管道减阻内涂层的涂敷工艺及质量控制

为有效提高长输管道输送能力,我国引进管道减阻内涂层技术,并在西气东输管道建设工程中得到应用。介绍了减阻内涂层的涂敷工艺和在内涂层生产过程中质量控制等方面的内容,文中较详细地对内涂层质量的检测方法及注意事项进行了逐条的叙述。为今后国内管道减阻内涂层的质量控制提供了直接并可借鉴的成功经验。     

Performance Analysis of Fair Channel Sharing Policies in an Integrated Cellular Voice/Data Network

We study channel sharing in an integrated cellular voice/data network with a finite queue for data call requests that cannot be served immediately upon arrival. Using analytical techniques, a comparison of different fair channel sharing policies is made. As a main result, a closed-form expression is derived for the expected sojourn time (waiting time plus transfer time) of a data call, conditional on its size, indicating that the sojourn time is proportional to the call size. This attractive proportionality result establishes an additional fairness property for the channel sharing policies proposed in the paper. Additionally, as a valuable intermediate result, the conditional expected sojourn time of an admitted data call is obtained, given the system state at arrival, which may serve as an appreciated feedback information service to the data source. An extensive numerical study is included to compare the proposed policies and to obtain insight in the performance effects of the various system and policy parameters.     

壳聚糖包裹磁流体的制备及其物性表征

采用共沉淀法制备纳米Fe3O4磁粒子,经离心分离后利用超声分散将纳米磁粒子弥散于壳聚糖溶液中形成了具有高度生物兼容性的壳聚糖包裹磁流体。利用XRD、TEM、红外光谱和磁天平对产物进行物性表征。探讨了壳聚糖质量、反应温度、超声分散时间和pH值对产物磁性的影响,结果表明:在反应温度为45℃,超声时间为55 min,pH值大于9,壳聚糖质量为0.15 g的条件下,制备的磁粒子约为15 nm左右,磁化饱和强度38.4 mT,抗氧化性高的壳聚糖包裹磁流体。该磁流体可作为X射线造影剂、靶向药物载体。     

Induction of a heat-shock-type response in Saccharomyces cerevisiae following glucose limitation

The protein pattern of yeast cells which have arrested proliferation in response to glucose exhaustion is drastically different from that of exponentially growing cells (Boucherie, 1985). In this study, we used two-dimensional gel electrophoresis to characterize the protein events responsible for these alterations. We found that the induction of heat-shock proteins is one of the major events responsible for these changes. This induction accounts for the synthesis of 18 of the 35 novel polypeptides observed in glucose-limited cells. It was shown to occur in combination with two other protein events: the derepression of carbon catabolite repressed proteins, which accounts for the synthesis of the other novel polypeptides, and an arrest of the synthesis of almost all the proteins present in exponentially growing cells. The time course of each of these events was determined by carrying out a detailed analysis of the pattern of proteins synthesized at various stages of a culture exhausting its glucose supply, and by the measurement of the rate of synthesis of individual polypeptides. The results showed in particular that the synthesis of most of the heat-shock proteins synthesized in glucose-limited cells was induced closely before glucose exhaustion, and that this synthesis was transient, climaxing by the time glucose was exhausted. Under the culture condition investigated, the entry into stationary phase associated with glucose limitation began several hours before glucose exhaustion. It was thus concluded that the observed induction of heat-shock proteins is directly related to the nutritional limitation and is independent from the arrest of cell proliferation.     

ITS－90（13．8～273．16K）国家温度基准组和工作基准组的建立

本文介绍了ＩＴＳ－９０（１３．８～２７３．１６Ｋ）国家温度基准组和工作基准组的建立、误差传递的研究、以及基准组和工作基准组的非唯一性的实验研究。实验表明，该基准组和工作基准组在全温区（１３．８～２７３．１６Ｋ）的总不确定度为２．７ｍＫ。研究了基准组在全温区的误差分布。     

卫生高职院校多媒体教学质量研究

多媒体教学已成为卫生高职院校的主要教学模式,但不少学校注重多媒体教学的硬件建设,在多媒体教学质量上重视不够。文章分析探讨影响多媒体教学质量的主要因素,提出提高多媒体教学质量的对策建议。     

Grid-Based Storage Architecture for Accelerating Bioinformatics Computing

This paper examines and investigates the relationship between bioinformatics data processing and its underlying computing architecture within the context of the International Nucleotide Sequence Database Collaboration (INSDC). INSDC exchanges sequence data on a daily basis across its three member organizations in USA, UK and Japan. We studied how this sequence database in MySQL can best take advantage of the increased transfer bandwidth of a grid-based storage architecture. Within the context of the UK Government Project “Grid-oriented Storage (GOS)” and the EC Project “EuroAsiaGrid,” GOS has been developed in our lab, which melds parallel streaming technique to meet the needs of WAN/Grid-based virtual organizations. A real-world test shows that the INSDC sequence database backuping operation, mysqldump, over the pipelined GOS architecture beats those over the classic infrastructures by six times over the link between Cambridge and Tokyo. When performing genomic sequence search against one million records via the underlying GOS architecture, the performance improvement of 67.3% has been achieved.

管道外防腐涂层技术的发展与应用现状

本文介绍了管道外防腐涂层的基本要求、国内管道外防腐涂层的发展历程、以及管道外防腐涂层技术，包括：石油沥青、煤焦油瓷漆、聚乙烯胶带、环氧煤沥青、熔结环氧粉末（FBE）、聚乙烯防腐层（2PE／3PE）、双层熔结环氧粉末、100％固体含量聚氨酯／聚脲涂层等，并且分析了各种防腐涂层在工程中的应用情况和存在的问题，提出了一些改进意见。     

Cluster computing and grid 2005 works in progress

The first in a two-part series of works-in-progress articles from cluster computing and grid 2005 deals with a project called Grid-Oriented Storage (GOS). GOS aims to support advanced data bank services and data reservoirs so that multiple computers and end users can share data on the grid. The second part deals with a dynamic estimation scheme for fault-free scheduling in grid systems.     

A scanning laser microscope system to observe static and dynamicmagnetic domain behavior

Scanning laser microscopes (SLMs) have been used to characterize the magnetic properties of materials for some time. The first SLM built was a purely static system capable of imaging magnetic domains. Dynamic capability was introduced with the development of the R-Theta microscope. However, this microscope utilizes a rotating drive. A scanning laser microscope has been designed to observe the dynamic behavior of domain switching during the thermomagnetic write process and the subsequent magnetization state (domain orientation) in stationary media, without the requirement for a rotating drive. It may also be used to write to the magneto-optic (MO) disk material thermomagnetically prior to imaging. Images are derived from the longitudinal and polar magneto-optic Kerr effects. In this paper, the different configurations for imaging are described and some initial images are presented