Characterization of micellar systems produced by new amphiphilic conjugates of poly(ethylene glycol)

This study proposes polymeric micelles produced using new amphiphilic conjugates between amino- or carboxy-mPEG₂₀₀₀ and three different α-lipoamino acids (PEG-LAA). The characterization of these colloidal systems showed CMC values, in the order of 10^?5?M, that are interesting in the view of an in vivo administration. The PEG-LAA micelles also showed a good stability at 37?°C and upon dilution in aqueous media. Using a colored probe as a model lipophilic compound, the loading efficiency and in vitro release profile were also outlined.     

FAME Production and Fatty Acid Profiles from Moist Chlorella sp. and Nannochloropsis oculata Biomass

In the present study, we investigated the production of fatty acid methyl esters (FAME) from moist Chlorella sp. and Nannochloropsis oculata biomass using a hydrolysis–esterification process. Additionally, we evaluated for the first time the fatty acid profile before and after this process. Hydrolysis of the lipid fraction was performed on a moist biomass in the presence of differing amounts of an acid catalyst in both 50 and 100 % w/w water relative to the biomass. The esterification of the crude extracts of the free fatty acids (FFA) was then investigated. The experiments show that in the presence of 50 % w/w water relative to the biomass, the hydrolysis–esterification process results in higher FFA and FAME yields. The analysis of the fatty ester profiles did not reveal any degradation of the FFA from the microalgae biomass under the hydrolysis–esterification conditions. The results were compared with both extraction–transesterification and direct transesterification processes using dry biomass. The extraction–transesterification and hydrolysis–esterification processes resulted in similar FAME yields and similar profiles of the fatty esters from dry and moist biomass materials, respectively.     

变幅油缸摩擦力的研究及其在力矩限制器中的应用

通过对汽车起重机臂架系统及其变幅油缸的受力分析,结合大量试验数据与理论函数推导出变幅油缸摩擦力的函数关系,并成功地应用于力矩限制器的研发中。基于该摩擦力函数模型开发的力矩限制器,载荷精确计算的误差控制在±4％内,国标为±5％,并已经批量生产及应用。     

Color‐Coded Super‐Resolution Small‐Molecule Imaging

Although the development of super‐resolution microscopy dates back to 1994, its applications have been primarily focused on visualizing cellular structures and targets, including proteins, DNA and sugars. We now report on a system that allows both monitoring of the localization of exogenous small molecules in live cells at low resolution and subsequent super‐resolution imaging by using stochastic optical reconstruction microscopy (STORM) on fixed cells. This represents a powerful new tool to understand the dynamics of subcellular trafficking associated with the mode and mechanism of action of exogenous small molecules.     

Coil design optimization for an induction evaporation process: Simulation and experiment

For the purpose of utilizing induction heating in the evaporation process, the effects of induction coil design and droplet size on induction heating efficiency are investigated. Electro-magnetic simulations with various induction coil designs were conducted to predict the electro-magnetic field distribution. The induction coils were fabricated in order to verify the simulation results under atmospheric evaporation test conditions. The electro-magnetic simulation results indicated that the magnetic field became widened around the Zn droplet when the size of the Zn droplet increased. This in turn attributed to the increase in induction heating energy efficiency. The energy efficiency of the induction coil with 4-windings was the highest among the 3-, 4-, and 5-windings induction coils. Energy efficiency tendencies derived by the atmospheric evaporation tests corresponded well to the simulation results, and maximum energy efficiency was measured to be 42% under the atmospheric evaporation tests.     

TA2钛板掺杂钒离子渗碳层的耐腐蚀性能

为提高钛基双极板的耐腐蚀性能和导电性,在TA2纯钛的表面进行双辉离子渗碳,另外为降低渗碳温度,在渗碳过程中掺杂钒。使用扫描电镜和能谱分析、X射线衍射对改性层的组织结构、化学成分、物相组成进行研究,并测得改性层的界面接触电阻率、耐腐蚀性能。结果表明,在优化的制备工艺参数下,在TA2表面生成结构致密的TiC改性层、钒掺杂渗碳改性层。当压实力为140 N/cm²时,730℃下制备的钒掺杂渗碳改性层、850℃下制备的TiC改性层、TA2基体的界面接触电阻率分别是1.17、3.66、14.71 mΩ/cm²。在模拟双极板的工作环境中,测得730℃下制备的钒掺杂渗碳改性层、850℃下制备的TiC改性层的自腐蚀电流密度分别是5.238、7.563μA/cm²,均比TA2基体的腐蚀电流密度低1个数量级。在离子渗碳的过程中掺杂钒可以有效降低渗碳的工艺温度,并且提高TA2基体的导电性和耐腐蚀性能。     

公路工程地质勘察中彩色地质图数字化方法

利用AutoCAD2004精确制图功能和Photoshop强大的图像处理能力,解决AutoCAD图形和图像混编时其功能的不足,绘制一套具有透明性质的彩色地质图,并给出详细的操作步骤,具有较强的实用性。     

基于SR7265硬件的虚拟锁相放大器、频谱仪、阻抗计和半导体参数分析仪

锁相放大器是用来测量微弱信号的专用仪器.即使噪音上千倍于被测信号,通过锁相放大器,也能得到精确结果.随着数字信号处理技术在仪器中的应用,可编程仪器变得越来越灵活.结合虚拟仪器的技术,论文通过对SR7265的硬件重新编程,在同一个硬件上实现了虚拟锁相放大器、虚拟频谱仪、虚拟阻抗计和虚拟半导体参数分析仪等等功能.本虚拟仪器采用了4层的逻辑结构.同样的功能也在一个FPGA板上成功地部署.     

Investigation of cure kinetics in epoxy/multiwalled carbon nanotube nanocomposites

With the increased interest in thermoset resin nanocomposites, it is important to understand the effects of the material on nanoscale characteristics. In this study, a curing reaction of an epoxy resin, which contained 0.25, 0.50, or 1.00 wt % of multiwalled carbon nanotubes (MWCNTs), at different heating rates was monitored by differential scanning calorimetry; cure kinetics were also evaluated to establish a relationship between crosslinking (network formation) and mechanical properties. MWCNT concentrations above 0.25 wt % favored crosslinking formation and decreased the activation energy (E_a) in the curing reaction. Examination of the kinetic mechanism suggests that the MWCNT locally restricted the spatial volume and favored the formation of nodular morphology in the resin, especially for high MWCNT concentrations. The MWCNT exhibited some entanglement in the matrix, which hindered a more pronounced effect on the mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39857.