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1.
用激光光解方法研究了富勒烯(C60 / C70)与N,N,N′,N′-四-(对甲基苯)-4,4′-二胺-1,1′-二苯碲醚电荷转移复合物的特征. 通过观察在近红外区瞬间吸收带,富勒烯(C60 / C70)激发三线态,富勒烯(C60 / C70)阴离子自由基和N,N,N′,N′-四-(对甲基苯)-4,4′-二胺-1,1′-二苯碲醚阳离子自由基的出现,测定了在苯腈溶液中从N,N,N′,N′-四-(对甲基苯)-4,4′-二胺-1,1′-二苯碲醚到富勒烯(C60 / C70)激发三线态的量子转化产率和电子转移常数.  相似文献   

2.
该文使用飞秒时间分辨泵浦-探测磁光克尔光谱技术,研究了飞秒激光加热GdFeCo磁光薄膜跨越铁磁补偿温度时,净磁矩方向发生转变而引起磁化反转的反常克尔磁滞回线。通过测量不同激发功率下以及不同泵浦脉冲数下的反常克尔回线,揭示反常回线包含连续脉冲激发产生的积累效应以及外场磁化史的记忆效应,对反常回线的形成起源做了深入探索和详细研究。研究结果对于深入理解GdFeCo合金薄膜中稀土-过渡金属间的反铁磁耦合特性以及磁化反转的机理具有重要意义。  相似文献   

3.
用调Q红宝石激光在苯中激发受激拉曼散射。将受激散射的泵光与斯托克斯光以一定的角度入射到豆油中,在满足波矢配的条件下得到相干反斯托拉曼散射(CARS)。反斯托克斯光的出现是食用豆油中含有微量苯的定性指示。  相似文献   

4.
报道了包层泵浦调Q光纤激光器的实验研究。采用连续光泵浦方式,在激光谐振腔中,利用多模硅光纤中的非线性效应-受激Brillouin散射(SBS)进行自调Q,得到了纳秒量级的脉冲输出;改用脉冲光泵浦方式,实现了重复频率连续可调,稳定的纳秒量级光脉冲输出,脉宽(FWHM)小于2ns,峰值功率大于8kw。  相似文献   

5.
合成并表征了N-(对硝基苯偶氮苯)-苯胺基苯,制备了掺N-(对硝基苯偶氮苯)-苯胺基苯聚合物薄膜,并测试其光谱特性和折射率.根据光谱特性分析用632.8 nm的He-Ne激光用光泵浦测试法研究了薄膜光致双折射效应.结果表明该样品薄膜具有良好的光学性质并有望成为新型的光信息存储材料.  相似文献   

6.
含Nd(Ⅲ)配合物的合成、结构及近红外发光性能   总被引:1,自引:1,他引:0  
采用恒温磁力搅拌的方法,以1,10-菲啰啉(phen)、对氨基苯甲酸为配体,合成了1种Nd(Ⅲ)配合物[Nd(p-NH2 C6 H4 CO2)3(p-NH2 C6 H4 CO2 H)(phen)2]·2H2 O·2phen,通过X光单晶衍射仪确定了该配合物的晶体结构.并在室温下测定了固态粉末的IR,UV-Vis-NIR光谱以及激发和发射光谱.该配合物在近红外区表现出明显的Nd(Ⅲ)离子特征发射,这主要归功于配体的敏化作用.  相似文献   

7.
综述了西北核技术研究所在光泵浦XeF(C-A)激光技术研究方面取得的成果,研制的10 J级激光器最大输出能量为18.7 J,总转换效率达到0.25 %,在国际上首次实现了XeF(C-A)激光重频运行,运行频率0.1~1 Hz;描述了光泵浦源的结构和供气装置的研制;介绍了在高重频光泵浦源和激光线宽压缩研究方面的最新进展,光泵浦源最高运行频率达90 Hz,XeF(C-A)激光线宽已被压缩到1 nm。  相似文献   

8.
在GaP :V3 晶体中 ,对 3 A2  3 T1(F) ,3 A2  3 T1(P)以及3 A2  3 T2 (F) 3组自旋允许跃迁均已在实验中测得了它们的精细结构 .同时考虑静电、晶场和自旋 轨道耦合作用 ,计算了GaP :V3 的旋轨耦合分裂 ,理论计算与实验符合很好 .此外 ,还对这 3组自旋允许跃迁的精细结构进行了识别 ,结果表明 ,3 A2 3 T1(P)跃迁的 3条 13874,13890和 13946cm-1分别对应E′ T′2 ,T1′ 和A′;3 A2  3 T1(F)跃迁的 3条锐线86 97,8711和 876 0cm-1分别对应A′ T′2 ,E′ 和T1′;而3 A2  3 T2 (F)跃迁的 3条锐线 6 382 ,6 397和6 399cm-1则分别对应T′2 ,T1′ 和E′.  相似文献   

9.
合成了新的三价金属铊与配体邻啡咯啉(Phen)和8-羟基喹啉(Oxine)的络合物,并应用多核核磁共振(1H,13C和205Tl)渡谱和振动光谱,系统地对所合成的络合物进行了溶液和固相的表征.204T1核磁共振波谱表明,单配体络合物[T1(phen)] 3+,双配体络合物[T1(phen)2] 3+和三配体络合物[T1(phen)3] 3+以化学平衡的形式存在于二甲基砜(DMSO)和乙腈(CH3CN)溶液中.并在DMSO溶液中,测定了三配体络舍物[T1(phen)3] (ClO4)3 (1)和四配体络舍物ETl(oxine)4] (ClO4)3(2)的1H和13C NMR谱,其自旋-自旋耦合常数(T1(I=1/2)-13C和Tl(I=1/2)-1H)均被观测到.从二维共振谱(13C-1H COSY图谱),四配体络合物FTl(oxine)4] 3+中C-H联结和其复杂的自旋-自旋耦合1H NMR图谱均被明确地归属和指认.紫外-可见光谱表明配体到金属的电荷转移吸收谱(LMCT)分别为315 nm(ε=1.65×103mol-1·cm-1)(1)和375 nm(ε=7.48×103mol-1·cm-1)(2).由此可见,三价铊与配体邻啡咯啉(Phen)和8-羟基喹啉(Oxine)均都生成了稳定的络合物.  相似文献   

10.
相干反斯托克斯喇曼光谱(简称CARS)是七十年代发展起来的一项新的光谱技术,是激光喇曼光谱技术的一种补充和发展.它具有效率高、光谱及空间分辨率强、抗荧光干扰等特点.由我校物理系激光物理研究室研制的CARS光谱,用氮分子激光泵浦两台染  相似文献   

11.
Dudovich N  Oron D  Silberberg Y 《Nature》2002,418(6897):512-514
Molecular vibrations have oscillation periods that reflect the molecular structure, and are hence being used as a spectroscopic fingerprint for detection and identification. At present, all nonlinear spectroscopy schemes use two or more laser beams to measure such vibrations. The availability of ultrashort (femtosecond) optical pulses with durations shorter than typical molecular vibration periods has enabled the coherent excitation of molecular vibrations using a single pulse. Here we perform single-pulse vibrational spectroscopy on several molecules in the liquid phase, where both the excitation and the readout processes are performed by the same pulse. The main difficulty with single-pulse spectroscopy is that all vibrational levels with energies within the pulse bandwidth are excited. We achieve high spectral resolution, nearly two orders of magnitude better than the pulse bandwidth, by using quantum coherent control techniques. By appropriately modulating the spectral phase of the pulse we are able to exploit the quantum interference between multiple paths to selectively populate a given vibrational level, and to probe this population using the same pulse. This scheme, using a single broadband laser source, is particularly attractive for nonlinear microscopy applications, as we demonstrate by constructing a coherent anti-Stokes Raman (CARS) microscope operating with a single laser beam.  相似文献   

12.
采用633 nm激光器,检测了合成的N,N'-双水杨醛缩环己二胺产物在指纹区的拉曼光谱,并根据密度泛函理论对其拉曼光谱进行理论模拟.该分子拉曼光谱检测值和理论值比较表明:在位移800 cm-1,该物质有一特征峰,初步将其归属为C-N-C两碳原子围绕N原子的剪式振动和苯环碳骨架伸缩振动的协同振动,这是该物质多个原子的集体...  相似文献   

13.
采用相干反斯托克斯Raman散射(CARS)技术研究在不同pH值的水溶液中核糖核酸碱基-尿嘧啶结构,所得结果揭示出尿嘧啶环的伸缩,变形振动可在1000cm~(-1)附近产生一些Raman谱线,并发现这些谱线对溶液的pH值很敏感。然而这些现象在采用目前广泛应用的激光共振Raman光谱方法时是难以发现的。因此,CARS测量是一种可研究核酸残基振动结构及其和环境介质相互作用的有效方法。除它对样品或杂质引起的荧光干扰有明显抑制作用外,可以预期:这一方法也可用于获得在有关分子过程中所出现的瞬态粒子结构的信息。  相似文献   

14.
首次发现二甲基甲酰胺(DMF)溶液在添加适量的四(对硝基苯)卟啉(PNNNN)后,其865cm~(-1)处的Raman振动模所对应的CARS(相干反斯托克斯喇曼散射)光谱信号有明显的增强效应.从实验和理论两方面探讨了添加剂浓度变化对这种光谱信号增强效应的影响,并在四波混频理论的基础上,对上述增强效应的产生机理做了较细致的定性分析。  相似文献   

15.
基于分子轨道(MO)和自然跃迁轨道(NTO)成分计算分子片段间的电荷转移. 先用密度泛函理论(DFT)中的CAM-B3LYP方法, 在6-31G(d)基组水平上优化隐式溶剂H2O下苏氨酸(Thr)分子的几何构型,  再在相同理论方法下进行含时密度泛函理论(TDDFT)的电子激发计算, 给出隐式溶剂H2O下Thr分子体系电子激发过程中片段间电荷转移特征的对比结果. 结果表明: 在S1~S5激发态中, 仅S2中有一对MO32→MO33跃迁轨道占绝对优势, 可通过分析该轨道的成分讨论电荷转移; 其他激发态可通过NTO分析方法讨论电荷转移; S0向激发态S1,S3和S4电荷转移的主要贡献为NTO32→NTO33轨道, 与Hirshfeld和Becke方法的定性结果一致, 定量结果略有差别.  相似文献   

16.
Quantum measurement is a fundamental problem in quantum control theory and experiments.It can obtain unknown information of quantum systems,and can also change state of the systems inevitably.Both the outcome and back action could be used to control quantum systems.This paper presents recent research progress about optimal control of state transformation in finite-dimensional quantum systems by back action of non-selective quantum measurement,and optimal control of signal and background of CARS (coherent anti-Stokes Raman spectroscopy) by phase shaping technique.In measurement sequence control of finite-dimensional quantum systems,the necessary condition for critical points of the underlying state transformation objective is found to be a highly symmetric form as a chain of equalities,and analytical and numerical solutions in several cases are explored.In the CARS control,it is found that the maximal resonant signal and minimal background at a specific frequency can be achieved by shaping the probe pulse only while keeping pump and Stokes pulses in transform limited forms (TLFs).An arctan-type phase function is obtained for the probe pulse to simultaneously enhance the resonant signal and suppress the background.For broadband background elimination,we find that the optimal phase shaping scheme of probe pulse is quasi-time-delay while keeping the pump and Stokes pulses in TLFs.These conclusions could help design control strategies of quantum devices.  相似文献   

17.
为缩短金福菇母种的生长周期,研究了5种不同质量浓度的外源激素对金福菇营养生长阶段菌丝生长的影响,通过测定菌丝的日平均生长速度筛选出5种不同激素单独使用时的适宜质量浓度.实验结果表明,5种激素的适宜质量浓度分别为吲哚乙酸(IAA)1.0mg/L,2,4-二氯苯氧乙酸(2,4-D)1.5mg/L,6-苄氨基腺嘌呤(6-BA)1.5mg/L,赤霉素(GA)1.0mg/L,三十烷醇1.5mg/L.其中,GA对金福菇菌丝生长具有更大的促进作用,其适宜的质量浓度为1.0mg/L,长速提高15.77%.  相似文献   

18.
基于分子轨道(MO)和自然跃迁轨道(NTO)成分计算分子片段间的电荷转移. 先用密度泛函理论(DFT)中的CAM-B3LYP方法, 在6-31G(d)基组水平上优化隐式溶剂H2O下苏氨酸(Thr)分子的几何构型,  再在相同理论方法下进行含时密度泛函理论(TDDFT)的电子激发计算, 给出隐式溶剂H2O下Thr分子体系电子激发过程中片段间电荷转移特征的对比结果. 结果表明: 在S1~S5激发态中, 仅S2中有一对MO32→MO33跃迁轨道占绝对优势, 可通过分析该轨道的成分讨论电荷转移; 其他激发态可通过NTO分析方法讨论电荷转移; S0向激发态S1,S3和S4电荷转移的主要贡献为NTO32→NTO33轨道, 与Hirshfeld和Becke方法的定性结果一致, 定量结果略有差别.  相似文献   

19.
Expression pattern of GASA,downstream genes of DELLA,in Arabidopsis   总被引:3,自引:0,他引:3  
Separation and functional research of related components involved in gibberellins (GAs) signaling are important to clarify the mechanism of GA functioning. Research on the downstream components of DELLA, the key factor of the GA signaling pathway, is limited at present. GASA (GA-Stimulated in Arabidopsis) family contains 15 genes usually regulated by GA in Arabidopsis thaliana. All GASA proteins have a cleavable signal peptide in N terminus and a conserved GASA domain including 12 cysteines in C terminus. RT-PCR analysis revealed that the expression of GASA4 and GASA6 were down-regulated, but GASA 1 and GASA9 were up-regulated in the DELLA mutants, gai-t6 and rga-24, as well as the double mutant, consisting with the results that GASA4 and GASA6 were induced, but GASA1 and GASA9 were inhibited by exogenous GA3. In addition, the expression patterns of other GASA genes were regulated by GA and ABA, separately or cooperatively. Most of GASA genes were expressed in roots, stems, leaves, flowers and developing siliques. GUS gene driven by the promoters of GASA6, GASA7, GASA8, GASA9, GASAIO, GASA11 and GASA12were used as reporters and it was found that all GASA genes expressed in the growing and differentiating organs and abscission zones, suggesting the role of these genes in cell growth and differentiation. This study provided an important basis for functional study of the GASA gene family in the GA and ABA signaling pathway.  相似文献   

20.
本文测量了键联于核酸的激发态水溶铜卟啉共振拉曼光谱.结果表明,位于1550cm~(-1)和1346cm~(-1)附近的两条谱带归属于受激铜卟啉拉曼带,其强度与核酸和铜卟啉的种类、核酸所含的(AT)_n结构和受激铜卟啉沟槽键联于核酸的能力有关.文中对插入DNA中GC位置上的基态铜卟啉在受激状态下能沟槽键联于—ATAT一位置这一现象作了定性的解释.  相似文献   

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