生物降解ε—己内酯／d,l—丙交酯共聚物的合成与表征

采用一种新型的稀土配位化合物Ｙ（ＣＦ３ＣＯＯ）３／Ａｌ（ｉ－Ｂｕ）３为催化剂，制备了不同组成的ε－己内酯／ｄ，ｌ－丙交酯共聚物，并用ＧＰＣ、ＮＭＲ和ＤＳＣ表征了共聚物的结构．结果表明通过改变初始投料中两种单体的比例，可以调节共聚酯的化学结构，而共聚物的形态则受结构影响很大．     

生物降解聚合物膜的制备及防肌腱粘连作用

生物降解聚合物膜的制备及防肌腱粘连作用甘志华景遐斌＊（中国科学院长春应用化学研究所高分子物理联合开放研究实验室长春１３００２２）张仲文徐莘香（白求恩医科大学第一临床医院长春）关键词肌腱粘连，生物降解，聚合物膜１９９６－０７－２１收稿，１９９６－０９－...     

儿茶酚在预活化聚酰胺膜多酚氧化酶电流传感器上的响应特性

本采用预活化聚酰膜固定多酚氧化酶并与浸蜡石墨极组合成传感器，测定儿茶酚的线范围２．×１０－７－１．２５×１０＾－５ｍｏｌ／Ｌ。检出限１．５×１０＾－７ｍｏｌ／Ｌ。酶的固定时间仅需１－２ｍｉｎ，５个月之后被固定酶的活性未见下降，活性酶膜的制备，贮存，替换均很方便，对传感器的机理进行了探讨。     

(La0.8Sr0.2)0.9MnO3–Gd0.2Ce0.8O1.9 composite cathodes prepared from (Gd, Ce)(NO3) x -modified (La0.8Sr0.2)0.9MnO3 for intermediate-temperature solid oxide fuel cells

Development of high performance cathodes with low polarization resistance is critical to the success of solid oxide fuel cell (SOFC) development and commercialization. In this paper, (La_0.8Sr_0.2)_0.9MnO₃ (LSM)–Gd_0.2Ce_0.8O_1.9(GDC) composite powder (LSM ~70 wt%, GDC ~30 wt%) was prepared through modification of LSM powder by Gd_0.2Ce_0.8(NO₃) _x solution impregnation, followed by calcination. The electrode polarization resistance of the LSM–GDC cathode prepared from the composite powder was ~0.60 Ω cm² at 750 °C, which is ~13 times lower than that of pure LSM cathode (~8.19 Ω cm² at 750 °C) on YSZ electrolyte substrates. The electrode polarization resistance of the LSM–GDC composite cathode at 700 °C under 500 mA/cm² was ~0.42 Ω cm², which is close to that of pure LSM cathode at 850 °C. Gd_0.2Ce_0.8(NO₃) _x solution impregnation modification not only inhibits the growth of LSM grains during sintering but also increases the triple-phase-boundary (TPB) area through introducing ionic conducting phase (Gd,Ce)O_2-δ, leading to the significant reduction of electrode polarization resistance of LSM cathode.     

贮氢电极电化学阻抗谱及其数学模型

从分析贮氢电极的放电过程着手，建立了具有明显物理意义贮氢电极电化学阻抗谱的数学模型，以该数学模型为基础，讨论了与电极材料性质和电极荷电状态相联系的一些参数。     

On the mechanism of alkane S1 decay

Results of photodecomposition studies of liquid cyclohexane n-octane, n-decane and methylcyclohexane with 7.6 eV photons are reported for various temperatures. In all cases the yield of molecular elimination decreases with decreasing temperature. In the presence of xenon this yield is also found to decrease. The fluorescence decay rate of cyclohexane and methylcyclohexane as obtained from pulse radiolysis measurements, shows a considerable temperature dependence, and is increased in the presence of xenon. The results of the photodecomposition experiments and of the fluorescence experiments are compared and discussed.     

石墨炉原子吸收分光光度法测定土壤中的镉

采用硝酸、高氯酸、氢氟酸消解土壤样品,用石墨炉原子吸收分光光度法测定土壤中镉的含量。线性回归方程为A=0.01733c-1.03×10~(-5),相关系数r=0.999 2,回收率为95％～105％,相对标准偏差RSD为7.5％～8.1％,方法检出限为0.019mg/kg。试验结果表明,该方法能满足环境土壤样品监测要求。     

Mechanically Interlocked Hydrogel–Elastomer Hybrids for On‐Skin Electronics

Soft electronics that seamlessly interface with skin are of great interest in health monitoring and human–machine interfaces. However, achieving mechanical softness, skin adhesiveness, and high conductivity concurrently has always been a major challenge due to the difficulty in bonding dissimilar materials while retaining their respective properties. Herein, the mechanically interlocked hydrogel–elastomer hybrid is reported as a viable solution to this problem. Hydrogels with low moduli and high adhesiveness are employed as the substrate, while porous elastomer webs are used as matrices to load conductive films and lock the hydrogels through a mechanically interlocked structure. The bonding strength between the hydrogel and elastomer in the interlocking hybrid structure is 14.3 times of that obtained via the physical stacking method. As a proof of concept, interlocking hybrids are used as on‐skin electrodes for electrophysiological signal recording including electromyography and electrocardiography. The robust hybrid electrodes are able to detect signals after multiple cycles. The proposed strategy not only is an effective approach to achieve interlocking structures, but also provides a new perspective for soft and stretchable electronics.     

纳米材料的结构Ⅰ:四氟化硅纳米粒子的结构(英文)

通过超声膨胀产生了直径约为4．3nm的SiF4纳米粒子，并用电子衍射表征其结构．在选择的射流部分中，粒子大小的分布是很窄的，因而可以用541个分子构成的分子簇进行结构精化．在SiF4的纳米粒子中，分子的堆积可用大块物质的立方晶体结构来模拟.还谈到纳米粒子表面上由于平动和转动运动引起的分子混乱．     

A novel three-dimensional cobalt (III) complex via hydrogen bonds: [Co(tacn)2] (ClO4)3 (tacn=1,4,7-triazacyclononane)

A novel cobalt (III) complex has been synthesized and its structure was determined. The structure consists of Co(tacn)₂³⁺ ions and ClO₄⁻, each cobalt (III) ion was six-coordinated with six nitrogen atoms of two tacns. Hydrogen bonds widely exist between the oxygen atoms of ClO₄⁻ and the nitrogen and carbon atoms of tacn, resulting in a unique three-dimensional network. The electronic spectra were measured and assigned in the strong-field approximation, giving the values of the parameter: Δ, B and C.