求解弹性梁的普遍化方法

介绍了一种求解弹性梁的新方法．该方法利用奇异函数与拉普拉斯变换相结合的方法导出弹性梁弯曲变形的普遍表达式，并利用边界条件确定约束力，对具有任意支承形式、受力状况和阶梯形状的静定或超静定梁具有普适性．     

高中数学情境教学创设探讨

情境教学,能够使抽象性、概括性强的数学知识形象化、直观化,能够给学生进行启发性帮助,培养学生的数学思维,有效降低高中数学学习的难度,帮助学生消除畏难情绪,培养学习数学的兴趣和增强解题信心,提高学习数学的效率.     

Quantitative Single-Ion Irradiation by ASIPP Microbeam

A single-ion microbeam facility has been constructed by the microbeam research group in ASIPP (Institute of Plasma Physics, Chinese Academy of Science). The system was designed to deliver defined numbers of hydrogen ions produced by a van de Graaff accelerator, covering an energy range from 200 keV to 3 MeV, into living cells (5μm-20μm diameter) growing in culture on thin plastic films. The beam is collimated by a 1-μm inner diameter HPLC (high performance liquid chromatograph) capillary, which forms the micron-dimensional beam-line exit. A microbeam collimator, a scintillation ion counting system and a fast beam shutter, which constitute a precise dosage measuring and controlling system, jointly perform quantitative single-ion irradiation. With this facility, we can presently acquire ion-hitting efficiency close to 95%.