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Spatiotemporal characteristics of seed rain and soil seed bank of artificial Caragana korshinskii Kom. forest in the Tengger Desert, China
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作者 SHEN Jianxiang WANG Xin +9 位作者 WANG Lei WANG Jiahui QU Wenjie ZHANG Xue CHANG Xuanxuan YANG Xinguo CHEN Lin QIN Weichun ZHANG Bo NIU Jinshuai 《Journal of Arid Land》 SCIE CSCD 2024年第4期550-566,共17页
Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants durin... Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles. 展开更多
关键词 ecological restoration soil seed bank seed rain artificial forest vegetation desertification Caragana korshinskii Tengger Desert
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Properties and Characterization of Two Clays Raw Material from Mountain District (West of Côte d’Ivoire) for Use in Low-Carbon Cements
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作者 Wedjers Max Robin Manouan Bi Irié Hervé Gouré Doubi +3 位作者 Lébé Prisca Marie-Sandrine Kouakou Atta Kouamé Brice Koffi Alfred Niamien Kouamé Namory Méité 《Advances in Materials Physics and Chemistry》 CAS 2024年第8期137-145,共9页
This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the exper... This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements. 展开更多
关键词 QUARTZ KAOLINITE Mountain District low-carbon Cements
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Research on Early Warning of Banking Crises from the Perspective of Credit Structures
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作者 Zhou Yuqin Luo Zixuan Wu Shan 《Contemporary Social Sciences》 2024年第3期45-63,共19页
The relationship between credit expansion and banking crises is complex and cannot be fully explained by total credit alone.A systematic analysis of the relationship between the amount and structure of total credit an... The relationship between credit expansion and banking crises is complex and cannot be fully explained by total credit alone.A systematic analysis of the relationship between the amount and structure of total credit and banking crises is important for an objective prediction of the influence of potential financial risks.This paper,drawing on data from 15 selected countries,delves into the power of credit indicators in the early warning of banking crises from the perspectives of industrial structure,sector structure,and term structure of credit.Various machine learning methods were used,including Logistic Regression,Random Forest,Decision Tree,Support Vector Machine(SVM),Bagging,and Boosting models.The empirical findings indicate that credit expansion plays a crucial role in triggering banking crises.However,total credit is better suited for the early warning of short-term banking crises,whereas credit structure is more useful for the early warning of long-term banking crises.Moreover,in an early warning system,identifying key early warning indicators is more meaningful than merely increasing the number of indicators.Machine learning can somewhat enhance the early warning power,but it may not always be robust.Therefore,more attention should be paid to potential systemic banking crises resulting from an imbalance in credit structure while regulating the total credit threshold. 展开更多
关键词 banking crises credit expansion transnational empirical evidence structural perspective
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Does China's digital economy contribute to low-carbon transition?
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作者 LI Jun-jun HUANG Xin-yu +2 位作者 CHEN Mu ZHANG Meng-jiang ZHANG Zhen 《Ecological Economy》 2024年第2期102-122,共21页
The digital economy,as a new emerging economic form,has become an important power for realizing Chinese-style modernization and promoting green development in China.This paper measures the digital economy and low-carb... The digital economy,as a new emerging economic form,has become an important power for realizing Chinese-style modernization and promoting green development in China.This paper measures the digital economy and low-carbon transition index based on the data of 30 provinces in China from 2013 to 2020 and analyzes the mechanism and path of the digital economy affecting low-carbon transition using the fixed effect panel data model and the threshold effect model.It is found that,(1)The digital economy and low-carbon transition in China are various in different regions,with characteristics of being unbalanced and insufficient.(2)The digital economy significantly promotes low-carbon transition,with the greatest influence in the Central region,followed by the Eastern region and the Western region.Under different dimensions,the development of informatization and digital transactions promote low-carbon transition,but the development of the internet plays an inhibiting role.(3)The higher the degree of urbanization and environmental regulation,the greater the influence of the digital economy on low-carbon transition. 展开更多
关键词 digital economy low-carbon transition threshold effect model instrumental variables quantile regression
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Effect of ZrC Modified Graphite on Structure and Properties of Low-carbon Al_(2)O_(3)-C Refractories
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作者 HU Chen WANG Xing +3 位作者 LIU Zhenglong DING Jun YU Chao DENG Chengji 《China's Refractories》 CAS 2024年第1期18-22,共5页
To address the issues of reduced performance and shortened lifespan during the low-carbonizating process of Al_(2)O_(3)-C refractories,nano-crystalline ZrC modified graphite was prepared using Zr powder and flake grap... To address the issues of reduced performance and shortened lifespan during the low-carbonizating process of Al_(2)O_(3)-C refractories,nano-crystalline ZrC modified graphite was prepared using Zr powder and flake graphite as raw materials,with NaCl and NaF mixed salt serving as the medium.The flake graphite was gradually replaced by ZrC modified graphite in the preparation of Al_(2)O_(3)-C refractories,and its impact on the material’s structure and properties was investigated.The results indicate that,compared to samples with only flake graphite,the introduction of 1 mass%to 5 mass%nano-crystalline ZrC modified graphite can significantly enhance the mechanical performance of low-carbon Al_(2)O_(3)-C refractories.When 5 mass%ZrC modified graphite is added,the mechanical properties of the samples are optimal,with the cold modulus of rupture and elastic modulus reaching 22.5 MPa and 65.0 GPa,respectively. 展开更多
关键词 ZRC modified graphite low-carbon Al_(2)O_(3)-C refractories microstrcucture mechanical properties
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The Impact of the Monetary Policy During the COVID-19 in the Brazilian Banking Sector
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作者 Karina Robial Michele Nascimento Jucá 《Chinese Business Review》 2024年第2期60-75,共16页
The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazi... The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazil basic interest rate is denominated Selic.The application of these policies requires the protagonist of bank’s financial intermediation.This study aims to verify two events-under the perspective of the efficient markets’theory.The first is the communication of the first death by COVID-19-and the subsequent,Selic rate reduction to 2%p.a.-and its effects on bank’s shares prices.The hypotheses presented are:H1-The announcement of the first death by COVID-19 negatively impacts the banks’shares returns and H2-The announcement of the Selic interest rate-during the COVID-19-positively impacts the return of the banks’shares.We adopt event study methodology in a final sample of nine and 15 banks to Events 1 and 2 respectively.The results confirm H1 as well as the semi-strong informational efficiency market.H2 is not confirmed.Results confirm the non-effectiveness of the anticyclical policy of basic interest rate reduction.This contributes to the discussion about the impacts of COVID-19 and the efficacy of anticyclical policies. 展开更多
关键词 monetary policy COVID-19 bankS Brazil event study
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Performance Evaluation of Low-Carbon and Clean Transformation of China’s Coal Economy
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作者 Liangfeng Zhu 《Journal of Environmental Science and Engineering(B)》 2024年第1期21-38,共18页
In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.Th... In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.The data collection for this paper includes data on deep processing of Chinese coal products from 2009 to 2020,as well as data on asset structure evolution and financial performance of 34 listed companies in the Chinese coal mining.Entropy value method is used to calculate the entropy value of low-carbon transformation,and the regression analysis is used to study the performance of cleaner transformation,the conclusion is as follows:(1)From 2009 to 2020,in China’s total energy consumption,coal consumption accounted for 71.6%in 2009 and 56.8%in 2020,the goals set by the state have been achieved.(2)The national goal of reducing the proportion of coal consumption and reducing carbon emissions has forced the transformation of deep processing of coal products.The transformation of coal enterprises towards low-carbon and clean production has achieved remarkable results.(3)From 2009 to 2020,the non coal industry income of 34 listed companies in China’s coal mining industry increased by 8.21%annually.At the same time,the asset structure was adjusted,and nearly 80%of the asset structure evolution showed an orderly development trend.(4)The regression analysis results show that the entropy value of coal deep processing products and the entropy value of asset structure adjustment are significantly related to transformation performance.The paper proposes to summarize the successful experience of China’s coal energy economic transformation,lay a foundation for achieving the carbon peak and carbon neutral goals in the future,further increase the intensity of coal deep processing,increase the proportion of clean energy in total energy consumption,and strive to control asset operation towards the goal of increasing the proportion of non coal industry income. 展开更多
关键词 Coal economy low-carbon and clean transformation deep processing of coal evolution of asset structure performance appraisal
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Research on the Impact of the Digital Transformation of Commercial Banks
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作者 Jinjin Gao 《Proceedings of Business and Economic Studies》 2024年第5期132-137,共6页
The development of the digital economy has presented both opportunities and challenges for the transformation of commercial banks.This article aims to conduct a literature review on the impact of digital transformatio... The development of the digital economy has presented both opportunities and challenges for the transformation of commercial banks.This article aims to conduct a literature review on the impact of digital transformation on commercial banks and to explore the multi-dimensional effects it brings.Through a review and analysis of relevant domestic and international literature,this paper first defines the connotation of digital transformation in commercial banks.It then conducts a literature analysis and research on the strategic governance,business performance,and risk management aspects of the digital transformation of commercial banks from multiple perspectives.Based on the analysis of the existing literature,the paper explores directions for future in-depth research and offers corresponding policy suggestions,providing a theoretical and practical foundation for the future digital development of commercial banks. 展开更多
关键词 Commercial bank Digital transformation bank performance
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ISO Certification and Technical Efficiency in the Banking Sector:An Evidence from WAEMU’s Countries Using the DEA Method
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作者 Gnoleba Martin Zahore 《Economics World》 2024年第2期55-68,共14页
In the view of the international organization of standardization,the introduction of ISO standards is typical of quality management systems oriented towards strengthening the efficiency of enterprises.Business banks a... In the view of the international organization of standardization,the introduction of ISO standards is typical of quality management systems oriented towards strengthening the efficiency of enterprises.Business banks are not excluded from this requirement.The current study aims to evaluate the effect of ISO certification on the technical performance of WAEMU banks.Using BCEAO data(2020),the DEA model and Tobit estimates show that ISO certification has no effect on the efficiency scores of the banks in the sample.It is therefore appropriate for these banks to work on improving their business climate. 展开更多
关键词 business banks DEA technical efficiency ISO WAEMU TOBIT
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Research on the Impact of Digital Transformation on the Business Performance of Commercial Banks
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作者 Zhengyu Wu 《Proceedings of Business and Economic Studies》 2024年第3期227-235,共9页
Nowadays,with the development of the digital economy,commercial banks are actively conducting digital transformation.Studying the impact of the digital transformation of commercial banks on their operating performance... Nowadays,with the development of the digital economy,commercial banks are actively conducting digital transformation.Studying the impact of the digital transformation of commercial banks on their operating performance can help commercial banks form a stronger core competitiveness and promote high-quality financial development.Based on the above background,this article first describes the status and development of digital transformation and development of commercial banks,and secondly analyzes whether Chinese commercial banks’digital transformation is conducive to improving their operating performance.Thirdly,by selecting the data of the listed commercial banks in the ten years of 2012–2022,this article obtains the empirical testing of the digital transformation on different property rights.Finally,the higher the level of digitalization,the higher the digital level,the more significantly promotes the performance of commercial banks.Finally,based on the above analysis,this article puts forward feasibility opinions on commercial banks and related regulators. 展开更多
关键词 Commercial banks Digital transformation Business performance Property rights
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A Mechanism for Digital Finance to Drive Green and Low-Carbon Development
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作者 Shenhui Huang 《Proceedings of Business and Economic Studies》 2024年第3期59-64,共6页
Given the global focus on green and low-carbon development and the increasing prominence of digital finance,it is particularly important to explore how to leverage digital finance to achieve these environmental goals.... Given the global focus on green and low-carbon development and the increasing prominence of digital finance,it is particularly important to explore how to leverage digital finance to achieve these environmental goals.This study,through mechanism analysis,deeply examines how China’s digital finance promotes green and low-carbon development and elucidates the positive interaction between digital finance and the green industry.The study found that digital finance,through more flexible and efficient financial functions,alters the cost structure of carbon emissions,and reduces the risks and costs of green investments,thereby creating a cooperative green mechanism benefiting all parties,and guiding social groups toward a green and low-carbon transformation.Additionally,the rapid development of digital finance has strengthened the implementation of environmental protection policies,effectively promoted the expansion of the environmental protection industry,and established the green ethos as a mainstream concept in financial development.This study aims to provide reference perspectives and suggestions,assist policymakers in promoting the green and lowcarbon development of digital finance,and offer insights into the integrated development of digital finance and the green environmental protection industry. 展开更多
关键词 Digital finance Green and low-carbon development Carbon emission cost Environmental protection policy Green environmental protection industry
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Study on the Countermeasures to Improve the Public Outdoor Leisure and Fitness Function on the Two Rivers and Four Banks in the Main Urban Area of Chongqing
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作者 Yuan Li Dexin Li 《Journal of Architectural Research and Development》 2024年第6期51-57,共7页
The main urban area of Chongqing is surrounded by two rivers and set against each other.With its unique waterfront landscape,it has the resource conditions to become a leisure tourism destination.Intending to enhance ... The main urban area of Chongqing is surrounded by two rivers and set against each other.With its unique waterfront landscape,it has the resource conditions to become a leisure tourism destination.Intending to enhance people’s happiness,improve city quality,and promote Chongqing’s main urban area to become a tourist destination,this paper finds out the existing problems in the construction of public outdoor leisure and fitness facilities on the two rivers and four banks of Chongqing’s main urban area through investigation and analysis based on relevant experiences at home and abroad,takes the value chain theory as the guidance,and to find solutions to the problem.On this basis,combined with the law of economic operation,this paper puts forward the guiding ideology,principles,development goals,functional orientation,and development path for the improvement of public outdoor leisure and fitness on two rivers and four banks in the main city of Chongqing,and accordingly puts forward the policy system and guarantee measures for its improvement. 展开更多
关键词 Two rivers and four banks in the main city of Chongqing Public outdoor recreation and fitness Policy measure
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多核共享缓存bank冲突分析及其延迟最小化 被引量:5
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作者 张吉赞 古志民 《计算机学报》 EI CSCD 北大核心 2016年第9期1883-1899,共17页
在硬实时多核系统中,共享资源冲突的问题为硬实时任务的最差情况下执行时间(WCET)分析带来了新挑战.虽然现有的共享缓存冲突分析技术在storage冲突方面已取得研究进展,但对于bank冲突而言,现有研究仍局限于通过界定bank冲突延迟上限来... 在硬实时多核系统中,共享资源冲突的问题为硬实时任务的最差情况下执行时间(WCET)分析带来了新挑战.虽然现有的共享缓存冲突分析技术在storage冲突方面已取得研究进展,但对于bank冲突而言,现有研究仍局限于通过界定bank冲突延迟上限来分析和处理bank冲突.该文通过优化核-bank映射关系来使硬实时多核系统中的bank冲突延迟最小化,即在对bank冲突延迟进行分析的基础上,首先通过优化核-bank之间的映射关系来消除bank冲突;若无法消除,则需要寻找能使bank冲突延迟最小化的核-bank映射关系解,并为此设计了一种基于多核总线请求时间序列的bank冲突延迟求解算法.最后,文中设计了能够对总线访问延迟进行消重的多核硬实时任务WCET估算方法.实验结果表明:文中所提的优化方法可消除这类bank冲突或使其延迟最小化,文中所提的WCET估算方法与现有估算方法相比可获得更精确的最差情况下执行时间(WCET). 展开更多
关键词 多核系统 硬实时任务 优化 核到bank映射 bank冲突延迟 最差情况下执行时间
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Preparation of DNA from Silica Gel Dried Mini_amount of Leaves of Oryza rufipogon for RAPD Study and Total DNA Bank Construction 被引量:30
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作者 谢中稳 葛颂 洪德元 《Acta Botanica Sinica》 CSCD 1999年第8期807-812,共6页
Gene resources of Oryza rufipogon Griff. play a crucial role in rice breeding, and hence to study their conservation is of utter importance. The authors describe a method for preparation of DNA from mini_amount of... Gene resources of Oryza rufipogon Griff. play a crucial role in rice breeding, and hence to study their conservation is of utter importance. The authors describe a method for preparation of DNA from mini_amount of the silica_gel_dried leaves of Oryza rufipogon . The high molecular weight DNAs of 1?168 individuals representing 44 populations have been obtained with high yields, which could be used for RAPD PCR and construction of total DNA bank of this species. The template DNA from silica_gel_dried leaves stored for one year at room temperature gave the same RAPD results as that from the newly prepared silica_gel_dried leaves. The optional template DNA concentrations for amplification ranged from 3.1 ng to 50 ng. In addition, the quality and quantity of the template DNAs that affect RAPD results are also discussed. 展开更多
关键词 DNA preparation Total DNA bank RAPD Oryza rufipogon
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Heterogeneity in Soil Seed Banks in a Mediterranean Coastal Sand Dune 被引量:9
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作者 于顺利 Marcelo STERNBERG +1 位作者 蒋高明 Pua KUTIEL 《Acta Botanica Sinica》 CSCD 2003年第5期536-543,共8页
Characteristics of total soil seed banks and permanent soil seed banks in three microhabitats in a Mediterranean coastal sand dune were investigated by using natural germination method combined with physically scannin... Characteristics of total soil seed banks and permanent soil seed banks in three microhabitats in a Mediterranean coastal sand dune were investigated by using natural germination method combined with physically scanning separation method. The composition and structure of soil seed banks were analyzed between the microhabitats by using functional group method. The distribution patterns of soil seed bank were also analyzed between the microhabitats. We also analyzed the relationship between seed size and seed persistence in soil. The results show greatly spatial heterogeneity existed in soil seed bank of the Mediterranean coastal sand dune, even in the same microhabitats seed distribution was uneven. Sometimes a great difference occurred between them. Microhabitats significantly affected the distribution patterns of total soil seed banks and seed banks of the functional groups. The open area generally had the greater densities of seeds, but the seed densities under shrub and in trail were lower than that in the open area. Legumes seeds accounted for 76.0% total persistent seed banks. Annual and perennial grasses produced transient seed banks as no seeds were retrieved from the sieved soils. Seed persistence of legumes, umbeliferaes, perennial forbs, compositaes, annual forbs, crucifer decreased gradually. They were 50.1%, 45.6%, 40.6%, 6.3%, 5.6% and 0.6% respectively in the soil. There was a positive relationship between seed size and seed persistence. Bigger seeds had higher persistence, and vice versa. 展开更多
关键词 MICROHABITATS soil seed banks persistent soil seed bank spatial heterogeneity
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Approach and Strategy of Constructing Low-carbon Communities 被引量:3
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作者 陈江美 李志英 《Meteorological and Environmental Research》 CAS 2010年第7期97-101,共5页
The developing focus of low-carbon society is constructing low-carbon cities which are based on the construction of low-carbon communities.The main ways of constructing low-carbon communities conclude low carbonizatio... The developing focus of low-carbon society is constructing low-carbon cities which are based on the construction of low-carbon communities.The main ways of constructing low-carbon communities conclude low carbonization of planning and designing,low carbonization of construction materials,low carbonization of community environment,low carbonization of energy system,low carbonization of energy use and low carbonization of life style.The basic strategies of constructing low-carbon communities contain enhancing propaganda and education,strengthening technical innovation,cultivating low-carbon culture,advocating public participation and consolidating leadership in organizations. 展开更多
关键词 low-carbon economy low-carbon city low-carbon community APPROACH STRATEGY China
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Effect of Different Soak Treatments on Breaking Seed Dormancy in Soil Seed Bank from Different Degraded Grasslands 被引量:6
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作者 魏学红 格桑卓玛 《Agricultural Science & Technology》 CAS 2010年第8期173-175,共3页
[Objective] The aim was to study the effect of different soak treatments on breaking seed dormancy in soil seed bank from different degraded grasslands. [Method] Different concentrations of H2SO4,GA3 and KNO3 were use... [Objective] The aim was to study the effect of different soak treatments on breaking seed dormancy in soil seed bank from different degraded grasslands. [Method] Different concentrations of H2SO4,GA3 and KNO3 were used for soaking the seeds in the soil seed bank from different degraded grasslands,and the germination number of seeds was detected. [Result] When the seeds from soil seed bank were soaked with 60%,70%,80% and 90% H2SO4,the germination number of seeds was 0,indicating that the germination of seeds was inhibited; when the seeds were soaked with GA3,the germination number of seeds increased with the concentration of GA3 increasing. When the concentration of GA3 increased to 0.10%,the germination of seeds was inhibited; when the seeds were soaked with 0.2% KNO3,the germination number of seeds was greater than the blank control. [Conclusion] The number of remaining seeds was more in the soil seed banks collected from moderately degraded grassland and heavily degraded grassland; while the number of remaining seeds was small in the soil seed banks collected from lightly degraded grassland and extremely degraded grassland. 展开更多
关键词 Different degraded grasslands Soil seed bank Soak DORMANCY
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基于回答集编程的Banks选举求解方法 被引量:1
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作者 赖河蒗 陈红英 +1 位作者 赖博先 柯万添 《计算机工程》 CAS CSCD 2013年第8期266-269,共4页
采用启发式算法的Banks选举在进行求解时执行效率较低。为解决该问题,提出一种基于回答集编程(ASP)的求解方法。通过建立Banks选举问题到ASP问题的映射,编写相对应的ASP,调用回答集求解器进行求解,得到的每一个ASP模型就是Banks选举问... 采用启发式算法的Banks选举在进行求解时执行效率较低。为解决该问题,提出一种基于回答集编程(ASP)的求解方法。通过建立Banks选举问题到ASP问题的映射,编写相对应的ASP,调用回答集求解器进行求解,得到的每一个ASP模型就是Banks选举问题的一个解。实验结果表明,当问题规模为200时,该方法的求解时间为4.196 s,求解效率高于手工启发式方法。 展开更多
关键词 回答集编程 banks选举 计算复杂度 求解器 启发式算法 最大传递子图
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Characteristics of Soil Seed Bank and Natural Regenerations in Pinus densata Natural Forest of Southeast Tibet 被引量:6
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作者 卢杰 李照青 +1 位作者 唐晓琴 薛敬丽 《Agricultural Science & Technology》 CAS 2017年第7期1248-1254,共7页
Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yal... Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yalu Tsangpo River, Nyang River and Parlung Zangbo River. In this study, with P. densata forest distributed in southeast Tibet as research object, the seed rain, soil seed bank, seed germination and natural regeneration of P. densata were monitored and ana- lyzed by field investigation, located monitoring and indoor experimental analysis. The results showed that the average intensity of the seed rain of P. densata was 249.30±78.42 seeds/m2, in which the intensity of full seeds was 168.09±56.36 seeds/m2, the intensity of seeds damaged by worms was 41.11±20.25 seeds/m2, and the intensity of empty seeds was 40.10±21.04 seeds/m2. The intensity of the seed rain exhibited a single-peak trend of increasing at first and decreasing then over time. The spatial distribution patterns in the whole seed falling process and at different seed falling time all exhibited clumping distribution, and within in certain range, with the distance from the seed tree increasing, the diffusion intensity of the seed rain was weakened, exhibiting approximately normal distribution. In average density of P. densata seeds in the soil seed bank of P. densata was 231 seeds/m2, in which 62.77% of seeds were distributed in the litter layer, and 37.23% of seeds were distributed in the soil layer, and about 8% of seeds were lost during the pro- cess from seed rain to soil seed bank. Field sowing observation showed that the accumulated germination rate curve of P. densata fitted with Logistics equation y= 91.404/(1+e66194.449). The height structure, basal diameter structure and age structure of seedlings and young trees of P. densata were all of reverse "J" type, indicating good natural regeneration of P. densata. This study would provide a science basis for protection and resource management of P. densata, and further enrich the eval- uation content of national ecological safety curtain of the Tibet plateau. 展开更多
关键词 Pinus densata natural foresti Seed rain Soil seed bank Seed germi-nation Natural regeneration Southeast Tibet
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Cultivation and Management of Low-carbon Scenic Spots——A case study of Yuntai Mountain Scenic Area in Henan Provicne of China 被引量:1
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作者 史云 田甜 许晓明 《Journal of Landscape Research》 2011年第4期57-60,64,共5页
After analysis of connotation of low-carbon scenic spots,the paper considered that a perfect low-carbon scenic spot is a comprehensive integrity with satisfying tourists' lowest tourist experience effect as the pr... After analysis of connotation of low-carbon scenic spots,the paper considered that a perfect low-carbon scenic spot is a comprehensive integrity with satisfying tourists' lowest tourist experience effect as the premise and with low energy consumption,low pollution and low emission as the foundation.Low-carbon tourist scenic spots had been classified into three types which are ecological type,cultural type and coupling type of ecology and culture.Representatives of each type of tourist scenic spot were illustrated.It proposed that government should play the leading role in cultivation of low-carbon scenic spot;tourism industry should enhance self supervision;tourism development mode should be transformed and upgrading of tourist products should be realized.By taking Yuntai Mountain Scenic Area of Henan Province for example,based on low-carbon tourist resources,low-carbon development of management,following measures realizing low-carbon economy were put forward:① purifying air quality and beautifying environment of scenic area;② sifting laggard productivity and protecting ecological resources in the scenic area by many means;③ sticking to low-carbon environmental protection concept and completing infrastructure service;④ developing tourist native products and souvenirs based on local resources;⑤ applying electronic access control ticket system,intelligent monitor system and LED information and communication platform,so as to achieve low-carbon management. 展开更多
关键词 low-carbon SCENIC SPOT CULTIVATION and development Yuntai MOUNTAIN SCENIC Area Management
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