试论企业集团的内部关系协调

要使企业集团真正形成群体优势，充分发挥集团的作用，关键的一个问题就是在企业集团组建起来后，如何有效地协调、处理好集团内部的各种关系，从而调动集团成员的积极性，增强的凝聚力，保证企业集团和谐、有序地发展。针对这一问题，就企业集团的经营管理体制、联结纽带以及利益关系等方面进行了一些探讨。认为建立合理的经营管理体制是协调好企业集团内部关系的保证；建立和利用多种联结纽带，是协调好企业集团内部关系的有效手段     

Catalytic aquathermolysis of Shengli heavy crude oil with an amphiphilic cobalt catalyst

An interfacially active cobalt complex,cobalt dodecylbenzenesulfonate,was synthesized.Elemental analysis,atomic absorption spectroscopy,Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis,and surface/interfacial tension determination were performed to investigate the properties of the catalyst.Results showed that the synthesized catalyst showed active interfacial behavior,decreasing the surface tension and interfacial tension between heavy oil and liquid phase to below 30 and 1.5 mN/m,respectively.The catalyst was not thermally degraded at a temperature of 400 ℃,indicating its high thermal stability.Catalytic performance of the catalyst was evaluated by carrying out aquathermolysis.The viscosity determination showed that the viscosity of the heavy oil decreased by 38%.The average molecular weight,group compositions,and average molecular structure of various samples were analyzed using elemental analysis,FT-IR,electrospray ionization Fourier transform ion cyclotron resonance(ESI FT-ICR MS),and ~1H nuclear magnetic resonance.Results indicated that the catalyst could attack the sulfur- and O_2-type heteroatomic compounds in asphaltene and resin,especially the compounds with aromatic structure,leading to a decrease in the molecular weight and then the reduction in the viscosity of heavy oil.Therefore,the synthesized catalyst might find an application in catalytic aquathermolysis of heavy oil,especially for the high-aromaticity heavy oil with high oxygen content.     

双季铵基邻苯二甲酸酯表面活性剂的合成及性能

采用N,N-二甲基乙醇胺与邻苯二甲酰氯反应得到二(二甲基胺基乙基)邻苯二甲酸酯(Ⅰ),然后Ⅰ再分别与正溴代十四烷和正溴代十六烷反应,经处理后得到邻苯二甲酸酯基Gemini表面活性剂SHZ14(双十四代邻苯二甲酸酯双子表面活性剂)和SHZ16(双十六代邻苯二甲酸酯双子表面活性剂),两步反应的总收率分别为46.1%和49.7%。采用最大气泡压力法和电导法分别测定了SHZ14和SHZ16的表面张力和临界胶束浓度,并考察了其增溶性、乳化性能和泡沫性能和Krafft点,发现均优于传统表面活性剂十四烷基三甲基溴化铵和十六烷基三甲基溴化铵,并且SHZ16的表面活性要稍好于SHZ14,说明双子表面活性剂性能要优于传统表面活性剂性能,同时碳原子个数增加,表面活性也略有增加。     

西门子金融服务公司的职能及启示

西门子金融服务公司成立以来,以服务、运营和利润为三大职能,承担了资产类和费用类两大业务,整合集团资金,以产融结合带动集团整体战略和投资策略,发挥了应有作用,逐渐演化成追求“全能型”目标的大型、综合金融运营实体。这给国内大型企业集团财务公司的发展指出了一个方向。     

Aflatoxins and fumonisins in rice and maize staple cereals in Northern Vietnam and dietary exposure in different ethnic groups

Mycotoxins in food are increasingly a food safety hazard concern in particular in developing countries. This study was performed to determine the occurrence and determinants of aflatoxin and fumonisin contamination in rice and maize and to assess health risks through dietary intake exposure among ethnic minority groups in northern Vietnam. A total of 111 rice and 102 maize samples, were tested for occurrence of fungi and mycotoxins, i.e. aflatoxins (AF’s) and fuminisin B (FB). Results showed that 107 (96.4%) rice and 84 (82.4%) maize samples were contaminated by fungi. Aspergillus flavus was found in 68 (61.3%) rice and 30 (29.4%) maize samples, Aspergilus parasiticus in 40 (36.0%) rice and 27 (26.7%) maize samples. AF’s - were detected in 27 rice (24.3%) and 27 maize samples (26.4%) at minimum and maximum levels in rice of 2.06 and 77.8 ng/g and 20.5 and 110 ng/g in maize, respectively. Nine (8.1%) rice and 24 (23.5%) maize samples contained FB at ranges of 2.3–624 ng/g in rice and 5.6–89.8 ng/g in maize. Data collected through interviews and observations in households showed that type of crop, storage duration and presence of fungi, particularly mycotoxigenic fungi were important risk factors for AF’s and FB contamination. Based on daily food consumption data, the estimated average exposure dose of aflatoxin B₁(AFB₁) from rice was 21.7 ng/kg bw/day for adults and 33.7 ng/kg bw/day for children. For FB, the rice based average exposure amounted to 536 ng/kg bw/day for adults and 1019 ng/kg bw/day for children. The calculated excess risk of liver cancer incidence by ingestion of cereals containing AFB₁ was 1.5 per 100,000 adults and 2.3 per 100,000 children per year. The average intake of FB was calculated to be lower than the tolerable diet intake (TDI). Our findings highlight that rice and maize are contaminated with mycotoxins at levels representing actual health hazards for the ethnic minority groups consuming these stable cereals. Proper drying and storage conditions in households are likely to reduce the mycotoxin contamination.     

PRELIMINARY STUDIES OF ASPHALTENE AGGREGATES BY LOW VACUUM SCANNING ELECTRON MICROSCOPY

A study of vacuum residue and asphaltenes from a Mexican oil refinery was performed using low vacuum scanning electron microscopy (LV-SEM) to determine the morphology of aggregates, and energy dispersive spectroscopy (EDS) to get the elemental composition of them. Irregular shaped particles were observed on vacuum residue, with a size range from 10 to 30 μm, that emerged from the oily fraction under the action of the electron beam. Those particles were sulphur and silicon rich. We also found some particles with important concentrations of Mg, Cl, K, and Fe. Asphaltenes precipitated with different n-alkane solvents showed slight differences in morphology. Fragile particles of several sizes were analyzed (230 × 130 μm to 730 × 240 μm); most of them presented a smooth face side by side with a rough one. Higher magnification of the smooth faces showed some randomly distributed pores. Rough facets tended to show larger pores. Some inclusions were also found; the sizes of those ranged from 7 to 25 μm. EDS revealed that sulphur and silicon are more abundant in the inclusions. Some Fe and Mg rich particles were also found. All the samples presented small amounts of V, and some of them Zn and Sn, whose concentration depends on the solvent used.     

利用相对密度、残炭值和馏出温度计算结构族组成

文中整理了20套原料油的分析数据,通过拟合的方法,得到了折光指数和相对分子质量与原料油的相对密度、残炭值和50%馏出温度的关联式。利用关联式可以对炼油厂的常规分析数据(包括密度、残炭值、50%馏出温度和硫含量)进行计算,得出原料油的结构族组成。     

Determination of Functional Groups in Mexican Vacuum Residua

The aim of this work is to determine the presence of carbonyl groups in the resin and asphaltene fractions of Mexican vacuum residua. It is known that these groups are disintegrated when the crude is subjected to high temperatures, so it is possible that the vacuum residua do not contain these groups anymore or may have fewer percentages of them. To carry out this determination, the residua were first fractionated into their four principal components—saturates, aromatics, resins, and asphaltenes—commonly known as SARA fractions. The technique used is this work is based on the standard method ASTM D4124-01 (2001), which has two different methods for the separation, the short and the large method; in the present work the short method was used. Furthermore, the fractions were analyzed using the Fourier-transform infrared (FTIR) spectroscopy technique to determine the different chemical compounds in each fraction. The results reveal the presence of the carbonyl groups in the resins and asphaltene fractions, as expected.     

基于SGM方法的复杂反应网络自动生成中的分子识别

根据分子结构中结构基团个数少于或等于原子个数的规律,提出了基于结构族概念识别分子的 SGM 方法(Structural groups-based method),发展了新的分子识别工具--连通识别符(Connectivity ID)。连通识别符可以有效地提取分子特征,也可以容易地进行识别同分异构体分子。实例研究表明,SGM 方法是有效的分子识别工具。     

An Algorithm for Pseudocompound Delumping and Lumping into Homologous Groups

An algorithm for pseudocompound delumping and lumping into homologous groups is developed. This algorithm is useful for modeling refineries when using commercial simulators and detailed reactor models. Generally, commercial simulators represent petroleum fractions using pseudocompounds; however, reactor models and their kinetics are based on known compounds. This algorithm delumps the pseudocompounds into homologous groups that are represented by model compounds, which are then used by a detailed reactor model. After the reaction, the outlet stream is lumped again to pseudocompounds that are used in the remaining operations of the commercial simulator. The lumping operations are based on mass balance principles and fundamental properties of the hydrocarbon mixture. This algorithm is applied to the modeling of a hydrotreatment unit that belongs to the Mexican System of Refineries which uses a detailed three phase trickle bed reactor. The problem is to delump and lump the pseudocompounds, which represent light gas oil, into paraffins, naphthenes, and mono and polyaromatics. Results show a good agreement with industrial data.