期刊文献+
共找到520篇文章
< 1 2 26 >
每页显示 20 50 100
Protein-encapsulated long-wavelength fluorescent probe hybrid for imaging lipid droplets in living cells and mice with non-alcoholic fatty liver
1
作者 Han-Min Wang Yan-Chen Li +8 位作者 Lu-Lu Sun Ming-Ye Tang Jia Liu Jiahao Cai Lei Dong Jia Li Yi Zang Hai-Hao Han Xiao-Peng He 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第11期448-453,共6页
Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atheroscleros... Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atherosclerosis.The aberrant accumulation of lipid droplets(LDs)in hepatocytes is a prominent signature of NAFLD.However,conventional techniques lack the capability to effectively monitor the dynamic changes in LD levels during NAFLD with living organisms.Hence,it is imperative to develop LD-specific long-wavelength fluorescent probes with high imaging contrast for the in-situ diagnosis of NAFLD.In this study,we synthesized a new LD-selective long-wavelength fluorescent probe,denoted as LD-1,based on the twisted intramolecular charge transfer(TICT)mechanism.The probe exhibits a large Stokes shift and intensive fluorescence emission in nonpolar and viscous solutions.By self-assembling LD-1 with bovine serum albumin(BSA),a biocompatible,long-wavelength fluorescent probe hybrid,LD-1@BSA,was formed,allowing for LDs to be selectively imaged in hepatocytes.Moreover,LD-1@BSA successfully discriminates NAFLD cells before and after drug treatment,and achieves non-invasive and real-time monitoring of LD accumulation in a mouse model of NAFLD. 展开更多
关键词 Lipid droplets imaging fluorescent probe Large stokes shift Protein encapsulation Non-alcoholic fatty liver
原文传递
Laser Cooling Using Anti-Stokes Fluorescence in Yb^(3+)-Doped Fluorozirconate Glasses 被引量:1
2
作者 Xu Tian-ming Li Cheng-fang +1 位作者 Zhou Xiao Zhong Jia-cheng 《Wuhan University Journal of Natural Sciences》 CAS 2002年第2期177-181,共5页
The fluorozirconate glasses ZBLANP( ZrF\-4-BaF\-2-LaF\-3-AlF\-3-NaF-PbF\-2) doped with different Yb\+ 3+ concentration were prepared. The Raman spectra and absorption spectra are measured to substantiate the existenc... The fluorozirconate glasses ZBLANP( ZrF\-4-BaF\-2-LaF\-3-AlF\-3-NaF-PbF\-2) doped with different Yb\+ 3+ concentration were prepared. The Raman spectra and absorption spectra are measured to substantiate the existence of phonon-assisted emission. After analyzing the normalized absorption spectra of samples with different Yb\+ 3+-doped concentration, we calculated the maximum cooling effect in the 3 wt% Yb\+ 3+-doped sample pumped at 1 012.5 nm. The corresponding cooling capability is about -4.09 ℃/W and the cooling efficiency reaches 1.76%. 展开更多
关键词 anti-stokes fluorescence Yb^(3+)-doped ZBLANP glass cooling efficiency
下载PDF
A pyrene-based ratiometric fluorescent probe with a large Stokes shift for selective detection of hydrogen peroxide in living cells
3
作者 Qingxin Chen Ke Cheng +6 位作者 Wanhe Wang Liu Yang Yusheng Xie Ling Feng Jie Zhang Huatang Zhang Hongyan Sun 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2020年第5期490-497,共8页
Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been report... Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems. 展开更多
关键词 Hydrogen peroxide fluorescent probe PYRENE Ratiometric detection Large stokes shift
下载PDF
FPM DOFS中stokes或anti-stokes的频移分析 被引量:3
4
作者 宋牟平 汤伟中 周文 《光通信技术》 CSCD 北大核心 1997年第1期46-50,共5页
近年来分布式光纤传感器(DOFS)发展很快,利用四波混频脉冲移位的分布式光纤传感器(FPMDOFS)是最近提出的一种新型分布式光纤传感技术,本文对FPMDOFS中stokes/anti-stokes频移进行了理论分析,给出频移计算公式,并指出在激励光... 近年来分布式光纤传感器(DOFS)发展很快,利用四波混频脉冲移位的分布式光纤传感器(FPMDOFS)是最近提出的一种新型分布式光纤传感技术,本文对FPMDOFS中stokes/anti-stokes频移进行了理论分析,给出频移计算公式,并指出在激励光脉冲功率衰减较大的情况下,应考虑由自相位调制引起的stokes/anti-stokes中心频率偏移。 展开更多
关键词 分布式 光纤传感器 四波混频 频移 FPMDOFS
下载PDF
基于anti-Stokes Raman散射温度效应的温度解调理论研究 被引量:2
5
作者 赵玮 赵晓铭 +1 位作者 王莲芬 周友杰 《光电子技术与信息》 2005年第2期38-42,共5页
激光脉冲进入光纤中,与光纤分子相互作用,产生Raman散射和Raylei曲散射。由于Raman散射具有温度效应,其散射光强度受温度调制,可作为温度信息的载体,用于温度解调及测温系统设计。本文提出了可行的温度解调方法及理论推导,并推导出单通... 激光脉冲进入光纤中,与光纤分子相互作用,产生Raman散射和Raylei曲散射。由于Raman散射具有温度效应,其散射光强度受温度调制,可作为温度信息的载体,用于温度解调及测温系统设计。本文提出了可行的温度解调方法及理论推导,并推导出单通道和双通道条件下的测温关系,设计出两种条件下的传感器系统。 展开更多
关键词 斯托克斯散射 反斯托克斯散射 瑞利散射 温度解调
下载PDF
用液芯光纤研究stokes/anti-stokes拉曼强度比测温
6
作者 黄保坤 高淑琴 +2 位作者 里佐威 陈建 陆国会 《光学技术》 CAS CSCD 2004年第4期446-448,共3页
液芯光纤可以使拉曼光谱强度提高103倍。研究了在stokes/anti stokes拉曼光谱强度比测温中如何获得理想测温结果的方法。用长为5.20m、内径为50μm的含C6H6和CCl4混合液体的液芯光纤,获得了高强度CCl4的±218cm-1,±314cm-1和&#... 液芯光纤可以使拉曼光谱强度提高103倍。研究了在stokes/anti stokes拉曼光谱强度比测温中如何获得理想测温结果的方法。用长为5.20m、内径为50μm的含C6H6和CCl4混合液体的液芯光纤,获得了高强度CCl4的±218cm-1,±314cm-1和±459cm-1的拉曼光谱。利用各光谱带的stokes与anti stokes的强度比(Is/Ia),确定了液芯光纤所在处的温度。实验结果表明,±459cm-1的强度比的实验值与理论值符合得很好,±218cm-1为较好,±314cm-1稍差一些。从理论和实验两方面总结了拉曼频移、光纤损耗、溶剂效应、仪器响应等对测温结果的影响。 展开更多
关键词 液芯光纤 拉曼光谱 stokes/anti-stokes拉曼光谱强度比
下载PDF
Selective excitation of molecular mode in a mixture by femtosecond resonance-enhanced coherent anti-Stokes Raman scattering spectroscopy 被引量:2
7
作者 He Ping Li Si-Ning +4 位作者 Fan Rong-Wei Li Xiao-Hui Xia Yuan-Qin Yu Xin Chen De-Ying 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期526-530,共5页
Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics. Due to the spectrally broad laser pulses, usually poorly resolved spectra result... Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics. Due to the spectrally broad laser pulses, usually poorly resolved spectra result from this broad spectroscopy. However, it can be demonstrated that by the electronic resonance enhancement optimization control a selective excitation of specific vibrational mode is possible. Using an electronically resonance-enhanced effect, iodine molecule specific CARS spectroscopy can be obtained from a mixture of iodine-air at room temperature and a pressure of 1 atm (corresponding to a saturation iodine vapour as low as about 35 Pa). The dynamics on either the electronically excited state or the ground state of iodine molecules obtained is consistent with previous studies (vacuum, heated and pure iodine) in the femtoseeond time resolved CARS spectroscopy, showing that an effective method of suppressing the non-resonant CARS background and other interferences is demonstrated. 展开更多
关键词 ultrafast spectroscopy coherent anti-stokes Raman scattering vibrational analysis resonance enhancement
下载PDF
椭圆偏振激光抽运应变光纤的受激anti-Stokes拉曼散射
8
作者 杨鹏 王业超 宦克为 《长春理工大学学报(自然科学版)》 2020年第4期14-18,共5页
研究不同椭圆偏振激光抽运应变光纤产生的anti-Stokes拉曼光谱特征。0 Pa压力时,椭圆偏振光相差180°~360°,激发anti-Stokes光出现几率大于0°~180°的anti-Stokes光。对光纤施加水平单边压力,在一定的压力值下,两种... 研究不同椭圆偏振激光抽运应变光纤产生的anti-Stokes拉曼光谱特征。0 Pa压力时,椭圆偏振光相差180°~360°,激发anti-Stokes光出现几率大于0°~180°的anti-Stokes光。对光纤施加水平单边压力,在一定的压力值下,两种椭圆偏振相差的anti-Stokes光出现几率几乎相等;进一步增大压力,破坏了光纤传输条件,高阶anti-Stokes光消失。椭圆偏振光相差与压力引起的光纤双折射,共同导致了频移和峰值半高全宽的变化。同时,高阶anti-Stokes光谱也存在缺级现象,拉曼响应时间、简并四波混频的出现及其响应时间是引起这种现象的根源。这为光纤激光中抑制、增强或选择某一阶anti-Stokes光谱提供了一种新方法。 展开更多
关键词 非线性光学 反斯托克斯拉曼光谱 应变 光纤
下载PDF
基于萘酰亚胺和三苯胺的能量转移型大Stokes位移聚集诱导发光分子
9
作者 金怡彤 黄文灵 +2 位作者 蒋娜 周慧敏 瞿祎 《上海工程技术大学学报》 CAS 2023年第3期290-295,共6页
聚集诱导发光(AIE)现象是近年来光电功能材料的研究热点之一.已开发的聚集诱导发光材料其发射光谱大都位于短波长的蓝绿光区域.利用发色团光谱重叠构建高效的能量转移过程,实现了大Stokes位移的聚集诱导发光分子的构建.使用实验室开发... 聚集诱导发光(AIE)现象是近年来光电功能材料的研究热点之一.已开发的聚集诱导发光材料其发射光谱大都位于短波长的蓝绿光区域.利用发色团光谱重叠构建高效的能量转移过程,实现了大Stokes位移的聚集诱导发光分子的构建.使用实验室开发的4-苯基萘酰亚胺(NIP)蓝光聚集诱导发光分子作为能量给体,使用红光的氰基乙烯基三苯胺(TPACN)为能量受体,构建出的分子(NIPTPACN)可以在360 nm紫外光激发下,实现608 nm的红光聚集诱导发光.NIPTPACN的Stokes位移达到248 nm,聚集态荧光发光强度是单纯使用氰基乙烯基三苯胺的82.6倍.该研究成功实现了基于能量转移的大Stokes位移聚集诱导发光分子构建,为长波发光和大Stokes位移聚集诱导发光分子的设计提供了新的策略. 展开更多
关键词 萘酰亚胺 聚集诱导发光 stokes位移 荧光共振能量转移
下载PDF
A non-peptide-based chymotrypsin-targeted long-wavelength emission fluorescent probe with large Stokes shift and its application in bioimaging
10
作者 Chuanfeng Fan Jian Gao +10 位作者 Yingkai Gao Xintong Yang Gaoning Li Xiaochun Wang Fei Li Jin Zhou Haifeng Yu Yi Huang Jin Chen Yingying Shan Li Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第10期430-436,共7页
As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an inno... As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an innovative long-wavelength emission fluorescent probe TCF-CHT was designed and synthesized for the high specificity detection of CHT,which utilized TCF-OH and a mimetic peptide substrate 4-bromobutyryl as chromogenic group and recognition group,respectively.TCF-CHT exhibited excellent selectivity and eye-catching sensitivity(8.91 ng/m L)towards CHT,“off-on”long-wavelength emission at 670 nm and large Stokes shift(140 nm).Furthermore,the successful fulfillment and perfect performance in imaging endogenous CHT in complex organisms(P815 cells,HepG2 cells,zebrafish and tumor-bearing mice)verified its potential as a powerful tool for the recognition of CHT in complicated biological environments. 展开更多
关键词 CHYMOTRYPSIN fluorescent probe Long-wavelength emission Large stokes shift BIOIMAGING
原文传递
Simultaneous measurements of global vibrational spectra and dephasing times of molecular vibrational modes by broadband time-resolved coherent anti-Stokes Raman scattering spectrography 被引量:2
11
作者 尹君 于凌尧 +3 位作者 刘星 万辉 林子扬 牛憨笨 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期385-391,共7页
In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC), the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of variou... In broadband coherent anti-Stokes Raman scattering (CARS) spectroscopy with supercontinuum (SC), the simultaneously detectable spectral coverage is limited by the spectral continuity and the simultaneity of various spectral components of SC in an enough bandwidth. By numerical simulations, the optimal experimental conditions for improving the SC are obtained. The broadband time-resolved CARS spectrography based on the SC with required temporal and spectral distributions is realised. The global molecular vibrational spectrum with well suppressed nonresonant background noise can be obtained in a single measurement. At the same time, the measurements of dephasing times of various molecular vibrational modes can be conveniently achieved from intensities of a sequence of time-resolved CARS signals. It will be more helpful to provide a complete picture of molecular vibrations, and to exhibit a potential to understand not only both the solvent dynamics and the solute-solvent interactions, but also the mechanisms of chemical reactions in the fields of biology, chemistry and material science. 展开更多
关键词 coherent anti-stokes Raman scattering photonic crystal fibre SUPERCONTINUUM molecular vibrational spectrum dephasing time time-resolved measurement
下载PDF
Selective excitation and suppression of coherent anti-Stokes Raman scattering by shaping femtosecond pulses 被引量:1
12
作者 张诗按 张晖 +1 位作者 王祖赓 孙真荣 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第4期198-202,共5页
Femtosecond coherent anti-Stokes Raman scattering (CARS) suffers from poor selectivity between neighbouring Raman levels due to the large bandwidth of the femtosecond pulses. This paper provides a new method to real... Femtosecond coherent anti-Stokes Raman scattering (CARS) suffers from poor selectivity between neighbouring Raman levels due to the large bandwidth of the femtosecond pulses. This paper provides a new method to realize the selective excitation and suppression of femtosecond CARS by manipulating both the probe and pump (or Stokes) spectra. These theoretical results indicate that the CARS signals between neighbouring Raman levels are differentiated from their indistinguishable femtosecond CARS spectra by tailoring the probe spectrum, and then their selective excitation and suppression can be realized by supplementally manipulating the pump (or Stokes) spectrum with the π spectral phase step. 展开更多
关键词 coherent anti-stokes Raman scattering (CARS) selective excitation selective suppression pulse shaping
下载PDF
Coherent coupling between vibrational modes of C-H bonds at different positions studied by femtosecond time-resolved coherent anti-Stokes Raman scattering 被引量:1
13
作者 杜鑫 何兴 +2 位作者 刘玉强 王英惠 杨延强 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期248-251,共4页
We performed femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) measurements on liquid toluene and PVK film. For both samples, we selectively excited the CH stretching vibrational modes and ob... We performed femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) measurements on liquid toluene and PVK film. For both samples, we selectively excited the CH stretching vibrational modes and observed the expected quantum beat signals. The frequency of the well-defined beats is in good agreement with the energy difference between the two simultaneously excited modes, which demonstrates that a coherent coupling between the vibrational modes of the C H chemical bonds exists at the different positions of the molecules. The dephasing times of the excited modes are obtained simultaneously. 展开更多
关键词 femtosecond time-resolved coherent anti-stokes Raman scattering coherent coupling quantum beat
下载PDF
Antibody Pattern: Correlation of Age and Gender in ANA and Anti-ds-DNA Prevalence
14
作者 Usama Ahmed Hijazi Mallick +1 位作者 Amber Khan Muhammad Zubair 《Journal of Clinical and Nursing Research》 2024年第6期373-381,共9页
The study was designed to find the prevalence of ANA antibodies and anti-dsDNA antibodies in samples tested at AFIP Rawalpindi and their correlation with age and gender and to find positive and negative predictive val... The study was designed to find the prevalence of ANA antibodies and anti-dsDNA antibodies in samples tested at AFIP Rawalpindi and their correlation with age and gender and to find positive and negative predictive values of ANA antibodies.For this purpose,twelve thousand nine hundred sixty-seven(12,967)patients were analyzed for ANA with four hundred sixty-eight(468)healthy samples tested as control and four thousand seven hundred three(4,703)patients tested for ds-DNA antibodies.Retrospective data of all samples tested by indirect immunofluorescence(IF)for ANA antibodies and dsDNA antibodies was collected.To address positive and negative predictive values another control group(autoimmunity not suspected)of serum samples was taken from the healthy population.For the first group,age,gender,ANA antibodies and ds-DNA antibodies results(both tests performed by IIF)data was collected from a computer record cell;for the second control group,ANA antibodies were performed by IIF.12,967 and 4,703 samples(Group 1)were tested for ANA antibodies and dsDNA antibodies,respectively,during this period.1,119(9%)and 99(2%)were found positive for ANA antibodies and ds DNA antibodies.Among these positive samples,850(76%)and 73(74%)were females respectively.Gender predisposition towards autoimmunity(ANA)was found significant with a P value of(P=0.001).Relation of age was also found significant with anti-ANA antibodies with a P value of(P=0.001).This study shows a negative correlation between age(P=0.025)and gender(P=0.001)with anti-dsDNA which is also significant.High prevalence was found below the mean age of 38 years(SD±16.635)for ANA antibodies and the mean age of 35 years(SD±15.066)for ds-DNA antibodies.The age of ANA antibodies and dsDNA antibodies positive patients ranged from 1 year old to 98 years old and 2 years old to 95 years old respectively.In the second(autoimmunity-free)control group,a total of 468 samples were tested for ANA antibodies and 9(2%)were found positive.Positive predictive value(PPV)was 8.6%and negative predictive value(NPV)was 98%.ANA is a sensitive test for autoimmunity and it is significantly related to female gender and increasing age.The low prevalence of ANA antibodies among clinically suspected cases suggests that rationalization of test prescriptions is needed.Anti-ds-DNA is also a sensitive test for diagnosis of SLE and it is significantly related to female gender and increasing age. 展开更多
关键词 ANA anti ds-DNA AUTOIMMUNITY SLE Immune fluorescence
下载PDF
Theoretical and experimental investigations of coherent phonon dynamics in sapphire crystal using femto-second time-resolved coherent anti-Stokes Raman scattering
15
作者 杜鑫 张明福 +4 位作者 何兴 孟庆琨 宋云飞 杨延强 韩杰才 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第12期315-321,共7页
We report on the theoretical and the experimental investigations of the coherent phonon dynamics in sapphire crystal using the femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) technique. The... We report on the theoretical and the experimental investigations of the coherent phonon dynamics in sapphire crystal using the femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) technique. The temporal chirped white-light continuum (WLC) is used for the Stokes pulse, therefore we can perform the selective excitation of the phonon modes without using a complicated laser system. The expected quantum beat phenomenon is clearly observed. The theoretical formulas consist very well with the experimental results. The dephasing times of the excited phonon modes, the wavenumber difference, and the phase shift between the simultaneously excited modes are obtained and discussed. This work opens up a way to study directly high-frequency coherent phonon dynamics in bulk crystals on a femtosecond time scale and is especially helpful for understanding the nature of coherent phonons. 展开更多
关键词 coherent phonon femtosecond time-resolved coherent anti-stokes Raman scattering DEPHASING quantum beat
下载PDF
Analysis of detection limit to time-resolved coherent anti-Stokes Raman scattering nanoscopy
16
作者 刘伟 刘双龙 +1 位作者 陈丹妮 牛憨笨 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期124-129,共6页
In the implementation of CARS nanoscopy, signal strength decreases with focal volume size decreasing. A crucial problem that remains to be solved is whether the reduced signal generated in the suppressed focal volume ... In the implementation of CARS nanoscopy, signal strength decreases with focal volume size decreasing. A crucial problem that remains to be solved is whether the reduced signal generated in the suppressed focal volume can be detected. Here reported is a theoretical analysis of detection limit (DL) to time-resolved CARS (T-CARS) nanoscopy based on our proposed additional probe-beam-induced phonon depletion (APIPD) method for the low concentration samples. In order to acquire a detailed shot-noise limited signal-to-noise (SNR) and the involved parameters to evaluate DL, the T-CARS process is described with full quantum theory to estimate the extreme power density levels of the pump and Stokes beams determined by saturation behavior of coherent phonons, which are both actually on the order of ~ 109 W/cm2. When the pump and Stokes intensities reach such values and the total intensity of the excitation beams arrives at a maximum tolerable by most biological samples in a certain suppressed focal volume (40-nm suppressed focal scale in APIPD method), the DL correspondingly varies with exposure time, for example, DL values are 103 and 102 when exposure times are 20 ms and 200 ms respectively. 展开更多
关键词 break through the diffraction limit coherent anti-stokes Raman scattering nonlinear optics de-tection limit
下载PDF
Improvement in the calculation of anti-Stokes energy transfer and experimental justification based on Er_(0.01)Yb_xY_(1 0.01 x)VO_4 crystal
17
作者 陈晓波 卢建 +5 位作者 张蕴芝 徐小灵 冯宝华 王策 Gregory J. Salamo 杨国建 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第9期604-611,共8页
The improvement on the calculation of anti-Stokes energy transfer rate is studied in the present work. The additional proportion coefficient between Stokes and anti-Stokes light intensities of quantum Raman scattering... The improvement on the calculation of anti-Stokes energy transfer rate is studied in the present work. The additional proportion coefficient between Stokes and anti-Stokes light intensities of quantum Raman scattering theory as compared with the classical Raman theory is introduced to successfully describe the anti-Stokes energy transfer. The theoretical formula for the improvement on the calculation of anti-Stokes energy transfer rate is derived for the first time in this study. The correctness of introducing coefficient exp{△E/kT} from well-known Raman scatter theory is demonstrated also. Moreover, the experimental lifetime measurement in Er0.01YbxY1-0.01-xVO4 crystal is performed to justify the validity of our important improvement in the original phonon-assisted energy transfer theory for the first time. 展开更多
关键词 improvement of anti-stokes energy transfer Raman scattering quantum and classical theory Er0.01YbxY1-0.01-xVO4 crystal
下载PDF
Improved anti-Stokes energy transfer between rare earth ions in Er(0.5)Yb(9.5):FOV oxyfluoride vitroceramics explains the strong color reversal
18
作者 陈晓波 王策 +5 位作者 Gregory J.Salamo Naruhito Sawanobori 康栋国 Masaaki Ohtsuka 杨国建 彭芳麟 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第12期5523-5533,共11页
The widely used energy transfer theory is a foundation of luminescence, in which the rates of Stokes and anti-Stokes processes have the same calculation formula. An improvement on the anti-Stokes energy transfer to ex... The widely used energy transfer theory is a foundation of luminescence, in which the rates of Stokes and anti-Stokes processes have the same calculation formula. An improvement on the anti-Stokes energy transfer to explain the fluorescence intensity reversal between the red and green fluorescence of Er(0.5)Yb(9.5):FOV is reported in the present article. The range of the intensity reversal Z was measured to be 877. Dynamic processes for 16 levels were simulated. A coefficient, the improvement factor of the intensity ratio of Stokes to anti-Stokes processes in quantum Raman theory compared to classical Raman theory, is introduced to successfully describe the anti-Stokes energy transfer. A new method to calculate the distance between the rare earth ions, which is critical for the energy transfer calculation, is proposed. The validity of these important improvements is also proved by experiment. 展开更多
关键词 improvement of anti-stokes energy transfer NANOMATERIAL Era+yb^3+ co-doped rare earth ion material
下载PDF
Selective Excitation of Two-pulse Femtosecond Coherent Anti-Stokes Raman Scattering in a Mixture
19
作者 Hui Zhang Xianghua Feng +3 位作者 Zhongqiu Yu Xia Li Shian Zhang Zhenrong Sun 《Optics and Photonics Journal》 2013年第2期38-42,共5页
In this paper, we experimentally study the selective excitation of two-pulse femtosecond coherent anti-Stokes Raman scattering (CARS) in a mixture of dibromomethane (CH2Br2) and chloroform (CHCl3) by adaptive pulse sh... In this paper, we experimentally study the selective excitation of two-pulse femtosecond coherent anti-Stokes Raman scattering (CARS) in a mixture of dibromomethane (CH2Br2) and chloroform (CHCl3) by adaptive pulse shaping based on genetic algorithm. Second harmonic generation frequency-resolved optical gating (SHG-FROG) traces indicate that the spectral amplitude and phase of the optimal pulse are both modulated. Finally, we discuss the physical mechanism for the selective excitation of femtosecond CARS based on the retrieved information from SHG-FROG traces. 展开更多
关键词 Coherent anti-stokes RAMAN Scattering Selective EXCITATION PULSE SHAPING
下载PDF
混合染料荧光选择性增强受激拉曼散射Stokes波 被引量:5
20
作者 左浩毅 高洁 杨经国 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2007年第3期552-555,共4页
报道用不同混合比的罗丹明6G(R6G)和罗丹明B(RB)混合染料荧光选择性放大CCl4和苯的受激拉曼散射不同阶次Stokes波。CCl4二至五阶Stokes波分别被混合摩尔比为20∶2,20∶13及20∶40(R6g∶RB)的R6G和RB的混合染料荧光放大;一阶Stokes波强... 报道用不同混合比的罗丹明6G(R6G)和罗丹明B(RB)混合染料荧光选择性放大CCl4和苯的受激拉曼散射不同阶次Stokes波。CCl4二至五阶Stokes波分别被混合摩尔比为20∶2,20∶13及20∶40(R6g∶RB)的R6G和RB的混合染料荧光放大;一阶Stokes波强度被混合溶液削弱。这是由于到二至五阶Stokes波分别位于以上三种混合溶液荧光峰附近,并且都远离了R6G和RB的吸收峰,混合溶液的荧光增强作用大于吸收作用,因此这几阶Stokes被混合溶液荧光放大。而CCl4的一阶Stokes位于RB吸收峰附近,又远离各混合溶液荧光峰,溶液的吸收作用大于荧光增强作用,导致一阶Stokes被混合溶液削弱。文章还报道了苯的一、二和三阶Stokes波分别被不同混合比的R6G和DCM的混合乙醇溶液放大,并预测了该方法应用前景。 展开更多
关键词 混合染料荧光 选择性增强 stokes
下载PDF
上一页 1 2 26 下一页 到第
使用帮助 返回顶部