Aeromagnetic and radio echo ice-sounding measurements show much greater area of the dufek intrusion, antarctica

A combined aeromagnetic and radio echo ice-sounding survey made in 1978 in Antarctica over the Dufek layered mafic intrusion suggests a minimum area of the intrusion of about 50,000 square kilometers, making it comparable in size with the Bushveld Complex of Africa. Comparisons of the magnetic and subglacial topographic profiles illustrate the usefulness of this combination of methods in studying bedrock geology beneath ice-covered areas. Magnetic anomalies range in peak-to-through amplitude from about 50 nanoteslas over the lowermost exposed portion of the section in the Dufek Massif to about 3600 nanoteslas over the uppermost part of the section in the Forrestal Range. Theoretical magnetic anomalies, computed from a model based on the subice topography fitted to the highest amplitude observed magnetic anomalies, required normal and reversed magnetizations ranging from 10(-3) to 10(-2) electromagnetic units per cubic centimeter. This result is interpreted as indicating that the Dufek intrusion cooled through the Curie isotherm during one or more reversals of the earth's magnetic field.     

基于代理（Agent）的入侵检测系统设计

文章提出了一种基于Agent的入侵检测系统模型,该模型是一个层次结构,主要由监控中心Agent、评估分析Agent、信息收集Agent等组成.并对该系统模型最底层的基于网络Agent的设计与实现进行了研究,基于网络的Agent有数据报捕获模块、协议解析模块、规则分析模块、检测分析模块等组成.     

Diffusive isotopic contamination of mafic magma by coexisting silicic liquid in the muskox intrusion

Shifts in (87)Sr/(86)Sr and (143)Nd/(144)Nd ratios measured in cumulates from the upper levels of the Muskox mafic intrusion indicate that isotopic and bulk chemical exchange were decoupled across a mafic-silicic liquid interface during crystallization of the intrusion. Modeling of diffusive exchange between liquid layers demonstrates that isotopic compositions of silicate liquids in layered magma chambers may be strongly affected by this process on time scales of 10(3) to 10(4) years. Diffusive contamination can be used to place constraints on the physical processes and time scales of magmatic systems.     

Strontium isotope fractionation in the kiglapait intrusion

The initial ratio of strontium-87 to strontium-86 rises systematically from 0.70395 to 0.70662 over the upper 10 percent of the Kiglapait layered intrusion. This ratio is strongly correlated with potassium and rubidium. Contamination, exchange, and magma mixing fail to account for the increase, which is ascribed to the imperfect retention of radiogenic strontium-87 in feldspar-like structural units of the melt inherited from the magma source. These accidents in chemical discrimination persist most readily in anhydrous melts.     

人工免疫技术在农业信息化建设中的应用

分析了web网站在农业信息化建设中的作用和web网站中的安全问题，介绍了入侵检测技术和人工免疫理论的基本思想以及人工免疫技术在入侵检测领域中的应用。     

内装式分层卸油鹤管

通过对气阻校核公式的分析，提出了消除气阻的两个有效途径：①通过改变卸油顺序，使卸油温度下油品的饱和蒸气压大的油品在鹤管最高点与油罐车油面的标高差小的时候通过鹤管最高点。②通过改变鹤管，使鹤管距罐底的距离减小。以这两点为依据，设计出了内装式是分层卸油鹤管。该鹤管与油罐车焊接在一起，且部分操作可在地面进行，操作简单，安全可靠，运用修正后的气阻校核公式，以中国三大火炉之一的重庆地区为典型示例，对内装式分     

Evidence for sediment eruption on deep sea floor, gulf of Mexico

A large crater has been discovered on the sea floor, Gulf of Mexico, in a water depth of 2176 meters. Deep-tow high-resolution imagery shows that the crater is cut into a low hill surrounded by near-surface concentric faults. Approximately 2 million cubic meters of ejected sediment forms a peripheral debris field. The low hill and faults may be related to mud diapirism or intrusion of gas hydrates into near-surface sediments. A recent eruption evacuated sediments from the crater, apparently because of release of overpressured petrogenic gas.     

Model for the intrusion of batholiths associated with the eruption of large-volume ash-flow tuffs

Pyroclastic eruption and the intrusion of batholiths associated with large-volume ash-flow tuffs may be driven by a decrease in reservoir pressure caused by the low density of the magma column due to vesiculation. Batholithic intrusion would then be accomplished by the subsidence and settling of kilometer-sized crustal blocks through the magma chamber, resulting in eventual collapse to form large caldera structures at the surface. Such a model does not require the formation of a large, laterally extensive, shallow magma chamber before the onset of large-volume ash-flow eruptions. Eruption could commence directly from a deeper reservoir, with only a small channelway being opened to the surface before the onset of catastrophic ash-flow eruptions of the scale of Yellowstone or Long Valley. Such a model has wide-ranging implications, and explains many of the problems inherent in the simple collapse model involving shallow magna chambers as well as the process and timing of batholith intrusion in such cases.     

带压电层圆柱形杆中波的传播

基于Hamilton原理的矩阵形式,得到带压电层圆柱形杆中波传播的基本方程式;采用幂级数的不同幂次近似方法表达杆件中的位移函数;通过变分求得特征方程式;进而求得弹性简谐波在带压电层的圆柱杆件中传播时的频散关系和位移场.通过实例计算,得到了压电圆柱杆件中波传播的频散关系,讨论了压电层对波传播的影响.计算结果表明,这种方法能够得到较好的收敛结果.     

基于规范化软构件技术的农业专家系统开发平台研究

本文详细分析了农业专家系统平台的软构件流程,提出了一种面向对象方法的自适应软件总线机制规范,该规范可为构件的集成和重用提供基础。建立一个公共的构件底层框架,用分层研究、逐层嵌入的方法与应用环境进行交互,能为农业技术人员提供一个人性化、易操作的农业专家系统开发平台。     

基于MPLS的分布式网络入侵检测方法

MPLS 网络结构具有很好的通信和分布式特征,是分布式网络入侵检测的理想架构。针对分布式网络入侵检测系统体系结构中的通信部件,将 MPLS 技术和分布式网络入侵检测结合在一起,探讨了基于 MPLS 的分布式网络入侵检测的工作过程。采用 MPLS 技术实现分布式入侵检测是有效的,解决了传统的分布式网络入侵检测的通信及部件的分布问题,与此同时还保留了传统的分布式网络入侵检测的独立性、集中性和分布性这些优势。     

Fracture-controlled paleo-fluid flow in Candor Chasma, Mars

Color observations from the High Resolution Imaging Science Experiment on board the Mars Reconnaissance Orbiter reveal zones of localized fluid alteration (cementation and bleaching) along joints within layered deposits in western Candor Chasma, Mars. This fluid alteration occurred within the subsurface in the geologic past and has been exposed at the surface through subsequent erosion. These findings demonstrate that fluid flow along fractures was a mechanism by which subsurface fluids migrated through these layered deposits. Fractured layered deposits are thus promising sites for investigating the geologic history of water on Mars.     

Particle-stabilized defect gel in cholesteric liquid crystals

Dispersions of colloidal particles in cholesteric liquid crystals form an unusual solid by stabilizing a network of linear defects under tension in the ideal layered structure of the cholesteric. The large length scales of the cholesteric liquid crystals allowed direct observation of the network structure, and its properties were correlated with rheological measurements of elasticity. This system serves as a model for a class of solids formed when particles are mixed with layered materials such as thermotropic and lyotropic smectic liquid crystals and block copolymers.     

Magmatically triggered slow slip at Kilauea Volcano, Hawaii

We demonstrate that a recent dike intrusion probably triggered a slow fault-slip event (SSE) on Kilauea volcano's mobile south flank. Our analysis combined models of Advanced Land Observing Satellite interferometric dike-intrusion displacement maps with continuous Global Positioning System (GPS) displacement vectors to show that deformation nearly identical to four previous SSEs at Kilauea occurred at far-field sites shortly after the intrusion. We model stress changes because of both secular deformation and the intrusion and find that both would increase the Coulomb failure stress on possible SSE slip surfaces by roughly the same amount. These results, in concert with the observation that none of the previous SSEs at Kilauea was directly preceded by intrusions but rather occurred during times of normal background deformation, suggest that both extrinsic (intrusion-triggering) and intrinsic (secular fault creep) fault processes can lead to SSEs.     

结合IDS的网络入侵诱骗模型的研究

在分析当前网络入侵诱骗技术并总结其弊端的基础上,提出一种新的入侵诱骗模型.在系统运行时,该模型结合入侵检测系统IDS(Intrusion Detection System),两者优势互补,当检测到有入侵行为时,才进行入侵诱骗,从而提高了网络的安全性.     

基于朴素贝叶斯的渔业文本分类器研究

通过阐述朴素贝叶斯文本分类器的算法原理及其用于建立渔业文本分类器的优点,给出了基于朴素贝叶斯的渔业文本分类器的基本结构,并用实验验证了该结构的性能。结果表明,基于渔业词库的朴素贝叶斯渔业文本分类器具有比普通文本分类器更好的性能。     

在线社会网络多维度链式信任计算算法

针对在线社会网络中用户间的复杂关联和信任问题,本文提出一种链式优化方法来降低用户关联的复杂性,同时结合多维度用户评价、时间衰减、共谋识别以及目标用户信誉值几方面综合计算目标用户的动态信任值,建立了在线社会网络优化及信任计算算法,有效地解决了在线社会网络的信任计算问题.     

数据挖掘技术在入侵检测系统中的应用研究

介绍了入侵检测系统和数据挖掘的有关概念,比较了误用检测与异常检测方法的优缺点,探讨了数据挖掘技术在入侵检测系统中的应用,提出系统的体系结构,并分析了系统的工作流程及其特点。     

小麦撒播、沟播、三行分层施肥条播试验初报

进行了小麦固氮菌拌种撒播、沟播和三行分层施肥条播大田试验,结果表明,固氮菌拌种,667m2增产33.5kg,沟播的平均产量比撒播增产13.2%,三行分层施肥条播比沟播的平均产量增产38.5%,比撒播增产56.8%。     

Heat flow and hydrothermal circulation in the cascade range, north-central Oregon

In north-central Oregon a large area of near-zero near-surface conductive heat flow occurs in young volcanic rocks of the Cascade Range. Recent advective heat flux measurements and a heat-budget analysis suggest that ground-water circulation sweeps sufficient heat out of areas where rocks younger than 6 Ma (million years ago) are exposed to account for the anomalously high advective and conductive heat discharge measured in older rocks at lower elevations. Earlier workers have proposed that an extensive midcrustal magmatic heat source is responsible for this anomalously high heat flow. Instead, high heat flow in the older rocks may be a relatively shallow phenomenon caused by regional ground-water flow. Any deeper anomaly may be relatively narrow, spatially variable, and essentially confined to the Quaternary (less than 2 Ma) arc. Magmatic intrusion at a rate of 9 to 33 cubic kilometers per kilometer of arc length per million years can account for the total heat flow anomaly. Deep drilling in the areas of high heat flow in the older rocks could indicate which model is more appropriate for the near-surface heat flow data.