Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensi...Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.展开更多
In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving ...In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.展开更多
【目的】对关键核心技术识别相关成果进行系统综述,厘清其研究重点与发展脉络,以期为后续研究提供参考。【文献范围】基于关键核心技术的系统分析制定检索式,在Web of Science和CNKI数据库中进行文献检索,获取661篇论文进行定量分析,经...【目的】对关键核心技术识别相关成果进行系统综述,厘清其研究重点与发展脉络,以期为后续研究提供参考。【文献范围】基于关键核心技术的系统分析制定检索式,在Web of Science和CNKI数据库中进行文献检索,获取661篇论文进行定量分析,经人工筛选得到61篇代表性文献进行综述。【方法】首先,归纳关键核心技术的概念特点及检索策略以明晰综述范围;其次,分析关键核心技术的特征体系及识别标准以厘清研究思路;然后,整理关键核心技术的识别方法及分类体系以明确研究框架;最后,探讨现有研究的局限问题及不足之处以展望研究趋势。【结果】关键核心技术具有重要性、创新性、价值度、保护度和辐射性五大特征,其识别标准有采用单特征、双特征和三特征及以上三类,其识别标准的计量方法可分为基于专家智慧与基于数据驱动两大类,后者又可分为依托计量统计、依托文本挖掘以及依托深度学习三种类型。【局限】以人工筛选得到的代表性文献为基础进行综述,可能未全覆盖相关研究。【结论】需要综合利用不同方法的优势,探索新的数据源,解析关键核心技术动态演化规律以全面精准地识别关键核心技术。展开更多
基于Web of Science与中国知网数据库旱涝急转相关文献,利用CiteSpace软件对年度发文量、关键词共现与突现进行分析,系统综述了旱涝急转的识别方法、成因及影响的研究进展,并展望今后旱涝急转相关研究问题。结果表明:①旱涝急转的发文...基于Web of Science与中国知网数据库旱涝急转相关文献,利用CiteSpace软件对年度发文量、关键词共现与突现进行分析,系统综述了旱涝急转的识别方法、成因及影响的研究进展,并展望今后旱涝急转相关研究问题。结果表明:①旱涝急转的发文量逐年增加,国内发文量占总发文量的53.2%,研究历经初步探索(2005—2010年)、快速发展(2011—2018年)和稳定发展(2019—2024年)三阶段;外文研究在2018年后加速增长至2023年达峰值。②国内聚焦时空演变与大气环流机制,关键词以趋势分析,降水,低频振荡为主;国外侧重气候变化背景下旱涝急转的变化与影响,热点集中于Yangtze River,vegetation等。③旱涝急转目前缺乏统一、全面的识别方法;其成因分析多局限于气象因素,对其他成因的研究较为缺乏;其灾害影响研究主要集中于农业与植被,对社会经济、城市生态等领域的探讨较为薄弱。展开更多
基金Projects 50574072, 50874089 and 50534049 supported by the National Natural Science Foundation of China08JK366 by the Special Scientific Foundation of Educational Committee of Shaanxi Province
文摘Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.
基金Supported by Shandong Provincial Natural Science Foundation in China(ZR2011CM034)~~
文摘In the research, changes of apple chemistry, and molecule, under stresses, are n terms of morphology, physiology, bio- illustrated and research and identifica- tion methods of apple resistance are explored involving drought-resistance, flood-re- sistance, salt-stress resistance, cold-hardiness and heat-resistance. In addition prospects of apple resistance research are proposed, as well.
文摘【目的】对关键核心技术识别相关成果进行系统综述,厘清其研究重点与发展脉络,以期为后续研究提供参考。【文献范围】基于关键核心技术的系统分析制定检索式,在Web of Science和CNKI数据库中进行文献检索,获取661篇论文进行定量分析,经人工筛选得到61篇代表性文献进行综述。【方法】首先,归纳关键核心技术的概念特点及检索策略以明晰综述范围;其次,分析关键核心技术的特征体系及识别标准以厘清研究思路;然后,整理关键核心技术的识别方法及分类体系以明确研究框架;最后,探讨现有研究的局限问题及不足之处以展望研究趋势。【结果】关键核心技术具有重要性、创新性、价值度、保护度和辐射性五大特征,其识别标准有采用单特征、双特征和三特征及以上三类,其识别标准的计量方法可分为基于专家智慧与基于数据驱动两大类,后者又可分为依托计量统计、依托文本挖掘以及依托深度学习三种类型。【局限】以人工筛选得到的代表性文献为基础进行综述,可能未全覆盖相关研究。【结论】需要综合利用不同方法的优势,探索新的数据源,解析关键核心技术动态演化规律以全面精准地识别关键核心技术。
文摘基于Web of Science与中国知网数据库旱涝急转相关文献,利用CiteSpace软件对年度发文量、关键词共现与突现进行分析,系统综述了旱涝急转的识别方法、成因及影响的研究进展,并展望今后旱涝急转相关研究问题。结果表明:①旱涝急转的发文量逐年增加,国内发文量占总发文量的53.2%,研究历经初步探索(2005—2010年)、快速发展(2011—2018年)和稳定发展(2019—2024年)三阶段;外文研究在2018年后加速增长至2023年达峰值。②国内聚焦时空演变与大气环流机制,关键词以趋势分析,降水,低频振荡为主;国外侧重气候变化背景下旱涝急转的变化与影响,热点集中于Yangtze River,vegetation等。③旱涝急转目前缺乏统一、全面的识别方法;其成因分析多局限于气象因素,对其他成因的研究较为缺乏;其灾害影响研究主要集中于农业与植被,对社会经济、城市生态等领域的探讨较为薄弱。
