Hydrogen storage comparison of M doped vanadium oxide nanotubes (M = Mo,Zr and W): A molecular simulation study

Zr, Mo and W doped Vanadium oxide nanotube were considered as remarkable materials for hydrogen storage applications. Monte Carlo molecular simulation was performed to study the adsorption behavior of hydrogen molecules on Vanadium oxide nanotubes (VONTs). The effects of temperature, pressure and mole percent of hydrogen on adsorption capacity of VONTs were investigated to provide deep insight of adsorption behavior. The results represented that hydrogen adsorption is an increasing function of pressure and at about 50 MPa all three metal doped VONT has maximum hydrogen capacity. At 5 MPa and room temperature, the hydrogen capacities of Mo, W and Zr doped VONTs were 1.39, 0.88 and 1.43 w% respectively. With temperature increment up to room temperature, more reduction in initial hydrogen capacity were observed in Mo and Zr doped VONTs.Evaluating hydrogen adsorption of Zr doped VONT from pure and hydrogen /nitrogen mixtures at 300 K indicated that under 2 Mpa, modifications in adsorption capacities were insignificant after N2 addition to the environment. Therefore, Zr doped VONT in hydrogen /nitrogen mixture environment can act as a capable adsorbent for Hydrogen storage system in comparison with Mo and W doped VONTs.     

SLOPE/W在某露天煤矿采掘场边坡稳定性分析中的应用

某煤矿采掘场非工作帮边坡为软岩高边坡,为分析边坡是否存在潜在安全隐患而影响施工进度及施工安全,进行了非工作帮边坡的稳定性分析。采用Geo-studio软件中的Slope/W模块建立了边坡的计算模型,并用Bishop法和Morgenstern-price法对暴雨工况和暴雨叠加地震工况进行计算,得出边坡的稳定性系数。推测的滑面计算结果与边坡稳定性评价的标准进行对比,发现计算结果与现场勘察后预测结论基本一致。该边坡整体稳定性为基本稳定。更多还原     

高压静电破乳中离散液滴的动力学分析

考虑乳化液离散液滴的直径分布,对高压直流静电破乳过程中离散液滴的运动进行了理论模拟。模拟及实验结果表明,在高压静电作用下,离散滴液从一侧电极向另一侧电极运动。沿液滴运动方向,液滴浓度逐渐增大,并在电极附近达到最大。随着静电作用时间的延长,电极附近液滴浓度近似呈线性规律增大。在相同的作用时间内,高电压液滴浓度的增长幅度要更大。因此,尽可能提高施加电压要比单纯延长静电作用时间的破乳效果更好。此外,大的液滴运动速度更快,故对于离散相滴径较大的乳化液,破乳效率会更高。     

基于GPRS的热量表无线抄表系统设计

介绍了基于GPRS的热量表无线抄表系统,论述了热量表远程抄表系统的组成、功能、特点,这种基于BENQ公司M23模块和Winbond公司W77E58单片机的热量表无线抄表系统成本低廉,性能稳定可靠。     

W型锅炉风箱并联管道各个挡板开度的计算

W型火焰锅炉在运行过程中改善燃烧器的二次风供风系统的配风结构是保证炉内形成良好的空气动力场和稳定燃烧的关键,但是目前此类锅炉的二次风供风系统的调节基本上是凭经验进行的。利用流体力学管路理论对此种锅炉二次风供风系统建立数学模型,并根据某电厂实际运行数据对二次风供风系统挡板开度进行的计算结果与现场运行情况基本一致,证明这种方法在实际工程应用中是可行的,为此类锅炉的二次风供风系统的挡板调节提供了一种理论依据。     

混凝土渗透性测试方法的改进及水胶比的影响

本文阐述了目前混凝土渗透性的测试方法当中存在的共同缺陷,以及渗透性测试方法的改进建议和改进方法.同时,阐述了水胶比与毛细孔最可几孔径尺寸对混凝土渗透速率的影响,并提出关于混凝土最小水胶比的设置建议.     

H9P2W15V3/C催化1,4-丁二醇环化脱水制备四氢呋喃

以活性炭为载体,通过浸渍法制备了H9P2W15V3/C催化剂,对催化剂进行FT-IR表征。以催化1,4-丁二醇脱水制备四氢呋喃为探针反应,考察催化剂的酸催化性能。通过正交实验得出了最佳条件反应：w（催化剂）=3.93%（相对1,4丁二醇质量）,反应温度为185～190 ℃,反应时间为40 min,四氢呋喃平均收率达93.30%,催化剂重复使用3次,产率仍可达90.94%。本工艺具有绿色、安全、操作简单、收率高等优点。     

W对铸态高铬铸铁组织和性能的影响

采用金相显微镜、扫描电镜观察显微组织,X射线衍射分析相组成,并测定洛氏硬度、冲击韧度及耐磨性,研究了w(W)量对高铬铸铁组织及性能的影响。结果表明:含钨高铬铸铁的铸态组织为马氏体+奥氏体+碳化物;W在碳化物和基体中均匀分布,w(W)量为1%时,高铬铸铁硬度为58.75HRC,冲击韧度为11.18J/cm~2;w(W)量达到3%时,高铬铸铁冲击韧度明显下降;w(W)量在0~3%范围内渐增时,随着w(W)量的增加,耐磨性不断提高。     

3Cr2W8V钢制三辊穿孔顶头的热处理

分析了无缝钢管的生产工艺要求,介绍了3Cr2W8V钢制三辊穿孔顶头的热处理工艺。     

Formation of periodic patterns in the (Ni,W)/Al diffusion couples

Formation of periodic patterns was observed in the (Ni,W)/Al finite diffusion couples after annealing at 600 °C. The individual layers in the patterns grew parallel to the original interface between the counterparts of the diffusion couples. A combination of the scanning electron microscopy, energy dispersive analysis of characteristic X-rays and X-ray diffraction revealed that the periodic patterns consisted of Al₄W/Al₅W layers, which were embedded either in the Al₃Ni or in the Al₃Ni₂ matrix depending on the local Al concentration. The Al₃Ni matrix developed in the Al-rich part of the sample, the Al₃Ni₂ matrix in the (Ni,W)-rich part of the sample. The microstructure analysis was accompanied by nanoindentation experiments that were performed in selected phases, which developed in the samples. The kinetic of the formation of the periodic patterns was investigated with the aid of diffusion couples that were annealed for 1, 3, 6 and 24 h. It was confirmed that the formation of the periodic patterns in the (Ni,W)/Al diffusion couples at 600 °C is a diffusion-controlled process. A model was suggested to describe this process and compared with existing models from literature.