可作为新震源的列车振动及实验研究

利用地震仪器对火车通过大同—秦岭铁路线产生的振动进行了观测. 观测中使用了两套宽频带地震仪和一套短周期地震仪,共获得距铁路0～2.15km的9个观测点的38次列车振动观测数据,全部记录均可分辨出清晰的地震波形. 研究表明：运动列车会在铁路沿线2～3km范围内产生明显的地面振动,接收到的振动频谱在0.05～20Hz范围内平坦,信号频带较宽,观测重复性好. 列车振动为利用地震勘探方法探测地下浅层结构提供了一种重复性很好的新震源.     

Theoretical Calculation Model of Heat Transfer for Deep-derived Supercritical Fluids with a Case Study

Based on a set of equations established by Duan et al. (1992, 1996) for a geofluid system H2O-CO2-CH4(-N2), a formula is obtained to calculate the heat changes. Combining the geological T-P conditions (geothermal gradients and lithostatic and hydrostatic pressures), the enthalpy of some typical geofluids is figured out. Then the principles of heat transfer of deep-derived supercritical fluids are discussed. The result shows that deep-derived geofluids can bring a large amount of thermal heat and release most heat to the shallow surroundings as they move up, because the molar enthalpies vary very greatly from the deep to shallow, increasing with the increases of T and P. Generally, more than tens of kilojoules heat per molar can be released. Furthermore, the molar enthalpy is affected by the compositions of the geofluids, and the molar enthalpy of CO2, CH4, or N2 is greater than that of H2O, being twice, more than twice, and about 140% of H2O, respectively. Finally, a case study is conducted by investigat     

山东渤南油田古近系沙河街组沙二段及沙三段低渗透储层成岩储集相

渤南油田位于济阳坳陷的渤南洼陷内,是山东省胜利油田储量最大的亿吨级深层低渗透断块岩性油藏,主要含油层系为古近系沙河街组沙二段和沙三段,属中孔低渗透砂岩储层。低渗透砂岩储层的成因机理十分复杂,为了更精确地预测有效储层的分布及其内部储集性能的差异,应用成岩储集相的概念在渤南油田三区古近系沙河街组开展了低渗透储层质量评价的研究。该项研究是建立在储层沉积相、成岩作用研究的基础上,通过分析低渗透储层成岩作用对储集物性的影响及成岩作用阶段划分,认为造成本区储层砂岩渗透率较低的主要原因是成岩期各种自生矿物的充填和胶结作用。选用流动层带指标、孔隙度、渗透率、粒度中值、泥质含量、孔喉半径均值和变异系数等七项参数,采用聚类分析和判别分析方法,将渤南油田三区古近系沙河街组划分为四类成岩储集相,阐述了各类成岩储集相的特征,并结合沉积相,实现了成岩储集相的时空展布。研究成果将对低渗透砂岩储层的开发起到指导作用。     

Remote Sensing Geological Exploration Model for Copper and Gold Deposits in the East Tianshan, Xinjiang

Based on the identification and enhancive processing of information about strata, structure, magmatite, and alteration in ore-concentrated area in the eastern Tianshan, an exploration mode of remote sensing geology is established. The mode covers basic images composed of TM (7, 4, 1), Munsell space transformation for recognizing rock type, directional matched filtering for enhancing structures, multi-layer separating and extracting weak alteration information. It will provide a rapid and effective method for geological mapping and metallogenic prediction in this region.     

碎石土振动压实动态监测方法研究

根据结构振动理论,分析了振动压实机械与被压土体的相互作用机理,研究了碎石土振动压实动态监测的理论依据,建立了一套适用于加速度监测仪的振动压实动态监测数据采集系统．在大量室内试验数据的基础上,研究了振动压实过程中加速度电信号响应随碎石土密实度的变化规律,发现二者具有显著的线性相关性．研究结果为实现快速有效的碎石土路基密实度实时动态监测提供了理论依据和工程指导．     

基于Applet-CORBA的空间物流信息平台体系

现代科学技术的迅速发展,尤其是信息技术的迅速发展,极大地促进了物流管理技术的发展。在供应链的“四流”,即物流、商流、资金流、信息流中,信息流提升到了前所未有的高度,信息获取和处理的实时性和准确性是物流管理成败的关键。本文首先简单介绍了物流管理技术、空间信息技术以及这两种技术集成的优势,然后结合当前分布计算技术中最具发展潜力的CORBA技术,设计了基于Applet-CORBA的空间物流信息平台,并对系统的体系结构进行了分析。     

COMMENT ON “WHO WILL FEED CHINA”

I.MR.BROWN'SMAINOPINIONMr.LesterBrown,'presidentoftheWorldWatchinstituteintheU.S.A,publishedalongicicletitledas"WhowillfeedChina"in1994(Brown,1995),whicharousedgreatresponSeSfromhomeandabroadandattractedmuchattentionfromallsides.Theadnideasofthearticleincludethefollowingthreepoints:(1)ItisestimatedthatthepopulationofChinawillincrare490whitionfrom1990tO2030,uptol,600whition;thecultivatedlandofChinaisaffectedbythemedeAnzationoftheeconomy,andisevendisap~ng;inaddition,thepotentiality…     

POLYCULTURE OF SCALLOP CHLAMYS FARRERI AND KELP LAMINRIA JAPONICA IN SUNGO BAY

Several polyculture models of scallop Chlamys farreri and kelp Laminaria japonica currently employedin Sungo Bay and other parts of northern China are described in this paper. Economic benefits of differ-ent polyculture models are analysed based on the growth rate, culture density and market price. In addi-tion, site selection, critical environmental conditions and polyculture problems are discussed in detail.     

Normal fault zone evolution and fault scarp degradation in the Aegean region

Abstract The initial stages of rift-basin evolution are periods of great landform change. Fault scarps are newly created axes of erosion which, along with footwall uplands, act as sediment sources for subsiding hanging wall basins. Scarps formed during neotectonic normal faulting of Mesozoic carbonates in mainland Greece and western Turkey display a varied pattern of degradation related to the history of fault development and variations in fault zone architecture. Alternating zone-parallel compact breccia sheets and incohesive breccia belts, of contrasting resistance to erosion, underlie scarps. Meso-scale slip-plane phenomena, such as corrugations, gutters, comb fractures, and pluck holes, together with geomorphological features, such as subsurface solution pipes, and vegetation result in initial variations in the denudability of erosionally resistant compact breccia sheets. Migration with time of slip-plane activity within a fault zone into its hanging wall (i.e. intrafault-zone hanging wall collapse) adds to the structural heterogeneity of fault scarp footwalls. Quaternary talus, whether offset across a fault, banked unconformably against a slip plane, or faulted against a reactivated slip plane, has a dampening effect on degradation. The complexities of fault zone architecture combined with a history of hanging wall collapse lead, in the Aegean region, to non-uniform degradation and scarps which are commonly stepped and occasionally cavitated.     

Podiform Chromitites in the Luobusa Ophiolite (Southern Tibet): Implications for Melt-Rock Interaction and Chromite Segregation in the Upper Mantle

The Luobusa ophiolite in the Indus—Yarlung Zangbo sutureof southern Tibet hosts the largest known chromite deposit inChina. The podiform chromitites occur in a well-preserved mantlesequence consisting of harzburgite with abundant lenses of dunite.The harzburgites have relatively uniform bulk-rock compositionswith mg-numbers [100 Mg/(Mg + Fe)] ranging from 89 to 91 andshow flat, unfractionated, chondrite-normalized platinum groupelement (PGE) patterns. Their accessory chromite varies widelyin cr-number [100Cr/(Cr + Al)] (18–66). These rocks areessentially residua left after extraction of mid-ocean ridgebasalt (MORB)-type magmas. The podiform chromitites displaynodular, massive, disseminated and banded textures and typicallyhave dunite envelopes that grade into the surrounding harzburgiteand diopsidic harzburgite with increasing pyroxene contents.They consist of relatively uniform chromite with high cr-numbers(74–82), have strongly fractionated, chondrite-normalizedPGE patterns with enrichment in Os, Ir and Ru relative to Rh,Pt and Pt, and are believed to have formed from a boniniticmagma produced by a second stage of melting. Dunites containaccessory chromite intermediate in composition between thoseof harzburgite and chromitite and are believed to be the productsof reaction between new boninitic magmas and old MORB-type peridotites.The melt-rock reaction removed pyroxene from the peridotitesand precipitated oli-vine, forming dunite envelopes around thechromitite pods. The melts thus became more boninitic in compositionand chromite saturated, leading to precipitation of chromitealone. The interplay of melt-rock interaction, chromite fractionationand magma mixing should lead to many fluctuations in melt composition,producing both massive and disseminated chromitites and phaselayering within individual podiform bodies observed in the Luobusaophiolite. KEY WORDS: boninitic magmas; dunite envelope; melt—rock interaction; MORB peridotities; podiform chromitites ^*Corresponding author. Present address: Department of Geology, Laurentian University, Sudbury, Ont, Canada P3E 2C6.