Theory and Computation of Amplitudes of Terrestrial Line Spectra     

Ari Ben-Menahem  Moshe Israel  Uri Levité 《Geophysical Journal International》1971,25(4):307-406

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Abundance of cosmic-ray elements from sulfur to nickel as a function of atmospheric depth     

J. H. Crane  M. H. Israel  J. Klarmann  J. F. Ormes  R. J. Protheroe 《Astrophysics and Space Science》1983,94(1):211-222

The measured elemental composition of cosmic rays with charge 16≤Z≤28 as a function of atmospheric depth was compared with a propagation calculation including energy loss. The resulting composition at the top of the atmosphere has better precision than previously possible on balloon borne experiments, and agrees well with the only satellite data available in this charge range. The extrapolation method also provides checks on assumed cross-sections for interactions of cosmic rays in air.  相似文献   

Interaction mean-free-path of cosmic-ray Fe in air     

J. H. Crane  D. D. Guo  M. H. Israel  J. Klarmann 《Astrophysics and Space Science》1983,94(1):201-209

The interaction mean-free-path of cosmic-ray iron in air has been determined by observing the change in flux as a function of atmospheric depth. A large detector and a large variation in altitude during the balloon flight result in a high precision measurement. The result is in agreement, though slightly larger than the mean-free-path deduced from the measurements of interactions of iron on different targets at the Bevalac accelerator.  相似文献   

Water transport through Lake Kinneret sediments traced by tritium     

M. Stiller  I. Carmi  K.O. Münnich 《Earth and Planetary Science Letters》1975,25(3):297-304

The transport of water through the sediments of Lake Kinneret was estimated using tritium of fallout origin as a tracer. The calculation model takes into account the diffusion of the tracer and its decay, and allows for the advective flux through the sediment pores as a free parameter. The dependence of the interstitial diffusion constant on the porosity was assumed identical to that for chloride ions. Tritium profiles in nine cores were used for estimating the advective fluxes and velocities, by finding the best fit between data and model. Water advective fluxes of 3.4 g cm^?2 yr^?1 into the lake were found. This water flux is negligible in the hydrological balance of Lake Kinneret; but it carries along 7% of the unaccounted-for chloride input to the lake.  相似文献   

Timing the transport of water through the upper vadose zone in a Karstic system above a cave in Israel     

H. Even  I. Carmi  M. Magaritz  R. Gerson 《地球表面变化过程与地形》1986,11(2):181-191

Chemical and isotopic analysis of karst water dripping over a one year period from seeps in a cave above the Cenomanian aquifer in the Judea hills of Israel lead to several conclusions: (i) The tritium ages and the chemical composition of water from different seeps in a karstic cave vary greatly, (ii) The reservoirs in the upper part of the vadose zone hold water for up to several decades, (iii) Some of the cave seeps are mixtures of the old and more recent meteoric water from paths of different length, (iv) The history of storm events can only be traced in some of the seeps, (v) For most dripping seeps there is no immediate response of seepage discharge to the rainfall intensity and quantity—i.e. the seepage discharge is fairly constant.  相似文献   

Detection of the water level in fractured phreatic aquifers using nuclear magnetic resonance (NMR) geophysical measurements   总被引：1，自引：0，他引：1  

Israel Gev  Mark Goldman  Boris Rabinovich  Michael Rabinovich  Arie Issar 《Journal of Applied Geophysics》1996,34(4):277-282

Correlation of geophysical data collected using the NMR method in the Negev Desert, Israel, with hydrogeological data from nearby observation wells is presented. The experiment was conducted near Kibbutz Revivim in the Besor drainage system (Fig. 1). The objective of the survey was to detect groundwater layers in the Quaternary cover filling and Eocene fractured aquifers down to a depth of 100 m. The experiment was performed using a combination of two different geophysical techniques, namely the NMR and time domain electromagnetic (TDEM) methods. The geophysical results were verified by measuring the water level in three observation wells, two of which were drilled several months after the geophysical survey was carried out.The water level measured in these follow-up observation wells shortly after drilling did not coincide with the geophysical data. However, it settled over a period of time and finally stabilized at a depth very similar to that obtained from the NMR measurements. This phenomenon is caused by the fractured nature of the phreatic aquifer. Since the flow of water in such aquifers is confined by the fractures, the appearance of water in the well during or shortly after drilling is determined solely by the intersection of the well and the fracture. Our experiments showed that geophysical measurements in fractured phreatic aquifers may have a distinct advantage over direct borehole measurements, since the former average the depth to the water table over large areas (several thousand square meters) while the latter are limited by the area of the borehole cross-section (several tens of square centimeters).  相似文献   

川滇菱形块体顺时针转动的构造学与古地磁学证据   总被引：22，自引：3，他引：22       下载免费PDF全文

徐锡伟  程国良  于贵华  宋方敏  向宏发  张兰凤  Hagai Ron  王洋龙  闻学泽 《地震地质》2003,25(1):61-70

川滇菱形块体内部受NE向丽江 -小金河断裂的切割 ,可进一步划分为川西北次级块体和滇中次级块体等南北 2个部分 ;各次级块体东边界断裂有规律地左旋滑动、西边界断裂的右旋滑动及其滑动速率值的差异 ,反映出新生代时期各次级块体作向SE的水平滑移叠加绕垂直轴顺时针转动的复合运动。其中 ,川西北次级块体SE向的水平滑移速率 5mm/a ,顺时针转动角速度 1 4°/Ma ;滇中次级块体SE向的水平滑移速率 3 5mm/a ,顺时针转动角速度约 1 5°/Ma。在滇中次级块体内部姚安、大姚、永仁、昆明北马街等地采集到约 90个古新世地层的定向样品 ,通过交变退磁和热退磁获得了它们各自的剩磁矢量 (实验磁偏角和磁倾角 ) ,由实测磁偏角与期望磁偏角相比可知川滇地区滇中次级块体中新世早期以来的顺时针转动累积量可达 30°～ 4 8°。次级块体的整体转动与块边活动断裂的左旋滑动符合左旋走滑断裂作用区块体作顺时针转动的运动学模式  相似文献   

Die halbtägige Welle des Iuftelektrischen Potentialgefälles     

H. Israel 《Meteorology and Atmospheric Physics》1948,1(2):247-251

Zusammenfassung Die Tagesgänge des luftelektrischen Potentialgefälles an Festlandstationen kann man in ihrem ortszeitgebundenen Anteil auffassen als einfache Schwingung mit einem Mindestwert in den frühen Morgen- und einem Maximalwert in den Nachmittagsstunden, über die eine im Laufe des Jahres schwankende und von Ort zu Ort verschiedene austauschbedingte Einsenkung während des Tages überlagert ist. Es läßt sich zeigen, daß die Tiefe dieser Einsenkung um so größer sein, muß, je größer der mittlere Kern- und Großionengehalt des Meßortes ist. Damit finden die Unterschiede im Gang des Potentialgefälles benachbarter Stationen sowie die Änderungen dieses Charakters in Davos von 1909/10 zur Meßperiode 1923/26 eine qualitative Erklärung.

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Summary The diurnal variations of the potential gradient of atmospheric electricity at continental stations can be interpreted, in their share connected to local time, as a simple oscillation with a minimum in the early morning and a maximum in the afternoon; above this oscillation a depression is superposed during the day, caused by turbulence exchange, showing fluctuations in the course of the year and different from place to place. It can be shown that the amplitude of this depression must be so much greater the greater is the average content of nuclei and large ions of the place of measurements. Therewith the differences of the gradient's variation of neighbouring stations and the alteration of their character from 1909/10 at Davos to the period of measurements in 1923/26 find a qualitative explanation.

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Résumé On peut considérer la variation diurne du gradient de potentiel électrique de l'atmosphère dans les stations terrestres, du moins celle qui est liée au temps local, comme une oscillation simple avec un minimum tôt le matin et un maximum l'après-midi; une baisse diurne, variable suivant le moment de l'année et le lieu d'observation, vient s'y superposer. On peut montrer que cette baisse est d'autant plus accusée que la teneur moyenne en noyaux et en gros ions est plus élevée. Cela permet d'expliquer les divergences de variation diurne du gradient électrique entre stations rapprochées, ainsi que la différence constatée dans les séries d'observations de 1909/10 et 1923/26 à Davos.

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Mit 2 Textabbildungen.  相似文献   

Problems of monitoring the ecological consequences of ocean pollution     

Yu. A. Israel  Alla V. Tsiban 《Journal of Oceanography》1981,36(6):293-314

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Shear Strength Development with Burial in Eel River Margin Slope Sediments   总被引：1，自引：0，他引：1  

Jacques Locat  Homa Lee  Robert Kayen  Ken Israel  Marie-Claude Savoie    ric Boulanger 《Marine Georesources & Geotechnology》2002,20(2):111-135

As part of the STRATAFORM project, a series of cores were obtained from the Eel River Margin area of Eureka, California. The geotechnical analysis of intact specimens and of reconstituted samples provides some insight on the development of shear strength with burial. The results show the effect of bioturbation in the early part of the lifetime of a sediment. SEDCON tests were used to proposed various relationships which help predict the changes in density, liquidity index, and strength as a function of depth. These relationships are found useful from near the water sediment-interface down to a depth of at least 400 m in the sediment column.  相似文献