海南岛旅游气候资源及其开发利用

海南岛是我国最具热带气候特色的地区，它的旅游资源十分丰富。按生物气候指标评价，全岛各地每年11月至翌年3月皆是适宜旅游季节，其中12月和1月是最佳旅游季节，4－10月虽然局部地区短暂时间有闷热和皮感热风，但级别较低，又有海陆风和山谷风调节，仍可划分为旅游季节。根据气候特点合理规划开发不同地区的景点。注意防避不利出行旅游的灾害性天气现象。     

回转式薄壁钢管矫直机传动功率计算

本文介绍一种以可变曲率弓形管旋转运动校直薄壁钢管的新型矫直机,分析了钢管在矫直过程中的弹塑性变形特点,并推导出矫直机传动动率的计算方法。     

北京地区局地强风暴发生的环境条件

采用１９８０～１９８８年北京地区局地强风暴和北京探空资料，研究了本地区局地强风暴发生的环境条件，有利的环境条件是：对流层低层为低压；层结不稳定和中下层位势不稳定；中低层水汽含量高和对流层深厚气层中相对湿度大．局地强风暴生成与中层干燥、高空强风和垂直风速切变无明显关系．     

行星际MHD激波的速度

本文导出了ＭＨＤ激波相对子上游介质传播速度的一般公式，指出ＭＨＤ激波的相对速度由激波上下游密度比、上游激波角、上游等离子体β值和温度决定．在低β高温等离子体中激波相对速度较大，密度比和激波角越大相对速度也越大．在不同流速的太阳风中激波相对速度均随日心距下降，但都比气体爆炸激波预言的慢．     

浅水风波波高,波周期分布

通过浅水风波试验，探讨了浅水波高、波周期的分布形式，重点分析了水深因素对波高、波周期分布的影响，给出了浅水波高、波周期分布的表达式，并确定了浅水特征波高间的关系。     

浅析EJB是去是留

目前针对到底该不该使用EJB的争议不断，本文就程序员是否应该采用EJB技术进行分析。对何时使用EJB，何时根本不用EJB，何时用Spring取代EJB进行阐述。     

仪表风干燥器的PLC控制系统

本文介绍了可编程控制器（PLC）在仪表风干燥器控制系统中的应用，并给出了PLC控制的软、硬件系统设计，实践证明该控制系统先进可行并具有实用价值。     

The outbreak pattern of the SARS cases in Asia

The severe acute respiratory syndrome (SARS) caused tremendous damage to many Asia countries, especially China. The transmission process and outbreak pattern of SARS is still not well understood. This study aims to find a simple model to describe the outbreak pattern of SARS cases by using SARS case data commonly released by governments. The outbreak pattern of cumulative SARS cases is expected to be a logistic type because the infection will be slowed down due to the increasing control effort by people and/or due to depletion of susceptible individuals. The increase rate of SARS cases is expected to decrease with the cumulative SARS cases, as described by the traditional logistical model, which is widely used in population dynamic studies. The instantaneous rate of increases were significantly and negatively correlated with the cumulative SARS cases in mainland of China (including Beijing, Hebei, Tianjin, Shanxi,the Autonomous Region of Inner Mongolia) and Singapore. The basic reproduction number R0 in Asia ranged from 2.0 to 5.6 (except for Taiwan, China). The R0 of Hebei and Tianjin were much higher than that of Singapore, Hongkong, Beijing, Shanxi, Inner Mongolia, indicating SARS virus might have originated differently or new mutations occurred during transmission. We demonstrated that the outbreaks of SARS in many regions of Asia were wall described by the logistic model, and the control measures implemented by governments are effective. The maximum instantaneous rate of increase, basic reproductive number, and maximum cumulative SARS cases were also calculated by using the logistic model.     

气固两相流风洞内颗粒运动特性研究

对气固两相流风洞试验段的两相三维流场进行了数值模拟。对于两相流采用欧拉双流体模型,计算时选取标准k-ε两方程模型。模拟结果表明：试件迎风面和背风面颗粒浓度较大,但背风面粒子分布梯度随流速变化更明显;背风面区域由于重力作用,粒径越大的颗粒沉积越显著;试件迎风面颗粒沉积总量受粒径和流速的影响较大,但背风面沉积量受到的影响不明显。研究结果有助于分析两相流风洞中的流动特征,并能根据颗粒分布情况合理采取回收措施,为进行砂尘环境试验提供参考。