Strong convergence theorems for equilibrium problems and relatively nonexpansive mappings in Banach spaces

The purpose of the paper is to introduce modified Halpern and Ishikawa iteration for finding a common element of the set of fixed points of a relatively nonexpansive mapping and the set of solutions of an equilibrium problem in Banach spaces. We also consider two strong convergence theorems for relatively nonexpansive mappings with some proper restriction.     

In Situ Synthesis of Reduced Graphene Oxide and Gold Nanocomposites for Nanoelectronics and Biosensing

In this study, an in situ chemical synthesis approach has been developed to prepare graphene–Au nanocomposites from chemically reduced graphene oxide (rGO) in aqueous media. UV–Vis absorption, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy were used to demonstrate the successful attachment of Au nanoparticles to graphene sheets. Configured as field-effect transistors (FETs), the as-synthesized single-layered rGO-Au nanocomposites exhibit higher hole mobility and conductance when compared to the rGO sheets, promising its applications in nanoelectronics. Furthermore, we demonstrate that the rGO-Au FETs are able to label-freely detect DNA hybridization with high sensitivity, indicating its potentials in nanoelectronic biosensing.     

基于Windows Mobile的切削用量计算软件的开发

为了实现数控加工中切削用量的便捷计算,开发基于Windows Mobile的切削用量计算软件.该软件采用触摸按钮完成切削参数的输入,且具有输入数据的自动校验功能,实现了切削用量的便捷计算.经测试,该软件在多普达TOUCH HD型号或其他Windows Mobile操作系统的智能手机上均能正常运行,表明其具有良好的通用性.     

关于数据仓库分库策略和应用场景的探讨

应用系统随着用户数和业务量的增长,数据规模会变得越来越大,数据仓库面临的存储压力和性能压力都与日俱增。为了满足业务系统发展的需要,数据仓库面临的主要问题就是如何持续的提升处理分析能力,仓库的物理拆分便成了一种首要的选择方案。针对不同的应用场景拟定合理的数据仓库分库策略显得越发重要,该文结合数据仓库建设项目中分库实施遇到的问题,对各种不同的分库策略和场景进行分析和探讨。     

博弈结构、生产方式与双方道德风险组织激励

基于委托代理理论给出了双方道德风险组织激励问题的基本分析框架,建立合作与非合作博弈结构下双方道德风险组织激励问题的规划模型。以分析框架与规划模型为基础,引入线性生产与协作生产两种具体的生产方式,全面对比分析了不同博弈结构、不同生产方式下双方道德风险组织激励的均衡努力、最优契约和效用水平,揭示了不同博弈结构、不同生产方式下双方道德风险组织激励问题的特点与规律。     

Optimization of multi-stage countercurrent extraction of antioxidants from Ginkgo biloba L. leaves

Multi-stage countercurrent extraction (MCE) as a novel extraction technique was used to extract antioxidants from Ginkgo biloba leaves. Orthogonal array design (OAD) was employed to optimize the ratio of 60% ethanol to raw material (8–16 mL/g), extraction time (30–60 min) and extraction temperature (60–80 °C) to obtain a high yield of antioxidants from G. biloba leaves by MCE. The optimum conditions were a ratio of 60% ethanol to raw material of 16 mL/g and extraction time of 30 min at 80 °C. Under these conditions, the yields of flavonoids and total phenolics were 1.74% and 2.42%, respectively, and DPPH radicals scavenging activity of the extract was 89.97%. Compared with heat-reflux extraction, MCE had obvious advantages of less extraction time and lower solvent and energy consumption. It may be used as a promising technique for the extraction of bioactive compounds from plant materials.     

Growth of large-sized graphene thin-films by liquid precursor-based chemical vapor deposition under atmospheric pressure

Large-sized thin-films composed of single- and few-layered graphene have been synthesized by chemical vapor deposition (CVD) on copper foils under atmospheric pressure using ethanol or pentane as the precursor. Confocal Raman measurements, transmission electron microscopy and scanning tunneling microscopy show that the majority part of the obtained films exhibit hexagonal graphene lattice. Optical microscopy and electrical measurements confirm the continuity of these films. It is also found that the CVD-grown graphene films with ethanol as the precursor exhibit lower defect density, higher electrical conductivity, and higher hall mobility than those grown with pentane as the precursor. This liquid-precursor-based atmospheric pressure CVD synthesis provides a new route for simple, inexpensive and safe growth of graphene thin-films.     

CO2 and pollutant emissions from passenger cars in China

In this paper, CO₂ and pollutant emissions of PCs in China from 2000 to 2005 were calculated based on a literature review and measured data. The future trends of PC emissions were also projected under three scenarios to explore the reduction potential of possible policy measures. Estimated baseline emissions of CO, HC, NO_x, PM₁₀ and CO₂ were respectively 3.16×10⁶, 5.14×10⁵, 3.56×10⁵, 0.83×10⁴ and 9.14×10⁷ tons for China’s PCs in 2005 with an uneven distribution among provinces. Under a no improvement (NI) scenario, PC emissions of CO, HC, NO_x, PM₁₀ and CO₂ in 2020 are respectively estimated to be 4.5, 2.5, 2.5, 7.9 and 8.0 times that of 2005. However, emissions other than CO₂ from PCs are estimated to decrease nearly 70% by 2020 compared to NI scenario mainly due to technological improvement linked to the vehicle emissions standards under a recent policy (RP) scenario. Fuel economy (FE) enhancement and the penetration of advanced propulsion/fuel systems could be co-benefit measures to control CO₂ and pollutant emissions for the mid and long terms. Significant variations were found in PC emission inventories between different studies primarily due to uncertainties in activity levels and/or emission factors (EF).     

关于导师制对提高材料化学专业本科毕业论文质量的探讨

本科毕业论文是高等院校人才培养计划的重要组成部分,是必须的实践教学环节,其质量的高低是一所高校教育教学质量的直接反映。当前高校本科毕业论文现状,反映出本科生的科研意识淡薄、科研能力低下的问题相当突出。本科生科研导师制对解决时下本科毕业论文存在的问题具有积极意义,值得尝试。     

Tuning the optical properties of metamaterials based on gold nanowire arrays embedded in alumina

We fabricated a series of gold nanowires/alumina composite films with different wire lengths. Optical transmission measurements confirmed that the composite films exhibit transverse and longitudinal surface plasmon resonances. We show that the wavelength of the longitudinal resonance is sensitive to nanowire length, while that of the transverse resonance is not. The experimental results are in agreement with the modeled results based on the Maxwell Garnett effective medium theory. Moreover, the window for negative refraction of the samples can be tuned in synchronism with the longitudinal resonance by the nanowire length.