首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
本文研究了四-(对-羰基苯基)卟啉(TCPP)在H2O/CF3COOH、H2O/CCI3COH和H2O/CH3COOH溶液中的UV-Vis吸收光谱、荧光光谱和拉曼光谱。实验表明,TCPP在H2O/CH3COOH和H2O/CCI3COOH溶液中以分子态的N-质子化卟啉H8TCPP^2+存在,而在H2O/CF3COOH中则形成H8TCPP^2+的J-聚集体。J-聚集体显示,UV-Vis吸收光谱和荧光光  相似文献   

2.
在无水乙醇溶液中分别合成了Eu^2+离子、Tb^3+离子与2,2‘-联吡啶、1,10-邻菲罗啉押种配合物,研究了配合物的荧光性质,由于Phen含有较大范围的共轭π键和较好的刚性平面,含Phen配合物的荧光强度均要比配合物的强;配合物的高分辨荧光光谱表明,Eu^3+离子在Eu(Dipy)2Cl3’2H2O和Eu(Phen)2Cl3.2H2O配合物中处于C1或C2或C5的对称性位置。  相似文献   

3.
稀土离子Eu3+掺杂Y2SiO5晶体的光谱和结构研究   总被引:7,自引:5,他引:2  
用514.5nm、488.0nm的Ar^+激光和441.6nm的He-Cd激光激发Eu^2+:Y2SiO5晶体的获得了一系列窄带荧光谱线,其中双重谱线结构源于Eu3^+离子发光中在该材料中占据两种不等价的非对称光学格位,测得了Eu^3+:Y2SiO5的X射线多晶衍射谱的面间距数据;计算了晶格常数和晶在角度,通过和非掺杂Y2SiO5晶体数据的比较,探讨了Eu^2+和Y2SiO5格位的相互影响。  相似文献   

4.
P538萃取锰(Ⅱ)的研究   总被引:1,自引:0,他引:1  
在25±0.5℃,用P538的环己烷溶液从NaClO4-HClO4介质中萃取Mn(Ⅱ)的反应机理为离子交换机理,萃取焓△H=-196kJ.mol^-1并用Cl^-离子水合作用和Mn^2+与Cl^-形成配合物的竞争解释了萃取分配比与水相中NaCl浓度的关系。  相似文献   

5.
低温宽带NaCl(OH^—):(F^+2)H色心激光的实验研究   总被引:2,自引:1,他引:1  
林碧洲  许承晃 《光学学报》1994,14(4):46-350
在NaCl晶体中掺入OH^-离子可以有效地提高F^+2心的稳定性。采用四镜折迭X型像散补偿腔,获得了峰值波长1.57μm、输出功率>250mW的低温宽带NaCl(OH^-):(F^+2)H色心激光。本文着重讨论OH^-对F^+2心的稳定作用和影响色心激光振荡的各种因素。  相似文献   

6.
给出了NaF及其掺杂质Li^+、Mg^2+、Cu^2+和OH^-五种样品的F2心在偏振的氮分子激光照射下的二向色性吸收特性,对各种样品中F2心的转向效率进行了比较,并对结果进行了机理性的分析。  相似文献   

7.
析相光度法测定铜(Ⅱ)的研究   总被引:3,自引:0,他引:3  
本文研究了Cu-PEG-DDTC(铜试剂)(NH4)2SO4体系的析相光度法并应用于测定Cu。最宜酸度为3.6-9.0(NaAc-HAc,NH4Cl-NH3.H2O)缓冲溶液,其络合物的最大吸收位于450nm,表观摩尔吸光系数为9.05×10^3L.mol^-1.cm^-1,Cu浓度在0-30μg/L范围内服从比耳定律,铜与DDTC形成组成为1:2的稳定络合物。该方法用于铝合金中铜的测定,获得了满  相似文献   

8.
在355、532nm激光波长下用TOF质谱研究了C4H5N-(H2O)n氢键团簇体系的多光子电离。二波长下均得到一系列C4H5N-(H2O)n^+及质子化产物C4H5N-(H2O)nH^+。355nm下可能存在双光子共振电离过程,使得该波长下吡咯母体及团簇离子信号较532nm有明显增强。  相似文献   

9.
报道γ-射线辐照从Ni^2+-CuT^2+混合水溶液环境中制备复相纳米级超细粉的物理化学过程及其相应的产物,分析了影响产物组成和粒径晶粒度的各种因素,制得Cu-Cu2O、Cu-Ni-Cu2O和Cu-Ni等多种复相纳米级超细粉体。  相似文献   

10.
报道了Cu^+,Eu^2+共激活的Ca1-xMgnS的发光性质,基质组分变化与荧光性质的关系,Cu^+和Eu^2+在纯CaS基质中的发射光谱分别位于430nm及630nm附近,随着基质中Mg含量的增加,红,蓝区发射峰值波长基本不变,但强度发生明显改变,当n为0.25时,红区发射强度最强。  相似文献   

11.
同位素位移实验测量   总被引:1,自引:1,他引:0  
马洪良 《物理实验》2003,23(3):10-12
利用光栅光谱仪测量了氢-氘灯谱线的同位素位移。利用具有高分辨、选择性激发等特点的共线快离子束-激光光谱学方法测量了^142-146,148,150Nd^ 同位素位移,结合King-plot和理论计算得到质量位移、场位移和特殊质量位移。  相似文献   

12.
A simple method is applied to calculating the isotope shifts (ISs) on 5S1/2 → 4D3/2,5/2 transitions of 87,88Sr+. First we have calculated the ISs of lower transitions on a series of alkali-like systems such as B2+, Ca+ and Ba+, which are in agreement with other works. Then the ISs on 5S1/2 → 4D3/2,5/2 transitions of 87,88Sr+, which are useful to study the Sr+ optical frequency standard, are evaluated.  相似文献   

13.
A method for accurate measurement of magnetic susceptibility and determination of the shape factor in an NMR tube is shown. The combination of accurate shape factor determination with susceptibility measurement leads to improved accuracy when measuring chemical shift. This is important for comparing samples in different solvents or under different conditions, such as temperature, solvent, and pH.  相似文献   

14.
The Raman–Nath diffraction in acousto–optic effect was studied theoretically and experimentally in the paper.Up to now,each order of diffracted light in Raman–Nath diffraction was still considered simply to be just frequency-shifted and to be a plane wave.However,we find that the phase and frequency shifts occur simultaneously and individually in Raman–Nath diffraction.The findings demonstrate that,in addition to the frequency shift,the optical phase of each order of diffracted light is also shifted by the sound wave and fluctuates with the sound wave and is related to the location in the acoustic field from which the diffracted light originates.As a result,the wavefront of each order of diffracted light is modulated to fluctuate spatially and temporally with the sound wave.Obviously,these findings are significant for applications of Raman–Nath diffraction in acousto–optic effect because the optical phase plays an important role in optical coherence technology.  相似文献   

15.
16.
Nanoscaled or porous silicon (p-Si) with and without surface passivation exhibits unusually tunable properties that its parent bulk does never show. Such property tunability amplifies the applicability of Si in the concurrent and upcoming technologies. However, consistent understanding of the fundamental nature of nanoscaled Si remains a high challenge. This article aims to address the recent progress in this regard with focus on reconciling the tunable dielectric, electronic, phononic, and photonic properties of p-Si in terms of skin dominance. We show that the skin-depth bond contraction, local quantum entrapment, and electron localization is responsible for the size-induced property tunability. The shorter and stronger bonds between undercoordinated skin atoms result in the local densification and quantum entrapment of the binding energy and the bonding electrons, which in turn polarizes the dangling bond electrons. Such local entrapment modifies the Hamiltonian and associated properties such as the band gap, core level shift, Stokes shift (electron–phonon interaction), phonon and dielectric relaxation. Therefore, given the known trend of one property change, one is expected to be able to predict the variation of the rest based on the notations of the bond order–length–strength correlation and local bond average approach (BOLS-LBA). Furthermore, skin bond reformation due to Al, Cu, and Ti metallization and O and F passivation adds another freedom to enhance or attenuate the size effect. The developed formulations, spectral analytical methods, and importantly, the established database and knowledge could be of use in engineering p-Si and beyond for desired functions.  相似文献   

17.
利用WGD-6型光学多道分析仪和温度传感器设计了测量不同电流下发光二极管(LED)温度和光谱特性的实验,并测定了紫、蓝、绿、黄和红光二极管管温随电流变化和光谱的变化。各种二极管随电流的增加温度升高,紫、蓝和黄光LED升温速率要快。随电流增加,紫、黄和红光LED有明显的红移,绿光LED有明显的蓝移,而蓝光LED先蓝移后红移。随电流的增加LED有光输出饱和现象。电流的增加引起LED半峰宽宽化,红光LED宽化幅度最大,可达15nm。  相似文献   

18.
Strong atmospheric turbulence is a major hindrance in wireless optical communication systems. In this paper, the performance of a wireless optical communication system is analyzed using different modulation formats such as, binary phase shift keying-subcarrier intensity modulation (BPSK-SIM), differential phase shift keying (DPSK), differential phase shift keying-subcarrier intensity modulation (DPSK-SIM), M-ary pulse position modulation (M-PPM) and polarization shift keying (PolSK). The atmospheric channel is modeled for strong atmospheric turbulences with combined effect of turbulence and pointing errors. Novel closed-form analytical expressions for average bit error rate (BER), channel capacity and outage probability for the various modulation techniques, viz. BPSK-SIM, DPSK, DPSK-SIM, PolSK and M-PPM are derived. The simulated results for BER, channel capacity and outage probability of various modulation techniques are plotted and analyzed.  相似文献   

19.
CH3Li–FArH–X (X?=?H2, OC, N2, P2, CO2, CO, BeH2) trimers have been investigated using quantum chemical calculations at the QCISD/6-311++G(2d,2p) level. The results show that the lithium bonding has a prominent effect on the strength and properties of the hydrogen bonding. The hydrogen-bonding interaction energy is increased by 160–340% due to the presence of lithium bonding. The Ar–H stretch vibration shows a blue shift in the FArH–X (X?=?H2, OC, N2, CO2, CO) dimer, but a red shift in the FArH–X (X?=?P2, BeH2) dimer. The red shift is increased in the corresponding trimer, while the blue shift shows a different change. The blue shift is also increased in CH3Li–FArH–X (X?=?H2, OC, N2, CO2) trimers, but it changes to a red shift in the CH3Li–FArH–CO trimer. The shift change is consistent with the explanation given by Joseph and Jemmis.  相似文献   

20.
A new technique has been developed to measure isotope shifts of high-lying atomic levels using multi-step photoionization. This technique has been demonstrated with the measurement of isotope shift between235U and238U isotopes in the energy level at 34372.992 cm−1. The value of isotope shift thus measured matches well with the value reported in literature.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号