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1.
激光烧蚀叠氮化钠产生的团簇离子及其分布   总被引:1,自引:0,他引:1  
用飞行时间质谱研究了激光烧蚀叠氮化钠固体产生的正负团簇离子的组成及其分布,产生的团簇系列包括:(Na(NaN3)n)^+,(Na3(NaN3)n)^+,(Na4N(NaN3)n)^+,(Na5(NaN3)n)^+,(NaN3)n)^+,(Nan)^+,(N3(NaN3)n)^-,(Na(NaN3)n)^-,(NaN3)n)^-,(N(NaN3)n)^-,提出正负团簇离子形成的可能机理,分析了影响因  相似文献   

2.
用飞行时间质谱仪探测了直接激光气化碱式碳酸镁样品产生的质谱,结果表明:氧化镁团簇与同时产生的水分子发生了原位溶剂化反应并产生了各种尺寸的溶剂化氧化团簇离子,这些团簇离子包括:(Mg(H2O)m)^+(m=0,1,2,3),(Mg(MgO)H2O)m(m=1,2,3,4)(H(MgO)(H2O)m)^+(m=0,1,2,3,4,5,6),(H(MgO)2(H2O)m)^+(m=0,1,2,3,4,5  相似文献   

3.
不同金属离子与色氨酸作用的荧光光谱研究   总被引:2,自引:0,他引:2  
研究了不同金属离子对色氨酸的荧光强度的影响。结果表明,在一定条件下当达到一定浓度时,Cu(Ⅱ),Fe(Ⅲ),Mo(Ⅵ)对色氨酸的荧光有猝灭作用,而此时Zn(Ⅱ),Mn(Ⅱ),Cr(Ⅲ),Co(Ⅱ),Ca(Ⅱ)和Na(Ⅰ)则对色氨酸的荧光几乎没有影响。  相似文献   

4.
本文成功地合成了一系列新型Pb-1222相层状铜氧化物(Pb0.5Cd0.5)(Sr0.9R0.1)2(R'0.7Ce0.3)2。Cu2Ox,R=R'=Y,Pr,Sm,Eu,Gd,Dy,Ho以及(R,R’)=(La,Eu),(Sm,Gd),(Sm,Eu),(La,Gd),(Eu,Gd),(Nd,Eu),(Nd,Dy),(Nd,Y),(Nd,Er).X-射线衍射和电子衍射表明它们属于四方晶系,其结构与(Pb,CU)-1222相结构相似.其中(R',R')=(Eu,Gd)的样品在氧气中成相得到23K的超导转变临界温度.  相似文献   

5.
本成功地合成了一系列新型Pb-1222相层状铜氧化物(Pb0.5Cd0.5)(Sr0.9R0.1)2(R‘0.7Ce0.3)2Cu2Oz,R=R’=Y,Pr,Sm,Eu,Gd,Dy,Ho以有(R,R‘)=(La,Eu),Sm,Gd),(Sm,Eu),(La,Gd),(Eu,Gd),(Nd,Dy),(Nd,Y),(Nd,Er)。  相似文献   

6.
AuthorIndextoVolumeB3,1994Alda,J.--(3),265GuoHong--(2),129,137;(4),317;(5),421;Bernabeu,E.--(3),265(6),529,533CatShangda--(4)...  相似文献   

7.
元素在探针表面上的原子化机理研究   总被引:3,自引:0,他引:3  
探针原子人经法是一种新技术,本文系统地总结了用探针原子化法研究Au(1B),Sr(ⅡA),Cd(ⅡB),Al(ⅢA),La,Sm,Fu(ⅢB),Ge,Sn,Pb(ⅣA),Sb,Bi(ⅤA),V(ⅤB),Cr,Mo(ⅥB),Mn(ⅦB),Fe,Co,Ni,Pt(Ⅷ)等20个元素的原子化机理了起源于卤化物分解的元素有Au与Pt,起源于氧化物分解的元素有Cd,Al,La,Sm,Eu,Ge,Mn与Fe。  相似文献   

8.
用紫外可见吸收光谱研究了二种新尾式卟啉:5-邻(4-(3-吡啶氧基)丁氧基)苯基10,15,20三苯在卟啉(O-PyTpp)和5-邻(4-(1-咪唑基)丁氧基)苯基10,15,20三苯基卟啉(O-ImTPP)的铁(Ⅲ)和锰(Ⅲ)配合物:O-PyTPPFe(Ⅲ),Cl,O-ImTPPFe(Ⅲ),Cl-PyTPPMn(Ⅲ),Cl,O-ImTPPMn(Ⅲ)Cl与含氮配体的轴向配位性质,结果表明,对于铁(  相似文献   

9.
张建民  徐可为 《物理学报》2004,53(1):176-181
根据弹性理论和多晶膜的屈服强度公式,计算了附着在基体上体心立方多晶薄膜中不同取向晶粒中的应变能密度.结果表明:1)在屈服之前,对Fe和Ta两种薄膜,4个最小的应变能密度对应的晶粒取向依次为(100),(510),(410)和(511);对Cr,Mo,Nb和V四种薄膜,4个最小的应变能密度对应的晶粒取向依次为(111),(332),(322)和(221);对W膜,应变能密度与晶粒取向无关.2)在屈服的体心立方多晶膜中,4个最小的应变能密度对应的晶粒取向依次为(100),(111),(110)和(411).从 关键词: 体心立方多晶薄膜 晶粒取向 应变能密度 织构  相似文献   

10.
从掺杂晶体(Na^+,K^+Ag^+,Pb^2+)x(NH4)1-xNO3相变时,拉曼峰强与温度的变化关系着手,深入人了掺杂离子效应,揭示了其中的标度性质,本文分不下列算:(1)前言,(2)实验;(3)lnIr与In│T-Tc│之线性关系,(4)不同振动模对不同掺杂程度的反应;(5)v1振动模对不同离子掺杂的刻画;(6)反转行为,(7)dc与M^1/2的线性关系。(8)掺杂效应的标度性,(9)结语  相似文献   

11.
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.  相似文献   

12.
A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.  相似文献   

13.
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.  相似文献   

14.
A multi-conjugate adaptive optics (MCAO) can offer a possibility of widening field of view (FOV) characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle's expressions of two deformable mirrors (DMs) MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.  相似文献   

15.
Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.  相似文献   

16.
The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results.  相似文献   

17.
18.
With a novel light-weight and absolutely calibrated ultraviolet (UV) spectrometer, UV skylight radiances and O3 slant column densities are measured by balloon-borne limb measurements in Xinjiang area, China. UV skylight radiances measured at the height of 31 km are compared with the results from Modtran in the wavelength range from 290 to 420 nm. O3 slant column densities are derived from radiance spectra in the Huggins bands (320 - 335 nm) using differential optical absorption spectroscopy method. And the parameter exhibits a good correlation with the same value simulated by radiative transfer model (Tracy). The O3 profile simultaneously measured by an O3 sonde is used as input in Tracy calculations. The O3 sonde is launched on the same balloon.  相似文献   

19.
For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanoparticles and nanogratings enhancement have been proposed recently.But in practice, these structures have obvious disadvantages.In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parameters on the performance is investigated by using rigorous coupled wave analysis (RCWA).Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters.The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes.Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.  相似文献   

20.
Novel polymer distributed feedback(DFB)gratings are fabricated based on photopolymerization to reduce lasing threshold of polymer lasers.A photopolymer formulation sensitive to 355-nm ultraviolet(UV)light is proposed for the fabrication of polymer gratings and it can be used to form polymer films by spin-coating process.A very low surface-relief depth ranging from 12.5 to about 1.0 nm has been demonstrated with a refractive-index modulation of about 0.012.The experimental results indicate that such polymer gratings have promising potentials for the fabrication of low-order DFB organic semiconductor lasers.  相似文献   

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