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Tropical cyclone hazards analysis based on tropical cyclone potential impact index 被引量:5
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作者 XIAO Fengjin YIN Yizhou +2 位作者 LUO Yong SONG Lianchun YE Dianxiu 《Journal of Geographical Sciences》 SCIE CSCD 2011年第5期791-800,共10页
Tropical cyclone,a high energy destructive meteorological system with heavy rainfall and gale triggered massive landslides and windstorms,poses a significant threat to coastal areas.In this paper we have developed a T... Tropical cyclone,a high energy destructive meteorological system with heavy rainfall and gale triggered massive landslides and windstorms,poses a significant threat to coastal areas.In this paper we have developed a Tropical Cyclone Potential Impact Index (TCPI) based on the air mass trajectories,disaster information,intensity,duration,and frequency of tropical cyclones.We analyzed the spatial pattern and interannual variation of the TCPI over the period 1949-2009,and taking the Super Typhoon Saomai as an example have examined the relationship between the TCPI and direct economic losses,total rainfall,and maximum wind speed.The results reveal that China's TCPI appears to be a weak decreasing trend over the period,which is not significant overall,but significant in some periods.Over the past 20 years,the TCPI decreased in the southern China coastal provinces of Hainan,Guangdong and Guangxi,while it increased in the southeastern coastal provinces of Zhejiang,Fujian and Taiwan.The highest values of TCPI are mainly observed in Taiwan,Hainan,the coastal areas of Guangdong and Fujian and Zhejiang's southern coast.The TCPI has a good correlation (P=0.01) with direct economic loss,rainfall,and maximum wind speed. 展开更多
关键词 tropical cyclone potential impact index temporal and spatial variation direct economic losses Typhoon Saomai
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Spatial Distribution of Integrated Impact Index of Mega-event——A Case Study of Expo '99 Kunming 被引量:7
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作者 DAI Guangquan BAO Jigang 《Chinese Geographical Science》 SCIE CSCD 2008年第3期214-223,共10页
Taking the affinity between events and media as a conceptualization base, a total of 1032 related news re-ports of Expo '99 Kunming, gathered from the internet data bank of China INFOBANK from 1992 to 2003, are us... Taking the affinity between events and media as a conceptualization base, a total of 1032 related news re-ports of Expo '99 Kunming, gathered from the internet data bank of China INFOBANK from 1992 to 2003, are used as data sources. After classifying them with a communication research method-the content analysis, a data bank for SPSS is set up, and a mathematic model called the Integrated Impact Index of Expo '99 Kunming is constituted. With the model, the spatial distribution of the total integrated impacts of Expo '99 Kunming on the regions or cities with different regional scales is analysed quantitatively. The conclusions are: 1) the Expo '99 Kunming made obvious integrated impacts on the regions or cities of every scale, especially in the venue city and the region-Kunming City and Yunnan Province; 2) it had corresponding impacts on other provinces; 3) the spatial distribution of Integrated Impact Index had a disaggregation with both plane extension and spotted decentralization; and 4) there was a distance decay law in all three scales of regions (Kunming City, Yunnan Province and the whole China), which incarnated the spatial extension law of the integrated impact of a special mega-event. 展开更多
关键词 Expo '99 Kunming Integrated impact index MEGA-EVENT Yunnan Province
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Mechanical response and impact tendency index correction of gangue-coal combined structure
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作者 WEN Zhi-jie XU Chang-long +2 位作者 GONG Feng-qiang ZUO Yu-jun SONG Zhen-qi 《Journal of Central South University》 2025年第6期2288-2306,共19页
To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with... To investigate the mechanical response during failure and the impact tendency characteristics of gangue-coal combined structure,uniaxial compression tests were conducted on nine groups of combined structures,each with varying gangue thicknesses and positions.The response patterns of compressive strength,elastic modulus,pre-peak accumulated energy,elastic energy index,and impact energy index were systematically analyzed.Furthermore,a new index for evaluating the impact tendency of gangue-containing coal was proposed,and its effectiveness was verified.The findings are as follows:(1)As the gangue thickness increases,both the compressive strength and the pre-peak energy of the combined structure decrease,whereas the elastic modulus increases accordingly.When the gangue is located in the lower middle position,the combined structure exhibits the lowest compressive strength and elastic modulus but the highest pre peak energy.(2)As the gangue shifts toward the middle position of the combined structure,the failure mode gradually transitions from comple te“crushing”failure to an incomplete“point-type”failure.As gangue thickness further increases,the failure region evolves from overall failure to localized failure,with the degree of failure shifting from complete to incomplete.The K_(crc)value corresponding to“crushing”complete failure is higher and has a stronger impact tendency compared to“point-type”incomplete failure.(3)The proposed comprehensive impact instability evaluation index K_(crc)for the gangue-coal combined structure has shown a significant positive correlation with compressive strength(R_(c))and impact energy index(K_(E)),further verifyi ng its rationality in comprehensively assessing the impact tendency of gangue-containing coal bodies.Applying this index to the evaluation of gangue-containing coal seams provides a more accurate reflection of their impact tendency compared with the residual energy index,which has a wide range of potential applications and practical significance. 展开更多
关键词 gangue-coal combined structure mechanical response peak elastic energy density difference impact tendency comprehensive impact instability index
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Assessing the socio-cultural impact of urban revitalisation using Relative Positive Impact Index(RPII) 被引量:1
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作者 Shahim Abdurahiman A.K.Kasthurba Affa Nuzhat 《Built Heritage》 CSCD 2024年第1期67-83,共17页
Urban heritage is a vital resource that connects communities to their local identity.Unplanned developments and rapid urbanisation often harm the authenticity of historic areas,disrupting the cultural fabric and alter... Urban heritage is a vital resource that connects communities to their local identity.Unplanned developments and rapid urbanisation often harm the authenticity of historic areas,disrupting the cultural fabric and altering their character.This study introduces the Relative Positive Impact Index(RPll),a novel technique for assessing the socio-cultural impacts of urban revitalisation.The significance of RPII lies in its ability to quantitatively evaluate the impacts on the cultural fabric and integrity of historic urban areas,which is crucial for sustainable urban development.The study's objective is to apply RPII in evaluating qualitative socio-cultural characteristics in historic urban areas,with a focus on four main criteria and 16 sub-criteria,in the case of the Kuttichira precinct.The methodology integrates the analysis of published literature,a quantitative survey mapping the stakeholders'perception,and qualitative insights.This approach facilitates an in-depth understanding of how urban revitalisation affects local socio-cultural dynamics,preserving the authenticity and character of historic areas.The study reveals that the revitalisation project in Kuttichira positively impacts the socio-cultural fabric of the area,maintaining cultural integrity and addressing social challenges.These findings offer valuable insights for sustainable urban development and policymaking in historic areas.The study recommends the application of RPll in other urban precincts for comparative analysis and further development of urban development practices,contributing to informed urban policy and planning decisions. 展开更多
关键词 urban revitalisation socio-cultural impact relative positive impact index urban heritage sustainability
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The impact of tourism on soils in Zhangjiajie World Geopark 被引量:3
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作者 石强 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期167-170,共4页
The soil hardness, soil water content and soil bulk density along the trails of six scenic spots in the Zhangjiajie World Geopark were measured and analyzed, and the integrated effects of tourism trampling on soils we... The soil hardness, soil water content and soil bulk density along the trails of six scenic spots in the Zhangjiajie World Geopark were measured and analyzed, and the integrated effects of tourism trampling on soils were evaluated for each scenic spots by calculating its soil impact indexes (SII) in the park. The results indicated that visitors' activities caused a serious influence on the soil in the park, especially in the two most used scenic spots-- Yellowstone Village and Gold Whip Stream. The impact of tourism on soil mainly occurred within 3 m along the trails. The impact shapes are classified into six type as single-sided node type, double-sided node type, cross node type, single-sided linkage type, double-sided linkage type and short-cut linkage type. Of six types of impact shapes, the single-sided node type and double-sided type were dominant. The average water contents of soil for six scenic spots at sample areas of 1 m, 2 m and 3 m from trial is 36.6%, 24.5% and 2.2% lower than that of the control area, respectively. The average soil hardness for six scenic spots at 1m, 2 m, and 3m from the trails tramped increased 167.9%, and 122.2%, and 15.8%, respectively, compared with the control area. Soil bulk density increased 26.5% at 1 m and 20.9% at 2 m from the trails. The main countermeasures for reducing the range and extent of tourism impact on soil are discussed. 展开更多
关键词 TOURISM Zhangjiajie World Geopark Tourism impact impact shapes Soil impact indexes Soil bulk density Soil hardness
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Impact of body mass index on outcomes of 48281 patients undergoing first time cadaveric liver transplantation
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作者 Subhashini Ayloo Scott Hurton +1 位作者 Matthew Cwinn Michele Molinari 《World Journal of Transplantation》 2016年第2期356-369,共14页
AIM: To investigate possible disparities in perioperative morbidity and mortality among different body mass index(BMI) groups and to simulate the impact that these differences might have had on the cohort of patients ... AIM: To investigate possible disparities in perioperative morbidity and mortality among different body mass index(BMI) groups and to simulate the impact that these differences might have had on the cohort of patients undergoing cadaveric liver transplantation(LT).METHODS: All adult recipients undergoing first time LT for benign conditions and receiving a whole graft from brain-dead donors were selected from the united network of organ sharing registry. From January 1994 to June 2013, 48281 patients satisfied the inclusion criteria and were stratified by their BMI. The hypothesis that abnormal BMIs were independent predictors of inferior outcomes was tested with univariate and multivariate regression analyses.RESULTS: In comparison to normal weight recipients, underweight and morbidly obese recipients had increased 90-d mortality(adjusted OR = 1.737; 95%CI: 1.185-2.548, P = 0.005)(adjusted OR = 1.956; 95%CI: 1.473-2.597, P = 0.000) respectively and inferior patients' survivals(adjusted HR = 1.265; 95%CI: 1.096-1.461, P = 0.000)(adjusted HR = 1.157; 95%CI: 1.031-1.299, P = 0.013) respectively. Overall, patients' 5-year survival were 73.9% for normal-weight, 71.1% for underweight, 74.0% for overweight, 74.4% for class Ⅰ obese, 75.0% for class Ⅱ obese and 71.5% for class Ⅲ obese recipients. Analysis of hypothetical exclusion of underweight and morbidly obese patients from the pool of potential LT candidates would have improved the overall survival of the entire cohort by2.7%(95%CI: 2.5%-3.6%).CONCLUSION: Selected morbidly obese patients undergoing LT for benign conditions had 5-year survival rates clinically comparable to normal weight recipients. Impact analysis showed that exclusion of high-risk recipients(underweight and morbid obese patients) would not significantly improve the overall survival of the entire cohort of patients requiring LT. 展开更多
关键词 OBESITY impact analysis SURVIVAL Liver TRANSPLANTATION Body mass index
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Grey-theory based algorithm for impact assessment of green design
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作者 李鹏忠 陈炳森 +1 位作者 张为民 黄淑娟 《Journal of Southeast University(English Edition)》 EI CAS 2004年第1期85-89,共5页
Life cycle assessment (LCA) is an important content of green design;the major phase of LCA is impact assessment. After classifying the impact factors, with grey-system theory, the evaluating grey-groups and their whit... Life cycle assessment (LCA) is an important content of green design;the major phase of LCA is impact assessment. After classifying the impact factors, with grey-system theory, the evaluating grey-groups and their whitening weighing functions are defined;the grey-cluster analysis of each classified impact is performed;based on analyzing results, the calculating method of classified impact index is given. By range of action, the impact classes are grouped to three groups - global impact, regional impact, and local impact;the calculating methods of grouped and overall impact index are presented. Finally, an application example of comparative choice of a category of products - three materials, steel, aluminum and engineering plastics is given. 展开更多
关键词 green design impact assessment grey-theory ALGORITHM impact index
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高水平中医药期刊的发展特征及其影响力提升举措——以入选第一期“中国科技期刊卓越行动计划”中医药期刊为例
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作者 李鹏 李琳 +2 位作者 胡小洋 秦娟 刘英虹 《天津科技》 2026年第1期78-84,共7页
以2019年入选第一期“中国科技期刊卓越行动计划”的中医药期刊(包括7种梯队期刊+2种高起点新刊,4种中文期刊+5种英文期刊)为研究对象,从期刊的基本特征、国内外数据库收录、国内/国际影响力指标的变化情况,深入分析当前卓越中医药期刊... 以2019年入选第一期“中国科技期刊卓越行动计划”的中医药期刊(包括7种梯队期刊+2种高起点新刊,4种中文期刊+5种英文期刊)为研究对象,从期刊的基本特征、国内外数据库收录、国内/国际影响力指标的变化情况,深入分析当前卓越中医药期刊的发展现状和影响力提升效果。研究发现:当前绝大多数中医药期刊的国际/国内影响力获得了提升,但部分期刊发文量出现下降情况;英文期刊中部分刊期较长,发文量较低,需依托国际出版平台进行传播;中文期刊开放获取比例不高,国际重要数据库收录率不高。建议中医药期刊加强集群化建设,并建议主管部门实行差异化扶持,以实现中医药期刊整体水平的提升。 展开更多
关键词 卓越计划 中医药期刊 影响因子 可被引文献量 科技期刊世界影响力指数 CiteScore 影响力
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有机污染物微生物降解机制及生物指示效应研究进展
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作者 张泽晗 尚长健 +4 位作者 贾永锋 胡良远 杨芊芊 尤迪 刘瑶 《中国环境科学》 北大核心 2026年第2期1000-1014,共15页
针对当前研究存在的微生物降解有机污染物机制认识不足、环境因子影响复杂且其对自然衰减进程的指示作用不明确等问题,梳理了微生物降解代谢机制、关键环境因子的调控作用及自然衰减评估中微生物指标的应用.研究表明,有机污染物的生物... 针对当前研究存在的微生物降解有机污染物机制认识不足、环境因子影响复杂且其对自然衰减进程的指示作用不明确等问题,梳理了微生物降解代谢机制、关键环境因子的调控作用及自然衰减评估中微生物指标的应用.研究表明,有机污染物的生物降解具有多途径协同的特征,微生物在功能基因调控下合成特定生物酶通过多种途径实现高效降解.污染物浓度、电子供/受体等关键环境因子通过调控微生物活性与群落结构,直接影响自然衰减效能,生物代谢产物、微生物群落结构和功能基因等微生物指标能够有效指示自然衰减的进程与潜力.基于上述,本文深入了微生物代谢机制、环境因子作用及其指示功能的系统性理解,不仅构成了优化自然衰减管理的核心理论基础,也为建立基于微生物响应的监测与调控策略提供了科学依据. 展开更多
关键词 自然衰减 有机污染 生物降解 环境影响因子 微生物指标
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陕西省多时间尺度干旱对植被动态变化的影响
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作者 宁泽楷 宋赪 +2 位作者 张亚军 李奇 李佩 《干旱区研究》 北大核心 2026年第1期156-166,共11页
在不同时间尺度上分析植被对干旱的时空响应,量化干旱对植被变化的相对影响,对于因地制宜地开展生态修复和防灾减灾具有重要意义。本文基于2000—2020年陕西省85个气象站的观测数据,计算标准化降水蒸散指数(SPEI),结合归一化植被指数(ND... 在不同时间尺度上分析植被对干旱的时空响应,量化干旱对植被变化的相对影响,对于因地制宜地开展生态修复和防灾减灾具有重要意义。本文基于2000—2020年陕西省85个气象站的观测数据,计算标准化降水蒸散指数(SPEI),结合归一化植被指数(NDVI),采用趋势分析、偏相关分析以及岭回归分析,研究SPEI和NDVI的时空变化特征及其相关性,量化各季节SPEI对年尺度NDVI变化的相对影响。结果表明:(1)2000—2020年陕西省春季的干旱频率最高,达42.6%,其次是夏季(29.7%),秋季和冬季分别为21.6%和21.9%。陕北地区的干旱频率最高(29.6%),其次为陕南地区(28.7%)和关中地区(27.9%)。全省约89.7%的区域呈现出缓慢湿润化趋势,其中,呈湿润化趋势的面积占比为春季>夏季>秋季>冬季。(2)陕西省NDVI在陕南地区、关中地区和陕北地区的平均值分别为0.89、0.77和0.57,全省约88.0%的区域植被呈显著改善。(3)陕西省约53.2%的区域SPEI和NDVI呈现不显著正相关,6.9%的区域相关性显著,主要分布在陕北地区;呈不显著负相关的区域主要分布于关中地区。(4)春季、夏季、秋季和冬季的SPEI对年尺度NDVI变化的相对影响程度大于50%的区域分别约占全省面积的31.1%、23.7%、0.5%和15.3%。 展开更多
关键词 SPEI NDVI 相关性分析 相对影响系数
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基于应力集中指数的冲击危险性评价方法研究
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作者 鞠成润 张宁博 +4 位作者 许乾海 肖曼曼 杨新文 孙连烨 胡宇恒 《华北科技学院学报》 2026年第1期147-153,共7页
冲击地压是煤矿开采过程中典型的煤岩动力灾害,对我国煤矿安全生产构成严重威胁。针对现有冲击危险性评价方法普遍存在的指标单一性及动静载应力耦合机制分析不足等问题,本研究提出一种基于多源应力集中指数的综合评价方法。该方法通过... 冲击地压是煤矿开采过程中典型的煤岩动力灾害,对我国煤矿安全生产构成严重威胁。针对现有冲击危险性评价方法普遍存在的指标单一性及动静载应力耦合机制分析不足等问题,本研究提出一种基于多源应力集中指数的综合评价方法。该方法通过构建静载、地质、采动及顶板动载扰动四类应力集中指数,定量表征工作面在不同回采阶段的应力集中程度,进而集成综合应力集中指数K,并依此划分冲击危险等级。结合山西某矿1200孤岛工作面工程实例,采用FLAC^(3D)数值模拟分析其应力演化规律,并利用现场监测数据对评价结果进行验证。研究结果表明,该方法能够有效辨识工作面开采期间的冲击危险区域,证明了基于应力指数的冲击危险性评价的可行性,为煤矿安全开采和冲击危险性评价分析提供了新思路。 展开更多
关键词 应力集中指数 冲击危险性 评价方法 动静载分析 冲击地压
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基于IMPACT模式的护理管理结合低升糖指数膳食管理对2型糖尿病患者饮食行为及自护能力的影响 被引量:7
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作者 宋春苗 刘伟平 +2 位作者 康格平 朱海慧 陈静 《临床医学研究与实践》 2023年第36期130-133,共4页
目的分析基于IMPACT模式的护理管理结合低升糖指数膳食管理对2型糖尿病(T2DM)患者饮食行为及自护能力的影响。方法选取2021年1月至12月收治的100例T2DM患者为研究对象,按照随机数字表法将其分为对照组与观察组,各50例。对照组采用常规... 目的分析基于IMPACT模式的护理管理结合低升糖指数膳食管理对2型糖尿病(T2DM)患者饮食行为及自护能力的影响。方法选取2021年1月至12月收治的100例T2DM患者为研究对象,按照随机数字表法将其分为对照组与观察组,各50例。对照组采用常规护理干预,观察组在对照组基础上加基于IMPACT模式的护理管理结合低升糖指数膳食管理。比较两组的饮食行为、自护能力以及血糖控制水平。结果干预后,观察组的饮食行为量表各维度评分高于对照组,差异具有统计学意义(P<0.05)。干预后,观察组的自我护理能力测定量表(ESCA)各维度评分高于对照组,差异具有统计学意义(P<0.05)。干预后,观察组的空腹血糖(FBG)、餐后2 h血糖(2 h PBG)水平低于对照组,差异具有统计学意义(P<0.05)。结论基于IMPACT模式的护理管理结合低升糖指数膳食管理不仅能够改变患者饮食行为,还能加强其自护能力,以此提高血糖控制水平,值得推广。 展开更多
关键词 基于impact模式的护理管理 低升糖指数膳食管理 饮食行为 自护能力 血糖控制
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Bibliometrics: tracking research impact by selecting Lhe appropriate metrics 被引量:21
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作者 Ashok Agarwal Damayanthi Durairajanayagam +18 位作者 Sindhuja Tatagari Sandro C Esteves Avi Harlev Ralf Henkel Shubhadeep Roychoudhury Sheryl Homa Nicolas Garrido Puchalt Ranjith Ramasamy Ahmad Majzoub Kim Dao Ly Eva Tvrda Mourad Assidi Kavindra Kesai Reecha Sharma Saleem Banihani Edmund Ko Muhammad Abu-Elmagd Jaime Gosalvez Asher Bashiri 《Asian Journal of Andrology》 SCIE CAS CSCD 2016年第2期296-309,J0008,共15页
Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a ... Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist's profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact. 展开更多
关键词 article-level metrics BIBLIOMETRICS citation counts H-index impact factor research databases research impact research productivity traditional metrics
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Numerical test and evaluating method of impact trend of rock-coal system
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作者 蒋金泉 程家国 +1 位作者 曲华 董建军 《Journal of Coal Science & Engineering(China)》 2008年第1期12-18,共7页
The impact trend of reck-coal system was studied by the method of accumulating and releasing of deformation energy and interaction of rock-coal system. The system model of roof-coal-floor was established. Based on the... The impact trend of reck-coal system was studied by the method of accumulating and releasing of deformation energy and interaction of rock-coal system. The system model of roof-coal-floor was established. Based on the RFPA software, rock fracture process analysis system, the numerical test of deformation, fracture and energy transmission of nonlinear and nonhomogeneous rock-coal system, and the numerical test and evaluating method of impact trend of reck-coal system were achieved. When the same coal seam was in different roof and floor conditions, the fracture process of reck-coal system can be classified as gradual, sudden and delayed fracture three kinds, and their impact trend can be classified as void, intense and medium correspondingly. The rock-coal system's impact trend is evaluated by the system impact index p and burst expanding forms. The criteria μ are μ〈1.0, 1.0≤μ〈l .5 and μ≥1.5 when the impact trend is void, intense or medium, which are tested and verified by the No.2 and No.4 coal seams in Sun- cun mine. 展开更多
关键词 impact trend rock-coal system numerical test impact energy index evaluating method
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Dimensional analysis of the impact toughness test for synthetic diamond grits
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作者 杨慧 麦绿波 +4 位作者 卢灿华 仝毅 王志涛 张凤岭 黄风雷 《Journal of Beijing Institute of Technology》 EI CAS 2016年第1期1-6,共6页
The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the dia... The method,in which a few carats of diamond grits are placed inside a capsule together with a steel ball,shaken for a number of times,and the unbroken ratio of the grits is then used to evaluate the quality of the diamond,has been well established for many years.However,the unbroken percentage,in an equivalent view,represents the impact toughness of the grits and cannot reflect the value of the crushing energy.Most of the previous empirical formulas obtained from experiments by scholars cannot be applied to practical tests.In this paper,a dimensional analysis was applied to investigate the impact toughness experiment,and the dimensionless relationship has been built among those variables such as the toughness index,the impact time,the impact frequency and the crushing energy per unit area.According to the results of a large number of experiments with synthetic diamond grits of mesh size 45/50,the percentage of the broken grits H is proportional to the impact time T^(1.14) when the impact frequency is 2400 r/min,and the impact frequency f^(2.576) when the number of impacts is 2000. 展开更多
关键词 synthetic diamond toughness index dimensional analysis impact toughness test
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Preliminary Assessment of Anthropogenic Impact on Some Ecological Components of Abesan River, Lagos, Nigeria
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作者 Julius I. Agboola Abiodun A. B. Denloye 《Journal of Water Resource and Protection》 2011年第2期98-104,共7页
The impact of anthropogenic disturbances on water quality parameters, diversity of macrophytes and benthic macro fauna of Abesan River, Lagos, Nigeria is reported. Some Physico-chemical and biological assessment were ... The impact of anthropogenic disturbances on water quality parameters, diversity of macrophytes and benthic macro fauna of Abesan River, Lagos, Nigeria is reported. Some Physico-chemical and biological assessment were carried out at three sampling stations located at downstream (AR-1), midstream (AR-2) and upstream (AR-3) with different levels of disturbance. Results of measured physico-chemical parameters showed that there was no significant difference (P > 0.05) in temperature, total acidity and chloride values between the sampling stations. Although, Total solids, conductivity, DO, Sulphate, BOD and COD were significantly higher (P < 0.05) at Stn.AR-1 than at Stns. AR-2 and AR-3, all physico-chemical parameters measured were within the limits of the Lagos State Environmental Protection Agency (LASEPA) and the World Health Organization (WHO) regulatory standards except for high COD concentration in downstream station. Aquatic vegetation (macrophyte) diversity was relatively abundant at upstream and downstream stations, suggesting possible impact of human activities on macrophyte diversity at midstream station where highest level of disturbance occurred. Chironomid larvae were the most abundant invertebrate fauna found in all three sampling stations but more abundant at sampling station AR-2 which corresponds to point of effluent entry to river where human activities is most intense. There is evidence that anthropogenic activities impact on the water quality of Abesan River. Biotic indices such as Sorensenen’s Index of Similarity and Margalef Index show that Abesan River is lightly polluted. The implications of these results and the need to monitor the water quality of Abesan River are highlighted. 展开更多
关键词 BIOINDICATORS Biotic index ANTHROPOGENIC impact RIVER AFRICA
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Spatially Explicit Modeling of Long-Term Drought Impacts on Crop Production in Austria
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作者 Franziska Strauss Elena Moltchanova Erwin Schmid 《American Journal of Climate Change》 2013年第3期1-11,共11页
Droughts have serious and widespread impacts on crop production with substantial economic losses. The frequency and severity of drought events may increase in the future due to climate change. We have developed three ... Droughts have serious and widespread impacts on crop production with substantial economic losses. The frequency and severity of drought events may increase in the future due to climate change. We have developed three meteorological drought scenarios for Austria in the period 2008-2040. The scenarios are defined based on a dry day index which is combined with bootstrapping from an observed daily weather dataset of the period 1975-2007. The severity of long-term drought scenarios is characterized by lower annual and seasonal precipitation amounts as well as more significant temperature increases compared to the observations. The long-term impacts of the drought scenarios on Austrian crop production have been analyzed with the biophysical process model EPIC (Environmental Policy Integrated Climate). Our simulation outputs show that—for areas with historical mean annual precipitation sums below 850 mm— already slight increases in dryness result in significantly lower crop yields i.e. depending on the drought severity, between 0.6% and 0.9% decreases in mean annual dry matter crop yields per 1.0% decrease in mean annual precipitation sums. The EPIC results of more severe droughts show that spring and summer precipitation may become a limiting factor in crop production even in regions with historical abundant precipitation. 展开更多
关键词 LONG-TERM DROUGHT Modeling Dry DAY index BIOPHYSICAL impactS Spatial Variability EPIC Austria
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BSQ-1催化剂在Spherizone工艺聚丙烯装置上的应用 被引量:1
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作者 李秀军 《合成树脂及塑料》 北大核心 2025年第3期32-36,共5页
采用BSQ-1催化剂在300 kt/a Spherizone工艺聚丙烯装置上生产了低熔体流动速率高抗冲共聚聚丙烯K8003,对BSQ-1催化剂在Spherizone工艺中的活性、立构定向性、氢调敏感性及该催化剂使用时的生产稳定性进行考察,并对产品进行分析。结果表... 采用BSQ-1催化剂在300 kt/a Spherizone工艺聚丙烯装置上生产了低熔体流动速率高抗冲共聚聚丙烯K8003,对BSQ-1催化剂在Spherizone工艺中的活性、立构定向性、氢调敏感性及该催化剂使用时的生产稳定性进行考察,并对产品进行分析。结果表明:与进口催化剂相比,BSQ-1催化剂在多区循环反应器中的活性高约10%,氢调敏感性基本一致;所制聚丙烯等规指数较采用进口催化剂高,抗冲击性能基本一致,表明BSQ-1催化剂在Spherizone工艺中具有替代进口催化剂的潜力。 展开更多
关键词 抗冲共聚聚丙烯 BSQ-1催化剂 SPHERIZONE工艺 抗冲击性能 等规指数
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Experimental Study on the Mechanical Parameters Relating to the Impact Tendency of Coal Sample
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作者 Diaka Cisse Hao Wang +1 位作者 Mingyang Wen Zhanghao Liu 《World Journal of Engineering and Technology》 2023年第3期569-585,共17页
Coal burst remains one of the gravest safety risks that will be encountered in mining in the future, because the stress conditions will become more complex as mining depths increase. Various influencing elements exist... Coal burst remains one of the gravest safety risks that will be encountered in mining in the future, because the stress conditions will become more complex as mining depths increase. Various influencing elements exist, and varied geological and mining circumstances might result in diverse coal burst phenomena. The impact propensity of coal has variations as a result of the distinct physical and mechanical qualities of each. To identify the impact propensity of coal and then understand the rules of coal burst occurrence, laboratory tests can be conducted to identify the physical and mechanical parameters affecting coal samples. The mechanical properties, energy absorption, and energy dissipation characteristics of coal samples were examined experimentally in this paper using coal samples that were taken from the mine. On the basis of the evaluation of the impact inclination parameters for four fundamental coal samples, novel impact inclination indicators and the relationship between the fractures in the coal sample and the impact inclination parameters were discussed. The following are the key conclusions: 1) On-site samples of No. 15 coal from the Qi yuan Coal Mine were taken (15 s) and processed in accordance with the guidelines for the coal specimen impact inclination test. The accuracy of the specimen was sufficient for the test. 2) Analysis is done on the mechanical relevance and calculation techniques of the four fundamental coal sample impact tendency characteristics, dynamic failure time (DT), elastic strain energy index (W<sub>ET</sub>), impact energy index (K<sub>E</sub>), as well as uniaxial compressive strength (R<sub>C</sub>). 3) Regarding the rock burst danger of rock samples, the potential use of the ratio of pre-peak and post- peak deformation modulus to Kλ and the residual elastic strain energy index C<sub>EF</sub> as the impact propensity indices of coal samples are discussed. It is possible to utilize two new impact propensity indices to evaluate the impact propensity of coal samples, according to test results that reveal a linear correlation between two new impact inclination indexes and four fundamental impact tendency indexes. 4) The statistical analysis of the crack ratio with the four impact propensity indicators after coal specimen failure, and the correlation among the crack ratio with the indicators, are both done. The findings indicate that the four impact propensity indicators have a linear relationship with the crack ratio of the coal sample surface cracks. 展开更多
关键词 Coal Burst Coal impact Trend Parameter Elastic Modulus index Residual Elastic Strain Energy index
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Characteristics and Causes of Meteorological Drought in Zhejiang Province(1971-2020):Insights from Comprehensive Discrimination Indices
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作者 XIAO Jing-jing MA Hao +5 位作者 GUO Fen-fen LIU Zan ZHANG Yu-hui LI Zheng-quan WANG Zhi-hai MA Shang-qian 《Journal of Tropical Meteorology》 2025年第4期434-452,共19页
This study examines the multi-scale spatio-temporal evolution of drought characteristics in Zhejiang Province.We propose a comprehensive index to identify drought days and events by incorporating three widely used mon... This study examines the multi-scale spatio-temporal evolution of drought characteristics in Zhejiang Province.We propose a comprehensive index to identify drought days and events by incorporating three widely used monitoring indices:the precipitation anomaly percentage,relative humidity index,and standardized precipitation index.The analysis reveals a significant long-term decreasing trend in the frequency of drought days across Zhejiang Province from 1971 to 2020,with a total of 170 drought events being identified.An Empirical Orthogonal Function(EOF)analysis of precipitation anomalies during these events reveals a dominant province-wide monopole mode,alongside a secondary northsouth inverse dipole,a third tripole,and a fourth southwest-northeast inverse dipole.Furthermore,a composite analysis of the drought events demonstrates a widespread increase in temperature across all stations,with a strong spatial correspondence between the temperature anomalies and their associated frequency.The study identifies 21 extreme drought events,characterized by spatially inconsistent precipitation patterns across the entire province. 展开更多
关键词 DROUGHT comprehensive drought index climate influence combined climate impact index agricultural effects
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