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Combining BPANN and wavelet analysis to simulate hydro-climatic processes a case study of the Kaidu River, North-west China

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Frontiers of Earth Science 2013年第2期7卷 227-237页

作者： Jianhua xU yaning CHEN Weihong LI Paul y. peng yang yANG Chunan SONG Chunmeng-WEI yulian HONG The Key Laboratory of GIScience of the Education Ministry of China The Research Center for East-West Cooperation in China East China Normal University Shanghai 200241 China The Key Laboratory of Oasis Ecology and Desert Environment Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Department of Community Health and Epidemiology Queen's University Kingston K7L 3N6 Canada

Using the hydrological and meteorological data in the Kaidu River Basin during 1957-2008, we simulated the hydro-climatic process by back-propagation artificial neural network （BPANN） based on wavelet analysis （WA）, and then compared the simulated results with those from a multiple linear regression （MLR）. The results show that the variation of runoff responded to regional climate change. The annual runoff （AR） was mainly affected by annual average temperature （AAT） and annual precipitation （AP）, which revealed different varia- tion patterns at five time scales. At the time scale of 32-years, AR presented a monotonically increasing trend with the similar trend of AAT and AP. But at the 2-year, 4- year, 8-year, and 16-year time-scale, AR presented non-linear variation with fluctuations of AAT and AP. Both MLR and BPANN successfully simulated the hydro- climatic process based on WA at each time scale, but the simulated effect from BPANN is better than that from MLR.

关键词： hydro-climatic process Kaidu River simulation wavelet analysis (WA) back-propagation artificial neural network (BPANN) multiple linear regression (MLR)

A numerical study of the impacts of sediment composition on debris flows

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Journal of Hydrodynamics 2022年第4期34卷 620-633页

作者： Abiola Abraham Adebiyi peng Hu Institute of Port Coastaland Ofshore EngineeringOcean CollegeZhejiang UniversityZhoushan 316021China

Debris flows in their natural environments are made up of different sediment sizes,even though they are often considered to be uniform in numerical *** prompted the present study to investigate the behaviors of debris flows with nonuniform sediment composition.A model is developed to investigate nonuniform debris flows and the characteristic behavior of their *** model’s framework of mass and momentum equations and mass exchange with the bed are solved using the shock-capturing finite volume *** model is first tested with a uniform sediment laboratory experiment,where there is a good *** model is then tested against two flume experiments with different bed water content and *** model performed well in both cases,however,the slight underprediction in the second case can be associated with the complexity of debris flows which may not be fully captured by physical *** model is further used to investigate different compositions of debris flows including mixed grain sizes,mean size,fine and coarse sediment size,and no erosion/*** modeling of the mixed grain sizes produced a more accurate result,and this justifies the consideration of nonuniform sediment sizes in the numerical studies of debris *** enhance the understanding of frontal coarsening and rear fining in experimental debris flow,the model is also used to investigate cases with different sediment compositions,and the model was able to reproduce the frontal coarsening and rear fining observed in experiments.

关键词： Debris flows numerical modeling finite volume method(FVM) sediment composition erosion debris coarsening

Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

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China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao Qiao Jian Li xiao-yang Luo peng peng xian-tao yan xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

STUDy ON THE HOT DEFORMATION BEHAVIORS OF Al-Zn-Mg-Cu-Cr ALUMINUM ALLOy

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Acta Metallurgica Sinica(English Letters) 2008年第2期21卷 109-115页

作者： G. y. Lin Z.F. Zhang H. Zhang D.S. peng J. Zhou School of Materials Science and Engineering Central South University Changsha 410083 China

The hot deformation behaviors and microstructures of A1-Zn-Mg-Cu-Cr aluminum alloy have been studied using thermal simulation test, optical microscopy and transmission electron microscopy. As a result, the true stress versus true strain curves and the microstructures under various deformation conditions are obtained. The microstructures gradually incline to dynamic-recrystallization with the deformation temperature rising and the recrystallization grains refine with the decrease of deformation temperature or with raising the strain rates. The quantitative relationship between the Zener-Hollomon parameter （Z） and average recrystallization grain size in the subsequent heat treatment is set up.

关键词： A1-Zn-Mg-Cu-Cr aluminum alloy Hot deformation True stressvs true strain curve Microstructure

Drivers of soil erosion and subsurface loss by soil leakage during karst rocky desertification in SW China

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International Soil and Water Conservation Research 2022年第2期10卷 217-227页

作者： xudong peng Quanhou Dai College of Forestry Guizhou UniversityGuiyang550025China Institute of Soil Erosion and Ecological Restoration Guizhou UniversityGuiyang550025China The Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region(Ministry of Education) Collaborative Innovation Center for Mountain Ecology&Agro-Bioengineering(CICMEAB)Research Center of Soil Erosion and Ecological RestorationGuizhou UniversityGuiyang550025China

As an extreme manifestation of environmental degradation,karst rock desertification is caused by soil loss and rock *** some areas with serious rocky desertification,there is no soil to be eroded or *** soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures,pipelines,sinkholes,etc.,which directly reduce soil resources and accelerate rocky ***,the factors driving soil erosion and subsurface loss by soil leakage are still *** experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province,*** factors,including rainfall intensity,slope gradient,bedrock exposure rate and subsurface fissure degree,were considered in the *** found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential *** intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between *** slope gradient plays a leading role only in subsurface fissure flow leakage *** bedrock exposure rate drives the surface soil erosion rate,shows a critical value(30%),and dominates the fissure flow leakage loss *** fissure density plays an important role in the surface loss of soil and water;however,an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and *** this result,obtained from laboratory simulations,may differ at the field scale or larger,it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.

关键词： Driving factors Karst rocky desertification Soil erosion Subsurface leakage Southwest China

Experimental Study on the Identification of Scholte Waves Based on Acoustic Pressure Field Measurement

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Journal of Ocean University of China 2023年第5期22卷 1193-1200页

作者： LIANG Minshuai peng Linhui College of Marine Technology Ocean University of ChinaQingdao 266100China

Scholte waves at the seafloor interface are generally identified by their velocity features and seismic fields,which are measured using ocean bottom seismometers and *** methods are effective in cases where there is a considerable difference between the velocities of Scholte and acoustic waves in ***,they are ineffective when the velocities of these two types of waves are close to each ***,in this paper,a method based on acoustic pressure field measurement for identifying Scholte waves is proposed according to their excitation and propagation *** proposed method can overcome the limitations on the velocities of two types of waves.A tank experiment is designed and conducted according to the proposed method,and an ocean environment is scaled down to the laboratory *** measurements are obtained along virtual arrays in the water column using a robotic *** show that changes in Scholte wave amplitudes,depending on different source depths and propagation distances,are consistent with the theoretical *** means that Scholte waves generated at the seafloor interface are successfully measured and identified in the acoustic pressure field.

关键词： interface waves at seafloor measurement of Scholte waves identification of Scholte waves

The discovery of Late Triassic hypabyssal mafic dykes in the Huozhou complex and their geological significance:Evidence from petrology,geochemistry,and geochronology

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Acta Geochimica 2024年第6期43卷 1013-1036页

作者： Haiyan Liu Chong peng College of Geographical Sciences Shanxi Normal UniversityTaiyuan 030031China Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China School of GeoSciences University of EdinburghEdinburgh EH93JWUK

The Huozhou complex in the Trans-North China Orogen exhibits two events of mafic magmatism(separated by ca.700 Ma):Neoproterozoic(920±15 Ma)Shimenyu diabase and Late Triassic(217±2.5 Ma)xingtangsi *** have focused on systematic petrology,zircon U-Pb dating,Lu-Hf isotopes,and *** research findings indicate that the Late Triassic xingtangsi diabase of the Huozhou complex can be classified as a transitional type between intermediate and mafic rocks based on their SiO_(2)*** classification is supported by an average SiO_(2)content of 53.94%,ranging from 53.33%to 54.28%.In the Zr/TiO_(2)*** diagram,all samples lie within the range of *** zircons from the Late Triassic xingtangsi diabase have lowε_(Hf)(t)values ranging from-12.7 to-8.7,with an average ***,the single-stage model age T_(DM1)is estimated to be between 1207 and 1701 *** findings suggest that the magma responsible for the dyke originated from either partial melting or an enriched mantle source inside the Meso-Proterozoic lithospheric *** elevated concentrations of Th(thorium)and LREEs(light rare earth elements),as well as the Th/yb and Th/Nb ratios,suggest the potential incorporation of subducted sediments within the magma source *** rock displays negative Nb,Ta,Zr,Hf,and Ti *** geochemical attributes align with the distinctive traits observed in volcanic rocks found within island *** formation of the Late Triassic xingtangsi diabase is likely associated with the geological context of an arc setting,which arises from the collision between the yangtze plate and the North China Craton.

关键词： Trans-North China Orogen Huozhou complex Geochemistry Hf isotope North China Craton

Unconstrained Methods for Generalized Complementarity Problems

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Journal of Computational Mathematics 1997年第3期15卷 253-264页

作者： J.M. peng y. yuan(State Key Laboratory of Scientific and Engineering Conputing, ICMSEC, Chinese Academy of Sciences, Beijing, China) CHINESE ACAD SCI ICMSECSTATE KEY LAB SCI & ENGNBEIJINGPEOPLES R CHINA

In this paper, the generalized complementarity problem is formulated as an unconstrained optimization problem. Our results generalize the results of [9]. The dimensionality of the unconstrained problem is the same as that of the original problem. If the mapping of generalized complementarity problem is differentiable, the objective function of the unconstrained problem is also differentiable. All the solutions of the original problem are global minimizers of the optimization problem. A generalized strict complementarity condition is given. Under certain assumptions, local properties of the correspondent unconstrained optimization problem are studied. Limited numerical tests are also reported.

关键词： In Px Math

Recent progress in targeting the sialylated glycan-SIGLEC axis in cancer immunotherapy

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Cancer Biology & Medicine 2023年第5期20卷 369-384页

作者： yingyan yu Wenjie peng Department of General Surgery of Ruijin Hospital Shanghai Institute of Digestive Surgeryand Shanghai Key Laboratory for Gastric NeoplasmsShanghai Jiao Tong University School of MedicineShanghai 200025China Shanghai Center for Systems Biomedicine Shanghai Jiao Tong UniversityShanghai 200240China

Malignant tumors are complex structures composed of cancer cells and tumor microenvironmental *** this complex structure,cells cross-talk and interact,thus jointly promoting cancer development and ***,immunoregulatory molecule-based cancer immunotherapy has greatly improved treatment efficacy for solid cancers,thus enabling some patients to achieve persistent responses or ***,owing to the development of drug-resistance and the low response rate,immunotherapy against the available targets PD-1/PD-L1 or CTLA-4 has limited *** combination therapies have been proposed to enhance the response rate,severe adverse effects are ***,alternative immune checkpoints must be *** SIGLECs are a family of immunoregulatory receptors(known as glyco-immune checkpoints)discovered in recent *** review systematically describes the molecular characteristics of the SIGLECs,and discusses recent progress in areas including synthetic ligands,monoclonal antibody inhibitors,and Chimeric antigen receptor T(CAR-T)cells,with a focus on available strategies for blocking the sialylated glycan-SIGLEC *** glyco-immune checkpoints can expand the scope of immune checkpoints and provide multiple options for new drug development.

关键词： SIGLEC sialylated glycan glyco-immune checkpoint high affinity SIGLEC-ligands anti-SIGLEC antibodies