988 resultados para 377


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A sandwich-type plate with metal facings and felt core, fastened by bolts, was studied using both test and finite-element analysis. This type of plate is cheap, light, damping-effective and without pollution; therefore, it is widely used in astronautical engineering. The tests were conducted for different felt thicknesses, bolt numbers, and fastening forces. The results show that the damping depends on friction between the plates and the felt. As compared with an identical stiffness solid plate, the damping of laminated plates can be increased up to 30 times. A mesh with rectangular elements was adopted in the finite-element analysis. In accordance with the slipping mechanism, a rectangular plate clamped on one edge was analyzed with the foregoing elements to determine the resonant frequency and the damping. The difference between the calculated and tested results was within 5 percent for the resonant frequency.

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采用MSC.Marc非线性有限元软件,对薄板激光变曲过程中的温度场进行了数值模拟,得到了引起薄板激光弯曲形的温度场的变化规律。通过温度传感器测量与激光扫描线相对应的薄板下表面温度变化的规律来验证数值模拟的结果。模拟值与实测值基本吻合,表明数值模拟结果可作为激光加工工艺参数选择的依据。

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利用基于分子模型的统计模拟方法-信息保存方法(IP)统计模拟了实验条件下微槽道气体流动,仔细讨论了用IP方法模拟长槽道稀薄气流时遇到的问题,并给出了解决的方法,即采取守恒形式的控制方法避免质量流量计算误差积累,并利用超松弛方法使收敛过程加速。将IP计算结果与压力分布和质量流量实验数据进行了比较。

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One of the causes of lower artesian pressure, water waste and aquifer contamination is the misuse and insufficient care of artesian wells. In 1953, Senate Bill No. 57, entitled "An Act to Protect and Control the Artesian Waters of the State" (see Appendix) became a law. This law was passed through the efforts exerted by leading members of the Senate and the House of Representatives, who understood the need for a wise and controlled expenditure of our most valuable natural resource. The State Geologist and his authorized representatives were designated by this law to enforce this conservation measure; however, no financial provision was included for the 1953-55 biennium. The proposed program of the Florida Geological Survey for this biennium did not include the funds nor provide any full-time personnel for the enforcement of this statute. As a result, little actual work was accomplished during these two years, although much time was given to planning and discussion of the problem. Realizing that this program could provide additional basic data needed in the analysis of the water-supply problem, the State Geologist sought and was granted by the 1955 Legislature adequate funds with which to activate the first phase of the enforcement of Florida Statute No. 370.051-054. Enumerated below is a summary of the progress made on this investigation as outlined previously: 1. Data have been collected on 967 wildly flowing wells in 22 counties. 2. Chloride determinations have been run on 850 of the 967 wells. 3. Of the 967 wells, 554 have chlorides in excess of the 250 ppm, the upper limit assigned by the State Board of Health for public consumption. 4. Water escapes at the rate of 37, 762 gallons per minute from these 967 wells. This amounts to 54, 377, 280 gallons per day. The investigation is incomplete at this time; therefore, no final conclusions can be reached. However, from data already collected, the following recommendations are proposed: 1. That the present inventory of wildly flowing wells be completed for the entire State. 2. That the current inventory of wildly flowing wells be expanded at the conclusion of the present inventory to include all flowing wells. 3. That a complete statewide inventory program be established and conducted in cooperation with the Ground Water Branchof the U.S. Geological Survey. 4. That the enforcement functions as set down in Sections 370.051/.054, Florida Statutes, be separated from the program to collect water-resource data and that these functions be given to the Water Resources Department, if such is created (to be recommended by the Water Resources Study Commission in a water policy law presented to the 1957 Legislature). 5. That the research phase (well inventory) of the program remain under the direction of the Florida Geological Survey. (PDF contains 204 pages.)

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Joseba A. Lakarra & José Ignacio Hualde, arg., Studies in Basque and Historical Linguistics in memoriam of R. L. Trask - R. L. Trasken oroitzapenetan ikerketak Euskalaritzaz eta Hizkuntzalaritza Historikoaz

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文中综述了结构破坏的尺度律和尺寸效应的研究进展,尤其将重点放在准脆性材料的分析上,因为它们的尺寸效应是重要和复杂的.在回顾了尺寸效应研究的悠远发展史以后。着重讨论了三种主要类型的尺寸效应,即由于强度随机性引起的统计尺寸效应、能量释放的尺寸效应和由于微裂纹或断裂的分形特性可能引起的尺寸效应.得出了这些理论应用的明确结论.之后讨论了如何运用已知的尺寸效应律来测量材料的断裂特性,并采用内聚裂纹模型(cohesivecrackmodel)、非局域化有限元模型和离散元模型等对尺寸效应进行模化.文中还进而分析了尺寸效应在压缩失效和车相关材料行为下的有关问题,并讨论了在断裂扩展区描述含微裂纹材料所需的损伤本构关系.最后也讨论了尺寸效应对准脆性材料的多种应用,这些材料包括,如混凝土、海冰、纤维复合材料、岩石和陶瓷等.本文包含了参考文献377篇.

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Blake, Sacramento. Diccionario bibliographico brazileiro. Rio de Janeiro: Typ. Nacional, 1883-1902.v. 2, p. 377

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Eterio Pajares, Raquel Merino y José Miguel Santamaría (eds.)

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ENGLISH: Logbook records of tuna vessels fishing in the eastern Pacific Ocean were used to prepare charts showing the distribution of yellowfin tuna and skipjack catches by i-degree area, by quarter of the year, and by gear, for the years 1967-1970. Recent changes in the geographical distribution of yellowfin catch are illustrated. Also given are annual catch statistics and the composition of the international tuna fishing fleets which operated in the Commission's Yellowfin Regulatory Area each year, 1962-1970. SPANISH: Los registros de los cuadernos de bitácora de los barcos pesqueros de atún en el Océano Pacífico oriental se usaron para preparar gráficos que presentan para los años de 1967-1970, la distribución de captura del atún aleta amarilla y barrilete por área de 1 grado, trimestre del año y, por las artes. Se ilustran los recientes cambios en la distribución geográfica de la captura del atún aleta amarilla. Se presentan también las estadísticas de captura anual y la composición de la flota internacional de pesca, que explota cada año el Area Reglamentaria de la Comisión, 1962-1970. (PDF contains 95 pages.)

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Commercial pond fish culture practice is comparatively new in Nigeria. It is therefore very important that simple guidelines be provided for the establishment, development, and management of such projects. The objective of this paper is to fulfill this urgent need. All aspects of commercial pond fish culture are dealt with. Fish pond operations comprise of pond preparation, stocking, rearing, and harvesting. These have been highlighted in the text, bearing in mind that the most important principle of fish culture is the acquisition of maximum production of marketable-size pond fish from a given unit area