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51.
共焦非稳腔中ps激光的内腔倍频   总被引:2,自引:1,他引:1  
吴逢铁 《光子学报》1998,27(6):490-493
考虑倍频晶体相位匹配接收角(Angular acceptance)对倍频转换效率的影响,设计了正支(p支)共焦非稳腔Nd:YAP锁模激光器。平行光通过晶体实现完全相位匹配。以BBO和KTP作为腔内倍频元件,分别获得80.6%和60.2%的高效倍频转换,及几十mJ的绿光输出。同时实验测定其它有关参数。  相似文献   
52.
Sun XY  Liu B  Weng WT  Jiang YB 《Talanta》2004,62(5):1035-1040
Fluorescent reagent sodium 1-naphthylamine diacetate (NADA) was assembled onto gold electrodes via its electrostatic interaction with cysteine (Cys) that was directly assembled on the gold electrode surface. Formation of the self-assembled bilayers was confirmed and primarily characterized by cyclic voltammetry and X-ray photoelectron spectra (XPS). The Cys modification of the gold electrode prevented direct adsorption of NADA onto the gold electrode and hence eliminated fluorescence quenching by gold. Strong fluorescence was observed from the NADA self-assembled bilayers at gold surface and was highly efficiently quenched by Cu2+ that allowed for an extremely highly sensitive detection of Cu2+ with a detection limit of 0.2 ppt and quantitative detection range of 0.5–9 ppt. The fluorescence from NADA/Cys/Au can be easily regenerated and therefore the present report showed a reusable method for immobilizing reagent in fabricating fluorescent chemosensors.  相似文献   
53.
干涉理论对bottle beam的描述   总被引:13,自引:0,他引:13       下载免费PDF全文
曾夏辉  吴逢铁  刘岚 《物理学报》2007,56(2):791-797
对轴棱锥产生的贝塞尔光聚焦特性的描述,我们提出一种有别于惠更斯-菲涅耳衍射积分理论的解析表达.这种解析表达基于干涉理论的基础,它能够模拟计算出聚焦透镜置于最大准直距离之外以及在聚焦透镜焦平面以后的光束行为,能够更好地描述bottle beam的形成过程,这些结果用衍射积分理论是得不到的.我们还得到了与Wei用几何光学分析所得出的当z0max将产生hollow beam的不同结论.所有理论计算结果都得到实验的有力验证. 关键词: bottle beam 贝塞尔光 轴棱锥 光镊  相似文献   
54.
 采用衍射积分理论和干涉理论分别对轴棱锥产生的Bessel光的传输特性进行描述,并讨论了其适用条件和优缺点。数值模拟了光传输的3维强度分布,同时进行相关参数的实验测定。数值模拟和实验结果表明:在最大无衍射距离内,衍射理论能很好地描述Bessel光的轴上光强分布,当接近或超出最大无衍射距离时,干涉理论也能较好地描述Bessel 光的强度分布,实验结果和理论分析基本吻合。  相似文献   
55.
A method for obtaining small bottle light beams, e.g. 0.92λ×0.4λ, in a high numerical-aperture lens system is proposed and numerically demonstrated. This can be achieved by changing the radius of each zone of the binary element and polarization rotation angle of the cylindrically polarized vectorial vortex beam. It is found that the transversal and axial sizes of this bottle beam are equal to about 0.92λ and 0.4λ, respectively. In addition, the connection between angular momentum and topological Pancharatnam charge is also shown.  相似文献   
56.
A novel complex [Cu(acac)(dppe)]n (1) [acac = acetylacetone; dppe = 1,2-bis(diphenylphosphino)ethane] was obtained by solution reactions and structurally characterized by X-ray diffraction. The crystal structure analysis indicates that the title complex is characteristic of a polymeric chain formed by the dppe ligands bridging neighboring copper centers. The copper atom is in a distorted tetrahedral geometry. Photoluminescent investigation reveals that the title complex displays a strong emission in bluelight region.  相似文献   
57.
朱森  苏丽  王立飞 《东北数学》2008,24(3):196-206
Abstract: We consider an approximation problem related to strongly irreducible operators, that is, does the direct sum of a strongly irreducible operator in B∞(Ω) and certain operator have a small compact perturbation which is a strongly irreducible operator in B∞(Ω)? In this paper, we prove that the direct sum of any strongly irreducible operator in B∞(Ω) and certain biquasitriangular operator have small compact perturbations which are strongly irreducible operators in B∞(Ω).  相似文献   
58.
In this paper, hybrid bidirectional associative memory neural networks with discrete delays is considered. By ingeniously importing real parameters di > 0(i = 1,2,···,n) which can be adjusted, we establish some new sufficient conditions for the dynamical characteristics of hybrid bidirectional associative memory neural networks with discrete delays by the method of variation of parameters and some analysis techniques. Our results generalize and improve the related results in [10,11]. Our work is significant...  相似文献   
59.
Let T be a tilting A-module over a path algebra of Dynkin type.We prove thatif the indecomposable direct summands of T are in the different (?)-orbits of the AR-quiverof A,then T is a complete slice module.  相似文献   
60.
In [ 2 ], D.Hoff analyzes an implicit finite difference scheme for the mixed initial -value Dirichlet problem for a system of two conservation laws with artif ficial viscosity . The system is a model for isentropic flow in one space dimen-sion .However, in [2], there is an additional condition on the state function p(v),(?)For polytropic gas, p(v) = k2v, where k>0 and 1<γ≤3,the condition (*) is equivalent to 1<γ<2. In the present note, we remove the restriction(*),so that the main results of [2] still hold for the general state function p(v) with p′(v)<0, p″(v)>0.  相似文献   
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