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A Line Search SQP-type Method with Bi-object Strategy for Nonlinear Semidefinite Programming

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 388-409页

作者： wen-hao FU Zhong-wen CHEN School of Mathematical Sciences Suzhou University of Science and TechnologySuzhou 215009China School of Mathematical Sciences Soochow UniversitySuzhou 215006China

We propose a line search exact penalty method with bi-object strategy for nonlinear semidefinite *** each iteration,we solve a linear semidefinite programming to test whether the linearized constraints are consistent or *** search direction is generated by a piecewise quadratic-linear model of the exact penalty *** penalty parameter is only related to the information of the current iterate *** line search strategy is a penalty-free *** and local convergence are analyzed under suitable *** finally report some numerical experiments to illustrate the behavior of the algorithm on various degeneracy situations.

关键词： nonlinear semidefinite programming bi-object strategy global convergence rate of convergence

Effects of precipitates and inclusions on the fracture toughness of hot rolling X70 pipeline steel plates

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 805-811页

作者： Mai-wen Zhou hao Yu School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

In order to investigate the fracture toughness, crack tip opening displacement （CTOD） experiments were conducted on two X70 pipeline steel plates with different rolling processes. Atter the experiments, optical microscopy （OM）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） were employed to observe the microstructure and fracture morphology. The effects of precipi- tates on the fracture toughness and the crack initiation mechanism induced by inclusions were analyzed. The CTOD result shows that the steel with a lower finishing cooling temperature has a higher fracture toughness. Inchisiom with different shapes and two kinds of precipi- tates with different sizes were observed. It can be concluded that precipitates with different sizes have different effects and mechanisms on the fracture toughness. Distinguished fi＇om the earlier researches, inclusions enriched in silicon can be also served as the crack initiation.

关键词： pipeline steel crack propagation precipitates inclusions fracture toughness

Achievement of chaotic synchronization trajectories of master-slave manipulators with feedback control strategy

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Acta Mechanica Sinica 2010年第3期26卷 433-439页

作者： Qingkai Han Lina hao hao Zhang Bangchun wen School of Mechanical Engineering and Automation Northeastern University 110004 Shenyang China

This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master-slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numer- ical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master-slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization con- trol strategy. This synchronization control strategy proves the synchronization＇s feasibility and controllability for com- plicated motions generated by master-slave manipulators.

关键词： Master-slave manipulators - Chaoticsynchronization trajectory - Feedback control

Effect of roasting activation of rare earth molten salt slag on extraction of rare earth,lithium and fluorine

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Journal of Rare Earths 2023年第2期41卷 300-308页

作者： Zhifang Tong Xiaofei Hu hao wen Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341099China

A new process was proposed to extract rare earth elements(REEs),Li and F from electrolytic slag of rare earth molten salt by synergistic roasting and acid ***,the thermodynamic analysis of roasting reaction was carried out,then the effects of roasting factors on leaching REEs,Li and F in slag were *** additions,the mineral phase and morphology of molten salt slag,roasting slag and acid leaching slag were characterized,and the migration mechanism of REES,Li and F minerals in roasting and leaching process was *** results show that the synergistic roasting and activation of molten salt slag by CaO and Al_(2)(SO_(4))_(3)are thermodynamically *** optimum roasting conditions are as follows:molten salt slag of 20 g,Al_(2)(SO_(4))_(3)of 31.25 g and CaO of 6.25 g,roasting temperature of 1173.15 K and reaction time of 2 h,under this condition,the leaching rates of Nd,Pr,Gd,Li and F are 92.47%,91.56%,91.08%,96.69%and 96.8%,respectively.X-ray powder diffraction(XRD)and scanning electron microscopy-energy dispersive X-ray spectroscopy(SEM-EDS)analysis show that the rare earth fluoride(REF3)in molten salt slag transforms into soluble rare earth oxide(REO)after roasting and *** leaching,the leaching residue is mainly strip CaSO4,indicating that REES,Li and F can be fully extracted from molten salt slag.

关键词： Rare earth molten salt electrolytic slag Thermodynamic analysis Activation roasting Efficient extraction

Temperature field simulation of polyolefin-absorber mixture by FDTD-FDM model during microwave heating

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2900-2917页

作者： Xiaodong Jing hao wen Zhihong Xu State Key Laboratory of Multiphase Complex Systems Beijing Engineering Research Centre of Process Pollution ControlInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

This work has performed a numerical simulation of the temperature field during microwave heating of polyolefin-absorber mixture by means of a combined electric and thermal model.A finite difference time domain was used to model the electric field distribution within the cavity,while the finite difference method was used to calculate the temperature field distribution in different *** study has focused only on the process from room temperature to 500 K for reducing heating time and energy *** temperature range is a process with high energy consumption,difficult to control and great influence on the follow-up *** dependence of dielectric properties and thermal properties of heated materials are fully considered and simulated through an iterative *** simulation results show that input power,the size and location of the heated materials,the position of the waveguide,and the kinds of microwave absorbers are important factors affecting the heating *** a result,the uniform temperature distribution(the temperature difference Tdb10 K)can be achieved by choosing the appropriate input power(500–2000 W),the appropriate proportion of microwave absorber(the volume ratio of Si C to HDPE is 30:70),and combining with the moving and rotating of the heated *** uniform temperature field obtained without mechanical stirring is very important for reducing energy consumption and subsequent reactions.

关键词： Microwave heating Temperature field Finite difference time domain Finite difference method

Counting Multiplicities in a Hypersurface over Number Fields

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Algebra Colloquium 2018年第3期25卷 437-458页

作者： hao wen Chunhui Liu Department of iVlathematicM Sciences Tsinghua University Beijing 100084 China Department of Mathematics Faculty of Science Kyoto University Kyoto 606-8502 Japan

We fix a counting function of multiplicities of algebraic points in a projective hypersurface over a number field, and take the sum over all algebraic points of bounded height and fixed degree. An upper bound for the sum with respect to this counting function will be given in terms of the degree of the hypersurface, the dimension of the singular locus, the upper bounds of height, and the degree of the field of definition.

关键词： algebraic point counting multiplicities height function over projective space intersection tree rational point

Wave height estimation using the singular peaks in the sea echoes of high frequency radar

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Acta Oceanologica Sinica 2018年第1期37卷 108-114页

作者： ZHOU hao wen Biyang School of Electronic Information Wuhan University

The popular methods to estimate wave height with high-frequency（HF） radar depend on the integration over the second-order spectral region and thus may come under from even not strong external interference. To improve the accuracy and increase the valid detection range of the wave height measurement, particularly by the smallaperture radar, it is turned to singular peaks which often exceed the power of other frequency components. The power of three kinds of singular peaks, i.e., those around ±1,±√2 and ±1√2 times the Bragg frequency, are retrieved from a one-month-long radar data set collected by an ocean state monitoring and analyzing radar,model S（OSMAR-S）, and in situ buoy records are used to make some comparisons. The power response to a wave height is found to be described with a new model quite well, by which obvious improvement on the wave height estimation is achieved. With the buoy measurements as reference, a correlation coefficient is increased to 0.90 and a root mean square error（RMSE） is decreased to 0.35 m at the range of 7.5 km compared with the results by the second-order method. The further analysis of the fitting performance across range suggests that the peak has the best fit and maintains a good performance as far as 40 km. The correlation coefficient is 0.78 and the RMSE is 0.62 m at 40 km. These results show the effectiveness of the new empirical method, which opens a new way for the wave height estimation with the HF radar.

关键词： high frequency radar wave height Bragg peak singular peak ocean state monitoring and analyzing radar

A REVIEW ON RESEARCH ON DEVELOPMENT OF LIGAMENT CONSTITUTIVE RELATIONS ON MACRO, MESO, AND MICRO LEVELS

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Acta Mechanica Solida Sinica 2013年第4期26卷 331-343页

作者： Chao Wan Zhixiu hao Shizhu wen State Key Laboratory of Tribology Tsinghua University

Ligaments are densely connective soft tissues capable of maintaining stability and function of knee *** an important factor,the constitutive relation of ligament would affect its biomechanics and further play an essential role in the research on ligament injury,healing and *** objective of this paper is to provide an overview of the current research on ligament constitutive relations on the macro,meso,and micro levels as well as the anatomy and histological structure of *** studies of biomechanical behaviors during ligament injury and healing periods have also been *** on the research on ligament constitutive relation in the past three decades,a discussion of some research perspectives is also presented,such as a validated accurate measuring method of in situ strain in ligament,a new constitutive relation involving the distribution of ultra-structural properties,and a rational estimation of ligament injury and healing process by the change of its ultra-structural or histological characteristics.

关键词： constitutive relation ligament ultra-structure macro meso micro

Doped-TiO_2 Photocatalysts and Synthesis Methods to Prepare TiO_2 Films

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Journal of Materials Science & Technology 2008年第5期24卷 675-689页

作者： Ying GUI hao DU Lishi wen Division of Surface Engineering of Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Graduate School of Chinese Academy of Sciences： Beijing 100039 China

TiO2 is a promising photocatalyst. However, the low photocatalytic efficiency calls for the modification of TiO2. Metal- and nonmetal-doping of TiO2 have been proved to be effective ways to enhance photocatalytic properties. This review provides a deep insight into the understanding of the metal- and nonmetal-doped TiO2 photocatalysts. This article begins with the introduction of the crystal structures of TiO2 and applications of TiO2 materials. We then reviewed the doped-TiO2 system in two categories：（1） metal-doped TiO2 photocatalysts system, and （2） nonmetal-doped TiO2 photocatalysts system. Both experimental results and theoretical analyses are elaborated in this section. In the following part, for the advantages of TiO2 thin films over particles, various preparation methods to obtain TiO2 thin films are briefly discussed. Finally, this review ends with a concise conclusion and outlook of new trends in the development of TiO2-based photocatalysts.

关键词： TiO2 films Photocatalysis Metal-doping Nonmetal-doping DFT