中国西部农村经济发展面临的挑战及对策

根据中国西部农村自然条件和社会条件 ,分析了西部农村经济发展中面临的问题 ,并提出了相应的对策 :抓住历史机遇 ,转变思想观念 ;改善基础设施 ,发挥设施功能 ;增加资金投放 ,提高投入水平 ;发展文化教育 ,加快人才培育 ;强化政府职能 ,提高管理水平

石油烃、Cu~(2+)单一与复合污染对沙蚕的毒性效应

在实验室模拟条件下研究了石油烃、Cu2+单一与复合污染对沙蚕的毒性效应.试验的结果表明,沙蚕的死亡率与石油烃、Cu2+的浓度呈显著相关关系.其半数致死浓度LC50分别为:30.2～116.26μg/L(石油烃);449.52～1130.34μg/L(Cu2+).沙蚕体内Cu2+的积累量随着暴露溶液中Cu2+浓度的上升而增加,当Cu2+的浓度>500μg/L时,这一变化十分显著;而沙蚕体内石油烃的含量随着暴露溶液中石油烃浓度的升高无显著变化.而Cu2+和石油烃复合污染对沙蚕的毒性作用较为复杂,在不同的处理中,表现出了协同和拮抗两种作用方式.同时,在Cu2+与石油烃复合污染条件下,沙蚕体内Cu2+的积累量也有显著变化.在复合处理组中,当Cu2+的浓度达到500μg/L时,Cu2+在沙蚕体内的积累量与Cu2+单一污染相比,Cu2+在沙蚕体内积累量相比显著降低.

Microarray based Raman spectroscopic detection with gold nanoparticle probes

microarray approach based on surface-enhanced Raman spectroscopic (SERS) was developed for detection of spotted peptide, peptide-protein or protein-antibody interaction. The procedure involves the attachment of peptide-capped gold nanoparticles followed by silver deposition for signal enhancement. The attachment of the gold nanoparticles is achieved by standard avidin-biotin chemistry. The well-known biomolecular recognition pairs, IgG/protein A and biotin/avidin, were used to demonstrate proof-of-concept of the SERS assay.

以DNA为模板构造苯胺-DNA复合物纳米线和聚苯胺纳米导线

在溶液中,以DNA为模板构造出了线性的苯胺-DNA复合物纳米线.用压缩气流将得到的复合物纳米线拉直并固定到云母基底上.用原子力显微镜(AFM)可观察到形貌规整的苯胺-DNA复合物纳米线.苯胺单体在溶液中能从各个方向上组装到DNA分子上,从而使DNA模板分子的表面包裹了一层苯胺.以苯胺-DNA复合物纳米线为前驱体通过进一步化学氧化聚合得到了以DNA为模板的聚苯胺纳米导线.

扫描探针显微镜在纳米加工中的应用

扫描探针显微镜不仅能对材料表面形貌进行原子级观测 ,还能够对单个的分子、原子及纳米粒子进行操纵。本文综述了扫描探针显微镜在纳米加工中对自组装单层膜的扫描探针刻蚀以及“蘸写笔”两方面的应用情况

Ultrathin multilayer films incorporating Keggin-type heteropolyanion clusters

Two new ultrathin multiplayer films have been successfully prepared fi-om Keggin-type heteropoly acids H-4[SiW12O40] and H-3[PMo12O40] with polyelectrolytes PEI, PSS, and PAH, using the electrostatic layer-by-layer self-assembly, technique. The XR results reveal their film thickness at nanoscale (similar to 20 nm). According to the AFM images, it is believed that the surface roughness (rough degree of film surface) of the polyelectrolyte-polyoxometalate film greatly depends on the kind of polyoxometalates.

Studies on electrostatic adsorption of proteins on modified surface by real-time surface plasmon resonance technique

The elucidation of key influence factors for electrostatic adsorption is very important to control protein nonspecific adsorption on modified surfaces. In this study, real-time surface plasmon resonance technique is used to characterize the electrostatic adsorption of two proteins (mouse IgG and protein A) on carboxymethyldextran-modified surface. The results show that protein solution pH and ionic strength are key influence factors for efficient electrostatic adsorption. The influence of protein, solution pH on the amount of electrostatic adsorption depends on the type of the charge and the charge density of both protein and modified matrix on the surface. The electrostatic adsorption process involves a competition between the positively charged protein and other positively charged species in the buffer solution. A decrease of ionic strength leads to an increasing electrostatic adsorption. The kinetic adsorption constants of protein A at different pH values were also calculated and compared.

ESR数据系统的研制

报道了电子自旋磁共振谱仪与ＩＢＭＰＣ微型机联用，建立了所需要的硬件系统，包括接口和放大器，研制了分辨率为１２位的ＡＤ／ＤＡ转换器，达到同步采样控制，并实现了Ｘ－Ｙ记录仪，示波器，绘图仪与打印机的输出，同时系统软件配有信号采样、信号累加、信号平滑、谱线加减、测量ｇ因子及Ａ值，ＥＳＲ谱的一、二次积分等一系列数据处理程序，还具有谱线模拟、线形分析等一些应用软件，对于谱的定量和解析极为方便，大大提高了谱仪的功能.

无线寻呼信息的计算机实时处理

在分析国际无线寻呼标准编码POCSAG(Post Office Code Standardization Adviso-ry Group)码的基础上,利用现有BB机的射频接收部分,以MCS-51单片微处理器为主体,设计了一个最小系统,实现对无线寻呼信号的射频解调、同步接收、通信纠错等处理,然后通过RS-232C标准串行接口传送到IBM-PC微型计算机中,进行信息译码,并在微机监视器上实时显示.

色散型光谱仪的通用计算机系统

通过微机技术与仪器改造技术相结合,探索了色散型光谱仪更新的新途径。以IBM微机为主系统,微机扫描控制器(MSC)为从系统,由RS-232串行通信口连接,以对话方式通讯、协议、交换信息。MSC的使用使系统具备了通用性和灵活性,在色散性光谱仪功能开发上具有广泛应用前景。该系统适用于红外、紫外、可见等色散型光谱仪。原机的测光系统与机械系统基本不变,由于增加了光谱数据处理能力,提高了光谱仪的使用性能。

AN EXPERT SYSTEM FOR SOLVENT-EXTRACTION OF RARE-EARTHS

An expert system for solvent extraction of rare earths has been developed using LISP. The goal of this project was to mimic the chemists' inferential abilities to assist in the process of solvent extraction of rare earths. The system includes frequently used extractants, separation of specific rare earths, recommendation of procedures for the separation of mixtures of rare earths using (2-ethylhexyl)phosphonic acid 2-ethylhexyl monoester, selection of parameters for counter-current extraction and methods for evaluation of the technique, and the economics of the processing. The expert system runs on an IBM-PC/XT.