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121.
Rong Chen Zhijun Qiao Shouming Zhou 《Mathematical Methods in the Applied Sciences》2019,42(18):6999-7010
Considered herein is a two‐component Novikov equations (called Geng‐Xue system for short) with cubic nonlinearities. The persistence properties and some unique continuation properties of the solutions to the system in weighted Lp spaces are established. Moreover, a wave‐breaking criterion for strong solutions is determined in the lowest Sobolev space by using the localization analysis in the transport equation theory, and we also give a lower bound for the maximal existence time. 相似文献
122.
Satoshi Someya Satoshi Yoshida Koji Okamoto Yan Rong Li Manabu Tange Mohammad Mezbah Uddin 《显形杂志》2010,13(1):41-47
Abstract
Droplets impinging on a hot surface that is near the Leidenfrost temperature were experimentally investigated. Ejection of jets from the top of the droplet was observed during the transient interaction between the droplet and a hot wall. We term this phenomenon jet ejection from droplets. When the bottom of the droplet initially impacts the hot surface, a jet is to be ejected from the top of the droplet. The jet ejection occurred only at low impact velocities and around the wetting limit temperature. It was not observed when droplets were dropped from large heights or when the surface was at a high temperature. 相似文献123.
Pomponlike La2(MoO4)3 microstructures assembled with single-crystalline nanoflakes have been facilely fabricated via a surfactant-assisted ultrasound route for the first time. Various synthesis conditions were examined, such as the surfactant concentration, the molecular structure of surfactants, and the pH value. The obtained pomponlike microstructures were characterized by X-ray diffraction (XRD), (field-emission) scanning electron microscopy [(FE)SEM], transmission electron microscopy (TEM), and nitrogen adsorption/desorption isotherms. It has been revealed that a minimum concentration of sodium dodecylsulfate (SDS) was required for the formation of pomponlike La2(MoO4)3 microstructures. When the SDS concentration is above 0.02 mol L−1, the pomponlike microstructures become more perfect, and the size is also increased with the increasing SDS concentration. Under the same sonication, similar pomponlike microstructures were obtained when a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), was used instead of the anionic surfactant SDS, indicating that the hydrophobic alkyl chains are an important factor for the formation of the pomponlike La2(MoO4)3 microstructures. It is also found that the pomponlike La2(MoO4)3 microstructures can only be obtained within an optimal pH range of 8.0–9.0 under sonication. Based on TEM, Fourier transform infrared spectroscopy (FT-IR) and solubilization experiment, a formation mechanism of pomponlike La2(MoO4)3 microstructures was proposed, in which the collaborative action of surfactants and sonication plays a key role. Furthermore, the porosity of the pomponlike La2(MoO4)3 microstructures were discussed. 相似文献
124.
Arthur E. Martell Ramunas J. Motekaitis Eric T. Clarke Rita Delgado Yizhen Sun Rong Ma 《Supramolecular chemistry》2013,25(3-4):353-363
Abstract In our studies of the stability constants of metal complexes, we have investigated a number of macrocyclic ligands with pendant donor groups. The ligands are characterized by the fact that they have nitrogen donors in the macrocyclic ring and oxygen or sulfur donors in the pendant arms. These ligands represent seven different macrocycles, and by varying the pendant donor groups, ten different ligands are indicated. The affinities of these ligands for fifteen metal ions will be described. The Fe(III) complex of triazanonane with o-hydroxypyridyl or o-hydroxybenzyl pendant donor groups are the most stable ferric complexes ever reported. The In(III) complex of triazacyclononane with pendant mercaptoethyl donor groups, is exceptionally stable. Also, the Ca(II) complex of DOTA probably has the highest stability of any calcium(II) complex. These, and other comparisons will be made on the basis of the thermodynamic stability constant data for the ligands described. 相似文献
125.
Functionalized multiwall carbon nanotubes (f-MWCNTs) with varying functionalization degrees were prepared by chemical methods. The effect of f-MWCNTs on the cure kinetics of bismaleimide–triazine (BT) resin was studied through nonisothermal differential scanning calorimetry (DSC) methods. The reaction activation energy (E α ) was determined by Flynn–Wall–Ozawa method. The results show that f-MWCNTs have more acceleration ability than pristine MWCNTs, due to more groups on the surface of f-MWCNTs than that of pristine MWCNTs. The activation energy was decreased from a value of 91.3 kJ mol?1 for the neat BT resin to 74.2 kJ mol?1 at the small mass loading (1.0 %) of f7-MWCNTs. The effect of f-MWCNTs on the reaction mechanism has been investigated. It shows that the f-MWCNTs accelerate the cure reaction of BT resin by providing the Lewis acids (H+) to make the “Diels–Alder” reaction and “ENE” reaction of BT resins more efficient. These findings offer useful insights into the cure technology of thermosetting resin filled with f-MWCNTs, without negative effect on the cure reaction. 相似文献
126.
探讨了碳纤维(CF)表面镍金属的化学镀工艺,制备了镀镍碳纤维(NiCF),采用密炼工艺制备了ABS基体复合材料,研究了CF和NiCF含量对复合材料的导电性能及电磁屏蔽效能的影响。结果表明:采用化学镀的方法在碳纤维表面镀覆了金属镍,所形成的镀层均匀致密;镀覆时间为5min时,镀镍后的碳纤维电阻率降低两个数量级;复合材料电阻率随CF、NiCF含量的增加而逐渐减小;复合材料电磁屏蔽效能随CF、NiCF含量的增加而逐渐增加,当NiCF含量为25%(wt)(约13.3vol%)时,电磁屏蔽效能最高可达51dB。 相似文献
127.
Lan Yu Qi Wang Lu Dai Wei-Ying Li Rong Chen Mian HR Mahmood Hai-Yang Liu Chi-Kwong Chang 《中国化学快报》2013,24(6):447-449
Pseudo-first order reaction rate constants of 5,10,15-tris(pentafluorophenyl)corrole Mn(V)-oxo (F15CMn(V)-oxo),5,15-bis(pentafluorophenyl)-10-(phenyl)corrole Mn(V)-oxo(F10CMn(V)-oxo),5,15- bis(phenyl)-10-(pentafluorophenyl)corrole Mn(V)-oxo(F5CMn(V)-oxo) and 5,10,15-tris(phenyl)corrole Mn(V)-oxo(F0CMn(V)-oxo) with a series of alkene substrates in different solvents were determined by UV-vis spectroscopy.The results indicated that the oxygen atom transfer pathway between Mn(V)-oxo corrole and alkene is solvent-dependent. 相似文献
128.
选用在有机废水处理中已经得到广泛使用的商业化树脂Amberlite XAD-4作参照,通过等温吸附实验和吸附动力学实验研究了单宁酸和邻羧基苯甲酰基修饰的吸附树脂(分别命名为FZH-11和FZH5)对1,2-苯并异噻唑-3-酮的吸附性能。结果表明,修饰后的树脂FZH-11和FZH5对1,2-苯并异噻唑-3-酮具有较高的吸附容量,吸附过程存在化学吸附作用。1,2-苯并异噻唑-3-酮在FZH-11和FZH5树脂上的吸附过程符合准一级动力学方程,颗粒内扩散是吸附过程的主要速度控制步骤。FZH-11和FZH5树脂经酸液脱附可重复利用,废水在得到有效治理的同时实现了1,2-苯并异噻唑-3-酮的资源化回收利用。 相似文献
129.
130.