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1.
球墨铸铁一体化锚具锚固体系是在总结国内近 2 0年来预应力筋锚具应用基础上针对无粘结预应力筋开发的专用锚具,它的特点是张拉端锚具采用球墨铸铁将垫板与锚环一体化,材料用量少,结构紧凑,锚固可靠;固定端锚具设计为摩擦片式挤压锚,挤压锚制作方便,锚固更为可靠,其性能符合国标GB/T14 370 - 2 0 0 0的有关要求,同时也适用于 2 0 0 0MPa级预应力筋。此外该锚固体系的最大特点是可以完全实现预应力筋全长封闭  相似文献   
2.
稀土永磁电机由于其高效、高功率密度的特点,在轨道交通牵引系统的设计中受到了广泛和密切的关注。由于其全封闭式结构,牵引电动机的负载能力主要受限于冷却系统的散热能力。建立了一台永磁牵引电动机的全封闭式自循环空-空冷却系统,通过对参数散热敏感性的分析,确定了适宜的冷却结构参数范围。针对该冷却结构,应用有限公式法进行三维温度场数值计算,确定了散热系统的结构参数,并用流固耦合仿真验算了计算结果。  相似文献   
3.
Emotion theorists have long debated whether valence, which ranges from pleasant to unpleasant states, is an irreducible aspect of the experience of emotion or whether positivity and negativity are separable in experience. If valence is irreducible, it follows that people cannot feel happy and sad at the same time. Conversely, if positivity and negativity are separable, people may be able to experience such mixed emotions. The authors tested several alternative interpretations for prior evidence that happiness and sadness can co-occur in bittersweet situations (i.e., those containing both pleasant and unpleasant aspects). One possibility is that subjects who reported mixed emotions merely vacillated between happiness and sadness. The authors tested this hypothesis in Studies 1–3 by asking subjects to complete online continuous measures of happiness and sadness. Subjects reported more simultaneously mixed emotions during a bittersweet film clip than during a control clip. Another possibility is that subjects in earlier studies reported mixed emotions only because they were explicitly asked whether they felt happy and sad. The authors tested this hypothesis in Studies 4–6 with open-ended measures of emotion. Subjects were more likely to report mixed emotions after the bittersweet clip than the control clip. Both patterns occurred even when subjects were told that they were not expected to report mixed emotions (Studies 2 and 5) and among subjects who did not previously believe that people could simultaneously feel happy and sad (Studies 3 and 6). These results provide further evidence that positivity and negativity are separable in experience. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
4.
Previous studies reveal age by valence interactions in attention and memory, such that older adults focus relatively more on positive and relatively less on negative stimuli than younger adults. In the current study, eyeblink startle response was used to measure differences in emotional reactivity to images that were equally arousing to both age groups. Viewing positive and negative pictures from the International Affective Picture System had opposite effects on startle modulation for older and younger adults. Younger adults showed the typical startle blink pattern, with potentiated startle when viewing negative pictures compared to positive pictures. Older adults, on the other hand, showed the opposite pattern, with potentiated startle when viewing positive pictures compared to viewing negative and neutral pictures. Potential underlying mechanisms for this interaction are evaluated. This pattern suggests that, compared with younger adults, older adults are more likely to spontaneously suppress responses to negative stimuli and process positive stimuli more deeply. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
5.
This paper describes first experimental steps of an attempt to replace evacuated multifoils by metal-coated dielectric fibers as a new superisolation. Calculations of the Rosseland mean of spectral extinction coefficients for thin highly relective fibers show that radiation transport can be reduced to the same extent that is achievable with multifoils. Experimental results of extinction coefficients and thermal conductivity of Al-coated glass fibers are reported. Apparently, the metal coating does not increase seriously the small solid thermal conductivity of pure glass fibers. The procedure for optimizing this insulation is thus reduced to an optimization of its extinction properties.  相似文献   
6.
为保证万能式和塑料外壳式断路器、交流和直流接触器、继电器的机械寿命及其附件特性的试验可靠性、准确性与集成性,开发了多功能综合试验台,可同时对4种不同类型产品进行全自动的测试.采用工业控制计算机经ISA总线进行控制,按照预先设置的方式进行试验,并对各种特性的测试状态进行实时监控,试验台可实现对不同类型产品的多工位同时运行.具有测试数据准确、功能齐全、电源选择灵活、硬件线路控制可靠等优点.  相似文献   
7.
<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586  相似文献   
8.
给出了泛函微分方程x(t)=f(t,xx)及其被扰动方程x(t)=f(t,xt)+g(t,xt)的零解为完全全局渐近稳定的一个Razumikhin定理;推广和改进了有关结果  相似文献   
9.
纸浆绿色漂白技术新进展   总被引:2,自引:4,他引:2       下载免费PDF全文
回顾了国内外纸浆绿色漂白技术的现状,主要介绍了H2O2漂白、臭氧漂白、生物漂白、电化学漂白以及其他漂白技术的新进展。  相似文献   
10.
董旭敏 《化肥设计》2004,42(2):37-39
介绍了变换系统采用的全低变工艺流程、升温硫化流程和控制指标,总结了全低变装置的实际运行效果和操作要领。  相似文献   
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