KTiOPO4波导的扩散性质及波导测量的研究

采用不同来源的ＫＴＰ样品，利用离子交换法制备ＫＴＰ平面波导。借助于ｍ线技术测量了有效折射率，并利用逆ＷＫＢ法计算了波导的折射率分布、扩散深度和扩散系数，发现其扩散性质差异。产生原因可能与其双晶结构有关。本文学讨论了精确测量单轴或双轴晶衬底上小的方法，提出了一个测量判据。     

含蒽醌结构新型共聚酯染料的合成及性能

以溶液聚合法合成了以１,５－二－β－羟乙醚基蒽醌为染料单体的新型共取酯染料,通过紫外－可见、核磁共振、热重等方法对聚合物性能进行表征,将其作为色母在毛细管流变仪上对聚酯纤维进行共混染色,并测定其光宾度。     

酯交换法合成L-天冬酰胺叔丁酯

由氨基酸合成多肽时,除了参与成肽的羧基需要活化以外,不参与反应的羧基则需要保护,叔丁酯基是常用的羧基保护基之一。叔丁酯基空间位阻大,比较稳定,在大多数形成肽键的缩合反应条件下不分解,必要时又可方便地在三氟乙酸中脱去。由于叔丁基的位阻大,酸催化下由叔丁醇和氨基酸直     

Read-only memory disk with AgO_x super-resolution mask layer

A novel read-only memory (ROM) disk with an AgOx mask layer was proposed and studied in this letter. The AgOx films sputtered on the prernastered substrates, with pits depth of 50 nm and pits length of 380 nm, were studied by an atomic force microscopy. The transmittances of these AgOx films were also measured by a spectrophotometer. Disk measurement was carried out by a dynamic setup with a laser wavelength of 632.8 nm and a lens numerical aperture (NA) of 0.40. The readout resolution limit of this setup was λ/(4NA) (400 nm). Results showed that the super-resolution readout happened only when the oxygen flow ratios were at suitable values for these disks. The best super-resolution performance was achieved at the oxygen flow ratio of 0.5 with the smoothest film surface. The super-resolution readout mechanism of these ROM disks was analyzed as well.     

流动注射-分光光度法间接测定微量苯胺

1　引　　言苯胺有致癌作用 ,是环境污染控制的重要指标之一。目前标准方法采用重氮化偶合反应分光光度法测定 ,也有用气相色谱法测定或者用极谱法测定。本文研究了在ＫＢｒ存在下 ,稀盐酸介质中苯胺与亚硝酸盐迅速进行重氮化反应 ,根据剩余亚硝酸盐与碘化钾反应生成单质碘 ,遇淀粉变蓝的高灵敏反应原理 ,采用流动注射分析法进行了实验条件的优化 ,建立了流动注射分光光度法间接测定微量苯胺的新方法 ,线性范围 0 .0～ 1.0× 10 - 3ｍｏｌ Ｌ ,测量速度 30次 ｈ ,用于棉纺厂废水、印染厂废水和河水中微量苯胺的测定 ,获得了满意结果 ,回收率…     

微型加工设备在高分子材料综合实验教学中的应用

高分子材料的综合实验包含了分子聚合、性能表征、产物加工、样品测试四类实验,产物加工实验是承上启下的关键实验教学环节,有助于提升学生对高分子材料从聚合到样品应用的全流程认知程度,增强学生对理论知识与实际操作相互关系的理解,培养学生解决复杂工程问题的能力。某高校材料科学与工程国家级教学实验示范中心在高分子材料综合实验教学课程开设中,将自主研发的微型加工设备引入产物加工实验教学,构建了包含极限式加工工艺研究、对比式配方设计、独立-合作式操作加工设备,串联理论-测试-加工知识的特色实验教学模式。     

基于脉冲直流电喷雾离子化的自动化原位质谱分析系统及其应用

脉冲直流电喷雾离子化质谱（PDESI-MS）分析具有原位、实时、快速和可分析微量样品等优点。然而,目前的PDESI-MS系统需手动操作进行样品处理和质谱进样,存在操作繁琐、步骤多、误差大和准确度低等问题。本工作研制了一套高通量、全自动化和一体化的PDESI-MS系统,探索了其在真核生物（单个膀胱癌细胞）和原核生物（细菌单菌落）中小分子代谢物原位检测分析中的应用。结果表明,本自动化PDESI-MS系统可有效检测不同菌种代谢物,实现了不同类型大肠杆菌的分类定型;同时,皮升级液滴产生技术使其可应用于单细胞检测。自动化PDESI-MS系统可实现高精度、高密度、高重复度和高自动化的原位样品萃取,特别是微量小体积样品的分析,在食品安全、再生医学、药物筛选和临床治疗等领域具有极大的应用潜力和良好的发展前景。     

CHEMICAL MODIFICATION OF SULFHYDRYL GROUPS OF E.coli LEUCYL-tRNA SYNTHE-TASE AND SEQUENCING OF [~(14)C]NEM-LABELED PEPTIDES

The chemical modification of the sulfhydryl groups of E. coli Leucyl--tRNA synthetase(LeuRS) by DTNB, NEM and IAA resulted in a time-dependent loss of both amino-acid acti-vation and aminoacylation activities in parallel. The second-order reaction constants of DTNB,NEM and IAA were 1700, 150 and 0.46 mol/L~(-1) min~(-1) respectively. Chemical stoichiometryshowed that only one sulfhydryl group of LeuRS was essential for both activities. Substratesleucine and Leu-AMP protected the active sulfhydryl group from modification, suggestingthat the modified sulfhydryl group is located in or near the active site region responsiblefor amino-acid activation. [~(14)C]NEM--labeled LeuRS was subjected to tryptic digestion, andpeptides were separated and sequenced. 179 Cys~*-Asp-Thr-Leu182 was identified as the major[~(14)C]NEM-labeled site in LeuRS. This result is consistent with the previous observationthat the region for Leu--AMP formation was located at the N--terminal part of LeuRS.     

ARGINYL-tRNA SYNTHETASE FROM Escherichia coli AFFINITY LABELING WITH 3''''-OXIDIZED tRNA~(Arg)

The covalent modification of E. coli arginyl-tRNA synthetase by the 2',3'-dialdehydederivative of tRNA~(Arg) (tRNA_(ox)~(Arg)) resulted in the complete inactivation of the ATP-PPi ex-change and aminoacylation activities of the enzyme. Sodium dodecyl sulfate polyacrylamide gelelectrophoresis of the ArgRS-tRNA_(ox)~(Arg) covalent complexes indicated that two bands simulta-neously appeared on the gel parallel with inactivation corresponding to different higher mo-lecular weights. This result was different from that of the other aminoacyl-tRNA synthetaselabeling systems as previously reported. Upon the ribonuclease treatment of the modifiedArgRS, less than 15% of both the initial ATP-PPi exchange and aminocylation activities wererecovered. During the whole process of labeling and RNase treatment, the two activities ofthe enzyme were closely associated.     

PET/PT双组分弹性长丝的热收缩性能及卷曲形成机理探讨

由于纺丝线上PET/PTT复合长丝中各组分受到的纺丝张力差异导致两组分存在潜在的热收缩性差异.从纺丝线下来的成品丝只有通过后道热处理,才能有效释放潜在的热收缩差异,获得理想、可用的卷曲弹性.通过TMA测试了PET/PTT双组分复合弹性长丝及其对应单组分纤维的热收缩性能.同样的外作用力下,PET/PTT纤维的收缩应变更接近PET纤维、远小于PTT纤维.同样预张力约0.2N下,PET/PTT、PET、PTT纤维的收缩应力依次变大.结果表明PET纤维具有较小的收缩应力和较小的收缩应变,PTT纤维具有较大的收缩应力和较高的收缩应变.这导致后道热处理过程中,PTT组分发生强烈的尺寸收缩,并带动收缩较小的PET组分位于纤维外侧并形成更为细密的卷曲.