994 resultados para 146-892C
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851 p. : il.
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国家自然科学基金项目(30730032)
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[EN] Atemschaukel approaches the falling apart and survival in a historically loaded space, such as a labour camp. This novel offers a relevant research field for the space analysis, focused from the perspective of the Spatial Turn, as not only this theoretical frame but also Herta Müller herself conceive of space as a process, unterstood as a reciprocal interaction with the social practice, thus as a spatial and social construct. The representation of space in Atemschaukel is described in this article as a “swinging movement between boxes and abyss”, where the discourse of Leopold Auberg’s memories oscillates between closed and square spaces, on one hand, and open and giddy spaces, on the other hand. In this oscillating movement it is the open spaces that will most clearly show the process of inner destruction of the subject in such oppressive situations as on labour camps, as well as the permanent damages of deportation.
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To resolve the diffraction problems of the pulsed wave field directly in the temporal domain, we extend the Rayleigh diffraction integrals to the temporal domain and then discuss the approximation condition of this diffraction formula. (C) 1997 Optical Society of America.
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Artisanal fisheries resources and its exploitation trends in Cross River State were evaluated using questionnaire and participatory Rapid Appraisal (PRA) methods for a period of 5 years (1991-1995). They were open-access or unrestricted access fishing in Cross River State within the period under view. It was also discovered that, they were no proper records from the Department of fisheries. There was a decline in the relative abundance of the stock that constituted the important marine and freshwater fisheries in Cross River State Artisanal fisheries (small-scale fisheries) yielded 146,076 metric tons within the period. It was suggested therefore, that government should enforce the policies that restrict open-access in marine artisanal fisheries in Cross River State
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In 1993 and 1994 hatching and rearing of cod eggs and larvae from the western stock was carried out aiming at data about the reproduction biology of this species. This paper describes the hatching methods and first results of the correlation between various biotic and abiotic factors, naturally fertilized eggs from a broodstock, and the amount of viable larvae.
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From the beginning of the oil and gas exploration in the North Sea the impact of offshore installations, especially pipelines, on the fishery has been thoroughly discussed and investigated. Since fishing activities in the vicinity of pipelines are not prohibited, special precautions have to be taken to prevent towed fishing gear from being fouled by a pipeline. Until now all recommendations for the installation of pipelines are based on the results of tests with trawls crossing one pipeline. New problems will arise if parallel pipelines are installed as planned in the near future.
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基于周期性极化铌酸锂晶体(PPLN)的准相位匹配光参变放大过程,通过倾斜周期极化铌酸锂晶体中极化域(极化光栅)一定角度,实现了介于共线匹配方式和非共线匹配方式之间的一种半非共线型准相位匹配方式,并以该匹配方式下的各光矢量几何关系得出相位匹配曲线,找到在特定抽运光和信号光波长下能获得宽带增益放大的周期极化长度。并研究其极化倾斜角度与温度特性。模拟计算表明,在合适的角度与温度条件下,该方式可以532 nm抽运光抽运的信号光在800 nm和1064 nm处均获得宽带光参变放大。
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The present work is concerned with the processes of sand movement in the region of the Elbe estuary. In the first part the results of various investigations which have given indications of the regional transport directions are collected together. The interpretation of the results of a large number of continuous current recordings gives a picture of the resulting transport to be expected under the influence of the tides with those current conditions. This partial translation of the original paper provides the summary of this paper the regional distribution of the flood and ebb flow zones.
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This document contains the findings of the fourth Participatory Rural Appraisal (PRA) carried out under the LVFRP. Its principal objectives were to develop base-line information on a Ugandan beach for the 3-beaches survey of the LVFRP.
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This report presents the results of an investigation of a method of underwater propulsion. The propelling system utilizes the energy of a small mass of expanding gas to accelerate the flow of a large mass of water through an open ended duct of proper shape and dimensions to obtain a resultant thrust. The investigation was limited to making a large number of runs on a hydroduct of arbitrary design, varying between wide limits the water flow and gas flow through the device, and measuring the net thrust caused by the introduction and expansion of the gas.
In comparison with the effective exhaust velocity of about 6,000 feet per second observed in rocket motors, this hydroduct model attained a maximum effective exhaust velocity of more than 27,000 feet per second, using nitrogen gas. Using hydrogen gas, effective exhaust velocities of 146,000 feet per second were obtained. Further investigation should prove this method of propulsion not only to be practical but very efficient.
This investigation was conducted at Project No. 1, Guggenheim Aeronautical Laboratory, California Institute of Technology, Pasadena, California.