Cloning of Candida albicans SEC14 gene homologue coding for a putative essential function

The yeast SEC14 gene product is required for the transport of proteins from the Golgi complex. We have cloned the homologous Candida albicans SEC14 gene (CaSEC14) by functional complementation of a Saccharomyces cerevisiae thermosensitive mutant, sec14. Some putative TATA boxes have been identified in CaSEC14 and, contrary to S. cerevisiae SEC14, no introns were found in the Candida homologue. Sequence analysis revealed that CaSec14p is a 301 amino acid protein, 67% identical to S. cerevisiae and Kluyveromyces lactis Sec14p, and 61% identical to the 300 amino-terminal residues of Yarrowia lipolytica Sec14p. Hydrophatic profile analysis of CaSec14p suggests a soluble protein without transmembrane domains, as has been described for the S. cerevisiae counterpart. While it was easy to disrupt one allele of SEC14 in C. albicans, repeated attempts to disrupt the second allele were unsuccessful, thus suggesting that the gene could be essential for vegetative growth in C. albicans. The sequence has been deposited in the EMBL data library under Accession Number X81937.     

Sequencing analysis of a 40·2 kb fragment of yeast chromosome X reveals 19 open reading frames including URA2 (5′ end), TRK1, PBS2, SPT10, GCD14, RPE1, PHO86, NCA3, ASF1, CCT7, GZF3, two tRNA genes,three remnant delta elements and a Ty4 transposon

The complete sequence of a 40 247 bp DNA segment located on the left arm of chromosome X of Saccharomyces cerevisiae has been determined and analysed. The sequence encodes the 5′ coding region of the URA2 gene and 18 open reading frames of at least 100 amino acids. Ten of these correspond to known genes, whereas eight correspond to new genes. In addition, the sequence contains a tRNA-Ala gene, a tRNA-Asp gene, a Ty4 transposable element and three delta elements. The sequence has been deposited in the EMBL databank under Accession Numbers: Z49405, Z49404, Z49403, Z49402, Z49401, Z49400, Z49399, Z49398, Z49397, Z49396, Z49394, Z49392, Z49391, Z49390, Z49389, Z49387, Z49386, Z49385.     

锌酞菁-紫精-二茂铁三元化合物分子内光致电子转移及光电转换性能的研究

本文合成了锌酞菁、紫精与二茂铁经共价键相连接的两亲性新的三元化合物,测定了它的吸收光谱、荧光光谱、荧光寿命和瞬态吸收及其衰减,并与二元化合物锌酞菁-紫精进行了比较,结果表明:在DMF和表面活性剂溶液中三元化合物都发生了有效的分子内光致电子转移反应,给出了稳定的电荷转移离子对,其寿命长达100μs以上,表明存在着一个两步电子转移过程,用LB膜技术成功地组装了三元化合物的分子,并检测到明显的光电效应。     

Modeling for Predicting Flow Stress of Al-14Cu-7Ce Alloy at Elevated Temperature

在应变速率0.001~1 s-1、温度573~823 K的条件下,采用Gleeble 3500热模拟试验机对Al-14Cu-7Ce合金进行等温热压缩实验,并根据真应力-真应变的计算数值,建立了Al-14Cu-7Ce合金高温流变应力本构方程。结果表明,流变应力符合速率方程€=ADLGb/kT(sinhaLG)n;其中,应变的影响通过多项式拟合方式耦合进入材料常数A,αL和n。所建立的本构方程能够准确预测Al-14Cu-7Ce合金高温流变应力,实验条件下控制合金热变形的主要机制是位错攀移。     

HTR-PM中~(14)C产生与释放行为研究

~(14)C具有较长的半衰期,可与稳定同位素一起进入生物圈,从而在核电站的环境影响评价中受到关注.本文基于HTR-PM给出了产生~(14)C的各反应模型,并代以HTR-PM参数,对HTR-PM中~(14)C的年产生量和气态释放量作出估算.最后,将计算结果与CANDU堆型进行了比较.     

环境~(14)C监测的质量控制

本文介绍了环境中14C分析测量过程中的质量控制措施。通过优化分析规程、加入质量控制样品、不定期参加各级比对、定期检验测量设备、规范的数据记录和审核等质量控制措施,对空气和生物样品中的14C测量进行质量控制,达到提高对环境14C监测准确性和有效性的目的。     

Template-assisted synthesis of high packing density SrLi2Ti6O14 for use as anode in 2.7-V lithium-ion battery

SrLi₂Ti₆O₁₄ has been prepared by using mesoporous TiO₂ brookite as a template and reactant. The prepared particles retained the rounded shape of the precursor, leading to high dispersivity and high packing density. The material has been further electrochemically characterized in both half and full cells. It shows good cycling stability and rate capability. A 2.7-V cell has been built by combining a SrLi₂Ti₆O₁₄ anode with a 4-V spinel cathode of LiMn₂O₄. This cell has a higher voltage compared to the 2.5-V LiMn₂O₄/Li₄Ti₅O₁₂ system.     

秦山核电基地外围环境大气3H、14C水平监测

自1992年,浙江省辐射环境监测站对秦山核电基地外围环境辐射水平进行了连续的监督性监测。1993~2005年,基地外围环境大气中3H浓度和以CO2形态释放的14C含量监测结果表明:与基地运行前本底水平及杭州市区对照点比较,夏家湾和杨柳村监测点大气3H浓度有逐步升高趋势;随着2002年12月并网机组的再次增加,在2003~2005年,夏家湾监测点大气3H浓度年平均值分别为129、201和348mBq/m3,分别为1993~2002年总平均值(34.8 mBq/m3)的3.7、5.8和10倍;夏家湾和杨柳村大气中以CO2形态释放的14C含量与杭州市对照点处相同水平。