洁净室的洁净度影响因素分析及改进措施

通过日常积累的大量数据对于上送侧回的乱流洁净室的洁净度影响因素及影响效果进行了分析,并据此提出了此类洁净室的日常运行中的改进措施。     

BDNF genotype moderates the relation between physical activity and depressive symptoms.

Objective: To test whether the BDNF gene interacts with exercise to predict depressive symptoms. Physical activity is associated with a range of positive health outcomes, including fewer depressive symptoms. One plausible mechanism underlying these findings involves Brain-Derived Neurotrophic Factor (BDNF), a protein hypothesized to limit or repair the damage caused by stress. Physical activity increases expression of BDNF, which may enhance brain health. BDNF expression is controlled by the BDNF gene. Compared with individuals without a BDNF met allele, met-allele carriers have a lower expression of BDNF, which has been associated with Major Depressive Disorder. Design: Eighty-two healthy adolescent girls were genotyped for the BDNF val66met polymorphism, and their depressive symptoms and physical activity were assessed using questionnaires. Main Outcome Measures: BDNF genotype, Children’s Depression Inventory, and the Physical Activity Questionnaire for Older Children and Adolescents. Results: The BDNF polymorphism was found to moderate the relation between exercise and depressive symptoms: being physically active was protective for girls with a BDNF met allele (fewer depressive symptoms) but not for girls with the val/val polymorphism. Conclusion: By integrating psychological and biological factors, the present study enhances our understanding of how physical activity contributes to resilience to psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

论混凝土路面质量控制

水泥砼路面的好坏直接影响路面的使用质量和行车的舒适性。因此提高砼道路的质量就成为道路好坏的关注重点     

Are MIS research instruments stable? An exploratory reconsideration of the computer playfulness scale

Computer systems have changed significantly in the past decades and this means that MIS research instruments developed when surveying users of legacy systems could be out-of-date. However, these instruments are often considered stable. We undertook an empirical exploratory investigation of the unidimensionality of the computer playfulness scale because several academics had reported inconsistent item loadings that they could not explain. As a result of our investigation, we concluded that the original computer playfulness construct consists of two correlated but distinct factors when administered to today's IS users. Negatively worded items had no impact on the properties of the scale. Temporal structural stability was hypothesized as an explanation of the observed shift in this construct's psychometric properties.     

梯状光纤延迟线编解码器的设计与实现

梯状光纤延迟线编解码器是各类延迟线编解码器中最有前途的一种。文章就其设计方法进行了详细的分析和讨论，并着重分析了其中光纤耦合器的最佳耦合因子的设计。将不同情况下的耦合因子对自相关峰值和旁瓣抑制比的影响作了比较。研究表明，要实现正确的解码，各点的最佳耦合因子应使旁瓣抑制比和自相关峰值达到最大。据此设计的编解码器具有良好的性能。     

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地下储气库的建造是一项大型、复杂的系统工程，其优化设计不仅需要满足经济上的要求，还要考虑其功能、技术、安全及环境等诸多因素的影响。地下储气库的优化设计属于多因素的综合评价问题，为此介绍了地下储气库优化设计的灰色关联分析法。首先根据地下储气库工程的实际情况构建地下储气库的评价指标（因素）体系和由各评价指标构成的预选方案，在众多预选方案的基础上构建理想方案，通过计算各预选方案与理想方案的关联程度来确定最优方案；构建了由年综合费用、垫底气量、最大地层压力、注采井数、压缩机站功率和使用寿命等指标构成的储气库综合评价指标体系，在关联度的计算中引入了因素的权重并介绍了权重计算的层次分析法。由于考虑了各项评价指标的权重，使得分析结果更符合工程实际。     

EFFECT OF GEAR WIDTH AND HELIX ANGLE ON FACTOR OF DYNAMIC LOAD OF DOUBLE CIRCULAR ARC HELICAL GEARING

Based on theory of mechanical dynamics, meshing characteristic as well as the dynamic model of double circular arc helical gearing, an analysis approach and a computer program have been developed for studying the state of dynamic load and factor of dynamic load of the gearing, the changing situation of dynamic load and dynamic load factor vs some affecting factors such as gear width, helix angle and accuracy grade etc are investigated. A series of conclusions are obtained: ①With the increasing in the values of gear width, the dynamic load factor appears slow decreasing tendency in most region of gear width. ② When the accuracy grades of the gearing are improved, the values of dynamic load factor decrease.③ The value of dynamic load factor appears a decreasing tendency with the increasing of value of helix angle at the same ratio of critical rotational speed.     

浅谈自动扶梯梯级链的安全系数和销轴比压

通过对自动扶梯梯级链的安全系数和销轴比压的原理分析，对照不同国家的标准和计算基准，提出对自动扶梯梯级链设计的合理要求。     

对无线侧接通率的性能分析与研究

首先对无线侧系统接通率原理进行了介绍,接着对各个阶段影响系统接通率的因素进行了较为详细的分析,并结合北电设备进行了案例阐述,提供了一般性的解决思路。