ELEMENTARY VIEW OF GREENHOUSE EFFECT OF THE ATMOSPHERES OF VARIOUS PLANETS          下载免费PDF全文

H. L. Kuo 《Acta Meteorologica Sinica》1992,6(2):251-253

The global mean temperatures of the atmosphere and the surface of various planets of the solar system are deter-mined by taking the system as in radiative equilibrium,with the atmosphere taken as transparent to solar radiation butwith an albedo α,and composed of N layers each of which absorbs all infrared radiation that falls on it,and a top layerof partial absorptivity a,while the surface is taken as black.It is found that,for the earth's atmosphere with α=0.33,N=0,a=0.83,it gives the current observed mean surface temperature T_s=15℃ and the effective mean radiative temper-ature of the atmosphere T_a=242.6K.On the other hand;the atmosphere of Venus is characterized by α=0.70 andN=70,which yields a surface temperature of about 700K.It is also found that surface evaporation and absorption of solar radiation by the atmosphere tend to lower the sur-face temperature.  相似文献   

THE CALCULATION AND ANALYSIS OF SLOPE NET RADIATION IN CHINA^*     

Weng Duming  Sun Zhi''an  Shi Bing 《Acta Meteorologica Sinica》1991,5(2):242-251

By using the climatological calculating method for each component of slope surface net radiation proposed by the authors,calculations and analyses are done of the distribution features of slope net radiation in China with emphasis on the discussion of variations of slope net radiation in typical stations and sites with slope direction,slope,latitude and season.The distribution features of net radiation on the north and south slopes are,for the first time,mapped and discussed,revealing the great difference on the national basis,and thus acquiringa new interesting result that the negative-value area of winter net radiation on the north slope(20°)can reach Yunnan and Guizhou Provinces and middle and upper reaches of the Changjiang River.  相似文献   

万洋山—诸广山花岗岩带铀成矿的区域地质背景     

姚振凯  朱蓉斌 《湖南地质》1991,10(1):9-16

万洋山—诸广山复式花岗岩带,经历多期次的构造-岩浆活动,受到东西向和南北向的深部构造控制。岩带内北东、北北东、东西、南北及北西向五组线型断裂构造及规模不一的中心型环状构造发育。铀成矿的时空分布,受中生代南北向和东西向构造-岩浆活动带交汇区的宏观制约。矿床定位与中心型小环状构造交切及不同方向的线型断裂交叉密切有关。矿源既来自铀源层和花岗岩,也来自上地幔岩浆源。区域内地质-成矿事件复杂,经过了槽、台、洼三大演化阶段。地洼阶段构造-岩浆活动次数最多,最强烈。铀成矿作用形成于地洼阶段中晚期,即白垩-第三纪。铀成矿以内生热液(热水)为主,叠加有后生淋积矿化。  相似文献   

西昆仑山地区太阳分光辐射分布特征   总被引：1，自引：0，他引：1  

魏耀宏  林振耀 《高原气象》1992,11(3):249-258

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Hydrodynamic effects in a reservoir with semicircular cross-section and absorptive bottom     

T. Szczesiak  B. Weber 《Soil Dynamics and Earthquake Engineering》1992,11(4)

A three-dimensional dam-reservoir system under seismic load is analysed. The dam is assumed to be rigid. The reservoir is an infinite channel with semi-circular cross-section. The exact analytical solution, based on the assumption of potential fluid motion is presented, as well as numerical results for selected parameters.The most significant parameters are: the direction and frequency content of the seismic input; the radiation damping at the reservoir bottom; and the compressibility of the fluid. The response of the system depends strongly on the direction of the input ground motion. This is shown by the transfer functions as well as by the pressure time histories due to two earthquakes with different frequency content. The energy absorption at the reservoir bottom is important. A simple plane-wave model shows, that even for a rock foundation, the amount of transmitted energy can reach up to 80%. For comparison the case without bottom absorption is also shown. Compressbility has to be included to capture the resonance effects. The exact analytical solution is also used to verify numerical results obtained by a new method that combines a finite element model with a rigorous radiation boundary for the infinite channel in the time domain.  相似文献   

1988年9月张掖地区的太阳辐射状况的初步分析   总被引：3，自引：2，他引：3  

季国良  江灏 《高原气象》1990,9(2):194-201

1988年8～9月,在河西走廊的化音和张掖地区进行了一次预备性观测实验。本文利用预备观测中所取得的少量资料,分析了干旱地区太阳辐射各个分量和太阳分光谱辐射的一些气候学特征。结果表明:该地区秋季大气透明度较好;光资源充足;兰紫光在总辐射中所占比例较大;地表净辐射具有平原地区的特征,其值介于平原与高原地区之间。  相似文献   

Radiation patterns of point sources situated close to structural interfaces and to the earth's surface     

Pert Jílek  Vlastislav Červený 《Pure and Applied Geophysics》1996,148(1-2):175-225

The seismic wave field is considerably influenced by local structures close to the source and to the receiver. This applies to sources and receivers situated close to localized inhomogeneities, to structural interfaces, to the earth's surface, etc. In this paper we concentrate our attention mainly to the ray-theoretical radiation patterns of point sources situated close to the structural interfaces and to the earth's surface. In numerical modeling of high-frequency seismic wave fields by the ray method, the interaction of the source with the earth's surface has not usually been taken into account.The proposed procedure of the computation of the radiation patterns of point sources situated directly on structural interfaces and on the earth's surface is based on the zero-order approximation of the ray method, assuming that the length of the ray between the source and the receiver is long. The derived equations are extended to point sources located close to structural interface, to the earth's surface and to thin transition layers using the hybrid ray-reflectivity method, seeervený (1989). The thin layer need not be homogeneous; it may include an arbitrary inner layering (transition layers, laminas, etc.) The only requirement is for the layer to be thin. Roughly speaking, we require its thickness to be less than one quarter of the prevailing wavelength. The hybrid ray-reflectivity method describes well even certain non-ray effects (tunneling.S ^* waves, etc.). Explicit analytical expressions for radiation patterns for all above listed point sources are found. These expression have a local character and may be easily implemented into computer codes designed for the routine computation of ray amplitudes and synthetic ray seismograms in 2-D and 3-D, laterally varying isotropic layered and block structures by the ray method.Numerical examples of radiation patterns ofP andS waves of point sources situated close to the earth's surface and to a thin low-velocity surface layer are presented and discussed. The explosive point source (center of dilatation) and the vertical and horizontal single force point sources are considered. It has been ascertained that the radiation patterns of point sources depend drastically on the depth of the source below the surface even if the depths vary within one quarter of the prevailing wavelength.  相似文献   

COBE observations of the microwave counterpart of GRBs     

R. K. Schaefer  S. Ali  M. Limon  L. Piccirillo 《Astrophysics and Space Science》1995,231(1-2):331-334

We have used the data from the COBE satellite to search for delayed microwave emission (31 - 90 GHz) from Gamma Ray Bursts (GRBs). The large 7° beam of COBE is well matched to the large positional uncertainties in the GRB locations, although it also means that fluxes from (point source) GRB objects will be diluted. In view of this we are doing a statistical search of the GRBs which occurred during the currently released COBE DMR data (years 1990 and 1991), which overlap 200 GRBs recorded by GRO. Here we concentrate on just the top 10 GRBs (in peak counts/second). We obtain the limits on the emission by comparing the COBE fluxes before and after the GRB at the GRB location. Since it is thought that the microwave emission should lag the GRB event, we have searched the GRB position for emission in the few months following the GRB occurrence.  相似文献   

Identifying calcium-containing mineral species in the JEB Tailings Management Facility at McClean Lake,Saskatchewan     

《Applied Geochemistry》2016

The JEB Tailings Management Facility (TMF) is central to reducing the environmental impact of the McClean Lake uranium mill facility that is operated by AREVA Resources Canada. This facility has been designed around the idea that elements of concern (e.g., U, As, Ni, Se, Mo) will be controlled through equilibrium with precipitants. Confirming the presence of calcium-containing carbonates in the JEB TMF is the first step in determining if gypsum (CaSO₄·2H₂O) controls the concentration of HCO₃⁻ (aq), limiting the formation of soluble uranyl bicarbonate complexes. A combination of X-ray diffraction (XRD), X-ray absorption near-edge spectroscopy (XANES), and microprobe X-ray fluorescence (XRF) mapping was used to analyze a series of tailings samples from the JEB TMF. Calcium carbonate in the form of calcite (CaCO₃), aragonite (CaCO₃), and dolomite (CaMg(CO₃)₂) were identified by analysing Ca K-edge μ-XANES spectra coupled with microprobe XRF mapping. This is the first observation of these phases in the JEB TMF. The combination of μ-XANES and XRF mapping provided a greater sensitivity to low concentration calcium species compared to the other techniques used, which were only sensitive to the major species present (e.g., gypsum).  相似文献   

福建霜冻时空分布特征及环流背景分析          下载免费PDF全文

吴幸毓  林毅  陈文键  何小宁 《大气科学学报》2016,39(4):501-509

利用福建省内68个地面测站1981—2011年1—4月、10—12月逐日观测资料,结合最低地表温度、天气现象、最低气温作为福建霜冻判别指标,探讨福建霜冻气候特征及环流背景形势。研究发现:1)福建年平均霜冻天数、初(终)霜冻日、无霜冻期具有明显地域差异,等值线基本呈东北—西南走向,与台站海拔高度具有良好相关性。区域平均初霜冻日、终霜冻日、无霜冻期总体分别呈推迟、提前、延长的变化趋势。2)全省大范围霜冻天气呈现发生频率低、过程持续时间短、总体逐渐减少的特征。3)霜冻越强,发生越晚,结束越早,且出现天数越少。4)随着形势场特征线略有南压,霜冻逐渐增强,反之减弱。  相似文献