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101.
The heat diffusion across the stochastic magnetic field is studied numerically. The stochastic field is generated by the overlap of two magnetic islands. The parameter w/wc, is found tobe an important parameter in charactering the transport, where w is the magnetic island width, and wc is the critical island width for flattening the electron temperature across an island. For w/wc < 1, the enhanced radial heat diffusivity χr is proportional to the parallel heat diffusivity χ∥, and the heat transport is dominated by the additive effect of individual islands. For w/wc > 3, χr is also proportional to χ∥ and the additional degradation of the energy confinement due to stochastic magnetic field becomes apparent. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
102.
通过氯甲基化聚砜(CMPSF)与4-羟基水杨醛(HSA)的亲核取代反应,将水杨醛(SA)基团键合在聚砜侧链,制得改性聚砜PSF-SA;再经PSF-SA的醛基分别与苯胺(AN)和环己胺(CA)发生席夫碱反应,获得了两种侧链键合了水杨醛型双齿席夫碱配基的功能化聚砜PSF-SAN和PSF-SCA,产物的结构由红外光谱和核磁共振氢谱表征。以两种功能化聚砜为大分子配体,与Tb(Ⅲ)离子及Eu(Ⅲ)离子分别配位,制得了二元高分子-稀土配合物,初步探索了配合物的光致发光性能。本文重点研究了功能化聚砜PSF-SAN和PSFSCA的制备反应,考察与分析了主要因素对CMPSF与HSA之间亲核取代反应的影响规律。结果表明,对于该亲核取代反应,适宜的溶剂为极性较强的N,N-二甲基乙酰胺,80℃为适宜的反应温度。大分子配体PSFSAN对Eu(Ⅲ)离子的荧光发射产生强烈的敏化作用,配合物PSF-(SAN)_3-Eu(Ⅲ)发射红光;大分子配体PSF-SCA对Tb(Ⅲ)离子的荧光发射也产生敏化作用,配合物PSF-(SCA)_3-Tb(Ⅲ)发射绿光。 相似文献
103.
Three calcium coordination compounds, [Ca(CPA)(H2O)4]·(CPA), 1, [Ca(MCPA)2(H2O)2]·H2O, 2, and [Ca(TCPA)2(H2O)3]·2H2O, 3 [HCPA = 3-chlorophenoxyacetic acid, HMCPA = 2-methyl-4-chlorophenoxyacetic acid, and HTCPA = 2,4,6-trichlorophenoxyacetic acid], have been synthesized by the microwave method with advantages that include shorter reaction times, lower energy consumption, and higher product yield. The structures have been characterized by IR, elemental analysis, and single-crystal X-ray diffraction. Influences on the crystal structures by changing the number and position of chlorine substituent group in phenoxyacetic acid are discussed. Steric hindrance effects involving the Cl and an ability to form the O–H?Cl hydrogen bonds enrich the structure diversity. TG analysis reveals that the thermostability for the three compounds is 3 > 1 > 2, which could be influenced by the existence of hydrogen bonds (O–H?Cl and O–H?O). 相似文献
104.
To investigate the effect of different imidazole-containing ligands on the structure of coordination polymers, two new Zn(II) coordination polymers based on 1,4-cyclohexanedicarboxylic acid (H2cda) and two different imidazole-containing ligands, [Zn(cda)(bib)0.5]n (1) and [Zn(cda)(bmib)0.5]n (2) (bib = 1,4-bis(imidazol-1-yl)benzene and bmib = 1,4-bis(2-methylimidazol-3-ium-yl)benzene), have been synthesized and characterized by single-crystal X-ray diffraction. Complex 1 shows a 3-D structure with point symbol (4.82.103).(4.82). Complex 2 displays a 2-D layer structure with an –AB– stacking sequence. 相似文献
105.
High Temperature Affects Photosynthetic and Molecular Processes in Field‐Cultivated Vitis vinifera L. × Vitis labrusca L. 下载免费PDF全文
High‐temperature stress markedly influences grape growth and development. However, how high‐temperature stress response differs between controlled and field‐cultivated grape is poorly understood. In this study, the effects of heat treatment on grapevines were studied for changes in photosystem II (PSII) activity and expression levels of heat‐responsive genes and heat shock protein HSP21. July 31st, 2015 was considered as the post high‐temperature treatment (“42°C”; temperatures above 40°C for a period of time each day ranging from 1–7 h) under field cultivation in our experiment. The recovery of chlorophyll fluorescence indicators and the increasing expression of heat‐responsive genes and the heat shock protein HSP21 suggested the development of heat tolerance in the form of acclimation in grape. Changes in various parameters of photosynthetic pigment fluorescence and of the electron transport chain (Fv/Fm, PIABS, Wk, RCQA, ΦPo, and ΦEo) between “42°C” and the 45°C treatment demonstrated that the donor side, reaction center, and acceptor side of PSII were influenced by a critical high temperature. Furthermore, the difference between the two cultivation conditions studied was attributed to other environmental factors and inherent tree vigor. 相似文献
106.
Dongbing Zha 《Mathematical Methods in the Applied Sciences》2016,39(15):4484-4495
In this paper, we give an alternative proof to the global existence result, which is originally owing to the pioneering work of Klainerman and Christodoulou, for the Cauchy problem of quasilinear wave equations with null condition in three space dimensions. The proof can display the following three features simultaneously: the Lorentz boost operator is not employed in the generalized energy estimates; the generalized energy of the solution will be always small, which was first observed by Alinhac; and the initial data are not assumed to have a compact support. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
107.
In this work, the electrophoretic mobility (EPM) measurement of individual cells was investigated by a simple on-chip electrophoresis system with LIF multipoint detection. The system enabled the characterization of cell electrophoresis behavior as well as the fluorescence signal from individual cells simultaneously. The measurement yielded the electropherograms of a large number of cells labeled with dye, in which the migration time and migration distance could be obtained easily. The EPM has been demonstrated to be different between the K562 cells and K562 cells treated with anticancer drug arsenic trioxide (As2O3). The K562 cells were found to exhibit a lower EPM compared to the cells after drug addition with different concentration. In this preliminary study, over 300 cells could be analyzed within 2 h, demonstrated a much higher analysis throughput compared with traditional methods. The established system is simple and fast, which is expected to be a promising method for evaluating cell surface properties and to be useful in clinical and pharmaceutical applications. 相似文献
108.
Long alpha-Fe(2)O(3) hollow fibers have been prepared through a facile sol-gel combined co-electrospinning technique using ferric citrate as precursor, and alpha-Fe and gamma-Fe(2)O(3) hollow fibers have been obtained by reduction and reoxidation at different conditions. The outer diameter of the as-prepared hollow fibers is 0.5-5 microm with wall thickness of 200-800 nm. The obtained tubular fibers were characterized by thermal gravimetric (TG), FT-IR spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Raman techniques. In addition, magnetic properties of alpha-Fe and gamma-Fe(2)O(3) hollow fibers have also been investigated. 相似文献
109.
110.