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New Vacuum Solar Telescope Achieves Narrowband Infrared Solar Imaging Observation at He I 10830 A

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Research in Astronomy and Astrophysics 2024年第5期24卷 76-84页

作者： wei-Jie Meng fang-Yu xu Zhen-Yu Jin Yunnan Observatories Chinese Academy of SciencesKunming 650011China Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China University of Chinese Academy of Sciences Beijing 100049China

The near-infrared imaging channel constitutes a crucial component of the multichannel high-resolution imaging system of the New Vacuum Solar Telescope(NVST). We have successfully achieved high-resolution, narrowband imaging of the chromosphere using He I 10830 A triplet within this channel, which significantly enhances the imaging observation capabilities of NVST. This paper provides a concise overview of the optical system associated with the near-infrared imaging channel, detailing data processing procedures and presenting several observed images. Leveraging a high-resolution image reconstruction algorithm, we were able to generate a narrowband image near the diffraction limit at 10830 A with a temporal resolution of less than 10 s.

关键词： instrumentation detectors-instrumentation high angular resolution-Sun chromosphere-Sun infrared

Superior compound coatings prepared by low-temperature vanadium-nitrocarburizing duplex treatment

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Rare Metals 2024年第4期43卷 1828-1835页

作者： Gen Jin fang-fang xu xun-xun Hu Yue xu School of Chemistry Beihang UniversityBeijing100191China Guobiao(Beijing)Testing and Certification Co. LtdBeijing100088China School of Materials Science and Engineering Beihang UniversityBeijing100191China

Superior compound coatings were prepared on CK45 steel surface by vanadium-nitrocarburizing duplex treatment in low-temperature salt *** this study,the microhardness,the phase constitution and the compositional distribution in the coatings prepared under different conditions were systematically *** results indicated that the reactions among activated vanadium,carbon and nitrogen atoms occurred on the steel surface,leading to the formation of compound coatings composed of outermost and compound *** mechanism for the formation of compound layer as well as the growth kinetics of the layer was also *** the duplex treatment,the wear and corrosion resistances of steel surface were significantly *** was found that the growth kinetics of compound layer obeyed the parabolic law,with the activation energy of 122.82 kJ·moL^(-1).

关键词： Vanadium-nitrocarburizing duplex treatment Compound coatings Microstructure Formation mechanism Growth kinetics

A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： wei wei Feng GUAN Xin fang College of Intelligent Science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

Life cycle assessment of homogeneous Fenton process as pretreatment for refractory pharmaceutical wastewater

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 1-11页

作者： Maojun Zou Jie wei Yuanyuan Qian Yanjing xu Zhihuang fang xuejing Yang Zhiyuan Wang School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Engineering Laboratory of Lean Operational Technologies for Full Water System East China University of Science and TechnologyShanghai 200237China Mcwong Environmental Technology Company Limited Shanghai 200135China National Engineering Laboratory of High Concentration and Refractory Organic Wastewater Treatment Technology East China University of Science and TechnologyShanghai 200237China

The applicability of the life cycle assessment(LCA)to the Fenton process should be considered not only at the laboratory-scale but also at the *** this study,the LCA process was applied to evaluate the homo-geneous Fenton process for the treatment of high salinity pharmaceutical *** potential environmental impacts were calculated using Simapro software implemen-ting the CML 2001 methodology with normalization factors of 1995 *** data obtained directly from the full-scale wastewater treatment plant and labora-tory were used to conduct a life cycle inventory analysis,ensuring highly accurate *** normalized results,the Fenton process reveals sensitive indicators,primarily toxi-city indicators(human toxicity,freshwater aquatic toxicity,and marine aquatic toxicity),as well as acidification and eutrophication impacts,contributed by hydrogen peroxide and iron sludge incineration,***,hydrogen peroxide and iron sludge incineration contribute significantly,accounting for at least 78%of these *** sludge treatment phase,treatment of iron mud and infrastructure of hazardous waste incineration plants were the key contributors of environmental impacts,adding up to more than 95%.This study suggests the need to develop efficient oxidation processes and effective iron sludge treatment methods to reduce resource utilization and improve environmental benefits.

关键词： advanced oxidation processes full-scale life cycle assessment Fenton process pharmaceutical high-salinity wastewater

Machine learning-based performance predictions for steels considering manufacturing process parameters:a review

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Journal of Iron and Steel Research International 2024年第7期31卷 1555-1581页

作者： wei fang Jia-xin Huang Tie-xu Peng Yang Long Fu-xing Yin Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300132China Institute of New Materials Guangdong Academy of ScienceGuangzhou 510651GuangdongChina

Steels are widely used as structural materials,making them essential for supporting our lives and ***,further improving the comprehensive properties of steel through traditional trial-and-error methods becomes challenging due to the continuous development and numerous processing parameters involved in steel *** address this challenge,the application of machine learning methods becomes crucial in establishing complex relationships between manufacturing processes and steel *** review begins with a general overview of machine learning methods and subsequently introduces various performance predictions in steel *** classification of performance pre-diction was used to assess the current application of machine learning model-assisted *** important issues,such as data source and characteristics,intermediate features,algorithm optimization,key feature analysis,and the role of environmental factors,were summarized and *** insights will be beneficial and enlightening to future research endeavors in this field.

关键词： Steel Manufacturing process Machine learning Performance prediction Algorithm

Thermal stability improvement and microstructure optimization of high cobalt content Nd-Fe-B magnets via terbium grain boundary diffusion

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Journal of Rare Earths 2024年第8期42卷 1531-1538,I0004页

作者： Jiyuan xu Ruiyang Meng Jing Liu Jiateng Zhang Rui Han Yikun fang Shengzhi Dong wei Li Division of Functional Materials Research Central Iron and Steel Research InstituteBeijing100081China

The substitution of Fe by Co in the 2:14:1 phase is an effective method to increase the Curie temperature and enhance the thermal stability of the Nd-Fe-B ***,the accumulation of Co ele ment at the grain boundaries(GBs) changes the GBs from nonmagnetic to ferromagnetic and causes the thinlayer GBs to become rare,In this paper,the method of diffusing Tb element was chosen to improve the microstructure and temperature stability of high-Co *** original sintered Nd_(28.5)Dy_(3)-CO_(x)e_(bal)M_(0.6)B_(i)(x=0,6 wt%,12 wt%;M = Cu,Al,Zr) magnets with different Co contents were diffused with Tb by grain boundary diffusion(GBD).After GBD,high-Co magnets exhibit more continuously distributed thin-layer GBs,and their thermal stability is significantly *** high-Co magnets(x=6 wt%),the absolute value of the temperature coefficient of coercivity decreases from 0.603%/K to0.508%/K in the temperature range of 293-413 K,that of remanence decreases from 0.099%/K to 0.091%/K,and the coercivity increases from 18.44 to 25.04 *** electron microscopy(TEM)characterization reveals that there are both the 1:2 phase and the amorphous phase in the high-Co magnet before and after GBD,EDS elemental analysis shows that Tb element is more likely to preferentially replace the rare earth elements in the 2:14:1 main phase than in the 1:2 phase and the amorphous *** concentration of Tb at the edge of the main phase is much higher than that in the 1:2phase and amorphous phase,which is beneficial to the improvement of the *** preferential replacement of Tb elements at the edge of the 2:14:1 phase and thin-layer GBs with a more continuous distribution are synergistically responsible for improving the thermal stability of high-Co *** study indicates that GBD is an effective method to improve the microstructure and thermal stability of high-Co magnets.

关键词： Nd-Fe-B magnets Coercivity Grain boundary diffusion Thermal stability Micro structure Rare earths

Capturability-based Fuzzy Footstep Planner for a Biped Robot with Centroidal Compliance

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Journal of Bionic Engineering 2024年第1期21卷 84-100页

作者： Zihan xu Qin fang Yong Ren Chengju Liu Robot and Artificial Intelligence Lab(RAIL) College of Electronic and Information EngineeringTongji UniversityShanghai 201804China Applied Technology College Soochow UniversitySuzhou 215000China

Compliance motion and footstep adjustment are active balance control strategies from learning human subconscious *** force estimation without direct end-actuator force measurement and the optimal footsteps based on complex analytical calculation are still challenging tasks for elementary and kid-size position-controlled *** this paper,an online compliant controller with Gravity Projection Observer(GPO),which can express the external force condition of perturbations by the estimated Projection of Gravity(PoG)with estimation covariance,is proposed for the realization of disturbance absorption,with which the robustness of the humanoid contact with environments can be *** fuzzy footstep planner based on capturability analysis is proposed,and the Model Predictive Control(MPC)is applied to generate the desired *** fuzzification rules are well-designed and give the corresponding control output responding to complex and changeable external *** validate the presented methods,a series of experiments on a real humanoid robot are *** results verify the effectiveness of the proposed balance control framework.

关键词： Biped walking Centroidal compliance Gravity projection observer Fuzzy footstep planner

A disk I/O optimized system for concurrent graph processing jobs

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Frontiers of Computer Science 2024年第3期18卷 13-29页

作者： Xianghao xu fang WANG Hong JIANG Yongli CHENG Dan FENG Peng fang School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Department of Computer Science&Engineering University of Texas at ArlingtonArlingtonTX 76019USA College of Computer and Data Science Fuzhou UniversityFuzhou 350108China Zhejiang Lab Hangzhou 311121China

In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity *** the other hand,with the rapidly growing need of analyzing graphs in the real-world,graph processing systems have to efficiently handle massive concurrent graph processing(CGP)***,due to the inherent design for single graph processing job,existing out-of-core graph processing systems usually incur unnecessary data accesses and severe competition of I/O bandwidth when handling the CGP *** this paper,we propose GraphCP,a disk I/O optimized out-of-core graph processing system that efficiently supports the processing of CGP *** proposes a benefit-aware sharing execution model to share the I/O access and processing of graph data among the CGP jobs and adaptively schedule the graph data loading based on the states of vertices,which efficiently overcomes above challenges faced by existing out-of-core graph processing ***,GraphCP adopts a dependency-based future-vertex updating model so as to reduce disk I/Os in the future *** addition,GraphCP organizes the graph data with a Source-Sorted Sub-Block graph representation for better processing capacity and I/O access *** evaluation results show that GraphCP is 20.5×and 8.9×faster than two out-of-core graph processing systems GridGraph and GraphZ,and 3.5×and 1.7×faster than two state-of-art concurrent graph processing systems Seraph and GraphSO.

关键词： graph processing disk I/O concurrent jobs

Experimental distillation of tripartite quantum steering with an optimal local filtering operation

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Photonics Research 2024年第3期12卷 552-562页

作者： QIAN-XI ZHANG XIAO-xu fang HE LU School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Shenzhen Research Institute of Shandong University Shenzhen 518057China

Multipartite Einstein-Podolsky-Rosen(EPR)steering admits multipartite entanglement in the presence of uncharacterized verifiers,enabling practical applications in semi-device-independent *** applications generally require stronger steerability,while the unavoidable noise weakens steerability and consequently degrades the performance of quantum information ***,we propose the local filtering operation that can maximally distill genuine tripartite EPR steering from N copies of three-qubit generalized Greenberger-Horne-Zeilinger states,in the context of two semi-device-independent *** optimal filtering operation is determined by the maximization of assemblage *** and numerical results indicate the advantage of the proposed filtering operation when N is finite and the steerability of initial assemblages is ***,a proof-of-principle demonstration of two-copy distillation is realized with the optical *** advantage of the optimal local filtering operation is confirmed by the distilled assemblage in terms of higher assemblage fidelity with perfectly genuine tripartite steerable assemblages,as well as the greater violation of the inequality to witness genuine tripartite steerable *** results benefit the distillation of multipartite EPR steering in practice,where the number of copies of initial assemblages is generally finite.

关键词： filtering distillation optimal