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91.
选取着火温度、燃尽率和残灰碳氢含量等指标,利用程序升温热重技术研究了CuSO4和K2CO3对铁法高灰烟煤(TF)的催化助燃效果,同时通过分布活化能(DAEM)动力学模型探讨了活化能变化与催化助燃效果的关系.结果表明,CuSO4和K2CO3的添加比例均为2%时,TF煤的着火温度分别降低了44.3℃和31.1℃;最终燃尽率从92.19%分别提高到94.75%和96.13%,而残灰含碳量从6.91%分别降到3.37%和2.39%.TF煤燃烧的分布活化能在转化率<15%,20%~85%,>90%三阶段呈现不同的规律性变化,CuSO4和K2CO3对TF煤燃烧的分布活化能影响主要发生在转化率20%~85%之间:CuSO4的添加使得TF煤燃烧的分布活化能呈现波动性变化,而K2CO3能够明显降低TF煤燃烧的分布活化能. 相似文献
92.
在设计热功率为1 MW的热态模化实验台上,研究了带有燃尽风的径向浓淡双调风旋流燃烧器的运行特点,得到燃尽风布置的相对位置、一次风率、内二次风率、外二次风率以及二次风旋流强度对NOx生成和飞灰含碳量的影响.结果表明:旋流对冲的煤粉浓淡燃烧配合采用燃尽风(OFA)空气分级燃烧技术,对降低NOx的生成和减少飞灰含碳量非常有益;只有合理地设计和布置OFA燃烧器,才能在降低NOx生成量的同时,尽量减少飞灰含碳量;增大一次风率时,NOx的生成量先增加后减少,而飞灰含碳量先减少后增加;增加内、外二次风的旋流强度,NOx的生成量不断提高,而飞灰含碳量则呈现降低趋势. 相似文献
93.
Bakker Arnold B.; Demerouti Evangelia; Euwema Martin C. 《Canadian Metallurgical Quarterly》2005,10(2):170
This study tested and refined the job demands-resources model, demonstrating that several job resources play a role in buffering the impact of several job demands on burnout. A total of 1,012 employees of a large institute for higher education participated in the study. Four demanding aspects of the job (e.g., work overload, emotional demands) and 4 job resources (e.g., autonomy, performance feedback) were used to test the central hypothesis that the interaction between (high) demands and (low) resources produces the highest levels of burnout (exhaustion, cynicism, reduced professional efficacy). The hypothesis was rejected for (reduced) professional efficacy but confirmed for exhaustion and cynicism regarding 18 out of 32 possible 2-way interactions (i.e., combinations of specific job demands and resources). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
The optimal heating trajectories to minimize the time required for the organic additives removal in yttria-stabilized zirconia (YSZ) green tapes were determined using a dynamic optimization method. The removal process model was described by the mass transport of the volatile gas evolved from the thermal decomposition of the organic additives inside the tapes and the kinetics of the decomposition. The pressure buildup of the sample tapes formed by the volatile gas can be estimated by a numerical simulation method; meanwhile, the deformation (strain) of the tape caused by the pressure buildup was measured by a thermal mechanical analyzer (TMA) during the thermal processing. Results show that the formation of the maximum pressure buildup at the center of the cubic tape is influenced by the sample size and heating conditions. In addition, the dynamic strain at the center of the sample measured by TMA agrees with the formation of the pressure buildup estimated by the numerical calculation. Moreover, the optimal heating trajectories determined by the dynamic optimization scheme with the constraint of the formation of the maximum pressure buildup were verified from the tape deformation analysis by the TMA tests. 相似文献
95.
Rubino Cristina; Luksyte Aleksandra; Perry Sara Jansen; Volpone Sabrina D. 《Canadian Metallurgical Quarterly》2009,14(3):289
We extend existing stressor-strain theoretical models by including intrinsic motivation as a mediator between well-established job stressors and burnout. Though the link between situational stressors and burnout is well established, little is known about mechanisms behind this relationship. With a sample of 284 self-employed individuals, we examined motivation as a mediator to explain why situational factors impact 3 dimensions of burnout: emotional exhaustion, cynicism, and inefficacy. Motivation is an explanatory mechanism that drives human behavior and thought, and thus may have an impact on important well-being outcomes. As expected, intrinsic motivation was a full mediator for the effect of perceived fit on the inefficacy dimension of burnout. Unexpectedly, neither perceived fit nor motivation was related to the other 2 dimensions of burnout, and role ambiguity had only a direct effect on the inefficacy dimension; it was also unrelated to exhaustion and cynicism. We discuss implications of these findings for researchers as well as for practitioners. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
热泵热水器以制取热水为目的,有别于普通制冷或空调设备。热泵热水器运行时冷凝温度和冷凝压力很高,对压缩机的可靠性和应用技巧提出了较高要求。涡旋压缩机以其可靠性好、效率高,在热泵热水器中得到了大量应用。 相似文献
97.
Dimensions of teacher self-efficacy and relations with strain factors, perceived collective teacher efficacy, and teacher burnout. 总被引:2,自引:0,他引:2
In this study, the authors developed and factor analyzed the Norwegian Teacher Self-Efficacy Scale. They also examined relations among teacher self-efficacy, perceived collective teacher efficacy, external control (teachers' general beliefs about limitations to what can be achieved through education), strain factors, and teacher burnout. Participants were 244 elementary and middle school teachers. The analysis supported the conceptualization of teacher self-efficacy as a multidimensional construct. They found strong support for 6 separate but correlated dimensions of teacher self-efficacy, which were included in the following subscales: Instruction, Adapting Education to Individual Students' Needs, Motivating Students, Keeping Discipline, Cooperating With Colleagues and Parents, and Coping With Changes and Challenges. They also found support for a strong 2nd-order self-efficacy factor underlying the 6 dimensions. Teacher self-efficacy was conceptually distinguished from perceived collective teacher efficacy and external control. Teacher self-efficacy was strongly related to collective teacher efficacy and teacher burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Comparing two burnout interventions: Perceived job control mediates decreases in burnout. 总被引:1,自引:0,他引:1
H?tinen Marja; Kinnunen Ulla; Pekkonen Mika; Kalimo Raija 《Canadian Metallurgical Quarterly》2007,14(3):227
This quasi-experimental study compared the effects of two rehabilitation interventions on burnout and perceived job conditions during a 1-year intervention among female white-collar workers. The participatory intervention (n = 20), involving rehabilitation activities that focused on the individual as well as on individual-organizational levels, assessed exhaustion, cynicism and perceived job control during a 1-year period. Increased job control served as a mechanism through which exhaustion and cynicism decreased in this intervention. The traditional intervention (n = 32), involving rehabilitation activities focusing mainly on the individual level, resulted in a reduction in time pressures during one year. Furthermore, both interventions improved perceived workplace climate. Compared to the traditional approach, the participatory intervention was a more effective strategy for treating burnout. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Although almost all literature on burnout implicitly assumes that burnout is primarily caused by stressful employee-customer interactions, only a few studies have addressed this empirically. A principal-components analysis of a newly developed instrument assessing various forms of customer-related social stressors (CSS) in 3 different service jobs (N = 591) revealed 4 themes of CSS: disproportionate customer expectations, customer verbal aggression, disliked customers, and ambiguous customer expectations. These 4 CSS predict burnout beyond a variety of control variables. Contrary to other predictors of burnout analyzed in previous studies, the amount of variance explained in exhaustion (14%) by the 4 CSS scales is not higher than for personal accomplishment (14%) and is considerably lower than for depersonalization (23%). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
功率MOS、IGBT单粒子烧毁、栅穿效应模拟实验研究 总被引:2,自引:0,他引:2
建立了利用^252Gf裂片源,模拟空间重离子引起的单粒子烧毁、栅穿效应的实验方法和测试装置,开展了功率MOS器件、IGBT的单粒子烧毁、栅穿效应的模拟试验研究,给出了被试器件单粒子烧毁、栅穿效应的损伤阈值,以及随器件偏置的变化规律。 相似文献