浙江长兴二叠系和三叠系界限地层的碳同位素   总被引：15，自引：0，他引：15       下载免费PDF全文

陈锦石  邵茂茸  霍卫国  姚御元 《地质科学》1984,(1):88-93

研究海相碳酸盐岩的碳和氧同位素已有三十多年,积累了数千个数据,其目的在于研究古海洋碳和氧同位素的演变。在此期间,一部分研究者认为,海相碳酸盐岩的δ¹³C值在0±2范围内变化,未表现出与地质时代相关的变化趋势(Clayton和Degens,1959;Degens和Epstein,1962;Keith和Weber,1964;Galimov,1965;Becker和Clayton,1972;Schidlowski等,1975)。但是,另一些学者,如Jeffery等(1955),Baertschi(1975),Compston(1960),Weber(1967),Garrels和Parry(1974)却认为,海相碳酸盐岩的δ¹³C值随地质时代而有规律地变化。  相似文献   

锆石的裂变径迹年龄测定技术          下载免费PDF全文

陈祥高  张忠奎  臧文秀 《地质科学》1984,(1):94-97

六十年代初发展起来的核裂变径迹测定年龄技术,已在地质年代学、宇宙年代学和考古工作等领域得到了广泛应用。裂变径迹测定年龄技术,是应用各种天然矿物或材料中微量杂质铀的自发裂变碎片,在绝缘固体介质中产生的辐射损伤痕迹(即裂变径迹)测定年龄的方法。该法的优点之一是应用范围广,在火成岩、沉积岩和变质岩中常可找到合适的测定对象。  相似文献   

“福建-岭南地块”质疑   总被引：1，自引：0，他引：1       下载免费PDF全文

杨志坚  陈玉华 《地质科学》1984,(3):244-252

亚洲大多数地质学家认为,渤海、东海、黄海和日本海等海域,是新生代逐渐形成的。这样,就有理由认为,今天的我国东部大陆与朝鲜半岛和日本列岛,在前新生代的地质构造发展,是一脉相连的。关于它们之间的连接图式,日本地质学家小林贞一,在三十年代初曾提出“秦岭-汉城地轴”,五十年代初又提出“福建-岭南地块”之说。  相似文献   

太行山区元古代早期和中期地层的古地磁学测定结果及其地质意义   总被引：1，自引：0，他引：1       下载免费PDF全文

刘椿  王启超  张建中  陈伯延  袁相国  陈惠霞  刘海山 《地质科学》1984,(4):455-460

最近十余年来,我国古地磁学工作者曾对南方震旦纪地层以及北方蓟县的元古代地层做过一些古地磁学测定,并且对某些地质现象进行了解释。但是,对再早一些时期岩石的古地磁学研究仍属空白。地球的基本磁场主要起源于地球内部,它的参量必然反映地球的内部特征。按照地磁场的轴向地心偶极子假定,古地磁学的典型研究成果——视古地磁极移动轨迹应与地壳的构造发育演化过程有着内在的联系。太行山区是华北地台中、下元古界一个颇为发育的地区,本文简要报道作者对分布在该区地质年龄约为-2300百万年至-1650百万年的滹沱超群和长城系的古地磁学初步测定结果,并结合太行山区元古代早期和中期的大地构造问题提出粗浅的看法。  相似文献   

THE ASIAN SUMMER MONSOON AND ITS RELATIONS TO THE RAINFALL IN CHINA     

Chen Longxun  Luo Shaohu  Shen Rugui 《大气科学进展》1984,1(2):263-276

In this paper, four problems are discussed: (1) the monsoon circulation over southern Asia; (2) the seasonal variation of the general circulation of the atmosphere; (3) the influence of the monsoon on the rainfall in southwestern China; and (4) the source region of water vapor for the rainfall in the Changjiang valley.  相似文献   

Uncoupled multi-layer model for the transfer of sensible and latent heat flux densities from vegetation     

J. Chen 《Boundary-Layer Meteorology》1984,28(3-4):213-225

The sensible heat flux density C and the latent heat flux density E are coupled in the case of a multi-layer model of vegetation. Therefore two linearly independent combinations of C and E, the enthalpy flux density H and the saturation heat flux density J, are introduced. Two electrical analogues, for H and J, are designed. They are equivalent to the resistance scheme for C and E, but uncoupled. Penman's formulas for C and E, which are applicable only to single-layer models, can be expressed equivalently in terms of H and J. This version of Penman's formulas can be extended easily to multi-layer canopies.  相似文献   

The medium-range variations of the summer monsoon circulation system over east asia     

Chen Longxun  Jin Zuhui 《大气科学进展》1984,1(2):224-245

The Asian monsoon circulation system can be divided into two subsystems, i.e., the East Asian monsoon system(EA MS) and the Indian monsoon system (IMS). In this paper the main elements including the Indian monsoon trough, the South Asian high. the upper easterly jet etc. and the interactions between EAMS and IMS arc dealt with. The basic emphasis is put on the medium-range variations of the EAMS. Some significant results arc obtained.  相似文献   

Design and test of an improved scheme for global spectral model with reduced truncation error   总被引：2，自引：0，他引：2  

Chen Jiabin  Ji Liren  Wu Wanli 《大气科学进展》1987,4(2):156-168

An improved scheme of spectral model has been investigated in this paper. Through the introduction of a reference atmosphere, prognostic variables become smoother on the tilled sigma-surface over mountains or a frontal zone, and thus truncation errors are reduced. As a result, the problems about Gibbs waves and negative value of model topography on the sea, which are encountered in the current spectral model in the world, can be solved by the improved scheme. For comparison we have performed the numerical integrations of barotropic and baroclinic Rossby-Haurwitz waves, as well as the prediction of real cases with the improved scheme and the current scheme of spectral model. These results show that the scheme presented in the paper is better than the current scheme of spectral model.  相似文献   

渤海湾西部海陆风的空间结构   总被引：12，自引：1，他引：12  

于恩洪  陈彬  白玉荣 《气象学报》1987,45(3):379-381

海陆风虽然只是距海岸线两侧几十公里的一种中尺度现象,但它对沿海一带的天气有很大的影响。它不仅对大范围的空气运动有作用,而且可以改变局地气候。 研究海陆风,对进一步开发利用沿海风能资源,弄清空气污染规律和中小尺度天气的物理机制,提高短时天气预报准确率都有重要意义。 作者在1983年—1984年间的春、秋、夏、冬分别进行了有关海陆风观测。观测站的分布见图1。  相似文献   

NUMERICAL SOLUTION TO THE PROBLEM ON DIFFUSION OF CATALYTIC AGENTS RELEASED FROM AN AIRPLANE          下载免费PDF全文

Shen Yiming  Chen Jihang 《Acta Meteorologica Sinica》1987,1(2):190-197

A solution to the problem on diffusion of catalytic agents released from an airplane is sought.The variation of falling velocities of agent particles with the altitudes is taken into account in the study of the problem.A comparison is also made between the calculated results obtained by using the finite-difference method and those by using the analytic method,the similarities and the differences between the two methods are revealed.  相似文献