制备泡沫铝的一种新方法:烧结溶解法

烧结溶解法是近几年发展起来的一种制造泡沫铝的新工艺，具有可以精确控制孔洞形状，尺寸和孔隙率及其分布等特点，具有较好的质量价格综合指数，是生产均匀或梯度微细开孔中密度泡沫铝的有效方法，所制泡沫铝在吸能，吸音等领域有广泛的应用前景。本文简要介绍烧结溶解法的原理与工艺，所制泡沫铝的组织特征与机械性能，并讨论与其它各类现有方法相比所具有的优势与局限。     

Application of the Constrained Predicated Nets and Interval Logic to Production Systems

1 .INTRODUCTIONDuetotheireconomicsignificanceandclosenesstopersons,productionsystemsmustbemodeledbeforetheirimplementationanduse,thus,amethodwhichspecifies ,analyzesandsynthesizestheproductionsys tems—discreteeventsystems (DES)hasbeenestab lishedanddevelopedstepbystepinrecentyears.DESmethodspecifiestheplantbasedonitsdiscretecharacters,however,intherealworld ,therearefewplantsthatcanbemodeledbypurelydiscretemathe maticalmodelbecausetherearealwayssomecontinu ousparametersforstudyinnearlya…     

A rapid and accurate 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay for quantification of bacteriocins with nisin as an example

The objective of this study is to propose a more accurate and faster MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay (MCA) for quantitative measurement of polypeptide bacteriocins in solutions with nisin as an example. After an initial incubation of nisin and indicator bacterium Micrococcus luteus NCIB 8166 in tubes, MTT was added for another incubation period. After that, nisin was quantified by estimating the number of viable bacteria based on measuring the amount of purple formazan produced by cleavage of yellow tetrazolium salt MTT. Then MCA was compared to a standard agar diffusion assay (ADA). The results suggested a high correlation coefficient (r ²=0.975±0.004) between optical density (OD) and the inhibitory effect of nisin on a bacterial strain Micrococcus luteus NCIB 8166 at a range of 0.125~32 IU/ml. The MCA described in this study was very quick. Quantification of nisin took only 7~8 h and the detection limit was at the level of 0.125 IU/ml when compared to 12 IU/ml and 24~28 h for ADA. The MCA provides an accurate and rapid method for quantification of nisin in solutions and is expected to be used for quantification of other antimicrobial substances.     

太中银线吕梁段方案研究

文章以太中银线吕梁段方案为例,分析了影响线路方案的主要因素,强调了线路选线过程中的主要技术标准以及与地方规划协调的重要性。     

HACCP在石油行业野外施工食堂中应用的绩效分析

将HACCP这一世界公认的食品安全控制系统引入野外施工食堂卫生管理当中.方法采用文献检索,事故分析、现场调查和Delphi等研究方法,通过对野外施工食源性疾病危害分析、建立关键控制点,形成野外施工食堂管理HACCP管理规范,并组织实施.结果实施HACCP体系后,从业人员手、餐具、菜墩、抹布的抽查合格率有显著提高,食堂从业人员以及参加施工人员对饮食卫生以及食堂卫生管理知识的掌握显著提高.结论在野外施工食品卫生管理中引入HACCP管理体系,控制食源性疾病取得了良好的绩效.     

A Digital Right Management Model for Distribution of Digital Audiovisual Content

0 IntroductionDue to the success of Internet technology and the emer-gence of wide band network,downloading encoded dig-ital audiovisual content files via HTTP,FTP,etc ,had gainedfavor amongInternet users because of thei mmediate access todesired content . Digital Right Management (DRM) system,can satisfy the content provider by encrypting digital audiovi-sual content andli miting access to onlythose people who haveacquired a proper license to play backthe content[1].DRMas defined bythe …     

钢筋混凝土桁架筒的分析与研究

就钢筋混凝土桥架简体系进行了初步的分析与研究，表明这种结构体系有着良好的力学性能、抗震性能，且经济效益显著，有广阔的发展前景。     

高校图书馆工作人员的信息素养

本文从图书馆发展需要与图书馆员自身发展的需要出发,论述了图书馆员应具备的信息素养,阐述了信息素养的内涵,分析了图书馆员信息素养的现状,并提出了培养图书馆员信息素养的举措。