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Overview of 6π 1,5-Electrocyclization over the Past 40 Years

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Chinese Journal of Chemistry 2023年第6期41卷 725-740页

作者： Zhiqiang huang Wei Liu Wen-xiong Zhang Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Rare Earth Materials Chemistryand Applications&Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

As an important part of pericyclic reaction,6π 1,5-electrocyclization plays an important role in organic synthesis and chemical *** types of five-membered rings could be constructed via 1,5-electrocyclization with high atom *** elegant works have been reported in this field in the past few ***,it still needs a lot of effort in further advancements of 1,5-electrocyclization.

关键词： Electrocyclization Five-membered Rings Heterocyclic Compounds Pericyclic Reaction

Analysis and Application of the Singularity Locus of the Stewart Platform

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 133-140页

作者： MA Jianming huang Qitao xiong Haiguo HAN Junwei State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China

The direct use of the determinant of Jacobian matrix being equal to zero for the singularity analysis is generally difficult which is due to complexity of the Jacobian matrix of 6-DOF parallel manipulators,especially for Stewart ***,several scholars make their great contribution to the effective solution of this problem,but neither of them find the right *** paper gives a brief analysis of the kinematics of the Stewart platform and derives the Jacobian matrices of the system through the velocity *** the basis of the traditional classification of singularities,the second type of singularity is *** assumption of any three of the six variables of the Stewart platform as constant is made,then the analytical expression of singularity locus equation of the second type singularity which contains another three pose variables is *** singularity locus is represented in the three-dimensional space through the derived *** correctness and validity of the proposed method are verified through ***,the singularity analysis of an electric Stewart platform in its desired workspace and reachable workspace is ***,one can easily identify whether singularity exists in a given workspace of a Stewart platform and determine whether the existed singularity can be avoided through the proposed *** proposed method also provides theoretical principle for the design and application of the Stewart platform and has great significance for the trajectory planning and control.

关键词： parallel manipulator Stewart platform Jacobian matrix singularity locus workspace

A simple algorithm to improve the performance of the WENO scheme on non-uniform grids

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Acta Mechanica Sinica 2018年第1期34卷 37-47页

作者： Wen-Feng huang Yu-Xin Ren xiong Jiang Tsinghua University Beijing 100084 China China Aerodynamics Research and Development Center Mianyang 621000 China

This paper presents a simple approach for improving the performance of the weighted essentially nonoscillatory(WENO) finite volume scheme on non-uniform grids. This technique relies on the reformulation of the fifthorder WENO-JS(WENO scheme presented by Jiang and Shu in J. Comput. Phys. 126:202–228, 1995) scheme designed on uniform grids in terms of one cell-averaged value and its left and/or right interfacial values of the dependent *** effect of grid non-uniformity is taken into consideration by a proper interpolation of the interfacial values. On nonuniform grids, the proposed scheme is much more accurate than the original WENO-JS scheme, which was designed for uniform grids. When the grid is uniform, the resulting scheme reduces to the original WENO-JS scheme. In the meantime,the proposed scheme is computationally much more efficient than the fifth-order WENO scheme designed specifically for the non-uniform grids. A number of numerical test cases are simulated to verify the performance of the present scheme.

关键词： WENO scheme Non-uniform grids Shock capturing Finite volume methods

Quantitative study on interactions between interfacial misfit dislocation networks and matrix dislocations in Ni-based single crystal superalloys

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Acta Mechanica Solida Sinica 2017年第4期30卷 345-353页

作者： Jun xiong Yaxin Zhu Zhenhuan Li Minsheng huang Department of Mechanics Huazhong University of Science and Technology State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment

The interactions between the moving dislocation within matrix channel and the interfacial misfit dislocation networks on the two-phase interfaces in Ni-based single crystal superalloys are studied carefully via atomic modeling, with special focus on the factors influ- encing the critical bowing stress of moving dislocations in the matrix channel. The results show that the moving matrix dislocation type and its position with respect to the interfacial misfit dislocation segments have considerable influences on the interactions. If the moving matrix dislocation is pure screw, it reacts with the interracial misfit dislocation segments toward dislocation linear energy reduction, which decreases the critical bowing stress of screw dislocation due to dislocation linear energy release during the dislocation reactions. If the moving matrix dislocation is of 60^-mixed type, it is obstructed by the interaction between the mixed matrix dislocations and the misfit interfacial dislocation segments. As a result, the critical bowing stress increases significantly because extra interactive energy needs to be overcome. These two different effects on the critical bowing stress become in- creasingly significant when the moving matrix dislocation is very close to the interracial misfit dislocation segments. In addition, the matrix channel width also has a significant influence on the critical bowing stress, i.e. the narrower the matrix channel is, the higher the critical bowing stress is. The classical Orowan formula is modified to predict these effects on the critical bowing stress of moving matrix dislocation, which is in good agreement with the computational results.

关键词： Dislocation interaction Misfit dislocation networks Molecular dynamics Matrix dislocation Ni-based single crystal superalloys

Effect of reclaimed water effluent on bacterial community structure in the Typha angustifolia L. rhizosphere soil of urbanized riverside wetland, China

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Journal of Environmental Sciences 2017年第5期29卷 58-68页

作者： Xingru huang Wei xiong Wei Liu Xiaoyu Guo College of Resources Environment and Tourism Capital Normal University Beijing 100048 China Belting Municipal Key Laboratory of Resources Environment and GIS Beijing 100048 China Urban Environmental Processes and Digital Modeling Laboratory Beijing 100048 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

In order to evaluate the impact of reclaimed water on the ecology of bacterial communities in the Typha angustifolia L. rhizosphere soil, bacterial community structure was investigated using a combination of terminal restriction fragment length polymorphism and 16S rRNA gene clone library. The results revealed significant spatial variation of bacterial communities along the river from upstream and downstream. For example, a higher relative abundance of γ-Proteobacteria, Firmicutes, Chloroflexi and a lower proportion of β-Proteobacteria and ε-Proteobacteria was detected at the downstream site compared to the upstream site. Additionally, with an increase of the reclaimed water interference intensity, the rhizosphere bacterial community showed a decrease in taxon richness, evenness and diversity. The relative abundance of bacteria closely related to the resistant of heavy-metal was markedly increased, while the bacteria related for carbon/nitrogen/phosphorus/sulfur cycling wasn＇t strikingly changed. Besides that, the pathogenic bacteria markedly increased in the downstream rhizosphere soil since reclaimed water supplement, while the possible plant growth-promoting rhizobacteria obviously reduced in the downstream sediment. Together these data suggest cause and effect between reclaimed water input into the wetland, shift in bacterial communities through habitat change, and alteration of capacity for biogeochemical cycling of contaminants.

关键词： Reclaimed water T-RFLP 16S rRNA gene clone library Bacterial community structure

Combinatorial auction algorithm for project portfolio selection and scheduling to maximize the net present value

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第7期11卷 562-574页

作者： Yong-yi SHOU yi-lun huang Department of Management Science & Engineering Zhejiang University Hangzhou 310058 China Department of Instrument Science & Engineering Zhejiang University Hangzhou 310027 China

Scheduling projects at the activity level increases the complexity of decision making of project portfolio selection but also expands the search space to include better project portfolios. An integer programming model is formulated for the project portfolio selection and scheduling problem. An iterative multi-unit combinatorial auction algorithm is proposed to select and schedule project portfolios through a distributed bidding mechanism. Two price update schemes are designed to adopt either a standard or an adaptive Walrasian tatonnement process. Computational tests show that the proposed auction algorithm with the adaptive price update scheme selects and schedules project portfolios effectively and maximizes the total net present value. The price profile generated by the algorithm also provides managerial insights for project managers and helps to manage the scarce resources efficiently.

关键词： Project management Portfolio selection Combinatorial auction Project scheduling

A sparse algorithm for adaptive pruning least square support vector regression machine based on global representative point ranking

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Journal of Systems Engineering and Electronics 2021年第1期32卷 151-162页

作者： HU Lei yi Guoxing huang Chao School of Astronautics Harbin Institute of TechnologyHarbin 150001China

Least square support vector regression(LSSVR)is a method for function approximation,whose solutions are typically non-sparse,which limits its application especially in some occasions of fast *** this paper,a sparse algorithm for adaptive pruning LSSVR algorithm based on global representative point ranking(GRPR-AP-LSSVR)is *** first,the global representative point ranking(GRPR)algorithm is given,and relevant data analysis experiment is implemented which depicts the importance ranking of data ***,the pruning strategy of removing two samples in the decremental learning procedure is designed to accelerate the training speed and ensure the *** removed data points are utilized to test the temporary learning model which ensures the regression ***,the proposed algorithm is verified on artificial datasets and UCI regression datasets,and experimental results indicate that,compared with several benchmark algorithms,the GRPR-AP-LSSVR algorithm has excellent sparsity and prediction speed without impairing the generalization performance.

关键词： least square support vector regression(LSSVR) global representative point ranking(GRPR) initial training dataset pruning strategy sparsity regression accuracy

A comparative study of fuzzy weights of evidence and random forests for mapping mineral prospectivity for skarn-type Fe deposits in the southwestern Fujian metallogenic belt, China

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Science China Earth Sciences 2016年第3期59卷 556-572页

作者： ZHANG Zhen Jie ZUO Ren Guang xiong yi Hui School of Earth Sciences and Resources China University of Geosciences State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences

Recent studies have pointed out that the widespread iron deposits in southwestern Fujian metallogenic belt(SFMB)(China) are skarn-type deposits associated with the Yanshanian granites. There is still excellent potential for mineral exploration because large areas in this belt are covered by forest. A new predictive model for mapping skarn-type Fe deposit prospectivity in this belt was developed and focused on in this study, using five criteria as evidence:(1) the contact zones of Yanshanian granites(GRANITE);(2) the contact zones within the late Paleozoic marine sedimentary rocks and the carbonate formations(FORMATION);(3) the NE-NNE-trending faults(FAULT);(4) the zones of skarn alterations(SKARN); and(5) the aeromagnetic anomaly(AEROMAGNETIC). The fuzzy weights of evidence(FWof E) method, developed from the classical weights of evidence(Wof E) and based on fuzzy sets and fuzzy probabilities, could provide smaller variances and more accurate posterior probabilities and could effectively minimize the uncertainty caused by omitted or wrongly assigned data and be more flexible than the Wof E. It is an efficient and widely used method for mineral potential mapping. Random forests(RF) is a new and useful method for data-driven predictive mapping of mineral prospectivity method, and needs further scrutiny. Both prospectivity results respectively using the FWof E and RF methods reveal that the prediction model for the skarn-type Fe deposits in the SFMB is successful and efficient. Both methods suggested that the GRANITE and FORMATION are the most valuable evidence maps, followed by SKARN, AEROMAGNETIC, and FAULT. This is coincident with the skarn-type Fe deposit mineral model in the SFMB. The unstable performance experienced when FORMATION was omitted might indicate that the highest uncertainty and risk in follow-up exploration is related to the sequences. In addition, the performance of the RF method for the skarn-type Fe deposits prospectivity in the SFMB is better than

关键词： Mineral prospectivity mapping Fuzzy weights of evidence Random forest Skarn-type Fe Makeng deposit

A parameter formula connecting PID and ADRC

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Science China(Information Sciences) 2020年第9期63卷 175-187页

作者： Sheng ZHONG yi huang Lei GUO Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

This paper presents a parameter formula connecting the well-known proportional-integralderivative(PID) control and the active disturbance rejection control(ADRC). On the one hand, this formula gives a quantitative lower bound to the bandwidth of the extended state observer(ESO) used in ADRC,implying that the ESO is not necessarily of high gain. On the other hand, enlightened by the design of ADRC, a new PID tuning rule is provided, which can guarantee both strong robustness and nice tracking performance of the closed-loop systems under the PID control. Moreover, it is proved that the ESO can be rewritten as a suitable linear combination of the three terms in PID, which can give a better estimate for the system uncertainty than the single integral term in the PID controller. Theoretical results are verified also by simulations in the paper.

关键词： nonlinear uncertain systems proportional-integral-derivative PID active disturbance rejection control ADRC extended state observer ESO