激光光解
激光光解的相关文献在1990年到2022年内共计95篇,主要集中在化学、物理学、生物化学
等领域,其中期刊论文80篇、会议论文11篇、专利文献230236篇;相关期刊28种,包括辐射研究与辐射工艺学报、高等学校化学学报、光谱学与光谱分析等;
相关会议11种,包括第十六届全国分子光谱学学术会议、2010年全国辐射技术与辐射改性材料发展论坛、中国核学会2009年学术年会等;激光光解的相关文献由205位作者贡献,包括姚思德、王文锋、林维真等。
激光光解—发文量
专利文献>
论文:230236篇
占比:99.96%
总计:230327篇
激光光解
-研究学者
- 姚思德
- 王文锋
- 林维真
- 林念芸
- 吴国忠
- 韩镇辉
- 付海英
- 孙晓宇
- 朱起鹤
- 汪世龙
- 赵红卫
- 倪亚明
- 刘艳成
- 宋钦华
- 张鹏
- 李海霞
- 陆长元
- 马建华
- 潘景喜
- 王文峰
- 高振
- 伍新燕
- 储高升
- 刘江文
- 唐睿智
- 崔执凤
- 张兆霞
- 张志成
- 张永康
- 徐业平
- 朱紫红
- 朱红平
- 洪文生
- 王文兵
- 王玫
- 苗金玲
- 邓宇
- 邢兆国
- 郭钟宁
- 陈从香
- 陈家富
- 韩春英
- 麦文豪
- 黄志刚
- 余敏
- 刘海川
- 吴成泰
- 周鸣飞
- 张兴初
- 张霞
-
-
李陶琦;
丁可伟;
刘红利;
卜建华;
杨斌;
刘卫;
葛忠学
-
-
摘要:
为了制备新型高氮含量的原子簇材料,分别将金属铁、钴和镍粉末与氮化硼制成的底物,经波长532nm激光溅射生成了杂氮团簇FeN^(+)_(n)、CoN^(+)_(n)和NiN^(+)_(n),并采用波长266nm激光进行了光解。结果表明,不同底物生成的金属杂氮团簇具有不同特点:3种金属杂氮团簇最高含氮原子数分别为8、12和8;铁杂氮团簇有2种偶数氮原子团簇,其中FeN^(+)_(8)离子峰强度较高;钴杂氮团簇有4种偶数氮原子团簇,团簇离子峰相对强度从6到8随氮原子数增加而提高、从8到12随氮原子数增加而降低,其中CoN^(+)_(8)离子峰强度最高;镍杂氮团簇有2种偶数氮原子团簇NiN+6和NiN^(+)_(8),其离子峰相对强度随氮原子数增加而增高;FeN^(+)_(8)、CoN^(+)_(8)和NiN^(+)_(8)光解通道分别为1个、1个和2个,对应的光解产物分别为Fe^(+)、Co^(+)及Ni^(+)和NiN^(+)_(2)。
-
-
李晓峰;
颜蓓蓓;
张大源;
李红;
李博;
陈冠益;
李中山
-
-
摘要:
实现火焰反应区和不同中间组分的在线二维瞬态成像,在湍流燃烧的基础研究中具有十分重要的意义.用Nd∶YAG激光器的5倍频输出(212.8 nm)作为光源,通过激光光解诱导荧光技术在甲烷/空气预混火焰中,成功实现了火焰反应区的瞬态成像,并首次采用该技术实现了CH3的在线瞬态成像测量.分析了该方法同其他荧光标示物在反应区二维瞬态成像方法的优势,并研究了火焰燃烧过程中其他燃烧中间产物和不同燃空比对CH3单脉冲成像的影响,讨论了现有条件下该技术的应用范围.根据实验结果,在燃空比Φ=1.2的条件下,在反应区我们获得了信噪比约为8的单脉冲成像,分析火焰中CH3的单脉冲成像结果可知火焰燃空比在1.0~1.4之间时,或者火焰中CH3的浓度大于9.3×1015molecules·cm-3信噪比较好.该项技术在动力机械及其他研究领域的应用有十分重要的参考价值.%Online instantaneous two-dimensional imaging of reaction zone and different intermediate species in flames are important and fundamental in the research of turbulence combustion.In methane/air premixed flames,the instantaneous imaging of flame reaction zone is achieved using laser photodissociation-induced fluorescence technique with the 5th harmonic (212.8 nm) of an Nd ∶ YAG laser as excitation source.The online instantaneous imaging of CH3 radicals was accomplished for the first time with this technique.The advantage of this technique was analyzed over other typical PLIF techniques in terms of visualization of flame reaction zone.The influences of other combustion intermediates and flame equivalence ratio to the single-shot imagining of CH3 were studied,and the application range of the technique was also discussed.The result shows that single shot imaging of reaction zones in our measurement with a signal-to-noise ratio (SNR) of 8.Single shot imaging of CH3 has better SNR by LPIF in premixed methane/air flames with the equivalence ratio from 1.0 to 1.4,or when the concentration of CH3 is higher than 9 × 1015 molecules · cm-3.The results provide very important information for the application of this technology in power machinery and other field.
-
-
李海霞;
刘艳成;
唐睿智;
张鹏;
马六逵;
魏驰原;
王文锋
-
-
摘要:
The reactions of triplet-state difloxacin (DFX) with various amino acids and deoxyguanylic acid in aqueous media were studied using laser flash photolysis.Tryptophan,tyrosine,cysteine,and 2'-deoxyguanosine5'-monophosphate (dGMP) were found to completely quench the triplet state of DFX in aqueous solution,the corresponding second-order rate constants being 1.97 x 108,1.48 x 108,1.72 x 108,and 6.92 x 107 dm3·mol-1·s-1.The quenching mechanism involves electron transfer to the photoexcited triplet state of DFX from the tryptophan,tyrosine,cysteine,and dGMP moieties,followed by fast protonation of the resulting DFX anion radical.%本文利用激光光解法研究了二氟沙星激发态氧化损伤氨基酸和脱氧鸟苷酸等生物小分子.实验结果显示二氟沙星激发态水溶液氧化损伤色氨酸,酪氨酸,半胱氨酸和脱氧鸟苷酸的速率常数分别为1.97×108,1.48×108,1.72×108,6.92×107 dm3·mol-1·s-1.通过光谱分析和实验数据分析可以得出激发态二氟沙星氧化损伤色氨酸,酪氨酸,半胱氨酸和脱氧鸟苷酸是通过电子转移的方式进行的.
-
-
李海霞;
刘艳成;
唐睿智;
张鹏;
徐宇列;
王文锋
-
-
摘要:
采用纳秒级激光光解瞬态研究技术,以乙腈作为溶剂,研究在355 nm激光作用下产生二氟沙星(DFX)激发三重态,并利用能量转移的实验进一步研究了二氟沙星激发三重态的性质.结果显示,萘普生和二氟沙星的二元体系在355 nm激光作用下,二氟沙星首先被激发为其激发三重态(580 nm),二氟沙星激发三重态与萘普生发生激发能转移,产生萘普生激发三重态(440 nm).通过能量转移的方法确定了二氟沙星在乙腈溶剂中产生的激发三重态在最大吸收波长580 nm处的摩尔消光系数为8,900 dm3/mol·cm.通过改变二氟沙星的浓度测得其激发三重态在乙腈体系中的自衰变速率常数和三重态平均寿命(τ)分别为5.39×106 s-1和2.8μs.
-
-
李海霞;
周保昌;
刘艳成;
唐睿智;
张鹏;
李景烨;
王文锋
-
-
摘要:
对二氟沙星在中性水溶液中的光化学性质进行了研究.在pH值为7.17的水溶液中二氟沙星的紫外吸收峰位于273 nm (摩尔消光系数ε=33000 dm3∙mol-1∙cm-1),323 nm (ε=15500 dm3∙mol-1∙cm-1),335 nm (ε=15500 dm3∙mol-1∙cm-1)处.荧光吸收和发射光谱均显示二氟沙星具有pH效应,其pKa(电离平衡常数)测定分别为5.9和9.8.二氟沙星的荧光量子产额较低,在pH=3.00时达到最大值,为0.06.同时对二氟沙星在中性水溶液中的激光光解和脉冲辐解进行详细研究.激光光解研究发现在水溶液中二氟沙星的三重激发态位于620 nm,其摩尔消光系数为7900 dm3∙mol-1∙cm-1.通过能量转移的方法得到其三重激发态的能量为263.5 kJ∙mol-1,三重激发态的量子产额为0.21.在激光激发下,二氟沙星进行单光子电离其量子产额为0.02.脉冲辐解研究表明二氟沙星可以与水合电子(e-aq)及羟基自由基(∙OH)快速反应,其二级反应动力学常数分别为1.72×1010和1.0×1010 dm3∙mol-1∙s-1.本文对二氟沙星光化学性质的研究有助于确定其光敏毒性的产生机理.%The photochemical properties of difloxacin (DFX) were investigated in neutral aqueous solution. DFX aqueous solution showed intense absorption with one peak at 273 nm (molar absorption coefficientε=33000 dm3∙mol-1∙cm-1) and two other peaks at 323 and 335 nm (ε=15500 dm3∙mol-1∙cm-1) with the same molar absorption coefficient. Both the absorption and emission properties of DFX were pH-dependent. The acid dissociation constant (pKa) for the protonation equilibria of the ground state (5.9 and 9.8) were determined spectroscopical y. DFX fluoresces weakly, and its maximum quantum yield for fluorescence emission was 0.06 at pH 3. Laser flash photolysis and pulse radiolysis studies were carried out to characterize the transient species of DFX aqueous solution. Triplet-triplet absorption reached a maximum at 620 nm with a molar absorption coefficient of 7900 dm3∙mol-1∙cm-1. The energy transfer method was used to estimate the triplet energy of DFX, which was 263.5 kJ∙mol-1. The quantum yield of triplet formation was determined to be 0.21. Furthermore, DFX showed monophotonic photoionization with a quantum yield of 0.02. Pulse radiolysis indicated that DFX could react with e-aq and∙OH, and the bimolecular rate constants for these reactions were 1.72×1010 and 1.0×1010 dm3∙mol-1∙s-1, respectively. It is expected that this research may be helpful in determining the phototoxicity mechanism of DFX.
-
-
付海英;
曹西艳;
邢兆国;
吴国忠
-
-
摘要:
选择氧杂蒽酮(XAN)为探针分子,利用纳秒级瞬态光解技术研究在1-丁基-3-甲基咪唑六氟磷酸盐离子液体([bmim][PF6])以及离子液体与常规溶剂中的光化学行为,探索不同溶剂对氧杂蒽酮激发三线态态(3XAN*)的最大吸收峰的影响:3XAN*在纯乙腈(MeCN)中的吸收峰在630 nm,而在[bmim][PF6]作溶剂的体系中激发态的吸收峰发生蓝移,而且纯离子液体体系中3XAN*的产额显著增加.进一步探索离子液体对光诱导3XAN*与萘(NAP)之间的能量转移及与N,N-二甲基苯胺(DMA)之间的电子转移的影响,结果表明:[bmim][PF6]/MeCN的二元体系中随着[bmim][PF6]浓度的增大,氧杂蒽酮与萘之间的能量转移速率减小,测得在乙腈和纯离子液体中3XAN*与NAP之间能量转移速率常数分别为1.2×1010mol· L-1·S-1和1.1×108mol·L-1·s-1.%The transient photochemical behavior of xanthone(XAN) in 1-butyl-3-methyl imidazolium hexafluoride phosphate ionic liquid ([bmim][PF6]) or binary mixed solution with acetonitrile (MeCN) was investigated by nano-second laser photolysis techniques.The spectral blue shift of 3XAN* was observed in the neat [bmim][PF6] or IL/MeCN mixture solution compared to MeCN solution.And the yield was also increased.Moreover,the energy transfer rate constant of XAN and naphthalene (NAP)was affected by the concentrations of ionic liquid.The values decreased rapidly with increasing VIL.For example,the values were 1.2×1010 mol · L-1 · s-1 in MeCN,and 1.1 × 108 mol · L-1 · s-1 in [bmim][PF6],respectively.The photo-induced electron transfer between XAN and N,N-dimethylaniline was also investigated by changing the concentrations of [bmim][PF6]in binary solution.
-
-
曹西艳;
付海英;
朱莉;
吴国忠
-
-
摘要:
以355 nm激光为激励光源,研究2-甲基蒽醌(MAQ)光敏氧化芳香氨基酸(色氨酸、酪氨酸、苯丙氨酸)的光化学行为.在乙腈-水体积比1∶1的混合体系中,2-甲基蒽醌三重激发态(3MAQ*)的吸收峰位于390,450和590nm,利用3MAQ*与电子给体的电子转移反应确定其阴离子自由基的特征吸收峰为390和490nm.2-甲基蒽醌与色氨酸、酪氨酸、苯丙氨酸的瞬态反应都显示随着590 nm激发三重态的衰减,出现490nm 2-甲基蒽醌阴离子自由基的生成,并进一步确定了2-甲基蒽醌与色氨酸、酪氨酸和苯丙氨酸的电子转移反应的速率分别为3.0×109,1.1×109和1.8×108 L·mol-1·s-1.同时吉布斯自由能(△G)的计算结果也表明2-甲基蒽醌的激发三重态与色氨酸、酪氨酸、苯丙氨酸电子转移反应在热力学上是可行的.
-
-
储根柏;
陈军;
刘付轶;
盛六四
-
-
摘要:
Gas-phase radicals can react rapidly with various gaseous molecules, which play a vital role in catalyzing reactions in atmospheric, combustion and interstellar chemistry. A range of experimental techniques such as fluorescence and absorption spectrometry have been employed to study the reaction processes of gas-phase radicals and acquired some important results. Despite of the sufficient sensibility in the measurement of transient species, most of these techniques are limited to small radicals with small molecules, inaccessible to bigger radicals or multiplexed detection. Lately, a combination of flow reactor, flash laser photolysis and synchrotron radiation (SR) photoionization mass spectrometry (PIMS), serves as a universal, multiplexed, selective and sensitive method, ideal for the chemical kinetics study. Pulsed photolysis laser is used to initiate radical reaction, SR vacuum ultraviolet (VUV) light source to ionize the molecules emerging from the side pinepole and mass spectrometer to detect multiple species in the reactions ( especially many-atom species). A plenty of original works such as the studies of CN, OH and alkylperoxy radical reactions have been done using double-focusing mass spectrometer or time-of-flight mass spectrometer and identified to be in fair agreement with the previous methods. Furthermore, the extra ordinary capability of time- and energy- resolution can be widely applicable in the kinetics study of some important radicals such as alkylperoxy and aromatic radicals in atmospheric, combustion, and interstellar chemistry.%气相自由基能与各种气体发生快速反应,在大气化学、燃烧化学和星际化学等重要的化学过程中起着关键性的催化作用。许多实验方法(例如荧光法和吸收法)已经用于研究气相自由基反应动力学过程,并取得许多重要的成果,但这些技术局限于探测小分子自由基反应。流动管反应器和闪光光解结合光电离质谱的实验技术以其通用性、多重探测性、选择性和灵敏性等多种优势,成为研究气相自由基反应的主要实验方法。本文介绍利用高通量、高分辨、连续可调的同步辐射光电离质谱开展多种自由基反应研究所取得的一些独创性的成果。另外,该技术具有独有的时间分辨、能量分辨和异构体分辨的能力,能够广泛用于大气化学、燃烧化学和星际化学中一些重要的气相自由基(如烷氧自由基、烃类自由基等)反应宏观动力学过程的研究。
-
-
付海英;
邢兆国;
吴国忠
-
-
摘要:
利用纳秒级时间分辨激光光解装置,以Nd:YAG激光器三倍频后的355 nm激光作为激发光源,研究了芘在常规溶剂乙腈、丙酮、环己烷、1-丁基-3-甲基咪唑六氟磷酸离子液体([Bmim][PF6])、N-丁基吡啶四氟硼酸离子液体([BuPy][BF4])以及三乙基庚基铵双三氟甲磺酰亚胺(R4NNTf2)的瞬态光解行为,比较了芘在各类体系中的瞬态光谱及反应动力学行为.研究表明芘在离子液体中各类瞬态物种的寿命均较常规溶剂延长,且反应速率常数随着离子液体的类型的变化而不同.与[Bmim][PF6]和R4NNTf2相比,[BuPy][BF4]最为活泼,认为主要是由于[BuPy][BF4]自身参加了反应.%The photochemistry of pyrene in conventional solvents (acetone, acetonitrile, cyclohexane) and ionic liquids [Bmim][PF6 ], [BuPy][BF4 ], R4 NNTf2 was investigated by time-resolved laser photolytic techniques. The transient absorption spectra of the excited pyrene and other radical species were compared. The absorption hand of pyrene cation radical was observed in the acetone, acetronitrile and pyridiniurn ionic liquid [BuPy][BF4 ] systems. Only excited triplet pyrene was observed in cyclohexane and [Bmim][PF6 ] and R4 NNTf2. The result demonstrates that there was an interaction between pyrene and solvents, and the pyrene cation radical was formed by electron transfer from the excited state of pyrene to acetonitrile, acetone and [BuPy][BF4 ].The possible mechanisms of the six systerna were suggested.
-
-
朱光来;
吴国忠;
崔执凤;
许新胜
-
-
摘要:
Using benzil (BZ) as a probe molecule, the photochemical properties of the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and its binary mixed solutions with acetonitrile (MeCN) were investigated by nanosecond laser photolysis.We found that the decay of the triplet excited state of benzil (3BZ*) in a N2-saturated solution followed mono-exponential kinetics.Along with the increase in the volume fraction (VIL) of [bmim][BF4]in the mixed solvents, the absorption peak of 3BZ* did not change.However, the effect of different VIL values on the photoinduced electron transfer process in the mixture of [bmim][BF4]/MeCN was obvious.Moreover, the apparent rate constant (kgr) of the formed radical decreased obviously with an increase in VIL.When the ratio of [bmim][BF4]was sufficiently high, the electron transfer reaction between 3BZ* and triethylamine or N,N,N',N' -tetramethyl-p-phenylenediamine was retarded.%利用纳秒级激光光解瞬态吸收光谱研究了联苯甲酰(BZ)在离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim][BF4])与乙腈(MeCN)混合体系中的光化学反应行为.考察了探针分子BZ存在下[bmim][BF4]/MeCN比例对体系中化学反应动力学的影响.实验发现:在N2饱和条件下,BZ溶液经激光辐照后产生的激发三线态3BZ遵循一级反应动力学规律衰减.离子液体(IL)相对比例增加对3BZ瞬态吸收峰的位置和强度没有产生明显影响.但离子液体体积分数ViL的变化对[bmim][BF4]/MeCN混合溶剂中光诱导电子转移的影响却非常显著,总体上电子转移产生的自由基的表观生成速率常数kgr随[bmim][BF4]的VIL增大而减小.在[bmim]BF4]比例足够大的情况下,3BZ与三乙胺或四甲基对苯二胺之间的电子转移被抑制.
-
-
-
-
-
张鹏;
李海霞;
刘艳成;
王文锋
- 《2010年全国辐射技术与辐射改性材料发展论坛》
| 2010年
-
摘要:
利用激光光解与脉冲辐解技术研究了几种氟喹诺酮类药物(Fluoroquinolones,FQs),主要包括依诺沙星(Enoxacin,ENX)、诺氟沙星(Norfloxacin,NFX)和环丙沙星(Ciprofloxacin,CPX)的激发态、阴阳离子自由基的光化学性质。同时,研究了三种药物与不同氨基酸在不同条件下的光诱导反应。实验结果表明:FQs在无氧条件下,经355nm激光激发后,可以直接氧化色氨酸(TrpH)和酪氨酸 (TyrOH);而在有氧条件下,氨基酸的氧化是I 型和II型机理共同作用的结果。FQs 的激发态与精氨酸(Arg)、甘氨酸(Gly)和半胱氨酸(Cys)之间并没有明显的猝灭反应发生。
-
-
朱红平;
王文锋;
王文锋;
张兆霞;
赵红卫;
姚思德
- 《四川成都辐射研究与辐射工艺研讨会》
| 2005年
-
摘要:
利用纳秒级激光光解瞬态吸收光谱装置,研究了褪黑激素(melatonin,ML)的光物理和光化学性质.在266 nm激光的作用下,ML可被激发产生激发三重态(3 ML*),又可光电离生成水合电子和阳离子自由基(ML(+);并对SO4(-、核黄素(riboflavin,RF)激发三重态与ML间的电荷转移反应进行了研究,测得了反应速率常数分别为8.0(109和1.4(109 dm3(mol-1(s-1;同时还研究了ML清除ABTS阳离子自由基(ABTS(+)的能力,并与其它抗氧化剂进行了比较.
-
-
-
-
-
-
朱大章;
孙冬梅;
汪世龙;
孙晓宇;
倪亚明;
姚思德
- 《中国核学会2009年学术年会》
| 2009年
-
摘要:
波长小于190 nm 的真空紫外线能量较高,可使H2O 解离成HO·,而防护相对容易,因此在高级氧化技术处理水中有机污染物中具有良好的前景.本文以功率为200 W 的可辐射185 nm 和254 nm 紫外光的低压石英汞灯为光源,处理含有典型N-杂环化合物--喹啉和异喹啉的水溶液,研究喹啉、异喹啉的降解规律,考察了降解过程中污染物浓度、COD、TOC 的变化规律,并对喹啉和异喹啉的降解过程进行了比较.结果表明,在给定的实验条件下,喹啉和异喹啉均能够迅速降解.底物浓度在10 min 内接近于0,表观一级反应速率常数分别为0.41±0.02 min-1和0.19±0.01min-1,而COD、TOC 也能在30 min 内降为0.喹啉比异喹啉的降解速率更快.为了研究喹啉降解速率更快的机理,用脉冲辐解研究了喹啉、异喹啉分别与HO·的反应,结果表明HO·与喹啉的反应速率比异喹啉快.同时用激光闪光光解研究了喹啉与异喹啉的在紫外光作用下的变化,发现喹啉和异喹啉都会发生光电离,喹啉光电离的量子效率更高.