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1.
飞秒时间分辨取样光谱仪的研制   总被引:1,自引:0,他引:1  
研制的飞秒(10^15s)时间分辨取样光谱仪由三部分组成;(1)飞秒激光探针弥散补偿光学系统,(2)氩激光泵浦参钛兰宝石飞秒激光系统,(3)信号探测,数据采集分析处理掺钛兰宝石飞秒激光器在7W氩激光全线泵浦下,能输出平均功率400mW、持续期50fs到500fs的脉冲,其光谱可在750nm到920nm范围内调经LBO晶体倍频,能得到375nm到460nm的二次谐波,整体取样光谱仪的时间分辨为90f  相似文献   

2.
曹宵鸣  陆靖  范康年 《化学学报》2006,64(18):1865-1870
用超短脉冲激发动力学光谱理论在两电子体系下模拟了飞秒时间分辨的荧光亏蚀谱, 再现了实验中所得荧光亏蚀谱的双指数衰减和凹陷两种现象, 这两种现象分别是由于探测脉冲使电子激发态上振动基态和较高振动态的分子受激发射而产生的.  相似文献   

3.
利用飞秒光学外差光学克尔效应技术获得了咪唑类离子液体1-丁基-3-甲基咪唑六氟磷酸盐([bmim][PF6])体系中反映分子间相互作用的低频光谱. 结果分析中, 利用Brownian振子时间相关函数的精确表达式对光学克尔效应动力学数据中的核振动部分进行模拟, 在时域上获得各个振动组分的时间演化行为, 并进而通过快速Fourier变换获得各个振动组分的频域光谱和总加和光谱. 此外还利用低频拉曼光谱技术测量了离子液体[bmim][PF6]的低频光谱, 并和飞秒光学外差光学克尔效应实验的结果进行对比, 发现两种方法获得的低频光谱相近. 实验结果表明Brownian振子时间相关函数的精确表达式可用来解析离子液体体系中低频振动的时间演化行为.  相似文献   

4.
合成了由六次甲基四胺与H3PW12O40·nH2O,H4SiW12O40·nH2O和H4GeW12O40·nH2O 形成的具有非线性光学性质的电荷转移盐,并由元素分析,红外光谱,电子光谱进行了表征。结果表明固体中阴阳离子之间存在强的相互作用;非线性光学性质研究表明,三种电荷转移盐的倍频效应分别为KH2PO4(KDP) 的0 .17 ,0 .25 和0 .06 倍;三阶非线性系数分别为6.2 ×10- 13esu,8 .1 ×10 - 13esu和4 .3 ×10 - 13esu。  相似文献   

5.
时间分辨荧光光谱技术是研究激发态弛豫、能量传递以及电荷转移等光化学过程的重要且直接的工具.飞秒时间分辨荧光非共线光参量放大光谱技术是一种新发展的具有高时间分辨率、宽探测带宽、高增益的时间分辨光谱技术.本文对该技术的基本原理与工作特性、系统配置、荧光收集和会聚、数据采集模式、时问分辨光谱数据处理等进行了系统阐述.最后简单介绍了飞秒时间分辨荧光非共线光参量放大光谱技术在物理、生物和化学领域的3个典型应用,并以此展现该技术的高时间分辨率、宽光谱探测及高增益优势.  相似文献   

6.
汤桂娜  孔宏伟 《分析化学》1996,24(3):269-273
利用二元混合物的混合光谱与其中某一组分光谱的比值对波长求导,可达到分辨重叠光谱的目的。本文研究了用比光谱-导数-紫外分光光度法同时测定水样中NO3^-和NO2^-,以“减法技术”求导,兼具导数光度法能消除低频背景和高频噪声干扰及线性回归法分辨能力强的优点。方法避免了一般光度法需加入试剂而可能引起的误差。在PH7-9条件下测量203nm-219nm的光吸收值,用比光谱-导数技术处理,同时测定合成度样  相似文献   

7.
Eu(MBA)2NO3Phen配合物的发光光谱   总被引:6,自引:0,他引:6  
在77K测定了Eu(o-MBA)_2NO_3Phen和Eu(m-MBA)_2NO_3Phen配合物的激发光谱,发光光谱和时间分辨光谱。光谱数据说明由于邻甲基的位阻影响,在Eu(o-MBA)_2NO_3Phen配合物里存在化学环境稍有不同的两种Eu ̄(3+)格位,它们的局部对称性分别为c_2v和c_1,c_2或c_s。在Eu(m-MBA)_2NO_3Phen配合物里,仅存在一种Eu ̄(3+)格位,它类似于前一个配合物的c_2v对称性的Eu ̄(3+)格位。  相似文献   

8.
电荷转移器件在原子发射光谱中的应用(Ⅲ)   总被引:5,自引:0,他引:5  
本文分三部分对国内外原子发射光谱的固态光学多道检测系统特别是电荷转移器件(CTDs)检测器近10年来的发展进行了综合评价。本篇为其中的第三部分,着重讨论了CTDs-AES系统中光谱信号的采集和处理,光谱诊断,CTDs系统的制冷以及CTDs-AES的主要研究课题。  相似文献   

9.
角分辨飞行时间法研究紫外激光烧蚀Ta2O5的反应   总被引:2,自引:1,他引:2  
利用角分辨飞行时间法研究了355nm脉冲激光烧蚀Ta2O5的反应,由四极质谱测得的煤蚀产物除了O,Ta,TaO和TaO2中性碎片外,在较高激光能量密度时还有O,Ta,TaO,TaO2离子碎片,它们的飞行时间(TOF)谱可以用于级分带质心速度的Maxwell-Bolztmann分布函数较好地拟合,原生离子碎片的平均动能与激光能量密度无关,烧蚀产物原生离子和中性粒子的角分布可以分别用acos^nθ(n  相似文献   

10.
偶氮苯聚合物(PAZOS)的合成及其三阶非线性光学特性   总被引:1,自引:0,他引:1  
合成及表征了一种偶氮苯聚合物聚「3-甲基-4-二(N,N-氧亚乙基)氨基-4-硝基偶氮苯癸二酰」通过简并四波混频方法研究了这种聚合物膜的三阶非线性光学性质,测得三三阶非线性光学系数X^(3)为6.6*10^-6esu,并考察了其相位共轭光产生特性及光致异构动力学。  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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