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Biological sources, paleoenvironment, and organic matter enrichment in source rocks of the Ordovician Majiagou Formation, Ordos Basin, China:Evidence from biomarkers,microfossils, and inorganic geochemical analyses

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Journal of Palaeogeography 2024年第1期13卷 92-115页

作者： Jing-Jing Cao Wen-Zhe Gang shang-Ru yang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Bejing)Beijing 102249China College of Geosciences China University of Petroleum(Bejing)Beijing 102249China Oil and Gas Technology Research Institute PetroChina Changqing Oifield CompanyXi'an 710018Shaanxi ProvinceChina

Carbonate deposits in the Ordovivian Majiagou Formation are significant source rocks for natural gas generation in the Ordos Basin, northwestern China. Previous studies mainly focused on the organic matter enrichment mechanism of shales rather than carbonate rocks. The biological sources and paleoenvironment of carbonate source rocks, and the main controlling factors of organic matter enrichment in the carbonate source rocks were studied in this paper in combination with evidence from biomarkers, microfossils and inorganic geochemistry analysis. The results show that four types of microfacies were identified in the Majiagou Formation, respectively as: mud flat microfacies, mud-dolomite flat microfacies, dolomite flat microfacies, and open marine microfacies. The biological sources of organic matter are chiefly planktonic algae, followed by bacteria. The mud flat and mud-dolomite flat contain a high abundance of terrigenous detrital inputs, as indicated by the high content of Al_(2)O_(3), TiO_(2), Th, and Zr. The low Sr/Cu and high Rb/Sr values reveal warm and humid paleoclimate conditions in the mud flat and mud-dolomite flat, whereas the dolomite flat and open marine were likely formed in hot and arid paleoclimate conditions. The mud flat and mud-dolomite flat deposits were characterized by high paleoproductivity of the Majiagou Formation. Low Sr/Ba values were found in the mud flat samples, indicating fresh to brackish water condition, whereas samples of other facies have a relatively high degree of salinity. Based on U_(auth), Mo_(auth), Cr_(auth), Co_(auth), δCe, and δEu values, the mud flat microfacies was formed in a suboxic and anoxic environment, whereas the mud-dolomite flat, dolomite flat and open marine microfacies were within dysoxic to oxic conditions. A model of organic matter enrichment in the Majiagou Formation is thus established. The level of terrigenous detrital inputs is the principal factor of organic matter enrichment in the Majiagou Formation,

关键词： Biological source Microfacies Trace elements Organic matter Majiagou Formation Ordos Basin

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AstroPose:Astronaut pose estimation using a monocular camera during extravehicular activities

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Science China(Technological Sciences) 2024年第6期67卷 1933-1945页

作者： LIU ZiBin LI You WANG ChunHui LIU Liang GUAN BangLei shang yang YU QiFeng College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China Key Laboratory of Human Factors Engineering China Astronaut Research and Training CenterBeijing100094China

With the completion of the Chinese space station,an increasing number of extravehicular activities will be executed by astronauts,which is regarded as one of the most dangerous activities in human space *** guarantee the safety of astronauts and the successful accomplishment of missions,it is vital to determine the pose of astronauts during extravehicular *** article presents a monocular vision-based pose estimation method of astronauts during extravehicular activities,making full use of the available observation ***,the camera is calibrated using objects of known structures,such as the spacesuit backpack or the circular handrail outside the space ***,the pose estimation is performed utilizing the feature points on the *** proposed methods are validated both on synthetic and semi-physical simulation experiments,demonstrating the high precision of the camera calibration and pose *** further evaluate the performance of the methods in real-world scenarios,we utilize image sequences of Shenzhou-13 astronauts during extravehicular *** experiments validate that camera calibration and pose estimation can be accomplished solely with the existing observation resources,without requiring additional complicated *** motion parameters of astronauts lay the technological foundation for subsequent applications such as mechanical analysis,task planning,and ground training of astronauts.

关键词： monocular camera astronaut pose estimation camera calibration

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Endoscopic retrograde appendicitis treatment for periappendiceal abscess: A case report

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World Journal of Clinical Cases 2024年第4期12卷 801-805页

作者： Qiao-Mei Li Bin Ye Jun-Wei Liu shang-Wen yang Department of Gastroenterology Lishui Central HospitalThe Fifth Affiliated Hospital of Wenzhou Medical UniversityLishui 323000Zhejiang ProvinceChina

BACKGROUND Acute appendicitis is the most common abdominal *** present,the main treatments for periappendiceal abscess include antibiotics and ***,the complications and mortality of emergency surgery are *** preferred therapy is conservative treatment with antibiotics first,ultrasound-guided puncture drainage or surgical treatment is followed when *** retrograde appendicitis therapy(ERAT)for acute uncomplicated appendicitis have been proved clinically effective,but it is rarely used in periap-pendiceal *** SUMMARY We report a patient admitted to hospital because of“right lower abdominal pain for six days”.The computerized tomography(CT)of patient showed that appendicitis with fecaliths and abscess in the *** patient was treated by CT-guided puncture and drainage of abdominal abscess combined with ERAT to remove appendiceal fecaliths,irrigation and stent *** The patient did not receive surgery because of impoverished *** pain did not recur during the follow-up *** case confirms the value of ERAT in the treatment of periappendiceal abscess.

关键词： Transparent cap Colonoscopy Endoscopic retrograde appendicitis therapy Periappendiceal abscess Case report

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Research on the solid particle erosion wear of pipe steel for hydraulic fracturing based on experiments and numerical simulations

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Petroleum Science 2024年第4期21卷 2779-2792页

作者： Si-Qi yang Jian-Chun Fan Ming-Tao Liu De-Ning Li Jun-Liang Li Li-Hong Han Jian-Jun Wang shang-Yu yang Si-Wei Dai Lai-Bin Zhang State Key Laboratory of Oil and Gas Equipment CNPC Tubular Goods Research Institute Key Laboratory of Oil and Gas Safety and Emergency Technology China University of Petroleum Oil Production Technology Research Institute of Liaohe Oilfield Company Tianjin Gas Storage Branch PetroChina Dagang Oilfield Company Petroleum Production Engineering Research Institute Daqing Oilfield Company

Erosion wear is a common failure mode in the oil and gas industry. In the hydraulic fracturing, the fracturing pipes are not only in high-pressure working environment, but also suffer from the impact of the high-speed solid particles in the fracturing fluid. Beneath such complex conditions, the vulnerable components of the pipe system are prone to perforation or even burst accidents, which has become one of the most serious risks at the fracturing site. Unfortunately, it is not yet fully understood the erosion mechanism of pipe steel for hydraulic fracturing. Therefore, this article provides a detailed analysis of the erosion behavior of fracturing pipes under complex working conditions based on experiments and numerical simulations. Firstly, we conducted erosion experiments on AISI 4135 steel for fracturing pipes to investigate the erosion characteristics of the material. The effects of impact angle, flow velocity and applied stress on erosion wear were comprehensively considered. Then a particle impact dynamic model of erosion wear was developed based on the experimental parameters, and the evolution process of particle erosion under different impact angles, impact velocities and applied stress was analyzed. By combining the erosion characteristics, the micro-structure of the eroded area, and the micro-mechanics of erosion damage, the erosion mechanism of pipe steel under fracturing conditions was studied in detail for the first time. Under high-pressure operating conditions, it was demonstrated through experiments and numerical simulations that the size of the micro-defects in the eroded area increased as the applied stress increased, resulting in more severe erosion wear of fracturing pipes.

关键词： Erosion wear Applied stress Particle impact dynamics Erosion mechanism

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我国竞技体育高质量发展原则遵循与行动方略

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体育文化导刊 2024年第1期 56-62页

作者：杨尚剑山东大学体育学院济南250061

运用文献资料、逻辑分析等方法,探究我国竞技体育发展成就、原则遵循,并提出行动方略。成就:竞技体育后备人才培养体系日趋成熟,竞技运动训练科学化水平大幅提升,国际竞技体育赛场屡创佳绩,竞技体育“放管服”改革卓有成效。原则遵循:... 详细信息

运用文献资料、逻辑分析等方法,探究我国竞技体育发展成就、原则遵循,并提出行动方略。成就:竞技体育后备人才培养体系日趋成熟,竞技运动训练科学化水平大幅提升,国际竞技体育赛场屡创佳绩,竞技体育“放管服”改革卓有成效。原则遵循:以运动员为中心的全面发展为核心要旨,以科技引领运动训练为主要驱动,以竞赛成绩的质量提升为追求目标,以社会化与市场化改革为重点任务。行动方略:深化体教融合对运动员发展的全方位辐射,提升科技引领竞技训练的全过程效能,创新竞技体育项目协调发展的新模式,打造多元协同的新型竞技体育治理格局。

关键词：竞技体育高质量发展原则遵循行动方略

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Haplotype-resolved and chromosome-scale genomes provide insights into co-adaptation between the Amur tiger and Amur leopard

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Zoological Research 2024年第3期45卷 464-467页

作者： Hai-Meng Li Bo-yang Liu Min-Hui Shi Le Zhang shang-Chen yang Sunil Kumar Sahu Liang-Yu Cui Shan-Lin Liu Nicolas Dussex Yue Ma Dan Liu Wei-Yao Kong Hao-Rong Lu Yue Zhao Love Dalén Huan Liu Tian-Ming Lan Guang-Shun Jiang Yan-Chun Xu College of Wildlife and Protected Area Northeast Forestry UniversityHarbinHeilongjiang 150040China State Key Laboratory of Agricultural Genomics BGI ResearchShenzhenGuangdong 518083China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China College of Life Sciences Zhejiang UniversityHangzhouZhejiang 310058China BGI Research WuhanHubei 430074China Department of Entomology College of Plant ProtectionChina Agricultural UniversityBeijing 100193China Centre for Palaeogenetics Svante Arrhenius väg 20CStockholm 10691Sweden Department of Zoology Stockholm UniversityStockholm 10691Sweden Department of Bioinformatics and Genetics Swedish Museum of Natural HistoryStockholm 10691Sweden Heilongjiang Siberian Tiger Park HarbinHeilongjiang 150000China Jinlin Provincial Academy of Forestry Science ChangchunJilin 130033China China National GeneBank BGI ResearchShenzhenGuangdong 518120China Guangdong Provincial Key Laboratory of Genome Read and Write BGI ResearchShenzhenGuangdong 518083China BGI Life Science Joint Research Center Northeast Forestry UniversityHarbinHeilongjiang 150040China Feline Research Center of National Forestry and Grassland Administration College of Wildlife and Protected AreaNortheast Forestry UniversityHarbinHeilongjiang 150040China National Forestry and Grassland Administration Research Center of Engineering Technology for Wildlife Conservation and Utilization HarbinHeilongjiang 150040China

DEAR EDITOR,Big cats,such as Amur tigers(Panthera tigris altaica)and Amur leopards(*** orientalis),are apex predator and have evolved specialized traits for hunting and carnivory(Moya et al.,2022),thus playing a crucial role in maintaining biodiversity and ecosystem integrity by regulating prey-predator ***,human-induced pressures,habitat fragmentation,and environmental alterations have restricted these species in small and isolated ***,all extant big cats are categorized as endangered or threatened according to their conservation *** tigers and Amur leopards share overlapping geographic ranges,habitats,and certain prey species in the forests of Northeast Asia(Jiang et al.,2015).To reduce interspecies conflict,these carnivores exhibit differentiated dietary and temporal *** tigers predominantly prey on large ungulates,while Amur leopards hunt small to medium-sized animals(Sugimoto et al.,2016).Additionally,they occupy different temporal niches,with tigers being active at night and leopards more active during the *** spatial and temporal niche partitioning,interspecific competition between these two species is ***,benefiting from their greater size,have a competitive advantage over leopards,which can manifest in occasional leopard predation by tigers and declines in leopard populations with increasing tiger density(Jiang et al.,2015).Tigers also displace leopards from marginal habitats in nature reserves where they coexist.

关键词： habitat Panthera resolved

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甘草泻心汤联合复方嗜酸乳杆菌对儿童轮状病毒性肠炎的疗效及免疫功能的影响

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中国病原生物学杂志 2024年第10期19卷 1142-1146页

作者：尚扬毛庆东芜湖市中医医院儿科安徽芜湖241000

目的分析甘草泻心汤联合复方嗜酸乳杆菌治疗儿童轮状病毒性肠炎的疗效以及对儿童免疫功能的影响。方法选择2023年1月-2023年12月在本院接受治疗的82例湿热证轮状病毒性肠炎儿童,根据随机数字表+信封袋法将其分为联合组(41例)和单一组... 详细信息

目的分析甘草泻心汤联合复方嗜酸乳杆菌治疗儿童轮状病毒性肠炎的疗效以及对儿童免疫功能的影响。方法选择2023年1月-2023年12月在本院接受治疗的82例湿热证轮状病毒性肠炎儿童,根据随机数字表+信封袋法将其分为联合组(41例)和单一组(41例);联合组在对症治疗的基础上给予甘草泻心汤联合复方嗜酸乳杆菌治疗,单一组在对症治疗的基础上给予复方嗜酸乳杆菌治疗;比较两组轮状病毒性肠炎症状缓解时间、临床疗效、免疫功能以及炎症因子水平。结果联合组腹泻完全停止时间、脱水纠正时间、轮状病毒抗原转阴时间以及恢复正常体温时间均短于单一组(P0.05)。治疗后两组VIP、MOT、GAS水平显著下降(P<0.05);与单一组相比,联合组治疗后VIP、MOT、GAS水平显著下降(P<0.05)。治疗后两组双歧杆菌、嗜酸乳酸菌水平上升、大肠埃希菌水平下降(P<0.05);与单一组相比,联合组治疗后双歧杆菌、嗜酸乳酸菌水平上升、大肠埃希菌水平下降(P<0.05)。结论甘草泻心汤联合复方嗜酸乳杆菌治疗儿童轮状病毒性肠炎能够有效缓解患儿的临床症状,抑制炎症因子与胃肠激素水平,提高免疫功能,调节肠道菌群。

关键词：轮状病毒性肠炎甘草泻心汤复方嗜酸乳杆菌免疫功能

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石墨烯基材料在电磁屏蔽领域的研究进展

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新型炭材料（中英文） 2024年第2期39卷 223-239页

作者：杨赏娟曹赟贺艳兵吕伟清华大学深圳国际研究生院广东深圳518055

通信技术在为人类的生活带来便利的同时,其产生的电磁辐射对社会安全、人体健康产生的危害也受到了社会各界的广泛关注,宽屏蔽范围、高吸收效率和高稳定性的电磁屏蔽材料逐渐成为研究热点。石墨烯是一种导电性高、比表面积大且可调控性... 详细信息

通信技术在为人类的生活带来便利的同时,其产生的电磁辐射对社会安全、人体健康产生的危害也受到了社会各界的广泛关注,宽屏蔽范围、高吸收效率和高稳定性的电磁屏蔽材料逐渐成为研究热点。石墨烯是一种导电性高、比表面积大且可调控性高的轻质材料,可有效实现电磁衰减,保护精密电子设备和人体健康,在电磁屏蔽领域具有广阔的应用前景。本综述从电磁屏蔽的基本原理与石墨烯基材料的结构特性角度,阐述了石墨烯及其衍生物的电磁屏蔽特点,总结了结构调控以及表面异质化、复合化策略在电磁屏蔽领域的应用。结构调控有利于提高石墨烯基材料对电磁波的吸收损耗和多重反射损耗;表面异质化和复合化策略有利于提高石墨烯基材料的界面极化和磁特性,从而加强对电磁波的吸收损耗和磁损耗。总结了石墨烯基电磁屏蔽材料的改性方法,旨在为开发新一代绿色、轻薄、高屏蔽带宽的电磁屏蔽材料提供启发,指明石墨烯基电磁屏蔽材料的未来发展方向。

关键词：石墨烯电磁屏蔽结构调控异质掺杂复合材料

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并网光伏系统中3L-T-type QZSI参与电网电压不平衡控制

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科学技术与工程 2024年第11期24卷 4510-4519页

作者：王强李上杨张津三峡大学电气与新能源学院宜昌443002 智慧能源技术湖北省工程研究中心宜昌443002

针对传统逆变器在不平衡网压情况下工作时较难抑制输入电网有功功率振荡分量的问题,提出一种基于三电平T型准阻抗源逆变器(three level T-type quasi-Z source inverter,3L-T-type QZSI)抑制有功功率振荡分量的控制策略。从功率理论推... 详细信息

针对传统逆变器在不平衡网压情况下工作时较难抑制输入电网有功功率振荡分量的问题,提出一种基于三电平T型准阻抗源逆变器(three level T-type quasi-Z source inverter,3L-T-type QZSI)抑制有功功率振荡分量的控制策略。从功率理论推导得到其并网的参考电流,实现并网有功功率恒定且以单位功率因数为目标的控制策略。即:使用二阶广义积分器(second-order generalized integrator,SOGI)完成电压的正负序分离;再结合基于载波的电平位移脉宽调制(level-shift pulse width modulation,LS-PWM)技术,用以调节功率开关直通状态的占空比和叠加的平衡分量,实现直流侧电压控制和中点电压平衡。最后,在Simulink平台上模拟了电网电压不平衡情况,对间歇性能源不同出力情况进行了仿真,仿真结果表明,该策略可有效抑制间歇性能源的有功功率二倍频波动,有利于实现中点电位平衡和间歇性能源并网稳定运行。

关键词：三电平逆变器电网电压不平衡恒定有功功率直通占空比中点电位平衡

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基于聚类算法和图神经网络的短时交通流预测

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吉林大学学报（工学版） 2024年第6期54卷 1593-1600页

作者：张玺君余光杰崔勇尚继洋兰州理工大学计算机与通信学院兰州730050

针对现有预测模型未充分利用交通流数据时空相关性的问题,本文提出了一种深度学习模型,将聚类算法、图神经网络(GNN)和门控循环单元(GRU)相结合。首先,利用聚类算法将预处理后的数据划分为不同类型的流量模式;其次,采用GNN提取复杂路网... 详细信息

针对现有预测模型未充分利用交通流数据时空相关性的问题,本文提出了一种深度学习模型,将聚类算法、图神经网络(GNN)和门控循环单元(GRU)相结合。首先,利用聚类算法将预处理后的数据划分为不同类型的流量模式;其次,采用GNN提取复杂路网交通流的空间相关性,结合道路的皮尔逊相关性分析和节点的局部聚类系数,挖掘潜在的节点连接关系;再次,使用GRU提取交通流数据之间的时间相关性,通过自注意力机制捕获数据之间的相互依赖关系;最后,通过残差连接将GRU和GNN的输出与原始输入结合,经过全连接层得出最终的预测结果。多组实验结果证明,本文提出的模型预测精度优于其他基线模型及对比的模型。

关键词：交通流预测图神经网络聚类算法门控循环单元皮尔逊相关系数局部聚类系数

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