Presage

上一期介绍了精工渐进镜片系列中的旗舰产品——高端定制渐进PX系列,并留下一个疑问：＂一副怎样的镜架,才能够与PX相配满分、演绎出无限种可能性呢？＂答案就在本期内容中。——Eyewear之路的匠心独运是Glasses还是Eyewear？通过搜索引擎检索,眼镜在互联网上是这样被定义的：＂眼镜,是以矫正视力或保护眼睛为目的的简单光学器件,由镜片、镜架组成。它既是保护眼睛的工具,又是一种美容装饰品。＂曾经,＂Glasses＂是英语中代表＂眼镜＂的第一词汇。

用于放疗剂量验证的新型片状Presage胶体剂量计特性研究

目的明确用于放疗剂量验证的新型片状Presage胶体剂量计的吸收光谱、剂量线性、量程、稳定性等关键剂量响应特性。方法使用放疗加速器对同批次片状Presage剂量计进行系列照射实验,使用分光光度计测量照射前后剂量计在400-700 nm可见光范围内的吸收光谱,使用胶片平板扫描仪测量照射前后R-G-B 3通道的吸光度变化。结果片状Presage在628 nm处有明显吸收峰且峰值吸光度随受照剂量呈显著线性变化趋势(R^2=0.9999),而在490 nm附近存在平缓吸收谷且谷区吸光度随受照剂量变化不大。胶体平板扫描仪R通道的吸光度测量灵敏度远大于G与B通道,在<10 Gy范围内,R通道吸光度随受照剂量呈高度线性变化(R^2=0.9999),而在大量程范围则呈显著二次变化趋势(R^2=0.9999)。该剂量计的量程范围>94.6 Gy,在照射后1 h内吸光度变化可忽略,之后则呈现缓慢上升趋势,上升速度与受照剂量呈正相关,同时,未发现剂量梯度区出现梯度模糊现象。结论新型片状Presage胶体剂量计在一定范围内具有良好剂量线性,量程大、梯度保持性好、无分割效应,提示在大分割多靶点放疗的积分剂量验证中具有潜在应用优势。

Oral Presentation——Opportunity or Suffering

This paper is about a reflective practice happened in the author' s College English teaching.Since 2005,a 5-minute oral-presentation was required for all the students in turn,in order to raise opportunities for them to practice oral English.But the students' responses were always disappointing since they only took the task as a burden.After the teacher lift the limits on presentation time,form,sequence,partner,etc.,better learning outcomes were achieved.When reflecting on this change,Biggs'3P Models of "constructive alignment" is taken into account.Any teaching and learning activity (TLA) cannot put the students' and the teacher' s presage aside since the students' ability,interests,motivation as well as the teacher' s objective,assessment approach and so on are co-determinants of a successful TLA.Further suggestions are given based on this reflection at the end of the paper.