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Spatiotemporal evolution of wildfire activity during the PaleoceneEocene Thermal Maximum in China

Science China Earth Sciences 2025年

作者： Xueting WANG Zuoling CHEN linlin cui Xu WANG State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences College of Earth and Planetary Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

The Paleocene-Eocene Thermal Maximum（PETM） was the most prominent warming event in the Cenozoic and serves as a geological analog for the current global warming driven by anthropogenic CO2emissions from burning fossil *** a primary disruptor of Earth's ecosystems, wildfire activity affects the balance of ecosystems, the global carbon cycle, and climate change. Therefore, studying the evolution and driving mechanisms of wildfires during the PETM is essential for predicting wildfire activity under global warming scenarios and for understanding the carbon cycle in the context of wildfire disturbances. Current research on wildfires during the PETM has mainly focused on the Northern Hemisphere, particularly Europe and North America, whereas studies on Chinese mainland remain limited. In this study, we analyzed black carbon（BC）concentration and carbon isotope(δ13C) in the Beigou section of the Nanyang Basin and the Xilutian section of the Fushun Basin to reconstruct the spatiotemporal evolution of wildfires in arid/semi-arid and humid zones. We integrated these findings with those of previous studies on the paleoclimate of the research area to elucidate the driving mechanisms behind wildfire occurrences. Our results indicate that wildfire activity weakened at the onset of the PETM, with the negative carbon isotope period characterized by low wildfire activity, except for a brief resurgence in the Nanyang Basin. During the recovery phase of the PETM, wildfire activity gradually increased, returning to the pre-PETM levels. The prolonged low wildfire state was likely caused by extremely high temperatures and precipitation as well as the resulting vegetation succession. During the PETM recovery phase, increased wildfire activity transformed “short-term carbon sinks” of the biological-atmospheric carbon cycle into “long-term carbon sinks” through the burial of BC. This process of carbon sink conversion may have acted as a negative feedback mechanism, contributing to carbo

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Spatiotemporal evolution of C3/C4 vegetation and its controlling factors in southern China since the last glacial maximum

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Science China Earth Sciences 2019年第8期62卷 1256-1268页

作者： linlin cui Jianfang HU Xu WANG Institute of Geology and Geophysics Chinese Academy of SciencesBeijing100029China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Guanzhou Institute of Geochemistry Chinese Academy of SciencesBeijing510640China

To date, few research have been reported on the evolution of C3/C4 vegetation in southern China, and the main mechanism influencing the evolution of C3/C4 vegetation is unclear. That makes it difficult for researchers to understand the competition mechanism of C3 and C4 plants under different climate environments and its relationship with the climate factors. It is also not conducive for researchers to assess the influence of future climate change on regional C3/C4 vegetation. Exactly, C3/C4 vegetation change in the regional-scale will have a significant impact on the global carbon cycle and agricultural ***, it is especially important to reconstruct the evolutionary history of C3/C4 vegetation in southern China and clarify the influencing mechanism of climate change. In this study, we systematically analyzed stable carbon isotope(δ13 C) of the longchain n-alkanes in sediment samples from eight lakes and four peat profiles in southern China, to reconstruct the spatiotemporal evolution of C3/C4 vegetation in these regions since the Last Glacial Maximum(LGM) and to investigate the climate factors that affect the C4 plant abundance change in the research area. The integrated long-chain n-alkane(C27–C33) stable carbon isotope results of samples from Zhanjiang Huguangyan Maar Lake, Xingyun Lake, Lugu Lake and Dingnan peat showed that, from the LGM to the Early Holocene, C4 plant relative abundance exhibited a gradually increasing trend from 21% to 34%. In the Middle Holocene, the C4 plant abundance significantly declined and reached a lowest value of 10%. In space, the C4 plant abundance generally exhibited a gradually declining trend from south to north in the LGM and the Early Holocene, while it showed an opposite trend in the Holocene Climate Optimum(6.0 cal ka BP). It reflected that the main influencing factor on C4 plants spatial distribution was changing from temperature to precipitation. This study indicated that temperature was the dominant facto

关键词： Stable carbon isotope Long-chain n-alkanes C3/C4vegetation Last Glacial Maximum Holocene Climate Optimum period

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Centennial-scale monsoon collapses during Marine Isotope Stage(MIS)7e detected in a northern Chinese stalagmite record

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Science China Earth Sciences 2023年第12期66卷 2941-2952页

作者： Wuhui DUAN Ming TAN Lisheng WANG Xuefeng WANG Zhibang MA linlin cui Zhengyi XIAO Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences Beijing 100029China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Occurrence or absence of centennial-scale climatic variability during Marine Isotope Stage(MIS)7e,the first peak interval of the Penultimate Interglacial,remains ambiguous due to the limited available high-resolved ***,we present a decadal-resolved stalagmiteδ^(18)O record from northern China spanning from 242.3 to 236.8 ka BP,covering *** composite KLSδ^(18)O record,integrating this study with the previous record in the same cave,shows a descending trend from TerminationⅢto MIS7e,which follows the increasing Northern Hemisphere summer insolation(NHSI).This observation further emphasizes the important influence of NHSI on the glacial/interglacial *** are more large-amplitude,millennial-to centennial-scale variability occurring during TerminationⅢcompared with MIS7e,implying that ice-sheet decay potentially plays an important role in climatic *** centennial-scale summer monsoon collapses,peaking at~242.1,~240.8,~239.3 and~238.2 ka BP,are detected in our new record,indicating the pervasiveness of the intra-interglacial climatic *** the lack of solar activity and freshwater outbursts data during MIS7e,it is not possible to conclude about the drivers of the identified abrupt climatic *** the dynamic mechanisms of sub-millennial climatic anomalous during early Holocene,we tentatively propose that slowdown of the meridional overturning circulation caused by freshwater fluxes into North Atlantic and/or attenuated solar irradiance is the potential forcing for the abrupt climate events within ***,attenuated solar irradiance could also result in climatic anomalies through low-latitude processes.

关键词： Northern China Stalagmiteδ~(18)O record Marine Isotope Stage(MIS)7e Centennial-scale monsoon collapses Freshwater and/or solar activity forcings

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Multi-scale variability of water discharge and sediment load into the Bohai Sea from 1950 to 2011

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Journal of Geographical Sciences 2015年第1期25卷 85-100页

作者： REN Huiru LI Guosheng cui linlin HE Lei Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

This paper examines the changes in the time series of water discharge and sediment load of the Yellow River into the Bohai Sea. To determine the characteristics of abrupt changes and multi-scale periods of water discharge and sediment load, data from Lijin station were analyzed, and the resonance periods were then calculated. The Mann-Kendall test, order clustering, power-spectrum, and wavelet analysis were used to observe water discharge and sediment load into the sea over the last 62 years. The most significant abrupt change in water discharge into the sea occurred in 1985, and an abrupt change in sediment load happened in the same year. Significant decreases of 64.6% and 73.8% were observed in water discharge and sediment load, respectively, before 1985. More significant abrupt changes in water discharge and sediment load were observed in 1968 and 1996. The characteristics of water discharge and sediment load into the Bohai Sea show periodic oscillation at inter-annual and decadal scales. The main periods of water discharge are 9.14 years and 3.05 years, whereas the main periods of sediment load are 10.67 years, 4.27 years, and 2.78 years. The significant resonance periods between water discharge and sediment load are observed at the following temporal scales： 2.86 years, 4.44 years, and 13.33 years. Water discharge and sediment load started to decrease after 1970 and has decreased significantly since 1985 for several reasons. Firstly, the precipitation of the Yellow River drainage area has reduced since 1970. Secondly, large-scale human activities, such as the building of reservoirs and floodgates, have increased. Thirdly, water and soil conservation have taken effect since 1985.

关键词： water discharge sediment load resonance periods abrupt changes multi-scale periods Yellow River Bohai Sea

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A Novel Model for Describing Rail Weld Irregularities and Predicting Wheel-Rail Forces Using a Machine Learning Approach

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 555-577页

作者： linlin Sun Zihui Wang Shukun cui Ziquan Yan Weiping Hu Qingchun Meng State Key Laboratory of High-Speed Railway Track System China Academy of Railway Sciences Corporation LimitedBeijing100081China Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China School of Aeronautic Science and Engineering Beihang UniversityBeijing100191China

Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed *** can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and *** researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry ***,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric *** this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to *** vertical dynamic forces in the time and frequency domains were compared under different running *** forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed ***,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is *** results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the *** ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.

关键词： Rail weld irregularity high-speed railway vehicle-track coupled dynamics wheel/rail dynamic vertical force artificial neural networks

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Determination of clumped isotopes in carbonate using isotope ratio mass spectrometer: Effects of extraction potential and long-term stability

Determination of clumped isotopes in carbonate using isotope...

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中国科学院地质与地球物理研究所2014年度（第14届）学术年会

作者： linlin cui Xu Wang Institute of Geology and Geophysics Chinese Academy of Sciences Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences

In this study, we developed an instrument tuning method for analyzing clumped isotope on carbonates using isotope ratio mass spectrometer(IRMS). The ion source extraction potential is found governing accuracy and precision for CO2 clumped isotope analysis, with 90% extraction as an optimum *** this condition, we obtained a relatively stable linearity of mass spectrometer, as shown by little variation in slopes(0.0075–0.0077) for three heated CO2 gas lines(plot of △47 vs. δ47) observed over a period of one year. By contrast, the intercepts of the heated gas lines displayed a larger variation, ranging from 0.79 m to 0.89 m, which may be partially contributed by some artificial factor, e.g., variable cooling rates of heated CO2 gases. Nevertheless, repeated measurements on NBS 19 demonstrate long-term reproducible △47 values, comparable with previously published results. The stable linearity of the IRMS results ensures that clumped isotopes can be analyzed precisely without frequently constructing a reference frame through heated CO2 gases. Our results provide a basis for optimizing IRMS performance for clumped isotope analysis.

关键词： Clumped isotope Carbonate △47 value Isotope ratio mass spectrometry Extraction potential Linearity effect

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企业群体协同机制的形式化建模及存在性

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清华大学学报（自然科学版） 2008年第4期48卷 486-489页

作者：崔琳琳柴跃廷清华大学自动化系国家CIMS工程技术研究中心北京100084

针对企业群体合作机制研究缺乏形式化定义的问题,基于对供需链协调问题没有从对策论的角度出发,显式地考虑集体理性的局限性分析,提出企业群体(供需链)协同问题,并对它进行形式化定义及协同机制的存在性证明。该文将企业群体协同定义为... 详细信息

针对企业群体合作机制研究缺乏形式化定义的问题,基于对供需链协调问题没有从对策论的角度出发,显式地考虑集体理性的局限性分析,提出企业群体(供需链)协同问题,并对它进行形式化定义及协同机制的存在性证明。该文将企业群体协同定义为企业群体在某种合作机制下,各成员企业在个体满意的前提下,达到整体效用最大化的状态。进而建立了企业群体长期交易的重复博弈模型,并基于无名氏定理证明了协同解的存在性。理论证明指出,只要企业足够关注长远目标,供需链(企业群体)总可以实现协同。

关键词：供需链协同博弈论重复博弈

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Perinatal outcome and postnatal health in children born from cryopreserved embryos

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Journal of Bio-X Research 2018年第3期1卷 120-123页

作者： Shiqin Zhu linlin cui Zi-Jiang Chen Center for Reproductive Medicine Shandong Provincial Hospital Affiliated to Shandong University National Research Center for Assisted Reproductive Technology and Reproductive Genetics the Key Laboratory of Reproductive Endocrinology(Shandong University) Ministry of EducationJinanShandong Province Center for Reproductive Medicine Renji HospitalSchool of MedicineShanghai Jiao Tong University Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics ShanghaiChina

Frozen-thawed embryo transfer(FET)has been increasingly adopted as an adjunct to in vitro fertilization or intracytoplasmic sperm injection in recent *** can reduce the risks of ovarian hyperstimulation syndrome and multiple pregnancies,and may even improve pregnancy outcomes in some subgroups such as patients with polycystic ovary ***,embryo cryopreservation may cause DNA damage,epigenetic changes,and alterations to gene expression profiles,and the potential impacts of cryopreservation on the embryos and on the long-term health of the resulting offspring are receiving increasing ***,we aim to summarize the impact of cryopreservation on the embryos,perinatal outcomes,and long-term health of the offspring,hoping to explore the potential mechanisms and help guide the next steps in designing clinical *** this review,we found that there was no apparent difference in most perinatal outcomes between neonates born following FET and fresh embryo transfer,except for higher risks of large-for-gestational age and macrosomia in FET *** on the long-term health and development of FET children are currently lacking;however,the limited evidence so far has found no risk of growth retardation,or chronic or malignant ***,well-designed,prospective studies taking full consideration of the confounding factors,including parental information,lifestyle,and environmental factors,are needed to confirm these conclusions.

关键词： embryo cryopreservation FET in vitro fertilization long-term offspring

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Holocene changes in fire frequency in the Daihai Lake region(north-central China):indications and implications for an important role of human activity

Holocene changes in fire frequency in the Daihai Lake region...

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中国科学院地质与地球物理研究所2013年度（第13届）学术年会

作者： Xu Wang Jule Xiao linlin cui Zhongli Ding Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences

Black carbon(BC) content in a sediment core from Daihai Lake,Inner Mongolia,was analyzed to reconstruct a high-resolution history of fires occurring in northern China during the Holocene and to examine the impacts of natural changes and human activities on the fire *** black carbon mass sedimentation rate(BCMSR) was disintegrated into two components:the background BCMSR and the BCMSR peak,with the BCMSR peak representing the frequency of fire *** the background BCMSR and the magnitude of the BCMSR peak display a close relation with the percentage of tree pollen from the same sediment core,suggesting that regional vegetation type would be a factor controlling the intensity of *** inferred fire-episode frequency for the Holocene exhibits two phases of obvious increases,i.e.,the first increase from <5 to～10 episodes/1000 yrs occurring at 8200 *** BP when the vegetation of the lake basin shifted from grasses to forests and the climate changed from warm/dry to warm/humid condition,and the further increase to a maximum frequency of 13 episodes/1000 yrs occurring at 2800 *** BP when herbs and shrubs replaced the forests in the lake basin and the climate became cool/*** increases in the fire frequency contradict the previous interpretation that fires occurred frequently in the monsoon region of northern China when steppe developed under the cold/dry *** thus suggest that human activities would be responsible for the increased frequencies of fires in the Daihai Lake region in terms that the appearance of early agriculture and the expansion of human land use were considered to take place in northern China at ca 8000 and 3000 *** BP, respectively.

关键词： Fire history Climate change Black carbon Vegetation Human activity Holocene

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人格特质对非注意视盲和安全风险感知失败的影响:来自眼动试验的证据

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中国安全科学学报 2024年第8期34卷 11-17页

作者：李乃文崔琳琳辽宁工程技术大学工商管理学院辽宁葫芦岛125105

非注意视盲是一种与选择性注意或不注意有关的人因失误。为减少建筑工人高空作业非注意视盲导致的安全事故,选取30名被试参与一项试验,分析非注意视盲在安全风险感知失败中的重要性,以及影响非注意视盲和安全风险感知失败的人格特质相... 详细信息

非注意视盲是一种与选择性注意或不注意有关的人因失误。为减少建筑工人高空作业非注意视盲导致的安全事故,选取30名被试参与一项试验,分析非注意视盲在安全风险感知失败中的重要性,以及影响非注意视盲和安全风险感知失败的人格特质相关因素,建立实用的安全管理策略。结果表明:非注意视盲占安全风险感知失败的50%。另外,人格特质与非注意视盲和安全风险感知失败有明显的关系,外向性、严谨性和开放性与非注意视盲和安全风险感知失败有显著的相关关系;低外向性、高严谨性和低开放性的作业人员拥有更低的安全风险感知失败和非注意视盲的比例。

关键词：人格特质非注意视盲安全风险感知失败眼动试验高空作业危险识别

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