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Role of outdoor trees on pedestrian wind and thermal conditions around a pre-education building for sustainable energy management
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作者 LI Xiao-jie TANG Hui-li 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2039-2053,共15页
Finding sustainable energy resources is essential to face the increasing energy demand.Trees are an important part of ancient architecture but are becoming rare in urban areas.Trees can control and tune the pedestrian... Finding sustainable energy resources is essential to face the increasing energy demand.Trees are an important part of ancient architecture but are becoming rare in urban areas.Trees can control and tune the pedestrian-level wind velocity and thermal condition.In this study,a numerical investigation is employed to assess the role of trees planted in the windward direction of the building complex on the thermal and pedestrian wind velocity conditions around/inside a pre-education building located in the center of the complex.Compared to the previous studies(which considered only outside buildings),this work considers the effects of trees on microclimate change both inside/outside buildings.Effects of different parameters including the leaf area density and number of trees,number of rows,far-field velocity magnitude,and thermal condition around the main building are assessed.The results show that the flow velocity in the spacing between the first-row buildings is reduced by 30%-40% when the one-row trees with 2 m height are planted 15 m farther than the buildings.Furthermore,two rows of trees are more effective in higher velocities and reduce the maximum velocity by about 50%.The investigation shows that trees also could reduce the temperature by about 1℃around the building. 展开更多
关键词 sustainable management energy trees urban area thermal condition building
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Concentrations of foliar and surface soil in nutrients Pinus spp. plantations in relation to species and stand age in Zhanggutai sandy land, northeast China 被引量:5
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作者 陈广生 曾德慧 陈伏生 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第1期11-18,J001,共9页
The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, ... The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Keywords coniferous trees - foliar nutrient concentration - limiting nutrients - N - P ratio - Zhanggutai sandy land CLC number S718.55 Document code A Article ID 1007-662X(2004)01-0011-08 Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. ChinaResponsible editor: Song Funan 展开更多
关键词 coniferous trees foliar nutrient concentration limiting nutrients N P ratio Zhanggutai sandy land
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托卡马克中的电磁兼容设计
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作者 胡思明 秦品健 +1 位作者 范叔平 季幼章 《核聚变与等离子体物理》 CAS CSCD 北大核心 1992年第2期100-104,110,共6页
本文提出了托卡马克中电磁兼容的设计方法,指出了建立地系统监测的必要性,并通过HT-6B装置着重介绍了“地树”的设计。
关键词 托卡马克 电磁兼容 地树
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Analysis of organic acids in selected forest litters of Northeast China 被引量:7
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作者 宋金凤 崔晓阳 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第4期285-289,共5页
Larch (Larix olgensis), Manchurian ash (Fraxinus mandshurica), Korean pine (Pinus koraiensis) and White birch (Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were ... Larch (Larix olgensis), Manchurian ash (Fraxinus mandshurica), Korean pine (Pinus koraiensis) and White birch (Betula platyphylla) are the major planting species in northeast China. The samples of forest litters were collected from the stands of the above 4 species in Laoyeling and Jianlagou experiment stations of Maorshan Exp. Forest Farm (45?2-45?0N, 127?0-127?8E), Northeast Forestry University, in early October 2002. Quantitative analysis and qualitative analysis were carried out on the organic acids existing in freshly fallen litters (L layer) and hemi-decomposed litters (F layer) of the four forest species by using Gas Chromatogram system. A wide variety of organic acids were identified, including oxalic, malonic, fumaric, succinic, maleic, malic, citric, C16:0, C18:0, C18:1, C18:2, C18:3 and C20:0 acids. In respect of L litters of all samples, the oxalic acid content (over 30 mg/g) was the highest of the seven low-molecular-weight organic acids identified, while the content of oleic or linoleic (above 40 mg/g) was found to be highest among the six high aliphatic acids identified. As to F litters, oxalic acid content was also the highest, followed by linoleic and oleic. For the same tree species or the same forest, the kinds and contents of organic acids in L litters were more abundant than that in F litters. 展开更多
关键词 Forest litter Organic acid Capillary gas chromatography
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Stochastic Air Traffic Flow Management for Demand and Capacity Balancing Under Capacity Uncertainty
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作者 CHEN Yunxiang XU Yan ZHAO Yifei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第5期656-674,共19页
This paper introduces an innovative approach to the synchronized demand-capacity balance with special focus on sector capacity uncertainty within a centrally controlled collaborative air traffic flow management(ATFM)f... This paper introduces an innovative approach to the synchronized demand-capacity balance with special focus on sector capacity uncertainty within a centrally controlled collaborative air traffic flow management(ATFM)framework.Further with previous study,the uncertainty in capacity is considered as a non-negligible issue regarding multiple reasons,like the impact of weather,the strike of air traffic controllers(ATCOs),the military use of airspace and the spatiotemporal distribution of nonscheduled flights,etc.These recessive factors affect the outcome of traffic flow optimization.In this research,the focus is placed on the impact of sector capacity uncertainty on demand and capacity balancing(DCB)optimization and ATFM,and multiple options,such as delay assignment and rerouting,are intended for regulating the traffic flow.A scenario optimization method for sector capacity in the presence of uncertainties is used to find the approximately optimal solution.The results show that the proposed approach can achieve better demand and capacity balancing and determine perfect integer solutions to ATFM problems,solving large-scale instances(24 h on seven capacity scenarios,with 6255 flights and 8949 trajectories)in 5-15 min.To the best of our knowledge,our experiment is the first to tackle large-scale instances of stochastic ATFM problems within the collaborative ATFM framework. 展开更多
关键词 air traffic flow management demand and capacity balancing flight delays sector capacity uncertainty ground delay programs probabilistic scenario trees
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Walnut Tree Grafting Experiments in Different Areas in Yunnan Province 被引量:1
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作者 赵廷松 范志远 +8 位作者 谭凤琼 王洪艳 潘莉 邹伟烈 杜春花 刘娇 曾清贤 饶绍松 王斌 《Agricultural Science & Technology》 CAS 2017年第4期704-706,共3页
Yunnan has an area of 2.88 million hm2 walnut trees. Due to freezing in- jury and rapid growth, however, there are a lot of iron walnuts or inferior-quality walnuts ready for grafting. In five years, we conducted expe... Yunnan has an area of 2.88 million hm2 walnut trees. Due to freezing in- jury and rapid growth, however, there are a lot of iron walnuts or inferior-quality walnuts ready for grafting. In five years, we conducted experiments in Kunming (Yunnan Academy of Forestry), Gongshan County, Gucheng City, Luliang County, and Ludian County by cleft grafting, veneer grafting, bark grafting and whip grafting. The grafting approaches should be selected according to grafting requirements, characteristics, and survival rate. For example, with a low survival rate, cleft grafting can be abandoned, and the rest approaches might be chosen as per practical demands. 展开更多
关键词 YUNNAN Different areas Walnut trees Grafting experiment
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Effects of climate factors on the height increment of poplar protec-tion forest in the riverbank field
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作者 李海梅 何兴元 王奎玲 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期177-180,共4页
Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, C... Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by step-wise regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height increment of poplar protection forest and climatic factors was developed. The order of grey relevance for the effect of climatic factors on the height increment of poplar protection forest is: light>water>heat, and it could be interpreted that the poplar increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis for the in-tensive cultivation and regeneration of the poplar protection forest in riverbank field in similar regions in China. 展开更多
关键词 Riverbank field Poplar protection forest Tree height Increment Climate factor
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Studies on adaptability of Populus bolleana and other Poplar trees in northwest Shanxi Province 被引量:2
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作者 吕皎 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第1期31-34,共5页
Through five years (1996-2000) experiment, the growth characteristics and resistance to insect and cold of the seven poplar varieties including P. po pularis, P. opera, P. pseudo-simonii, P. beijinensis, P. bolleana,... Through five years (1996-2000) experiment, the growth characteristics and resistance to insect and cold of the seven poplar varieties including P. po pularis, P. opera, P. pseudo-simonii, P. beijinensis, P. bolleana, P. ( eurameri cana and P. simonii, which were planted in loess hilly land in northwest Shanxi Province, were tested under different planting densities and site conditions. A randomized block design and three times repetition were adopted in the test. Bas ed on the test results in arid and cold area of the northwest Shanxi, the hybrid poplar trees taking Populus cathaysna as their female parent could be selected for afforestation, such as P. popularis and P. opera, and the growing space of s ingle plant should be larger than 20 m2. P. bolleana as an introduced tree speci es grows well in this area, but its growth is likely affected by ground water co ndition. On the site with relatively abundant soil water, P. bolleana usually su ffer from frost crack at its trunk base. As a result, P. bolleara is suited to p lanting in the site where is short of soil water. P. x euramericana is not suita ble for large-scale afforestation, especially in arid slopes and ridges of loess hilly land . 展开更多
关键词 Poplar trees Arid and cold area ADAPTABILITY Shanxi Province
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Classification Method for Dongting Lake Wetland Based on Geographic Information
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作者 朱晓荣 张怀清 《Agricultural Science & Technology》 CAS 2012年第10期2175-2179,2196,共6页
[Objective] This study aimed to improve the accuracy of remote sensing classification for Dongting Lake Wetland.[Method] Based on the TM data and ground GIS information of Donting Lake,the decision tree classification... [Objective] This study aimed to improve the accuracy of remote sensing classification for Dongting Lake Wetland.[Method] Based on the TM data and ground GIS information of Donting Lake,the decision tree classification method was established through the expert classification knowledge base.The images of Dongting Lake wetland were classified into water area,mudflat,protection forest beach,Carem spp beach,Phragmites beach,Carex beach and other water body according to decision tree layers.[Result] The accuracy of decision tree classification reached 80.29%,which was much higher than the traditional method,and the total Kappa coefficient was 0.883 9,indicating that the data accuracy of this method could fulfill the requirements of actual practice.In addition,the image classification results based on knowledge could solve some classification mistakes.[Conclusion] Compared with the traditional method,the decision tree classification based on rules could classify the images by using various conditions,which reduced the data processing time and improved the classification accuracy. 展开更多
关键词 Geographic information Decision tree classification
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Influence of Preparation Factors on the Sustained Release of Nifedipine from Eudragit RL/RS Microspheres 被引量:1
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作者 傅崇东 蒋雪涛 +1 位作者 胡晋红 张万国 《Journal of Chinese Pharmaceutical Sciences》 CAS 1997年第4期31-38,共8页
Sustained release Eudragit RL/RS microspheres encapsulating nifedipine were prepared using the acetone/liquid paraffin emulsion solvent evaporation method. The influence of different preparation factors on release o... Sustained release Eudragit RL/RS microspheres encapsulating nifedipine were prepared using the acetone/liquid paraffin emulsion solvent evaporation method. The influence of different preparation factors on release of the drug in vitro was investigated. The release rate of nifedipine from the microspheres increased with increasing Eudragit RL/RS ratio and stirring rate during the preparation, and with decreasing the polymer concentration of internal phase and microsphere size. It was found that a linear relationship existed between the microsphere size and the time of 50% drug release. The drug release rate increased with increasing nifedipine content from 4.2 to 16.7% and was more rapid than the dissolution rate of pure nifedipine particles. However, the release rate of the microspheres with 26.6% drug content decreased significantly and was slower than the dissolution rate of pure drug particles. This was attributed mainly to the nifedipine dispersion state in the microspheres as confirmed by the differential thermal analysis and X ray diffraction study, which showed that nifedipine was present in an amorphous or molecular state in the microspheres with 4.2, 9.4 and 16.7% drug, whereas partly in the crystalline state in the microspheres with 26.6% drug. The amounts released for less than 70% nifedipine can be fitted to Higuchi square root of time model, independent of polymer ratio, drug content and microsphere size. 展开更多
关键词 Sustained release microspheres NIFEDIPINE Eudragit RL/RS Release rate
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Evaluation on Suitability of Camellia sinensis Planting Based on GIS
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作者 唐欣 马友华 於忠祥 《Agricultural Science & Technology》 CAS 2015年第9期2055-2059,共5页
Camellia sinensis is an important commercial crop in China. Suitability evaluation of tea tree planting, which is an embodiment of agricultural planting based on Geographic Information System(GIS), includes overlay ... Camellia sinensis is an important commercial crop in China. Suitability evaluation of tea tree planting, which is an embodiment of agricultural planting based on Geographic Information System(GIS), includes overlay analysis, hierarchical analysis,artificial intellegence, multivariable linear regression and fuzzy evaluation. Via a series of functions of GIS such as data query, retrieve and management, we can be informed of current situation and problems in tea plant development, find out areas which are appropriate or inappropriate for Camellia sinensis planting and figure out corresponding planting schemes and policies. Science and technology are the basic solution to modernization of Camellia sinensis planting. It is necessary to set up decision information and plantation management systems in agriculture on account of GIS, which are important channels to regionalization of Camellia sinensis planting suitability. 展开更多
关键词 Camellia sinensis(tea plant) GIS(geographic information system) Suitability evaluation
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Application of Wenner Configuration to Estimate Soil Water Content in Pine Plantations on Sandy Land 被引量:8
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作者 ZHU Jiao-Jun KANG Hong-Zhang Y. GONDA 《Pedosphere》 SCIE CAS CSCD 2007年第6期801-812,共12页
To estimate the mean value of surface soil water content rapidly,accurately,and nonintrusively,field investigations on soil electrical resistivity(SER)with the Yokogawa 324400 earth resistivity meter and the surface(0... To estimate the mean value of surface soil water content rapidly,accurately,and nonintrusively,field investigations on soil electrical resistivity(SER)with the Yokogawa 324400 earth resistivity meter and the surface(0-150 cm)soil water content(SWC)with time domain reflectometry(TDR),together with the abiotic factors including soil texture,structure. and salinity concentrations were conducted in the Mongolian pine(Pinus sylvestris var.mongolica)plantations on a sandy land.The measurement of SER was based on the 4-probe Wenner configuration method.Relationships between the values of SWC and SER were obtained based on analysis of the abiotic factors of the research site,which play a key role in affecting the soil electrical resistivity.Results indicate that the SER meter could be used to estimate the mean value of SWC in the Mongolian pine plantations on the sandy land during the growing seasons.The bulky nature of the equipment simplified the cumbersome measurements of soil water content with the general methods.It must be noted that the Wenner configuration method could only provide the mean values of the SWC,and the soil texture,structure, temperature,and solute concentrations influenced the SER and further affected the estimation of the SWC by the SER meter.Therefore,the results of this study could be applied on a sandy land during the growing seasons only.However, the SWC of other soil types also may be obtained according to the individual soil types using the procedures of this study. 展开更多
关键词 Mongolian pine plantation sandy land soil electrical resistivity soil water content Wenner configuration method
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Integrating TM and Ancillary Geographical Data with Classification Trees for Land Cover Classification of Marsh Area 被引量:14
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作者 NA Xiaodong ZHANG Shuqing +3 位作者 ZHANG Huaiqing LI Xiaofeng YU Huan LIU Chunyue 《Chinese Geographical Science》 SCIE CSCD 2009年第2期177-185,共9页
The main objective of this research is to determine the capacity of land cover classification combining spec- tral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjia... The main objective of this research is to determine the capacity of land cover classification combining spec- tral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjiang Plain, Heilongjiang Province, China. Semi-variograms and Z-test value were calculated to assess the separability of grey-level co-occurrence texture measures to maximize the difference between land cover types. The degree of spatial autocorrelation showed that window sizes of 3×3 pixels and 11×11 pixels were most appropriate for Landsat TM im- age texture calculations. The texture analysis showed that co-occurrence entropy, dissimilarity, and variance texture measures, derived from the Landsat TM spectrum bands and vegetation indices provided the most significant statistical differentiation between land cover types. Subsequently, a Classification and Regression Tree (CART) algorithm was applied to three different combinations of predictors: 1) TM imagery alone (TM-only); 2) TM imagery plus image texture (TM+TXT model); and 3) all predictors including TM imagery, image texture and additional ancillary GIS in- formation (TM+TXT+GIS model). Compared with traditional Maximum Likelihood Classification (MLC) supervised classification, three classification trees predictive models reduced the overall error rate significantly. Image texture measures and ancillary geographical variables depressed the speckle noise effectively and reduced classification error rate of marsh obviously. For classification trees model making use of all available predictors, omission error rate was 12.90% and commission error rate was 10.99% for marsh. The developed method is portable, relatively easy to im- plement and should be applicable in other settings and over larger extents. 展开更多
关键词 land cover classification classification trees Landsat TM ancillary geographical data MARSH
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Risk Assessment of Secondary Geological Disasters Induced by the Yushu Earthquake 被引量:6
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作者 NIU Quanfu CHENG Weiming +3 位作者 LIU Yong XIE Yaowen LAN Hengxing CAO Yanrong 《Journal of Mountain Science》 SCIE CSCD 2012年第2期232-242,共11页
The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for ... The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area. 展开更多
关键词 Yushu Earthquake Secondary geological disasters (SGD) Hazard assessment Socio-economic vulnerability Risk assessment
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Lifeline system network reliability calculation based on GIS and FTA 被引量:3
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作者 汤爱平 欧进萍 +1 位作者 陆钦年 张克绪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2006年第4期398-403,共6页
Lifelines, such as pipeline, transportation, communication, electric transmission and medical rescue systems, are complicated networks that always distribute spatially over large geological and geographic units. The q... Lifelines, such as pipeline, transportation, communication, electric transmission and medical rescue systems, are complicated networks that always distribute spatially over large geological and geographic units. The quantification of their reliability under an earthquake occurrence should be highly regarded, because the performance of these systems during a destructive earthquake is vital in order to estimate direct and indirect economic losses from lifeline failures, and is also related to laying out a rescue plan. The research in this paper aims to develop a new earthquake reliability calculation methodology for lifeline systems. The methodology of the network reliability for lifeline systems is based on fault tree analysis (FTA) and geological information system (GIS). The interactions existing in a lifeline system ale considered herein. The lifeline systems are idealized as equivalent networks, consisting of nodes and links, and are described by network analysis in GIS. Firstly, the node is divided into two types: simple node and complicated node, where the reliability of the complicated node is calculated by FTA and interaction is regarded as one factor to affect performance of the nodes. The reliability of simple node and link is evaluated by code. Then, the reliability of the entilre network is assessed based on GIS and FTA. Lastly, an illustration is given to show the methodology. 展开更多
关键词 network reliability( NR) lifeline earthquake engineering( LEE) fault tree analysis(FTA) geographic information system(GIS)
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Introduction of Pinus radiata for afforestation:a review with reference to Aba, China
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作者 毕慧泉 Jack Simpson +4 位作者 李荣伟 颜红 吴宗兴 蔡诗民 Robert Eldridge 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第4期311-322,共12页
Pinus radiata D. Don, native to a Californian coastal environment, has been introduced to many parts of the world as an exotic species for afforestation. It is now a major plantation species in the Southern Hemisphere... Pinus radiata D. Don, native to a Californian coastal environment, has been introduced to many parts of the world as an exotic species for afforestation. It is now a major plantation species in the Southern Hemisphere. In 1990, it was introduced to the heavily degraded, dry Min river valley area in Aba prefecture of Sichuan Province, P. R. China. Survival and growth of young trees planted at several sites appear to be reasonable. This review is to serve as an introduction to the large body of literature on P. radiata for forest scientists in China. It covers the following aspects: P. radiata in its native environment and in ex situ plantations, provenance and genetic variations, environmental limitations and climate niche, diseases and pests, lessons from unsuccessful introductions, and the use of P. radiata for ecological restoration. The early growth of P. radiata planted in the dry river valley area is briefly described. Potential problems associated with the introduction of P. radiata in Aba and future research needs are also identified. 展开更多
关键词 Pinus radiata Species introduction Ecological restoration Dry river valley.
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Effects of coastal afforestation on some soil properties in Lakshmipur coast of Bangladesh 被引量:2
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作者 K. M. Shaifullah M. Mezbahuddin +1 位作者 M. Sujauddin S. M. S. Haque 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第1期32-36,共5页
Coastal zones comprising important intertidal tropical and subtropical ecosystems are characterized by high productivity, diversity and unique zonation of various plant and animal communities. The comparison of some s... Coastal zones comprising important intertidal tropical and subtropical ecosystems are characterized by high productivity, diversity and unique zonation of various plant and animal communities. The comparison of some selected physicochemical soil properties viz. texture, particle density, moisture content, pH, organic carbon and total nitrogen between planted site (Telir char) and barren site (Boyar char) has been investigated at surface (0-10 cm) and subsurface (10-45 cm) soil across three different land strips viz. inland, middle part and sea side in Lakshmipur coast of Bangladesh. Sand particles in the soil were lower in planted site than barren site. The reverse trend was found in case of both silt and clay percentage. Coastal afforestation had a significant effect on soil binding process since a common trend of increment in soil particle density was noticed. Maximum increment (20.43% to 23.30%) in soil moisture content was recorded in surface soil across the seaside while at subsurface soil both across the middle part (19.53% to 22.30%) and sea side (20.19% to 22.96%). Moreover, the highest reduction in soil pH was recorded at surface soil (7.27 to 6.60) across the sea side and subsurface soil (7.16 to 6.67) in inland due to the influence of coastal plantation. Across all the land strips and the soil depths studied, soil organic carbon was higher in planted site than in barren site with only exception at subsurface soil in the middle part (0.50% in both sites). Total soil nitrogen in the study area was increased at both depths due to forestation with the highest increment in the inland at both surface and subsurface soil. 展开更多
关键词 MANGROVES PLANTATION physicochemical properties soil depth
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A necklace of pearl in high altitude medicine and hypoxic physiology in Yushu Earthquake 被引量:3
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作者 Fan Ming 《Engineering Sciences》 EI 2013年第2期2-4,共3页
During Yushu Earthquake,a large number of rescuers flocked to the mountainous quake areas. Under such a very specific circumstance,a high incidence of acute altitude illness was observed in rescuers who rapidly travel... During Yushu Earthquake,a large number of rescuers flocked to the mountainous quake areas. Under such a very specific circumstance,a high incidence of acute altitude illness was observed in rescuers who rapidly traveled from near sea level to an altitude of 4 000 m. It is evident that acute altitude illness leads to a significant human and economic toll,and also seriously influences the mountain rescue operation. So what does this teach us about mountain rescue in Yushu? Professor Wu Tianyi and many other authors collected shining points of the experiences and drew the lessons from the Yushu Earthquake into this special issue in Engineering Sciences which is like to thread pearl beads for a necklace. What readers learn from this special issue will have implications for the health and well-being of all high altitude populations all over the world. 展开更多
关键词 Yushu Earthquake 973 Project acute altitude illness learn by experiences and lessons
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Automatic Partition of Chinese Sentence Group 被引量:3
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作者 陈怡疆 史晓东 周昌乐 《Journal of Donghua University(English Edition)》 EI CAS 2010年第2期177-180,共4页
Automatic partition of Chinese sentence group is very important to the statistical machine translation system based on discourse. This paper presents an approach to this issue: first, each sentence in a discourse is ... Automatic partition of Chinese sentence group is very important to the statistical machine translation system based on discourse. This paper presents an approach to this issue: first, each sentence in a discourse is expressed as a feature vector; second, a special hierarchical clustering algorithm is applied to present a discourse as a sentence group tree. In this paper, local reoccurrence measure is proposed to the selection of key phras and the evaluation of the weight of key phrases. Experimental results show our approach promising. 展开更多
关键词 sentence group automatic partition of sentence group sentence group tree local reoccurrence measure
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Sleep quality alterations in healthy workers at high altitude in Yushu area 被引量:1
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作者 Wu Tianyi Li Wenxiang +3 位作者 Zhang Jianqing Qi Shengui Hao Lijuan Wen Jialin 《Engineering Sciences》 EI 2013年第2期54-60,共7页
During the period of reconstruction after Yushu Earthquake, a large number of sea-level or lowland workers ascended there and worked at altitudes between 3 750 m and 4 878 m which is a hypoxic environment. To investig... During the period of reconstruction after Yushu Earthquake, a large number of sea-level or lowland workers ascended there and worked at altitudes between 3 750 m and 4 878 m which is a hypoxic environment. To investigate the sleep quality at that altitude, we performed two full polysomnographies (PSGs) in 10 volunteers, who were healthy male workers, aged 31 :i:6.6, born and living at sea level, without experience of pre-altitude expo- sure. The assessment of subjective sleep quality was performed twice in each volunteer. The first investigations were carried out at sea level in Jinan city (pB=760 torr, 1 torr=133.322 4 Pa). The second studies were performed at an altitude of 3 750 m (pB=416 tort) in Yushu Jiegu in the same 10 workers after they lived and worked at that alti- tude for 5 months. At sea level, workers presented a normal sleep structure and a higher oxygenation during sleep. However, as compared to sea-level sleep, at 3 750 m, workers had a shorter total sleep time (TST) (p 〈 0.001), a longer stage 1 non-rapid eye movement (nREM) sleep (p 〈 0.05) and a shorter 3+4 nREM and rapid eye movement (REM) sleep (p 〈 0.05) with a severe sleep hypoxemia (p 〈 0.01). Our data suggested that sea-level workers revealed a disturbed sleep and a bad sleep quality with a significant sleep hypoxemia at altitude of 3 750 m. Strengthening the prevention and treatment are thereby sorely necessary. 展开更多
关键词 Yushu reconstruction SEA-LEVEL high altitude healthy workers sleep quality
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