Characterization of New DNA Aptamers for Anti-HIV-1 Reverse Transcriptase

HIV-1 RT is a necessary enzyme for retroviral replication, which is the main target for antiviral therapy against AIDS. Effective anti-HIV-1 RT drugs are divided into two groups; nucleoside inhibitors (NRTI) and non-nucleoside inhibitors (NNRTI), which inhibit DNA polymerase. In this study, new DNA aptamers were isolated as anti-HIV-1 RT inhibitors. The selected DNA aptamer (WT62) presented with high affinity and inhibition against wild-type (WT) HIV-1 RT and gave a KD value of 75.10±0.29 nM and an IC₅₀ value of 84.81±8.54 nM. Moreover, WT62 decreased the DNA polymerase function of K103 N/Y181 C double mutant (KY) HIV-1 RT by around 80 %. Furthermore, the ITC results showed that this aptamer has small binding enthalpies with both WT and KY HIV-1 RTs through which the complex might form a hydrophobic interaction or noncovalent bonding. The NMR result also suggested that the WT62 aptamer could bind with both WT and KY mutant HIV-1 RTs at the connection domain.     

挤压机的振动分析和数值计算

本文建立了3150吨卧式挤压机振动分析的力学-数学模型,进行了数值计算,并绘出了相应的相轨线图。理论计算的结果与现场测试数据基本一致。这种用集中质量法建立模型及用相轨线图进行定性分析的方法对各种型式的挤压机、压力机设计研究均有普遍的参考价值。     

硬质合金冷挤压凹模的热处理强化

本文叙述了ＷＣ－Ｃｏ硬质合金特别是ＹＧ２５牌号硬质合金的渗硼淬火热处理强化工艺和不同钴含量的合金的强化处理效果以及强化处理的合金应用效果，并对其强化机理进行了讨论。     

热爆合成－热挤压TiNi棒材的组织结构和性能

研究了热爆合成－热挤压法制得的ＴｉＮｉ合金棒材的组织结构和性能。研究结果表明，所制取的棒材具有用传统法——熔铸法生产ＴｉＮｉ合金的性能，证明了用该法制取ＴｉＮｉ型材的途径是可行的     

线激光--机器视觉测量系统中的多传感器融合技术研究

针对逆向工程中直接从线激光扫描的数据云图中提取物体边界不仅繁琐而且精度也不好保证，为此提出建立线激光—机器视觉测量系统，先利用三日视觉获得物体初始边界，然后利用曲线延拓的方法并考虑影响延拓误差的因素，从而在满足一定精度要求的前提下实现不同传感器信息的融合。     

反求工程的产品几何建模技术研究

分析了目前在反求工程产品几何建模中广泛应用的曲面模型的局限性，指出反求工程为实现创新功能必须采用产品特征模型，提出了基于实体造型的特征建模方法。这种方法可以避免曲面模型的缺陷，拓宽反求工程的应用范围，是实现三维重构的新方法。探讨了有关的理论和关键技术。     

冷却强度及变形程度对挤压AZ31镁合金组织性能的影响

选择AZ31镁合金为原材料,在400℃下挤压散热片型材,就冷却强度及变形程度对制品的性能(抗拉强度和导电率)及组织结构的影响进行研究。结果显示:挤压温度为400℃,制品经水冷却,变形程度大的型材具有更高的抗拉强度和导电率。     

固液挤压下陶瓷粒子增强铝基复合材料组织特点及其形成机制

本文使用接触反应法制备ＴｉＣｐ／ＬＹ１２复合材料熔体，然后经固液挤压直接制取复合板材与棒材。使用背散射扫描电镜对Ｔ６处理后的复合板材组织特点进行观察，揭示了颗粒的分布特征、基体组织特点及其成因。     

NUMERICAL SIMULATION STUDY ON DEFORMATION UNIFORMITY OF EQUAL CROSS SECTION LATERAL EXTRUSION

Equal cross section lateral extrusion (ECSLE) is an effective method realizing pure shear deformation.The influence of friction factor on the deformation uniformity of ECSLE was investigated with rigid plastic finite element method.The result shows that the non-uniform deformation in extrusion is caused mainly by the friction between workpiece and die.The higher the friction factor is.the more uneven plastic deformation resulted in extruded workpiece.The relation curve of deformation uniformity vs. friction factor was drawn based on the analysis result. The curve can be used as a basis of ECSLE process design.     

Unique microstructure and property of a 2024 aluminum alloy subjected to upsetting extrusion multiple processing

The microstructure and hardness of a 2024 aluminum alloy subjected to multi-pass upsetting extrusion at ambient temperature were studied. Experimental results indicated that with the number of upsetting extrusion passes increasing, the grains of the alloy are gradually refined and the hardness increases correspondingly. After ten passes of upsetting extrusion processing, the grain size decreases to less than 200 nm in diameter and the sample maintains its original shape, while the hardness is double owing to equal-axial ultrafine grains and work hardening effect caused by large plastic deformation.