantitatively and allow the stakeholders to understand the economic structure of the supply chain system. This can enable the decision makers to analyze the interrelation effect and impact of changing one sector demand or changing resource efficiency to impact other sectors in the system.
  相似文献   

17.
18.
齐宇  朱坦  高帅  王军锋  汲奕君  张墨  卜欣欣 《生态学报》2016,36(22):7335-7345
产业园区循环化改造是我国在"十二五"期间和今后一个时期内的一项重要工作,也是在园区层面实施循环发展的主要内容。物质流分析(MFA)是产业生态学的核心分析方法,正在成为资源环境管理领域有效的分析工具。通过梳理物质流分析方法的发展历程,指出产业园区循环化改造应用物质流分析存在注重物质规模而忽视环境影响、黑箱过程不利定量研究、小区域研究适用性不强以及隐藏流造成的数据误差等方面问题,同时通过大量调查实践,认为园区循环化改造可从企业开展清洁生产、促进园区内和园区间的产业共生、加强园区资源循环基础设施建设3个领域入手,在将园区全部企业分为生产性企业、再生性企业和资源循环基础设施企业3种类型基础上,提出关键流概念及其识别思路,探索构建物质流路径归类评价方法框架,归纳出8条典型物质流路径,为提升园区物质流管理水平提供方法依据,并选取天津经济技术开发区作为典型案例进行研究,最后对我国产业园区循环化改造应用物质流分析方法进行了展望。  相似文献   

19.
This study is a pioneering effort to quantify the materials stocked in the road network of a developing country, Vietnam, and analyze its relationships to the country's recent economic development. National road networks function as capital and infrastructure investments that are necessary catalysts for countries’ development, while requiring the extraction of vast amounts of construction materials for expansion and maintenance causing environmental impacts. However, there has so far been little research on the subject, especially in developing countries. We compile material stock and flow accounts for Vietnam's roads from 2003 to 2013 on the national and provincial levels, finding that approximately 40% of the domestic consumption of construction materials is for expanding and maintaining the road network, and the materials stocked in the road network doubled from 1,321 million metric tons in 2003 to 2,660 million metric tons in 2012. Material stock growth rates closely resembled those of gross domestic product (GDP) in this period, suggesting a codependency of physical infrastructure development and economic development. On the provincial level, our results show local disparities in the stock and its capacity to support the transportation of passengers and freight, especially considering the surging growth of vehicles in urban centers. By showcasing the challenges of conducting a material flow and stock analysis in a developing country, this study not only sheds light on Vietnam's transportation material stock and its policy implications, but also serves as a case study for further work in similar countries.  相似文献   

20.
This study looks into material flow trends in the Philippines from 1985 to 2010 by utilizing the methodology of economy‐wide material flow analysis. Using domestic data sources, this study presents disaggregated annual material flow trends in terms of four major material categories, namely: biomass; fossil energy carriers; ores and industrial minerals; and construction minerals. The results describe in detail the growth of material flows in a high‐density country at the onset of its development and reveal the shift of material consumption from dominance of renewable materials in 1985 to nonrenewable materials in 2010. IPAT analysis shows that the increase in material consumption was driven by population growth from 1985 to 1998 and by growth in affluence from 1999 to 2010. However, high inequalities amidst the growing economy suggest that a small group of wealthy people have influenced the acceleration of material consumption in the Philippines. The results of this research are intended to provide a thorough analysis of the processes occurring in Philippine economic growth in order to assist in tackling implications for the important issue of sustainable resource management.  相似文献   

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