Structural characterization and electrochemical performance of lithium trivanadate synthesized by microwave sol-gel method

The Li_1+xV₃O₈ material was successfully synthesized at 450 °C in short sintering duration by microwave sol-gel route. X-ray diffraction suggests oxygen defects in the lattice. Based on Randles-Sevcik formula, cyclic voltammograms measurements were conducted to measure Li⁺ ion diffusion coefficient. The material exhibits high discharge capacity of 250 mA g⁻¹ at 0.2 mA/cm² after 30 cycles in the range of 2.0-4.0 V. Alternating current impedance tests show that the growth of the charge transfer resistance at 0.4 mA/cm² is more rapid than that of at 0.2 mA/cm² as the galvanostatical charge-discharge continues.     

Synthesis of pH-sensitive hollow polymer microspheres and their application as drug carriers

The pH-sensitive hollow poly(N,N′-methylene bisacrylamide-co-methacrylic acid) (P(MBAAm-co-MAA)) microspheres were prepared by a two-stage distillation precipitation polymerization to afford a core-shell poly(methacrylic acid)/poly(N,N′-methylene bisacrylamide-co-methacrylic acid) (PMAA/(P(MBAAm-co-MAA))) microsphere with subsequent removal of poly(methacrylic acid) (PMAA) core. PMAA/P(MBAAm-co-MAA) core-shell microspheres were synthesized by the second-stage copolymerization of N,N′-methylene bisacrylamide (MBAAm) as crosslinker and the functional methacrylic acid (MAA) comonomer in acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as initiator. The pH-responsive properties of hollow P(MBAAm-co-MAA) microspheres were investigated by dynamic laser scattering (DLS). The loading and controlled-release behavior of the drug for hollow P(MBAAm-co-MAA) microspheres was strongly dependent on the pH values with doxorubicin hydrochloride (DXR) as a model molecule. The core-shell and hollow polymer microspheres were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), DLS and elemental analysis.     

对黑龙江省电网抗扰动能力的分析

根据黑龙江省电网电源集中,地区之间联系薄弱,网架结构不合理等特点,在进行大量暂态稳定计算基础上,指出了我省电网的实际抗扰动能力;并提出了必要的措施和自动装置,以提高电网的抗扰动能力,满足电网运行方式变化的需要.     

电力变压器的合理选用

本文简述变压器运行时各种损耗关系及影响变压器运行效率的其它因素,概述八十年代学术界对选择变压器容量的各种观点,建议在基本建设及更新设备时应优先选用低损耗变压器。     

关于炭黑利润大幅下滑的思考

炭黑用途约90％是橡胶用炭黑,而在橡胶用炭黑中又有约75％是用于轮胎补强剂。据中国橡胶工业协会炭黑分会统计（以下简称据统计）,在2000～2008年间,我国炭黑处于高速增长期,炭黑产量平均增长率为17％,同时,炭黑企业结构也发生了快速变化,原来的化工部十大炭黑国企所剩无几,目前由股份制公司、民营公司、合资（包括台资）公司平分秋色,从上世纪90年代初开始,我国大力发展湿法造粒炭黑,特别是从2002年,国家发布淘汰1万吨／年以下干法造粒炭黑生产工艺以后,湿法造粒炭黑产能快速增长。     

硫铁矿渣陶粒及其高强度混凝土的试验研究

讨论了硫铁矿渣陶粒实验室试验、工业试验,利用陶粒配制了高强度混凝土。试验结果表明：利用硫铁矿渣完全可以生产高强度陶粒和高强度陶粒混凝土。     

蓝宝石衬底表面SiO2薄膜的应力分析

采用射频磁控反应溅射法分别在Si和蓝宝石衬底上沉积SiO2薄膜.通过改变沉积薄膜的工艺参数,考察反应气体流量比、沉积温度、射频功率等因素对SiO2薄膜内应力的影响.采用压痕裂纹法分析了镀膜前后蓝宝石的表面应力.结果表明:制备SiO2薄膜时,工艺参数影响SiO2薄膜的成分,当O2/Ar流量比值为1.25,衬底温度为300℃,射频功率为100 W时,可以制备出化学计量比的SiO2薄膜,此时薄膜中的内应力较小;制备的SiO2薄膜呈压应力状态,镀SiO2薄膜可以改变蓝宝石的表面应力,蓝宝石的表面应力已由原来的拉应力变为压应力.     

固溶体Ce1-xEuxO2-δ的导电性能

利用溶胶-凝胶法,经800℃焙烧10h合成了Ce1-xEuxO2-δ(x=0.05～0.50)固溶体.用X射线衍射仪检测了样品的结构,测量了样品的阻抗谱和电子顺磁共振谱.结果表明:当掺杂量x≤0.40时,固溶体的结构为单相立方萤石结构,晶胞参数随x的增加而增大.样品中存在Ce3 ,掺杂Eu3 可以抑制Ce4 离子的还原.通过掺杂使固溶体Ce1-xEuxO2-δ(x=0.10～0.40)的电导率提高,随着掺杂量x增加,电导率增大,并在x=0.20时达到最大值(500℃的电导率σ500℃=1.07×103S/cm);电导活化能减小,x=0.20时,电导活化能Ea达到最小值,为0.72eV.     

起重机械安全技术管理工作常出现的问题及相应对策

<正>1前言在唐钢金恒公司,起重机械数量较多、流动性强、使用分散,在生产过程中起重机安全事故时有发生,严重影响了生产的顺利进行,针对这一现象,我们成立了起重机整改小组,根据事故的特点,分析原因,提出改进措施,重点加强使用环节     

The inner-shell film: an immediate structure participating in pearl oyster shell formation

In mollusks, the inner shell film is located in the shell-mantle zone and it is important in shell formation. In this study, we found that the film was composed of two individual films under certain states and some columnar structures were observed between the two individual films. The inner shell film was separated with the process of ethylenediaminetetraacetic acid (EDTA) treatment and the film proteins were extracted. Amino acid analysis showed that the film proteins may consist of shell framework proteins. The calcite crystallization experiment showed that the film proteins could inhibit the growth of calcite, while the CaCO(3) precipitation experiment showed that the film proteins could accelerate the rate of CaCO(3) precipitation. All these results suggested that the film plays an important role in shell formation. It may facilitate the aragonite formation by inhibiting the growth of calcite and accelerate the shell growth by promoting the precipitation of CaCO(3) crystals.