Impacts of the Detection of Cassiopeia A Point Source

Very recently the Chandra first light observation discovered a point-like source in the Cassiopeia A supernova remnant. This detection was subsequently confirmed by the analyses of the archival data from both ROSAT and Einstein observations. Here we compare the results from these observations with the scenarios involving both black holes (BHs) and neutron stars (NSs). If this point source is a BH, we offer as a promising model a disk-corona type model with a low accretion rate in which a soft photon source at approximately 0.1 keV is Comptonized by higher energy electrons in the corona. If it is an NS, the dominant radiation observed by Chandra most likely originates from smaller, hotter regions of the stellar surface, but we argue that it is still worthwhile to compare the cooler component from the rest of the surface with cooling theories. We emphasize that the detection of this point source itself should potentially provide enormous impacts on the theories of supernova explosion, progenitor scenario, compact remnant formation, accretion to compact objects, and NS thermal evolution.     

磁层顶的法向和形状

利用ISEE1& 2 ,AMPTE/IRM和IMP8的高分辨率数据 ,以及MV和TD分析法首次给出了在同一辨认原则下找到的所有磁层顶穿越的法线方向 .在此基础上 ,用分段拟合法研究了磁层顶的平均位形 .结果表明 :(ⅰ )大多数磁层顶穿越是切向间断面 ;(ⅱ )赤道面内的磁层顶存在着某种不对称性 ;(ⅲ )无论行星际磁场南向还是北向 ,夜间一侧的磁层顶截面的张角明显大于白天一侧 ,现有经验模型采用的简单单一曲线可能难以完整描述整个磁层顶的位形 .     

海拔高度对土壤温度的影响(节译)

对土壤温度的季节性变化,曾进行了广泛的研究。其中如何区分气象因子和土壤物理特性对地温的影响感到因难。本文通过实例证明,至少在英国,后者的影响和前者相比是次要的;其次的难题是所能得到的多数土壤温度资料是09时(世界时)的定时记录。本文指出,仔细考虑所能得到的有限的连续观测资料,可以在一定程度上解决这难题。最后文章指出,在夏天,土壤温度随海拔的升高而大辐度的下降(比气温降得快),在冬天,地温随海拔的升高降温减慢,有时甚至增温,多数情况下,比气温降温小,这些重要的现象,认为可以得到解释。     

野外地质尺

使用所推荐的野外地质尺可以迅速和简捷地做出图表资料,由于这种尺可以代替一些工具,因而使用起来方便.此外,还能节约大量的时间(见图).     

Rapid increase in copper concentrations in a new marina, San Diego Bay

Concentrations of copper in water rose rapidly following the introduction of boats to a new marina in San Diego Bay. Two months after the marina reached half its capacity, a majority of water samples exceeded chronic and acute criteria for dissolved copper, and copper concentrations in several samples exceeded the highest concentrations observed in another marina that has been listed as an impaired water body. A box model suggested that a small fraction of the leached copper was sequestered in sediment. Copper concentrations in water entering the marina from the bay was more than half the chronic concentration limit, so only 50% of marina boat capacity could be accommodated without exceeding the chronic criterion more than 50% of the time. Copper concentrations in water may increase rapidly following boat introduction in small marinas, but could return to pre-introduction levels by controlling boat numbers or reducing use of copper-based paints.     

不同围压下岩石中泊松比的各向异性

由弹性波纵横波速比计算得到的泊松比,在利用地震波反演地下结构和物质组成时,可以提供比单纯地利用纵波或者横波波速更强的约束. 为了研究不同岩石中泊松比及其各向异性随围压的变化,选取19块典型的岩石样品,在不同围压下沿相互正交的3个方向同时测量纵、横波速度,并通过计算得到了泊松比及其各向异性. 结果表明,在大部分样品中泊松比各向异性与纵波速度各向异性有一定的相关性,但在有的样品中泊松比各向异性与纵波速度各向异性没有明显的关系,甚至表现出完全相反的变化规律. 由于泊松比也表现出很强的各向异性,在排除微裂隙的影响后有的仍可以达到30髎以上,在利用实际地震波传播数据通过泊松比反演地下物质结构时必须考虑其各向异性的影响.     

基于开放互操作标准的分布式地理空间模型共享研究

传统的单机环境和封闭式网络环境由于有限的资源利用能力, 难以充分支持分散地学数据、模型等资源的共享与应用集成。基于网络环境的信息交换特点, 提出了分布式地理空间模型共享的服务体系。该体系以数据、模型、元数据等互操作要素为核心, 通过网络将数据、模型等网络节点进行开放式耦合。针对地理空间模型服务的互操作问题, 提出了分布式环境下的模型共享服务交互接口, 该接口定义了模型服务元数据、模型服务的交互操作、模型服务的通讯方式等交互规则, 尽可能地降低模型服务与模型终端之间在数据交换、功能调用等方面的互操作困难。为了降低将模型共享为模型服务的实现难度, 设计和开发了地理空间模型共享平台, 并介绍了在该平台上发布地理空间模型的2种方法。最后介绍了研究成果在Prairie生态模型共享方面的应用实践。     

RECORD OF BLOCK ROTATION AND MAGNETIC FIELD REVERSALS IN THE TETHYAN HIMALAYA (HIDDEN VALLEY, CENTRAL NEPAL)

RECORD OF BLOCK ROTATION AND MAGNETIC FIELD REVERSALS IN THE TETHYAN HIMALAYA (HIDDEN VALLEY, CENTRAL NEPAL)     

SERPENTINIZATION OF THE MANTLE WEDGE BY FLUIDS DERIVED FROM CONTINENTAL CRUSTAL MATERIAL: EVIDENCE FROM Nd ISOTOPIC SIGNATURES OF SERPENTINITES (TSO MORARI DOME,ELADAKH)

SERPENTINIZATION OF THE MANTLE WEDGE BY FLUIDS DERIVED FROM CONTINENTAL CRUSTAL MATERIAL: EVIDENCE FROM Nd ISOTOPIC SIGNATURES OF SERPENTINITES (TSO MORARI DOME,ELADAKH)1　deSigoyerJ ,GuillotS .Glaucophane bearingeclogitesintheTsoMoraridome (easternLadakh ,NWHimalaya) [J] .Euro peanJournalofMineralogy ,1997,9:10 73～ 10 83. 2　deSigoyerJ,ChavagnacV ,VillaIM ,etal.DatingtheIndiancontinentalsubductionandcollisionalthicke…