矿井掘进地质工作研究

基于矿井掘进地质工作是矿井地质极为重要的组成部分,它与矿井开拓地质和回采地质密切相连,是确保矿井安全高效生产的重要环节。根据多年的实践经验,总结了矿井掘进地质工作的主要内容、工作方法及作业技巧。结果表明方法针对性和实用性强,简单易行,对广大矿井地质工作者的实践操作具有一定的借鉴意义和指导意义。     

细胞毒素类抗癌药物的研究进展

综述了近年来细胞毒素类抗癌药物的研究概况,根据作用机制重点介绍了几类细胞毒素类抗癌药物的合成和结构特点,并对其化学合成方法进行了评价。     

Combustion properties of a low-vulnerability propellant: an experimental and theoretical study using laser ignition

Ignition and combustion characteristics of a low-vulnerability propellant based on RDX are studied experimentally. Ignition is obtained using a laser diode. Experiments are performed in a cylindrical closed-volume reactor for different initial pressures and initial propellant masses under nitrogen and argon surrounding atmospheres. Ignition delays, maximal overpressures, and propagation rates are obtained for different initial pressures and laser powers. Thermodynamic predictions of overpressures are also compared with experimental ones. Finally, ignition probabilities for different laser powers and gaseous atmospheres are investigated using a revised Langlie method.     

Premixed ignition behavior of C9 fatty acid esters: A motored engine study

An experimental study on the premixed ignition behavior of C₉ fatty acid esters has been conducted in a motored CFR engine. For each test fuel, the engine compression ratio was gradually increased from the lowest point (4.43) to the point where significant high temperature heat release (HTHR) was observed. The engine exhaust was sampled and analyzed through GC-FID/TCD and GC-MS. Combustion analysis showed that the four C₉ fatty acid esters tested in this study exhibited evidently different ignition behavior. The magnitude of low temperature heat release (LTHR) follows the order, ethyl nonanoate > methyl nonanoate ? methyl 2-nonenoate > methyl 3-nonenoate. The lower oxidation reactivity for the unsaturated fatty acid esters in the low temperature regime can be explained by the reduced amount of six- or seven-membered transition state rings formed during the oxidation of the unsaturated esters due to the presence of a double bond in the aliphatic chain of the esters. The inhibition effect of the double bond on the low temperature oxidation reactivity of fatty acid esters becomes more pronounced as the double bond moves toward the central position of the aliphatic chain. GC-MS analysis of exhaust condensate collected under the engine conditions where only LTHR occurred showed that the alkyl chain of the saturated fatty acid esters participated in typical paraffin-like low temperature oxidation sequences. In contrast, for unsaturated fatty acid esters, the autoignition can undergo olefin ignition pathways. For all test compounds, the ester functional group remains largely intact during the early stage of oxidation.     

聚乙烯醇产品用途的新进展

介绍了近年来聚乙烯醇产品在各个工业领域中的新途径，说明这种化工原料有广泛的使用价值。     

长壁孤岛工作面冲击失稳能量释放激增机制研究

煤矿开采中跳采形成的孤岛工作面由于容易产生应力集中，来压强度高，极容易发生冲击地压。基于唐山矿孤岛工作面的地质条件和周期来压步距的监测结果，通过数值分析的方法，研究孤岛工作面煤岩体能量释放的动态特征，揭示工作面前方能量释放激增机制，对比普通工作面和孤岛工作面能量场的区别，介绍冲击地压预警防治措施。数值模拟结果显示，长壁孤岛工作面回采时随着直接顶的随采随冒，采空区悬空面积的不断增大，使得老顶积聚大量的弹性能。若老顶发生周期性垮落，弹性能将瞬间释放，此时工作面和顺槽巷道极易冲击失稳。由研究结果可知，孤岛工作面周期来压时顶底板和煤层的能量激增可做为判断冲击失稳的前兆信息之一。因此，微震监测等手段可以根据此结论预测潜在的矿山动力灾害。针对老顶周期性断裂时积聚能量的突然释放规律，运用强制放顶、超前卸压孔、开切卸压槽和卸压爆破、煤层注水等技术可以提前释放煤层内积聚的弹性能，达到良好的冲击地压防治效果。     

复杂地质煤巷快速掘进技术研究

随着我国经济的快速发展，其对煤的需求量越来越大，带动了我国煤矿业的快速发展。机械化的加入加快了煤的开采，但在开采过程中出现了巷道易片帮等问题，研究分析了控制片帮的解决办法，并对其施工工艺进行优化，在解决巷道片帮的问题中，使用的方法为短掘短支，该方法既快捷又简单，解决了煤巷快速掘进技术中的不足，但该方法也仍旧存在着一些需要改善的地方。     

谈谈我国500kV输变电设备的技术进步与发展

述评了我国500kV输变电设备研究、制造、运行经验的水平及发展趋势，介绍了在实现引进技术国产化的基础上500kV输变电设备在电力生产和建设中发挥的作用。     

玻璃微珠的应用研究进展

介绍了玻璃微珠的类型及其特性,综述了近年来玻璃微珠的应用研究进展,包括在建材、塑料、橡胶、涂料、医药等领域的应用情况。改性后的玻璃微珠可应用于电磁屏蔽和吸波材料的制备,拓宽了其应用范围,并分析了其应用前景。