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981.
Yue Li Xin-Xin Jiang Hong-Mei Liu Xiao-wei Li Xiao-Jun Luo Xun Liao Yan Zhao 《Journal of separation science》2023,46(14):2300195
The inhibition of tyrosinase is considered to be a common therapeutic strategy for some hyperpigmentation disorders. Screening of tyrosinase inhibitors is of great significance to the treatment of pigmentation diseases. In this study, tyrosinase was covalently immobilized on magnetic multi-walled carbon nanotubes for the first time, and the immobilized tyrosinase was applied for ligand fishing of tyrosinase inhibitors from complex medicinal plants. The immobilized tyrosinase was characterized by transmission electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and thermo-gravimetric analyzer, which indicated that tyrosinase was immobilized onto magnetic multi-walled carbon nanotubes. The immobilized tyrosinase showed better thermal stability and reusability than the free one. The ligand was fished out from Radix Paeoniae Alba and identified as 1,2,3,4,6-pentagalloylglucose by ultra-performance liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry. 1,2,3,4,6-pentagalloylglucose was found to be a tyrosinase inhibitor with similar half maximal inhibitory concentration values of 57.13 ± 0.91 μM compared to kojic acid (41.96 ± 0.78 μM). This work not only established a new method for screening tyrosinase inhibitors but also holds considerable potential for exploring the new medicinal value of medicinal plants. 相似文献
982.
Xinlin Huang Chuang Wang Dr. Chuanfa Li Dr. Meng Liao Jiaxin Li Haibo Jiang Yao Long Xiangran Cheng Kun Zhang Pengzhou Li Prof. Bingjie Wang Prof. Huisheng Peng 《Angewandte Chemie (International ed. in English)》2023,62(24):e202303616
Fiber lithium-ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium-ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi-axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes. In comparison to typical solid copper wires, the braided fiber current collector hosted 139 % graphite with only 1/3 mass. The fiber graphite anode with braided current collector delivered high specific capacity of 170 mAh g−1 based on the overall electrode weight, which was 2 times higher than that of its counterpart solid copper wire. The resulting fiber battery showed high energy density of 62 Wh kg−1. 相似文献
983.
Ziwei Xu Hongwei Dong Dr. Wanmiao Gu Dr. Zhen He Fengming Jin Dr. Chengming Wang Dr. Qing You Prof. Dr. Jin Li Prof. Dr. Haiteng Deng Dr. Lingwen Liao Dr. Dong Chen Prof. Dr. Jun Yang Prof. Dr. Zhikun Wu 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308441
Lattice tuning at the ≈1 nm scale is fascinating and challenging; for instance, lattice compression at such a minuscule scale has not been observed. The lattice compression might also bring about some unusual properties, which waits to be verified. Through ligand induction, we herein achieve the lattice compression in a ≈1 nm gold nanocluster for the first time, as detected by the single-crystal X-ray crystallography. In a freshly synthesized Au52(CHT)28 (CHT=S-c−C6H11) nanocluster, the lattice distance of the (110) facet is found to be compressed from 4.51 to 3.58 Å at the near end. However, the lattice distances of the (111) and (100) facets show no change in different positions. The lattice-compressed nanocluster exhibits superior electrocatalytic activity for the CO2 reduction reaction (CO2RR) compared to that exhibited by the same-sized Au52(TBBT)32 (TBBT=4-tert-butyl-benzenethiolate) nanocluster and larger Au nanocrystals without lattice variation, indicating that lattice tuning is an efficient method for tailoring the properties of metal nanoclusters. Further theoretical calculations explain the high CO2RR performance of the lattice-compressed Au52(CHT)28 and provide a correlation between its structure and catalytic activity. 相似文献
984.
Pengzhou Li Dr. Meng Liao Dr. Shuquan Cui Jiaxin Li Dr. Lei Ye Yibei Yang Chuang Wang Prof. Bingjie Wang Prof. Huisheng Peng 《Angewandte Chemie (International ed. in English)》2023,62(17):e202300705
Flexible batteries based on gel electrolytes with high safety are promising power solutions for wearable electronics but suffer from vulnerable electrode-electrolyte interfaces especially upon complex deformations, leading to irreversible capacity loss or even battery collapse. Here, a supramolecular sol-gel transition electrolyte (SGTE) that can dynamically accommodate deformations and repair electrode-electrolyte interfaces through its controllable rewetting at low temperatures is designed. Mediated by the micellization of polypropylene oxide blocks in Pluronic and host-guest interactions between α-cyclodextrin (α-CD) and polyethylene oxide blocks, the high ionic conductivity and compatibility with various salts of SGTE afford resettable electrode-electrolyte interfaces and thus constructions of a series of highly durable, flexible aqueous zinc batteries. The design of this novel gel electrolyte provides new insights for the development of flexible batteries. 相似文献
985.
986.
987.
特征线法在求解非线性液相吸附色谱模型中的应用 总被引:1,自引:0,他引:1
本文应用特征线法求解非线性液相吸附色谱分离过程模型,论述了特征线法的原理和步骤,讨论了时间步长和空间步长对模型数值解的影响,并用色谱分离甘露醇和山梨醇以及分离蔗糖和还原糖的实验进行验证,用特征线法计算的理论流出曲线与实验流出线吻合较好。本文还分折了模型中各个参数的灵敏度,结果表明:吸附等温方程Q=Ci*/(ai+biCi*)中参数ai比参数bi以及总传质系数ki有更高的灵敏度。 相似文献
988.
Automatic computer programs are developed to calculate one- two-, and three-dimensional Debye functions. Prior tables of these functions are critically reviewed. Also, strategies are derived to calculate Debye temperatures from heat capacities. Both, simple three-dimensional Debye analyses and Tarasov analyses were carried out on 35 linear macromolecules. The experimental heat capacities for these analyses were collected in the ATHAS data bank. It is shown that the skeletal heat capacity of linear macromolecules is often best represented by only two vibrations per chain atom. For most of the all-carbon chain macromolecules the intramolecular skeletal heat capacity can be given by Cvs=D1[520 (28/MW)1/2] whereMW is the molecular mass andD
1 represents the one-dimensional Debye function. Polyoxides show a higher intramolecular theta temperature, but a lower intermolecular theta temperature. Double bonds and phenylene groups in the chain increase the intramolecular theta temperature.Dedicated to Prof. Dr. F. H. Müller.On leave from the Lumumba Peoples' Friendship University, Moscow, USSR. 相似文献
989.
A time-stepping finite-element (FE) and boundary-element (BE) coupling method was implemented to include 3D transient eddy
current under electromagnetic heating effects in electromagnetic launchers. Lagrangian formulations were used to model electromagnetic
and thermal diffusive processes with moving conductors. The finite-element formulation was employed for the general diffusion
equation in a bounded conductor region including rail and armature; while, in the exterior region, the boundary element method
was developed for Laplace's equation. The coupled boundary was employed directly on the surface of conductors and no special
treatment on boundary was required. The electromagnetic and temperature fields were coupled through iterative calculations.
This method results in considerable time saving in modeling as it eliminates the surrounding air region. 相似文献
990.
L.X. Zhang Z.F. Yang B. Chen G.Q. Chen Y.Q. Zhang 《Communications in Nonlinear Science & Numerical Simulation》2009,14(11):4022-4031
Presented in this paper is an overview of energy consumption in rural China in view of temporal and spatial variations. Characterized by steadily decreased proportion of biomass use and increased percentage of coal and electricity use, coal and biomass are still the major energy sources in rural areas, accounting for nearly 80% of the total rural energy consumption. Moreover, the energy consumption varies significantly across provinces both in total sum and by fuel types due to diversities of geographic features, economic development levels and local energy source availability. Three statistical groups are clustered associated with quantitative change and structural change, exhibiting evident transition from noncommercial energy pattern to commercial energy pattern. Much more work need to be done to cope with the forthcoming dramatic changes associated with booming rural economy and newly released policy from the points of both energy security and environmental pressure in China. 相似文献