SHRIMP U-Pb geochronology of the detrital zircons from the Longshoushan Group and its tectonic significance

Sixty-two geologically meaningful U-Pb dates were obtained by using SHRIMP technique for the detrital zircons in three metasedimentary rocks from stratigraphically uppermost parts of the Longshoushan Group in the present study. Eighty percents of these dates range from 1.7 Ga to 2.2 Ga with a peak at 1.8-2.0 Ga and twenty percents from 2.3 Ga to 2.7 Ga. The youngest detrital zircon is dated at 1724±19 Ma which is interpreted as the maximum depositional age of the metasedimentary rocks. Therefore, the age for the diagenesis and lithification of the original sedimentary rocks of the Longshoushan Group before the metamorphism must be younger than 1724±19 Ma. Comparison of the age histograms of these detrital zircons with the ages of the igneous rocks on the surrounding older massifs suggests that the sediments of the Longshoushan Group were most likely derived from the Alaxa Block and Tarim Craton. This implies that the affinity between Alaxa Block and Tarim Craton was strong and that they might have been a unified craton during middle-early Proterozoic time.     

SHRIMP U-Pb zircon age of tuff from the Kunyang Group in central Yunnan： Evidence for Grenvillian orogeny in South China

Whether or not Grenvillian orogeny occurred in South China still remains highly controversial because high-quality,discriminating data are lacking,and therefore,the key to resolve this matter is to find datable volcanic and/or sedimentary rocks related to Grenvillian orogeny. Such rocks are apparently present in the Fuliangpeng Member from the lower-middle part of Kunyang Group in central Yunnan; here the unit is more than 100 m thick and consists of andesitic ignimbrite,tuffite,terrigeous clastic rocks and carbonates. These volcanic rocks,developed south of the Sibao fold-thrust belts,represent the earliest calc-alkaline volcanic activity in late Precambrian time from central Yunnan and are coeval with both a change in sedimentary facies from detritus to carbonates and the beginning of seismite development elsewhere. Two samples for SHRIMP analysis were collected from this volcanic unit. Sample G3-29-2,from the bottom of Fuliangpeng Member,is an ignimbrite,and about 100 zircon crys-tals recovered from it have euhedral shapes and display relatively simple sector zonation under cathodoluminescent (CL) imaging,suggesting a magmatogenic origin. Twenty-five of the zircons were analyzed and a weighed-mean U-Pb age of 1032±9 Ma was obtained. Sample G3-29-3 from uppermost part of Fuliangpeng Member is a tuffite,and many rounded,evidently detrital zircons were recovered. Nine of these zircons were analyzed,and the oldest single-grain U-Pb zircon age is 1938±26 Ma,im-plying that Paleoproterozoic basement developed in Cathaysia. The dating result,combined with the geotectonic research on the Fuliangpeng Member,leads us to conclude that late Mesoproterozoic orogenic volcanic activity occurred in the western part of South China,and that the related collision of Yangtze and Cathaysian cratons was an integral part of the assembly of Rodinia.     

基于DirectShow组件技术的视音频存储系统的实现

采用Windows平台下的DirectShow组件技术，以及MPEG-4和DSPGroup TrueSpeech(TM)视音频压缩算法，在Visual C 6．0开发环境下实现从摄像头捕捉视频，从麦克风捕捉音频，并将视音频数据压缩后合并输出到AVI文件。数据压缩比达到100：1，节省了存储空间，实现了视频的预览。     

完达山集团呼叫中心系统的应用研究

文章分析了完达山集团实施呼叫中心具体背景,并简要介绍了小型呼叫中心的系统结构,在此基础上,结合乳品行业的特点,提出了呼叫中心系统功能设计思路及系统实现环境,对乳品企业如何通过建立呼叫中心提高服务质量,具有一定的借鉴作用.结果证明,应用呼叫中心系统能够较大的提高企业运作和管理效率,最大限度地满足经销商及客户需求.     

MH1井区二叠系下乌尔禾组沉积微相及有利储层预测

MH1井区主体位于玛湖凹陷南斜坡区,作为南斜坡区重点开发区域,MH1井区目前仍存在沉积相认识不精确、储层分类不明确等问题。通过岩心观察、结合测录井资料,进行沉积微相精细描述及有利储层分布预测研究。结果表明：MH1井区二叠系下乌尔禾组为一套由西北向东南发育的扇三角洲相,可识别出9个沉积微相类型,根据扇三角洲前缘的岩性分布,将前缘划分为内外前缘。根据试油资料,发现主要有利储层集中在内前缘部分。根据孔隙度、渗透率,将MH1井区下乌尔禾组储层分为3类。其中Ⅰ类储层孔隙度渗透率均为最好,为有利储层,Ⅱ类储层次之,Ⅲ类储层孔隙度、渗透率均为最差,作为非储层类型。研究结果为MH1井区下乌尔禾组后续的评价、开发提供新的地质依据,为其他扇三角洲发育区的油气勘探评价提供借鉴。     

双曲型方程的含参分组显式并行算法

对双曲型方程ut aux=0构造一族含双参数的有效分组显式并行算法(GER,GEL,AGE).当θ≤0,θ1≥1时,稳定性条件一般为.其局部截断误差一般为o(τ h),特别当取θ θ1=1时,AGE是绝对稳定的.并列举了数值例子验证了理论分析的正确性,表明了算法的可行性与有效性.     

DeviceNet网络的通信研究

参照DeviceNet协议规范,概述了DeviceNet网络的通信原理,并以工业现场中使用较多的仅限组2从设备为对象,重点阐述了网络的构建.该方法已成功实现了主从站间的基本数据通信,对进一步开发具体的从站产品具有参考意义.     

拓扑学的几个公理系统的独立性

本文证明了:度量空间、拓扑空间、同胚映射、拓扑群和线性拓扑空间的公理系统的独立性。     

求群特征标的一个方法

本文讨论了群代数中类和元素的几个性质,并利用它们给出求特征标的一种方法。     

基于软件测试组的绩效管理模型研究

在IT产业迅速发展的今天,软件质量一直是许多软件公司十分关心的问题,随着软件产品规模的不断扩大,软件质量保证成了软件产品中最关键的环节。而软件质量保证最重要的环节是软件测试,因此科学合理的管理测试人员,发挥每个人的作用就显得尤为重要。在一个高效运作的团队,必须有一套科学、合理、较为完整的绩效评定系统。这样员工的工作积极性能够得到尽可能大的提高,企业文化在绩效评定系统中可以充分体现,将企业发展与员工表现结合。目前的测试小组里还没有一套有效的绩效评定体系,以至于评定测试员的工作情况很难判定,不能很好适应项目的进展和长期有效的提高测试人员的工作积极性。