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Global Climate Internal Variability in a 2000-year Control Simulation with Community Earth System Model(CESM)

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Chinese Geographical Science 2015年第3期25卷 263-273页

作者： WANG Zhiyuan LI Yao liu bin liu Jian State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Virtual Geographic Environment of Ministry of Education School of Geography ScienceNanjing Normal University

Using the low-resolution （T31, equivalent to 3.75°× 3.75°） version of the Community Earth System Model （CESM） from the National Center for Atmospheric Research （NCAR）, a global climate simulation was carried out with fixed external forcing factors （1850 Common Era. （C.E.） conditions） for the past 2000 years. Based on the simulated results, spatio-temporal structures of surface air temperature, precipitation and internal variability, such as the E1 Nifio-Southem Oscillation （ENSO）, the Atlantic Multi-decadal Oscilla- tion （AMO）, the Pacific Decadal Oscillation （PDO）, and the North Atlantic Oscillation （NAO）, were compared with reanalysis datasets to evaluate the model performance. The results are as follows： 1） CESM showed a good performance in the long-term simulation and no significant climate drift over the past 2000 years; 2） climatological patterns of global and regional climate changes simulated by the CESM were reasonable compared with the reanalysis datasets; and 3） the CESM simulated internal natural variability of the climate system performs very well. The model not only reproduced the periodicity of ENSO, AMO and PDO events but also the 3-8 years vari- ability of the ENSO. The spatial distribution of the CESM-simulated NAO was also similar to the observed. However, because of weaker total irradiation and greenhouse gas concentration forcing in the simulation than the present, the model performances had some differences from the observations. Generally, the CESM showed a good performance in simulating the global climate and internal natu- ral variability of the climate system. This paves the way for other forced climate simulations for the past 2000 years by using the CESM.

关键词： Community Earth System Model (CESM) climate simulation past 2000 years climate system intemal variability

A Unified Shared-Private Network with Denoising for Dialogue State Tracking

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Journal of Computer Science & Technology 2021年第6期36卷 1407-1419页

作者： Qing-bin liu Shi-Zhu He Kang liu Sheng-Ping liu Jun Zhao National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Beijing Unisound Information Technology Co. LtdBeijing 100096China

Dialogue state tracking(DST)leverages dialogue information to predict dialogues states which are generally represented as slot-value ***,previous work usually has limitations to efficiently predict values due to the lack of a powerful strategy for generating values from both the dialogue history and the predefined *** predicting values from the predefined value set,previous discriminative DST methods are difficult to handle unknown *** generative DST methods determine values based on mentions in the dialogue history,which makes it difficult for them to handle uncovered and non-pointable ***,existing generative DST methods usually ignore the unlabeled instances and suffer from the label noise problem,which limits the generation of mentions and eventually hurts *** this paper,we propose a unified shared-private network(USPN)to generate values from both the dialogue history and the predefined values through a unified ***,USPN uses an encoder to construct a complete generative space for each slot and to discern shared information between slots through a shared-private ***,our model predicts values from the generative space through a shared-private *** further utilize reinforcement learning to alleviate the label noise problem by learning indirect supervision from semantic relations between conversational words and predefined slot-value *** results on three public datasets show the effectiveness of USPN by outperforming state-of-the-art baselines in both supervised and unsupervised DST tasks.

关键词： dialogue state tracking unified strategy shared-private network reinforcement learning

Nanoparticles as contrast agents for photoacoustic brain imaging

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Aggregate 2021年第1期2卷 4-19页

作者： Xingang liu Yukun Duan bin liu Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhouChina

Photoacoustic(PA)imaging has emerged as a promising technique for real-time detection and diagnosis of brain-related pathologies,due to its advantages in deep penetration of ultrasound imaging and high resolution of optical fluorescence *** herein provide an overview on the latest developments of nanoparticles as contrast agents specifically designed for PA imaging of brain tumor,and brain vascular and other brain-related *** design considerations of high-performance PA contrast agents for brain-related disease diagnosis are discussed,which include(1)strong absorption in NIR or NIR-Ⅱ window,(2)good biocompatibility,(3)high photothermal conversion efficiency,(4)precise nanostructure control,and(5)spe-cific targeting *** and perspectives of developing more robust and universal contrast agents for enhanced PA imaging are discussed at the end.

关键词： brain imaging contrastagent nanoparticle photoacousticimaging

Transition Metal Boride-Based Materials for Electrocatalytic Water Splitting

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Chinese Journal of Structural Chemistry 2022年第9期41卷 8-44页

作者： Feng-Ge Wang Xin liu Qian-Xi Lv bin liu Yong-Ming Chai bin Dong State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China

Electrocatalytic water splitting to produce hydrogen is an eco-friendly way to achieve sustainable utilization of renewable *** industrial application of water electrolysis, which is severely limited by slow kinetic reactions on electrode surfaces, requires the development of highly reactive, low-cost and stable electrocatalytic materials. Transition metal borides/borates have recently emerged as promising electrocatalytic materials for catalyzing hydrogen/oxygen evolution reactions(HER/OER) in inexpensive electrolyzers. However, so far, there has been little comprehensive summary of transition metal borides/borates. Here, this review provides the latest research progress on transition metal borides/borates for electrocatalytic water splitting. The structural characteristics of transition metal borides/borates and their synthesis methods in recent years are discussed. Then, the theoretical and experimental progress of transition metal borides including single-metal borides, multi-metal borides, borate derived and other nanocomposites containing boron(boron-doped nanocomposites/substrate with boron) in electrocatalytic reaction and the role of boron in regulating electrocatalytic performance are further emphasized. Finally, the potential challenges and future prospects of transition metal borides/borates in electrocatalysis are presented.

关键词： transition metal borides/borates electrocatalysts hydrogen evolution reaction(HER) oxygen evolution reaction(OER) overall water splitting

THE EFFECTS OF PHYSIOLOGICAL FLOW WAVEFORM ON WALL SHEAR STRESS IN CAROTID BIFURCATION MODEL

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Journal of Hydrodynamics 2009年第5期21卷 669-674页

作者： liu bin liu Xin-yue DING Zu-rong Department of Engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China

Numerical models of carotid bifurcation were constructed using a combination of tuning-fork bifurcation and straight or curved common carotid. The different inlet velocity profiles of the common carotid were generated for Bloch flow waveform and Holdsworth flow waveform, respectively. The effects of the different flow waveform for the common carotid on Wall Shear Stress （WSS） and Oscillatory Shear Index （OSI） of carotid bifurcation were studied by CFD method. The results show that the physiological flow waveform of curved common carotid has a significant effect on OSI. In particular, the OSI on the outer walls of carotid sinus and external carotid becomes higher in the inward-curved common carotid for Holdsworth flow waveform. But, in both cases of low WSS and high OSI, the effects of flow waveforms are smaller than those of the curved common carotid. The study reveals that the exact knowledge of the physiological flow waveform, vascular geometry and inlet velocity profile is important for hemodynamic numerical simulation of artery bifurcation.

关键词： carotid bifurcation physiological flow waveform Wall Shear Stress (WSS) Oscillatory Shear Index (OSI) numerical simulation

Research on low carbon emission optimization operation technology of natural gas pipeline under multi-energy structure

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Petroleum Science 2022年第6期19卷 3046-3058页

作者： En-bin liu Yong Peng Shan-Bi Peng bin Yu Qi-Kun Chen Petroleum Engineering School Southwest Petroleum UniversityChengdu610500China School of Civil Engineering and Geomatics Southwest Petroleum UniversityChengdu610500China China Petroleum Pipeline Engineering Corporation Hebei065000China School of Engineering Cardiff UniversityCardiffCF243AAUK

In order to reduce the carbon emissions of natural gas pipelines,based on the background of different energy structures,this paper proposes a general low carbon and low consumption operation model of natural gas pipelines,which is used to fine calculate the carbon emissions and energy consumption of natural gas *** this paper,an improved particle swarm optimization(NHPSO-JTVAC)algorithm is used to solve the model and the optimal scheduling scheme is *** a parallel pipeline located in western China as an example,the case is *** results show that after optimization,under the existing energy types,the pipeline system can reduce 31.14%of carbon emissions,and after introducing part of new energy,the pipeline system can reduce 34.02%of carbon emissions,but the energy consumption has increased.

关键词： Natural gas Pipeline optimization NHPSO-JTVAC algorithm Carbon emission New energy

Warm deformation behavior and work-softening mechanism of Fe- 6.5wt.%Si alloy

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Journal of Iron and Steel Research International 2020年第3期27卷 342-354页

作者： Xiang-ju Shi Yong-feng Liang bin-bin liu Bao Zhang Feng Ye State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

Warm deformation behavior of the Fe-6.5wt.%Si alloy was studied by isothermal compression in the temperature range of 300-700℃.The results show that the influence of the ordered phases on the flow stress gradually weakens with increasing deformation *** flow stress of the furnace-cooled sample with the high degree of order at 300℃is higher than that of the quenched sample with the low degree of order,and the flow stresses of both samples are nearly the same at 500-700℃.The hardness difference between two samples deformed at 500℃gradually decreases with increasing strain,accompanying with a reduction in hardness of the furnace-cooled sample,which indicates a work-softening *** analyses of dislocation configurations and ordered structure suggest that the dynamic recovery and deformation-induced disorder result in the work-softening *** appropriate deformation temperature window for improving the formability of the Fe-6.5wt.%Si alloy is about 500-600℃.

关键词： Fe-6.5wt.%Si alloy Work softening Ordered structure Dynamic recovery Anti-phase boundary Dislocation

GEANT4 simulation of water volume fraction measurement in dehydrated crude oil

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Nuclear Science and Techniques 2007年第4期18卷 198-203页

作者： JING Chunguo XING Guangzhong liu bin College of Electric Engineering Yanshan University Qinhuangdao 066004 China

Online measurement of water volume fraction (WVF) in dehydrated crude oil is a difficult task due to very little water in dehydrated crude oil and high precision requirements. We presents a method to measure water volume fraction in dehydrated crude oil with γ-ray densitometry. The Monte Carlo computer simulation packet GEANT4 was used to analyze the WVF measuring sensitivity of the γ-ray densitometry at different γ-ray energies, and effects of temperature, pressure, salinity and oil components on WVF measurement. The results show that the γ-ray densitometry has high sensitivity in γ-ray energy ranges of 16~25keV, and it can distinguish WVF changes of 0.0005. The calculated WVF decreases about 0.0002 with 1℃ of temperature increase and they have approximately linear relation with temperature when water volume fraction remains the same. Effects of pressure, salinity and oil components on water volume fraction can be neglected. Experiments were done to analyze sensitivity of the γ-ray densitometry. The results , as compared with simulations, demonstrate that simulation method is reliable and it is feasible to gauge low water volume fraction using low energy γ-rays.

关键词：石油脱水含水率密度测试

The Practice of Forward Prospecting of Adverse Geology Applied to Hard Rock TBM Tunnel Construction： The Case of the Songhua River Water Conveyance Project in the Middle of Jilin Province

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Engineering 2018年第1期4卷 131-137页

作者： Shucai Li Lichao Nie bin liu Geotechnical and Structural Engineering Research Center Shandong University Jinan 250061 China

An increasing number of tunnels are being constructed with tunnel-boring machines （TBMs） due to the increased efficiency and shorter completion time resulting from their use. However, when a TBM encoun- ters adverse geological conditions in the course of tunnel construction （e.g., karst caves, faults, or frac- tured zones）, disasters such as water and mud inrush, collapse, or machine blockage may result, and may severely imperil construction safety. Therefore, the advance detection of adverse geology and water-bearing conditions in front of the tunnel face is of great importance. This paper uses the TBM tun- neling of the water conveyance project from Songhua River as a case study in order to propose a compre- hensive forward geological prospecting technical system that is suitable for TBM tunnel construction under complicated geological conditions. By combining geological analysis with forward geological prospecting using a three-dimensional （3D） induced polarization method and a 3D seismic method, a comprehensive forward geological prospecting technical system can accurately forecast water inrush geo-hazards or faults in front of the TBM tunnel face. In this way, disasters such as water and mud inrush, collapse, or machine blockage can be avoided. This prospecting technical system also has reference value for carrying out the forward prospecting of adverse geology for potential TBM tunneling and for ensuring that a TBM can work efficiently.

关键词： Hard rock TBM tunnels Comprehensive forward prospecting Geological analysis3D induced polarization3D seismic methodAdverse geology