Ni-Foam Structured Ni-Phyllosilicate Ensemble as an Efficient Monolithic Catalyst for CO2 Methanation

This work proposed a new path to synthesize Ni-phyllosilicate through the reaction of nickel hydroxide and silica sol on the surface of Ni-foam to form the monolithic Ni-phyllosilicate/Ni-foam catalyst. Ni-phyllosilicate could reprint the morphology of nickel hydroxid and firmly anchor on the framework of Ni-foam, which obtained fine Ni particles of 2.8 nm after reduction in H₂ at 650 °C, resulting in high catalytic activity for CO₂ methanation. In addition, the Ni-phyllosilicate/Ni-foam catalyst showed high long-term stability in a 100 h-lifetime test owing to the combined effects of surface confinement of Ni-phyllosilicate, firm anchoring between Ni-phyllosilicate and Ni-foam, as well as the high heat transfer property of Ni-foam.

Graphical Abstract

     

五氧化二钽薄膜的制备及其I-U特性

本文利用脉冲直流反应磁控溅射的方法制备了五氧化二钽 (Ta2 O5)薄膜 ,俄歇电子能谱仪测试了薄膜的成分含量 ,椭偏仪测试了Ta2 O5薄膜的厚度和折射率 ,XRD分析了薄膜的晶体结构 ,并且分别研究了氧气含量、基底温度等成膜工艺对薄膜的影响。研究结果表明薄膜的成分主要是由氧气含量决定的。利用金属 绝缘体 (介质膜 ) 金属 (MIM)结构初步对Ta2 O5薄膜进行了电学性能的测试 :皮安电流电压源测试了薄膜的I U特性 ,制备出的薄膜折射率在 2 1～ 2 2 ,MIM的I U特性曲线显示了较好的对称性和低的漏电流密度     

基于群智能混合算法的物流配送路径研究

针对物流车辆路径优化问题,考虑到基本蚁群算法有收敛速度慢、易陷入局部最优的缺点,采用了一种双种群蚁群算法,在蚁群的基础上引入差分进化(DE)和粒子群算法(PSO)。通过在PSOAS种群和DEAS种群之间建立一种信息交流机制,使信息能够在两个种群中传递,以免某一方因错误的信息判断而陷入局部最优点。通过matlab仿真实验测试,表明该群智能混合算法可以较好地解决TSP的问题。     

500kV气体绝缘金属封闭开关设备盆式绝缘子放电故障原因分析

本文介绍了某±800kV换流站恢复送电过程中发生放电故障的500kV气体绝缘金属封闭开关设备盆式绝缘子现场解体情况,结合继电保护动作分析,追溯设备出厂试验结果,并对盆式绝缘子进行了电场模拟分析,最终确定了盆式绝缘子放电故障原因.     

硼酸在润滑油添加剂领域的应用现状

硼元素引入润滑油添加剂中可改善和提高油品的抗磨性能以及热稳定性能等。硼元素是通过硼酸与碱性化合物反应而引入添加剂分子上的，因而，硼酸已逐步成为润滑油添加剂的重要原料之一。介绍了硼酸在润滑油添加剂中的应用现状，包括含硼清净剂、含硼分散剂、含硼极压抗磨剂、含硼防锈剂。主要介绍了世界各大石油公司生产含硼润滑油添加剂的商品牌号、合成方法等。指出随着中国汽车工业的发展，环保、节能法规的不断出台与执行力度的加大，含硼等环保、节能型润滑油添加剂将得到广泛的使用，其中硼化丁二酰亚胺市场潜力巨大。     

Stability Analysis for Time-delay Systems via a Novel Negative Condition of the Quadratic Polynomial function

This paper studies the stability analysis problem for time-varying delay systems. An appropriate Lyapunov-Krasovskii functional (LKF) is constructed where its derivative is a quadratic polynomial function of the delay. A novel negative condition of the mentioned quadratic function with two variable parameters is developed to ensure that the LKF derivative is negative, reducing conservatism on some similar results. Besides, an extended version of Bessel-Legendre inequality is introduced to be employed in the stability analysis of time-varying delay systems. Then, some stability criteria with less conservatism are derived for two kinds of the time-varying delay. Finally, the effectiveness of the proposed stability criteria is demonstrated through three examples.

     

黄河流域三门峡水文测区泥沙密度试验分析

黄河流域三门峡水文测区地处黄河中下游,测区所辖水文站分布在晋、陕、甘、豫区间,是黄河流域多沙、粗沙区,也是治理黄河泥沙的重点区域。多年来,测区各水文站大多采用置换法推求泥沙水样的沙重,泥沙密度值均取经验值2.70 g/cm~3。为了验证这一数值的准确性,在1990~1995年试验的基础上,于2007年和2013年,在本测区黄河干流和重要支流的12个水文站和库区取样,进行密度试验。通过统计分析,求出本测区黄河干流各站的泥沙密度值为2.71g/cm~3、支流各站的泥沙密度为2.73g/cm~3。     

Multistatic passive radar imaging algorithm for the gapped aperture

Due to usually a small number of narrowband external illuminators and their uneven distribution, a single external illuminator and several receivers are used to synthetize aperture equivalently. The form of the target echo of the multistatic passive radar system is analyzed, and then the relationship of Fourier transform pair between target scattering function and the echo received by radar is deduced. Based on the prior knowledge of sparse distribution of the target, the algorithm of Compressed Sensing is used to recover the scattering coefficient of targets. Finally, the positions of receivers have been optimized by minimizing the correlation of the dictionary matrix based on minimizing the correlation coefficient of the dictionary matrix by the algorithm of Simulated Annealing (SA). Simulations show that the performance of the recovery of the image is improved significantly after optimizing.     

基于二阶锥规划的共形阵列宽带方向图综合

针对目前共形阵列方向图综合算法中全局优化算法计算复杂度高,已有凸优化算法不能处理宽带信号的问题,提出了一种基于二阶锥规划的共形阵列宽带恒定束宽方向图综合方法。该算法首先推导并建立了更为简单的共形阵列宽带信号模型;然后在频域上构造空间响应变化约束,并在空域上构造方向图的目标函数和约束条件;最后利用二阶锥规划求得最优权矢量,实现宽带信号方向图综合。理论分析和仿真结果表明,该方法能够有效地获得期望信号并抑制干扰信号,在计算复杂度上低于全局优化算法,且阵列响应具有良好的频率一致性。     

辽河油田茨9区水平井开发方案预测

茨9区油藏为发育边水的中孔中高渗油藏,利用直井开发的弊端日益凸现,水平井开发可行性研究的论证认为,该区油藏部署水平井开发优势明显。在剩余油分布规律的基础上利用数值模拟的方法对茨9区进行水平井开发方案设计,确定了水平井开发的目的层位、水平井段方向以及长度,并利用数值模拟对开发方案进行结果预测,结果表明水平井开发从累积产油量以及含水上升情况等方面都远优于直井开发,综上为茨9区的进一步开发提出新的方向。