Evaluating the reliability of microsatellite genotyping from low-quality DNA templates with a polynomial distribution model

Molecular studies using trace DNA, such as from museum specimens, ancient or forensic samples and samples obtained noninvasively, often have a common problem of low quality of DNA templates. Amplification errors, such as allelic dropout and false allele, may arise during polymerase chain reaction (PCR) using such samples. A mathematical model which treats homozygotes and heterozygotes discriminately has been developed to measure sample quality and compute the confidence level of using multipletube approaches. We use plucked hair samples collected from 26 individual Sichuan snub-nosed monkeys (Rhinopithecus roxel- lana) to test the model. In this case, a confidence level of 99% can be achieved by three positive PCRs. If the sample quality is very poor and requires many PCR replicates, an alternative multiplestep genotyping method is recommended. This model enables researchers to optimize experimental protocols through pilot studies and obtain reliable genetic information using noninvasive sampling method.     

二氟甲烷/四氟乙烷/1,1-二氟乙烷与N,N-二甲基甲酰胺/N,N-二甲基乙酰胺/二甘醇二甲醚工质对体系热力学分析

在实验测定了二氟甲烷(R32)-二甘醇二甲醚(DMEDEG)、R32-N,N-二甲基乙酰胺(DMAC)、1,1-二氟乙烷(R152a)-N,N-二甲基甲酰胺(DMF)、R152a-DMAC和R152a-DMEDEG 5个体系的气液相平衡数据的基础上，补充了文献中R32-DMF、四氟乙烷(R134a)-DMF和R134a-DMEDEG 3个体系的数据。采用PR方程为关联模型，比较了R32/R134/R152与DMF/DMAC/DMEDEG这8个工质对体系的气液相平衡行为。从化学结构出发，用氢键理论分析了这8个工质对的热力学行为，并结合制冷剂和吸收剂的热物性，解释了吸收制冷循环性能系数COP随发生温度的变化规律。     

Cytological mechanisms of interspecific incrossability and hybrid sterility between Oryza sativa L. and O. alta Swallen

Oryza sativa and O. alta belong to AA and CCDD genomes in Oryza, respectively. Interspecific repro-ductive isolation limits the transfer of favorable genes from O. alta into O. sativa. The cytological mechanisms of interspecific incrossability and hybrid sterility between O. sativa and O. alta were studied systematically in this paper. We indentified two cytological causes of interspecific incrossabil-ity. First, we observed embryo sac incompatibility that caused fertilization barriers of variable severity such as non-fertilization, fertilization stagnation and egg cell single-fertilization. Second, we observed hybrid inviability, the major cause for incrossability, apparent from hybrid embryo developmental stagnation and embryo abortion. Hybrid sterility included both embryo sac sterility and pollen sterility. The hybrid embryo sac was completely sterile and exhibited mainly embryo sac degeneration. Hybrid pollen was also sterile and mainly typical abortive. Hybrid sterility was mainly caused by severely ab-normal meioses of megasporocytes and pollen mother cells; it is the most important abnormality, being chromosome sterility. Several methods are suggested to overcome the interspecific reproductive iso-lation between O. sativa and O. alta.     

以本体为指导的Web网页信息抽取方法

针对Web网页中事物描述信息的特点,提出了一种通过本体指导网页信息抽取的方法。首先建立抽取对象的本体模型,并为本体属性概念添加定位信息映射模型,通过映射模型定位和分离样本页中包含语义信息的数据块,结合路径分析算法生成抽取规则,之后利用抽取规则对同类网页中的事物描述信息进行抽取,最后以资源描述框架（RDF）数据格式储存信息。抽取性能测试实验表明,抽取结果具有较高的准确率,与无规则抽取方法相比,具有更高的抽取效率。     

Passive seismic experiment and ScS wave splitting in the southwestern subbasin of South China Sea

The seismic experiment of 3D array of OBS in the southwestern sub-basin of the South China Sea(SCS) is briefly introduced in this paper.The data analysis of broadband OBS shows that totally 93 earthquakes with magnitude of Ms 6.0-6.9 and 10 earthquakes with magnitude above Ms 7.0 were recorded in high quality during this experiment,especially the catastrophic earthquake Ms 9.0 occurred in the east sea area of Japan on March 11,2011.The anisotropy parameters inversion of ScS wave of four events above Ms 7.0 indicates that the fast direction of shear wave is N58°E parallel to the ceased spreading ridge of the southwestern sub-basin of SCS(the slow direction is S35°E perpendicular to the spreading ridge),which means the spreading ridge is under compressing stress at present and the cessation of seafloor spreading is related to such stress field as well.     

超慢速扩张洋中脊NTD的蛇纹石化地幔:海底广角地震探测

非转换断层不连续(NTD)在超慢速扩张洋中脊高频度出现,其地壳速度结构与相邻的岩浆扩张中心(NVR)差别明显.结合表层断层多和减薄的地壳,说明NTD在超慢速洋中脊扩张理论、热液活动甚至矿产资源方面有十分重要的意义.本文使用2条海底广角地震测线的数据,使用射线追踪正反演的方法,获得了西南印度洋中脊28~29扩张段之间NTD下方的地壳及上地幔速度结构.结果表明:(1)NTD下方地壳较薄(3.2~4.5 km),洋壳层2厚约2.0 km,洋壳层3较薄(1.0 km)甚至缺失;(2)洋壳层2表层速度横向差异大,表明存在较多断裂;(3)洋壳层3出现低速区,成因可能是受浅部大断裂或地幔蛇纹石化作用影响;(4)上地幔顶部速度存在低速异常(7.2 km/s),结合NTD地壳较薄(5 km)和表层断裂多的特征,认为是上地幔发生大规模蛇纹石化作用导致低速,为进一步理解和区分莫霍面与蛇纹石化前缘(Serpentinization Front)提供了一个很好的例证.     

A new way to generate seismic waves for continental crustal exploration

An airgun experiment was conducted in a reservoir,with the total volume of the airgun array being 6000 cubic inch. The energy released by one excitation was estimated to be 6.68×106 J,which corresponded to a 3.4 kg TNT explosion. A 180 km long profile composed of 100 portable short period seismometers was deployed as a receiver system of the airgun signals. Two remarkable results can be drawn from the experiment: (1) the airgun explosion is harmless to the dam and the fish,and this kind of airguns can be regarded as a green and environmental protection seismic source on land; (2) seismic wave gener-ated by this airgun source can be recorded by permanent stations with offset larger than 200 km. And the wave amplitudes recorded by nearby and remote stations are equivalent to the wave generated by 800 kg dynamite explosion. The airguns can be used as a light to illuminate the continental crustal structure of an area of about 100000 km2.     

The application of large volume airgun sources to the onshore-offshore seismic surveys： implication of the experimental results in northern South China Sea

Onshore-offshore seismic experiments were carried out for the first time in northern South China Sea using large volume airgun sources at sea and seismic stations on land. The experimental results indicate that seismic signals from the new airgun array of R/V Shiyan 2 can be detected as far as 255 km. The signal effective area reaches nearly 50000 km2, which covers Hong Kong and Pearl River Delta. Compared with the old airgun array, the signal amplitude, propagation distance and effective area of the new airgun array have been increased notably, which demonstrates that the upgrade of the airgun source was successful. Comparisons with previous experimental results in other regions show that the shooting effect of the new airgun array is similar to those best airgun sources in the world. Especially, it is a new breakthrough in using the permanent seismic stations onshore to record long distance airgun signals offshore, which has great significance to the realization of the "seismic radar" concept and the 3D seismic surveys of crustal structure in coastal areas.