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Science China Chemistry 2021年第9期64卷 1522-1529页

作者： Zhanghong Guo Xiaowei Chen Hao Fang Xiaowei Zhao Zhiyong Jiang international Scientific and technological Cooperation Base of Chiral Chemistry Henan UniversityKaifeng475004China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang453007China

The first enantioselective Beckwith-Enholm cyclization reaction is reported *** cooperative photoredox and chiral hydrogen-bonding catalysis mediated by visible light,cyclization of carbonyls with azaarene-based olefins as a new reaction system offers a general and divergent synthetic pathway to furnish a variety of highly valuable enantioenriched azaarenefunctionalized carbocyclic and heterocyclic alcohols,which bear adjacent 1,2-or nonadjacent 1,3-stereocentres on distinct cyclic frameworks,in high yields and enantio-and *** good compatibility of various azaarenes and carbonyls as well as the diversity of cyclic structures of the products underscores the generality of the catalysis *** addition to the ability to precisely introduce deuterium into molecules in an enantioselective manner,the considerable synthetic value of this method includes the excellent antioxidant stress potential of the *** particular,molecule 29 was determined to be a promising lead compound for antioxidant stress drug design.

关键词： photoredox catalysis asymmetric catalysis Beckwith-Enholm cyclizations azaarenes antioxidant stress

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Fold catastrophe model of strike-slip fault earthquake

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Applied Mathematics and Mechanics(English Edition) 2010年第3期31卷 349-362页

作者：潘岳李爱武 School of Civil Engineering Qingdao Technological University School of Science Qingdao Technological University

Using a differential form of the potential energy function and taking the effect of work applied by external force in far field into account, the mechanism of strike-slip fault earthquake is analyzed. The research indicates that each characteristic displayed with a fold catastrophe model in the catastrophe theory corresPonds to a specific primary characteristic of the strike-slip fault earthquake. The fold catastrophe can describe the positions of starting and end points of a fault failure and the distance of fault dislocation. These include the description of stability of the surrounding rock-fault system before and after the earthquake. Two different illustrations about elastic energy releasing amount of the surrounding rock with the fault failure are shown with the primary characteristics mutually demonstrated. The intensity of strike-slip fault earthquake is related to the surrounding rock press and the stiffness ratio of surrounding rock and fault. The larger the surrounding rock press, the smaller the stiffness ratio. The larger the included angle between the tangential stress axis and the causative fault surface, the stronger the earthquake.

关键词： fault earthquake fold catastrophe model end point of failure failure criterion energy import rate elastic energy releasing amount

Understanding the electrode reaction process of dechlorination of 2,4-dichlorophenol over Ni/Fe nanoparticles: Effect of pH and 2,4-dichlorophenol concentration

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Journal of Environmental Sciences 2019年第10期31卷 13-20页

作者： Kaiyuan Zheng Yuqiao Song Xu Wang Xin Li Xuhui Mao Dihua Wang School of Resources and Environmental Sciences Wuhan University Wuhan 430079 China Hubei international Scientific and technological Cooperation Base of Sustainable Resource and Energy Wuhan University Wuhan 430079China

Herein,with the exploitation of iron and nickel electrodes,the 2,4-dichlorophenol(2,4-DCP)dechlorinating processes at the anode and cathode,respectively,were separately studied via various electrochemical techniques(e.g.,Tafel polarization,linear polarization,electrochemical impedance spectroscopy).With this in mind,Ni/Fe nanoparticles were prepared by chemical solution deposition,and utilized to test the dechlorination activities of 2,4-DCP over a bimetallic *** the iron anode,the results showed that higher 2,4-DCP concentration and solution acidity aggravated the corrosion within the *** charge transfer resistance(Rct)values of the iron electrode were 703,473,444,and 437Ω·cm2 for the initial 2,4-DCP concentrations of0,20,50,and 80 mg/L,*** the bulk pH of the 2,4-DCP solution varied from 3.0,5.0to 7.0,the corresponding Rct values were 315,376,and 444Ω·cm2,*** the nickel cathode,the reduction current densities on the electrode at-0.75 V(*** calomel electrode)were 80,106,and 111μA/cm2,for initial 2,4-DCP concentrations of 40,80,and125 mg/*** dechlorination experiments demonstrated that when the initial pH of the solution was 7.0,5.0,and 3.0,the dechlorination percentage of 2,4-DCP by Ni/Fe nanoparticles was 62%,69%,and 74%,respectively,which was in line with the electrochemical experiments.10 wt.%Ni loading into Ni/Fe bimetal was affordable and gave a good dechlorination efficiency of 2,4-DCP,and fortunately the Ni/Fe nanoparticles remained comparatively stable in the dechlorination processes at pH 3.0.

关键词： 2,4-Dichlorophenol(2,4-DCP) Dechlorination Corrosion Catalytic hydrogenation Ni/Fe particles

A metamaterial-free fluid-flow cloak

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National Science Review 2022年第9期9卷 212-218页

作者： Fuyang Tay Youming Zhang Hongyi Xu Honghui Goh Yu Luo Baile Zhang Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University School of Electrical and Electronic Engineering Nanyang Technological University Centre for Disruptive Photonic Technologies Nanyang Technological University

The model of ide al fluid flow around a cylindrical obstacle exhibits a long-established physical picture,where originally straight streamlines are deflected over the whole space by the *** by transformation optics and metamaterials,recent theories have proposed the concept of fluid cloaking,which is able to recover the straight streamlines,as if the obstacle did not ***,such a cloak,similar to all previous transformation-optics-based devices,relies on complex metamaterials with inhomogeneous parameters and is difficult to *** we deploy the theory of scattering cancellation and report on the experimental realization of a fluid-flow cloak without *** clo ak is realized by engineering the geometry of the fluid channel,which effectively cancels the dipole-like scattering of the *** clo aking effect is demonstrated through the direct observation of recovered straight streamlines in the fluid *** work sheds new light on conventional fluid control and may find application in microfluidic devices.

关键词： invisibility cloaks metamaterials fluid-flow control

Orientation Dependence of Photoelectron Angular Distribution in Nitrogen Molecule Irradiated by XUV Laser Field

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Chinese Physics Letters 2016年第1期33卷 40-43页

作者：杨晓东高明田园 Department of Optical and Electrical Information Xi'an University of Technological Information College of Optoelectronic engineering Xi'an Technological University

We theoretically study the dependence of photoelectron angular distribution on laser polarization direction in nitrogen molecules. The approach is based on the time-dependent density functional theory at the level of local density approximation complemented by self-interaction correction. It is found that photoelectron emission in one photon regime could be considered as a probing tool for the main character of different types of molecular orbitals （σ or π）. The pattern of emitted photoelectrons strongly depends on the polarized angle of the laser, for σ orbital, the number of photoelectron decreases with increasing the polarized angle, while for π orbital, it has the inverse relation to the polarized angle, which reveals the multi-electron effect in molecules. On the other hand, concerning the total photoelectron emission, one should take into account a few occupied orbitals instead of only the outmost one.

关键词： of is on in HOMO Orientation Dependence of Photoelectron Angular Distribution in Nitrogen Molecule Irradiated by XUV Laser Field that by

Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

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Chinese Journal of Aeronautics 2016年第4期29卷 1084-1095页

作者： Li Benkai Li Changhe Zhang Yanbin Wang Yaogang Jia Dongzhou Yang Min School of Mechanical Engineering Qingdao Technological University

Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM-III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that (1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient; (2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient; (3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil; (4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils; (5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature; (6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and (7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 degrees C grinding temperature, and 42.7% energy ratio coeffi

关键词： Base oil Carbon chain length Energy ratio coefficient Grinding force Grinding temperature MQL grinding Vegetable oil Viscosity

Specific grinding energy and surface roughness of nanoparticle jet minimum quantity lubrication in grinding

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Chinese Journal of Aeronautics 2015年第2期28卷 570-581页

作者： Zhang Dongkun Li Changhe Jia Dongzhou Zhang Yanbin Zhang Xiaowei School of Mechanical Engineering Qingdao Technological University

Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication （MQL）, and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The speci- fic grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were sig- nificantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%, respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%, and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS：, carbon nanotube （CNT）, and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore, the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume con- centrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used. Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased. Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration.

关键词： Grinding Minimal quantity of lubrica-tion (MQL) Nanoparticle Specific grinding energy Surface roughness

A New Approach to Design and Optimize Sizing of Hybrid Microgrids in Deregulated Electricity Environment

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CSEE Journal of Power and Energy Systems 2022年第2期8卷 569-579页

作者： Astitva Kumar Mohammad Rizwan Uma Nangia Delhi technological university Delhi 110042India

The demand for electrical energy in urban and suburban areas is increasing drastically because of various *** electricity bill has increased significantly due to increased comfort levels and uses of modern ***,the demand response along with the power generated from renewable energy resources is playing an important role in reducing electricity bills without compromising any *** this paper,a novel framework is proposed for the selection of renewable energy resources and sizing optimization with reduced costs and increased productivity for the *** simultaneous process of selecting the appropriate renewable energy resources and sizing is covered in three stages:initially,the prediction of power from the renewable energy resources to perform a feasibility analysis is ***,the sizing of the battery energy storage system for a grid integrated system to meet the load profile is ***,the performance analysis of the proposed microgrid in a deregulated electricity environment is *** modeling of the proposed hybrid microgrid considers load flexibility and the stochastic behavior of renewable energy ***,the net metering concept(bi-directional energy exchange)is *** the developed model,the percentage of annualized return of investment(AROI)is found to be 6.8%with a payback period of 6.67 years.

关键词： Hybrid systems load management metaheuristic technique renewable

Comparative Study on Response Surfaces for Reliability Analysis of Spatially Variable Soil Slope

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China Ocean Engineering 2015年第1期29卷 81-90页

作者：李亮褚雪松 School of Civil Engineering Qingdao Technological University

This paper focuses on the performance of the second-order polynomial-based response surfaces on the reliability of spatially variable soil slope. A single response surface constructed to approximate the slope system failure performance function G（X）（called single RS） and multiple response surfaces constructed on finite number of slip surfaces （called multiple RS） are developed, respectively. Single RS and multiple RS are applied to evaluate the system failure probability pf for a cohesive soil slope together with Monte Carlo simulation （MCS）. It is found thatpe calculated by single RS deviates significantly from that obtained by searching a large number of potential slip surfaces, and this deviation becomes insignificant with the decrease of the number of random variables or the increase of the scale of fluctuation. In other words, single RS cannot approximate G（X） with reasonable accuracy. The value of pc from multiple response surfaces fits well with that obtained by searching a large number of potential slip surfaces. That is, multiple RS can estimate G（X） with reasonable accuracy.

关键词： probabilistic slope stability analysis response surface method Monte Carlo simulation

Fuzzy Diffusion Distance Learning for Cartoon Similarity Estimation

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Journal of Computer Science & Technology 2011年第2期26卷 203-216页

作者：俞俊谢福顺 School of Computer Engineering Nanyang Technological University

In this paper, a novel method called fuzzy diffusion maps （FDM） is proposed to evaluate cartoon similarity, which is critical to the applications of cartoon recognition, cartoon clustering and cartoon reusing. We find that the features from heterogeneous sources have different influence on cartoon similarity estimation. In order to take all the features into consideration, a fuzzy consistent relation is presented to convert the preference order of the features into preference degree, from which the weights are calculated. Based on the features and weights, the sum of the squared differences （L2） can be calculated between any cartoon data. However, it has been demonstrated in some research work that the cartoon dataset lies in a low-dimensional manifold, in which the L2 distance cannot evaluate the similarity directly. Unlike the global geodesic distance preserved in Isomap, the local neighboring relationship preserved in Locally Linear Embedding, and the local similarities of neighboring points preserved in Laplacian Eigenmaps, the diffusion maps we adopt preserve diffusion distance summing over all paths of length connecting the two data. As a consequence, this diffusion distance is very robust to noise perturbation. Our experiment in cartoon classification using Receiver Operating Curves shows fuzzy consistent relation＇s excellent performance on weights assignment. The FDM＇s performance on cartoon similarity evaluation is tested on the experiments of cartoon recognition and clustering. The results show that FDM can evaluate the cartoon similarity more precisely and stably compared with other methods.

关键词： fuzzy diffusion maps similarity diffusion distance cartoon recognition cartoon clustering