单齿泵削角的优化设计

给出了单齿泵削角的优化模型与计算实例，并对理论设计与实验进行了比较分析。     

微加速度计粘附问题的研究及应用

粘附是影响微机电系统(MEMS)可靠性的重要因素之一。针对MEMS的典型产品——微加速度计的粘附问题进行了研究,给出了2种典型的微加速度计的表征粘附特性的剥离数的表达式,并分析了将粘附条件应用于微加速度计的多学科设计优化之中,分析了其对系统结构设计产生的影响。     

磷酸盐玻璃中Er~(3+)离子的光跃迁和激光作用

给出了Li-Al磷酸盐玻璃中Er~(3+)离子发射特性(Ar、σ_ρ、β、τ_γ)的计算结果。报道了Cr~(3+)→Yb~(3+)→Er~(3+)的一种有效能量转移,并获得了室温下3J1.54μm波长的激光输出。     

点阵汉字无级变倍算法

本文给出了由一种汉字字库得到任意大小汉字点阵的算法.该算法能对任意二值点阵图像进行放大平滑.简单放大是按字节进行运算,速度快;最佳平滑操作不是对简单放大后的点阵按位操作,而是根据原点阵的特性,在需要平滑的地方进行操作,需操作的位数不会超过图像总点数的5％.用该方法输出的汉字质量和速度都令人满意.     

液闪测氡中闪烁杯的氡气泄漏

本文简要介绍了液闪测氡中氡气自闪烁杯泄漏的实验结果。实验中对三种玻璃闪烁杯盖的密封性能作了检查,结果表明,这三种闪烁杯均不能满足液闪法测氡中对氡的密封要求。采用一层1mm 厚的橡胶垫片和一层0.01mm 厚的铝化聚脂膜作衬垫,代替原来的聚乙烯或纸板衬垫,解决了其中两种闪烁杯的氡气泄漏问题。建议在使用商品闪烁杯测氡时,应首先检查其对氡的密封性,必要时需采取补救措施,以保证测量结果的可靠性。     

Nd3+ Doped Silicate Glass Photonic Crystal Fiber with Random Hole Distributions

The fabrication of one kind of large core area Nd3 doped silicate glass photonic crystal fiber, and demonstration of the fiber's waveguidence properties were reported. This fiber owns a random air hole distribution in the cladding. The measured minimum loss of this kind of fiber is 10 dB·m-1 at 660 nm. These fibers can sustain only a single mode at least over wavelength ranging from 660 nm to 980 nm.     

Long-term effect of perinatal and postnatal asphyxia on developing human auditory brainstem responses: peripheral hearing loss

Peripheral hearing was assessed by examining brainstem auditory evoked responses (BAER) in children who suffered perinatal or postnatal asphyxia, particularly in those with residual neurodevelopmental deficits, to investigate the long-term effect of asphyxia on the developing auditory sensitivity. The BAER data were collected at least 6 months after the episode of asphyxia. Of the children who suffered perinatal asphyxia, hearing loss was found more frequently in those who exhibited residual neurodevelopmental deficits (17.1%) than in those who did not (6.3%), but this difference did not reach statistical significance. This implied that the long-term effect of perinatal asphyxia on the peripheral auditory system and its effect on the central nervous system may be relatively discrete or not closely correlated. The occurrence of hearing loss did not appear to be closely related to the degree of perinatal asphyxia, although hearing loss occurred more frequently in the children after severe asphyxia compared to those after mild asphyxia. There was no evidence for permanent hearing loss in the children who survived severe, prolonged postnatal asphyxia and exhibited residual neurodevelopmental deficits. These findings suggest that a critical period of particular sensitivity to the effect of hypoxia may exist during the development of the human peripheral auditory system. This period may range from some time prenatally to some time shortly after birth, probably the third postnatal month. After that, hypoxia is unlikely to lead to permanent hearing loss.     

均三甲苯胺的合成及其应用

介绍了均三甲苯胺的合成工艺、反应机理、国内外产品的质量指标、提高质量与收率的途径,并对产品的应用作了讨论。