Identity-based blind signature from lattices

Blind signature allows a user to get a signature of a signer on an arbitrary message,and the verifier can convince that the signature is indeed signed by the signer without leaking any information about the message.This property is necessary when the user’s privacy needs protection,such as a bank bill,a trade secret,etc.As an alternative of public key infrastructure,the identity-based system can simplify the key management procedures in certificate-based public key systems.Inspired by the requirement of identity-based blind signature in the post quantum world,we research on identity-based blind signature based on hard lattice problems under the random Oracle model.We propose a construction built upon the blind signature by Rückert,and it is proved to be one-more unforgeable against selective identity and chosen message attacks(s ID-CMA)and unconditionally blind.The proposed scheme has 2 moves,and its security can be reduced to the small integer solution(SIS)problem.     

赤点石斑鱼MHC IA基因的克隆与表达多态性分析

采用RACE技术,成功克隆获得赤点石斑鱼(Epinephelus akaara)非特异性免疫因子MHC IA基因的4个cDNA全序列,序列全长为1 680bp,含有3′UTR、启动子、多肽结合区(α1)、IGC区(α2)、跨膜区、胞质区和5′UTR区,编码区大小为1 074～1 080bp,共编码357～359个氨基酸,推测蛋白质分子质量约41.66ku.氨基酸序列分析发现赤点石斑鱼MHC IA分子具有经典MHC蛋白分子的空间结构,在多肽结合区则存在极其丰富的变异.利用Real time PCR和SSCP技术研究了赤点石斑鱼MHC IA的组织表达特异性和表达多态性,发现其在头肾、心、肝等12个组织器官中均能有效表达,在头肾,脾,胸腺等免疫组织表达量不仅高,表达多态性也异常丰富,而在与外界环境接触较多的鳃、肌肉、肠等组织表达较弱.此外,根据MHC IIB分子中相对保守的IGC区氨基酸序列构建了脊椎动物的系统进化树,也表明了该分子的IGC区氨基酸序列可以作为研究鱼类物种间进化关系的良好标记.     

Changes in physical features of Glacier No. 1 of the Tianshan Mountains in response to climate change

This study analyzes the changes in glacier zones and snow composition of Glacier No.1 in the Tianshan Mountains of China since 1961,and their possible relations with climate.It is found that precipitation dominated the snow composition and that air temperature and precipitation controlled the distribution of glacier zones,but interannual change in precipitation had a relatively large effect on glacier zones and snow composition during 1963–1981 (P10) and 1963–1989 (P11).However,during 1982–2007 (P20) and 19...     

化学镀铁工艺中络合剂用量的优化实验

通过化学镀铁工艺构建应用于惯性约束核聚变实验用铁黑腔,在化学镀铁镀液配方中,络合剂是镀速和镀层孔隙率重要的影响因素。文中首先通过单一络合物实验初步得出了柠檬酸钠、乳酸和丙酸的初步范围,并通过正交试验优化了化学镀铁溶液中各络合物浓度,并讨论了不同浓度的络合剂对镀速和镀层孔隙率的影响关系。     

影响特低渗气藏气体渗流能力因素分析

为了有效地开发特低渗气藏,就必须搞清楚这类储层的渗流规律。通过室内模拟实验发现。储层基质渗透率的不同,气体的渗流特征也不同,压力越大,流量的增幅越大;在不含水的条件下不存在启动压力,含水饱和度对气体渗流能力影响很大,当含水达到一定值时,在储层中就会存在非达西渗流特征和启动压力梯度;净围压的变化对气体渗流也会产生一定的影响,特别是特低渗储层,随着净围压的增加,其流量随之减小。通过实验得出,含水饱和度和净围压变化对气体渗流能力影响最大。     

基于Delphi的数据库连接池的设计与实现

在基于WEB的多层系统开发中.决定系统应用性能的一个重要因素和难点就是如何加快数据库连接速度,数据库连接池技术的出现解决了这个问题。在对数据库连接池技术进行分析的基础上。设计并实现了一个基于Delphi合理有效的数据库连接池。     

Factor-GARCH模型研究与理论探讨

结合国外研究现状，对解决多维GARCH模型的方法——Factor-GARCH模型进行了系统的讨论．将投资组合的收益率Rt表述为潜在公共因子的函数形式，并对函数形式中的一些变量和假定给出了理论和现实的解释；将投资组合的协方差Ht的结构进一步细化，将其表述为可观测变量的线性函数．并指出了今后的研究方向。     

Near-infrared spectroscopy-based quantification of substrate and aqueous products in wastewater anaerobic fermentation processes

In this study, a Fourier transform near-infrared （FT-NIR） technique was used for process monitoring of anaerobic fermentation. Orthogonal signal correction （OSC） method was used as NIR spectral pre- processing options. Calibration models were established and the validation of the method was per- formed with the sucrose, ethanol and volatile fatty acids （VFAs） contents determined by the anthrone and gas chromatography methods, respectively. Spectral range and the number of internal latent variables were optimized for the best correlation coefficient. Test set validation of sucrose resulted in excellent measurement of prediction performance and the correlation coefficient of determination is 0.930. Similar prediction statistics for individual VFA and total VFA contents were obtained. These re- sults proved that the NIR spectroscopy technology is able to quantify the contents of both volatile fatty acids and sucrose in wastewater anaerobic fermentation process.     

Relationship between topology and functions in metabolic network evolution

What is the relationship between the topological connections among enzymes and their functions during metabolic network evolution? Does this relationship show similarity among closely related organisms? Here we investigated the relationship between enzyme connectivity and functions in metabolic networks of chloroplast and its endosymbiotic ancestor, cyanobacteria (Synechococcus sp. WH8102). Also several other species, including E. coli, Arabidopsis thaliana and Cyanidioschyzon merolae, were used for the comparison. We found that the average connectivity among different functional pathways and enzyme classifications (EC) was different in all the species examined. However, the average connectivity of enzymes in the same functional classification was quite similar between chloroplast and one representative of cyanobacteria, syw. In addition, the enzymes in the highly conserved modules between chloroplast and syw, such as amino acid metabolism, were highly connected compared with other modules. We also discovered that the isozymes of chloroplast and syw often had higher connectivity, corresponded to primary metabolism and also existed in conserved module. In conclusion, despite the drastic re-organization of metabolism in chloroplast during endosymbiosis, the relationship between network topology and functions is very similar between chloroplast and its precursor cyanobacteria, which demonstrates that the relationship may be used as an indicator of the closeness in evolution.     

基于REV的岩质边坡力学参数模拟试验方法

从岩体宏观连续性假设出发,引入岩体表征单元体(REV)概念.首先根据岩块的三轴与卸载回弹试验以及结构面的室内直剪试验确定其基本力学参数;然后以数值模拟试验方法,依据当岩体区域体积达到并超过岩体REV尺寸时其力学性质趋于稳定的变化规律,对岩质边坡岩体REV的存在以及大小进行确定;最后根据满足REV尺寸的三维模型最终计算出对应边坡岩体的力学参数.