钝化多孔硅光致发光谱的时间演化特性

通过改变溶液的组成成份,用水热腐蚀技术原位制备出具有不同表面钝化状况的四类多孔硅样品.将上述样品室温下存放于空气中,其光致发光谱的时间演化特性差异很大.其中,氢钝化多孔硅的发光强度衰减最快,峰位蓝移量也最大,而铁钝化多孔硅的发光强度和峰位则几乎不发生变化.红外吸收谱实验揭示出这种差异可能来源于样品表面钝化成份的不同.此发现为一步原位制取具有稳定发光性能的多孔硅提供了新的思路.     

双重介质油藏数值模拟并行算法研究

裂缝型碳酸盐岩油藏非均质性极强,数值模拟运算时间长,迫切需要一种切实可行的解决方法。介绍了区域分解法在数值模拟中的应用方法,提供了油藏数值模拟串行算法并行化的一般策略与方法。基于已开发的双重介质油藏数值模拟串行算法及建立的Windows平台PC集群网络并行计算环境,利用消息传递界面（MPI库）实现了并行过程中所有消息的传递功能。通过对国内某实际碳酸盐岩油田的模拟表明,并行后的算法是成功的,2个PC加速比高达1.86,4个PC达到3.46,8个PC达到6.89。通过模拟还发现,并行数值模拟时,存在最佳的子区域规模和数目。该算法解决了大规模碳酸盐岩油藏数值模拟时间长的问题,具有实际的应用价值。     

Effects of binder strength and aggregate size on the compressive strength and void ratio of porous concrete

To test the influence of binder strength, porous concretes with 4 binder strengths between 30.0-135.0 MPa and 5 void ratios between 15%-35% were tested. The results indicated that for the same aggregate, the rates of strength reduction due to the increases in void ratio were the same for binders with different strengths. To study the influence of aggregate size, 3 single size aggregates with nominal sizes of 5.0, 13.0 and 20.0 mm (Nos. 7, 6 and 5 according to JIS A 5001) were used to make porous concrete. The strengths of porous concrete are found to be dependent on aggregate size. The rate of strength reduction of porous concrete with small aggregate size is found to be higher than that with larger aggregate size. At the same void ratio, the strength of porous concrete with large aggregate is larger than that with small aggregate. The general equations for porous concrete are related to compressive strength and void ratio for different binder strengths and aggregate sizes.     

Characterization of Fe3Si-based coatings on low silicon steel by pulsed Nd:YAG laser cladding

The Fe₃Si based coating was produced on the Fe-1 Si steel surface by a pulsed Nd:YAG (yttrium aluminum garnet) laser. Its phase constitution and microstructure were characterized by using X-ray diffraction (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM) with associated energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The hyperfine structure of the coating was studied by Mrssbauer spectra (MS) and the magnetic property was also measured at room temperature by a vibrating sample magnetometer (VSM). The obtained coating is pore and crack-free with dense microstructure and high Si content. The metallurgical bonding between the coating and the substrate was realized. The microstructure of the coating is typical fine dendrites. The major phase was confirmed by XRD and TEM to be the ordering D0₃ structured Fe₃Si phase. In addition, there were smaller amounts of the Fe₅Si₃ phase and the γ-Fe phase in the coating. Compared with the substrate, the laser cladding coating has a lower saturation magnetization and a higher coercive force. The poor magnetic property might be because of rapid solidification microstructure and phase constitution in the coating.     

4-(三甲基硅基)苯乙炔单体的合成及其聚合物的制备

通过2种途径合成了4-(三甲基硅基)苯乙炔(SPA)单体,采用核磁共振谱(NMR)和傅里叶变换红外光谱(FT-IR)进行了表征,在Pd(PPh3)2Cl2和金属共催化剂催化下制备了聚4-三甲基硅基苯乙炔poly(SPA).探讨了聚合物的成膜性.     

格子Boltzmann法研究陶瓷过滤管基体内的稳态和非稳态流动

为了深入了解陶瓷过滤管内的微观过滤机理,将格子Boltzmann方法用于陶瓷过滤管基体内的流动研究,对流体在多孔介质内的稳态和非稳态流动进行了计算。结果表明,流体在稳态流动时,流体的速度和压力间的关系符合达西渗透定律,证明了LB计算程序的可靠性。可以得到多孔介质内的微观速度分布及变化规律。多孔介质内的孔喉处流体速度较大,局部最大速度可以达到表观过滤速度的数十倍。孔隙内各点的局部速度随压降的变化而线性变化,且在入口边界固定时,孔隙中各点的速度不随时间改变。非稳态流动时,通过给定随计算步数变化的入口压力值,分析了局部速度随入口压力的变化趋势,结果表明两者变化一致。     

三维蒸汽辅助重力驱油过程的自适应网格法

针对蒸汽辅助重力热采稠油过程中,蒸汽腔周围存在的物理量变化十分剧烈的锋面及计算计算网格必须足够的小的问题,为了有效提高对蒸汽辅助重力驱油问题的数值计算效率,研究了考虑井筒与油藏间相互耦合的三维均匀油藏的蒸汽辅助重力驱油问题的自适应网格方法,自适应网格法和均匀精细网格法之间的计算结果对比表明自适应网格法可以大幅度地提高对于蒸汽辅助重力驱油这一复杂流场的计算速度并具有很好的精度。     

H4SiW12O40/SiO2光催化剂的制备及其光催化制氢活性研究

利用溶胶-凝胶法制备了H4SiW12O40/SiO2光催化剂,并通过UV-Vis、FT-IR、TG-DTA等手段进行了表征,表明负载SiO2后,杂多阴离子与SiO2表面相互作用,使SiW12波数发生不同程度的位移.以乙醇为电子给体,考察了催化剂的光催化制氢活性,并探讨光催化活性的影响因素.     

多孔金属材料吸声性能优化分析

近年来,多孔金属材料作为一种新型材料,因其具有优良的吸声性能而越来越引起人们的关注。而在多孔金属材料一侧添加背衬是一种提高吸声性能的有效可行的方法。通过分析影响多孔金属材料吸声性能的主要因素,推导出材料的最佳厚度范围;进一步针对有无空气背衬的比较,分析其对多孔金材料吸声性能的影响。结果验证了材料背后留有空腔,能有效地提高材料的吸声性能。     

低渗透气藏气体渗流速度修正式

渗流的基本规律达西定律,是100多年前法国水利工程师达西提出的,他是通过液体实验得到的。对于气体渗流来讲,存在着滑脱效应,特别是在低渗、低速和低压时,滑脱效应更为显著。在考虑了气体渗流的特点后,结合分子扩散理论得到了考虑滑脱效应的气体渗流速度方程,为进一步开展低渗透气藏渗流理论研究,油藏工程研究和动态分析建立了基础。