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排序方式: 共有254条查询结果,搜索用时 15 毫秒
81.
Nonlinear Dynamics - In this paper, an extended state observer-based adaptive prescribed performance control technique is proposed for a class of nonlinear systems with full-state constraints and... 相似文献
82.
83.
Yue Wang Jing Feng Song Wu Huihui Shao Wenxuan Zhang Kun Zhang Hanyilan Zhang Qingyun Yang 《Molecules (Basel, Switzerland)》2022,27(6)
A new derivatization high-performance liquid chromatography method with ultraviolet detection was developed and validated for the quantitative analysis of methanesulfonate genotoxic impurities in an innovative drug for the treatment of non-alcoholic fatty liver disease. In this study, sodium dibenzyldithiocarbamate was used as a derivatization reagent for the first time to enhance the sensitivity of the analysis, and NaOH aqueous solution was chosen as a pH regulator to avoid the interference of the drug matrix. Several key experimental parameters of the derivatization reaction were investigated and optimized. In addition, specificity, linearity, precision, stability, and accuracy were validated. The determined results of the samples were consistent with those obtained from the derivatization gas chromatography–mass spectrometry analysis. Thus, the proposed method is a reliable and practical protocol for the determination of trace methanesulfonate genotoxic impurities in drugs containing mesylate groups. 相似文献
84.
85.
A Gold-Platinum nanoparticle-decorated titania nanotubular electrode is fabricated by electrochemically depositing Au and Pt nanoparticles onto a highly-oriented titania nanotube array. The prepared electrode, characterized by SEM and EDX, shows remarkably improved catalytic activities in the oxidation of hydrogen peroxide. By modifying the electrode with glucose oxidase (GOx) the resultant glucose biosensor exhibits a high sensitivity to glucose in the range of 0 to 1.8 mM with a response time of 3 s and detection limit of 0.1 mM. 相似文献
86.
In this paper, we modify the original physiological model of artificial pancreas by introducing the insulin secretion time
delay. The non-resonant double Hopf bifurcation is analyzed by the Center Manifold Theorem and Normal Form Method. Numerical
results supporting the theoretical analysis are presented in some typical parameter regions. It is shown that the critical
value of technological delay and the area of death island of the non-resonant double Hopf bifurcation in the modified model
are far less than those in the original model. This implies that when the secretion delay appears, the smaller technological
delay can induce the double Hopf bifurcation. In addition, the region IV with complex coexisting bi-stability also decreases sharply. Furthermore, the rich dynamics such as various period, quasi-period
and chaotic behaviors are found when some key parameters are changed. The obtained results can have important theoretical
guidance for the diagnosis and treatment of diabetes patients. 相似文献
87.
88.
Yiwei Zeng Jiangang Lu Xiaohua Yan Minzhu Lin Xianren Meng Xioshan Wu Qingyun Tu Zhenjin Lin 《Hyperfine Interactions》1992,70(1-4):1219-1222
Two main superconducting phases, 1223 and 2223 in TiBaCa3Cu3O8.5 superconductor, are identified by powder x-ray analysis and57Fe Mössbauer spectroscopy analysis. The Mössbauer fitting results shown that iron atoms in the lattice substitute two inequivalent sites of copper atoms for each main phase. The temperature dependence of Mössbauer parameters are obtained, and several problems are discussed which relate to the electric charge transfer which takes place around the superconducting transition temperature, the lattice dynamics and the effect on oxygen deficiency at different temperatures. 相似文献
89.
Qingyun Kang Mingyu Chu Prof. Panpan Xu Dr. Xuchun Wang Shiqi Wang Prof. Muhan Cao Prof. Oleksandr Ivasenko Prof. Tsun-Kong Sham Prof. Qiao Zhang Prof. Qiming Sun Prof. Jinxing Chen 《Angewandte Chemie (International ed. in English)》2023,62(47):e202313174
Chemical upcycling that catalyzes waste plastics back to high-purity chemicals holds great promise in end-of-life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilization of the transition state. This approach involves the synthesis of p-Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA-15 support, using a precise impregnation method. The unique design of the p-Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high-value liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g ⋅ gRu−1 ⋅ h−1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2, and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics. 相似文献
90.
Zhang Sen Liu Qi Wang Wei Lv Hangbing Zuo Qingyun Wang Yan Li Yingtao Lian Wentai Long Shibing Wang Qin Liu Ming 《Applied Physics A: Materials Science & Processing》2011,105(4):1003-1009
The performances of bulk-heterojunction (BHJ) solar cells are investigated for time-dependent thermal annealing with different
morphology evolution scales, having special consideration for the diffusion and aggregation of fullerene derivative molecules
based on blends of poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM). Meaningfully, rapid formation of dot-like and needle-like crystalline PCBM structures
of a few micrometers up to 60 μm in size is obtained with thermal annealing treatment from 2 to 15 min, which dynamically
reflects a fast process of PCBM molecule and cluster aggregation. Upon ultrasonic-assisted processing and annealing treatment,
the scale of P3HT crystals is drastically increased in view of X-ray diffraction (XRD) patterns, leading to a high hole mobility.
And, the P3HT domains can be gradually converted into larger P3HT crystals approved by the decreased full width at half-maximum
in the XRD patterns. Corresponding current–voltage curves are measured in quantity and we propose a model to explain the effect
of the crystalline degree of P3HT domains and aggregation of PCBM molecules and clusters on the phase segregation, expressing
a viewpoint towards high performance of BHJ solar cells. 相似文献