抗差加权两阶段估计及其应用

在系统误差为随机变量的情况下，利用加权两阶段估计及抗差加权两阶段估计研究半参数模型得到了参数及非参数的估计；接着，讨论了估计量的影响函数及渐近方差协方差；最后，运用自由水准网的例子说明本文方法的有效性。     

Investigation of the Early Multiplication Processes of the Glow Discharge Formation in Neon Filled Diode at 1.33 mbar Pressure

The results of the investigation of the glow discharge time and space development in the neon‐filled diode at 1.33 mbar are presented. The glow is of the diffusion type with saturation current value of 0.2 mA. The temporal development of the light intensity, emitted perpendicularly on the diode axis from many different parts of the diode, is registered. Using this temporal development, the spatial development of the emitted light is examined. Electrically registered (by the oscilloscope) the total current through the diode reaches the saturation for 1.5 ms, which corresponds to the classical presumption of the formative time delay. The prebreakdown current is registered measuring the emitted light from diode gap. The investigation of light shows the increase of excitation in the gap at least 3 ms before any significant current has been registered (I < 1 µA). The negative glow appears in the diode gap near the anode and in the next a few milliseconds covers the cathode indicating the presence of the multiplication processes in the diode. The stationary regime in the diode is established for about 10 ms. Using this detection method, three stages of the discharge formation can be easily distinguished. These results indicate that the prebreakdown processes in the diode gap can be associated with the first stage of the breakdown formation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Study on the Information Capability of Dielectric Spectra in Monitoring Nonisothermal Cure Processes

The monitoring of nonisothermal cure processes by means of nondestructive dielectric spectrometry is considered for two epoxy systems with araldite resins. It is demonstrated that the dielectric characteristics at different frequencies have different sensitivities to the recognition of cure processes. An attempt to evaluate the cure process from dielectric measurements by artificial neural networks is made. It is shown that a properly trained artificial neural network allows one to detect all stages of the cure process to a high accuracy.     

湖蛙早期胚胎发育的初步观察

本文报道了对湖蛙早期胚胎发育的初步观察。湖蛙早期胚胎发育分25个期,在28±1℃条件下,整个发育过程需176.4h,与其他无尾两栖类比较,湖蛙发育速度缓慢;具明显的孵化期,胚体伸长较早;在鳃盖形成中,外鳃出现脱落现象.     

Thermogravimetric studies on poly(methyl methacrylate), poly(tetrahydrofuran) and their blends

TG studies are given for PMMA prepared by radical polymerization, PTHF prepared by cationic polymerization, and their blends. A procedure is proposed for determining the activation energy, frequency factor, and the order of events corresponding to the respective stages of the multistage TG curves. The order of the initial event of PMMA is not the 1st. It is shown for this discussion that the relationship between mass loss and time of the 2nd order reaction is similar to that of the depolymerization including the vaporization process at the earlier times. Some of TG curves of PTHF are not dependent on the heating rate. This independence depends on the size of sample. The order of event of PTHF, which is obtained from TG curves dependent on the heating rate, is the 0th. The event order equal to the 0th reflects major contribution of vaporization in the event. The TG behaviors shown by the procedure mentioned above for the PMMA/PTHF blends with the smaller PMMA or PTHF contents cancel those of PMMA or PTHF. This revised version was published online in July 2006 with corrections to the Cover Date.     

抗肿瘤药物输送系统

大多数小分子抗肿瘤药物均存在水溶性差、给药量大、体内半衰期短等问题,它们经口服或静脉注射给药后,只能通过自由扩散方式进入细胞,往往缺乏选择性,同时,对肿瘤细胞和正常细胞产生细胞毒性,具有较强的毒副作用,甚至对患者造成二次伤害。因此,它们在临床应用上受到很大限制。通过选择适宜的载体材料构筑抗肿瘤药物输送系统（如胶束、凝胶、纳米粒子等）,不仅可以延长小分子抗肿瘤药物的半衰期、降低其毒副作用,而且还可提高其溶解性和生物利用度,因而受到广大科研人员及制药企业的广泛重视。到目前为止,抗肿瘤药物输送系统的发展历史已有60多年,大致可分为传统型、智能型和靶向型三个不同的发展阶段。本文将从这三个不同发展阶段来综述抗肿瘤药物输送系统及其最新的研究进展,并对其未来的发展进行展望。     

教师资格认证下师范生教育实践能力培养模式探索

以学科教学知识(pedagogical content knowledge, PCK)为基础, 通过立体化核心课程群和"观摩—见习—研习—实训—实习"五阶段一体化实践教学体系构建, 引入教师职业资格标准, 师范生将已有的化学学科专业知识、技能和教育科学知识运用于中学化学教育、教学和研究工作;建立可观察、可测量、可操作的科学的成长档案袋, 达到系统全面地提升师范生教育实践能力的目的, 实现教育实践能力培养模式的创新探索。     

基于在线二维色谱的不同生长时期鹿茸的比较蛋白质组分析

建立了基于在线二维弱阴离子交换色谱-反相液相色谱(2D-WAX-RPLC)的蛋白质分离系统,并用于不同生长时期鹿茸的比较蛋白质组分析。以5种标准蛋白质的混合物为样品,考察了系统的重现性。通过改变标准蛋白质之间的浓度比,研究了该系统进行蛋白质相对定量的能力。在此基础上,针对4个不同生长时期的鹿茸样品,分别采用5种不同的方法进行蛋白质提取,经2D-WAX-RPLC分离后,收集各生长时期对应蛋白质的峰高最大比超过2的组分。酶解后,采用微柱反相液相色谱-串联质谱(μRPLC-MS/MS)进行肽段的分离鉴定;共从9个差异蛋白质峰中鉴定到了22个差异蛋白质。研究结果表明,利用基于蛋白质水平的在线二维液相色谱分离技术找寻差异蛋白质,具有重现性好、自动化程度高等优点,可用于开展比较蛋白质组学的研究。