关于康普顿散射性质的讨论

康普顿效应是X射线通过物质时发生散射,除波长不变部分外,还有波长变长的部分出现.康普顿把这种现象解释为X射线的光子与电子碰撞的结果.通过对康普顿散射的仔细分析,可推出康普顿散射是弹性散射,光子也不可以任意分割.     

Student Opportunity to Learn Related to Student Achievement of Objectives in a Probability Unit

Abstract

The purpose of this investigation was to explore the relationship between pupil achievement of specified objectives and the opportunity to learn them. Opportunity to learn was measured by four counts of substantive teacher statements and teacher-pupil interchanges, these same counts given as percent of total interaction, a count of problems attempted per pupil, and a teacher rating of content emphasis. Twenty-three teachers taught a probability unit containing eighteen objectives to twenty-six classes. They gave a pretest, taught for three class periods, and gave a posttest. The design for the analysis was a two-way nested analysis of covariance. In general, the contention that a student’s achievement of an objective is related to the opportunity to learn the objective was supported. Other areas relating to achievement were teacher perception of emphasis, student work, and teacher information.     

Applications of Compton scattering

1 Introduction a Compton scattering is well known, and its applications are studied by physicists, chemists and specialists in many fields. Some applications are relatively mature and relevant instruments have been developed such as ComScan; whereas the o…     

对康普顿效应的两点讨论

本文针对康普顿效应的原理和现象展开了两点讨论:光子与物质作用形式的选择性和利用布拉格公式导出康普顿效应中波长的增量。     

X射线康普顿散射成像实验装置研发

该文围绕高性能X射线康普顿散射成像需求,开展了大视场、高分辨率Schmidt物镜的研发及成像实验研究.基于光学设计,研制了分离式的Schmidt物镜,解决了物镜在子午方向和弧矢方向存在分辨率差异的问题,提高了物镜的成像分辨率.开展了X射线康普顿散射成像实验研究,检验了物镜的灵敏度和分辨率.实验结果表明,Schmidt物...     

潮兜1号隧道Ⅳ级围岩相似材料配比试验

为配制可模拟目标围岩的相似材料,在铁晶砂材料的基础上,采用石膏和水泥两种胶结材料,设置骨胶比、(m_铁粉+m_重晶石粉)/m_骨料、m_铁粉/(m_铁粉+m_重晶石粉)及m_石膏/m_水泥4个因素,一个因素设5个水平,共25组配比的正交试验方案。通过敏感性和线性回归分析,研究力学参数对影响因素的显著性及力学参数与各因素之间的定量关系。结果表明：相似材料力学参数可满足大部分类型岩体模型试验对材料力学参数的要求;对各因素及重晶石粉在骨料中占比与力学参数之间进行敏感性分析,其影响效果规律性强,可确定围岩相似材料配比;线性回归方程可量化参数与影响因素之间的关系,通过对比试验结果和回归分析结果,二者吻合性较强。     

从主体间性把握译者与文本的关系

译者与文本之间的关系历来就是翻译中一个争论不休的话题。二者经常体现为主现与客观、意译与直译、归化与并化等的二元对立。也有学者试图把这种二元对立辩证统一起来,但是无论从实践上还是理论上到底如何统一并没有给予明确的指导。文章尝试利用主体间性来统一这种对立的观念。并提出两种途径来实现译者与文本之间的主体间性。即价值无涉与文化移情,并把这两种途径落实到译者的现实生活当中。因此就为译者如何努力扮演好译者的角色提供了方向。     

微气泡激光散射特性研究

根据Mie散射理论研究了在水介质中微空气泡的光散射特性,给出了相应的散射强度分布、散射光的偏振度与散射角的关系,以及前向散射光强与气泡半径的关系.发现在一定波长下,前向散射光强与气泡半径呈线性关系,为空气泡的测量提供了理论模型.     

通过带有调节器量子线的光场辅助隧穿

The paper studies photon-associated transmission through a quantum wire with a side-coupled stub tuner,to which an external microwave field applies,in terms of the approach developed by Cai.The inelastic scattering of an incoming electron and thd photon field lead to photon-electronic transmission though quantum wier.It is found that single photon absorbing (emitting) of the incoming electron in the stub can bring about antiresonant transmission in the quantum wire.The influence of the feedback mechanism from inelastic scattering process on elastic channel transmission is also examined.Total transmission coefficient as a function of photon energy exhibits non-periodic oscillation peaks.With the increasing of photon-electron coupling constant,the amplitude of these oscillation peaks enhances.     

染料芬顿氧化脱色参数计算的新方法研究

以活性紫为模型染料,讨论了芬顿氧化脱色过程中散射和染料中间体对反应速率常数和脱色率的影响,提出了一种新的参数计算方法．结果表明,脱色体系的残留色度是由游离染料、两种中间体及散射四部分组成．若采用传统的测定反应速率常数和脱色率的方法,散射及中间产物的存在将导致较大的系统误差．采用多元线性回归分析法,从总残留色度中区分出散射及中间产物所占比例后,所得脱色率和反应速率常数更为合理．     

我国工业产能利用率测算方法研究——基于单位资本存量工业增加值指标

依据单位资本存量工业增加值(=工业增加值/工业资本存量)和单位资本存量工业产能(=工业产能/工业资本存量)之间的关系,在单位资本存量工业产能是年度的线性函数的假设下,提出利用单位资本存量工业增加值来拟合单位资本存量工业产能的合理原理和方法,并据此构建工业产能利用率的测算方法。应用该方法测算我国1978-2005年的工业产能利用率,测算结果能反映我国的现实情况。     

豆渣固体发酵生产灵芝菌丝粉条件优化及三萜化合物含量的测定

利用豆渣代料固体发酵灵芝菌丝粉,结果表明菌丝生长势与菌丝培养温度、培养料/糖比密切相关,培养温度在28℃,料/糖比为100：2,菌丝生长势最强;以单位重量菌丝粉含三萜化合物量为目标函数,利用豆渣培养基培养灵芝菌丝体的最佳条件则为料/糖比为100：2;培养温度为24℃;培养时间为菌丝满瓶后12d.每g菌丝粉三萜化合物含量可达2.44mg.灵芝菌丝特有三萜化合物含量可间接反映菌丝粉中纯菌丝含量及灵芝多糖的含量.     

Neural network and principal component regression in non-destructive soluble solids content assessment: a comparison

Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR) (a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data. Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.     

《工业工程概论》双语课程教学内容重构实践与探讨

《工业工程概论》是一门为培养学生工业工程的基本理论与方法以及国际化视野的双语课程。针对该课程教学内容多而分散等问题,结合各教学单元知识点的结构与特点,从教学内容整合、教学内容细化、教学内容更新三个角度出发,开展教学内容重构方面的实践,并从教学资源建设、教学模式改革、考核方式变革等方面对教学内容重构的有效实施展开探讨。     

高速运动介质球的散射特性研究

研究了高速运动的介质目标对任意频率电磁渡的散射,系统地导出了坐标系相对沿着z轴运动时的坐标变换关系、波矢量变换关系以及电磁场的变换关系。首次给出了两个相对作高速匀速运动的球坐标系中的三角函数的变换关系以及矢量的球坐标分量的变换关系,为研究高速运动目标的电磁波散射奠定了理论基础。利用Mie理论。详细地研究了高速运动介质球的散射特性,得到了散射截面的解析表达式并对其进行了仿真和讨论。结果表明:介质球做高速运动时,前向散射大于后向散射,和其它的观察方位相比,入射波频率对散射的影响不大,多普勒效应起主要作用,目标表面上的二次辐射源以电偶极辐射为主。     

亚、超高斯信号后非线性混合盲分离的一种块自适应算法

本文研究了后非线性混合信号的盲分离 .后非线性混合信号是由线性混合的每一路信号分别经过一个非线性畸变产生的 .因此分离这种信号需要在适用于线性混合的线性分离结构前放置一个用于补偿非线性畸变的非线性校正部分 .本文用一种最大似然方法推导了一般后非线性分离结构的学习公式 .在前人一些工作的基础上 ,提出了一种用于亚、超高斯信号后非线性混合的盲分离算法 .该算法用多层感知器对分离结构的非线性校正部分进行建模 ,迭代过程中根据一稳定性条件在分别适用于亚、超高斯信号的概率模型间进行切换并以块自适应方式工作 .通过对模拟信号及实际信号 (图像和语音 )的实验证明了该算法的有效性 .     

Evaluation on Fabrication and Properties of Composite Polyurethane Coatings with Wollastonite Partially Substituting for Rutile Titanium Dioxide

This study aims to prepare a composite polyurethane coating through a facile synthesis process. Titanium dioxide, which is a component of the prepared hydroxyl acrylic resin polyurethane varnish, was partially substituted by wollastonite, and an optimal substitution ratio was obtained. Analyses based on scanning electron microscope, powder X-ray diffraction, and Raman scattering measurements demonstrated that the addition of wollastonite caused nearly no change in the basic structure of the coating. Coating with a substitution ratio of 25% showed high thermal stability, good cover effect, considerable moisture-proof and water resistance ability, great acidic and basic resistance, and improved performance and hardness in performance tests. Furthermore, the production cost was reduced significantly at this substitution ratio.     

铜的流动注射光散射法测定

利用自制的流通池,提出了流动注射分析与光散射光谱法联用的测定技术;探讨了铜的流动注射和光散射光谱测定工作条件,铜的线性范围为0～400μg/mL,检出限为3.266μg/mL,测定频率为48次/h;实验结果表明所建立的方法快速、所需的化学试剂少.     

与推求总散射截面有关问题的讨论

能量为E的粒子被某一势阱散射，如果推求总散射截面常常易忽视物理背景，本以题设的条件为依据，明确了总散射截面公式的上、下限，从而得出与献[1]不一致的结论。     

决明子对鸡蛋胆固醇含量的影响

选择体重、产蛋率相近的430日龄健康罗曼褐蛋鸡48只,随机分为2组,每组4个重复,每个重复6只鸡,对照组饲喂基础日粮,试验组在基础日粮中添加1%决明子粉,预试期1周,试验期6周。研究决明子对罗曼褐蛋鸡生产性能、鸡蛋胆固醇含量及血清生化指标的影响。结果表明,日粮中添加1%决明子鸡蛋中的蛋白质、脂肪含量分别比对照组提高10.54%(P0.05)和9.86%(P0.05);每克蛋黄胆固醇含量比对照组降低27.00%(P0.01),每枚鸡蛋胆固醇含量比对照组降低32.85%(P0.01);添加决明子对蛋鸡的生产性能没有显著影响(P0.05),但降低了蛋鸡血清中低密度脂蛋白胆固醇(LDL-C)(P0.01)、总胆固醇(TC)(P0.01)和甘油三酯(TG)(P0.05)的含量,增加了血清高密度脂蛋白胆固醇(HDL-C)(P0.01)的浓度量。说明决明子具有显著降低鸡蛋胆固醇含量,改善鸡蛋品质的作用。