Ethernet—PON QoS实现方案

以Ethernet为基础的无源光网络(Ethernet—PON)是未来实现带宽、多业务综合接入的重要技术手段，如何提供服务质量(QoS)保证是EPON接入的核心技术之一。首先分别介绍EPON技术和轮询算法、业务分级，然后对基于轮询算法和业务分级的动态带宽分配进行探讨，并对解决Ethernet-PON的QoS问题进行分析研究。     

A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)

Severe Acute Respiratory Syndrome (SARS) is a newly identified infectious disease[1—5]. The global outbreak of SARS has been threatening the health of people worldwide and has killed 353 people and infected more than 5462 in 27 countries, as reported by WHO on April 29, 2003 (http://www.who.int/csr/sarscountry/en). Although it has been recognized that a variant of virus from the family of coronavirus might be the candidate pathogen of SARS[1—5], its identity as the unique pathogen sti…     

铂(II)与胺类配合物的合成、晶体结构和抗肿瘤活性研究

研究铂(II)与三种胺类配合物的合成、晶体结构和体外抗肿瘤活性,化合物1的X-射线单晶结构分析表明:这是一个很少见的具有四方锥几何构型的铂(II)配合物,顺式平面四方形配位的铂的轴向上有第5个配位原子。其抗肿瘤活性实验显示3个配合物对几种研究的癌细胞都有较强的抑制作用。     

Microstructure and functional morphology of the Early Cambrian problematical fossil Rhombocorniculum

Rhombocorniculum cancellatum from the Lower Cambrian of southern Shaanxi Province (South China) is represented by the dextral and sinistral tooth-like sclerites (both in nearly equal numbers), indicating that the body plan of the organism with these sclerites probably was bilaterian. The main feature of the microstructure of the sclerites is the presence of longitudinally arranged, mutually contiguous hollow tubules, the shared walls consisting of microcrystalline apatite. In transverse cross sections, the sclerite wall mainly exhibits a spongy structure, with pore size decreasing adapically. Functional morphological analysis indicates that the sclerites serve as a defensive rather than a grasping function.     

Early Cambrian eodiscoid trilobites of the Yangtze Platform and their stratigraphic implications

Analysis of the taxonomy and stratigraphic distribution of the Early Cambrian eodiscoid trilobites of the Yangtze Platform indicates that species of Tsunyidiscus and Hupeidiscus can be used for biostratigraphic correlation. T. aclis occurs only in the lower Qiongzhusian, T. armatus occurs in the lower and middle Qiongzhusian, while T. niutitangensis and T. tingi occur mainly in the middle and upper Qiongzhusian, with only T. tingi extending upward into the lower Canglangpuian. H. orientalis first appears in the upper Qiongzhusian, reaching peak abundance in the lower Canglangpuian and becoming extinct above the Drepanuroides Zone. Biostratigraphic and lithostratigraphic correlations indicate that the limestone in the lower part of the Mingxinsi Formation, the Upper Member of Jiumenchong Formation, and the upper part of the Middle Member of the Huangbailing Formation, can be correlated with each other as Hupediscus, an index fossil of the lower Canglangpuian, is abundant in all these units. The lower part of the Niutitang and Jiumenchong formations in eastern Guizhou, which mainly represent Qiongzhusian strata, can be correlated with the Lower Member of the Huangbailing Formation. The basal part of the Niutitang Formation, which may be equivalent to the Upper Meishucunian Shiyantou Formation in eastern Yunnan, is very condensed. Well-preserved sponge faunas and non-mineralized fossils in the lower part of the Niutitang and Hetang formations are not older than Qiongzhusian in age.     

Initial organic geochemical investigation on Late Neoproterozoic-Early Cambrian sediments in the Yangtze region, China

Totally 19 samples of typical Upper Proterozoic-Lower Cambrian sedimentary rocks were collected and analyzed for an organic geochemical investigation. Almost all these rocks have high TOCs, super-maturities and similar biomarker distribution. As an exception, however, the Sinian Nantuo Tillite shows much lower TOCs and little phytane and pristane in comparison with those in other strata, which implies a very faint photosynthetic process, and a restricted euphotic zone and quite limited sunlight within the sedimentary water column during the Sinian glaciation age in the western Yangtze region providing an evidence for palaeo-oceanic environment of the Neoproterozoic Snowball Earth age.     

滨南油田低渗欠注井酸化增注技术研究与应用

提出了一种针对滨南低渗油田欠注井酸化增注的系统实验研究方法。根据储层特征分析了注污水和重复酸化对地层的损害及对酸化液的选取原则。根据长岩心酸化流动模拟实验进行了酸化工艺参数优选及其评估分析。现场施工证明该酸化液体系适应性较好 ,工艺参数合理 ,能够较好地解除地层中有机物和无机物堵塞 ,提高注水量 ,降低泵注压力 ,在低渗油田注水井中具有推广价值。     

东营凹陷胜坨地区沙三-沙四段扇体特征与岩性油气藏

东营凹陷胜坨地区沙四段、沙三段沉积时期 ,发育了洪积扇、近岸水下扇和浊积扇 3种扇体沉积 ,根据其沉积、成藏特征分析了 3种扇体的成藏规律和分布特点。研究结果表明 ,沙四段沉积期主要发育洪积扇 ,岩性以砾岩、含砾砂岩为主 ,断层附近砂体的储集性能好 ,多形成背斜和断块油气藏 ;沙三段下部沉积期发育近岸水下扇 ,岩性以砾岩、含砾砂岩为主 ,扇中储集物性最好 ,多形成构造岩性油气藏 ;沙三段中部沉积期发育浊积扇 ,岩性以砂岩为主 ,储集性能好 ,但砂体薄 ,多形成透镜体和上倾尖灭油气藏     

Asymptotic Approximations of Jacobi Polynomials and Their Zeros with Error Bounds

IntroductionUniform asymptotic expansions and error boundsof the (α,β>- 1 ) two- term approximations of theJacobi polynomials P(α,β)n ( cosθ) were obtained[1] .Their result wassin θ2α cosθ2βP(α,β)n ( cosθ) =Γ( n +α + 1 )n!θsinθ1/ 2 Jα( Nθ)Nα +θB0 (θ) Jα+1( Nθ)Nα+1+σ2 ,|σ2 |≤ E2 θ2 +αN -2 ,　 0≤θ≤ π2 ,where E2 is a construct.Baratella and Gatteschiused the first two terms of this expansion[2 ] toconstructa more accurate one- term approximation:x(θ)x′(θ)…     

玉米淀粉与丙烯酸胺接枝共聚物的制备

本文研究玉米淀粉与丙烯酰胺接枝共聚物的合成工艺及其在造纸工艺中用作干强剂、助留/助滤剂的效果。研究表明玉米淀粉与丙烯酰胺的质量比为5:3.5,引发剂硝酸铈铵用量为0.2g,反应时间为3h,反应温度为62℃,聚合物质量较好。