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Response of environmental sensitive grain size group in Core FJ04 from mud area in the north of East China Sea to East Asian winter monsoon evolvement
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作者 孙晓燕 李希彬 +1 位作者 岳晓峰 门翔 《Marine Science Bulletin》 CAS 2011年第2期1-12,共12页
AMS14C dating and grain-size analysis for Core FJ04, located at mud area in the North of East China Sea provide us a high-resolution grain-size distribution curve varying with depth and time. This paper got environmen... AMS14C dating and grain-size analysis for Core FJ04, located at mud area in the North of East China Sea provide us a high-resolution grain-size distribution curve varying with depth and time. This paper got environmental sensitive grain-size group by using standard deviation method, and proved that the selected sensitive grain-size group is an important proxy which can be used to reconstruct intensity of East Asian Winter Monsoon (EAWM). Then we got reconstruction of EAWM evolvement since 3 ka B.P., which revealed two main phases: (1) 3 - 1.15ka B.P., relative weak EAWM with middle frequency fluctuation; (2) 1.15 - 0ka B.P., really strong EAWM with high frequency fluctuation. And 1.15 ka B.P. is a distinct turning point. During the whole period, 11 intense events of EAWM were recorded and correlated well with other climate records, but the response extent was different, which showed consistency of climate change and particularity of region response. 展开更多
关键词 shelf of East China Sea mud area sensitive grain size group East AsianWinter Monsoon
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Study on Conceptual Planning of Group Landscapes in Urban Core Areas—A Case Study of Conceptual Landscape Planning of the Core Area in Shuangsong Group,Wanzhou District of Chongqing City,China
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作者 廖春艳 沈一 《Journal of Landscape Research》 2012年第2期9-11,17,共4页
The planning site was divided into a spatial structure of"one center,one corridor,two axes,two belts and three communities"and traffic system designed to a 3-grade road system of"artery,secondary artery... The planning site was divided into a spatial structure of"one center,one corridor,two axes,two belts and three communities"and traffic system designed to a 3-grade road system of"artery,secondary artery and by-pass".Meanwhile,a 3-ring structure of the planning site was constructed:diffusion waterfront landscape belt,waterfront pathway and core eco-green island.Finally,the planning concepts for major ecological constructions were given.This study tried to explore the group eco-landscape pattern in urban core areas so as to provide a strategic instruction for the regional sustainable development. 展开更多
关键词 Urban core areas Ecological landscapes Shuangsong group in Wanzhou DISTRICT of CHONGQING City CONCEPTUAL landscape planning
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扬子板块西南缘早前寒武纪地质演化:来自撮科元古宙变沉积岩碎屑锆石U-Pb年龄、Hf-O同位素的制约
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作者 高嘉敏 谢士稳 +3 位作者 刘倩 王舫 陶鹏 龙涛 《岩石学报》 SCIE EI CAS 北大核心 2025年第1期304-320,共17页
扬子板块的太古宙-古元古代基底出露十分有限,制约了对扬子早前寒武纪地质演化的认识。本次研究对扬子板块西南缘撮科地区的大红山群和昆阳群变沉积岩开展了碎屑锆石原位U-Pb年龄、Hf-O同位素及微量元素研究。测年结果显示,大红山群谐... 扬子板块的太古宙-古元古代基底出露十分有限,制约了对扬子早前寒武纪地质演化的认识。本次研究对扬子板块西南缘撮科地区的大红山群和昆阳群变沉积岩开展了碎屑锆石原位U-Pb年龄、Hf-O同位素及微量元素研究。测年结果显示,大红山群谐和锆石年龄分布于3092~1786Ma之间,最年轻碎屑锆石年龄为1786Ma,限定大红山群最大沉积时代为古元古代晚期。昆阳群谐和锆石年龄分布于2874~1031Ma之间,最年轻碎屑锆石年龄为1031Ma,表明昆阳群最大沉积时代为中元古代晚期。除少量较年轻锆石(<1.75Ga)外,昆阳群和大红山群具有相似的年龄分布特征,两个主要的年龄峰为2.0~1.85Ga和2.4~2.2Ga。尽管古元古代碎屑锆石的年龄峰与撮科地区已报道的古元古代岩浆活动期次一致,但仅有少部分碎屑锆石的Hf-O同位素特征与撮科古元古代岩浆岩相似,大多数碎屑锆石Hf-O同位素组成与加拿大Rae克拉通古元古代变沉积岩中碎屑锆石相似,暗示古元古代碎屑物质可能仅少部分来自撮科地区已识别的古元古代岩浆岩,而大部分可能来自与Rae克拉通发育的古元古岩浆岩相似的源区。大红山群和昆阳群中1.9~1.03Ga的碎屑锆石可能来自扬子西南缘发育的古元古代晚期-中元古代晚期岩浆岩。结合前人的资料,我们认为我国撮科和越南北部的Phan Si Pan带经历了与加拿大Rae克拉通相似的古元古代演化过程,支持2.4~2.3Ga扬子西南缘卷入Arrowsmith造山事件,并与Rae克拉通一起参与哥伦比亚超大陆聚合过程的认识。 展开更多
关键词 扬子西南缘 撮科地区 哥伦比亚超大陆 大红山群和昆阳群 碎屑锆石
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Stromatolite characteristics of Mesoproterozoic Shennongjia Group in the northern margin of Yangtze Block, China 被引量:6
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作者 Hong-wei Kuang Zheng-xiu Fan +6 位作者 Yong-qing Liu Nan Peng Zhi-cai Zhu Zhen-rui Yang Zhi-xian Wang Hui-liang Yu Quan Zhong 《China Geology》 2019年第3期364-381,共18页
Mesoproterozoic Shennongjia Group in Shennongjia Area can be divided into three subgroups in ascender order. Of which the lower subgroup includes Yingwodong, Dayanping, Macaoyuan, Luanshigou, Dawokeng and Kuangshishan... Mesoproterozoic Shennongjia Group in Shennongjia Area can be divided into three subgroups in ascender order. Of which the lower subgroup includes Yingwodong, Dayanping, Macaoyuan, Luanshigou, Dawokeng and Kuangshishan formations;the middle subgroup is formed by Yemahe, Wenshuihe and Shicaohe formations;the upper subgroup consists of Songziyuan and Wagangxi formations. Stromatolites developed very well in the carbonate rocks of each subgroup in Shennongjia Group. Based on descriptions of stromatolites macrotypes and their characteristics, this paper studied the formation environments, discussed the relationship among types, sizes, abundance of stromatolites and sedimentary environment, and established the formation and development pattern of stromatolites. As a result, this research also reveals the paleoenvironment and paleoclimate during the period of the Shennongjia Group deposited, which is beneficial to the study of paleoenvironment, paleogeography and paleoclimate, stratigraphic succession and regional correlation of the northern edge of Yangtze block. Stromatolites of Shennongjia Group are mainly conical, columnar, domal, wavy, stratiform and stromatolite reefs. The columnar and conical stromatolites are well developed. Conical stromatolites are mainly monomers, with a variety of pyramidal types, ranging in diameter from a few millimeters to several meters and formed in the high energy subtidal zone and tidal lagoon environment. Most of the columnar stromatolites are medium to small sizes implied a wide and gentle slope environment at that time. Stratiform (including wavy) stromatolites are larger scales and extends far away and distributed most widely in almost every horizon in the carbonate rocks. Stratiform stromatolites can be formed in low energy environments such as subtidal and intertidal zones and supratidal belts. Wavy stromatolites often developed in the hydrodynamic energy condition from weak energy intertidal zone gradually strengthened to the below of the high energy supratidal. Although stromatolite reefs can be a single or multiform combination, they developed mainly consisted of laminar or small walled columnar and large domal stromatolites. Shicaohe Formation also partially developed large domical stromatolites, the depositional environment is from the upper intertidal to supratidal zone. Stromatolite in Shennongjia Group usually appears as a combination of “Stratiform (wavy)-dome-columnar-coniform ” or “stratiform-dome-coniform-columnar-dome-stratiform ” vertieally, which represents the seawater depth from shallower to deeper or from shallow to deep and then to shallow again. These phenomenons generally reflected a stable sea level and companied with a high frequency oscillation. Comprehensive researches on the stratigraphy, sedimentary facies, sedimentary environment and the stromatolite types and their characteristics in the Shennongjia Group indicated that the Shennongjia Area is located on a gentle slope of carbonate platform in the passive continental edge, generally, i.e., one of warm and humid climate shallow water zone or/and a cold-drought climate, and had been experienced with eustatic cycles during the Shennongjia Group deposited. 展开更多
关键词 STROMATOLITE MESOPROTEROZOIC Shennongjia group Shennongjia area Northern MARGIN of YANGTZE CRATON GEOLOGICAL survey engineering China
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Basic Features of the Crustal Structure in the Lower Yangtze and Its Neighboring Area in the Chinese Mainland: Review of Deep Seismic Sounding Research 被引量:3
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作者 Bai Zhiming Wu Qingju +1 位作者 Xu Tao Wang Xiao 《Earthquake Research in China》 CSCD 2016年第3期298-315,共18页
The Deep Seismic Sounding( DSS) projects carried out from the 1970 s in the lower Yangtze region and its neighboring area were reviewed in this paper,then the basic wave group features of those wide angle reflection /... The Deep Seismic Sounding( DSS) projects carried out from the 1970 s in the lower Yangtze region and its neighboring area were reviewed in this paper,then the basic wave group features of those wide angle reflection / refraction record sections,and of the crustal structure are summarized. It shows that there were in total five clear wave groups on the record sections,which include the first arrival Pg,the reflection P1 from the bottom interface of the upper crust,the reflection P3 from the bottom interface of the middle crust,the strong reflection Pm from the Moho boundary,and the refraction Pn from uppermost mantle. In general,these phases are easily consistently traced and compared,despite some first arrivals being delayed or arriving earlier than normal due to the shallow sedimentary cover or bedrocks. In particular,in the Dabie Mountain region the seismic events of a few gathered shots always have weak reflection energy,are twisted,or exhibit disorganized waveforms, which could be attributed to the disruption variations of reflection depth,the broken Moho,and the discontinuity of the reflection boundary within crust. The regional crustal structures are composed of the upper,middle and lower crust,of which the middle and lower layers can be divided into two weak reflection ones. The crustal thickness of the North China and Yangtze platform are 30km- 36 km,and the Moho exhibits a flat geometry despite some local uplifts. The average pressure velocity in lower crust beneath this two tectonic area is 6. 7 ± 0. 3km / s. Nevertheless,beneath the Dabieshan area the crustal thickness is 32km- 41 km,the Moho bends down sharply andtakes an abrupt 4km- 7km dislocation in the vertical direction. The average pressure velocity in the lower crust beneath the Dabieshan area is 6. 8 ± 0. 2km / s. 展开更多
关键词 Deep seismic sounding projects Wave group feature Crustal structure feature Anhui Province and its neighboring area
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An empirical analysis on factors influencing ecological migration in minority areas of China 被引量:1
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作者 Huang Lijun Sun Shudong 《Ecological Economy》 2009年第3期290-297,共8页
Taking Ningxia Hui Autonomous Region as an example, this research makes an empirical analysis on the factors influencing the migration activities of the research subject: the southern mountainous farmers who don't... Taking Ningxia Hui Autonomous Region as an example, this research makes an empirical analysis on the factors influencing the migration activities of the research subject: the southern mountainous farmers who don't emigrate and the farmers who immigrated in Hongsibao Development Zone. With Probit Model, the research shows that the age, educational degree, farming land per capita, number of school-aged children, vocational training experience and the quantity of gained information are all the factors which influence the farmers' emigration choice. However, the influential strength of the factors is different. The research aims to provide the government with more scientific evidences for its policies of promoting ecological migration and to encourage more poverty families to immigrate into the areas suitable for living. 展开更多
关键词 Ethnic group areas Ecological migration Influential factors
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Anomalies of Precursory Group and Grouped Strong Earthquakes in the Sichuan-Yunnan Region 被引量:1
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作者 ShiShaoxian ChengWanzheng 《Earthquake Research in China》 2004年第4期348-356,共9页
Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of pr... Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of precursory groups (ID) and the values of short-term and impending anomaly in near-source area (NS). Using these methods, we calculate the observational data of deformation, underground fluid and hydrochemical constituents obtained from different seismic stations in the Sichuan-Yunnan region and conclude that the synthetic precursory anomalies of a single strong earthquake with M S6.0 differ greatly from those of the grouped strong earthquakes, for the anomalous information of precursory groups are more abundant. The three methods of extracting the synthetic precursory anomaly and the related numerical results can be applied into the practice of prediction to the grouped strong earthquakes in the Sichuan-Yunnan region. Inhomogeneous degree (ID) of synthetic precursory anomaly can be identified automatically because it takes the threshold of distributive characteristics of the anomalies of precursory group as its criterion for anomaly. 展开更多
关键词 Anomalies of precursory group Synthetic information Short-term and impending characteristic anomaly in the near-source area Prediction of the grouped strong earthquakes
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Factors that Affect Social Stability of Rural Areas in Ganzi District
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作者 LUO Xue-ling LI Pei-lin FU Xin-he 《Asian Agricultural Research》 2011年第6期43-45,83,共4页
Through the sample investigation of Kangding County, Daofu County, Luhuo County and Xiangcheng County in Sichuan Province in 2010 and by combining the quantitative and qualitative methods, various kinds of indexes fro... Through the sample investigation of Kangding County, Daofu County, Luhuo County and Xiangcheng County in Sichuan Province in 2010 and by combining the quantitative and qualitative methods, various kinds of indexes from the aspects of society, politics, economy and values in Ganzi District are analyzed, as well as the factors that affect the rural social stability of current Ganzi District area. The results show that rural areas of Ganzi District are stable on the whole, but the economic development level is backward; the social security measures are imperfect; disputes among rural residents still exist and most of them are economic disputes; the disputes among ethnics are mainly caused by religious belief; the autonomous situation of partial rural residents are bad and rural residents' evaluation on social justice is low. Therefore, it should establish and perfect relevant prevention and control mechanism. 展开更多
关键词 Ethnic groups Rural areas Social stability China
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Overlay Share Mesh for Interactive Group Communication with High Dynamic
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作者 吴言华 蔡云泽 许晓鸣 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第1期1-8,共8页
An overlay share mesh infrastructure is presented for high dynamic group communication systems, such as distributed interactive simulation (DIS) and distributed virtual environments (DVE). Overlay share mesh infrastru... An overlay share mesh infrastructure is presented for high dynamic group communication systems, such as distributed interactive simulation (DIS) and distributed virtual environments (DVE). Overlay share mesh infrastructure can own better adapting ability for high dynamic group than tradition multi-tree multicast infrastructure by sharing links among different groups. The mechanism of overlay share mesh based on area of interest (AOI) was discussed in detail in this paper. A large number of simulation experiments were done and the performance of mesh infrastructure was studied. Experiments results proved that overlay mesh infrastructure owns better adaptability than traditional multi-tree infrastructure for high dynamic group communication systems. 展开更多
关键词 area of interestc (AOI) overlay architecture group communication share mesh
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Research on Tourism Development Strategy of Zhaoqing Seven Star Cave Scenic Area in the Context of Guangdong-Hong Kong-Macao Greater Bay Area
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作者 Haiming CHEN Min ZHAO Xuejuan KONG 《Meteorological and Environmental Research》 CAS 2022年第5期40-44,共5页
The national strategy of"Guangdong-Hong Kong-Macao Greater Bay Area"has replaced the original Pearl River Delta economic circle.As one of them,the economic development of Zhaoqing City ushered in a historic ... The national strategy of"Guangdong-Hong Kong-Macao Greater Bay Area"has replaced the original Pearl River Delta economic circle.As one of them,the economic development of Zhaoqing City ushered in a historic opportunity.Other cities in Greater Bay Area provide sufficient tourist resources for the development of Zhaoqing’s tourism industry.Under the new situation,Seven Star Cave,the leading scenic spot in Zhaoqing,should firmly grasp the national strategic dividend of the"Guangdong-Hong Kong-Macao Greater Bay Area",accelerate the transformation and upgrading,and enhance the market competitiveness.In this paper,the data are collected by nominal group technique,and are integrated into SWOT matrix for analysis.The development strategy of Zhaoqing Seven Star Cave Scenic Area is obtained by matching internal and external factors. 展开更多
关键词 Guangdong-Hong Kong-Macao Greater Bay area Zhaoqing Seven Star Cave Scenic area Nominal group technique SWOT matrix analysis
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The Research About non-agriculture shift confronting the rural vulnerable farmers in the underdeveloped areas of China
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作者 Liu junwei 《International English Education Research》 2014年第9期79-80,共2页
This paper reveals the law of non-agriculture shift of the vulnerable groups in underdeveloped rural areas in china, and put forward the "second shift" category, namely the vulnerable groups is bound to work in citi... This paper reveals the law of non-agriculture shift of the vulnerable groups in underdeveloped rural areas in china, and put forward the "second shift" category, namely the vulnerable groups is bound to work in cities; return to participate in local non-agricultural activities; then begin second non-agriculture shift. The paper discusses the "second shift" feature; Finally, draw policy Implications of the "second shift". 展开更多
关键词 the vulnerable groups underdeveloped rural areas in china second shift
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甘肃省某三甲医院医疗服务能力评价及改进措施探析 被引量:1
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作者 杜旦 张国华 +1 位作者 虢海月 张铭 《联勤军事医学》 CAS 2024年第6期528-532,共5页
目的基于疾病诊断相关分组(diagnosis-related groups,DRGs)应用过程的研究,评价甘肃省某三级甲等综合医院的医疗服务能力。方法收集作者医院2019-01-01/2021-12-31日住院病案首页数据,对DRGs指标数据进行对比分析,依据“二八原则”以... 目的基于疾病诊断相关分组(diagnosis-related groups,DRGs)应用过程的研究,评价甘肃省某三级甲等综合医院的医疗服务能力。方法收集作者医院2019-01-01/2021-12-31日住院病案首页数据,对DRGs指标数据进行对比分析,依据“二八原则”以相对权重(relativeweight,RW)和出院人次将全院734个DRGs组划分成优势病种区、核心病种区、重点病种区、普通病种区、提升病种区和下沉病种区,分析各科室病种分区情况。结果该医院总体病例组合指数(case-mixindex,CMI)呈略微下降趋势,出院人数增幅较大,2021年较2019年上升了10.73%,总手术占比、四级手术占比及微创手术占比分别上升了6.56%、3.62%、0.71%;时间消耗指数均<1且持续降低,药耗费用有所增加;有68.31%的出院患者均集中在RW<1的DRGs组;优势病种区和核心病种区各包括30和148个DRGs组,总体CMI分别为2.288和2.539,均处于较高水平;重点病种区和普通病种区各包括90和261个DRGs组,总体CMI相对较低,分别为0.837和0.800;提升病种区和下沉病种区各包括13和63个DRGs组,总体CMI分别为0.303和0.317,均处于较低水平。结论该院的医疗服务能力有所提升,但医疗服务效率有待改善。根据病种分区结果,进一步优化全院病种结构,增加优势病种、核心病种等高权重病种的患者收治比例。以目标值为导向,按月度开展DRGs病种分析和对比,逐步提升全院整体医疗服务能力,为患者提供更加优质的医疗服务。 展开更多
关键词 疾病诊断相关分组 病例组合指数 病种分区
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襄阳都市圈旅游一体化发展路径研究 被引量:1
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作者 朱运海 王椰 梅丽 《襄阳职业技术学院学报》 2024年第3期14-21,共8页
中国式现代化和新发展格局对区域旅游一体化提出了新的要求。旅游一体化是城市一体化的重要组成部分,襄阳都市圈旅游一体化发展问题要立足汉江流域、南襄盆地、中西部新通道的大格局来分析,最为关键的就是“襄十随神”城市群旅游一体化... 中国式现代化和新发展格局对区域旅游一体化提出了新的要求。旅游一体化是城市一体化的重要组成部分,襄阳都市圈旅游一体化发展问题要立足汉江流域、南襄盆地、中西部新通道的大格局来分析,最为关键的就是“襄十随神”城市群旅游一体化。襄阳都市圈各城市地域相接、交通相连、文脉相通,共饮一江汉水,旅游一体化基础良好。围绕五大主题游线,重点做好增加旅游一体化合作收益、拓展襄阳旅游中心城市功能、谋划城市群旅游新格局、丰富城市群旅游形象和业态等方面的工作。 展开更多
关键词 襄阳都市圈 “襄十随神”城市群 旅游一体化 文旅融合发展
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辽东宽甸钴矿勘查区变基性岩地球化学特征和年代学研究
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作者 廉涛 孙莉 +2 位作者 王舫 刘福来 邓文婷 《岩石矿物学杂志》 CAS CSCD 北大核心 2024年第5期1281-1301,共21页
以辽东宽甸钴矿勘查区南辽河群里尔峪组变基性岩为研究对象,通过全岩地球化学组成和锆石年代学研究,讨论了里尔峪组变基性岩形成的构造背景以及钴的来源。地球化学分析结果显示,钻孔中变基性岩为正斜长角闪岩,具有一致的稀土元素配分模... 以辽东宽甸钴矿勘查区南辽河群里尔峪组变基性岩为研究对象,通过全岩地球化学组成和锆石年代学研究,讨论了里尔峪组变基性岩形成的构造背景以及钴的来源。地球化学分析结果显示,钻孔中变基性岩为正斜长角闪岩,具有一致的稀土元素配分模式,弱Eu负异常,显示E-MORB的地球化学特征。详细的矿物化学分析和地质温压计算结果表明,含辉石斜长角闪岩(ZK2-1)记录了峰期高角闪岩相变质温压条件,p=0.82~1.00 GPa和t=712~751℃;(含辉石)斜长角闪岩(ZK1-1和ZK3-1)记录了峰后退变质阶段的温压条件,分别为p=0.42~0.81 GPa和t=688~759℃、p=0.59~0.85 GPa和t=703~739℃。锆石SHRIMP U-Pb定年结果表明,变基性岩中变质锆石记录的年龄为1857~1850 Ma。综合宽甸地区变基性岩地球化学和年代学结果,推测其原岩为古元古代中期拉斑玄武岩,形成于伸展环境,并且在其形成过程中岩浆经历了显著的地壳物质混染,暗示古元古代中期打开的洋盆规模可能有限。通过与南、北辽河群变基性岩全岩地球化学特征对比研究,认为宽甸地区变基性岩不是钴矿化的主要成矿物质来源,有关钴矿化的物质来源仍需进一步研究。 展开更多
关键词 变基性岩 宽甸 里尔峪组 古元古代 变质事件 钴矿化
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农村扩中群体的家庭财务报表识别机制研究:基于浙江共同富裕先行示范区的实践探索
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作者 孙同全 赵虹 +2 位作者 苏岚岚 冯兴元 董翀 《中国软科学》 CSSCI CSCD 北大核心 2024年第8期97-109,共13页
基于家庭财务报表构建扩中群体识别机制对提高财政支持政策的精准性、加快实现共同富裕具有重要意义。在厘清浙江省现有扩中群体识别机制构建取得的进展与存在的不足的基础上,梳理农业经营主体家庭财务报表的编制探索、应用进展及对扩... 基于家庭财务报表构建扩中群体识别机制对提高财政支持政策的精准性、加快实现共同富裕具有重要意义。在厘清浙江省现有扩中群体识别机制构建取得的进展与存在的不足的基础上,梳理农业经营主体家庭财务报表的编制探索、应用进展及对扩中群体识别的启示,进而提出基于家庭财务报表改进扩中群体识别指标的思路和完善识别机制的建议。分析表明,现有实践从财产、社保、职业、收入等维度构建相对富裕群体的识别指标体系并运用排除法锁定扩中群体有其合理性和推广价值,但还面临标准设置权威性与精准性欠佳、指标选取不足、缺乏动态修正机制等挑战。浙江省农业融资担保有限公司探索编制了农业经营主体家庭财务报表,对完善扩中群体识别机制产生有益启发。基于家庭财务报表识别扩中群体存在关键收入与支出数据缺乏、资产价值评估标准难统一、线下数据采集质量不高、数据动态更新与共享机制滞后等不足。鉴于此,从排除法指标调整、修正类指标补充和直接类指标拣选3个方面提出改进扩中群体识别的可能思路,并从完善农村家庭财务报表设计、改进家庭结构画像和经济画像规则、强化数字化支撑、完善配套支撑机制等方面提出政策建议。 展开更多
关键词 扩中群体识别 家庭财务报表 共同富裕 农村 数字化
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基于多机场终端区交通态势的航班延误预测 被引量:1
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作者 张兆宁 查子奇 《科学技术与工程》 北大核心 2024年第12期5220-5226,共7页
为了针对性地制定后续优化措施,以降低多机场终端区内航班延误所带来的不利影响,并提高多机场系统内各机场的运营效率,进行多机场终端区航班延误的预测研究。首先,考虑多机场终端区交通态势对航班延误的影响,在对多机场终端区交通态势... 为了针对性地制定后续优化措施,以降低多机场终端区内航班延误所带来的不利影响,并提高多机场系统内各机场的运营效率,进行多机场终端区航班延误的预测研究。首先,考虑多机场终端区交通态势对航班延误的影响,在对多机场终端区交通态势进行分析的基础上,建立6个描述终端区交通态势的指标。接着,构建反向传播(back propagation,BP)神经网络航班延误预测模型,将终端区交通态势指标、航班信息和天气环境数据等作为输入,航班延误时间作为输出,并利用粒子群优化算法(particle swarm optimization,PSO)优化BP神经网络进行训练。通过实例验证和分析,基于多机场终端区交通态势的航班延误预测能够有效提高预测准确率,同时,通过粒子群优化BP神经网络的预测模型预测准确率均高于一般的考虑交通态势的BP和遗传算法优化的BP神经网络模型(genetic algorithm and back propagation,GA-BP)。 展开更多
关键词 多机场 航班延误预测 终端区交通态势 反向传播(BP)神经网络 粒子群优化算法(PSO)
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面向多区域防洪的珠江流域水库群协同调度模型研究 被引量:1
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作者 杨辉辉 李媛媛 +1 位作者 黄锋 刘永琦 《中国防汛抗旱》 2024年第10期27-34,共8页
珠江流域洪水组成与遭遇复杂多变,防洪保护对象多而分散,且兼顾供水、生态、发电、航运、库区安全等多种任务,水库群防洪调度面临多区域、多目标协同调度技术难题。以位于西江、北江、东江上的水库为研究对象,基于流域防洪格局和防洪任... 珠江流域洪水组成与遭遇复杂多变,防洪保护对象多而分散,且兼顾供水、生态、发电、航运、库区安全等多种任务,水库群防洪调度面临多区域、多目标协同调度技术难题。以位于西江、北江、东江上的水库为研究对象,基于流域防洪格局和防洪任务阐明了水库群多区域协同防洪的调度节点和角色定位,提出了嵌套式多维属性的模型功能结构,构建了珠江流域水库群多区域协同防洪调度模型。以流域防洪极为不利的2005年6月中下游型大洪水为例进行流域水库群防洪调度模型研究,结果表明,通过龙滩水库加大拦蓄,岩滩水库、百色水库、西津水库、飞来峡水库等西江、北江水库群协同调度,可将西江梧州站洪峰流量削减至安全泄量50 400 m^(3)/s以下,较原设计调度方案多削减3 200 m^(3)/s,将三角洲思贤滘(马口+三水)断面洪峰削减至62 700 m^(3)/s,较原设计调度方案多削减4 500 m^(3)/s,有效保障了粤港澳大湾区城市的防洪安全。 展开更多
关键词 多区域协同防洪调度 嵌套式多维属性模型 珠江水库群 粤港澳大湾区 防洪安全
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姬塬地区长8油层组储层特征分析
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作者 廖宇斌 李涛 +3 位作者 于志栋 肖骁 王守志 刘国文 《科学技术与工程》 北大核心 2024年第6期2246-2254,共9页
为确定长8油层储层现今表征,储层物性受黏土矿物胶结物控制模式,储层沉积作用和沉积后期所经历的成岩变化,通过铸体薄片、扫描电镜等方法研究了储层基本特征和成岩作用及沉积作用,在整体低渗的背景下,部分位于相对渗透率较高区域的油井... 为确定长8油层储层现今表征,储层物性受黏土矿物胶结物控制模式,储层沉积作用和沉积后期所经历的成岩变化,通过铸体薄片、扫描电镜等方法研究了储层基本特征和成岩作用及沉积作用,在整体低渗的背景下,部分位于相对渗透率较高区域的油井有较高的产量,理清研究区长8储层富集规律,对地区内岩石孔隙度下降因素进行剖析。结果表明,姬塬地区有利储层多发育水下分流河道和河口坝沉积,特别是砂体中心部位储层物性是最好,可见长8油层组的储集性能和渗流性能好,即粒间孔型、粒间孔+溶孔型和溶孔+粒间孔型。溶孔型、粒间孔+微孔型两种孔隙组合类型的渗流性能较差。微孔型和溶孔+微孔型两种孔隙组合类型的储集空间主要由半径极小的微孔构成,连通性较差,其孔隙内表面积和渗流阻力,储集性能和渗流性能较差。 展开更多
关键词 鄂尔多斯盆地 长8油层组 姬塬地区 储层特征 主控因素
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山东省济宁市主城区岩土工程勘察标准地层划分
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作者 谭秀全 胡波 +4 位作者 徐书名 李森 罗学俊 王彦明 张帆 《城市地质》 2024年第4期521-528,共8页
济宁市主城区在工程建设活动中积累了大量岩土工程勘察数据,因缺乏统一的岩土工程勘察地层标准,限制了这些宝贵的数据资源整合与共享。文章通过对“济宁市城市地质调查”项目施工的382个工程地质钻孔数据及“济宁市环城高架”等212个建... 济宁市主城区在工程建设活动中积累了大量岩土工程勘察数据,因缺乏统一的岩土工程勘察地层标准,限制了这些宝贵的数据资源整合与共享。文章通过对“济宁市城市地质调查”项目施工的382个工程地质钻孔数据及“济宁市环城高架”等212个建设项目的岩土工程勘察数据进行系统的分析研究,开展了60 m以浅地层的系统梳理和划分工作。根据沉积时代、成因类型与沉积环境、物质成分与结构特征和物理力学指标,60 m以浅地层可划分为10个工程地质层组。依据地层年代、成因类型、岩性、颜色、物理力学性质等地质特征,进一步划分为24个岩土工程勘察标准地层主层,44个亚层。为了便于推广使用,圈定了分布广泛、便于识别的3个标志层:⑦层黏土、⑭层黏土和⑱层黏土。 展开更多
关键词 济宁市 主城区 工程地质层组 岩土工程勘察 标准地层
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潍坊地区患者ABO血型鉴定困难原因分析
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作者 王立萍 李书杰 +4 位作者 吴晓春 刘凯 李新菊 冀宝军 孙福廷 《医学检验与临床》 2024年第6期11-15,54,共6页
目的:探讨分析潍坊地区患者ABO血型鉴定困难原因,解决疑难输血问题。方法:应用全自动血型分析仪对2020年12月-2023年10月潍坊地区239388例患者血型标本进行ABO血型初检,正反定型不符的标本加做试管法+镜检、不规则抗体筛查等实验,仍无... 目的:探讨分析潍坊地区患者ABO血型鉴定困难原因,解决疑难输血问题。方法:应用全自动血型分析仪对2020年12月-2023年10月潍坊地区239388例患者血型标本进行ABO血型初检,正反定型不符的标本加做试管法+镜检、不规则抗体筛查等实验,仍无法确定血型的,应用PCR-SSP法检测ABO血型基因,SSP荧光PCR染料法鉴定血型亚型,必要时进行Sanger基因序列分析。结果:239388份标本检出正反不符标本248份,研究分析结果为:①ABO亚型所致95例(4.0/万),其中B基因发生突变频率(65/95)明显高于A基因(28/95);②抗原减弱所致94例(3.9/万),其中B抗原表达减弱(62/94)比A抗原减弱(29/94)更常见;③不规则抗体阳性所致34例(1.4/万),其中抗M抗体(25/34)检出率最高;④反定型抗体减弱/缺失所致25例(1.0/万),其中抗B抗体减弱或缺失(22/25)最常见。结论:血清学与分子生物学结合可以准确鉴定患者血型,有效解决患者血型鉴定困难导致的疑难输血问题。 展开更多
关键词 潍坊地区 ABO血型 基因序列分析
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