巧用PPT多层模板制作华丽的字幕效果

每年我都帮老师制作课件,参加教育部组织的课件大赛并获奖,有很多心得。我们先来看题图,一首歌颂教师的诗句逐一从左下方向右上方飞出。用动画实现的吧?对!但是PPT自带的动画(如飞入、切入、渐变、上升等效果)在起点时就能看到所有字幕,这个例子中的诗句为什么能先藏起来呢?这就是"遮罩板"的妙用。在PPT中使用多层模板,利用层次关系就可以精确定位字幕出现和消失的位置,获得很不错的视觉效果,与Flash媲美,方法很简单!     

Color encoding for polychromatic single-channel optical pattern recognition

The common multichannel system for recognizing colored images is replaced by a color-encoded single-channel system. Amethod inspired by the Munsell color system is used for encoding the different colors as phase and amplitude functions. It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results. An implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested. Computer simulations that demonstrate the capabilities of the suggested method are given as well as a comparison with previously published multichannel performance.     

Microbial growth and biochemical changes on naturally contaminated chilled-beef subcutaneous adipose tissue stored aerobically

Naturally contaminated beef-brisket fat showed a psychrotroph count of 4 × 10(9) CFU/cm(2) after 14 days of aerobic refrigerated storage (5°C ± 1°C). Pseudomonas was the predominating genus. Other micro-organisms, such as Enterobacteriaceae and Brochothrix thermosphacta, grew up to 2·5 × 10(8) cfu/cm(2) and 1·6 × 10(8) cfu/cm(2), respectively. Concentrations of different substrates that could support microbial growth were measured. Glucose concentration dropped to approximately one-third of the initial level during the first week of storage. Lactic acid also declined. Free fatty acids increased significantly (P < 0·05) during refrigeration. However, other lipid-deterioration indices, such as the thiobarbituric acid number and the peroxide value, remained unchanged. Beef subcutaneous fat had a high initial microbial load and a capacity to support extensive bacterial growth. It may therefore constitute an important source of contamination for meat and manufactured meat products.     

Fractional-Fourier-transform calculation through the fast-Fourier-transform algorithm

A method for the calculation of the fractional Fourier transform (FRT) by means of the fast Fourier transform (FFT) algorithm is presented. The process involves mainly two FFT's in cascade; thus the process has the same complexity as this algorithm. The method is valid for fractional orders varying from -1 to 1. Scaling factors for the FRT and Fresnel diffraction when calculated through the FFT are discussed.     

基于QoS的Web服务选择算法综述*

服务选择算法是影响组合服务的QoS和服务组合性能高低的关键因素。针对近几年来基于QoS的Web服务选择算法的发展状况进行了综述,介绍和总结了当前基于QoS的Web服务选择问题模型,对服务选择策略进行了分类,并对当前的一些典型的基于QoS的Web服务选择算法进行了系统的分析和评论。最后指出了现有算法中的不足之处,展望了该领域的进一步研究方向。     

异步电机电磁噪声的槽配合方案优化

异步电机的电磁噪声问题一直是国内外各大电机制造公司面临的难题,随着高功率密度异步电机的出现,其电磁噪声的解决将会更加困难。本文通过一台高功率密度电机就电磁噪声问题对所选槽配合进行优化对比,制造出低噪声高功率密度电机,希望能对同行有点帮助。     

Physical and thermal strain of firefighters according to the firefighting tactics used to suppress wildfires

The aim of this study was to analyse the physiological strain of firefighters, using heart rate (HR) and core temperature, during real wildfire suppression according to the type of attack performed (direct, indirect or mixed). Three intensity zones were established according to the HR corresponding to the ventilatory threshold (VT) and respiratory compensation threshold (RCT): zone 1, RCT. The exercise workload (training impulse (TRIMP)), the physiological strain index (PSI) and the cumulative heat strain index(CHSI) were calculated using the time spent in each zone, and the HR and core temperature, respectively. Significantly higher mean HR, time spent in Z2 and Z3 and TRIMP h(-1) were found in direct and mixed versus indirect attacks. The highest PSI and CHSI were observed in the direct attack. In conclusion, exercise strain and combined thermal strain, but not core temperature during wildfire suppression, are related to the type of attack performed. STATEMENT OF RELEVANCE: Our findings demonstrated that wildfire firefighting is associated with high physiological demands, which vary significantly depending on the tactics chosen for performing the task. These results should be kept in mind when planning programmes to improve wildland firefighters' physical fitness, which will allow improvement in their performance.     

基于免疫网络的异态电磁信号监测模型

针对人工免疫系统运用于信号密度适中的日常异态信号监测时,系统对检测器数量要求过高的问题,本文对现有的模型进行了改进,提出了基于免疫网络的异态电磁信号监测模型。模型引入数据正向压缩和检测器相互抑制的机制,使得系统对检测器数量的要求明显降低。本文采用实际无线电监测数据对模型进行了检验,并与基于阴性选择的模型进行对比,验证了该模型在信号密度适中的日常监测中可大幅减少对检测器数量的要求,提高了监测效率。     

快速的演化神经网络模型的研究与应用*

针对演化学习的速度较慢、模型的稳定性较差等,利用梯度下降计算改进演化算法,极大地提高了模型的学习速度,对那些需要及时优化工艺参数的生产过程,该种模型有很好的应用前景。