检索结果-南通市图书馆

Geochemistry,Zircon U-Pb Age and Hf Isotope of the Huilanshan Granitoids in the North Dabie Terrane:Implications for Syn-Collapse Magmatism of Orogen

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2019年第3期30卷 636-646页

作者： shengxin liu Haijin Xu School of Earth Sciences China University of Geosciences

Syn-collapse magmatism is a critical issue for evolution of the continental *** Dabie Orogen is a typical orogen which was suffered from a complete *** kinds of granitoids,namely,the coarse-grained diorite and the fine-grained granite,are recognized at the center of the Luotian extensional dome,providing an opportunity to decipher the syn-collapse magmatism in the Dabie *** diorites(125±3 Ma)are high K calc-alkaline rocks,with low SiO2(51.9 wt.%–56.6 wt.%)and high MgO(3.5 wt.%–4.0 wt.%)*** are enriched in LREE and LILEs(e.g.,Ba,K,Rb)and depleted in HFSEs(e.g.,Ta,Nb,and Hf)with low ratio of Sr/Y(30.82–46.89).The granites(118±2 Ma)are shoshonite series rocks,with relatively high SiO2(68.9 wt.%–72.6 wt.%)and low MgO(0.32 wt.%–0.66 wt.%)*** are also enriched in LREE and LILEs with weakly negative Eu anomalies(δEu=0.81–0.85),and are depleted in HFSEs with low Sr contents(338 ppm–477 ppm)and Sr/Y ratios(23.80–33.13).Therefore,the two kinds of granitoids have no geochemical characteristics of adakitic rocks,suggesting that they were generated from a normal or thinned crust *** diorites have quite negative zirconεHf(t)values(-18.4 to-21.1),suggesting they were from partial melting of the mafic lower continental *** granites have relatively higher zirconεHf(t)values(-14.4 to-18.1).The granites also contains a series of old inherited zircon cores,such as two upper intercept ages of 2 628±41 and 1 840±37 Ma,and a concordant age of 807±9 *** these features suggest that the granites were generated from partial melting of the felsic middle-lower continental ***,the Huilanshan Early Cretaceous granitoids coupled with the Luotian extensional dome revealed the collapsed process of the Dabie Orogen.

关键词： orogenic collapse magmatism partial melting lower continental crust Dabie Orogen

大学生完美主义与考试焦虑的关系及反刍思维的中介作用

在线全文

学校读者我要写书评

暂无评论

预防医学情报杂志 2024年第3期40卷 307-313页

作者：姚昕慧刘盛鑫天津中医药大学管理学院天津301617

目的探究大学生完美主义与反刍思维、考试焦虑的关系以及反刍思维的中介作用。方法于2022年8至9月,采用方便抽样的方式,使用中文版Frost多维完美主义量表(CFMPS)、反刍思维量表(RRS)和考试焦虑量表(TAS)在校大学生进行问卷调查。运用SPS... 详细信息

目的探究大学生完美主义与反刍思维、考试焦虑的关系以及反刍思维的中介作用。方法于2022年8至9月,采用方便抽样的方式,使用中文版Frost多维完美主义量表(CFMPS)、反刍思维量表(RRS)和考试焦虑量表(TAS)在校大学生进行问卷调查。运用SPSS 25.0对数据进行独立样本t检验、单因素方差分析、Pearson相关分析与中介效应分析等。结果本次研究的584名大学生反刍思维得分为(44.46±11.98)分,考试焦虑得分为(18.57±8.72)分,消极完美主义得分为(60.29±15.12)分,积极完美主义得分为(21.34±5.30)分。积极完美主义与反刍思维、考试焦虑呈负相关(r分别为-0.120、-0.126,P值均小于0.001);消极完美主义与反刍思维、考试焦虑呈正相关(r分别为0.416、0.317,P值均小于0.01)。反刍思维对消极完美主义和考试焦虑起部分中介作用,相对效应值为61.00%,对积极完美主义和考试焦虑起完全中介作用,相对效应值为47.98%。结论完美主义与反刍思维是影响考试焦虑的重要因素。消极完美主义既能够直接提升考试焦虑水平,又能够通过反刍思维间接提高考试焦虑水平。积极完美主义者能够调整反刍思维,降低个体的考试焦虑水平。

关键词：完美主义反刍思维考试焦虑中介效应

在线全文

学校读者我要写书评

暂无评论

致密砂岩裂缝网络复杂性及其影响因素研究

地质力学学报 2024年第4期30卷 563-578页

作者：刘圣鑫付汇琪冯兴强韩晓祥王炳乾中国地质科学院地质力学研究所北京100081 中国地质调查局油气地质力学重点实验室北京100081 吉林省地质矿产局二所吉林吉林132001 中国矿业大学(北京)力学与土木工程学院北京100083

裂缝网络分析在油气藏勘探开发过程中发挥着着重要作用,致密砂岩裂缝网络复杂性分析对水力压裂优化、裂缝网络预测、裂缝建模等具有重要意义。文章结合致密砂岩复杂的裂缝网络动态演化的实验研究,明确了裂缝网络的分形和多重分形谱特征... 详细信息

裂缝网络分析在油气藏勘探开发过程中发挥着着重要作用,致密砂岩裂缝网络复杂性分析对水力压裂优化、裂缝网络预测、裂缝建模等具有重要意义。文章结合致密砂岩复杂的裂缝网络动态演化的实验研究,明确了裂缝网络的分形和多重分形谱特征,深入分析了裂缝网络的复杂性及其主控因素。通过岩石力学和X射线CT扫描实验确定了岩石力学和裂缝网络特征;通过扫描电镜实验、裂缝网络的分形分析定量化表征了致密砂岩微观组构和裂缝网络的分形特征。研究结果表明:致密砂岩的石英含量为28.08~52.88%,黏土含量为11.54~25.45%,粒度为61.18~184.55μm,孔隙度为8.125%~10.296%;单轴抗压强度介于69.09~188.33 MPa,弹性模量介于31.69~92.76 GPa;分形维数(DB)为1.28~2.35,谱宽(Δα)平均值为1.0851~1.3638。裂缝的萌生、扩展贯穿于应力–应变的全过程,裂缝网络的复杂性主要受控于致密砂岩的微观组构特征,并且具有明显的围压和尺度效应。三维裂缝网络的分形维数、多重分形谱的谱宽平均值可分别表征裂缝空间分布的复杂性和非均质性,两者之间具有相对的独立性。砂岩中石英、长石等脆性矿物含量越高、储层孔隙度越大、砂岩组成粒度越小裂缝网络分形维数越大,谱宽平均值越小;无围压情况下,样品裂缝网络的复杂性主要受控于微观组构特征,且随着轴向压力的增加而增加;存在围压的情况下,围压起主导作用,围压越大分形维数越小,谱宽平均值越大。而黏土矿物不利于复杂裂缝的形成;小尺度样品的分形维数和谱宽平均值大于尺度大样品的分形维数和谱宽平均值。砂岩的弹性模量和抗压强度与分形维数和谱宽平均值具有一定的正相关性。

关键词：致密砂岩裂缝网络分形维数多重分形谱岩石力学

The Seismic Induced Soft Sediment Deformation Structures in the Middle Jurassic of Western Qaidamu Basin

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2013年第4期87卷 979-988页

作者： LI Yong SHAO Zhufu MAO Cui YANG Yuping liu shengxin Guangzhou Institute of Geochemistry Chinese Academy of Sciences Graduate school Chinese Academy of Sciences School of Geo-Science China University of Petroleum

Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, such as convoluted bedding, liquefied sand veins, load and flame structures, slump structures and sliding-overlapping structures. Based on their genesis, soft-sediment deformation structures can be classified as three types： seismic induced structures, vertical loading structures, and horizontal shear structures. Based on their geometry and genesis analysis, they are seismic-induced structures. According to the characteristics of convoluted bedding structures and liquefied sand veins, it can be inferred that there were earthquakes greater than magnitude 6 in the study area during the middle Jurassic. Furthermore, the study of the slump structures and sliding- overlapping structures indicates that there was a southeastern slope during the middle Jurassic. Since the distance from the study area to the Altyn Mountain and the Altyn fault is no more than 10km, it can be also inferred that the Altyn Mountain existed then and that the AItyn strike-slip fault was active during the middle Jurassic.

关键词： Soft-sediments deformation structure sliding-overlapping structure paleoseismology,AItyn strike-slip fault

天津市小学生生活方式与近视风险的列线图预测模型构建

在线全文

学校读者我要写书评

暂无评论

中国学校卫生 2024年第1期45卷 21-24,29页

作者：刘盛鑫杜蓓金楠唐春玉宋德胜张欣魏瑞华天津中医药大学管理学院天津301617 天津医科大学眼科医院/眼视光学院/眼科研究所/国家眼耳鼻喉疾病临床医学研究中心天津市分中心/天津市视网膜功能与疾病重点实验室天津医科大学公共卫生学院

目的探讨天津市小学生生活方式与近视的关联,构建列线图模型预测近视风险,为小学生近视精准防控提供科学依据。方法于2022年4—7月,采用普查的方式对天津市15个区的373180名小学生进行裸眼远视力检查、屈光检测和生活方式相关问卷调查... 详细信息

目的探讨天津市小学生生活方式与近视的关联,构建列线图模型预测近视风险,为小学生近视精准防控提供科学依据。方法于2022年4—7月,采用普查的方式对天津市15个区的373180名小学生进行裸眼远视力检查、屈光检测和生活方式相关问卷调查。采用多因素Logistic回归模型分析小学生生活方式与近视的关联,并构建近视风险的列线图预测模型。结果天津市小学生近视检出率为37.6%。多因素Logistic回归模型分析结果显示,每日户外活动时长1~2 h(OR=0.94)和>2 h(OR=0.84)、每日近距离电子产品使用时长>2 h(OR=1.03)、每日近距离纸质材料读写时长1~2 h(OR=1.02)和>2 h(OR=1.09)、每周新鲜蔬菜摄入2~6次(OR=0.93)和≥7次(OR=0.88)均与近视关联有统计学意义(P值均<0.01)。近视风险列线图预测模型表明,影响天津市小学生近视患病风险的因素依次是年级、近视家族史、性别、每日户外活动时长、每周新鲜蔬菜摄入频率、每日近距离纸质材料读写时长和每日近距离电子产品使用时长。结论天津市小学生生活方式与近视存在关联,所构建的列线图模型可以为识别近视重点干预人群及采取有针对性的防控措施提供科学依据。

关键词：生活方式近视列线图回归分析学生

TiC钢结硬质合金与堆焊过渡层的界面组织及性能研究

在线全文

学校读者我要写书评

暂无评论

热加工工艺 2024年第11期53卷 37-41,48页

作者：吴书菲魏炜马贺祥陈永刘胜新黄智泉郑州大学材料科学与工程学院河南郑州450001 郑州机械研究所有限公司河南郑州450001

采用ERNiCrMo-3焊丝在TiC钢结硬质合金上堆焊过渡层,使用扫描电子显微镜、能谱仪、显微硬度计、万能试验机对不同热输入下TiC钢结硬质合金/ERNiCrMo-3熔敷金属界面的组织性能进行研究。结果表明:TiC钢结硬质合金和ERNiCrMo-3熔敷金属之... 详细信息

采用ERNiCrMo-3焊丝在TiC钢结硬质合金上堆焊过渡层,使用扫描电子显微镜、能谱仪、显微硬度计、万能试验机对不同热输入下TiC钢结硬质合金/ERNiCrMo-3熔敷金属界面的组织性能进行研究。结果表明:TiC钢结硬质合金和ERNiCrMo-3熔敷金属之间存在厚度为60~150μm的熔合区。随着焊接热输入的增加,熔合区的厚度逐渐增加;当热输入为3.5 kJ/cm时,界面处组织分布均匀,无气孔、裂纹以及晶粒异常长大现象。母材和堆焊金属之间存在元素扩散现象,二者实现了冶金结合;母材和堆焊焊缝之间存在一个硬度逐渐变化的缓冲区域;TiC钢结硬质合金/ERNiCrMo-3堆焊金属界面剪切强度最高可达到443 MPa,满足恶劣工况下对耐磨件与基体结合性能的要求。

关键词： TiC钢结硬质合金堆焊过渡层界面

Characteristics, Genesis, and Sedimentary Environment of Duplex-Like Structures in the Jurassic Sediments of Western Qaidam Basin, China

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2015年第5期26卷 677-689页

作者： Liangtian Ni Jianhua Zhong Zhufu Shao Yong Li Cui Mao shengxin liu School of Geoscience China University of Petroleum Qingdao Institute of Marine Geology

A particular type of soft-sediment deformation structure, similar to imbricate structure, is developed in the Jurassic strata at Honggouzi, western Qaidam Basin, China. We refer to this structure as a duplex-like deformation structure, because it is inferred to have been formed by the action of fast-moving, submarine gravity current sediments gliding across a pre-existing semiconsolidated sedimentary layer. The layers of duplex-like structure crop out in the southeastern limb of the core of a medium-sized anticline. The average dip direction of the duplex-like structure is 301.2° and the average dip angle is 54.7°. Duplex-like deformed laminations are composed mainly of weakly metamorphosed, extremely poorly sorted, feldspathic lithic graywacke. Sericite can be observed along bedding planes. The duplex-like structure occurs within a sequence of river-channel fine conglomerate, interchannel carbonaceous mudstone（shale）, shallow-water delta sand-shale, shallow-lake calcareous mudstone, olistostromes, and a turbidite. At the bottom of the sequence, we found brownish-red shallow-lake calcareous mudstone and carbonaceous mudstone and at the top olistostromes whose genesis is related to the slip and drag of a slumped body of submarine sediment. In combination with other symbiotic and associated structures, it is considered that the duplex-like structure was formed by the slumping and subsequent movement and traction of delta-front semiconsolidated sediments over the bottom sediments of a shore or shallow-lake sedimentary environment, probably triggered by an earthquake. The attitude of the duplex-like structure indicates that the direction of gliding was from NW301.2° toward SE121°, which is consistent with the current location of the Altun Mountains, indicating that the Altun Mountains existed in the Jurassic. The orogenesis of these mountains likely involved seismic activity, and an earthquake was the triggering factor in the formation of the duplex-like structure by ca

关键词： duplex-like structure soft-sediment deformation turbidity current slumping and glid-ing western Qaidam Basin

从新能源车回归模型预测无人船艇动力系统的发展

在线全文

学校读者我要写书评

暂无评论

柴油机 2024年第2期46卷 21-26页

作者：刘圣鑫陈武超严忠胜王天驰上海船用柴油机研究所上海201108

基于多元线性回归方法,探究新能源汽车商业成功的影响因素并总结动力系统发展规律,包括动力方案选择与设计参数重要度排序等,在此基础上建立新能源汽车动力系统模型,再针对船舶的具体情况做出修正,将得到的模型迁移到无人船艇上,从而预... 详细信息

基于多元线性回归方法,探究新能源汽车商业成功的影响因素并总结动力系统发展规律,包括动力方案选择与设计参数重要度排序等,在此基础上建立新能源汽车动力系统模型,再针对船舶的具体情况做出修正,将得到的模型迁移到无人船艇上,从而预估无人船艇动力系统未来发展趋势。

关键词：多元线性回归无人船艇新能源乘用车动力系统

Characteristics and sedimentary processes of lamina-controlled sand-particle imbricate structure in deposits on Lingshan Island, Qingdao, China

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2014年第8期57卷 1061-1076页

作者： SHAO ZhuFu ZHONG JianHua LI Yong MAO Cui liu shengxin NI LiangTian TIAN Yuan CUI XinYing liu YunTian WANG XiaoNan LI WeiHua LIN GangShan School of Geosciences China University of Petroleum Guangzhou Institute of Geochemistry Chinese Academy of Sciences Institute of Qinghai Oilfield CNPC

Imbricate structure is a common sedimentary structure and is well developed in sandy sediments. Here, we report a lamina- controlled fine-sand-particle imbricate structure in a set of very fine grained sedimentary rocks （fine sandstone, siltstone, and mudstone） at the Dockyard and Qianceng Cliff areas of Lingshan Island, Qingdao, Shandong, China. Sets of up to 300 laminae are found in stratigraphic profiles in these areas. The laminae are generally less than 1 mm thick, with most being 0.3-0.4 mm thick and the thinnest being 〈0.1 ram. The dip angle of the imbricate structure varies widely, between 0° and 90°, with an av- erage dip angle of about 40°-50°, which is higher than that of imbricate riverbed gravels （about 34°）. The dip angle is a func- tion of the shape and sorting of the particles, as well as the hydrodynamic conditions under which these fine-grained sediments were deposited. Several profiles show well-developed multiscale, soft-sediment deformation structures. Flute casts, load casts, and groove casts are also common. Fragments of carbon remains occur widely and commonly constitute stringers several mil- limeters thick and up to 10 cm long, together with fine clasts. Vitrain lenticles are also common. Based on the imbricate struc- ture of the Lingshan Island deposits, it is shown that in addition to paleocurrent analysis, the imbricate structure can be used to infer information about fluid properties, transport characteristics, and sedimentary processes of the depositional environment. A near-bottom underflow, either of authigenic origin or derived from cold river water in winter in a delta interdistributary bay or delta-front environment, is inferred to have provided the hydrodynamic setting in which this imbricate structure formed. The imbricate structure, together with other sedimentary structures and features, shows that the sedimentary rocks on Lingshan Is- land were deposited in an inland, shallow-water environment, such as a delta, and not in a d

关键词： laminae sand particle-supported imbricate structure Lingshan Island

同方期刊数据库