钱塘江和信江间的越岭运河试析     

祝示康  王宗涛  赵洛金  王成农  张福祥 《地理研究》1988,7(4):54-63

本文从钱塘江与信江间的沟通与河系网络关系,分析了越岭运河的重要意义.对择选区的自然条件作了评述,并对选择路线和运河型式的不同方案作了比较研究.  相似文献   

海原断裂的古地震及特征地震破裂的分级性讨论   总被引：14，自引：0，他引：14       下载免费PDF全文

冉勇康  邓起东 《第四纪研究》1998,18(3):271-278

海原断裂高湾子地点三维探槽揭露了全新世5次事件的位移量。由老至新走滑位移量分别为：5．6±2．3,1．5±1．1,1．5±1．2,2±1和7±0．5m。古地震对比反映出,晚第四纪以来断裂带发生的14次事件中,仅有2～3次事件为贯穿全断裂的破裂事件,说明古地震并不都具有1920年海原大地震的强度。特征地震和段落存在分级性。破裂分级的现象不是孤立的,但多发生在走滑断裂上。  相似文献   

西部干旱区内陆河流域脆弱生态环境研究进展——以新疆塔里木河流域为例   总被引：28，自引：1，他引：28  

王让会  游先祥 《地球科学进展》2001,16(1):39-44

干旱区内陆河流域的脆弱生态环境是在长期的演变过程中形成的。人类对自然资源，特别是水资源的不合理利用，加剧了脆弱生态环境的演变过程，影响了干旱区的生态安全。从国内外脆弱生态环境研究进展状况以及以塔里木河流域为典型代表的干旱区内陆河流域自然地理特征分析中，揭示了脆弱生态环境的特征及演变规律。近一个世纪以来，人们针对内陆河流域的人与环境问题、水资源问题（包括水文地质、水资源变化特征、水环境变化特征）、气候以及自然地理学领域做了大量的研究工作。随着国家西部发展战略的逐步实施，干旱区内陆河流域将成为西部地区重要的资源开发与经济发展潜力巨大的地区。  相似文献   

Sensitivity of a regional climate model to land surface parameterization schemes for East Asian summer monsoon simulation     

Wenkai Li  Weidong Guo  Yongkang Xue  Congbin Fu  Bo Qiu 《Climate Dynamics》2016,47(7-8):2293-2308

  相似文献   

地对空微波遥感温度、水汽廓线的联合求解   总被引：2，自引：0，他引：2  

薛永康  林海 《气象学报》1984,42(4):423-430

本文讨论了地对空微波遥感时5毫米吸收带各通道间的相关性,对各种地对空温度反演方法进行了比较。并应用蒙特卡洛法和统计控制法进行了温度、水汽的联合反演,挑选了最佳反演通道,取得了较为满意的数值结果。  相似文献   

岫岩玉的穆斯堡尔谱学研究     

邱兆明  黄俊杰 《矿物岩石》1992,12(3):27-33

岫岩玉是我国的主要玉种之一,属于蛇纹石玉。在X射线衍射、红外光谱、可见光吸收谱,及电子显微镜等项研究确切查明主体矿物为叶蛇纹石的基础上,选两个优质玉样进行~(57)Fe穆斯堡尔谱学研究。岫岩玉的穆斯堡尔谱由两组四级双峰构成,第一组双峰(δ=1.12,△=2.73与2.72mm/s)系由镁氧八面体中的Fe~(2+)形成,另组双峰(δ=0.35与0.36,△=0.63与0.55mm/s)反映的是镁氧八面体中的Fe~(3+),Fe~(3+)/Fe~(2+)分别为0.90与0.78。铁是参与叶蛇纹石晶格的组分;Fe~(3+)与Fe~(2+)均处镁氧八面体中;Fe~(3+)/Fe~(2+)近于与小于1是制约它呈绿色的主要因素。  相似文献   

A New Index Developed for Fast Diagnosis of Meteorological Roles in Ground-Level Ozone Variations     

Weihua CHEN  Weiwen WANG  Shiguo JIA  Jingying MAO  Fenghua YAN  Lianming ZHENG  Yongkang WU  Xingteng ZHANG  Yutong DONG  Lingbin KONG  Buqing ZHONG  Ming CHANG  Min SHAO  Xuemei WANG 《大气科学进展》2022,39(3):403-414

China experienced worsening ground-level ozone(O₂) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T₂), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T₂× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O₂pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O₂concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O₂pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O₂variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.  相似文献   

黄铁矿及毒砂中负氧化数金的发现及判定     

Oiu Zhaoming  Rang Mei  Qiu Longwei 《吉林大学学报(地球科学版)》1994,(2)

作者在以突破金的氧化态（价态）为先导的研究中，使用光电子能谱对９个金矿区的黄铁矿与毒砂进行了研究。发现它们之中广泛出现有结合能为８３（８２．８～８３．２）ｅＶ的峰，经分析对比后，指认它为Ａｕ峰（４ｆ＿（７／２）。但它的结合能小于Ａｕ￣０（约８４ｅＶ），更小于Ａｕ￣（１＋）及Ａｕ￣（３＋）．根据结合能与氧化态的关系，判定８３ｅＶ峰为负氧化数金（负价金）所引起。即黄铁矿与毒砂中存在有负氧化数金。  相似文献   

Paleoseismological Study of the Late Quaternary Slip-rate along the South Barkol Basin Fault and Its Tectonic Implications, Eastern Tian Shan, Xinjiang     

WU Fuyao  RAN Yongkang  XU Liangxin  CAO Jun  LI An 《《地质学报》英文版》2017,91(2):429-442

The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault(SBF) in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Quaternary activity, paleoseismology, and deformation characteristics of the fault provide important clues for understanding the tectonic process of the eastern Tian Shan orogen and implementing seismic mitigation. Through interpretation of high-resolution satellite images, unmanned aerial vehicle measurements, and detailed geological and geomorphic investigations, we suggest that the fault exhibits clear left-lateral slip along its western segment. Paleoseismic trenches dug near Xiongkuer reveal evidence of six large paleoearthquakes. The four latest paleoearthquakes were dated: the oldest event occurred at 4663 BC–3839 BC. Data on the horizontal offsets along the probable 1842 Barkol earthquake coseismic rupture suggest clear multiple relationships between cumulative offsets and possible ~4 m of coseismic left-lateral slip per event. From the cumulative offsets and 14 C sample ages, we suggest an average Holocene left-lateral slip rate of 2.4–2.8 mm/a on the SBF, accounting for ~80% of lateral deformation within the entire eastern Tian Shan fault system. This result is comparable with the shortening rate of 2–4 mm/a in the whole eastern Tian Shan, indicating an equal role of strike-slip tectonics and compressional tectonics in this orogen, and that the SBF may accommodate substantial lateral tectonic deformation.  相似文献   

龙门山断裂带映秀-北川断裂的古地震及其复发间隔初步研究(英文)   总被引：2，自引：0，他引：2  

冉勇康  Xiwei Xu  Wenshan Chen  Lichun Chen  Shaopen Dong  Hu Wang 《国际地震动态》2010,(6):28-29

The activity of the Longmenshan thrust belt has concentrated mainly on its Wenchuan-Maoxian Fault, Yingxiu-Beichuan Fault, and Guanxian-Jiangyou fault since the Quaternary time.  相似文献