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Mineralogical properties and co-sintering characteristics of fluxed iron ore with magnetite concentrates

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Journal of Iron and Steel Research(International) 2024年第2期31卷 318-328页

作者： Le-le Niu Zheng-jian liu Jian-liang Zhang yao-zu Wang Zhen-xing Yang Si-da li Chang-dong Shan Ben feng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing100083China Xinxing Casting Pipe Xinjiang Co. Bayingol841300XinjiangChina

To investigate the feasibility of co-sintering of fluxed iron ore with magnetite concentrates, the mineralogical properties of a novel fluxed iron ore were studied using particle size analysis, microscopic morphology characterization, and X-ray diffraction Rietveld analysis. Following that, the experiments for granulation performance and basic sintering characteristics were designed under seven different fluxed iron ore ratios, and the integrated ranking of different fluxed iron ore ratios was determined using gray relation analysis. Finally, the results of the industrial trails were combined with the feasibility analysis. Test and experimental results show that the fraction of the fluxed iron ore particles larger than 0.5 mm can account for more than 48%, and the particles have two morphologies: spherical-rough and flaky-smooth. Ca elements are found in the form of calcite (CaCO3) and dolomite (CaMg(CO3)2). The average particle size of granules and powder removal rate can be improved from 2.50 to 3.16 mm and 39.60% to 24.20%, respectively, with the increase in the fluxed iron ore ratio. Furthermore, the fluxed iron ore can improve assimilability and liquid fluidity of magnetite concentrates. In terms of overall granulation performance and sintering characteristics, the fluxed iron ore ratios are graded from best to worst as follows: 12%, 15%, 9%, 18%, 21%, 6% and 3%. The industrial trails show that when the fluxed iron ore ratio is increased, the beneficial effect of the superior sintering characteristics of the fluxed iron ore itself is ideally balanced with the negative effect of the lower amount of additional CaO at 12% ratio, and thus, it is feasible to bring the fluxed iron ore into production at a level of roughly 12%.

关键词： Fluxed iron ore Magnetite concentrate Granulation performance Sintering characteristics Gray relation analysis

Mirrorless MEMS imaging:a nonlinear vibrational approach utilizing aerosol-jetted PZT-actuated fiber MEMS scanner for microscale illumination

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Microsystems & Nanoengineering 2024年第1期10卷 175-192页

作者： Wei-Chih Wang Ming-yao li Kuan-Chang Peng Yi-feng Hsu Benjamin Estroff Pao-Yun Yen David Schipf Wen-Jong Wu Department of Power Mechanical Engineering National Tsing Hua UniversityNo.101Section 2Kuang-Fu RoadHsinchuTaiwan 30013China Institute of NanoEngineering and Microsystems National Tsing Hua UniversityNo.101Section 2Kuang-Fu RoadHsinchuTaiwan 30013China Department of Mechanical Engineering University of WashingtonSeattleWA 98195USA Department of Electrical Engineering University of WashingtonSeattleWA 98195USA Department of Engineering Science and Ocean Engineering National Taiwan UniversityTaiwanChina

This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic *** scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT(lead zirconate titanate)bimorph push-pull actuators on a stainless-steel substrate,effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer *** leveraging nonlinear vibration,the scanner achieves a spiral scan pattern from a single signal input,in addition to the expected two-dimensional scanning and target illumination from two phase-shifted *** capability is further enhanced by a novel process to taper the optical fiber,which reduces illumination scattering and tunes the fiber to the resonant frequencies of the *** precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom *** validation showcases the successful generation of a spiral scan pattern with a 60μm diameter scan area and a 10 Hz frame rate,effectively reconstructing scanned images of 5μm lines,cross patterns(15μm in length with a 5μm gap),and structures of a Psychodidae wing.

关键词： steel fiber scanner

Uniqueness on Difference Operators of Meromorphic Functions of Infinite Order

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Acta Mathematica Sinica,English Series 2024年第2期40卷 511-527页

作者： Hui li Ming liang FANG Xiao yao School of Science China University of Mining and TechnologyBeijing 100083P.R.China Institute of Mathematics Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing 100190P.R.China School of Sciences Hangzhou Dianzi UniversityHangzhou 310012P.R.China School of Mathematical sciences and LPMC Nankai UniversityTianjin 300071P.R.China

We investigate the uniqueness problems of meromorphic functions and their difference operators by using a new *** is proved that if a non-constant meromorphic function f shares a non-zero constant and ∞ counting multiplicities with its difference operators Δcf(z) and Δ_(c)^(2)f(z), thenΔcf(z)≡Δ_(c)^(2)f(z).In particular,we give a difference analogue of a result of *** method has two distinct features:(ⅰ) It converts the relations between functions into the corresponding *** makes it possible to deal with the uniqueness problem by linear algebra and combinatorics.(ⅱ) It circumvents the obstacle of the difference logarithmic derivative lemma for meromorphic functions of infinite order,since this method does not depend on the growth of the ***,the idea in this paper can also be applied to the case for several variables.

关键词： Uniqueness meromorphic functions difference operators infinite order

Core-shell nanoparticle enhanced Raman spectroscopy in situ probing the composition and evolution of interfacial species on PtCo surfaces

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Nano Research 2024年第6期17卷 4687-4692页

作者： Jing liu Han-liang Zhong Xiangyu li Mu-Fei Yue Wei-Min Yang Xueqiu You Jing-Hua Tian yao-Hui Wang Jian-feng li Fujian Provincial Key Laboratory of Oceanic Information Perception and Intelligent Processing School of Ocean Information EngineeringJimei UniversityXiamen 361021China College of Chemistry Fuzhou UniversityFuzhou 350108China State Key Laboratory of Physical Chemistry of Solid Surfaces MOE Key Laboratory of Spectrochemical Analysis and InstrumentationiChEMCollege of Chemistry and Chemical EngineeringCollege of MaterialsCollege of EnergyXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Shenzhen Research Institute of Xiamen University Shenzhen 518000China

The composition and evolution of interfacial species play a key role during electrocatalytic *** the structural evolution and intermediate during catalytic process by in situ characterization can shed new light on the electrocatalytic reaction mechanism and develop highly efficient ***,directly probing the interfacial species is extremely difficult for most spectroscopic techniques due to complicated interfacial environment and ultra-low surface ***,electrochemical core-shell nanoparticle enhanced Raman spectroscopy is utilized to probe the composition and evolution processes of interfacial species on Au@Pt,Au@Co,and Au@PtCo core-shell nanoparticle *** spectral evidences of interfacial intermediates including hydroxide radical(OH*),superoxide ion(O_(2)^(−)),as well as metal oxide species are directly captured by in situ Raman spectroscopy,which are further confirmed by the both isotopic experiment and density functional theory *** results provide a mechanistic guideline for the rational design of highly efficient electrocatalysts.

关键词： in situ Raman core-shell nanoparticle PtCo interfacial species composition and evolution

Effects of ignition voltage and electrode structure on electric ignition and combustion characteristics of Ammonium Dinitramide(ADN)-based liquid propellants in electric ignition mode in inert gas environment

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Chinese Journal of Aeronautics 2024年第4期37卷 229-242页

作者： Lei li Guoxiu li Hongmeng li Zhaopu yao Tao ZHANG Jinze WU Shuo ZHANG School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Beijing Institute of Control Engineering Beijing 100190China

Hydrazine is toxic and carcinogenic, which greatly increases the difficulty of application and no longer meets the needs of green aerospace. As a green propellant, the Ammonium Dinitramide(ADN)-based liquid propellant has the advantages of higher specific impulse, being non-toxic,pollution-free, and easy storage. However, an ADN-based space engine in orbit has exposed the problems of high-temperature deactivation of catalysts and cold-start failure. An active ignition technology—electric ignition technology was explored in this paper to break through the technical bottleneck of catalyst deactivation and the inability to a cold start. An experimental system of a constant-volume combustor for the ADN-based liquid propellant based on the electric ignition method was established. The electric ignition and combustion characteristics of the ADN-based liquid propellant in a volume combustor with an electric ignition method were studied. The influencing mechanisms of the ignition voltage and the electrode structure on the electric ignition characteristics of the ADN-based liquid propellant were investigated. An elevation of the ignition voltage could facilitate the ignition process of the ADN-based liquid propellant, curtail electric energy input and heating effect, while exerting an adverse impact on the combustion process of the *** increase in the ignition voltage enhanced the ignition process of the propellant while simultaneously suppressing its combustion process when utilizing mesh electrodes. Compared to the strip electrodes, the mesh electrodes increased the contact area between the electrodes and the propellant,increased the electric energy input power in the electric ignition process, and reduced the ignition delay time. The mesh electrodes could promote the combustion process of the propellant to a certain extent.

关键词： ADN-based liquid propellant Resistive ignition Electrical ignition characteristic Combustion Inert gas

Precisely modulating covalent and coordination bonds in the porous network for highly selective metal ion extraction

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Science China Chemistry 2024年第4期67卷 1039-1040页

作者： Jie li Xiao feng Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster ScienceMinistry of EducationAdvanced Technology Research Institute(Jinan)Frontiers Science Center for High Energy MaterialSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Scandium(Sc)is recognized as a“strategic”and“critical”element by several countries,including the *** Russia,owing to its wide range of applications in high-tech fields such as superconductivity,alloys,lasers,nucle... 详细信息

关键词： alloys coordination network

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： Yang li Qing Yu feng-feng Chen Jia-wen He Hong-mei Yang Meng-nie li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary

A dual-function selection system enables positive selection of multigene CRISPR mutants and negative selection of Cas9-free progeny in Arabidopsis

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aBIOTECH 2024年第2期5卷 140-150页

作者： feng-Zhu Wang Ying Bao Zhenxiang li Xiangyu Xiong Jian-feng li State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China

The CRISPR/Cas9 technology revolutionizes targeted gene knockout in diverse organisms including ***,screening edited alleles,particularly those with multiplex editing,from herbicide-or antibiotic-resistant transgenic plants and segregating out the Cas9 transgene represent two laborious *** solutions to facilitate these processes rely on different selection ***,by taking advantage of the opposite functions of a D-amino acid oxidase(DAO)in detoxifying D-serine and in metabolizing non-toxic D-valine to a cytotoxic product,we develop a DAO-based selection system that simultaneously enables the enrichment of multigene edited alleles and elimination of Cas9-containing progeny in Arabidopsis *** five DAOs tested in Escherichia coli,the one encoded by Trigonopsis variabilis(TvDAO)could confer slightly stronger D-serine resistance than other *** expression of TvDAO in Arabidopsis allowed a clear distinction between transgenic and nontransgenic plants in both D-serine-conditioned positive selection and D-valine-conditioned negative *** a proof of concept,we combined CRISPR-induced single-strand annealing repair of a dead TvDAO with D-serine-based positive selection to help identify transgenic plants with multiplex editing,where D-serine-resistant plants exhibited considerably higher co-editing frequencies at three endogenous target genes than those selected by ***,D-valine-based negative selection successfully removed Cas9 and TvDAO transgenes from the survival offspring carrying inherited ***,this work provides a novel strategy to ease CRISPR mutant identification and Cas9 transgene elimination using a single selection marker,which promises more efficient and simplified multiplex CRISPR editing in plants.

关键词： CRISPR Genome editing D-amino acid oxidase Cas9-free Selection marker

Reaction pathways and selectivity in the chemo-catalytic conversion of cellulose and its derivatives to ethylene glycol:A review

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Chinese Journal of Chemical Engineering 2024年第2期66卷 310-331页

作者： yao li Yuchun Zhang Zhiyu li Huiyan Zhang Peng Fu College of Agricultural Engineering and Food Science Shandong University of TechnologyZibo 255000China Key Laboratory of Energy Thermal Conversion and Control Ministry of EducationSchool of Energy and EnvironmentSoutheast UniversityNanjing 210096China

Biomass-to-ethylene glycol is an effective means to achieve high-value utilisation of cellulose but is hindered by low conversion efficiency and poor catalyst activity and *** and cellobiose are derivatives of cellulose conversion to ethylene glycol,and it is found that studying the reaction process of both can help to understand the reaction mechanism of *** is desirable to develop a reusable,highly active catalyst to convert cellulose into ethylene *** ideal catalyst might have one or more active sites described the conversion steps ***,we discuss the catalyst development of celluloseto-ethylene glycol,including tungsten,tin,lanthanide,and other transition metal catalysts,and special attention is given to the reaction mechanism and kinetics for preparing ethylene glycol from cellulose,and the economic advantages of biomass-to-ethylene glycol are briefly *** insights given in this review will facilitate further development of efficient catalysts,for addressing the global energy crisis and climate change related to the use of fossil fuels.

关键词： Ethylene glycol Cellulose Catalyst Retro-aldol condensation Hydrolysis Kinetics