Cognitive processes in complex tasks: introduction and discussion

This paper points out that the fusional limits of binocular stereoscopic viewing are an important factor, not only determining the reproduction range of stereoscopic images, but also the conformity between the stereoscopic display and stereoscopic vision. Experimental results showed that fusional limits increase in proportion to the field of view angle, and that they are affected not only by the size of the viewing target, but also by the effects that the environment has on the target. These findings explain the differences between binocular vision in real space and binocular vision in a stereoscopic display. Finally, the conditions under which observers arc able to view images of stereoscopic displays without excessive visual strain are discussed.     

Change of search time and non-search time in X-ray baggage screening due to training

As found in studies of aircraft structural inspection, the time used for judging if a part of an aircraft shows tiny cracks is composed of search time, used for actively scanning, and non-search time, used for matching and decision while fixating a region of interest (Drury et al. 1997 Drury, C. G., Spencer, F. W. and Schurman, D. . Measuring human detection performance in aircraft visual inspection. Proceedings of the 41st annual Human Factors and Ergonomics Society meeting. Albuquerque, NM. pp.304–308. NM. Santa Monica, CA: HFES.  [Google Scholar]). These findings can be applied to detection of threats by X-ray screening of passenger bags at airports. To investigate whether search time and non-search time change when an experienced screener is given additional training in recognising threat objects in passenger bags, data from a European airport were analysed. A comparison of detection performance and reaction time between two large groups of screeners, one trained for 6 months, shows a large impact of training on overall performance and on both search and non-search components of the task. There was also a small but consistent decline in performance measures with screener age. This study shows a way to localise the effect of training on threat detection performance for aviation security screening. Analysis of the time needed for screening each passenger bag showed that training had a significant effect, particularly on the non-search part of the searching process (i.e. identification, recognition, decision, response execution, etc.).     

Mg-Al-Eu三元层状化合物的结构和荧光记忆效应

研究了Mg-Al-Eu三元层状氢氧化物（TLH）分别在无CO2的去离子纯水（pH=7）、苯丙氨酸水溶液（pH=5）以及苯丙氨酸钠水溶液（pH =8,9,11）体系中的结构和荧光记忆效应.X射线衍射（XRD）测试结果发现：400℃煅烧后的TLH在这不同的体系中都能很好地重构成原始的TLH结构.荧光光谱（FL）研究结果表明：400℃煅烧后的TLH在一定时间内也能较好地恢复其原始的荧光性质;但超过一定时间后,其荧光性质将发生变化,这种荧光的变化可能与其重构产物在不同溶液体系中的浸泡时间和体系的pH有关;此外,还发现重构产物的结晶度和粒子尺寸与溶液体系的pH以及浸泡时间有关.     

Vacuum preloading combined electroosmotic strengthening of ultra-soft soil

To assess the effectiveness of vacuum preloading combined electroosmotic strengthening of ultra-soft soil and study the mechanism of the process, a comprehensive experimental investigation was performed. A laboratory test cell was designed and applied to evaluate the vacuum preloading combined electroosmosis. Several factors were taken into consideration, including the directions of the electroosmotic current and water induced by vacuum preloading and the replenishment of groundwater from the surrounding area. The results indicate that electroosmosis together with vacuum preloading improve the soil strength greatly, with an increase of approximately 60%, and reduce the water content of the soil on the basis of consolidation of vacuum preloading, howeve~ further settlement is not obvious with only 1.7 mm. The reinforcement effect of vacuum preloading combined electroosmosis is better than that of electroosmosis after vacuum preloading. Elemental analysis using X-ray fluorescence proves that the soil strengthening during electroosmotic period in this work is mainly caused by electroosmosis-induced electrochemical reactions, the concentrations of Al2O3 in the VPCEO region increase by 2.2%, 1.5%, and 0.9% at the anode, the midpoint between the electrodes, and the cathode, respectively.     

基于ANSYS/Fluent的FSAE赛车限流阀的仿真优化研究

为设计赛车进气效果最佳的限流阀,本文采用Solidworks软件,建立赛车发动机限流阀三维实体模型,利用ANSYS中Fluent模块对限流阀模型内流场进行分析,得到限流阀内部的压力场和速度场分析云图,根据分析结果选取锥形口的限流阀结构,并对限流阀的设计参数进行优化分析.分析结果表明,为保证发动机气流流量的供应和进气气流的稳定,选择出口锥角为14°,进口直径为50 mm,渐缩长度为50 mm,渐扩长度为90 mm的限流阀,发动机气流流量的供应和进气气流较为稳定,进气效果最理想.该研究改善了FSAE赛车限流阀对发动机动力性能的影响.     

词汇搭配教学对学生英语水平的影响

词汇搭配是语言学习的难点,然而在传统英语教学中过分强调语法而忽视了词汇搭配。选取郑州大学76名一年级学生为研究对象,考察了词汇搭配教学对学生英语水平的影响,通过数据分析得出结论:词汇搭配教学有助于学生对语言知识的记忆,能够显著提高学生英语水平。     

大学生公德教育及其正能量效应实现途径

公德教育是大学生基础文明修养的重要内容,是高校德育乃至高等教育的重要组成部分。近年来,我国的公德教育取得较大成就,然而在现实中仍频频出现大学生社会公德缺失现象,如何使公德教育的＂正能量＂效应得以实现,是当前大学思想政治教育亟待研究的重要课题。     

探析成人二语习得过程中语言输出的途径

在我国成人教育迅速发展的步伐中,对成人二语习得的研究日益增加。本文提出了当今成人英语教育和学习中只重视语言输入而忽视语言输出的不足,分析总结语言输出的重要性以及对成人英语学习影响,从四个方面探讨了成人英语学习中有效的语言输出途径,以求有效地增加成人英语学习中的语言输出,切实提高成人二语习得的效果。     

承德市污水处理厂污水处理效果评价

为了了解承德市9个污水处理厂的污水处理效果、主要超标污染物及不同处理工艺的处理效果,对2010年承德市9个污水处理厂的监测数据进行了统计评价。结果表明,不同污染物去除率不同,去除率最高的是阴离子洗涤剂、氨氮,去除率最低的是总磷、总氮和石油类;主要超标污染物是悬浮物、生化需氧量。不同处理工艺污染物处理效果基本相同。     

Research on the improved frequency-domain equalization algorithm for OFDM underwater acoustic communication

The traditional OFDM frequency-domain equalization algorithm depends on the long circular prefix to overcome the bad influences caused by multi-path effects in the underwater acoustic channel. But the redundant long prefix is actually a serious waste of energy and bandwidth in underwater systems, which restrains the OFDM signal's advantages of high channel utilization greatly. Aiming at the defects of the traditional equalization algorithm, this paper brings forward a new frequency-domain equalization algorithm based on the analysis of the influences caused by multi-path effects and the equalization theory and structure. The results of simulation show that the new algorithm can compensate the multi-path effects efficiently with few circular prefixes and make sure the high-speed and reliability of the underwater acoustic communication system. Finally, based on the amount of computing, a simple algorithm is given.