Ancient DNA sequences of rice from the low Yangtze reveal significant genotypic divergence

Rice (Oryza sativa) was first domesticated in the lower and middle Yangtze regions of China, and rice remains have been found in many Chinese archaeological sites. Until now, only phenotypic archeobotanical evidence, such as the spikelet bases of ancient grains, has been used to speculate on the domestication process and domestication rate of rice. In this study, we sequenced 4 genomic segments from rice remains in Tianluoshan, a site of the local Hemudu Neolithic culture in the low Yangtze and two other archaeological sites (~2400 and 1200 BC, respectively). We compared our sequences with those of the current domesticated and wild rice (O. rufipogon) populations. At least two genotypes were found in the remains from each site, suggesting a heterozygotic state of the rice seeds. One ancient genotype was not found in the current domesticated population and might have been lost. The rice remains belonged to the japonica group, and most if not all were japonica-type, suggesting that the remains might be at an early stage of indica-japonica divergence or an indica-japonica mixture. We also identified sequences with significant similarity to those from species of Sapindales, Zygophyllales, and Brassicales, which is consistent with the identification of other plant remains in the Tianluoshan site and the common rice field weeds such as mustards in southern China.     

基于{V_8O_(24)}~(8-)阴离子簇的一维Zn(Ⅱ)配合物的合成及晶体结构

利用水热合成技术,合成了1个基于{V8O24}8-阴离子簇的Zn(Ⅱ)配合物[Zn2(Hdpa)3]2V8O24(dpa=2,2′-dipyridylamine),通过X-射线单晶和粉末衍射、红外光谱和热重-差热分析手段进行了表征.单晶X-射线衍射分析表明化合物是由2种不同的阳离子片段([Zn(dpa)2]2+和[Zn(dpa)]2+)连接{V8O24}8-阴离子簇形成的1D带状结构,其中{V8O24}8-阴离子簇展示了清晰的椅式构型,2个[Zn(dpa)]2+单元分别被支撑在椅式构型的两侧.     

有限双向E类保序变换半群的Green关系和正则性

设(X,≤)是全序集,T(X)是X上的全变换半群,E为X上的任意的非平凡等价关系,设E*O(X)={α∈T(X):x,y∈X,(x,y)∈E,x≤y(xα,yα)∈E,xα≤yα}则E*O(X)是T(X)的子半群;当X是有限和E是凸时,研究了E*O(X)的Green关系,并证明了它是正则子半群.     

反馈对放大器噪声特性的影响(理论研究)

本文定量地导出了反馈放大器的E_n—I_n等效输入噪声模型参量与基本放大器和反馈网络的模型参量间的解析关系式,给出了低噪声反馈放大器的设计要点。     

Secure multi-party computation solution to Yao''s millionaires'' problem based on set-inclusion

Secure multi-party computation is a focus of international cryptography in recent years. Protocols for Yao's millionaires' problem have become an important building block of many secure multi-party computation protocols. Their efficiency are crucial to the efficiency of many secure multi-party computation protocols. Unfortunately, known protocols for Yao's millionaires' problem have high computational complexity or communication complexity. In this study, based on the 1-out-of-m oblivious transfer and set-inclusion problem, we propose a new protocol to solve this problem. This new protocol is very efficient in terms of both computational and communication complexities. Its privacy-preserving property is also proved by simulation paradigm which is generally accepted in the study of secure multi-party computation. We also compare the information leakage of our new protocol and the known protocols.     

从认知语用角度看会话中人称指示语的映射现象

会话中的人称指示语总是体现“自我为中心”的特性,这个特性也成为会话的基本原则。但生活中人们总会违反这个原则,将指示中心转移到其他的参与者身上,出现指示映射现象。本文对指示映射的各种表现以及其生成和推导的认知语用过程作了分析和描述。     

澳洲鳗、日本鳗和欧洲鳗的RAPD初步比较分析

运用RAPD技术,以日本鳗Anguilla japonicus、欧洲鳗Anguilla anguilla和澳洲鳗Anguilla australia尾鳍DNA作为模板,在20种随机引物中筛选出4种随机引物进行扩增反应,得到这3种鳗鱼DNA的RAPD扩增片段,通过比较这3种鳗鱼的扩增条带的特异性、种间相似性指数(日本鳗和欧洲鳗之间的相似指数为0.556 5,日本鳗和澳洲鳗、欧洲鳗和澳洲鳗的相似指数分别为0.510 2和0.5278)和遗传距离,探讨这3种鳗鱼的遗传差异,为鳗鱼的种质鉴定奠定基础。     

用切向流超滤系统测定聚合物驱产出液中聚合物质量浓度

在聚合物驱过程中,由于聚合物相对分子质量和水解度发生变化,常规的淀粉-碘化镉质量浓度检测方法已不适用于油井产出液中聚合物质量浓度的检测.针对上述问题,本文应用美国Millipore切向流超滤系统,消除了油井产出液中盐和表面活性剂等杂质的影响,通过对油井产出液中聚合物的分离、超滤浓缩、真空干燥,研究出聚合物质量浓度测定的新方法——超滤浓缩恒重法.研究结果表明,该方法具有较高的精确性,满足现场检测的要求,解决了目前现场产出液中聚合物质量浓度检测不准确的难题,而现场用淀粉-碘化镉法测得油井产出液中聚合物质量浓度值与该方法相比明显偏低,有待于进一步改进.     

安康试验点精神发育迟滞遗传方式的探讨

目的探讨安康试验点精神发育迟滞的遗传方式,为该试验点精神发育迟滞儿童的综合防治提供依据。方法运用分离分析法和多基因阈值理论进行遗传流行病学分析。结果在安康试验点人群中,由非特异性精神发育迟滞和神经型亚克汀病所致精神发育迟滞的遗传率分别为86.61 11.10%和81.80 9.76%,最大似然法和理论子女总数法计算结果表明,不同婚配类型子女的患病率与理论患病率均无显著性差异。结论安康试验点存在两种精神发育迟滞,它们的遗传方式可能均为具有主效基因的多基因遗传。     

双调和ABEL-POISSON算子对共轭HLDER函数类的逼近

建立了共轭双调和Abel-Poisson算子对共轭H lder函数类的逼近上界和逼近下界.