安钢400m2烧结机系统一次、二次混合机改造

针对400 m2烧结机系统一、二次混合机故障频繁的问题,通过考察分析并参照以往的维修经验,对其进行了一系列改造,包括:托辊座轴承固定方式改进;一混喷水装置优化;圆筒出料端防磨,进料端防倒料改造;以及润滑系统油路改进和防冻等.改造后,一、二次混合机月平均故障时间分别由0.82 h和2.35 h降至0.1h和0.25 h,...     

圆筒混合机清壁装置的设计

针对烧结机混合制粒系统所用圆筒混合机简体内壁粘料后,影响混匀与制粒效果、影响烧结机的正常稳定生产、增加烧结风机功耗、增大混合机运转负荷、降低混合机使用寿命问题,设计了一种可靠的混合机清壁装置,实现了不停机清壁,保证了混合机及烧结机的正常稳定运行.     

柔性传动圆筒混合机的开发与应用

圆筒混合机主要用于钢铁和有色金属冶炼烧结物料的混合和制粒作业。柔性传动圆筒混合机是新型物料混合制粒设备。分析了圆筒混合机传统设计中存在的问题 ,介绍了柔性传动圆筒混合机的研制和使用情况。     

抑制圆筒混合机粘料的措施

烧结混合机圆筒粘料是各企业普遍存在的问题。承钢结合自身原料特点,通过在圆筒混合机进口端加装陶瓷衬板,安装在线清料装置,改进打水方式等措施,很好地抑制了圆筒混合机粘料问题,减轻了工人的劳动强度,提高了生产效率。     

提高混合机运行稳定性实践

针对圆筒混合机长时间运行后存在的振动大、故障频繁等问题,通过混合机系统减震技术、主减速机强制润滑技术、混合机加水、加汽设施优化等技术的实施,有效解决上述问题。同时对稳定生产、提高系统作业率、解决部分关键设备运行故障率高的问题,以及对稳定烧结生产、降低混合机系统故障率、降低吨矿成本提供了有利条件。     

陶瓷衬板在宣钢360m~2烧结机圆筒混合机上的应用

针对宣钢炼铁厂360 m2烧结机一、二次圆筒混合机衬板存在的粘料、磨损等问题,经过分析论证选择了陶瓷衬板,并进行了陶瓷衬板代替尼龙衬板改造。改造后,解决了混合机的粘料问题,降低了混合机的运行负荷和停机率,改善了制粒效果,每年产生的经济效益384.49万元。     

圆筒混合机安装调试产生的问题及解决措施的研究

现阶段随着国家重工业的不断发展,对冶金的需求量不断增加,随着烧结生产的大规模投入使用,对圆筒混合机的需求量不断增加。圆筒混合机的安装与调试严重影响到烧结生产线的工作。本文通过多次对圆筒混合机安装进行调试,分析了现阶段圆筒混合机生产线上所存在的一些问题,并提出解决措施,保证设备安装过程中不出现问题,为烧结厂带来更高的经济价值提供技术参考。     

烧结竖炉干燥混合机性能优化设计

针对烧结厂干燥混合机处理混合料能力与竖炉全负荷生产不匹配问题,从剖析干燥混合机性能参数设计入手,通过改造,实现干燥混合机的性能优化,保证烧结竖炉稳定运行。     

混合机在线清料装置的研发与应用

为了解决钒钛磁铁矿烧结混合机粘料所带来的不利影响,研发了一种混合机在线自动清料装置。该装置的研发与应用提高了混合机的制粒效果,彻底杜绝了烧结机工序因混合机粘料而被迫停机的问题,降低烧结机故障停机率1.47%,且烧结过程主要参数和烧结矿主要经济技术指标均得到了明显的改善。     

稀土含油尼龙衬板在烧结混合机上的应用

圆筒混合机是烧结生产过程中的重要设备，本文介绍了广钢烧结厂首次在圆筒混合机内安装衬板后解决了简体内壁粘料的问题，提高了烧结矿的产量和质量，降低了生产成本，为圆筒混合机的改造提供了依据。     

Evaluations and expectancies of alcohol and marijuana problems among college students.

Two studies examined the associations between evaluations (good-bad) and expected likelihood (likely-unlikely) of alcohol- and marijuana-related problems and hazardous consumption and problems among college students. Participants provided data on alcohol use, alcohol-related problems, and expectancies and evaluations of alcohol problems; marijuana use indices, marijuana-related problems, marijuana effect expectancies, and likelihood and evaluations of marijuana problems. Evaluations of alcohol problems were positively related to the number of binge drinking occasions and alcohol-related problems. The interaction between evaluations and expectancies was significant in predicting the number of binge drinking occasions. Expectancies demonstrated a curvilinear relationship with binge drinking and alcohol-related problems. Marijuana users evaluated marijuana-related problems as less negative and less likely to occur than did nonusers. Expectancies, but not evaluations, of negative consequences were significantly associated with marijuana use intensity. Expectancies of problems demonstrated a curvilinear relationship with marijuana-use intensity and marijuana problems. Men evaluated alcohol and marijuana problems less negatively than did women. In summary, the expected likelihood of alcohol-marijuana problems and the evaluation of such problems represent a vulnerability factor associated with increased liability for hazardous alcohol and marijuana use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parent psychopathology, parenting, and child internalizing problems in substance-abusing families.

A structural model accounting for child internalizing problems in substance-abusing families was tested. Parents receiving substance abuse treatment (N = 242) completed forms about children between the ages of 6 and 18 who resided in their home. The effects of parent gender, child gender, and child age were controlled. Negative parenting was examined as a mediator between parent internalizing and externalizing problems and child anxiety and affective problems using path analysis. Negative parenting mediated relations only between parent internalizing problems and child affective problems. High-positive involvement moderated relations between parent externalizing problems and child internalizing problems. Relations between parent externalizing problems and child anxiety and affective problems were significant only among families in which high-positive involvement was present. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male and female estimates of personal problems of men and women.

100 male and 100 female undergraduates estimated the types of problems males and females would present at a counseling center. Of 75 problems on a problem checklist, 35 problems were seen as being more typically female whereas only 16 were seen as being more typically male. Sex differences in estimates were found for 13 problems; however, these differences did not affect whether the problems were seen as male or female. Of the 16 male problems, 8 were vocational-educational problems, while none of the female problems was vocational-educational. A 2nd purpose of the study was to look at sex differences in problems presented by actual clients at a university counseling center. Of the 75 problems on the checklist, sex differences were found for only 3 problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adults' representations of division facts: A consequence of learning history?

In this study, division was exclusively examined to determine the strategies that are used to solve simple division problems and to identify factors relating to particular strategy use. Thirty-two participants (aged 18-43 yrs) were asked to solve two sets of 64 simple division problems (from 4÷2 to 81÷9) and error, latency, and strategy report data were collected. Fewer errors were made on easy problems, which were also solved more quickly than difficult problems. Participants used retrieval, multiplication, and other strategies to solve the problems and tended to use retrieval more on easy than difficult problems and used multiplication more on difficult problems than easy problems. Unexpected age differences in strategy use were also found. Older participants tended to rely more heavily on retrieval than younger participants. These results suggest that older participants may have stronger representations for simple division problems than younger participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Compound Problem Solving: Insights from the Workplace for Engineering Education

For engineering educators who incorporate real-world problems into their teaching, it is essential to understand real-world problem solving and the nature of problems for better design of the instruction. Prior research provided evidence that real-world problems involve many stakeholders, are complex, and have multiple solutions and solution paths. The purpose of this paper is to provide additional insights particularly into the structure/class of workplace problems and associated models of expertise. This paper describes the findings of a study that employed a two-step process: (1)?a single-case study of a steel engineer generating a model of compound problem solving and (2)?a multi-case comparison of 90 problem-solving narratives of other engineers to the single case. The study is located in a U.S. context. Results indicate that real-world problems are intertwined problems (compound problems) and that transitions from one problem type to another within a compound problem are a unique class of problems themselves. These transition problems have properties that are not represented in other problem types and provide insights into expertise and expertise development in problem solving.     

Equivalence in symbolic and nonsymbolic contexts: Benefits of solving problems with manipulatives.

Children's failure on equivalence problems (e.g., 5 + 4 = 7 + __) is believed to be the result of misunderstanding the equal sign and has been tested using symbolic problems (including "="). For Study 1 (N = 48), we designed a nonsymbolic method for presenting equivalence problems to determine whether Grade 2 children's difficulty is due to the presence of symbols or to a more fundamental misunderstanding of equivalence. Children's superior performance on nonsymbolic versus symbolic problems suggests that children fail to map their understanding of equivalence onto problems presented with the symbols of arithmetic. For Study 2 (N = 32), we implemented a within-subject design to assess whether experience with nonsymbolic problems would facilitate performance on symbolic problems. This hypothesis was confirmed. Exposure to nonsymbolic problems may have enabled children to map their successful concepts and strategies to symbolic equivalence problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of noise level and difficulty of task in performing division.

Ss worked division problems for 20 min. in the presence of 98 db.-108 db. of noise while Ss of comparable mean ability in arithmetic worked the problems under conditions of room noise. Under each condition 1 group of Ss worked "easy" problems and another group worked "difficult" problems. Intense noise produced no effect on mean number of problems correctly solved. Variability of performance was significantly greater with easy problems under intense noise conditions than under room-noise conditions, although there was no difference with difficult problems. There was no evidence of a decrement in performance within the 20-min. session attributable to noise level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can memory requirements account for species' differences in invisible displacement tasks?

We tested the hypothesis that poor performance on the Piagetian invisible displacement task is related to increased memory requirements. Rhesus monkeys and orangutans received 3 types of problems (invisible, visible, and no transfer problems) each containing a number of steps equivalent to that of standard invisible displacements. If failure to solve invisible displacements was due to increased memory requirements, then the primates should perform at chance level on all 3 problems. However, rhesus monkeys solved visible and no transfer problems, but not invisible transfer problems. Half of the orangutans solved all 3 transfer problems, although their performance on invisible transfer problems was lower than that on the other problems. A subsequent cuing phase led to improved performance, and a few monkeys solved invisible transfer problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An affective-motivational model of marijuana and alcohol problems among college students.

The study examined models of marijuana (n = 309) and alcohol (n = 731) problems. Impulsivity was directly associated with both marijuana- and alcohol-related problems. Negative mood regulation expectancies were indirectly associated with marijuana problems through coping motives. Sensation seeking was indirectly associated with alcohol problems through enhancement motives. Affect lability and negative affect were indirectly associated with alcohol problems though coping motives. In both models, coping motives were directly associated with use-related problems. A multigroup analysis indicated that the association between negative affect and coping motives as well as use and problems was stronger among participants using both alcohol and marijuana relative to alcohol only. Enhancement motives were a stronger predictor of alcohol use among participants using alcohol only. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceived self-efficacy and everyday problem solving among young and older adults.

This research tested the hypothesis that age differences in both self-efficacy perceptions and problem-solving performance would vary as a function of the ecological relevance of problems to young and older adults. The authors developed novel everyday problem-solving stimuli that were ecologically representative of problems commonly confronted by young adults (young-adult problems), older adults (older adult problems), or both (common problems). Performance on an abstract problem solving task lacking in ecological representativeness (the Tower of Hanoi problem) also was examined. Although young persons had higher self-efficacy beliefs and performance levels on the Tower of Hanoi task problem and the young-adult problems, this pattern reversed in the domain of older adult problems, where the self-efficacy beliefs and performance of older persons exceeded those of the young. (PsycINFO Database Record (c) 2010 APA, all rights reserved)