Optical observations of the broad-lined type Ic supernova SN 2012ap

The optical observations of the type Ic supernova(SN Ic) SN 2012 ap in NGC 1729 are presented. A comparison with other SNe Ic indicates that SN 2012 ap is highly reddened(with E(B- V)host～0.8 mag) and may represent one of the most luminous SNe Ic ever observed, with an absolute V-band peak magnitude of ～-19.3±0.5 mag after extinction correction. The near-maximum-light spectrum shows wide spectral features that are typical of broad-lined SNe Ic. One interesting feature in the spectrum is the appearance of some narrow absorption features that can be attributed to the diffuse interstellar bands, consistent with the large reddening inferred from the photometric method. Based on the light curves and the spectral data, we estimate that SN 2012 ap produced a56 Ni mass of ～ 0.3 ± 0.1M in the explosion, with an ejecta mass of 2.4+0.7-0.7M and a kinetic energy of E5K= 1.1+0.4-0.4× 102 erg. The properties of its progenitor are also briefly discussed.     

3-D finite element modeling for evolution of stress field and interaction among strong earthquakes in Sichuan-Yunnan region

Introduction Sichuan-Yunnan region is a major area with frequent strong earthquakes in Chinese mainland, especially the middle-southern segment of South-North Seismic Zone, where many strong earth-quakes occurred in history. In the past 30 years, Sichuan-Yunnan region has two seismically active periods: one is from Tonghai earthquake in 1970 to Longling-Songpan earthquake in 1976, the other is from Lancang earthquake in 1988 to now. During this two periods, the M=7.7 Tonghai, M=7.1 Dagua…     

Study on Flow Field Around Vertical Breakwater Under Different Overtopping Conditions Based on Numerical Simulation

A numerical wave flume is constructed based on the Reynolds Averaged Navier-Stokes (RANS) equations with turbulence closure by a modified k-ε model to study the viscous interactions of waves with vertical breakwaters for different overtopping cases. The governing equations,the turbulence model,boundary conditions,and solution method for the numerical wave flume are introduced briefly. The reliability of the numerical wave flume is examined by comparing the numerical results with the experimental measurement...     

The Ground Deformation Disaster in the City of Tianjin Associated with the Tangshan Earthquake

In this paper,a study of the principal characteristics of the ground deformation disasters in the city of Tianjin caused by the Tangshan earthquake is based on the results from the recent remeasurements of the geodetic controlling network of Tianjin and from on-site investigations after the earthquake.These results show that only the ground deformation in the Ninghe and Hangu areas near the epicenter reflect directly the co-seismic crustal stress,while the serious ground deformation and the engineering earthquake damages in the urban districts of Tianjin are controlled to a great extent by the local engineering geological structures,showing a kind of secondary disaster.Several suggestions are also proposed in the paper concerning the counter-measures for reducing the earthquake damage in big cities.     

NUMERICAL EXPERIMENT OF THE INFLUENCES OF HEAT AND WIND STRESS ON THE EQUATORIAL OCEAN CIRCULATION

A time-dependent linear model on the equatorial beta plane is developed in this paper.Its verticalstructure consists of two active layers with equal density and temperature above the thermocline and aquasi-stationary layer with constant density below the thermocline.The results of nurnericat experiments show that the direct influence of heat on the equatorial ocean ismuch smaller than that of wind stress.Nevertheless,through the tropical ocean-atmosphere interaction,the change of wind stress resulting from the thermal forcing may set a determinant effect on the equilibriumand anomalous development of the ocean-almosphere circulation.     

模糊数学方法在分析日本东海地区地震前兆中的应用

本文把模糊模式识别的直接方法用于检测日本东海地区地震活动性、体积应变、地下水位、地下水氡含量、地倾斜和潮位中的前兆变化。此方法可消除诸如降雨和气温变化等干扰,使我们能更清晰地识别出地震前兆。此外,还把模糊相似方法和模糊聚类方法应用于识别地震空区及检验地震活动随时间变化的相似性。上述方法在日本其他地区同样有效,即将编入日本气象研究所板内地震预报计划中的计算机系统内。     

天津及邻区1999～2000年地震震源机制研究

文中使用的是天津市、河北省地震台的 P,Pn波初动方向资料 ,研究了 1 999～ 2 0 0 0年发生在天津及邻区的 4个地震的震源机制。其中 1 999年 8月 1 1日河北省大城县 ML 3.1地震发生在大城断裂上 ,震源机制解的节面 (走向 2 0 8°,倾角 54°,滑动角 1 2°)与大城断裂的走向一致。2 0 0 0年 1月 2 6日蓟县 ML 3.3地震发生在蓟县 -邦均断裂上 ,震源机制解的节面 (走向 2 85°,倾角 77°,滑动角 1 38°)与蓟县 -邦均断裂的走向一致。表明这两个断层在活动 ,这两个地震发生在多年来 (有感 )地震不多的地区 ,并且是发生在首都圈中部 ,应该引起注意     

AN IMPROVED LAND-SURFACE PROCESS MODEL AND ITS SIMULATION EXPERIMENT——PART I:LAND-SURFACE PROCESS MODEL AND ITS“OFF-LINE”TESTS AND PERFORMANCE ANALYSES

Based on the existing land-surface schemes and models,an improved Land-surface ProcessModel(LPM-ZD)has been developed.It has the following major characteristics:(1)Thecombination of physical equations and empirical analytical formulae are used to construct thegoverning equations of soil temperature and moisture.Higher resolution of model level andphysical equations are adopted for the upper soil layers,and for the lower soil layers,lowerresolution of model level is adopted and empirical analytical formulae are used.(2)In land surfacehydrological process,the sub-grid distribution of rainfall and its effects are taken into account.(3)A simple snow cover submodel has been used,which includes effects of snow cover on soilthermodynamics and hydrology,as well as albedo.By use of this model and three groups of point observation data,a series of“off-line”testshave been carried out.The simulation results indicate that land-surface process model has goodperformance and can well simulate diurnal and seasonal variation of land surface processes for manykinds of land surface covers(forest,grass,crops and desert)in different climate zone.The resultssimulated by the model are consistent with the observations.Later,by use of one group ofobservation data and the model,a series of sensitivity experiments have been done.It is shownthat the model is much sensitive to some parameters,such as initial soil moisture,vegetationphysical parameters as well as the proportion of the grid covered with rain.Therefore it is muchimportant for land-surface process model to define these parameters as accurately as possible.     

THE STUDY OF RETRIEVAL THEORY AND METHODS FROM SATELLITE REMOTE SENSING FOR METEOROLOGICAL PARAMETERS OVER EASTERN ASIA—PART Ⅱ:ISPRM AND VSPRM2

Based on the practice of improved simultaneous physical retrieval model(ISPRM),in the lightof the functional analysis approach,the variational simultaneous physical retrieval model(VSPRM)has been developed.Its approximation of 1st degree is VSPRM1,which is identicalwith the ISPRM.Its approximation of 2nd degree is VSPRM2,more advanced than the VSPRM1.This paper has analyzed the function of VSPRM2,pointing out the potentiality of synergy retrievalof this model.Also,it has dealt with the problem of parameterization of water vapor's kernelfunctions and retrieval of water vapor remote sensing.Because of the characteristics of this strong ill posed inverse problem,prior information mustbe used wisely in order to get the accurate calculation of radiance R.In the previous paper,wediscussed how to build the best first guess field,the way to determine the P_s and to correct thecalculation of radiance.In this paper,we continue discussing in depth about the calculation oftransmittance,the determination of surface parameters and the selection for an optimumcombination of channels for the low-level sounding.The long-term experiment and comparison work under operational environment have shownthat the ISPRM is useful for retrieval of temperature and water vapor parameters over Chinaincluding the Tibetan Plateau,and it further proves the scientific nature of well-posed inversetheory.     

Associations of decimetric type Ⅲ bursts with coronal mass ejections and Hα flares

We present a statistical study of decimetric type Ⅲ radio bursts,coronal mass ejections(CMEs),and Hα flares observed in the period from July 2000 to March2005.In total,we investigated 395 decimetric type Ⅲ radio burst events,21% of which showed apparent correlation to CMEs that were associated with Hα flares.We noticed that the Hα flares which were strongly associated with CMEs were gradual events,and82% of them took place before CMEs appeared in the field of view of LASCO C2;that most of the CME-associated radio bursts started in the frequency range around750 MHz with a frequency drifting rate of several hundred MHz s-1,of which both positive and negative ones were recognized; and that the correlation of type Ⅲ radio bursts to CMEs without associated flares is fairly vague,less than 9%.