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effects of contaminant metal ions on precipitation recovery of rare earth elements using oxalic acid

Journal of Rare earths 2022年第3期40卷 482-490,I0005页

作者： Wencai Zhang Aaron Noble bin Ji Qi Li Department of Mining and Minerals engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA24061USA

Solution equilibrium calculations were performed in this study to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements(Ce^(3+),Nd^(3+),and Y^(3+))using oxalic acid as a *** metal ions,Al^(3+) and Fe^(3+),are found to considerably affect the precipitation efficiency of *** Al^(3+) and Fe^(3+)concentrations are increased by 1×10^(−4) mol/L,in order to achieve an acceptable cerium recovery of 93%from solutions containing 1×10^(−4) mol/L Ce^(3+),oxalate dosage needs to increase by 1.2×10^(−4) and 1.68×10^(−4) mol/L,*** great impacts on the required oxalate dosage are also observed for Nd^(3+) and Y^(3+),which indicates that oxalic acid consumption and cost will be largely increased when the trivalent metal ions exist in Ree-concentrated *** of the divalent metal ions on the oxalate dosage are ***,solution equilibrium calculation results show that the precipitation of Fe^(3+) and Ca^(2+)(e.g.,hematite and Ca(C_(2)O_(4))∙H_(2)O(s))likely occurs during the oxalate precipitation of Rees at relatively high pH(e.g.,pH 2.5),which will reduce rare earth oxalate product *** addition to the metal ions,anionic species,especially SO_(4)^(2-),are also found to negatively affect the precipitation recovery of *** example,when 0.1 mol/L SO_(4)^(2-) occurs in a solution containing 1×10^(−4) mol/L Ce^(3+) and 4×10^(−4) mol/L oxalate,the pH needs to be elevated from 2.0 to 3.3 to achieve the acceptable ***,findings from this study provide guidance for the obtainment of high-purity rare earth products from solutions containing a considerable amount of contaminant metal ions by means of oxalic acid precipitation.

关键词： Rare earth elements Oxalic acid Precipitation Contaminant metal ions

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Tectonic rotation in the western South-Dabashan orogenic belt in late Mesozoic

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Chinese Science Bulletin 2010年第14期55卷 1423-1429页

作者： WANG bin ZHANG GuoWei Department of Geology Northwest University Xi'an 710069 China

A paleomagnetic study was carried out on early-Middle Jurassic sediments in the Zhenba area, the western South-dabashan orogenic belt. Stepwise thermal demagnetization isolated the characteristic high temperature component (HTC) (D=37.1°,I=46.1°, α95=10.1°), which passed the fold test. By comparing the corresponding pole of HTC (57.6°N, 196.6°e, A95=9.9°) with coeval reference poles for the Sichuan basin, we detected a 26.5°±9.0° clockwise rotation of the study area relative to the stable Sichuan basin. We interpret that this rotation was caused by obstruction of the Hannan block during thrusting of the Dabashan, and occurred around early Cretaceous.

关键词：顺时针旋转大巴山晚中生代西部造山带构造四川盆地中侏罗世

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Regional environmental Differentiation in China Sincethe Mid-Pleistocene Inferred from Lake Recordsand Its Relation with east Asian Monsoons

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Acta Geologica Sinica(english edition) 1998年第3期72卷 314-320页

作者： Wang Sumin x.e bin Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing Jiangsu 210008

Abstract: Comparative study of long lake records in different regions in China can provide some significant information about the regional differentiation of the environment and Asian monsoon activities. However, intensively studied lacustrine cores with a span of a few hundred thousand years are very rare in China. The available examples are only three long cores from the Zoigê basin in the eastern Qinghai-Tibet plateau, the Qaidam basin in the northern Qinghai-Tibet plateau and the Dianchi basin in the Yunnan plateau respectively. The results show that the regional environmental differentiation since the Mid-Pleistocene involved three stages, i.e. 780–480, 480–160, 160–0 ka B.P. In each of the three stages different regions of China had their own distinctive environmental characteristics, indicating that the uplift of the Qinghai-Tibet plateau played a major role in the environmental differentiation process.

关键词： Mid-Pleistocene regional differentiation Asian monsoon lacustrine deposits

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Changes of Atmospheric Circulation since the Last Interstadial as Indicated by the Lake-status Record in China

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Acta Geologica Sinica(english edition) 2000年第4期74卷 836-845页

作者： x.e bin YU Ge Nanjing Institute of Geography and Limnology Chinese Academy of SciencesNanjing 210008

The effective precipitation and the frame of atmospheric circulation in the past three key periods, i.e. 30 ka BP, 18 ka BP and 6 ka BP, have been analyzed on the basis of the palaeolake status record produced by the Chinese Lake Status Data Base. The results show that the west-central part of China was characterized by high lake-levels at 30 ka BP, resulting from strengthened southwest monsoons; whereas the high lake stand, occurring in the west-central part of China at 18 ka BP, was caused by the southward shift and the strengthening of westerlies although the high-stand distribution was reduced. Meanwhile, the east-central part of China was under the control of strong winter monsoons at 18 ka BP. The high lake-levels, which occurred in the east-central part of China at 6 ka BP, are related to the enhanced east-Asian summer monsoons; while the lowering of the lake-level in the west-central part of China at 6 ka BP was due to the northward shift and corresponding shrink of the westerlies.A comparison between the lake status and the palaeoclimate models has shown that there do exist discrepancies between the geological evidence and the model simulations. The agreement between them provides a possible mechanical explanation on the geological phenomena, but the discrepancy shows that the model needs to be revised to a great ex.ent.

关键词： Lake-status Data Base atmospheric circulation Last Interstadial Last Glacial Maximum Mid-Holocene

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Insight into vertical piezoelectric characteristics regulated thermal transport in van der Waals two-dimensional materials

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Rare Metals 2024年第2期43卷 770-779页

作者： Dong-Hai Wei e Zhou Jin-Yuan xu Hui-Min Wang Chen Shen Hong-bin Zhang Zhen-Zhen Qin Guang-Zhao Qin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Hunan Key Laboratory for Micro-Nano energy Materials and Device and School of Physics and Optoelectronics Xiangtan UniversityXiangtan411105China Institute of Materials Science Technical University of DarmstadtAlarich-Weiss-Str.264287DarmstadtGermany School of Physics and Microelectronics Zhengzhou UniversityZhengzhou450001China

The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key ***,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically *** different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study *** performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic ***,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%*** research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.

关键词： Thermal conductivity Piezoelectric effect 2D materials Bilayer BN Strain engineering

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emerging Strategies in enhancing Singlet Oxygen Generation of Nano-Photosensitizers Toward Advanced Phototherapy

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Nano-Micro Letters 2022年第7期14卷 293-341页

作者： Mohammad Tavakkoli Yaraki bin Liu Yen Nee Tan Institute of Materials Research and engineering The Agency for ScienceTechnology and Research(A*STAR)2 Fusionopolis Way#08-03Innovis 138634Singapore Department of Chemical and Biomolecular engineering National University of Singapore4 Engineering Drive 4Singapore 117585Singapore Faculty of Science Agriculture and EngineeringNewcastle UniversityNewcastle Upon Tyne NE17RUUK Newcastle Research and Innovation Institute Newcastle University in Singapore80 Jurong East Street 21#05-04Singapore 609607Singapore

The great promise of photodynamic therapy(PDT) has thrusted the rapid progress of developing highly effective photosensitizers(PS) in killing cancerous cells and bacteria. To mitigate the intrinsic limitations of the classical molecular photosensitizers, researchers have been looking into designing new generation of nanomaterial-based photosensitizers(nano-photosensitizers) with better photostability and higher singlet oxygen generation(SOG) efficiency, and ways of enhancing the performance of existing photosensitizers. In this paper, we review the recent development of nano-photosensitizers and nanoplasmonic strategies to enhance the SOG efficiency for better PDT performance. Firstly, we explain the mechanism of reactive oxygen species generation by classical photosensitizers, followed by a brief discussion on the commercially available photosensitizers and their limitations in PDT. We then introduce three types of new generation nanophotosensitizers that can effectively produce singlet oxygen molecules under visible light illumination, i.e., aggregation-induced emission nanodots, metal nanoclusters (erent design approaches to synthesize these nano-photosensitizers were also discussed. To further enhance the SOG rate of nano-photosensitizers, plasmonic strategies on using different types of metal nanoparticles in both colloidal and planar metal-PS systems are reviewed. The key parameters that determine the metal-enhanced SOG(Me-SOG) efficiency and their underlined enhancement mechanism are discussed. Lastly, we highlight the future prospects of these nanoengineering strategies, and discuss how the future development in nanobiotechnology and theoretical simulation could accelerate the design of new photosensitizers and Me-SOG systems for highly effective image-guided photodynamic therapy.

关键词： Nano-photosensitizer Reactive oxygen species Aggregation-induced emission Metal nanocluster Carbon dots Metalenhanced singlet oxygen generation

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Security analysis of a new stream cipher

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Science in China(Series F) 2006年第3期49卷 286-301页

作者： ZHANG bin FeNG Dengguo State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing 100080 China

In this paper, we analyze the security of a new stream cipher-COSvd（2,128）. This cipher was proposed by e. Filiol et al. at the eCRYPT SASC＇2004 （The State of the Art of Stream Ciphers）. It uses clock-controlled non-linear feedback registers together with an S-box controlled by a chaotic sequence and was claimed to prevent any existing attacks. However, our analysis shows that there are some serious security flaws in the design of the S-box, resulting in heavy biased byte distribution in the keystream. In some broadcast applications, this flaw will cause a ciphertext-only attack with high success rate. Besides, there are also many security flaws in other parts of the cipher. We point out these flaws one by one and develop a divide-and-conquer attack to recover the secret keys from O（2^26）-byte known plaintext with success rate 93.4597% and complexity O（2^113）, which is much lower than 2^512, the complexity of exhaustive search.

关键词： stream cipher divide-and-conquer attack non-linear feedback shift registers (NLFSR) chaotic sequence.

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Phase constitution of the noble metal thin-film complex solid solution system Ag-Ir-Pd-Pt-Ru in dependence of elemental compositions and annealing temperatures

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Nano Research 2022年第6期15卷 4827-4836页

作者： bin xiao xiao Wang Alan Savan Alfred Ludwig Materials Discovery and Interfaces Institute for MaterialsRuhr University Bochum44780 BochumGermany Zentrum für Grenzflächendominierte Höchstleistungswerkstoffe(ZGH) Ruhr University Bochum44780 BochumGermany

Multiple-principal element alloys hold great promise for multifunctional material discovery(e.g.,for novel electrocatalysts based on complex solid solutions)in a virtually unlimited compositional ***,the phase constitution of the noble metal system Ag-Ir-Pd-Pt-Ru was investigated over a large compositional range in the quinary composition space and for different annealing temperatures from 600 to 900°C using thin-film materials ***-dependent x-ray diffraction mapping of the asdeposited thin-film materials library indicates different phases being present across the composition space(face-centered cubic(fcc),hexagonal close packed(hcp)and mixed fcc+hcp),which are strongly dependent on the Ru *** general,low Ru contents promote the fcc phase,whereas high Ru contents favor the formation of an hcp solid-solution ***,a temperature-induced phase transformation study was carried out for a selected measurement area of fcc-Ag_(5)Ir_(8)Pd_(56)Pt_(8)Ru_(23).With increasing temperature,the initial fcc phase transforms to an intermediate C14-type Laves phase at 360°C,and then to hcp when the temperature reaches 510°*** formation and disappearance of the hexagonal Laves phase,which covers a wide temperature range,plays a crucial role of bridging the fcc to hcp phase *** obtained composition,phase and temperature data are transformed into phase maps which could be used to guide theoretical studies and lay a basis for tuning the functional properties of these materials.

关键词： noble metal high-entropy alloys phase transformation combinatorial synthesis and high-throughput characterization

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A review of nonlinear piezoelectric energy harvesting interface circuits in discrete components

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Applied Mathematics and Mechanics(english edition) 2022年第7期43卷 1001-1026页

作者： bin ZHANG Hongsheng LIU Shengxi ZHOU Jun GAO School of Mechanical Electrical and Information EngineeringShandong UniversityWeihai 264209Shandong ProvinceChina School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

Piezoelectric energy harvesting is considered as an ideal power resource for low-power consumption gadgets in vibrational *** energy extraction efficiency depends highly on the interface circuit,and should be highly improved to meet the power *** nonlinear interface circuits in discrete components have been ex.ensively explored and developed with the advantages of easy implementation,stable operation,high efficiency,and low *** paper reviews the state-of-the-art progress of nonlinear piezoelectric energy harvesting interface circuits in discrete ***,the working principles and the advantages/disadvantages of four classical interface circuits are ***,the improved circuits based on the four typical circuits and other types of circuits are introduced in detail,and the advantages/disadvantages,output power,efficiency,energy consumption,and practicability of these circuits are ***,the future development trends of nonlinear piezoelectric energy harvesting circuits,e.g.,self-powered extraction,low-power consumption,and broadband characteristic,are predicted.

关键词： piezoelectric nonlinear energy harvesting discrete component interface circuit

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Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

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Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： Hong-bin Dai Jian Miao Jia-xin Lin School of Materials Science and engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUeNT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

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