肠炎沙门氏菌2种rDNA 16s—23s基因间隔区序列分析

采用凝胶分离ＰＣＲ产物的方法，对肠炎沙门氏菌中种ｒＤＮＡ１６ｓ－２３ｓ基因间隔区进行克隆和序列分析。肠为沙门氏菌小ｒＤＮＡ１６ｓ－２３ｓ基因间隔区，全长３５４个碱基对，包含１个谷氨酸ｔＲＮＡ基因。大ｒＤＮＡ１６ｓ－２３ｓ基因间隔区，全长５１８个碱基对，其中包含异亮氨酸和丙氨酸２个ｔＲＮＡ基因。它们分别与大肠杆菌的２个ｒＲＮＡ操纵子ｒｒｎＥ和ｒｒｎＨ有较高的序列相似性。肠炎沙门氏菌大ｒＤＮＡ１６ｓ－     

短碳纤维增强橡胶基密封复合材料的热残余应力数值分析

以碳纤维/丁腈橡胶基密封复合材料为对象,采用ABAQUS有限元分析软件,建立含有界面相的三维有限元模型,研究了橡胶基复合材料热残余应力的分布规律.探讨了制备温度、界面相厚度、界面相模量描述方法、纤维体积分数、纤维直径对热残余应力的影响.结果表明:制备温度的变化对纤维和界面相的热残余应力影响较大;界面相厚度对纤维的残余应力的影响比其对自身的影响大;梯度界面有利于降低复合材料的热残余应力;适当提高纤维体积分数和增加纤维直径都有助于改善复合材料热残余应力的分布.     

通过聚乙二醇键合巯基苯并噻唑的交联聚苯乙烯基螯合树脂的合成及其吸附性能

以氯甲基化聚苯乙烯为原料，合成了在聚苯乙烯基体和杂环功能基2-巯基苯并噻唑（MBZ）之间引入聚氧乙烯亲水性悬臂的新型螯合树脂，对所合成的树脂进行了元素分析、红外光谱和扫描电镜表征，对比研究了引入悬臂前后树脂对Hg^2＋等5种金属离子的静态吸附性能．实验结果表明：经过多步反应，引入亲水性悬臂之后，树脂的表面形貌没有变化，仍保留大孔结构，吸附选择性和功能基的利用率显著提高．     

Characteristics of rDNA intergenic spacer region from a waterbloom cyanobacteria species Oscillatoria sp.

Sequence of rDNA intergenic spacer region (ISR) from a waterbloom cyanobacterial species Oscilla-toria sp. was determined and analyzed. The results of sequence comparison showed that the spacer had a high level sequence divergence, suggesting the sequence may be a target sequence for developing cyanobacteria genus- and species-specific oligonucleotide probes. In addition, a 20bp sequence of rDNA ISR was found highly conserved in all species of cyanobacteria, which was not found in other eubacteria. This conserved sequence within a variable region indicates that it might be a functional oligonucleotide in the processing of the rRNA precursor.     

两种眼蚤rDNA ITS1序列的克隆与分析

首次研究伏河眼蚤异常亚种Ophthalmopsylla volgensis extrema Ioff et Scalon，1953和长突眼蚤Ophthalmopsylla kiritschenkoi Wagner，1930 rDNA第一内转录间隔区（ITS1）序列，并比较两者差异，为蚤类分子系统发育的研究提供重要的基础...     

不粘煤与主焦煤中溶剂抽提组分的碳化特性

对预热神木不粘煤及柳林主焦煤中不同溶剂抽提组分的碳化特性分别进行了比较研究。两种煤中不同溶剂抽提组分其碳化特性不同。煤及其溶剂抽提组分在碳化过程中中间相形成能力受其主组分的控制。     

Mo含量对Ti–Mo系铁素体钢热稳定性影响

The effects of tempering holding time at 700°C on the morphology, mechanical properties, and behavior of nanoparticles in Ti–Mo ferritic steel with different Mo contents were analyzed using scanning electron microscopy and transmission electron microscopy. The equilibrium solid solution amounts of Mo, Ti, and C in ferritic steel at various temperatures were calculated, and changes in the sizes of nanoparticles over time at different Mo contents were analyzed. The experimental results and theoretical calculations were in good agreement with each other and showed that the size of nanoparticles in middle Mo content nano-ferrite (MNF) steel changed the least during aging. High Mo contents inhibited the maturation and growth of nanoparticles, but no obvious inhibitory effect was observed when the Mo content exceeded 0.37wt%. The tensile strength and yield strength continuously decreased with the tempering time. Analysis of the strengthening and toughening mechanisms showed that the different mechanical properties among the three different Mo content experiment steels were mainly determined by grain refinement strengthening (the difference range was 30–40 MPa) and precipitation strengthening (the difference range was 78–127 MPa). MNF steel displayed an ideal chemical ratio and the highest thermodynamic stability, whereas low Mo content nano-ferrite (LNF) steel and high Mo content nano-ferrite (HNF) steel displayed relatively similar thermodynamic stabilities.     

rDNA片断序列分析技术及其在植物系统与进化研究中的应用

根据PCR-RFLP分析、微卫星序列分析、SSCP分析和核酸序列分析的原理及技术要点及其在rDNA序列分析中的具体运用，以及nrDNA在植物分类学、植物系统发育、中药材道地性鉴定及5SrDNA在鉴定体细胞杂种方面的研究进展，确认核rDNA是一个优良的分子标记，主要体现在：序列能够提供足够多的具有系统发育信息的核苷酸位点，且该序列易于排序，在植物分类、系统发育等方面应用前景广阔。     

相间合成绝缘间隔棒大挠度屈曲研究及应用

用大挠度理论分析了相间合成绝缘间隔棒大挠度屈曲问题，并确定了几种不同芯棒直径的相间合成绝缘间隔棒在大挠度屈曲时发生强度失效的极限值。试验研究证明了相间合成绝缘间隔棒在大挠度屈曲变形时其屈曲性态与其放置形式无关。提出了选择相间合成绝缘间隔棒芯棒直径新的设计方法和选择条件。并用此新的设计条件研制了我国第一条北京安定—廊坊２２０ｋＶ紧凑型线路用的相间合成绝缘间隔棒，现已有３００多支间隔棒在安—廊线挂网运行。     

液晶性共聚脂的分子结构与相变温度的关系

应用ＤＳＣ和 Ｘ光衍射研究了１２种热致液晶性规则共聚酯。探讨了聚合物链结构与共聚酯从晶态向液晶态的相转变温度ＴＣＮ之间的关系。结果表明：共聚酯的ＴＣＮ随对数比浓粘度的增大而升高，然后趋于稳定；介晶单元的苯环上引入氯取代基可降低共聚酯的ＴＣＮ和结晶度：一般情况下，共聚酯的ＴＣＮ随介晶单元的增长而升高；柔性间隔基增长，共聚酯的ＴＣＮ先降低，然后升高。