Deep Metallogenic Speciality of Lithosphere in Amur Province, Russia

When the spatial parameters of regional ore-magmatic systems of Russian Amur Province is estimated,the deep seismic results and gravity data are most often used. In the first case,the correlation of ore-deposits with the thickness of the sialic crys-talline complexes and the crust bottom depth are considered (Kokorin, 1988; Sukhov etal., 2000; Moiseenko,1996),in second case the spatial laws of deposit distribution relative to the regional Bouge minimums explained by “granitization”and lowd…     

The X-ray Background (Deep Fields, Luminosity Functions and Type-Ⅱ Quasars)

1　IntroductionDeepX raysurveysindicatethatthecosmicX raybackground (XRB)islargelyduetoaccretionontosupermassiveblackholes,integratedovercosmictime .Inthesoft (0 .5-2keV)bandmorethan 90 %oftheXRBfluxhasbeenresolvedusing 1 .4MsecobservationswithROSAT[1 ]andrecently 1 -2MsecChandraobservations [2 ,3 ]and 1 0 0ksecobservationswithXMM Newton [4] .Intheharder (2 -1 0keV)bandasimilarfractionofthebackgroundhasbeenresolvedwiththeaboveChandraandXMM Newtonsurveys,reachingsourcedensitiesofabou…     

Generation of Reactive Oxygen Species in Different Fractions of the Coelomocytes of Holothurian Eupentacta fraudatrix in Response to the Thermostable Toxin of Yersinia pseudotuberculosis in Vitro

Pure fraction (92% - 95%) of phagocytes (FP) and a mixture of amoebocytes (62%) and morula cells (38 % )-FPMC- of the holothurian Eupentacta fraudatrix ( Holothuroidea,Dendrochirota ) were obtained by using ficoll-verographine step gradient. Basal production of reactive oxygen species (ROS) in FP quantified by using reduction of nitroblue tetrazolium (NBT) was more than twice that in FPMC. Thermostable toxin of Yersinia pseudotuberculosis (TST) at differentconcentrations ( 0.2; 0.5; 2.5 μg/ml, but not 0.1 μg/ml) stimulated NBT reduction in FPMC after 24 h incubation. In FP, TST at concentrations of 0.1 and 0.2 μg/ml inhibited and at concentrations of 0.5 and 2.5 μg/ml stimulated NBT reduction after 24 h incubation. Maximal effect was observed in FP and FPMC at TST concentrations of 0.5 and 0.2 μg/ml, respectively. Addition of catalase (0.7 μg/ml) to the cells treated with TST (2.5 μg/ml) was followed by a decrease in NBT reduction compared to that under toxin treatment alone. TST stimulated superoxide dismutase activity in ccncentration-dependent manner (maximum at 0.5 μg/ml concentration in FP) after 24 htreatment, and this stimulation was prevented by a commercial catalase. Plant lectin concanavalin A stimulated NBT reduction more than 5-fold in FPMC compared to the control. With addition of TST, lectin stimulated ROS to lesser extent than that with lectin alone. When catalase, TST, and lectin were added into the FPMC simultaneously, ROS increase was similar to that under lectin treatment alone. On the whole, data obtained indicated that ROS generation in holothurian coelomocytes especially occurs in both stimulated and not stimulated phagocytes, and that changes in ROS production by these cells may be one of the mechanisms of antibacterial protection of holothurians.     

Convective Boundary Layer in the Region of the Monsoon Trough-A Case Study

A case study of the convectively driven monsoon boundary layer has been carried out using the aerological observations at four stations in the region of monsoon trough during Monsoon Trough Boundary Layer Experiment (MONTBLEX) 1988. The Convective Boundary Layer (CBL) in the region of monsoon trough did not show double mixing line structure. A single mixing line representing the CBL with different stabilities with respect to the convective activities was observed.     

地球早期历史研究的进展——1970—1980年研究工作述评

引言自1970年即前次佩思太古宙问题的国际讨论会以来,有关太古宙问题的研究已取得很大的进展。第一次讨论会主要涉及到绿岩带和经济地质问题。在这十年间,研究工作已扩大到其他领域:甚至在格陵兰和拉布拉多发现了比以前记录到的更老的岩层;从行星学研究取得了重要的反馈(feed-back);为了填补直接知识的空白,对地球-月球双星系统、大气圈、海洋的成因和生命本身进行了大量的研究,而且现在已扩大到4500—     

Anisotropic Beam Model for the Spectral Observations of Radio Burst Fine Structures on 1998 April 15

A fine structure consisting of three almost equidistant frequency bands was observed in the high frequency part of a solar burst on 1998 April 15 by the spectrometer of Beijing Astronomical Observatory in the range 2.6-3.8GHz. A model for this event based on beam-anisotropic instability in the solar corona is presented. Longitudinal plasma waves are excited at cyclotron resonance and then transformed into radio emission at their second harmonic.The model is in accordance with the observations if we suppose a magnetic field strength in the region of emission generation of about 200G.     

南非食肉动物的大小和第四纪气候变化的关系

通过对非洲17种食肉类动物的切齿长度和南纬之间关系的分析来确定其个体是否就象伯格曼定理(Bergman｀s Rule)所指出的那样,在寒冷的气候中趋于变大.由于得到现代资料的支持,中、晚第四纪的温度可以从一些化石样品中平均切齿长度来推断,比如采自南非开普省的Equus洞穴、Elandsfonfein、SeaHarvest、Duinebontein和SwartkliP等地的样品.该项研究有问题的一点就是把切齿长度和纬度作为必要条件,但是,它们不是分别为身体大小和温度的完全代替物.对某些种来说,另一困难就是,比较少的可利用的现代标本是不同纬度分布的结合.但仍有14个种的切齿长度随纬度往南而趋于增加,而堆积在较冷条件下的那些化石标本,其相同种的切齿较长,这件较冷条件是从沉积学、孢粉学或地球化学资料推测的.如果有不同纬度的大量现代样品,那么各种切齿长度和纬度之间数学关系的精确度可以对南非过去温变作定量估算.     

14C测定年代报告(二)

本报告公布本实验室1984年9月至1986年2月测定的¹⁴C年代数据48个。