991 resultados para 154-928
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通过 3种密度硬质聚氨酯泡沫塑料的拉伸实验 ,研究了它们的应力 -应变特性及其应变率效应。同时 ,为确定泡沫塑料拉伸失效机理 ,对材料进行了扫描电镜下的细观拉伸实验 ,观察了试件表面胞体的变形与失效过程 ,再结合宏观拉伸试件断口的扫描电镜分析 ,进一步讨论了泡沫塑料在拉伸加载下的失效机理。基于泡沫塑料的拉伸应力 -应变曲线 ,用数值方法拟合了泡沫塑料的拉伸本构关系。
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1955年,钱学森冲破重重阻挠回到祖国,并与钱伟长等一道创建了中国科学院力学研究所。2005年12月6日,我所召开“庆祝中国科学院力学研究所建所50周年暨钱学森同国50周年大会”,中国科学院副院长曹健林、两弹一星功勋奖章获得者陈能宽院士、钱学森的学术秘书涂季同志、钱学森的儿子钱永刚、女儿钱永真、国防科工委、总装备部、中国工程物理研究院、中国海洋石油总公司、国家自然科学基金委、兄弟院所和高校的有关领导和专家学者以及力学所职工共计300余人出席了大会,路甬祥院长、白春礼常务副院长、原国务委员、中国科学院原党组书记张劲夫同志为力学所建所50年和钱老回国50年题词。
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“细观力学面临的新挑战国际会议”(“International Conference on New Challenges in Mesomechanis”)于2002年8月26~30日在丹麦奥尔堡(Aalborg)召开,由奥尔堡大学(Aalborg University)主办。与会人数约120人,分别来自丹麦、中国、希腊、俄国、德国、美国、英国、日本等20多个国家。会议上报告论文100余篇。我国有12人(包括大陆、香港、台湾)参加会议,在会上作了10个报告。
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[ES]La fibrilación ventricular (VF) es el primer ritmo registrado en el 40\,\% de las muertes súbitas por paro cardiorrespiratorio extrahospitalario (PCRE). El único tratamiento eficaz para la FV es la desfibrilación mediante una descarga eléctrica. Fuera del hospital, la descarga se administra mediante un desfibrilador externo automático (DEA), que previamente analiza el electrocardiograma (ECG) del paciente y comprueba si presenta un ritmo desfibrilable. La supervivencia en un caso de PCRE depende fundamentalmente de dos factores: la desfibrilación temprana y la resucitación cardiopulmonar (RCP) temprana, que prolonga la FV y por lo tanto la oportunidad de desfibrilación. Para un correcto análisis del ritmo cardiaco es necesario interrumpir la RCP, ya que, debido a las compresiones torácicas, la RCP introduce artefactos en el ECG. Desafortunadamente, la interrupción de la RCP afecta negativamente al éxito en la desfibrilación. En 2003 se aprobó el uso del DEA en pacientes entre 1 y 8 años. Los DEA, que originalmente se diseñaron para pacientes adultos, deben discriminar de forma precisa las arritmias pediátricas para que su uso en niños sea seguro. Varios DEAs se han adaptado para uso pediátrico, bien demostrando la precisión de los algoritmos para adultos con arritmias pediátricas, o bien mediante algoritmos específicos para arritmias pediátricas. Esta tesis presenta un nuevo algoritmo DEA diseñado conjuntamente para pacientes adultos y pediátricos. El algoritmo se ha probado exhaustivamente en bases de datos acordes a los requisitos de la American Heart Association (AHA), y en registros de resucitación con y sin artefacto RCP. El trabajo comenzó con una larga fase experimental en la que se recopilaron y clasificaron retrospectivamente un total de 1090 ritmos pediátricos. Además, se revisó una base de arritmias de adultos y se añadieron 928 nuevos ritmos de adultos. La base de datos final contiene 2782 registros, 1270 se usaron para diseñar el algoritmo y 1512 para validarlo. A continuación, se diseñó un nuevo algoritmo DEA compuesto de cuatro subalgoritmos. Estos subalgoritmos están basados en un conjunto de nuevos parámetros para la detección de arritmias, calculados en diversos dominios de la señal, como el tiempo, la frecuencia, la pendiente o la función de autocorrelación. El algoritmo cumple las exigencias de la AHA para la detección de ritmos desfibrilables y no-desfibrilables tanto en pacientes adultos como en pediátricos. El trabajo concluyó con el análisis del comportamiento del algoritmo con episodios reales de resucitación. En los ritmos que no contenían artefacto RCP se cumplieron las exigencias de la AHA. Posteriormente, se estudió la precisión del algoritmo durante las compresiones torácicas, antes y después de filtrar el artefacto RCP. Para suprimir el artefacto se utilizó un nuevo método desarrollado a lo largo de la tesis. Los ritmos desfibrilables se detectaron de forma precisa tras el filtrado, los no-desfibrilables sin embargo no.
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[EN]A study was conducted on crossbred steers (n=275; 376±924 kg) to evaluate performance and carcass quality of cattle fed wheat or corn dried distillers’ grains with solubles (DDGS). The control ration contained 86.6% rolled barley grain, 5.7% supplement and 7.7% barley silage (DM basis). The four treatments included replacement of barley grain at 20 or 40% of the diet (DM basis) with wheat or corn DDGS. Steers were slaughtered at a common end weight of 645 kg with 100 steers randomly (n=20 per treatment) selected for determination of the retail yield of sub-primal boneless boxed beef (SPBBB). Data were analyzed as a completely randomized design using pen as the experimental unit. Feeding increasing levels of wheat DDGS led to a quadratic increase in dry matter intake (DMI) (P<0.01), whereas increasing levels of corn DDGS led to a quadratic decrease in DMI (P=0.01). Average daily gain was not influenced (P=0.13) by feeding wheat or corn DDGS, but cattle fed corn DDGS exhibited a quadratic increase (P=0.01) in gain:feed. As a result, a quadratic increase (P<0.01) in calculated NEg of the diet was observed as corn DDGS levels increased. A linear decrease (P=0.04) in days on feed (169, 166 and 154 d) was noted when increasing levels of wheat DDGS (0, 20 and 40%) were fed. Dressing percentage increased in a linear fashion with wheat DDGS (P<0.01) inclusion level and in a quadratic fashion (P=0.01) as corn DDGS inclusion level increased although other carcass traits were not affected (P=0.10) by treatment. The results indicate that replacement of barley grain with corn or wheat DDGS up to 40% of the diet (DM) can lead to superior performance (improved gain:feed or reduced days on feed, respectively) with no detrimental effect on quality grade or carcass SPBBB yield.
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Ejemplar dedicado a: Beñat Oihartzabali gorazarre - Festchrift for Bernard Oyharçabal/ Ricardo Etxepare, Ricardo Gómez, Joseba Andoni Lakarra ( eds.)
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Lei nº 12.663, de 5 de junho de 2012, que dispõe sobre as medidas relativas à Copa das Confederações Fifa 2013, à Copa do Mundo Fifa 2014 e à Jornada Mundial da Juventude 2013, que serão realizadas no Brasil; altera as Leis nos 6.815, de 19 de agosto de 1980, e nos 10.671, de 15 de maio de 2003; e estabelece concessão de prêmio e de auxílio especial mensal aos jogadores das seleções campeãs do mundo em 1958, 1962 e 1970
Effects of shear on eggs and larvae of striped bass, morone saxatilis, and white perch, M. americana
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Shear stress, generated by water movement, can kill fish eggs and larvae by causing rotation or deformation. Through the use of an experimental apparatus, a series of shear (as dynes/cm2)-mortality equations for fixed time exposures were generated for striped bass and white perch eggs and larvae. Exposure of striped bass eggs to a shear level of 350 dynes/cm2 kills 36% of the eggs in 1 min; 69% in 2 min, and 88% in 4 min; exposure of larvae to 350 dynes/cm2 kills 9.3% in 1 min, 30.0% in 2 min, and 68.1% in 4 min. A shear level of 350 dynes/cm2 kills 38% of the white perch eggs in 1 min, 41% in 2 min, 89% in 5 min, 96% in 10 min, and 98% in 20 min. A shear level of 350 dynes/cm2 applied to white perch larvae destroys 38% of the larvae in 1 min, 52% in 2 min, and 75% in 4 min. Results are experimentally used in conjunction with the determination of shear levels in the Chesapeake and Delaware Canal and ship movement for the estimation of fish egg and larval mortalities in the field.
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Parte 1 - Decisões
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Parte 1 - Leis.
Symplectoscyphus glacialis (Jaderholm, 1904) y Symplectoscyphus plectilis (Hickson & Gravelly, 1907)
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Fish collections under varying ecological conditions were made by trawling and seining, monthly and quarterly in depths of <1 m to depths of 3 m of the Florida Bay portion of Everglades National Park, Florida. From May 1973 through September 1976, a total of 182,530 fishes representing 128 species and 50 families were taken at 27 stations. An additional 21 species were identified from sportfish-creel surveys and supplemental observations. Most of the species collected were juveniles of species that occur as adults in the Florida Bay creel census survey, or were small species that were seasonal residents. Marked temporal and spatial abundance of the catches was observed. The greatest numbers and biomass of the fishes occurred in the wet season (summer/fall), whereas lowest numbers and biomass appeared during the dry season (winter/spring) The greatest abundance and diversity of fishes was found in western Florida Bay followed by eastern and central Bay regions respectively. Overall, five species comprised 75% of the numerical total while eleven species made up 75% of the total biomass. Collections were dominated numerically by anchovies (Engraulidae), especially Anchoa mitchilli, in western Florida Bay. Mojarras (Gerridae), mostly silver jenny Eucinostomus gula, and porgies (Sparidae), especially pinfish Lagodon rhomboides, dominated numerically in central and eastern portions of the Bay, respectively. Except for salinity, other measured physico-chemical parameters (water temperature, pH, dissolved oxygen, and turbidity) showed no variation beyond ranges considered normal for shallow, tropical marine environments. Salinity varied from 0 to 66 ppt near the mainland. Nearshore hypersaline conditions (>45 ppt) persisted for nearly 2 years during the 1974 - 1975 severe drought period. Significant reductions in fish abundance/diversity were observed in relation to hypersaline conditions. Bay-wide macrobenthic communities were mapped (presence/absence) and were primarily comprised of turtle grass (Thalassia), shoalgrass [(Diplanthera = (Halodule)], and/or green algae Penicillus. Seasonal dieoff of seagrasses was observed in north-central Florida Bay. (PDF contains 107 pages)
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Estimates of length at birth and early postnatal growth are made for the northern and southern populations of the offshore spotted dolphin in the offshore eastern tropical Pacific. Length at birth is estimated to be 85.4 cm for the northern population and 83.2 cm for the southern population. Analyses of series of monthly distributions of length revealed two cohorts born each year in the northern population, at least in the northern inshore part of its geographic range, but only one cohort born each year in the southern population. Growth curves fitted to the means of the monthly distributions of length gave estimates of length at 1 year of 126.2 and 132.6 cm and length at 2 years of 154.3 and 154.9 cm for the two cohorts in the northern population. and length at 1 year of 127.9 cm for the southern population. A growth curve fitted to lengths and ages (in dental growth layer groups) from the northern population gave estimates of lengths at 1 and 2 years of 123.0 and 143.0 cm, respectively.