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Improving hydrogen embrittlement resistance of a modified press hardening steel by introducing retained austenite as hydrogen trap

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Journal of Iron and Steel Research International 2022年第11期29卷 1864-1872页

作者： wei Ding kai yang Yu Gong Li Wang Ji-yao Hong wei Li Xue-jun Jin Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Institute of Advanced Steels and Materials School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Development and Application Technology of Automotive Steels BaoSteel Research InstituteShanghai 201900China

The effect of retained austenite(RA)with higher mechanical stability on hydrogen embrittlement resistance of a modified 22MnB5(C 0.22,Si 0.8,Mn 1.5,B 0.002,Fe balance,in wt.%)press hardening steel(PHS)has been ***-step quenching and partitioning(Q&P)treatment was applied to PHS,and around 6 vol.%ultra-fine RA was *** ultra-fine RA was found to act as stronger hydrogen trap than dislocations and grain boundaries in martensitic matrix and can decrease the apparent diffusion coefficient of hydrogen from 5.97×10^(-7) to 3.83×10^(-7) cm^(2) s^(-1),which was verified by the combination of thermal desorption spectroscopy analysis and hydrogen permeation *** higher mechanical stability of the ultrafine RA assures enough stability of the hydrogen trap,which results in better hydrogen embrittlement resistance in Q&P-treated PHS than the conventional directly quenched PHS.

关键词： Hydrogen embrittlement Press hardening steel Quenching and partitioning Retained austenite Thermal desorption spectroscopy Hydrogen permeation

Observation of double pseudowaves in an ion-beam-plasma system

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Chinese Physics B 2018年第8期27卷 350-355页

作者： Zi-An wei Jin-Xiu Ma kai-yang Yi Department of Modern Physics and CAS Key Laboratory of Geospace Environment University of Science and Technology of ChinaHefei 230026China

Pseudowaves, known as burst-ion signals, which are different from plasma normal modes, exist frequently in ion- wave excitation experiments when launching the waves by applying a pulsed voltage to a negatively biased grid. In previous experiments, only one kind of the pseudowave was observed. In this paper, we report the observation and identification of double pseudowaves in an ion-beam-plasma system. These pseudowaves originate from two ion groups： the burst of the beam ions and the burst of the background ions. It was observed that the burst of the background ions was in the case of high ion beam energy, while the burst of the beam ions was in the case of low ion beam energy. By observing the dependence of the signal velocities on the characteristics of the excitation voltage, these pseudowaves can be identified. It was also observed that the burst ion signal originating from the background ions can interact with slow beam mode and that originating from the beam ions can interact with fast beam mode.

关键词： ion-beam-plasma system normal modes pseudowaves wave-particle interaction

Homogeneous distributed natural pyrite-derived composite induced by modified graphite as high-performance lithium-ion batteries anode

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International Journal of Minerals,Metallurgy and Materials 2023年第7期30卷 1353-1362页

作者： Juan Yu Yinbo wei Bicheng Meng Jiaxin Peng kai yang Tianxing Chen Naixing yang Xiuyun Chuan School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China School of Earth and Space Sciences Peking UniversityBeijing 100871China Shaanxi Key Laboratory of Nano-Materials and Technology School of Mechanical and Electrical EngineeringXi’an University of Architecture and TechnologyXi’an 710055China School of Resources Engineering Xi’an University of Architecture TechnologyXi’an 710055China

Natural minerals-based energy materials have attracted enormous attention because of the advantages of good materials consistency,high production,environmental friendliness,and low *** uniform distribution of grains can effectively inhibit the aggregation of active materials,improving lithium storage *** this work,natural graphite is modified by polyvinylpyrrolidone to obtain modified graphite with reduced size and better *** pyrite composite polyvinylpyrrolidone-modified graphite(pyrite/PG)material with uniform particle distribution is obtained by the ball milling *** subsequent calcination process converts pyrite/PG into Fe_(1-x)Scompounded with polyvinylpyrrolidone-modified graphite(Fe_(1-x)S/PG).The homogeneous grain distributions of active material can facilitate the faster transfer of electrons and promote the efficient utilization of active *** as-prepared Fe_(1-x)S/PG electrode exhibits a remarkably reversible specific capacity of 613.0 mAh·g^(-1)at 0.2 A·g^(-1)after 80 cycles and an excellent rate capability of 523.0 mAh·g^(-1)at 5 A·g^(-1).Even at a higher current density of 10 A·g^(-1),it can deliver a specific capacity of 348.0 mAh·g^(-1).Moreover,the dominant pseudocapacitance in redox reactions accounts for the impressive rate and cycling *** work provides a low-cost and facile method to fabricate natural mineral-based anode materials and apprise readers about the impact of uniform particle distribution on lithium storage performance.

关键词： natural pyrite modified graphite anode lithium-ion batteries homogeneous grain distributions

A regularization algorithm for estimating the multimodal size distribution of nanoparticles from multiangle dynamic light scattering

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Particuology 2018年第6期16卷 30-39页

作者： Lei Li Kecheng yang wei Li kai Li Long Yu Min Xia School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Wuhan University Scientific Journals Press Wuhan 430072China

The multiangle dynamic light scattering (MDLS)technique provides more robust,reproducible,and accu- rate particle size distributions (PSDs)than single-angle dynamic light ***,in MDLS,the determination of peak locations is difficult but significant,particularly for multimodal *** this paper,a self-adaptive algorithm,the iterative recursion nonnegative Tikhonov-Phillips-Twomey (IRNNT-PT)algorithm,is proposed for the estimation of the PSD from MDLS *** algorithm optimizes the weighting coefficients,distinguishes features of PSDs and chooses the optimal inversion method from two regularization algorithms *** simulations and experimental results for unimodal and multimodal distributions are presented to demonstrate both the validity and noise immunity of the IRNNT-PT algorithm,and demonstrate that the proposed algorithm can be well applied to reconstruct PSDs from MDLS measurements.

关键词： Dynamic light scattering Particle size distribution Inverse scattering Mie theory Scattering measurements

Synthesis and Characteristics of Fe_3C Nanoparticles Embedded in Amorphous Carbon Matrix

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Chemical Research in Chinese Universities 2010年第3期26卷 348-351页

作者： yang kai-yu XU wei ZHANG Yu ZHENG wei-tao WANG Xin Center of Test Science State Key Laboratory of lnorganic Synthesis and Preparative Chemistry College of Chemistry Key Laboratory of Automobile Materials Ministry of Education College of Materials Science and Engineering Jilin University Changchun 130012 P R. China

We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images show the existence of nanometric dark grains（Fe3C） embedded in a light matrix（amorphous carbon） in the samples. X-ray photoelectron spectroscopy experiment exhibit that the chemical bonding state in the films corresponded to sp3/sp2 amorphous carbon, sp^3 C-N（287.3 eV） and C15 in Fe3C（283.5 eV）. With increasing deposition time, the ratio of amorphous carbon increased. The magnetic measurements show that the value of in-lane coercivity increased with increasing carbon matrix concentration（from about 6.56× 10^3 A/m for film without carbon structures to approximately 2.77× 10^4 and 5.81 × 10^4 AJm for nanocomposite films at room temperature and 10 K, respectively）. The values of saturation magnetization for the synthesized nanocomposites were lower than that of the bulk Fe3C （ 140 Am^2/kg）.

关键词： Fe3C nanoparticle Amorphous carbon Plasma enhancement chemical vapor deposition(PECVD) Magnetic property

Insight into Biophysicochemical Principles of Biopolymers through Simulation and Theory

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Chinese Journal of Polymer Science 2023年第9期41卷 1342-1354,I0005页

作者： Hai-Xiao Wan Duo Xu Xue-wei Dong kai yang Li-Tang Yan State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing100084China Center for Soft Condensed Matter Physics and Interdisciplinary Research&School of Physical Science and Technology Soochow UniversitySuzhou215006China

The development of biopolymers for biomedical applications has traditionally been based on new ***,there is growing recognition that the biological responses can be regulated by the physical as well as the chemical properties of *** the biophysicochemical principles regarding biopolymers is thereby of great importance in the generation of advanced ***,this review article seeks to provide a conceptual framework demonstrating how the approaches of tailored computer simulations and theoretical analysis are harnessed to explore the physicochemical principles of biopolymer cellular *** briefly introduce the theoretical and simulation methods used in this field,summarize the typical findings based on these approaches,and describe the correlations between theoretical results and ***,the future prospects for the theoretical aspect of biopolymers and their biophysicochemical interactions are *** knowledge might be critical from the perspective of advantageous and safe use of designer biomaterials.

关键词： Biopolymers Computer simulation Theoretical analysis Biophysicochemical interaction Biophysics

Mesenchymal stem/stromal cells-derived exosomes for osteoporosis treatment

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World Journal of Stem Cells 2023年第3期15卷 83-89页

作者： kai-Lun Huo Tie-Yi yang wei-wei Zhang Jin Shao Postgraduate Training Base in Shanghai Gongli Hospital Ningxia Medical UniversityYinchuan 750004the Ningxia Hui Autonomous RegionChina Department of Orthopedics Pudong New Area Gongli HospitalSchool of Medical TechnologyUniversity of Shanghai for Science and TechnologyShanghai 200135China Department of Urology Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China

Osteoporosis is a systemic bone disease,which leads to decreased bone mass and an increased risk of fragility ***,there are many anti-resorption drugs and osteosynthesis drugs,which are effective in the treatment of osteoporosis,but their usage is limited due to their contraindications and side *** regenerative medicine,the unique repair ability of mesenchymal stem cells(MSCs)has been favored by *** exosomes secreted by MSCs have signal transduction and molecular delivery mechanisms,which may have therapeutic *** this review,we describe the regulatory effects of MSCs-derived exosomes on osteoclasts,osteoblasts,and bone *** aim to summarize the preclinical studies of exosome therapy in ***-ermore,we speculate that exosome therapy can be a future direction to improve bone health.

关键词： Mesenchymal stem cells Exosome Osteoporosis Osteoblasts Osteoclasts Bone immunity

Predicting gas-bearing distribution using DNN based on multi-component seismic data: Quality evaluation using structural and fracture factors

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Petroleum Science 2022年第4期19卷 1566-1581页

作者： kai Zhang Nian-Tian Lin Jiu-Qiang yang Zhi-wei Jin Gui-Hua Li Ren-wei Ding College of Earth Sciences and Engineering Shandong University of Science and TechnologyQingdaoShandong266590China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong266237China

The tight-fractured gas reservoir of the Upper Triassic Xujiahe Formation in the Western Sichuan Depression has low porosity and permeability. This study presents a DNN-based method for identifying gas-bearing strata in tight sandstone. First, multi-component composite seismic attributes are *** strong nonlinear relationships between multi-component composite attributes and gas-bearing reservoirs can be constrained through a DNN. Therefore, we identify and predict the gas-bearing strata using a DNN. Then, sample data are fed into the DNN for training and testing. After optimized network parameters are determined by the performance curves and empirical formulas, the best deep learning gas-bearing prediction model is determined. The composite seismic attributes can then be fed into the model to extrapolate the hydrocarbon-bearing characteristics from known drilling areas to the entire region for predicting the gas reservoir distribution. Finally, we assess the proposed method in terms of the structure and fracture characteristics and predict favorable exploration areas for identifying gas reservoirs.

关键词： Multi-component seismic exploration Tight sandstone gas reservoir prediction Deep neural network(DNN) Reservoir quality evaluation Fracture prediction Structural characteristics

Piezoresistive behavior of elastomer composites with segregated network of carbon nanostructures and alumina

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Nano Materials Science 2023年第3期5卷 312-318页

作者： Chun-Yan Tang Lei Liu kai Ke Bo Yin Ming-Bo yang wei yang College of Polymer Science and Engineering Sichuan UniversityState Key Laboratory of Polymer Materials EngineeringChengdu610065SichuanChina

Electrically conductive elastomer composites(CECs)with segregated networks of conductive nanofillers show high potential in stretchable strain sensors due to balanced mechanical and electrical properties,yet the sensitivity at low strain is generally insufficient for practical ***,we report an easy and effective way to improve the resistive response to low strain for CECs with segregated network structure via adding stiff alumina into carbon nanostructures(CNS).The CEC containing 0.7 wt%CNS and 5 wt%Al_(2)O_(3) almost sustains the same elasticity(elongation at break of~900%)and conductivity(0.8 S/m)as the control,while the piezoresistive sensitivity is significantly *** polyurethane(TPU)composites with a segregated network of hybrid nanofillers(CNS and Al_(2)O_(3))show much higher strain sensitivity(Gauge factor,GF-566)at low strain(45%strain)due to a local stress concentration effect,this sensitivity is superior to that of TPU/CNS composites(GF-11).Such a local stress concentration effect depends on alumina content and its distribution at the TPU particle *** addition,CECs with hybrid fillers show better reproducibility in cyclic piezoresistive behavior testing than the *** work offers an easy method for fabricating CECs with a segregated filler network offering stretchable strain sensors with a high strain sensitivity.

关键词： Thermoplastic polyurethane Carbon nanostructures Alumina Conductive elastomer composites Stretchable strain sensor