研究环形光阑的衍射场

由波前相因子判断法并考虑到孔径的影响,来揭示环形光阑的夫琅禾费衍射场所含成分。分别给出衍射场的积分表达式,进而导出像面衍射场振幅分布公式,并显示出像面衍射场光强分布图。为光阑的夫琅禾费衍射场的分析提供了一种新的分析方法。     

分析五方孔的衍射场

采用波前相因子判断法研究五方孔的衍射场,得出五方孔衍射场所含基元成份。根据惠更斯-菲涅耳原理,导出像面上的振幅分布公式及像面上的光强分布公式等。并利用数值模拟的方法得出五方孔的衍射图样。结果表明,在验证衍射理论的同时,还拓展了衍射的概念,为深入理解光的衍射提供理论基础。     

倾斜因子对单缝夫琅和费衍射强度的影响

一般教材在讨论夫琅和费单缝衍射时都没有考虑倾斜因子对光强分布的影响，本给出了考虑倾斜因子时的光强分布，并指出当缝的宽度较宽时，倾斜因子的影响可以忽略．     

杨氏双缝实验中的干涉与衍射现象

杨氏双缝干涉实验中观测的干涉条纹实际上是位于单缝衍射中央明条纹区域内。实际工作中可以将这两个实验综合起来,学生在这个过程中可以清楚单缝衍射与双缝干涉之间的不可分离的关系,有助于学生将理论知识应用于实际,活学活用,促进学生理论水平的提高。     

光单缝和多缝衍射的几率波分析

光具有波粒二象性,从量子力学的几率波出发,利用描述微观粒子的波函数,导出了光的单缝和多缝夫琅禾费衍射光强分布规律,所得结果与波动光学中用惠更斯-菲涅耳原理给出的结论一致,此方法有利于学生对量子力学中波函数的概念和统计意义的理解,进一步认识光的本性。     

杨氏双缝干涉光强公式的两种推证

杨氏双缝干涉实验是物理波动光学中最基本的实验,由对杨氏双缝实验的分析、推证所得到的两相干光波的干涉光强公式,是整个光学干涉问题的基础。不论是分波阵面法的菲湟耳双面镜干涉,劳埃镜干涉,还是分振幅法的种种薄膜干涉：坡耳实验、劈尖、牛顿环等,所依据的基本原...     

不等长双缝夫琅禾费衍射光强分布

根据夫琅禾费衍射与傅立叶变换的关系,数值计算了由宽度相同而长度不同双缝组成衍射平面的夫琅禾费衍射光强分布,结果表明双缝长度之比是影响干涉条纹的可见度的主要因素。     

利用黑白照相制作光的干涉衍射实验元件——双缝和单缝的制作

双缝和单缝在干涉和衍射实验中是非常重要的,这些元件的好坏,直接影响干涉和衍射的实验效果。参考用书上是这样介绍制作双逢的:如图1所示,E是一块覆铜绝缘板,按虚线挖一个长方孔,在覆铜面上用锡焊牢一根直径0.1～0.6mm的细铜丝A、B,要绷直,再焊上两个刮     

双缝干涉实验的考点

如图1所示,灯丝发出的光,经过滤片后变成单色光,再经过单缝S时发生衍射,这时单缝S相当于单色光源．衍射光波同时到达双缝S1和S2,再次发生衍射,双缝S1、S2相当于两个单色相干光源．     

Geometrical Reasoning in Wave Situations: The case of light diffraction and coherent illumination optical imaging

This particular study is part of a research programme on the difficulties encountered by students when learning about wave phenomena in a three‐dimensional medium in the absence or presence of obstacles. It focuses on how students reason in situations in which wave optics need to be used: diffraction of light by an aperture, imaging in the presence of diffraction, and coherent illumination imaging. Paper and pencil questionnaires were designed and two hundred French students (aged 19–23) were questioned after lessons on wave optics. Tendencies towards geometrical reasoning are shown to recur. Students reason at a macroscopic level, following the rays of the incident light, instead of reasoning at an elementary waves level in using the phase concept and the Huygens–Fresnel principle. Consequently, for them, the image of a point source located at infinity is behind the image focus plane of the lens when diffraction has to be considered. Moreover, it is not possible to have the image of the source and of an illuminated diaphragm behind one lens: these images cannot exist simultaneously or are merged. Some remarks are made on the way waves are taught in France and some pedagogical implications are discussed.     

晶体的X射线衍射物相分析方法研究

该文提出了一种基于多元判断分析算法的晶体物相分析模型,开展了晶体的X射线衍射物相分析研究。模型利用主成分分析算法提取晶体衍射谱的特征信息,结合光谱角匹配和相关系数算法对衍射谱的轮廓和相关度进行分析。实验测量了单晶和多晶物质的X射线衍射谱,构建了样本数据库,利用模型对实测衍射谱进行了物相分析。样本的训练结果表明,与单一的物相分析算法相比,多元判断分析算法对实测的衍射谱具有更高的识别精度,相似度最接近的两种晶体的SD值可达0.8,实现了对晶体物相类别的精确识别。     

有关相律中独立浓度限制条件数的若干问题

介绍了独立浓度限制条件数的概念,讨论独立浓度限制条件涉及的相平衡系统中各组分的浓度等关系问题.分析不同情况下独立浓度限制条件的表达形式,指出确定其数值时应注意的由相同物质组成的系统在不同情况下独立浓度限制条件数可能不同等问题.     

Cantor分形光栅衍射场的自相似性分析

用平移相因子描述Cantor型分形光栅衍射场，分析了这一类型衍射场的自相似性。     

Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

INTRODUCTION Platelet activating factor (PAF), a kind of pho-spholipids compound, synthesized and secretedmainly by neutrophilic granulocyte, platelet, is ahighly potent chemical mediator in inflammationand allergic reactions and induces microvascularleakage in several tissues (Chung, 1997). PAFs arefew in vivo, have short half life (only about 30seconds) and rapidly convert to lyso-PAF that hasno bio-activity and is both the metabolite and pre-cursor of PAF (Rao, 1998). Lyso-P…     

Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results: rHPLC is more convenient, sensitive, specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.     

项目决策阶段影响工程造价的主要因素

项目决策正确,意味着对项目建设做出科学的决断,选出最佳投资行动方案,达到资源的合理配置。这样才能合理地估计和计算工程造价,并且在实施最优投资方案过程中,有效地控制工程造价。项目决策失误,主要体现在不该建设的项目进行投资建设,或者项目建设地点的选择错误,或者投资方案的确定不合理等。诸如此类的决策失误,会直接带来不必要的资金投入和人力、物力及财力的浪费,甚至造成不可弥补的损失。在这种情况下,合理地进行工程造价的计价与控制已经毫无意义了。因此,要达到工程造价的合理性,事先就要保证项目决策的正确性,避免决策失误。     

稳恒磁场对人白血病细胞K562生长抑制作用研究初报

人白血病细胞K5 6 2经3,6 ,9,12 ,2 4 ,36 ,4 8,6 0 ,72h不同时间磁场处理后,利用MTT法检测其生长活性,台盼蓝拒染法进行活细胞计数.结果表明,K5 6 2细胞经9mT稳恒磁场处理0～72h后,从12h起磁场对细胞生长有显著的抑制效应(p <0 .0 5 ) .K5 6 2细胞生长曲线结果与MTT实验具有良好的一致性.