A Convenient Synthetic Method of Metal Dendritic Porphyrins

Metal porphyrins are natural antioxidant reagent1-3. However, due to the characteristics of structures, they are only soluble in inorganic acids and part of polar organic solvents. Thus, it is limited to be used as effective pharmaceutical preparations. T…     

Optimal conclusive teleportation of a d-dimensional two-particle unknown quantum state

A conclusive teleportation protocol of a d-dimensional two-particle unknown quantum state using three d- dimensional particles in an arbitrary pure state is proposed. A sender teleports the unknown state conclusively to a receiver by using the positive operator valued measure（POVM） and introducing an ancillary qudit to perform the generalized Bell basis measurement, We calculate the optimal teleportation fidelity. We also discuss and analyse the reason why the information on the teleported state is lost in the course of the protocol,     

A Lower Bound for {a+b:aA, bB, and P(a,b)≠0}

Let A and B be two finite subsets of a field . In this paper, we provide a non-trivial lower bound for {a+b:aA, bB, and P(a,b)≠0} where P(x,y) [x,y].     

On invertible substitutions with two fixed points

Let ? be a primitive substitution on a two-letter alphabet {a,b} having two fixed points ξ_a and ξ_b. We show that the substitution ? is invertible if and only if one has ξ_a=abξ and ξ_b=baξ. To cite this article: Z.-X. Wen et al., C. R. Acad. Sci. Paris, Ser. I 334 (2002) 727–731.     

长波长大应变InGaAs/InGaAsP分布反馈激光器的材料生长与器件制备

采用低压金属有机化合物气相沉积法(LP-MOCVD)生长并制作了1.6—1.7μm大应变InGaAs/InGaAsP分布反馈激光器.采用应变缓冲层技术，得到质量良好的大应变InGaAs/InP体材料.器件采用了4个大应变的量子阱，加入了载流子阻挡层改善器件的温度特性.1.66μm和1.74μm未镀膜的3μm脊型波导器件阈值电流低(小于15mA)，输出功率高(100mA时大于14mW).从10—40℃，1.74μm激光器的特征温度T₀=57K，和1.55μm InGaAsP分布反馈激光器的特征温度相当. 关键词： MOCVD InGaAs/InGaAsP 应变量子阱 分布反馈激光器     

Absorption Complex between Porphyrin and Phenothiazine in Reverse Micelles

Porphyrin derivatives attract much more interest in photodynamic therapy (PDT). Their importance as therapeutic drugs and targeting agents has been widely recognized1, and many of the efforts have been put towards crafting new porphyrin-based molecular entities to achieve enhanced tumor localization, better tissue penetration and increased singlet oxygen quantum yield2. The states of porphyrins in tissue models such as micelles, lipid bilayers are extensively investigated focusing more or l…     

Searching for a counterfeit coin with b-balance

We consider the classical problem of searching for a heavier coin in a set of n coins, n-1 of which have the same weight. The weighing device is b-balance which is the generalization of two-arms balance. The minimum numbers of weighings are determined exactly for worst-case sequential algorithm, average-case sequential algorithm, worst-case predetermined algorithm, average-case predetermined algorithm.We also investigate the above search model with additional constraint: each weighing is only allowed to use the coins that are still in doubt. We present a worst-case optimal sequential algorithm and an average-case optimal sequential algorithm requiring the minimum numbers of weighings.     

Synthesis and Properties of a Heteronuclear Ag（Ⅰ）/Ni（Ⅱ） Complex

Introduction Itiswell knownthatcyanogroupsincyanometa latessuchas[Ag(CN)2]-unitscanbeusedasbridg ingligandsandapolymericstructurecanbeformed throughsilver silver(argentophilic)interactions.This propertyhasbeenexploredintheconstructionofmany oligomericandp…     

北京自由电子激光最近进展──实现饱和振荡

北京自由电子激光(BFEL)装置于1993年底在10.68μm处实现了饱和振荡.输出激光能量为3mJ,饱和平顶宽度2μs.对应饱和振荡平均功率为210kW(宏脉冲),峰值功率约为20MW,比自发辐射高8个量级,单程小讯号净增益为24%,转换效率为0.45%,与理论预期结果相符.光束质量接近衍射极限.目前装置可工作于9-11μm.