关于“光学工程”学科课程建设的几点思考

简要地论述了目前国内光学工程教学现状,分析了在光学工程教学与科研领域中处于一流地位的多所美国大学的教学方式,如亚利桑那大学、罗切斯特大学以及加州大学等,仔细研究了它们关于光学工程学科的课程设置、教学大纲和教学课件。结合作者在教学中的实际体会,对国内的光学工程学科的大学教学提出了几点建议,即师生共享教学大纲,注重实验与工程,丰富网络资源。     

专业课程实验教学的改革与实践

从实验教学的实际出发,分析了专业课程实验的特点,即知识结构的综合性、实验分布的零散性、授课时段的特殊性以及实验系统的复杂性;围绕提高实验教学质量这一目的,针对专业课程实验教学的现状,提出了理顺实验体系、巧施实验教学方法、规范实验报告要求、量化实验考核标准、开放实验资源等一系列具体改革措施。实验教学改革的实践证明,该改革措施能有效地激发学生对实验课程的学习兴趣,增强学生进行实验研究的动手能力,引导学生的创新思维。     

Convective Froude number and Byram’s energy criterion of Australian experimental grassland fires

A subset of experimental fires, conducted in the Northern Territory, Australia, in July and August 1986, was analysed to examine the role of the convective Froude number and Byram’s energy criterion (P_w/P_f) in the behaviour of grassland fires. Forms of these dimensionless numbers were obtained from the literature as were functions relating independent variables in these formulations to measured quantities. It was found that Byram’s energy criterion is simply the inverse cube of the convective Froude number and thus, was not examined in detail. It was found that the convective Froude number is not reflected in the observed behaviour of fires, as previous authors have suggested, despite the range of experimental conditions (wind speed 1.5–7.5 ms⁻¹, rate of spread 0.05–2.82 ms⁻¹).     

水铳的传入及其在中国消防史上的意义

介绍了《奇器图说》中关于灭火的机械——水铳,以及水铳的制作、使用和性能,论述了水铳传人中国的意义,指出水铳（“洋水龙”）的传人是中国消防技术史上的一件大事,标志着中国和西方的消防技术逐步走上了融合发展之路。     

A generalization of Lehmann’s Theorem on the comparison of uniform location experiments

Summary We generalize a result of Lehmann on the comparison of location experiments with uniform distributions on intervals. We compare a location experiment consisting of uniform distributions on parallelepipeds with a location experiment consisting of uniform distributions on convex bodies. We show that the first experiment can only be more informative than the second one if the convex bodies in the second experiment are themselves parallelepipeds. Further we show that the length of the edges of these parallelepipeds must fulfill a condition similar to the condition on the length of the intervals in Lehmanns result.     

Approximate Solutions of Continuous Dispersion Problems

The problem of positioning p points so as to maximize the minimum distance between them has been studied in both location theory (as the continuous p-dispersion problem) and the design of computer experiments (as the maximin distance design problem). This problem can be formulated as a nonlinear program, either exactly or approximately. We consider formulations of both types and demonstrate that, as p increases, it becomes dramatically more expensive to compute solutions of the exact formulation than to compute solutions of the approximate formulation.     

Generating beta random rate variables from probabilistic estimates of fireline production times

An extension of probabilistic PERT/CPM is proposed as a framework for soliciting expert opinion to characterize random variables for stochastic treatment in simulation models. By eliciting minimum, modal, ninetieth percentile, and maximum estimates, the distribution of variables with probability density functions of beta form can be explicitly characterized without relying on the traditional, but empirically unverified, assumption of a standard deviation equal to one-sixth of the range. This practical and inexpensive technique is illustrated by application to a wildfire protection planning problem – estimating the time required to produce a given length of fireline by different firefighting resources under diverse conditions. The estimated production times are an essential input to a planning model of initial attack on wildland fires used by the California Department of Forestry and Fire Protection, and provide that agency with useful rules-of-thumb for use in firefighter training.     

深圳地铁车站通风与火灾的仿真模拟及现场测试

地铁环境控制通风系统的任务是在正常运行期间为地铁乘客提供舒适的环境,以及在紧急情况下能够迅速疏散乘客并尽可能减少损失．不同城市的气候条件、室外温湿度差异很大,因此选用何种环控方案,应根据客观条件、工程造价、运行效果等方面综合分析．为此,结合深圳地铁一号线的设计情况,建立了地铁车站的物理模型和数学模型,根据设计条件和实验情况确定物理模型的边界条件,分别对地铁车站正常工况和火灾工况进行了模拟分析与现场测试,并将模拟结果与实测结果进行了对比分析,验证了CFD模拟的可行性和正确性．     

钢骨混凝土抗火性能非线性分析

进行了12个钢骨混凝土柱火灾下反应的试验．利用有限单元法和有限差分法的混合解法，编制有限元计算程序，得到钢骨混凝土柱的温度分布和极限承载力的数值计算方法．通过程序计算与火灾试验结果的对比分析，验证了分析理论和计算程序的可靠性．通过各种受火时间、长细比和偏心距的钢骨混凝土柱抗火性能的计算，得出了相应的极限承载力计算公式．     

火灾时隧道火风压及其对通风影响的试验研究

借助大比例火灾模型试验，研究了火灾工况下隧道内压力场的发展变化状态及火风压产生的机理，分析了通风速度、火灾规模、隧道坡度和烟流蔓延长度等对火风压的影响规律，以及火灾对隧道通风系统的影响．试验结果表明：火风压随着上述影响因素的增大而单调增大，但增长速率减缓；同时，火灾引起的火风压会极大地影响隧道的正常通风．建议对于长大隧道，发生火灾时，应及时将烟流的蔓延长度控制在尽可能短的范围内，以便减弱火风压对通风系统的影响．