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Cross-Lagged Relationship between Physical Activity Time,Openness and Depression Symptoms among Adolescents:Evidence from China 被引量:4
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作者 Xiaojie Cao Qinyu Zhang Xinqiao Liu 《International Journal of Mental Health Promotion》 2023年第9期1009-1018,共10页
The relationship between physical activity time,openness and depression symptoms among adolescents is a cutting-edge research direction in the field,yet it remains unclear.This study is based on a sample of 7924 stude... The relationship between physical activity time,openness and depression symptoms among adolescents is a cutting-edge research direction in the field,yet it remains unclear.This study is based on a sample of 7924 students from a nationally representative China Education Panel Survey database and examines the bidirectional relationships between physical activity time,openness and depression symptoms among Chinese adolescents.Descriptive analysis showed that during the 7th and 8th grades,the average physical activity time decreased to less than one hour per day,accompanied by a decreasing trend in openness and a slight worsening in depression symptoms.Correlation analysis showed a significant negative correlation between physical activity time and depression symptoms,a significant positive correlation between physical activity time and openness,and a significant negative correlation between depression symptoms and openness.The results from cross-lagged models indicated a bidirectional relationship between physical activity time and openness,with physical activity time significantly positively predicting openness in the following year and openness significantly positively predicting physical activity time in the following year.In addition,depression symptoms had a unidirectional negative predictive effect on openness.The conclusions provide empirical evidence for education administration and schools to promote the physical and mental health development of adolescents worldwide. 展开更多
关键词 Physical activity time DEPRESSION openness adolescents
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Toward a sustainable future:Examining the interconnectedness among Foreign Direct Investment(FDI),urbanization,trade openness,economic growth,and energy usage in Australia
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作者 Liton Chandra VOUMIK Md.Hasanur RAHMAN +3 位作者 Md.Maznur RAHMAN Mohammad RIDWAN Salma AKTER Asif RAIHAN 《Regional Sustainability》 2023年第4期405-415,共11页
The energy demand in Australia is increasing with the industrialization and rapid economic growth.This study analyzed the relationships among the economic growth,Foreign Direct Investment(FDI),trade openness,urbanizat... The energy demand in Australia is increasing with the industrialization and rapid economic growth.This study analyzed the relationships among the economic growth,Foreign Direct Investment(FDI),trade openness,urbanization,and energy usage in Australia based on the data from World Development Indicators(WDI)from 1972 to 2021.The results indicates that there is a cointegration among economic growth,FDI,trade openness,urbanization,and energy usage,which was traced through the autoregressivedistributed lag(ARDL).The Zivot-Andrews unit root test reveals that energy usage,economic growth,FDI,urbanization,and trade openness show significant structural breaks in 1993,1996,1982,2008,and 1994,respectively.The ARDL model shows that economic growth has a positive and significant effect on energy usage in the long-run(0.814)and short-run(0.809).Moreover,the results also show that FDI(0.028)and trade openness(0.043)have positive impacts on energy usage in the long-run.However,urbanization shows a negative and significant influence on energy usage in the long-run(–0.965).Then,the research demonstrates a unidirectional causation between energy usage and trade openness,with energy usage significantly causing trade openness.The current study endorses energy consumption policies and investment strategies for a paradigm shifting from a reliance on fossil fuels as the primary energy source to renewable energy sources.These findings have profound implications for sustainable energy usage. 展开更多
关键词 Renewable energy Foreign Direct Investment(FDI) Trade openness URBANIZATION Climate change Marshallian Demand Function
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OPENING TO THE CHALLENGE --An economy thrives in openness and withers in seclusion
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作者 Qiu Hui 《China Report ASEAN》 2023年第12期22-23,共2页
pening-up has always been a hot topic at the China International Import Expo(CIIE),the world's first import expo held at the national level.During the sixth CIIE,the Hongqiao International Economic Forum held on N... pening-up has always been a hot topic at the China International Import Expo(CIIE),the world's first import expo held at the national level.During the sixth CIIE,the Hongqiao International Economic Forum held on November 6 attracted many participants from government departments,academia,and the business sector to conduct in-depth discussions on global trade and the challenges it faces.Participants agreed that multi-party dialogue is key to the issue. 展开更多
关键词 discussions OPEN agreed
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网络大模型专题导读
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作者 唐宏 熊先奎 《中兴通讯技术》 北大核心 2024年第2期1-1,共1页
OpenAI公司基于“Scaling Law”哲学,通过堆叠算力,使用模块化易于扩展且擅长捕捉长距离依赖关系的Transformer神经网络,构建了自回归、生成式的千亿以上参数量大模型,在多个人工智能(AI)领域取得了SOTA效果。目前,OpenAI正在通过图像... OpenAI公司基于“Scaling Law”哲学,通过堆叠算力,使用模块化易于扩展且擅长捕捉长距离依赖关系的Transformer神经网络,构建了自回归、生成式的千亿以上参数量大模型,在多个人工智能(AI)领域取得了SOTA效果。目前,OpenAI正在通过图像、视频等一系列多模态学习,力图实现“World Model”“World Simulator”,以建立物理世界映射。它的实战成果给全世界AI从业者提供了一种目前看来行之有效且朝向通用人工智能(AGI)发展的方法论和技术路线。 展开更多
关键词 OPEN 长距离依赖 World 神经网络 易于扩展 自回归 参数量 多模态学习
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经鼓室口咽鼓管球囊扩张术的疗效及咽鼓管功能的影响
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作者 谢先荣 付亚峰 刘伟清 《中国耳鼻咽喉头颈外科》 CSCD 2024年第2期122-124,共3页
目的探讨经鼓室口咽鼓管球囊扩张(balloon dilatation Eustachian tuboplasty,BET)联合腺样体消融术对慢性分泌性中耳炎(chronic secretory otitis media,CSOM)患儿的疗效及咽鼓管功能的影响。方法选取2020年6月~2022年12月间在中山市... 目的探讨经鼓室口咽鼓管球囊扩张(balloon dilatation Eustachian tuboplasty,BET)联合腺样体消融术对慢性分泌性中耳炎(chronic secretory otitis media,CSOM)患儿的疗效及咽鼓管功能的影响。方法选取2020年6月~2022年12月间在中山市小榄人民医院就诊的CSOM患儿82例作为研究对象,采用随机数字表法分为对照组和观察组,每组41例。对照组接受腺样体消融术+鼓膜切开置管术治疗,观察组接受腺样体消融术+鼓膜切开置管术+BET术。比较两组手术相关指标及住院时间、临床症状、咽鼓管功能、临床疗效及随访6个月并发症及复发情况。结果两组术中出血量比较,差异无统计学意义(P>0.05),与对照组相比,观察组手术时间更长,住院时间更短(P<0.05)。与对照组相比,观察组中耳积液消失时间、耳鸣消失时间、鼓膜愈合时间、听力恢复时间均更短(P<0.05)。与治疗前相比,治疗后两组咽鼓管评分(Eustachian tube score,ETS)升高、咽鼓管功能障碍评分量表(Eustachian tube dysfunction questionnaire-7,ETDQ-7)评分降低(P<0.05),观察组ETS评分高于对照组,ETDQ-7评分则低于对照组(P<0.05)。观察组临床总有效率高于对照组,差异具有统计学意义(P<0.05)。两组并发症发生率比较,差异无统计学意义(14.63%vs.9.76%,P>0.05),与对照组相比,观察组复发率更低,差异具有统计学意义(21.95%vs.2.44%,P<0.05)。结论经鼓室口BET联合腺样体消融术有助于提高CSOM患儿的临床疗效,改善咽鼓管功能,促进术后恢复,减少复发率,且并发症发生率低。 展开更多
关键词 伴渗出液中耳炎(Otitis Media with Effusion) 咽鼓管(Eustachian Tube) 扩张术(Dilatation) 腺样体切除术(Adenoidectomy) 咽鼓管球囊扩张术(balloon dilatation Eustachian tuboplasty) 咽鼓管鼓室口(tympanic opening of Eustachian tube)
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视频智能生成工具Sora应用实践与核心要素分析
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作者 张雪(整理/撰写) 《现代电影技术》 2024年第6期63-64,共2页
美国人工智能(AI)技术公司Open AI继2022年底推出大语言模型Chat GPT之后,于2024年2月发布视频生成模型Sora,该模型能够通过输入文本/图片/视频,智能生成最长时长为60秒、分辨率为1080p的高品质风格化视频,在视频生成领域具有里程碑意义... 美国人工智能(AI)技术公司Open AI继2022年底推出大语言模型Chat GPT之后,于2024年2月发布视频生成模型Sora,该模型能够通过输入文本/图片/视频,智能生成最长时长为60秒、分辨率为1080p的高品质风格化视频,在视频生成领域具有里程碑意义,生成视频在对真实世界的认知和模拟方面取得了优异性能,Open AI称其为“世界模拟器”。 展开更多
关键词 OPEN 语言模型 智能生成 输入文本 生成模型 CHAT 风格化 真实世界
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内审人员须紧握大模型技术“长缨”
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作者 陈宋生 《中国内部审计》 2024年第5期1-1,共1页
近年来,大数据与云计算等新兴技术发展方兴未艾,给各行各业带来深远影响。2022年11月,OpenAI公司的大语言模型ChatGPT的横空问世,更是引领了生成式人工智能技术的新浪潮。我国随之出台一系列政策鼓励人工智能技术的发展。2017年7月,国... 近年来,大数据与云计算等新兴技术发展方兴未艾,给各行各业带来深远影响。2022年11月,OpenAI公司的大语言模型ChatGPT的横空问世,更是引领了生成式人工智能技术的新浪潮。我国随之出台一系列政策鼓励人工智能技术的发展。2017年7月,国务院《新一代人工智能发展规划》提出,促进人工智能与各产业领域深度融合,形成数据驱动、人机协同、跨界融合、共创分享的智能经济形态。2023年7月,国家网信办等七部委联合发布《生成式人工智能服务管理暂行办法》,鼓励生成式人工智能技术在各行业、各领域的创新应用。 展开更多
关键词 人工智能技术 数据驱动 人机协同 语言模型 内审人员 Open 跨界融合 智能经济
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人工智能加速走进生活,高校如何培养人
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作者 周扬帆 《教育家》 2024年第26期8-10,共3页
近年来,人工智能迅速崛起,成为全球科技领域最热门的话题之一。特别是OpenAI公司开发的人工智能聊天机器人程序ChatGPT于2022年11月推出以来,以其为代表的大语言模型在各个领域不断展现出强大的应用潜力,它不仅能处理自然语言、生成文... 近年来,人工智能迅速崛起,成为全球科技领域最热门的话题之一。特别是OpenAI公司开发的人工智能聊天机器人程序ChatGPT于2022年11月推出以来,以其为代表的大语言模型在各个领域不断展现出强大的应用潜力,它不仅能处理自然语言、生成文字内容,还能进行一系列复杂的任务,从写作与翻译到编程与数据分析,为工作和生活提供支持。大语言模型的出现,使得人工智能技术不再是远在实验室的产物,而是普及到了千家万户,成为人们日常生活的一部分。 展开更多
关键词 人工智能 智能聊天机器人 语言模型 数据分析 自然语言 OPEN CHAT 实验室
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Sora与Solaris——虚拟替代真实突破模糊的界限
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作者 余春娜 《天津美术学院学报》 2024年第3期14-17,共4页
2023年10月29日,天津美术学院影视与传媒艺术学院举办了“交点”──2023大学生科技美术设计创新作品大赛暨双一流专业建设背景下动画与数字媒体艺术专业学术论坛系列活动。大赛设立了AIGC这一新赛道,同时也开设了以AI技术为基本点的学... 2023年10月29日,天津美术学院影视与传媒艺术学院举办了“交点”──2023大学生科技美术设计创新作品大赛暨双一流专业建设背景下动画与数字媒体艺术专业学术论坛系列活动。大赛设立了AIGC这一新赛道,同时也开设了以AI技术为基本点的学术论坛。在这一论坛上,诸多学者、在校生针对当时AIGC的技术发展进行了深入的思考与探讨。时至今日,短短3个多月的时间,OpenAI就发布了全新的文生视频模型Sora。这也不禁让人感叹,在我们刚刚对这一领域出现的成果进行观察剖析,从而获得了一些理解与掌握之后,它又再一次迅速地突破了我们的认知边界。 展开更多
关键词 AI技术 SOLARIS 天津美术学院 学术论坛 OPEN 视频模型 双一流 数字媒体艺术专业
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基于Openness可视化参数的二维地貌显示 被引量:2
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作者 张洁 梁明剑 邵延秀 《国土资源遥感》 CSCD 北大核心 2015年第3期172-176,共5页
Openness是一种二维地貌的可视化参数,不受光源设置和邻近地形遮蔽的影响,更强调地形的凹凸,使得直观的立体感更强。该参数不仅可以从多种来源的DEM数据计算获取,也可以用于不同精细程度的地貌分析。闽江入海口地区具有丰富的构造地貌类... Openness是一种二维地貌的可视化参数,不受光源设置和邻近地形遮蔽的影响,更强调地形的凹凸,使得直观的立体感更强。该参数不仅可以从多种来源的DEM数据计算获取,也可以用于不同精细程度的地貌分析。闽江入海口地区具有丰富的构造地貌类型,基于SRTM(90 m)高程数据计算该地区的Openness参数,探讨该参数在地形地貌方面的初步应用。通过闽江入海口地区构造地貌的分析结果表明,Openness参数方法比传统的地形晕渲等常用二维可视化方法编制的图件效果更好,更强调地形的凹凸感,能够更详细地反映实际地形地貌的细节。 展开更多
关键词 openness参数 地形地貌 闽江入海口
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COMPLETE KAHLER METRICS WITH POSITIVE HOLOMORPHIC SECTIONAL CURVATURES ON CERTAIN LINE BUNDLES(RELATED TO A COHOMOGENEITY ONE POINT OF VIEW ON A YAU CONJECTURE) 被引量:1
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作者 段晓曼 关庄丹 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期78-102,共25页
In this article,we study Kahler metrics on a certain line bundle over some compact Kahler manifolds to find complete Kahler metrics with positive holomorphic sectional(or bisectional)curvatures.Thus,we apply a strateg... In this article,we study Kahler metrics on a certain line bundle over some compact Kahler manifolds to find complete Kahler metrics with positive holomorphic sectional(or bisectional)curvatures.Thus,we apply a strategy to a famous Yau conjecture with a co-homogeneity one geometry. 展开更多
关键词 Kahler Metrics complete Riemannian metrics open complex manifolds holomorphic bisectional curvature C*bundle almost homogeneous manifolds
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ChatGPT在学术期刊出版领域的应用 被引量:1
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《中国组织工程研究》 CAS 北大核心 2024年第23期I0001-I0001,共1页
ChatGPT是人工智能研究机构OpenAI在2022年11月30日发布的聊天机器人程序,它能够通过理解和学习人类的语言来进行对话,还能根据聊天的上下文进行互动,真正像人类一样来聊天交流,甚至可以写电子邮件、完成文案、制作视频脚本及撰写包括... ChatGPT是人工智能研究机构OpenAI在2022年11月30日发布的聊天机器人程序,它能够通过理解和学习人类的语言来进行对话,还能根据聊天的上下文进行互动,真正像人类一样来聊天交流,甚至可以写电子邮件、完成文案、制作视频脚本及撰写包括学术论文在内的各类文章。 展开更多
关键词 人工智能研究 聊天机器人 电子邮件 CHAT Open 脚本 GPT 学术期刊出版
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“大模型技术及应用”专栏序言
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作者 高新波 孙宏滨 《数据采集与处理》 CSCD 北大核心 2024年第3期501-501,共1页
生成式AI与具身智能正在成为新一轮人工智能发展的热潮,其背后的核心技术就是大模型。自2022年11月美国OpenAI公司发布聊天机器人应用程序ChatGPT以来,其强大的自然语言生成能力与广泛适用性引起了全世界范围的关注。随后,大模型在场景... 生成式AI与具身智能正在成为新一轮人工智能发展的热潮,其背后的核心技术就是大模型。自2022年11月美国OpenAI公司发布聊天机器人应用程序ChatGPT以来,其强大的自然语言生成能力与广泛适用性引起了全世界范围的关注。随后,大模型在场景分析、视频生成、常识推理、行为决策等方面也有突出表现。国内也相继发布了文心一言、ChatGLM、百川、千问等大模型产品。学术界和产业界都在探索利用大模型解决更多、更具挑战性的问题与潜在应用。2023年,美国科技公司Palantir推出的军事人工智能平台(AIP)和Scale AI公司推出的“多诺万(Donovan)”军事决策辅助系统等也对大模型军事应用进行了初步探索。 展开更多
关键词 自然语言生成 人工智能 聊天机器人 常识推理 应用程序 场景分析 决策辅助系统 OPEN
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基于STM32的智能送药机器人 被引量:1
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作者 苗旭焘 张宇晨 成尔卓 《物联网技术》 2024年第2期131-134,共4页
本文针对药品无接触配送的问题,设计了一款基于STM32的智能送药机器人系统,该系统可以替代传统人工取送药,进行无接触配送。系统分为多个智能送药机器人,每个机器人均通过基于OpenMV的机器视觉模块识别病房号数字,通过HX711重量传感器... 本文针对药品无接触配送的问题,设计了一款基于STM32的智能送药机器人系统,该系统可以替代传统人工取送药,进行无接触配送。系统分为多个智能送药机器人,每个机器人均通过基于OpenMV的机器视觉模块识别病房号数字,通过HX711重量传感器检测药物是否处于机器人中,通过ToF激光雷达进行测距避障,同时多个机器人之间通过BT08B蓝牙模块通信,实现协同工作。智能送药在一定程度上缓解了医疗行业人力资源紧张的情况,同时在取送药方面能够有效降低医院内人员流动带来的病毒传播风险。本文首次提出的多设备协同运行的智能送药机器人支持数据互传,能够实现更高效快速的药品配送,为研究智能医疗机器人方向的学者提供了新的研究依据和视角,也为智能医疗机器人的发展提供了一定借鉴和参考。 展开更多
关键词 智能送药机器人 数字识别 激光测距 STM32 Open MV 蓝牙通信
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OpenAI发布首个文生视频模型Sora 被引量:1
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《电器》 2024年第3期63-63,共1页
2024年2月16日,OpenAI发布首个文生视频模型Sora。Sora模型可以通过文本描述生成60秒长视频,还可以对视频色彩风格等要素精确理解,创造出人物表情丰富、情感生动的视频内容。据介绍,Sora模型有三大突出亮点,实现了AIGC领域的里程碑式进展。
关键词 文本描述 OPEN 表情丰富 色彩风格 视频 AI 突出亮点
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Artificial Self-Recovery Opens up a New Journey of Autonomous Health of Mechanical Equipments
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作者 Xin Pan Haoyu Zhang +3 位作者 Jinji Gao Weimin Wang Zhinong Jiang Lidong He 《Engineering》 SCIE EI CAS CSCD 2024年第6期22-26,共5页
1.Introduction With the implementation of modern production strategies,such as“Industry 4.0”and“Made in China 2025,”the development of high-end mechanical equipment is gradually reaching a high degree of parameter... 1.Introduction With the implementation of modern production strategies,such as“Industry 4.0”and“Made in China 2025,”the development of high-end mechanical equipment is gradually reaching a high degree of parameterization,digitalization,networking,and intelligence[1].High-end mechanical equipment no longer consists of traditional single devices,but is closely linked to the overall production process;that is,a variety of devices interact with each other and collectively form a complex system.However,faults can lead to production delays throughout the system and even seriously threaten the safety of workers[2].In addition,equipment operating in unmanned air or space vehicles(including space robots)cannot be repaired by humans if they break down[3].Until recently,the typical method of addressing machine faults was primarily the“fault cure”method,which involves manually shutting down,inspecting,and repairing the equipment to restore normal operation.Accordingly,the maintenance cycle of the traditional“fault cure”method is time-consuming,and the quality of the maintenance depends on the skills of the technician[4]. 展开更多
关键词 COLLECTIVE consuming OPEN
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大模型或将颠覆人工智能发展范式我国需完善人工智能产业生态
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作者 张雅妮 孙瑶 王懿 《中国信息化》 2024年第7期43-45,共3页
美国OpenAI公司推出语言大模型ChatGPT,被业界认为是人工智能从专业智能向通用智能演进的里程碑事件,具有划时代意义。美国科技巨头纷纷跟进,微软推出能处理文本、图像多种信息的多模态大模型GPT4,谷歌采用多模态大模型开发更具有通用... 美国OpenAI公司推出语言大模型ChatGPT,被业界认为是人工智能从专业智能向通用智能演进的里程碑事件,具有划时代意义。美国科技巨头纷纷跟进,微软推出能处理文本、图像多种信息的多模态大模型GPT4,谷歌采用多模态大模型开发更具有通用能力的机器人。大模型有望成为通往通用人工智能的可行途径,或将引发通用人工智能研究范式的根本性转变,需要加紧布局。我国在人工智能产业的核心技术创新生态,“大模型+统一计算架构+图形处理器”生态以及数据、算法、算力“三位一体”生态需要加快完善,抓住短暂的窗口期加紧推进。 展开更多
关键词 统一计算架构 人工智能 图形处理器 机器人 谷歌 通用能力 Open 多模态
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Effect of screening colonoscopy frequency on colorectal cancer mortality in patients with a family history of colorectal cancer
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作者 Li Zheng Bin Li +3 位作者 Ling Lei Li-Jia Wang Zhi-Ping Zeng Jian-Dong Yang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第2期354-363,共10页
BACKGROUND Colorectal cancer is a common malignant tumor in China,and its incidence in the elderly is increasing annually.Inflammatory bowel disease is a group of chronic non-specific intestinal inflammatory diseases,... BACKGROUND Colorectal cancer is a common malignant tumor in China,and its incidence in the elderly is increasing annually.Inflammatory bowel disease is a group of chronic non-specific intestinal inflammatory diseases,including ulcerative colitis and Crohn’s disease.We included the clinicopathological and follow-up data of patients with colorectal cancer who underwent laparoscopic colectomy or open colectomy at our Gastrointestinal Department between January 2019 and December 2022.Surgical indicators,oncological indicators,and survival rates were compared between the groups.The results of 104 patients who met the above criteria were extracted from the database(laparoscopic colectomy group=63,open colectomy group=41),and there were no statistically significant differences in the baseline data or follow-up time between the two groups.RESULTS Intraoperative blood loss,time to first ambulation,and time to first fluid intake were significantly lower in the laparoscopic colectomy group than in the open colectomy group.The differences in overall mortality,tumor-related mortality,and recurrence rates between the two groups were not statistically significant,and survival analysis showed that the differences in the cumulative overall survival,tumor-related survival,and cumulative recurrence-free rates between the two groups were not statistically significant.CONCLUSION In elderly patients with colorectal cancer,laparoscopic colectomy has better short-term outcomes than open colectomy,and laparoscopic colectomy has superior long-term survival outcomes compared with open colectomy. 展开更多
关键词 Colorectal cancer Laparoscopic surgery Open surgery PROGNOSIS Laparoscopic colectomy Open colectomy
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Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries
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作者 Xin Chen Yu Zhang +5 位作者 Chang Chen Huinan Li Yuran Lin Ke Yu Caiyun Nan Chen Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期154-164,共11页
Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult... Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery. 展开更多
关键词 Atomically dispersed Open hollow structure Discharge product LITHIUM Oxygen battery
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Analytical solution for the effective elastic properties of rocks with the tilted penny-shaped cracks in the transversely isotropic background
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作者 Zheng-Qian Ma Xing-Yao Yin +2 位作者 Zhao-Yun Zong Yuan-Yuan Tan Ya-Ming Yang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期221-243,共23页
Seismic prediction of cracks is of great significance in many disciplines,for which the rock physics model is indispensable.However,up to now,multitudinous analytical models focus primarily on the cracked rock with th... Seismic prediction of cracks is of great significance in many disciplines,for which the rock physics model is indispensable.However,up to now,multitudinous analytical models focus primarily on the cracked rock with the isotropic background,while the explicit model for the cracked rock with the anisotropic background is rarely investigated in spite of such case being often encountered in the earth.Hence,we first studied dependences of the crack opening displacement tensors on the crack dip angle in the coordinate systems formed by symmetry planes of the crack and the background anisotropy,respectively,by forty groups of numerical experiments.Based on the conclusion from the experiments,the analytical solution was derived for the effective elastic properties of the rock with the inclined penny-shaped cracks in the transversely isotropic background.Further,we comprehensively analyzed,according to the developed model,effects of the crack dip angle,background anisotropy,filling fluid and crack density on the effective elastic properties of the cracked rock.The analysis results indicate that the dip angle and background anisotropy can significantly either enhance or weaken the anisotropy degrees of the P-and SH-wave velocities,whereas they have relatively small effects on the SV-wave velocity anisotropy.Moreover,the filling fluid can increase the stiffness coefficients related to the compressional modulus by reducing crack compliance parameters,while its effects on shear coefficients depend on the crack dip angle.The increasing crack density reduces velocities of the dry rock,and decreasing rates of the velocities are affected by the crack dip angle.By comparing with exact numerical results and experimental data,it was demonstrated that the proposed model can achieve high-precision estimations of stiffness coefficients.Moreover,the assumption of the weakly anisotropic background results in the consistency between the proposed model and Hudson's published theory for the orthorhombic rock. 展开更多
关键词 Effective elastic property Tilted crack Transverse isotropy Analytical solution Crack opening displacement
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