SARS相关冠状病毒与其他已知冠状病毒的膜蛋白的多序列联配

1　Introduction　SARSisthefirstnewlyidentifiedseriousinfectiousdiseasethathumanbeingisfacingatthebeginningofthe 2 1stcentury .Ithasbeen primarilyrecognizedthatavariantofvirusfromthecoronavirusfamilymightbethecandidatepathogenofSARS ,asreportedbyWHO (WorldHealthOrganization)onApril 2 9,2 0 0 3(http ://www .who .int/csr/sarscountry/en) .　Coronaviruseswerefirstisolatedfromchickensin1937.Therearenowapproximately 15speciesinthisfamily.Coronavirusparticlesareirregularlyshaped ,roundabout 6 0 …     

空间中平面位置关系研究

利用线性方程组解的理论讨论空间中两个平面、三个平面及个平面间位置关系,给出用矩阵的秩判定以上关系的方法和结论。     

INSAR相位解缠的半参数解算方法

建立半参数回归模型,将系统误差加入,导出了模型正则化矩阵时参数平差的计算方法,用直接法得到了相位解缠的估计量,给出了相应的公式,并通过实例证明了该方法的有效性。     

Association of matrix metalloproteinase-9 C1562T polymorphism and coronary artery disease: a meta-analysis简

Objective

Many investigations have studied the associations between matrix metalloproteinase-9 (MMP-9) C1562T polymorphisms and coronary artery disease (CAD). However, the conclusions of these studies were inconsistent. Therefore, this study was aimed at clarifying the association between MMP-9 C1562T polymorphisms and CAD in a large-scale meta-analysis.

Methods

The PubMed and Embase databases were retrieved to collect all publications on the association between MMP-9 C1562T polymorphisms and CAD. Then the odd ratios (ORs) and 95% confidence intervals (95% CIs) for C1562T TT+TC versus CC genotype between CAD and the control groups were evaluated. Subgroup analysis was also performed according to different races. The meta-analysis was performed by Stata 10.0.

Results

Sixteen case-control studies were included in our meta-analysis, involving 11 032 CAD patients and 4628 non-CAD controls. Compared with C allele carriers, East Asian T allele carriers TT+TC had a significantly higher risk of CAD (OR=1.43; 95% CI: 1.03–1.99; P=0.031); however, there were no significant associations in Western populations (OR=1.06; 95% CI: 0.96–1.18; P=0.240) or West Asians (OR=1.13; 95% CI: 0.75–1.70; P=0.565). When further analyzing the association between C1562T polymorphisms and myocardial infarction (MI, the most serious type of CAD), the risk of TT+TC genotype versus CC genotype for MI was significantly higher for the overall (OR=1.21; 95% CI: 1.04–1.40; P=0.012) and for East Asians (OR=1.58; 95% CI: 1.26–1.97; P=0.000) but not in Western populations (OR=1.12; 95% CI: 0.99–1.26; P=0.078).

Conclusions

Our meta-analysis suggested an obvious ethnic difference in the association between MMP-9 C1562T polymorphisms and CAD. MMP-9 C1562T polymorphism was significantly related to CAD in East Asians. However, no significant associations were observed in either West Asians or Western populations.     

基于TRIZ的TG80型压棒机给排油装置的研究与设计

TG80型压棒机是国内多数烟厂采用的主流除尘设备之一,采用液压系统控制原理。其中给排油系统效率低直接影响到压棒机的生产效率。文章以TRIZ为理论为指导方法,描述了机械设计中的矛盾问题,并建立解决矛盾矩阵,分析了"生产效率"、"可靠性"、"运动物体的形状"之间的矛盾关系,最终运用TRIZ的创新原理找到创新最优解。在满足生产及保证可靠性的同时,减少了给排油次数及单次耗时,提高生产效率。     

与四阶对合矩阵可交换的反对合矩阵

讨论与四阶对合矩阵可交换的反对合矩阵。主要结果如下：对于四阶对合矩阵A,如果A≠±I（I是单位矩阵）,那么与A可交换的全体反对合矩阵可以分为四类：±iI、±iA、tr（A）=±2和tr（A）=0。     

TDTMF: A recommendation model based on user temporal interest drift and latent review topic evolution with regularization factor

This paper constructs a novel enhanced latent semantic model based on users’ comments, and employs regularization factors to capture the temporal evolution characteristics of users’ potential topics for each commodity, so as to improve the accuracy of recommendation. The adaptive temporal weighting of multiple preference features is also improved to calculate the preferences of different users at different time periods using human forgetting features, item interest overlap, and similarity at the semantic level of the review text to improve the accuracy of sparse evaluation data. The paper conducts comparison experiments with six temporal matrix-based decomposition baseline methods in nine datasets, and the results show that the accuracy is 31.64% better than TimeSVD++, 21.08% better than BTMF, 15.51% better than TMRevCo, 13.99% better than BPTF, 9.24% better than TCMF, and 3.19% better than MUTPD ,which indicates that the model is more effective in capturing users’ temporal interest drift and better reflects the evolutionary relationship between users’ latent topics and item ratings.     

中国区域劳动生产率趋同或趋异的非参数分析

运用动态分布法对中国29个省市区在1985-2003年间的区域劳动生产率差距进行了分析。结论表明,中国并没有出现新古典经济增长理论所预期的水平趋同现象,而是出现了中间层弱化和两极强化的“U”形差距扩大化现象。如果任由经济照此发展下去,中国区域劳动生产率差距将会以比目前略有缓解的两极分化而告终。     

矩阵在解线性方程组中的应用

线性方程组的求解是代数学中一个比较重要的内容,线性方程组求解过程中,掌握各种求解线性方程组的方法是至关重要的。基于线性方程组和矩阵之间的联系,可以用线性方程组系数和常数项所构成的行列式矩阵来研究线性方程组的求解问题。本文主要讨论矩阵的秩在方程组的解的判断中的应用以及线性方程求解中如何应用矩阵的初等变换。