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Mechanical Characteristics and Mechanism of Granite Subjected to Coupling Effect of Acidic Corrosion and Freeze-Thaw Cycles

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Journal of Earth Science 2021年第5期32卷 1202-1211页

作者： Suran Wang Youliang Chen Jing Ni Guanlin Liu Tomas Manuel Fernandez-Steeger Chao Xu Department of Geotechnical Engineerings Tongji University Shanghai 200092China Department of Civil Engineerings University of Shanghai for Science and Technology Shanghai 200093China Institute for Applied Geosciences Technical University of BerlinBerlin 10587Germany

The typical climatic and environmental conditions in Central Asia are major natural factors causing local rock masses to face considerable risks of damage due to constant freeze-thaw cycles. In addition, these are exacerbated by the dense acidic environments in certain industrialized areas, such as Northern Sinkiang, china. To provide local engineering design with workable solutions, it is crucial to analyze the mechanical performance of rock masses and its mechanisms under the coupling action of corrosive acid and freeze-thaw cycles. In this study, granite samples from the northern Tien Shan Mountains near Urumchi, Xinjiang Province, as well as two kinds of sandstone samples for comparison, were subjected to different soaking conditions, including nitric acid soaking at various pH values. One or both of the freeze-thaw cycle tests and uniaxial compression test were then executed. Speculations regarding the mechanism of the performance of granite rock masses under the action of corrosive acid and freeze-thaw cycles were developed based on the results of these tests. X-ray diffraction and scanning electron microscopy were implemented to demonstrate the feasibility of the speculated mechanism. In this paper, the identification of the white crumb-like substance as SiO_(2) gel were confirmed.

关键词： granite sandstone acidic environment freeze-thaw cycle test XRD SEM

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Some new symmetric relations and prediction of left- and right-handed neutrino masses using Koide's relation

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Chinese Physics C 2017年第4期41卷 27-32页

作者：黄永畅 Syeda Tehreem Iqbal 雷震王雯宇 Institute of Theoretical Physics Beijing University of Technology Beijing 100124 China

The masses of the three generations of charged leptons are known to completely satisfy Koide＇s mass relation,but the question remains of whether such a relation exists for *** this paper,by considering the seesaw mechanism as the mechanism generating tiny neutrino masses,we show how neutrinos satisfy Koide＇s mass relation,on the basis of which we systematically give exact values of both left-and right-handed neutrino masses.

关键词： Koide's mass relation neutrino mass seesaw mechanism.

Single-crystal microplates of two-dimensional organic-inorganic lead halide layered perovskites for optoelectronics

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Nano Research 2017年第6期10卷 2117-2129页

作者： Dewei Ma Yongping Fu Lianna Dang Jianyuan Zhai Ilia A. Guzei Song Jin Department of Chemistry University of Wisconsin-Madison Madison Wisconsin 53706 USA Department of Applied Physics Zhejiang University of Technology Hangzhou 310014 China

Organic-inorganic hybrid perovskites attract considerable attention owing to their applications in high-efficiency solar cells and light emission. Compared with three-dimensional perovskites, two-dimensional （2D） layered hybrid perovskites have a higher exciton binding energy and potentially higher light- emission efficiency. The growth of high-quality crystalline 2D perovskites with a well-defined nanoscale morphology is desirable because they can be suitable building blocks for integrated optoelectronics and （nano）photonics. Herein, we report the facile solution growth of single-crystal microplates of 2D perovskites based on a 2-phenylethylammonium （C6HsCH2CH2NHG PEA） cation, （PEA）2PbX- （X = Br, I）, with a well-defined rectangular geometry and nanoscale thickness through a dissolution-recrystallization process. The crystal structures of （PEA）2PbX4 are first confirmed using single-crystal X-ray diffraction. A solution-phase transport-growth process is developed to grow microplates with a typical size of tens of micrometers and thickness of hundreds of nanometers on another clean substrate different from the substrate coated with lead-acetate precursor film. Surface-topography analysis suggests that the formation of the 2D microplates is likely driven by the wedding-cake growth mechanism. Through halide alloying, the photoluminescence emission of （PEA）2Pb（Br, I）4 perovskites with a narrow peak bandwidth is readily tuned from violet （-410 nm） to green （-530 nm）.

关键词： layered lead-halide perovskite,phenylethylammonium lead-halide perovskites,microplate,nanoplate dissolution-recrystallization,photoluminescence

High-performance supercapacitors based on Ni_(2)P@CNT nanocomposites prepared using an ultrafast microwave approach

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Frontiers of Chemical Science and Engineering 2021年第4期15卷 1021-1032页

作者： Yunrui Tian Haishun Du Shatila Sarwar Wenjie Dong Yayun Zheng Shumin Wang Qingping Guo Jujie Luo Xinyu Zhang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Department of Chemical Engineering Auburn UniversityAuburnAL 36849USA

We present a one-step route for the preparation of nickel phosphide/carbon nanotube(Ni_(2)P@CNT)nanocomposites for supercapacitor applications using a facile,ultrafast(90 s)microwave-based ***2P nanoparticles could grow uniformly on the surface of CNTs under the optimized reaction conditions,namely,a feeding ratio of 30:50:25 for CNT,Ni(NO_(3))_(2)-6H_(2)O,and red phosphorus and a microwave power of 1000 W for 90 *** study demonstrated that the single-step microwave synthesis process for creating metal phosphide nanoparticles was faster and simpler than all the other existing *** results showed that the specific capacitance of the optimal Ni2P@CNT-nanocomposite electrode displayed a high specific capacitance of 854 F•g^(-1) at 1 A•g^(-1) and a superior capacitance retention of 84% after 5000 cycles at 10 Ag^(-1).Finally,an asymmetric supercapacitor was assembled using the nanocomposite with activated carbon as one electrode(Ni_(2)P@CNT//AC),which showed a remarkable energy density of 33.5 W•h•kg^(-1) and a power density of 387.5 W·kg^(-1).This work will pave the way for the microwave synthesis of other transition metal phosphide materials for use in energy storage systems.

关键词： Ni_(2)P CNT supercapacitors nanocomposites microwave

Heterogeneous lamella design to tune the mechanical behaviour of a new cost-effective compositionally complicated alloy

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Journal of Materials Science & Technology 2022年第1期96卷 113-125页

作者： Yu Yin Qiyang Tan Qiang Sun Wangrui Ren Jingqi Zhang Shiyang Liu Yingang Liu Michael Bermingham Houwen Chen Ming-Xing Zhang School of Mechanical and Mining Engineering University of QueenslandQLD 4072Australia College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

A heterogeneous lamella(HL)design strategy was applied to manipulate mechanical properties of a new cost-effective Fe_(35)Ni_(35)Cr_(25)Mo_(5)compositionally complicated alloy(CCA).The HL structure was produced by single-step heat treatment(800℃for 1 h)after cold *** HL structure consists of alternative lamellae regions of coarse-grained FCC matrix(5-20μm),and regions containing ultra-fine grains or subgrains(200-500 nm)together with nanoprecipitates(20-500 nm)and annealing *** compared with other cost-effective CCAs,the 800℃annealed sample with HL structure demonstrated a comparable tensile property,with yield strength over 1.0 GPa and total elongation of~13%.Formation of the annealing twins and nanoprecipitates decorated HL structure was a result of the concurrent partial recrystallization and precipitation ofσphase at the shear bands with a high density of lattice defects(***-density dislocation walls and deformation twins).The latter restricted the growth of recrystallized grains,leading to the formation of ultrafine subgrains within the HL *** high yield strength resulted from the multistage hetero-deformation induced(HDI)strengthening and precipitation strengthening associated with heterogeneous lamella structures containing *** ductility was originated from the coexistence of multiple deformation mechanisms,which started with dislocation slip and formation of stacking faults at the initial stage,followed by nano-twinning at the higher strain *** HL design strategy,comprising composition and thermomechanical process designs,and the resultant microstructure tuning,open a broader window for the development of cost-effective CCAs with enhanced performance.

关键词： High entropy alloys Compositionally complicated alloys Heterogeneous lamella structure Nanoprecipitates Recrystallization Mechanical properties

Probing into the Yield Plateau Phenomenon in Commercially Pure Titanium During Tensile Tests

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Acta Metallurgica Sinica(English Letters) 2021年第5期34卷 701-709页

作者： Xiaohui Shi Zuhan Cao Zhiyuan Fan Ruipeng Guo Junwei Qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China

To explain the intrinsic mechanism of the yield plateau phenomenon in commercially pure titanium,the tensile behaviors of commercially pure titanium specimens after 91.6%cryorolling and subsequent annealing at 280℃,335℃,450℃and 600℃have been *** results show that the yield plateau phenomenon is a result of dislocation behaviors controlled by grain size and thus only exists within a given range of mean grain size.αgrain boundaries are the main dislocation multiplication sources of commercially pure ***-grained microstructure could offer numerous dislocation multiplication locations during *** the applied stress is above the yielding strength,dislocations multiply rapidly and the mobile dislocation density is *** retrieve the imposed strain rate,the mean dislocation velocity is bound to be ***,it takes time for them to interact with each *** a result,the movement of dislocations is hardly blocked and the deformation could continue at a nearly constant applied ***,the so-called yield plateau behavior presents in the tensile *** disappearance of yield plateau phenomenon in coarse-grained and ultrafi ne-grained microstructures is attributed to the quick realization of the mutual interactions among dislocations at the initial stage of tensile test.

关键词： Yield plateau Commercially pure titanium Tensile test Grain size Dislocation

A porous Co_(3)O_(4)-carbon paper electrode enabling nearly 100% electrocatalytic reduction of nitrate to ammonia

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Materials Reports(Energy) 2023年第3期3卷 41-47页

作者： Xufeng Rao Jiaying Yan Koji Yokoyama Xiaolin Shao Chihiro Inoue Mei-fang Chien Yuyu Liu Institute for Sustainable Energy/College of Sciences Shanghai UniversityShangda Road 99BaoshanShanghai200444PR China Graduate School of Environmental Studies Tohoku UniversityAoba KuAoba 6-6-20 AramakiSendaiMiyagi9808579Japan

Co_(3)O_(4) was synthesized on carbon paper(CP)using a facile method to improve electrochemical nitrate-toammonia conversion *** resulting Co_(3)O_(4)-CP electrode demonstrated an exceptional Faradaic efficiency of almost 100% across a broad range of application conditions,with a peak NH3 yield of 3.43 mmol h^(-1) cm^(-2)(2.25 mol gCo^(-1) h^(-1)).

关键词： Nitrate Electroreduction Ammonia Catalyst Co_(3)O_(4)

The Environment Significance of Aerinite——First Discovered in the UBC Cliffs

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Acta Geologica Sinica(English Edition) 2020年第1期94卷 103-113页

作者： WANG Guanyu WANG Hejing School of Earth and Space Sciences Peking University Beijing 100871 China

To analyze the composition and structure of the pale blue outcrop from the UBC Cliffs and research the environmental significance of aerinite recorded in the sediments, mineral composition, bulk chemical composition and structural analyses were carried out by means of X-ray diffraction(XRD), field emission scanning electron microscope(FESEM), transmission electron microscope(TEM), electron microprobe analysis(EMPA) and X-ray fluorescence spectra(XRF). Quartz, feldspar, mica, chlorite and aerinite as well as a small amount of amphibole, calcite, clinopyroxene, rutile, perovskite and apatite are recorded in the sediments. It is reported for the first time that the aerinite occurs in a high latitude area and in sediments paragenetic with mica and chlorite. The large span in grain size shows a typical characteristic of fluvioglacial sediments. Geochemistry characteristics(CIA, CIW, PIA, WIP and ICV) verify that there is virtually no chemical weathering. Mineralogy and geochemistry features of the UBC Cliffs sediments indicate that aerinite is accommodate to the high latitude and cold, dry climate. As the sediments show high similarity to those of their provenance, they have great significance in the identification of the forming condition and origin of the aerinite.

关键词： UBC Cliffs sediments aerinite muscovite chlorite environment significance

Mixed phase sodium manganese oxide as cathode for enhanced aqueous zinc-ion storage

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Chinese Journal of Chemical Engineering 2020年第8期28卷 2214-2220页

作者： Xinyu Wang Xinghua Qin Qiongqiong Lu Mingming Han Ahmad Omar Daria Mikhailova Institute of Materials and Technology Dalian Maritime UniversityDalian 116026China Leibniz Institute for Solid State and Materials Research(IFW)Dresden e.V. Helmholtzstraße 2001069 DresdenGermany School of Materials Science and Engineering Central South UniversityChangsha 410083China

Aqueous zinc-ion batteries have been regarded as a promising alternative to large-scale energy storage, due to associated low-cost, improved safety and environmental friendliness. However, a high-performance cathode material for both rate capability and specific capacity is still a challenge. One kind of the more promising candidates are sodium manganese oxide(NMO) materials, although they suffer from individual issues and need to be further improved. Herein, we present a novel mixed phase NMO material composed of nearly equal amounts of Na(0.55)Mn2O4 and Na(0.7)MnO(2.05). The structured configuration with particle size of 200–500 nm is found to be beneficial towards improving the ion diffusion rate during the charge/discharge process. Compared with Na(0.7)MnO(2.05) and Na(0.55)Mn2O4, the mixed phase NMO demonstrates an enhanced rate capability and excellent long-term cycling stability with a capacity retention of 83% after 800 cycles. More importantly, the system also delivers an impressive energy density and power density, as 378 W·h·kg^-1 at 68.7 W·kg^-1, or 172 W·h·kg^-1 at 1705 W·kg^-1. The superior electrochemical performance is ascribed to the fast Zn^2+ diffusion rate because of a large ratio of capacitive contribution(63.9% at 0.9 m V·s^-1). Thus, the mixed phase route provides a novel strategy to enhance electrochemical performance, enabling mixed phase NMO as very promising material towards large-scale energy-storage applications.

关键词： Aqueous zinc-ion battery Sodium manganese oxide Mixed phase High energy density