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One Step Fabrication of Co3O4-PPy Cathode for Lithium-O2 Batteries

Chinese Journal of Chemistry 2017年第1期35卷 35-40页

作者： xuan Shao Tao Zhang Zhaoyin wen CAS Key Laboratory of Materials for Energy Conversion Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

Conventional binders in the cathode of Li-O2 batteries are insulated, and integrate with the catalyst and the conducting carbon-support by physical mixing. This limits the transfer of electrons, degrades the cathode structure due to swelling, and finally leads to capacity fading and is deleterious to cycleability. In this study, we realized, for the first time, a one-step fabricated Co3O4-PPy cathode characterized by an in-situ formed conductive polymer binder. The functional binder, polypyrrole （PPy）, was synthesized through electrical method, which acted as both the binder and supporting material in the Li-O2 battery. Based on the conductive property of PPy, we obtained the Co3O4-PPy@Ni electrode via the process of CV electro-deposition. This method results in uniform distribution of Co3O4 nanoparticles and can simplify the preparation process of the air cathodes. The Li-O2 battery with the Co3O4-PPy@Ni cathode can discharge/charge for over 30 cycles under the limited specific capacity of 1000 mAh/g. The cycleability and impedance spectra of the Li-O2 battery with the functional binder of PPy are superior to the battery with conventional binders. Conventional binders in the cathode of Li-O2 batteries are insulated, and integrate with the catalyst and the conducting carbon-support by physical mixing. This limits the transfer of electrons, degrades the cathode structure due to swelling, and finally leads to capacity fading and is deleterious to cycleability. In this study, we realized, for the first time, a one-step fabricated Co3O4-PPy cathode characterized by an in-situ formed conductive polymer binder. The functional binder, polypyrrole （PPy）, was synthesized through electrical method, which acted as both the binder and supporting material in the Li-O2 battery. Based on the conductive property of PPy, we obtained the Co3O4-PPy@Ni electrode via the process of CV electro-deposition. This method results in uniform distribution of Co3O4 nanoparticles and can simplify

关键词： conductive polymer pyrrole binder lithium-O2 battery

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Color-tunable circularly polarized electroluminescence from a helical chiral multiple resonance emitter with B–N bonds

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Science China Chemistry 2023年第9期66卷 2612-2620页

作者： Li Yuan Zhen-long Tu Jun-Wei Xu Hua-Xiu Ni Zhi-Ping Mao wen-Ye Xu You-xuan Zheng State Key Laboratory of Coordination Chemistry Collaborative Innovation Center of Advanced MicrostructuresJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Shenzhen Institute of Information Technology Shenzhen 518172China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China Guangzhou Research&Creativity Biotechnology Co.Ltd. Guangzhou 510700China

Chiral B,N-doped polycyclic aromatic hydrocarbons with circularly polarized luminescence(CPL) and small full-width at halfmaxima(FWHM) are promising multiple resonance(MR) emitters for CP organic light-emitting diodes(CP-OLEDs).This work presents a pair of chiral MR enantiomers,P/M-o[B-N]_(2)N_(2),featuring B–N bonds incorporated within a[7]-helicene *** enantiomers exhibit narrow 0-0 and 0-1 electronic transition bands,whose relative intensity can be fine-tuned by increasing doping concentrations,resulting in redshifts of the emission peak from 542 to 592 *** enantiomers show mirrorsymmetric CPL spectra with an asymmetry factor(|g_(PL)|) of 1.0×10^(-3).The hyperfluorescent CP-OLEDs with double-sensitized emitting layers display a FWHM of 33 nm,an external quantum efficiency of 25.1%,and a|g_(EL)|factor of 7.7×10^(-4).Notably,the CP-OLEDs realize color-tunable CP electroluminescence peak from 553 to 613 nm by regulating the vibrational *** work provides a novel concept for the design of helical CP-MR materials and CP-OLEDs,highlighting their potential for future applications in advanced optoelectronic devices.

关键词： chiral multiple resonance material helical chirality circularly polarized luminescence narrowband emission color-tunable circularly polarized electroluminescence

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Black hole evaporation and its remnants with the generalized uncertainty principle including a linear term

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Communications in Theoretical Physics 2024年第2期76卷 125-136页

作者： Bo Yu Zheng-wen long College of Physics Guizhou UniversityGuiyang550025China

In recent years,researchers have investigated the evaporation of Schwarzschild black holes using various forms of the generalized uncertainty principle(GUP),metric quantum correction,and noncommutative geometry,***,there are differences between the GUP correction and the other two methods in terms of describing the later stages of black hole ***,some studies argue that the GUP with a negative parameter cannot effectively correct black hole evaporation,while others contend that the positivity or negativity of the GUP parameters should not affect the correction *** the above into consideration,we reconsider black hole evaporation with the generalized uncertainty principle including a linear term(LGUP),and examine the case of negative *** results indicate that the evaporation behavior of both Schwarzschild black holes and Reissner–Nordstr?m black holes,under LGUP correction,is consistent with the results of metric quantum correction and non-commutative ***,the negative parameter LGUP can also effectively correct for black hole evaporation.

关键词： black hole evaporation generalized uncertainty principle negative parameter

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Bismuth nanorods confined in hollow carbon structures for high performance sodium-and potassium-ion batteries

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Journal of Energy Chemistry 2022年第4期31卷 787-796页

作者： Hongli long Xiuping Yin xuan Wang Yufeng Zhao Liuming Yan College of Sciences&Institute for Sustainable Energy Shanghai UniversityShanghai 200444China

Bismuth has drawn widespread attention as a prospective alloying-type anode for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its large volumetric ***,such material encounters drastic particle pulverization and overgrowth of solid-electrolyte interphase(SEI)upon repeated(de)alloying,thus causing poor rate and cycling ***,we report a unique structure design with bismuth nanorods confined in hollow N,S-codoped carbon nanotubes(Bi@NS-C)fabricated by a solvothermal method and in-situ thermal ***-situ SEM observations confirm that such a design can significantly suppress the size fining of Bi nanorods,thus inhibiting the particle pulverization and repeated SEI growth upon charging/*** as achieved Bi@NS-C demonstrates outstanding rate capability for SIBs(96.5%capacity retention at 30 A g^(-1) vs.1 A g^(-1)),and a record high rate performance for PIBs(399.5 m Ah g^(-1)@20 A g^(-1)).Notably,the as constructed full cell(Na_(3)V_(2)(PO_(4))_(3)@C|Bi@NS-C)demonstrates impressive performance with a high energy density of 219.8 W h kg^(-1) and a high-power density of 6443.3 W kg^(-1)(based on the total mass of active materials on both electrodes),outperforming the state-of-the-art literature.

关键词： Bismuth anode Hollow structure Composites High rate performance Sodium-and potassium-ion batteries

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On Holder Dependence of the Parameterized Hartman–Grobman Theorem

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Acta Mathematica Sinica,English Series 2022年第1期38卷 137-147页

作者： wen Meng ZHANG Peng LIU xuan LEI School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

The well-known Hartman-Grobman Theorem says that a C~1 hyperbolic diffeomorphism F can be locally linearized by a homeomorphismΦ.For parameterized systems F_(θ),known results show that the corresponding homeomorphismsΦ_(θ)exist uniquely in a functional space equipped with the supremum norm and depend continuously on the parameterθ.In this paper,we further extend the results to Holder dependence ofΦ_(θ)onθby Pugh's strategy,but introducing a kind of special Holder norm instead of the usual supremum norm in the proof to control the linear parts of F_(θ).This requires a new Holder linearization result for every F_(θ).

关键词： Holder linearization dependence on parameter hyperbolicity

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The simultaneous removal of ammonium and manganese from surface water by MeO_x:Side effect of ammonium presence on manganese removal

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Journal of Environmental Sciences 2019年第3期31卷 346-353页

作者： xuan Tian Ruifeng Zhang Tinglin Huang Gang wen Key Laboratory of Northwest Water Resource Environment and Ecology MOE Xi'an University of Architecture and Technology Shaanxi Key Laboratory of Environmental Engineering Xi'an University of Architecture and Technology

Manganese and ammonium pollution in surface water sources has become a serious *** this study, a pilot-scale filtration system was used to investigate the effect of ammonium on manganese removal during the simultaneous removal of ammonium and manganese from surface water using a manganese co-oxide filter film(MeO_x ). The results showed that the manganese removal efficiency of MeO_x in the absence of ammonium was high and stable, and the removal efficiency could reach 70% even at 5.5 °C. When the influent ammonium concentration was lower than 0.7 mg/L, ammonium and manganese could be removed simultaneously. However, at an ammonium concentration of 1.5 mg/L, the manganese removal efficiency of the filter gradually decreased with time(from 96% to 46.20%). Nevertheless, there was no impact of manganese on ammonium removal. The mechanism by which ammonium negatively affected manganese removal was investigated, demonstrating that ammonium affected manganese removal mainly through two possible mechanisms. On one hand, the decreased p H caused by ammonium oxidation was unfavorable for the oxidation of manganese by MeO_x ; on the other hand, the presence of ammonium slowed the growth of new MeO_x and retarded the increase in the specific surface area of the Me Ox-coated sand, and induced changes in the morphology and crystal structure of Me Ox. Consequently, the manganese removal efficiency of the filter decreased when ammonium was present in the inlet water.

关键词： Surface water Manganese Ammonium MeO_x Side effect

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Dynamic Power Saving via Least-Square Self-Tuning Regulator in the Virtualized Computing Systems

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Journal of Systems Science & Complexity 2015年第1期28卷 60-79页

作者： wen Chengjian long Xiang MU Yifen School of Computer Science and Engineering Beihang University Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of Sciences

In recent years,power saving problem has become more and more important in many fields and attracted a lot of research *** this paper,the authors consider the power saving problem in the virtualized computing *** there are multiple objectives in the system as well as many factors influencing the objectives,the problem is complex and *** authors will formulate the problem as an optimization problem of power consumption with a prior requirement on performance,which is taken as the response time in the *** solve the problem,the authors design the adaptive controller based on least-square self-tuning regulator to dynamically regulate the computing resource so as to track a given reasonable reference performance and then minimize the power consumption using the tracking result supplied by the controller at each *** is implemented based on the data collected from real machines and the time delay of turning on/off the machine is included in the *** results show that this method based on adaptive control theory can save power consumption greatly with satisfying the performance requirement at the same time,thus it is suitable and effective to solve the problem.

关键词： Adaptive control green computing least square self-tuning regulator (LS-STR) performance constraint power saving.

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Visible light-mediated C—P bond formation reactions

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Science Bulletin 2019年第5期64卷 337-350页

作者： Bao-Gui Cai Jun xuan wen-Jing Xiao Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials College of Chemistry & Chemical Engineering Anhui University Key Laboratory of Pesticide & Chemical Biology Ministry of Education College of Chemistry Central China Normal University

Organophosphorus compounds have attracted continuous attention in materials science, agrochemical and pharmaceutical fields due to their unique bioactivities. Thus, the development of novel and robust manners for the construction new C—P bond has therefore gained great interests in synthetic organic chemistry. Because of their intrinsic sustainability and green chemistry character, visible light-induced photoredox catalysis has been widely applied in the construction of new chemical bonds, including the formation of C—P bond. In this review, we summarized recent achievements in C—P bond formation reactions initiated by visible light-induced photoredox catalysis, which mainly focusing on the discussion of reaction design and the mechanism.

关键词： C-P bond formation Organophosphorus compounds Photoredox catalysis Visible light

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Contrasting Magnetism in Isovalent Layered LaSr3NiRuO4H4 and LaSrNiRuO4 due to Distinct Spin-Orbital States

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Chinese Physics Letters 2019年第7期36卷 98-102页

作者： xuan wen Ke Yang Hua Wu Laboratory for Computational Physical Sciences (MOE) State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 Collaborative Innovation Center of Advanced Microstructures Nanjing 210093

The recently synthesized first 4d transition-metal oxide-hydride LaSr3NiRuO4H4 with the unusual high H:O ratio surprisingly displays no magnetic order down to 1.8 K. This is in sharp contrast to the similar unusual low-valent Ni^+-Ru^2+ layered oxide LaSrNiRuO4 which has a rather high ferromagnetic(FM) ordering Curie temperature TC^250 K. Using density functional calculations with the aid of crystal field level diagrams and superexchange pictures, we find that the contrasting magnetism is due to the distinct spin-orbital states of the Ru^2+ions(in addition to the common Ni+S = 1/2 state but with a different orbital state): the Ru^2+S = 0 state in LaSr3NiRuO4H4, but the Ru^2+S= 1 state in LaSrNiRuO4. The Ru^2+S = 0 state has the(xy)^2(xz, yz)^4 occupation due to the RuH4O2 octahedral coordination, and then the nonmagnetic Ru2+ions dilute the S= 1/2 Ni^+ sublattice which consequently has a very weak antiferromagnetic superexchange and thus accounts for the presence of no magnetic order down to 1.8 K in LaSr3NiRuO4H4. In strong contrast, the Ru^2+S = 1 state in LaSrNiRuO4 has the(3z^2-r^2)^2(xz, yz)^3(xy)^1 occupation due to the planar square RuO4 coordination, and then the multi-orbital FM superexchange between the S= 1/2 Ni^+ and S= 1 Ru^2+ions gives rise to the high TC in LaSrNiRuO4. This work highlights the importance of spin-orbital states in determining the distinct magnetism.

关键词： The recently synthesized LaSr3NiRuO4H4

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Enabling Highly Efficient k-Means Computations on the SW26010 Many-Core Processor of Sunway TaihuLight

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Journal of Computer Science & Technology 2019年第1期34卷 77-93页

作者： Min Li Chao Yang Qiao Sun wen-Jing Ma wen-long Cao Yu-long Ao Institute of Software Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Mathematical Sciences Peking UniversityBeijing 100871China Center for Data Science Peking UniversityBeijing 100871China peng Cheng Laboratory Shenzhen 518052China

With the advent of the big data era,the amounts of sampling data and the dimensions of data features are rapidly *** is highly desired to enable fast and efficient clustering of unlabeled samples based on feature similarities. As a fundamental primitive for data clustering,the k-means operation is receiving increasingly more attentions *** achieve high performance k-means computations on modern multi-core/many-core systems,we propose a matrix-based fused framework that can achieve high performance by conducting computations on a distance matrix and at the same time can improve the memory reuse through the fusion of the distance-matrix computation and the nearest centroids *** implement and optimize the parallel k-means algorithm on the SW26010 many-core processor,which is the major horsepower of Sunway *** particular,we design a task mapping strategy for load-balanced task distribution,a data sharing scheme to reduce the memory footprint and a register blocking strategy to increase the data *** techniques such as instruction reordering and double buffering are further applied to improve the sustained *** on block-size tuning and performance modeling are also *** show by experiments on both randomly generated and real-world datasets that our parallel implementation of k-means on SW26010 can sustain a double-precision performance of over 348.1 Gflops,which is 46.9% of the peak performance and 84%of the theoretical performance upper bound on a single core group,and can achieve a nearly ideal scalability to the whole SW26010 processor of four core *** comparisons with the previous state-of-the-art on both CPU and GPU are also provided to show the superiority of our optimized k-means kernel.

关键词： parallel k-means performance optimization SW26010 processor Sunway TaihuLight

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