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本讨论了温度,搅拌和时间三要素对感光乳剂和工艺过程的影响,指出了上述影响的后果和严格过程控制的重要性,提出克服的措施。 相似文献
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通过试验研究了焊条直径和铁粉加入量对焊条熔化参数的影响.试验结果表明,焊条直径增加,焊条药皮重量系数、熔敷效率增加,熔化速度和熔敷速度降低;熔敷金属中合金元素Mn、Si含量增加,但Mn、Si的过渡系数减小.当增加药皮中铁粉加入量,药皮重量系数、熔敷效率和熔敷速度增加。熔化速度降低,由于铁粉的稀释作用使熔敷金属中合金元素Mn、Si含量及过渡系数降低。 相似文献
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等离子喷涂工艺参数对粉末熔化的影响 总被引:7,自引:0,他引:7
改变真空等离子喷涂工艺条件可调节等离子功率,以及等离子炬的温度、速度和离子化率,从而决定粉末在等离子炬中的行为。本工作研究了喷涂工艺参数如电流、Ar流量、H2流量、气压和喷涂距离与等离子功率的定量关系,用喷扫实验测定了这工艺参数的变化驿钛粉末熔化程度的影响。等离子功率与电流、Ar和H2流量分别成正比、线性及平方根关系,与气压无关。电流和H2流量的影响最大,增加电流和H2流量大大促进粉末熔化。气和喷 相似文献
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沥青基活性碳纤维研究:1.沥青纤维的不熔化处理 总被引:1,自引:1,他引:0
利用热分析,红外光谱研究了通用型沥青纤维的不熔化机理,同时对影响不熔化反应的诸因素进行了实验研究。结果表明,不熔化处理使沥青纤维碳氧基团含量增大,形成碳氧网络,使纤维熔点提高,强度上升。不熔化温度,时间,氧化剂深度及升温速率是不熔化处理的主要影响因素,它们影响不熔化纤维的结构与性能,影响沥青繁华纤维的碳化和活化。 相似文献
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石油沥青纤维不熔化处理的研究 总被引:1,自引:0,他引:1
本文以两种石油沥青为原料,利用TG、DSC、IR、元素分析等手段,对两种沥青纤维的不熔化处理进行了研究,计算了这两种沥青纤维的动力学参数。结果表明,两种沥青纤维在空气中的不熔化反应均为一级反应,但它们的反应活化能不同,分别为:EIPF=36.9KJ/mol,EAPE=59。33KJ/mol。它们的反应速度常数也不相同。同时也发现沥青纤维的不熔化程度对炭纤维的抗拉强度起很大的影响。 相似文献
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对矩形腔内相空材料的接触熔化过程进行了实验研究,观测记录了熔化现象和规律,并进行了分析,给出一些有益的结论。 相似文献
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通过大量的熔化焊接头度样的观察和研究,提出了熔化焊接头特征区域划分新方案。文中详细地讨论了各特征区域的形成过程。并归纳出“不均匀混合区”和“不完全熔化区”的形貌特征。 相似文献
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Recent contributions suggest that non-economic factors could be important motivational drivers of scientific mobility. We investigate this hypothesis in a sample of foreign researchers in Italy and Portugal, examining their willingness to leave the host country. We distinguish between economic factors, non-economic relational factors and non-economic aspirational factors. Controlling for the relevant contextual variables, we find that foreign researchers, unsatisfied with aspirational factors (e.g. level of independence, autonomy, intellectual challenge and social status), are more likely to leave their host country and move to a third country than they are to return to their countries of origin. Relational and economic factors, such as salary and benefits, do not demonstrate any additional impact. 相似文献
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制造企业竞争力分析及其提高策略 总被引:9,自引:0,他引:9
分析了影响制造企业竞争力的各种要素,提出应根据企业自身的具体情况确定竞争力诸要素以及它们的重要性顺序。建立了竞争力的未桶模型,认为竞争力诸要素的水平应相互协调。最后讨论了我国制造企业提高自身竞争力的策略。 相似文献
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A survey of authors of highly cited papers in 22 fields was undertaken in connection with a new bibliometric resource called Essential Science Indicators (ESI®). Authors were asked to give their opinions on why their papers are highly cited. They generally responded by describing specific internal, technical aspects of their work, relating them to external or social factors in their fields of study. These self-perceptions provide clues to the factors that lead to high citation rate, and the importance of the interaction between internal and external factors. Internal factors are revealed by the technical terminology used to describe the work, and how it is situated in the problem domain for the field. External factors are revealed by a different vocabulary describing how the work has been received within the field, or its implications for a wider audience. Each author's response regarding a highly cited work was analyzed on four dimensions: the author perception of its novelty, utility, significance, and interest. A co-occurrence analysis of the dimensions revealed that interest, the most socially based dimension, was most often paired with one of the other more internal dimensions, suggesting a synergy between internal and external factors. 相似文献
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单位待遇不高、能力得不到发挥和领导对自己不重视,以及看不到单位的发展前途是高学历员工离职的最主要内部诱因;外单位提供丰厚的经济待遇、良好的工作环境等外部诱因是高学历员工离职的外部诱因.据此提出了要把高学历员工作为企业第一资源并给予高度重视;要逐步提高高学历员工的福利待遇;要为高学历员工提供充分发挥才能的机会和加强高学历员工职业生涯规划设计四项主要的管理措施. 相似文献
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In this paper, the work of Lin and Abel [Lin SC, Abel JF. Variational approach for a new direct-integration form of the virtual crack extension method. Int J Fract 1988;38:217-35] is further extended to the general case of multiple crack systems under mixed-mode loading. Analytical expressions are presented for stress intensity factors and their derivatives for a multiply cracked body using the mode decomposition technique. The salient feature of this method is that the stress intensity factors and their derivatives for the multiple crack system are computed in a single analysis. It is shown through two-dimensional numerical examples that the proposed method gives very accurate results for the stress intensity factors and their derivatives. It is also shown that the variation of mode I and II displacements at one crack-tip influence the mode I and II stress intensity factors at any other crack. The computed errors were about 0.4-3% for stress intensity factors, and 2-4% for their first order derivatives for the mesh density used in the examples. 相似文献
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In managing the situational factors to improve the performances of production and inventory control systems, the sequence for managing the factors should not be arbitrarily decided, since the factors are not independent but are inter-related. To determine the suitable sequence, the inter-relationships among the situational factors are studied. Based on these relationships, a hierarchy of the factors is obtained by using Fuzzy Interpretative Structural Modelling (FISM). In addition, indirect relationships between the factors are also studied. Based on their driver power and dependence, the factors are classified into sectors. The approach presented can be used as a guideline for determining the sequence for managing the situational factors. 相似文献
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Environmental factors and objectives are formally identified during the scoping stage of environmental impact assessment (EIA) to structure and focus individual assessments. Environmental factors are broad components of the environment, while objectives set the desired outcome for a specific factor. This research assesses the utility of environmental factors and objectives in EIA practice based upon a combination of literature review and interviews with 21 EIA practitioners from Western Australia. Further to providing focus and structure for EIA, practitioners also use environmental factors and objectives for decision-making throughout the process. The majority of practitioners also note that factors and objectives are value adding and useful to their EIA practice. Due to their inherent subjective natures, interviewees noted a lack of consistency regarding how to meet the objectives and challenges in determining the significance of impacts on a factor. Identified opportunities to enhance use of objectives and factors in EIA included provision of more guidance, especially criteria or standards to apply and improve knowledge sharing between EIA stakeholders. 相似文献
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G. S. Watson 《技术计量学》2013,55(3):371-388
This paper discusses the problem of group screening methods wherein f factors are sub-divided into groups of k factors each, forming g “group-factors”. The group factors are then studied using a Plackett and Burman design in Q + 1 runs. The two versions of the group factors are formed by maintaining all component factors at their upper and lonrer levels respectively. All factors in groups found to have a large effects are then studied in a second stage of experiments. The author discusses the problems of detection and false detection of factors, optimum group size, size of program, and the role of costs in this sequential form of experimentation. 相似文献
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综述了离子液体的种类、合成及纯化方法。离子液体的纯度对其物理化学性质至关重要,是研究其应用的首要问题。本文介绍了离子液体的合成方法,并对比了其优缺点,发现合成方法对离子液体的纯度起着关键作用,指出了影响离子液体纯度的因素,分析对比了离子液体的纯化方法,包括真空干燥、有机溶剂萃取、重结晶、吸附剂法、分子筛法等,根据影响因素种类的不同,优选纯化方法,并对离子液体的发展进行了展望。 相似文献