基于BaLuF5∶Yb3+,E3+纳米晶掺杂的聚合物光波导放大器

为提高聚合物光波导放大器的增益性能,利用高温法合成了BaLuF5∶Yb3+,Er3+纳米晶,并分别对纳米晶的形貌、晶体结构和近红外发射特性进行了表征.测试结果表明,纳米晶平均粒径为13 nm,并在1 530 nm处具有较强的发射,荧光半高宽为50 nm.将合成的纳米晶掺杂入SU-8聚合物作为光波导放大器的芯层材料,使用光刻显影等工艺,在表面长有二氧化硅的硅衬底上制备出了聚合物光波导放大器.当980 nm波长泵浦光功率为280 mW、信号光波长为1 530 nm且功率为0.1 mW时,在长度为1.1 cm的光波导放大器中,获得了3.95 dB的相对增益.     

凸六边形的相对长边与相对短边

就Doliwaka和Lassak提出的凸n－边形的相对边问题，讨论n＝6的情形，将凸六边形嵌入到平等四边形内（边可重叠），利用对应边的边长比的关系可证任意凸六边形均有相对长边，有平行对边的凸六边形必有相对短边。     

双周期平面弹性具相对位移混合边值问题的三种提法及解法

给出双周期基本胞腔内含若干个任意形状孔洞的具相对位移的平面弹性混合边值问题的三种提法，并采用复变函数方法，建立数学模型，推广方法构造出复应力函数解的形式。并以其中的问题为例，将其归结为正则型的具Ｗｅｉｅｒｓｔｒａｓｓξ核的奇异积分方程。     

用解析方法建立两个三角形的亲似对应(Ⅰ)

本文解决的是射影几何中建立两个三角形亲似对应的问题.本文对亲似对应问题进行了分析,根据亲似对应的特点,将问题简化,并在此基础上推导出建立两个三角形亲似对应的数学公式及计算方法.     

Method for Risky Multiobjective Group Decision-Making and Its Application

The multiobjective group decision-making problem under risk is common in reality. This paper focuses on the study about risky multiobjective group decision-making problem where the index value is not certain. We give indexes classifying method and index normalizing formula of this type problem. By building objective function that minimizes general weighted distance from every alternative to the relatively best and worst alternative, the optimal membership degree of every decision-maker to every alternative can be obtained, and by building another objective function that minimizes general weighted distance from the optimal membership degree of every decision-maker to every alternative to the group optimal alternative and the group inferior alternative, the optimal membership degree of every decision-maker to every alternative can be obtained, which are both based on probability theory and fuzzy theory. Aftermost a model is established which collects group preferences. This method provides a new idea and     

一种改进的相对轨道动力学模型

线性化的Clohessey-Whiltshire(C-W)方程描述相对运动虽然方便,但是精度不高,为了解决这一问题,提出了一种C-W方程的改进形式。首先基于C-W方程的推导,分析了在对中心引力取近似的过程中导致原方程不准确的数学原因和物理现象;然后通过对简化部分的数量级进行分析和比较,将原推导过程中忽略掉的部分重要内容重新予以考虑,并运用数学变换将新加入的内容合并转化,最终给出了一组非齐次线性常系数微分方程,在不增加计算复杂度的情况下提高了精度。仿真验证表明该方程在圆轨道下相对于C-W方程精度改善很多,小椭圆轨道下也消除了C-W方程的长期误差。     

The role of repair in radiobiology

Summary Apart from cancer and mutation induction, radiobiological effects on mammals are mostly attributable to cell death, defined as loss of proliferative capacity. Survival curves relate retention of that capacity to radiation dose, and often manifest a quasi-threshold (shoulder). The shoulder is attributable to an initial mechanism of repair (Q-repair) which is gradually depleted as dose increases. Another form of repair, which is not depleted (P-repair), increases the dose required to deliver an average of one lethal event per cell (dose D₀). Neither form of repair can unambiguously be linked with repair of defects in isolated DNA. An important initial lesion may well be disruption of the complex structural relationship between the DNA, nuclear membrane and associated proteins. One form of P-repair may be restoration of that structural relationship.     

西昌人工与自动酸雨观测记录差异规律研究

利用西昌国家基本气象站2021年人工和自动的酸雨观测数据,对TCYII 1型酸雨自动观测系统和人工系统的降水采样偏差及完整性、测量数据的准确性和一致性、设备硬件及软件通讯的故障率进行了对比分析。结果表明：正常情况下,2套系统数据的完整性、准确性、一致性较好。酸雨自动观测系统在采样方式及样品保存方面具备一定优势,能够保证观测数据更接近于自然雨水的数值,更贴近真实情况。自动观测系统面临单轨运行,它的手动操作设置、部分配件需厂家优化改进。上级主管部门对自动系统测量阈值的设定、采样中出现的漏采、空采、多采等特殊情况,仍需进一步明确处理办法。     

关于纺织机械噪声评价标准的探讨

机器噪声的污染问题,日益受到世界各国的重视和关注,现在国际上对机器噪声的测量,主要采用声功率级。但用这种声功率级的评价指标尚有某些不足之处,本文拟在声功率级基础上,提出“机器噪声相对声功率系数”的概念,作为评价、比较、改进机器噪声及综合质量的补充指标,以弥补声功率级的不足。