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A Class of Quadratic Matrix Equations over Finite Fields

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Algebra Colloquium 2023年第1期30卷 169-180页

作者： yin chen Xinxin Zhang School of Mathematics and Statistics Northeast Normal University Changchun 130024China Department of Mathematics and Statistics Queen's University KingstonK7L3N6Canada

We exhibit an explicit formula for the cardinality of solutions to a class of quadratic matrix equations over finite *** prove that the orbits of these solutions under the natural conjugation action of the general linear groups can be separated by classical conjugation invariants defined by characteristic *** also find a generating set for the vanishing ideal of these orbits.

关键词： matrix equations general linear groups finite fields separating invariants

Controlled Synthesis of CuO Nanoparticles by TritonX-100-based Microemulsions

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Journal of Wuhan University of Technology(Materials Science) 2014年第4期29卷 647-650页

作者：沈长斌 chen yin School of Materials Science and Engineering Dalian Jiaotong University Liaoning Key Materials Laboratory for Railway Dalian Jiaotong University

CuO nanoparticles were synthesized by using microreactors made of Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic synthesis parameters were determined. The results of thermo gravimetric/differential thermal analysis（TG/DTA） of the precursor products indicated that the proper calcination temperature was about 500 ℃. The nanoparticles were characterized by X-ray diffraction（XRD）, transmission electron microscopy（TEM） and UV-visible spectra. It was indicated that the grain size was highly dependent on the ratio of water to surfactant（R）. With the R value increasing, the particles size became larger.

关键词： synthesis microemulsion CuO nanoparticles

Thermal instability of a viscoelastic fluid in a fluid-porous system with a plane Poiseuille flow

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Applied Mathematics and Mechanics(English Edition) 2020年第11期41卷 1631-1650页

作者： chen yin Chunwu WANG Shaowei WANG College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Engineering Mechanics School of Civil EngineeringShandong UniversityJinan 250061China

The thermal convection of a Jeffreys fluid subjected to a plane Poiseuille flow in a fluid-porous system composed of a fluid layer and a porous layer is studied in the paper.A linear stability analysis and a Chebyshevτ-QZ algorithm are employed to solve the thermal mixed *** the case in a single layer,the neutral curves of the two-layer system may be bi-modal in the proper depth ratio of the two *** find that the longitudinal rolls(LRs)only depend on the depth *** the existence of the shear flow,the effects of the depth ratio,the Reynolds number,the Prandtl number,the stress relaxation,and strain retardation times on the transverse rolls(TRs)are also ***,the thermal instability of the viscoelastic fluid is found to be more unstable than that of the Newtonian fluid in a two-layer *** contrast to the case for Newtonian fluids,the TRs rather than the LRs may be the preferred mode for the viscoelastic fluids in some cases.

关键词： viscoelastic fluid thermal convection Poiseuille flow fluid-porous system

ACTIVE FRONT STEERING DURING BRAKING PROCESS

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 64-70页

作者： chen Deling chen Li yin chengliang ZHANG Yong School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240China

An active front steering （AFS） intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation （HILS） system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

关键词： Active front steering(AFS) Handling stability Yaw rate Sideslip angle Hardware-in-the-loop-simulation (HILS)

Ideal-comparability over Regular Rings

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Acta Mathematica Sinica,English Series 2006年第2期22卷 417-424页

作者： Huan yin chen Miao Sen chen Department of Mathematics Zhejiang Normal University

We introduce the concept of ideal-comparability condition for regular rings. Let I be an ideal of a regular ring R. If R satisfies the I-comparability condition, then R is one-sided unit-regular if and only if so is R/I. Also, we show that a regular ring R satisfies the general comparability if and only if the following hold：（1） R/I satisfies the general comparability; （2） R satisfies the general I-comparability condition; （3） The natural map B（R） → B（R/I） is surjective.

关键词： Ideal-Comparability Regular Rings

Metalizing reduction and magnetic separation of vanadium titano-magnetite based on hot briquetting

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International Journal of Minerals,Metallurgy and Materials 2014年第3期21卷 225-233页

作者： Shuang-yin chen Man-sheng Chu School of Materials and Metallurgy Northeastern University

To achieve high efficiency utilization of Panzhihua vanadium titano-magnetite, a new process of metalizing reduction and magnetic separation based on hot briquetting is proposed, and factors that affect the cold strength of the hot-briquetting products and the efficiency of reduction and magnetic separation are successively investigated through laboratory experiments. The relevant mechanisms are elucidated on the basis of microstructural observations. Experimental results show that the optimal process parameters for hot briquetting include a hot briquetting temperature of 475°C, a carbon ratio of 1.2, ore and coal particle sizes of less than 74 μm. Additionally, with respect to metalizing reduction and magnetic separation, the rational parameters include a magnetic field intensity of 50 mT, a reduction temperature of 1350°C, a reduction time of 60 min, and a carbon ratio of 1.2. Under these above conditions, the crushing strength of the hot-briquetting agglomerates is 1480 N, and the recovery ratios of iron, vanadium, and titanium are as high as 91.19%, 61.82%, and 85.31%, respectively. The new process of metalizing reduction and magnetic separation based on hot briquetting demonstrates the evident technological advantages of high efficiency separation of iron from other valuable elements in the vanadium titano-magnetite.

关键词： magnetite hot briquetting ore reduction magnetic separation

TWO IMPROVED ALGORITHMS AND IMPLEMENTATION FOR A SINGULARLY PERTURBED PROBLEM ON MOVING MESHES

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Journal of Systems Science & Complexity 2011年第6期24卷 1232-1240页

作者： Qin ZHOU Yanping chen yin YANG School of Mathematics Hunan International Economics University Changsha 410205 China School of Mathematical Sciences South China Normal University Guangzhou 510631 China School of Mathematics and Computational Science Xiangtan University Xiangtan 411105 China

This paper applies a difference scheme to a singularly perturbed problem. The authors provide two algorithms on moving mesh methods by using Richardson extrapolation which can improve the accuracy of numerical solution. In traditional algorithms of moving meshes, the initial mesh is a uniform mesh. The authors change it to Bakhvalov-Shishkin mesh, and prove that it improves efficiency by numerical experiments. Finally, the results of the two algorithms are analyzed.

关键词： Algorithm equidistribution principle moving mesh method Richardson extrapolation singularly perturbed problem.

Prototype Design and Experimental Study on Locust Air-Posture Righting

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Journal of Bionic Engineering 2014年第3期11卷 459-468页

作者： Diansheng chen Junmao yin Kewei chen Kai Zhao Benguang Zhang Robotics Institute Beihang University Beijing 100191 P. R. China

Locust has the capacity to maintain a righting posture and glide through attitude adjustment after leaping. A prototype inspired by the dynamic mechanism of attitude adjustment of locusts was developed. The prototype consists of a pair of wings driven by a four-bar mechanism, and a 2 Degree of Freedom （DOF） tail to imitate the movement of the locust abdomen. The power source, microcontroller, wireless data transmission module, and attitude sensors are contained in the fuselage. Experiments imitating the flight of locust were conducted to determine the mechanism of locust Subsequent Attitude Adjustment （SAA）. The tethered prototype was driven by the movement of the tail and the flapping of the wings. Results show that the pitch and yaw of the tail, and the asymmetric action of the flapping wings significantly influence the posture of the prototype. These findings suggest that both the wiggling abdomen and flapping wings contribute to the locust SAA in the air. This research lays the groundwork and technical support for the probable design and development of practical jumping robots with attitude adjustment function.

关键词： attitude adjustment locust air-posture righting prototype design wiggling tail flapping wing

Optic tecta I superficial inter neurons detect motion in larval zebrafish

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Protein & Cell 2019年第4期10卷 238-248页

作者： chen yin Xiaoquan Li Jiulin Du Institute of Neuroscience State Key Laboratory of NeuroscieneeCenter for Excellenee in Brain Science and Intelligenee TechnologyChinese Academy of SciencesShanghai 200031China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China School of Life Science and Technology ShanghaiTech UniversityShanghai 200031China

Detection of moving objects is an essential skill for animals to hunt prey,recognize conspecifics and avoid *** zebrafish,as a vertebrate model,primarily uses its elaborate visual system to distinguish moving objects against background *** optic tectum(OT)receives and integrates inputs from various types of retinal ganglion cells(RGCs),including direction-selective(DS)RGCs and size-selective RGCs,and is required for both prey capture and predator ***,it remains largely unknown how motion information is processed within the *** we performed in vivo whole-cell recording and calcium imaging to investigate the role of superficial interneurons(SINs),a specific type of optic tecta I neurons,in motion detection of larval *** mainly receive excitatory synaptic inputs,exhibit transient ON-or OFF-type of responses evoked by light flashes,and possess a large receptive field(RF).One fifth of SINs are DS and classified into two subsets with separate preferred ***,SINs show size-dependent responses to moving *** are efficiently activated by moving objects but not static ones,capable of showing sustained responses to moving objects and having less visual adaptation than periventricular neurons(PVNs),the principal tecta I ***,ablation of SINs impairs prey capture,which requires local motion detection,but not global looming-evoked ***,starvation enhances the gain of SINs'motion responses while maintaining their size tuning and *** results indicate that SINs serve as a motion detector for sensing and localizing sized moving objects in the visual field.

关键词： optic tectum motion detection direction selectivity visual adaptation zebrafish