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Optical system for extremely large spectroscopic survey telescope

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 158-174页

作者： Ding-qiang su Hua bai Xiangyan Yuan Xiangqun Cui Key Laboratory of the Ministry of Education School of Astronomy and Space ScienceNanjing UniversityNanjing 210023China Nanjing Institute of Astronomical Optics and Technology(NIAOT) Chinese Academy of SciencesNanjing 210042China University of Chinese Academy of Sciences Nanjing 211135China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 101408China

This article presents research work on a spectroscopic survey *** idea is as follows:for such a telescope,a pure reflecting optical system is designed,which should have an aperture and a field of view(FOV)both as large as possible and excellent image quality,and then a strip lensm(lens-prism)atmospheric dispersion corrector(S-ADC)is added,only for correcting the atmospheric *** the fund limitation and the simplicity of scaling up,some 12-m telescopes are designed as ***,Korsch,and Meinel put forward the four-mirror Nasmyth systems I and II,which are used in this *** of 1.5°,2°,and 2.5°are *** all systems,the image qualities are *** the S-ADC relaxes the optical glass size restriction,this 12-m telescope with a FOV of 2.5°can be magnified in proportion to a 16-m *** etendue(from Frenchétendue)and focal surface will now be the largest in the *** such a telescope,a pure reflecting optical system can also be obtained.A subsequent coudésystem is designed with excellent image quality.

关键词： telescopes spectroscopic survey

A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple subway Tunnels

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2893-2915页

作者： Shen Yan Dajiang Geng ning Dai Mingjian Long Zhicheng bai College of Civil Engineering Tongji UniversityShanghai200092China China Construction 4th Engineering Bureau 6th Corp. Ltd.Shanghai201199China Department of Civil and Architecture Engineering Hubei Polytechnic UniversityHuangshi435003China

According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock *** address this challenge,a subterranean transfer structure spanning multiple subway tunnels was *** on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam *** resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer *** research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent *** established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate *** pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.

关键词： Crossing tunnels transfer structure force mechanism simplify analysis layered soil mass

An aircraft brake control algorithm with torque compensation based on RBF neural network

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Chinese Journal of Aeronautics 2024年第1期37卷 438-450页

作者： ning bai Xiaochao LIU Juefei LI Zhuangzhuang WANG Pengyuan QI Yaoxing SHANG Zongxia JIAO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing 100191China Key Laboratory of Advanced Aircraft Systems(Beihang University) Ministry of Industry and Information TechnologyBeijing 100091China Research Institute for Frontier Science Beihang UniversityBeijing 100191China ningbo Institute of Technology of Beihang University Ningbo 315800China Tianmushan Laboratory Xixi Octagon CityYuhang DistrictHangzhou 310023China

The wheel brake system of an aircraft is the key to ensure its safe landing and rejected takeoff.A wheel’s slip state is determined by the brake torque and ground adhesion torque,both of which have a large degree of *** is this nature that brings upon the challenge of obtaining high deceleration rate for aircraft brake *** overcome the disturbances caused by the above uncertainties,a braking control law is designed,which consists of two parts:runway surface recognition and wheel’s slip state *** runway surface recognition,the identification rules balancing safety and braking efficiency are defined,and the actual identification process is realized through recursive least square method with forgetting *** slip state tracking,the LuGre model with parameter adaptation and a brake torque compensation method based on RBF neural network are proposed,and their convergence are *** effectiveness of our control law is verified through simulation and ground *** in the experiments on the ground inertial test bench,compared to the improved pressure-biased-modulation(PBM)anti-skid algorithm,fewer wheel slips occur,and the average deceleration rate is increased by 5.78%,which makes it a control strategy with potential for engineering applications.

关键词： Aircraft landing Brakes Disturbance observer Neural networks Runway identification

Effects of operating conditions on iron(hydr)oxides evolution and ciprofloxacin degradation in potassium ferrate-ozone stepwise oxidation system

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Journal of Environmental Sciences 2024年第1期135卷 367-378页

作者： Xiaochen Li Yifan Wang ning Wang Mei Li Maomao bai Jingtao Xu Hongbo Wang School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJinan 250101China Resources and Environment Innovation Institute Shandong Jianzhu UniversityJinan 250101China

In this study,a stepwise oxidation system of potassium ferrate(K_(2)FeO_(4))combined with ozone(O+3)was used to degrade ciprofloxacin(CIP).The effects of pH and pre-oxidation time of K_(2)FeO_(4) on the evolution of K_(2)FeO_(4) reduction products(iron(hydr)oxides)and CIP degradation were *** was found that in addition to its own oxidation capacity,K_(2)FeO_(4) can also influence the treatment effect of CIP by changing the catalyst *** presence of iron(hydr)oxides effectively enhanced the mineralization rate of CIP by catalyzing *** pH value can influence the content and types of the components with catalytic ozonation effect in iron(hydr)*** K_(2)FeO_(4) pre-oxidation stage can produce more iron(hydr)oxides with catalytic components for subsequent ozonation,but the evolution of iron(hydr)oxides components was influenced by O_(3) *** can also avoid the waste of oxidation capacity owing to the oxidation of iron(hydr)oxides by O_(3) and free *** intermediate degradation products were identified by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS).Besides,the degradation pathways were *** the degradation products of CIP,the product with broken quinolone ring structure only appeared in the stepwise oxidation system.

关键词： Potassium ferrate reduction products Catalytic ozonation Ciprofloxacin Potassium ferrate pre-oxidation time

Graph-decomposed k-NN searching algorithm on road network

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Frontiers of Computer Science 2024年第3期18卷 243-245页

作者： Wei JIANG Bo ning Guanyu LI Mei bai Xiao JIA Fangliang WEI Faculty of Information Science and Technology Dalian Maritime UniversityDalian 116026China Jiangxing Intelligence Inc. Shenzhen 518100China

1 Introduction The k-NN(k Nearest Neighbors)searching problem on road network constitutes a crucial aspect of location-oriented services,which has boasted the practical implications.

关键词： services searching network

Simultaneous detection of flare-associated kink oscillations and extreme-ultraviolet waves

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Science China(Technological Sciences) 2024年第5期67卷 1592-1601页

作者： LI Dong HOU ZhenYong bai XianYong LI Chuan FANG Matthew ZHAO HaiSheng WANG JinCheng ning ZongJun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing210023China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming650216China School of Earth and Space Sciences Peking UniversityBeijing100871China National Astronomical Observatories Chinese Academy of SciencesBeijing100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing100049China School of Astronomy and Space Science Nanjing UniversityNanjing210023China Key Laboratory of Modern Astronomy and Astrophysics Ministry of EducationNanjing UniversityNanjing210023China Columbus Academy GahannaOhio43230USA Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China Yunnan Observatories Chinese Academy of SciencesKunming650216China

Kink oscillations,which are frequently observed in coronal loops and prominences,are often accompanied by extreme-ultraviolet(EUV)***,much more needs to be explored regarding the causal relationships between kink oscillations and EUV *** this article,we report the simultaneous detection of kink oscillations and EUV waves that are both associated with an X2.1 flare on 2023 March 03(SOL2023-03-03T17:39).The kink oscillations,which are almost perpendicular to the axes of loop-like structures,are observed in three coronal loops and one *** short loop shows in-phase oscillation within the same period of 5.2 min at three *** oscillation could be triggered by the pushing of an expanding loop and interpreted as the standing kink *** lags are found between the kink oscillations of the short loop and two long loops,suggesting that the kink wave travels in different *** kink oscillations of one long loop and the prominence are possibly driven by the disturbance of the coronal mass ejection(CME),and that of another long loop might be attributed to the interaction of the EUV *** onset time of the kink oscillation of the short loop is nearly same as the beginning of an EUV *** fact demonstrates that they are almost *** EUV wave is most likely excited by the expanding loop structure and shows two *** leading component is a fast coronal wave,and the trailing one could be due to the stretching magnetic field lines.

关键词： coronal loops solar flares solar prominence solar oscillations extreme-ultraviolet wave magnetohydrodynamic

Restraining growth of Zn dendrites by poly dimethyl diallyl ammonium cations in aqueous electrolytes

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Rare Metals 2024年第8期43卷 3735-3747页

作者： Xiang-Xin Zhang Yuan-Qiang Chen Chang-Xin Lin Yuan-Sheng Lin Guo-Lin Hu Yong-Chuan Liu Xi-Lai Xue su-Jing Chen Zhan-Lin Yang bai-Sheng Sa Yi-ning Zhang Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Helmholtz Institute Ulm(HIU) 89081 UlmGermany Karlsruhe Institute of Technology(KIT) 76021 KarlsruheGermany College of Materials Science and Engineering Fuzhou UniversityFuzhou350108China

Metallic zinc is an excellent anode material for Zn-ion batteries,but the growth of Zn dendrite severely hinders its practical ***,an efficient and economical cationic additive,poly dimethyl diallyl ammonium(PDDA) was reported,used in aqueous Zn-ion batteries electrolyte for stabilizing Zn *** growth of zinc dendrites can be significantly restrained by benefiting from the pronounced electrostatic shielding effect from PDDA on the Zn metal ***,the PDDA is preferentially absorbed on Zn(002) plane,thus preventing unwanted side reactions on Zn *** to the introduction of a certain amount of PDDA additive into the common ZnSO_(4)-based electrolyte,the cycle life of assembled Zn‖Zn cells(1 mA·cm^(-2) and 1 mAh·cm^(-2)) is prolonged to more than 1100 *** response to the perforation issue of Zn electrodes caused by PDDA additives,the problem can be solved by combining foamy copper with zinc *** real application,Zn-ion hybrid supercapacitors and MnO_(2)‖Zn cells were assembled,which exhibited excellent cycling stability with PDDA *** work provides a new solution and perspective to cope with the dendrite growth problem of Zn anode.

关键词： PDDA Electrostatic shielding effect Zn anode Zn dendrites

Simultaneous integration of Fe clusters and NiFe dual single atoms in nitrogen-doped carbon for oxygen reduction reaction

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Nano Research 2024年第4期17卷 2291-2297页

作者： Jirong bai Yuebin Lian Yaoyao Deng Mei Xiang Peng Xu Quanfa Zhou Yawen Tang Yaqiong su Research Center of Secondary Resources and Environment School of Chemical Engineering and MaterialsChangzhou Institute of TechnologyChangzhou 213022China Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China School of Chemistry Engineering Research Center of Energy Storage Materials and Devices of Ministry of EducationNational Innovation Platform(Center)for Industry-Education Integration of Energy Storage TechnologyXi’an Jiaotong UniversityXi’an 710049China

Atomically-dispersed iron-based electrocatalysts are promising substitutes for noble metal electrocatalysts because of excellent performance in oxygen reduction reaction(ORR).Rationally modulating the local coordination environment of the Fe site and optimizing the binding energy of oxygen reduction intermediates are effective strategies to optimize ORR ***,we report a new method in which Ni is introduced to construct NiFe dual single atoms and iron nanoclusters loaded on the nitrogen-doped carbon with a highly porous *** design plays a synergistic role of dual single atoms and clusters,optimizes the 3d orbital and Fermi level of Fe,breaks the symmetrical structure of Fe-N_(4),and effectively improves the adsorption/desorption behavior of the oxygen-containing *** tests show FeNCs/NiFeSAs-NC has an excellent intrinsic *** calculations show the oxygen-containing species on the Ni active site will move to the middle of NiFe(bridge site connection)after optimization and that the key step is OH desorption,with a reaction energy of 0.27 *** electron exchange between NiFe-N6 and Fe-cluster is very strong,further indicating the introduction of Ni species and Fe clusters has a regulatory effect on the electronic structure of Fe-N_(4).

关键词： NiFe dual single atoms Fe clusters OH*adsorption energy oxygen reduction reaction

An Improved Z-buffer Accelerated PO Method for EM Scattering from Electrically Large Targets

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Chinese Journal of Electronics 2024年

作者： Jiangfei bai Shunchuan YANG Donglin su School of Electronics and Information Engineering Beihang University Research Institute for Frontier Science Beihang University

The physical optical(PO) method is widely used to solve the electromagnetic scattering problems involved electrically large structures, in which each surface element is required to determine whether it is blocked by others. It may suffer from the computational efficiency issue through elementwise shadowing testing. In this paper, an efficient Z-buffer based shadowing testing method is proposed to accelerate this procedure. In the proposed method,all triangular facets are first mapped to a grid plane as the Z-buffer method, and for each grid cell, all projected triangles intersecting it are recorded. Then, rigorous shadowing testing is made for all facets recorded in the grid where the centroid of each triangle is projected. It can avoid a large number of redundant operations for pairs of triangles with no occlusion relation, which lead to the same accuracy as the traditional rigorous shadowing testing method with significantly efficiency improvement. Four numerical examples are carried out to validate its accuracy and efficiency.

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