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A High Precision Comprehensive Evaluation Method for Flood Disaster Loss Based on Improved Genetic Programming 被引量:2
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作者 ZHOU Yuliang LU Guihua +2 位作者 JIN Juliang TONG Fang ZHOU Ping 《Journal of Ocean University of China》 SCIE CAS 2006年第4期322-326,共5页
Precise comprehensive evaluation of flood disaster loss is significant for the prevention and mitigation of flood disasters. Here, one of the difficulties involved is how to establish a model capable of describing the... Precise comprehensive evaluation of flood disaster loss is significant for the prevention and mitigation of flood disasters. Here, one of the difficulties involved is how to establish a model capable of describing the complex relation between the input and output data of the system of flood disaster loss. Genetic programming (GP) solves problems by using ideas from genetic algorithm and generates computer programs automatically. In this study a new method named the evaluation of the grade of flood disaster loss (EGFD) on the basis of improved genetic programming (IGP) is presented (IGP-EGFD). The flood disaster area and the direct economic loss are taken as the evaluation indexes of flood disaster loss. Obviously that the larger the evaluation index value, the larger the corresponding value of the grade of flood disaster loss is. Consequently the IGP code is designed to make the value of the grade of flood disaster be an increasing function of the index value. The result of the application of the IGP-EGFD model to Henan Province shows that a good function expression can be obtained within a bigger searched function space; and the model is of high precision and considerable practical significance. Thus, IGP-EGFD can be widely used in automatic modeling and other evaluation systems. 展开更多
关键词 automatic modeling evaluation of flood disaster loss genetic algorithm genetic programming
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Numerical and Experimental Evaluation of Shine-Through Loss and Beam Heating Due to Neutral Beam Injection on EAST 被引量:1
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作者 Jin-Fang Wang Ying-Ying Li +13 位作者 Bin Wu Yu-Qing Chen Jun Li Yong-Jian Xu Long-Xi Chen Bao-Long Hao Deng Zhou Juan Huang Si-Ye Ding Zhen Yang Ya-Wei Hou Xiao-Juan Liu Nong Xiang Institute of Plasma Physi 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第5期46-50,共5页
This research applies experimental measurements and NUBEAM,ONETWO and TRANSP modules to investigate the shine-through(ST)loss ratio and beam heating percentage of neutral beam injection on EAST.Measurements and simula... This research applies experimental measurements and NUBEAM,ONETWO and TRANSP modules to investigate the shine-through(ST)loss ratio and beam heating percentage of neutral beam injection on EAST.Measurements and simulations confirm that the ST loss ratio increases linearly with beam energy,and decreases exponentially with plasma density.Moreover,using the multi-step fitting method,we present analytical quantitative expressions of ST loss ratio and beam heating percentage,which are valuable for the high parameter long-pulse experiments of EAST. 展开更多
关键词 Numerical and Experimental evaluation of Shine-Through loss and Beam Heating Due to Neutral Beam Injection on EAST
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Factor value determination and applicability evaluation of universal soil loss equation in granite gneiss region
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作者 Wen-hai ZHANG Xing-nan ZHANG Zhi-dong GAO 《Water Science and Engineering》 EI CAS 2009年第2期87-97,共11页
Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation an... Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation analysis of runoff and soil loss during 364 rainfall events, a simplified and convenient mathematical formula suitable for calculating the rainfall erosivity factor (R) for the local region was established. Other factors of the universal soil loss equation (USLE model) were also determined. Relative error analysis of the soil loss of various plots calculated by the USLE model on the basis of the observed values showed that the relative error ranged from -3.5% to 9.9% and the confidence level was more than 90%. In addition, the relative error was 5.64% for the terraced field and 12.36% for the sloping field in the practical application. Thus, the confidence level was above 87.64%. These results provide a scientific basis for forecasting and monitoring soil and water loss, for comprehensive management of small watersheds, and for soil and water conservation planning in the region. 展开更多
关键词 granite gneiss region soil erosion universal soil loss equation factor value applicability evaluation
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Disaster Loss Evaluation and Characteristics of the Seismic Hazard of the Nilka-Gongliu Earthquake with M_S6. 0
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作者 Tan Ming Tang Lihua +8 位作者 Wu Guodong Chang Xiangde Zhang Yong Song Lijun Li Yang Li Yigang Wang Wei Shi Guangling Li Zhihai 《Earthquake Research in China》 2014年第2期261-273,共13页
The epicenter intensity of Nilka-Gongliu earthquake with MS6. 0 was Ⅶ degrees; no fatalities but many residential buildings and public facilities were moderately damaged during the earthquake. Traffic and water conse... The epicenter intensity of Nilka-Gongliu earthquake with MS6. 0 was Ⅶ degrees; no fatalities but many residential buildings and public facilities were moderately damaged during the earthquake. Traffic and water conservation facilities were damaged to a certain extent but after emergency repair,production and life in the disaster area were not influenced. According to a sample survey of the earthquake filed,this earthquake caused direct economic loss of approximately 678. 46 million yuan( RMB),and the reconstruction funds required will be about 1. 20349 billion yuan( RMB). 展开更多
关键词 The Nilka-Gongliu earthquake Disaster loss evaluation Characteristic of seismic hazard
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A STUDY ON ECONOMY EVALUATION ON THE PROFIT AND LOSS OF GEOLOGIC ENVIRONMENTAL QUALITY ABOUT GEOLOGIC ENVIRONMENTAL EXPLOITATION PROJECT
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《石家庄经济学院学报》 1995年第S1期106-109,共4页
The problems of environmental geology refer to the geologic phenomena, incidents or accidents arising from action of environmental geology. The action is mainly the mutual influence between human activity and geologic... The problems of environmental geology refer to the geologic phenomena, incidents or accidents arising from action of environmental geology. The action is mainly the mutual influence between human activity and geologic environment. When human activity is uncoordinated with objective laws of the geologic environment, the problems of environmental geology or economic loss would occur.Therefore,the level and the changing orientation of geologic environmental quality are relative to the types of human activity,particularly relative to human intentional-activities of geologic environmental exploitation project. The geologic environment fitting to mining may not fit to urban construction,and fitting to water conservancy and hydroelectric projects may not fit to communication,and so on.Economy evaluation on the profit and loss of geologic environmental quality is exactly to depict the level of the profit and loss of geologic environmental quality about geologic environmental exploitation projects and the 展开更多
关键词 TH A STUDY ON ECONOMY evaluation ON THE PROFIT AND loss OF GEOLOGIC ENVIRONMENTAL QUALITY ABOUT GEOLOGIC ENVIRONMENTAL EXPLOITATION PROJECT
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Earthquake Loss Evaluation of Buildings Based on Story EDP-DV Functions
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作者 Zhaoping Jia Ziyan Wu Qi'ang Wang 《建筑工程(中英文版)》 2013年第3期52-59,共8页
关键词 地震损失评估 故事 直接经济损失 抗震性能 运动强度 分布函数 建筑物 地震响应
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Study on evaluation of cities' ability reducing earthquake disasters 被引量:9
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作者 张风华 谢礼立 范立础 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第3期349-361,377,共13页
Cities ability reducing earthquake disasters is a complex system involving numerous factors, moreover the re-search on evaluating cities ability reducing earthquake disasters relates to multi-subject, such as earthqua... Cities ability reducing earthquake disasters is a complex system involving numerous factors, moreover the re-search on evaluating cities ability reducing earthquake disasters relates to multi-subject, such as earthquake sci-ence, social science, economical science and so on. In this paper, firstly, the conception of cities ability reducing earthquake disasters is presented, and the ability could be evaluated with three basic elements the possible seis-mic casualty and economic loss during the future earthquakes that are likely to occur in the city and its surround-ings and time required for recovery after earthquake; based upon these three basic elements, a framework, which consists of six main components, for evaluating citys ability reducing earthquake disasters is proposed; then the statistical relations between the index system and the ratio of seismic casualty, the ratio of economic loss and re-covery time are gained utilizing the cities prediction results of earthquake disasters which were made during the ninth five-year plan; at last, the method defining the comprehensive index of cities ability reducing earthquake disasters is presented. Thus the relatively comprehensive theory frame is set up. The frame can evaluate cities ability reducing earthquake disasters absolutely and quantitatively and consequently instruct the decision-making on reducing cities earthquake disasters loss. 展开更多
关键词 evaluation of cities ability reducing earthquake disasters seismic casualty economic loss re-covery time index system grey correlation comprehensive index of cities ability reducing earthquake dis-asters
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Cost-benefit Analysis of Land Development Projects Based on Fuzzy Comprehensive Evaluation Model 被引量:1
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作者 Zhengben DAI Xingchen HU Haoran CHENG 《Asian Agricultural Research》 2019年第6期12-14,共3页
Ecological and environmental issues have always been the focus of government work. The economic losses caused by air pollution,water pollution,noise pollution and solid waste pollution caused by land use development p... Ecological and environmental issues have always been the focus of government work. The economic losses caused by air pollution,water pollution,noise pollution and solid waste pollution caused by land use development projects are estimated,and the total population economic losses are incorporated into project costing. Using the analytic hierarchy process,four benefit indicators and five cost indicators are selected for constructing a fuzzy comprehensive evaluation model to evaluate the cost-benefit of projects of different scales. The projects of different scales are ranked according to the level of comprehensive scores. The results show that large-scale projects are cost-effective and stable over the long term,and there are differences in the main sources of pollution-caused economic losses for projects of different scales. At last,reasonable policy suggestions are made to relevant planning and management personnel. 展开更多
关键词 Pollution-caused ECONOMIC lossES COST-BENEFIT Fuzzy COMPREHENSIVE evaluation
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Economic Evaluation Method of Photovoltaic Power Generation Installed in Ordinary Homes 被引量:1
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作者 Yasushi Iwasaki Kayoko Yamamoto 《Smart Grid and Renewable Energy》 2014年第6期137-151,共15页
This study aims to develop an economic evaluation method for installing photovoltaic power generation in ordinary homes using GIS (Geographic Information Systems). The conclusions can be summarized in the following th... This study aims to develop an economic evaluation method for installing photovoltaic power generation in ordinary homes using GIS (Geographic Information Systems). The conclusions can be summarized in the following three points: 1) This method determines the profit and loss and payback period in order to evaluate the installation of photovoltaic power generation, taking into account the price of equipment, solar battery module conversion efficiency, subsidy, electricity purchase price, service life and rate for selling electricity. 2) The proposed evaluation method was applied to Kanagawa Prefecture in Japan, providing plural scenarios. Using a solar battery module conversion efficiency of more than 15%, it is possible to make the payback period shorter than the 20-year service life and anticipate a profit in almost the whole area. 3) The areas suitable for photovoltaic power generation are Kawasaki City and Ninomiya-machi. It is necessary to adopt measures to increase the subsidy and install photovoltaic power generating systems in specific places in areas where subsidies are not provided in enough amounts. 展开更多
关键词 Photovoltaic Power Generation ECONOMIC evaluation SUBSIDY PROFIT and loss and Payback PERIOD GIS (Geographic Information Systems)
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Evaluation of Tomato Genetic Resources for Response to Water Deficit
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作者 Adriana Sacco Barbara Greco +2 位作者 Antonio Di Matteo Rosalba De Stefano Amalia Barone 《American Journal of Plant Sciences》 2013年第12期131-145,共15页
Water deficit strongly affects plant yield and quality. However, plants can minimize drought injury by adaptation mechanisms that have evolved to escape harmful conditions. The response to water deprivation is a compl... Water deficit strongly affects plant yield and quality. However, plants can minimize drought injury by adaptation mechanisms that have evolved to escape harmful conditions. The response to water deprivation is a complex trait controlled by several genes. In order to gain a deeper understanding of drought response mechanisms in tomato, a collection of 27 genotypes was studied under different water deficit conditions. Since developmental stages might be differently influenced by drought, analyses were carried out on young plantlets during fruit setting. The only genotype that showed good performances both as water retention and fruit production was the ecotype Siccagno. All the genotypes were analyzed at molecular level with the aim of detecting structural polymorphisms in selected stress-responsive genes. In addition, the expression level of a number of these genes was measured in the genotypes more tolerant to water deficit. Many polymorphisms were detected in six stress-responsive genes, and some could imply significant modifications in the protein structure. Furthermore, the expression analysis by RT-qPCR of three stress-responsive genes allowed arguing that a higher level of expression of the gene erd15 might be related to the better response to water deficit exhibited by Siccagno. Similarly, the lower expression of eight genes in the same genotype analysed through a microarray experiment confirmed the involvement of these stress-related genes in the tomato response to drought. Further investigations are required for a better comprehension of the mechanisms underlying response to water deficit in tomato by exploiting the genetic resource identified as more tolerant. The use of new technologies able to globally analyze structural polymorphism and expression level of genes will succeed to identify crucial genes involved in stress response in the ecotype Siccagno grown under different water regimes. 展开更多
关键词 Drought-Tolerance WATER loss Rate Relative WATER Content Yield evaluation Gene POLYMORPHISMS
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Re-Evaluation of the Safety of Laser-Assisted Subepithelial Keratectomy
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作者 Yuji Kumano Yumi Soejima +5 位作者 Shinichiro Numa Hiroyasu Matsui Ikuko Zushi Masahito Shigematsu Takaaki Matsui Teruo Nishida 《Open Journal of Ophthalmology》 2014年第3期79-85,共7页
Purpose: Additional analyses of outcomes of laser-assisted subepithelial keratectomy (LASEK) are still necessary to improve the safety of LASEK. Therefore, in our study, outcomes were assessed retrospectively in 561 e... Purpose: Additional analyses of outcomes of laser-assisted subepithelial keratectomy (LASEK) are still necessary to improve the safety of LASEK. Therefore, in our study, outcomes were assessed retrospectively in 561 eyes that underwent LASEK treatment. Methods: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA) and residual spherical equivalent were analyzed at 3 and 6 months postoperatively. We assessed four subgroups based on the degree of preoperative myopia considering mean BSCVA and loss of two or more lines. Results: Mean UCVAs and BSCVAs were obtained at 3 and 6 months postoperatively (1.23/1.35 and 1.23/1.37, respectively). The mean predictability was within ±0.125 diopters. Conversely, the safety indexes were 0.94 and 0.96 respectively, and the efficacy indexes were 0.86 and 0.86 at 3 and 6 months postoperatively, respectively. 8.4% eyes and 5.2% eyes lost two or more lines of BSCVA at 3 and 6 months postoperatively, respectively. The mean BSCVAs of the high or ultra-high groups were significantly lower than those of the low or mild groups both 3 months and 6 months postoperatively. The incidence rates of losing two or more lines of BSCVA in the high or ultra-high myopia groups were significantly greater than in the low or mild groups at 3 months and 6 months postoperatively. Conclusion: LASEK predictably corrected myopia achieving >1.2 in UCVA and BSCVA. However, the safety and efficacy indexes were <1.0, which were related to the loss of two or more lines of BSCVA. Since the incidence rates of losing two or more lines of BSCVA were greater in the high or ultra-high myopia groups, we consider LASEK as more safely performed in patients with low to mild preoperative myopia. 展开更多
关键词 BSCVA LASEK loss of Two or More LINES PREOPERATIVE MYOPIA RE-evaluation
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鲜叶摊放失水程度对夏季绿茶品质的影响
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作者 唐海燕 曾维超 《贵州农业科学》 CAS 2024年第5期111-115,共5页
【目的】探明夏季茶鲜叶不同摊放失水程度对绿茶品质的影响,为有效改善夏季绿茶品质提供理论依据。【方法】以湖北五峰群体种1芽2叶、1芽3叶为原料(夏暑茶鲜叶),进行不同摊放失水程度处理(摊放失水10%、15%、20%、25%)后加工成干茶样,... 【目的】探明夏季茶鲜叶不同摊放失水程度对绿茶品质的影响,为有效改善夏季绿茶品质提供理论依据。【方法】以湖北五峰群体种1芽2叶、1芽3叶为原料(夏暑茶鲜叶),进行不同摊放失水程度处理(摊放失水10%、15%、20%、25%)后加工成干茶样,测定其生化成分含量,结合感官审评对其品质进行综合评价。【结果】感官品质中,摊放失水15%的茶样香气得分最高,为81.25分;摊放失水20%的茶样滋味得分最高,为77.83分;感官品质总分以摊放失水15%的茶样得分最高(78.61分),显著(P<0.05)高于摊放失水25%茶样。理化成分中,摊放失水10%和失水15%的茶样可溶性糖含量分别为22.29 g/kg和21.83 g/kg,显著高于摊放失水20%和25%茶样;茶多酚含量分别为177.29 g/kg和177.25 g/kg,显著低于摊放失水20%和25%茶样;摊放失水15%的茶样氨基酸含量最高,达32.59 g/kg,显著高于摊放失水25%茶样;摊放失水15%的酚氨比最低,仅5.44,显著低于摊放失水25%茶样。【结论】夏季茶树鲜叶摊放失水15%后加工制成绿茶的酚氨比最低、感官品质最好、滋味浓强、基本无苦涩味、清香带栗香。 展开更多
关键词 夏季绿茶 摊放失水程度 品质 感官审评
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陆相页岩层系岩心中气态烃井场测定技术初步应用及展望 被引量:1
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作者 贾梦瑶 鲍云杰 +6 位作者 李志明 申宝剑 曹婷婷 刘鹏 杨振恒 卢龙飞 黎茂稳 《石油实验地质》 CAS CSCD 北大核心 2024年第1期183-190,共8页
陆相页岩层系的流体分析是页岩油甜点评价的重要基础,针对岩心样品中气态烃易于散失的特性和页岩油钻井现场的需求,研发了井场岩心气态烃快速采集测定装置及方法,探讨了基于岩心气态烃分析和热解含油性分析资料快速计算视气油比和估算... 陆相页岩层系的流体分析是页岩油甜点评价的重要基础,针对岩心样品中气态烃易于散失的特性和页岩油钻井现场的需求,研发了井场岩心气态烃快速采集测定装置及方法,探讨了基于岩心气态烃分析和热解含油性分析资料快速计算视气油比和估算游离油损失的方法。研究表明,该装置适用于全直径岩心和块状样品的气态烃检测,既可以实现全直径岩心在常温、常压下逸散气态烃的采集测定,也可以测定块状岩心样品的气态烃总量,气态烃检测相对误差10%,测试结果可以转换为单位质量岩样气态烃含量。全直径岩心逸散气分析可实现岩心气态烃的非破坏式采集和测定,反映了页岩层系垂向上含油气性及其非均质性的变化特征。视气油比可反映页岩层系含油气性和可流动性的趋势,视气油比越大,代表相应页岩层系页岩油可流动性越好。利用视气油比可估算岩心经历降压降温脱气过程中游离烃的损失量,在建立岩心降温降压脱气过程的热解游离烃损失恢复方法中具有较大应用潜力。岩心气态烃井场测定技术丰富了适用于井场的岩心流体分析实验技术手段和方法,为陆相页岩层系流体评价及甜点确定提供数据支撑。 展开更多
关键词 气态烃含量 视气油比 游离油损失恢复 可流动性评价 页岩油气 陆相页岩
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网式过滤器水头损失动态变化规律 被引量:1
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作者 郑长娟 朱德兰 +5 位作者 高洒洒 张锐 赵泽晋 李路明 KHUDAYBERDI Nazarov 柳昌新 《农业工程学报》 EI CAS CSCD 北大核心 2024年第8期62-70,共9页
网式过滤器是微灌系统的关键部件之一,对过滤杂质,减缓滴头堵塞起到重要作用,但过滤器水头损失往往随拦截杂质的增多而增大,导致滤网破损或系统被迫停机。为明晰过滤器水头损失变化规律,该研究采用文献数据归纳分析和试验相结合的方法,... 网式过滤器是微灌系统的关键部件之一,对过滤杂质,减缓滴头堵塞起到重要作用,但过滤器水头损失往往随拦截杂质的增多而增大,导致滤网破损或系统被迫停机。为明晰过滤器水头损失变化规律,该研究采用文献数据归纳分析和试验相结合的方法,对7种网式过滤器水头损失数据开展聚类分析;以Y型网式过滤器为例,测试不同流量、泥沙浓度和沙粒级配对过滤器水头损失的影响,以减少水头损失激增、提高拦沙效果为主要目标开展综合评价,优选过滤器适宜的运行工况。结果表明:1)不同类型网式过滤器水头损失随时间变化可分为平稳增加阶段和突然增加阶段,突然增加阶段的水头损失增长速率更大,堵塞均匀度均大于1。2)相同流量和浓度下,以>100~125μm泥沙为主的Ⅲ级配和以>125~150μm泥沙为主Ⅳ级配含沙水较以>54~75μm泥沙为主Ⅰ级配和以>100~125μm泥沙为主Ⅱ级配含沙水更容易产生水头损失激增。相同流量下,高浓度工况更容易出现水头损失激增;相同浓度下,流量为3.5 m^(3)/h时最容易使过滤器水头损失激增。3)CRITIC-TOPSIS综合评价结果表明排名前3的分别是流量2.5 m^(3)/h、泥沙浓度60 mg/L工况下Ⅲ、Ⅳ和Ⅱ级配含沙水,综合得分指数分别为0.726、0.712和0.711;低泥沙浓度、大颗粒级配和高泥沙浓度、小颗粒级配在流量2.5 m^(3)/h时综合性能好,高泥沙浓度、大颗粒级配在流量4.5 m^(3)/h综合性能好,低泥沙浓度、小颗粒级配在3种流量下综合性能差异不大。研究可为减少过滤器水头损失和增加运行时长提供参考。 展开更多
关键词 流量 滴头 泥沙 网式过滤器 水头损失 激增 文献分析 综合评价
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枯竭气藏型储气库多周期损耗计算方法及其应用 被引量:1
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作者 张平 黄发木 +5 位作者 付亚平 孙云峰 苏海波 鲁俊 王健 杨火海 《大庆石油地质与开发》 CAS 北大核心 2024年第2期86-92,共7页
地下储气库在生产运行过程中不可避免地会产生天然气损耗。目前对储气库气体损耗的研究仅停留在定性描述阶段,无法满足储气库经济性定量评价的要求。结合清单分析理论和注采机理实验,针对地下储气库注采过程中存在的微渗漏、溶解扩散、... 地下储气库在生产运行过程中不可避免地会产生天然气损耗。目前对储气库气体损耗的研究仅停留在定性描述阶段,无法满足储气库经济性定量评价的要求。结合清单分析理论和注采机理实验,针对地下储气库注采过程中存在的微渗漏、溶解扩散、异常漏气和宏观漏气现象,建立了天然气损耗评价数学模型,对地下储气库气体损耗进行定量评价。结果表明:宏观驱替过程中的气体损耗是储气库气体损耗的主要组成部分,随着注采周期的增加而减小;在此基础上,建立了储气库型储气库天然气损耗定量评价方法,并以中原油田某地下储气库天然气损耗计算结果为例,利用该方法核算了该储气库自建库以来的各部分损耗情况并制定了降低损耗的技术对策。依托该计算方法可合理制定降低储气库天然气损耗政策,提供泄漏风险预警,提高储气库经济效益和注采安全性。 展开更多
关键词 地下储气库 天然气损耗 宏观驱替 注采周期 定量评价
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磷指数模型在美国的应用和发展
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作者 马华 雷秋良 +6 位作者 杜新忠 赵营 李影 安妙颖 武淑霞 樊秉乾 刘宏斌 《农业环境科学学报》 CAS CSCD 北大核心 2024年第5期965-973,共9页
磷是植物生长必需的营养元素之一,在农业生产中起着关键作用。然而,长期过量的磷肥投入导致土壤磷素水平增加,进而加大了土壤磷素流失风险,造成农业非点源磷污染,同时这也成为导致水体富营养化的主要因素之一。因此,识别和管理农业非点... 磷是植物生长必需的营养元素之一,在农业生产中起着关键作用。然而,长期过量的磷肥投入导致土壤磷素水平增加,进而加大了土壤磷素流失风险,造成农业非点源磷污染,同时这也成为导致水体富营养化的主要因素之一。因此,识别和管理农业非点源磷的流失风险关键区,成为面源污染亟待解决的关键问题。磷指数模型起源于20世纪90年代,是评估农田磷流失潜力和指导磷管理决策的重要工具之一。根据研究区特点,美国众多学者在各州设立了不同的磷指数指标体系,优化了磷指数的组成因子、计算方法和分级标准。本文对美国各州磷指数模型评价体系进行了综述和评价,指出了磷指数模型的局限性,提出了改进方向,以期为我国磷素管理方法提供借鉴。 展开更多
关键词 磷指数 非点源污染 磷素迁移 评价体系 流失风险
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测定驱油用聚合物静态吸附浓度损失的新方法及其应用
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作者 李佳慧 闫新政 《石油化工》 CAS CSCD 北大核心 2024年第6期884-889,共6页
建立了一种测定(含)聚合物溶液静态吸附浓度损失的新方法,即运动黏度法。该方法是在静态吸附过程中同时开展待测组和参照组实验,建立参照组溶液的比浓黏度-质量浓度曲线,测定待测组溶液的黏度并代入上述方程,计算得到溶液质量浓度及静... 建立了一种测定(含)聚合物溶液静态吸附浓度损失的新方法,即运动黏度法。该方法是在静态吸附过程中同时开展待测组和参照组实验,建立参照组溶液的比浓黏度-质量浓度曲线,测定待测组溶液的黏度并代入上述方程,计算得到溶液质量浓度及静态吸附浓度损失,同时对该方法进行可行性验证。实验结果表明,该方法控制增比黏度在0.2~1.5之间,比浓黏度-质量浓度线性关系良好,精密度的相对标准偏差为0.61%,重复性的相对标准偏差为0.043%,用于单一常规聚合物溶液质量浓度测定时与淀粉-碘化镉法测定结果一致。与淀粉-碘化镉法相比,该方法具有不受杂质离子颜色干扰、无需控制化学反应进程、适用性广的优点,可广泛应用于(含)聚合物溶液静态吸附浓度损失的测定,为驱油用聚合物的评价和优选提供指导。 展开更多
关键词 聚合物溶液 运动黏度 浓度 浓度损失 性能评价
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特大暴雨下残垣丘陵沟壑区水土流失与梯田措施效益评价
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作者 赵妍 周珊珊 +3 位作者 高云飞 王满 靳琪 刘姗姗 《水土保持通报》 CSCD 北大核心 2024年第5期92-99,共8页
[目的]开展场次暴雨水土流失评估与措施效益评价,分析暴雨造成的土壤侵蚀状况,评价梯田措施效益,为常规水土流失动态监测提供有效补充。[方法]以甘肃“2022·7·15”特大暴雨发生地庆城县和暴雨中心湫沟小流域为研究区,利用日... [目的]开展场次暴雨水土流失评估与措施效益评价,分析暴雨造成的土壤侵蚀状况,评价梯田措施效益,为常规水土流失动态监测提供有效补充。[方法]以甘肃“2022·7·15”特大暴雨发生地庆城县和暴雨中心湫沟小流域为研究区,利用日降雨量数据与全国水土流失动态监测项目相关成果,基于次暴雨降雨侵蚀力,采用改进的CSLE模型计算土壤侵蚀模数,分析暴雨降雨侵蚀力与多年均降雨条件下全年降雨侵蚀力的关系,以及次暴雨条件下不同土地利用类型土壤侵蚀强度等级的空间分布,探讨梯田对区域水土流失的影响。[结果]庆城县该次暴雨产生的降雨侵蚀力达到多年均降雨条件下全年降雨侵蚀力的1.85倍,暴雨中心降雨侵蚀力达到多年均降雨条件下全年降雨侵蚀力的4.88倍。暴雨造成的强烈级以上土壤侵蚀面积是2021年全年强烈级以上土壤侵蚀面积的3.46倍,暴雨中心达6.93倍。场次特大暴雨造成的强烈以上等级土壤侵蚀主要分布在旱地、草地和灌木林地。庆城县现状梯田面积325 km^(2),相较于无梯田措施情景,县域土壤侵蚀量减幅达72.87%。[结论]加强退耕还林还草、坡耕地综合整治、旱作梯田建设等水土保持工作,是特大暴雨条件下水土流失灾害防治的有效手段。 展开更多
关键词 特大暴雨 次降雨侵蚀力 水土流失 梯田 效益评价
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兰彻斯特方程在分布式海战背景下的应用
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作者 陶鹏 丁凡 《火力与指挥控制》 CSCD 北大核心 2024年第10期82-90,102,共10页
为解决分布式海战背景下海上联合作战系统顶层方案效能评估问题,开展基于兰彻斯特方程的海上分布式混合作战理论模型研究及其应用探索。拟基于经典兰彻斯特方程,考虑分布式海上作战下的分层次作战与混合作战特点,建立考虑远距离打击作... 为解决分布式海战背景下海上联合作战系统顶层方案效能评估问题,开展基于兰彻斯特方程的海上分布式混合作战理论模型研究及其应用探索。拟基于经典兰彻斯特方程,考虑分布式海上作战下的分层次作战与混合作战特点,建立考虑远距离打击作战与近距离交战并行的分布式混合海战理论模型,并在时间维度进行了离散化处理,以一组典型海上作战案例来验证理论模型的可行性。仿真结果表明,分布式混合海战理论模型对于初步求解分布式海战问题具有一定帮助;在分布式作战状态下,战场胜负将不只取决于单兵交换率、单一域作战,还将取决于兵力的整体配置部署、联合体系战术决策与体系协同效果等,高低搭配的大小作战编组方案对于制海权争夺大有裨益。所构建的分布式混合海战理论模型对于海上联合作战系统方案的顶层效能评估与兵力结构设计具有一定价值,具有较好的可行性与实用性。 展开更多
关键词 分布式海战 兰彻斯特方程 作战编组 效能评估 兵力损耗
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维持性血液透析病人动静脉内瘘失功预测模型的系统评价
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作者 陈烁烁 刘晓琴 +1 位作者 李进 王李胜 《全科护理》 2024年第17期3189-3192,共4页
目的:分析并评价维持性血液透析病人动静脉内瘘失功的风险预测模型,以期为临床提供参考依据。方法:计算机检索Embase、the Cochrane Library、Web of Science、PubMed等英文数据库及中国知网、中国生物医学文献数据库、万方数据库等中... 目的:分析并评价维持性血液透析病人动静脉内瘘失功的风险预测模型,以期为临床提供参考依据。方法:计算机检索Embase、the Cochrane Library、Web of Science、PubMed等英文数据库及中国知网、中国生物医学文献数据库、万方数据库等中文数据库中有关维持性血液透析病人动静脉内瘘失功预测模型的文献,由2名具有循证能力的研究者按照文章的纳入、排除标准提取文献,再根据预测模型研究的偏倚风险评估工具对纳入的文献进行偏倚风险及适用性评价。结果:共纳入6篇动静脉内瘘失功风险预测模型,其中回顾性队列研究3篇,前瞻性队列研究3篇;单中心研究5篇,多中心研究1篇,预测动静脉早期失功的模型3篇,预测动静脉内瘘晚期失功模型3篇。6个模型的受试者工作特征曲线下面积(AUC)均大于0.700,纳入模型中预测动静脉内瘘失功的预测因子最多的是年龄、血压、有无糖尿病、置管史、吻合的动脉静脉血管直径及病人的钙磷乘积等,6项研究使用性较好,但是均存在一定的偏倚风险。结论:维持性血液透析病人动静脉内瘘失功风险预测模型的研究尚处在发展阶段,未来临床工作者应该开发性能好、偏倚风险较低的预测模型,进行外部或内部验证,用于临床。 展开更多
关键词 维持性血液透析 动静脉内瘘 模型 失功 系统评价
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