Ascending phase of solar cycle 25 tilts the current El Nino-Southern oscillation transition

自2020年初夏,赤道太平洋地区出现拉尼娜现象并持续两年半多(以下简称2020拉尼娜),对其未来演变的预测引起了很多关注,考虑到11年太阳周期活动对热带太平洋SST异常可能存在锁相影响,本研究分析了当前太阳活动周(即第25太阳周(SC25))对目前热带太平洋ENSO现象未来演变的调节作用,基于历史太阳周的统计特征,作者对第25太阳周达到其最大值的时间提出三种可能的情景,并讨论了不同情景下的太阳活动对未来两年ENSO演变的可能影响,第25太阳周的持续上升阶段在一定程度上抑制了当前2023厄尔尼诺现象发展为超级事件.

Spratlies Archipelago as the Australasian Tektite Impact Crater, Details of Formation &Richard Muller’s Dust Cloud Explanation for the Mid-Pleistocene Ice Age Cycle Transition

Several significant events of a geological nature occurred approximately 800 ka before the present: (1) Australasian tektite fall (AA), (2) Brunhes-Matuyama geomagnetic reversal (BMR), (3) mid-Pleistocene changes in ice age cycles. Add to these the undated fault system (4) in the South-West (SW) of the South China Sea (SCS). Here we offer a unified cause for all four of these in (5), an impact in the SCS of a large, massive cosmic object, likely a comet, obliquely coming from the SW at an extremely shallow angle, striking the Sunda shelf yet unexploded with the shock of its compressed air bow wave, and causing the continual shelf and slope to collapse, resulting in the fault system (4), then traveling almost tangentially to the surface, exploding at impact with the sea surface, ejecting the tektites (1), creating the formation underlying the later atolls of Spratlies Archipelago (6), Nansha Islands in Chinese, & causing the BMR (2). An explanation of event (3) was Richard Muller’s hypothesis of planet Earth passing through an interplanetary dust cloud periodically due to ecliptic precession. Here we hypothesize this cloud actually is a belt of Australasian tektites ejected into space at super-orbital velocities that Earth encounters about every 100 ka.

Reversed rotation of limit cycle oscillation and dynamics of low-intermediate-high confinement transition

The dynamics of the confinement transition from L mode to H mode（LH） is investigated in detail theoretically via the extended three-wave coupling model describing the interaction of turbulence and zonal flow（ZF） for the first time.Thereinto, turbulence is divided into a positive-frequency（PF） wave and a negative-frequency（NF） one, and the gradient of pressure is added as the auxiliary energy for the system. The LH confinement transition is observed for a sufficiently high input energy. Moreover, it is found that the rotation direction of the limit cycle oscillation（LCO） of PF wave and pressure gradient is reversed during the transition. The mechanism is illustrated by exploring the wave phases. The results presented here provide a new insight into the analysis of the LH transition, which is helpful for the experiments on the fusion devices.

The Relationship between the El Nio/La Nia Cycle and the Transition Chains of Four Atmospheric Oscillations. Part Ⅱ:The Relationship and a New Approach to the Prediction of El Nio

ABSTRACT The authors explored the connection and transition chains of the Northern Oscillation （NO） and the North Pacific Oscilla tion （NPO）, the Southern Oscillation （SO）, and the Antarctic Oscillation （AAO） on the interannual timescale in a companion paper. In this study, the connection between the transition chains of the four oscillations （the NO and NPO, the SO and AAO） and the El Nifio/La Nifia cycle were examined. It was found that during the transitions of the four oscillations, alternate anticyclonic/cyclonic correlation centers propagated from the Western Pacific to the Eastern Pacific along both sides of the equator. Between the anticyclonic/cyclonic correlation centers, the zonal wind anomalies also moved eastwardly, favoring the advection of sea surface temperature anomalies from the tropical Western Pacific to the Eastern Pacific. When the anti cyclonic anomalies arrived in the Eastern Pacific, the positive phase of NO/SO and La Nifia were established and vice versa. Thus, in 4-6 years, with an entire transition chain of the four oscillations, an E1 Nifio/La Nifia cycle completed. The eastward propagation of the covarying anomalies of the sea level pressure, zonal wind, and sea surface temperature was critical to the transition chains of the four oscillations and the cycle of E1 Nifio/La Nifia. Based on their close link, a new empirical prediction method of the timing of E1 Nifio by the transition chains of the four oscillations was proposed. The assessment provided confidence in the ability of the new method to supply information regarding the long-term variations of the ocean and atmosphere in the tropical Pacific.

Synchronization transition of limit-cycle system with homogeneous phase shifts

The behaviors of coupled oscillators, each of which has periodic motion with random natural frequency in the absence of coupling, are investigated when phase shifts are considered. In the system of coupled oscillators, phase shifts are the same between different oscillators. Synchronization and synchronization transition are revealed with different phase shifts. Phase shifts play an important role for this kind of system. When the phase shift α〈 0.5π, the synchronization state can be attained by increasing the coupling, and the system cannot reach the synchronization state while α≥ 0.5π. A clear scaling between complete synchronization critical coupling strength Kpc and α - 0.5π is found.

Effects of Spin Transition and Cation Substitution on the Optical Properties and Iron Partitioning in Carbonate Minerals

The high-pressure behavior of deep carbonate dictates the state and dynamics of oxidized carbon in the Earth's mantle,playing a vital role in the global carbon cycle and potentially influencing long-term climate change.Optical absorption and Raman spectroscopic measurements were carried out on two natural carbonate samples in diamond-anvil cells up to 60 GPa.Mg-substitution in high-spin siderite FeCO_(3)increases the crystal field absorption band position by approximately 1000 cm^(-1),but such an effect is marginal at>40 GPa when entering the low-spin state.The crystal field absorption band of dolomite cannot be recognized upon compression to 45.8 GPa at room temperature but,in contrast,the high-pressure polymorph of dolomite exhibits a strong absorption band at frequencies higher than(Mg,Fe)CO_(3)in the lowspin state by 2000–2500 cm^(-1).Additionally,these carbonate minerals show more complicated features for the absorption edge,decreasing with pressure and undergoing a dramatic change through the spin crossover.The optical and vibrational properties of carbonate minerals are highly correlated with iron content and spin transition,indicating that iron is preferentially partitioned into low-spin carbonates.These results shed new light on how carbonate minerals evolve in the mantle,which is crucial to decode the deep carbon cycle.

Panorama of the Opening-Closing Tectonics Theory in China

The opening-closing tectonics theory, a theory about opening-closing tectonics, is a viewpoint regarding geotectonics suggested by a group of Chinese scientists. Opening and closing are two basic geological movements, which may result in a series of structures. The highest level of opening is the appearance of oceans and the highest level of closing is the consolidation of continents. Based on field investigations, the authors consider that identifying the marks of opening-closing tectonics is the basis of the issue and classifying the types of opening-closing tectonics is the key of the issue. This paper briefly discusses the substance and the future of the study on the opening-closing tecton cs in China. The authors hope to share relevant information with geoscientists in the world in this field.

Expanding the Wilson Cycle Based on Worldwide Comparison of Continental Structures Revealed by Lithospheric Geophysical Investigations

Worldwide comparison of lithospheric investigation results achieved from projects of COCORP, BIRPS, DEKORP, LITHOPROBE, ICDP, ECORS and SINOPROBE enables us to expand the classical Wilson cycle, which mainly describes evolution of ocean plates, into a complete and detailed cycle that describes generation, development and evolution of both ocean and continent plates. The expanded Wilson cycle presented in this paper introduces the evolution sequences of continental lithospheric processes by adding into the classical Wilson cycle with ocean-continent transition, continental collision and accretion, as well as continental rifting and splitting in details. These mentioned continental lithospheric processes have been presented by the author in a series of recent review papers in detail, and their summary and further deduction is presented in this paper.

Sandstone-concrete interface transition zone (ITZ) damage and debonding micromechanisms under freeze-thaw

The sufficient bond between concrete and rock is an important prerequisite to ensure the effect of shotcrete support. However, in cold regions engineering protection system, the bond condition of rock and concrete surface is easily affected by freeze-thaw cycles, resulting in interface damage, debonding and even supporting failure. Understanding the micromechanisms of the damage and debonding of the rock-concrete interface is essential for improving the interface protection.Therefore, the micromorphology, micromechanical properties, and microdebonding evolution of the sandstone-concrete interface transition zone(ITZ) under varying freeze-thaw cycles(0, 5, 10, 15, 20) were studied using scanning electron microscope, stereoscopic microscope, and nano-indentation. Furthermore, the distribution range and evolution process of ITZ affected by freeze-thaw cycles were defined. Major findings of this study are as follows:(1) The microdamage evolution law of the ITZ under increasing freeze-thaw cycles is clarified, and the relationship between the number of cracks in the ITZ and freeze-thaw cycles is established;(2) As the number of freeze-thaw cycles increases, the ITZ's micromechanical strength decreases, and its development width tends to increase;(3) The damage and debonding evolution mechanisms of sandstone-concrete ITZ under freeze-thaw cycles is revealed, and its micromechanical evolution model induced by freeze-thaw cycles is proposed.

Multiple transition metals modulated hierarchical networks for high performance of metal-ion batteries

Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped Ni S with N-based carbon(Fe Co-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 m Ah g^(-1)(vs. Li/Li^(+)) and 454 m Ah g^(-1)(vs. Na/Na^(+)), respectively, after 100 cycles.Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.

The Permian-Triassic Transitional Zone: Jordan, Arabian Plate;Linked to Siberian Large Igneous Province and Neo-Tethys Breakup Degassing via Climate Forcing, Atmospheric Hazard and Metal Toxicity

End-Permian Gondwana siliciclastics (50 - 70 m) of the Um Irna F exposed along the NE Dead Sea, exhibit carbonate-free fining upward cycles (FUC) deposited during acid flash flood events under tropical climate. Several ferruginous paleosol intercalations cover periods of drying upward formation (DUP) under semiarid/arid climates. Thin grey pelite beds interbedded between paleosol and overlying FUC, are interpreted as tephra deposits sourced in Siberian LIP- and Neo-Tethys (NT)-Degassing. The Wadi Bassat en Nimra-section exhibits the P-T transitional zone where flash flood deposits meet supra-/intertidal sediments of the southward-directed transgressive NT. Decreasing flash-flooding continued through the Lower Scythian (Ma’in F.) during transgression, reworking, and resedimentation. Two euryhaline foraminifera-bearing limestone beds are discussed as indicators for the end of mass extinction (recovery phase: ca. 250.8 - 250.4 Ma) possibly correlating with the Maximum Flooding Surface MFS Tr 10 (ca. 250.5 Ma) on the Arabian Shelf (Khuff cycles B;A). Comparable data from the Germanic Basin as FUC/DUP-cycles, tephrasuspicious “Grey Beds” with high concentrations of As, Co, Pb, Zn, and Cu as well as the U-Pb Age data of the Siberian LIP meet the PTB-Zone between the MFSs Intervals P 40 (ca. 254 Ma)/Tr 10 (ca 250.5 Ma) on the Arabian Shelf. MFS (Tr 10, 20, 30) and SBs resp. on the Arabian Plate, as well as Scythian Substage boundaries correlate with ∂13 C-excursions recorded at Musandam, UAE. Thereby, the ratio of greenhouse gases (+climate forcing)/aerosols und tephra (-climate forcing) takes a significant influence on the ∂13C-Variation.

Greenhouse gas emission analysis and measurement for urban rail transit: A review of research progress and prospects

Rail transit plays a key role in mitigating transportation system carbon emissions.Accurate measurement of urban rail transit carbon emission can help quantify the contribution of urban rail transit towards urban transportation carbon emission reduction.Since the whole life cycle of urban rail transit carbon emission measurement involves a wide range of aspects,a systematic framework model is required for analysis.This research reviews the existing studies on carbon emission of urban rail transit.First,the characteristics of urban rail transit carbon emission were determined and the complexity of carbon emission measurement was analyzed.Then,the urban rail transit carbon emission measurement models were compared and analyzed in terms of the selection of research boundaries,the types of greenhouse gas(GHG)emissions calculation,and the accuracy of the measurement.Following that,an intelligent station was introduced to analyze the practical application of digital collaboration technology and energy-saving and carbon-reducing system platforms for rail transit.Finally,the urgent problems and future research directions at this stage were discussed.This research presents the necessity of establishing a dynamic carbon emission factor library and the important development trend of system integration of carbon emission measurement and digital system technology.

基于实际地铁线路的全生命周期碳排放研究

在双碳战略的重大战略部署下,对轨道交通全生命周期碳排放进行研究,合理量化其碳排放水平是实现交通部门碳达峰、碳中和的重要措施。本文基于北京某新建地铁线路,对轨道交通全生命周期碳排放进行分析,建立了轨道交通全线、全生命周期的碳排放计算模型,并定量计算新建地铁线路全线、全生命周期的碳排放量。同时,对建设阶段和运营阶段的降碳措施做出分析,定量评估其降碳潜力。对全长81 km新建地铁线路进行碳排放量计算,得到建设阶段碳排放量为257万t CO_(2)eq,运营阶段为5.35万t CO_(2)eq/a,50年运营周期总计碳排放量524万t CO_(2)eq。建设阶段使用可再生材料及预制结构可减少碳排放量7%;运营阶段综合采用多种节能降碳措施后,可降碳27%;50年运营周期降碳潜力总计17%。该模型的建立对城轨交通全生命周期碳排放定量计算有指导意义,降碳措施的研究成果以期为城轨交通完成绿色低碳转型、实现交通部门碳达峰、碳中和提供参考。

城市轨道交通数字孪生标准体系研究

随着国家“新基建”战略对于建设数字孪生城市建设的指引,我国城市轨道交通工程作为城市公共基础设施的重要组成部分进入了新的发展时期,通过构建数字孪生体系将会加快推动城市轨道交通工程全生命周期智能化进程。本文主要研究了城市轨道交通数字孪生标准体系构建的重点方向:首先阐述了城市轨道交通数字孪生标准体系构建的目的与意义以及当前城市轨道交通数字孪生标准化现状,并就标准体系构建的重点原则进行了分析;其次结合目前制造业的数字孪生模型架构和技术体系,建立了城市轨道交通领域的数字孪生标准体系架构;最后结合国内目前城市轨道交通领域技术体系标准制定的现状,详细分析了物理实体、虚拟实体、平台与服务、连接与集成等技术标准的构建基础与思路,以期促进数字孪生技术在我国城市轨道交通领域的全面推广应用。

调制转移光谱对激光频率起伏分辨率的影响因素分析及优化方法

采用电光位相调制器对泵浦光进行位相调制,得到射频调制转移光谱(MTS),并研究MTS光谱的类色散信号中心过零点斜率优化问题。通过改变泵浦光的调制频率,泵浦光与探测光的光斑大小,研究MTS光谱信号过零点斜率与二者之间的参数依赖关系,在泵浦光调制频率为~3.6 MHz(大约是自然线宽的0.69倍)时,得到最佳的MTS光谱信号。最后利用最优的MTS光谱将DL Pro@852 nm激光频率锁定到铯原子D2线(F=4)-(F=5’)循环跃迁,在60 min采样时间内激光频率起伏约为170 kHz,与自由运转时激光器~11 MHz的频率起伏相比,频率起伏得到了显著改善。

ELP-SOD融合蛋白的纯化及其脂质体制备

目的:通过重组E.coli细胞表达类弹性蛋白多肽超氧化物歧化酶(elastin-like polypeptides-superoxide dismutase,ELP-SOD)融合蛋白,利用ELP蛋白有温度敏感的相变特性,经过三轮可逆相变循环(ITC)获得高活性的纯化ELP-SOD酶。结合脂质体包裹技术制备具有较长半衰期和酶活性的ELP-SOD脂质体,为重组人源SOD在医疗、保健、化妆品等领域的应用奠定基础。方法:利用SDS-PAGE及Tanon3500凝胶成像系统、Image studio软件对ELP-SOD进行纯度检测;采用改良的邻苯三酚自氧化法(325 nm法)测定SOD融合蛋白的酶活性;调节不同的pH值及温度梯度测定融合蛋白的pH稳定性及热稳定性;添加Cu^(2+)/Zn^(2+)提高ELP-SOD酶活性;以大鼠血浆进行模拟体内半衰期实验;用不同浓度ELP-SOD的培养基分别与人脐静脉内皮细胞(HUVEC)和小鼠成纤维细胞(L929细胞)孵育来验证细胞毒性;薄膜水化法制备ELP-SOD脂质体并测定其包封率;制备小鼠离体皮肤,采用TP-6透皮扩散仪进行体外释放实验,用Franz扩散池考察ELP-SOD脂质体运载ELP-SOD的透皮效率。结果:ELP-SOD融合蛋白的最高表达量为10 mg/L,纯度为97.8%,酶比活为4894.5 U/mg;其在pH 5.0~8.0、温度低于60℃时稳定性较高;ELP的接入对于SOD的半衰期有一定的延长作用,且有较好的生物安全性;ELP-SOD脂质体的包封率达到80%以上,能够进一步延长ELP-SOD的半衰期,且其透皮效率明显高于ELP-SOD。结论:通过可逆热相变性技术简化了ELP-SOD融合蛋白纯化步骤,并结合脂质体制备技术,延长了酶蛋白生物半衰期,提高了生物利用度。

自适应循环发动机快速推力变化过渡过程性能初步研究

自适应循环发动机是基于变循环发动机设计理念基础并充分考虑飞发一体化设计、热管理等综合性能的面向未来飞行平台的先进动力装置,可通过诸多可调机构实现发动机涵道比、增压比、流量以及工作模式的灵活改变,从而适应不同飞行任务的复杂任务剖面需求,获得更大飞行包线内的性能优化。本文基于自适应循环发动机的性能计算仿真模型,在相关研究基础上结合模式转换和加减速过程实现快速推力变化过程,根据模式转换与加减速控制规律设计,开展典型算例下的快速推力变化过渡过程性能分析并验证其控制规律设计方法可行性,在亚声速巡航工况下,发动机在以M3模式叶尖风扇最小角度状态下,低压转子相对物理转速从0.6加速至1.0,最大可使终止推力增大32.4%,相较于单一模式加减速过渡过程,推力变化范围更宽,加速时间更短,转速变化范围更小。

基于专利视角的制氢技术成熟度分析

为响应国家“双碳”目标,推动清洁能源的发展和利用,合理规划布局制氢技术路线,首先对专利初始数据进行处理,构建测度数据集,并基于构建的测度指标体系计算得到了技术成熟度值;其次,根据技术成熟度值拟合技术生命周期曲线,确定了每种制氢技术所处的技术生命周期阶段;最后,从技术应用广度、技术先进性、技术竞争潜力、技术影响力4方面对技术成熟度进行了综合分析。结果表明:目前最普遍使用的煤气化制氢技术已进入衰退期,而电解水制氢技术近年来发展较快,已经进入成熟阶段,预计未来一段时间内将快速成长为主流制氢技术路线。中国应围绕技术潜力较大的制氢路线,通过渐进替代以实现制氢结构的绿色、高效,助力能源结构转型。

考虑模态转换的组合动力飞机任务性能快速评估方法

工作在较宽飞行范围的高马赫数组合动力飞机,其动力性能受到飞行条件/飞行姿态以及模态转换的影响,并进一步影响其飞行任务性能。为尽可能真实并快速地评估组合动力飞机的飞行任务性能,提出了一种考虑模态转换的组合动力飞机任务性能快速评估方法,并量化研究了不同飞行轨迹、不同模态转换区间对飞行任务性能的影响。首先建立了高马赫数飞机的飞行动力学模型,将飞行姿态考虑进任务分析中;随后建立了组合动力的非安装及安装性能计算模型,飞行轨迹中可实时模拟动力装置的性能;最后建立了模态转换模拟模型,可分析模态转换过程对飞行任务性能的影响。结果表明:该文研究的飞行马赫数为5的组合动力飞机,巡航高度由海拔20 km升高至27 km,巡航距离增加18.3%,总航程增加21.9%;将模态转换马赫数区间由低马赫数2~2.3向高马赫数2.2~2.5范围移动,爬升加速段距离增加8.4%,爬升加速时间增加5.8%。

过渡循环对风力机疲劳评估的影响及修正

随着风力机的装机容量和尺寸的不断增大,其运行环境更为复杂,疲劳问题突出,需要准确预测风力机结构遭受的实际疲劳损伤。通过对1.5 MW风力机的塔底应变进行长期监测,研究了不同方法在处理雨流计数后残余数据点问题上的准确性。首先,通过采用不同的计算时窗,分析过渡循环对疲劳损伤的影响,选择的计算时窗越短,得到的疲劳损伤误差越大,当计算时窗为10 min时,误差达到了20.7%。然后,使用残波串联法处理残余数据点,此时选择不同的计算时窗得到的损伤值均与将监测时段内所有数据作为连续序列得到的结果相同,证明了该方法在处理雨流残余数据时的准确性。该成果为风力机结构疲劳损伤在线预测提供了解决方法,可以更加准确的得到构件的实时损伤。