Hydrologic Response to Future Climate Change in the Dulong-Irra-waddy River Basin Based on Coupled Model Intercomparison Project 6

Within the context of the Belt and Road Initiative(BRI)and the China-Myanmar Economic Corridor(CMEC),the Dulong-Ir-rawaddy(Ayeyarwady)River,an international river among China,India and Myanmar,plays a significant role as both a valuable hydro-power resource and an essential ecological passageway.However,the water resources and security exhibit a high degree of vulnerabil-ity to climate change impacts.This research evaluates climate impacts on the hydrology of the Dulong-Irrawaddy River Basin(DIRB)by using a physical-based hydrologic model.We crafted future climate scenarios using the three latest global climate models(GCMs)from Coupled Model Intercomparison Project 6(CMIP6)under two shared socioeconomic pathways(SSP2-4.5 and SSP5-8.5)for the near(2025-2049),mid(2050-2074),and far future(2075-2099).The regional model using MIKE SHE based on historical hydrologic processes was developed to further project future streamflow,demonstrating reliable performance in streamflow simulations with a val-idation Nash-Sutcliffe Efficiency(NSE)of 0.72.Results showed that climate change projections showed increases in the annual precip-itation and potential evapotranspiration(PET),with precipitation increasing by 11.3%and 26.1%,and PET increasing by 3.2%and 4.9%,respectively,by the end of the century under SSP2-4.5 and SSP5-8.5.These changes are projected to result in increased annual streamflow at all stations,notably at the basin’s outlet(Pyay station)compared to the baseline period(with an increase of 16.1%and 37.0%at the end of the 21st century under SSP2-4.5 and SSP5-8.5,respectively).Seasonal analysis for Pyay station forecasts an in-crease in dry-season streamflow by 31.3%-48.9%and 22.5%-76.3%under SSP2-4.5 and SSP5-8.5,respectively,and an increase in wet-season streamflow by 5.8%-12.6%and 2.8%-33.3%,respectively.Moreover,the magnitude and frequency of flood events are pre-dicted to escalate,potentially impacting hydropower production and food security significantly.This research outlines the hydrological response to future climate change during the 21st century and offers a scientific basis for the water resource management strategies by decision-makers.

Projective synchronisation with non-delayed and delayed coupling in complex networks consisting of identical nodes and different nodes

This paper first investigates the projective synchronisation problem with non-delayed and delayed coupling between drive-response dynamical networks consisting of identical nodes and different nodes. Based on Lyapunov stability theory, several nonlinear controllers are applied to achieve the projective synchronisation between the drive-response dynamical networks; simultaneously the topological structure of the drive dynamical complex networks can be exactly identified. Moreover, numerical examples are presented to verify the feasibility and effectiveness of the theorems.

Mechanics analysis of a wheelchair robot with wheel-track coupling mechanism

A barrier-free wheelchair robot with a mechanism coupled by wheel and track is presen- ted in this paper. Using the wheelchair, the lower limb disabled persons could be more relaxed to take part in outdoor activities whether on flat ground or stairs and obstacles in the city. The wheel- track coupling mechanism is designed and the stability of the bodywork of the wheelchair robot on the stairs is analyzed. In order to obtain the stability of wheelchair robot when it climbs obstacles, centroid projection method is applied to analyze the static stability, stability margin is proposed to provide the stability under some dynamic forces, and the push rod rotation angle in terms of the guaranteed stability margin is given. Finally, the dynamic model of the wheelchair robot based on Lagrange equation is established, which can be a theoretical foundation for the wheelchair control system design.

Projection of precipitation extremes over South Asia from CMIP6 GCMs

Extreme precipitation events are one of the most dangerous hydrometeorological disasters,often resulting in significant human and socio-economic losses worldwide.It is therefore important to use current global climate models to project future changes in precipitation extremes.The present study aims to assess the future changes in precipitation extremes over South Asia from the Coupled Model Intercomparison Project Phase 6(CMIP6)Global Climate Models(GCMs).The results were derived using the modified Mann-Kendall test,Sen's slope estimator,student's t-test,and probability density function approach.Eight extreme precipitation indices were assessed,including wet days(RR1mm),heavy precipitation days(RR10mm),very heavy precipitation days(RR20mm),severe precipitation days(RR50mm),consecutive wet days(CWD),consecutive dry days(CDD),maximum 5-day precipitation amount(RX5day),and simple daily intensity index(SDII).The future changes were estimated in two time periods for the 21^(st) century(i.e.,near future(NF;2021-2060)and far future(FF;2061-2100))under two Shared Socioeconomic Pathway(SSP)scenarios(SSP2-4.5 and SSP5-8.5).The results suggest increases in the frequency and intensity of extreme precipitation indices under the SSP5-8.5 scenario towards the end of the 21^(st) century(2061-2100).Moreover,from the results of multimodel ensemble means(MMEMs),extreme precipitation indices of RR1mm,RR10mm,RR20mm,CWD,and SDII demonstrate remarkable increases in the FF period under the SSP5-8.5 scenario.The spatial distribution of extreme precipitation indices shows intensification over the eastern part of South Asia compared to the western part.The probability density function of extreme precipitation indices suggests a frequent(intense)occurrence of precipitation extremes in the FF period under the SSP5-8.5 scenario,with values up to 35.00 d for RR1mm and 25.00-35.00 d for CWD.The potential impacts of heavy precipitation can pose serious challenges to the study area regarding flooding,soil erosion,water resource management,food security,and agriculture development.

Numerical Simulation of Projection Welding Processes for Door Hinge of Automobile Based on Coupled Fields Analysis

Projection welding is a variation of electric resistance welding with the dynamic changes of the flow paths for heat and electrical properties with changing temperature caused by the large plastic deformation collapse of projection. As the joint type between the auto door hinge and the inner plate, projection welding may bring welding distortions and would affect the assembly quality of auto body. A comprehensive electric-thermal-mechanical numerical simulation was performed to quantitatively simulate the processes of projection welding by using a coupled finite element method. The mechanism of projection collapse and the formation process of nugget were discussed and good conclusions have been achieved comparing with the test results.

Projected Regional 1.50℃and 2.00℃Warming Threshold-crossing Time Worldwide Using the CMIP6 Models

The Paris Agreement aims to limit global warming to well below 2.00℃and pursue efforts to limit the temperature increase to 1.50℃.However,the response of climate change to unbalanced global warming is affected by spatial and temporal sensitivities.To better understand the regional warming response to global warming at 1.50℃and 2.00℃,we detected the 1.50℃and 2.00℃warming threshold-crossing time(WTT)above pre-industrial levels globally using the Coupled Model Intercomparison Project phase 6(CMIP6)models.Our findings indicate that the 1.50℃or 2.00℃WTT differs substantially worldwide.The warming rate of land would be approximately 1.35–1.46 times that of the ocean between 60°N–60°S in 2015–2100.Consequently,the land would experience a 1.50℃(2.00℃)warming at least 10–20 yr earlier than the time when the global mean near-surface air temperature reaches 1.50℃(2.00℃)WTT.Meanwhile,the Southern Ocean between 0°and 60°S considerably slows down the global 1.50℃and 2.00℃WTT.In 2040–2060,over 98.70%(77.50%),99.70%(89.30%),99.80%(93.40%),and 100.00%(98.00%)of the land will have warmed by over 1.50℃(2.00℃)under SSP(Shared Socioeconomic Pathway)1–2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5,respectively.We conclude that regional 1.50℃(2.00℃)WTT should be fully considered,especially in vulnerable high-latitude and high-altitude regions.

FGOALS高分辨率气候模式系统模式研制与应用综述

当今气候系统模式发展的重要趋势之一,是通过提高模式的空间分辨率,改进对气候系统中多尺度相互作用过程和极端事件的模拟能力。过去5年里,中国科学院大气物理研究所发展并完善了25 km分辨率大气环流分量模式FAMIL2.2、1/10°分辨率海洋环流分量模式LICOM3.0,并以此为基础建立了高分辨率气候系统模式FGOALS-f3-H。利用上述高分辨率模式,开展了大量的数值模拟试验和预报/预测研究,其中包括国际耦合模式比较计划第六阶段(CMIP6)的高分辨率模式比较子计划(HighResMIP),建立了海洋环流预测系统(LFS)等。初步评估分析表明,相对于低分辨率模式,高分辨率模式对气候平均态和气候变率的模拟能力均有明显改进。其中高分辨率大气环流模式可以更好地模拟台风、极端降水事件,高分辨率海洋模式可以更好地模拟海洋中尺度涡旋和西边界流,而高分辨率耦合模式则可以更好重现中尺度海气相互作用过程、热带不稳定波动(TIW)等事件。

政府公益创投与项目制的耦合机制分析

我国政府公益创投出现了与政府购买服务趋同、难以赋能社会组织的突出问题。基于耦合共振理论的分析表明,政府购买服务所内含的项目制逻辑与公益创投存在张力,但二者在目标、流程和中介组织上存在耦合的可能性。对J省XL公益创投的案例分析显示,在基本条件具备的前提下,政府主导下的社会化、有控制的授权、复合型赋能和多重激励等机制能够将耦合的可能性转化为现实。公益创投与项目制的耦合体现了项目制所具有的弹性空间和公益创投转型发展的可能方向。

长江流域旱涝急转演变特征及其社会经济暴露度

旱涝急转是指干旱和洪水之间的快速转变,对农业生产和人类安全造成巨大威胁。本研究基于月尺度的旱涝急转量级指数,分析了长江流域历史和未来四种旱涝急转事件,并通过滑窗法构建了旱涝急转量级的时变函数,揭示了未来旱涝急转风险变化。同时,结合共享社会经济路径量化了人口和经济受旱涝急转风险变化影响的程度。结果显示,历史时期长江流域中下游旱涝急转事件频发,旱–涝和涝–旱事件每10年发生10~12次,而旱–涝–旱和涝–旱–涝事件每10年发生3~4次。未来旱–涝–旱和涝–旱–涝事件预计大幅增加,其中长江上游部分地区增长了约7倍。对于历史基准期50年一遇的旱涝急转事件,未来发生概率将增加5~10倍,给长江流域的人口和经济带来重大影响。

深中通道岛隧结合部波流特性及覆盖层稳定性试验研究

基于岛隧工程结合部与传统隧道、近岸陆地工程衔接存在明显差别,以及在设计上面临的新难题,为保证深中通道岛隧结合部沉管隧道覆盖层在极端恶劣条件下的安全性和可靠性,对结合部区域范围内波流特性和防护结构的稳定性进行了研究。通过开展物理模型试验,模拟了包括波浪和水流之间变化角度的水动力场,以及波流耦合作用护面块体稳定性;揭示了岛隧结合部波流耦合效应,总结了波高比(H_(s)′/H_(s))和流速比(U′/U)与相对流速(U/C)、波陡(H_(s)/L)、相对水深(d/L)和波流夹角(α)变化规律,并导出了相应的计算公式;同时通过多组试验对比优化,获得了护面块体最优稳定重量,导出了波流耦合作用下护面块体稳定重量的计算方法。研究结果不仅解决了深中通道重大工程的实际问题,也为今后海底沉管隧道覆盖层的建设提供基础数据和技术支撑。

双碳视角下长江经济带碳排放-经济-环境耦合协调度分析

以长江经济带为分析对象,从多元耦合协调度与空间视角出发,利用耦合协调度模型对2008—2019年该区域内11个省市的碳排放-经济-环境三系统的耦合协调度进行探究,并使用莫兰指数对耦合协调度进行空间相关性分析。研究结果表明:长江经济带各子系统均呈现波动增长的趋势并趋于平衡,整体耦合协调度类型由中度耦合协调转变为高度耦合协调;从各省市层面来看,耦合协调度呈现出“东高西低、下游>中游>上游”的阶梯状地域分布特征;长江经济带耦合协调度存在显著的空间集聚性,主要表现为下游江浙沪的高-高聚集与上游的低-低聚集。为促进该区域的高水平协调发展,未来可以从优化产业结构、促进深度合作等方面进行突破。

南水北调中线工程输水建筑物整流累积效应研究

为分析输水建筑物整流对南水北调中线工程输水能力的影响,以陶岔渠首闸至十二里河渡槽渠段为例,建立一二维耦合水动力模型,其中渠道段采用一维模型,4个输水建筑物段(刁河渡槽、湍河渡槽、严陵河渡槽和淇河倒虹吸)采用二维模型,利用多年实测数据对耦合模型进行率定。分别对无整流方案和15种整流方案进行模拟计算,分析不同整流方案对上下游的影响,进而确定水头损失最小的整流方案。结果表明:单体整流影响范围为建筑物上下游3~5 km,多个建筑物整流的累积效果小于单个建筑物整流效果的线性叠加;对渠段中间2个输水建筑物(湍河渡槽、严陵河渡槽)进行整流的效果优于对上下游2个输水建筑物(刁河渡槽、淇河倒虹吸)进行整流的效果。

Variability of the Pacific subtropical cells under global warming in CMIP6 models

The Pacific subtropical cells(STCs)are shallow meridional overturning circulations connecting the tropics and subtropics,and are assumed to be an important driver of the tropical Pacific decadal variability.The variability of STCs under global warming is investigated using multimodal outputs from the latest phase of the Coupled Model Inter-comparison Project(CMIP6)and ocean reanalysis products.Firstly,the volume transport diagnostic analysis is employed to evaluate how coupled models and ocean reanalysis products reproduce interior STC transport.The variation of heat transport by the interior STC under the high-emissions warming scenarios is also analyzed.The results show that the multimodal-mean linear trends of the interior STC transport along 9°S and 9°N are-0.02 Sv/a and 0.04 Sv/a under global warming,respectively,which is mainly due to the combined effect of the strengthened upper oceanic stratification and the weakening of wind field.There is a compensation relationship between the interior STC and the western boundary transport in the future climate,and the compensation relationship of 9°S is more significant than that of 9°N.In addition,compared with ocean reanalysis products,the coupled models tend to underestimate the variability of the interior STC transport convergence,and thus may lose some sea surface temperature(SST)driving force,which may be the reason for the low STC-SST correlation simulated by the model.The future scenario simulation shows that the heat transport of interior STC is weakened under global warming,with a general agreement across models.

Comparative Assessment of Impacts of Future Climate Change on Runoff in Upper Daqinghe Basin,China

Assessing runoff changes is of great importance especially its responses to the projected future climate change on local scale basins because such analyses are generally done on global and regional scales which may lead to generalized conclusions rather than specific ones.Climate change affected the runoff variation in the past in the upper Daqinghe Basin,however,the climate was mainly considered uncertain and still needs further studies,especially its future impacts on runoff for better water resources management and planning.Integrated with a set of climate simulations,a daily conceptual hydrological model(MIKE11-NAM)was applied to assess the impact of climate change on runoff conditions in the Daomaguan,Fuping and Zijingguan basins in the upper Daqinghe Basin.Historical hydrological data(2008–2017)were used to evaluate the applicability of the MIKE11-NAM model.After bias correction,future projected climate change and its impacts on runoff(2025–2054)were analysed and compared to the baseline period(1985–2014)under three shared social economic pathways(SSP1-2.6,SSP2-4.5,and SSP5-8.5)scenarios from Coupled Model Intercomparison Project Phase 6(CMIP6)simulations.The MIKE-11 NAM model was applicable in all three Basins,with both R^(2)and Nash-Sutcliffe Efficiency coefficients greater than 0.6 at daily scale for both calibration(2009–2011)and validation(2012–2017)periods,respectively.Although uncertainties remain,temperature and precipitation are projected to increase compared to the baseline where higher increases in precipitation and temperature are projected to occur under SSP2-4.5 and SSP5-8.5 scenarios,respectively in all the basins.Precipitation changes will range between 12%–19%whereas temperature change will be 2.0℃–2.5℃ under the SSP2-4.5 and SSP5-8.5 scenarios,respectively.In addition,higher warming is projected to occur in colder months than in warmer months.Overall,the runoff of these three basins is projected to respond to projected climate changes differently because runoff is projected to only increase in the Fuping basin under SSP2-4.5 whereas decreases in both Daomaguan and Zijingguan Basins under all scenarios.This study’s findings could be important when setting mitigation strategies for climate change and water resources management.

工程材料专业复合教学模式创新设计及实践效果

为了实现复合材料与工程专业人才培养质量的提升,构建以目标为导向、学生通过实质参与进行有效学习的格局,提出基于对分课堂与项目式教学的紧耦合关系构建复合型教学模式。以《程序设计基础》课程为对象,以“航空复合材料库存管理系统”为主线构建项目式对分课堂教学模式,从实施策略和实施路径进行了理论分析与实践探索。实践效果表明:项目式对分课堂实施过程明确,有较强的可操作性,对教师与学生双方的能力都有一定的提升,符合应用型本科院校课程教学特点,是一种互利共生的教学模式。

基于耦合协调性的区域洪水资源利用评价

为全面理解和优化区域水资源利用格局、提高区域水资源利用率,以南水北调东线工程江苏段主要涉及的徐州、宿迁、淮安3个城市为研究对象,以2010-2022年数据为基础从基于洪水资源开发利用的水资源利用、经济社会发展、生态环境保护3个维度,采用共23项指标在使用熵权法确定权重的基础上,构建基于洪水资源开发利用的水资源利用-经济社会-生态环境系统容量耦合协调发展模型,并结合匹配度模型进行比较分析,运用障碍度模型分析影响耦合协调发展的因素。结果表明:3个城市的综合系统发展水平均由初级阶段上升到良好阶段。徐州、宿迁和淮安市的耦合协调度变化分别为勉强协调到良好协调、初级协调到良好协调以及初级协调到中级协调,而3个城市耦合协调度在后期均超越匹配度,达到理想协调状态。影响协调度的主要障碍因子为洪水资源利用潜力、森林覆盖率以及洪水资源量,且对于3个系统的障碍度分析,3个城市各自有不同的主导影响因素,徐州市复合系统耦合协调度主要受水资源利用影响较大,宿迁市受经济社会影响较大,而淮安市则受生态环境影响较大,因此,各市应当合理利用水库及蓄滞洪区的削峰、调蓄能力,增加洪水资源可利用量,提高洪水资源利用效率,降低洪灾发生频率,在保证经济和生态用水效率的同时,减少因洪灾带来的经济及生态损失。

A CMIP6-based assessment of regional climate change in the Chinese Tianshan Mountains

Climate warming profoundly affects hydrological changes,agricultural production,and human society.Arid and semi-arid areas of China are currently displaying a marked trend of warming and wetting.The Chinese Tianshan Mountains(CTM)have a high climate sensitivity,rendering the region particularly vulnerable to the effects of climate warming.In this study,we used monthly average temperature and monthly precipitation data from the CN05.1 gridded dataset(1961-2014)and 24 global climate models(GCMs)of the Coupled Model Intercomparison Project Phase 6(CMIP6)to assess the applicability of the CMIP6 GCMs in the CTM at the regional scale.Based on this,we conducted a systematic review of the interannual trends,dry-wet transitions(based on the standardized precipitation index(SPI)),and spatial distribution patterns of climate change in the CTM during 1961-2014.We further projected future temperature and precipitation changes over three terms(near-term(2021-2040),mid-term(2041-2060),and long-term(2081-2100))relative to the historical period(1961-2014)under four shared socio-economic pathway(SSP)scenarios(i.e.,SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5).It was found that the CTM had experienced significant warming and wetting from 1961 to 2014,and will also experience warming in the future(2021-2100).Substantial warming in 1997 was captured by both the CN05.1 derived from interpolating meteorological station data and the multi-model ensemble(MME)from the CMIP6 GCMs.The MME simulation results indicated an apparent wetting in 2008,which occurred later than the wetting observed from the CN05.1 in 1989.The GCMs generally underestimated spring temperature and overestimated both winter temperature and spring precipitation in the CTM.Warming and wetting are more rapid in the northern part of the CTM.By the end of the 21st century,all the four SSP scenarios project warmer and wetter conditions in the CTM with multiple dry-wet transitions.However,the rise in precipitation fails to counterbalance the drought induced by escalating temperature in the future,so the nature of the drought in the CTM will not change at all.Additionally,the projected summer precipitation shows negative correlation with the radiative forcing.This study holds practical implications for the awareness of climate change and subsequent research in the CTM.

硫酸烷基化装置聚结-吸附耦合脱酸技术应用总结

介绍了国内自主研发的聚结-吸附耦合干法脱酸技术在某石化硫酸烷基化装置中的工业应用情况。结果表明:聚结-吸附耦合干法脱酸技术代替碱洗、水洗系统后,烷基化油各项指标均符合要求,产品烷基化油中硫质量分数在8μg/g以下;与碱水洗工艺相比,采用聚结-吸附耦合干法脱酸工艺后,反应副产物被酸膜萃取和吸附脱除,分馏系统干式操作,避免了下游设备和管道的腐蚀;酸耗和能耗分别降低10%和8%,实现了节水及污水的零排放。在装置满负荷情况下,聚结-吸附耦合干法脱酸系统切出吸附罐后仍能保障产品合格。装置运行情况表明,聚结-吸附耦合干法脱酸技术中聚结起主要作用,吸附起保障作用。该技术不仅提高了装置本质安全性,而且降低了装置消耗量和废水排放量。

CMIP 6 models simulation of the connection between North/South Pacific Meridional Mode and ENSO

The subtropical North and South Pacific Meridional Modes(NPMM and SPMM)are well known precursors of El Niño-Southern Oscillation(ENSO).However,relationship between them is not constant.In the early 1980,the relationship experienced an interdecadal transition.Changes in this connection can be attributed mainly to the phase change of the Pacific decadal oscillation(PDO).During the positive phase of PDO,a shallower thermocline in the central Pacific is responsible for the stronger trade wind charging(TWC)mechanism,which leads to a stronger equatorial subsurface temperature evolution.This dynamic process strengthens the connection between NPMM and ENSO.Associated with the negative phase of PDO,a shallower thermocline over southeastern Pacific allows an enhanced wind-evaporation-SST(WES)feedback,strengthening the connection between SPMM and ENSO.Using 35 Coupled Model Intercomparison Project Phase 6(CMIP6)models,we examined the NPMM/SPMM performance and its connection with ENSO in the historical runs.The great majority of CMIP6 models can reproduce the pattern of NPMM and SPMM well,but they reveal discrepant ENSO and NPMM/SPMM relationship.The intermodal uncertainty for the connection of NPMM-ENSO is due to different TWC mechanism.A stronger TWC mechanism will enhance NPMM forcing.For SPMM,few models can simulate a good relationship with ENSO.The intermodel spread in the relationship of SPMM and ENSO owing to SST bias in the southeastern Pacific,as WES feedback is stronger when the southeastern Pacific is warmer.

基于生态安全的毛乌素沙地水资源承载力评价

毛乌素沙地地区作为我国生态治理成功有效的典型区域,相较于其他主要沙漠、沙地而言,具有资源丰富、水热配合好等优点,同时也是受到人类活动及气候变化威胁较大的生态脆弱区,如何保障生态安全的同时协调社会经济高质量发展,成为了当地所需解决的首要难题。以内蒙古鄂尔多斯毛乌素沙地地区为研究对象,构建基于生态安全的综合水资源承载力评价体系,运用投影寻踪法计算综合水资源承载力评价值,引入障碍度模型遴选地区承载力优势指标与劣势指标,采用耦合协调度模型测算资源-生态-社会系统耦合发展现状。结果表明:2000年至今毛乌素沙地地区的水资源承载力总体时间上呈现曲折上升趋势,但仍有提升空间,在空间上形成了“南北高,中心低”的空间分布特点,期间地下水供水能力、灌溉水利用系数和三产用水定额等是水资源承载力系统的主要“优势指标”,而人口、灌溉面积以及城镇化率则是阻碍水资源承载力提升的关键“劣势指标”,地区内各旗县耦合协调度从“十五”规划至今一直在中等水平范围内浮动。