Hydrodynamical models of type II supernovae     

I. Yu. Litvinova  D. K. Nadyozhin 《Astrophysics and Space Science》1983,89(1):89-113

A series of hydrodynamical models of type-II supernova outbursts (SNII) has been calculated. Approximate relations connecting the total outburst energy ε, the mass of envelope ejectedM, the presupernova radiusR, and the amount of ionizing quanta radiated by the supernovaeN _H with such values as the duration of the light curve plateau Δt, and absolute magnitude in the wavelength bandV and photospheric velocityU _PH observed near the middle of the plateau have been established. Advantage has been taken of the relations to obtain a preliminary evaluation for the characteristics of the average SN II: ε=7×10⁵⁰ erg,M=6M _⊙,R=500R _⊙,N _H=2×10⁵⁸. The SNIIs with plateau-like light curves seem to be accounted for by thermonuclear explosions of degenerate cores of red giant stars and result in a total disruption of the star without any stellar remnant. To the contrary, SNIIs with linear light curves have substantially different properties (in particular, they throw considerably less massive envelopes off). These SNII must signify the birth of collapsed objects—neutron stars (pulsars) or black holes.  相似文献   

Statistical analysis of sand grain/bed collision process recorded by high-speed digital camera   总被引：1，自引：0，他引：1  

DAWEI WANG  YUAN WANG  BIN YANG  WEI ZHANG† 《Sedimentology》2008,55(2):461-470

A high‐speed digital camera was employed to record the sand grain/bed collision process. With image processing and a statistical method, a series of parameters of the collision process were obtained. The results show that the collision process of a grain with rebounding can be represented by two parameters: the kinetic energy restitution coefficient and the collision angle. Both parameters satisfy a normal distribution, and they are dependent on one another. With an increase of the collision angle, the distribution of the kinetic energy restitution gradually reduces from a broad to a narrow range with low values. The percentage of vertical velocity restitution coefficients greater than 1 can reach 70% or more, which ensures that the settling time of the sand grains in the air increases and that they receive more energy from the air to progress the saltation movement.  相似文献   

Georgii Pavlovich Leonov (on the centenary of his birth)     

D. Yu. Pushcharovskii  E. E. Milanovskii  A. M. Nikishin  N. V. Koronovskii  O. V. Yapaskurt  I. S. Barskov  D. P. Naidin  V. T. Frolov  D. I. Panov 《Moscow University Geology Bulletin》2008,63(5):350-351

  相似文献   

Evolution of melt composition during intrusion of basalts into a silicic magma chamber   总被引：3，自引：0，他引：3  

P. Yu. Plechov  I. S. Fomin  O. E. Mel’nik  N. V. Gorokhova 《Moscow University Geology Bulletin》2008,63(4):247-257

The article describes heat exchange between basaltic and rhyolite melts accompanied by fractional crystallization of phases in a basaltic melt. A numerical model has been developed for the homogenization mechanism of magma composition during intrusion of basaltic magma batches into felsic magma chambers. The results of numerical modeling demonstrate that the time needed for cooling the basalts and their fractionation to rhyolite melts is much shorter than the time required for chemical interaction based on diffusive mechanisms.  相似文献   

Changes of deformational and reservoir properties of arenaceous-argillaceous rocks due to operation of underground gas storage facilities     

G. A. Golodkovskaya  I. V. Kalinichenko  Yu. L. Filimonov  V. G. Khloptsov 《Moscow University Geology Bulletin》2008,63(3):162-170

This paper discusses issues of the decline of the reservoir properties of arenaceous-argillaceous rocks as a result of declining porosity due to long-term operation of underground gas storage facilities. An analysis of the many-year operation of storage facilities, as well as calculation, has revealed that the active capacity of a storage reservoir gradually decreases under certain conditions of underground storage operations. We performed a series of experiments with model specimens in order to support the hypothesis of decreasing reservoir (capacity-filtration) properties because of changes in the value and structure of the pore space. These experiments showed that the cyclic loading and unloading of arenaceous-silty rocks during long-term operation of underground gas storage facilities can significantly decrease the reservoir parameters of reservoirs created within worked out gas-and-gas condensate fields. Laboratory studies of model specimens corresponding to feldspar sandstone in their composition, porosity, and strength proved that porosity considerably decreases in such reservoirs at actually existing values of formation pressure. Tests of sand performed under conditions close to those existing during the development of hydrocarbon fields also showed that their permeability gradually decreases in the process of cyclic changes of effective pressure.  相似文献   

Silica phase transformations in the petroliferous sequences     

Yu. K. Burlin  I. I. Plyusnina 《Moscow University Geology Bulletin》2008,63(3):154-161

The joint evolution of organic matter and silica in petroliferous sequences is considered in the terms of the laws of transformation of dispersion systems. The dispersion systems are transformed under conditions of low-temperature solid-phase processes accompanied by the silica phase transition and dehydration that favors the evolution of organic matter.  相似文献   

太湖平原西北部全新世古河道沉积特征及环境演变   总被引：1，自引：0，他引：1  

舒军武  王伟铭  陈晔 《地层学杂志》2008,32(2):146-152

粒度、磁化率定量数据分析在判明第四系沉积物的来源、识别沉积分异作用、解译古沉积相和环境方面有着重要作用。对太湖平原西北部卜弋桥ZK01钻孔上部全新统如东组进行了粒度和磁化率测试分析,结合该孔孢粉成果,揭示研究区全新世古河道沉积环境和气候明显经历了3个阶段:1)11000—9500cal.aBP,沉积物主要由粉砂组成,粒度证据表明水动力条件较强,孢粉证据显示该阶段气候较温暖湿润;2)9500—3900cal.aBP,沉积物砂组分含量大幅增加,粒度资料显示古河道水动力明显增强,孢粉植被表明该时期处于全新世大暖期,气候暖湿稳定;3)3900cal.aBP以来,粉砂组分在沉积物中占优势,粒度结果表明该阶段水动力显著减弱,孢粉资料和磁化率证据表明研究区自该阶段特别是后期以来逐步出现了明显的人类活动迹象。  相似文献   

鄂尔多斯盆地西峰地区长8砂岩微观非均质性的实验分析     

刘林玉  王震亮  柳益群 《岩矿测试》2008,27(1):29-32

通过真实砂岩微观模型实验,客观地分析了鄂尔多斯盆地西峰地区长8砂岩的微观非均质性特征,发现该区长8储层为致密型砂岩,直观地显示出长8砂岩储层具有很强的微观非均质性,砂岩的成岩作用和孔隙结构是影响鄂尔多斯盆地西峰地区长8砂岩储层微观非均质性的主要原因。在低渗透砂岩中,引起砂岩产生强烈的非均质性,而这些砂岩则形成长8砂岩储层的高渗带。  相似文献   

氢化物发生及其在分析检测领域的应用   总被引：2，自引：2，他引：0  

郑大中  郑若锋  王惠萍 《岩矿测试》2008,27(1):55-59

论述了氢化物发生的条件和普遍性及其在分析检测领域的应用,这些领域包括试样分解,分离富集,容量分析、比色分析、原子荧光光谱、原子吸收光谱、电感耦合等离子体原子发射光谱、电感耦合等离子体质谱等分析测试技术。  相似文献   

安徽省黄山地区唐家坞组生物地层   总被引：2，自引：0，他引：2  

孙乘云  杜森官  王有生 《地层学杂志》2008,32(3)

安徽省南部黄山市刘村一带唐家坞组的时代以往归为晚志留世,新近在唐家坞组中采获腕足类、瓣鳃类、腹足类等多门类化石,并首次采获胞石、鹦鹉螺等化石,其中胞石Conochitina(Densichitana)dens的时代为兰多维列世末至文洛克世初期,含这些化石的层位相当于秀山动物群的层位。结合地质情况分析,唐家坞组时限主要属于早志留世。  相似文献