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Co-occurrence Patterns of Above-ground and Below-ground Mite Communities in Farmland of Sanjiang Plain, Northeast China 被引量:7
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作者 LIN Lin GAO Meixiang +3 位作者 LIU Dong ZHANG Xueping WU Haitao WU Donghui 《Chinese Geographical Science》 SCIE CSCD 2014年第3期339-347,共9页
One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, litt... One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, little is known with regard to co-occurrence patterns in above-ground and below-ground communities. In this paper, we used a null model to test non-randomness in the structure of the above-ground and below-ground mite communities in farmland of the Sanjiang Plain, Northeast China. Then, we used four tests for non-randomness to recognize species pairs that would be demonstrated as significantly aggregated or segregated co-occurrences of the above-ground and below-ground mite communities. The pattern of the above-ground mite commu- nity was significantly non-random in October, suggesting species segregation and hence interspecific competition. Additionally, species co-occurrence patterns did not differ from randomness in the above-ground mite community in August or in below-ground mite com- munities in August and October. Only one significant species pair was detected in the above-ground mite community in August, while no significant species pairs were recognized in the above-ground mite community in October or in the below-ground mite communities in August and October. The results indicate that non-randomness and significant species pairs may not be the general rule in the above-ground and below-ground mite communities in farmland of the Sanjiang Plain at the fine scale. 展开更多
关键词 above-ground mite below-ground mite mite communities co-occurrence patterns interspecific competition species pairassociations
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Biomass and dominance of conservative species drive above-ground biomass productivity in a mediterranean-type forest of Chile 被引量:4
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作者 Ariel Isaías Ayma-Romay Horacio E.Bown 《Forest Ecosystems》 SCIE CSCD 2019年第4期339-351,共13页
Background: Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivi... Background: Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivity. One challenge in current forest management depends on identifying and manipulating these mechanisms to enhance productivity. This study assessed the extent to which these mechanisms control aboveground biomass productivity(AGBP) of a Chilean mediterranean-type matorral. AGBP measured as tree aboveground biomass changes over a 7-years period, was estimated for twelve 25 m × 25 m plots across a wide range of matorral compositions and structures. Variables related to canopy structure, species and functional diversity, species and functional dominance, soil texture, soil water and soil nitrogen content were measured as surrogates of the four mechanisms proposed. Linear regression models were used to test the hypotheses. A multimodel inference based on the Akaike’s information criterion was used to select the best models explaining AGBP and for identifying the relative importance of each mechanism.Results: Vegetation quantity(tree density) and mass-ratio(relative biomass of Cryptocarya alba, a conservative species) were the strongest drivers increasing AGBP, while niche complementarity(richness species) and soil resources(sand, %) had a smaller effect either decreasing or increasing AGBP, respectively. This study provides the first assessment of alternative mechanisms driving AGBP in mediterranean forests of Chile. There is strong evidence suggesting that the vegetation quantity and mass-ratio mechanisms are key drivers of AGBP, such as in other tropical and temperate forests. However, in contrast with other studies from mediterranean-type forests, our results show a negative effect of species diversity and a small effect of soil resources on AGBP.Conclusion: AGBP in the Chilean matorral depends mainly on the vegetation quantity and mass-ratio mechanisms.The findings of this study have implications for matorral restoration and management for the production of timber and non-timber products and carbon sequestration. 展开更多
关键词 above-ground biomass productivity Diversity Niche complementarity MASS-RATIO Mediterranean Soil resources
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Influence of decorative materials on cooling load of residential apartments
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作者 Shahraein Masoud Taheri 赵立华 孟庆林 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期156-160,共5页
The influence of a polyvinyl chloride(PVC)-panel on the cooling load of a residential apartment in Mashad,Iran,is analyzed by the DeST-h software.And the summer natural ventilation of the residential apartment is in... The influence of a polyvinyl chloride(PVC)-panel on the cooling load of a residential apartment in Mashad,Iran,is analyzed by the DeST-h software.And the summer natural ventilation of the residential apartment is investigated to determine the wind speed into the apartment through the computational fluid dynamics software.The evaluation results of the indoor wind velocity show that most parts of the apartment are comfortable.The cooling load of the penthouse can be decreased about 10.5% or 6.5% when an air layer exists or does not exist between the ceiling and the PVC-panel,respectively,indicating that the existence of the air layer can decrease the cooling load.However,the effect of the increase in the air layer's thickness on the decrease in the cooling load is obvious.Adding a thin layer of air between the ceiling and the PVC-panel is a good step toward sustainable buildings. 展开更多
关键词 residential apartments natural ventilation energy consumption decorative materials Mashad
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Estimation of the Above-ground Biomass of Tamarix Species along a Transect at the Tarim River's Middle Reaches 被引量:3
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作者 努尔比亚.阿布力米提 努尔巴依.阿布都沙力克 +1 位作者 于苏云江.吗米提敏 Niels Thevs 《Agricultural Science & Technology》 CAS 2011年第2期301-304,共4页
[Objective] The purpose was to research the distribution characteristics of Tamarix species above-ground biomass of Tarim River's middle reaches and to find out best-fit linear-regression model of Tamarix species in ... [Objective] The purpose was to research the distribution characteristics of Tamarix species above-ground biomass of Tarim River's middle reaches and to find out best-fit linear-regression model of Tamarix species in this area.[Method] By dint of the most common sampling method PCQ,five samples in the middle reaches of Tarim River were collected.The best-fit linear-regression model of Tamarix species of this area was set up,based on the fieldwork and the model of Evangelista and obtained the distribution rules of Tamarix species of Tarim River's middle reaches.[Result] The result indicated that this model fitted for the estimation of aboveground biomass of the study area.According to the distribution rules of aboveground biomass,it was clear that underground water was the major element which decided the distribution of aboveground biomass.[Conclusion] The study provided theoretical basis for the calculation of biomass of Tamarix. 展开更多
关键词 above-ground biomass Tamarix species Linear-regression analysis
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Estimating above-ground biomass by fusion of LiDAR and multispectral data in subtropical woody plant communities in topographically complex terrain in North-eastern Australia 被引量:2
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作者 Sisira Ediriweera Sumith Pathirana +1 位作者 Tim Danaher Doland Nichols 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第4期761-771,共11页
We investigated a strategy to improve predicting capacity of plot-scale above-ground biomass (AGB) by fusion of LiDAR and Land- sat5 TM derived biophysical variables for subtropical rainforest and eucalypts dominate... We investigated a strategy to improve predicting capacity of plot-scale above-ground biomass (AGB) by fusion of LiDAR and Land- sat5 TM derived biophysical variables for subtropical rainforest and eucalypts dominated forest in topographically complex landscapes in North-eastern Australia. Investigation was carried out in two study areas separately and in combination. From each plot of both study areas, LiDAR derived structural parameters of vegetation and reflectance of all Landsat bands, vegetation indices were employed. The regression analysis was carded out separately for LiDAR and Landsat derived variables indi- vidually and in combination. Strong relationships were found with LiDAR alone for eucalypts dominated forest and combined sites compared to the accuracy of AGB estimates by Landsat data. Fusing LiDAR with Landsat5 TM derived variables increased overall performance for the eucalypt forest and combined sites data by describing extra variation (3% for eucalypt forest and 2% combined sites) of field estimated plot-scale above-ground biomass. In contrast, separate LiDAR and imagery data, andfusion of LiDAR and Landsat data performed poorly across structurally complex closed canopy subtropical minforest. These findings reinforced that obtaining accurate estimates of above ground biomass using remotely sensed data is a function of the complexity of horizontal and vertical structural diversity of vegetation. 展开更多
关键词 FUSION above-ground biomass LiDAR multispectral data subtropical plant communities
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Global patterns in above-ground net primary production and precipitation-use efficiency in grasslands 被引量:5
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作者 QIN Xiao-jing HONG Jiang-tao +1 位作者 MA Xing-xing WANG Xiao-dan 《Journal of Mountain Science》 SCIE CSCD 2018年第8期1682-1692,共11页
The above-ground net primary production(ANPP) and the precipitation-use efficiency(PUE) regulate the carbon and water cycles in grassland ecosystems, but the relationships among the ANPP, PUE and precipitation are sti... The above-ground net primary production(ANPP) and the precipitation-use efficiency(PUE) regulate the carbon and water cycles in grassland ecosystems, but the relationships among the ANPP, PUE and precipitation are still controversial. We selected 717 grassland sites with ANPP and mean annual precipitation(MAP) data from 40 publications to characterize the relationships ANPP–MAP and PUE–MAP across different grassland types. The MAP and ANPP showed large variations across all grassland types, ranging from 69 to 2335 mm and 4.3 to 1706 g m^(-2), respectively. The global maximum PUE ranged from 0.19 to 1.49 g m^(-2) mm^(-1) with a unimodal pattern. Analysis using the sigmoid function explained the ANPP–MAP relationship best at the global scale. The gradient of the ANPP–MAP graph was small for arid and semi-arid sites(MAP <400 mm). This study improves our understanding of the relationship between ANPP and MAP across dry grassland ecosystems. It provides new perspectives on the prediction and modeling of variations in the ANPP for different grassland types along precipitation gradients. 展开更多
关键词 Litter decomposition Alpine communities Tea bag index Carbon cycle above-ground net primary production Precipitation-use efficiency Sigmoid function Precipitation gradients
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Estimating canopy closure density and above-ground tree biomass using partial least square methods in Chinese boreal forests 被引量:5
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作者 LEI Cheng-liang JU Cun-yong +3 位作者 CAI Ti-jiu J1NG Xia WEI Xiao-hua DI Xue-ying 《Journal of Forestry Research》 CAS CSCD 2012年第2期191-196,共6页
Boreal forests play an important role in global environment systems. Understanding boreal forest ecosystem structure and function requires accurate monitoring and estimating of forest canopy and biomass. We used parti... Boreal forests play an important role in global environment systems. Understanding boreal forest ecosystem structure and function requires accurate monitoring and estimating of forest canopy and biomass. We used partial least square regression (PLSR) models to relate forest parameters, i.e. canopy closure density and above ground tree biomass, to Landsat ETM+ data. The established models were optimized according to the variable importance for projection (VIP) criterion and the bootstrap method, and their performance was compared using several statistical indices. All variables selected by the VIP criterion passed the bootstrap test (p〈0.05). The simplified models without insignificant variables (VIP 〈1) performed as well as the full model but with less computation time. The relative root mean square error (RMSE%) was 29% for canopy closure density, and 58% for above ground tree biomass. We conclude that PLSR can be an effective method for estimating canopy closure density and above ground biomass. 展开更多
关键词 above-ground tree biomass bootstrap method canopy clo- sure density partial least square regression (PLSR) VIP criterion
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Plant cover as an estimator of above-ground biomass in semi-arid woody vegetation in Northeast Patagonia,Argentina 被引量:1
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作者 Laura B RODRIGUEZ Silvia S TORRES ROBLES +3 位作者 Marcelo F ARTURI Juan M ZEBERIO Andrés C H GRAND Néstor I GASPARRI 《Journal of Arid Land》 SCIE CSCD 2021年第9期918-933,共16页
The quantification of carbon storage in vegetation biomass is a crucial factor in the estimation and mitigation of CO2 emissions.Globally,arid and semi-arid regions are considered an important carbon sink.However,they... The quantification of carbon storage in vegetation biomass is a crucial factor in the estimation and mitigation of CO2 emissions.Globally,arid and semi-arid regions are considered an important carbon sink.However,they have received limited attention and,therefore,it should be a priority to develop tools to quantify biomass at the local and regional scales.Individual plant variables,such as stem diameter and crown area,were reported to be good predictors of individual plant weight.Stand-level variables,such as plant cover and mean height,are also easy-to-measure estimators of above-ground biomass(AGB)in dry regions.In this study,we estimated the AGB in semi-arid woody vegetation in Northeast Patagonia,Argentina.We evaluated whether the AGB at the stand level can be estimated based on plant cover and to what extent the estimation accuracy can be improved by the inclusion of other field-measured structure variables.We also evaluated whether remote sensing technologies can be used to reliably estimate and map the regional mean biomass.For this purpose,we analyzed the relationships between field-measured woody vegetation structure variables and AGB as well as LANDSAT TM-derived variables.We obtained a model-based ratio estimate of regional mean AGB and its standard error.Total plant cover allowed us to obtain a reliable estimation of local AGB,and no better fit was attained by the inclusion of other structure variables.The stand-level plant cover ranged between 18.7%and 95.2%and AGB between about 2.0 and 70.8 Mg/hm^(2).AGB based on total plant cover was well estimated from LANDSAT TM bands 2 and 3,which facilitated a model-based ratio estimate of the regional mean AGB(approximately 12.0 Mg/hm^(2))and its sampling error(about 30.0%).The mean AGB of woody vegetation can greatly contribute to carbon storage in semi-arid lands.Thus,plant cover estimation by remote sensing images could be used to obtain regional estimates and map biomass,as well as to assess and monitor the impact of land-use change on the carbon balance,for arid and semi-arid regions. 展开更多
关键词 above-ground biomass SHRUBLANDS ratio estimation carbon storage remote sensing PATAGONIA
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A New Design of Student Apartment Bed Based on Kansei Engineering and Ergonomics 被引量:6
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作者 SU Ming-yu YANG Guang-hui 《Computer Aided Drafting,Design and Manufacturing》 2014年第3期70-74,共5页
Aiming at the defects of the products available on the market at present and basing on the Kansei Engineering and Ergonomics, a new kind of student apartment bed which can prove its humanity more clearly is designed, ... Aiming at the defects of the products available on the market at present and basing on the Kansei Engineering and Ergonomics, a new kind of student apartment bed which can prove its humanity more clearly is designed, and its design direction is gotten through the questionnaire and the design starts from the real actual needs of students. After the original design was finished, the later investigation on the students was engaged with and made the engineering analysis. The conclusion is that the sum of "perfect" and "good" membership rates is up to 64%, hence the comprehensive assessment of the design is perfect. That is to say, this design is able to realize and meet the needs of users, and there is no doubt that it will have a good business prospects. 展开更多
关键词 Kansei Engineering ERGONOMICS new student apartment combined bed HUMANIZATION
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Putting Faces to Names: Snapshots of Two Committee Meetings, 95 Years Apart, Emphasize Continuous International Cooperation in the Atmospheric Sciences 被引量:1
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作者 Hans VOLKERT 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第5期571-575,共5页
1.Introduction Spectacular advances have been made in the atmospheric sciences on a global level during a period of one hundred years or more,which is arguably most evident through"the quiet revolution of numeric... 1.Introduction Spectacular advances have been made in the atmospheric sciences on a global level during a period of one hundred years or more,which is arguably most evident through"the quiet revolution of numerical weather prediction"(Bauer et 展开更多
关键词 Co work Putting Faces to Names:Snapshots of Two Committee Meetings 95 Years apart Emphasize Continuous International Cooperation in the Atmospheric Sciences
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介词except(for)、besides、apart from及but for在实践中的应用
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作者 马志辉 《本溪冶金高等专科学校学报》 2003年第2期48-49,共2页
在英语作为母语的国家 ,人们在使用语言中重于语言在客观中的应用习惯 ,并以此来掌握一些常用词在生活中的正确使用形式和方法。而与此相悖的则是许多非英语母语国家的人们在学习英语中则重于一种语法的系统化 ,以一种不变的定式来使用... 在英语作为母语的国家 ,人们在使用语言中重于语言在客观中的应用习惯 ,并以此来掌握一些常用词在生活中的正确使用形式和方法。而与此相悖的则是许多非英语母语国家的人们在学习英语中则重于一种语法的系统化 ,以一种不变的定式来使用这些常用词 ,造成在实践应用中的错误甚至于被误解。现以题目中一组词作为例子 。 展开更多
关键词 英语 介词 语法 EXCEPT BESIDES apart from BUT for
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Model-based estimation of above-ground biomass in the miombo ecoregion of Zambia 被引量:1
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作者 James Halperin Valerie LeMay +2 位作者 Emmanuel Chidumayo Louis Verchot Peter Marshall 《Forest Ecosystems》 SCIE CSCD 2016年第4期258-274,共17页
Background:Information on above-ground biomass(AGB) is important for managing forest resource use at local levels,land management planning at regional levels,and carbon emissions reporting at national and internati... Background:Information on above-ground biomass(AGB) is important for managing forest resource use at local levels,land management planning at regional levels,and carbon emissions reporting at national and international levels.In many tropical developing countries,this information may be unreliable or at a scale too coarse for use at local levels.There is a vital need to provide estimates of AGB with quantifiable uncertainty that can facilitate land use management and policy development improvements.Model-based methods provide an efficient framework to estimate AGB.Methods:Using National Forest Inventory(NFI) data for a^1,000,000 ha study area in the miombo ecoregion,Zambia,we estimated AGB using predicted canopy cover,environmental data,disturbance data,and Landsat 8 OLI satellite imagery.We assessed different combinations of these datasets using three models,a semiparametric generalized additive model(GAM) and two nonlinear models(sigmoidal and exponential),employing a genetic algorithm for variable selection that minimized root mean square prediction error(RMSPE),calculated through cross-validation.We compared model fit statistics to a null model as a baseline estimation method.Using bootstrap resampling methods,we calculated 95% confidence intervals for each model and compared results to a simple estimate of mean AGB from the NFI ground plot data.Results:Canopy cover,soil moisture,and vegetation indices were consistently selected as predictor variables.The sigmoidal model and the GAM performed similarly;for both models the RMSPE was -36.8 tonnes per hectare(i.e.,57% of the mean).However,the sigmoidal model was approximately 30% more efficient than the GAM,assessed using bootstrapped variance estimates relative to a null model.After selecting the sigmoidal model,we estimated total AGB for the study area at 64,526,209 tonnes(+/- 477,730),with a confidence interval 20 times more precise than a simple designbased estimate.Conclusions:Our findings demonstrate that NFI data may be combined with freely available satellite imagery and soils data to estimate total AGB with quantifiable uncertainty,while also providing spatially explicit AGB maps useful for management,planning,and reporting purposes. 展开更多
关键词 National Forest Inventory above-ground biomass Miombo REDD+ Generalized additive model Nonlinear model Landsat 8 OLI
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Electricity consumption propensity of different household members in apartment house
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作者 KIM Yu-lan SEO Youn-kyu +2 位作者 JEON Gyu-yeob HONG Won-hwa KIM Kwang-woo 《Journal of Chongqing University》 CAS 2012年第1期19-25,共7页
South Korea is an energy-guzzling country.Economic reasons in the country force its households to save more energy.Household energy consumption in South Korea has grown slow compared to other sectors and household ene... South Korea is an energy-guzzling country.Economic reasons in the country force its households to save more energy.Household energy consumption in South Korea has grown slow compared to other sectors and household energy consumption per capita is lower than the OECD (Organization for Economic Co-operation and Development) average.However,its per capita electricity use soared and expected to keep climbing mainly due to the increasing number of one-person household.To establish effective strategy against a possible electricity shortage,the amount of electricity energy consumption needs to be understood clearly first.We adopted both general survey and detailed survey for people living in apartment housings and collected data on electrical instrument use according to individual schedule.Based on these data,we tried to analyze electricity consumption patterns resulting from energy using activities at home and find out electricity using tendency according to each family member's characteristics in apartment housings. 展开更多
关键词 apartment house electricity consumption LIFESTYLE household members
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The Profit Model of Long-Term Lease Apartments Under Multi-Agent Supply
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作者 LI Shuoyang LIU Qunhong 《Journal of Landscape Research》 2018年第6期109-112,共4页
The acceleration of urbanization has led to an increase in the number of urban floating population, which leads to more demands for the housing rental market. With the support of policies, long-term lease apartments h... The acceleration of urbanization has led to an increase in the number of urban floating population, which leads to more demands for the housing rental market. With the support of policies, long-term lease apartments have begun to emerge. However, under the multi-subject supply, longterm lease apartments have encountered problems such as small profits in their development. Starting from the background of the development of long-term lease apartments, this study classified the main types of long-term lease apartments, analyzed the four profit models of comprehensive profit, expansion of rent difference, REITs and value-added services based on their business models, and proposed corresponding suggestions on the profitability of long-term lease apartments according to the current situation of profit difficulty of long-term lease apartments and the lack of profit models. 展开更多
关键词 MULTI-AGENT supply LONG-TERM LEASE apartMENT PROFIT model
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Outdoor Environmental Landscape Design of the Apartment for the Elderly in Southern Cities of China
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作者 ZHOU Bo CHEN Sihua +2 位作者 LI Xiaoyun YU Hanqing HUANG Wenhan 《Journal of Landscape Research》 2016年第1期23-25,30,共4页
On the basis of environmental psychology and environment-behavior science, this paper took Beijing Oriental Sun City Elderly Apartment for example to explore outdoor environmental landscape design schemes of the elder... On the basis of environmental psychology and environment-behavior science, this paper took Beijing Oriental Sun City Elderly Apartment for example to explore outdoor environmental landscape design schemes of the elderly apartment suitable for geomorphologic features, climatic conditions, and humanistic background of southern cities against the background of population aging in China, so as to provide references for the outdoor environment construction for the elderly apartment. 展开更多
关键词 Southern cities apartment for the elderly Environmental landscape OUTDOOR
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The role of furniture in exposure to non-ionizing radiation in a residential apartment
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作者 Vasil Bilero 《Natural Science》 2012年第4期258-263,共6页
This article concerns the sources of non-ionizing radiation in a normal inhabited environment. Measurements show that residents are exposed to non-ionizing radiation in levels both below and above the European normati... This article concerns the sources of non-ionizing radiation in a normal inhabited environment. Measurements show that residents are exposed to non-ionizing radiation in levels both below and above the European normative. Excess is present due to the fact that, producers of electronic equipment and appliances, those who use them, as well as those involved in the construction of housing, have insufficient acquaintance with non-ionizing radiation. Producers are advised to increase the coefficient of safety towards non-ionizing radiation by renewing technology. Users are advised to operate apparatus with the lowest possible power, to minimise time exposed to sources, to maximise the distance from them and to renew their appliances. Construction workers should take non-ionizing radiation more into consideration when furnishing of houses. 展开更多
关键词 ROLE FURNITURE Non-Lonizing RADIATION RESIDENTIAL apartMENT
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Assessment of tree diversity and above-ground biomass in coffee agroforest dominated tropical landscape of India's Central Western Ghats
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作者 Guddappa M.Devagiri Anil Kumar Khaple +3 位作者 Hosuru B.Anithraj Cheppudira G.Kushalappa Amaresh Kumar Krishnappa Shashi Bhushan Mishra 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第3期1005-1015,共11页
The purpose of this study was to quantify the changes in tree diversity and above-ground biomass associated with six land-use types in Kodagu district of India's Western Ghats. We collected data on species richnes... The purpose of this study was to quantify the changes in tree diversity and above-ground biomass associated with six land-use types in Kodagu district of India's Western Ghats. We collected data on species richness,composition and above-ground biomass(AGB) of trees,shrubs and herbs from 96 sample plots of 0.1 ha. Totals of83 species from 26 families were recorded across the landuses. Tree species richness, diversity and composition were significantly higher in evergreen forest(EGF) than in other land-uses. Similarly, stem density and basal area were greater in EGF compared to other land-uses. Detrended correspondence analysis(DCA) yielded three distinct groups along the land-use intensities and rainfall gradient on the first and second axes, respectively. The first DCA axis accounted for 45% and second axis for 35% of the total variation in species composition. Together the first two axes accounted for over 2/3 of the variation in species composition across land-use types. Across the land-uses,AGB ranged from 58.6 Mg ha-1 in rubber plantation to327.3 Mg ha-1 in evergreen forest. Our results showed that species diversity and AGB were negatively impacted bythe land-use changes. We found that coffee agroforests resembled natural forest and mixed species plantation in terms of tree diversity and biomass production, suggesting that traditional coffee farms can help to protect tree species, sustain smallholder production and offer opportunities for conservation of biodiversity and climate change mitigation. 展开更多
关键词 WESTERN Ghats COFFEE agroforest Land-use changes Diversity above-ground biomass Carbon
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Allometric prediction of above-ground biomass of eleven woody tree species in the Sudanian savanna-woodland of West Africa
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作者 Louis Sawadogo Patrice Savadogo +5 位作者 Daniel Tiveau Sidzabda Djibril Dayamba Didier Zida Yves Nouvellet Per Christer Oden Sita Guinko 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第4期475-481,524,共8页
Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We devel... Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We developed species-specific allometric models to predict aboveground biomass for 11 native tree species of the Sudanian savanna- woodlands. Diameters at the base and at breast height, with species means ranging respectively from 11 to 28 cm and 9 to 19 cm, and the height of the trees were used as predictor variables. Sampled trees spanned a wide range of sizes including the largest sizes these species can reach. As a response variable, the biomass of the trees was obtained through destructive sampling of 4 754 trees during wood harvesting. We used a stepwise multiple regression analysis with backward elimination procedure to develop models separately predicting, total biomass of the trees, stem biomass, and biomass of branches and twigs. All species- specific regression models relating biomass with measured tree dimen- sions were highly significant (p 〈 0.001). The biomass of branches and twigs was less predictable compared to stem biomass and total biomass, although their models required fewer predictors and predictor interac- tions. The best-fit equations for total above-ground biomass and stem biomass bad R2 〉 0.70, except for the Acacia species; for branches including twig biomass, R2-values varied from 0.749 for Anogeissus leiocarpa to 0.183 for Acacia macrostachya. The use of these equations in estimating available biomass will avoid destructive sampling, and aid in planning for sustainable use of these species. 展开更多
关键词 ALLOMETRY above-ground biomass indigenous woody species linear regression site specific equation
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Finite element modelling of the pull-apart formation: implication for tectonics of Bengo Co pull-apart basin, southern Tibet 被引量:1
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作者 Ganesh Raj Joshi Daigoro Hayashi 《Natural Science》 2010年第6期654-666,共13页
The tectonic deformation and state of stress are significant parameters to understand the active structure, seismic phenomenon and overall ongoing geodynamic condition of any region. In this paper, we have examined th... The tectonic deformation and state of stress are significant parameters to understand the active structure, seismic phenomenon and overall ongoing geodynamic condition of any region. In this paper, we have examined the state of stress and crustal deformation during the formation of the Beng Co pull-apart basins produced by an enéchelon strike-slip fault systems using 2D Finite Element Modelling (FEM) under plane stress condition. The numerical modelling technique used for the experiments is based on FEM which enables us to analyze the static behavior of a real and continues structures. We have used three sets of models to explore how the geometry of model (fault overlap and pre-existing weak shear zone) and applied boundary conditions (pure strike-slip, transpressional and transtensional) influence the development of state of stress and deformation during the formation of pull-apart basins. Modelling results presented here are based on five parameters: 1) distribution, orienttation, and magnitude of maximum (σH max) and minimum (σH max) horizontal compressive stress 2) magnitude and orientation of displacement vectors 3) distribution and concentration of strain 4) distribution of fault type and 5) distribution and concentration of maximum shear stress (σH max) contours. The modelling results demonstrate that the deformation pattern of the en-échelon strike-slip pull-apart formation is mainly dependent on the applied boundary conditions and amount of overlap between two master strike-slip faults. When the amount of overlap of the two master strike-slip faults increases, the surface deformation gets wider and longer but when the overlap between two master strike-slip faults is zero, block rotation observed significantly, and only narrow and small surface deform ation obtained. These results imply that overlap between two master strike-slip faults is a significant factor in controlling the shape, size and morphology of the pull-apart basin formation. Results of numerical modelling further show that the pattern of the distribution of maximum shear stress (τmax) contours are prominently depend on the amount of overlap between two master strike-slip faults and applied boundary conditions. In case of more overlap between two masters strike-slip faults, τ max mainly concentrated at two corners of the master faults and that reduces and finally reaches zero at the centre of the pull-apart basin, whereas in case of no overlap, τmax largely concentrated at two corners and tips of the master strike-slip faults. These results imply that the distribution and concentration of the maximum shear stress is mainly governed by amount of overlap between the master strike-slip faults in the en-échelon pull-apart formation. Numerical results further highlight that the distribution patterns of the displacement vectors are mostly dependent on the amount of overlap and applied boundary conditions in the en-échelon pull-apart formation. 展开更多
关键词 State of Stress Deformation Regime PULL-apart FORMATION Numerical Modelling Southern TIBET
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Horizontal Fire Spread in a Contemporary Apartment Based on a Real Fire
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作者 Stefanie Schubert-Polzin Alexander Saupe Ulrich Krause 《Open Journal of Civil Engineering》 2019年第4期367-385,共19页
The apartment fire tests comprise a set of two full-scale fire experiments in a dwelling building made from pre-fabricated concrete elements in April 2013. Two apartments were nearly identically furnished and fully in... The apartment fire tests comprise a set of two full-scale fire experiments in a dwelling building made from pre-fabricated concrete elements in April 2013. Two apartments were nearly identically furnished and fully instrumented with thermocouples, video cameras and gas extraction probes. The apartments were ignited successively whereupon the fire in the second apartment developed freely to post-flashover conditions and got the main focus in this report. The apartment was completely furnished with contemporary furniture and objects, and had an average fire load density for residential occupancy. A full description of the fire load, ventilation conditions and instrumentation are provided. The focus of this report is primarily to obtain conclusions on the horizontal spread of smoke throughout the apartment during the fire growth period. Velocities of smoke spreading were measured to be in the range below 0.05 m/s which means that the smoke migrated over the longest distance throughout the apartment for about 3 to 4 minutes while the flame did not leave the initial fire room. The main aim of the experiments was to collect a comprehensive set of data from a realistic and contemporary fire scenario to validate numerical simulations. 展开更多
关键词 apartMENT FIRE HORIZONTAL FIRE Spread Smoke SPREADING FULL-SCALE FIRE Test
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