检索结果-南通市图书馆

Journal of Systems Engineering and Electronics 2010年第6期21卷 1090-1094页

作者： Fu Chen Guangzhou Zhao xiaoming yu College of System Science and Engineering Zhejiang University Hangzhou 310027 P. R. China Key Laboratory of Tobacco Processing Technology Zhengzhou Tobacco Research Institute of CNTC Zhengzhou 450001 P. R. China

An efficient algorithm is proposed for computing the solution to the constrained finite time optimal control （CFTOC） problem for discrete-time piecewise affine （PWA） systems with a quadratic performance index. The maximal positively invariant terminal set, which is feasible and invariant with respect to a feedback control law, is computed as terminal target set and an associated Lyapunov function is chosen as terminal cost. The combination of these two components guarantees constraint satisfaction and closed-loop stability for all time. The proposed algorithm combines a dynamic programming strategy with a multi-parametric quadratic programming solver and basic polyhedral manipulation. A numerical example shows that a larger stabilizable set of states can be obtained by the proposed algorithm than precious work.

关键词： constrained optimal predictive control multi-parametric quadratic programming dynamic programming receding horizon control positively invariant set.

Effect of minor content of Gd on the mechanical and degradable properties of as-cast Mg-2Zn-xGd-0.5Zr alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第4期35卷 503-511页

作者： Junxiu Chen Lili Tan xiaoming yu Ke Yang Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China

RE-containing Mg alloys used as biodegradable medical implants exhibit good promising application due to their good mechanical properties and degradation resistance. In this work, effect of Gd on the microstructure, mechanical properties and biodegradation of as-cast Mg-2Zn-xGd-0.5Zr alloys was investigated. The results showed that there were mainly α-Mg, I-phase, W-phase and MgZn2 phase in Mg-Zn-Gd-Zr alloys. With increase of the Gd content, the strength of the alloys was enhanced due to the second phase strengthening and grain refinement. The degradation resistance of Mg-2Zn-0.5Zr alloy was increased by adding 0.5%–1% Gd due to the uniformly distributed second phases which acted as a barrier to prevent the pitting corrosion. However, increasing Gd content to 2% reduced the degradation resistance of the alloy due to the galvanic corrosion between the matrix and the second *** good degradation resistance and mechanical properties of as-cast Mg-2Zn-1Gd-0.5Zr alloy makes it outstanding for biomaterial application.

关键词： Mg-2Zn-0.5Zr-Gd allo Microstructure Mechanical properties Biodegradation

Biodegradable Materials for Bone Repairs:A Review

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2013年第6期29卷 503-513页

作者： Lili Tan xiaoming yu Peng Wan Ke Yang Institute of Metal Research Chinese Academy of Sciences72 Wenhua Road

With attractive research and development of biomaterials, more and more opportunities have been brought to the treatments of human tissue repairs. The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions, and the long-term effect of exotic substance to human body should be reduced as lower as possible. For this purpose, biodegradable materials, including polymers, magnesium alloys and ceramics, have attracted much attention for medical applications due to their biodegradable characters in body environment. This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs. Relevant history and research progresses are summarized.

关键词： Biomaterial Biodegradable Polymer Magnesium Ceramie Bone repair

Novel Concise Synthesis of （-）-Clausenamide1

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2013年第3期31卷 344-348页

作者： Di Liu xiaoming yu Liang Huang State Key Laboratory of Bioactive Substance and Function of Natural Medicine Beijing Key Laboratory of ActiveSubstance Discovery and Drugability Evaluation Institute of Materia Medica Chinese Academy of Medical Sci-ences & Peking Union Medical College Beijing 10050 China

A six-step synthesis of （-）-clausenamide is described. Optically pure （R,E）-1,3-diphenylallylic alcohol was ac-etylated and then subjected to an Ireland-Claisen rearrangement, giving the γ,δ-unsaturated acid, which underwent a substrate-induced stereoselective bromolactonization to afford the expected all-equatorial substituted bromo-δ-lac-one. An unusual chemo-selective aminolysis of the lactone resulted in the formation of a γ,δ-epoxy-amide in stereospecific manner. Base-promoted cyclization of this intermediate and the subsequent Davis oxidation furnished the synthesis, delivering the final product in 〉99% ee and up to 34% overall yield.

关键词： (-)-clausenamide diastereoselective synthesis Ireland-Claisen rearrangement diastereoselectivebromo|actonization bromo-c^-lactone aminolysis

Optical properties of conductive silver-nanowire films with different nanowire lengths

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2017年第11期10卷 3706-3714页

作者： xiaoming yu Xuan yu Jianjun Zhang Liqiao Chen yunqian Long Dekun Zhang Innovation Application Institute Zhejiang Ocean University Zhoushan 316004 China College of Electronic Information and Optical Engineering Nankai University Tianjin 300071 China

Transparent electrodes made of silver nanowires （Ag NWs） exhibit a higher flexibility than conventional indium tin oxide *** this reason,Ag NWs may find applications in future flexible electronic and optoelectronic ***,different optoelectronic devices have different specific requirements for Ag *** example,the optical transmittance haze is an important but rarely studied aspect of Ag NW *** this study,the optical transmittance and optical scattering of long （5-50 μm,L-NWs） and short （1-20 μm,S-NWs） Ag NW films were *** L-NWs exhibited better optical transmission than the S-NWs,whereas the S-NWs exhibited better light-scattering properties than the *** results indicate that the L-NWs are suitable for touch-screen displays,whereas the S-NWs are better suited as transparent conductive films for solar *** analyzed the scattering ratio of forward-scattered light to backscattered light for both the L-NWs and S-NWs and discovered that the mesh size affected the scattering *** longer wavelengths,a larger mesh yielded a higher backscattering ratio,whereas a smaller mesh yielded a lower backscattering *** formulated an equation for calculating the reflection haze using the total reflection （Ag NWs/glass）,R and the reflection of glass,*** reflection haze of the S-NWs and L-NWs exhibited different trends in the visible-near-infrared *** omnidirectional scattering model for the Ag NWs was used to evaluate the Ag NW scattering *** results of this study have great significance for the evaluation of the performance of Ag NWs in optoelectronic devices.

关键词： transparent electrode silver nanowires transmittance haze factor forward scattering and backscattering reflection-haze factor

Near-infrared spectroscopy and chemometric modelling for rapid diagnosis of kidney disease

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2017年第2期60卷 299-304页

作者： Mengli Fan Xiuwei Liu xiaoming yu Xiaoyu Cui Wensheng Cai Xueguang Shao Research Center for Analytical Sciences College of Chemistry Nankai University Tianjin 300071 China Laboratory of Clinic People's Hospital of Gaomi City Gaomi 261000 China Tianjin Key Laboratory of Biosensing and Molecular Recognition Tianjin 300071 China State Key Laboratory of Medicinal Chemical Biology Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300071 China

Rapid diagnosis is important for efficient treatment in clinical *** study aimed at development of a method for rapid and reliable diagnosis using near-infrared(NIR)spectra of human serum samples with the help of chemometric *** NIR spectra of sera from 48 healthy individuals and 16 patients with suspected kidney disease were *** wavelet transform(DWT)and variable selection were adopted to extract the useful information from the *** component analysis(PCA),linear discriminant analysis(LDA)and partial least squares discriminant analysis(PLSDA)were used for discrimination of the *** of the two-class sera was obtained using LDA and PLSDA with the help of DWT and variable ***-LDA produced 93.8%and 83.3%of the recognition rates for the validation samples of the two classes,and 100%recognition rates were obtained using *** results demonstrated that the tiny differences between the spectra of the sera were effectively explored using DWT and variable selection,and the differences can be used for discrimination of the sera from healthy and possible *** spectroscopy and chemometrics may be a potential technique for fast diagnosis of kidney disease.

关键词： near-infrared spectroscopy discrimination serum kidney disease chemometrics

Rational design, synthesis, and biological evaluation of novel C6-modified geldanamycin derivatives as potent Hsp90 inhibitors and anti-tumor agents

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第2期34卷 434-439页

作者： Ruxuan Wang Rentao Zhang Haoran Yang Nina Xue Xiaoguang Chen xiaoming yu State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Heat shock protein 90(Hsp90) is an appealing anticancer drug target that provoked a tremendous wave of investigations. Geldanamycin(GA) is the first identified Hsp90 inhibitor that exhibited potent anticancer activity, but the off-target toxicity associated with the benzoquinone moiety hampered its clinical application. Until now, structure optimization of GA is still in need to fully exploit the therapeutic value of Hsp90. Due to the structural complexity and synthetic challenge of this compound family, conventional optimization is bound to be costly but high efficiency is expected to be reachable by combining the art of rational design and total synthesis. Described in this paper is our first attempt at this approach aiming at rational modification of the C6-position of GA. The binding affinities towards Hsp90 of compound 1(C6-ethyl) and 2(C6-methyl) were designed and predicted by using Discovery Studio. These compounds were synthesized and further subjected to a thorough in vitro biological evaluation. We found that compounds1 and 2 bind to Hsp90 protein with the IC_(50) of 34.26 nmol/L and 163.7 nmol/L, respectively. Both compounds showed broad-spectrum antitumor effects. Replacing by ethyl, compound 1 exhibited more potent bioactivity than positive control GA, such as in G2/M cell cycle arrest, cell apoptosis and client proteins degradations. The results firstly indicated that the docking study is able to provide a precise prediction of Hsp90 affinities of GA analogues, and the C6 substituent of GA is not erasable without affecting its biological activity.

关键词： Hsp90 inhibitors Geldanamycin derivatives Total synthesis Structure-activity relationship Anticancer

A Nitrogen, Sulfur co-Doped Porphyrin-based Covalent Organic Framework as an Efficient Catalyst for Oxygen Reduction

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2022年第1期38卷 167-172页

作者： yu xiaoming MA yunchao LI Cuiyan GUAN Xinyu FANG Qianrong QIU Shilun State Key Laboratory of Inorganic Synthesis&Preparative Chemistry Jilin UniversityChangchun 130012P.R.China Key Laboratory of Preparation and Application of Environmental Friendly Materials Ministry of Education Jilin Normal UniversityChangchun 130103P.R.China

Oxygen reduction reaction(ORR) is a significant reaction for energy conversion systems(such as fuel cells, metal-air batteries, etc.). It is an urgent need to develop cheap, durable and highly-active catalysts for efficient ORR. Hence, we report a metal-free nitrogen and sulfur co-doped porphyrin-based covalent organic framework(COF) as a high-efficiency ORR catalyst[the onset potential(Eo) is 0.79 V and the half-wave potential(E1/2) is 0.70 V]. The double doping of N and S atoms causes uneven charge distribution around carbon atoms, which can act as catalytic active centers, improving ORR activity. Compared with single-atom doping, double atoms doping exhibits a higher activity due to the synergistic effect between different elements. These results demonstrate that reasonable design of stable metal-free COFs with a high electrochemical activity can promote their wide applications.

关键词： Covalent organic framework(COF) Oxygen reduction reaction co-Doped material

Improving performance of ZnO Schottky photodetector by inserting MXenes modified-layer

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第7期34卷 423-427页

作者： Cheng Wu Xinzhi Luo xiaoming yu Xuan yu Kun Lin Minghao Li Zhenhua Li yu Cao Yingtang Zhou School of Marine Engineering Equipment Zhejiang Ocean UniversityZhoushan 316022China National Engineering Research Center for Marine Aquaculture Zhejiang Ocean UniversityZhoushan 316022China School of Electrical Engineering Northeast Electric Power UniversityJilin 132012China

The development of low-cost and high-performance ZnO Schottky photodetectors (PDs) has drawn intensive attention,but still a challenge due to their poor conductivity and low light utilization ***,we introduce Ti_(3)C_(2)T_(X) into ZnO films to fabricate Schottky UV PDs via facile spin-coated *** fabricated ZnO/Ti_(3)C_(2)T_(X)/ZnO compound film shows outstanding performance on photocurrent,responsivity,noise equivalent power (NEP),normalized detection rate (D~*),and linear dynamic region (LDR),compared with the original Zn O *** photocurrent is significantly increased by 466%,and the responsivity is improved by one order of *** addition,it exhibits relatively low NEP (5.99×10^(-11)W),strong D~*(2.53×10~9 Jones),and high LDR (28 dB).The superior performance is ascribed to the enhanced conductivity and light absorption of ZnO film after introduction of Ti_(3)C_(2)T_(X) modification layer,leading to simultaneously faster electron transfer,lower the radiation recombination of electron and holes on the ZnO/Ti_(3)C_(2)T_(X)/ZnO compound *** work provides a facile way to develop low-cost and highperformance ZnO Schottky PDs.

关键词： MXenes Ti_(3)C_(2)T_(X) Schottky Photodetector Responsivity Normalized detectivity

NIR-II ?uorescence in vivo confocal microscopy with aggregation-induced emission dots

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第6期64卷 410-416页

作者： Wenbin yu Bing Guo Hequn Zhang Jing Zhou xiaoming yu Liang Zhu Dingwei Xue Wen Liu Xianhe Sun Jun Qian State Key Laboratory of Modern Optical Instrumentations Centre for Optical and Electromagnetic Research College of Optical Science and Engineering Zhejiang University Department of Chemical and Biomolecular Engineering National University of Singapore Department of Urology Sir Run-Run Shaw Hospital College of Medicine Innovation Center for Minimally Invasive Technique and Device Zhejiang University Interdisciplinary Institute of Neuroscience and Technology (ZIINT) Zhejiang University Joint Research Laboratory of Optics of Zhejiang Normal University and Zhejiang University Zhejiang Normal University

Significantly reduced tissue scattering of fluorescence signals in the second near-infrared(NIR-Ⅱ,1,000–1,700 nm)spectral region offers opportunities for large-depth in vivo ***,most reported works concerning NIR-II fluorescence in vivo bioimaging are realized by wide-field illumination and 2D-arrayed detection(e.g.,via InGaAs camera),which has high temporal resolution but limited spatial resolution due to out-of-focus *** NIR-II fluorescence imaging with confocal microscopy is a good approach to achieve high-spatial resolution visualization of biosamples even at deep *** this presented work,a NIR-II fluorescence confocal microscopic system was *** using a kind of aggregation-induced emission(AIE)dots as NIR-II fluorescent probes,800 lm-deep 3D in vivo cerebrovascular imaging of a mouse was obtained,and the spatial resolution at 700 lm depth could reach 8.78 ***,the time-correlated single photon counting(TCSPC)technique and femtosecond laser excitation were introduced into NIR-II fluorescence confocal microscopy,and in vivo confocal NIR-II fluorescence lifetime microscopic imaging(FLIM)of mouse cerebral vasculature was successfully realized.

关键词： Confocal microscopy NIR-II fluorescence AIE dots In vivo cerebrovascular imaging TCSPC FLIM imaging