模型毒物急性毒性尿液核磁共振氨谱标记物的二阶段聚类分析

采用现代核磁共振技术，通过分析给药肝、肾损伤模型化合物异硫氰酸α-萘酯（灌胃150mg／kg体重）和二溴乙胺氢溴酸盐（腹腔注射250mg／kg体重）24h内Wistar大鼠尿液的^1H NMR谱，由尿液中内源性代谢物浓度变化研究了肝、肾模型毒物在大鼠体内的急性毒性。首次利用模式识别技术中的二阶段聚类分析方法解析大鼠尿液^1H NMR谱确定了模型化合物尿液^1H NMR标记物。结果表明，应用核磁共振和二阶段聚类分析相结合的方法，可提供模型化合物毒性比较清楚的认识。该方法也可用于金属化合物、中药及其它药物的毒性分类和预测研究以及建议各类靶向毒性的NMR标记物。     

渗硼并两步处理硬质合金微晶金刚石涂层工具研究

研究了固体粉末渗硼并碱酸两步处理预处理硬质合金基体的表面组织、形貌、粗糙度,并在处理过的硬质合金基体上,用强电流直流伸展电弧等离子体CVD法沉积微晶金刚石薄膜涂层.进一步的涂层质量表征,附着力测试及切削实验研究结果表明,这种涂层质量高、附着力好(压痕测试临界载荷大于1500N).金刚石涂层工具的切削加工性能明显优于无涂层硬质合金工具.在加工ZAlSi12合金时,微晶金刚石涂层车刀片、铣刀片的切削寿命是无涂层车刀片、铣刀片切削寿命的32倍和26倍.     

用计算全息元件实现光学Perfect shuffle网络

本文介绍了一种实现光学perfect shuffie(PS)网络的方法,它是用计算机产生全息片(CGH)的方法制作的元件,该元件可以很简单地实现二维光学PS网络,实验结果表明,该方法是可行的,效果好,能推广到其它的变换网络。     

全息照相实验条件的探讨

本文就全息照相实验中的仪器、防震、隔光等条件的宽容度进行了探讨。为普及全息照相实验拓宽了道路。     

拍摄二步彩虹全息的新方法

本文提出与Benton法不同的拍摄二步彩虹全息的新方法.利用二次正全息像获得了二步彩虹全息的正重现像.分析表明,重现像的模、轴向放大率是匹配的,而且本方法排除了Benton二步法中使用会聚参考光的主要缺点.文中同时给出实验结果.     

参考光垂直照射的光路设置

介绍了一种新的参考光垂直照射的全息照相实验的光路设置。     

水-盐酸两步法分离瓜环混合物

根据各元瓜环在水和盐酸两种溶剂中溶解度的不同, 提出了一种通过水-盐酸两步分离混合瓜环的方法. 探讨了溶剂用量、盐酸浓度等因素对分离效果的影响, 确定了最佳的分离工艺条件, 使CB[5], CB[6], CB[7]和CB[8]的分离产率分别达到78.9%, 92.0%, 88.0%和75.0%. 分离得到的瓜环单体经核磁共振检测, 纯度在95%以上, 其中CB[5]的纯度达到98%. 研究结果表明, 本工艺是一种简单有效的分离混合瓜环的方法.     

Two-step surfactant binding of solvated and cross-linked poly(N-isopropylacrylamide-co- (2-acrylamido-2-methyl propane sulfonic acid))

 A solvated and cross-linked copolymer of N-isopropylacrylamide (IPAAm) and 2-(acrylamido)-2-methyl propane sulfonic acid (AMPS) was synthesized and its interaction with cationic surfactant lauryl-pyridinium chloride (C₁₂PyCl) was investigated. The solvated copolymer exhibited a lower critical solution temperature (LCST) in water, which was extensively shifted to a higher temperature due to the increase of hydrophilicity introduced by AMPS. In C₁₂PyCl solution, LCST of the copolymer was dramatically decreased due to the binding of C₁₂PyCl to AMPS unit, forming a stoichiometric complex. However, in the concentrated C₁₂PyCl solution, its LCST increased due to the non-stoichiometric complex formation. This phenomenon was further examined in the cross-linked copolymer, analyzed by binding isotherms. Two-step binding of surfactant was demonstrated followed by gel shrinking and re-swelling. This binding mechanism was further discussed regarding the effect of charge density and the hydro-phobicity of the main-chain backbone in terms of electrostatic and hydrophobic interactions. Received: 13 May 1997 Accepted: 13 August 1997     

豆类秸秆两级热解特性研究

利用热裂解仪-气相色谱/质谱联用仪(Py-GC/MS)对黄豆秆进行了两级热解。结果表明,随着第一级热解温度(t1)的升高,第一级热解产物总峰面积逐渐增大,第二级热解产物总峰面积逐渐减小;在第一级热解产物中,酸类、酮类和呋喃类等源于纤维素和半纤维素的产物含量在t1为400和450℃时较高;在t1为450和500℃的条件下,第二级热解产物中烃类产物的含量高达20%以上。两级热解可以在第一级和第二级热解中分别获取不同的高含量产物,如乙酸、糠醛、愈创木酚、甲苯和苯等,实现生物质的选择性热解。     

FABRICATION AND APPLICATION OF NEAR-FIELD OPTICAL FIBRE PROBE

In this paper, the fabrication of a large cone angle near-field optical fibre probe, using the two-step chemical etching method and bent probe, is introduced, and the controlling parameters of the coated Cr－Al film at the probe tip are presented. The scanning electron microscopy images display that the tip diameter of the uncoated large cone angle fibre probe obtained is less than 50nm, the cone angle over 90°, and the diameter of light aperture at the coated probe tip is less than 100nm. The measured results of the optical transmission efficiency for various probe tips show that the uncoated straight optical fibre probe, film-coated straight probe and film-coated bent probe are 3×10^-1, 2×10^-3, and 1×10^-4 times that of the flat fibre probe, respectively. In addition, the force images and near-field optical images of a standard sample are acquired using a large cone angle and film-coated bent probe.