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A multi-model analysis of glacier equilibrium line altitudes in western China during the last glacial maximum

Science China Earth Sciences 2019年第8期62卷 1241-1255页

作者： Dabang JIANG Yeyi liu Xianmei lang Institute of Atmospheric Physics Chinese Academy of SciencesBeijing100029China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing100101China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing210044China University of Chinese Academy of Sciences Beijing100049China

Based on numerical experiments undertaken with nine climate models, the glacier equilibrium line altitudes(ELAs)in western China during the last glacial maximum(LGM) are investigated to deepen our understanding of the surface environment on the Tibetan Plateau. Relative to the preindustrial period, the summer surface air temperatures decrease by 4–8°C while the annual precipitation decreases by an average of 25% across the Tibetan Plateau during the LGM. Under the joint effects of reductions in summer temperature and annual precipitation, the LGM ELAs in western China are lowered by magnitudes that vary with regions. The ELAs in the southern margin and northwestern Tibetan Plateau decline by approximately 1100 m;the central hinterland, by 650–800 m;and the eastern part, by 550–800 m, with a downward trend from southwest to northeast. The reduction in ELAs is no more than 650 m in the Tian Shan Mountains within China and approximately 500–600 m in the Qilian Mountains and Altai Mountains. The high-resolution models to reproduce the low values of no more than 500 m in ELA reductions in the central Tibetan Plateau, which are consistent with the proxy records from glacier remains. The accumulation zones of the Tibetan Plateau glaciers are mainly located in the marginal mountains during the LGM and have areas 2–5 times larger than those of the modern glaciers but still do not reach the central part.

关键词： Last glacial maximum Western China Equilibrium line altitudes Glacier Simulation

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Nuclear magnetic moments for J~π=2_1^+ state of ^(10)Be with ab initio Monte Carlo shell model calculation

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Science China(Physics,Mechanics & Astronomy) 2014年第2期57卷 239-243页

作者： liu lang LI Jian School of Science Jiangnan University College of Physics Jilin University

The magnetic moment of 2＋1 state for 10Be are calculated and investigated in terms of single particle orbits for protons and neutrons under the framework of ab initio Monte Carlo shell model method in an emax=3 model space. The reduced matrix elements of orbital and spin angular momentum are evaluated. It is found that the orientations of orbital angular momentum in different single particle orbits are consistent. Conversely, the orientations of spin in different single particle orbits tend to be chaotic. The nuclear magnetic moment of 2＋1 state for 10Be is obtained as 1.006 ,UN and is discussed in regards to the contribution of orbital and spin angular momentum both for protons and neutrons. The corresponding g-factor is also given.

关键词： nuclear magnetic moment Monte Carlo shell model 10Be ab initio

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Performance of Nb_(0.8)Zr_(0.2) Layer-Modified AISI430 Stainless Steel as Bipolar Plates for Direct Formic Acid Fuel Cells

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Acta Metallurgica Sinica(English Letters) 2021年第1期34卷 77-84页

作者： Yuanyuan liu Zhongmin lang Jinlong Cui Shengli An Inner Mongolia Key Laboratory of Coal Chemical Engineering and Comprehensive Utilization School of Chemistry and Chemical EngineeringInner Mongolia University of Science and TechnologyBaotou 014010China School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014010China

To improve the interfacial conductivity and corrosion resistance of AISI430 stainless steel(430 SS)as bipolar plates for direct formic acid fuel cells(DFAFCs),a Nb_(0.8)Zr_(0.2) layer has been successfully synthesized via the pulsed laser deposition(PLD)technique on the surface of 430 *** Nb_(0.8)Zr_(0.2) layer is smooth,uniform,and comparatively compact without any surface flaw and *** under the simulated anodic environment of DFAFCs(0.05 M H_(2)SO_(4)+2 ppm HF+10 M HCOOH at 70℃)shows that the corrosion resistance of 430 SS is obviously ameliorated after the PLD *** addition,the interfacial contact resistance of Nb_(0.8)Zr_(0.2)-430 SS(6.0 mΩcm^(2))is much smaller than that of bare 430 SS(151.3 mΩcm^(2))at the clamping force of 140 N cm^(-2).Besides,diff erent from the highly increased interfacial contact resistance of bare 430 SS,the Nb_(0.8)Zr_(0.2)-430 SS shows a minor increase resistance after potentiostatic tests in simulated anodic environment of DFAFCs.

关键词： Corrosion resistance Nb_(0.8)Zr_(0.2) layer Direct formic acid fuel cell Interfacial contact resistance Bipolar plates

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Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 140-147页

作者： Di-Chao Chen Xie liu Changqing Xu Da-Jian Wu Ying Cheng Xiao-Jun liu School of Physics and Technology Nanjing Normal University Key Laboratory of Modern Acoustics School of Physics Nanjing University

Vortex transmutation utilizes a periodic system, which not only enables the alteration of the topological charge(TC) of unstable input vortices but also facilitates their transformation into stable structures. This approach is crucial for investigating the characteristics of vortices in various wave systems. Here, we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES). The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete symmetry. Our results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures, enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

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Nuclear current and antimagnetic rotation in ^(105)Cd

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Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2420-2424页

作者： liu lang ZHAO PengWei State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

The effects of the nuclear current in the antimagnetic rotation band of 105Cd have been investigated in a fully self-consistent and microscopic way by using the tilted axis cranking relativistic mean-field *** was found that the inclusion of nuclear current leads to a higher angular momentum and thus a larger kinetic moment of inertia at a given rotational *** a consequence,the B(E2) values with current are always smaller than those without current.

关键词： covariant density functional theory tilted axis cranking model nuclear current antimagnetic rotation

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A seismogram digitization and database management system

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Acta Seismologica Sinica(English Edition) 2001年第3期14卷 333-341页

作者： liu Zheng-kai 1. Department of Electronic Engineering and Information Science University of Science and Technology of China 230026 Hefei China 2. Seismological Bureau of Shanghai 200063 Shanghai China 3. Institute of Geophysics China Seismological Bureau 100081 Beijing China 4. Seismological Bureau of Anhui Province 230031 Hefei China

This paper introduces a 'Seismogram Digitization and Database Management System' (SDDMS), which is developed using Delphi3, and present the key technique of automatically extracting wave data from paper seismograms. The system have various functions, such as paper seismogram digitization, database management and data analysis, etc. With this system it is possible to analyze historical paper seismograms using modern computers. Application of this system will be of help to the progress in earthquake prediction and seismological researchers.

关键词： seismogram digitization database management wave data extraction P315.63

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Liver transplantation versus liver resection for hepatocellular carcinoma: a meta-analysis

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Hepatobiliary & Pancreatic Diseases International 2014年第3期13卷 234-241页

作者： Xin-Sen Xu Chang liu kai Qu Yan-Zhou Song Peng Zhang Yue-lang Zhang Department of Hepatobiliary Surgery First Affiliated Hospital School of Medicine Xi'an Jiaotong University Department of Radiology First Affiliated Hospital School of Medicine Xi'an Jiaotong University

BACKGROUND: Liver transplantation(LT) and liver resection(LR) are currently considered the standard treatment of patients with hepatocellular carcinoma(HCC). However, the outcomes of LT and LR are still *** SOURCES: MEDLINE, EMBASE, and Cochrane Library were searched for relevant studies. Surgical safety indices such as treatment-related morbidity and mortality, and efficacy indices such as overall and tumor-free survival outcomes were evaluated. Weighted mean differences and odds ratios(ORs)were calculated using a random-effects ***: Seventeen studies were included in this *** achieved significantly higher rates of surgeryrelated morbidity(OR=1.47; 95% CI: 1.02-2.13) and mortality(OR=2.12; 95% CI: 1.11-4.05). Likewise, the 1-year survival rate was lower in LT(OR=0.86; 95% CI: 0.61-1.20). However, the 3-and 5-year survival rates were significantly higher in LT than in LR and the ORs were 1.12(95% CI: 0.96-1.30) in 3 years and1.84(95% CI: 1.49-2.28) in 5 years. Furthermore, the tumorfree survival rate in LT was significantly higher than that in LR in 1, 3, 5 years after surgery, with the ORs of 1.72(95% CI:1.24-2.41), 3.75(95% CI: 2.94-4.78) and 5.64(95% CI: 4.35-7.31),***: One-year morbidity and mortality are higher in LT than in LR for patients with HCC. However, long-term survival and tumor-free survival rates are higher in patients treated with LT than those treated with LR.

关键词： hepatocellular carcinoma liver transplantation hepatectomy

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A DISSIPATION-PRESERVING INTEGRATOR FOR DAMPED OSCILLATORY HAMILTONIAN SYSTEMS

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Journal of Computational Mathematics 2022年第4期40卷 570-588页

作者： Wei Shi kai liu College of Mathematical Sciences Nanjing Tech UniversityNanjing 211816China School of Statistics and Data Science Nanjing Audit UniversityNanjing 210023China

In this paper,based on discrete gradient,a dissipation-preserving integrator for weakly dissipative perturbations of oscillatory Hamiltonian system is *** solution of this system is a damped nonlinear ***,lots of nonlinear oscillatory mechanical systems including frictional forces lend themselves to this *** new integrator gives a discrete analogue of the dissipation property of the original ***,since the integrator is based on the variation-of-constants formula for oscillatory systems,it preserves the oscillatory structure of the *** properties of the new integrator are *** convergence is analyzed for the implicit iterations based on the discrete gradient integrator,and it turns out that the convergence of the implicit iterations based on the new integrator is independent of k Mk,where M governs the main oscillation of the system and usually k Mk≫*** significant property shows that a larger stepsize can be chosen for the new schemes than that for the traditional discrete gradient integrators when applied to the oscillatory Hamiltonian *** experiments are carried out to show the effectiveness and efficiency of the new integrator in comparison with the traditional discrete gradient methods in the scientific literature。

关键词： Weakly dissipative systems Oscillatory systems Structure-preserving algorithm Discrete gradient integrator Sine-Gordon equation Continuousα-Fermi-Pasta-Ulam system

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GENERAL FULL IMPLICIT STRONG TAYLOR APPROXIMATIONS FOR STIFF STOCHASTIC DIFFERENTIAL EQUATIONS

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Journal of Computational Mathematics 2022年第4期40卷 541-569页

作者： kai liu Guiding Gu School of Mathematics Shanghai University of Finance and EconomicsShanghai 200433China College of Science Hunan University of Technology and BusinessChangsha 410205China

In this paper,we present the backward stochastic Taylor expansions for a Ito process,including backward Ito-Taylor expansions and backward Stratonovich-Taylor *** construct the general full implicit strong Taylor approximations(including Ito-Taylor and Stratonovich-Taylor schemes)with implicitness in both the deterministic and the stochastic terms for the stiff stochastic differential equations(SSDE)by employing truncations of backward stochastic Taylor *** demonstrate that these schemes will converge strongly with corresponding order 1,2,3,....Mean-square stability has been investigated for full implicit strong Stratonovich-Taylor scheme with order 2,and it has larger meansquare stability region than the explicit and the semi-implicit strong Stratonovich-Taylor schemes with order *** can improve the stability of simulations considerably without too much additional computational effort by using our full implicit *** full implicit strong Taylor schemes allow a larger range of time step sizes than other schemes and are suitable for SSDE with stiffness on both the drift and the diffusion *** numerical experiment show these points.

关键词： Stiff stochastic differential equations Approximations Backward Stochastic Taylor expansions Full implicit Taylor methods

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Asymptotic false discovery control of the Benjamini-Hochberg procedure for pairwise comparisons

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Science China Mathematics 2025年第1期 223-252页

作者： Weidong liu Dennis Leung Qi-Man Shao School of Mathematical Sciences Shanghai Jiao Tong University School of Mathematics and Statistics University of Melbourne Department of Statistics and Data Science SICMSouthern University of Science and Technology

In a one-way analysis-of-variance(ANOVA) model,the number of pairwise comparisons can become large even with a moderate number of *** by this,we consider a regime with a growing number of groups and prove that,when testing pairwise comparisons,the Benjamini-Hochberg(BH) procedure can asymptotically control false discoveries,despite the fact that the involved t-statistics do not exhibit the wellknown positive dependence structure required for exact false discovery rate(FDR) *** Tukey's perspective that the difference between the means of any two groups cannot be exactly zero,our main result provides control over the directional false discovery rate and directional false discovery proportion.A key technical contribution of our work is demonstrating that the dependence among the t-statistics is sufficiently weak to establish the convergence result typically required for asymptotic FDR *** analysis does not rely on conventional assumptions such as normality,variance homogeneity,or a balanced design,thereby offering a theoretical foundation for applications in more general settings.

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