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A non-precious metal catalyst for oxygen reduction prepared by heat-treating a mechanical mixture of carbon black,melamine and cobalt chloride

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Chinese Chemical Letters 2013年第12期24卷 1109-1111页

作者： yu-jun si Zhong-Ping Xiong Chang-Guo Chen Ping Liu Hui-Juan Wu College of Chemistry and Pharmaceutical Engineering Sichuan University of Science and Engineering College of Chemistry and Chemical Engineering Chongqing University

A non-precious metal catalyst CoMe]C for the oxygen reduction reaction is prepared by heat-treating a mechanical mixture of carbon black, melamine and cobalt chloride at 600 under nitrogen atmosphere for 2 h. The catalytic activity of CoMe/C is characterized by the electrochemical linear sweep voltammetry technique. The onset reduction potential of the catalyst is 0.55 V （vs. SCE） at a scanning rate of 5 mV/s in 0.5 mol/L H2SO4 solution. The formation of the ORR activity sites of CoMe/C is facilitated by metallic β- cobalt.

关键词： Oxygen reduction Non-precious metal catalyst Preparation Mechanical method

Can serum immunoglobulin G4 levels and age serve as reliable predictors of relapse in autoimmune pancreatitis?

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World Journal of Gastroenterology 2024年第5期30卷 512-515页

作者： jun-Min Song si-yu Sun Department of Gastroenterology Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

We are writing in response to the paper published in the World Journal of Gastroenterology by Zhou et *** authors identified higher serum immunoglobulin(Ig)G4 levels and age over 55 years as independent risk factors for disease *** notable strengths,it is crucial to address potential ***,the cohort study included 189 patients with autoimmune pancreatitis(AIP)type 1(with higher IgG4 seropositivity and higher relapse)and 24 with type 2(with lower IgG4 seropositivity and lower relapse).Consequently,most,if not all,AIP type 2 patients were assigned to the normal group,possibly inflating the association of higher serum IgG4 levels with relapse and potentially exaggerating the association of older age with ***,the authors did not provide sufficient details regarding AIP diagnosis,such as the ratio of definitive vs probable cases and the proportion of *** cases where histological evidence is unavailable or indeterminate,AIP type 2 may be misdiagnosed as definitive type 1,and type 1 may also be misdiagnosed as probable type 2,particularly in cases with normal or mildly elevated serum IgG4 ***,in this retrospective study,approximately one-third of the consecutive patients initially collected were excluded for various ***,the impact of nonrandom exclusion on relapse outcomes should be carefully *** conclusion,the paper by Zhou et al offers plausible,though not entirely compelling,evidence suggesting a predictive role of elevated serum IgG4 levels and advanced age in AIP *** foundation for future investigations lies in ensuring a reliable diagnosis and accurate disease subtyping,heavily dependent on obtaining histological *** this regard,endoscopic ultrasound-guided fine-needle biopsy emerges as a pivotal component of the diagnostic process,contributing to mitigating biases in future explorations of the disease.

关键词： Autoimmune pancreatitis Immunoglobulin Endoscopic ultrasound Relapse Age

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

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Nuclear Science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-jun Wang si-Sheng Wang Zheng-Huang Su Li yu yu-Zhu Wang Bo Sun Wen Wen Xing-yu Gao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of Science Beijing100049China

A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2 μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2 M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2 M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.

关键词： Crystallography White-beam Laue microdiffraction Beamline Synchrotron

Carbon dots-derived three-dimensional-ordered macroporous host with high penetrability and catalytic activity for LSBs under lean electrolyte

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Rare Metals 2024年第6期43卷 2560-2573页

作者： Jiao-Zi Duan Hua-yu Pei Quan Yang Xue Li Xin Ba Xue Yong jun-Ling Guo si-yu Lu Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China Country State Center for International Cooperation On Designer Low-Carbon&Environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Hubei Institute of Quality Supervision Inspection Wuhan 430061China Department of Chemistry University of SheffieldSheffeld S37HFUK

The practical energy density of lithium-sulfur batteries(LSBs)is seriously limited by the high electrolyte-to-sulfur ratios(E/S).The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures the uniform distribution of a lean electrolyte and high catalytic activity that can suppress"shuttle effect"via accelerating the slow conversion of soluble poly sulfides to insoluble *** the easy-to-infiltrate structures,the three-dimensional-ordered macroporous(3DOM)structure is easier to scale preparation and more suitable for the existing industrial ***,it is difficult to obtain the 3DOM with(1)high penetrability due to the high viscosity of frequently-used organic polymer precursors and(2)high catalytic activity due to the low confinement effect,meaning that uniformly dispersed small-sized catalytic materials are difficult to load on ***,using carbon dots(CDs)with both organic and inorganic properties as a precursor and aggregation limiting agent,a 3DOM host with high penetrability and homodispersed Ni particles of small sizes(Ni-CDs-3DOM)was *** this host:(1)CDs precursor with suitable viscosity can improve the penetrability.(2)CDs can effectively inhibit the agglomeration of Ni particles.(3)Uniformly dispersed small-size Ni particles offer high-efficiency catalytic activity toward sulfur ***,the Ni-CDs-3DOM/sulfur cathode exhibits high sulfur utilization and stable cycling performance even under high sulfur loading(5.5 mg·cm^(-2))and low E/S(6.5μl·mg^(-1)).This work indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.

关键词： Lithium-sulfur batteries Carbon dots Catalytic action Easy-to-infiltrate structure Lean electrolyte

Energy-efficient buffer and service rate allocation in manufacturing systems using hybrid machine learning and evolutionary algorithms

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Advances in Manufacturing 2024年第2期12卷 227-251页

作者： si-Xiao Gao Hui Liu jun Ota Key Laboratory of Traffic Safety on Track of Ministry of Education Institute of Artificial Intelligence and Robotics(IAIR)School of Traffic and Transportation EngineeringCentral South UniversityChangsha410075People’s Republic of China Research into Artifacts Center for Engineering School of EngineeringThe University of TokyoTokyoJapan

Currently,simultaneous buffer and service rate allocation is a topic of interest in the optimization of manufacturing *** allocation problems have been solved previously to satisfy economic requirements;however,owing to the progress of green manufacturing,energy conservation and environmental protection have become increasingly ***,an energy-efficient approach is developed to maximize the throughput and minimize the energy consumption of manufacturing systems,subject to the total buffer capacity,total service rate,and predefined energy *** energy-efficient approach integrates the simulated annealing-non-dominated sorting genetic algorithm-II with the honey badger algorithm-histogram-based gradient boosting regression *** former algorithm searches for Pareto-optimal solutions of sufficient *** latter algorithm builds prediction models to rapidly calculate the throughput,energy consumption,and energy *** examples show that the proposed hybrid approach can achieve a better solution quality compared with previously reported ***,the prediction models can rapidly evaluate manufacturing systems with sufficient *** study benefits the multi-objective optimization of green manufacturing systems.

关键词： Energy-efficient allocation Multi-objective optimization Energy efficiency Energy consumption Machine learning

Operando measurement of lattice deformation profiles of synchrotron radiation monochromator

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Nuclear Science and Techniques 2024年第7期35卷 8-19页

作者： yue Zhang Zhong-Liang Li Shang-yu si Lian Xue Hong-Xin Luo Xiao-Wei Zhang jun Hu Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China ShanghaiTech University Shanghai201210China University of the Chinese Academy of Sciences Beijing100049China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of ScienceBeijing100049China

This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident *** nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond *** diagrams of the 333 diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the *** increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/*** maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 *** on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident *** study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.

关键词： Synchrotron radiation Monochromator Lattice deformation X-ray dynamic diffraction

Homochirality in Ferroelectrochemistry

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Chinese Journal of Chemistry 2024年第10期42卷 1133-1144页

作者： Hang Peng jun-Chao Qi yu-si Liu Jia-Mei Zhang Wei-Qiang Liao Ren-Gen Xiong Ordered Matter Science Research Center Nanchang UniversityNanchangJiangxi 330031China

What is the most favorite and original chemistry developed in your research group?We originally proposed the design principle for molecular ferroelectrics:ferroelectrochemistry,including quasi-spherical theory,the introduction of homochirality,and H/F *** changed the blind search for molecular ferroelectrics into targeted chemical design,which will develop into a new discipline.

关键词： Molecular ferroelectrics Homochirality Ferroelectricity Chemical design Point groups

Research on the solid particle erosion wear of pipe steel for hydraulic fracturing based on experiments and numerical simulations

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Petroleum Science 2024年第04期21卷 2779-2792页

作者： si-Qi Yang Jian-Chun Fan Ming-Tao Liu De-Ning Li jun-Liang Li Li-Hong Han Jian-jun Wang Shang-yu Yang si-Wei Dai Lai-Bin Zhang State Key Laboratory of Oil and Gas Equipment CNPC Tubular Goods Research Institute Key Laboratory of Oil and Gas Safety and Emergency Technology China University of Petroleum Oil Production Technology Research Institute of Liaohe Oilfield Company Tianjin Gas Storage Branch PetroChina Dagang Oilfield Company Petroleum Production Engineering Research Institute Daqing Oilfield Company

Erosion wear is a common failure mode in the oil and gas industry. In the hydraulic fracturing, the fracturing pipes are not only in high-pressure working environment, but also suffer from the impact of the high-speed solid particles in the fracturing fluid. Beneath such complex conditions, the vulnerable components of the pipe system are prone to perforation or even burst accidents, which has become one of the most serious risks at the fracturing site. Unfortunately, it is not yet fully understood the erosion mechanism of pipe steel for hydraulic fracturing. Therefore, this article provides a detailed analysis of the erosion behavior of fracturing pipes under complex working conditions based on experiments and numerical simulations. Firstly, we conducted erosion experiments on AIsi 4135 steel for fracturing pipes to investigate the erosion characteristics of the material. The effects of impact angle, flow velocity and applied stress on erosion wear were comprehensively considered. Then a particle impact dynamic model of erosion wear was developed based on the experimental parameters, and the evolution process of particle erosion under different impact angles, impact velocities and applied stress was analyzed. By combining the erosion characteristics, the micro-structure of the eroded area, and the micro-mechanics of erosion damage, the erosion mechanism of pipe steel under fracturing conditions was studied in detail for the first time. Under high-pressure operating conditions, it was demonstrated through experiments and numerical simulations that the size of the micro-defects in the eroded area increased as the applied stress increased, resulting in more severe erosion wear of fracturing pipes.

关键词： Erosion wear Applied stress Particle impact dynamics Erosion mechanism

Topological Stability and Entropy for Certain Set-valued Maps

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Acta Mathematica sinica,English Series 2024年第4期40卷 962-984页

作者： yu ZHANG yu jun ZHU School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this paper,the dynamics(including shadowing property,expansiveness,topological stability and entropy)of several types of upper semi-continuous set-valued maps are mainly considered from differentiable dynamical systems points of *** is shown that(1)if f is a hyperbolic endomorphism then for eachε>0 there exists a C^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has theε-shadowing property,and moreover,if f is an expanding endomorphism then there exists a C^(1)-neighborhood U of f such that the induced set-valued map F_(f,U)has the Lipschitz shadowing property;(2)when a set-valued map F is generated by finite expanding endomorphisms,it has the shadowing property,and moreover,if the collection of the generators has no coincidence point then F is expansive and hence is topologically stable;(3)if f is an expanding endomorphism then for eachε>0 there exists a C^(1)-neighborhood U of f such that h(F_(f,U,ε))=h(f);(4)when F is generated by finite expanding endomorphisms with no coincidence point,the entropy formula of F is ***,the dynamics of the set-valued maps based on discontinuous maps on the interval are also considered.

关键词： Set-valued map orbit space hyperbolic endomorphism perturbation shadowing expansiveness topological stability entropy