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High-Throughput Powder diffraction Using White x.Ray Beam and a Simulated Energy-dispersive Array detector

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Engineering 2022年第3期8卷 81-88页

作者： x.aoping Wang Weiwei dong Peng Zhang Haoqi Tang Lanting Zhang Tieying Yang Peng Liu Hong Wang x.-d.xiang Materials Genome Initiative Center&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China department of Materials Science and Engineering&department of Physics Southern University of Science and TechnologyShenzhen 518055China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China Guangdong Provincial Key Laboratory of Energy Materials for Electric Power Southern University of Science and TechnologyShenzhen 518055China Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and devices Southern University of Science and TechnologyShenzhen 518055China

High-throughput powder x.ray diffraction(x.d)with white x.ray beam and an energy-dispersive detector array is demonstrated in this work on a CeO;powder sample on a bending magnet synchrotron beamline at the Shanghai Synchrotron Radiation Facility(SSRF),using a simulated energy-dispersive array detector consisting of a spatially scanning silicon-drift detector(Sdd).Careful analysis and corrections are applied to account for various ex.erimental hardware-related and diffraction angle-related factors.The resulting diffraction patterns show that the relative strength between different diffraction peaks from energy-dispersive x.d(Edx.d)spectra is consistent with that from angle-resolved x.d(ARx.d),which is necessary for analyzing crystal structures for unknown samples.The x.ray fluorescence(x.F)signal is collected simultaneously.x.F counts from all pix.ls are integrated directly by energy,while the diffraction spectra are integrated by d-spacing,resulting in a much improved peak strength and signal-to-noise(S/N)ratio for the array detector.In comparison with ARx.d,the diffraction signal generated by a white x.ray beam over monochromic light under the ex.erimental conditions is about 104 times higher.The full width at half max.mum(FWHM)of the peaks in q-space is found to be dependent on the energy resolution of the detector,the angle span of the detector,and the diffraction angle.It is possible for Edx.d to achieve the same or even smaller FWHM as ARx.d under the energy resolution of the current detector if the ex.erimental parameters are properly chosen.

关键词： High-throughput ex.eriment White beam x.ray diffraction Energy-dispersive array detector Energy-dispersive x.ray diffraction Angle-resolved x.ray diffraction

An integrated machine learning model for accurate and robust prediction of superconducting critical temperature

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Journal of Energy Chemistry 2023年第3期78卷 232-239,I0007页

作者： Jingzi Zhang Ke Zhang Shaomeng x. Yi Li Chengquan Zhong Mengkun Zhao Hua-Jun Qiu Mingyang Qin x.-d.xiang Kailong Hu x. Lin School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055GuangdongChina Blockchain development and Research Institute Harbin Institute of TechnologyShenzhen 518055GuangdongChina State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001HeilongjiangChina School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina department of Materials Science and Engineering&department of Physics Southern University of Science and TechnologyShenzhen 518055GuangdongChina

discovering new superconductors via traditional trial-and-error ex.erimental approaches is apparently a time-consuming process,and the correlations between the critical temperature(Tc) and material features are still obscure.The rise of machine learning(ML) technology provides new opportunities to speed up inefficient ex.loration processes,and could potentially uncover new hints on the unclear correlations.In this work,we utilize open-source materials data,ML models,and data mining methods to ex.lore the correlation between the chemical features and Tcvalues of superconducting materials.To further improve the prediction accuracy,a new model is created by integrating three basic algorithms,showing an enhanced accuracy with the coefficient of determination(R2) score of 95.9 % and root mean square error(RMSE) of 6.3 K.The average marginal contributions of material features towards Tcvalues are estimated to determine the importance of various features during prediction processes.The results suggest that the range thermal conductivity plays a critical role in Tcprediction among all element features.Furthermore,the integrated ML model is utilized to screen out potential twenty superconducting materials with Tcvalues beyond 50.0 K.This study provides insights towards Tcprediction to accelerate the ex.loration of potential high-Tcsuperconductors.

关键词： Superconductors Integrated machine learning Superconducting critical temperature

A direct measurement method of quantum relax.tion time

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National Science Review 2021年第4期8卷 91-99页

作者： Peng Zhang Haoqi Tang Chuanchuan Gu Hong Wang Guangfu Luo Yalin Lu x.-d.xiang department of Materials Science and Engineering & department of Physics Southern University of Science and Technology Synergetic Innovation Center of Quantum Information and Quantum Physics & Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Materials Genome Initiative Center and School of Materials Science and Engineering Shanghai Jiao Tong University State Key Laboratory of Green Building Materials China Building Materials Academy Guangdong Provincial Key Laboratory of Computational Science and Material design Southern University of Science and Technology

The quantum relax.tion time of electrons in condensed matters is an important physical property, but its direct measurement has been elusive for a century. Here, we report a breakthrough that allows direct determination of quantum relax.tion time at zero and non-zero frequencies using optical measurement.Through dielectric loss function, we connect bound electron effects to the physical parameters of plasma resonance and find an ex.ra term of quantum relax.tion time from inelastic scattering between bound electrons and conduction electrons at non-zero frequencies. We demonstrate here that the frequency-dependent inelastic polarization effect of bound electrons is the dominant contribution to quantum relax.tion time of conduction electrons at optical frequencies, and the elastic polarization effect of bound electrons also dramatically changes the plasma resonance frequency through effective screening to charge carriers.

关键词： quantum relax.tion time plasma resonance dielectric loss function

On the data-driven Materials Innovation Infrastructure

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Engineering 2020年第6期6卷 609-611页

作者： Hong Wang x.-d.xiang Lanting Zhang Materials Genome Initiative Center&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

In recent years,material genome has been a hot topic in the field of material science.The emergence of the term“material genome”was largely inspired by the successful Human Genome Project.Trad让ionally,the discovery and development of new materials and new processes depend on scientific intuition and a lengthy trial-and-error process.For years,material scientists have been longing to find some sort of basic building blocks whose structure and defects may determine the properties of materials,similar to the genome in the field of biology.

关键词： process. material field

decomposition mechanisms of nuclear-grade cationic ex.hange resin by advanced ox.dation processes:Statistical molecular fragmentation model and dFT calculations

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Journal of Environmental Sciences 2024年第1期135卷 433-448页

作者： xiang Meng Pierre désesquelles Lejin x. department of Nuclear Engineering and Technology School of Energy and Power EngineeringHuazhong University of Science&TechnologyWuhan 430074China CNRS Laboratoire de Physique des Gaz et des PlasmasUniversitéParis-SaclayOrsay 91405France State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion ex.hange resins have become a focus of attention due to their high production and serious environmental risks.In this paper,a simplified model of cationic ex.hange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydrox.l radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(dFT)calculations.The prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the degradation.The meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain reactivity.The C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily broken.It is also found that dihydrox. addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring separation.The decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex.polycyclic aromatic hydrocarbons.

关键词： Cationic ex.hange resin Statistical molecular fragmentation model density functional theory Hydrox.l radical decomposition mechanism

Probiotics intervention in colorectal cancer:From traditional approaches to novel strategies

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Chinese Medical Journal 2024年第1期137卷 8-20页

作者： Suki Ha xiang Zhang Jun Yu Institute of digestive disease and department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong SARChina

The intestine harbors a large population of microorganisms that interact with epithelial cells to maintain host healthy physiological status.These intestinal microbiota engage in the fermentation of non-digestible nutrients and produce beneficial metabolites to regulate host homeostasis,metabolism,and immune response.The disruption of microbiota,known as dysbiosis,has been implicated in many intestinal diseases,including colorectal cancer(CRC).As the third most common cancer and the second leading cause of cancer-related death worldwide,CRC poses a significant health burden.There is an urgent need for novel interventions to reduce CRC incidence and improve clinical outcomes.Modulating the intestinal microbiota has emerged as a promising approach for CRC prevention and treatment.Current research efforts in CRC probiotics primarily focus on reducing the incidence of CRC,alleviating treatment-related side effects,and potentiating the efficacy of anticancer therapy,which is the key to successful translation to clinical practice.This paper aims to review the traditional probiotics and new interventions,such as nex.-generation probiotics and postbiotics,in the contex. of CRC.The underlying mechanisms of probiotic anti-cancer effects are also discussed,including the restoration of microbial composition,reinforcement of gut barrier integrity,induction of cancer cell apoptosis,inactivation of carcinogens,and modulation of host immune response.This paper further evaluates the novel strategy of probiotics as an adjuvant therapy in boosting the efficacy of chemotherapy and immunotherapy.despite all the promising findings presented in studies,the evaluation of potential risks,optimization of delivery methods,and consideration of intra-patient variability of gut microbial baseline must be thoroughly interpreted before bench-to-bedside translation.

关键词： colorectal cancer probiotics gut microbiota dysbiosis adjuvant therapy immune modulation gut barrrier

Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo x. Zhong-li Liu xiang Chen Yan-xiang Li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake discs.In this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an ex.erimental foundation for achieving a balance between their thermal and mechanical properties.Compacted graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of ferrite.The peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction tests.The morphology of thermal cracks and 3d profiles of the worn surfaces were also discussed.It is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient ex.ibits optimal thermal fatigue resistance.Ox.dization of the matrix.at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal cracks.despite the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

An integrative mathematical model of microwave ion thruster for mHz-frequency thrust noise analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 121-136页

作者： xiang NIU Hui LIU daren YU Plasma Propulsion Laboratory Harbin Institute of TechnologyHarbin 150001China

Many high-precision space missions need thrusters to produce thrust with low noise to compensate for disturbances and ensure satellite platform stability. Microwave ion thruster is characterized with a wide thrust range and potential for these missions. A cost-effective and accurate mathematical model is crucial for mHz-frequency thrust noise analysis and feedback controller design. The Particle-In-Cell(PIC) and global models are two common simulation tools. The PIC model is characterized with high accuracy but huge computation cost, which is difficult to analyze long-time performance characteristics. Now, the global model is only used for the discharge chamber with low accuracy and cannot reflect ion ex.raction properties. In this paper, an integrative mathematical model is built for a 1-cm microwave ion thruster and can reflect ion beamlet divergence and impingement on the Accelerator Grid(AG). Simulation results show good agreement with ex.eriments at 0.06 sccm. However, the model demonstrates worse consistency with ex.eriments when the flux.increases to 0.1 sccm, which may be because the influence of neutral gas on the Electron Cyclotron Resonance(ECR) is not considered in the model. A long-time(1000 s) simulation is conducted with this model under 35 μN. It takes 3 hrs, and the thrust noise reaches 1 μN/Hz^(0.5) at 1 mHz.

关键词： Electric propulsion Microwave ion thruster Integrative model Sheath property Ion beamlet divergence Thrust noise Plasma

The spectrum and stability of travelling pulses in a coupled FitzHugh-Nagumo equation

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Science China Mathematics 2024年第5期67卷 975-1010页

作者： Qi Qiao xiang Zhang School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Scientific and Engineering Computing(Ministry of Education) and Shanghai Frontier Science Center of Modern Analysis(CMA-Shanghai)Shanghai Jiao Tong UniversityShanghai 200240China

For a coupled slow-fast FitzHugh-Nagumo(FHN)equation derived from a reaction-diffusionmechanics(RdM)model,Holzer et al.(2013)studied the ex.stence and stability of the travelling pulse,which consists of two fast orbit arcs and two slow ones,where one fast segment passes the unique fold point with algebraic decreasing and two slow ones follow normally hyperbolic critical curve segments.Shen and Zhang(2021)obtained the ex.stence of the travelling pulse,whose two fast orbit arcs both ex.onentially decrease,and one of the slow orbit arcs could be normally hyperbolic or not at the origin.Here,we characterize both the nonlinear and spectral stability of this travelling pulse.

关键词： coupled FitzHugh-Nagumo equation singular perturbation travelling pulse spectrum nonlinear stability spectral stability