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71.
黄思龙  梁家珊 《柳钢科技》2007,(F09):271-274
介绍柳钢35t转炉方坯连铸机系统优化措施,通过优化使生产稳定性提高,铸坯质量得到改善,提高各项经济技术指标。  相似文献   
72.
Ecological momentary assessment (EMA) consists of assessing phenomena in real time in the natural environment. EMA allows for more fine-grained analyses of addictive behavior and minimizes threats to internal validity, such as recall biases and errors. However, because of the intensive monitoring involved in EMA, measurement reactivity is a concern. To test whether EMA with palmtop personal computers induces reactivity, the authors compared smoking-related outcomes between smokers using EMA and those not using EMA during a quit attempt. The use of no-EMA control groups has been rare in reactivity investigations to date. The EMA protocol included event-contingent assessments (smoking episodes, urge episodes) and random assessments. Outcomes included biologically confirmed abstinence and self-report measures of withdrawal, self-efficacy, motivation, affect, and temptations. Participants were smokers motivated to quit (N = 96). They were randomized to 1 of 3 groups: EMA for the week preceding a planned quit date, EMA for the week following the quit date, and no EMA. Abstinence rates did not differ between the groups at Day 7 or at Day 28 postcessation. For the 20 subscales assessed at each of 3 assessment times, there were significant differences between participants with and without EMA experience for 3 subscales at the 1st of 3 assessment times, and significant differences for 3 different subscales at the 3rd assessment time. These differences suggest some reactivity to EMA, although the inconsistent pattern across time indicates that further research is needed to definitively conclude that EMA induces reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
73.
Stimulus control of ring swimming was studied with male Siamese fighting fish (Betta splendens) using 2-component multiple schedules in which the components were correlated with the presence or absence of air bubbles in the water. In Experiment 1, either response-independent mirror presentations or extinction was juxtaposed with immediate response-dependent mirror presentations. Rates of ring swimming generally were higher with immediate reinforcement than with either response-independent mirror presentations or extinction. In Experiment 2, different durations of response-dependent mirror presentations were juxtaposed. Generally, higher rates of ring swimming occurred with 15-s than with 0-, 1-, or 3-s durations. Results demonstrate that stimulus control of responding can be established with these fish under several conditions of differential reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
The continuous network design problem (CNDP) is characterized by a bilevel programming model, in which the upper level problem is generally to minimize the total system cost under limited expenditure, while at the lower level the network users make choices with regard to route conditions following the user equilibrium principle. In this paper, the bilevel programming model for CNDP is transformed into a single level convex programming problem by virtue of an optimal-value function tool and the relationship between System Optimum (SO) and User Equilibrium (UE). By exploring the inherent nature of the CNDP, the optimal-value function for the lower level user equilibrium problem is proved to be continuously differentiable and its derivative in link capacity enhancement can be obtained efficiently by implementing user equilibrium assignment subroutine. However, the reaction (or response) function between the upper and lower level problem is implicit and its gradient is difficult to obtain. Although, here we approximately express the gradient with the difference concept at each iteration, based on the method of successive averages (MSA), we propose a globally convergent algorithm to solve the single level convex programming problem. Comparing with widely used heuristic algorithms, such as sensitivity analysis based (SAB) method, the proposed algorithm needs not strong hypothesis conditions and complex computation for the inverse matrix. Finally, a numerical example is presented to compare the proposed method with some existing algorithms.  相似文献   
75.
Examination of the assumptions underlying consistency perspectives in social and personality psychology reveals that they are based on an independent, individualistic view of the self. If the self is constructed as relational or interdependent with others, consistency may be less important in social behavior and well-being. Using a variety of measures of well-being, the studies showed that there is a weaker relation between consistency and well-being for individuals with a highly relational self-construal than for those with a low relational self-construal. Study 3 examined the association between the self-construal, consistency, authenticity, and well-being. These findings reveal the importance of a cultural analysis of theories of the self, personality, and well-being for further theory development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
76.
钻井井架力学性能分析   总被引:7,自引:7,他引:0  
钻井井架作为钻机系统设备中的关键部分,其力学性能直接关系到整套钻机系统的安全生产。文章推导了常用于分析钻井井架力学性能的理论,即线性屈曲、几何非线性和双重非线性理论。提出同时用这三种理论对钻井井架进行综合比较分析,从而合理地预见井架力学性能的方法。以A形钻井井架为例,进行了详细的分析,得到了井架的失稳形式、极限承载、破坏特征及薄弱部位,为钻井井架的设计、优化与评定提供了参考。  相似文献   
77.
The continuous production of hydrogen from cyclohexanes is achieved effectively using Pt/ACF (ACF = activated carbon fiber) catalysts in a fixed-bed flow reactor. The Pt catalysts are more effective than a Pd/ACF catalyst for the reaction. Besides cyclohexane, methylcyclohexane, 1,4-dimethylcyclohexane, and p-menthane can also be employed as hydrogen source in the reaction system.  相似文献   
78.
十二烷硫基硼酸铈的合成及摩擦学行为研究   总被引:2,自引:0,他引:2  
合成了油溶性化合物十二烷硫基硼酸铈(简称CeDMB),并用作润滑油添加剂。采用四球摩擦试验机和环—块试验机评价了其抗磨减摩性能。结果表明,十二烷硫基硼酸铈使HVI500基础油的抗磨性能得到明显改善,承载能力明显提高,摩擦系数明显降低。扫描电子显微镜(SEM)观察证实磨斑表面含有沉积物膜,结合X—射线光电子能谱(XPS)分析,可以推断添加剂在摩擦过程中发生摩擦化学反应,生成的Ce2O3、CeO2和B2O3沉积在摩擦副表面,形成润滑膜,从而改善其抗磨减摩性能。  相似文献   
79.
Precast bridges are often constructed as single span for dead load, but continuous for live load. A diaphragm connection is provided for negative moment continuity. However, the connection may also be subjected to positive moments due to time-dependent effects. Because these moments may be large enough to damage the diaphragm or even the girders, a positive moment connection is often provided. This paper reports on a study to determine the types of positive moment connections used across the country and to identify potential problems with these types of connections. A questionnaire survey was conducted to assess the state of practice for precast prestressed concrete bridges made continuous. The survey provides valuable information on this type of bridge and updates a previous survey on this subject.  相似文献   
80.
The theory of planned behavior suggests attitudes are a product of salient beliefs. This study examined whether aggregating salient beliefs was plausible within a more biologically centered information-processing environment. A neural network was used to examine associations among beliefs relating to exercise intention. Data on intentions and behavioral, normative, and control beliefs from 114 respondents were used to train (by error backpropagation) a neural network to associate beliefs with intention. The R2 between the network's estimated and self-reported intention was .66. The network's representation comprised 6 belief profiles associated with high, moderate, or low behavioral intention. The neural network accommodated complex relationships among beliefs and belief-intention associations and indicated how high-level constructs such as attitudes may be viewed as the best fit (compromise state) between aroused beliefs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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