铀矿床的天然类似物研究

本文叙述连山关铀矿床内的地下水和铀矿体中的12 9I和2 39Pu的测量结果。研究表明 ,铀矿床内的地下水把12 9I从铀矿石中淋滤出来 ,12 9I在地质环境中具有活泼的地球化学特征 ;铀矿体中积累的2 39Pu自该矿床形成 190 0Ma以来未发生迁移。     

X-ray analysis of the cluster 3C 129

The cluster 3C 129 is classified as a rich cluster. An analysis of the properties of the cluster 3C 129 from ROSAT PSPC and HRI, Einstein IPC, and EXOSAT ME observations is presented. The mean temperature from a joint fit of the ROSAT PSPC and EXOSAT ME data is 5.5(±0.2) keV. The luminosity is 0.6×10⁴⁴ erg s⁻¹ in 0.2–2.4 keV and 2.7×10⁴⁴ erg s⁻¹ in 0.2–10 keV. We find a cooling flow with a rate of ∼84 M_⊙ yr⁻¹. The central gas density is 6×10⁻³ cm⁻³, and the ICM mass is 3.6×10¹³ M_⊙. The total cluster mass is ∼5×10¹⁴ M_⊙. The X-ray morphology shows an east–west elongation, which is evidence for a recent merger event. The radio source 3C 129.1 is located near the X-ray centre. Another cluster member galaxy (the radio galaxy 3C 129) is a prototype of head-tailed radio galaxies, and is located in the west part of the cluster. The tail points along the gradient of intracluster gas pressure. There are no significant point X-ray sources associated with the AGNs of the two radio galaxies.     

Phylogeography of Acesta clams from submarine seamounts and escarpments along the western margin of North America

Genetic connectivity and habitat characteristics were examined in two species of Acesta clams (Bivalvia: Limidae) from submarine seamounts and continental slopes along the western North America margin. Two species were identified from dive videos obtained with submarine remotely operated vehicles that surveyed a 2200‐km range between 27° and 46° N latitude. Acesta sphoni was only found at shallower habitats (545–860 m depth) in the southern part of this range, whereas Acesta mori was more abundant and widely distributed in deeper habitats (1029–1996 m). Both species occurred on seamounts and on the walls of submarine canyons and continental slopes. Segregation of these species by depth exposes them to correlated differences in water temperatures and dissolved oxygen concentrations. Ninety‐eight individuals sampled from seven seamounts and one escarpment locality were characterized with DNA‐barcodes based on 643 base pairs of mitochondrial cytochrome‐c ‐oxidase subunit I (COI). Further analysis of these sequences revealed no significant geographical subdivision across the sampled range. This lack of differentiation suggests ongoing genetic exchange between the seamount populations and those possibly distributed along the continental margins. Examination of regional bathymetric profiles suggested that an abundance of suitable habitat might exist along these margins.     

“嫦娥一号”探月卫星发射期间太阳活动现象监测

为发射“嫦娥一号”探月卫星,保障其在空间环境运行的安全和国家载人航天计划的正常实施,云南天文台全日面Hα色球望远镜为中国科学院空间环境研究预报中心实时提供太阳活动数据资料,协作完成特殊时期空间环境监测任务。     

Windows平台的计算机串口测试软件

串口数据测试对于应用研究而言，具有重要的实用价值。目前，常用的是基于DOS操作系统的测试软件，使用不便。基于应用研究工作之需要，使VC＋＋6．0开发了一套基于Windows平台的串口测试软件，可以运行于目前流行的操作系统Windows95，Windows98，以及Windows2000平台。     

Isotropic Homogeneous Universe with a Bulk Viscous Fluid in Lyra Geometry

Exact solutions are obtained for an isotropic homogeneous universe with a bulk viscous fluid in the cosmological theory based on Lyra’s geometry. The viscosity coefficient of the bulk viscous fluid is assumed to be a power function of the mass density. Cosmological models with time dependent displacement field have been discussed for a constant value of the deceleration parameter. Finally some possibilities of further problems and their investigations have been pointed out.     

县域尺度中国网络诈骗时空分布特征研究

随着互联网的发展和普及,违法犯罪活动逐渐向网络空间渗透,网络诈骗作为一种典型的网络犯罪,严重威胁社会治安稳定。基于裁判文书网数据库的25 597份网络诈骗一审判决书,采用自然语言处理技术提取了2017—2020年中国县域尺度网络诈骗案件,分析了网络诈骗的时空分布特征。空间自相关分析结果表明,网络诈骗案件多集中在东南沿海地区,包括江苏、浙江、上海、福建以及广东一带。随着时间的变化,2019年安徽、河南的聚集区逐渐消失,而湖南、重庆等地形成了明显的聚集区。网络诈骗犯罪者主要来自福建、湖北、河南、广东、湖南,不同省份的网络诈骗犯罪者分布模式有显著差异,江苏、浙江的网络诈骗犯罪者来源较为分散,广东、福建、河南的网络诈骗犯罪者来源相对集中。     

Subduction and Collision of the Jinsha River Paleo-Tethys: Constraints from Zircon U-Pb Dating and Geochemistry of the Ludian Batholith in the Jiangda–Deqen–Weixi Continental Margin Arc

The Jiangda–Deqen–Weixi continental margin arc(DWCA) developed along the base of the Changdu–Simao Block and was formed as a result of the subduction of the Jinsha River Ocean Slab and the subsequent collision. The Ludian batholith is located in the southern part of the DWCA and is the largest batholith in northwest Yunnan. Granite samples from the Ludian batholith yield an early Middle Permian age of 271.0 ± 2.8 Ma. The geochemical data of the early Middle Permian granitoids show high Si2 O, low P2 O5 and MgO contents that belong to calc-alkaline series and peraluminous I-type rocks. Their εHf(t) values range from-5.01 to +0.58, indicating that they were formed by hybrid magmas related to the subduction of the Jinsha River Tethys Ocean. The monzonite and monzogranite samples yield Late Permian ages of 250.6 ± 1.8 Ma and 252.1 ± 1.3 Ma, respectively. The Late Permian granitoids are high-K calc alkaline and shoshonite series metaluminous I-type rocks. Their εHf(t) values range from-4.12 to-1.68 and from-7.88 to-6.64, respectively. The mixing of crustal and mantle melts formed the parental magma of the Late Permian granitoids. This study, combined with previous work, demonstrates the process from subduction to collision of the Jinsha River Paleo-Tethys Ocean.     

A new identification method for five species of oysters in genus Crassostrea from China based on high-resolution melting analysis

The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetie studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I （COI） of five common Crassostrea species in China （including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas） and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers （Oyster- COI-1）, we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.