JP3—1型示波极谱仪电源及显示系统的故障维修

本阐明了JP3—1型示波极谱仪电源及显示系统的工作原理，并举例说明这两部分的故障维修。     

Magnetically assisted removal and separation of cationic dyes from aqueous solution by magnetic nanocomposite hydrogels

Magnetic poly(acrylic acid‐acrylamide‐butyl methacrylate) (P(AAB)) nanocomposite hydrogels were prepared and used as adsorbents for removal and separation of cationic dyes from aqueous solution. These magnetic P(AAB) nanocomposite hydrogels were characterized by scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). It was found that these magnetic P(AAB) nanocomposite hydrogels had magnetic responsive characters. The dynamic swelling, removal, and separation of cationic dye, crystal violet (CV), and basic magenta (BM) by these magnetic nanocomposite hydrogels were studied. The adsorption capacity and isotherm studies of cationic dyes onto magnetic P(AAB) nanocomposite hydrogels have been evaluated. The magnetic P(AAB) nanocomposite hydrogels containing Fe₃O₄ particles can be easily manipulated in magnetic field for removal and separation of cationic dyes from aqueous solution. Adsorption process agreed very well with the Langmuir and Freundlich models. Copyright © 2010 John Wiley & Sons, Ltd.     

Carbon-supported Pd-Co nanocatalyst as highly active anodic electrocatalyst for direct borohydride/hydrogen peroxide fuel cells

Journal of Solid State Electrochemistry - Pd/C and Pd-Co/C nanocatalysts are prepared via a simple and environmentally friendly method and are used as anodic catalyst for direct...     

强光一号加速器测量电缆补偿技术

 为满足快信号测试要求,提出了利用滤波器原理设计补偿器来提高传输线带宽,以减小信号在传输过程中的畸变和损失。针对强光一号加速器测试电缆特性,设计制作了小型化的带宽补偿器。通过采用该电缆补偿技术,强光一号加速器测量电缆补偿后的传输带宽达到200 MHz,幅度为原始信号的1/3,满足了强光一号加速器测试电缆快信号传输的要求。给出了原始信号、未补偿信号及补偿后信号的比较结果,证明补偿后的信号明显比未补偿信号更接近原始信号,原始信号经电缆传输后造成的前沿损失和波形畸变通过带宽补偿器后获到了明显的补偿和修复。编制了专用补偿器设计软件,使补偿器初期设计中的极零对寻找、元器件参数计算等工作实现自动化。     

Electrochemical behavior of spherical LiNi1/3Co1/3Mn1/3O2 as cathode material for aqueous rechargeable lithium batteries

Spherical LiNi_1/3Co_1/3Mn_1/3O₂ powders have been synthesized from co-precipitated spherical metal hydroxide. The electrochemical performances of the LiNi_1/3Co_1/3Mn_1/3O₂ electrodes in 1 M LiNO₃, 5 M LiNO₃, and saturated LiNO₃ aqueous electrolytes have been studied using cyclic voltammetry and ac impedance tests in this work. The results show that LiNi_1/3Co_1/3Mn_1/3O₂ electrode in saturated LiNO₃ electrolyte exhibits the best electrochemical performance. An aqueous rechargeable lithium battery containing LiNi_1/3Co_1/3Mn_1/3O₂ cathode, LiV_2.9Ni_0.050Mn_0.050O₈ anode, and saturated LiNO₃ electrolyte is fabricated. The battery delivers an initial capacity of 98.2 mAh g⁻¹ and keeps a capacity of 63.9 mAh g⁻¹ after 50 cycles at a rate of 0.5 C (278 mA g⁻¹ was assumed to be 1 C rate).     

520 mJ langasite electro-optically Q-switched Cr, Tm, Ho:YAG laser

A flash lamp pumped 2.09 μm Cr, Tm, Ho:YAG laser utilizing a self-grown La(3)Ga(5)SiO(14) crystal as the electro-optic Q-switch generator is proposed and demonstrated for the first time. Operating at 3 Hz repetition rate, 520 mJ pulse energy with 35 ns pulse width is achieved by optimizing the Q-switch delay time and compensating for the thermal depolarization with a quarter-wave plate. The corresponding peak power is 14.86 MW, and the Q-switched-to-normal-mode energy extraction efficiency is 66.3%. To our knowledge, this Q-switched giant pulse is the best result reported to date in 2.09 μm laser resonator.     

Mm(NiCoMnAl)5贮氢合金中铝对直封型MH/Ni电池性能的影响

制作电池前在正极活性物质βＮｉ（ＯＨ）２微粒表面沉积５％Ｃｏ,抑制了γＮｉＯＯＨ的产生,并能有效地防止βＮｉ（ＯＨ）２在充放循环过程中粉化,通过对电池充放电曲线的测量、Ｘ射线分析,探明了用前处理方法可消除贮氢合金中铝对正极活性物质的影响．     

用分光光度法测定固相络合物的组成

以镍－丁二酮肟显色体系和钇－８－羟基喹啉显色体系为例，对萘相中络合物的测量原理和测定方法进行探讨，测得镍与丁二酮肟萘相络合物的组成比以及钇与８－羧基喹啉萘相络合物的组成比均为１：２。     

Nearly monodispersed LiFePO<Subscript>4</Subscript>F nanospheres as cathode material for lithium ion batteries

Tavorite-structured lithium transition metal fluorophosphates have been considered as a good alternative to olivine-type cathode for lithium-ion batteries due to its exceptional ionic conductivity and excellent thermal stability. In this work, nearly monodisperse LiFePO₄F nanospheres with high purity are successfully synthesized by a solid-state route associated with chemically induced precipitation method for the first time. The synthesized LiFePO₄F presents nearly monodisperse nanospheres particles with average particle size of ~?500 nm. Cyclic voltammetry data exhibit a clear indication of the Fe³⁺/Fe²⁺ redox couple that involves a two-phase transition. Its electrochemical behaviors are examined by galvanostatic charge-discharge. The results show that the initial discharge capacity is 110.2 mAh g^?1 at 0.5 C, after 200 cycles is still retained 104.0 mAh g^?1 with the retention rate of 94.4%. The excellent cycle performance is mainly attributed to the uniform nanospheres-like morphology which is not only beneficial to shorten the transport distance of ions and electrons, but also improve the interface area between electrode and electrolyte, and thus improve the kinetics of Li ions.     

吡啶在几种Y型沸石上的吸附量热研究

用微量量热计测定了在室温至600 K范围内吡啶在NaY、CaY、R_EY和HY这几种Y型沸石上的吸附热。实验结果表明, 在这四种沸石上, 存在两种不同类型的酸中心, 一种是B酸中心; 另一种是非活化的L酸中心。B酸中心的酸强度随温度的升高而增加, 而非活化的L酸中心则随温度的升高而减小。在NaY沸石表面上, 只有Na~+一种非活化的L酸中心; 在HY沸石表面上则只有一种B酸中心。在R_EY和CaY表面上, 同时存在着B酸中心和非活化的L酸中心。高温时, 吡啶先吸附在强酸中心H~+上。室温时吡啶在所有试样上的吸附量均在3.0～3.2 mmolg~(-1)之间, 该值正好对应于超笼和β笼中的吸附中心数。