壳体中性曲面变形后的度量张量和曲率张量

为了从数学角度更好地描述壳体中性曲面如何变形,通过渐近分析和张量分析,给出了当壳体中性曲面发生形变时度量张量和曲率张量改变量的完整表达式.提出的度量张量的改变量与Ciarlet给出的一致,而曲率张量的改变量比Ciarlet给出的更精确.由于度量张量和曲率张量的改变量是构造Koiter型线性、非线性弹性壳体模型的重要组成部分,因此提出新的Koiter型非线性弹性壳体模型,理论上比Ciarlet的非线性模型误差更小.这为火箭、导弹、航天飞船等国防领域和火车、汽车等工业领域的研究提供了更好的数学基础.     

Therapeutic angiogenesis induced by human hepatocyte growth factor gene in hindlimb ischemia of dogs

A preclinical study of treating peripheral srtery occlusive disease(PAD) was performed by using a hepatocyte growth factor(HGF) gene-expressing vector,plasmid pUDKH,in a dog model with complete ischemia of one hindlimb.After ligation of femoral artery of one hindlimb,pUDKH was transferred directly into the ischemic limb muscles.The angiogenic activity of the plasmid pUDKH was evaluated.On D 30 after injecting once of pUDKH at differ-ent doses into local muscles immediately after operation,the degree of augmentation of collateral vessel formation was significantly greater than that treated by blank vector.In addition,the blood flow rate of femoral artery in dogs treated with pUDKH was recovered on D90,while the folw rate was only 1/5 tp 1/3 in control dogs.The pulse amplitude of pUDKH-treated dogs was recovered on D90,but it was hardly detectable in most of the control dogs.The side effects of intramuscular transfection of pUDKH were also investi-gated,and no significant positive change was found.It is suggested that angiogenesis induced by HGF gene has the potential for clincal use in the treatment of peripheral arte-rial diseases.     

计算机性能与异构计算

介绍了传统的高性能计算机的局限性和异构计算的基本原理;指出异构计算具有更高的计算资源利用率,计算任务的总体执行时间最短。     

代理人公平偏好下的长短期业绩目标与薪酬激励契约研究

以薪酬激励合约为中介,通过植入代理人公平偏好的异质性,构建代理人长短期业绩目标的多任务委托代理模型.基于该模型探究了代理人最优:在公平偏好下,代理人风险厌恶程度越强,委托人给予代理人最优长短期激励薪酬越少,固定薪酬与总体薪酬越多;代理人能力、公平偏好对最优长短期薪酬激励契约的影响与代理人风险偏好类型相关;代理人公平偏好程度及最优长短期薪酬激励强度对固定薪酬及总体薪酬的影响取决于各任务间的相关系数.     

Whole-genome sequencing of liver cancers identifies etiological influences on mutation patterns and recurrent mutations in chromatin regulators

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. We sequenced and analyzed the whole genomes of 27 HCCs, 25 of which were associated with hepatitis B or C virus infections, including two sets of multicentric tumors. Although no common somatic mutations were identified in the multicentric tumor pairs, their whole-genome substitution patterns were similar, suggesting that these tumors developed from independent mutations, although their shared etiological backgrounds may have strongly influenced their somatic mutation patterns. Statistical and functional analyses yielded a list of recurrently mutated genes. Multiple chromatin regulators, including ARID1A, ARID1B, ARID2, MLL and MLL3, were mutated in ～50% of the tumors. Hepatitis B virus genome integration in the TERT locus was frequently observed in a high clonal proportion. Our whole-genome sequencing analysis of HCCs identified the influence of etiological background on somatic mutation patterns and subsequent carcinogenesis, as well as recurrent mutations in chromatin regulators in HCCs.     

多模光纤斑纹场及其应用

本文研究了He-Ne 激光照明的单根多模阶跃折射率型光纤及多模光纤束产生的斑纹场的特性,讨论了不同芯径的光纤组成的多模光纤束产生的斑纹场之间的差别,并将它们与毛玻璃板斑纹场进行了比较.通过实验验证了所得结论的正确性,证明了多模光纤束辐射的斑纹场可以用于光学测量和信息处理.     

Sustained firing in auditory cortex evoked by preferred stimuli

It has been well documented that neurons in the auditory cortex of anaesthetized animals generally display transient responses to acoustic stimulation, and typically respond to a brief stimulus with one or fewer action potentials. The number of action potentials evoked by each stimulus usually does not increase with increasing stimulus duration. Such observations have long puzzled researchers across disciplines and raised serious questions regarding the role of the auditory cortex in encoding ongoing acoustic signals. Contrary to these long-held views, here we show that single neurons in both primary (area A1) and lateral belt areas of the auditory cortex of awake marmoset monkeys (Callithrix jacchus) are capable of firing in a sustained manner over a prolonged period of time, especially when they are driven by their preferred stimuli. In contrast, responses become more transient or phasic when auditory cortex neurons respond to non-preferred stimuli. These findings suggest that when the auditory cortex is stimulated by a sound, a particular population of neurons fire maximally throughout the duration of the sound. Responses of other, less optimally driven neurons fade away quickly after stimulus onset. This results in a selective representation of the sound across both neuronal population and time.     

Sequence and analysis of chromosome 5 of the plant Arabidopsis thaliana

The genome of the model plant Arabidopsis thaliana has been sequenced by an international collaboration, The Arabidopsis Genome Initiative. Here we report the complete sequence of chromosome 5. This chromosome is 26 megabases long; it is the second largest Arabidopsis chromosome and represents 21% of the sequenced regions of the genome. The sequence of chromosomes 2 and 4 have been reported previously and that of chromosomes 1 and 3, together with an analysis of the complete genome sequence, are reported in this issue. Analysis of the sequence of chromosome 5 yields further insights into centromere structure and the sequence determinants of heterochromatin condensation. The 5,874 genes encoded on chromosome 5 reveal several new functions in plants, and the patterns of gene organization provide insights into the mechanisms and extent of genome evolution in plants.     

Stochastic DEA model with undesirable outputs: An application to the prediction of anti-HIV therapy efficiency

This paper proposes a stochastic prediction DEA model with undesirable outputs and simplifies the process using chance-constrained techniques in order to obtain an equivalent linear programming formulation. The existence and stability of the optimal solutions have been proved. And the model is used to describe and predict the efficiency of anti-HIV therapy in AIDS patients.     

财经新传媒的盈利模式初探

在传统纸质媒体时代,经济资讯成为新闻的一个内容,或以专版或以专刊形式出现。在新的传播手段和载体,如电脑、手机等助力下,经济资讯传播形式变得多样,而电子软件技术的运用,给经济资讯生动灵活的内容注入了生命力。本文要研究的是,财经新传媒时代,经济资讯内容如何变化、形式如何变化、盈利模式如何变化。研究采用的方法是个案法,即选择财经资讯新传媒,如大智慧、万得资讯、掌上网、东方财富网、金融界、上海钢联、生意宝、上证手机报等,看看他们怎么将形式与内容结合起来实现盈利的。