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Luminescence properties of a new yellow long-lasting phosphorescence phosphor NaAlSiO_4:Eu^(2+),Ho^(3+)

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Journal of Rare Earths 2014年第9期32卷 792-796页

作者：庞然赵然贾永雷李成宇苏锵 State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of the Chinese Academy of Sciences

A new aluminosilicate long-lasting phosphor with composition of NaA1SiO4：Eu2＋,Ho3＋ was synthesized and investigated. Under UV light excitation, the phosphor emitted yellow light corresponding to the characteristic emission of Eu2＋ due to 5d-4f transi- tion. Bright yellow phosphorescence sustaining for more than 30 rain was observed after ceasing the excitation. The phosphorescence intensity decay obeyed a fl decay law, indicating a tunneling electron-hole recombination process in the phosphor. Four peaks ap- peared in the thermoluminescence curve and the ones at 322 and 370 K were thought to account for the long lasting phosphorescence at room temperature. The Ho3＋ ion incorporated into the phosphor did not give any light but dramatically increased the intensities of both photoluminescence and phosphorescence via promoting defect levels in the phosphor.

关键词： NaAlSiO4 luminescence long lasting phosphorescence phosphor rare earths

Phase inversion in a lightweight high Al content refractory high-entropy alloy

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Journal of Materials Science & Technology 2023年第19期150卷 124-137页

作者： Kuan Gao Yuexin Chu Weihua Zhou Yong Tian Yong Zhang Yi Li Beijing Advanced Innovation Center of Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110004China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

Adding Al is an important strategy to obtain ultrahigh specific strength in BCC refractory high-entropy alloys(RHEAs).However,the main structure typically transitions from disordered BCC to ordered B2 with increasing Al concentration,leading to poor *** the present study,a phase inversion in a high-Al-content B2-RHEA(Zr_(40)Ti_(28)Nb_(12)Al_(20))was systematically studied through thermo-mechanical *** grains of the single B2 phase transformed inversely to the BCC+B2 microstructure with a dispersion of spherical B2 precipitates in the BCC *** evolution of the microstructure began with the decomposition of the B2 phase into Al-rich and Al-poor *** subsequent coarsening of the Al-rich B2 precipitates continuously consumes Al and Zr atoms from the *** depletion of Al and Zr in the matrix drives it to gradually form the disordered BCC structure and eventually transform to a single BCC phase *** phase inversion enhanced tensile ductility of the RHEA while still maintaining its high specific *** current study provides a novel idea for inhibiting Al-induced brittleness of RHEAs at high Al content.

关键词： High-entropy alloys Tensile properties Ordered B2 phase Strengthening mechanism Phase inversion

Isotope shift of the 2s^(2)S_(1/2)→ 2p^(2)P_(1/2,3/2) transitions of Li-like Ca ions

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Chinese Physics B 2021年第4期30卷 206-210页

作者：张登红张芳军丁晓彬董晨钟 Key Laboratory of Atomic and Molecular Physics and Functional Materials of gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070China

The mass-and field-shift parameters of the two 2s^(2)S_(1/2)→ 2p^(2)P_(1/2,3/2) transitions in the Li-like Ca ions are calculated by using multi-configuration Dirac-Hartree-Fock(MCDHF) and the relativistic configuration interaction(RCI) methods with the inclusion of the transverse photon(Breit) interaction,vacuum polarization and self-energy *** addition,the mass shift and field shift of these two transitions are calculated,where the field shift is calculated by using the evaluated value δ(r^(2)) obtained by [Atomic Data and Nuclear Data Tables 99 69(2013)].It is found that the mass shift of Li-like Ca ions is greater than the field shift.

关键词： isotope shift multi-configuration Dirac-Hartree-Fock(MCDHF) mass shift field shift

Helical wire electrochemical discharge machining on large-thickness Inconel 718 alloy in lowconductivity salt-glycol solution

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Chinese Journal of Aeronautics 2023年第5期36卷 522-533页

作者： Weijing KONG Yongbin ZENG Ziyu LIU Xiaoyun HU Huanghai KONG College of Mechanical&Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transporting electrolytic products in the narrow machining gap. This paper proposes a novel hybrid machining technique that combines the characteristics of WECM and wire electric discharge machining(WEDM), namely, helical wire electrochemical discharge machining. The formation mechanism of electrical discharge in salt-glycol solution was *** and simulation were conducted to verify the machining mechanism and investigate the performance of the proposed technique. The results show that as the recast layer can be removed by electrochemical action during the proposed process, the surface quality is effectively *** surface roughness of the slit sidewall after machining reaches Ra= 0.12 μm. Minimum standard deviation of the slit after machining reaches 5 μm. Moreover, the existence of the discharges significantly improves the transport of the electrolytic products, thus ensuring high machining efficiency. In the experiments, the maximum feed rate of the helical wire electrochemical discharge machining reaches 7 μm/s(12.6 mm^(2)/min). Finally, mortise structures of Inconel 718 with good machining accuracy and surface quality are fabricated with a feed rate of 5 μm/s(9 mm^(2)/min),demonstrating that electrical discharge assisted helical wire ECM is a promising technique for machining large-thickness hard metal materials.

关键词： Hybrid machining Helical wire Inconel 718 Low-conductivity salt-glycol solution WECDM

A tandem asymmetric oxidation-oxa-Michael sequence for dearomatization ofβ-naphthols

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Chinese Chemical Letters 2022年第9期33卷 4273-4276页

作者： Linqing Wang Haiyong Zhu Tianyu Peng Yingfan Xu Yanzhe Hou Shixin Li Shiming Pang Hailong Zhang Dongxu Yang Key Laboratory of Preclinical Study for New Drugs of gansu Province Institute of Drug Design&SynthesisSchool of Basic Medical SciencesLanzhou UniversityLanzhou 730000China

A catalytic asymmetric hydroxylative dearomatization reaction has been disclosed,and the products can smoothly transform into spiroannulation adducts by simply treated with a base under mild *** in-situ generated magnesium catalytic methods are developed by application of combinational *** concise transformaitons of the spiroannulation adducts have been carried out.

关键词： Oxidative dearomatization Oxa-Michael reaction Asymmetric reaction Chiral ligands Magnesium catalyst

Boundary effect of toppling failure based on three-dimensional mechanical model

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Journal of Mountain Science 2022年第11期19卷 3314-3322页

作者： CAI Jun-chao ZHENG Da JU Neng-pan HUANG Run-qiu ZHAO Wei-hua School of Civil Engineering Henan University of Science and TechnologyLuoyang 471023China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Environment and Civil Engineering Chengdu University of TechnologyChengdu 610059China

Previous researches on the mechanical model of toppling failure mainly concentrated on twodimensional mechanical model(TwDM) analysis. The TwDM analysis assumes the width of the slab beam is unit width without considering the lateral constraint force. The assumed conditions are obviously different from the site conditions, thus there is a certain difference between the calculated results and the field work. A three-dimensional mechanical model(ThDM)of toppling failure was established, considering that the slab beam was mainly subject to self-weight, the frictional resistance of interlayer and lateral constraint force. Due to the progressive characteristics of toppling failure, the concept and the formula of the first fracture depth(FFD) of toppling was raised and constructed. The case study indicates that the ThDM is more effective and can be accurately used to calculate the toppling fracture depth of the slab beam. The FFD decreases proportionally with the increase of slab beam width. FFD grows fast when the slab beam width is less than 2.0 m and it tends to be stable when the slab beam width is above 2.0 m. The FFD decreases with the increase of the lateral constraint coefficient, indicating that the boundary condition of the free space is positively correlated with the stability and depth of toppling. This is a good explanation of the free space effect. This study provides a reference for the stability evaluation and prevention-control design of toppling slope in the future.

关键词： Boundary effect Toppling failure Three-dimensional mechanical model(ThDM) First fracture depth(FFD) Free face Slope failure

Physical random function model of ground motions for engineering purposes

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Science china(Technological Sciences) 2011年第1期54卷 175-182页

作者： WANG Ding LI Jie School of Civil Engineering Tongji University Shanghai 200092 China State Key Laboratory of Disaster Reduction in Civil Engineering Shanghai 200092 China

A physical random function model of ground motions for engineering purposes is presented with verification of sample level. Firstly,we derive the Fourier spectral transfer form of the solution to the definition problem,which describes the one-dimensional seismic wave field. Then based on the special models of the source,path and local site,the physical random function model of ground motions is obtained whose physical parameters are random variables. The superposition method of narrow-band harmonic wave groups is improved to synthesize ground motion samples. Finally,an application of this model to simulate ground motion records in 1995 Kobe earthquake is described. The resulting accelerograms have the frequencydomain and non-stationary characteristics that are in full agreement with the realistic ground motion records.

关键词：随机地震动物理模型函数模型工程用地震地面运动 Fourier 地震波场随机变量

Electrochemical incineration of dimethyl phthalate by anodic oxidation with boron-doped diamond electrode

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Journal of Environmental Sciences 2009年第10期21卷 1321-1328页

作者： HOU Yining QU Jiuhui ZHAO Xu LIU Huijuan State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. Graduate School of the Chinese Academy of Sciences Beijing 100039 China

The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond （BDD） as anode. Electrolyses were carded out at constant current density （1.5-4.5 mA/cm^2）. Complete mineralization was always achieved owing to the great concentration of hydroxyl radical （-OH） generated at the BDD surface. The effects of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency were investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography （HPLC） revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography- Mass Spectrometry （GC-MS） and a general pathway for the electrochemical incineration of DMP on BDD was proposed.

关键词： dimethyl phthalate anodic oxidation boron-doped diamond mineralization

Recent developments of anti-plasticized membranes for aggressive CO_(2)separation

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Green Chemical Engineering 2023年第1期4卷 1-16页

作者： Yongchao Sun Xiaoyu Wang Xiangcun Li Wu Xiao Yan Dai Canghai Ma Gaohong He State Key Laboratory of Fine Chemicals R&D Center of Membrane Science and TechnologySchool of Chemical EngineeringDalian University of TechnologyDalian116023China Panjin Institute of Industrial Technology Liaoning Key Laboratory of Chemical Additive Synthesis and SeparationDalian University of TechnologyPanjin124221China

Membrane separation technology provides an effective alternative to mitigate the massive carbon emission with high carbon capture productivity and *** the context of operating membranes under high CO_(2)pressures allows increased separation productivity and reduced gas compression cost,which,however,often leads to CO_(2)induced plasticization,a key hurdle for current gas separation *** this review,we reviewed the latest development of membranes with anti-plasticization resistance,potentially suited for operation under high CO_(2)feed ***,the separation performance of polymeric membranes,inorganic membranes,and mixed matrix membranes under high CO_(2)feed pressures are *** to enhance CO_(2)induced plasticization of those membranes are also *** conclude the recent progress of membranes for high CO_(2)pressures with perspectives and an outlook for future development.

关键词： Carbon dioxide High feed pressure Plasticization Polymeric membranes Inorganic membranes Mixed matrix membranes