砖填充墙钢筋砼框架的抗震优化设计

本文在分析总结国内外关于填充墙框架抗侧力性能资料的基础上,提出采用“等效斜撑框架模型”对砖填充墙钢筋砼框架进行抗震设计,并用可行方向法对此类结构进行抗震优化设计,编制了相应的计算机程序IFOSD-88(Fortran77),对于一般多层填充墙框架结构,经2～3次迭代即可获得稳定的结果。文末给出一个工程设计实例,计算结果表明,与现行设计方法相比,工程造价可降低8％左右。     

一种防空C~3I系统的效能分析方法

本文讨论了一种评定C~3I系统效能的方法。这种方法是根据系统完成使命的能力和系统的内部结构两方面的分析来完成的。通过对IFFN系统的评定,对本方法进行了举例说明。     

MNT和DNT同分异构体的偶极矩实测和计算

用“溶液法”实测了o-、m-、p-MNT和2,3-、2,4-、2,5-、2,6-、3,4-以及3,5-DNT共9个化合物在CCl_4溶液中的偶极矩;用MINDO/3法计算了它们的气相偶极矩。二者符合良好,线性相关系数为0.996。     

Quantitative genetic models of sexual selection

Summary Quantitative genetic models of sexual selection have disporven some of the central tenets of both the handicap mechanism and the sexy son hypothesis. These results suggest that the good genes approach to sexual selection may generally lead to erroneous results.Runaway sexual selection seems possible under a wide variety of circumstances. Quantittive genetic models have revealed runaway processes for sexually selected attributes expressed in both sexes and for attributes of parental care. Furthermore, the runaway could occur simultaneously in a series of populations that straddle an environmental gradient. While the models support the feasibility of runaway processes, empirical studies are needed to evaluate whether runaways actually happen. Estimates of critical genetic parameters are particularly needed, as well as measures of natural and sexual selection acting on the same population.The models also show that sexual selection has tremendous potential to produce population differentiation, particularly in epigamic traits. Differentiation is promoted by indeterminancy of evolutionary outcome, transient differences among populations during the final slow approach to equilibrium, sampling drift among equilibrium populations, and the tendency of sexual selection to amplify geographic variation arising from spatial differences in natural selection. Recent work with two- and three-locus models of sexual selection has produced results that parallel the results of the polygenic models^36–38,58. Thus the feature of indeterminate equilibria (outcome dependent on initial conditions) is common to both types of model.     

雀替型阻尼器加固箍头榫木框架结构的抗震性能

为研究广府古建筑木结构的抗震性能及加固方法,采用菠萝格木材,设计并制作了两榀不同结构形式的典型广府木祠堂箍头榫框架,提出并制作了用于木结构榫卯节点加固的雀替型阻尼器,对雀替型阻尼器加固前后的木框架进行低周往复荷载试验,研究结构的抗震性能及阻尼器的加固效果。研究结果表明：阻尼器可以弥补初次加载产生的损伤,在转角不大时给残损的榫卯节点提供较高的初始刚度,并在榫卯节点自身开始闭合时与之协同受力,提高节点刚度、极限承载能力和耗能能力,使得加固试件的极限承载能力高于未加固试件;未加固试件经过加载,出现了榫卯脱离、榫卯局部压屈现象,加固试件的破坏形式主要为榫卯脱离、榫卯局部压屈和竖向顺纹劈裂裂缝;各节点的滞回曲线呈现明显的“捏缩”现象,榫卯节点强度退化系数均大于0.83,在循环荷载作用下表现出稳定的承载性能,随节点转角的增大,各节点的环线刚度、等效粘滞阻尼系数呈现逐渐减小并趋于稳定的趋势;边跨框架试件节点的等效粘滞阻尼系数逐渐稳定于0.1～0.2,而中跨框架试件节点的等效粘滞阻尼系数逐渐稳定于0.05～0.1,且经过阻尼器加固,边跨框架与中跨框架试件的总滞回耗能分别提高了67%和19%。     

利用早停可微架构搜索的三维点云模型分类

针对现有三维点云分类网络采用人工设计费时费力的问题,提出早停可微架构搜索(early-stopping differentiable architecture search,ES-DARTS)算法。利用从人工设计网络架构中提取到的先验知识,预定义一个包含高效候选操作的搜索空间,可快速搜索出适用于三维模型分类任务的高性能网络模型;通过追踪网络搜索阶段各候选操作的权重变化,找出跳跃连接操作在双重优化过程中发挥不公平竞争作用的临界点并在此处停止搜索,以保证各候选操作之间的稳定性,解决DARTS算法搜索过程中易出现性能崩溃的问题。提出的算法在ModelNet40数据集上达到了93.2%的识别准确率,比当前人工设计的主流网络具有更高的识别准确率。     

基于掺铕钨酸盐荧光强度比的非接触温度传感

为了突破传统测温技术应用的局限性,利用NaY （WO₄）₂：Eu³⁺玻璃陶瓷（glass ceramics,GC）实现了具有非接触、实时响应、自校准等优势的双模荧光强度比（luminescence intensity ratio,LIR）测温。采用高温熔融淬灭法制备出含NaY （WO₄）₂：Eu³⁺纳米晶的透明GC样品,并进行系列光谱测量和热敏性能分析。结果表明,样品中Eu³⁺的激发态能级⁵D₁和⁵D₀和基态能级⁷F₂和⁷F₀为两对独立的热耦合能级,可分别基于这两对热耦合能级实现性能优异的双模LIR温度传感。该双模LIR测温技术数据可靠、测温范围广、灵敏度高,再结合GC材料优势,是可用于光纤温度传感器的核心技术材料。     

3—己烯—1—醇及其酯类的合成和香气研究

介绍了叶醇(cis-3-己烯-1-醇)及其异构体的实用合成路线。由顺反混合(或全反式)3-己烯-1-醇制备了一系列羧酸酯,研究了这些化合物的结构与香气的关系,从中发现一些有实用价值的新香料。     

计算旋转螺旋面三维边界层的一种积分方法

本文将计算二维层流边界层的Thwaites方法和计算二维湍流边界层的Truckenbrodt方法推广,用以求解旋转系统的“准三维”边界层方程,得到了计算旋转螺旋面上三维边界层的一种可迭代求解的积分方法.应用此方法进行了两例计算.计算结果与理论精确解或实验测量的对比表明,本文方法是有效的.     

Effects of a new cholecystokinin antagonist (GE 410) on the smooth muscle of the guinea pig ileum

Summary Suc-Tyr-(SE)-Met-Gly-Trp-Met-Asp--phenethylamide (GE 410) competitively antagonized the contractions of smooth muscle strips from guinea pig ileum (pA₂=7.6, n=0.95) induced by cholecystokinin-octapeptide (CCK8). GE 410 inhibited the electrically-induced cholinergically mediated contractile responses and the [³H]ACh release in the ileum, as well as the CCK-stimulated electrical contractile responses and the [³H]ACh release in the cholinergic nerve terminals. The results suggest the existence of CCK-receptors not only in the smooth muscles but also on the neurons.