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阴阳学说与中国人的宇宙观 被引量:6
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作者 侯宏堂 《安徽师范大学学报(社会科学版)》 2003年第1期62-69,共8页
中国人的传统宇宙观可以剖析为四个层面,即源于混沌观、气化生生观、有机整体观和时空合一观,而这些观念无一不与"阴阳"紧密相关。阴阳学说是中国人传统宇宙观的哲学根基。
关键词 源于混沌 气化生生 有机整体 时空合一 阴阳学说
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A comprehensive review of carbon sequestration of seagrass in China from 2013
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作者 HUANG Xiaotong 《Marine Science Bulletin》 2024年第1期31-41,共11页
Seagrass is not only known for its ecological role,but also for its high capacity on the carbon sequestration.Although the area of seagrass meadows was less than 0.2%of the world’s oceans,the yearly organic carbon bu... Seagrass is not only known for its ecological role,but also for its high capacity on the carbon sequestration.Although the area of seagrass meadows was less than 0.2%of the world’s oceans,the yearly organic carbon burial of seagrass reached 10%of that in the ocean.Anthropogenic activities in the past two decades and the climate change have led to a significant decrease of seagrass meadow.Since seagrass is widely distributed along the coastline of China,it is necessary to put more efforts on the seagrass conservation and restoration,which will consequently be a suitable nature based solution for mitigating the climate change.This paper provides a comprehensive review on the following five aspects:1)the seagrass distribution in China;2)the role that seagrass plays in the climate mitigation;3)carbon sequestration of seagrass in China;4)loss of seagrass habitats and 5)the restoration of seagrass habitat in China since 2013.Current research gap and prospective research direction were also pointed out in this study. 展开更多
关键词 SEAGRASS carbon sequestration climate mitigation RESTORATION DISTRIBUTION ecological role
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Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998 被引量:35
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作者 曹明奎 陶波 +2 位作者 李克让 邵雪梅 Stephen D PRIENCE 《Acta Botanica Sinica》 CSCD 2003年第5期552-560,共9页
A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in clima... A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains. 展开更多
关键词 China net primary productivity (NPP) soil heterotrophic respiration (HR) net ecosystem productivity (NEP) climate change
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Assessment of Climate for Agricultural Suitability and Optimal Allocation of Agricultural Production in the Guanzhong Region, Shaanxi Province 被引量:2
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作者 杨忍 刘彦随 任志远 《Agricultural Science & Technology》 CAS 2012年第11期2379-2384,2448,共7页
Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method.... Based on spatial climatic data of agriculture and the experiment data, the models of agro-ecological assessment of climate for agricultural suitability in this study were developed using the fuzzy mathematical method. Three coefficients, in- cluding the resource coefficient (Cr), the efficiency coefficient (Ce), and the utility co- efficient (K), were used in the models, which were calculated based on temperature, moisture, and sunshine duration data of Guanzhong region, Shaanxi Province. The results indicated that resource coefficient was higher in west of the region than that in east, and higher in south (especially in the Central Shaanxi Plain) than that in the Weibei plateau. The value of Cr changed from 6.5 to 9.2 from north to plain area. Spatial change of efficiency coefficient was obvious, lower in the northeast than in the central plain, and the value of Ce changed from 2.3 to 6.5 from the northeast to the central plain. As for utility coefficient, it was lower in northeastern part of the Weibei plateau and in southern mountain areas than that in the central plain, showing significant latitudinal zonality. Furthermore, the value of K increased from 0.35 to 0.78 from northeast to the central plain, and decreased from 0.78 to 0.53 from the central plain to southern mountain areas. These indicated that climate resource in the central plain region was more abundant and potential, compared with other regions. GuanZhong region was classified into three larger agricultural zones and three small independent zones, according to agro-ecological assessment. Light, heat and water resources should be made use of in an efficient way in spatial allo- cation of agricultural production. For example, water facilities should also be im- proved in Weibei plateau region where highly-qualified fruit should be enhanced and fruit processing industrial chain should be shaped. Large-scale production area of wheat should be increased in central irrigation region and more vegetable bases should be developed around large and medium-scale cities. Thanks for outstanding water conservation function, the three-dimensional agriculture including medicine and other sideline production should be developed in Qinling Mountains and the special- ized commercial agriculture should be accelerated in independent small zones, ac- cording to local conditions. In the research, different crop varieties were developed in corresponding regions as per current eco-climatic conditions. 展开更多
关键词 Assessment of climate for agricultural suitability Optimal allocation ofagricultural production Guanzhong region
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Potassium superoxide oxygen generation rate and carbon dioxide absorption rate in coal mine refuge chambers 被引量:4
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作者 Gao Na Jin Longzhe +3 位作者 Hu Haohao Huang Xiao Zhou Li Fan Linyu 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第1期151-155,共5页
The effects of the molding pressure of a KO2 oxygen plate and the initial concentration of CO2 on the oxygen generation rate, the oxygen generation efficiency, and the carbon dioxide absorption rate were studied using... The effects of the molding pressure of a KO2 oxygen plate and the initial concentration of CO2 on the oxygen generation rate, the oxygen generation efficiency, and the carbon dioxide absorption rate were studied using a YES-300 hydraulic press to alter the pressure when forming the oxygen plate used in a coal mine refuge chamber. In addition, changes in the initial concentration of CO2 used in the closed- box model were made by adjusting the CO2 supply system, and a CD-7 multi-function parameter instrument was employed to monitor and record the changes of O2 and CO2 concentration in the closed-box model. Results indicate that the oxygen generation rate of KO2 oxygen plates, the oxygen generation efficiency, and the carbon dioxide absorption rate decrease when there is an increase in the pressure used to mold the oxygen plates, but those values increase when the initial CO2 concentration increases. When the initial concentration of CO2 in the dosed-box model is 3.5% and the forming pressure is 10 kN, the average oxygen generation rate of 15 g KO2 oxygen plate is 11.88 ×10^-3 L/min, the oxygen generation efficiency is 80.3%, and the average CO2 absorption rate is 11.0 × 10^-3 L/min. Compared with the condition where the initial CO2 concentration is 1.5%, the results show that average oxygen genera- tion rate of oxygen plates increases by 88,9%, the oxygen generation efficiency increases by 88.9%, and the CO2 absorption rate increases by 100%. 展开更多
关键词 Potassium superoxideOxygen generation rateOxygen generation efficiencyCarbon dioxide absorption rateConcentration
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Performance evaluation of a diesel engine by using producer gas from some under-utilized biomass on dual-fuel mode of diesel cum producer gas 被引量:1
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作者 D.K.Das S.P.Dash M.K.Ghosal 《Journal of Central South University》 SCIE EI CAS 2012年第6期1583-1589,共7页
Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(f... Producer gas through gasification of biomass can be used as an alternate fuel in rural areas due to high potential of biomass resources in India.Experiments were conducted to study the performance of a diesel engine(four stroke,single cylinder,5.25 kW) with respect to its thermal efficiency,specific fuel consumption and diesel substitution by use of diesel alone and producer gas-cum-diesel(dual fuel mode).Three types of biomass,i.e.wood chips,pigeon pea stalks and corn cobs were used for generation of producer gas.A producer gas system consisting of a downdraft gasifier,a cooling cum cleaning unit,a filtering unit and a gas air mixing device was designed,fabricated and used to power a 5.25 kW diesel engine on dual fuel mode.Performance of the engine was reported by keeping biomass moisture contents as 8%,12%,16%,and 21%,engine speed as 1 600 r/min and with variable engine loads.The average value of thermal efficiency on dual fuel mode was found slightly lower than that of diesel mode.The specific diesel consumption was found to be 60%-64% less in dual fuel mode than that in diesel mode for the same amount of energy output.The average diesel substitution of 74% was observed with wood chips followed by corn cobs(78%) and pigeon pea stalks(82%).Based on the performance studied,the producer gas may be used as a substitute or as supplementary fuel for diesel conservation,particularly for stationary engines in agricultural operations in the farm. 展开更多
关键词 biomass gasification producer gas downdraft gasifier diesel engine
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Developing bioenergy to tackle climate change:Bioenergy path and practice of Tianguan group
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作者 ZHANG Xiao-Yang 《Advances in Climate Change Research》 SCIE CSCD 2016年第1期17-25,共9页
Biomass energy would become the most potential renewable energies, for whether wind power or photovoltaic, would be restricted by the nature thus cannot provide stable power, while biomass energy is the only renewable... Biomass energy would become the most potential renewable energies, for whether wind power or photovoltaic, would be restricted by the nature thus cannot provide stable power, while biomass energy is the only renewable energy that can be used in the form of gas, liquid or solid stage, it could replace the fossil energy, lead a positive influence on the control of the greenhouse gases. Across the globe, the biomass produced through photosynthesis is about 200 Gt, or 99 Gtce per year. If 10% of the biomass is utilized, more than 4 Gt of fuel ethanol and other bioenergy products can be produced, equivalent to 4.13 Gt of petroleum consumed by the world in 2014. Therefore, bioenergy can be a feasible alternative to fossil energy. 展开更多
关键词 Climate change BIOENERGY Greenhouse gas
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Life Cycle Cost of Electricity Generation from Biomass Gasifier 被引量:5
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作者 Debabrata Lahiri Gokul Achariee 《Journal of Energy and Power Engineering》 2013年第11期2060-2067,共8页
India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY (Rejiv Gandhi Grammen Vidyutikaran Yojana), the rate of village electrification is much lower as household connec... India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY (Rejiv Gandhi Grammen Vidyutikaran Yojana), the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers (both dual fuel and pure gas type) and compare with that of diesel generating sets by using the concept of LCC (life cycle costing) and Homer software. It is found that the cost of per unit electricity generation (kWh) has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent. 展开更多
关键词 Biomass gasifier DIESEL OFF-GRID life cycle costing.
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An analysis of China's CO_2 emission peaking target and pathways 被引量:15
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作者 HE Jian-Kun 《Advances in Climate Change Research》 SCIE 2014年第4期155-161,共7页
China has set the goal for its CO2 emissions to peak around 2030, which is not only a strategic decision coordinating domestic sustainable development and global climate change mitigation but also an overarching targe... China has set the goal for its CO2 emissions to peak around 2030, which is not only a strategic decision coordinating domestic sustainable development and global climate change mitigation but also an overarching target and a key point of action for China's resource conservation, environmental protection, shift in economic development patterns, and CO2 emission reduction to avoid climate change. The development stage where China maps out the CO2 emission peak target is earlier than that of the developed countries. It is a necessity that the non-fossil energy supplies be able to meet all the increased energy demand for achieving CO2 emission peaking. Given that China's potential GDP annual increasing rate will be more than 4%, and China's total energy demand will continue to increase by approximately 1.0%--1.5% annually around 2030, new and renewable energies will need to increase by 6%-8% annually to meet the desired CO2 emission peak. The share of new and renewable energies in China's total primary energy supply will be approximately 20% by 2030. At that time, the energy consumption elasticity will decrease to around 0.3, and the annual decrease in the rate of CO2 intensity will also be higher than 4% to ensure the sustained growth of GDE To achieve the CO2 emission peaking target and substantially promote the low-carbon deve!opment transformation, China needs to actively promote an energy production and consumption revolution, the innovation of advanced energy technologies, the reform of the energy regulatory system and pricing mechanism, and especially the construction of a national carbon emission cap and trade system. 展开更多
关键词 CO2 emission peak Energy revolution Climate change China's carbon emission mitigation target
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Mixed signals in trends of variance in high-elevation tree ring chronologies
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作者 George P MALANSON 《Journal of Mountain Science》 SCIE CSCD 2017年第10期1961-1968,共8页
Increases in climate variability, including extremes, may be expected with anthropogenic climate change, but some evidence is contrary. The issue is important because the consequences of variability can be critical fo... Increases in climate variability, including extremes, may be expected with anthropogenic climate change, but some evidence is contrary. The issue is important because the consequences of variability can be critical for ecosystems. It has long been known and often rehearsed that ecological consequences of increased variability may be greater than those that result from expected changes in mean temperature and precipitation. Tree rings have been useful indicators of ecological response to climate change and used as proxies for climate variability;work in the Rocky Mountains, USA, has been particularly informative. Chronologies from two high elevation species ranging over 2500 km were analyzed for changes in variance through time. These spatially extensive and disaggregated tree ring records do not show a consistent pattern of change in variance over the past 500 or 100 years; heteroscedasticity has recently been greater. A lack of consistent response in growth over a period encompassing changes in mean climate indicates that mountain environments, with inconsistent trends in temperature and precipitation,may be too complex to act as sentinels. 展开更多
关键词 Climate change Variance Pinus albicaulis Pinus flexilis Rocky Mountains
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Options for Managing Livestock Production Systems to Adapt to Climate Change 被引量:1
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作者 Evangelia N. Sossidou Eleni Tsiplakou George Zervas 《Journal of Earth Science and Engineering》 2014年第7期415-427,共13页
This paper discusses recent research findings together with management schemes in preventing and managing of thermal stress by handling external and internal factors in livestock production systems. Preventive measure... This paper discusses recent research findings together with management schemes in preventing and managing of thermal stress by handling external and internal factors in livestock production systems. Preventive measures against thermal stress are described as basic structural adjustments and the modifications that can be implemented readily, according to animal health and welfare requirements and refer to (1) environmental modification and thermal comfort in various housing systems; (2) action on animals, such as genetic selection for breeds resistant to infectious disease, parasites and climate extremes; (3) action on feed and (4) action on staff handling the animals. Moreover, measures to be taken both in situations of chronic thermal stress and heat or cold strokes are presented as they are applied to (1) limit stress, (2) monitor the temperature felt by animals, (3) adapt diet and drinking water supplies and (4) correct physiological imbalances. Examples are given for different farm species (cattle, sheep, goat, poultry and pigs) and different production systems (intensive, extensive and alternative). The paper concludes with a practical guide for the effective handling of thermal stress at farm level, summarizing the results from recent research studies on the specific topic. 展开更多
关键词 Livestock production MANAGEMENT thermal comfort.
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Climate Change Adaptation for People and Nature:A Case Study from the U.S.Southwest
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作者 Patrick D.MCCARTHY 《Advances in Climate Change Research》 SCIE 2012年第1期22-37,共16页
In the U.S.Southwest,global climate change,acting in concert with extant stressors such as urbanization and over-allocation of water resources,is changing ecosystems in measureable and sometimes dramatic ways.Twenty-f... In the U.S.Southwest,global climate change,acting in concert with extant stressors such as urbanization and over-allocation of water resources,is changing ecosystems in measureable and sometimes dramatic ways.Twenty-first century projections indicate accelerating climate change and cascading ecological consequences.Effects observed to date include large-scale forest dieback,large and severe wildfires,and changes in the flow regimes of rivers and streams with attendant changes to riparian and aquatic ecosystems.Rising temperatures and changing precipitation patterns are pushing ecosystems across physiological and ecological thresholds,causing widespread mortality and,in some cases,major changes in composition,structure and function.These changes have prompted action by the conservation community to reduce the adverse effects of climate change.The Southwest Climate Change Initiative(SWCCI),a project led by The Nature Conservancy,works with local stakeholders in affected landscapes,reduces adverse impacts on ecological and social systems using scientific knowledge and practical tools.The Initiative has learned through practical experience that: 1) managers must embrace change and manage for resilience rather than resistance;2) strong local science-management partnerships are critical to effective adaptation planning and implementation;3) planners and managers must broaden the scope and accelerate the pace of conservation activities if ecosystem services are to be sustained;4) adaptation often does not require radically new or different management practices,rather,conservationists already have many of the tools they need;and 5) rapid documentation and widespread communication of methods and findings can build rapidly regional capacity for climate change adaptation.Our experience suggests that adaptation efforts can be effective if they are focused at the local scale;employ learning networks;and engage in ecosystem-based adaptation:the sustainable management,conservation and restoration of ecosystems so that they continue to provide the services that allow people to thrive in changing environments. 展开更多
关键词 climate change adaptation ecosystem-based adaptation ecological thresholds learning networks
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Lake-margin ecosystems of saline lakes of the Borzya group(Zabaikalsky Krai, Russia) during the initial filling phase
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作者 Evgenia P.GORLACHEVA Gazhit Ts.TSYBEKMITOVA +4 位作者 Alexey V.AFONIN Natalya A.TASHLIKOVA Ekaterina Yu.AFONINA Alexey P.KUKLIN Natalia V.SALTANOVA 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第4期871-878,共8页
This article presents the results of hydrochemical and hydrobiological studies of shallow saline lakes of the Borzya group(Zabaikalsky Krai, Russia) at the initial filling phase. The lake-margin ecosystems of the stud... This article presents the results of hydrochemical and hydrobiological studies of shallow saline lakes of the Borzya group(Zabaikalsky Krai, Russia) at the initial filling phase. The lake-margin ecosystems of the studied lakes are characterized by varying degrees of salinity from polyhaline to brine water. Cyclical variations of meteorological conditions and high salinity determined that the compositions of the aquatic organisms are specific, mostly between stenohaline and euryhaline species, the quantities are low, and the community structures are simple. 展开更多
关键词 saline lakes HYDROCHEMISTRY WEEDS ZOOPLANKTON ZOOBENTHOS
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Linear Generator Used in Hybrid System Solar Biomass
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作者 Angelo Jose Junqueira Rezek Carlos Rocha +6 位作者 Wladimir Cobas Electo E. S. Lora Paulo S. P. Correa Jr.t Osvaldo J. Venturini Rubenildo Andrade Jose C. Escobar Marcelo Pirani 《Journal of Mechanics Engineering and Automation》 2015年第6期382-385,共4页
The aim of this paper is to present the linear generator (Stirling solar dish) in the context of a HSSB (hybrid system solar biomass), project P & D (research and development P & D 0041, in cooperation and part... The aim of this paper is to present the linear generator (Stirling solar dish) in the context of a HSSB (hybrid system solar biomass), project P & D (research and development P & D 0041, in cooperation and partnership with CPFL--LIght and Force Paulista Company-Campinas, Piratininga, S.P. Brazil). The other components of the system will be the solar ORC (organic Rankine cycle), the rotary Stifling and the biomass gasifier. The integration of the complete system will be described in the paper, and is projected to be hydraulic one. 展开更多
关键词 Linear generator Stirling solar dish electric-hydraulic integration.
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Primary estimation of Chinese terrestrial carbon sequestration during 2001-2010 被引量:8
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作者 Qiufeng Wang Han Zheng +1 位作者 Xianjin Zhu Guirui Yu 《Science Bulletin》 SCIE EI CAS CSCD 2015年第6期577-590,M0003,共15页
Quantifying the carbon budgets of terrestrial ecosystems is the foundation on which to understand the role of these ecosystems as carbon sinks and to mitigate global climate change. Through a re-examination of the con... Quantifying the carbon budgets of terrestrial ecosystems is the foundation on which to understand the role of these ecosystems as carbon sinks and to mitigate global climate change. Through a re-examination of the conceptual framework of ecosystem productivity and the integration of multi-source data, we assumed that the entire terrestrial ecosystems in China to be a large-scale regional biome-society system. We approximated the carbon fluxes of key natural and anthropogenic processes at a regional scale, including fluxes of emissions from reactive carbon and creature ingestion, and fluxes of emissions from anthropogenic and natural disturbances. The gross primary productivity, ecosystem respiration and net ecosystem productivity (NEP) in China were 7.78, 5.89 and 1.89 PgC a^-1, respectively, during the period from 2001 to 2010. After accounting for the consumption of reactive carbon and creature ingestion (0.078 PgC a^-1), fires (0.002 PgC a^-1), water erosion (0.038 PgC a^-1) and agri- cultural and forestry utilization (0.806 PgC a^-1), the final carbon sink in China was about 0.966 PgC a^-1; this was considered as the climate-based potential terrestrial eco- system carbon sink for the current climate conditions in China. The carbon emissions caused by anthropogenic disturbances accounted for more than 42 % of the NEP, which indicated that humans can play an important role in increasing terrestrial carbon sequestration and mitigating global climate change. This role can be fulfilled by reducing the carbon emissions caused by human activities and by prolonging the residence time of fixed organic carbon in the large-scale regional biome-society system through the improvement of ecosystem management. 展开更多
关键词 Gross primary productivity Netecosystem productivity Ecosystem respirationCarbon sink CHINAFLUX
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A trait-based approach to assess climate change sensitivity of freshwater invertebrates across Swedish ecoregions 被引量:3
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作者 Leonard SANDIN Astrid SCHMIDT-KLOIBER +2 位作者 Jens-Christian SVENNING Erik JEPPESEN Nikolai FRIBERG 《Current Zoology》 SCIE CAS CSCD 2014年第2期221-232,共12页
Freshwater habitats and organisms are among the most threatened on Earth, and freshwater ecosystems have been subject to large biodiversity losses. We developed a Climate Change Sensitivity (CCS) indicator based on ... Freshwater habitats and organisms are among the most threatened on Earth, and freshwater ecosystems have been subject to large biodiversity losses. We developed a Climate Change Sensitivity (CCS) indicator based on trait information for a selection of stream- and lake-dwelling Ephemeroptera, Plecoptera and Trichoptera taxa. We calculated the CCS scores based on ten species traits identified as sensitive to global climate change. We then assessed climate change sensitivity between the six main ecoregions of Sweden as well as the three Swedish regions based on lilies. This was done using biological data from 1,382 stream and lake sites where we compared large-scale (ecoregional) patterns in climate change sensitivity with potential future exposure of these ecosystems to increased temperatures using ensemble-modelled future changes in air temperature. Current (1961-1990) measured temperature and ensemble-modelled future (2100) temperature showed an increase from the northernmost towards the southern ecoregions, whereas the predicted temperature change increased from south to north. The CCS indicator scores were highest in the two northernmost boreal ecoregions where we also can expect the largest global climate change-induced increase in temperature, indicating an unfortunate congruence of exposure and sensitivity to climate change. These results are of vital importance when planning and implementing management and conservation strategies in freshwater ecosystems, e.g., to mitigate increased temperatures using riparian buffer strips. We conclude that traits information on taxa specialization, e.g., in terms of feeding specialism or taxa having a preference for high altitudes as well as sensitivity to changes in temperature are important when assessing the risk from future global climate change to freshwater ecosystems [Current Zoology 60 (2): 221-232, 2014]. 展开更多
关键词 Climate change Indicators Traits FRESHWATER MACROINVERTEBRATES ECOREGIONS
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Chemical vapor deposition growth of large-scale hexagonal boron nitride with controllable orientation 被引量:15
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作者 Xiuju Song Junfeng Gao +11 位作者 Yufeng Nie Teng Gao Jingyu Sun Donglin Ma Qiucheng Li Yubin Chen Chuanhong Jin Alicja Bachmatiuk Mark H. Rummeli Feng Ding Yanfeng Zhang Zhongfan Liu 《Nano Research》 SCIE EI CAS CSCD 2015年第10期3164-3176,共13页
Chemical vapor deposition (CVD) synthesis of large-domain hexagonal boron nitride (h-BN) with a uniform thickness is very challenging, mainly due to the extremely high nucleation density of this material. Herein, ... Chemical vapor deposition (CVD) synthesis of large-domain hexagonal boron nitride (h-BN) with a uniform thickness is very challenging, mainly due to the extremely high nucleation density of this material. Herein, we report the successful growth of wafer-scale, high-quality h-BN monolayer films that have large single-crystalline domain sizes, up to -72 μm in edge length, prepared using a folded Cu-foil enclosure. The highly confined growth space and the smooth Cu surface inside the enclosure effectively reduced the precursor feeding rate together and induced a drastic decrease in the nucleation density. The orientation of the as-grown h-BN monolayer was found to be strongly correlated to the crystallographic orientation of the Cu substrate: the Cu (111) face being the best substrate for growing aligned h-BN domains and even single-crystalline monolayers. This is consistent with our density functional theory calculations. The present study offers a practical pathway for growing high-quality h-BN films by deepening our fundamental understanding of the process of their growth by CVD. 展开更多
关键词 hexagonal boron nitride Cu foil domain size ORIENTATION chemical vapordeposition (CVD)
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Serpentinization, abiogenic organic compounds, and deep life 被引量:12
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作者 WANG XianBin OUYANG ZiYuan +3 位作者 ZHUO ShengGuang ZHANG MingFeng ZHENG GuoDong WANG YongLi 《Science China Earth Sciences》 SCIE EI CAS 2014年第5期878-887,共10页
The hydrocarbons and other organic compounds generated through abiogenic or inorganic processes are closely related to two science subjects, i.e., energy resources and life's origin and evolution. "The earth's prim... The hydrocarbons and other organic compounds generated through abiogenic or inorganic processes are closely related to two science subjects, i.e., energy resources and life's origin and evolution. "The earth's primordial abiogenic hydrocarbon theory" and "the serpentinization of abiogenic hydrocarbon theory" are the two mainstream theories in the field of related studies. Ser- pentinizafion generally occurs in slow expanding mid-ocean ridges and continental ophiolites tectonic environment, etc. The abiogenic hydrocarbons and other organic compounds formed through the serpentinization of ultramafic rocks provide energy and raw materials to support chemosynthetic microbial communities, which probably was the most important hydration reac- tion for the origin and early evolution of life. The superposition of biological and abiological processes creates big challenge to the identification of the abiogenic organic materials in serpentinite-hosted ecosystem. Whether abiotic (inorganic) process can form oil and gas resource is a difficult question that has been explored continuously by scientific community for more than a century but has not yet been solved. However, some important progress has been made. The prospecting practice of abiogenic hydrocarbons in commercial gases from the Songliao Basin, China, provides an important example for exploring abiogenic natural gas resources. 展开更多
关键词 ultramafic rocks scrpentinization abiogenic origin organic compound origin of life
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A review of ecological impacts of global climate change on persistent organic pollutant and mercury pathways and exposures in arctic marine ecosystems 被引量:7
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作者 Melissa A. MCKINNEY Sara PEDRO +5 位作者 Rune DIETZ Christian SONNE Aaron T. FISK Denis ROY Bjorn M. JENSSEN Robert J. LETCHER 《Current Zoology》 SCIE CAS CSCD 2015年第4期617-628,共12页
Bioaccumulative and biomagnifying contaminants, such as persistent organic pollutants (POPs) and mercury (Hg), have for decades been recognized as a health concern in arctic marine biota. In recent years, global c... Bioaccumulative and biomagnifying contaminants, such as persistent organic pollutants (POPs) and mercury (Hg), have for decades been recognized as a health concern in arctic marine biota. In recent years, global climate change (GCC) and related loss of arctic sea ice have been observed to be driving substantial change in arctic ecosystems. This review summarizes findings documenting empirical links between GCC-induced ecological changes and alterations in POP and Hg exposures and pathways in arctic marine ecosystems. Most of the studies have reported changes in POP or Hg concentrations in tissue in relation to GCC-induced changes in species trophic interactions. These studies have typically focused on the role of changes in abun- dance, habitat range or accessibility of prey species, particularly in relation to sea ice changes. Yet, the ecological change that re- suited in contaminant trend changes has often been unclear or assumed. Other studies have successfully used chemical tracers, such as stable nitrogen and carbon isotope ratios and fatty acid signatures to link such ecological changes to contaminant level variations or trends. Lower sea ice linked-diet changes/variation were associated with higher contaminant levels in some popula- tions of polar bears, ringed seals, and thick-billed murres, but the influence of changing trophic interactions on POP levels and trends varied widely in both magnitude and direction. We suggest that future research in this new area of GCC-linked ecotox- icology should focus on routine analysis of ancillary ecological metrics with POP and Hg studies, simultaneous consideration of the multiple mechanisms by which GCC and contaminant interactions can occur, and targeted research on changing exposures and toxicological effects in species known to be sensitive to both GCC and contaminants [Current Zoology 61 (4): 617-628, 2015]. 展开更多
关键词 Climate change Ecological change CONTAMINANTS TRENDS ARCTIC Marine ecosystems
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From solar terms to medical terms(Part Ⅰ): A first step with big data
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作者 CHEN Ge SHI Jie 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第9期1707-1718,共12页
The story of the Twenty-four Solar Terms(24-ST_s) is one of the most popular elements in Chinese culture, which has a profound influence on agriculture production, health care, and even daily life in both ancient and ... The story of the Twenty-four Solar Terms(24-ST_s) is one of the most popular elements in Chinese culture, which has a profound influence on agriculture production, health care, and even daily life in both ancient and modern China. This traditional calendric system was invented by the Chinese ancestors through combining fundamental astronomical knowledge with climatic and phenological conditions in the Yellow River Basin some 2000 years ago. Although the basic philosophy of the 24-ST_s remains valid for the country as a whole to date, their regional robustness has been increasingly challenged by accumulating observational data in terms of temporal shift and spatial inhomogeneity. To tackle these issues, we propose to recalibrate the medically related critical timings of Great Heat and Great Cold in the classic ST system by using big meteorological data, and adjust them by introducing geographically correlated analytical models. As a result, a novel calendric system, called the Twenty-four Medical Terms(24-MT_s), has been developed as an upgraded version of the traditional 24-ST_s. The proposed 24-MT_s are characterized by two striking features with respect to the 24-ST_s: A varying duration of each MT instead of a fixed one for the ST, and a geographically dependent timing for each MT instead of a unified one for the entire nation. As such, the updated 24-MT_s are expected to provide a more realistic estimate of these critical timings around the year, and hence, a more precise guidance to agronomic planning and health care activity in China. 展开更多
关键词 Solar Terms Medical Terms Big Data
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