Mass and isotopic concentrations of water-insoluble refractory carbon in total suspended particulates at Mt.Waliguan Observatory(China)

Mass concentration and isotopic values δ¹³C and ¹⁴C are presented for the water-insoluble refractory carbon（WIRC） component of total suspended particulates（TSP）,collected weekly during 2003,as well as from October 2005 to May 2006 at the WMO-GAW Mt.Waliguan（WLG） site.The overall average WIRC mass concentration was（1183±120）ng/m³（n = 79）,while seasonal averages were 2081 ±1707（spring）,454±205（summer）,650±411（autumn）,and 1019±703（winter） ng/m3.Seasonal variations in WIRC mass concentrations were consistent with black carbon measurements from an aethalometer,although WIRC concentrations were typically higher,especially in winter and spring.The δ¹³C PDB value（-25.3 ± 0.8）%.determined for WIRC suggests that its sources are C₃ biomass or fossil fuel combustion.No seasonal change in δ¹³C PDB was evident.The average percent Modern Carbon（pMC） for ¹⁴C in WIRC for winter and spring was（67.2 ± 7.7）%（n = 29）.Lower pMC values were associated with air masses transported from the area east of WLG,while higher pMC values were associated with air masses from the Tibetan Plateau,southwest of WLG.Elevated pMC values with abnormally high mass concentrations of TSP and WIRC were measured during a dust storm event.     

旋光性与电光效应交互作用及其对旋光晶体电光Q开关的影响

研究了晶体的旋光性与电光效应的交互作用、以及此交互作用对 旋光晶体电光Q开关的影响. 关键词： 旋光性 电光效应 电光Q开关 3Ga₅SiO₁₄晶体')" href="#">La₃Ga₅SiO₁₄晶体     

Gain Spectrum in an Asymmetric Double Quantum Well

We propose a scheme for light amplification in an asymmetric double quantum well, where two excited states are coupled by resonant tunnelling through a thin barrier in a three-level system of electronic subbands. By applying a single driving laser, the steady state gain can be obtained. The calculated gain spectrum for an asymmetric GaAs/AlGaAs double quantum well structure was presented.     

最大无关组的判定定理及其它

本文给出了一个判定最大无关组的充要性定理及其证明．同时对用矩阵的行变换求最大无关组这一问题进行了点滴分析并介绍了一个解齐次线性方程组的简便方法。     

Gd_xY_（1－x）P_5O_（14）：Ce，Tb的发光和能量传递Ⅱ．Ce→

研究了Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ＿（０．０１），Ｔｂ＿（０．０２）体系中Ｇｄ的子晶格在Ｃｅ→Ｇｄ→Ｔｂ能量传递中的中介作用规律及ＧｄＰ＿５Ｏ＿（１４），ＧｄＰ＿５Ｏ＿（１４）：Ｃｅ，ＧｄＰ＿５Ｏ＿（１４）：Ｔｂ和Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ，Ｔｂ的荧光光谱、激发光谱。结果表明，当ｘ＞０．７时，结构从单斜Ⅱ（Ｃ２／ｃ）的层状结构变为单斜Ｉ（Ｐ２＿１／ｃ）的带状结构，Ｃｅ￣（３＋）的发射光谱和Ｇｄ￣（３＋）的吸收光谱交迭增加等是Ｃｅ￣（３＋）→Ｇｄ￣（３＋）→Ｔｂ￣（３＋）能量传递几率增加的主要原因。     

循环矩阵的逆

称为n阶循环矩阵,易知,一个n阶循环矩阵有n个循环矩阵,用Aa_0,Aa_1,…Aa_(n-1)分别表示主对角线上元素为a_0,a_1,…a_(n-1),的n阶循环矩阵,设     

往事回忆

 常常收到青年朋友的来信,希望本刊披露微观世界奥秘的同时,邀请国内著名物理学家谈谈他们是怎样选择物理学这一艰难的道路,并为之奋斗一生.为此,本刊新辟《物理学家回忆录》,由中科院学部委员卢鹤绂教授主持.这里发表的《往事回忆》一文,是卢先生抱病为其家乡丛书《莱州文史资料》撰写的.征得先生同意,在本刊首次公开发表,并亲笔书写题名.广大读者将从中获得有益的启示.     

具有非负Gaus曲率的整体C1,14超曲面

本文借助蜕化椭圆型ＭｏｎｇｅＡｍｐｅｒｅ方程Ｄｉｒｉｃｈｌｅｔ问题的可解性，在较弱的条件下，证明了以给定的非负函数为Ｇａｕｓ曲率，以已知的空间曲线为边界的整体Ｃ１，１４超曲面的存在唯一性．