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Effect of Central Multiphase Microstructure of Thick Plates on Work Hardening and Crack Propagation

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 325-338页

作者： Lei hu Liqin Zhang feng hu Kuan zheng Guohong Zhang Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan430081China Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081China Analysis and Testing Center Wuhan University of Science and TechnologyWuhan430081China

The effect of multiphase microstructure in the center segregation zones(CSZ)of high-strength steel thick plates on work hardening characteristics and crack initiation/propagation were *** was correlated with deformation damage behavior by using Taylor factor(TF)gradients,kernel average misorientation(KAM),and geometric necessary dislocation(GND)*** results show that the segregation leads to a mixed structure of ferrite(soft phase)and martensite/bainite(hard phase)in the center of the thick *** to the 1/4 thickness(1/4 T)region,grain refinement occurred in the CSZ,with KAM values increasing from 0.24 to 0.49 and a decrease in the proportion of high-angle grain boundaries(>15°)from 77.4 to 51.8%.In the process of deformation,due to the influence of grain refinement and adjacent martensite/bainite,ferrite grains were divided into structural units with different TF *** higher KAM value and GND density at the interface between soft/hard phases resulted in severe work *** addition,the presence of micron-sized inclusions in the CSZ caused local strain concentration and non-continuous deformation of the matrix,which induced crack *** fracture surface showed a mixed mode of brittle cleavage fracture and ductile fracture.

关键词： Thick plate Center segregation zone Multiphase microstructure Taylor factor Crack propagation

Enhanced Kerr Nonlinearities Caused by Cross Talk Between Optical and Microwave Transitions

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Communications in Theoretical Physics 2008年第10期50卷 961-964页

作者： hu zheng-feng DENG Jian-Liao DU Chun-Guang WANG Yu-Zhu The Key Laboratory of Quantum Optics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Science Shanghai 201800 China Department of Physics Tsinghua University Beijing 100084 China

We investigate the enhanced Kerr nonlinearities in four-level atomic vapors driven by a coupling,probe andmicrowave *** the optical one-photon and two-photon resonant conditions,the linear and nonlinear responsesof the weak probe field can be modified by the cross talk among optical and microwave *** enhanced Kerrnonlinearity can form bright optical solitons of the probe field.

关键词： cross-phase modulation Kerr nonlinearity atom-field interaction

厌氧颗粒污泥高效反硝化处理高盐度树脂再生液

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中国给水排水 2024年第7期40卷 19-26页

作者：李忠强骆倩黄慧敏梅荣武胡正峰张胜军浙江省生态环境科学设计研究院浙江杭州310007 浙江师范大学地理与环境科学学院浙江金华321019 浙江环科环境研究院有限公司浙江杭州310007 国家环境保护水污染控制工程技术<浙江>中心浙江省环境污染控制技术研究重点实验室浙江杭州310007

针对目前离子交换树脂再生液高盐度的问题,在上流式污泥床反应器内接种厌氧颗粒污泥,采用连续进水的方式逐步提高进水NO_(3)^(-)-N负荷和盐度,对污泥进行驯化。优化反应器运行参数,得到最适盐度为2.0%、HRT为12 h、C/N为3.3、上升流速为... 详细信息

针对目前离子交换树脂再生液高盐度的问题,在上流式污泥床反应器内接种厌氧颗粒污泥,采用连续进水的方式逐步提高进水NO_(3)^(-)-N负荷和盐度,对污泥进行驯化。优化反应器运行参数,得到最适盐度为2.0%、HRT为12 h、C/N为3.3、上升流速为1.5 m/h。在该参数下TN去除率达90%以上,出水TN低于10 mg/L,极限脱氮与再生液处理混合出水TN<1.5 mg/L,达到地表水Ⅳ类标准,处理费用为0.587元/m^(3)。对运行前中后期的颗粒污泥进行电镜和高通量测序,污泥表面杆状菌明显增多,变形菌门占比随时间增加,反硝化杆菌逐渐成为优势菌种。该城镇污水处理厂尾水树脂极限脱氮及高盐度再生液处理技术经济高效,为树脂再生废水的处理提供了新的选择。

关键词：树脂再生液颗粒污泥反硝化高盐度微生物群落

Fracture mechanism of inclusions in thick plate center under tensile loading

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Journal of Iron and Steel Research International 2024年第5期31卷 1196-1209页

作者： Lei hu Li-qin Zhang feng hu Guo-hong Zhang Kuan zheng Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan430081HubeiChina Department of Applied Physics Wuhan University of Science and TechnologyWuhan430081HubeiChina Analysis and Testing Center Wuhan University of Science and TechnologyWuhan430081HubeiChina

Segregation of solute atoms in the center of thick plates of the tempered steel can cause an inhomogeneous structural transformation and generate micron-sized inclusions,which leads to lamellar tearing of thick plate and decreases the plasticity and *** formation and fragmentation mechanisms of micron-sized inclusions,like MnS and(Nb,Ti)C,in the center of thick plates were investigated by using thermodynamic calculations,finite element simulations,and electron backscatter diffraction characterization *** results show that micron-sized inclusions nucleate and grow in the liquid phase,and under tensile loading,they exhibit three fragmentation *** local stress during the fragmentation of inclusions is lower than the critical fracture stress of adjacent grains,and phase boundaries can effectively impede crack propagation into the *** existence of a low proportion of high-angle grain boundaries(58.1%)and high Kernel average misorientation value(0.534°)in the segregation band promotes inclusions fragmentation and crack *** difference in crack initiation and propagation direction caused by the morphology of inclusions and physical properties,as well as different matrix arrest abilities,is the main reasons for the diversity of inclusion fragmentation.

关键词： Thick plate Inclusion Finite element simulation Critical fracture stress Fracture mechanism

Interference of a Narrowband Biphoton with Double Electromagnetically Induced Transparency in an N-Type System

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Chinese Physics Letters 2012年第4期29卷 75-78页

作者： CHEN Peng QIAN Jun CHEN Dong-Yuan hu zheng-feng WANG Yu-Zhu Key Laboratory for Quantum Optics Center for Cold Atom PhysicsShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800 Robert R.McCormick School of Engineering and Applied Science Northwestern UniversityEvanstonIllinois 60208USA

We predict the possibility of the interference of narrow-band biphotons generated by spontaneous four-wave mixing with double electromagnetically induced transparency configuration in cold *** an N-type fourlevel system,an auxiliary optical field Ωm can create double transparency windows for anti-Stokes *** the slow light effects in the double transparency windows are very strong,two four-wave mixing channels could exist due to the splitting of the phase matching *** biphoton generated from the two four-wave mixing channels can cause interference and shows Rabi oscillations in two-photon *** interference mechanism will complement the understanding of interference at the two-photon level.

关键词： transparency mixing photon

Construction of Pd-doped RuO_(2) nanosheets for efficient and stable acidic water oxidation

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Green Energy & Environment 2024年第6期9卷 937-948页

作者： Yibo Liu Xing hu Chenxi Liu Shan Zhu Kezhu Jiang feng Liu Shijian zheng Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology College of Materials Science and EngineeringHebei University of TechnologyTianjin300401China Yunnan Precious Metals Lab Co. LTDKunming650100China

RuO_(2) has been considered a potential alternative to commercial IrO_(2) for the oxygen evolution reaction(OER)due to its superior intrinsic ***,its inherent structure dissolution in acidic environments restricts its commercial *** this study,we report a novel Pd-doped ruthenium oxide(Pd–RuO_(2))nanosheet catalyst that exhibits improved activity and stability through a synergistic effect of Pd modulation of Ru electronic structure and the two-dimensional *** catalyst exhibits excellent performance,achieving an overpotential of only 204 mVat a current density of 10 mA cm^(-2).Impressively,after undergoing 8000 cycles of cyclic voltammetry testing,the overpotential merely decreased by 5 *** PEM electrolyzer with Pd0.08Ru0.92O_(2) as an anode catalyst survived an almost 130 h operation at 200 mA cm^(-2).To elucidate the underlying mechanisms responsible for the enhanced stability,we conducted an X-ray photoelectron spectroscopy(XPS)analysis,which reveals that the electron transfer from Pd to Ru effectively circumvents the over-oxidation of Ru,thus playing a crucial role in enhancing the catalyst's ***,density functional theory(DFT)calculations provide compelling evidence that the introduction of Pd into RuO_(2) effectively modulates electron correlations and facilitates the electron transfer from Pd to Ru,thereby preventing the overoxidation of ***,the application of the two-dimensional structure effectively inhibited the aggregation and growth of nanoparticles,further bolstering the structural integrity of the catalyst.

关键词： Oxygen evolution reaction Pd-doped ruthenium oxide Two-dimensional structure Electron transfer Stability

Gain and Absorption of a Probe Light in an Open Tripod Atomic System

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Chinese Physics Letters 2012年第5期29卷 122-125页

作者： hu zheng-feng LIN Jin-Da DENG Jian-Liao HE hui-Juan WANG Yu-Zhu The Key Laboratory of Quantum Optics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

We theoretically investigate an open four-level atomic system interacting with control,probe and microwave *** there is no repumping light and a microwave field is applied,the probe light can be absorbed or amplified,which has different features than those of a system whose populations are pumped into only one ground *** this system the microwave field and the population distributions of the ground states can be used as switches to control the propagation of the probe light.

关键词： pumped pumping microwave

A CNN-SVR model for NO_(2)profile prediction based on MAX-DOAS observations:The influence of Chinese New Year overlapping the 2020 COVID-19 lockdown on vertical distributions of tropospheric NO_(2)in Nanjing,China

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Journal of Environmental Sciences 2024年第7期141卷 151-165页

作者： Xin Tian Zijie Wang Pinhua Xie Jin Xu Ang Li Yifeng Pan feng hu Zhaokun hu Mingsheng Chen Jiangyi zheng Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key laboratory of Environmental Optical and Technology Anhui Institute of optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China

In this study,a hybrid model,the convolutional neural network-support vector regression model,was adopted to achieve prediction of the NO_(2)profile in Nanjing from January 2019to March *** the sudden decline in NO_(2)in February 2020,the contribution of the Coronavirus Disease-19(COVID-19)lockdown,Chinese New Year(CNY),and meteorologi cal conditions to the reduction of NO_(2)was ***_(2)vertical column densities(VCDs) from January to March 2020 decreased by 59.05%and 32.81%,relative to the same period in 2019 and 2021,*** the period of 2020 COVID-19,the average NO_(2)VCDs were 50.50%and 29.96%lower than those during the pre-lockdown and post-lockdown pe riods,*** NO_(2)volume mixing ratios(VMRs)during the 2020 COVID-19 lock down significantly decreased below 400 *** NO_(2)VMRs under the different wind fields were significantly lower during the lockdown period than during the pre-lockdown period This phenomenon could be attributed to the 2020 COVID-19 *** NO_(2)VMRs be fore and after the CNY were significantly lower in 2020 than in 2019 and 2021 in the same period,which further proves that the decrease in NO_(2)in February 2020 was attributed to the COVID-19 *** source analysis of an NO_(2)pollution episode during the lockdown period showed that the polluted air mass in the Beijing-Tianjin-Hebei was trans ported southwards under the action of the north wind,and the subsequent unfavorable meteorological conditions(local wind speed of<2.0 m/sec)resulted in the accumulation o pollutants.

关键词： MAX-DOAS CNN-SVR Nitrogen dioxide COVID-19 Chinese New Year Regional transport

High-frequency repetitive transcranial magnetic stimulation promotes neural stem cell proliferation after ischemic stroke

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Neural Regeneration Research 2024年第8期19卷 1772-1780页

作者： Jing Luo Yuan feng Zhongqiu Hong Mingyu Yin Haiqing zheng Liying Zhang Xiquan hu Department of Rehabilitation Medicine The Third Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Hepatobiliary Surgery The Third Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Prolife ration of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction *** magnetic stimulation(TMS)has recently emerged as a tool for inducing endogenous neural stem cell regeneration,but its underlying mechanisms remain unclea r In this study,we found that repetitive TMS effectively promotes the proliferation of oxygen-glucose deprived neural stem ***,repetitive TMS reduced the volume of cerebral infa rction in a rat model of ischemic stro ke caused by middle cerebral artery occlusion,im p roved rat cognitive function,and promoted the proliferation of neural stem cells in the ischemic ***-sequencing found that repetitive TMS activated the Wnt signaling pathway in the ischemic penumbra of rats with cerebral ***,PCR analysis revealed that repetitive TMS promoted AKT phosphorylation,leading to an increase in mRNA levels of cell cycle-related proteins such as Cdk2 and *** effect was also associated with activation of the glycogen synthase kinase 3β/β-catenin signaling pathway,which ultimately promotes the prolife ration of neural stem ***,we validated the effect of repetitive TMS on AKT *** found that repetitive TMS promoted Ca2+influx into neural stem cells by activating the P2 calcium channel/calmodulin pathway,thereby promoting AKT phosphorylation and activating the glycogen synthase kinase 3β/β-catenin *** findings indicate that repetitive TMS can promote the proliferation of endogenous neural stem cells through a Ca2+influx-dependent phosphorylated AKT/glycogen synthase kinase 3β/β-catenin signaling *** study has produced pioneering res ults on the intrinsic mechanism of repetitive TMS to promote neural function recove ry after ischemic stro *** results provide a stro ng scientific foundation for the clinical application of repetitive ***,repetitive TMS treatment may not only be an efficient an

关键词： AKT/β-catenin signaling brain stimulation Ca2+influx cell proliferation ischemic stroke middle cerebral artery occlusion neural stem cells neurological rehabilitation repetitive transcranial magnetic stimulation