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971.
Qianqian Cao Chuncheng Zuo Yanhong Ma Lujuan Li Siyan Chen Zhangyou Hu 《Journal of Polymer Science.Polymer Physics》2011,49(12):882-889
We report molecular dynamics simulations on bottle‐brush polyelectrolytes end‐grafted to a planar surface. For each bottle‐brush polyelectrolyte, flexible charged side chains are anchored to one neutral main chain. The effects of the counterion valence and the grafting density on the density profiles and the structural characteristics of the brush were studied in this work. It is found that the electrostatic repulsion between charged monomers in the side chains leads an extended conformation of the brush in a solution containing monovalent counterions, while strong electrostatic binding of multivalent counterions to the side chains has a significant contribution to the collapse of the brush. For the trivalent case, the distribution of end monomers in the main chains becomes broader upon decreasing the grafting density, as compared with the monovalent case. However, the position of the distribution for the monovalent case is relatively insensitive to the change of the grafting density. Additionally, with increased counterion valence, enhanced electrostatic correlation between counterions and charged side chains also weakens the diffusive ability of counterions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
972.
Deng Yaoming Kang Tianxing Song Xiaona Ma Zhen Zuo Xiaoxi Shu Dong Nan Junmin 《Journal of Solid State Electrochemistry》2019,23(2):407-417
Journal of Solid State Electrochemistry - With the expanding applications, concerns about the charging safety of lithium-ion batteries (LIBs) have become more significant. In this paper, the... 相似文献
973.
Zuo‐Bing Wu 《国际流体数值方法杂志》2009,61(5):536-551
Experimental particle dispersion patterns in a plane wake flow at a high Reynolds number have been predicted numerically by discrete vortex method (Phys. Fluids A 1992; 4 :2244–2251; Int. J. Multiphase Flow 2000; 26 :1583–1607). To address the particle motion at a moderate Reynolds number, spectral element method is employed to provide an instantaneous wake flow field for particle dynamics equations, which are solved to make a detail classification of the patterns in relation to the Stokes and Froude numbers. It is found that particle motion features only depend on the Stokes number at a high Froude number and depend on both numbers at a low Froude number. A ratio of the Stokes number to squared Froude number is introduced and threshold values of this parameter are evaluated that delineate the different regions of particle behavior. The parameter describes approximately the gravitational settling velocity divided by the characteristic velocity of wake flow. In order to present effects of particle density but preserve rigid sphere, hollow sphere particle dynamics in the plane wake flow is investigated. The evolution of hollow particle motion patterns for the increase of equivalent particle density corresponds to that of solid particle motion patterns for the decrease of particle size. Although the thresholds change a little, the parameter can still make a good qualitative classification of particle motion patterns as the inner diameter changes. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
974.
<正>A high energy pulsed terahertz(THz) laser is studied experimentally.The laser cavity simply consists of a quartz glass waveguide,a coated GaAs input window,and a crystal quartz output window.NH3 is filled in the cavity as gain medium,and pumped by an 8-J line-tunable transversely excited atmospheric(TEA) CO_2 laser.When 9R(16) transition acts as the pump line,55.6-mJ THz radiation(90μm) is obtained at 730-Pa NH_3 pressure.The corresponding conversion efficiency is 13.54%.Energy and optimal pressure of amplified spontaneous emission and laser oscillation are compared. 相似文献
975.
976.
J. Zuo Y.-J. Tian J. Chen Y.-C. Wang S.-Q. Gao G.-H. Lu Z.-W. Li 《Applied physics. B, Lasers and optics》2008,91(3-4):467-473
We demonstrate stimulated Raman Stokes (SRS) scattering of carbon disulfide (CS2) influenced by a natural dye named all-trans-β-carotene in a liquid-core optical fiber (LCOF). These Stokes emissions can acquire the extra effects of seeding or suppression, both of which result from the optical properties of the carotenoids. Then, the efficient control of the selective developments of the Stokes lines by the natural dyes is available in LCOFs. Especially, the low threshold of the high-order Stokes lines, such as the 2nd Stokes line of CS2, can be more easily obtained through the seeding effect. The saturation intensity of the 1st Stokes line can be suppressed more when the concentration of all-trans-β-carotene in CS2 becomes high. Simultaneously, the threshold of the 1st Stokes line increases with the addition of the carotenoids. This result is expected to be worthy of new SRS-based fiber light sources for bio-medicine applications such as photodynamic therapy. 相似文献
977.
Chen Zuo Taihong Yan Weifang Zheng Chuanbo Li Xiaorong Wang 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(1):83-87
Kinetic studies of stripping of Np(IV) from 30% Tri-Butyl-Phosphate/Odourless Kerosene (TBP/OK) into a nitric acid solution
containing acetohydroxamic acid (CH3CONHOH) have been investigated using a Lewis cell. The different parameters affecting the back-extraction rate of Np(IV) such
as Np, TBP, nitric acid, nitrate, acetohydroxamic acid(AHA) concentration in addition to temperature, stirring speed and special
interfacial area were separately studied and a rate equation was deduced. Results have been compared among themselves and
other published works on similar systems. Mechanisms of stripping processes have been proposed. 相似文献
978.
Linjun Shao Yijun Du Minfeng Zeng Xiudong Li Wenting Shen Shufeng Zuo Yueqing Lu Xian‐Man Zhang Chenze Qi 《应用有机金属化学》2010,24(5):421-425
Homocoupling reactions of aryl bromides or iodides proceeded smoothly with palladium on carbon (Pd/C) catalyst, ethanol and base in dimethyl sulfoxide (DMSO) to afford exclusively symmetric biaryls in good to excellent yields. Ethanol was first used as a reducing agent in situ to reduce the Pd2+/C species into Pd0/C active species to complete the catalytic redox cycle. It was found that ethanol can promote the Pd/C‐catalyzed reductive homocoupling of aryl iodides and bromides efficiently in the presence of base. A reaction mechanism has been put forward and discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
979.
A new molecular magnet, [NO2BrBzPyCH3][Ni(mnt)2] ( 1 ) ([NO2BrBzPyCH3]+ = 1‐(2′‐bromo‐4′‐nitrobenzyl)‐2‐methylpyridinium, and mnt2– = maleonitriledithiolate), has been prepared and characterized by single crystal X‐ray diffraction and magnetic measurements. The Ni(III) ions of 1 form a quasi‐one‐dimensional alternating zig‐zag magnetic chain within a Ni(mnt)2– column by intermolecular Ni···S, Ni···Ni or π···π interactions, and the [NO2BrBzPyCH3]+ cations stack into a column via weak Br···O interaction, p···π stacking interactions and C‐H···O hydrogen bonds between the cations. Magnetic susceptibility measurements in the temperature range 1.8‐300 K show that 1 exhibits a spin‐gap transition around 180 K, and an antiferromagnetic interaction in the high‐temperature phase (HT) and spin gap behavior in the low‐temperature phase (LT). The transition for 1 is a second‐order phase transition as determined by DSC analyses. 相似文献
980.
Zheng ST Wu T Zuo F Chou C Feng P Bu X 《Journal of the American Chemical Society》2012,134(4):1934-1937
A new class of zeolite-type porous materials in which 3D frameworks are covalently functionalized with crystallographically ordered pendant metal clusters have been synthesized. This work demonstrates a new paradigm for and the feasibility of functionalizing zeolite-type frameworks through the conversion of extraframework sites in mineral zeolites into part of the framework for occupation by dangling metal clusters in metal-organic frameworks. 相似文献