丽江高美古台址和2m级望远镜项目(英文)     

陈东  王建成  许骏  罗国权  谭徽松  刘忠  张柏荣 《天文研究与技术》2003,(Z1)

自 1992年起云南天文台开始了在云南省西北部的天文选址。丽江高美古最终被选择作为未来中国地基天文光学观测的新址点。并且 ,在国家科技部 ,云南省政府 ,以及中科院的支持下 ,2m级天文望远镜项目在 2 0 0 0年 12月获得立项。在文中 ,我们简要的介绍了高美古台址的情况 ,并给出了 2 .4m望远镜的详细情况 ,以及其他相关情况。  相似文献   

EMERGY ANALYSIS OF GRAIN PRODUCTION SYSTEM IN JIANGSU AND SHAANXI PROVINCES     

LIUXin-wei CHENBai-ming ZHANGDing-xiang 《中国地理科学(英文版)》2004,14(3):209-214

Efficiency and sustainability of grain production are now important in China. In this study, the grain production systems of Jiangsu and Shaanxi Provinces were compared, to analyze their efficiency and sustainability in terms of utilization of natural resources, inputs of purchased energy and materials, and outputs. Flows of energy and materials between environment and human society were identified, and the natural and human work involved in generating inputs as materials or energy were valued in terms of equivalent amount of solar energy required for their production using emergy method. The results showed environmental resources were continually playing a less important role in the systems, when inorganic subsidiary emergy inputs increased drastically while organic ones decreased or increased little. Deterioration of input emergy structure affected the systems‘ efficiency and sustainability, resulting in emergy investment ratios and environmental loading ratios increasing while yield ratios and sustainability indices decreasing. In general, efficiency and sustainability of grain production in Jiangsu are worse than those in Shaanxi. This analysis also suggested that inorganic subsidiary emergy should be introduced properly, and peasants in Jiangsu should utilize natural conditions wisely while those in Shaanxi pay enough attention to soil and surface water conservation.  相似文献   

Southern Meridional Atmospheric Circulation Associated with IOD     

LIU Na CHEN Hongxia 《中国海洋大学学报(英文版)》2006,5(2):99-105

Using the monthly wind and sea surface temperature （SST） data, southern meridional atmospheric circulation cells associated with the Indian Ocean Dipole Mode （IOD） events in the Indian Ocean are for the first time described and examineS. The divergent wind and pressure vertical velocity are employed for the identification of atmospheric circulation cells. During the four different phases of the positive IOD events, the anomalous meridional Hadley circulation over the western Indian Ocean shows that the air rises in the tropics, flows poleward in the upper troposphere, sinks in the subtropics, and returns back to the tropics in the lower troposphere. The anomalous Hadley circulation over the eastern Indian Ocean is opposite to that over the western Indian Ocean. During positive IOD events, the meridional Hadley circulation over the eastern Indian Ocean is weakened while it is strengthened over the western Indian Ocean. Correlation analysis between the IOD index and the indices of the Hadley cells also proves that, the atmospheric circulation patterns are evident in every IOD event over the period of record.  相似文献   

Modelling the April 15 spectrum of Supernova 1993 J     

Zhang Qing  Wang Li-fan  Hu Jing-yao  P. A. Mazzali  Wang Zhen-ru 《Chinese Astronomy and Astrophysics》1995,19(4):426-431

We present the modeling of the ultraviolet and optical spectra obtained simultaneously on 1993 April 15 with the HST and at Lick Observatory. A Monte Carlo code is employed in the modeling and a comparison is made between models reported by different groups. With an atmosphere similar to the Sun in chemical composition, the observed spectral lines are well reproduced by a power law density structure of index around 20 except the strong H and HeI λ5876 lines which have peculiar absorption profiles. The photospheric velocity is found to be 9500 km/s and the blackbody temperature of the spectrum is 7990 K. For H and HeI λ5876, we suggest a two-component density structure which has a smoother layer located immediately outside the steeply decreasing inner envelope. The power law indices are most probably 20 and 3, respectively, with the transition point at about 13 000 km/s. In addition, this outer smooth layer serves to flatten the far UV spectrum as observed.  相似文献   

Isolation and pharmacological activities of bromophenols from Rhodomela confervoides     

Han Lijun  Xu Nianjun  Shi Jiangong  Yan Xiaojun  Zheng Chengkui 《中国海洋湖沼学报》2005,23(2):226-229

Four bromophenols were isolated from the extract of marine red alga,Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods inclding IR, MS, 1D, and 2D-NMR techniques, their structures were elucidated as (1) 3-bromo-4,5-dihydroxy benzoic acid methyl ester; (2) bis (2,3-dibromo-4,5-dihydroxybenzyl) ether; (3) 3,4-dibromo-5-(methoxymethyl)-1,2-benzenediol and (4) 3-bromo-4,5-dihydroxy-benzaldehyde. Compound 1 was first isolated from the algae in nature, and 1, 4 were found to have selective cytotoxic activities against KB, Bel 7402 and A549 cells, 2 showed powerful antibacterial activities againstStaphylococcus aurens andPseudomonas aeruginosa. Supported by National “863” Program (No. 2004AA625030, 2001AA620503), Quingdao marine sciences project (No. 04-2-NN-26) and Key Knowledge Innovative Project of the Chinese Academy of Sciences (KZCX3-SW-215).  相似文献   

用遗传算法解算病态方程   总被引：7，自引：1，他引：6  

曾群意  欧吉坤 《大地测量与地球动力学》2003,23(3):93-97

对应用遗传算法解决病态方程问题进行了探讨。利用拟合法而不是通过法方程求解参数，从而避免了法方程系数求逆，使病态方程的解答有了较好的结果。通过模拟计算并和其他方法进行比较，证明该方法是可行的和有效的。  相似文献   

同震阶变异常的特征与机制分析     

李兰生  刘建华 《大地测量与地球动力学》1992,(3)

本文对徐州地震台JB—72水平摆倾斜仪1988年11月至1989年5月间所记录到的24次同震阶变进行了深入分析,认为:a.造成同震阶变的原因是多方面的,而反应了地球应变场准静态调整的同震阶变才是有价值的价变异常;b.多观测手段的地震台站,同震阶变应该在不止一台仪器上得到响应。  相似文献   

宁远保安地区基性─超基性火山岩基本特征     

陈必河 《湖南地质》1994,(4)

本文论述了保安地区火山岩的地质、岩石、副矿物、岩石化学、微量元素、稀土元素、稳定同位素、火山岩相及火山机构等特征。并对其演化规律、形成机制与成矿作用的关系，作了初步探讨。  相似文献   

星际A型CH_3CH－H_2含超精细能级的碰撞跃迁速率系数的理论计算     

裴春传  曾琴 《天文学报》1995,(1)

本文作者利用ＩＯＳ近似模型，计算了星际分子云条件下Ａ型ＣＨ３ＣＮ－Ｈ２含超精细能级的碰撞跃迁速率系数。温度范围是２０Ｋ－１４０Ｋ。为研究分子云与恒星形成区的物理、化学性质提供了有用的基础分子数据。  相似文献   

On a new species ofPavlova (Prymnesiophyceae) from China     

C. K. Tseng  Chen Jiaofen  Zhang Zhefu 《中国海洋湖沼学报》1992,10(1):23-30

Pavlova viridis sp. nov. is described on the basis of light and electron microscope observations. The material was collected from the coast of haiyang county of Shandong, China. It is characterized by 1) yellowish green to green chloroplast, 2) rudimentary short flagellum 0.3 μm long and hook-shaped, 3) long flagellum with small spherical knob-scales, 4) absence of pyrenoid and stigma, and 5) marine habitat. This new species andP. salina seem to be most closely related to each other but their colour, the insertion of their three appendages, the shape of their knob scales, and their cell periplasts are quite different from one another. Contribution No. 1879 from the Institute of Oceanology, Academia Sinica  相似文献