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111.
Jiangbo She Chao Gao Kai Cui Chaoqi Hou Wei Zhao Wei Wei Bo Peng 《Structural chemistry》2008,19(6):905-910
A novel neodymium pentafluoropropionate binuclear complex, Nd(C2F5COO)3 · Phen (Phen: 1,10-phenanthroline), was synthesized and characterized by single-crystal X-ray diffraction, elemental analysis,
FT-IR spectra, UV–Vis–NIR absorption, and PL spectra. Single-crystal data show that the complex bears centrosymmetric dinuclear
structure with a planar ligand configuration. Four carboxylato groups act as η2-chelate-μ2-carboxylato-k1O:k1O′-bridge-ligands, the other two occupy the terminal position as monodentate ligands. At the same time, the C–O distances
appear averaged which indicate the three atoms of carboxylato forming electron-conjugate system. Hydrogen bond and π–π-stacking
link the binuclear to two-dimensional sheet. Optical spectra exhibit the complex possesses typical Nd(III) ion absorption
and photoluminescence emission. 相似文献
112.
We report the first 1H and 43Ca NMR characterization of Ca2+ ion binding to G-quartets. 相似文献
113.
Yao Fan Li Liu Donglei Sun Hanyue Lan Haiyan Fu Tianming Yang Yuanbin She Chuang Ni 《Analytica chimica acta》2016
As a popular detection model, the fluorescence “turn-off” sensor based on quantum dots (QDs) has already been successfully employed in the detections of many materials, especially in the researches on the interactions between pesticides. However, the previous studies are mainly focused on simple single track or the comparison based on similar concentration of drugs. In this work, a new detection method based on the fluorescence “turn-off” model with water-soluble ZnCdSe and CdSe QDs simultaneously as the fluorescent probes is established to detect various pesticides. The fluorescence of the two QDs can be quenched by different pesticides with varying degrees, which leads to the differences in positions and intensities of two peaks. By combining with chemometrics methods, all the pesticides can be qualitative and quantitative respectively even in real samples with the limit of detection was 2 × 10−8 mol L−1 and a recognition rate of 100%. This work is, to the best of our knowledge, the first report on the detection of pesticides based on the fluorescence quenching phenomenon of double quantum dots combined with chemometrics methods. What's more, the excellent selectivity of the system has been verified in different mediums such as mixed ion disruption, waste water, tea and water extraction liquid drugs. 相似文献
114.
Wei Sun Zhao-Hui Wang Meng-Yao She Zheng Yang Xi-Lang Jin Ya-Qi Wang Zhen Shi Jian-Li Li 《中国化学快报》2016,27(7):1077-1082
The inclusion behaviors of three native or modified CDs including p-CD,2-hydroxypropyl-β-CD(2-Hp-β-CD) and 2,6-dimethyl-β-CD(Me-β-CD) toward 5-amino-6-methyl-2-benzimidazolone(AMBI) were comparatively investigated by NMR and fluorescence titration in combination with IR spectra,X-ray diffractometry and scanning electron microphotographs.The experimental results jointly demonstrated that the phenyl ring of AMBI entered into the cavity of the CDs and located close to the narrow rims accompanied by the formation of the 1:1 inclusion complex with large stability constant in aqueous solution.The introduction of the hydroxypropyl unit to the host improved the solubility,ultimately effecting an obvious promoting in the fluorescence intensity and the stability constant 相似文献
115.
由于人为误操作和数据库系统异步因素,电力系统监控数据存在错误风险,需要对监控数据进行多点校核来保障其一致性和正确性,可靠的监控数据保证电力系统的安全运转;然而多点校核业务流复杂且对数据精度要求高,目前的人工校核方法不仅成本高,且精度和效率低,不能保证整个监控数据的实时校核工作;为自动化监控数据多点校核过程,需要对整个业务流建模,针对该问题,提出一种基于Petri网的监控数据多点校核动态建模方法;首先将监控系统的校核业务背景形式化Petri网中的具有不同约束的节点;然后使用工作流Petri方法对校核的业务流程进行形式化定义、并将该业务流程用Petri网建模成为网状模型;最后,针对该模型提出一种化简技术对其进行化简,并证实该化简方法的有效性和该模型能拟合监控数据多点校核的整个流程。 相似文献
116.
The facile total synthesis of the (−)-Heliconol A (ent-1) as well as its diastereoisomer 18 is described, in which different reaction sequences lead to different results. The osmylation of 15 followed by hydrolysis afforded a single isomer 18, otherwise, a mixture of ent-1 and 18 resulted. Other important processes include the catalytic asymmetric CBS reduction and induced osmylation. The synthesis proceeded with a sequence of 11 steps, affording ent-1 in 9.0% and 18 in 22% overall yield, respectively. 相似文献
117.
Concise and efficient total syntheses of 11-alpha-methoxycurvularin and 11-beta-methoxycurvularin were accomplished for the first time. The three-component linchpin coupling and intramolecular acylation reactions were key steps, in which we found the spectral data of 11-alpha-methoxycurvularin and 11-beta-methoxycurvularin, reported in the literature, were reversed with each other. 相似文献
118.
塑性全量理论的变分不等式模式及其无迭代解 总被引:1,自引:0,他引:1
变分不等式是解决一类带单侧约束的定常力学问题的有效数学工具.本文就弹塑性全量理论构造了等价的变分不等式模式,解除了弹塑性问题本构约束的不等式关系,比一般能量形式的描述更为简洁.它便于计算,具有可靠的数学依据,可以用二次规划法求解.计算时无需分级加载迭代,一步即可得收敛解. 相似文献
119.
激光拉曼光谱在玉石鉴定中的应用 总被引:4,自引:1,他引:3
本文提出玉石品种鉴定的新方法———激光拉曼光谱法。测试了一系列玉石的标准拉曼谱 相似文献
120.