干旱地区大气与地表特征对辐射加热场的影响   总被引：1，自引：0，他引：1  

杨文  季国良 《高原气象》1994,13(3):266-273

本文利用美国犹他大学气象系的辐射和云参数化模式，对ＨＥＩＦＥ期间张掖地区１９９１年春、夏、秋、冬四季资料进行了计算，讨论了晴天条件下的大气状况态地表反射率与地表比辐射率等因子对地气系统的太阳辐射收支以及短波加热率与长波冷却率分布的影响；揭示了不同季节的整层大气反射、透过与吸收特征，分析了大气中各主要吸收成分对加热率与冷却率的贡献，同时就辐射模式的垂直分辨率对加热率与冷却率的影响亦作了讨论。  相似文献   

间接确定磷灰石中碳酸根含量的几种方法对比   总被引：8，自引：0，他引：8  

刘羽 《岩矿测试》1994,13(2):109-112

采用Ｘ射线衍射峰对法，电子探针－化学式计算法与红外光谱法分别测定了２８个不同产状磷灰石中的结构碳酸根含量；对比评述了实验结果，讨论了三种间接测定方法的的优缺点及及各自的适用范围。  相似文献   

Measurements of chemically and biologically effective radiation reaching the ground     

U. Feister 《Journal of Atmospheric Chemistry》1994,19(3):289-315

Solar ultraviolet radiation at the surface has been measured at Potsdam on cloudless days by spectrometer OL 752/10. The measurements are compared with broad-band filter measurements and with model calculations using a modified version of Green's model, which is independent of the measurements. Input data to the model such as atmospheric ozone and aerosol optical thicknesses were measured by a Dobson and Brewer spectrophotometer as well as a Linke Feussner pyrheliometer, respectively. Differences between the model and the measurements are discussed in terms of uncertainties in the calibration and errors of instruments as well as uncertainties in the model calculations including the errors of input data. It is demonstrated that different chemically and biologically effective radiances can be determined from only one set of measured spectral irradiance components, i.e. global radiation and diffuse downward and upward directed radiation. Examples of diurnal variations of the photochemical production of ozone and hydroxyl radicals as determined from spectral irradiance measurements and measured concentrations of relevant trace gases are given.It is shown from the measured irradiance that relations between different effects of radiation to the biosphere depend on solar zenith angle, and to a certain extent also on atmospheric ozone. This has to be taken into account when adverse effects of changing UV radiation are evaluated. Radiation Amplification Factors derived from measurements correspond to those determined from model calculations.  相似文献   

Spectral characteristics of the seismic hazard between the alps and the dinarides     

L. Peruzza  L. Sirovich  D. Slejko 《Soil Dynamics and Earthquake Engineering》1994,13(3)

Empirical correlations between response spectra, magnitude, distance from the source and geological site conditions are introduced in a regional study of seismic hazard. A 350-year earthquake catalogue is treated by means of the statistics of extremes and both the spectral amplitudes (pseudovelocity) corresponding to a series of frequency bands are separately mapped, and the complete predicted response spectra calculated at some sites. Three kinds of geological site conditions are considered: thick and thin (less than 20 m deep) alluvium, and rock. A particular dependence of the results on the geographical distribution of earthquakes and on their magnitudes is commented. The seismic hazard of the study area is also computed by applying a traditional regression between peak ground velocity, magnitude and distance; a comparison with the seismic hazard given by the frequency dependent psuedovelocity indicates the extent of the uncertainty associated with the common practice of scaling response spectra directly from ground motion parameters.  相似文献   

核设施地震危险性估计中的几个问题   总被引：2，自引：0，他引：2       下载免费PDF全文

胡聿贤 《地震地质》1993,15(4):308-316

总结了地震安全性估计方法的现状与发展趋势,指出我国在用确定性方法确定设计地震动时,有些不确定性并未考虑,不少主观决定并非总是足够安全的。文中推荐了概率方法。场地影响分析中,特别是座落于软基上的核设施,需要对输入面的选择及土层反应分析中的多种不确定因素进行考虑。最后指出场地地震相关反应谱对座落于软基上的核设施的重要意义,以及大远震与小近震对反应谱的不同影响  相似文献   

国外雨滴谱分布函数的数值试验结果   总被引：4，自引：2，他引：4  

严采蘩  陈万奎 《气象》1993,19(9):14-18

采用文献［１］方法，对国外温带地区（北威尔士）＾［２］、亚热带地区（瓜得罗普岛）＾［３］和热带海洋（ＧＡＴＥ－１９７７）＾［４］雨滴谱分布进行了数值试验，结果表明：伽玛分布（ｎ（Ｄ）＝ａ．Ｄ＾ａｅ＾－λＤ）能很好地拟合这些实测雨滴谱，特别是非单调下降谱用伽玛分布拟合明显优于Ｍ－Ｐ分布拟合，Ｍ－Ｐ分布仅是伽玛分布的一个特例（α＝０）。  相似文献   

Seismic Wave Slowness-Vector Estimation From Broad-Band Array Data   总被引：1，自引：0，他引：1  

Shyh-Jeng Chiou  Bruce A. Bolt 《Geophysical Journal International》1993,114(2):234-248

  相似文献   

塔里木盆地北部油气地球化学特征及异常成因探讨     

周亚龙  杨志斌  张舜尧  张富贵  孙忠军 《地质学报》2022,96(7):2547-2561

为了发挥油气化探“迅速掌握全局快速缩小靶区”的战略性作用，服务油气化探全国扫面计划，选择塔里木含油气盆地北部开展低密度（1点/25km2）油气地球化学填图试点。油气化探填图指标土壤酸解烃、顶空气轻烃、荧光光谱、紫外吸收光谱和蚀变碳酸盐在大型油气田、油气富集区带上方均发育地球化学省异常，异常平面空间分布与地下油气富集区带具有良好的套合关系，对油气富集具有指示意义。区域性的荧光光谱等指标异常浓集中心沿轮台断裂等主干断裂带分布，与地下断裂位置良好的匹配性指示了油气大规模的运聚。甲烷碳同位素证实研究区油气地球化学省异常成因为热解成因，土壤样品三维荧光光谱发育共性峰，三维荧光光谱指纹特征反映了近地表土壤烃类异常与地下油气运移和油气藏类型相关。塔里木盆地北部地区油气地球化学填图试点结果表明，大型盆地可以采用甚低密度油气地球化学填图技术，圈出寻找大、中型油气田和油气富集区带的异常区，发挥油气化探“迅速掌握全局快速缩小靶区”的战略性作用。  相似文献   

Water in coesite: Incorporation mechanism and operation condition,solubility and P-T dependence,and contribution to water transport and coesite preservation     

Wei Yan  Yanyao Zhang  Yunlu Ma  Mingyue He  Lifei Zhang  Weidong Sun  Christina Yan Wang  Xi Liu 《地学前缘(英文版)》2021,12(1):313-326

A series of coesite,coexisting with or without a liquid phase,was synthesized in the nominal system SiO2-H2O at800-1450℃and 5 GPa.Micro-Raman spectroscopy was used to identity the crystalline phase,electron microprobe and LA-ICP-MS were employed to quantity some major and trace elements,and unpolarized FTIR spectroscopy was applied to probe the different types of hydrogen defects,explore water-incorporation mechanisms and quantify water contents.Trace amounts of A1 and B were detected in the coesite.Combining our results with the results in the literatures,we have found no positive correlation between the Al contents and the"Al"-based hydrogen concentrations,suggesting that previously proposed hydrogen-incorporation mechanism H^++Al^3+■Si^4+does not function in coesite.In contrast,we have confirmed the positive correlation between the B contents and the B-based hydrogen concentrations.The hydrogen-incorporation mechanism H^++B3^+■Si^4+readily takes place in coesite at different P-T conditions,and significantly increases the water content at both liquid-saturated and liquid-undersaturated conditions.For the SiO2-H2O system,we have found that type-Ⅰhydrogarnet substitution plays a dictating role in incorporating water into coesite at liquid-saturated condition,type-II hydrogarnet substitution contributes significantly at nearly dry condition,and both operate at conditions in between.The water solubility of coesite,as dictated by the type-Ⅰhydrogarnet substitution,positively correlates with both P and T,cH2O=-105(30)+5.2(32)×P+0.112(26)×T,with cH2O in wt ppm,P in GPa and T in℃.Due to its low water solubility and small fraction in subducted slabs,coesite may contribute insignificantly to the vertical water transport in subduction zones.Furthermore,the water solubility of any coesite in exhuming ultra-high pressure metamorphic rocks should be virtually zero as coesite becomes metastable.With an adequately fast waterdiffusion rate,this metastable coesite should be completely dry,which may have been the key factor to the partial preservation of most natural Coe.As a byproduct,a new IR experimental protocol for accurate water determination in optically anisotropic nominally anhydrous minerals has been found.Aided with the empirical method of Paterson(1982)it employs multiple unpolarized IR spectra,collected from randomly-orientated mineral grains,to approximate both total integrated absorbance and total integrated molar absorption coefficient.Its success relies on a high-level orientation randomness in the IR analyses.  相似文献   

新西兰兄弟潜火山中“蓝黏土”的呈色机理研究及地质意义     

赵茜  蔡元峰  潘宇观  张贺 《地质论评》2021,67(3):67040014-67040014

新西兰克马德克弧上发育一热液活动极为活跃的海底潜火山——兄弟火山,为了研究该地区热液成矿模式,IODP376科学家于2018年5~7月在火山口选取了5个位置进行了钻探工作,并获得数百米岩芯。其中U1530A号钻孔采样深度为453.1 mbsf（meter below sea floor）,共揭露76.77 m岩芯,部分呈现出一种蓝色调,被前人称作“蓝黏土”。为了查明其致色矿物、研究呈色机理及其地质意义,笔者等利用XRD、DR-UV-Vis、SEM、TEM对16.97-309.22 mbsf的11个样品进行了分析测试。根据测试结果可以将样品的矿物组合大致分为两类：①伊利石+绿泥石+殴泊-C+黄铁矿+硬石膏+石英±蓝铁矿;②叶蜡石+伊利石+石英±蓝铁矿。SEM和TEM形貌观察结果显示,蓝铁矿并不具有完好的晶形,甚至未发现微米级及以上尺寸的单颗粒,而仅以基质或胶结物形式均匀分布在样品中,最终导致样品被染色而呈现出不同色调的蓝色。蓝铁矿在IODP样品中的发现指示着研究区热液流体具有低温及还原性特征,且在蓝铁矿形成后也仍然保持着相对还原的环境而使得蓝铁矿能够稳定存在。  相似文献