简介：使用一种唯象的ＮＮ周边模型湮灭势，对１８０Ｍｅｖ的Ｐ－１２Ｃ弹性散射微分截面、极化角分布和自旋旋转参数进行了计算。结果表明，这种势模型与实验符合得较好。更多还原

简介：ＹｉｅｌｄｏｆＴｒａｎｓｔａｒｇｅｔＰｒｏｄｕｃｔｓｆｒｏｍＩｎｔｅｒａｃｔｉｏｎｏｆ４７ＭｅＶ／ｕ１２ＣＩｏｎｓｗｉｔｈＣｓＴａｒｇｅｔｓ￥ＬｉＺｏｎｇｗｅｉ；ＹａｎｇＷｅｉｆａｎ；ＺｈａｏＺｈｉｚｈｅｎｇａｎｄＭｕＷ?..

简介：ＭａｓｓＹｉｅｌｄＤｉｓｔｒｉｂｕｔｉｏｎｏｆＴａｒｇｅｔＲｅｓｉｄｕｅｓｆｒｏｍＩｎｔｅｒａｃｔｉｏｎｏｆＩｒｏｎｗｉｔｈ１３５ＭｅＶ／ｕ１２ＣＩｏｎｓ￥ＱｉｎＺｈｉ；ＬｉＷｅｎｘｉｎ；ＺｈａｏＬｉｎ；ＷｅｎＷａｎｘ...

简介：Thesingle-shotspiralmagneticresonanceimaging(MRI)techniquewasimplementedandoptimizedonaBrukerBiospec47/30scanner.Thetechniqueincludesthepulsesequenceforgenerationanddetectionofthek-spaceMRIsignal(freeinductiondecay(FID)),andPC-basedprogramsforthedatagridandimagereconstruction.Thetemporalresolutionis70ms(14imagespersecond),whichconsistsofadataacquisitiontimeasshortas13.7ms,aspin-echotimeof13.6msandamagnetizationrecoverytimeof43ms.Thismakesitpossibletotakereal-timeimagesofmovingobjects.Thetechniqueisdemonstratedusingapendulum(tube)filledwithwater.

简介：WereportonN-dopedp-typeZnOfilmswiththec-axisparalleltothesubstrate.ZnOfilmswerepreparedonana-Al2O3(0001)substratebysolid-sourcechemicalvapourdeposition(CVD),Zn(CH3COO)2.2H2OwasusedastheprecursorandCH3COONH4asthenitrogensource.Thegrowthtemperaturewasvariedfrom300℃to600℃,theas-grownZnOfilmdepositedat500℃showedp-typeconductionwithitsresistivityof42Ωcm,carrierdensity3.7×10^17cm^-3andHallmobility1.26cm^2V^-1.s^-1atroomtemperature,whicharethebestpropertiesforp-typeZnOdepositedbyCVD.Thep-typeZnOfilmpossessesatransmittanceofabout85%inthevisibleregionandabandgapof3.21eVatroomtemperature.

简介：该规划的目的是重新研究物理教育的内容和结构，这是由于在三个方面有了重大的发展：①过去的三十年里，物理知识爆炸性地增长；③认知心理学的研究，对学习进程有了新的认识，③计算机技术及其功能不断提高。