Carbon nanotube–polyaniline composites

The last decade has seen a growing interest in hybrid electrically conducting nanocomposites. This article aims to provide a detailed overview of the present status of research in carbon nanotube–polyaniline (CNT/PANI) composites, from processing to structural and property evaluations. CNT/PANI are synthesized by electrochemical and chemical processing. When chemical methods are used, the main challenge is to obtain processable CNT/PANI in the emeraldine salt (ES) form composites. Stable dispersions of ES–CNT in organic media are prepared using the post doping method, inverse emulsion polymerization, or ex situ polymerizations. On the contrary, stable water dispersions of CNT/ES are prepared using hydrophilization of a preformed CNT/ES composite, direct synthesis of micelle–CNT hybrid templates, interfacial polymerization, covalent functionalization of CNT with a water soluble polymer, or using electrostatic interactions between two oppositely charged ES and CNT aqueous colloids. Moreover, the strategies for the synthesis of ternary CNT/PANI composites incorporating noble metal nanoparticles, metal oxide, or graphene sheets are also presented and analyzed in depth. Finally, we give a review of potential applications, including chemical sensors, capacitors, fuel cells and electronic devices.     

七里村油田薄油层测井识别技术研究

针对常规测井曲线纵向分辨率不高,对薄油层的响应值不准确,导致薄油层漏失解释,同时非常规的高分辨率测井系列成本高等问题,本文基于薄层对常规测井响应特征影响分析,确定薄层敏感测井曲线,综合沃尔什反演法、分辨率匹配法、傅立叶频谱法多种提高常规测井曲线纵向分辨率方法,优选出最佳方法,结果表明：傅立叶频谱法处理后的测井曲线能够有效地反映地层的真实信息,通过测井曲线纵向分辨率提高处理以后,砂体划分精度明显比原结论更加精细,测井解释结论更加准确,对全区的开发和储量接替都起到了良好的作用。     

基于0.2 m高分辨率测井系列的表外薄差水淹层解释新技术

针对高含水油田测井分辨率不足的实际和表外储层有效解释方法的缺失,充分利用0.2 m高分辨率测井新系列独特的技术优势,准确求取薄差层地层水电阻率、含水饱和度、驱油效率等地质参数。在此基础上,通过水淹状态敏感参数的优选,成功建立起水淹状态方程和重心法相结合的水淹判别方法,既准确判断出遵循"四性关系"的储层水淹级别,又解决了特征参数正态性带来的矛盾,建立起表外薄差层解释新方法,填补了表外薄差层有效解释方法这一空白,形成与新测井技术相配套的水淹层解释新技术。通过4口取心井资料验证,薄差层解释符合率高达87.5%,为特高含水期油田持续稳产提供了有力技术支撑。     

Identification and Characterization of D‐Succinylase,and a Proposed Enzymatic Method for D‐Amino Acid Synthesis

Chiral amino acids are important intermediates for the pharmaceutical industry. We have developed a novel one‐pot enzymatic method for D ‐amino acid synthesis by the dynamic kinetic resolution of N‐succinyl‐dl ‐amino acids using D ‐succinylase (DSA) and N‐succinylamino acid racemase (NSAR, EC 4.2.1.113). The DSA from Cupriavidus sp. P4‐10‐C, which hydrolyzes N‐succinyl‐D ‐amino acids enantioselectively to their corresponding D ‐amino acids, was identified for the first time by screening soil microorganisms. Subsequently, the DSA gene was cloned and overexpressed in Escherichia coli. DSA was shown to comprise two subunits with molecular masses of 26 kDa and 60 kDa. Additionally, the NSAR gene from Geobacillus stearothermphilus NCA1503, which racemizes N‐succinylamino acids, was also cloned and overexpressed in E. coli. The highly purified DSA and NSAR prepared from each recombinant E. coli were characterized and used for D ‐amino acid synthesis. A one‐pot enzymatic method converted 100 mM N‐succinyl‐dl ‐phenylalanine to D ‐phenylalanine in 91.1% conversion with 86.7% ee. This novel enzymatic method may be useful for the industrial production of many D ‐amino acids.

     

Copper(II)‐Catalyzed Asymmetric 1,3‐Dipolar [3+4] Cycloaddition and Kinetic Resolution of Azomethine Imines with Azoalkenes

An unprecedented copper(II)‐catalyzed enantioselective 1,3‐dipolar [3+4] cycloaddition of azomethine imines with in situ formed azoalkenes has been realized. This strategy provides a facile access to biologically important 1,2,4,5‐tetrazepine derivatives in high yield with exclusive regioselectivity and high stereoselectivity. Moreover, enantioenriched azomethine imines could be obtained via an efficient kinetic resolution using the same approach.

     

超高分辨率石英光纤传像束

石英光纤传像束在医疗诊断、工业设备探伤、电力设施监测、大视场成像等领域具有重要应用。本文利用溶胶-凝胶法在像元单丝间隙中引入吸收剂,解决了传像束光串扰难题。采用一次复丝工艺,制备出外径为600 μm、像元为15 000的石英光纤传像束,像元单丝直径约4.4 μm,分辨率约为113 lp/mm。结果表明,传像束无暗丝、断丝,成像清晰,无畸变,达到了商品化使用需求。     

Autonomous Variable‐Resolution Map Building for Mobile Robots in Unknown Environments

This paper presents a method that allows simultaneous map building and path planning for mobile robots in unknown environments. A graphical representation of a workspace in variable resolutions is constructed using measurement data obtained by omnidirectional distance sensors. At the same time, a search for a feasible path to the target destination is executed using the constructed graph map. The proposed method is evaluated by performing simulations and experiments using an omnidirectional mobile robot equipped with laser range finders. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 59–69, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22493     

Improved spatial resolution in soil moisture retrieval at arid mining area using apparent thermal inertia

A surface soil moisture model with improved spatial resolution was developed using remotely sensed apparent thermal inertia (ATI). The model integrates the surface temperature derived from TM/ETM+ image and the mean surface temperature from MODIS images to improve the spatial resolution of soil temperature difference based on the heat conduction equation, which is necessary to calculate the ATI. Consequently, the spatial resolution of ATI and SMC can be enhanced from 1 km to 120 m (TM) or 60 m (ETM+). Moreover, the enhanced ATI has a much stronger correlation coefficient (R²) with SMC (0.789) than the surface reflectance (0.108) or the ATI derived only from MODIS images (0.264). Based on the regression statistics of the field SMC measurement and enhanced ATI, a linear regression model with an RMS error of 1.90% was found.     

Silica Colloidal Membranes with Enantioselective Permeability

Robust mesoporous membranes composed of silica spheres were surface-modified with chiral selector moieties, including small molecules, macrocycles, and polymers. Diffusion rates of enantiomers of a chiral dye through the resulting asymmetrically modified colloidal membranes were measured and the corresponding permselectivities were calculated. The membranes showed enantioselectivities in the range of 1.2–1.8, which were not significantly affected by the structure of the surface-immobilized chiral electors. This selectivity is on par with most reported polymer-based solid membranes and bulk liquid membranes. The enantioselectivity results from the surface-facilitated mechanism of transport of enantiomers through the mesopores.