A Study of the Molecular Cloud S64 with Multiple Lines of CO Isotopes

We report on a study of the molecular cloud S64 with observations at millimeter wavelengths of multiple molecular lines of CO isotopes.A weak outflow is found,and its physical parameters are estimated.The departure of the core of S64 from the S64 HII region indicates that there are still other star formation activities in that region.     

The lower limit of the Doppler factor for a Fermi blazar sample

We selected 457 blazars(193 flat spectrum radio quasars, 61 lowsynchrotron peaked blazars, 69 intermediate-synchrotron peaked blazars and 134high-synchrotron peaked blazars) from the second Fermi-LAT catalog(2FGL) of γ-ray sources, which have X-ray observations. We calculated the lower limits for their Doppler factors, δγ, and compared the lower limits with the available Doppler factors and the apparent superluminal velocities in the literature.     

鲜水河断裂带现今断层运动短周期事件的发现与初步研究

根据鲜水河断裂带上连续动态地壳形变台阵数据，首次揭示了中国大陆板内断层现今运动的短周期现象，包括蠕变阶、蠕变坡和脉动等，其持续时间为数分钟至数十小时。发现其空间分布与断层分段（闭锁或活动段）有关；其时间分布与强地震孕育过程有关。蠕变过程符合Ｌｏｍｎｉｚ提出的对数蠕变函数，可能是断层面不均匀结构中的局部流变行为。断层短周期事件对揭示断层不均匀结构和微破裂过程动力学有重要意义，并可能发展为一种新的地震前兆     

养殖对虾暴发性流行病—中国对虾肝胰腺坏死病研究

1993年我国沿海各省市养殖对虾发生了暴发性流行病,造成了极大的损失。本文报导我们在浙江省舟山市调查和研究的结果,发现肝胰腺坏死杆状病毒和弧菌并发感染是引起对虾死亡的主要原因。     

Nonlinear influences on ocean waves observed by X-band radar

The purpose of this study is to discuss the influence of signal nonlinearity upon X-band radar observations. A method for estimating the degree of nonlinearity by bispectral analysis was applied and discussed. We found that bispectral analyses from spatial radar backscatter series are similar to results obtained from water level time series. In addition, the average nonlinear degree from radar backscatter is related to wind speed. The accuracy of wave observations derived by consideration of the nonlinear effect from radar backscatter was also investigated. The estimated error in wave height from the radar data is also related to the degree of nonlinearity. In order to improve accuracy, the modulation transfer function method was applied in order to eliminate the influence of nonlinearity.     

稀有金属矿物微区同位素定年与示踪

作为战略性关键金属矿产资源, 钨、锡、铌、钽、锂、铍、铷、铯、锆、铪、稀土等稀有金属, 在国民经济与国家安全方面有着重要的研究意义。稀有金属矿石矿物微区同位素定年与示踪, 是开展稀有金属矿床成矿作用研究的最直接手段, 具有整体分析无可比拟的优点。近年来, 钨锡铌钽锆铪稀土等稀有金属矿物微区U-Pb定年与Sr-Nd-Hf同位素示踪发展迅速, 而锂铍铷铯等稀有金属矿物微区Rb-Sr/Lu-Hf定年正蓬勃发展。本文综述了黑钨矿、白钨矿、锡石、铌钽矿(铌钽氧化物类矿物的简称)、独居石、磷钇矿、氟碳铈矿等稀有金属矿物微区U-Pb定年与Sr-Nd-Hf同位素示踪技术主要进展, 展望了锂云母、铁锂云母、铯沸石、钾长石(天河石)等微区Rb-Sr定年与磷钇矿、磷灰石、褐帘石、独居石、黑钨矿、白钨矿等微区Sm-Nd和Lu-Hf定年的广阔前景, 获得如下认识: (1)低铀矿物U-Pb定年, 除了采用高灵敏度磁式等离子质谱外, 元素成像技术能很好地揭示微量元素之间相关性, 进而快速锁定高U/Pb区域, 提高低铀矿物U-Pb定年成功率; (2)铌钽矿-锡石激光微区Hf同位素能够直接示踪花岗岩-伟晶岩稀有金属成岩成矿物质源区, 但这方面工作仍需进一步加强; (3)碰撞/反应池等离子质谱的出现, 使高Rb/Sr、Sm/Nd或高Lu/Hf比矿物的同位素定年成为现实, 是未来稀有金属激光微区同位素年代学发展的新方向; (4)实验方法研发与标准物质研制相辅相成、相互促进, 仍是当前迫切需要解决的关键技术难题。随着战略性关键金属日渐成为国内外成矿作用研究的热点, 钨锡铌钽锂铍铷铯锆铪稀土等稀有金属矿物微区同位素定年与示踪方法研究, 必将为我国新一轮稀有金属矿床学研究做出应有的学术贡献。

     

Grain size and geochemistry of surface sediments in northwestern continental shelf of the South China Sea

Eighty-six surface sediments collected from the northwestern continental shelf of the South China Sea (SCS) were analyzed for grain size distribution, calcium carbonate, organic carbon, and major and trace element compositions to investigate sediment provenance and factors controlling their geochemical composition. Sediments from the eastern continental shelf of Hainan Island have higher sand and lower clay content, while the samples from the nearshore Hainan Island have higher contents of gravel and clay. Calcium carbonate contents in samples show a positive correlation with water depth in northwestern shelf of SCS, suggesting that it is related to biological factors. However, the nearshore sediments have higher contents of organic carbon compared to those of the outer shelf, possibly suggesting that the terrigenous organic matter usually deposited in nearshore environments such as bays and estuaries. Compared with the upper continental crust, the samples have relatively lower contents of SiO₂ and Al₂O₃, higher than those of the Pearl and Red river sediments. The low contents of K₂O and Na₂O in sediments from the northwestern continental shelf are consistent with intense chemical weathering in the river basin due to the seasonally hot and humid climate regime. The sediments mainly consist of three components, including the gravel fraction composed of calcareous debris, the sand fraction composed of quartz, and the silt and clay fractions mainly composed of clay minerals. The content of each component depends on grain size, sediment source, biogenesis, and hydrodynamic conditions, which finally controls the chemical composition of the sediments. The distributions of Co/Al₂O₃, Cr/Al₂O₃, and Zr/Sc ratios for sediments in the northwestern continental shelf suggest that source rocks are mainly composed of felsic rocks rather than mafic rocks. There is a distinct difference in sediment source between eastern and western shelf sediments; the eastern shelf sediments are characterized by high Zr/Sc ratios mainly derived from the Pearl River, while the western shelf sediments have relatively low values of Zr/Sc indicating a main contribution possibly sourced from the Red River Basin. Terrigenous materials from Hainan Island usually influence the geochemistry of sediments deposited in the nearshore area.     

宝鸡岩体颜家河超单元岩浆反序演化特征

本文依据宝鸡岩体颜家河超单元各单元的岩石组构、矿物成分、岩石化学和地球化学等方面的资料，研究了它们由早到晚的变化特征，并将各种特征有机地联系在一起，发现该超单元岩浆从早到晚存在着反序演化的特点，即由偏酸性岩浆向偏基性岩浆演化，并建立了该超单元的岩浆演化模式。     

Isolation and characterization of 49 polymorphic microsatellite loci for Decapterus maruadsi using SLAF-seq,and cross-amplification to related species

Decapterus maruadsi is a commercially important species in China, but has been heavily exploited in some areas. There is a growing need to develop microsatellites promoting its genetic research for the adequate management of this fishery resources. The recently developed specific-locus amplified fragment sequencing (SLAF-seq) is an efficient and high-resolution method for genome-wide microsatellite markers discovery. In this study, 28 905 microsatellites (mono- to hexa-nucleotide repeats) were identified using SLAF-seq technology, of which di-nucleotide was the most frequent (13 590, 47.02%), followed by mono-nucleotide (8 138, 28.15%), tri-nucleotide (5 727, 19.81%), tetra-nucleotide (1 104, 3.82%), pentanucleotide (234, 0.81%), and hexa-nucleotide (112, 0.39%). One hundred and thirty-two microsatellite loci (di- and tri-nucleotide) were randomly selected for amplification and polymorphism, of which 49 were highly polymorphic and well-resolved. The average number of alleles per locus was 13.63, ranging from 4 to 25, and allele sizes varied between 110 bp and 309 bp. The observed heterozygosity ( H_o ) and expected heterozygosity ( H_e ) ranged from 0.233 to 1.000 and from 0.374 to 0.959, with mean values of 0.738 and 0.836, respectively. The polymorphism information content (PIC) ranged from 0.341 to 0.941 (mean=0.806). However, 12 loci deviated from Hardy-Weinberg equilibrium. Furthermore, transferability tests were also successful in validating the utility of the developed markers in five phylogenetically related species of family Carangidae. A total of 48 microsatellite markers were successfully cross-amplified in Decapterus macarellus, Decapterus macrosoma, Decapterus kurroides, Trachurus japonicus, and Selaroides leptolepis. The present microsatellites provided the first known set of microsatellite DNA markers for D. maruadsi, D. macarellus, D. kurroides, and D. macrosoma, and would be useful for further population genetic and molecular phylogeny studies as well as help with the fisheries management formulation and implementation of the understudied species.