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Effect of precipitates on high-temperature strength and irradiation behavior of vanadium-based alloys

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Journal of Iron and Steel Research(International) 2018年第12期25卷 1270-1277页

作者： Shao-ning Jiang Li-qun Xu fa-rong wan School of Mechanical and Automotive Engineering Qilu University of Technology (Shandong Academy of Science) Jinan 250353ShandongChina School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

The formation of precipitates and their effect on mechanical properties and irradiation damage in V-4CraTi alloys have been investigated using transmission electron microscope,high-temperature tensile tests and high-voltage electron microscope (HVEM).V-4Cr-4Ti alloys were aged for 20-40 h at 873 K,and extremely fine precipitates were produced during the aging process,which coarsened with aging *** results of high-temperature (773,873 and 973 K)tensile tests showed an increase in strength with increasing aging time (i.e:,increasing size of precipitates)while a decrease in the uniform *** was evidence that presence of precipitates strengthened V-4Cr-4Ti *** situ HVEM observations showed that the precipitates restricted the growth rate of dislocation loops induced during electron irradiation at 773 *** interactions between precipitates and irradiation-induced dislocation loops were *** presence of particles alleviated the increase in irradiation hardening up to an irradiation dose of 3.42 dpa (displacement per atom).The precipitates shrank in size during electron irradiation,which was due to the dissolution of constituent atoms of the precipitates into the alloy matrix.

关键词： Aging Precipitate strengthening Electron irradiation Irradiation defect Dislocation loop

Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

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China Ocean Engineering 2024年第2期38卷 271-284页

作者： ZHOU Li wanG Guo-rong wan Min School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China Energy Equipment Institute Southwest Petroleum UniversityChengdu 610500China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental *** control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control ***,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each *** direction interference observers are designed to track the timevarying boundary *** this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead *** addition,the stability of the closed-loop system is proven by Lyapunov stability *** the system states are bounded,and the vibration offset of the riser converges to a small area of the initial ***,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

关键词： adaptive backstepping control disturbance observer flexible marine riser input dead zone vibration control

Transcriptional regulation in the development and dysfunction of neocortical projection neurons

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Neural Regeneration Research 2024年第2期19卷 246-254页

作者： Ningxin wang rong wan Ke Tang Precise Genome Engineering Center School of Life SciencesGuangzhou UniversityGuangzhouGuangdong ProvinceChina

Glutamatergic projection neurons generate sophisticated excitatory circuits to integrate and transmit information among different cortical areas,and between the neocortex and other regions of the brain and spinal *** development of cortical projection neurons is regulated by certain essential events such as neural fate determination,proliferation,specification,differentiation,migration,survival,axonogenesis,and *** processes are precisely regulated in a tempo-spatial manner by intrinsic factors,extrinsic signals,and neural *** generation of correct subtypes and precise connections of projection neurons is imperative not only to support the basic cortical functions(such as sensory information integration,motor coordination,and cognition)but also to prevent the onset and progression of neurodevelopmental disorders(such as intellectual disability,autism spectrum disorders,anxiety,and depression).This review mainly focuses on the recent progress of transcriptional regulations on the development and diversity of neocortical projection neurons and the clinical relevance of the failure of transcriptional modulations.

关键词： autism spectrum disorders cognition differentiation excitatory circuits intellectual disability neocortex neurodevelopmental disorders projection neuron specification transcriptional regulation

Formation of Vacancy-Type Dislocation Loops in Hydrogen-Ion-Implanted Fe–Cr Alloy

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Acta Metallurgica Sinica(English Letters) 2019年第5期32卷 566-572页

作者： Yu-Feng Du Li-Juan Cui Wen-Tuo Han fa-rong wan Department of Materials Physics and Chemistry School of Materials Science and Engineering University of Science and Technology

Fe-10 at.%Cr alloy was implanted with hydrogen ions at room temperature, followed by annealing at high *** annealing process made the defects develop into large dislocation loops. The nature of the dislocation loops formed after annealing was studied by the evolution of loops under in situ electron irradiation in high-voltage electron *** indicated that only interstitial-type loops were observed when annealed at 550 °C and below, but vacancy-type loops started to form at the temperature higher than 600 °C. According to the previous study of our group, the presence of chromium element made the formation temperature of vacancy-type loops higher than that in pure iron. The effect of alloying elements on the formation temperature of the vacancy-type loops was discussed.

关键词： Hydrogen implantation Interstitial-type loops Vacancy-type loops Fe–Cr alloy High-voltage electron microscope

Analysis of Oxides Formed on the Surface of the Alloy 690 in Hydrogenated Supercritical Water

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Acta Metallurgica Sinica(English Letters) 2016年第8期29卷 774-781页

作者： Jin Gao fa-rong wan Guo-ping Cao Kumar Sridharan Todd Allen School of Materials Science and Engineering University of Science and Technology Beijing Department of Materials Science and Engineering University of Wisconsin-Madison

The oxides formed on the surface of the alloy 690 in hydrogenated supercritical water at 400℃ for 1000 h were investigated using scanning electron microscopy,transmission electron microscopy,scanning transmission electron microscopy and energy-dispersive X-ray *** oxides on me surface of the alloy 690 exhibited multi-layer structure：an outer layer consisted of granular crystallites（NiO and NiFe_2O_4） and a compact inner layer（spinel and Cr_2O_3）.Chemical analysis indicated that the outer layer was enriched in nickel but depleted in chromium,whereas the inner layer was enriched in chromium and iron but depleted in *** inner layer was also characterized as layered structure by Fe-rich spinel on top of continuous Cr_2O_3 ***,Cr_2O_3 nodules were readily observed at the oxides/alloy interface.

关键词： Alloy 690 Supercritical water Oxides Corrosion

Upper-rim-modified thioether thiacalix[4]arene used for liquid-liquid extraction of Au(Ⅲ)and Pd(Ⅱ)in hydrochloric acid medium

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Chinese Journal of Chemical Engineering 2024年第2期66卷 110-118页

作者： Sheng wan rong Xie Jianhong fan Kewen Tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China

Gold(Au)and palladium(Pd)play an increasing role in the production and human life;Therefore,it is of great significance to study their recovery.A 5,11,17,23-tetra-ethylthio-25,26,27,28-tetra-hydroxyl thiacalix[4]arene(TCAET)was synthesized specifically for the capture of Au(Ⅲ)and Pd(Ⅱ)from HCl medium by liquid-liquid *** a 0.1 mol·L^(-1)HCl medium,the transfer of Au(Ⅲ)and Pd(Ⅱ)from the aqueous phase to the organic phase was highly efficient,with a transfer ratio of 100%for Au(Ⅲ)and 98%for Pd(Ⅱ).Furthermore,the extraction equilibrium time for Au(Ⅲ)was just 5 ***'s method data demonstrated that TCAET formed complexes with Au(Ⅲ)and Pd(Ⅱ)in a ratio of 2:3 and 1:1,respectively,during the extraction *** showed high selectivity toward Pd(Ⅱ)and Au(Ⅲ)over other competing metal ***,both Au(Ⅲ)and Pd(Ⅱ)could be successfully stripped from the loaded organic phases with a 1.0 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl and 0.5 mol·L^(-1)thiourea in 0.5 mol·L^(-1)HCl,*** obtained from five consecutive extraction-stripping cycles showed good reusability of TCAET toward Au(Ⅲ)and Pd(Ⅱ)*** conclusion can provide a certain reference for thiacalixarene in the recovery of precious metal species.

关键词： Thiacalixarene Upper-rim modification Liquid-liquid extraction Precious metal Thioether

Microstructure and Nano-hardness of Pure Copper and ODS Copper Alloy under Au Ions Irradiation at Room Temperature

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Acta Metallurgica Sinica(English Letters) 2016年第11期29卷 1047-1052页

作者： Jing Zhang Yong-Qin Chang Zhi-Meng Guo Ping-Ping Liu Yi Long fa-rong wan School of Materials Science and Engineering University of Science and Technology Beijing

The microstructure and nano-hardness of the pure copper and oxide dispersion-strengthened（ODS） copper alloy subjected to 1.4 Me V Au ions irradiation at room temperature were investigated. After irradiation, dislocation-loops form in both materials, while voids can only be generated in the pure copper. Compared with the irradiated pure copper, larger average diameter and lower number density of irradiation-induced dislocation-loops were detected in the ODS copper alloy, revealing that high-density dislocation and large volume of Al2O3 particles existing in the ODS copper alloy can act as effective sinks for the irradiation-induced defects. It was also detected that irradiation hardening in the ODS copper alloy is lower than that in the pure copper. The microstructure and nano-hardness results reveal that the ODS copper alloy has a better irradiation tolerance than the pure copper. In addition, the average diameter of the Al2O3 particles in the ODS copper alloy decreases after irradiation, because the Al–O chemical bonds are decomposed and the atoms are redistributed in the matrix during the irradiation process. This work reveals that the irradiation tolerance of the copper can be effectively enhanced by adding nano-sized Al2O3 particles into the matrix.

关键词： Oxide dispersion-strengthened copper alloy Ions irradiation Microstructure evolution Nano-hardness

Irradiation effects on nanocrystalline materials

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Frontiers of Materials Science 2013年第2期7卷 143-155页

作者： Yong-Qin CHANG Qiang GUO Jing ZHANG Lin CHEN Yi LONG fa-rong wan School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

In recent years, nanocrystalline materials with grain size below 100 nm have attracted much interest due to their excellent chemical, physical, and optical properties. This review focuses on the irradiation effects of nanocrystalline materials. It has been generally believed that nanocrystalline materials have a great potential to increase irradiation resistance in the future reactor because of a large fraction of grain boundaries or interfaces that could absorb and annihilate mobile defects which produced during irradiation. Some calculation results and experiment results revealed that nanocrystalline materials can enhance irradiation resistance, while some reports showed that nanocrystalline materials exhibit worse irradiation resistance, or even amorphous at a lower irradiation dose compared with their bulk materials. During the irradiation process, the grain growth dominated by irradiation dose, thermal effect or defects was also disputed. Irradiation is also an important tool to tailor the grain size, phase structure and physical properties of the materials.

关键词： nanocrystalline material irradiation resistance grain growth

RFFsNet-SEI:a multidimensional balanced-RFFs deep neural network framework for specific emitter identification

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Journal of Systems Engineering and Electronics 2024年第3期35卷 558-574,F0002页

作者： faN rong SI Chengke HAN Yi wan Qun School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Institute of Electronic and Electrical Engineering Civil Aviation Flight University of ChinaGuanghan 618307China

Existing specific emitter identification(SEI)methods based on hand-crafted features have drawbacks of losing feature information and involving multiple processing stages,which reduce the identification accuracy of emitters and complicate the procedures of *** this paper,we propose a deep SEI approach via multidimensional feature extraction for radio frequency fingerprints(RFFs),namely,***,we extract multidimensional physical RFFs from the received signal by virtue of variational mode decomposition(VMD)and Hilbert transform(HT).The physical RFFs and I-Q data are formed into the balanced-RFFs,which are then used to train *** introducing model-aided RFFs into neural network,the hybrid-driven scheme including physical features and I-Q data is *** improves physical interpretability of ***,since RFFsNet-SEI identifies individual of emitters from received raw data in end-to-end,it accelerates SEI implementation and simplifies procedures of ***,as the temporal features and spectral features of the received signal are both extracted by RFFsNet-SEI,identification accuracy is ***,we compare RFFsNet-SEI with the counterparts in terms of identification accuracy,computational complexity,and prediction *** results illustrate that the proposed method outperforms the counterparts on the basis of simulation dataset and real dataset collected in the anechoic chamber.

关键词： specific emitter identification(SEI) deep learning(DL) radio frequency fingerprint(RFF) multidimensional feature extraction(MFE) variational mode decomposition(VMD)