天然生物可降解材料在生物医学领域中的应用

天然生物可降解材料具有优良的生物相容性，良好的生物力学功能、物理化学性能、生物性能．且原料来源广泛，目前在生物医学领域得到了广泛应用。本文就应用最广的丝素、胶原和壳聚糖与甲壳质等几种主要的可生物降解材料在医学上的用途作一综述。     

灌区建筑物消能的探讨

常规的灌区消能建筑物,消能效果较差,消能效率低,容易在消力池后形成冲掏,采用综合消能不但提高消能效率,而且降低了工程规模和工程造价.     

装备采购招投标活动中的串通投标行为

随着各种形式的招标活动在军事装备采购中越来越多地被采用,串通投标等不法行为成为一个不可回避的问题。着重分析装备采购中串通投标罪的犯罪构成特征,并分析实践中本罪与行贿罪、受贿罪、侵犯商业秘密罪的罪数关系问题,目的是为军事装备采购单位及其相关人员提供法律上的参考,以保障装备采购工作健康有序地进行。     

老化对丁羟推进剂燃速性能影响的试验研究

试验研究了贮存老化对HTPB复合固体推进剂燃速性能影响。分别采用自然老化和加速老化的试验方法,对HTPB推进剂在贮存过程中燃速的变化规律进行了对照分析。自然老化采用库房中贮存的方坯,加速老化采用热加速老化方法,燃速测定为水下声发射方法。试验结果表明,HTPB推进剂在贮存过程中燃速有随时间下降趋势,但变化不明显。自然老化与加速老化结论比较一致,具有可比性,这初步表明加速老化试验可以用于推算HTPB推进剂的燃速老化性能,所获得结论可以为固体火箭发动机进一步寿命评估作参考。分析了老化过程引起燃速性能变化的2种机理:化学老化引起的推进剂组分分解和物理老化引起的裂纹和空洞。前者使燃速产生减小的趋势,后者使燃速有增加的趋势,但总体而言,化学老化是主要的,老化的长期效应是燃速略有减小。     

KNb3O8的制备及其光催化活性探讨

探讨了固相反应法制备类钙钛矿层状化合物KNb3O8的工艺。对该方法的合成温度、时间等工艺条件进行了详尽的研究。使用X射线衍射（XRD）、扫描电境（SEM）等测试手段对样品进行了表征，并用所制得的样品对酸性红G进行了光催化降解实验。结果表明，在900℃煅烧2h可以合成纯度较高的KNb3O8，且其具有较好的催化性能。     

Transmission through the band-gap states in Schottky-barrier carbon nanotube transistors

We have studied the minimum off-state leakage current of ultrascaled Schottky-barrier carbon nanotube transistors (SBCNTs) with midgap Schottky-barrier source/drain contacts. The off-state leakage current is separated into two parts: thermal emission around the top of the Schottky barrier and tunneling through the evanescent band-gap states. Because the transmission through deep band-gap states makes a dominant contribution for ultrascaled SBCNTs, the off-state minimum leakage current increases exponentially with decreasing scaling length of SBCNTs.     

锚杆拉拨力影响因素的数值试验研究

判断锚杆拉拔力的大小是锚固支护中的重要问题之一。它涉及到岩石、粘结剂和钢筋材料的性质以及在受力过程中材料之间的相互作用。尝试采用适用于进行非线性、非连续介质复杂机理研究的“岩石破裂过程分析”（RFPA）系统，用正交试验方法进行了一系列数值试验，对影响锚杆拉拔力的6个因素进行了分析研究，并与有关物理试验结果进行了对比，得出几点有参考意义的结论。     

Study on the reduction behavior of CoOOH during the storage of nickel/metal-hydride battery

The storage of nickel/metal-hydride (Ni-MH) battery with co-precipitated cobalt hydroxide and post-added cobalt compound as the additives for pasted Ni(OH)₂ electrode is studied in this paper by using galvanostatic charge–discharge, cyclic voltammetry and X-ray diffraction (XRD). It is shown that (I) capacity loss occurs only on the battery with post-added cobalt compound during the storage; (II) CoOOH derived from co-precipitated cobalt hydroxide has a better stability than the one from post-added cobalt compound and an irreversible reduction of the latter is observed; and (III) an inactive Co + 3O(OH) is obtained from Ni(OH)₂ electrode with post-added cobalt compound after the storage and should be responsible for the property deterioration of Ni-MH battery. Thus, it is important to increase the stability of CoOOH derived from post-added cobalt compound when Ni-MH battery suffers a long-term storage.     

Reliability analysis of a repairable k-out-of-n system with some components being suspended when the system is down

A k-out-of-n system with independent exponential components is investigated. It is assumed that some working components are suspended as soon as the system is down, repair starts immediately when a component fails and repair times are independent and exponentially distributed. Formulas for various reliability indices of the system including mean time between failures, mean working time in a failure–repair cycle, and mean down time in a failure–repair cycle are derived.     

Substrate temperature dependent morphology and resistivity of pulsed laser deposited iridium oxide thin films

Iridium oxide (IrO₂) thin films were deposited on Si (100) substrates by means of pulsed laser deposition technique at various substrate (deposition) temperatures ranging from 250 to 500 °C. Effects of substrate temperature on the crystalline nature, morphology and electrical properties of the deposited films were analyzed by using X-ray diffraction, Raman spectroscopy, Scanning electron microscopy and four-point probe method. It was found that the above properties were strongly dependent on the substrate temperature. The as-deposited films at all substrate temperatures were polycrystalline tetragonal IrO₂ and the preferential growth orientation changed with the substrate temperature. IrO₂ films exhibited fairly homogeneous thickness and good adhesion with the substrate, the average feature size increases with the substrate temperature. The room-temperature resistivity of IrO₂ films decreased with the increase of substrate temperature and the minimum resistivity of (42 ± 6) μΩ cm was obtained at 500 °C. The resistivity of IrO₂ films correlated well with the corresponding film morphology changes.