INVESTIGATION ON GEOSTROPHIC ADJUSTMENT,FRONTOGENESIS AND OSCILLATIONS     

潘益农  伍荣生 《Acta Meteorologica Sinica》2001,(3)

Geostrophic adjustment and frontogenesis are examined by means of the 2-D ARPS model.The simulation shows that.without the large-scale forcing,both the frontogenesis and frontolysisare observed during the geostrophic adjustment process and the intensity of the front oscillates inthe case of no discontinuity.The convergence (divergence) induced by the secondary circulation isthe most important factor for frontogenesis (frontolysis) at the top and bottom boundaries.Theamplitude and period of oscillation are dependent on the initial atmospheric stratification and theCoriolis frequency,and they are related to the inertio-gravity wave.  相似文献   

柴达木盆地东部烃源岩的生源与沉积环境   总被引：15，自引：5，他引：15  

刘洛夫 《古地理学报》2001,3(2):82-91

用色谱-质谱、稳定同位素质谱等分析测试技术，对柴达木盆地东部地区寒武系、奥陶系、泥盆系、石炭系和侏罗系岩样进行地球化学特征分析。从饱和烃生物标志化合物特征、正构烷烃单体碳同位素分布特征等方面入手，对该区的烃源岩的生源与沉积环境作了详细研究。结果表明，柴达木盆地东部地区古生界有机质多为菌、藻类生源，少数有陆源有机质混入（主要是石炭系）。有机质多为强还原环境的海相沉积，少数为海陆过渡相沉积。侏罗系在一些地区和层段并非典型的成煤环境，而是属于滨浅湖相，少数为半深湖-深湖环境，因此具有一定的生烃能力。  相似文献   

Probabilistic Seismic Hazard Assessment Along the Southeastern Coast of Vietnam     

Hong Phuong  Nguyen 《Natural Hazards》2001,24(1):53-74

On the basis of the analysis of geological, tectonic characteristics and earthquake manifestation features, a causative relation between geodynamic regime and seismicity has been established for the southeastern coastal zone and continental shelf of Vietnam. The probabilistic methods have been used to evaluate ground shaking effects at Nha Trang city aswell as for the entire study area. Short, intermediate and long term predictions of ground shaking (in the form of peak ground accelerationmaps) show high risks in the coastal zone of central Vietnam and in the southeastern continental shelf of the country.  相似文献   

Simulation of acid water movement in canals   总被引：1，自引：0，他引：1  

To Van Truong  Nguyen Tat Dac  Huynh Ngoc Phienc   《Journal of Hydrology》1996,180(1-4):361-371

An attempt to tackle the problem of the propagation of acid water in canals is described, and a mathematical model to simulate the acid water movement is developed, in which the jurbanite equilibrium is found to prevail. The processes of settling owing to sedimentation, precipitation and redissolution have been considered in the modelling. Data available from Tan Thanh, in the Plain of Reeds of the Mekong Delta in Viet Nam, are used as a case study.  相似文献   

五大连池火山构造地震空间分布及其构造含义   总被引：3，自引：0，他引：3  

张凤鸣  张守国 《东北地震研究》1996,12(4):17-22

在对五大连池地震台１９８３年以来观测到的五大连池火山区的地震记录复核的基础上，测定了火山构造地震的空间分布状态。研究结果表明该地区地震活动均为壳内地震。受火山构造环境影响，地震活动存在着外围边缘强，震源深度分布深；内部弱，震源深度分布浅的差异。火山区内部地震深度分布优势在５ｋｍ—８ｋｍ，有３个地震分布密集区，震中分布呈明显的沿火山构造断层成带分布特性。在地震条带交汇处，震源深度起伏变化大，是火山构造活动强烈部位  相似文献   

Covariations in oceanic dimethyl sulfide,its oxidation products and rain acidity at Amsterdam Island in the Southern Indian Ocean   总被引：5，自引：0，他引：5  

B. C. Nguyen  N. Mihalopoulos  J. P. Putaud  A. Gaudry  L. Gallet  W. C. Keene  J. N. Galloway 《Journal of Atmospheric Chemistry》1992,15(1):39-53

Simultaneous measurements of rain acidity and dimethyl sulfide (DMS) at the ocean surface and in the atmosphere were performed at Amsterdam Island over a 4 year period. During the last 2 years, measurements of sulfur dioxide (SO₂) in the atmosphere and of methane sulfonic acid (MSA) and non-sea-salt-sulfate (nss-SO₄ ^2-) in rainwater were also performed. Covariations are observed between the oceanic and atmospheric DMS concentrations, atmospheric SO₂ concentrations, wet deposition of MSA, nss-SO₄ ^2-, and rain acidity. A comparable summer to winter ratio of DMS and SO₂ in the atmosphere and MSA in precipitation were also observed. From the chemical composition of precipitation we estimate that DMS oxidation products contribute approximately 40% of the rain acidity. If we consider the acidity in excess, then DMS oxidation products contribute about 55%.  相似文献   

绥化台地电阻率异常与龙镇震群     

陆永发 《东北地震研究》1992,(2)

分析研究绥化地电台近十年地电观测资料,认为1986年发生在德都龙镇的中强震群,绥化台地电阻率存在趋势异常,并明显呈现短临异常前兆特征。同时,指出绥化台地电阻率趋势异常的继续存在及其周围250km范围内仍有发生中强地震的可能。  相似文献   

SEDIMENT MANAGEMENT IN NANQIN RESERVOIR     

CHEN Jingliang The Northwest Institute of Hydraulic Research ZHAO Keyu The Northwest Institute of Hydraulic Research 《国际泥沙研究》1992,(3)

In order to preserve the storage capacity of the Nanqin Reservoir for long-term service, several remedial measures have been worked out: (a) measures to control the upstream extension of backwater deposits and to prevent gravel bed load from entering into the reservoir, so that no armour layer will be formed; (b) sediment sluicing by density current to reduce deposits of suspended load; (c) periodical sediment flushing by emptying reservoir to restore the effective storage capacity. In addition, conceptions of flood plain elevation in reservoir, storage volume required in the routing of turbid flow (density flow), the storage capacity that can be restored after being lost by deposition, and the storage volume for sediment regulation are also discussed.  相似文献   

伸展地区铲式正断层作用及其大地测量观测   总被引：1，自引：1，他引：1  

桂Kun长 《地质论评》1993,39(3):196-204

铲式正断层作用是伸展构造区最主要的构造运动形式。本文根据铲式正断层作用的几何学、运动学特征,结合华北平原伸展区大地测量观测成果,探讨伸展区构造形变铲式正断层现今活动的地表形变效应及其动态特征。  相似文献   

青藏块体及其周边地震活动   总被引：1，自引：0，他引：1  

赵振才 《高原地震》1993,(2)

本文从青藏块体及其周边地区地震活动幕的划分入手,分析各期地震活动的图象特征,寻求本区地震发生的时空规律,探讨本区的地震活动与印度板块运动的内在联系,从而对今后本区地震活动的大形势进行了预测。  相似文献