|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Source mechanism of strong aftershocks (M_s≥5.6) of the 2008/05/12 Wenchuan earthquake and the implication for seismotectonics显示文摘Dozens of >M5, hundreds of >M4, and much more >M3 aftershocks occurred after the 2008/05/12 Wenchuan earthquake, which were well recorded by permanent and portable seismic stations. After relocated with P arrival, the >M3 aftershocks show two trends of distribution, with most of the aftershocks located along the north-east strike consistent with Longmenshan fault system, yet there is a north-west trend around the epicenter. It seems that substantially more aftershocks occur in regions with crystalline bedrocks. Then we collected waveform data from National Digital Seismograph Network and regional seismograph network of China, and employed 'Cut and Paste' method to obtain focal mechanisms and depths of the big aftershocks (M≥5.6). While most of those aftershocks show thrust mechanism, there are some strike slip earthquakes in the northern-most end of the rupture. Focal mechanisms show that the events located on the southern part of central Beichuan-Yingxiu Fault (BY) are mainly thrust earthquakes, which is consistent with initial mechanism of the main shock rupture. In the north part the aftershocks along the BY are also dominated by thrust slip, which is quite different from the right slip rupture of the main shock. Around Qingchuan-Pingwu Fault, the focal mechanisms are dominated by right-slip rupture with large depths (~18 km). So we suspected that in the north part the main shock might rupture on two faults: Beichuan Fault and Qingchuan-Pingwu Fault. The complex pattern of aftershock mechanisms argues for presence of a complicated fault system in the Longmenshan area. | ZHENG Yong1,2,MA HongSheng3,Lü Jian4,NI SiDao5,LI YingChun6 & WEI ShengJi2 1 Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China 2 Institute of Geophysics,Chinese Earthquake Administration,Beijing 100086,China 3 Institute of Earthquake Science,Chinese Earthquake Administration,Beijing 100086,China 4 Earthquake Administration of Jiangxi Province,Nanchang 330039,China 5 School of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China 6 Earthquake Administration of Jiangsu Province,Nanjing 210014,China | 2009 | Science China Earth Sciences2009，52，6： | 100 |
| 2 | 北祁连早古生代花岗质岩浆作用及构造演化显示文摘北祁连山中段花岗岩锆石SHRIMP定年结果表明,柯柯里岩体的斜长花岗岩和石英闪长岩的年龄分别为512Ma和501 Ma,野马咀和金佛寺花岗岩的年龄分别为508Ma和424Ma。结合区内其它花岗岩体的定年资料,根据花岗岩的岩石地球化学特征及岩体产出的构造位置、区域地质资料等,我们认为,早古生代北祁连洋板块向南俯冲,至少引发了两期花岗质岩浆作用,第一次岩浆作用形成柯柯里斜长花岗岩(512Ma)、野马咀花岗岩(508Ma)和柯柯里石英闪长岩(501 Ma),第二次花岗质岩浆作用形成牛心山花岗岩(477Ma)。由于往南俯冲的板块受到柴达木板块向北俯冲的影响,俯冲受阻,继而俯冲极性发生变化,转向北俯冲,形成了民乐窑沟(463Ma)等花岗岩侵入体。大约440Ma之后,洋盆闭合,柴达木陆块和阿拉善陆块对接碰撞,形成北祁连造山带。由于造山带根部岩石圈发生折沉作用,造山带上不同的块体伸展、滑塌,形成一系列碰撞后花岗岩如金佛寺花岗岩(424Ma)及牛心山岩体的石英闪长岩(435Ma)等。 | 吴才来 徐学义 高前明 李向民 雷敏 郜源红 Ronald B FROST Joseph L WOODEN | 2010 | 岩石学报2010，26，4： | 132 |
| 3 | 检测人群胰岛素敏感性的一项新指数显示文摘引入一个新的胰岛素敏感性指数--空腹血浆胰岛素与血糖乘积的倒数。该指数经美国两个种族共320例研究的材料证实与胰岛素钳技术测定的胰岛素敏感性指数胰岛素介导的葡萄糖代谢率(M)高度显著相关(r>0.7,P=0.0001)。以这一新指数分析874命名 国人(正常人201例,IGT307例,新诊断DM | 李光伟 Step.,L | 1993 | 中华内科杂志1993，32，10： | 2131 |
| 4 | 物种多维生态位宽度测度显示文摘经典的生态位宽度测度式基于物种在单一生态位维上各资源状态的分布比例量,而难以应用于物种在多维生态位空间的宽度测度。本文在n维生态位空间分割为分室的基础上,定义物种生态位宽度为物种在分室上分布与样本在分室的频率分布之间的吻合度。根据最小判别信息统计量,推导出一可基于物种分布比例量也可基于实测值的生态位宽度测度式,并以华南鼎湖山自然保护区的厚壳桂(Crypto-carya)群落中物种与土壤因子数据为例加以说明,结果表明优势树种具较宽生态位。 | 余世孝 奥.,L | 1994 | 生态学报1994，14，1： | 92 |
| 5 | 北阿尔金巴什考供盆地南缘花岗杂岩体特征及锆石SHRIMP定年显示文摘北阿尔金巴什考供盆地南缘花岗杂岩体呈近东西向分布,长约49公里,出露面积约90平方公里,与围岩之间为明显的侵入接触关系,接触界线为不规则的渡状、锯齿状。围岩为前寒武纪砂岩、片岩、泥岩及凝灰质砂岩。该杂岩体主要由巨斑花岗岩、红色花岗岩、灰白色似斑状花岗岩和粉红色似斑状花岗岩组成。杂岩体的主元素含量变化不大,SiO2为65.14%- 75.66%,全碱含量为7.49-8.96%,K2O/Na2O比值为1.12-2.68,岩石的里特曼指数平均为2.34,CIPW标准矿物计算均出现刚玉(AC)(平均为1.78),说明岩石铝过饱和;杂岩体的稀土总量变化于89.44×10-6-335.28×10-6之间,不同岩石类型均有负铕异常,且从巨斑花岗岩→灰白色似斑状花岗岩→红色似斑状花岗岩→红色花岗岩,负铕异常越来越明显,表现在Eu/ Eu+值由0.65→0.51→0.48→0.30。在微量元素蛛网图上,所有样品的微量元素丰度均高于原始地幔值,并具有相似的配分模式,即在Ba、Nb、Sr、P、Ti处呈明显的低谷,显示出S型花岗岩的特征。锆石SHRIMP U-Pb定年得出,巨斑花岗岩、红色中细粒花岗岩、灰白色和粉红色似斑状花岗岩的年龄分别为474.3±6.8Ma、446.6±5.2Ma、434.5±3.8Ma和431.1±3.8Ma。结合区域地质特征,我们认为,该杂岩体形成于同碰撞-碰撞后的构造环境。 | 吴才来 杨经绥 姚尚志 曾令森 陈松永 李海兵 戚学祥 Wooden J L Mazdab F K | 2005 | 岩石学报2005，21，3： | 85 |
| 6 | 青藏高原东缘活动构造显示文摘青藏高原东缘由岷山断块和龙门山构造带构成。以活动构造地貌学为主线,在解析该地区主干断裂晚第四纪以来活动的地质地貌表现的基础上,对一批断裂运动学和史前强震活动的定量数据进行分析研究,结果表明:在岷山断块中,虎牙断裂的平均左旋滑动速率为1.4 mm/a,垂直滑动速率为0.3 mm/a。岷江断裂的平均垂直滑动速率介于0.37 mm/a^0.53 mm/a之间,左旋位错量与垂直位错量大致相当;在龙门山构造带中,茂汶-汶川断裂、北川-映秀断裂和彭县-灌县断裂的平均垂直滑动速率均在1 mm/a左右,且几条主干断裂的右旋位错量与垂直位错量相当。结合震源机制解结果和GPS测量资料,建立晚新生代以来青藏高原东缘向南东方向逸出的构造变形模式。 | 周荣军 李勇 Alexander L Densmore Michael A Ellis 何玉林 王凤林 黎小刚 | 2006 | 矿物岩石2006，26，2： | 141 |
| 7 | 后新公共管理改革——作为一种新趋势的整体政府显示文摘 | Tom Christensen Per Lgreid 张丽娜 袁何俊 | 2006 | 中国行政管理2006，，9： | 248 |
| 8 | Changes in hippocampal connectivity in the early stages of Alzheimer's disease: evidence from resting state fMRI显示文摘 | Wang L Zang Y He Y Liang M Zhang X Tian L Wu T Jiang T Li K | 2006 | 中国生物学文摘2006，20，10： | 84 |
| 9 | Serum MicroRNA Signatures Identified in a Genome-Wide Serum MicroRNA Expression Profiling Predict Survival of Non-Small-Cell Lung Cancer(摘要)显示文摘 | Hu, ZB Chen, X Zhao, Y Tian, T Jin, GF Shu, YQ Chen, YJ Xu, L Zen, K Zhang, CY Shen, HB | 2010 | 南京医科大学学报(自然科学版)2010，30，7： | 141 |
| 10 | Laparoscopic Partial Nephrectomy With Segmental Renal Artery Clamping:Technique and Clinical Outcomes显示文摘Background:Warm ischemic injury is one of the most important factors affecting renal function in partial nephrectomy(PN).The technique of segmental renal artery clamping emerges as an alternative to conventional renal artery clamping for renal hilar control.Objective:To evaluate the feasibility and efficiency of laparoscopic PN(LPN) with segmental renal artery clamping in comparison with the conventional technique.Design,setting,and participants:A total of 75 patients underwent LPN from June 2007 to November 2009.All patients had T1a or T1b tumor in one kidney and a normal contralateral kidney.Thirty-seven patients underwent surgeries with main renal artery clamping,and 38 underwent surgeries with segmental artery clamping.Intervention:All procedures were performed by the same laparoscopic surgeon.Measurements:Blood loss,operation time,warm ischemia(WI) time,and complications affected renal function before and after operation were recorded.Results and limitations:All LPNs were completed without conversion to open surgery or nephrectomy.The novel technique slightly increased WI time(p < 0.001) and intraoperative blood loss(p = 0.006),while it provided better postoperative affected renal function(p < 0.001) compared with the conventional technique.The total complication rate was 12%.Among the 38 cases where segmental renal artery clamping was performed,7 had to convert to the conventional method.Tumor size and location influenced the number of clamped segmental arteries.Long-term postoperative renal function is still awaited.Conclusions:LPN with segmental artery clamping is safe and feasible in clinical practice.It minimizes the intraoperative WI injury and improves early postoperative affected renal function compared with main renal artery clamping.(C) 2010 European Association of Urology.Published by Elsevier B.V.All rights reserved. | Shao,P.F. Qin,C. Yin,C.J. Meng,X.X. Ju,X.B. Li,J. Lü,Q.A. Zhang,W. Xu,Z.Q.Shao,Pengfei Qin,Chao Yin,Changjun Meng,Xiaoxin Ju,Xiaobing Li,Jie Lü,Qiang Zhang,Wei Xu,Zhengquan] Nanjing Med Univ,Affiliated Hosp 1,Dept Urol,Nanjing,Peoples R China.Guangzhou Rd 300,Nanjing 210029,Peoples R China. | 2011 | 南京医科大学学报(自然科学版)2011，31，7： | 123 |
| 11 | GGE叠图法─分析品种×环境互作模式的理想方法显示文摘本文介绍一种分析作物区域试验结果的方法-GGE叠图法。首先,将原始产量数据减去各地 点的平均产量,由此形成的数据集只含品种主效应G和品种-环境互作效应GE,合称为GGE。对GGE 作单值分解,并以第一和第二主成分近似之。按照第一和第二主成分值将各品种和各地点放到一个平 面图上即形成GGE叠图。借助于辅助线,可以直观回答以下问题:(1)什么是某一特定环境下最好的 品种;(2)什么是某一特定品种最适合的环境;(3)任意两品种在各环境下的表现如何;(4)试验中品 种×环境互作的总体模式是怎样的;(5)什么是高产、稳产品种;(6)什么是有利于筛选高产、稳产品 种的环境。 | 严威凯 盛庆来 胡跃高 L A Hunt | 2001 | 作物学报2001，27，1： | 113 |
| 12 | 食管鳞状细胞癌基因组改变的确认显示文摘食管癌是最具侵袭性的癌症之一,居全球恶性肿瘤病死率的第六位。全球约70%的食管癌患者在中国,食管鳞状细胞癌是最常见的病理类型(〉90%)。目前,临床上对于食管鳞状细胞癌的早期诊断和治疗非常有限,患者5年生存率仅为10%。然而,直到目前对于导致食管鳞状细胞癌发病的完整基因组事件仍知之甚少。本组对158例食管鳞状细胞癌病例进行一次全面的基因组分析:其中17例食管鳞状细胞癌病例进行全基因组测序,71例进行外显子测序, | Song Y Li L Ou Y 崔淼 许春伟 张博 | 2014 | 临床与实验病理学杂志2014，30，11： | 129 |
| 13 | Osteoarthritis:toward a comprehensive understanding of pathological mechanism显示文摘Osteoarthritis(OA) is the most common degenerative joint disease and a major cause of pain and disability in adult individuals. The etiology of OA includes joint injury, obesity, aging, and heredity. However, the detailed molecular mechanisms of OA initiation and progression remain poorly understood and, currently,there are no interventions available to restore degraded cartilage or decelerate disease progression. The diathrodial joint is a complicated organ and its function is to bear weight, perform physical activity and exhibit a joint-specific range of motion during movement. During OA development, the entire joint organ is affected, including articular cartilage, subchondral bone, synovial tissue and meniscus. A full understanding of the pathological mechanism of OA development relies on the discovery of the interplaying mechanisms among different OA symptoms, including articular cartilage degradation, osteophyte formation, subchondral sclerosis and synovial hyperplasia, and the signaling pathway(s) controlling these pathological processes. | Di Chen Jie Shen Weiwei Zhao Tingyu Wang Lin Han John L Hamilton Hee-Jeong Im | 2017 | Bone Research2017，5，1： | 121 |
| 14 | Current concepts on osteonecrosis of the femoral head显示文摘It is estimated that 20000 to 30000 new patients are diagnosed with osteonecrosis annually accounting for approximately 10% of the 250000 total hip arthroplasties done annually in the United States. Thelack of level 1 evidence in the literature makes it difficult to identify optimal treatment protocols to manage patients with pre-collapse avascular necrosis of the femoral head, and early intervention prior to collapse is critical to successful outcomes in joint preserving procedures. There have been a variety of traumatic and atraumatic factors that have been identified as risk factors for osteonecrosis, but the etiology and pathogenesis still remains unclear. Current osteonecrosis diagnosis is dependent upon plain anteroposterior and frog-leg lateral radiographs of the hip, followed by magnetic resonance imaging(MRI). Generally, the first radiographic changes seen by radiograph will be cystic and sclerotic changes in the femoral head. Although the diagnosis may be made by radiograph, plain radiographs are generally insufficient for early diagnosis, therefore MRI is considered the most accurate benchmark. Treatment options include pharmacologic agents such as bisphosphonates and statins, biophysical treatments, as well as joint-preserving and joint-replacing surgeries. the surgical treatment of osteonecrosis of the femoral head can be divided into two major branches: femoral head sparing procedures(FHSP) and femoral head replacement procedures(FHRP). In general, FHSP are indicated at pre-collapse stages with minimal symptoms whereas FHRP are preferred at post-collapse symptomatic stages. It is difficult to know whether any treatment modality changes the natural history of core decompression since the true natural history of core decompression has not been delineated. | Joaquin Moya-Angeler Arianna L Gianakos Jordan C Villa Amelia Ni Joseph M Lane | 2015 | World Journal of Orthopedics2015，6，8： | 94 |
| 15 | 2019新型冠状病毒基因组特征和流行病学:病毒起源和受体结合的意义显示文摘研究者对来自9例新型冠状病毒肺炎住院患者的支气管肺泡灌洗液样本和培养的分离株进行了下一代测序。从这些个体中获得了严重急性呼吸综合征-冠状病毒2(severe acute respiratory syndrome-coronavirus 2,SARS-CoV-2)的完整和部分基因组序列。利用Sanger测序连接病毒重叠群以获得全长基因组,cDNA末端快速扩增确定终端区。对这些SARSCoV-2基因组和其他冠状病毒基因组进行了系统进化分析,以确定该病毒的进化史并有助于推断其可能的起源。 | 刘青(译) 刘莉(审校) Lu R Zhao X Li J Niu P Yang B Wu H Wang W Song H Huang B Zhu N Bi Y Ma X Zhan F Wang L Hu T Zhou H Hu Z Zhou W Zhao L Chen J Meng Y Wang J Lin Y Yuan J Xie Z Ma J Liu WJ Wang D Xu W Holmes EC Gao GF Wu G Chen W Shi W Tan W | 2020 | 中华高血压杂志2020，28，3： | 516 |
| 16 | 新冠肺炎的神经系统表现显示文摘2019年12月,一种新型冠状病毒被世界卫生组织(WHO)命名为COVID-19(新冠肺炎)。本研究报告了新冠肺炎住院患者的特征性神经系统表现。这项回顾性研究在中国武汉的三个急救中心完成。研究对象是在2020年1月16日至2020年2月19日之间确诊的患者。影像学评估包括胸部和头部CT,所有实验室检查均根据患者的临床治疗需求进行。回顾患者神经系统症状表现并将其分为中枢神经系统表现、周围神经系统表现和骨骼肌损伤表现三类。 | 杨思琪(译) 王继先(译) Mao L | 2020 | 中国康复2020，35，8： | 126 |
| 17 | 新辅助免疫治疗可以为MMR表达以及MMR缺失型早期结肠癌患者带来病理缓解显示文摘PD-1联合CTLA-4阻滞剂对晚期错配修复蛋白(MMR)缺失(dMMR)型结直肠癌患者的治疗非常有效,但对MMR表达(pMMR)的患者无效。我们假设在早期结肠癌患者中新辅助免疫疗法具有更好的疗效。在探索性NICHE研究中(Clinical Trials.gov:NCT03026140),dMMR或pMMR患者在手术前接受单剂量伊匹单抗(ipilimumab)和两剂量纳武单抗(nivolumab)治疗,pMMR患者联合或者不联合使用塞来昔布。本研究的主要观察指标是安全性和可行性。在纳入分析的40例患者中,包括21例dMMR患者和19例pMMR患者,他们均接受了治疗,其中3例经安全性讨论后仅接受了纳武单抗单药治疗。患者治疗耐受性良好,所有患者均接受了根治性切除且未延期进行,符合主要观察指标的观察预期。在接受伊匹单抗+纳武单抗治疗的患者(20例dMMR患者和15例pMMR患者)中,共35例可进行疗效和转化效果评估。在20例dMMR患者中,病理缓解率为100%(95%CI:86%~100%),有19例患者达到主要病理缓解(MPRs,残留存活肿瘤≤10%),其中包括12例患者达到完全病理缓解。在15例pMMR患者中,有4例达到病理缓解,其中包括3例主要病理缓解和1例部分缓解。CD8+PD-1+T细胞浸润情况可预测pMMR患者的治疗应答。基于这些数据认为,如果新辅助免疫治疗效果能被基于至少3年无病生存数据的更加大型的临床研究结果支持,那么其则有望作为特定结肠癌患者的标准治疗方案。 | 张荣欣 CHALABI M FANCHI L F DIJKSTRA K K | 2020 | 结直肠肛门外科2020，26，6： | 87 |
| 18 | A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)显示文摘The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s). | QIN E'de ZHU Qingyu YU Man FAN Baochang CHANG Guohui SI Bingyin YANG Bao PENG Wenming JIANG Tao LIU Bohua DENG Yongqiang LIU Hong ZHANG Yu WANG Cui LI Yuquan GAN Yonghua LI Xiaoyu L Fushuang TAN Gang CAO Wuchun, YANG Ruifu Institute of Microbiology and Epidemiology, Chinese Academy of Military Medical Sciences, Beijing 100071, China WANG Jian, LI Wei, XU Zuyuan, LI Yan, WU Qingfa, LIN Wei, CHEN Weijun, TANG Lin, DENG Yajun, HAN Yujun, LI Changfeng, LEI Meng, LI Guoqing, LI Wenjie, L Hong, SHI Jianping, TONG Zongzhong, ZHANG Feng, LI Songgang, LIU Bin, LIU Siqi, DONG Wei, WANG Jun, Gane K-S Wong, YU Jun & YANG Huanming* Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300 National Center for Genome Information, Beijing 101300, China | 2003 | Chinese Science Bulletin2003，48，10： | 121 |
| 19 | 青藏高原东缘龙门山晚新生代走滑挤压作用的沉积响应显示文摘成都盆地位于青藏高原东缘,夹于龙门山与龙泉山之间,盆地的长轴方向平行于龙门山,呈现为北东—南西向展布的线性盆地。盆地中充填了3.6Ma以来的半固结—松散堆积物,最大厚度为541m,在垂向上由下部的大邑砾岩、中部的雅安砾石层和上部的上更新统至全新统砾石层组成,其与下覆地层均为不整合接触,显示该盆地是一个单独的成盆期,并非是在中生代前陆盆地基础上形成的继承性盆地。在垂直于龙门山造山带方向上,成都盆地具不对称的楔形结构,沉积基底面整体向西呈阶梯状倾斜,盆地中充填的碎屑物质均来源于盆地西侧的龙门山,具横向水系和单向充填的特征;而且盆地的沉降中心具有逐渐向远离造山带方向迁移的特征,显示盆地的挤压方向垂直于龙门山主断裂,造成了成都盆地在垂直于造山带方向上的构造缩短。在平行于龙门山造山带方向上,成都盆地具有一系列的北东向延伸的次级凸起和凹陷,凹陷和凸起相间分布,且在空间上呈斜列形式展布于盆地的底部,其中次级凹陷(沉降中心)和冲积扇具有向平行龙门山造山带方向迁移的特征,表明成都盆地西缘的龙门山断裂具有右旋走滑的特征。鉴于以上特征,认为成都盆地是在龙门山造山带晚新生代走滑与逆冲的联合作用下形成的走滑挤压盆地。 | 李勇 周荣军 Densmore A L Ellis M A 黎兵 | 2006 | 沉积学报2006，24，2： | 65 |
| 20 | 塔里木盆地寒武纪—奥陶纪优质烃源岩沉积与古环境变化的关系:碳氧同位素新证据显示文摘对塔里木盆地东部塔东2井上震旦统和寒武系—奥陶系样品进行TOC和碳、氧同位素及微量元素分析,发现该井稳定碳、氧同位素值在寒武系—中奥陶统发生明显变化,该层还赋存高有机质丰度烃源岩,其TOC值的高低可反映当时的生物产率和埋藏率。碳和氧同位素值在寒武系/上震旦统分界处正向漂移,说明正好在进入寒武纪前气候明显变冷,海平面下降。接着,下寒武统底部以碳和氧同位素值的快速负向漂移为标志,表明古气候迅速变暖和海平面大幅度上升,烃源岩TOC值也达到全井柱最高值。古气候显著波动、海平面最高及其频繁变化和沉积物高TOC是早寒武世的显著特征;而晚寒武世—早奥陶世,同位素正向漂移,暗示海平面下降,沉积物TOC也随之下降并降至最低;到了早奥陶世末,即早、中奥陶世的过渡时期,同位素又开始负向漂移,TOC又开始升高;中奥陶世,同位素强烈负向漂移,TOC又升至新高。稳定碳、氧同位素值的变化及其所指示的古气候与海平面变化,以及与TOC的响应关系,指示冰期、冰后期之交,古气候迅速变暖和海平面大幅度上升有利于烃源岩发育;同时暗示,δ13C、δ18O与生烃母质生物的有机生产率、有机埋藏率之间存在某种内在联系。即高TOC含量反映高的有机生产率和高的有机埋藏率;而与其同步反方向变化的δ13C、δ18O则暗示海平面较高,沉积环境属远陆海域,表层水中生烃母质生物的光合作用很强。而有机质的高产率和高埋藏率,导致海水中δ12C和δ16O被大量地固定在沉积物中。这样,就使海水中相对富集13C和18O重同位素而使海水变“重”;而这种“重”海水,又导致了同时期浅水区碳酸盐沉积物的δ13C和δ18O值明显增高。 | 张水昌 R L WANG 金之钧 张宝民 王大锐 边立曾 | 2006 | 地质学报2006，80，3： | 65 |
您所在的机构暂未开通此部分的功能，请联系管理员