Ni catalyst promotion of a Cis-selective Pd catalyst for canola oil hydrogenation

A Ni catalyst was added to a cis-selective Pd catalyst in an attempt to further improve the Pd catalyst's cis-selectivity and activity for canola oil hydrogenation. The system was tested under reaction conditions known to be suitable for cis-selective hydrogenation with the Pd catalyst (50 ppm Pd, 70 °C, and 5.2 MPa). Although inactive on its own under these conditions, the addition of 100 ppm Ni increased the hydrogenation activity (from 2.12 to 2.49 10⁻² min⁻¹). Further addition of Ni up to 1000 ppm resulted in no further improvements in activity. The trans isomer contents of the oils hydrogenated with Pd and the Pd/Ni systems were similar. The level of conjugated dienes decreased rapidly during hydrogenation with both Pd alone and with the Pd/Ni combination and no changes in conjugation were detected in the presence of the Ni catalyst alone. The increased activity of the Pd/Ni system over Pd alone was attributed to adsorption of catalyst poisons from the oil by Ni.     

Stability of solutions of stochastic functional-differential equations with poisson switchings and entire prehistory

The Markov properties of the solutions of Ito-Skorokhod stochastic functional-differential equations (SFDEs) with entire prehistory are considered, the concept of a weak infinitesimal operator is introduced for a Markov process that is a solution of an SFDE, and the strong solution of the SFDE is analyzed for stability. Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 123–134, January–February 2009.     

Optimal control of stochastic dynamic systems with past history and poison switchings

An optimal control problem for systems of stochastic differential-functional linear equations with past history and Poisson switchings is formulated. The Bellman equation is solved for this problem.Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 112–118, November–December 2004.This revised version was published online in April 2005 with a corrected cover date.     

探讨单侧下回风局部百级洁净区的影响因素

本文运用CFD技术以疫苗车间接毒无菌室为例,探讨了干扰采用FFU单侧下回风形式的局部百级洁净区流场的各种因素和影响程度,这对类似局部百级洁净区的优化设计具有较重要的理论意义与工程应用价值。     

民用合成洗净剂的原料选择

本文介绍了民用合成洗净剂主要原料表面活性剂的毒性、刺激性、洗净性能和亲水亲油平衡值等。提供了民用合成洗净剂的原料选择思路。     

稀土在盐浴渗碳中的应用

本文研究了稀土在盐浴液体渗碳中的作用,试验表明加入稀土后,可使渗碳速度加快,渗层厚度增加,渗后淬火硬度提高,使零件达到≥HR15N89的技术要求。可取代剧毒的氰盐和微毒的“603”盐浴渗碳。     

Improving the Performance of Platinum Nanocrystal Catalysts by Square‐wave Potential Electrochemical Pretreatment

Cube‐shaped Pt nanocrystals (with the size of about 160 nm) are prepared by a square‐wave potential electrochemical pretreatment at the expense of Pt nanospheres. A cyclic voltammogram of Pt nanospheres in sulphuric acid shows two pairs of hydrogen adsorption/desorption peaks, which corresponds to the characteristics of a Pt polyoriented surface. However, a cyclic voltammogram of cubic Pt nanocrystals in sulphuric acid shows another pair of hydrogen adsorption/desorption peak at 0.22 V (vs. NHE), which corresponds to the characteristics of Pt (100) surface orientation. Cubic Pt nanocrystals show enhanced electrocatalytic activity over Pt nanospheres for methanol oxidation. The peak current density of cubic Pt nanocrystals is 1.39 mA cm^–2_Pt, which is 1.48 times that of Pt nanospheres. The poison resistant and oxygen reduction reaction (ORR) activity of cubic Pt nanocrystals are also enhanced compared with those of Pt nanospheres.     

化学实验楼的通风设计方式——华中师范大学逸夫化学楼通风设计

通过调查研究,提出了现有一些实验楼存在的问题。结合华中师范大学逸夫化学楼工程特点,对实验室有害气体的种类及散发量进行了分析,对通风柜排风系统、局部排风系统和气流组织设计进行了详细论述,对通风罩设计布置及通风机廊设备管线布置提出了自己的看法。同时对防火设计、消声减振设计及其材质的选择进行了介绍并对有害气体的净化处理及排放方式进行了介绍。     

A study on improvement of sodium cooled TRU burner design using burnable poison

A new design approach to improve safety characteristics of sodium cooled core for transuranic element transmutation is discussed. In the new option, some amount of fertile material is removed for reduction of sodium void reactivity. Simultaneously, a burnable absorber material is loaded in replacement of fertile material to compensate for reactivity drop during the fuel depletion. Two methods of burnable absorber loading are considered such as the homogeneous and the heterogeneous. In the results, it is found that the homogeneous loading cannot reduce the sodium void reactivity but makes the reactivity more positive. On the other hand, the heterogeneous loading can reduce the sodium void reactivity successfully. It is also found that the increment in burnup reactivity swing is negligible when the burnable poison is heterogeneously loaded. It is concluded that if the burnable poison material is loaded appropriately, the sodium void reactivity can be reduced without any significant penalty of increase in burnup reactivity swing.     

低荧光惰性降滤失剂XNJ-3的性能评价

为了兼顾探井、生产井（开发井）和环境保护等的要求，以直链饱和烃为原料，采用分散与聚集相平衡原理，研制成功了低荧光、低毒的钻井液惰性降滤失剂XNJ－3。对XNJ－3在淡水、正电胶和高密谋盐水钻井液中的作用进行了综合评价，并与磺化沥青进行了对比。结果表明，XNJ－3惰性降滤失剂具有良好的降滤失、润滑、防塌、封堵能力，抗温能力强（150℃以上）、抗盐能力强（7％NaCl 7%KCOOH)，与疏水缔合聚合物AP－P1、甲酸钾等处理剂配伍性好，并在高温（150℃）高密谋（密度为2.0g/cm^3）钻井液中表现出良好的降滤失效果和改善流变性能的能力；可用于正电胶MMH钻井液体系，且无荧光、低毒，整体效果明显优于磺化沥青HL－Ⅱ和SAS。