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1.
The Taipinghu Bridge is an important project, and the safety of rock masses of its foundation is very crucial. This article analyzes the potential causes of the deformation of the rock masses of the bridge foundation, and uses the Fast Lagrangian Analysis of Continua to analyze the geologic model. The simulating process shows that no mater in the excavating process or in the loading process the rock masses are suit for the engineering. The modeling and analyzing process can be used for reference. 相似文献
2.
The catastrophic Shikotan earthquake of October 4 (5), 1994, occurred in the Pacific Ocean. Its focus was located 80 km eastward of Shikotan Island. The stress state of the Earth’s crust in this area was estimated by the method of the cataclastic analysis of the whole range of the earthquake mechanisms. The performed reconstruction of the parameters of the current stress state of the Earth’s crust and the upper mantle in the area of the Southern Kuril Islands made it possible to establish that this area is characterized, on the one hand, by the presence of extensive areas of steady behavior of the stress tensor parameters and, on the other hand, by the presence of local sections of anomalously fast changes in these parameters. 相似文献
3.
陶正章 《中国地球化学学报》1991,10(3):288-293,T003
The carat is the unit of weight for diamonds and other gemstones.It corresponds to the average weight of the seeds of a leguminous tree.What kind of tree is this?We have studied the samples from Ethiopia,Egypt,Cyprus and the United States.The tree is neither“Kuara“nor“Locust“（Robina pseudoacacia Linn.）,but rather Carob(Ceratonia Siliqua).In Ethiopia,as called by local inhabitants,“Kuara“is a species of Erythrina-E.brucei rather than E.abyssinica.As might be expected,using the seeds as a means of weighing an extremely valuable commodity is not very scientific.Before 1907,at various times and in various countries,there were at least twenty-three stan-dards for the carat ranging from 187.00mg to 215.990mg.The metric carat equal to 200mg was proposed in Paris in 1907.It was adopted in the United States on July1,1913 and now is the world-accepted standard.But in reality,the standard of the carat is still confused with respect to its usage throughout the world .This is why the author reiterates that the standard of the car-at should be integrated with the metric system. 相似文献
4.
The Taipinghu Bridge is an important project，and the safety of rock masses of its foundation is very crucial．This article analyzes the potential causes of the deformation of the rock masses of the bridge foundation，and uses the Fast Lagrangian Analysis of Continua to analyze the
geologic model． The simulating process shows that no mater in the excavating process or in the loading process the rock masses are suit for the engineering．The modeling and analyzing process can be used for reference． 相似文献
5.
INTRODUCTIONIn comparison with studies on the geochemistryof the REE and trace elements of the Emeishan Per-mian basalts ,there has been onlyli mited research onthe platinum group elements ( PGE) . Preli minarystudies have been carried out on the PGE geochemis-try of the basalts in the Emeishan area ( QingyingPower Station profile) and Xinjie area (Zhang andLi ,1998) ,andinthe Shuicheng and Weining areasinGuizhou (Li et al .,2003) . There are no PGEanaly-sis data of the basaltsin… 相似文献
6.
With increasing high-quality geological and geophysical data it becomes clear that seismicity of the continents is characterized by linear patterns which are closely associated with tectonic features. The aim of this paper is to give reasonable interpretation for the earthquake distribution in the contiguous continent of the United States. Seismic lines and earthquake concentrated zones are defined, which reflect the characteristics of the continental seismotectonics. Similarities and differences in seismotectonics between the continental part of China and the contiguous continent of US are analysed. It is demonstrated that the spatial distribution of earthquakes can provide the information of the active structures in the earth's crust. The authors consider that the patterns of continental seismotectonics are not only controlled by the pre—existing tectonic frameworks and the current boundary dynamic conditions, but also possibly affected by dynamic factors of global tectonics at a higher level. 相似文献
7.
A simple mechanical model explaining the long-period (about 100-year) variations in the Earth’s rotational velocity is proposed. This model takes into account the gravitational interaction of the mantle with the solid core of the Earth and the fact that the core rotation leads that of the mantle. Well-known Earth parameters provide estimates of the gravitational torque that support the proposed model. The mathematical problem involved reduces to the classical problem of a nonlinear oscillator exposed to a constant torque. The well-known parameters of the core-mantle system result in a stable equilibrium and a stable limiting cycle on the phase cylinder of this oscillator. This equilibrium corresponds to a single angular velocity for the mantle and solid core, with no long-period oscillations in the length of the day. The limiting cycle corresponds to the core rotation leading the mantle rotation. In this case, the ellipsoidality of the gravitationally interacting bodies provides a periodic interchange of kinetic angular momentum between the mantle and solid core that results in long-period variations in the length of the day. The proposed model does not support the formerly widespread opinion that the core rotates more slowly than the mantle. 相似文献
8.
Guan Shaozeng 《《地质学报》英文版》1989,63(3):281-296
Since the coexistence of the Cretaceous and Palaeocene was ascertained in the Hengyang Basin of Hunan in the middle of the 1960's, the Cretaceous and Tertiary boundary has been discussed in several papers, but it still remains controversal. The points at issue are the connotation, stratigraphical position and lateral correlation of the Dongtang (or Chejiang) Formation. 相似文献
9.
Doklady Earth Sciences - An attempt to provide a new explanation for the change in the geodynamic regime in the Early Cretaceous is presented below. It accounts for data on a number of global... 相似文献
10.
11.
D. N. Rachkovskii 《Astronomy Reports》2005,49(8):654-658
A new formulation for the phase matrix for the scattering of radiation in a weak magnetic field is presented. The phase matrix is represented as a product of individual matrices that depend on the angle of incidence and the scattering angle. It is shown that the Hanle effect is absent in observations of scattered light in the solar atmosphere when the magnetic field is perpendicular to the atmosphere. In strong magnetic fields, the phase matrix depends only on the direction of the magnetic field relative to the basic coordinate system. 相似文献
12.
D. N. Rachkovskii 《Astronomy Reports》2009,53(2):153-159
Exact analytical expressions for the scattering phase matrix are presented for various models of a turbulent magnetic field having a symmetry axis in the solar atmosphere. The polarization of the scattered radiation in the plane of the scattering is shown to be virtually independent of the predominant direction of the turbulent magnetic field. The Hanle effect does not operate in a longitudinal magnetic field normal to the surface of the atmosphere, since the phase matrix has the form of a resonance phase matrix with zero magnetic field. 相似文献
13.
The development of the solar magnetic activity in cycle 24 has been analyzed. It has been shown that the significant north–south asymmetry of magnetic activity was accompanied by the asynchronous reorganization of solar magnetic fields in the northern and southern hemispheres. The formation of unipolar magnetic regions after the decay of activity centers has been studied. The meridional transport of unipolar magnetic regions leading to changes in the zonal structure of the solar magnetic field has been shown. Long-lived centers of flare activity have been found to exist during the periods of magnetic field restructuring. The spatiotemporal analysis of the flare ensemble making it possible to diagnose non-stationary processes in the solar atmosphere has been shown. 相似文献
14.
D. N. Rachkovskii 《Astronomy Reports》2010,54(9):832-839
The system of radiative-transfer equations for polarized radiation is solved analytically using an azimuth-averaged Hanle
phase matrix. A Milne-Eddington model with a constant ratio of the line and continuum absorption coefficients and a linear
dependence of the source function on optical depth is adopted for the atmosphere. The vector magnetic field is taken to be
constant with optical depth. The dependence of the linear polarization obtained during observations at the solar limb on the
magnitude and inclination of the magnetic field to the normal of the atmosphere is presented as an illustration of the theoretical
computations. The measured polarization corresponds to two magnetic-field values and several possible field inclinations.
The measured polarization is directly proportional to the quantum coefficient W
2 determining the resonance polarization in lines. 相似文献
15.
The Sun provides the main energy input to the terrestrial atmosphere, and yet the impact of solar variability on long-term changes remains a controversial issue. Direct radiative forcing is the most studied mechanism. Other much weaker mechanisms, however, can have a significant leverage, but the underlying physics is often poorly known. We review the main mechanisms by which solar variability may impact the terrestrial atmosphere on time scales ranging from days to millennia. This includes radiative forcing, but also the effect of interplanetary perturbations and energetic particle fluxes, all of which are eventually driven by the solar magnetic field. 相似文献
16.
南半球对流层气候年代际变化及其与太阳活动的联系 总被引：7，自引：0，他引：7
通过南半球对流层温度场谱分析和逐次滤波分析发现，南半球对流层大气温度场半个多世纪以来呈现明显的持续升温趋势，升温幅度由低层到高层逐步增加，其中地面层1 000 hPa年升温率为0.013℃/a，对流层中部500 hPa年升温率为0.019℃/ a，对流层上部300 hPa年升温率为0.036℃/ a；滤除南半球大气温度场的趋势变化，发现南半球大气温度场从地面层直至对流层顶广泛盛行着十分显著的与太阳磁场磁性22年周期变化相一致的变化周期。太阳磁场磁性周期变化趋势略有超前，分析认为，这是南半球对流层大气气候系统对太阳磁场周期性变化的响应。进一步分析还发现，南半球从地面层1 000 hPa到对流层顶，再到平流层中部10 hPa各层次大气温度变化22年周期分量振荡位相基本一致，周期振幅由低层到高层迅速增大，说明太阳磁场变化对对流层高层比低层影响大，对平流层影响更大。其中地面层1 000 hPa温度场的22年变化周期是在滤除趋势变化和11年周期之后才显现出来的，所以太阳磁场磁性周期变化对地面层气候的影响较小并且经常处于被掩盖状态；南半球地面层1 000 hPa温度场滤除趋势变化之后显示出十分显著的与太阳活动11年周期相一致的变化周期，分析认为，这是南半球对流层大气气候系统对太阳活动11周期性变化的响应。对流层上层300 hPa温度场滤除趋势变化和22年周期之后也显示出11年变化周期，而对流层中部500 hPa则无此周期反应，说明太阳活动11年周期对地面层1 000 hPa大气气候影响最明显，对流层中上层影响较弱。 相似文献
17.
Tatsuyuki Yamamoto Hideo Akiyoshi Keisuke Yoshikiyo Tetsuya Takahashi Yukiko Tanabe Sakae Kudoh Satoshi Imura Naoyuki Yamamoto 《地学前缘(英文版)》2013,4(6):647-653
A study on the effect of the solar ultra-violet radiation on the human skin fibroblast cells revealed that the production of matrix metalloproteinase-2 was inhibited by the radiation.A CO2 incubator connected by optical fibers to a reflector telescope for collecting the solar light was built at Syowa station by the 49th Japanese Antarctica Research Expedition.The direction of the telescope was continuously controlled by a sun-tracker to follow the movement of the Sun automatically.The intensity of the collected light was monitored by a portable spectrophotometer housed inside.The human skin fibroblast cells were incubated in the CO2 chamber to investigate the effect of the solar radiation at Syowa station and were compared with those reference experiments at a laboratory in Japan.The results showed cell damage by strong UV radiation.The production of matrix metalloproteinase-2 was prompted by the moderate UV-B,but was inhibited by the strong UV-B radiation,as studied under laboratory conditions in Japan.The effect of strong solar radiation at Syowa station involving the radiation of UV-B region was estimated to be of the same extent of the radiation caused by an artificial UV-B light with the intensity more than 50 mJ/cm2. 相似文献
18.
L. L. Kitchatinov 《Astronomy Reports》2008,52(3):247-255
The stability of a toroidal magnetic field in the rotating radiation zone of a star is analyzed to estimate the maximum possible magnitude of relic fields. Equations for small perturbations are obtained taking into account the finite diffusivity and the stabilizing effect of the subadiabatic stratification. The numerical solution of the eigenvalue problem indicates that the threshold field strength for the onset of instability in the radiation zone of the Sun is about 600 G. This figure sets an upper bound for the strength of the relic field. The assumption that magnetic instabilities are present in the solar radiation zone disagrees with the observed abundance of lithium. Our analysis of joint stability of toroidal field and nonuniform rotation shows that two-dimensional MHD solutions for the solar tachocline are stable against three-dimensional perturbations. 相似文献
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20.
D. N. Rachkovskii 《Astronomy Reports》2013,57(10):766-777
A new derivation of the matrix equations of radiative transfer in a magnetic field is presented, which is based on the classical approach of M. Born and V.E. Stepanov. Convenient vector relations making it possible to formulate the radiative-transfer equations in an arbitrary coordinate system and choose a convenient system of Stokes parameters are presented. The cases of the solar atmosphere and a stellar atmosphere with a dipolar magnetic field are presented as examples. The use of the radiative-transfer equations written in terms of two main oscillation components (the method of V.E. Stepanov) can lead to crude errors when the complex nature of the absorption coefficients is taken into account. 相似文献