基于平衡计分卡的供电企业战略管理指标体系研究

利用平衡计分卡的基本原理,结合供电企业管理实际,将战略目标分解为具体的指标,使管理可衡量、可评价,促进战略管理目标的实现。     

REFORMING OF N-OCTANE ON A Pt/Al2O 3 CATALYST. 1. PRODUCT DISTRIBUTION AND KINETIC ANALYSIS.

ABSTRACT

The conversion of n-octane on Pt/Al₂O₃ catalyst to hydrocracked products, isooctane, ethylbenzene, o-,p-,m-xylene and toluene was investigated in hydrogen in a Berty CSTR at three different partial pressures of n-octane, 101·325 KPa total pressure, temperatures between 400°C-460°C and W/F values up to 0·33gmincm^-3. The hydrocracked products were the most predominant. Of the other products, isooctane was present in the highest yield. A sequence of elementary steps based on the suggested reaction network of Ako and Susu (1986) was found to predict the experimental conversion-W/F data with the conversion of adsorbed isooctane to adsorbed o-xylene as the rate determining step. The activation energies for the forward and backward reactions of this step were determined to be 21·2 and 14·3 Kcal/gmol, respectively.     

Zn2+配位双模板印迹聚合物的制备表征及同时萃取升麻中的阿魏酸和咖啡酸

以Zn²⁺-阿魏酸-咖啡酸配合物为模板制备了双分子印迹聚合物,优化了制备条件,用傅里叶红外光谱和扫描电镜对分子印迹聚合物进行结构表征,测试了分子印迹聚合物的吸附特性,探讨了分子印迹聚合物固相萃取应用效能并对萃取条件进行了优化.结果表明,当预反应混合液中金属离子、模板总量(阿魏酸-咖啡酸摩尔比为2:3)、功能单体及交联剂用量比为1:1:3:30(摩尔比)时,所得印迹聚合物对两种模板(阿魏酸和咖啡酸)均具有最好的吸附性能,吸附量分别达51.12mg/g和70.26mg/g.吸附动力学测试表明吸附3h,分子印迹聚合物可达到吸附平衡.用分子印迹聚合物进行固相萃取时,优化的淋洗过程为1.00mL H₂O、1.00mL甲醇-H₂O (3/7,体积比)及1.00mL甲醇-H₂O-ACN (4/4/2,体积比),洗脱溶剂为2.00mL甲醇.在优化条件下,分子印迹聚合物可同时选择富集升麻初提液中的阿魏酸和咖啡酸,二者回收率分别为92.67%和95.42%,而且产品中杂质少于用硅胶萃取所得产品.     

高效产锰氧化酶鞘细菌的分离鉴定及酶学特性

从活性污泥中分离筛选锰氧化酶鞘细菌及研究酶学特性,利用尿素富集培养基、CGY平板及摇瓶复筛从水样中分离产锰氧化酶菌株,通过菌落形态观察、生理生化实验和16S rRNA基因序列对菌株进行鉴定,并对其发酵条件及所产锰氧化酶的酶学性质进行研究。结果表明,分离筛选到一株高产锰氧化酶的菌株FM-3,被鉴定为鞘细菌属纤发菌（Leptothrix）。该菌株的最适产酶条件为甘油添加量0.8%,蛋白胨添加量0.15 g/L,吐温-80添加量0.2%,30 ℃ 150 r/min振荡培养72 h,此时发酵液的锰氧化酶活性可达2 977.44 IU/mL。该菌株产锰氧化酶的最适温度和pH分别为40 ℃和7.0,添加一定量的Mg2+对锰氧化酶活性有增强作用,Ca2+、Cu2+对锰氧化酶影响不大,Pb2+、Zn2+、Ag+对锰氧化酶具有一定的抑制作用。     

TC4钛合金电塑性压缩流变应力分析

采用Gleeble-1500D热-力学模拟机,将不同晶粒尺寸的TC4试样分别以0、10、30、50和70℃/s的升温速度加热至700℃进行单向压缩并得到流变应力曲线图,结合SEM、TEM等研究了电流作用下TC4钛合金高温压缩过程中流变应力的变化及影响因素。结果表明,无电流时流变应力超过1000 MPa,在电流作用下可降至600 MPa以下。小电流下TC4试样发生动态再结晶,应力随应变快速增大到应力峰值,后又快速下降至稳定状态;大电流下发生动态回复,局部有动态再结晶,无应力峰值,应力最大值低于400 MPa,且电流越大,β相转变为α相的相变越完全。分析认为,TC4钛合金的流变应力受电流大小、动态再结晶和相变的共同影响,电流促进动态再结晶和相变并降低流变应力。     

A multi-functional Ru Mo bimetallic catalyst for ultra-efficient C3 alcohols production from liquid phase hydrogenolysis of glycerol

Ru and Mo bimetallic catalysts supported on active carbon modified by phosphotungstic acid (PW) were designed and applied in glycerol hydrogenolysis reaction. The physicochemical properties of the catalysts were characterized and the presence of active sites was investigated from the perspective of the glycerol hydrogenolysis performance. The MoO_x is highly selective for the C—O bond cleavage of glycerol molecules, which can reasonably regulate the strong C—C bond cleavage activity of Ru nanoparticles. By using sequential deposition of Ru and Mo supported on mesoporous PW-C, the characterization results show that the combination of isolated low-valence MoO_x with metal Ru particles can form “MoO_x-Ru-PW”, which provides highly catalytic activity toward C—O bond cleavage, selectively producing more C3 alcohols (mainly 1,2(3)-propanediol). The glycerol conversion of 1% Mo/Ru/PW-C catalyst was 59.6%, the selectivity of C3 alcohol was 96.1%, and the selectivity of propanediol (1,2(3)-propanediol) was 94.9%. It is noteworthy that the selectivity of 1,3-propanediol reached 20.7% when the PW was 21.07% (mass). This study provides experimental evidence for the tandem dehydration and hydrogenation mechanism of the multifunctional Mo/Ru/PW-C catalyst.     

Comparative studies of dehydrocyclization of n-octane and iso-octane on bifunctional and monofunctional Pt/Al2O3 catalysts

The dehydrocyclization of n-octane and iso-octane to ethyl benzene, and ortho-, para-, and meta-xylenes was investigated on mono- and bifunctional platinum/alumina catalysts in a microcatalytic reactor with hydrogen as carrier at 1.8 atm pressure and between temperatures of 573 and 763 K, using pulse technique. On bifunctional Pt/Al₂O₃ catalyst, the total conversion of both n-octane and iso-octane was found to start from a high value and decrease with increasing temperature for all pulse volumes investigated. However, iso-octane was found to be more reactive than n-octane. There was only one primary product, namely iso-octane, in the n-octane reaction. As regards the iso-octane reaction, two primary products, ethyl benzene and o-oxylene were identified. For both reactions, these primary products decreased to a minimum as temperatures increased. On monofunctional (non-acidic) Pt/Al₂O₃, the total conversion of n-octane increased with temperature and passed through a maximum. The primary products of the reaction were ethyl benzene and o-xylene.     

蛋白酶A敲除对酿酒酵母抗氧化性的影响

蛋白酶A(PrA)是酿酒酵母体内一种重要的非金属蛋白酶,参与液泡中多种酶的成熟加工和信号转导因子的调控等过程。本文考察蛋白酶A对单倍体酿酒酵母的抗氧化性影响。以正常单倍体酿酒酵母菌和蛋白酶A敲除的突变菌株为研究对象,探讨PEP4基因编码的蛋白酶A对酵母细胞氧化胁迫下的抗氧化调控作用。试验结果表明蛋白酶A敲除对酿酒酵母抗氧化能力有显著的负面影响。与对照菌相比,突变株在氧化应激下展现出抗氧化能力降低的特征。同时,逆境应激因子——海藻糖的积累也与酵母细胞中蛋白酶A的存在和氧化胁迫处理浓度有一定关联。     

KINETIC INVESTIGATION OF METHYLCYCLOPENTANE REFORMING ON FRESH AND DEACTIVATING Pt/Al2O3 CATALYST

The conversion of methylcyclopentane (MCP) in hydrogen on fresh and deactivating Pt/Al₂O₃ catalyst to hydrogenolysis products (2-methylpentane, 3-methylpentane and n-hexane), cyclohexane and benzene was studied in a Berty CSTR at various partial pressures of MCP and H₂, and at a total pressure of 1 atm. For the kinetic studies, temperatures between 370 - 400° and W/F values up to 0.33 g min/cm³ were used. The conversion of MCP was found to increase with increase in temperature at all the MCP partial pressures investigated. The hydrogenolysis products and benzene composition generally increased with increase in temperature and W/F. The mechanism for the reforming of MCP was similar to that proposed by Dartigues et al. (1978) except that the formation of hydrogenolysis products was accounted for in this formulation. Eleven rate models were developed and tested and six satisfied the set criteria. Since hydrogenation/dehydrogenation and desorption steps are relatively rapid, the conversion step to hydrogenolysis products was deemed the only rate determining step with an activation energy of 36.31 kcal/gmol. For the deactivation studies, the model of Corella and Asua (1982) was used for the development of two deactivation models. The only model found to predict the deactivation behavior was the step leading to the formation of the coke precursor as rate controlling.