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961.
Bin Zhao 《Journal of Thermal Analysis and Calorimetry》2012,107(1):387-393
In order to study the temperature changing rule of the crude oil in the storage tank, the wavelet finite element method, the
traditional finite element method and the test were used to carry out the numerical simulation. Firstly, the thermal wavelet
finite element was put forward established based on thermal finite element theory and the wavelet theory. And the computational
model and three boundary conditions were established. And then the temperature changing rule of the crude oil in the storage
tank in 24 h for three boundary conditions was obtained by using three methods, and the results showed that the wavelet finite
element method had advantages in the numerical analysis of the temperature changing rule of the crude oil in the storage.
And then the temperature distribution rule of the crude oil in the storage tank under different conditions in 5 h was obtained.
And the temperature changing mechanism of the crude oil was summarized finally. 相似文献
962.
Inside Cover: High‐Nuclear Organometallic Copper(I)–Alkynide Clusters: Thermochromic Near‐Infrared Luminescence and Solution Stability (Chem. Eur. J. 49/2016) 下载免费PDF全文
963.
Photoisomerization Mechanism of Ruthenium Sulfoxide Complexes: Role of the Metal‐Centered Excited State in the Bond Rupture and Bond Construction Processes 下载免费PDF全文
Dr. Huifang Li Lisheng Zhang lvyin Zheng Dr. Xun Li Dr. Xiaolin Fan Dr. Yi Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14285-14292
Phototriggered intramolecular isomerization in a series of ruthenium sulfoxide complexes, [Ru(L)(tpy)(DMSO)]n+ (where tpy=2,2’:6’,2’’‐terpyridine; DMSO=dimethyl sulfoxide; L=2,2’‐bipyridine (bpy), n=2; N,N,N’,N’‐tetramethylethylenediamine (tmen) n=2; picolinate (pic), n=1; acetylacetonate (acac), n=1; oxalate (ox), n=0; malonate (mal), n=0), was investigated theoretically. It is observed that the metal‐centered ligand field (3MC) state plays an important role in the excited state S→O isomerization of the coordinated DMSO ligand. If the population of 3MCS state is thermally accessible and no 3MCO can be populated from this state, photoisomerization will be turned off because the 3MCS excited state is expected to lead to fast radiationless decay back to the original 1GSS ground state or photodecomposition along the Ru2+?S stretching coordinate. On the contrary, if the population of 3MCS (or 3MCO) state is inaccessible, photoinduced S→O isomerization can proceed adiabatically on the potential energy surface of the metal‐to‐ligand charge transfer excited states (3MLCTS→3MLCTO). It is hoped that these results can provide valuable information for the excited state isomerization in photochromic d6 transition‐metal complexes, which is both experimentally and intellectually challenging as a field of study. 相似文献
964.
965.
966.
967.
Adhesive force between two solid surfaces can lead to stiction failure of the micro-electro-mechanical systems (MEMS) device. The competition between the adhesive force and the beam restoring force determines whether the stiction occurs or not. Previous models assume that the stuck beam deforms either as the arc-shape or the S-shape, which causes significant differences in the measurements of adhesion and disputations among researchers. The contact mechanics model presented in this paper shows that the assumptions of the arc-shape and S-shape on the beam deformation over-simplify the problem; both the arc-shaped deformation and S-shaped deformation significantly deviate from the real ones. The previous theories are shown to be incompatible with the recent experimental results. The model presented in this paper attempts to explain those new experimental results and resolve some disputations on the previous models. The instabilities of jump-in during loading process and jump-off during unloading process are also incorporated in this model. 相似文献
968.
Lei Sun Jiahui Geng Dr. Mengyou Gao Dr. Dehua Zheng Zhongxin Jing Qingyun Zhao Prof. Jianjian Lin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):10998-11004
Fe0.95S1.05 with high reactivity and stability was incorporated into WS2 nanosheets via a one-step solvothermal method for the first time. The resulted hybrid catalyst has much higher catalytic activity than WS2 and Fe0.95S1.05 alone, and the optimal WS2/Fe0.95S1.05 hybrid catalyst was found by adjusting the feed ratio. The addition of Fe0.95S1.05 was proven to be able to enhance the hydrogen evolution reaction (HER) activity of WS2, and vice versa. At the same time, it was found that the catalytic effect of the hybrid catalyst was the best when the feed ratio was W : Fe=2 : 1. In other words, we confirmed that there is a synergistic effect between W- and Fe-based sulfide hybrid catalysts, and validated that the reason for the improved HER performance is the strong interaction between the two in the middle sulfur. WS2/Fe0.95S1.05-2 hybrid catalyst leads to enhanced HER activity, which shows a low overpotential of ∼0.172 V at 10 mA cm−2, low Tafel slope of ∼53.47 mV/decade. This study supplies innovative synthesis of a highly active WS2/Fe0.95S1.05 hybrid catalyst for HER. 相似文献
969.
Huijie He Xu Fang Dr. Dong Zhai Wei Zhou Yimeng Li Wenling Zhao Dr. Chengcheng Liu Dr. Zhen Li Prof. Weiqiao Deng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(58):14390-14395
Imines are important intermediates in drug synthesis. Photocatalytic aerobic oxidative coupling of amines has been considered as a clean and promising way to produce imines and has attracted great attention. Herein, we designed and synthesized a novel two-dimensional porphyrin-based covalent organic framework (Por-BC-COF) which adopts an AA stacking mode with excellent crystallinity, high Brunauer–Emmett–Teller surface areas (1200 m2 g−1), wide light absorption range (200–1300 nm) and good stability in a variety of organic solvents. Por-BC-COF can be used as a metal-free heterogeneous photocatalyst for the photocatalytic oxidation of amines to imines under visible light and red light with a high yield (97 %). This work presents a novel and efficient COF photocatalyst in the application of light-driven organic synthesis. 相似文献
970.
Jie Feng Hongyang Zhao Wajid Ali Dandan Yin Xinyang Li Nawab Ali Khan Prof. Shujiang Ding 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(71):17818-17823
Coordination polymers are promising cathode materials for rechargeable alkaline batteries. Therefore, the precise modulation of these cathodes by chemical structure and in-depth structure transform study is necessary. Here, two model coordination polymer battery cathodes were designed to demonstrate the dynamic structure–performance relationship. We studied the electrochemical performance of two kinds of nickel-based coordination polymer, comprising a planar 2D cyanide-bridged network and a 3D cyanide-bridged network pillared by pyrazine molecules. The 2D coordination polymer showed serious voltage degradation with poor rate capability, whereas the 3D coordination polymer exhibited stable voltage output coupled with high rate at various current densities. The investigation revealed the underlining relationship of plateau voltage degradation and hydrolysis process of electrodes. It was revealed that the pyrazine pillar molecules in the 3D coordination polymer could suppress the hydrolysis and lead to the in situ formation of partially hydrolyzed structure with excellent electrochemical kinetics; this exhibited obvious smaller peak separation (27 mV compared with 149 mV) and hence an almost twofold increase in capacity retention (31.9 to 50.0 %) and energy density retention (18.2 to 35.9 %) at 10 A g−1. 相似文献