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Propagation properties of foreshock cavitons:Cluster observations 认领
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作者 WANG MengMeng YAO ShuTao +12 位作者 SHI QuanQi ZHANG Hui TIAN AnMin DEGELING Alexander William ZHANG Shuai GUO RuiLong SUN WeiJie LIU Ji BAI ShiChen SHEN XiaoChen ZHU XiaoQiong FU SuiYan PU ZuYin 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2020年第1期173-182,共10页
Foreshock cavitons are transient phenomena observed in the terrestrial foreshock region.They are characterized by a simultaneous depression of magnetic field magnitude and plasma density,which are bounded with enhance... Foreshock cavitons are transient phenomena observed in the terrestrial foreshock region.They are characterized by a simultaneous depression of magnetic field magnitude and plasma density,which are bounded with enhancements of these two parameters and surrounded by ultralow frequency(ULF)waves.Previous studies focused on the interplanetary magnetic field(IMF)conditions,solar wind(SW)conditions,and the growth of the foreshock waves related to the generation of foreshock cavitons.Previously,a multipoint spacecraft analysis method using Cluster data was applied to analyze only two foreshock cavitons,and this method did not consider uncertainties.In this study,multipoint spacecraft analysis methods,including the timing method,the minimum directional derivative(MDD)method,and the spatiotemporal difference(STD)method are applied to determine the velocity in both spacecraft and solar wind frames.The propagation properties show good agreement with previous results from simulations and observations that most cavitons move sunward in the solar wind frame,with the velocities larger than the Alfvén speed.The propagation properties of foreshock cavitons support the formation mechanism of cavitons in previous simulations,which suggested that cavitons are formed due to the nonlinear evolution of compressive ULF waves.We find that there is clear decreasing trend between the size of cavitons and their velocity in the solar wind frame.In addition,the timing method considering errors has been applied to study the evolution properties by comparing the velocities with errors of the leading and trailing edges,and we identify three stable cavitons and one contracting caviton,which has not been studied before.Most cavitons should remain stable when they travel toward the Earth’s bow shock.The relationship between the size of foreshock cavitons and their distance from the bow shock is also discussed. 展开更多
关键词 FORESHOCK transient phenomena cavitons nonlinear EVOLUTION of ULF WAVES PROPAGATION and EVOLUTION properties of structures multipoint SPACECRAFT methods
Emotional Stress: The Dialectics of Nature 认领
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作者 Evgeny Antonovich Yumatov 《神经系统科学与医药(英文)》 2020年第1期20-28,共9页
The article considers the biological nature and origins of emotional stress. Emotional stress is primarily formed within the mental activity of the brain in the form of pronounced negative emotions. The “Dynamic Theo... The article considers the biological nature and origins of emotional stress. Emotional stress is primarily formed within the mental activity of the brain in the form of pronounced negative emotions. The “Dynamic Theory of Emo-tions” characterizes the development of a continuous negative emotional state in conflicting behavioral situations when the subject is unable to satisfy its strong dominant need for a long time. The emotional stress is represented as having a dual nature, i.e. a biologically negative pathogenetic effect on health, but a positive impact on the adaptation of individuals, self-preservation of life, and evolutionary change in species. 展开更多
关键词 Emotions EMOTIONAL Stress PSYCHOSOMATIC DISEASES HEALTH ADAPTATION EVOLUTION
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Evolutionary and Pronostic Aspects of Cirrhosis at the University Hospital of Brazzaville (Congo) 认领
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作者 Jile Florient Mimiesse Ngalessami Mouakosso Marlyse +9 位作者 Ahoui Apendi Clausina Mongo Onkouo Arnaud Atipo-Ibara Ollandzobo Lucie Firmin Bossali Akoa Ngala Itoua-Ngaporo Rody Stéphane Ngami Mahoungou Gael Honal Deby Gassaye Atipo Ibara Blaise Irénée Ibara Jean-Rosaire 《肠胃病学期刊(英文)》 2020年第1期23-29,共7页
Introduction: cirrhosis is a serious pathology that leads to complications whose management remains difficult in our country. This study aimed to evaluate the evolutionary aspects of cirrhosis at the Brazzaville Unive... Introduction: cirrhosis is a serious pathology that leads to complications whose management remains difficult in our country. This study aimed to evaluate the evolutionary aspects of cirrhosis at the Brazzaville University Hospital. Patients and methods: this was a retrospective study over a period of 18 months (from January 2015 to July 2016), performed in the Gastroenterology Department of the Brazzaville University Hospital. All patients regularly followed for decompensated cirrhosis were included. The studied variables were the epidemiological, clinical and paraclinical characteristics, the occurrence of complications, the survival, and the causes of death. Univariate analysis was used to determine prognostic factors based on the Child Pugh score. Results: There were 43 patients, including 32 men and 11 women, with a mean age of 52 ± 9.5 years. Viral hepatitis B was the most common etiology (39.5%). Child Pugh stage C was found in 60.5%. Oesophageal varices were present in 93% of cases. Survival at 18 months was 72%. In univariate analysis, two variables were significantly associated with decreased survival, including Child Pugh stage C and esophageal varices (grade II and III). Conclusion: cirrhosis remains a worrying pathology because the diagnosis is often made at the stage of often serious complications putting at risk of vital prognosis. 展开更多
关键词 CIRRHOSIS Evolution BRAZZAVILLE
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2D MXene-Based Materials for Electrocatalysis 认领
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作者 Jiapeng Liu Wenchao Peng +2 位作者 Yang Li Fengbao Zhang Xiaobin Fan 《天津大学学报:英文版》 EI CAS 2020年第3期149-171,共23页
MXenes,as an emerging 2D material,are expected to exert a great influence on future energy storage and conversion technologies.In this review,we systematically summarize recent advances in MXene-based materials in ele... MXenes,as an emerging 2D material,are expected to exert a great influence on future energy storage and conversion technologies.In this review,we systematically summarize recent advances in MXene-based materials in electrocatalysis,particularly in the hydrogen evolution,oxygen evolution,oxygen reduction,nitrogen reduction,and CO2 reduction reactions.Crucial factors influencing the properties of these materials,such as functional groups,conductivity,and interface,are discussed,and challenges to the future development of MXene-based electrocatalysts are presented. 展开更多
关键词 2D material MXenes ELECTROCATALYST Hydrogen evolution reaction Oxygen evolution reaction OXYGEN reduction reaction Nitrogen reduction reaction CO2
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先秦时期中国思想教育实践的衍变--基于中西学界研究成果的对比分析 认领
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作者 柴鹏 丁三青 《河北工程大学学报:社会科学版》 2020年第1期61-64,共4页
中国学界对先秦思想教育实践的衍变进行了追本溯源和总结概括,并基于历史唯物主义哲学的立场建构起了现代化的学科研究体系。西方学界基于实证主义哲学的思维方式将对先秦时期中国思想教育实践活动的研究导向了世俗政治的实用主义立场,... 中国学界对先秦思想教育实践的衍变进行了追本溯源和总结概括,并基于历史唯物主义哲学的立场建构起了现代化的学科研究体系。西方学界基于实证主义哲学的思维方式将对先秦时期中国思想教育实践活动的研究导向了世俗政治的实用主义立场,不利于科学呈现我国先秦时期思想教育实践的历史原貌。先秦思想教育实践经历了从以生存为主到人文主义关怀凸显、从以宗教性活动为主到以政治活动为主的衍变过程。新时代唯有基于马克思主义历史观,在思想政治教育学科的语境下继续拓充与深化中国思想教育实践的研究,方能充分挖掘和发展中国优秀的传统教育思想。 展开更多
关键词 先秦 思想教育实践 衍变 比较研究 历史唯物主义
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Toward accurate measurement of property-dependent galaxy clustering I.Comparison of the Vmax method and the“shuffled”method 认领
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作者 Lei Yang Yi-Peng Jing +1 位作者 Zhi-Gang Li Xiao-Hu Yang 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2020年第4期87-98,共12页
Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution,as well as the universe.The redshift assignment for the random sample is one of the key steps to accurately measure ga... Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution,as well as the universe.The redshift assignment for the random sample is one of the key steps to accurately measure galaxy clustering.In this paper,by virtue of the mock galaxy catalogs,we investigate the effect of two redshift assignment methods on the measurement of galaxy two-point correlation functions(hereafter 2 PCFs),the Vmax method and the"shuffled"method.We have found that the shuffled method significantly underestimates both of the projected 2 PCFs and the two-dimensional 2 PCFs in redshift space,while the Vmax method does not show any notable bias on the 2 PCFs for volume-limited samples.For fluxlimited samples,the bias produced by the Vmax method is less than half of the shuffled method on large scales.Therefore,we strongly recommend the Vmax method to assign redshifts to random samples in the future galaxy clustering analysis. 展开更多
关键词 galaxies:statistics galaxies:galaxy formation and evolution large-scale structure of universe
六倍体小麦CBS基因家族全基因组分析 认领
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作者 郭富烨 苍晶 +7 位作者 卢秋巍 田宇 宋春华 任志鹏 孙仙泽 樊晓培 王多佳 付连双 《麦类作物学报》 CAS CSCD 北大核心 2020年第4期425-433,共9页
Cystathionineβ-synthase(CBS)基因家族在植物生长发育以及响应胁迫过程中具有重要作用,目前对CBS基因家族的研究报道较少。异源六倍体普通小麦(Triticum aestivum L.,AABBDD)作为重要的粮食作物,其CBS基因尚未得到系统研究。为研究小... Cystathionineβ-synthase(CBS)基因家族在植物生长发育以及响应胁迫过程中具有重要作用,目前对CBS基因家族的研究报道较少。异源六倍体普通小麦(Triticum aestivum L.,AABBDD)作为重要的粮食作物,其CBS基因尚未得到系统研究。为研究小麦中CBS基因的特征,本研究对小麦全基因组进行了分析,共发现136个属于32个同源组的CBS基因,系统发育树分析将其分为8组。将这些基因定位于小麦染色体上,并对它们的基因结构、保守基序以及结构域做进一步分析,发现三联体中的CBS结构域蛋白(CDCP)具有相似的结构。在不同温度下,大多数CBS基因的三联体具有相似的表达模式。在低温及冻害条件下CBS基因在小麦抗寒过程中发挥重要作用。 展开更多
关键词 小麦 CBS 进化 基因家族 胁迫
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基于语料库的中国外交话语主题词演变研究 认领
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作者 田绪军 李晓倩 《中国外语》 CSSCI 北大核心 2020年第2期16-25,共10页
本文基于中国外交话语历时语料库(1949-2018),依据批评话语分析,对新中国成立以来中国外交话语主题词进行考察,发现中国外交长期以来的主要对象包括美国、英国、日本和其他一些亚非拉国家,中国外交的目的是维护世界和平、反对战争、与... 本文基于中国外交话语历时语料库(1949-2018),依据批评话语分析,对新中国成立以来中国外交话语主题词进行考察,发现中国外交长期以来的主要对象包括美国、英国、日本和其他一些亚非拉国家,中国外交的目的是维护世界和平、反对战争、与世界各国人民建立良好的关系,通过合作促进共同发展。此外,通过对中国外交话语的考察,我们发现中国外交经历了政治优先的立国安邦时期、经济优先的富国强民时期,现在正处于中国特色大国外交时期。不同时期的国际国内政治、经济和社会环境的不断变化导致中国外交战略和外交客体、内容、范围与目的也随之演变,并通过外交话语在语言层面进行表征。 展开更多
关键词 演变 语料库 批评话语分析
典型巴东组泥质粉砂岩双轴压缩试验细观组构特征 认领
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作者 肖尊群 王鑫 +5 位作者 汤东桑 董琼英 姜亦男 杨凯 曹童童 邓震 《煤田地质与勘探》 CAS CSCD 北大核心 2020年第2期161-170,共10页
基于泥质粉砂岩室内双轴压缩试验,建立PFC2D颗粒流数值模型,以此来探究泥质粉砂岩破坏的细观机理。考虑组成泥质粉砂岩试样的颗粒形状,根据电镜扫描图勾选出5种典型颗粒形状,与圆形颗粒一起生成给定孔隙率的稳定数值试样。颗粒间选用平... 基于泥质粉砂岩室内双轴压缩试验,建立PFC2D颗粒流数值模型,以此来探究泥质粉砂岩破坏的细观机理。考虑组成泥质粉砂岩试样的颗粒形状,根据电镜扫描图勾选出5种典型颗粒形状,与圆形颗粒一起生成给定孔隙率的稳定数值试样。颗粒间选用平行粘结接触模型,选取弹性模量、泊松比、峰值应力分别对饱和、天然状态的泥质粉砂岩试样进行不同围压下的细观参数标定,然后进行双轴压缩试验模拟,分析试样在双轴压缩试验过程中颗粒法向接触力、切向接触力、配位数、孔隙率等细观组构参数的分布特征和演化规律。试验结果表明:双轴压缩试验的细观参数标定可不考虑抗剪强度指标黏聚力c和内摩擦角Φ值的影响。破坏前后,试样各方向统计范围内都存在法向接触力和切向接触力。围压的存在影响试样的起始配位数、孔隙率和试样破坏后的稳定配位数和孔隙率,对配位数和孔隙率的改变速率影响很小。试样空间孔隙率的演化在一定程度上反映了试样破坏时内部结构的变迁,能更加直观地反映试样的破坏模式。 展开更多
关键词 双轴压缩试验 微观组构 切向接触力 法向接触力 配位数 细观参数 演化
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Understanding Structural Evolution in the Synthesis of Advanced Energy Materials 认领
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作者 ZHANG Ming-Jian CHEN Yu-Sheng +1 位作者 PAN Feng REN Yang 《结构化学》 SCIE CAS CSCD 2020年第1期26-30,1共6页
Developing a variety of in situ characterization techniques to unravel the structural/chemical evolution during the synthesis of various advanced energy materials for studying the relationship among those experimental... Developing a variety of in situ characterization techniques to unravel the structural/chemical evolution during the synthesis of various advanced energy materials for studying the relationship among those experimental conditions and the structure is the key to implement the controllable synthesis of battery materials.This perspective summarizes the recent studies into structural evolution during in situ synthesis of various advanced energy materials by synchrotron X-ray diffraction technique and forecasts the more extensive applications in the future. 展开更多
关键词 structure evolution synthesis ADVANCED energy materials in SITU SYNCHROTRON X-RAY DIFFRACTION
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缅甸伊洛瓦底三角洲河道演变遥感研究 认领
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作者 陈丹 《江苏科技信息》 2020年第1期46-50,共5页
文章在遥感技术与地理信息系统的支持下,利用长时间序列遥感影像对缅甸伊洛瓦底三角洲主河道进行演变研究。采用有利于减少噪声的水体监测指数MNDWI计算方法以实现水陆分离,进而从河道长度、宽度、弯曲指数及辫状指数4个方面分析河道演... 文章在遥感技术与地理信息系统的支持下,利用长时间序列遥感影像对缅甸伊洛瓦底三角洲主河道进行演变研究。采用有利于减少噪声的水体监测指数MNDWI计算方法以实现水陆分离,进而从河道长度、宽度、弯曲指数及辫状指数4个方面分析河道演变规律。结果表明,河道长度、宽度、弯曲指数及辫状指数分别呈现不同程度的上升趋势。在此基础上,能够根据历史河道变化趋势预测河道未来演变位置,有利于及时进行风险防范,维护沿岸稳定。 展开更多
关键词 伊洛瓦底三角洲 河道 演变 遥感
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Study of the closure temperature of(U-Th)/He in detrital zircon obtained from natural evolution samples 认领
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作者 Chang'e CAI Nansheng QIU +3 位作者 Huili LI Daniel FSTOCKLI Jian CHANG Nian LIU 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2020年第3期412-424,共13页
Zircon(U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures.Zircon He ages and closure temperatures are very important parameters... Zircon(U-Th)/He thermochronometry was used as an effective indicator to study the thermal history of deep sedimentary basins with high temperatures.Zircon He ages and closure temperatures are very important parameters.In this paper,detrital zircon He closure temperature was studied by establishing the evolutionary pattern between zircon He ages and burial depth of borehole samples obtained from the Cenozoic strata in the Bohai Bay and Tarim basins,which have different thermal settings.The results show that the zircon He closure temperature of natural evolution samples is 200℃,which is higher than the temperature obtained from thermal simulation experiments(183℃).The temperature range of 140-200℃corresponds to the zircon helium partial retention zone.By properly understanding zircon He closure temperatures,zircon(U-Th)/He thermochronometry can provide a correct explanation of the He ages,and significant guidance in the study of the evolution of source rocks and the process of hydrocarbon accumulation in deep sedimentary basins. 展开更多
关键词 Zircon(U-Th)/He Natural evolution sample CLOSURE temperature Partial retention zone
Influence of Si Contents on the Microstructure Evolution and Mechanical Properties of Al Mg Si Cu Zn Alloys 认领
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作者 Liang Zhu Mingxing Guo +3 位作者 Jishan Zhang Gaojie Li Yu Wang Linzhong Zhuang 《哈尔滨工业大学学报:英文版》 EI CAS 2020年第1期10-18,共9页
The influence of different Si contents on the microstructure evolution and mechanical properties of Al Mg Si Cu Zn alloys was systematically studied using tensile testing,OM,SEM,EDS,and EBSD.The results indicate that ... The influence of different Si contents on the microstructure evolution and mechanical properties of Al Mg Si Cu Zn alloys was systematically studied using tensile testing,OM,SEM,EDS,and EBSD.The results indicate that the grain size of as cast alloys was gradually reduced with the increase of the Si content,which mainly resulted from the formation of many iron rich phases and precipitates during the casting process.During homogenization treatment,the plate likeβ AlFeSi phases in the alloy with a higher Si content easily transformed to the sphericalα Al(FeMn)Si phases,which is helpful for improving the formability of alloys.The microstructure evolution of the alloys was also greatly dependent on the content of Si that the number density and homogeneous distribution level of precipitates in the final cold rolled alloys both increased with the increase of the Si content,which further provided a positive effect on the formation of fine recrystallization grains during the subsequent solution treatment.As a result,the yield strength,ultimate tensile strength,and elongation of the pre aged alloys in the direction of 45°with respect to the rolling direction were all increased with increasing Si content. 展开更多
关键词 AL Mg SI CU ZN alloy Mg/Si ratio microstructure evolution MECHANICAL properties
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信息传媒技术发展对人本质的影响:异化与进化的辩证 认领
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作者 赵庆来 《长江师范学院学报》 2020年第1期73-78,123共7页
交往是人类所特有的社会行为,是人的社会存在方式,是人本质属性的呈现。信息是人类生存的先导要素,信息交互是人类社会交往的基本内容。信息交往方式的变革需求是信息技术发展的动力,信息技术应用引发了人的异化,但异化中又孕育着人本... 交往是人类所特有的社会行为,是人的社会存在方式,是人本质属性的呈现。信息是人类生存的先导要素,信息交互是人类社会交往的基本内容。信息交往方式的变革需求是信息技术发展的动力,信息技术应用引发了人的异化,但异化中又孕育着人本质的解放和进化,且向人类提供了为实现目的而开展实践的方向和切入点。降低信息技术应用对人的异化,需要人类不断提高对技术使用的伦理认识,使刚性的技术有人文性的引领。 展开更多
关键词 信息传媒技术 交往 异化 进化
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长江上游地区人与自然和谐共生关系演变:供需平衡视角 认领
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作者 何强 孔芳霞 文传浩 《河北地质大学学报》 2020年第2期87-94,共8页
在选取2001-2017年长江上游地区经济、社会、生态环境数据的基础上,论文运用综合指数法评价了供需平衡视角下"人"与"自然"和谐共生状态演变过程,在面板向量自回归模型的基础上研究人与自然和谐共生关系演变过程。... 在选取2001-2017年长江上游地区经济、社会、生态环境数据的基础上,论文运用综合指数法评价了供需平衡视角下"人"与"自然"和谐共生状态演变过程,在面板向量自回归模型的基础上研究人与自然和谐共生关系演变过程。研究表明:生态环境资源供给水平呈现先下降后上升,人类社会需求水平先呈现"波浪型"后上升的趋势特征以及"供过于求"逐渐演化为"求过于供",并且长江上游地区人类的社会活动是引起生态环境资源变化的原因,人类的社会活动对生态环境资源产生负反馈影响,这种负反馈影响经历了先增强后稳定的过程。 展开更多
关键词 供需 人与自然 和谐共生 演变 长江上游地区
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准噶尔盆地呼图壁河侏罗系齐古组点坝砂体叠迁样式及演化特征 认领
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作者 姚宗全 德勒恰提·加娜塔依 +4 位作者 张明玉 孙乐 王文峰 潘品百 黄博超 《地质学报》 EI CAS CSCD 北大核心 2020年第5期1578-1590,共13页
点坝砂体是我国重要的油气储集层之一。随着河道的迁移,点坝砂体内部构型具有复杂性和多变性,使得现代沉积和古代露头都难以完全完整定量表征。因此,常常需要结合现代沉积和古代露头,运用先进的辅助工具(如航拍、遥感影像等)和数学方法... 点坝砂体是我国重要的油气储集层之一。随着河道的迁移,点坝砂体内部构型具有复杂性和多变性,使得现代沉积和古代露头都难以完全完整定量表征。因此,常常需要结合现代沉积和古代露头,运用先进的辅助工具(如航拍、遥感影像等)和数学方法,对点坝砂体的分布和迁移过程进行表征。本文通过分析良好的野外露头并结合卫片,识别了准噶尔盆地南缘发育的侏罗系齐古组古代露头剖面上的点坝砂体,精细解剖了点坝的平面与剖面叠迁样式,并分别对扩张型、迁移型、扩张旋转型及迁移旋转型四种点坝砂体类型的平面结构表征参数(弯度、曲率及扩张系数)、剖面叠迁样式进行了分析,建立了点坝砂体叠迁模式。该研究对于油气开发具有现实的指导意义,为古河道重建和储层构型建模提供依据。 展开更多
关键词 点坝砂体 叠迁样式 演化特征 齐古组 准噶尔盆地
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创业生态系统40年:主体-环境要素演进视角 认领
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作者 沙德春 孙佳星 《科学学研究》 CSSCI CSCD 北大核心 2020年第4期663-672,695,共11页
创业生态系统构建优化是当前我国创业实践面临的重要问题,也是创业研究领域的热点论题。创业政策对创业生态系统优化具有重要推动作用,是认识创业生态系统的有益角度。构建基于政策视角的"主体-环境"中国创业生态系统发展演... 创业生态系统构建优化是当前我国创业实践面临的重要问题,也是创业研究领域的热点论题。创业政策对创业生态系统优化具有重要推动作用,是认识创业生态系统的有益角度。构建基于政策视角的"主体-环境"中国创业生态系统发展演进理论分析框架,以改革开放40年来国家层面的4391篇创业政策为数据来源,采用政策文献计量和政策文本内容分析方法,从创业主体要素、创业外部环境要素两个方面研究中国创业生态系统的发展过程和演进特征。研究结果表明:我国创业主体经历了率性主体、精英主体、弱势主体向大众主体的演进;系统环境首位要素由创业宣传、社会创业培训向有形基础设施演进;系统外部环境要素多领域协同发展的格局初步显现。 展开更多
关键词 创业生态系统 创业政策 政策文本分析 演进
中国老年教育政策法规的演进 认领
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作者 籍献平 马少荣 朱全友 《河北广播电视大学学报》 2020年第2期1-5,共5页
随着老年教育实践的深入和对老年教育认识的深化,中国老年教育政策法规的发展,经历了蕴意萌芽阶段、探索起步阶段、快速发展阶段和完善创新阶段。中国老年教育的政策法规内容也在发展中不断演进,逐步完善。但仍须加快老年教育立法,制定... 随着老年教育实践的深入和对老年教育认识的深化,中国老年教育政策法规的发展,经历了蕴意萌芽阶段、探索起步阶段、快速发展阶段和完善创新阶段。中国老年教育的政策法规内容也在发展中不断演进,逐步完善。但仍须加快老年教育立法,制定更具科学性和可操作性的具体政策法规,推动政策法规建设创新。 展开更多
关键词 老年教育 政策法规 发展过程 演进
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Small x phenomenology on gluon evolution through the BFKL equation in light of a constraint in multi-Regge kinematics 认领
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作者 Pragyan Phukan Madhurjya Lalung Jayanta Kumar Sarma 《理论物理通讯:英文版》 SCIE CAS CSCD 2020年第2期50-59,共10页
We investigate the impact of so-called kinematic constraint on gluon evolution at small x.Implanting the constraint on the real emission term of the gluon ladder diagram,we obtain an integro-differential form of the B... We investigate the impact of so-called kinematic constraint on gluon evolution at small x.Implanting the constraint on the real emission term of the gluon ladder diagram,we obtain an integro-differential form of the Balitsky-Fadin-Kuraev-Lipatov(BFKL)equation.Later we solve the equation analytically using the method of characteristics.We sketch the Bjorken x and transverse momentum kt2 dependence of our solution of unintegrated gluon distributions f(x,kt2)in the kinematic constraint supplemented BFKL equation and contrasted the same with the original BFKL equation.Then we extract the integrated gluon density xg(x,Q2)from unintegrated gluon distributions f(x,kt2)and compared our theoretical prediction with that of global data fits,namely NNPDF3.1 sx and CT14.Finally we illustrate the phenomenological implication of our solution for unintegrated gluon distribution f(x,kT2)towards exploring high precision HERA DIS data by the theoretical prediction of proton structure functions(F2 and FL). 展开更多
关键词 PARTON EVOLUTION equation GLUON distribution function perturbative QCD
古代碓演变考 认领
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作者 殷志华 《农业考古》 2020年第1期104-109,共6页
碓是古代重要的水稻加工工具。其雏形为杵臼,历经踏碓、畜力碓、水碓(槽碓)、连机水碓、碓磨综合体发展阶段;呈现形制复杂化、功能多样化、高效率发展特点;其技术由传统粮食作物区向少数民族地区流传,促进传统农业发展。其中,水碓是古... 碓是古代重要的水稻加工工具。其雏形为杵臼,历经踏碓、畜力碓、水碓(槽碓)、连机水碓、碓磨综合体发展阶段;呈现形制复杂化、功能多样化、高效率发展特点;其技术由传统粮食作物区向少数民族地区流传,促进传统农业发展。其中,水碓是古人合理充分运用水能的典范,作为一种兼具审美价值的物质资源,在现代社会仍有着重大的开发利用价值。 展开更多
关键词 古代 演变
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