热网管道热损失现场测试方法探讨

<正> 国外热网管道热损失测试多半采用热流计、红外测温仪、点温计等测试手段来实现。但现场测试时往往受到风、日照等非稳态影响。为探讨现场测试方法的可行性,采用了热流计法、表面温度法、温差法和焓降法来测量热网管道热损失。a.热流计法:用热流计直接测量管道保温层外表面热损失。b.表面温度法:测量管道保温层外表面温度、环境温度和风速,按对流换热和辐射换热公式来计算管道热损失。c.温差法:根据管道保温层内、外表面温度,内、外径以及实验室测得的保温材料导热系数,按径向一维导热计

Simples nacional : Estatuto nacional da microempresa e da empresa de pequeno porte

Apresenta a Lei Complementar nº 123, de 14 de dezembro de 2006, que institui o Estatuto Nacional da Microempresa e da Empresa de Pequeno Porte; altera dispositivos das Leis nºs 8.212 e 8.213, ambas de 24 de julho de 1991, da Consolidação das Leis do Trabalho (CLT), aprovada pelo Decreto-Lei nº 5.452, de 1º de maio de 1943, da Lei nº 10.189, de 14 de fevereiro de 2001, da Lei Complementar nº 63, de 11 de janeiro de 1990; e revoga as Leis nºs 9.317, de 5 de dezembro de 1996, e 9.841, de 5 de outubro de 1999.

薄层放电的磁流体力学旋转流动分析

<正> 磁流体力学旋转流问题中一般假设流体输运系数为常数。用磁流体力学方法处理电弧放电问题时,经常假设弧柱內外的输运系数分别为两个不同的常数,并取弧柱外介质的电导率为零。在气态裂变反应堆、核火箭及重元素的同位素分离器中,广泛采用交叉电磁场的方法产生等离子体的高速旋转流动。文献[8,9]研究了薄层放电的电磁驱动装置,用多对极实验得到一定的分离效果。可以认为,这类薄层放电的电流集中在

A finite deformation analysis of polycrystal by considering the influence of grain boundary

By combining grain boundary (GB) and its influence zone, a micromechanic model for polycrystal is established for considering the influence of GB. By using the crystal plasticity theory and the finite element method for finite deformation, numerical simulation is carried out by the model. Calculated results display the microscopic characteristic of deformation fields of grains and are in qualitative agreement with experimental results.

A stochastic jump and deterministic dynamics model of impact failure evolution with rate effect

Motivated by the observation of the rate effect on material failure, a model of nonlinear and nonlocal evolution is developed, that includes both stochastic and dynamic effects. In phase space a transitional region prevails, which distinguishes the failure behavior from a globally stable one to that of catastrophic. Several probability functions are found to characterize the distinctive features of evolution due to different degrees of nucleation, growth and coalescence rates. The results may provide a better understanding of material failure.

Crack growth by grain boundary cavitation in the transient and extensive creep regimes

Crack growth due to cavity growth and coalescence along grain boundaries is analyzed under transient and extensive creep conditions in a compact tension specimen. Account is taken of the finite geometry changes accompanying crack tip blunting. The material is characterized as an elastic-power law creeping solid with an additional contribution to the creep rate arising from a given density of cavitating grain boundary facets. All voids are assumed present from the outset and distributed on a given density of cavitating grain boundary facets. The evolution of the stress fields with crack growth under three load histories is described in some detail for a relatively ductile material. The full-field plane strain finite element calculations show the competing effects of stress relaxation due to constrained creep, diffusion and crack tip blunting. and of stress increase due to the instantaneous elastic response to crack growth. At very high crack growth rates the Hui-Riedel fields dominate the crack tip region. However. the high growth rates are not sustained for any length of time in the compact tension geometry analyzed. The region of dominance of the Hui-Riedel field shrinks rapidly so that the near-tip fields are controlled by the HRR-type field shortly after the onset of crack growth. Crack growth rates under various conditions of loading and spanning the range of times from small scale creep to extensive creep are obtained. We show that there is a strong similarity between crack growth history and the behaviour of the C(t) and C(t) parameters. so that crack growth rates correlate rather well with C(t) and C(t). A relatively brittle material is also considered that has a very different near-tip stress field and crack growth history.

The influence of momentum addition on the acceleration of the solar and stellar winds

The influence of the momentum addition, which may be associated with the average or fluctuation transverse component of the magnetic field or others, on the acceleration the solar wind or stellar wind is studied in a local streamtube. The results show that the larger the momentum addition the stronger the acceleration of the wind. For example, if the typical transverse magnetic field is about 0.1 of the longitudinal field, the velocity of the solar wind at 1 AU may be increased by 40%. The coronal hole may be considered as a streamtube, the presence of a high stream from the coronal hole may be explained by the existence of an average or fluctuation transverse magnetic field in the streamtube. A similar conclusion may be applied to the polar region, where the velocity of the solar wind will be larger than elsewhere as if there is a transverse component of magnetic field, as well as to the stellar wind. The influence of other parameters on the acceleration of the solar wind is also discussed. From the viewpoint of the solar wind mechanism, the present paper shows that the momentum addition in the subsonic flow region can increase the velocity of the solar wind at 1 AU.

¿Es tan perjudicial la televisión que ven los jóvenes y adolescentes?

[Es] En este trabajo se presentan los resultados de un estudio piloto realizado en la Comunidad Autónoma del País Vasco con una muestra de sujetos con edades comprendidas entre 12 y 40 años. Dentro de una investigación más amplia donde se pretende relacionar la dieta televisiva y los valores implícitos y explícitos que se perciben en los contenidos televisivos, se exponen algunas diferencias y semejanzas respecto a los hábitos y dieta televisiva de los diferentes grupos de edad. Los datos encontrados nos permiten concluir que los programas más visionados no son los más perniciosos para adolescentes y jóvenes, ni tampoco que el visionado de la televisión impida el desarrollo de otro tipo de actividades.

Expectativas e implicación educativa de las familias inmigrantes de escolares en educación primaria de la CAPV: bases para la intervención educativa

596 p.: graf.

Some considerations on coastal processes relevant to sea level rise

The effects of potential sea level rise on the shoreline and shore environment have been briefly examined by considering the interactions between sea level rise and relevant coastal processes. These interactions have been reviewed beginning with a discussion of the need to reanalyze previous estimates of eustatic sea level rise and compaction effects in water level measurement. This is followed by considerations on sea level effects on coastal and estuarine tidal ranges, storm surge and water level response, and interaction with natural and constructed shoreline features. The desirability to reevaluate the well known Bruun Rule for estimating shoreline recession has been noted. The mechanics of ground and surface water intrusion with reference to sea level rise are then reviewed. This is followed by sedimentary processes in the estuaries including wetland response. Finally comments are included on some probable effects of sea level rise on coastal ecosystems. These interactions are complex and lead to shoreline evolution (under a sea level rise) which is highly site-specific. Models which determine shoreline change on the basis of inundation of terrestrial topography without considering relevant coastal processes are likely to lead to erroneous shoreline scenarios, particularly where the shoreline is composed of erodible sedimentary material. With some exceptions, present day knowledge of shoreline response to hydrodynamic forcing is inadequate for long-term quantitative predictions. A series of interrelated basic and applied research issues must be addressed in the coming decades to determine shoreline response to sea level change with an acceptable degree of confidence. (PDF contains 189 pages.)

Un método para el taladro de aluminio que facilita la unión por remaches de los componentes aeronáuticos

189 p. : il. col.

Financiamento de campanhas : problemas do modelo atual e opções legislativas para enfrentá-los

Analisa o financiamento das campanhas, mostrando que os gastos eleitorais, de origem privada, têm crescido num ritmo exponencial. Em 2002, os gastos declarados à Justiça Eleitoral por partidos e candidatos nas campanhas para deputado federal alcançaram R$ 189,6 milhões; em 2010, esse valor chegou ao montante de R$ 908,2 milhões, um crescimento de 479% em oito anos. Na mesma direção, as campanhas presidenciais, que custaram R$ 94 milhões, em 2002, alcançaram a cifra de R$ 590 milhões em 2010, um crescimento de 627% em oito anos.

Escultura en los años 90 en el País Vasco: reconfigurando el pasado-presente

[ES] La creación escultórica en el País Vasco durante los años noventa se siguió nutriendo del entramado creativo de la década anterior, mientras se iban difuminando los últimos coletazos programáticos de la posmodernidad. Los jóvenes artistas de esta última década no plantean lenguajes originales, ni plantean la búsqueda de temáticas inéditas, simplemente se aboga por ubicarse en un marco espacial y temporal que les permita seguir creando en base a procesos anteriores, pero con perspectivas que les sirvan para analizar y experimentar las situaciones enclavadas en el presente.