972 resultados para Thermally transferred OSL
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The efforts involved in developing a small satellite for scientific purposes in China in recent years are introduced in the present paper. The project is arranged on a case to case principle depending upon requirements and financial support. The space technology of a satellite and rockets, which have been developed over a relatively longer period in China, have been transferred to the scientific research of small satellites for improvement of the quality requirements. The surplus payloads of the rocket and satellite are used as the payloads of the small satellite and scientific experiments at a low cost. As an example, the project of balloon satellites for atmospheric research was successfully completed in 1991. The experience of the project management is of great benefit for further organization and arrangement of other projects. Opportunities exist for surplus payloads to be used in the future, and a small satellite for magnetospheric research will be launched in 1993.
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The paper outlines the study of the evoluation of the thermally assisted visco-plastic shearing. Analytically, numerically and experimentally, it is demonstrated that the whole process of the shear consists of multi-stages. Owing to instability, early uniform unsteady shear deformation would transform into localization and finally a band-like shearing zone forms, which appears to be a quasi-steady dissipative structure. The mechanisms governing the processes are analyzed. Accompanying the shear banding, micro-damage also develops. The microscopic observations reveal the details of the cumulative damage.
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A study has been made of the microstructure of the thermally assisted band in a low carbon ferrite-pearlite steel, resulting from high speed torsional testing with an average strain rate of about 1500 s−1. Metallographic examination showed that there are several fine shear bands distributed over a deformed region (the gauge length of the specimen). The width of these bands is estimated to be of the order of magnitude of 50 μm, and the spacing between them is roughly about 100 μm. Detailed scanning electron microscopy studies indicate that damage of the microstructure within the band is very apparent, as evidenced by microcrack initiation and coalescence along the shear deformation band. However, there is no evidence that the material in the band had become microcrystalline or non-crystalline.
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In this paper we discuss coupling processes between a magnetic field and an unsteady plasma motion, and analyze the features of energy storage and conversions in active region. It is pointed out that the static force-free field is insufficient for a discussion of storage processes, and also the pure unsteady plasma rotation is not a perfect approach. In order to analyze the energy storage, we must consider the addition of poloidal plasma motion. The paper shows that because the unsteady poloidal flow is added and coupling occurs between the magnetic field and both the toroidal and the poloidal plasma flows, an unsteady process is maintained which changes the force-free factor with time. Hence, the energy in the lower levels can be transferred to the upper levels, and a considerable energy can be stored in the active region. Finally, another storage process is given which is due to the pure poloidal flow. The article shows that even if there is no twisted magnetic line of force, the energy in the lower levels may still be transferred to the upper levels and stored there.
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[ES] En los últimos tiempos existe un énfasis creciente en la comercialización de la investigación universitaria a través de la creación de empresas (spin-offs). Ahora bien, los fenómenos que el concepto de spin-off universitaria trata de abarcar no son homogéneos. Por esta razón, parece conveniente dilucidar las múltiples realidades que abarca organizándolas mediante tipologías.
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Infestations of the marine macrophytic alga Caulerpa taxifolia were discovered in Agua Hedionda Lagoon, California in 2000. Rapid response actions included containment under pvc tarps coupled with injection of liquid sodium hypochlorite. To assess the efficacy of these treatments, replicated sediment cores were removed from representative treated sites and transferred to grow-out facilities. Similar cores from uninfested (control) sediments were removed, inoculated with viable explants of C. taxifolia and placed in grow-out facilities. Results from two sampling periods (1 year, 2 years post-treatment) showed that no viable C. taxifolia emerged in cores, and that inoculated “control” sediments supported normal growth. Eelgrass ( Zostera marina L.) seedlings emerged from native seed-banks in “treated” cores, which also supported growth of some invertebrates (annelid worms and hydroids). This study provided essential verification of C. taxifolia eradication efforts, and demonstrates the feasibility of incorporating quality control/quality assurance components in rapid response actions. Results of this study also suggest that seeds of eelgrass are viable for at least two years. (PDF has 9 pages.)
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This report responds to the 1986 Beaches Bill which, in recognition of the potential deleterious impact on Florida's beaches of inlets modified for navigation, mandated a study of those inlets with identification of recommended action to reduce the impacts. This report addresses west Coast inlets; East Coast inlets are the subject of a companion report. There are 37 inlets along that portion of Florida's West Coast commencing from Pensacola Bay Entrance to Caxambas Pass at the south end of Marco Island. Compared to those on the East Coast, most West Coast inlets have not had the deleterious effects on the adjacent beaches, yet all modified inlets without proper management have the potential of impacting unfavorably on the adjacent shorelines. Moreover, at present there is interest in opening three West Coast entrances which either have been open in the past (Midnight Pass) or which have opened occasionally (Navarre Pass and Entrance to Phillips Lake). A review of inlets in their natural condition demonstrates the presence of a shallow broad outer bar across which the longshore transport Occurs. These shallow and shifting bar features were unsuitable for navigation which in many cases has led to the deepening of the channels and fixing with one or two jetty structures. Inlets in this modified state along with inappropriate maintenance practices have the potential of placing great ero$ional stress along the adjacent beaches. Moreover. channel dredging can reduce wave sheltering of the shoreline by ebb tidal shoals and alter the equilibrium of the affected shoreline segments. The ultimate in poor sand management practice is the placement of good quality beach sand in water depths too great for the sand to reenter the longshore system under natural forces; depths of 12 ft. or less are considered appropriate for Florida in order to maintain the sand in the system. With the interference of the nearshore sediment transport processes by inlets modified for navigation, if the adjacent beaches are to be stabilized there must be an active monitoring program with commitment to placement of dredged material of beach quality on shoreline segments of documented need. Several East Coast inlets have such transfer facilities; however. the quantities of sand transferred should be increased. Although an evolution and improvement in the technical capability to manage sand resources in the vicinity of inlets is expected, an adequate capability exists today and a concerted program should be made to commence a scheduled implementation of this capability at those entrances causing greatest erosional stress on the adjacent shorelines. A brief summary review for each of the 37 West Coast inlets is presented including: a scaled aerial photograph, brief historical information, several items related to sediment losses at each inlet and special characteristics relevant to State responsibilities. For each inlet, where appropriate, the above infor~tion is utilized to develop a recommenced action. (PDF has 101 pages.)
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用大气压非转移弧层流等离子体射流,对W-Mo-Cu铸铁表面进行熔凝相变强化处理,观察和测试了试样经不同弧电流处理后的表面层组织、硬度、耐磨性.结果表明,层流等离子体射流对铸铁表面的局部快速加热熔化和冷却凝固,明显改变了表面层的微观组织,提高了硬度和抗磨损性能.
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对在大气压条件下用非转移弧层流等离子体射流熔凝强化处理的W-Mo-Cu铸铁表面,采用光学显微镜、显微硬度计、磨损试验机、扫描电镜等,观察和测试了熔凝试样的表面层组织、硬度、耐磨性和磨损形貌.结果表明,熔凝后铸铁表面为初晶渗碳体和莱氏体组成的过共晶组织,硬度和耐磨性有了明显的提高.
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Experimentally observed, results are presented for the DCarcplasmajets and theirarc-rootbehaviors generated atreduced gas pressure and without or with an' applied magnetic field. Pure argon, argon -hydrogen or argon-nitrogen mixture is used as the plasma-forming gas. A specially designed copper mirror is constructed and used for better observing the arc-root behavior on the anode surface of the DC non-transferred arcplasma torch. It is shown that for the cases without applied magnetic field, the laminar plasmajets are stable and approximately axisymmetrical. The arc-root attachment on the anode surface is completely diffusive when argon is used as the plasma-forming gas, while the arc-root attachment often becomes constrictive when hydrogen or nitrogen is added into the argon. When an external magnetic field is applied, the arcroot tends to rotate along the anode surface of the non-transferred arcplasma torch.
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Characteristics of vaporized aviation kerosene injection in a supersonic model combustor were preliminarily investigated. The electrically storage type heater has a volume capacity of heating kerosene of 0.8 kg up to 670 K at a pressure of 5.5 Mpa. The temperature to cause pressurized kerosene jet being fully vaporized in Quiescent atmosphere was found to be 550 K at 4 Mpa however the pressurized hot kerosene remains in liquid state within the tube. The correspondent jet spray in Mach 2.5 vitiated air cross-flow were visualized by using stop schlieren photograph.It was found the penetration depth of the hot pressurized kerosene jet is approximately same with the temperature varied from 290 K to 550 k. at pressure of 4 Mpa. This results showed that the atomization process of hot kerosene jet spray in supersonic combustor could be bypassed and directly transferred to be gas state at temperature 550 K and pressure of 4 Mpa.
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ENGLISH: The following report describes the findings of an "El Niño" project carried out at the Department of Meteorology of the University of California, Los Angeles, at the request of, and with funds provided from, the Inter-American Tropical Tuna Commission. The project was, in its early stages, supervised by Professor M. Neiburger, but was in June 1959 transferred to Professor J. Bjerknes, who thereby became the sole author of this final report. Readers who may be interested in the general background of knowledge of the maritime meteorology of the Eastern Pacific are herewith referred to Professor Neiburger's final report of the "Subtropical Pacific Meteorology Project." That report, submitted in September 1958 to the Office of Naval Research, summarizes the results of all the meteorological soundings released at sea since 1949 from California in the north to Peru in the south. The soundings off Ecuador and Peru were all taken by the "Shellback" expedition during July 1952. Important as this first exploration of the atmosphere over the Eastern Equatorial Pacific was, it did not even begin to explore " El Niño " itself, which is confined to the southern summer season and, moreover, only reaches catastrophic proportions in a few exceptional years. SPANISH: Este estudio da a conocer los resultados de una investigación que, bajo el nombre de Proyecto "El Niño", ha sido efectuada en el Departamento de Meteorología de la Universidad de California, Los Angeles, a solicitud de la Comisión Interamericana del Atún Tropical y con fondos provistos por ésta. En sus primeras etapas, el proyecto fué supervisado por el Profesor M. Neiburger, pero en junio de 1959 fué transferido al Profesor J. Bjerknes, quien de este modo vino a ser el solo autor de este informe final. A los lectores interesados en los conocimientos de fondo de la meteorología marítima del Pacífico Oriental se les recomienda consultar el informe final del Profesor Neiburger intitulado "Subtropical Pacific Meteorology Project". Este informe, sometido a la "Office of Naval Research" en septiembre de 1958 sumariza los resultados de todos los sondeos meteorológicos efectuados en el mar desde 1949 en el área entre California en el norte y Perú en el sur. Todos los sondeos frente al Ecuador y el Perú fueron hechos por la Expedición "Shellback" durante el mes de julio de 1952. Importante como fué esta primera exploración de la atmósfera sobre el Pacífico Ecuatorial del Este, ni siquiera comenzó a explorar "El Niño" en sí, que se confina a la estación de verano en el sur y, más aún, sólo alcanza proporciones catastróficas en unos pocos años excepcionales.
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[ES] Este artículo analiza los determinantes de la rentabilidad primaria de los bonos de titulización hipotecaria (conocidos en la literatura como mortgage backed securities, o MBS) emitidos en España durante el periodo 1993-2011, periodo en el que el mercado español llegó a convertirse en el más importante de Europa continental. Los resultados obtenidos sobre el análisis de la población completa de MBS emitidos (262 tramos configurados sobre 94 fondos de titulización) indican que la estructuración multitramo de los MBS ha ayudado a reducir el riesgo percibido global de las emisiones de MBS, mediante la generación de mercados más completos y la reducción de los problemas derivados de la existencia de asimetrías informativas implícitas en el proceso de selección de los activos transmitidos por parte de la entidad cedente. Esta reducción del riesgo percibido ha tenido un efecto directo sobre la rentabilidad ofrecida por los bonos de titulización emitidos. Además, no se encuentran evidencias de que la emisión de MBS persiga la transmisión efectiva de riesgos, más bien al contrario. Las Entidades de crédito, por lo general, han retenido los tramos de primeras pérdidas, lo que ha contribuido a mantener en niveles muy bajos (por debajo de la rentabilidad de la deuda soberana) la rentabilidad ofrecida por los MBS. Precisamente, el escaso diferencial ofrecido por los bonos de titulización se debe a que los tramos retenidos no han ofrecido primas de rentabilidad ajustadas al riesgo inherente.
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A considerable amount of national EU funds for supporting fisheries has been transferred to the German fish processing in-dustry. The recently ratified European Fisheries Fund (EFF) again provides a significant sum. Yet the EU is lacking a data pool of sufficient precision, which is required as a basis to develop apt EU regulations in the future. Regulation No. 1639/2001 of the EU Commission commits the member states to collect these data. In this paper specifics of the data to be collected and the collection procedure are presented and linked to the CFP and to characteristics of the German fish processing industry.
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The use of self-contained, low-maintenance sensor systems installed on commercial vessels is becoming an important monitoring and scientific tool in many regions around the world. These systems integrate data from meteorological and water quality sensors with GPS data into a data stream that is automatically transferred from ship to shore. To begin linking some of this developing expertise, the Alliance for Coastal Technologies (ACT) and the European Coastal and Ocean Observing Technology (ECOOT) organized a workshop on this topic in Southampton, United Kingdom, October 10-12, 2006. The participants included technology users, technology developers, and shipping representatives. They collaborated to identify sensors currently employed on integrated systems, users of this data, limitations associated with these systems, and ways to overcome these limitations. The group also identified additional technologies that could be employed on future systems and examined whether standard architectures and data protocols for integrated systems should be established. Participants at the workshop defined 17 different parameters currently being measured by integrated systems. They identified that diverse user groups utilize information from these systems from resource management agencies, such as the Environmental Protection Agency (EPA), to local tourism groups and educational organizations. Among the limitations identified were instrument compatibility and interoperability, data quality control and quality assurance, and sensor calibration andlor maintenance frequency. Standardization of these integrated systems was viewed to be both advantageous and disadvantageous; while participants believed that standardization could be beneficial on many levels, they also felt that users may be hesitant to purchase a suite of instruments from a single manufacturer; and that a "plug and play" system including sensors from multiple manufactures may be difficult to achieve. A priority recommendation and conclusion for the general integrated sensor system community was to provide vessel operators with real-time access to relevant data (e.g., ambient temperature and salinity to increase efficiency of water treatment systems and meteorological data for increased vessel safety and operating efficiency) for broader system value. Simplified data displays are also required for education and public outreach/awareness. Other key recommendations were to encourage the use of integrated sensor packages within observing systems such as 100s and EuroGOOS, identify additional customers of sensor system data, and publish results of previous work in peer-reviewed journals to increase agency and scientific awareness and confidence in the technology. Priority recommendations and conclusions for ACT entailed highlighting the value of integrated sensor systems for vessels of opportunity through articles in the popular press, and marine science. [PDF contains 28 pages]