Al^3+置换对Ba4Pr28/3Ti18-yAl4y/3O54陶瓷晶体结构与微波介电性能的影响

通过标准固相法制备了Ba4Pr28/3Ti18-yAl4y/3O54(0≤y≤2)微波介质陶瓷,结合X射线衍射(XRD)、背散射(BSE)以及X射线能谱(EDS)研究了Al^3+置换对其晶体结构、微观形貌以及微波介电性能的影响。XRD分析表明,样品的主晶相均为正交钨青铜结构,晶胞参数及晶胞体积随Al^3+置换量的增大先减小后增大。BSE及EDS分析表明,当0≤y≤1.5时为单相结构,而当y=2.0时出现了少量第二相;晶粒尺寸和柱状晶粒的长度随Al3+置换量的增大略有减小。Al^3+置换能有效提升Ba4Pr28/3Ti18-yAl4y/3O54陶瓷的品质因数(Q×f),降低谐振频率温度系数(TCF),但介电常数(εr)减小。当y=1.5时,Ba4Pr28/3Ti18-yAl4y/3O54陶瓷具有较好的微波介电性能,εr=76.6,Q×f=10800 GHz,TCF=+55 ppm/℃。

Twenty-one cases of hemorrhoids treated with bloodletting at Yínjiāo(龈交 GV 28)

Objective To observe the clinical effect of bloodletting at Yínjiāo（龈交 GV 28） for hemorrhoid.Methods Positive points in the upper-labial frenum were found out in 21 cases,then after routine sterilization was applied in the local area,three-edged needle was used to puncture the positive points with 1-3 drops of blood out.This treatment was given every seven days,and 1-3 times in all.The clinical effect was observed half a year later.Results Fourteen were cured,6 improved,1 ineffective,and the total effective rate was 95.3%（20/21）.Conclusion Bloodletting at Yínjiāo（龈交 GV 28） can be used to treat hemorrhoids with remarkable effect.

等离子喷涂ZrO_28Y_2O_3涂层厚度测量方法研究

提出了利用激光非接触点扫描测量涂层厚度的方法。研究了激光照射新型材料 Zr O2 8Y2 O3涂层粗糙表面上光点的高斯分布 ,并利用扫描电子显微镜得到了涂层粗糙表面的显微精细结构。采用激光 -面阵 CCD传感器 -计算机数字图像处理技术测量涂层厚度。实验结果表明 :所提出的测量方法是可行的 ,测量涂层厚度的重复性误差在± 5 μm范围内。