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Study of inter-well interference in shale gas reservoirs by a robust production data analysis method based on deconvolution
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作者 Wen-Chao Liu Cheng-Cheng Qiao +5 位作者 Ping Wang Wen-Song Huang Xiang-Wen Kong Yu-Ping Sun He-Dong Sun Yue-Peng Jia 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2502-2519,共18页
In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering,this study proposes a robust production data analysis method based on deconvolut... In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering,this study proposes a robust production data analysis method based on deconvolution,which is used for multi-well inter-well interference research.In this study,a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established,and its Laplace solutions under two different outer boundary conditions were obtained.Then,an improved pressure deconvolution algorithm was used to normalize the scattered production data.Furthermore,the typical curve fitting was carried out using the production data and the seepage model solution.Finally,some reservoir parameters and fracturing parameters were interpreted,and the intensity of inter-well interference was compared.The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area.The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging.Besides,by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions,the strength of the interference between wells on the same well platform was well judged.This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells. 展开更多
关键词 Shale gas Inter-well interference DECONVOLUTION Production data analysis Typical curves Multi-stage fractured horizontal well
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Molecular Investigation of Theileria in Ixodid Ticks from Changzhi,Shanxi Province,China
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作者 Jia Cui Hua Xiang Rao +2 位作者 Yiping Liu Dongmei Li Juan Yu 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第8期922-925,共4页
Theileria is a tick-borne intracellular protozoan that typically parasitizes erythrocytes,lymphocytes,and macrophages and causes acute clinical symptoms in host animals,including high fever,anemia,jaundice,and swellin... Theileria is a tick-borne intracellular protozoan that typically parasitizes erythrocytes,lymphocytes,and macrophages and causes acute clinical symptoms in host animals,including high fever,anemia,jaundice,and swelling of superficial lymph nodes[1].Theileriosis can lead to high mortality rates,and its rising global prevalence has resulted in significant economic losses to livestock husbandry and the national economy[2]. 展开更多
关键词 HUSBANDRY SWELLING typically
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Call for knowledge systematization:An example from lithium ion batteries recycling
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作者 Yun Zhao Baohua Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期169-170,共2页
Scientific research is one of the primary ways to drive human civilization forward.Countless research institutions and researchers worldwide are dedicated to exploring the unknown,resulting in a flood of research find... Scientific research is one of the primary ways to drive human civilization forward.Countless research institutions and researchers worldwide are dedicated to exploring the unknown,resulting in a flood of research findings[1].For instance,Web of Science alone collects over 10,000 academic papers on a daily basis.While each research field typically has around 10%of review articles,these mainly focus on a limited portion of the subject,failing to provide a comprehensive and real-time updated overview.As a result,researchers or students in a particular field may spend several months,or even longer,comprehending the state of research that has developed over just a few years.The lack of systematic background often leads to redundant or similar studies,which is highly detrimental to the progress of science and technology. 展开更多
关键词 LITHIUM typically SPEND
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Dengue fever in Egypt:Current situation and future risks
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作者 Marwa Omar 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第10期429-431,共3页
Dengue or dengue fever(DF)is an acute infectious disease of a febrile nature.It is caused by the dengue virus(DENV),which belongs to the family Flaviviridae and has four antigenically distinctive serotypes(DENV-1,DENV... Dengue or dengue fever(DF)is an acute infectious disease of a febrile nature.It is caused by the dengue virus(DENV),which belongs to the family Flaviviridae and has four antigenically distinctive serotypes(DENV-1,DENV-2,DENV-3 and DENV-4).DENV is regarded as one of the most prevalent fast-emerging mosquito-borne viruses,which has a wide distribution in many tropical and subtropical regions worldwide.The virus is typically transmitted following the bite of an infected female mosquito of the species,Aedes(Ae.)aegypti and Ae.albopictus[1]. 展开更多
关键词 FEVER ACUTE typically
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On a special type of Ma-Minda function
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作者 S.Sivaprasad Kumar Shagun Banga 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第4期654-673,共20页
We introduce a primitive class of analytic functions,by specializing in many well-known classes,classify Ma-Minda functions based on its conditions and their interesting geomet-rical aspects.Further,study a newly de n... We introduce a primitive class of analytic functions,by specializing in many well-known classes,classify Ma-Minda functions based on its conditions and their interesting geomet-rical aspects.Further,study a newly de ned subclass of starlike functions involving a special type of Ma-Minda function introduced here for obtaining inclusion and radius results.We also establish some majorization,Bloch function norms,and other related problems for the same class. 展开更多
关键词 Ma-Minda function typically real function Hankel determinants sharp coefficient bounds radius problems logarithmic function
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Research on typical operating conditions of hydrogen production system with off-grid wind power considering the characteristics of proton exchange membrane electrolysis cell
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作者 Weiming Peng Yanhui Xu +4 位作者 Gendi Li Jie Song Guizhi Xu Xiaona Xu Yan Pan 《Global Energy Interconnection》 EI CSCD 2024年第5期642-652,共11页
Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation a... Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs. 展开更多
关键词 Wind power fluctuation Off-grid operation Hydrogen production by PEM electrolysis Neural network clustering Typical working conditions
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Improving the Accuracy of Vegetation Index Retrieval for Biomass by Combining Ground-UAV Hyperspectral Data-A New Method for Inner Mongolia Typical Grasslands
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作者 Ruochen Wang Jianjun Dong +3 位作者 Lishan Jin Yuyan Sun Taogetao Baoyin Xiumei Wang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期387-411,共25页
Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored t... Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored the original spectral information of typical grasslands in Inner Mongolia and examined the influence of spectral information on aboveground biomass(AGB)estimation.In order to improve the accuracy of vegetation index inversion of grassland AGB,this study combined ground and Unmanned Aerial Vehicle(UAV)remote sensing technology and screened sensitive bands through ground hyperspectral data transformation and correlation analysis.The narrow band vegetation indices were calculated,and ground and airborne hyperspectral inversion models were established.Finally,the accuracy of the model was verified.The results showed that:(1)The vegetation indices constructed based on the ASD FieldSpec 4 and the UAV were significantly correlated with the dry and fresh weight of AGB.(2)The comparison between measured R^(2) with the prediction R^(2) indicated that the accuracy of the model was the best when using the Soil-Adjusted Vegetation Index(SAVI)as the independent variable in the analysis of AGB(fresh weight/dry weight)and four narrow-band vegetation indices.The SAVI vegetation index showed better applicability for biomass monitoring in typical grassland areas of Inner Mongolia.(3)The obtained ground and airborne hyperspectral data with the optimal vegetation index suggested that the dry weight of AGB has the best fitting effect with airborne hyperspectral data,where y=17.962e^(4.672x),the fitting R^(2) was 0.542,the prediction R^(2)was 0.424,and RMSE and REE were 57.03 and 0.65,respectively.Therefore,established vegetation indices by screening sensitive bands through hyperspectral feature analysis can significantly improve the inversion accuracy of typical grassland biomass in Inner Mongolia.Compared with ground monitoring,airborne hyperspectral monitoring better reflects the inversion of actual surface biomass.It provides a reliable modeling framework for grassland AGB monitoring and scientific and technological support for grazing management. 展开更多
关键词 Aboveground biomass inversion model vegetation index unmanned aerial vehicle typical grassland
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Introduction to the Special Issue on ComputerModeling for Smart Cities Applications
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作者 Wenbing Zhao Chenxi Huang Yizhang Jiang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1015-1017,共3页
A significant fraction of the world’s population is living in cities. With the rapid development ofinformation and computing technologies (ICT), cities may be made smarter by embedding ICT intotheir infrastructure. B... A significant fraction of the world’s population is living in cities. With the rapid development ofinformation and computing technologies (ICT), cities may be made smarter by embedding ICT intotheir infrastructure. By smarter, we mean that the city operation will be more efficient, cost-effective,energy-saving, be more connected, more secure, and more environmentally friendly. As such, a smartcity is typically defined as a city that has a strong integration with ICT in all its components, includingits physical components, social components, and business components [1,2]. 展开更多
关键词 SMART typically SMART
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A Cascading Fault Path Prediction Method for Integrated Energy Distribution Networks Based on the Improved OPA Model under Typhoon Disasters
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作者 Yue He YaxiongYou +4 位作者 ZhianHe Haiying Lu Lei Chen Yuqi Jiang Hongkun Chen 《Energy Engineering》 EI 2024年第10期2825-2849,共25页
In recent times,the impact of typhoon disasters on integrated energy active distribution networks(IEADNs)has received increasing attention,particularly,in terms of effective cascading fault path prediction and enhance... In recent times,the impact of typhoon disasters on integrated energy active distribution networks(IEADNs)has received increasing attention,particularly,in terms of effective cascading fault path prediction and enhanced fault recovery performance.In this study,we propose a modified ORNL-PSerc-Alaska(OPA)model based on optimal power flow(OPF)calculation to forecast IEADN cascading fault paths.We first established the topology and operational model of the IEADNs,and the typical fault scenario was chosen according to the component fault probability and information entropy.The modified OPA model consisted of two layers:An upper-layer model to determine the cascading fault location and a lower-layer model to calculate the OPF by using Yalmip and CPLEX and provide the data to update the upper-layer model.The approach was validated via the modified IEEE 33-node distribution system and two real IEADNs.Simulation results showed that the fault trend forecasted by the novel OPA model corresponded well with the development and movement of the typhoon above the IEADN.The proposed model also increased the load recovery rate by>24%compared to the traditional OPA model. 展开更多
关键词 IEADNs OPA model cascading fault path prediction fault probability optimal power flow typical fault scenario
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Rare and lacking typical clinical symptoms of liver tumors:Four case reports
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作者 Yun Zhao Yu-Kun Bie +2 位作者 Guang-Ya Zhang Yi-Bin Feng Feng Wang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第10期4264-4273,共10页
BACKGROUND Rare liver tumors(RLTs)have an extremely low likelihood of forming,and some have been recorded only in isolated cases.The lack of normal clinical symptoms in RLTs makes preoperative diagnosis extremely chal... BACKGROUND Rare liver tumors(RLTs)have an extremely low likelihood of forming,and some have been recorded only in isolated cases.The lack of normal clinical symptoms in RLTs makes preoperative diagnosis extremely challenging,which results in frequent misinterpretation.The present case report helps enhance our ability to recognize and treat uncommon liver tumor disorders.CASE SUMMARY We describe four distinct examples of rare liver tumor diseases.These cases were all true cases with no conventional clinical signs or imaging findings.In all patients,hepatic occupancy was discovered on physical examination,which raised the preoperative suspicion of hepatic cancer.All tumors were surgically removed,and postoperative histology and immunohistochemistry were performed to confirm the diagnosis.The first patient had primary hepatic fibrosarcoma.The second case involved a primary hepatic neuroendocrine tumors.These two patients had malignant liver tumors,and both had extremely satisfactory surgical outcomes.The third case involved focal hepatic steatosis,and the fourth case involved a single necrotic nodule in the liver.These two patients had benign liver tumors,but they had already undergone surgery and did not require any postoperative care.CONCLUSION The number of patients with RLTs is small,and the clinical and imaging results are vague.Preoperative diagnosis is challenging,and patients are sometimes mistakenly diagnosed with liver cancer,which leads to unnecessary surgical therapy in certain individuals. 展开更多
关键词 Liver tumor Primary hepatic fibrosarcoma Primary hepatic neuroendocrine tumor Focal hepatic steatosis Solitary necrotic nodule of the liver Lack of typical clinical symptoms Case report
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Formulation of Work-Study Combined and Result-Oriented Integrated Curriculum Standards
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作者 Lianfang LI Chunhua DU +2 位作者 Fen YANG Yun LI Yanfei NIU 《Medicinal Plant》 2024年第3期79-83,共5页
According to the Annex Technical Regulations for Integrated Curriculum Development(Trial)in Document No.30 of the General Office of the Ministry of Human Resources and Social Security(2012),this paper studies the form... According to the Annex Technical Regulations for Integrated Curriculum Development(Trial)in Document No.30 of the General Office of the Ministry of Human Resources and Social Security(2012),this paper studies the formulation of the curriculum standards for the integration of Chinese medicinal materials production.We focus on the formulation ideas of the curriculum standards for the integration of Chinese medicinal materials production,the formulation process of the curriculum standards for the integration of Chinese medicinal materials production,including the description of typical work tasks,the determination of curriculum objectives,the analysis of study content,the description of referential study tasks,teaching implementation suggestions,assessment and evaluation suggestions,which can provide a reference for the development and research of other related integrated courses. 展开更多
关键词 Integration of WORK and STUDY WORK process Curriculum STANDARDS Production of Chinese MEDICINAL materials Typical WORK TASKS REFERENTIAL STUDY TASKS
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Analysis on Typical Spatio-temporal Characteristics of Open-cast Mining and Its Countermeasures
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作者 Qingyou AO Qiang FU +2 位作者 Zhihua LIU Yu XUN Lin LIN 《Asian Agricultural Research》 2024年第5期20-24,共5页
In order to deal with the special spatio-temporal environmental changes encountered in the process of open-cast mining,taking Huolinhe No.1 Open-cast Mine as the research object,this paper studied its typical problems... In order to deal with the special spatio-temporal environmental changes encountered in the process of open-cast mining,taking Huolinhe No.1 Open-cast Mine as the research object,this paper studied its typical problems in river reconstruction and cultural relics protection.The study focused on eight key core aspects,including the design optimization of the spatial layout of the mining area,the accurate estimation of the mineral resources reserves,the scientific theoretical demonstration of the mining scale,the fine analysis and calculation of the stripping ratio,the comprehensive consideration of the transport distance and efficiency,the accurate judgment of the best time for the implementation of the transformation,the analysis and evaluation of the slope stability,and the overall planning of the production system.The results show that the extracted problem-solving strategies and scheme system for special mining conditions can not only provide specific and practical guidance for Huolinhe No.1 Open-cast Mine,but also serve as a valuable reference and practical reference for other open-cast mine enterprises facing similar challenges. 展开更多
关键词 Open-cast mining in the mining area Typical space-time environment River reconstruction Cultural relics protection Spatial layout
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Steering Towards Progress
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作者 Gao Yuan 《China Report ASEAN》 2024年第8期18-21,共4页
Each Central Committee of the Communist Party of China(CPC)convenes at least one plenary session each year during its five-year term.Among these,the third plenary session attracts the most attention as it typically sh... Each Central Committee of the Communist Party of China(CPC)convenes at least one plenary session each year during its five-year term.Among these,the third plenary session attracts the most attention as it typically shines light on major decisions that embody the governing guidelines of the current central leadership. 展开更多
关键词 typically SESSION COMMUNIST
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Analysis of a Typical Case of Meteorological Service in Tangpu Reservoir
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作者 Quan SHAN Yuxin DING +2 位作者 Tingting GU Jinxin WANG Kai TANG 《Meteorological and Environmental Research》 2024年第2期44-47,共4页
The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better... The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models. 展开更多
关键词 Tangpu Reservoir Meteorological service Continuous rain Analysis of a typical case
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AUnique Brocade Thangka Depicting the ETIQUETTE INTERACTIONS DURING THE MING DYNASTY
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作者 Liu Dongmei Rigzintsho Huang Wenjuan(Translated) 《China's Tibet》 2024年第4期34-39,共6页
The traditional way of Chakrasamvara was typically depicted with a furrowed brow and intensescowl.However,thefigure in this Chakrasamvara Thangka instead features eyebrows resembling gentle waves and eyes that smile.D... The traditional way of Chakrasamvara was typically depicted with a furrowed brow and intensescowl.However,thefigure in this Chakrasamvara Thangka instead features eyebrows resembling gentle waves and eyes that smile.Does this suggest that thedepictions of Buddha can vary significantly,reflecting different cultural interpretations or different"memes"? 展开更多
关键词 GENTLE instead typically
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奥陶纪-志留纪边界附近火山活动记录:来华南周缘钾质斑脱岩的信息 被引量:46
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作者 胡艳华 孙卫东 +3 位作者 丁兴 汪方跃 凌明星 刘健 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第12期3298-3308,共11页
扬子地台内奥陶纪顶部的五峰组到志留纪底部的龙马溪组间存在着多个粘土岩层。前人研究结果认为这些粘土岩层为钾质斑脱岩,是火山喷发的凝灰质物质在海相环境沉积、蚀变的产物。这些斑脱岩广泛分布于扬子地台周缘,对理解奥陶纪-志留纪... 扬子地台内奥陶纪顶部的五峰组到志留纪底部的龙马溪组间存在着多个粘土岩层。前人研究结果认为这些粘土岩层为钾质斑脱岩,是火山喷发的凝灰质物质在海相环境沉积、蚀变的产物。这些斑脱岩广泛分布于扬子地台周缘,对理解奥陶纪-志留纪时华南所处的大地构造位置和相应的构造事件具有重要的意义。本文对采自扬子地台内湖北宜昌地区和贵州桐梓地区奥陶纪-志留纪界线剖面的斑脱岩层进行了矿物学及地球化学工作,旨在判定其形成的构造环境。矿物学研究表明上述岩石除了含有粘土矿物外,还含有石英、长石、黑云母、磷灰石、锆石等中酸性岩浆岩中的常见矿物,属典型的钾质斑脱岩。本文利用在风化过程中不活动元素对斑脱岩的原岩进行了恢复,结果也表明其原岩为中酸性火山岩,包括安山岩-英安岩-及流绞岩等。微量元素特征显示多数样品具有典型的岛弧火山岩的特征,很可能与北面早古生代秦岭洋的闭合过程中的板块俯冲有关,也可能是早古生代在华南板块东南缘外侧存在的一古老洋壳向华南板块的俯冲。有一个样品(YC0711)没有Nb的负异常,但是具有明显的Ti负异常,在Th/Yb-Nb/Yb判别图上落在岛弧区附近,其原岩可能是富铌玄武岩之类的特殊岛弧岩石。火山活动的峰期为晚奥陶世赫南特阶时代,与地质历史上第二大的生物大灭绝事件同时。前人认为该生物灭绝事件与冈瓦纳冰川有关。考虑到华南以及欧洲、北美等地均出现大规模晚奥陶世-早侏罗纪钾质斑脱岩,奥陶纪-志留纪边界的火山事件是具有全球规模的,所喷发的岩石多是富含挥发份的中酸性岩,对大气圈和生物圈具有十分重要的影响,本文认为火山活动很可能是造成晚奥陶世的生物大灭绝事件和冈瓦纳冰川的主要诱导因素。 展开更多
关键词 奥陶纪 志留纪 边界 火山活动 活动记录 华南板块 钾质斑脱岩 信息 Yangtze Block mass extinction VOLCANIC rocks 扬子地台 晚奥陶世 typical characteristics South China plate tectonic setting 事件 生物大灭绝 VOLCANIC activity geological events
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Effects of soil temperature and soil water content on soil respiration in three forest types in Changbai Mountain 被引量:9
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作者 王淼 李秋荣 +1 位作者 肖冬梅 董百丽 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期113-118,i002,共7页
Soil incubation experiments were conducted in lab to delineate the effect of soil temperature and soil water content on soil respirations in broad-leaved/Korean pine forest (mountain dark brown forest soil), dark coni... Soil incubation experiments were conducted in lab to delineate the effect of soil temperature and soil water content on soil respirations in broad-leaved/Korean pine forest (mountain dark brown forest soil), dark coniferous forest (mountain brown coniferous forest soil) and erman's birch forest (mountain soddy forest soil) in Changbai Mountain in September 2001. The soil water content was adjusted to five different levels (9%, 21%, 30%, and 43%) by adding certain amount of water into the soil cylinders, and the soil sample was incubated at 0, 5, 15, 25 and 35°C for 24 h. The results indicated that in broad-leaved/Korean pine forest the soil respiration rate was positively correlated to soil temperature from 0 to 35°C. Soil respiration rate increased with increase of soil water content within the limits of 21% to 37%, while it decreased with soil water content when water content was over the range. The result suggested the interactive effects of temperature and water content on soil respiration. There were significant differences in soil respiration among the various forest types. The soil respiration rate was highest in broad-leaved/Korean pine forest, middle in erman's birch forest and the lowest in dark coniferous forest. The optimal soil temperature and soil water content for soil respiration was 35°C and 37% in broad-leaved/Korean pine forest, 25°C and 21% in dark coniferous forest, and 35°C and 37% in erman's birch forest. Because the forests of broad-leaved/Korean pine, dark coniferous and erman's birch are distributed at different altitudes, the soil temperature had 4–5°C variation in different forest types during the same period. Thus, the soil respiration rates measured in brown pine mountain soil were lower than those in dark brown forest and those measured in mountain grass forest soil were higher than those in brown pine mountain soil. Key words Soil temperature - Soil water content - Soil respiration - The typical forest ecosystem in Changbai Mountain CLC number S7118.51 Document code A Foundation item: This study was supported by grant from the National Natural Science Foundation of China (No. 30271068), the grant of the Knowledge Innovation Program of Chinese Academy of Sciences (KZ-CX-SW-01-01B-12) and the grant from Advanced Programs of Institute of Applied Ecology Chinese Academy of Sciences.Biography: WANG Miao (1964-), male, associate professor in Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110016, P. R. China.Responsible editor: Song Funan 展开更多
关键词 Soil temperature Soil water content Soil respiration The typical forest ecosystem in Changbai Mountain
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Detecting Vegetation Fractional Coverage of Typical Steppe in Northern China Based on Multi-scale Remotely Sensed Data 被引量:15
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作者 李晓兵 陈云浩 +1 位作者 史培军 陈晋 《Acta Botanica Sinica》 CSCD 2003年第10期1146-1156,共11页
One of the study objectives of global change is land use/cover change (LUCC) by using multiscale remotely sensed data on global and regional scale. In this paper, field sample, digital camera, Landsat-ETM+ (ETM+, Enha... One of the study objectives of global change is land use/cover change (LUCC) by using multiscale remotely sensed data on global and regional scale. In this paper, field sample, digital camera, Landsat-ETM+ (ETM+, Enhanced Thematic Mapper) image and the National Oceanic and Atmospheric Administration/the advanced very high resolution radiometer (NOAA/AVHRR) image were integrated to detect, simulate and analyze the vegetation fractional coverage of typical steppe in northern China. The results show: (1) Vegetation fractional coverage measured by digital camera is more precise than results measured by other methods. It can be used to validate other measuring results. (2) Vegetation fractional coverage measured by 1 m 2 field sample change fluctuantly for different observers and for different sample areas. In this experiment, the coverage is generally high compared with the result measured by digital camera, and the average absolute error is 9.92%, but two groups measure results, correlation coefficient r(2) = 0.89. (3) Three kinds of methods using remotely sensed data were adopted to simulate the vegetation fractional coverage. Average absolute errors of the vegetation fractional coverage, measured by ETM+ and NOAA, are respectively 7.03% and 7.83% compared with the result measured by digital camera. When NOAA pixel was decomposed by ETM+ pixels after geometrical registry, the average absolute errors measured by this method is 5.68% compared with the digital camera result. Correction coefficients of three results with digital camera result r(2) are respectively 0.78, 0.61 and 0.76. (4) The result of statistic model established by NOAA-NDVI (NDVI, Normalized Difference Vegetation Index) and the vegetation fractional coverage measured by digital camera show lower precision (r(2) = 0.65) than the result of statistic model established by ETM+-NDVI and digital camera coverage then converted to NOAA image (r(2) = 0.80). Pixel decomposability method improves the precision of measuring the vegetation fractional coverage on a large scale. This is a significant practice on scaling by using remotely sensed data. Integrated application of multi-scale remotely sensed data in earth observation will be an important approach to promoting measuring precision of ecological parameters. 展开更多
关键词 multi-scale remote sensing typical steppe vegetation fractional coverage
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典型波纹翅片单元流动与传热特性的数值研究 被引量:4
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作者 王维斌 傅宪辉 +2 位作者 吴茂刚 冯茺蔚 牛洪成 《机械设计与制造》 北大核心 2010年第12期198-200,共3页
以两种典型的波纹翅片单元为研究对象,在合理简化条件下给出了物理模型和数学模型,通过流固界面的传热耦合,对不同进口风速下波纹翅片单元的流动及传热和阻力特性进行了数值研究。通过对传热系数,Nu数、压降以及涡量分布的对比分析,结... 以两种典型的波纹翅片单元为研究对象,在合理简化条件下给出了物理模型和数学模型,通过流固界面的传热耦合,对不同进口风速下波纹翅片单元的流动及传热和阻力特性进行了数值研究。通过对传热系数,Nu数、压降以及涡量分布的对比分析,结果表明:人字形翅片的传热性能优于波浪形翅片,而流动阻力性能却没有明显的劣势,其主要原因是翅片流场中涡流的产生与耗散存在差异。 展开更多
关键词 典型 波纹翅片 单元 流动及传热 传热特性 数值研究 TYPICAL transfer of flow 阻力性能 阻力特性 研究对象 物理模型 涡量分布 数学模型 流固界面 对比分析 传热性能 传热系数 传热耦合
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Dynamic of Chinas cultivated land and landcover changes of its typical regions based on remote sensing data 被引量:1
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作者 张佳华 董文杰 +2 位作者 王长耀 刘纪远 姚凤梅 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第3期183-186,210,共5页
Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigati... Using the multi-temporal Landsat data and survey data of national resources, the authors studied the dynamics of cultivated land and landcover changes of typical ecological regions in China. The results of investigation showed that the whole distribution of the cultivated land shifted to Northeast and Northwest China, and as a result, the ecological quality of cultivated land dropped down. The seacoast and cultivated land in the area of Yellow River Mouth expanded by an increasing rate of 0.73 kma-1, with a depositing rate of 2.1 kma-1. The desertification area of the dynamic of Horqin Sandy Land increased from 60.02% of the total land area in1970s to 64.82% in1980s but decreased to 54.90% in early 1990s. As to the change of North Tibet lakes, the water area of the Namu Lake decreased by 38.58 km2 from year 1970 to 1988, with a decreasing rate of 2.14 km2a-1. 展开更多
关键词 Remote sensing data Cultivated land Landcover change Typical ecological regions China
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