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941.
942.
Lei Zhang Wei Tong Jiyu Fan Changjin Zhang Renwen Li Yuheng Zhang 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,83(3):325-328
Ferrimagnetic spinel selenide CuCr2Se4 has been investigated by the
electron spin resonance (ESR) spectroscopy. Experimental results reveal that ESR signals
originate from the localized d-shell electrons of Cr3+ ions.
In addition, the ESR linewidth ΔH
PP
increases
linearly with decreasing temperature. It is suggested that the spin-orbit coupling may be
one of the contributions to the broadening of
ΔH
PP
. Our ESR results support the model of
the ferrimagnetic hybridization between localized 3d
3
electrons of Cr3+ with delocalized holes of Se 4p band. 相似文献
943.
<正>PTPMEG1 is an intracellular protein tyrosine phosphatase(PTP),which contains FERM and PDZ domains. This study focuses our attention on the expression,purification and characterization of catalytic domain of PTPMEG1(△MEG1) and preparation of its polyclonal antibody.A cDNA fragment encoding△MEG1 protein(amino acid residues 643—926) was amplified by PCR and then cloned into the pT7-7 vector.Both soluble and insoluble recombinant△MEG1 proteins were observed after induction by IPTG.Soluble△MEG1 was purified via two chromatographic steps,and the purified enzyme was characterized.With para-nitrophenylphosphate(pNPP) as a substrate,△MEG1 exhibited typical enzymatic characteristics of classic PTPs and classical Michaelis-Menten kinetics.Insoluble△MEG1,which was mainly distributed in the inclusion body of E.coli cells extracts,was purified by preparative electrophoresis gel for the preparation of the polyclonal antibody.A rabbit was immunized with△MEG1 purified by preparative electrophoresis to generate anti-△MEG1 antibody.Anti-serum was collected on 28th day after initial injection and purified via affinity chromatography.The purified polyconal antibody displayed a satisfactory titer and sensitivity. 相似文献
944.
A spontaneous ligand-replacement process at the external surface of Keplerate polyoxometalate molecular nanocapsules {Mo72Fe30} occurs when dissolving {Mo72Fe30} in pure methanol, with the water ligands coordinated to the Fe(III) centers of {Mo72Fe30} gradually being replaced by CH3OH ligands, resulting in the formation of partially hydrophobic nanocapsules. The new nanocapsules have negligible deprotonation capability and different solution behaviors. The methanol ligands can be easily exchanged back to water ligands when a small amount of water is added into the system. The exchange of water ligands dramatically changed the self-assembly behaviors of the {Mo72Fe30} clusters in solution. 相似文献
945.
Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines 下载免费PDF全文
Liang Yan Jing‐Kun Xu Chao‐Fan Huang Zeng‐Yang He Ya‐Nan Xu Prof. Dr. Shi‐Kai Tian 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13041-13045
A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl‐hydrazide‐catalyzed asymmetric OH‐substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2, 4 mol % (S)‐SegPhos, and 10 mol % 2,5‐dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity. 相似文献
946.
947.
Wang Xiaobo Ma Yongpeng Li Zhenxing Han Guanglu Guan Xidong Fan Kaiqi 《Journal of Applied Spectroscopy》2022,89(3):586-592
Journal of Applied Spectroscopy - A multi-ion chromogenic sensor based on a terpyridine moiety was developed for the semiquantitative, visual, and sensitive speciation analysis of Fe2+ and Co2+... 相似文献
948.
A new Hash function based on the generalized Henon map is proposed. We have obtained a binary sequence with excellent pseudo-random characteristics through improving the sequence generated by the generalized Henon map, and use it to construct Hash function. First we divide the message into groups, and then carry out the Xor operation between the ASCII value of each group and the binary sequence, the result can be used as the initial values of the next loop. Repeat the procedure until all the groups have been processed, and the final binary sequence is the Hash value. In the scheme, the initial values of the generalized Henon map are used as the secret key and the messages are mapped to Hash values with a designated length. Simulation results show that the proposed scheme has strong diffusion and confusion capability, good collision resistance, large key space, extreme sensitivity to message and secret key, and it is easy to be realized and extended. 相似文献
949.
This paper theoretically studies the double-pumped fibre-optical parametric amplifiers (FOPAs) in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed. 相似文献
950.
基于中纬度卷云冰晶双峰、热带卷云冰晶三峰分布模型,利用Mie散射理论计算了1~13脚范围内中纬度及热带卷云的消光系数、散射系数、吸收系数。计算结果表明,由不同形状冰晶构成的热带卷云的相应光学参数比中纬度卷云的光学参数大些,但11支子弹玫瑰形状的相应参数要小一些;两种卷云在2.8~3.1μm,9.8~13μm范围内都存在两个基本相同的透射通带;在计算中纬度卷云的光学参数时,可以只考虑中空六棱柱与实心六棱柱中的一种,但计算热带卷云的光学参数时,实心六棱柱与空心六棱柱需要同时考虑。 相似文献