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Response of runoff and its components to climate change in the Manas River of the Tian Shan Mountains

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Advances in Climate Change Research 2024年第1期15卷 62-74页

作者： Ze-Long YANG peng bai Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 10010lChina University of Chinese Academy of Sciences Beijing 100049China

A warming-wetting climate trend has led to increased runoff in most watersheds in the Tian Shan Mountains over the past few ***,it remains unclear how runoff components,that is,rainfall runoff(Rrain),snowmelt runoff(Rsnow),and glacier meltwater(Rglacier),responded to historical climate change and how they will evolve under future climate change ***,we used a modified Hydrologiska Byrans Vattenbalansavdelning(HBV)model and a detrending method to quantify the impact of precipitation and temperature changes on runoff components in the largest river(Manas River)on the northern slope of the Tian Shan Mountains from 1982 to 2015.A multivariate calibration strategy,including snow cover,glacier area,and runoff was implemented to constrain model parameters associated with runoff *** downscaled outputs of 12 general circulation models(GCMs)from the Sixth Coupled Model Intercomparison Project(CMIP6)were also used to force the modified HBV model to project the response of runoff and its components to future(2016-2100)climate change under three common socio-economic pathways(SSP126,SSP245,and SSP585).The results indicate that Rrain dominates mean annual runoff with a proportion of 42%,followed by Rsnow(37%)and Rglacier(21%).In terms of inter-annual variation,Rrain and Rsnow show increasing trends(0.93(p0.05)mm per year),while Rglacier exhibits an insignificant(p>0.05)decreasing trend(-0.12 mm per year),leading to an increasing trend in total runoff(1.12 mm per year,p>0.05).The attribution analysis indicates that changes in precipitation and temperature contribute 8.16 and 10.37 mm,respectively,to the increase in runoff at the mean annual *** wetting(increased precipitation)increases Rrain(5.03 mm)and Rsnow(3.19 mm)but has a limited effect on Rglacier(-0.06 mm),while warming increases Rrain(10.69 mm)and Rglacier(5.79 mm)but decreases Rsnow(-6.12 mm).The negative effect of glacier shrinkage on Rglacier has outweighed the

关键词： Tian Shan Rainfall runoff Snowmelt runoff Glacier meltwater Warming-wetting Tipping point

On the Existence and Uniqueness of Solutions to Stochastic Differential Equations Driven by G-Brownian Motion with Integral-Lipschitz Coefficients

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Acta Mathematicae Applicatae Sinica 2014年第3期30卷 589-610页

作者： Xue-peng bai Yi-qing LIN Institut de Recherche Mathématique de Rennes Université de Rennes1 School of Mathematics Shandong University Institut de Recherche Mathématique de Rennes Université de Rennes

In this paper, we study the existence and uniqueness of solutions to stochastic differential equations driven by G-Brownian motion （GSDEs） with integral-Lipschitz coefficients.

关键词： G-Brownian motion G-expectation G-stochastic differential equations G-backward stochastic differential equations integral-Lipschitz condition

Hydrogen embrittlement of X80 pipeline steel in H2S environment: Effect of hydrogen charging time, hydrogen-trapped state and hydrogen charging–releasing–recharging cycles

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International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 63-73页

作者： peng-peng bai Jie Zhou Bing-wei Luo Shu-qi Zheng peng-yan Wang Yu Tian State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China JAC Volkswagen Automotive Co. Ltd.Hefei 230601China SINOPEC Tenth Construction Company Ltd.Qingdao 266555China

This study investigated the susceptibility of X80 pipeline steel to hydrogen embrittlement given different hydrogen pre-charging times and hydrogen charging–releasing–recharging cycles in H2S *** fracture strain of the steel samples decreased with increasing hydrogen pre-charging time;this steel degradation could almost be recovered after diffusible hydrogen was removed when the hydrogen pre-charging time was<8 ***,unrecoverable degeneration occurred when the hydrogen pre-charging time extended to 16–30 ***,nanovoid formation meant that the hydrogen damage to the steel under intermittent hydrogen pre-charging–releasing–recharging conditions was more serious than that under continuous hydrogen pre-charging *** study illustrated that the mechanical degradation of steel is inevitable in an H2S environment even if diffusible hydrogen is removed or visible hydrogen-induced cracking is ***,the steel samples showed premature fractures and exhibited a hydrogen fatigue effect because the repeated entry and release of diffusible hydrogen promoted the formation of vacancies that aggregated into *** results provide valuable information on the mechanical degradation of steel in an H2S environment,regarding the change rules of steel mechanical properties under different hydrogen pre-charging times and hydrogen charging–releasing–recharging cycles.

关键词： high-strength steel hydrogen embrittlement corrosion hydrogen diffusion

Modelling and Optimizing Motherboard Functional Testing in Laptop Manufacturing

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Journal of Systems Science & Complexity 2024年第6期37卷 2406-2423页

作者： bai peng KANG Yu WANG Kangcheng ZHAO Yunbo DONG Shaojie Department of Automation University of Science and Technology of ChinaHefei 230026China Department of Automation&Institute of Advanced Technology University of Science and Technology of ChinaHefei 230026China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China Institute of Advanced Technology University of Science and Technology of ChinaHefei 230026China

Functional testing is key to fulfill quality control in laptop manufacturing and is of great economic ***,due to the unavailability of practical data,mathematical model and systematic perspective,it has barely been touched from the academic community to *** the first time,this work provides technical understanding of the key principles of functional testing,mathematically models the general framework,elucidates existing testing strategy under the proposed framework and model,and finally proposes a specified optimization strategy which outperforms existing *** work lays the model foundation for the further optimization of functional testing,and can be regarded as a good example of how a systematic approach can solve practical industrial challenges.

关键词： Laptop manufacturing modelling motherboard functional testing optimization

High Efficient Numerical Simulation of Infrared Radiation from a Hot Exhaust Nozzle

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Communications in Computational Physics 2012年第4期11卷 1182-1204页

作者： Haiyang Hu peng bai Qiang Wang China Academy of Aerospace Aerodynamics Beijing 100074P.R.China School of Jet Propulsion Beihang UniversityBeijing 100191P.R.China

A coupled model,capable of simulating transonic flow,solid heat conduction,species transport,and gas radiation,is developed that provides better computational treatment of infrared radiation from hot exhaust *** modeling of gas radiation is based on a statistical narrow-band correlated-k analysis,whose parameters are deduced from the HITEMP line-by-line *** improve computational efficiency,several methods are employed.A mixed analytical-numerical algorithm is described for the stiffness of the two-equation turbulence model and an alternating direction implicit pretreatment for the ill-conditioned matrix appearing in the coupled problem of flow and solid heat ***,an improved multigrid method and a symmetry plane treatment of the radiation transfer-energy equations are also *** numerical simulations are given to confirm the efficiency and accuracy of the numerical ***,an account of the aerothermodynamics and infrared characteristics for two types of nozzles are *** infrared radiation intensity of the Chevron ejecting nozzle is clearly smaller than that of the common axisymmetric ejecting *** computations can be performed on a personal computer.

关键词： Numerical simulation infrared radiation exhaust nozzle stiffness of two-equation turbulence model

Tidal energy budget in the Zhujiang(Pearl River) Estuary

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Acta Oceanologica Sinica 2016年第5期35卷 54-65页

作者： bai peng GU Yanzhen LI Peiliang WU Kejian Physical Oceanography Laboratory Ocean University of China College of Information Science and Engineering Ocean University of China

Tidal energy budget in the Zhujiang（Pearl River） Estuary（ZE） is evaluated by employing high-resolution baroclinic regional ocean modeling system（ROMS）. The results obtained via applying the least square method on the model elevations are compared against the tidal harmonic constants at 18 tide stations along the ZE and its adjacent coast. The mean absolute errors between the simulation and the observation of M_2, S_2, K_1 and O_1 are 4.6, 2.8, 3.2 and 2.8 cm in amplitudes and 9.8°, 15.0°, 4.6° and 4.6° in phase-lags, respectively. The comparisons between the simulated and observed sea level heights at 11 tide gauge stations also suggest good model performance. The total tidal energy flux incoming the ZE is estimated to be 343.49 MW in the dry season and larger than 336.18 MW in the wet season, which should due to higher mean sea level height and heavier density in the dry season. M_2, K_1, S_2, O_1 and N_2, the top five barotropic tidal energy flux contributors for the ZE,import 242.23（236.79）, 52.97（52.08）, 24.49（23.96）, 16.22（15.91） and 7.10（6.97） MW energy flux into the ZE in dry（wet） season, successively and respectively. The enhanced turbulent mixing induced by eddies around isolated islands and sharp headlands dominated by bottom friction, interaction between tidal currents and sill topography or constricted narrow waterways together account for the five energy dissipation hotspots, which add up to about 38% of the total energy dissipation inside the ZE.

关键词： tidal energy flux energy dissipation Zhujiang Estuary regional ocean modeling system

Direct Coupling Reaction of Diaryl Methanol with Ketones or Aldehydes Catalyzed by AlCl_(3)

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Chinese Journal of Chemistry 2014年第11期32卷 1176-1182页

作者： Zhiqiang Zhu peng bai Tiantian Wang Zhizhen Huang Department of Chemistry Zhejiang UniversityHangzhouZhejiang 310028China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

A novel coupling reaction of diaryl methanols with ketones or aldehydes has been developed under the catalysis of AlCl_(3).Various ketones and aldehydes could couple with 9H-xanthen-9-ol smoothly,affording coupling products in 48%-88%yields.A plausible mechanism using AlCl_(3) to activate both diaryl methanol and ketone or aldehyde is proposed.

关键词： coupling reaction alcohol ketone aldehyde AlCl_(3) catalysis

Observation of the supercritical Pearl River plume front under the downwelling-favorable winds

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Science China Earth Sciences 2015年第11期58卷 2059-2066页

作者： bai peng GU YanZhen LUO Lin ZHANG WanLei FAN KaiGuo College of Physical and Environmental Oceanography Ocean University of China College of Information Science and Engineering Ocean University of China Institute of Space and Earth Information Science Chinese University of Hong Kong State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Qinhuangdao Marine Environmental Monitoring Central Station of SOA 91039 Army PLA

For the Pearl River plume, the supercritical, distinct plume front appears in downwelling-favorable winds, which is easily observed due to the distinct boundary between the plume water and the ambient water. In this paper, in situ and satellite observations of a plume front are utilized to explore the Pearl River plume front properties under the downwelling-favorable winds. Field observations clearly show frontal structure, especially the two-layer structure in the plume water and the downward-motion of water in the frontal region. The Advanced Synthetic Aperture Radar(ASAR) images are also analyzed to unveil the plume front: there is a white stripe on the west side out of the river mouth under downwelling-favorable winds, which is identified as a supercritical plume front, and the width of the plume front is about 250 m. The normalized velocity gradient shows the intense velocity convergence in the front region. Also, analyses of ASAR images imply that the river discharge plays an important role in controlling the location and shape of the front.

关键词： cruise observations Pearl River plume front ASAR winds

A new bionic MAV's flapping motion based on fruit fly hovering at low Reynolds number

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Acta Mechanica Sinica 2007年第5期23卷 485-493页

作者： peng bai Erjie Cui Feng Li Weijiang Zhou Bingyan Chen China Academy of Aerospace Aerodynamics Beijing 100074 China

On the basis of the studies on the high unsteady aerodynamic mechanisms of the fruit fly hovering the aerodynamic advantages and disadvantages of the fruit fly flapping motion were analyzed. A new bionic flapping motion was proposed to weaken the disadvantages and maintain the advantages, it may be used in the designing and manufacturing of the micro air vehicles （MAV＇s）. The translation of the new bionic flapping motion is the same as that of fruit fly flapping motion. However, the rotation of the new bionic flapping motion is different. It is not a pitching-up rotation as the fruit fly flapping motion, but a pitching-down rota- tion at the beginning and the end of a stroke. The numerical method of 3rd-order Roe scheme developed by Rogers was used to study these questions. The correctness of the numerical method and the computational program was justified by comparing the present CFD results of the fruit fly flapping motion in three modes, i.e., the advanced mode, the symmetrical mode and the delayed mode, with Dickinson＇s experimental results. They agreed with each other very well. Subsequently, the aerodynamic characteristics of the new bionic flapping motion in three modes were also numerically simulated, and were compared with those of the fruit fly flap- ping. The conclusions could be drawn that the high unsteady lift mechanism of the fruit fly hovering is also effectively utilized by this new bionic flapping. Compared with the fruit fly flapping, the unsteady drag of the new flapping decreases very much and the ratio of lift to drag increases greatly. And the great discrepancies among the mean lifts of three flapping modes of the fruit fly hovering are effectively smoothed in the new flapping. On the other hand, this new bionic flapping motion should be realized more easily. Finally, it must be pointed out that the above conclusions were just drawn for the hovering flapping motion. And the aerodynamic characteristics of the new bionic flapping motion in forwa

关键词： Flapping wing Low Reynolds number.MAV's Unsteady Numerical simulation