用电测深法在水压致裂实验中确定岩石破裂方向的实验研究

1.测点布设及观测方法实验场地位于福建省南靖县汤坑盆地中央。盆地内分布有F_1、F_2、F_3和F_44组断裂,其中F_1为张性兼压扭性断裂,F_2为扭性断裂,F_3为张扭性断裂,F_4为压扭性断裂(图1)。     

1988年11月22日甘肃肃南5.7级地震

1.地震的基本参数及序列根据甘肃区域地震台网和全国地震台网测定,这次地震的基本参数是: 发震时刻:1988年11月22日01时46分1.7秒; 震中位置:北纬38°35′,东经99°32′,即肃南县城以南的祁连山中;     

Observation of organized structure in turbulent flow within and above a forest canopy

Ramp patterns of temperature and humidity occur coherently at several levels within and above a deciduous forest as shown by data gathered with up to seven triaxial sonic anemometer/thermometers and three Lyman-alpha hygrometers at an experimental site in Ontario, Canada. The ramps appear most clearly in the middle and upper portion of the forest. Time/height cross-sections of scalar contours and velocity vectors, developed from both single events and ensemble averages of several events, portray details of the flow structures associated with the scalar ramps. Near the top of the forest they are composed of a weak ejecting motion transporting warm and/or moist air out of the forest followed by strong sweeps of cool and/or dry air penetrating into the canopy. The sweep is separated from the ejecting air by a sharp scalar microfront. At approximately twice the height of the forest, ejections and sweeps are of about equal strength.In the middle and upper parts of the canopy, sweeps conduct a large proportion of the overall transfer between the forest and the lower atmosphere, with a lesser contribution from ejections. Ejections become equally important aloft. During one 30-min run, identified structures were responsible for more than 75% of the total fluxes of heat and momentum at mid-canopy height. Near the canopy top, the transition from ejection of slow moving fluid to sweep bringing fast moving air from above is very rapid but, at both higher and lower levels, brief periods of upward momentum transfer occur at or immediately before the microfront.     

A study of water balance in china

The water balance in C'hina is studied in this paper, which follows the papers on the radiation balance and the heat balance in China. Using the data from more than 200 meteorological stations for 1961-1970 and about 200 hydrometric stations bcforc1972, we, through the equation of water balance, have calculated the monthly and annual amounts of precipitation, evaporation, run-off and soil water variation. The water balance and the hydroclimatological characteristics of China arc given.     

震源区的断层构造与震源应力积累过程关系的实验研究

本实验研究了地壳内对压组合构造和对张组合构造中垂断层蠕滑,破裂错动时对主震断层(底断层)应力积累过程的影响,并结合实际地震活动中的一些现象进行了讨论。所得结论如下: 1.当垂断层蠕滑时,对压组合构造中垂直于底断层的压应力增大,它可以延迟主震发生但增大发震的能量;对张组合构造中垂直于底断层的压应力减小,剪应力略有增大,因而可以促使主震发生。2.如果垂断层某一部分为原来锁住的愈合断层或为完整介质,当其突然破裂错动时,可以使对张组合构造中的底断层的剪应力突然增大,同时压应力减小,因此前震序列中这类垂断层上的较大前震可看作底断层上主震即将来临的信号。3.由垂断层破裂前后单轴压力不变和位移不变的实验结果说明了地壳中主震断层应力集中的过程。4.底断层的主震破裂可以使处于引张状态的垂断层上余震发育甚至发生强余震。本文还应用实验结果对前震活动的条带现象进行了解释,这将有助于判定对压组合构造中主震的断层面。     

蛇纹石族矿物及其热转变产物的红外光谱研究

本文报道了蛇纹石族矿物及其热转变产物的红外光谱。在室温下斜纤蛇纹石,正纤蛇纹石,叶蛇纹石和利蛇纹石都具有各自的特征光谱。在结构资料基础上,我们解释了它们之间的光谱差异。无疑,红外光谱是区分各种蛇纹石矿物的有效手段。 样品加热到600—700℃时,3680cm~(-1)羟基带消失,这表明在该温度下蛇纹石矿物完全脱羟。与此同时,光谱中出现橄榄石870cm~(-1)的最强带和一个宽带1000cm~(-1),这说明蛇纹石已部分地转变为晶质橄榄石和形成一个无定形的中间相。800℃时,1060cm~(-1)新带的出现标志着顽火辉石的生成。在所有加热样品的光谱中都没有发现SiO_2吸收带,故可认为,在蛇纹石的热转变过程中没有出现SiO_2相。     

衍射指标h和k的互换问题

通过衍射线指标和面网指标的联系讨论了晶体的对称性对衍射指标h和k互换的影响。在下列情况下衍射指标h和k是不能互换的:在低级晶族;在四方晶系C_(4h)—4/m劳厄点群,六方品系C_(6h)—6/m劳厄点群和立方晶系T_h—m3劳厄点群对于hko和kkl型衍射;在三方晶系选取六方晶胞的情况下,在C_(3i)—3劳厄点群对于hol,okl,hko和hkl型衍射,在D_(3d)—3m劳厄点群对于holokl和hkl型衍射,以及在菱面体点阵除非h和k都是三的倍数。     

Research Status and Progress of Balloon-borne Cloud and Precipitation Particles Probe

The accurate observation of the microphysical structure of cloud and precipitation plays an important role in understanding the formation of clouds and precipitation. In-situ measurement using measuring instruments carried by meteorological balloons is an effective way to obtain the microphysical properties of cloud and precipitation particles, which is a supplementary means for aircraft to observe cloud and precipitation particles. This observation method plays a more and more important role in in-situ measurement. According to the difference of the working principle of the existing balloon-borne cloud and precipitation particles probes, the detectors can be divided into particle impact-sampling sensors, particle imaging sensors, light-scattering sensors, light intensity attenuation sensors and charge measurement sensors. The working principles, key technologies and main advantages and disadvantages of typical instruments were summarized, and their applications to detailed cloud structure acquisition, cloud remote sensing method establishment, cloud and precipitation physical process research and parameterization, and scientific observation of thunderstorm clouds were briefly introduced. Finally, the development trend of balloon-borne cloud precipitation particle detectors was prospected, which will provide reference for related technical research and equipment development.     

The Chemical Composition of Global Subducting Sediments and Its Geological Significance

Subducted sediments play an important role in crust-mantle interaction and deep mantle processes, especially for subduction zone magmatism and mantle geochemistry. The current rate of Global Subducting Sediments (GLOSS) is 0.5~0.7 km³/a. The GLOSS are composed of terrigenous material(76 wt.%), calcium carbonate(7 wt.%), opal(10 wt.%) and mineral-bound H₂O⁺(7 wt.%). The chemical compositions of GLOSS are similar to those of upper continental crust which is mainly controlled by the terrigenous materials, and yet the materials formed by marine processes will dilute the terrigenous materials. The components of subducted sediments are different among trenches. In the accretionary margin, the components of subducted sediments are similar to those of the upper crust, while in the non-accretionary margin the components are terrigenous materials plus those produced by marine processes. During subduction, subducted sediments will released fluids, melt or supercritical fluid to affect island arc/back-arc basin magmatism by means of aqueous fluid or sediment melt. In addition, a part of subducted sediments, together with underlying altered oceanic crust/lithosphere, recycle into the mantle and contribute to the mantle heterogeneity. Geochemical tracers indicate that subducted sediments play variable contributions to the magmatic processes in different tectonic setting. Thus, subducted sediments play an important role in two relatively independent dynamics systems (plate tectonics and mantle plume), as well as related mantle evolution models. As a result, by accurately calculating the compositions of subduction sediments and using various geochemical indicators, we can further limit the input and output fluxes of various elements or isotopes, and then obtain more accurately residual subducted components, which can provide us some important clues for geodynamic process.     

东海陆架盆地岩石密度与磁性

本文在东海陆架盆地２０口钻井１６０块岩心标本物测定和１７口钻井密度测井的基础上，通过整理、分析、统计，给出了东海陆架盆地的岩石密度和磁性特征。