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Multi-Granularity Neighborhood Fuzzy Rough Set Model on Two Universes
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作者 Ju Wang Xinghu Ai Li Fu 《Journal of Intelligent Learning Systems and Applications》 2024年第2期91-106,共16页
The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborho... The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborhood rough sets to two universes multi-granularity fuzzy rough sets, and discusses the two-universes multi-granularity neighborhood fuzzy rough set model. Firstly, the upper and lower approximation operators are defined in the two universes multi-granularity neighborhood fuzzy rough set model. Secondly, the properties of the upper and lower approximation operators are discussed. Finally, the properties of the two universes multi-granularity neighborhood fuzzy rough set model are verified through case studies. 展开更多
关键词 Fuzzy Set Two Universes Multi-granularity Rough Set Multi-granularity Neighborhood Fuzzy Rough Set
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Influence of Processing Parameters on Granularity Distribution of Superalloy Powders during PREP 被引量:2
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作者 HuanmingCHEN BenfuHU +2 位作者 YiwenZHANG HuiyingLI QuanmaoYU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第6期587-590,共4页
In order to investigate the influence of processing parameters on the granularity distribution of superalloy powders during the atomization of plasma rotating electrode processing (PREP), in this paper FGH95 superallo... In order to investigate the influence of processing parameters on the granularity distribution of superalloy powders during the atomization of plasma rotating electrode processing (PREP), in this paper FGH95 superalloy powders is prepared under different processing conditions by PREP and the influence of PREP processing parameters on the granularity distribution of FGH95 superalloy powders is discussed based on fractal geometry theory. The results show that with the increase of rotating velocity of the self-consuming electrode, the fractal dimension of the granularity distribution increases linearly, which results in the increase of the proportion of smaller powders. The change of interval between plasma gun and the self-consuming electrode has a little effect on the granularity distribution, also the fractal dimension of the granularity distribution changed a little correspondingly. 展开更多
关键词 FGH95 superalloy powders granularity distribution Plasma rotating electrode processing (PREP) Fractal dimension
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Integrating Coarse Granularity Part-Level Features with Supervised Global-Level Features for Person Re-Identification 被引量:1
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作者 CAO Jiahao MAO Xiaofei +2 位作者 LI Dongfang ZHENG Qingfang JIA Xia 《ZTE Communications》 2021年第1期72-81,共10页
Person re-identification(Re-ID)has achieved great progress in recent years.However,person Re-ID methods are still suffering from body part missing and occlusion problems,which makes the learned representations less re... Person re-identification(Re-ID)has achieved great progress in recent years.However,person Re-ID methods are still suffering from body part missing and occlusion problems,which makes the learned representations less reliable.In this paper,we pro⁃pose a robust coarse granularity part-level network(CGPN)for person Re-ID,which ex⁃tracts robust regional features and integrates supervised global features for pedestrian im⁃ages.CGPN gains two-fold benefit toward higher accuracy for person Re-ID.On one hand,CGPN learns to extract effective regional features for pedestrian images.On the other hand,compared with extracting global features directly by backbone network,CGPN learns to extract more accurate global features with a supervision strategy.The single mod⁃el trained on three Re-ID datasets achieves state-of-the-art performances.Especially on CUHK03,the most challenging Re-ID dataset,we obtain a top result of Rank-1/mean av⁃erage precision(mAP)=87.1%/83.6%without re-ranking. 展开更多
关键词 person Re-ID SUPERVISION coarse granularity
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A HYBRID GRANULARITY PARALLEL ALGORITHM FOR PRECISE INTEGRATION OF STRUCTURAL DYNAMIC RESPONSES
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作者 Yuanyin Li Xianlong Jin Genguo Li 《Acta Mechanica Solida Sinica》 SCIE EI 2008年第1期28-33,共6页
Precise integration methods to solve structural dynamic responses and the corresponding time integration formula are composed of two parts: the multiplication of an exponential matrix with a vector and the integratio... Precise integration methods to solve structural dynamic responses and the corresponding time integration formula are composed of two parts: the multiplication of an exponential matrix with a vector and the integration term. The second term can be solved by the series solution. Two hybrid granularity parallel algorithms are designed, that is, the exponential matrix and the first term are computed by the fine-grained parallel algorithra and the second term is computed by the coarse-grained parallel algorithm. Numerical examples show that these two hybrid granularity parallel algorithms obtain higher speedup and parallel efficiency than two existing parallel algorithms. 展开更多
关键词 dynamic response precise integration hybrid granularity parallel algorithm
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On Granularity in Information Systems Based on Binary Relation
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作者 Weihua Xu Shihu Liu +1 位作者 Xiaoyan Zhang Wenxiu Zhang 《Intelligent Information Management》 2011年第3期75-86,共12页
In this paper, some important issues of granularity are discussed mainly in information systems (ISs) based on binary relation. Firstly, the vector representation method of knowledge granules is proposed in an infor-m... In this paper, some important issues of granularity are discussed mainly in information systems (ISs) based on binary relation. Firstly, the vector representation method of knowledge granules is proposed in an infor-mation system based on binary relation to eliminate limitations of set representation method. Secondly, operators among knowledge granularity are introduced and some important properties of them are studied carefully. Thirdly, distance between two knowledge granules is established and granular space is constructed based on it. Fourthly, axiomatic definition of knowledge granularity is investigated, and one can find that some existed knowledge granularities are special cases under the definition. In addition, as an application of knowledge granular space, an example is employed to validate some results in our work. 展开更多
关键词 BINARY RELATION GRANULAR Space Information System ROUGH Set
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Dynamic Distribution Model with Prime Granularity for Parallel Computing
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作者 孙济洲 张绍敏 李小图 《Transactions of Tianjin University》 EI CAS 2005年第5期343-347,共5页
Dynamic distribution model is one of the best schemes for parallel volume rendering. How- ever, in homogeneous cluster system.since the granularity is traditionally identical, all processors communicate almost simulta... Dynamic distribution model is one of the best schemes for parallel volume rendering. How- ever, in homogeneous cluster system.since the granularity is traditionally identical, all processors communicate almost simultaneously and computation load may lose balance. Due to problems above, a dynamic distribution model with prime granularity for parallel computing is presented. Granularities of each processor are relatively prime, and related theories are introduced. A high parallel performance can be achieved by minimizing network competition and using a load balancing strategy that ensures all processors finish almost simultaneously. Based on Master-Slave-Gleaner ( MSG) scheme, the parallel Splatting Algorithm for volume rendering is used to test the model on IBM Cluster 1350 system. The experimental results show that the model can bring a considerable improvement in performance, including computation efficiency, total execution time, speed, and load balancing. 展开更多
关键词 granularity parallel computing load balancing dynamic distribution model
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A novel transmission energy minimization algorithm based on fine granularity scalability
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作者 吴彪 张颖 张兆扬 《Journal of Shanghai University(English Edition)》 CAS 2006年第2期123-126,共4页
This paper proposes an optimal solution to choose the number of enhancement layers in fine granularity scalability (FGS) scheme under the constraint of minimum transmission energy, in which FGS is combined with transm... This paper proposes an optimal solution to choose the number of enhancement layers in fine granularity scalability (FGS) scheme under the constraint of minimum transmission energy, in which FGS is combined with transmission energy control, so that FGS enhancement layer transmission energy is minimized while the distortion guaranteed. By changing the bit-plane level and packet loss rate, minimum transmission energy of enhancement layer is obtained, while the expected distortion is satisfied. 展开更多
关键词 fine granularity scalability(FGS) bit-plane level expected distortion transmission energy.
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Granularity of Knowledge Computed by Genetic Algorithms Based on Rough Sets Theory
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作者 Wenyuan Yang Xiaoping Ye +1 位作者 Yong Tang Pingping Wei 《南昌工程学院学报》 CAS 2006年第2期97-101,121,共6页
Rough set philosophy hinges on the granularity of data, which is used to build all its basic concepts, like approximations, dependencies, reduction etc. Genetic Algorithms provides a general frame to optimize problem ... Rough set philosophy hinges on the granularity of data, which is used to build all its basic concepts, like approximations, dependencies, reduction etc. Genetic Algorithms provides a general frame to optimize problem solution of complex system without depending on the domain of problem.It is robust to many kinds of problems.The paper combines Genetic Algorithms and rough sets theory to compute granular of knowledge through an example of information table. The combination enable us to compute granular of knowledge effectively.It is also useful for computer auto-computing and information processing. 展开更多
关键词 granularity of knowledge Genetic Algorithms Pawlak Model Rough Set Theory information table
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好氧颗粒污泥的解体机制及修复策略研究进展 被引量:3
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作者 郭媛 冯思琪 +3 位作者 权晨妍 李家科 王新华 时文歆 《中国环境科学》 EI CAS CSCD 北大核心 2024年第2期708-720,共13页
好氧颗粒污泥(AGS)技术被誉为有望替代活性污泥法的下一代污水生物法处理技术,但其存在长期运行下颗粒易解体而造成系统失稳的瓶颈问题,未能大规模化工程应用.通过文献分析和整理,系统归纳了造成AGS解体的各类不利因素及其危害阈值与作... 好氧颗粒污泥(AGS)技术被誉为有望替代活性污泥法的下一代污水生物法处理技术,但其存在长期运行下颗粒易解体而造成系统失稳的瓶颈问题,未能大规模化工程应用.通过文献分析和整理,系统归纳了造成AGS解体的各类不利因素及其危害阈值与作用机制,梳理了解体AGS的现有修复策略,成效及其再颗粒化机理,并基于现有研究的局限性对未来的研究方向进行展望,以期实现AGS系统a解体-再颗粒化”的动态稳定运行,推动污水厂采纳AGS技术而低碳化转型. 展开更多
关键词 好氧颗粒污泥 影响因素 解体 修复 生物强化
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Research on the Development Trend and General Applications of the Fuzzy Rough Granularity Computing Theory
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作者 Xin Li 《International Journal of Technology Management》 2016年第5期22-24,共3页
In this paper, we conduct research on the development trend and general applications of the fuzzy rough granular computing theory. Granular computing is a new concept of general information processing and computing pa... In this paper, we conduct research on the development trend and general applications of the fuzzy rough granular computing theory. Granular computing is a new concept of general information processing and computing paradigm which covers all the granularity the study of the theory, methods, techniques and the tools. In many areas are the basic ideas of granular computing, such as the interval analysis, rough set theory, clustering analysis and information retrieval, machine learning, database, etc. With the theory of domain known division of target concept and rule acquisition, in knowledge discovery, data mining and the pattern recognition is widely used. Under this basis, in this paper, we propose the fuzzy rough theory based computing paradigm that gains ideal performance. 展开更多
关键词 Development TREND APPLICATIONS Fuzzy ROUGH Granular COMPUTING THEORY
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Research on the Effects of the Contents of Radioactive Elements on Granularity and Climate Change:An Example of SZK1 and SZK2 Drill Holes Strata in the Fuzhou Basin
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作者 Zheng Rongzhang Xu Xiwei Li Jianping 《Earthquake Research in China》 2006年第4期469-478,共10页
Based on the content of radioactive elements (U, Th, K) of strata in two drill holes in the Fuzhou basin, and combined with the result of spore_pollen analysis, the relationship between radioactivity and lithology and... Based on the content of radioactive elements (U, Th, K) of strata in two drill holes in the Fuzhou basin, and combined with the result of spore_pollen analysis, the relationship between radioactivity and lithology and deposit environments is discussed and the results show that the content of radioactive substances is related to the granularity and lithology in sediment, and it is higher in argillaceous sediment (e.g. silt and clay), lower in sand sediment and in the middle in gravels between the above two kinds of sediment. The content of radioactive substances is also related to paleoclimate. A warm and humid environment is propitious to the deposition of radioactive substances, while a cool and dry climate is just the reverse. 展开更多
关键词 U-Th-K radioactive elements granularity PALEOENVIRONMENT Drill hole Fuzhou Basin
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有机负荷率对厌氧颗粒污泥处理畜禽养殖废水效能的影响探究 被引量:1
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作者 夏天虹 罗冰 +2 位作者 罗滔 董桂君 罗丹霞 《水处理技术》 CAS CSCD 北大核心 2024年第1期126-130,共5页
针对高浓度畜禽养殖废水厌氧处理效率低,构建了外循环厌氧反应器(EGSB),开展了进水有机负荷率(OLR)对EGSB处理畜禽养殖废水过程内污染物去除效能及颗粒污泥形成规律的影响,并解析相关作用机制。结果表明进水OLR提高至9.0 kg/(m^(3)·... 针对高浓度畜禽养殖废水厌氧处理效率低,构建了外循环厌氧反应器(EGSB),开展了进水有机负荷率(OLR)对EGSB处理畜禽养殖废水过程内污染物去除效能及颗粒污泥形成规律的影响,并解析相关作用机制。结果表明进水OLR提高至9.0 kg/(m^(3)·d),COD、氨氮及总磷去除维持在91.2%~95.3%、89.6%和76.9%,产气及甲烷产率分别提高至4.64~4.94 L/(L·d)和2.96~3.40 L/(L·d)。适宜提高OLR提高了污泥颗粒化,在工况III内,污泥浓度提高至6.1~6.5 g/L,大粒径污泥质量浓度增加。OLR提高增加了颗粒污泥内胞外聚合物(EPS)含量,并影响了EPS内蛋白质/多糖比值。此外,OLR能影响EGSB内微生物群落特征,且当OLR为9.0kg/(m^(3)·d)时,Firmicutes、Bacteroidetes和Proteobacteria是主要的门级别微生物,且相对丰度分别高达25.6%、16.5%和15.2%。研究结果为畜禽养殖废水高效处理提供一定理论依据。 展开更多
关键词 颗粒污泥 畜禽废水 甲烷 污泥浓度 胞外聚合物
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褪黑素对H_(2)O_(2)诱导蛋鸡卵巢颗粒细胞氧化应激损伤的保护作用 被引量:1
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作者 白康 郝二英 +4 位作者 任河陵 艾嘉伟 宁炜 黄仁录 陈辉 《中国家禽》 北大核心 2024年第9期1-7,共7页
为探讨褪黑素对蛋鸡卵巢颗粒细胞氧化应激损伤的保护作用,试验选取产蛋高峰期蛋鸡进行颗粒细胞分离培养,分别用0、12.5、25、50、100、200µmol/L H_(2)O_(2)处理3、6、9 h,根据颗粒细胞增殖活性和氧化指标变化建立氧化应激模型。... 为探讨褪黑素对蛋鸡卵巢颗粒细胞氧化应激损伤的保护作用,试验选取产蛋高峰期蛋鸡进行颗粒细胞分离培养,分别用0、12.5、25、50、100、200µmol/L H_(2)O_(2)处理3、6、9 h,根据颗粒细胞增殖活性和氧化指标变化建立氧化应激模型。试验分为4组:试验Ⅰ组为对照组,试验Ⅱ组为H_(2)O_(2)组,试验Ⅲ组为H_(2)O_(2)+Mel组,试验Ⅳ组为褪黑素组,利用CCK-8法、DCF法及TUNEL法分别检测各组细胞增殖率、活性氧(ROS)水平和凋亡率,q-PCR和Western blot检测抗氧化指标SOD1、SOD2、CAT、GPX3和PRDX3基因和蛋白的表达水平。结果显示:①与对照组相比,H_(2)O_(2)组细胞增殖率降低(P<0.05),丙二醛(MDA)水平增加(P<0.05),过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性下降(P<0.05);②与对照组相比,H_(2)O_(2)组细胞活性氧(ROS)水平、凋亡率增加(P<0.05),增殖活性降低(P<0.05),Ⅲ组细胞活性氧水平、凋亡率降低(P<0.05),增殖活性增加(P<0.05);③与对照组相比,H_(2)O_(2)组细胞SOD1、SOD2、CAT、GPX3和PRDX3等抗氧化基因和蛋白表达下降(P<0.05),而褪黑素干预后则促进了抗氧化基因和蛋白表达(P<0.05)。研究提示:褪黑素干预后缓解了H_(2)O_(2)对颗粒细胞的氧化应激损伤,其可通过清除活性氧及上调蛋鸡卵巢颗粒细胞抗氧化基因和蛋白的表达起保护作用。 展开更多
关键词 褪黑素 蛋鸡 卵巢颗粒细胞 氧化应激 保护
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热处理对选区激光熔化Al-Mn-Mg-Sc-Zr合金力学性能和腐蚀行为的影响 被引量:1
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作者 邓英 曹俊昌 +4 位作者 赖毅 郭一帆 梁美婵 潘清林 徐国富 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第4期1240-1251,共12页
以Al-4.77Mn-1.37Mg-0.67Sc-0.25Zr(质量分数,%)合金粉末为原料,在激光功率330 W和扫描速率700 mm/s下进行选区激光熔化(Selective laser melting,SLM)形成SLM Al-Mn-Mg-Sc-Zr合金,结合慢应变速率拉伸实验、电化学测试、析氢浸泡实验及... 以Al-4.77Mn-1.37Mg-0.67Sc-0.25Zr(质量分数,%)合金粉末为原料,在激光功率330 W和扫描速率700 mm/s下进行选区激光熔化(Selective laser melting,SLM)形成SLM Al-Mn-Mg-Sc-Zr合金,结合慢应变速率拉伸实验、电化学测试、析氢浸泡实验及显微组织表征手段,分析了(350℃,8 h)热处理对SLM Al-Mn-Mg-Sc-Zr合金力学性能和腐蚀行为的影响。结果表明:SLM Al-Mn-Mg-Sc-Zr合金力学性能优异,抗拉强度、屈服强度和伸长率分别为423 MPa、376 MPa和25.1%。热处理后,SLM Al-Mn-Mg-Sc-Zr合金晶内析出大量针棒状纳米Al_(6)Mn相,抗拉强度和屈服强度分别提升至509 MPa和478 MPa。此外,SLM Al-Mn-Mg-Sc-Zr合金具有良好的耐蚀性能,热处理可以促进SLM Al-Mn-Mg-Sc-Zr合金的钝化,在-0.5 V极化电位时出现钝化台阶,降低SLM Al-Mn-Mg-Sc-Zr合金的电流密度,增加SLM Al-Mn-Mg-Sc-Zr合金的阳极极化率,使SLM Al-Mn-Mg-Sc-Zr合金的平均析氢速率从0.242 mL/(cm^(2)·h)降至0.216 mL/(cm^(2)·h),应力腐蚀敏感因子从3.379%降至0.405%。与此同时,热处理也促进了晶内微米富Si相以及晶界富Mn相和Mg相的析出,增加了SLM Al-Mn-Mg-Sc-Zr合金点蚀形核位置,增大了SLM Al-Mn-Mg-Sc-Zr合金的晶界电化学成分非均匀性,降低了SLM Al-Mn-Mg-Sc-Zr合金的点蚀和晶间腐蚀抗力。 展开更多
关键词 选区激光熔化 热处理 应力腐蚀 晶间腐蚀 电化学 显微组织
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基于密度划分的分布式数据容错存储算法研究 被引量:2
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作者 翁锦阳 朱铁兵 柏志安 《吉林大学学报(信息科学版)》 CAS 2024年第1期67-73,共7页
为保证数据安全性,缓解数据存储空间,提出基于密度划分的分布式数据容错存储算法。过滤分布式数据高密度数据区域,将具有高度相似的目标划分到不同区域,通过数据来源样本点描述数据的密度分布,设定数据弹性,利用概率以及数据粒度推算出... 为保证数据安全性,缓解数据存储空间,提出基于密度划分的分布式数据容错存储算法。过滤分布式数据高密度数据区域,将具有高度相似的目标划分到不同区域,通过数据来源样本点描述数据的密度分布,设定数据弹性,利用概率以及数据粒度推算出对应的存储梯度和强度指数,并在信息存储中引入数据存储梯度和数据弹性,完成分布式数据容错存储。实验证明,所提算法有较高的容错性,带宽吞吐量平稳,平均路径长度较小,能提高网络数据的安全性。 展开更多
关键词 密度划分 分布式数据 数据容错存储 数据粒度 强度指数
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复杂应力条件下粗粒料的剪胀性研究进展 被引量:1
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作者 周跃峰 左永振 万航 《长江科学院院报》 CSCD 北大核心 2024年第8期104-112,共9页
粗粒料的剪胀性是其强度和变形研究的重要问题之一,它取决于颗粒排列、粒间压力等细微观作用;在宏观层面,受相对密度与应力状态的影响。围绕复杂应力条件下粗粒料的剪胀问题,从粗粒料力学特性的试验研究、粗粒料的剪胀性强度准则以及临... 粗粒料的剪胀性是其强度和变形研究的重要问题之一,它取决于颗粒排列、粒间压力等细微观作用;在宏观层面,受相对密度与应力状态的影响。围绕复杂应力条件下粗粒料的剪胀问题,从粗粒料力学特性的试验研究、粗粒料的剪胀性强度准则以及临界状态与剪胀性方面,对国内外的研究进展进行了系统论述。在此基础上,提出该领域呈现如下发展态势:①通过大型真三轴试验开展粗粒料剪胀率的试验研究与理论分析,能够促进粗粒料本构理论的发展进步;②结合应力路径试验中的应力变形规律研究,可实现从常规三轴条件下向复杂应力条件下的剪胀方程的进一步发展,从而体现强度与变形问题的统一;③采用状态参量去评价土体的松密状态与剪胀性,能够耦合应力状态与孔隙比,尽量避免“一种材料,多组参数”。研究结果表明状态参量和应力路径相结合的方法,使得粗粒料的力学特性研究更加具有科学性和系统性。 展开更多
关键词 粗粒料 剪胀性 真三轴试验 强度准则 状态参量
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面向知识结构分析的模糊概念格模型 被引量:1
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作者 智慧来 李金海 《软件学报》 EI CSCD 北大核心 2024年第5期2466-2484,共19页
知识空间理论使用数学语言对学习者进行知识评价与学习指导,属于数学心理学的研究范畴.技能与问题是构成知识空间的两个基本要素,深入研究两者之间的关系是知识状态刻画与知识结构分析的内在要求.在当前的知识空间理论研究中,没有明确... 知识空间理论使用数学语言对学习者进行知识评价与学习指导,属于数学心理学的研究范畴.技能与问题是构成知识空间的两个基本要素,深入研究两者之间的关系是知识状态刻画与知识结构分析的内在要求.在当前的知识空间理论研究中,没有明确建立技能与问题之间的双向映射,从而难以提出直观概念意义下的知识结构分析模型,也没有明确建立知识状态之间的偏序关系,不利于刻画知识状态之间的差异,更不利于规划学习者未来的学习路径.此外,现有的成果主要集中在经典的知识空间,没有考虑实际问题中数据的不确定性.为此,将形式概念分析与模糊集引入知识空间理论,建立面向知识结构分析的模糊概念格模型.具体地,分别建立知识空间与闭包空间的模糊概念格模型.首先,建立知识空间模糊概念格,并通过任意两个概念的上确界证明所有概念的外延构成知识空间.引入粒描述的思想定义技能诱导的问题原子粒,由问题原子粒的组合判定一个问题组合是否是知识空间中的一个状态,进而提出由问题组合获取知识空间模糊概念的方法.其次,建立闭包空间模糊概念格,并通过任意两个概念的下确界证明所有概念的外延构成闭包空间.类似地,定义问题诱导的技能原子粒,由技能原子粒的组合判定一个技能组合是否是闭包空间中某一知识状态所需的技能,进而提出由技能组合获取闭包空间模糊概念的方法.最后,通过实验分析问题数量、技能数量、填充因子以及分析尺度对知识空间与闭包空间规模的影响.结论表明知识空间模糊概念不同于现有的任何概念,也不能从其他概念派生而来.闭包空间模糊概念本质上是一种面向属性单边模糊概念.在二值技能形式背景中,知识空间与闭包空间中的状态具有一一对应关系,但这种关系在模糊技能形式背景中并不成立. 展开更多
关键词 形式概念分析 知识空间理论 粒计算 粒描述 模糊概念格
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基于CFD-DEM算法的气力输送气固两相流特性分析 被引量:2
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作者 禹言芳 石博文 +2 位作者 孟辉波 丁鹏程 姚云娟 《化工进展》 EI CAS CSCD 北大核心 2024年第3期1133-1144,共12页
超轻粉体颗粒由于质量较小,在运输过程中易受气流扰动而飘散,物料的管道气力输送过程不稳定,易发生堵塞。为了研究超轻粉体颗粒在旋流气力输送中气固两相流流动特性,采用计算流体力学与离散单元法(CFD-DEM),对Komax型静态混合器内气固... 超轻粉体颗粒由于质量较小,在运输过程中易受气流扰动而飘散,物料的管道气力输送过程不稳定,易发生堵塞。为了研究超轻粉体颗粒在旋流气力输送中气固两相流流动特性,采用计算流体力学与离散单元法(CFD-DEM),对Komax型静态混合器内气固两相流动特性进行数值模拟研究。研究发现,带有Komax型元件的水平管道可以改变颗粒的流动情况,改善了水平管道内颗粒堆积和分布不均匀的现象;分别从颗粒相和流体相的流动状态分析得到元件长径比Ar=3时为最优几何结构;通过正交实验极差分析得到影响气固两相流动特性的因素顺序:输送气速>颗粒质量流量>颗粒粒径。当元件Ar=3时,颗粒-颗粒和颗粒-管壁的碰撞次数与碰撞强度呈现负相关,结合出口颗粒流分散状态,优选输送气速为3~4m/s;主要考虑输送气速对管内压降的影响,提出了带有Komax型元件的水平管道气力运输过程中压降与输送气速和轴向位置的经验拟合式。 展开更多
关键词 静态混合器 多相流 稀相旋流气力输送 颗粒流 CFD-DEM耦合法 流动特性
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多舱共配绿色车辆路径问题的改进变邻域搜索算法 被引量:1
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作者 肖友刚 曹健 +2 位作者 陈婉茹 张得志 李双艳 《控制理论与应用》 EI CAS CSCD 北大核心 2024年第4期751-762,共12页
针对社区团购前置仓配送场景中“多中心、高时效、多品类、高排放”难题,本文提出多车场带时间窗的绿色多舱车车辆路径问题(MDMCG-VRPTW),构建混合整数线性规划模型,并设计改进的变邻域搜索算法(IVNS)实现求解.采用两阶段混合算法构造... 针对社区团购前置仓配送场景中“多中心、高时效、多品类、高排放”难题,本文提出多车场带时间窗的绿色多舱车车辆路径问题(MDMCG-VRPTW),构建混合整数线性规划模型,并设计改进的变邻域搜索算法(IVNS)实现求解.采用两阶段混合算法构造高质量初始解.提出均衡抖动策略以充分探索解空间,引入粒度机制以提升局部搜索阶段的寻优效率.标准算例测试结果验证了两阶段初始解构造算法和IVNS算法的有效性.仿真实验结果表明,模型与算法能够有效求解MDMCGVRPTW,且改进策略提高了算法的求解效率和全局搜索能力.最后,基于对配送策略和时效性的敏感性分析,为相关配送企业降本增效提供更多决策依据. 展开更多
关键词 多舱共配 绿色车辆路径 均衡抖动 粒度局部搜索 改进变邻域搜索算法
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白藜芦醇改善多囊卵巢综合征模型大鼠卵巢颗粒细胞线粒体功能和抑制凋亡的作用
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作者 胡俊 马智 +1 位作者 张洪英 王炼炼 《重庆医科大学学报》 CAS CSCD 北大核心 2024年第3期264-269,共6页
目的:观察白藜芦醇对多囊卵巢综合征(polycystic ovary syndrome,PCOS)模型大鼠卵巢颗粒细胞增殖和凋亡的影响以及线粒体的形态和功能的改变,并探讨其可能的保护机制。方法:32只雌性SD大鼠幼鼠随机分为2组,PCOS模型组(n=24)和模型对照组... 目的:观察白藜芦醇对多囊卵巢综合征(polycystic ovary syndrome,PCOS)模型大鼠卵巢颗粒细胞增殖和凋亡的影响以及线粒体的形态和功能的改变,并探讨其可能的保护机制。方法:32只雌性SD大鼠幼鼠随机分为2组,PCOS模型组(n=24)和模型对照组(n=8)。成功提取PCOS组颗粒细胞并体外培养,然后用不同浓度的白藜芦醇处理颗粒细胞,CCK-8法检测细胞活力的变化;Mito Tracker Deep Red染色观察细胞线粒体的形态变化;JC-1检测线粒体膜电位的变化;ATP检测试剂盒检测ATP的变化;分光光度计检测与凋亡密切相关casppase-3和caspase-9酶活性变化;最后,蛋白免疫印迹法检测颗粒细胞内caspase-3和caspase-9蛋白水平的变化。结果:白藜芦醇处理PCOS模型大鼠卵巢颗粒细胞后,颗粒细胞的增殖活性明显增强(P=0.000);Mito Tracker Deep Read染色结果显示线粒体质量明显增加,形状呈管状或长条状;颗粒细胞内ATP产量和线粒体膜电位也明显增加(P=0.000、P=0.000)。另外,白藜芦醇也降低了caspase-3和caspase-9酶活性和蛋白水平的表达(P=0.000、P=0.000)。结论:白藜芦醇抑制了PCOS模型大鼠卵巢颗粒细胞的凋亡,也促进了细胞的增殖,其机制与白藜芦醇改善颗粒细胞线粒体的形态和功能有关。 展开更多
关键词 白藜芦醇 颗粒细胞 线粒体 凋亡
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