同义密码子非随机使用的理论模型

利用ｋ＝２时分子序列进行模型研究了同义密码子的非随机使用，讨论了密码子使用频率以及信息参数Ｄ１，Ｄ２和Ｘ与选择力参数的依赖关系，另外，考虑到氨基酸相似因子，建立了密码使用频率的一个相似突变模型，研究了同义密码子的非随机使用。     

C─值悖论及其机制

基因组大小，即Ｃ值，与基因组中所含的遗传信息的认定数量间缺乏对应，这种Ｃ一值悖论是由非基因ＤＮＡ的增加所造成的．     

半经验分子轨道理论中Slater轨道指数对分子性质的一些影响

半经验分子轨道理论中 Slater 轨道指数§可表示成原子静电荷 q 的函数。本文按这种方法讨论了§随 q 的这种变化对分子性质的一些影响。     

Triplet repeat disorders: discussion of molecular mechanisms

Comparison of the growing number of disorders known to be associated with triplet repeat expansions reveals both common features and a diversity of molecular pathways. Despite significant progress towards the characterization of proteins coded by the mutant genes, the complex nature of these disorders requires identification of all molecular components of the triplet repeat pathways. In this brief review we will discuss recent progress in determining the molecular mechanisms of disorders with unstable trinucleotide mutations. Received 13 January 1999; received after revision 8 March 1999; accepted 9 March 1999     

The plasma membrane proton-translocating ATPase

Living cells require membranes and membrane transporters for the maintenance of life. After decades of biochemical scrutiny, the structures and molecular mechanisms by which membrane transporters catalyze transmembrane solute movements are beginning to be understood. The plasma membrane proton-translocating adenosine triphosphatase (ATPase) is an archetype of the P-type ATPase family of membrane transporters, which are important in a wide variety of cellular processes. The H+-ATPase has been crystallized and its structure determined to a resolution of 8 angstrom in the membrane plane. When considered together with the large body of biochemical information that has been accumulated for this transporter, and for enzymes in general, this new structural information is providing tantalizing insights regarding the molecular mechanism of active ion transport catalyzed by this enzyme.     

废水处理系统中功能菌株特异分子标记

用40条10碱基随机引物对油脂化工废水处理系统中分离到的降解脂肪酸和脂肪胺功能菌株FA-2。FA-3及对照菌株进行RAPD分析。筛选出长度为700bp的FA-2的特异性片段,并克隆到pMD 18-T载体上．根据测序结果,设计了1对SCAR(sequence characterized anlplfied region)引物,通过SCAR-PCR反应,获得SCAR标记,并通过对20个培养样品进行PCR扩增,验证了标记特异性．结果表明该标记可作为特异的分子标记用于污水处理系统中功能菌株FA-2的监测．     

磁盘表面形貌对润滑剂分布及磁头／磁盘之间润滑剂转移的影响

磁盘表层润滑剂在磁头与磁盘之间转移会影响磁头飞行的稳定性．本文采用改进后的粗粒珠簧模型,运用分子动力学方法,研究了磁盘上类金刚石薄膜（diamondlikecarbon,DLC）层粗糙度和磁盘表面凸起对润滑剂在磁盘表面分布及磁头／磁盘之间润滑剂转移的影响．研究结果表明,DLC层粗糙度对润滑膜平均厚度及磁盘表层粗糙度的影响很小;磁盘表面凸起对磁盘表层润滑剂分布的影响明显．类金刚石薄膜层的粗糙度和磁盘表层凸起均可增加转移到磁头上的润滑剂的体积．但磁盘表层粗糙度对磁头／磁盘之间润滑剂转移量的影响明显低于由磁盘表层凸起导致的磁头／磁盘之间润滑剂的转移量．     

分子电子学

作为纳米电子学的一个重要分支,分子电子学在近年来得到了巨大的发展,并成为国际上研究的热点。本文介绍了各种分子器件的制作技术及基本工作原理,回顾了近年来分子电子学的最新进展,展望了分子电子学的未来发展。     

用磷酸铝分子筛和硅磷酸铝分子筛作催化剂合成丙酸戊酯的研究

用新型磷酸铝分子筛和硅磷酸铝分子筛作催化剂,对丙酸和正戊醇液—固相酯化反应进行了研究.考察了合成条件及用不同方法制备的催化剂对醇产率的影响,当醇酸摩尔比为1.2∶1、催化剂用量为0.6～1.0g/mol丙酸、带水剂环己烷用量为5.0ml/mol丙酸,反应温度为140～160"C时,5hr酯化反应的酯产率大于98％.同时对酯产物的物理常数进行了测定,实测值与文献值相符.