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Improvements on the upper-ocean simulation from 2007 to 2018 in the Canada Basin

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Advances in Climate Change Research 2022年第2期13卷 196-204页

作者： Long-jiang MU Xiao-yu WANG Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China Frontier Science Center for Deep Ocean Multispheres and Earth System(FDOMES) Physical Oceanography LaboratoryOcean University of ChinaQingdao 266100China

The Beaufort Gyre reserves most of the freshwater in the Arctic *** shows that the freshwater content over 2016-2018 far exceeds the level over the plateau period *** the vertical temperature and salinity structure and their changes in the Beaufort Gyre is a way to understand the process related to such step *** configured a pan-Arctic sea ice-ocean model with a southern boundary at∼7°N in the Atlantic *** numerical simulation with sea surface salinity restoring,a latitude dependent horizontal diffusivity scaled by the squared buoyancy frequency,and a weak vertical diffusivity of 5×10^(−7) m^(2)s^(−1) in the Arctic Ocean better reproduces the sea ice extent,the Pacific summer halocline water,and the freshwater variations as *** sea surface salinity restoring mitigates the surface desalination in the North Atlantic Ocean,therefore a weaker ocean stratification prevents the excessive warming in the intermediate Arctic *** is also found that the weak vertical background diffusivity is the major factor in our model to preserve the vertical ocean structure in the Canada Basin and also the step change of freshwater *** addition to resolving eddy activities in high resolution models,the success in our low resolution model suggests that tuning the vertical diffusivity serves as another approach to simulate the increasing freshwater content in the recent decade.

关键词： Beaufort Gyre Numerical simulation Upper Arctic Ocean Freshwater content

Non-isothermal kinetics of synthesizing vanadium nitride by one-step method

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Rare Metals 2015年第10期34卷 738-743页

作者： jiang Dong yue yu Zheng-Liang Xue School of Materials and Metallurgy Wuhan University of Science and Technology

Vanadium nitride was synthesized by one-step method using V2O5 and carbon black as raw materials in nitrogen atmosphere. The phases of different reaction products prepared in different reaction temperatures were analyzed by X-ray diffraction(XRD), and the dynamic behavior of the process of synthesizing vanadium nitride(VN) by one-step method was studied with non-isothermal thermogravimetry. The mechanism function and kinetic parameters of reaction process were calculated by thermal gravimetric analyses(TGA), and the reaction rate equation was established. The XRD results show that for the samples tested with minimal VN after holding for 4 h at 1273 K, the main phase of products is VN at 1476 K, while some vanadium nitrides transform into vanadium carbides again over 1573 K. It is found that N2 is beneficial to stimulate reduction and proceed carbonization reaction,and the reduction and nitridation reaction can occur simultaneously. The activation energy of preparing VN by one-step method is 104.005 kJ·mol-1, and the frequency factor is 470.52 at 1280–1358 K, and 150.052 kJ·mol-1 and 2.35 9 104 at 1358–1426 K, respectively.

关键词： Vanadium nitride Reduction and nitridation Thermog

Nonlinear signal transduction network with multistate

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Chinese Physics B 2021年第11期30卷 666-675页

作者： Han-yu jiang Jun He School of Physics and Technology Nanjing Normal UniversityNanjing 210097China

Signal transduction is an important and basic mechanism to cell life *** stochastic state transition of receptor induces the release of signaling molecular,which triggers the state transition of other *** constructs a nonlinear sigaling network,and leads to robust switchlike properties which are critical to biological *** architectures and state transitions of receptor affect the performance of this biological *** this work,we perform a study of nonlinear signaling on biological polymorphic network by analyzing network dynamics of the Ca^(2+)-induced Ca^(2+)release(CICR)mechanism,where fast and slow processes are involved and the receptor has four conformational *** types of networks,Erdos–R´enyi(ER)network,Watts–Strogatz(WS)network,and BaraB´asi–Albert(BA)network,are considered with different *** dynamics of the biological networks exhibit different patterns at different time *** short time scale,the second open state is essential to reproduce the quasi-bistable regime,which emerges at a critical strength of connection for all three states involved in the fast processes and disappears at another critical *** pattern at short time scale is not sensitive to the network *** long time scale,only monostable regime is observed,and difference of network architectures affects the results more *** finding identifies features of nonlinear signaling networks with multistate that may underlie their biological function.

关键词： signal transduction biological network with multistate CICR nonlinear signaling

Numerical Simulation of Tsunami-Like Wave Impacting on Breakwater by CLSVOF/IB Method

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China Ocean engineering 2021年第5期35卷 676-686页

作者： AN Rui-dong jiang Da-peng yu Ching-hao LI yu-long State Key Laboratory of Hydraulics and Mountain River engineering Sichuan UniversityChengdu 610065China School of Marine engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China Technology Centre for Offshore and Marine Singapore(TCOMS)Singapore Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

In the current study,the treatment of air/water interface has been made on dam-break induced tsunami-like wave by the Coupled Level Set and Volume of Fluid(CLSVOF)three-dimensional *** overall CLSVOF method adopts a Tangent of Hy-perbola for INterface Capturing(THINC)scheme with the Weighted Linear Interface Calculation(WLIC)and Level Set(LS)function for capturing interface and calculating normal vector,*** far as THINC/WLIC scheme is concerned,since the convection problem of the VOF function can be solved well,the numerical diffusion can be *** spatial terms in the LS equation were discretized by the Optimized Compact Reconstruction Weighted Essentially Non-Oscillatory(OCRWenO)scheme with fourth-order accuracy,which can avoid false oscillation of LS *** combining CLSVOF method with Immersed Boundary(IB)method,the simulation of dam-break induced tsunami-like wave impacting on a stationary breakwater can be carried *** sensitivity,mass error and free-surface profile are first calculated for the tsunami-like wave problem to validate the proposed numerical algorithm,which shows excellent agreement between the numerical results and experimental ***-like waves with varied tailgater levels are then *** of velocity magnitude,free-surface profile and wave elevation of the tsunami-like wave are conducted to investigate its dynamics and kinematics.

关键词： dam-break tsunami-like bore CLSVOF method immersed boundary method breakwater

Development of a micro gas turbine combustor with T-type vaporizers

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航空动力学报 2007年第7期22卷 1118-1126页

作者： XU Quan-hong LIU Jun XU Jian LIN yu-zhen LIU Gao-en National Key Laboratory on Aero-engines School of Jet PropulsionBeijing 13niversity of Aeronautics and Astronautics Beijing 100083 China

The study includes the experimental investigation of the evaporation performance of T-type vaporizer,mainly studied the relationship of the inlet air temperature and vaporizer wall temperature with the evaporation ***,it studied the LBO(lean blow out) and combustion efficiency of the micro aero-engine combustor with T-type vaporizer on the normal pressure test *** inlet air condition is environmental pressure and *** gas analysis method is used to study the combustion efficiency,and the inlet air temperature is 300 K,400 K and 500 *** could be concluded that the evaporation performance is improved with the increasing of the inlet air temperature and vaporizer wall temperature;the average LBO is 0.003;the combustion efficiency rises with the inlet air temperature,and it remain constant when the fuel/air ratio changed in the range from 0.008 to *** vaporization ratio is the key factor to determine the combustion performance.

关键词：离心式喷气发动机燃烧室喷雾器索特平均直径燃气涡轮

Implicit high-order discontinuous Galerkin method with HWenO type limiters for steady viscous flow simulations

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Acta Mechanica Sinica 2013年第4期29卷 526-533页

作者： Zhen-Hua jiang Chao Yan Jian yu College of Aeronautics Science and engineering Beijing University of Aeronautics and Astronautics

Two types of implicit algorithms have been im- proved for high order discontinuous Galerkin （DG） method to solve compressible Navier-Stokes （NS） equations on tri- angular grids. A block lower-upper symmetric Gauss- Seidel （BLU-SGS） approach is implemented as a nonlin- ear iterative scheme. And a modified LU-SGS （LLU-SGS） approach is suggested to reduce the memory requirements while retain the good convergence performance of the origi- nal LU-SGS approach. Both implicit schemes have the sig- nificant advantage that only the diagonal block matrix is stored. The resulting implicit high-order DG methods are applied, in combination with Hermite weighted essentially non-oscillatory （HWenO） limiters, to solve viscous flow problems. Numerical results demonstrate that the present implicit methods are able to achieve significant efficiency improvements over explicit counterparts and for viscous flows with shocks, and the HWenO limiters can be used to achieve the desired essentially non-oscillatory shock tran- sition and the designed high-order accuracy simultaneously.

关键词： Discontinuous Galerkin (DG) scheme ~ Implicitmethod ~ HWenO ~ High order ~ Unstructured grids

An implicit symmetry constraint of the modified Korteweg-de Vries (mKdV) equation

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2008年第10期9卷 1457-1462页

作者： Ying YOU Jing yu Qiao-yun jiang Department of Mathematics Zhejiang University Hangzhou 310027 China School of Science Hangzhou Dianzi University Hangzhou 310018 China College of Science Nantong University Nantong 226007 China

In this paper, an implicit symmetry constraint is calculated and its associated binary nonlinearization of the Lax pairs and the adjoint Lax pairs is carried out for the modified Korteweg-de Vries (mKdV) equation. After introducing two new inde-pendent variables, we find that under the implicit symmetry constraint, the spatial part and the temporal part of the mKdV equation are decomposed into two finite-dimensional systems. Furthermore we prove that the obtained finite-dimensional systems are Hamiltonian systems and completely integrable in the Liouville sense.

关键词： Implicit symmetry constraint Completely integrable Hamiltonian system Modified Korteweg-de Vries (mKdV) equation

Study on neutron-gamma discrimination methods based on GMM-KNN and LabVIEW implementation

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Nuclear Science and Techniques 2024年第11期35卷 82-97页

作者： Ting-Meng Ding yu-Hang jiang Xuan-Xi Wang Xiao-Fei jiang Big Data and Information engineering GuiZhou UniversityGuiyang 550025China

Machine learning algorithms are considered as effective methods for improving the effectiveness of neutron-gamma(n-γ)*** study proposed an intelligent discrimination method that combined a Gaussian mixture model(GMM)with the K-nearest neighbor(KNN)algorithm,referred to as ***,the unlabeled training and test data were categorized into three energy ranges:0–25 keV,25–100 keV,and 100–2100 ***,GMM-KNN achieved small-batch clustering in three energy intervals with only the tail integral Q_(tail) and total integral Q_(total) as the pulse ***,we selected the pulses with a probability greater than 99%from the GMM clustering results to construct the training ***,we improved the KNN algorithm such that GMM-KNN realized the classification and regression algorithms through the LabVIEW *** outputs of GMM-KNN were the category or regression *** proposed GMM-KNN constructed the training set using unlabeled real pulse data and realized n-γdiscrimination of ^(241)Am-Be pulses using the LabVIEW *** experimental results demonstrated the high robustness and flexibility of *** when using only 1/4 of the training set,the execution time of GMM-KNN was only 2021 ms,with a difference of only 0.13%compared with the results obtained on the full training ***,GMM-KNN outperformed the charge comparison method in terms of accuracy,and correctly classified 5.52%of the ambiguous *** addition,the GMM-KNN regressor achieved a higher figure of merit(FOM),with FOM values of 0.877,1.262,and 1.020,corresponding to the three energy ranges,with a 32.08%improvement in 0–25 *** conclusion,the GMM-KNN algorithm demonstrates accurate and readily deployable real-time n-γdiscrimination performance,rendering it suitable for on-site analysis.

关键词： n-discrimination GMM KNN LabVIEW Classification Regression

Effect of beam current on microstructures and mechanical properties of joints of TZM/30CrMnSiA by electron beam welding

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Chinese Journal of Aeronautics 2021年第8期34卷 122-130页

作者： Ting WANG Bin yu Yifan WANG Siyuan jiang State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology at WeihaiWeihai 264209China Shandong Provincial Key Laboratory of Special Welding Technology Harbin Institute of Technology at WeihaiWeihai 264209China

Electron beam welding experiments of TZM alloy and 30CrMnSiA steel butt joints were carried out with different beam *** and chemical compositions of typical zones were analyzed by optical microscopy,scanning electron microscopy and X-ray *** mechanical properties of the joints were evaluated by tensile strength ***,nanoindentation tests were carried out to compare the brittleness of the reaction layer and other typical *** results illustrated that the reaction layer at the interface between fusion zone(FZ)and TZM alloy was the weak position of the joint,which was divided into Fe2Mo layer and a mixture layer of Fe2Mo and a-Fe *** the beam current increased,the thickness of the Fe2Mo layer decreased,which resulted in the increasing of the tensile strength of the *** the beam current exceeded 24 m A,the formation of the joint was poor with a low tensile *** the beam current was 24 mA,the joint presented the highest strength of 191.3 MPa and the joint fractured along the Fe2Mo layer near the TZM alloy side with a brittle fracture mode.

关键词： 30CrMnSiA Electron beam welding Mechanical properties Microstructure TZM alloy