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91.
Photodissociation of azulene-Kr van der Waals clusters at 266 and 248 nm was studied using velocity map ion imaging techniques with the time-sliced modification. Scattered azulene molecules produced from the dissociation of clusters were detected by one-photon vacuum ultraviolet ionization. Energy transfer distribution functions were obtained from the measurement of recoil energy distributions. The distribution functions can be described approximately by multiexponential functions. Fragment angular distributions were found to be isotropic. The energy transfer properties show significantly different behavior from those of bimolecular collisions. No supercollisions were observed under the signal-to-noise ratios S/N=400 and 100 at 266 and 248 nm, respectively. Comparisons with the energy transfer of bimolecular collisions in thermal systems and the crossed-beam experiment within detection limit are made. 相似文献
92.
To recover the full accuracy of discretized fractional derivatives, nonuniform mesh technique is a natural and simple approach to efficiently resolve the initial singularities that always appear in the solutions of time-fractional linear and nonlinear differential equations. We first construct a nonuniform L2 approximation for the fractional Caputo's derivative of order 1 < α < 2 and present a global consistency analysis under some reasonable regularity assumptions. The temporal nonuniform L2 formula is then utilized to develop a linearized difference scheme for a time-fractional Benjamin–Bona–Mahony-type equation. The unconditional convergence of our scheme on both uniform and nonuniform (graded) time meshes are proven with respect to the discrete H1-norm. Numerical examples are provided to justify the accuracy. 相似文献
93.
We consider difference schemes for nonlinear time fractional Klein-Gordon type equations in this paper. A linearized scheme is proposed to solve the problem. As a result, iterative method need not be employed. One of the main difficulties for the analysis is that certain weight averages of the approximated solutions are considered in the discretization and standard energy estimates cannot be applied directly. By introducing a new grid function, which further approximates the solution, and using ideas in some recent studies, we show that the method converges with second-order accuracy in time. 相似文献
94.
Dr. Wentao Xu Dr. Nikita Hanikel Dr. Kirill A. Lomachenko Dr. Cesare Atzori Dr. Alicia Lund Dr. Hao Lyu Zihui Zhou Prof. Dr. C. Austen Angell Prof. Dr. Omar M. Yaghi 《Angewandte Chemie (International ed. in English)》2023,62(16):e202300003
We report a synthetic strategy to link titanium-oxo (Ti-oxo) clusters into metal-organic framework (MOF) glasses with high porosity though the carboxylate linkage. A new series of MOF glasses was synthesized by evaporation of solution containing Ti-oxo clusters Ti16O16(OEt)32, linkers, and m-cresol. The formation of carboxylate linkages between the Ti-oxo clusters and the carboxylate linkers was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. The structural integrity of the Ti-oxo clusters within the glasses was evidenced by both X-ray absorption near edge structure (XANES) and 17O magic-angle spinning (MAS) NMR. After ligand exchange and activation, the fumarate-linked MOF glass, termed Ti-Fum, showed a N2 Brunauer–Emmett–Teller (BET) surface areas of 923 m2 g−1, nearly three times as high as the phenolate-linked MOF glass with the highest BET surface area prior to this report. 相似文献
95.
Shiwei Tao Dr. Baris Demir Dr. Ardeshir Baktash Yutong Zhu Dr. Qingbing Xia Prof. Yalong Jiao Yuying Zhao Dr. Tongen Lin Dr. Ming Li Dr. Miaoqiang Lyu Prof. Ian Gentle Prof. Lianzhou Wang Dr. Ruth Knibbe 《Angewandte Chemie (International ed. in English)》2023,62(39):e202307208
The irreversibility of anion intercalation-deintercalation is a fundamental issue in determining the cycling stability of a dual-ion battery (DIB). In this work, we demonstrate that using a partially fluorinated carbonate solvent can drive a beneficial fluorinated secondary interphase layer formation. Such layer facilitates reversible anion (de−)intercalation processes by impeding solvent molecule co-intercalation and the associated graphite exfoliation. The enhanced reversibility of anion transport contributes to the overall cycling stability for a Zn-graphite DIB—a high Coulombic efficiency of 98.5 % after 800 cycles, with an attractive discharge capacity of 156 mAh g−1 and a mid-point discharge voltage of ≈1.7 V (at 0.1 A g−1). In addition, the formed fluorinated secondary interphase suppresses the self-discharge behavior, preserving 29 times of the capacity retention rate compared to the battery with a commonly used carbonate solvent, after standing for 24 hours. This work provides a simple and effective strategy for addressing the critical challenges in graphite-based DIBs and contributes to fundamental understanding to help accelerate their practical application. 相似文献
96.
Sheng Xianxian Xu Zhiqiang Liu Yulong Wang Peng Dong Jiaqi Lu Zhanpeng Shan Ali Lyu Shuguang 《Research on Chemical Intermediates》2022,48(4):1645-1663
Research on Chemical Intermediates - In this study, the removal performance and degradation mechanisms of fluoranthene (FLT) in sodium percarbonate (SPC) activated by Fe(II) system were... 相似文献
97.
Depei Meng Yichong Lyu Dr. Chuanfa Ni Dr. Min Zhou Prof. Dr. Yang Li Prof. Dr. Jinbo Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(13):e202104395
S-(Trifluoromethyl)benzothioate (TFBT) has been developed as an inexpensive, bench-stable, and user-friendly trifluoromethylthiolation reagent, which can be easily synthesized by using KF as the only fluorine source. By using TFBT, trifluoromethylthiolates with various counterions can be readily obtained. The synthetic application of TFBT was demonstrated by trifluoromethylthiolation-halogenation of arynes, bis(trifluoromethylthiolation)–halogenation of 1,2-benzdiynes, nucleophilic substitution of alkyl halides, deoxytrifluoromethylthiolation of alcohols, and cross-coupling with aryl and vinyl boronic acids. 相似文献
98.
Niu Wan Takayuki Myo Chang Xu Hiroshi Toki Hisashi Horiuchi Mengjiao Lyu 《中国物理C(英文版)》2020,44(12):124104-124104-13
Using bare Argonne V4' (AV4'), V6' (AV6'), and V8' (AV8') nucleon–nucleon (begin{document}$NN$end{document} ![]()
![]()
) interactions, the nuclear equations of state (EOSs) for neutron matter are calculated with the unitary correlation operator and high-momentum pair methods. Neutron matter is described using a finite particle number approach with magic number begin{document}$N=66$end{document} ![]()
![]()
under a periodic boundary condition. The central short-range correlation originating from the short-range repulsion in the begin{document}$NN$end{document} ![]()
![]()
interaction is treated by the unitary correlation operator method (UCOM), and the tensor correlation and spin-orbit effects are described by the two-particle two-hole (2p2h) excitations of nucleon pairs, where the two nucleons with a large relative momentum are regarded as a high-momentum (HM) pair. With increasing 2p2h configurations, the total energy per particle of the neutron matter is well-converged under this UCOM+HM framework. Comparing the results calculated with AV4', AV6', and AV8' begin{document}$NN$end{document} ![]()
![]()
interactions, we demonstrate the effects of the short-range correlation, tensor correlation, and spin-orbit coupling on the density dependence of the total energy per particle of neutron matter. Moreover, the contribution of each Hamiltonian component to the total energy per particle is discussed. The EOSs of neutron matter calculated within the present UCOM+HM framework agree with the calculations of six microscopic many-body theories, especially the auxiliary field-diffusion Monte Carlo calculations. 相似文献
99.
Haiyan Lyu Suping Wang Ying Jin Rong Shen Jiayun Chen Chunyan Zhu Binbin Chen Caisheng Wu 《Biomedical chromatography : BMC》2020,34(11):e4932
Vitamin D measurements in biological fluids by liquid chromatography–tandem mass spectrometry (LC–MS/MS) have been widely used but remain challenging at very low concentration levels. Rapid, high recovery, sensitive and reliable measurements of vitamin D, as well as its primary metabolites using LC–MS/MS are urgently needed for a routine clinical laboratory. Herein, we reported a novel electrospray LC–MS/MS method for determining vitamin D and its primary metabolites using the supported liquid extraction method to achieve higher recoveries, with optimized pH values to achieve optimal derivatization efficiency for higher sensitivity and selected chromatographic conditions to shorten the separation time. The method has been validated with respect to selectivity, recovery, matrix effects, accuracy and precision, stabilities, carryover and dilution effects. The method has been successfully applied to quantify the VD plasma concentrations of depressive, schizophrenic patients and healthy individuals. The result showed that there were significant differences in plasma VD levels between mental disorder patients with healthy individuals, and the total VD levels in mental disorder patients were much higher than healthy individuals, which might require larger clinical samples for validation. 相似文献
100.
Benjamin P. Williams Dr. Allison P. Young Ilektra Andoni Dr. Yong Han Wei-Shang Lo Matthew Golden Jane Yang Lian-Ming Lyu Prof. Dr. Chun-Hong Kuo Prof. Dr. James W. Evans Prof. Dr. Wenyu Huang Prof. Dr. Chia-Kuang Tsung 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10661-10667
Controlling the surface composition of shaped bimetallic nanoparticles could offer precise tunability of geometric and electronic surface structure for new nanocatalysts. To achieve this goal, a platform for studying the intermixing process in a shaped nanoparticle was designed, using multilayered Pd-Ni-Pt core–shell nanocubes as precursors. Under mild conditions, the intermixing between Ni and Pt could be tuned by changing layer thickness and number, triggering intermixing while preserving nanoparticle shape. Intermixing of the two metals is monitored using transmission electron microscopy. The surface structure evolution is characterized using electrochemical methanol oxidation. DFT calculations suggest that the low-temperature mixing is enhanced by shorter diffusion lengths and strain introduced by the layered structure. The platform and insights presented are an advance toward the realization of shape-controlled multimetallic nanoparticles tailored to each potential application. 相似文献