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Storage, form, and influencing factors of karst inorganic carbon in a carbonate area in China

Science China Earth Sciences 2024年第3期67卷 725-739页

作者： Chaochao DU Xiaoyong BAI Yangbing LI Qiu TAN Cuiwei ZHAO Guangjie LUO Luhua WU fei CheN Chaojun LI Chen RAN Sirui ZHANG Lian XIONG Fengjiao SONG Biqin XIAO Zilin LI Yingying XUE Mingkang long Qing LUO Xiaoyun ZHANG Minghui LI Xiaoqian SheN Shu YANG State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China School of Geography and Environmental Sciences Guizhou Normal UniversityGuiyang 550001China CAS Center for Excellence in Quaternary Science and Global Change Xi'an 710061China Guizhou Provincial Key Laboratory of Geographic State Monitoring of Watershed Guizhou Normal CollegeGuiyang 550018China College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China

Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes(CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature(MAT), precipitation(MAP), evapotranspiration(ET), soil water(SM), and the normalized difference vegetation index(NDVI) to the CCSF. The results revealed that(1) China's CCSF was 22.76 t CO_(2)km^(-2)yr^(-1), which was higher than the global average(15.77 t CO_(2)km^(-2)yr^(-1)). The total carbonate rock chemical weathering carbon sink(CCS) was 4772.67×10^(4)t CO_(2), contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10^(4)km^(-2).(2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and7.27 t CO_(2)km^(-2)yr^(-1)in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively.(3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO_(2)km^(-2)yr^(-1).(4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in

关键词： Carbonate rocks Carbon sinks Patterns Influencing factors Thermodynamic dissolution modeling

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一种基于元学习的大口径射电望远镜俯仰轴承故障辨识方法研究

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天文学报 2024年第3期65卷 82-91页

作者：朱金浩许谦薛飞何飞龙梁娟许多祥中国科学院新疆天文台乌鲁木齐830011 中国科学院大学北京100049 中国科学院射电天文重点实验室乌鲁木齐830011 新疆射电天体物理重点实验室乌鲁木齐830011

在经过长期运行后大口径射电望远镜俯仰轴会出现微小扭曲,滚动轴承作为承载俯仰轴的核心部件,也会因长期承受交变载荷增加疲劳风险,导致轴承寿命以及望远镜指向精度的下降,极大影响望远镜的性能.以俯仰轴承为研究对象,开展故障辨识方法... 详细信息

在经过长期运行后大口径射电望远镜俯仰轴会出现微小扭曲,滚动轴承作为承载俯仰轴的核心部件,也会因长期承受交变载荷增加疲劳风险,导致轴承寿命以及望远镜指向精度的下降,极大影响望远镜的性能.以俯仰轴承为研究对象,开展故障辨识方法研究,可为望远镜天线的高性能运行提供重要支撑.为实现在有限数据和复杂工作条件下准确地辨识俯仰轴承故障,提出了一种小样本条件下基于元学习的故障辨识方法(Few-shot Meta-learning Fault Identification, FMFI).首先将不同工况下的原始信号转换为时频图像数据,之后按照元学习协议将数据样本随机采样到不同的学习任务中.在有限样本的条件下, FMFI可以通过训练任务中的样本信息获取通用的先验知识,在未知的测试任务下实现准确快速的故障辨识.选取了与望远镜俯仰轴承工况具有相似性的变负载轴承数据集进行实验,实验结果表明, FMFI方法具有很高的准确性和可靠性,为大口径射电望远镜俯仰轴承的主动运维和高质量服役提供了有力的技术支持.

关键词：望远镜仪器:俯仰轴承方法:数据分析方法:模式识别

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A high-resolution dataset for lower atmospheric process studies over the Tibetan Plateau from 1981 to 2020

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Big Earth Data 2024年第3期8卷 540-565页

作者： fei Li Shupo Ma Jinhuan Zhu Han Zou Peng Li Libo Zhou Department of Lower Atmospheric Observation Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina

ABSTRACT A high-resolution meteorological dataset(≤10 km)over the Tibetan Plateau(TP)is the foundation for investigating and predicting the weather and climate over *** TP Subregional Dynamical Downscaling(TPSDD)dataset is a newly developed high-spatial-temporal resolution gridded dataset for land‒air exchange pro-cesses and lower atmospheric structure studies over the whole TP region,taking the climate characteristics of each TP subregion into *** dataset spans from 1981 to 2020,covering the TP with a temporal resolution of 2 hr and spatial resolution of 10 *** elements of the dataset include near-surface land-air exchange parameters,such as downward/upward long-wave/shortwave radiation flux,sensible heat flux,latent heat flux,*** addition,the vertical distributions of 3-dimensional wind,temperature,humidity,and pressure from the surface to the lower stratosphere are also *** evaluations were con-ducted to verify the performance of the TPSDD dataset by compar-ing TPSDD/reanalysis with surface and vertical observations through the calculation of statistical *** results demonstrate the accuracy and superiority of this dataset against reanalysis data,which provides great potential for future climate change research.

关键词： Tibetan Plateau WRF model dynamical downscaling land‒air interaction the lower atmosphere

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Enhancing safety and efficiency in automated container terminals: Route planning for hazardous material AGV using LSTM neural network and Deep Q-Network

Journal of Intelligent and Connected Vehicles

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Journal of Intelligent and Connected Vehicles 2024年第1期7卷 64-77页

作者： fei Li Junchi Cheng Zhiqi Mao Yuhao Wang Pingfa Feng Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Information Science and Technology College Dalian Maritime UniversityDalian 116000China School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China

As the proliferation and development of automated container terminal continue,the issues of efficiency and safety become increasingly *** container yard is one of the most crucial cargo distribution centers in a *** Guided Vehicles(AGVs)that carry materials of varying hazard levels through these yards without compromising on the safe transportation of hazardous materials,while also maximizing efficiency,is a complex *** research introduces an algorithm that integrates long Short-Term Memory(LSTM)neural network with reinforcement learning techniques,specifically Deep Q-Network(DQN),for routing an AGV carrying hazardous materials within a container *** objective is to ensure that the AGV carrying hazardous materials efficiently reaches its destination while effectively avoiding AGVs carrying non-hazardous *** real data from the Meishan Port in Ningbo,Zhejiang,China,the actual yard is first abstracted into an undirected *** LSTM neural network can efficiently conveys and represents information in long time sequences and do not causes useful information before long time to be ignored,a two-layer LSTM neural network with 64 neurons per layer was constructed for predicting the motion trajectory of AGVs carrying non-hazardous materials,which are incorporated into the map as background ***,DQN is employed to plan the route for an AGV transporting hazardous materials,aiming to reach its destination swiftly while avoiding encounters with other *** tests have shown that the route planning algorithm proposed in this study improves the level of avoidance of hazardous material AGV in relation to non-hazardous material *** to the method where hazardous material AGV follow the shortest path to their destination,the avoidance efficiency was enhanced by 3.11%.This improvement demonstrates potential strategies for balancing efficiency and safety in automated ***,

关键词： container yard route planning hazardous material Automated Guided Vehicle(AGV) long Short-Term

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Experimental models for preclinical research in kidney disease

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Zoological Research 2024年第5期45卷 1161-1174页

作者： Jin Miao Huanhuan Zhu Junni Wang Jianghua Chen fei Han Weiqiang Lin Kidney Disease Center First Affiliated HospitalZhejiang University School of MedicineInstitute of NephrologyZhejiang UniversityKey Laboratory of Kidney Disease Prevention and Control TechnologyZhejiang ProvinceZhejiang Clinical Research Center of Kidney and Urinary System DiseaseHangzhouZhejiang 310003China Department of Nephrology Center for Regeneration and Aging MedicineFourth Affiliated Hospital of School of Medicineand International School of MedicineInternational Institutes of MedicineZhejiang UniversityYiwuZhejiang 322000China

Acute kidney injury(AKI)and chronic kidney disease(CKD)are significant public health issues associated with a long-term increase in mortality risk,resulting from various etiologies including renal ischemia,sepsis,drug toxicity,and diabetes *** preclinical models have been developed to deepen our understanding of the pathophysiological mechanisms and therapeutic approaches for kidney *** these,rodent models have proven to be powerful tools in the discovery of novel therapeutics,while the development of kidney organoids has emerged as a promising advancement in the *** review provides a comprehensive analysis of the construction methodologies,underlying biological mechanisms,and recent therapeutic developments across different AKI and CKD ***,this review summarizes the advantages,limitations,and challenges inherent in these preclinical models,thereby contributing robust evidence to support the development of effective therapeutic strategies.

关键词： Acute kidney injury Chronic kidney disease Mouse models

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自适应双稳态浮子式波浪能发电装置在不规则波中的能量捕获性能研究

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船舶力学 2024年第5期28卷 689-696页

作者：李扬张显涛肖龙飞上海交通大学海洋工程国家重点实验室上海200240 上海交通大学重庆研究院重庆401135

传统双稳态波能装置已被证实在规则波中可以通过添加“自适应”特性,来解决由阱内振荡引起的低能量吸收问题。本文以自适应双稳态浮子式波浪能发电装置为研究对象,探讨装置在不规则波中的能量捕获性能情况。通过四阶龙格库塔法数值求解... 详细信息

传统双稳态波能装置已被证实在规则波中可以通过添加“自适应”特性,来解决由阱内振荡引起的低能量吸收问题。本文以自适应双稳态浮子式波浪能发电装置为研究对象,探讨装置在不规则波中的能量捕获性能情况。通过四阶龙格库塔法数值求解装置的运动控制方程,探究在不同装置参数下,自适应双稳态浮子式波浪能发电装置和传统双稳态浮子式波浪能发电装置以及线性浮子式波浪能发电装置的能量捕获性能表现。结果表明,选取适当的装置参数可以使自适应双稳态浮子式波浪能发电装置显著提升能量捕获性能,而且与线性和常规双稳装置相比,更适应于实际海况中波浪能量捕获。

关键词：波浪能自适应双稳态能量捕获性能

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Structure,ferroelectric,and enhanced fatigue properties of sol–gel-processed new Bi-based perovskite thin films of Bi(Cu_(1/2)Ti_(1/2))O_(3)–PbTiO_(3)

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Chinese Physics B 2024年第5期33卷 608-615页

作者：宋伟宾席国强潘昭刘锦叶旭斌刘哲宏王潇单鹏飞张林兴鲁年鹏樊龙龙秦晓梅龙有文 Department of Physics Shanghai Normal UniversityShanghai 200234China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Institute for Advanced Materials Technology University of Science and Technology BeijingBeijing 100083China Songshan Lake Materials Laboratory Dongguan 523808China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Bi-based perovskite ferroelectric thin films have wide applications in electronic devices due to their excellent ferroelectric *** Bi-based perovskite thin films Bi(Cu_(1/2)Ti_(1/2))O_(3)–PbTiO_(3)(BCT–PT) are deposited on Pt(111)/Ti/SiO_(2)/Si substrates in the present study by the traditional sol–gel *** structures and related ferroelectric and fatigue characteristics are studied *** BCT–PT thin films exhibit good crystallization within the phase-pure perovskite structure,besides,they have a predominant(100) orientation together with a dense and homogeneous *** remnant polarization(2P_(r)) values at 30 μC/cm^(2) and 16 μC/cm^(2) are observed in 0.1BCT–0.9PT and 0.2BCT–0.8PT thin films,*** intriguingly,although the polarization values are not so high,0.2BCT–0.8PT thin films show outstanding polarization fatigue properties,with a high switchable polarization of 93.6% of the starting values after 10^(8) cycles,indicating promising applications in ferroelectric memories.

关键词： ferroelectric thin films perovskite PbTiO_(3)-BiMeO_(3)

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基于应力梯度和附加强化的多轴疲劳寿命建模

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兰州理工大学学报 2024年第4期50卷 43-49页

作者：刘俭辉王杰华飞龙赵贺兰州理工大学机电工程学院甘肃兰州730050

鉴于Manson-Coffin方程未考虑应力梯度和附加强化的影响,以及缺口附近非均匀应力场和非比例附加强化对疲劳损伤演化过程的影响,建立了适用于多轴缺口件的疲劳寿命预测模型.首先,考虑裂纹萌生和扩展的物理机制,借助坐标变换原理和临界面... 详细信息

鉴于Manson-Coffin方程未考虑应力梯度和附加强化的影响,以及缺口附近非均匀应力场和非比例附加强化对疲劳损伤演化过程的影响,建立了适用于多轴缺口件的疲劳寿命预测模型.首先,考虑裂纹萌生和扩展的物理机制,借助坐标变换原理和临界面理论,以最大剪切应变幅为损伤参量确定临界面位置;其次,分别对临界面的正应力和剪应力进行归一化处理,提出了考虑多轴应力集中系数和应力梯度影响指数的等效应力梯度因子;同时,考虑相位差、路径非比例和材料非比例对疲劳寿命的影响,提出了新的非比例附加强化因子;最后,结合Manson-Coffin方程建立了考虑应力梯度和非比例附加强化的多轴疲劳寿命预测模型,并将该模型、Manson-Coffin方程、LV模型和FS模型的预测寿命与实验寿命进行对比,结果表明该模型的预测精度优于其它3种模型的.

关键词：多轴缺口件应力梯度效应非比例附加强化效应寿命预测临界面法

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基于CFD的某商用车扬尘污染仿真优化分析

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机械设计与制造 2024年第6期400卷 177-181,186页

作者：肖飞田佳伟冯哲何水龙东风柳州汽车有限公司广西柳州544005 桂林电子科技大学机电工程学院广西桂林541004

针对某新型商用车在泥土路面低速行驶工况中,易扬起地面尘土造成局部空气污染问题。建立商用车CFD仿真分析模型,进行实验对标以验证仿真模型的精确性。将DPM离散相模型分析方法与离散动力学相结合,对商用车外流场中多相流进行数值仿真,... 详细信息

针对某新型商用车在泥土路面低速行驶工况中,易扬起地面尘土造成局部空气污染问题。建立商用车CFD仿真分析模型,进行实验对标以验证仿真模型的精确性。将DPM离散相模型分析方法与离散动力学相结合,对商用车外流场中多相流进行数值仿真,揭示了扬尘污染的产生机理。由此制定不同的扬尘治理方案,结合HyperStudy软件进行优化分析,寻求最佳扬尘治理方案,并开展实验验证。研究结果表明:通过优化风扇位置,更换“U型”护风罩并优化导风板尺寸的改进方案,扬尘颗粒数相较原车减少了44.67%,在保证散热性能的前提下,明显改善了扬尘污染现象。

关键词：扬尘污染 CFD仿真离散相模型流场控制多目标优化

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Effect of Chinese Medicine in Patients with COVID-19: A Multi-center Retrospective Cohort Study

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Chinese Journal of Integrative Medicine 2024年第11期30卷 974-983页

作者： ZHAO Guo-zhen YAN Shi-yan LI Bo GUO Yu-hong SONG Shuang HU Ya-hui GUO Shi-qi HU Jing DU Yuan LU Hai-tian YE Hao-ran REN Zhi-ying ZHU Ling-fei XU Xiao-long SU Rui LIU Qing-quan Beijing Hospital of Traditional Chinese Medicine Capital Medical University Beijing Institute of Traditional Chinese Medicine School of Clinical Medicine Beijing University of Chinese Medicine School of Acupuncture-Moxibustion and Tuina Beijing University of Chinese Medicine College of Integrated Chinese Medicine Tianjin University of Traditional Chinese Medicine

Objective: To evaluate the effectiveness and safety of Chinese medicine(CM) in the treatment of coronavirus disease 2019(COVID-19) in China. Methods: A multi-center retrospective cohort study was carried out, with cumulative CM treatment period of 3 days during hospitalization as exposure. Data came from consecutive inpatients from December 19, 2019 to May 16, 2020 in 4 medical centers in Wuhan, China. After data extraction, verification and cleaning, confounding factors were adjusted by inverse probability of treatment weighting(IPTW), and the Cox proportional hazards regression model was used for statistical analysis. Results:A total of 2,272 COVID-19 patients were included. There were 1,684 patients in the CM group and 588 patients in the control group. Compared with the control group, the hazard ratio(HR) for the deterioration rate in the CM group was 0.52 [95% confidence interval(CI): 0.41 to 0.64, Phe results were consistent across patients of varying severity at admission, and the robustness of the results were confirmed by 3 sensitivity analyses. In addition, the HR for all-cause mortality in the CM group was 0.29(95% CI: 0.19 to 0.44, Phe proportion of patients with abnormal liver function or renal function in the CM group was smaller. Conclusion: This real-world study indicates that the combination of a full-course CM therapy on the basic conventional treatment, may safely reduce the deterioration rate and all-cause mortality of COVID-19patients. This result can provide the new evidence to support the current treatment of COVID-19. Additional prospective clinical trial is needed to evaluate the efficacy and safety of specific CM interventions.(Registration No. ChiCTR2200062917)

关键词： Chinese medicine all-cause mortality cohort study coronavirus disease 2019 deterioration rate

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