论陕西省饮用天然矿泉水形成机理

饮用天然矿泉水是一种宝贵的地下矿产资源,它具有医疗保健作用,是补充人体必需的微量元素的主要途径之一。陕西饮用天然矿泉水的形成受深大断裂带、盆地中相对隆起带以及岩体所控制。     

大气低频振荡的水平波状结构的理论解释

本文把慢变介质中波动的传播理论应用于正压大气中传播的Rossby波。慢变介质与域的球面性和基流的纬向结构有关。得到了波射线路径方程,导出了波作用密度守恒关系和波动能量密度变化方程,这与观测结果是一致的,并给出了低频振荡水平波状结构的简单解释。     

A Scalable Intrusion Detection System for IPv6

0 IntroductionIPv6 ,as a new, widely available version of Internet proto-col , contains numerous features that make it attractivefroma securitystandpoint[1].IPv6is not a panaceafor securi-ty,though, because the basic mechanisms for transportingpackets across the network stay mostly unchanged,and theupper-layer protocols that transport the actual application dataare mostly unaffected.IPv6 is usually deployed without cryp-tographic protections of any kind in real environment[2].So,IPv6 securi…     

浅析校园网拥塞现象

通过对校园网中因大量突发性访问而造成的网络拥塞现象的分析,初步得出造成校园网拥塞的原因是带宽容量不足、处理器能力较弱、网络拓扑结构不合理及大量新型网络病毒的出现等.可以通过改善网络拓扑结构、更新或升级设备、采用负载均衡技术等措施来避免网络拥塞.     

变p值二叉树形冲突分解算法分析

 提出了一种二叉树形冲突分解的改进算法,通过对随机争用多址访问系统中的信息分组冲突分解的研究,给出了冲突信息分组平均分解次数的解析式和系统吞吐量的解析式,仿真实验表明,仿真实现结果与理论值相吻合.     

高强混凝土深梁承载能力的实验研究

为了检验CIRIA、ACI和弹性珩架三种计算模型的准确性，采用16处高强混凝土深梁样本，分别对应于不同的剪跨－厚度比率和混凝土强度，进行了承载能力实验，并将实验结果与三种计算模型的理论值进行比较。结果表明，弹性珩架模型获得较理想的效果，而CIRIA和ACI模型则偏于保守。     

国内外钻削加工现状

介绍了当前国内外钻削加工的方法、钻头材料、制造钻头的新工艺及一些新型的深孔加工钻头.     

价夸克分布与海夸克分布的核效应

由ｌ－Ａ深度非弹性散射实验数据结合ｐ－Ａ碰撞Ｄｒｅｌｌ－Ｙａｎ截面数据来分别考察束缚核子中价夸克分布与海夸克分布的核效应，提出了一种检验解释ＥＭＣ效应的理论模型的方法。     

Deep crustal structure of Baiyun Sag,northern South China Sea revealed from deep seismic reflection profile

This paper discusses deep crustal architecture of the Baiyun Sag of the Pearl River Mouth Basin, northern South China Sea based on velocity analysis, time-depth conversion and seismic interpretation of the deep seismic reflection profile DSRP-2002. The profile was acquired and processed to 14 S TWT by the China National Offshore Oil Corp. (CNOOC) in 2002. It extends across the Baiyun Sag of the Pearl River Mouth Basin, from the northern continental shelf of the SCS to the deepwater province. As the first deep seismic reflection profile in the Pearl River Mouth Basin, this profile reveals seismic phases from basement down to upper most mantle. The Moho surface appears in the profile as an undulating layer of varying thickness of 1-3 km. It is not a single reflector interface, but a velocity gradient or interconversion layer. The crust thins stepwisely from the shelf to the continental slope and the abyssal plain (from north to south), and also thins under depocenters. The crustal thickness is only 7 km in the depocenter of the main Baiyun Sag, which corresponds to a Moho upwelling mirroring the basement topography. In the lower slope and the ocean-continental transition zone of the southernmost portion of the profile, three sub-parallel, NW-dipping strong reflectors found at depths around 10--21 km are interpreted as indications of a subducted Mesozoic oceanic crust. Crustal faults exist in the northern and southern boundaries of the Baiyun Sag. The intense and persistent subsidence of the Baiyun Sag might be related to the long-term activity of the crustal faults.