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Recrystallization of Ni_3 Al Base Single Crystal Alloy IC6SX with Different Surface Mechanical Processes

Journal of Materials Science & Technology 2010年第10期26卷 883-888页

作者： yanan li School of Materials Scienceg and-Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China Beijing Institute of Aeronautical Materials Beijing 100095 China Fine Metals Branch Advanced Technology &: Materials Co. Ltd. (AT&M) Beijing 100081 China

The recrystallization behavior of Ni 3 Al base single crystal alloy IC6SX with different mechanical processes has been *** specimens of the alloy were treated by surface cleaning and cold working during the blades manufacture,and then heat treated in the temperature range of 800-1260℃ for 1 h to 4 *** microstrcture of the specimens were examined by optical and scaning electron microscopy,and the room temperature tensile property,stress rupture property under the test condition of 1100℃/130 MPa,and the thermal cycle fatigue resistance under 1100-20℃ of the specimens with and without recrystallization were carried *** experimental results showed that the initial recrystallization nucleation temperatures of the alloy by dry grit blasting,wet grit blasting,indentation,shot blasting and burnishing were 900-950℃/1 h,1000-1100℃/1 h,1200-1220℃/4 h,1220-1240℃/1 h and 1220-1240 C/1 h,respectively and the primal recrystallization completing temperatures of the alloy by those mechanical processes mentioned above were 1200-1210℃/1 h,1100-1200℃/1 h,1220-1240℃/4 h,1240-1260℃/1 h and 1240-1260℃/1 h,*** results also indicated that the deformation amount of the specimens by burnishing and dry grit blasting was bigger than that by wet grit blasting and shot blasting according to their recrystallization temperature and the microhardness profile below the surface of *** has been found that the recrystallization had no evident effect on mechanical properties of the alloy.

关键词： Ni3Al Single crystal alloy Recrystallization Surface layer

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Neural Stem Cell Competition

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Neuroscience Bulletin 2024年第2期40卷 277-279页

作者： yanan li Jie He State Key Laboratory of Neuroscience Institute of NeuroscienceCenter for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai 200031China University of Chinese Academy of Sciences Beijing 100049China

Cell competition is an adaptive surveillance mechanism to ensure the robustness of developmental outputs,maintain tissue integrity,and regulate tumor progression in multicellular organisms,which is highly conserved from invertebrates to vertebrates[1].At the cellular level,cell competition represents a non-cell-autonomous process in that cells can sense the fitness of their neighbors through cellular interactions,thereby eliminating low-fitness cells and expanding high-fitness counterparts,however,cells develop normally in homogenous populations.

关键词： thereby maintain eliminating

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CoN_(x)C active sites-rich three-dimensional porous carbon nanofibers network derived from bacterial cellulose and bimetal-ZIFs as efficient multifunctional electrocatalyst for rechargeable Zn–air batteries

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Journal of Energy Chemistry 2020年第12期29卷 323-332页

作者： Wenming Zhang Jingjing Chu Shifeng li yanan li ling li National-Local Joint Engineering Laboratory of New Energy Photoelectric Devices College of Physics Science and TechnologyHebei UniversityBaoding 071002HebeiChina

In this work, a CoNxC active sites-rich three-dimensional porous carbon nanofibers network derived from bacterial cellulose and bimetal-ZIFs is prepared via a nucleation growth strategy and a pyrolysis *** material displays excellent electrocatalytic activity for the oxygen reduction reaction, reaching a high limiting diffusion current density of -7.8 mA cm^(-2), outperforming metal–organic frameworks derived multifunctional electrocatalysts, and oxygen evolution reaction and hydrogen evolution reaction with low overpotentials of 380 and 107 mV, respectively. When the electrochemical properties are further evaluated, the electrocatalyst as an air cathode for Zn-air batteries exhibits a high cycling stability for63 h as well as a maximum power density of 308 mW cm^(-2), which is better than those for most Zn-air batteries reported to date. In addition, a power density of 152 mW cm^(-2) is provided by the solid-state Zn-air batteries, and the cycling stability is outstanding for 24 h. The remarkable electrocatalytic properties are attributed to the synergistic effect of the 3 D porous carbon nanofibers network and abundant inserted CoNxC active sites, which enable the fast transmission of ions and mass and simultaneously provide a large contact area for the electrode/electrolyte.

关键词： Bacterial cellulose Bimetal-ZIFs CoNxC active sites 3D nitrogen-doped porous carbon nanofiber Zn-air batteries

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Natural vibration and critical velocity of translating Timoshenko beam with non-homogeneous boundaries

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1523-1538页

作者： yanan li Jieyu DING Hu DING liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai Frontier Science Center of MechanoinformaticsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China School of Mathematics and Statistics Qingdao UniversityQingdao 266071Shandong ProvinceChina

In most practical engineering applications,the translating belt wraps around two fixed *** boundary conditions of the dynamic model are typically specified as simply supported or fixed *** this paper,non-homogeneous boundaries are introduced by the support *** the translating belt as the mechanical prototype,the vibration characteristics of translating Timoshenko beam models with nonhomogeneous boundaries are investigated for the first *** governing equations of Timoshenko beam are deduced by employing the generalized Hamilton's *** effects of parameters such as the radius of wheel and the length of belt on vibration characteristics including the equilibrium deformations,critical velocities,natural frequencies,and modes,are numerically calculated and *** numerical results indicate that the beam experiences deformation characterized by varying curvatures near the *** radii of the wheels play a pivotal role in determining the change in trend of the relative difference between two beam *** the results unearths that the relative difference in equilibrium deformations between the two beam models is more pronounced with smaller-sized *** the two wheels are of equal size,the critical velocities of both beam models reach their respective *** addition,the relative difference in natural frequencies between the two beam models exhibits nonlinear variation and can easily exceed 50%.Furthermore,as the axial velocities increase,the impact of non-homogeneous boundaries on modal shape of translating beam becomes more *** dealing with non-homogeneous boundaries is challenging,beam models with non-homogeneous boundaries are more sensitive to parameters,and the differences between the two types of beams undergo some interesting variations under the influence of non-homogeneous boundaries.

关键词： translating beam Timoshenko beam non-homogeneous boundary natural frequency critical velocity

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Semi-supervised Counting of Grape Berries in the Field Based on Density Mutual Exclusion

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Plant Phenomics 2023年第4期5卷 825-835页

作者： yanan li Yuling Tang Yifei liu Dingrun Zheng School of Computer Science and Engineering School of Artificial IntelligenceWuhan Institute of TechnologyWuhan 430205China Hubei Key Laboratory of Intelligent Robot Wuhan Institute of TechnologyWuhan 430073China

Automated counting of grape berries has become one of the most important tasks in grape yield ***,dense distribution of berries and the severe occlusion between berries bring great challenges to counting algorithm based on deep *** collection of data required for model training is also a tedious and expensive *** address these issues and cost-effectively count grape berries,a semi-supervised counting of grape berries in the field based on density mutual exclusion(CDMENet)is *** algorithm uses VGG16 as the backbone to extract image *** tasks based on density mutual exclusion are *** tasks exploit the spatial distribution pattern of grape berries in density levels to make full use of unlabeled *** addition,a density difference loss is *** feature representation is enhanced by amplifying the difference of features between different density *** experimental results on the field grape berry dataset show that CDMENet achieves less counting *** with the state of the arts,coefficient of determination(R^(2))is improved by 6.10%,and mean absolute error and root mean square error are reduced by 49.36%and 54.08%,*** code is available at.

关键词： Grape mutual backbone

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Residual stress with asymmetric spray quenching for thick aluminum alloy plates

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2200-2211页

作者： Ning Fan Zhihui li yanan li Xiwu li Yongan Zhang Baiqing Xiong State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China

Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy ***,the asymmetric or uneven spray water flow rate is inevitable under industrial production conditions,which leads to an asymmetric residual stress *** spray quenching treatment was conducted on self-designed spray equipment,and the residual stress along the thickness direction was measured by a layer removal method based on *** the asymmetric spray quenching condition,the subsurface stress of the high-flow rate surface was lower than that of the low-flow rate surface,and the difference between the two subsurface stresses increased with the increase in the difference in water flow *** subsurface stress underneath the surface with a water flow rate of 0.60 m^(3)/h was 15.38 MPa less than that of 0.15 m^(3)/*** simulated residual stress by finite element(FE)method of the high heat transfer coefficient(HTC)surface was less than that of the low HTC surface,which is consistent with the experimental *** FE model can be used to analyze the strain and stress evolution and predict the quenched stress magnitude and distribution.

关键词： aluminum alloy spray quenching residual stress layer removal method finite element method

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Synergistic inhibition of MEK and reciprocal feedback networks for targeted intervention in malignancy

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Cancer Biology & Medicine 2019年第3期16卷 415-434页

作者： yanan li Qingrong Dong Yukun Cui Department of Radiology First Clinical Medical CollegeShanxi Medical UniversityTaiyuan030001China GuangdongProvincial Key Laboratory of Breast Cancer Diagnosis and Treatment Shantou University Medical College Cancer HospitalShantou515041China

The RAS-RAF-MEK-ERK signaling pathway(MAPK signaling pathway) plays a significant role in multiple pathological behaviors and is most frequently dysregulated in more than 30% of human *** key elements in this pathway, MEK1/2 play crucial roles in tumorigenesis and the inhibition of apoptosis, which makes their inhibition an attractive antitumor *** of potent non-ATP-competitive allosteric MEK1/2 inhibitors have been developed that have produced substantial improvement in clinical outcomes over the past ***, the efficacy of these agents is limited, and response rates are variable in a wide range of tumors that harbor RAS and RAF mutations due to the development of resistance, which is derived mainly from the persistence of MAPK signaling and increased activation of the mutual feedback *** intrinsic and acquired resistance to MEK inhibitors necessitates the synergistic targeting of both pathways to restore the therapeutic effects of a single *** this review, the significant role of the MAPK pathway in carcinogenesis and its therapeutic potential are comprehensively examined with a focus on MEK ***, the activation of feedback networks accompanying MEK inhibition is briefly *** strategies that involve the simultaneous inhibition of the original and resistance pathways are highlighted and elaborately described on the basis of the latest research ***, the obstacles to the development of MEK-related combination systems are discussed in order to lay the groundwork for their clinical application as frontline treatments for individual patients with MAPK-hyperactivated malignancies.

关键词： MAPK signaling pathway MEK inhibitor reciprocal feedback networks combination therapy malignancy

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Efficient removal for multiple pollutants via Ag_(2)O/BiOBr heterojunction:A promoted photocatalytic process by valid electron transfer pathway

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Chinese Chemical Letters 2020年第10期31卷 2698-2704页

作者： Zhiruo Zhou yanan li Mingmei li Yi li Sihui Zhan College of Environmental Science and Engineering Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300071China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin University&Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin 300072China Tianjin Key Lab for Rare Earth Materials and Applications Tianjin 300072China

Multiple pollutants including pathogenic microorganism contaminations and emerging organic contaminations(EOCs)have shown a growing threat to the environment,especially the natural ***,the control and removal of pathogenic microorganism contaminations and EOCs have been greatly limited since limited knowledge of their environmental ***,a novel and efficient photocatalyst Ag_(2)O/BiOBr heterojunction was synthesized and used for removal of multiple pollutants including Escherichia coli(***),Staphylococcus aureus(***),tetracycline and acetaminophen under visible *** results showed that there were valid electron transfer pathways between BiOBr and Ag_(2)O,the main electron transfer direction was the BiOBr to Ag_(2)***-generated electrons were stored in Ag_(2)O and thus separation efficiency between holes and photo-generated electrons was obviously *** oxygen species were highly produced and eventually end up with the high efficiency of removal of multiple *** Ag_(2)O/BiOBr with Ag_(2)O content at 3%(the best performance)under visible light,log decrease of *** was 7.16(removal efficiency was 100%)in 120 min,log decrease of *** was 7.23(removal efficiency was 100%)in 160 min,C/C0 of tetracycline was 0.06 in 180 min,C/C0 of acetaminophen was 0.17 in 180 *** work could provide a promising candidate in the actual contaminated natural waters for cleaning multiple pollutants.

关键词： Water pollution Photocatalysis Multiple pollutants Electrons transfer channels

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Sediment settlement rate and consolidation time of flling reclamation in coal mining subsidence land

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International Journal of Coal Science & Technology 2022年第3期9卷 232-246页

作者： linghua Duo Zhenqi Hu Kun Yang yanan li Faculty of Geomatics East China University of TechnologyNanchang 30013China School of Environment and Spatial Informatics China University of Mining and TechnologyXuzhou 221116China Institute of Land Reclamation and Ecological Restoration China University of Mining and Technology(Beijing)D11 Xueyuan RoadHaidian DistrictBeijing 100083China

With the continuous growth of the population and the continuous reduction of cultivated land,China’s food security is greatly *** addition,China’s coal mining has been mainly underground mining,causing land subsidence and damaging existing cultivated *** efect intensifes the contradiction between the growth of the risk population and the reduction of cultivated *** reclamation of mining subsidence land with Yellow River sediment is often used as an efective way to improve the recovery rate of cultivated *** the reclamation time and realizing continuous flling are signifcant *** work presented in this paper studied the sediment settlement rate and consolidation time by combining theory,feld flling and reclamation tests and numerical simulations.A feld flling test study was carried out in the lowlands of Jibeiwang Village,Qihe County,Shandong Province,*** calculating the drainage consolidation time,the consolidation factor of 0.015656 m^(2)/d,and the time factor for sediment consolidation of 0.575 were *** sediment consolidation time for this test was 9.18 *** calculation of sediment deposition rate and consolidation time is of great practical signifcance to guide the Yellow River sediment flling,realize continuous flling,and save reclamation time and cost.

关键词： Yellow River sediment Mining subsidence land Filling reclamation Consolidation time

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Joint Doppler Shift and Channel Estimation for UAV mmWave System with Massive ULA

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China Communications 2022年第4期19卷 67-82页

作者： yanan li Yue Zhu Tiankui Zhang Dian Fan The China Academy of Information and Communications Technology Beijing 100191China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing key engineering laboratory of testing and validation for smart terminal and hardware

A joint Doppler shift and channel estimation method for the millimeter-wave communication system of an unmanned aerial vehicle(UAV) equipped with a large-scale uniform linear antenna(ULA) array has been proposed. Since Doppler shift induces intercarrier interference, the parameters of the channel paths have been decomposed into the Doppler shift and the channel information. In order to obtain the Doppler shift, a new estimation algorithm based on a combination of discrete Fourier transform and phase rotation has been proposed, which can determine the appropriate number of antennas. In addition to estimating the channel information, a low-complexity joint Doppler shift and channel estimation method has been designed that can quickly obtain accurate estimates. Furthermore, the achievable sum rate, the theoretical bounds of the mean squared errors, and the Cram?er-Rao lower bounds of the estimation method have been derived. The analysis and simulation results prove that the performance of the proposed approach is close to the theoretical inference.

关键词： ULA Doppler shift estimation channel estimation achievable sum rate

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