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141.
Applied Mathematics and Mechanics - The recently developed hard-magnetic soft (HMS) materials can play a significant role in the actuation and control of medical devices, soft robots, flexible... 相似文献
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Preparation of core–shell structure Fe3O4@SiO2 superparamagnetic microspheres immoblized with iminodiacetic acid as immobilized metal ion affinity adsorbents for His‐tag protein purification
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Qian Ni Bing Chen Shaohua Dong Lei Tian Quan Bai 《Biomedical chromatography : BMC》2016,30(4):566-573
The core–shell structure Fe3O4/SiO2 magnetic microspheres were prepared by a sol–gel method, and immobiled with iminodiacetic acid (IDA) as metal ion affinity ligands for protein adsorption. The size, morphology, magnetic properties and surface modification of magnetic silica nanospheres were characterized by various modern analytical instruments. It was shown that the magnetic silica nanospheres exhibited superparamagnetism with saturation magnetization values of up to 58.1 emu/g. Three divalent metal ions, Cu2+, Ni2+ and Zn2+, were chelated on the Fe3O4@SiO2–IDA magnetic microspheres to adsorb lysozyme. The results indicated that Ni2+‐chelating magnetic microspheres had the maximum adsorption capacity for lysozyme of 51.0 mg/g, adsorption equilibrium could be achieved within 60 min and the adsorbed protein could be easily eluted. Furthermore, the synthesized Fe3O4@SiO2–IDA–Ni2+ magnetic microspheres were successfully applied for selective enrichment lysozyme from egg white and His‐tag recombinant Homer 1a from the inclusion extraction expressed in Escherichia coli. The result indicated that the magnetic microspheres showed unique characteristics of high selective separation behavior of protein mixture, low nonspecific adsorption, and easy handling. This demonstrates that the magnetic silica microspheres can be used efficiently in protein separation or purification and show great potential in the pretreatment of the biological sample. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
144.
Juechen Ni Yijia Wang Haoke Zhang Jing Zhi Sun Ben Zhong Tang 《Molecules (Basel, Switzerland)》2021,26(2)
Luminogens with aggregation-induced emission (AIEgens) have been widely applied in the field of photodynamic therapy. Among them, aggregation-induced emission photosensitizers (AIE–PSs) are demonstrated with high capability in fluorescence and photoacoustic bimodal imaging, as well as in fluorescence imaging-guided photodynamic therapy. They not only improve diagnosis accuracy but also provide an efficient theranostic platform to accelerate preclinical translation as well. In this short review, we divide AIE–PSs into three categories. Through the analysis of such classification and construction methods, it will be helpful for scientists to further develop various types of AIE–PSs with superior performance. 相似文献
145.
Lv Xinrong Wang Yanfang Wang Ying-ao Lin Xiaoyun Ni Yongnian 《Journal of Solid State Electrochemistry》2021,25(6):1871-1880
Journal of Solid State Electrochemistry - In this work, the binary nanocomposite of crosslinked polyaniline nanorods (CPANINRs) and molybdenum disulfide (MoS2) is first synthesized by in situ... 相似文献
146.
Mengyuan Ge Guangwen Li Zibo Ni Ning Liu Yushan Liu Yuzhou Liu 《Journal of polymer science. Part A, Polymer chemistry》2020,58(21):3009-3017
Utilizing collective forces between reactant and multiple catalyst molecules has been unprecedented due to the difficulty in realizing high order catalysis. Inspired by the power of collective forces in enzymes and organic catalysts, herein we report a rare example of high order catalysis for ring opening reaction (ROR) of strained rings by methanol. ROR is an important way to produce various polysiloxanes, but usually suffers from serious side reactions especially at high conversion, and currently there is a need to design new reaction pathway to achieve low molecular dispersity. In our study, the judiciously designed strained spiral cyclosiloxanes enable a high order catalysis by methanol, and this new methodology leads to a cyclic polysiloxane with high molecular weight and low dispersity even at full conversion of reactants. Kinetic study indicates an extremely unusual high-order reaction involving multiple methanol molecules per reaction, also confirmed by quantum calculation which reveals the presence of zwitterionic ions stabilized by collecting force of hydrogen bonds by methanol molecules. The inherent driving force for this unusual phenomenon is dominated by enthalpy stabilization of the reactive intermediates through hydrogen bonding. The selective formation of Si O Si bonds, instead of silanol products, reflects the power of scientific design. 相似文献
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Jian Ni Lap Keung Chu Feng Wu Domenic Sculli Yuan Shi 《European Journal of Operational Research》2012
This paper addresses the problem of mitigating procurement risk that arises from volatile commodity prices by proposing a hedging strategy within a multi-stage time frame. The proposed multi-stage hedging strategy requires a commodity futures position to be correctly initialised and rebalanced with adequate volumes of short/long positions, so as to reduce the volatility in the total procurement cost that would otherwise be generated by varying commodity spot prices. The novelty in the approach is the introduction of the rebalancing of commodity futures position at defined intermediate stages. To obtain an efficient or near optimal multi-stage hedging strategy, a discrete-time stochastic control model (DSCM) is developed. Numerical experiments and Monte Carlo simulation are used to show that the proposed multi-stage hedging strategy compares favourably with the minimal-variance hedge and the one-stage hedge. A close-form optimal solution is also presented for the case when procurement volume and price are independent. 相似文献
150.
First-principles study of structural stability and elastic property of pre-perovskite PbTiO3
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The structural stability and the elastic properties of a novel structure of lead titanate,which is named preperovskite PbTiO3 (PP-PTO) and is constructed with TiO6 octahedral columns arranged in a one-dimensional manner,are investigated by using first-principles calculations.PP-PTO is energetically unstable compared with conventional perovskite phases,however it is mechanically stable.The equilibrium transition pressures for changing from preperovskite to cubic and tetragonal phases are 0.5 GPa and 1.4 GPa,respectively,with first-order characteristics.Further,the differences in elastic properties between pre-perovskite and conventional perovskite phases are discussed for the covalent bonding network,which shows a highly anisotropic character in PP-PTO.This study provides a crucial insight into the structural stabilities of PP-PTO and conventional perovskite. 相似文献