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Analysis on Suitable Distribution Area of Oriental Fruit Fly (Bactrocera dorsalis) Based on GARP Ecological Niche Model
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作者 刘建宏 熊小真 +2 位作者 杨丽英 熊忠平 潘涌智 《Plant Diseases and Pests》 CAS 2010年第6期34-38,共5页
[Objective] The paper was to provide the scientific basis for effective monitoring and early warning on oriental fruit fly in Jiangxi Province.[Method] Using the distribution data and environmental factor data of orie... [Objective] The paper was to provide the scientific basis for effective monitoring and early warning on oriental fruit fly in Jiangxi Province.[Method] Using the distribution data and environmental factor data of oriental fruit fly,the potential distribution area of oriental fruit fly in Jiangxi Province was predicted by GARP ecological niche model.[Result]The total suitable area for oriental fruit fly in Jiangxi province was over two thirds of the whole province.Most areas in southern Jiangxi basin ranged from 24° to 26° N were the high suitable area for oriental fruit fly,where the annual average temperature was 19-20℃.Part areas in north Ganzhou and small areas in southwest Ji'an,Wuzhou,Yingtan,southeast Shangrao ranged from 26° to 27° N were the moderate suitable areas for oriental fruit fly,where the annual average temperature was 18-19℃.The low suitable area was ranged from 26° to 30° N including Binhu,Ganjiang River,Wuhe,Yuanshui area and Southwestern Mountain of Jiangxi Province,where the annual average temperature was 17-18℃.Northeast and northwest areas in Jiangxi Province and coastal areas along the Yangtze River was predicted to be non-suitable area for oriental fruit fly,where the annual average temperature was 16-17℃.[Conclusion] The results showed that the actual distribution of oriental fruit fly basically was consistent with the distribution predicted by GARP. 展开更多
关键词 Oriental fruit fly GARP Potential distribution area JIANGXI
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Distribution area demarcation for logistic centers under geographical information system decision support system
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作者 潘文安 《Journal of Chongqing University》 CAS 2011年第1期14-22,共9页
Demarcating distribution area of goods is often guided by the rule of thumb by business proprietors. However, this method seems to be unsuitable when the demand points increase to a certain large extent. The present w... Demarcating distribution area of goods is often guided by the rule of thumb by business proprietors. However, this method seems to be unsuitable when the demand points increase to a certain large extent. The present work attempted to convert the problem of distribution area demarcation into a localized problem of warehouseing and networking, and tried to establish district-based planning mode based on location based heuristic (LBH). Two methods were used in this study: 1) the manual method to construct the mathematical model and conduct simulation; 2) the automatic method using TransCAD software of geographical information system (GIS) for simulation. By comparing the effects of the two methods, the research provides theoretical support for business proprietors to demarcate the distribution area rationally with the application of GIS system. The results show that GIS has very good graphics construction function to replace complex text, and the automatic demarcating mode with human-machine interaction provides a good business decision-making support. 展开更多
关键词 distribution area demarcation decision support system geographical information system
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Evaluation of Multi-Temporal-Spatial Scale Adjustment Capability and Cluster Optimization Operation Method for Distribution Networks with Distributed Photovoltaics
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作者 Jiaxin Qiao Yuchen Hao +2 位作者 Yingqi Liao Fang Liang Jing Bian 《Energy Engineering》 EI 2024年第9期2655-2680,共26页
Themassive integration of high-proportioned distributed photovoltaics into distribution networks poses significant challenges to the flexible regulation capabilities of distribution stations.To accurately assess the f... Themassive integration of high-proportioned distributed photovoltaics into distribution networks poses significant challenges to the flexible regulation capabilities of distribution stations.To accurately assess the flexible regulation capabilities of distribution stations,amulti-temporal and spatial scale regulation capability assessment technique is proposed for distribution station areas with distributed photovoltaics,considering different geographical locations,coverage areas,and response capabilities.Firstly,the multi-temporal scale regulation characteristics and response capabilities of different regulation resources in distribution station areas are analyzed,and a resource regulation capability model is established to quantify the adjustable range of different regulation resources.On this basis,considering the limitations of line transmission capacity,a regulation capability assessment index for distribution stations is proposed to evaluate their regulation capabilities.Secondly,considering different geographical locations and coverage areas,a comprehensive performance index based on electrical distance modularity and active power balance is established,and a cluster division method based on genetic algorithms is proposed to fully leverage the coordination and complementarity among nodes and improve the active power matching degree within clusters.Simultaneously,an economic optimization model with the objective of minimizing the economic cost of the distribution station is established,comprehensively considering the safety constraints of the distribution network and the regulation constraints of resources.This model can provide scientific guidance for the economic dispatch of the distribution station area.Finally,case studies demonstrate that the proposed assessment and optimization methods effectively evaluate the regulation capabilities of distribution stations,facilitate the consumption of distributed photovoltaics,and enhance the economic efficiency of the distribution station area. 展开更多
关键词 Distributed photovoltaic distribution station area assessment of adjustment capacity line transmission capacity economic optimization
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Analysis of the Distribution of Tulipa fosteriana and Tulipa ingens. The Importance of Protecting Wild Plants, in Particular Tulips All over the World
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作者 Shukrullozoda Roza Shukrullo Qizi Dekhkonov Davron Burxonovich +3 位作者 Khaydarov Khislat Kudratovich Umurzakova Zebuniso Iskandarovna Olimjonova Sadoqat Gùlomjon Qizi Norimova Guljakhon Komiljon Qizi 《American Journal of Plant Sciences》 CAS 2023年第5期613-624,共12页
The assessment of the distribution and importance of the protection of tulip varieties around the world and separately rare, wild-growing ancestors of cultivated tulips, in particular Tulipa fosteriana and Tulipa inge... The assessment of the distribution and importance of the protection of tulip varieties around the world and separately rare, wild-growing ancestors of cultivated tulips, in particular Tulipa fosteriana and Tulipa ingens on the globe, including Central Asia, Uzbekistan and the Samarkand region, was described. A distribution map was introduced to visualize the data. Information about the morphological description of the studied species was also given. 展开更多
关键词 distribution area Threat of Extinction Protection SUBPOPULATION “Hot Spot”
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Characteristics and distributions of humic acids in two soil profiles of the southwest China Karst area 被引量:2
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作者 Liangang Ma Baohua Xiao +2 位作者 Xinyue Di Weilin Huang Shijie Wang 《Acta Geochimica》 EI CAS CSCD 2016年第1期85-94,共10页
Characteristics and distributions of humic acid(HA) and soil organic matter(SOM) in a yellow soil profile and a limestone soil profile of the southwest China Karst area were systematically investigated to reveal their... Characteristics and distributions of humic acid(HA) and soil organic matter(SOM) in a yellow soil profile and a limestone soil profile of the southwest China Karst area were systematically investigated to reveal their evolutions in different soils of the study area. The results showed that characteristics and distribution of SOM along the two soil profiles were notably different. Total organic carbon(TOC) contents of soil samples decreased just slightly along the limestone soil profile but sharply along the yellow soil profile. TOCs of the limestone soils were significantly higher than those of the corresponding yellow soils, and C/N ratios of SOMs showed a similar variation trend to that of TOCs, indicating that SOM can be better conserved in the limestone soil than in the yellow soil. The soil humic acids were exhaustively extracted and further fractionated according to their apparent molecular weights using ultrafiltration techniques to explore underlying conservation mechanisms. The result showed that C/N ratios of HAs from different limestone soil layers were relatively stable and that large molecular HA fractions predominated the bulk HA of the top soil, indicating that HA in the limestone profile was protected while bio and chemical degradations were retarded. Combined with organic elements contents and mineral contents of two soils, weconcluded that high calcium contents in limestone soils may play a key role in SOM conservation by forming complexation compounds with HAs or/and enclosing SOMs with hypergene CaCO_3 precipitation. 展开更多
关键词 Soil Soil organic matter Humic acid Characteristics distribution Southwest China Karst area
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A study on zooplankton distribution patterns and indicator species in Kuroshio upstream area and adjacent East China Sea 被引量:4
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作者 He Dehua, Wang Chunsheng, Liu Hongbin and Yang Guanming( Received July 9, 1990 accepted November 12, 1990) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1992年第2期237-254,共18页
On the basis of the data of zooplankton biomass and three major taxa—— Copepoda, Chaetognatha andSiphonophora of May-June 1986, July-August and December 1987, the distributional patterns and the indicator species of... On the basis of the data of zooplankton biomass and three major taxa—— Copepoda, Chaetognatha andSiphonophora of May-June 1986, July-August and December 1987, the distributional patterns and the indicator species of zooplankton in the Kuroshio and adjacent waters of the East China Sea are preliminarily studied. The results are as follows:The horizontal distribution of zooplankton biomass and the abundance of copepods, chaetognaths and siphonophores arecurred in the continent area northwest of Taiwan and the south-centre section of the East China Sea continent, which are the mix front of different waters. Zooplankton in the water area inside of Ryukyu Islands presented low abundance and high diversity. There are clear seasonal variations in zooplankton biomass and abundance in the study area. The strength or weakness of different water masses and fronts is the basic reason for the variations of zooplankton biomass and abundance.The species composition of zooplankton in the study area is complex and varies, however, the tropic oceanic species predominates overwhelmingly. The distribution of different ecotype species evidences the distribution of different water masses and the state of mixture. The indicator species of each water mass are listed in the paper so as to provide grounds for the variation of currents in the Kuroshio area.The temperature and salinity of sea water are important factors affecting zooplankton distribution, composition and diversity , however the role of salinity is major. With the replacement of one season by another, the correlative levels of temperature and salinity to various zooplankton taxa are more or less significant. 展开更多
关键词 A study on zooplankton distribution patterns and indicator species in Kuroshio upstream area and adjacent East China Sea area
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Study on Temporal-spatial Distribution of Heavy Rain and Rainstorm in Different Functional Areas of Chongqing
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作者 Yuan Lin Mou Xinli +2 位作者 Zhang Meng Gu Yi Zhou Jie 《Meteorological and Environmental Research》 CAS 2014年第9期7-10,共4页
To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts( counties) as research object,monthly occurrence times of heavy rain and rainstorm in different functional a... To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts( counties) as research object,monthly occurrence times of heavy rain and rainstorm in different functional areas over the years and appearance month of the maximum rainfall were conducted statistics. Results showed that frequency distribution of heavy rain in whole year in different functional areas was different,but it was similar in the same functional zone. Temporal-spatial distribution of rainstorm was more independent,and there were different performances in various districts of each functional area. In urban functional core area and urban functional expansion area,rainstorm times was more,and the maximum precipitation was larger. In urban development new district,rainstorm times and the maximum precipitation were relatively smaller in whole Chongqing. In ecological conservation development area of northeast Chongqing,rainstorm duration was longer,and we needed prevention and control during June- September. In ecological protection area of southeast Chongqing,although rainstorm occurrence times was the most in Chongqing,the heavy rainstorm was less. 展开更多
关键词 Heavy rain Rainstorm Functional area Temporal-spatial distribution Chongqing China
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Producing areas and Export Distribution of Motorcycles
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《China's Foreign Trade》 2006年第15期8-9,共2页
关键词 Producing areas and Export distribution of Motorcycles
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The Potential Geographic Distribution of Radopholus similis in China 被引量:3
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作者 WANG Yun-sheng XIE Bing-yan +2 位作者 WAN Fang-hao XIAO Qi-ming DAI Liang-ying 《Agricultural Sciences in China》 CAS CSCD 2007年第12期1444-1449,共6页
The burrowing nematode (Radopholus similis) is one of the main quarantine pests in China, and the risk of invasion posed by this nematode is becoming more and more serious with regard to the international trade bein... The burrowing nematode (Radopholus similis) is one of the main quarantine pests in China, and the risk of invasion posed by this nematode is becoming more and more serious with regard to the international trade being intensified day by day. It is urgent to analyse the potential geographic distribution of R. similis in China. Genetic algorithm for rule-set prediction modeling system (GARP) and maximum entropy (MAXENT), the two niche models which have been widely used to predict the potential geographic distribution of alien species, were used to predict the distribution of R. similis in China. We also presented a model comparison of the results by both threshold-dependent and threshold-independent evaluations. It has been shown that the two niche models could be used to predict the potential distribution of R. similis reliably. The potential distribution of R. similis should be constricted within the south of China, such as Hainan, Guangdong, Guangxi, Fujian, Yunnan provinces, and Taiwan of China. The MAXENT gives a better prediction than that of GARP. R. similis can be introduced to China by flowers and nursery stock's international shipping. The predicted results indicate that R. similis can occur in south coastal area of China and Yunnan Province, which are the main flower and nursery stock's import-export areas in China. Consequently, a strong quarantine program is needed at the ports of such areas to prevent the pest from being introduced to China. 展开更多
关键词 Radopholus similes niche model GARP MAXENT suitable distribution area
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Using leaf area index(LAI) to assess vegetation response to drought in Yunnan province of China 被引量:4
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作者 Kwangchol KIM WANG Ming-cheng +3 位作者 Sailesh RANJITKAR LIU Su-hong XU Jian-chu Robert J.ZOMER 《Journal of Mountain Science》 SCIE CSCD 2017年第9期1863-1872,共10页
Climatic extremes such as drought have becoming a severe climate-related problem in many regions all over the world that can induce anomalies in vegetation condition. Growth and CO2 uptake by plants are constrained to... Climatic extremes such as drought have becoming a severe climate-related problem in many regions all over the world that can induce anomalies in vegetation condition. Growth and CO2 uptake by plants are constrained to a large extent by drought.Therefore, it is important to understand the spatial and temporal responses of vegetation to drought across the various land cover types and different regions. Leaf area index(LAI) derived from Global Land Surface Satellite(GLASS) data was used to evaluate the response of vegetation to drought occurrence across Yunnan Province, China(2001-2010). The meteorological drought was assessed based on Standardized Precipitation Index(SPI)values. Pearson's correlation coefficients between LAI and SPI were examined across several timescales within six sub-regions of the Yunnan. Further, the drought-prone area was identified based on LAI anomaly values. Lag and cumulative effects of lack of precipitation on vegetation were evident, with significant correlations found using 3-, 6-, 9-and 12-month timescale. We found 9-month timescale has higher correlations compared to another timescale.Approximately 29.4% of Yunnan's area was classified as drought-prone area, based on the LAI anomaly values. Most of this drought-prone area was distributed in the mountainous region of Yunnan.From the research, it is evident that GLASS LAI can be effectively used as an indicator for assessing drought conditions and it provide valuable information for drought risk defense and preparedness. 展开更多
关键词 MODIS Leaf area index distribution Standardized Precipitation Index(SPI) Drought Yunnan
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Distribution and Relative Abundance of the Tursiops truncatus in Lebanese Marine Waters (Eastern Mediterranean)
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作者 Gaby Khalaf Milad Fakhri +2 位作者 Christine Ohanian Carine Abi-Ghanem Lea David 《Journal of Life Sciences》 2013年第11期1196-1203,共8页
Data related to the presence of cetaceans and especially the bottlenose dolphin (Tursiops truncatus) in Lebanese marine waters (eastern Mediterranean) are almost non-existent. This article aims to delimit, for the... Data related to the presence of cetaceans and especially the bottlenose dolphin (Tursiops truncatus) in Lebanese marine waters (eastern Mediterranean) are almost non-existent. This article aims to delimit, for the first time, the areas of distribution and the relative abundance of T. truncatus along the Lebanese coasts in order to develop a strategy for the conservation of this species. Nine campaigns at sea, each lasting between 1 to 3 days, were conducted aboard the vessel "CANA" between September 2009 and August 2012 in Lebanese marine waters. A total of 1576 km in prospecting effort was covered along the Lebanese coast (220 km). Dolphins were mainly sighted in the central region of Lebanon (120 km) and 32 sightings and 91 individuals were recorded. The size of the groups were ranged from a minimum of one individual and a maximum of 7 individuals. Relative abundance of T. truncatus for the whole studied region is 0.06 individuals'km1 in prospecting effort while it is 0.11 individuals·km^-1 in Beirut area that offers habitats sought by this species. The bathymetric distribution of this species is spread over a wide range from a depth of 35 m to 1300 m. More than half of the individuals have been observed in areas where bathymetry ranges between 300 m and 600 m depths. 展开更多
关键词 Bottlenose dolphin areas of distribution relative abundance Lebanon eastern Mediterranean
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Fabrication of 32 Gb/s Electroabsorption Modulated Distributed Feedback Lasers by Selective Area Growth Technology
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作者 周代兵 王会涛 +8 位作者 张瑞康 王宝军 边静 安欣 陆丹 赵玲娟 朱洪亮 吉晨 王圩 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第5期66-68,共3页
A 32 Gb/s monolithically integrated electroabsorption modulated laser is fabricated by selective area growth technology. The threshold current of the device is below 13mA. The output power exceeds 10mW at 0V bias when... A 32 Gb/s monolithically integrated electroabsorption modulated laser is fabricated by selective area growth technology. The threshold current of the device is below 13mA. The output power exceeds 10mW at 0V bias when the injection current of the distributed feedback laser is 100mA at 25℃. The side mode suppression ratio is over 50 dB. A 32Gb/s eye diagram is measured with a 3.SVpp nonreturn-to-zero pseudorandom modulation signal at -2.3 V bias. A clearly opening eyediagram with a dynamic extinction ratio of 8.01 dB is obtained. 展开更多
关键词 Fabrication of 32 Gb/s Electroabsorption Modulated Distributed Feedback Lasers by Selective area Growth Technology EML EAM DFB InGaAs SAG
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计及源荷时序特性的低压台区分布式光伏接入分布鲁棒优化方法 被引量:1
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作者 周玉 王忠东 +3 位作者 赵双双 高凡 李悦 孟珊珊 《南京信息工程大学学报(自然科学版)》 CAS 北大核心 2023年第5期592-603,共12页
为提高低压配电台区中分布式光伏(DPV)的接入容量,促进光伏消纳,本文提出一种计及源荷时序特性的低压台区DPV接入分布鲁棒优化方法.首先,针对低压台区中分布式光伏出力和负荷需求的不确定性,提出一种基于优化聚类的源-荷联合时序场景生... 为提高低压配电台区中分布式光伏(DPV)的接入容量,促进光伏消纳,本文提出一种计及源荷时序特性的低压台区DPV接入分布鲁棒优化方法.首先,针对低压台区中分布式光伏出力和负荷需求的不确定性,提出一种基于优化聚类的源-荷联合时序场景生成方法;其次,计及电压约束、线路容量约束、逆变器无功补偿约束及光伏消纳约束等,构建低压台区分布式光伏接入分布鲁棒优化模型,在保证各典型场景最恶劣概率分布下的弃光率期望值符合要求的情况下,最大化低压台区中分布式光伏接入容量;然后,建立低压台区分布式储能接入的数学模型,以研究储能接入及其充放电机制对低压台区分布式光伏接入的影响;最后,以实际配电台区为例进行仿真计算,验证了本文模型的有效性. 展开更多
关键词 分布式光伏接入 低压配电台区 源荷协同 时序特性 分布鲁棒优化 优化聚类
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Advances in Research of Resources and Cultivation Techniques of Chinese Medicinal Material Radix Bupleuri 被引量:1
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作者 Ruyue BAI Xinyuan GAO +1 位作者 Jinyue WEI Shiying TANG 《Medicinal Plant》 CAS 2021年第4期78-82,共5页
At present,with the vigorous development of traditional Chinese medicines,wild Bupleurum chinense resources become increasingly depleted,and its cultivars have become the mainstream of the market.However,due to factor... At present,with the vigorous development of traditional Chinese medicines,wild Bupleurum chinense resources become increasingly depleted,and its cultivars have become the mainstream of the market.However,due to factors such as a large number of original plants,irregular planting techniques,and poor growth environment,the quality of cultivated B.chinense is uneven and it is difficult to achieve the expected efficacy.In order to protect the wild resources of B.chinense and expand the source of medicinal materials,this paper summarized the research advances of the main resource producing areas and cultivation techniques of B.chinense in combination with relevant documents published at home and abroad,and discussed the future development of B.chinense,to provide a reference for research and sustainable development of B.chinense resources. 展开更多
关键词 Bupleurum chinense RESOURCES distribution of main producing areas CULTIVATION BREEDING
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考虑广域源-荷协调的分布式鲁棒优化调度 被引量:1
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作者 万冰 蔺红 《科学技术与工程》 北大核心 2022年第28期12424-12431,共8页
对源荷双侧存在的不确定性进行精细化建模,可提升广域源荷协调调度结果的有效性。分别以风电功率和分时(time-of-use,TOU)电价为不确定变量,利用历史数据构建基于Wasserstein距离的概率分布模糊集来表征风电功率和分时电价的不确定性,... 对源荷双侧存在的不确定性进行精细化建模,可提升广域源荷协调调度结果的有效性。分别以风电功率和分时(time-of-use,TOU)电价为不确定变量,利用历史数据构建基于Wasserstein距离的概率分布模糊集来表征风电功率和分时电价的不确定性,并根据各类民用负荷特性建立分时电价引导下广域分布的民用负荷需求响应不确定模型。建立基于Wasserstein距离的广域源-荷协调双层分布式鲁棒优化调度模型,优化求解得到火电机组、风电场和各类广域民用负荷的调度计划。最后通过算例仿真验证所提方法可有效挖掘广域民用负荷调峰潜力,降低系统运行成本,提高风电消纳能力,平衡调度计划的经济性和鲁棒性。 展开更多
关键词 广域源-荷 需求响应 分布鲁棒 Wasserstein距离
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Characteristics and genesis of clay minerals in the northern margin of the Qaidam Basin 被引量:1
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作者 Wang Linlin Jiang Bo +2 位作者 Peng Dehua Yin Chengming Zeng Chunlin 《Mining Science and Technology》 EI CAS 2011年第1期141-145,共5页
In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples f... In order to develop appropriate reservoir protection measures in the northern margin of the Qaidam Basin and improve its oil and gas recovery efficiency,characteristics of clay minerals from eleven clay rock samples from the northern margin of the Qaidam Basin were investigated using X-ray diffraction analysis,the Scanning Electron Microscope(SEM)and energy spectrum analysis.Clay mineral composition and distribution characteristics of the main hydrocarbon reservoirs,i.e.,from the Jurassic and Paleogene-Neogene,were explored.We analyzed the main factors which affected these attributes.The results show that the major clay minerals in the northern margin are chlorite,kaolinite,illite,smectite and illite/smectite inter-stratified minerals.Illite is the most widely spread clay mineral in this area. Chlorite is mainly found in the entire Neogene and in shallow horizons of the Paleogene.Smectite is enriched in the shallow Paleogene-Neogene.There are large amounts of kaolinite and illite/smectite inter-stratified minerals in the Jurassic.The major factors affecting the different development of clay minerals in the region are properties of parent rocks,paleoclimate and paleowater media conditions, diagenesis transformation,tectonic and terrain conditions. 展开更多
关键词 Qaidam Basin Northern marginal area Clay mineral distribution characteristics Genesis
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Development of a drill energy utilization index for aiding selection of drill machines in surface mines 被引量:1
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作者 Kumar Suraj Rahul Talreja Murthy V.M.S.R. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期393-399,共7页
Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selec- t... Drill machines used in surface mines, particularly in coal, is characterized by a very poor utilization (around 40%) and low availability (around 60%). The main purpose of this study is to develop a drill selec- tion methodology and simultaneously a performance evaluation technique based on drill cuttings produced and drilling rate achieved. In all 28 blast drilled through were investigated. The drilling was accomplished by 5 different drill machines of Ingersoll-Rand and Revathi working in coal mines of Sonepur Bazari (SECL) and Block-II (BCCL). The drills are Rotary and Rotary Percussive type using tri- cone rock roller bits. Drill cuttings were collected and sieve analysis was done in the laboratory. Using Rosin Ramler Diagram, coarseness index (CI), mean chip size (d), specific-st trace area (SSA) and charac- teristic particle size distribution curves for all the holes drilled were plotted. The predictor equation for drill penetration rate established through multiple regressions was found to have a very good correlation with an index of determination of 0.85. A comparative analysis of particle size distribution curves was used to evaluate the drill efficiency. The suggested approach utilises the area under the curve, after the point of trend reversal and brittleness ratio of the respective bench to arrive at drill energy utilization index (DEUI), for mapping of drill machine to bench, The developed DEU1 can aid in selecting or mapping a right machine to right bench for achieving higher penetration rate and utilizations. 展开更多
关键词 Drill cutting parameter Coarseness index Mean chip size Specific surface area Particle size distribution curves Drill energy ptilization index
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Tensile Characteristics Evaluation of Corroded Reinforcing Bars Extracted from Actual Structures
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作者 Toshiyuki Kanakubo Michiaki Oyado 《Journal of Civil Engineering and Architecture》 2015年第12期1439-1451,共13页
The analysis used simple finite elements is performed to simulate the tensile behavior of corroded reinforcing bars extracted from three actual concrete structures. The cross-sectional area of the elements is set to h... The analysis used simple finite elements is performed to simulate the tensile behavior of corroded reinforcing bars extracted from three actual concrete structures. The cross-sectional area of the elements is set to have the actual distribution measured by 3D laser scanner system. The variable factor in the analysis is the length of the elements. The analysis results show that the length of the elements has a major influence on the deformation capacity after yielding. The calculated stress-strain curves, obtained using the elements with a length that is 2 times the bar diameter, are in good agreement with the tensile test results. The calculated stress-strain curves are modeled using a bi-linear model to facilitate the FEA (finite element analysis) of an overall concrete structure. From the analysis results, both the tensile and yield strengths decrease in proportion to the reduction of the minimum cross-sectional area of corroded bars. The ultimate strain has a remarkable decrement as the reduction of the minimum cross-sectional area. Formulas for determining these values are proposed as a function of the decrement ratio of the minimum cross-sectional area of a corroded bar. 展开更多
关键词 Corroded bar cross-sectional area distribution minimum cross-sectional area bi-linear model ultimate strain.
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Migration of Rural Labor and Income Growth and Distribution in Rural Areas of China
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作者 李实 Luo Jun +2 位作者 Zhang Hongyan Liu Hongyun Su Xuetao 《Social Sciences in China》 2000年第3期5-21,共17页
关键词 Migration of Rural Labor and Income Growth and distribution in Rural areas of China
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青海省农牧区典型供电模式研究
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作者 温生毅 黄存强 +1 位作者 安娟 省天骄 《青海电力》 2014年第2期1-4,共4页
结合青海农牧区特点,对配电网各电压等级电网结构、建设标准在典型供电区的适用性和匹配性进行研究,形成配电网的典型发展模式。
关键词 农牧区 典型供电模式 配电化
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