层间反应法制备CaGa2S4∶Ce电致发光器件

报道了用层间反应法制备ＣａＧａ２Ｓ４∶Ｃｅ薄膜，用电子束蒸发法交替沉积ＣａＳ∶Ｃｅ和Ｇａ２Ｓ３膜，然后经一定的处理，获得ＣａＧａ２Ｓ４∶Ｃｅ膜。Ｘ射线衍射、ＳＴＥＭ显微照片和ＥＤＸ等分析结果表明，产物为结晶度较好、符合ＣａＧａ２Ｓ４∶Ｃｅ化学计量比的发光薄膜，并得到了Ｃｅ３＋的蓝色发光谱。     

丙烯／长链α－烯烃共聚物的13C—NMR和红外光谱法测定组成

ssignment of Peaks of 13C nuclear magnetic resonannce spectra ofpropylene/pentene-- 1 and propylene/das-- 1 copolymers and determination ofcomposition of these copelymers by 13C NMR method were studied. The moreconvenient infrared method for determining composition of these copolymers, together with that of reported propylene/octene-- 1 copolymers, was established by construing curves of IR absorption ratios A_720cm--1/A_970cm--1 (A_733cm--1/A_970cm--1 forpentene copolymers) against ratios of two component ofcopolymer calculated from ¹³C-NMR spectra of experimental samples and blends of PP.respective homopolymer of known compositions. Linearity of these calibration cruves testifies the rationality in selecting the IR absortion peaks.     

球形La2O3∶Eu纳米晶的制备及其发光特性

近年来纳米材料的发展及纳米材料所具有的特异的光学性质,使得纳米发光材料引起越来越多的关注。La2O3结构简单,易于合成,价格便宜．因此以La2O3为基质的发光材料已有很多报道。Mekittric等研究认为,发光材料的形貌,如颗粒度、形状、结晶性等．是影响发光效率的一个重要因素．球形颗粒可以提高其密堆性．从而能有效地提高产品的发光亮度。     

海绵中提取的异臭椿萜类化合物作用靶标的识别

采取了包括化学结构相似性学习、靶标聚类分析以及反向对接筛选等多种方法在内的综合性策略, 尝试对中国南海海绵中提取得到的异臭椿萜类化合物进行生物学活性和作用靶标的预测. 结果表明: 这类化合物具有治疗心肌缺血和抗肿瘤的潜在生物学活性; 表皮细胞生长因子受体(EGFR), 焦点(局部)粘着斑激酶(FAK), 胰岛素样生长因子1受体 (IGF1-R), c-Src激酶以及血管表皮生长因子受体2 (VEGF-R2)是这类化合物可能的作用靶标. IC₅₀值从0.41 g·m^-3 (0.41 μg·mL^-1)到9.8 g·m^-3 (9.8 μg·mL^-1)不等. 活性数据显示这些海绵提取的海洋天然产物可作为先导化合物, 通过进一步的优化获得新的药物. 同时还讨论了化合物与预测靶标的结合模式, 结果显示四个化合物都与相应的受体有较好的结合.     

基于结合位点的辅酶A结合蛋白家族的分类

发展了一种基于分子相互识别的蛋白质分类方法, 应用数据挖掘策略与统计学聚类, 根据辅酶A (coenzyme-A, CoA)结合蛋白的结合模式特征数据, 通过对比和分析多种分类方法对该体系的分类准确度, 对这类体内重要的蛋白进行了分类方法学研究, 选择了最优的两步聚类法. 本研究工作设计和建立了一个分类参数, 可以简洁有效地评价出各个结合特征的显著性与重要性, 并以此为依据从所有特征中筛选出决定性的特征变量. 研究结果所得到的CoA结合蛋白的三个分类, 都具有显著的氢键与疏水结合特征; CoA可以与多个生物活性关键氨基酸残基形成氢键作用. 这些相互作用的共性及分类上的差异, 说明了配体与不同受体相互作用过程中结合模式上的细微差别, 对于以CoA结合蛋白为靶点的选择性调控分子设计具有重要的参考意义与指导作用.     

基于结构和药效团特征的人类腺苷受体拮抗剂选择性比较

腺苷受体是重要的治疗靶标,选择性腺苷受体拮抗剂具有广泛的临床应用前景.本文通过同源模建构建了腺苷A₁、A_2B和A₃受体的结构,采用LigandScout 3.12软件分别构建了腺苷受体四种亚型的拮抗剂药效团模型.然后利用Schrödinger程序中的Induced Fit Docking模块完成受体-拮抗剂结合模式的预测,并与药效团结果进行比对.结果发现,由于结合口袋部位的残基在家族间高度保守,模建得到的各个亚型受体的初始结构活性口袋部位极为相似,无法用于亚型选择性拮抗剂的识别.而腺苷受体四种亚型拮抗剂药效团的药效特征与空间排布都不同,并与以前突变实验信息相吻合.研究结果说明,结合口袋部位的优化是模建中的关键步骤,基于配体的药效团模型所包含的一系列药效特征元素如氢键受体、氢键供体、疏水基团、芳环中心,可以很好地表征受体结合部位氢键、疏水空腔的位置及其方向.本文研究结果可以为进一步的优化同源模建结果,寻找新型的人类腺苷受体选择性拮抗剂提供理论依据.     

SILURIAN-DEVONIAN COUPLING OF THE NORTH CHINA AND YANGTZE PLATES: EVIDENCE FROM THE GEOCHEMISTRY OF SEDIMENTARY ROCKS

Major and trace element compositions of a large number of Proterozoic-Tertiary finegrained clastic sedimentary rocks from the Qinling Orogenic Belt and its adjacent southern margin of the North China Platform and northern margin of the Yangtze Platform reveal that the North China and Yangtze plates were coupled during the period of Silurian to Devonian.     

华北与扬子板块志留—泥盆纪对接的沉积地球化学证据

本文根据对秦岭造山带与其相邻华北地台南缘,以及扬子地台北缘元古宙至第三纪各时代细粒碎屑沉积岩大量样品的主量、微量元素的研究结果,从沉积地球化学的角度论证了华北与扬子板块的对接应发生在志留-泥盆纪.     

肝靶向性磁共振成像造影剂——含D—半乳糖基的DTPA双酰胺钆…

通过二乙三胺五乙酸的双Ｎ－羟基琥珀酰亚胺活性酯与含氨基的乳糖或Ｄ－半乳糖衍生物反应，合成了８种含有Ｄ－半乳糖基的二乙三胺五乙酸非离子型配体，并进一步合成了其钆（Ⅲ）配合物，配体及配合物的结构经ＩＲ，＾１ＨＮＭＲ与元素分析表征，对配合物的体外驰豫性能和小鼠急性毒性作了初步研究，家兔在磁共振成像实验表明这种上类造影剂具有肝靶向的特性。     

Acceleration test of substrate-packaged fiber Bragg grating sensor北大核心CSCD

To test whether the fiber Bragg grating (FBG) sensor can endure the steady-state inertial loads caused by the acceleration and the sensing properties during the loads, a FBG strain and temperature sensor with aluminium alloy substrate package was designed, and the acceleration performance on the sensor was tested. The sizes of FBG strain and temperature sensor were designed and its package process was described. The strain and temperature sensing mechanisms of FBG sensor were analyzed, and the spectrum detection and demodulation system based on volume phase grating and linear array photodetector was developed. Finally, the acceleration test equipment was established, and the acceleration performance test of the selected FBG strain and temperature sensor was carried out in accordance with the requirements and methods of GJB150.15A acceleration test. The experimental results show that in the 2 min performance test before and after the acceleration test, the wavelength offset is below to ±50 pm, and the change of light intensity is below to 0.3 V. In acceleration test, the maximum fluctuation of wavelength offset is ±7 pm, and the light intensity is in the range of 1.3 V~4.003 V. It is proved that the designed FBG sensor has the ability to endure the acceleration loads and has the good sensing performance during the acceleration loads. Copyright ©2022 Journal of Applied Optics. All rights reserved.