1) Two-photon absorption cross-section
双光子吸收横截面积
2) Double LED and double light ways
双光源双光路
3) twin spot
双光点
1.
Microstructure and mechanical properties of twin spot laser welding of 5052 aluminum;
5052铝合金双光点激光焊接组织与性能
2.
Single spot laser and twin spot laser welding of aluminum alloy,with or without wire feeding,were carried out.
对铝合金薄板激光单光点和双光点焊接(包括不填丝和填丝)的焊缝成形、对接间隙和准直度容许裕度以及气孔状况进行了比较,并分析了双光点能量分布的激光对铝合金焊接的影响。
4) double light path
双光路
1.
Measurement of birefringence of a single axis crystal varying with temperature based on double light paths;
单轴晶体双折射率随温度变化的双光路测量
2.
We in detail presented the high accurate measurement of double light path.
着重叙述了高精度双光路测量法。
5) dual laser beam
双光束
1.
The experiments of single and dual laser beam brazing were carried out,in which the base metal is galvanized steel sheets and CuSi3 is used as filler metal.
以镀锌钢板为母材,以CuSi3焊丝为钎料,进行了单、双光束激光钎焊实验。
2.
The experiments of dual laser beam brazing of galvanized steel sheets with automatic wire feeding were carried out,in which CuSi3 was used as filler metal.
以CO2激光为热源,镀锌钢板为母材,CuSi3焊丝为钎料,进行了双光束激光自动填丝钎焊工艺试验。
6) two-photon
双光子
1.
Synthesis of a novel organic ligand with two-photon activity;
一种具有双光子活性的新型有机配体的合成
2.
Influence of refractive index mismatch on data bit in two-photon three-dimensional data storage;
折射率失配对双光子三维信息存储中信息点的影响
3.
Evolution of atom entropy in a moving cascade three-level atom in a two-photon process;
运动级联型三能级原子双光子过程的熵演化
参考词条
补充资料:单、双光子吸收法
单、双光子吸收法
SPA采用单一波长的γ射线125碘或241镅为发射源,计算其经过被测物后衰减率,再经一已知标准将其衰减值转换为骨矿含量或骨密度。通常只对四肢骨骼(如桡骨、尺骨)进行测量,并且主要测量皮质骨。为校正软组织产生的变异,测量时受检部位置于与软组织等当量的水袋中,采用多次扫描并取其均数,再除以受检骨的宽度,得骨的面密度,骨密度单位是g/cm2,其准确性约为6%,精确性在1%~2%,辐射剂量较小,通常低于10mRem(毫雷姆)。双光子吸收法(DPA)采用能发射两种不同能量光子的核素作放射源,利用高能和低能射线通过被测部位的不同衰减分布来计算骨的能量衰减分布,故可用来测量一些软组织变异大的部位如脊椎、髋等全身部位的骨矿含量,从而消除软组织及脊髓对测量结果的影响。DPA通常测量L1~L4的骨矿含量,结果以骨矿密度g/cm2表示。且辐射剂量较低,3~5μSv(4~6)。缺点为检查时间较长,并且DPA的测量是射线所经通路的衰减值的总和,无法区分皮质骨和松质骨的骨密度,另外,全身的骨矿含量的测量还受椎体边缘骨赘、椎体小关节肥大、压缩性骨折和钙化血管的影响。
说明:补充资料仅用于学习参考,请勿用于其它任何用途。