Investigation of alkaline complexant on ethanol synthesis from syngas over slurry CuZnAlOOH catalyst

A series of alkaline complexants promoted slurry CuZnAlOOH catalysts were prepared by a complete liquid-phase method. These catalysts were applied in a slurry bed reactor to selectively convert syngas into ethanol and higher alcohols (HAs). Herein, we showed that the addition of alkaline complexant remarkably enhanced both CO conversion and selectivity toward to ethanol and HAs in terms of ternary CuZnAlOOH catalyst. Besides, the formation of dimethyl ether (DME) was significantly suppressed. Interestingly, different from the traditional alkalis modified copper-based catalysts, these catalysts promoted by alkaline complexants mainly increased selectivity for ethanol, while not isobutanol. It also reduced the deactivation rate of the catalysts. These catalysts were comprehensively characterized by XRD, H₂-TPR, NH₃-TPD-MS, N₂ adsorption, FT-IR, XPS and TEM techniques. It was found that the increase of ethanol selectivity was related to the decrease of catalyst surface acidity, while the decrease of surface Cu⁺/(Cu⁰+Cu⁺) was regarded to the main reason for the catalysts deactivation. This paper showed that the introduction of alkaline complexants into Cu-based catalysts exhibited the potentiality to improve the stability and the yield of ethanol in a slurry bed reactor.     

完整和不完整缓和曲线在AutoCAD中的精确表示

提出了用三次样条曲线绘制缓和曲线的方法.基于缓和曲线参数方程可以用复合Simpson公式表示,推出了绘制完整缓和曲线所需等弧段数n和绘制不完整缓和曲线所需等弧段数n1的严密公式和简捷实用公式.通过算例分析,验证了本文所提出的绘制缓和曲线方法的有效性.     

从《万寿盛典图》解析清代北京城街道活动空间

以康熙《万寿盛典图》为对象,结合乾隆《京城全图》对所绘街道场景进行转译,解析清代北京城街道活动空间,发掘中国古代街道空间的内涵特征。结果表明:康熙《万寿盛典图》所描绘的清代北京城街道场景具有极强的写实性;其次,街道活动空间包含围合式、开放式、沿街式的形态类型,空间相对独立,实质性质与"广场"相似,串联分布,在街道上具有连贯性;最后指出,由于街道上的公共活动使得街道形态由线性空间发展为树状空间,形成富有变化的场所。     

2.4m跨声速风洞全模颤振变速压的控制策略

基于运动规律法的变速压智能控制策略,结合2.4m暂冲式跨声速风洞的特点进行设计.其采用的模糊算法将控制过程分为多个调节段,各段根据误差和误差变化率智能选择调节参数.当误差变化到一定范围内则采用神经元PID控制器对总压的精确调节.稳态控制器则采用单神经元PID控制器,保证在设定值附近具有良好的调节效果.应用结果表明,该策略满足全模颤振试验的特殊要求,取得了流场调节过程快速、准确、可靠的试验效果.     

依稀山房 北京宋庄“向京+瞿广慈”雕塑工作室设计

文章介绍了北京宋庄"向京+翟广慈"雕塑工作室设计,作者通过比较"向京+翟广慈"雕塑工作室和作者之前设计的宋庄艺术家工作室设计,总结了贯穿始终的设计线索以及此项目的设计特点,即雕塑工作室建筑的"山"型、路径连接的空间关系等。     

Shorter Communication: Evaluating Tests for Increasing Intensity of a Poisson Process

The problem of testing the hypothesis of a constant intensity against the alternative of an increasing intensity function in a nonhomogeneous Poisson process is studied, and six wellknown tests are considered. Three of the six are shown to have desirable power-function properties, whereas the other three do not have the properties. In fact, the tests without the desirable properties should not be used, nor should any nonparametric test be used.     

An element-free Galerkin forward solver for the complete-electrode model in electrical impedance tomography

An element-free Galerkin method (EFGM) is used for solving forward problem based on the complete electrode model (CEM) in electrical impedance tomography (EIT). The EFGM requires only nodal data and has the ability of providing mesh-independent solutions because no element connectivity is needed to be used in this method. However, direct imposition of Dirichlet boundary conditions for the EFGM is difficult because the shape functions employed in this method do not have the property of Dirac delta function. Solving the EIT forward problem based on the CEM by the EFGM, the effects of electrodes and contact impedances are taken into account and the complete solution of equations is provided without imposing Dirichlet boundary conditions. The numerical results are validated with experimental results obtained from a 2D circular homogeneous phantom, and the performance of the EFGM compared with the finite element method is also illustrated. Moreover, results obtained from the EFGM are presented for an inhomogeneous numerical phantom.     

运板车整车升降控制算法研究

通过对运板车自身特性的分析,以PID控制理论为基础,提出了具有长度和压力两套PID闭环的运板车整车升降控制算法,并通过试验,证明了该算法不但可以保证4个悬挂液压缸伸缩平稳同步,而且还可以保证所有悬挂液压缸不会因承载力不够而虚腿.     

Role of the Bay- and L-Regions in the Metabolic Activation and Carcinogenicity of Picene and Dibenz[ a,h ]anthracene

Early carcinogenicity tests found no evidence of activity for picene but found considerable initiating and carcinogenic activity for DBA. More recent investigation suggests that both pentacyclics are complete carcinogens when administered as single s.c. injections in NMRI mice, despite findings that picene acts as neither an initiating nor promoting agent. To investigate this contradiction, the complete carcinogenicity of both isomers was compared by s.c. injection in female Sprague-Dawley rats. The results demonstrated that 1 w mol of DBA administered three times weekly for 20 doses, induced sarcomas in all test animals by 33 weeks (100%). Similar treatment with picene did not induce sarcoma in any test animals by 37 weeks (0%). These present results agree with the earlier studies. It follows then that the metabolic activation and carcinogenicity of DBA and picene are dependent on the presence of an L-region, but are independent of the presence of a bay-region.     

Complete and ready simulation semantics are not finitely based over BCCSP, even with a singleton alphabet

This note shows that the complete and the ready simulation preorders do not have a finite inequational basis over the language BCCSP when the set of actions is a singleton. Moreover, the equivalences induced by those preorders do not have a finite (in)equational axiomatization either. These results are in contrast with a claim of finite axiomatizability for those semantics in the literature, which was based on the erroneous assumption that they coincide with complete trace semantics in the presence of a singleton set of actions.