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Commentary on "Association of daily sitting time and leisure-time physical activity with body fat among U.S.adults"
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作者 Barbara E.Ainsworth 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第2期127-129,共3页
In their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among U.S.Adults,Liao et al.^(1) analyzed data from the 2011-2018 National Health and Examination Survey to exam... In their study,association of daily sitting time and leisure-time physical activity (LTPA) with body fat among U.S.Adults,Liao et al.^(1) analyzed data from the 2011-2018 National Health and Examination Survey to examine associations between h/day sitting,meeting (or not meeting) the U.S.Physical Activity Guidelines of≥150 min/week of moderate-and vigorous-intensity LTPA,and combinations of sitting time and LTPA on totaland trunk percent body fat (BF%). 展开更多
关键词 u.s. ADULT AMONG
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The Reception Commemorating the 45th Anniversary of China-U.S.Diplomatic Ties Held in Beijing
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《International Understanding》 2024年第1期40-40,共1页
On January 5,the Chinese People's Association for Friendship with Foreign Countries and the Chinese People's Institute of Foreign Affairs jointly hosted a reception commemorating the 45th anniversary of the es... On January 5,the Chinese People's Association for Friendship with Foreign Countries and the Chinese People's Institute of Foreign Affairs jointly hosted a reception commemorating the 45th anniversary of the establishment of diplomatic relationship between China and the United States in Beijing.Member of the Political Bureau of the CPC Central Committee and Foreign Minister Wang Yi attended the commemoration and delivered aspeech.David Meale,ChargédAffaires at the U.S.Embassy in China,addressed the reception.He extended on behalf of the U.S.side congratulations on the anniversary,expressing the readiness of the U.S.to implement the consensus reached by the two heads of state and promote the steady development of U.S.-China relations.More than 350 people from all walks of life of both countries attended the reception. 展开更多
关键词 jointly u.s. behalf
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FREE SPEECH OR SINOPHOBIA? THE U.S. SENATE MUST DECIDE
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作者 Anthony Moretti 《China Report ASEAN》 2024年第4期63-64,共2页
The 100 men and women who make up the U.S.Senate will soon have an important choice.They will either affirm that the First Amendment matters or they will surrender to fear.The senators must decide whether to go along ... The 100 men and women who make up the U.S.Senate will soon have an important choice.They will either affirm that the First Amendment matters or they will surrender to fear.The senators must decide whether to go along with their colleagues in the House of Representatives and require the popular social media app TikTok to be sold to an American company.If they do endorse the House vote,then ByteDance must divest itself of TikTok or see the app will be banned on U.S.-based social media platforms. 展开更多
关键词 u.s. RENDER SOON
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Cross-Cultural Adjustment and Coping:U.S.Students in Taiwan Residents Higher Education
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作者 Wen-Ling Lou 《Sino-US English Teaching》 2024年第1期26-42,共17页
The aim of this study was to investigate the adjustment problems of students from the United States enrolled in universities in the East,specifically in Taiwan,their problems related to cultural adaptation,and the pro... The aim of this study was to investigate the adjustment problems of students from the United States enrolled in universities in the East,specifically in Taiwan,their problems related to cultural adaptation,and the process of adjustment to student life in Taiwan.Under investigation were cultural adjustment and coping skills as these students transitioned from West to East.Qualitative data were collected from interviews with participants and faculty members as well as participant observations.Results indicated that U.S.students found their own ways to acclimate to their new academic setting as well as to social relations,cross-cultural issues,and the linguistic environment in Taiwan to achieve effective adaptation.They made changes in themselves to cope with all situations they encountered.This study provides suggestions for international students abroad in Taiwan,for the Taiwan Residents government,and for universities or colleges in terms of what they should offer to current and future international students. 展开更多
关键词 adjustment cultural adjustment cross-cultural adaptation COPING u.s.students
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Analysis of Porter’s Five Forces Competitive Model in China’s Property Rights Trading Market
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作者 Weinong Wang 《Proceedings of Business and Economic Studies》 2024年第3期206-211,共6页
In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of th... In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market. 展开更多
关键词 Porter’s five forces competitive model Market optimization Innovative development
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Digital Disparities:How Artificial Intelligence Can Facilitate Anti-Black Racism in the U.S.Healthcare Sector
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作者 Anthony Victor Onwuegbuzia 《International Relations and Diplomacy》 2024年第1期40-50,共11页
This paper delves into the intricate interplay between artificial intelligence(AI)systems and the perpetuation of Anti-Black racism within the United States medical industry.Despite the promising potential of AI to en... This paper delves into the intricate interplay between artificial intelligence(AI)systems and the perpetuation of Anti-Black racism within the United States medical industry.Despite the promising potential of AI to enhance healthcare outcomes and reduce disparities,there is a growing concern that these technologies may inadvertently/advertently exacerbate existing racial inequalities.Focusing specifically on the experiences of Black patients,this research investigates how the following AI components:medical algorithms,machine learning,and natural learning processes are contributing to the unequal distribution of medical resources,diagnosis,and health care treatment of those classified as Black.Furthermore,this review employs a multidisciplinary approach,combining insights from computer science,medical ethics,and social justice theory to analyze the mechanisms through which AI systems may encode and reinforce racial biases.By dissecting the three primary components of AI,this paper aims to present a clear understanding of how these technologies work,how they intersect,and how they may inherently perpetuate harmful stereotypes resulting in negligent outcomes for Black patients.Furthermore,this paper explores the ethical implications of deploying AI in healthcare settings and calls for increased transparency,accountability,and diversity in the development and implementation of these technologies.Finally,it is important that I prefer the following paper with a clear and concise definition of what I refer to as Anti-Black racism throughout the text.Therefore,I assert the following:Anti-Black racism refers to prejudice,discrimination,or antagonism directed against individuals or communities of African descent based on their race.It involves the belief in the inherent superiority of one race over another and the systemic and institutional practices that perpetuate inequality and disadvantage for Black people.Furthermore,I proclaim that this form of racism can be manifested in various ways,such as unequal access to opportunities,resources,education,employment,and fair treatment within social,economic,and political systems.It is also pertinent to acknowledge that Anti-Black racism is deeply rooted in historical and societal structures throughout the U.S.borders and beyond,leading to systemic disadvantages and disparities that impact the well-being and life chances of Black individuals and communities.Addressing Anti-Black racism involves recognizing and challenging both individual attitudes and systemic structures that contribute to discrimination and inequality.Efforts to combat Anti-Black racism include promoting awareness,education,advocacy for policy changes,and fostering a culture of inclusivity and equality. 展开更多
关键词 Bias in algorithms Racial disparities in u.s.healthcare Discriminatory healthcare practices Black patient outcomes Automated decision-making and racism Machine Learning Natural language processing
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Model-based assessment of muscle forces and strain distribution in the femur of Cabot’s Tragopans(Tragopan caboti)
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作者 Xinsen Wei Zihui Zhang 《Avian Research》 SCIE CSCD 2023年第4期706-715,共10页
The hindlimbs play a crucial role in bird locomotion,making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour.However,a comprehensive anal... The hindlimbs play a crucial role in bird locomotion,making the biomechanical properties of the musculoskeletal system in these limbs a focal point for researchers studying avian behaviour.However,a comprehensive analysis of the mechanical performance within the long bones of hindlimbs during locomotion remains lacking.In the present study,the strain and deformation of the femur of Cabot’s Tragopans(Tragopan caboti)were estimated.We employed inverse simulation to calculate the force and moment of femoral muscles during mid-stance terrestrial locomotion and conducted finite element analysis to calculate femoral strain.Results showed that during mid-stance,the femur experiences combined deformation primarily characterized by torsion,bending,and compression.It emphasises the importance of considering the influence of varying loads on bone adaptation when investigating bone form-function relationships.Muscles were found to play a significant role in offsetting joint loads on the femur,subsequently reducing the deformation and overall strain on the bone.This reduction enhances femoral safety during locomotion,allowing birds to meet mechanical demands while maintaining a lightweight bone structure.Notably,the M.iliotrochantericus caudalis significantly reduces torsional deformation of the proximal femur,protecting the vulnerable femoral neck from high fracture risk induced by rotation load.Given that the femur torsion during terrestrial locomotion in birds is associated with changes in hindlimb posture due to their adaptation to flight,the characteristics of M.iliotrochantericus caudalis may provide insight into the locomotor evolution of theropods and the origin of avian flight. 展开更多
关键词 Cabot’s tragopan FEMUR Finite element analysis Inverse simulation Muscle force STRAIN
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Decoupling U.S.Economy from China Doomed to Fail
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作者 HE WEIWEN 《China Today》 2023年第6期44-45,共2页
The global supply chain is based on the global distribution of materials,technology,capital,labor,and markets and thus cannot be altered by political motives.KEEPING a sound and stable global supply chain will benefit... The global supply chain is based on the global distribution of materials,technology,capital,labor,and markets and thus cannot be altered by political motives.KEEPING a sound and stable global supply chain will benefit not only China and America,but also the world at large.Janet Yellen,U.S.secretary of treasury,has realized the devastating consequences of decoupling U.S.economy from Chinese economy when she spoke at John Hopkins Institute on April 20,2023.Yellen said,“The United States will assert ourselves when our vital interests are at stake.But we do not seek to decouple our economy from China’s.A full separation of our economies would be disastrous for both countries.It would be destabilizing for the rest of the world.” 展开更多
关键词 u.s. consequences ECONOMY
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Opportunities and Challenges for China-U.S.LNG Trade
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作者 Hou Mingyang He Jianyu 《China Oil & Gas》 CAS 2023年第6期36-40,共5页
Since the 1960s,the global natural gas industry has developed rapidly,and natural gas has become a fossil fuel that can balance supply stability,economic efficiency of consumption,clean and low-carbon features at the ... Since the 1960s,the global natural gas industry has developed rapidly,and natural gas has become a fossil fuel that can balance supply stability,economic efficiency of consumption,clean and low-carbon features at the current stage.However,there is a regional imbalance in the global demand for natural gas,and the continuous rise in geopolitical risks negatively affects the stability of the natural gas market.In recent years,LNG export capacity in the U.S.has continued to grow,and the potential for China-U.S.LNG trade in the future is enormous.From the perspective of development opportunities,strengthening LNG trade cooperation with the U.S.is conducive to the diversification of natural gas import sources for China.From the perspective of challenges,China-U.S.LNG trade cooperation also involves potential risks in terms of economy and channels. 展开更多
关键词 u.s. continued strengthening
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Will China-U.S.Relations Stabilize After the San Francisco Summit?--Mutually beneficial cooperation or antagonism and confrontation?That is the question
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作者 Li Shimeng 《China Report ASEAN》 2023年第12期32-34,共3页
At 1:35 p.m.local time on November 15,a four-hour summit between Chinese President Xi Jinping and U.S.President Joe Biden concluded at Filoli Estate in San Francisco.At a press briefing after the meeting,Wang Yi,membe... At 1:35 p.m.local time on November 15,a four-hour summit between Chinese President Xi Jinping and U.S.President Joe Biden concluded at Filoli Estate in San Francisco.At a press briefing after the meeting,Wang Yi,member of the Political Bureau of the CPC Central Committee and Minister of Foreign Affairs,said that“the two presidents had a very good,comprehensive,and in-depth meeting.” 展开更多
关键词 u.s. PING SUMMIT
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Quiet Lingering of The U.S.Debt Crisis
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作者 Cao Jing 《China Report ASEAN》 2023年第7期48-49,共2页
On June 3,U.S.President Joe Biden signed a debt ceiling bill,the“Fiscal Responsibility Act of 2023,”two days before the nation’s debt default deadline,temporarily averting a calamitous default on its debt.With the ... On June 3,U.S.President Joe Biden signed a debt ceiling bill,the“Fiscal Responsibility Act of 2023,”two days before the nation’s debt default deadline,temporarily averting a calamitous default on its debt.With the bill,the nation’s debt limit is officially suspended through January 1,2025. 展开更多
关键词 DEFAULT u.s. LIMIT
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Counteraction to China?Impact of the U.S.International Development Finance Corporation on China’s Development Finance
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作者 ZHOU Yiwen NIU Xinyi +1 位作者 NI Xintong XU Yue 《International Relations and Diplomacy》 2023年第4期161-170,共10页
The United States passed the Better Utilization of Investment Leading to Development(BUILD Act),as a counterweight to China’s overseas development activities.Under the Act,the US established a new federal agency,the ... The United States passed the Better Utilization of Investment Leading to Development(BUILD Act),as a counterweight to China’s overseas development activities.Under the Act,the US established a new federal agency,the U.S.International Development Finance Corporation(DFC),to enhance U.S.development financing capabilities.To better understand the impact of the DFC on China’s development finance,this article analyzes the DFC’s purpose,functions,structure,and funding.Then it focuses on the purpose of establishing the DFC,providing a preliminary analysis of the potential motivation for its establishment.It also compares the China Development Bank(CDB)and the DFC based on their focused sectors.Finally,through an in-depth analysis of financial frictions in China-U.S.relations,this article argues that the DFC competes with China’s overseas development financing activities in the context of broader strategic competition between China and the U.S. 展开更多
关键词 u.s.International Development Finance Corporation China Development Bank China’s development finance the Belt and Road Initiative(BRI) u.s.-China relations
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农业新质生产力:内涵特征、发展重点、面临制约和政策建议 被引量:40
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作者 姜长云 《南京农业大学学报(社会科学版)》 CSSCI 北大核心 2024年第3期1-17,共17页
结合学习习近平总书记关于发展新质生产力的重要论述,文章探讨了农业新质生产力的内涵要义和发展要求,揭示了发展农业新质生产力的意义和战略重点,分析了发展农业新质生产力面临的制约,提出要面向加快建设农业强国和把农业建成现代化大... 结合学习习近平总书记关于发展新质生产力的重要论述,文章探讨了农业新质生产力的内涵要义和发展要求,揭示了发展农业新质生产力的意义和战略重点,分析了发展农业新质生产力面临的制约,提出要面向加快建设农业强国和把农业建成现代化大产业的需求,科学处理农业新质生产力与农业传统生产力、仰望星空与脚踏实地、有为政府与有效市场、统筹高质量发展和高水平安全、农业新质生产力特殊性与新质生产力一般性等的关系。在此基础上,提出了发展农业新质生产力的若干政策建议。如实施若干重大工程或计划,完善激励机制,设立未来农业专项,加强和创新农业新质生产力支持体系,加强对农业农村基础设施和公共服务能力建设的支持,等等。 展开更多
关键词 新质生产力 科技创新 产业创新 农业强国建设 现代农业
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高标准农田建设参与对农民种粮收益的影响——基于农业新质生产力的中介作用 被引量:3
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作者 张应良 龚燕玲 《南京农业大学学报(社会科学版)》 CSSCI 北大核心 2024年第3期110-124,共15页
基于全国10省1032份农户的微观调查数据,使用内生转换回归模型实证分析了高标准农田建设参与对农民种粮收益的影响。研究发现:(1)高标准农田建设参与显著提升农民种粮收益,且平均处理效应表明,参与高标准农田建设可使农民种粮收益提高2.... 基于全国10省1032份农户的微观调查数据,使用内生转换回归模型实证分析了高标准农田建设参与对农民种粮收益的影响。研究发现:(1)高标准农田建设参与显著提升农民种粮收益,且平均处理效应表明,参与高标准农田建设可使农民种粮收益提高2.77%。(2)异质性分析表明,相较于小农户,规模户参与高标准农田建设能够提升种粮收益;高标准农田建设参与不仅促进兼业农户增加种粮收益,而且促进纯农户增加种粮收益;相较于非粮食主产区,粮食主产区农户参与高标准农田建设的种粮收益提升效果更明显。(3)机制分析表明,高标准农田建设参与通过提升农业新质生产力水平,从而提高农民种粮收益。据此,鼓励农民积极参与高标准农田建设管理工作,制定出台农户参与高标准农田建设的差异化政策,同时加快培育和发展农业新质生产力,以实现农民种粮收益提升。 展开更多
关键词 高标准农田建设 农民种粮收益 农业新质生产力 内生转换回归模型
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滇东南薄竹山花岗岩年代学、地球化学特征及地质意义
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作者 黄建国 任涛 +2 位作者 刘红卫 罗光明 管申进 《矿物岩石地球化学通报》 CAS CSCD 北大核心 2024年第3期621-635,共15页
滇东南薄竹山地区W-Sn-Pb-Zn多金属矿床与该区大型复式花岗岩体有密切的成因联系。为了探讨该花岗岩体的侵位时代、岩石成因及形成背景,对薄竹山花岗岩开展了岩石地球化学、锆石U-Pb定年及Hf同位素测试。结果表明,该花岗岩可划分为两期... 滇东南薄竹山地区W-Sn-Pb-Zn多金属矿床与该区大型复式花岗岩体有密切的成因联系。为了探讨该花岗岩体的侵位时代、岩石成因及形成背景,对薄竹山花岗岩开展了岩石地球化学、锆石U-Pb定年及Hf同位素测试。结果表明,该花岗岩可划分为两期,其中晚期花岗岩LA-ICP-MS锆石U-Pb年龄为(87.08±0.55)~(87.29±0.69)Ma。两期花岗岩均具高的SiO_(2)(63.37%~72.07%)、K_(2)O(4.96%~6.19%),贫Fe、Mg的特征,A/CNK值为1.03~2.42,轻重稀土元素分异明显(LREE/HREE=14.0~26.5),Eu明显负异常(δEu=0.38~0.62),富含大离子亲石元素Rb、Th、U及稀土元素La、Ce、Nd,亏损Ba、Ta、Nb、Sr、Y和Yb,ε_(Hf)(t)值为−9.31~−5.14,具有高钾钙碱性过铝质S型花岗岩的地球化学和同位素特征;Hf同位素二阶段模式年龄(t_(DM2))为1476~1737 Ma,说明岩浆可能来源于早中元古代下地壳部分熔融。综合研究认为,薄竹山花岗岩是白垩纪伸展背景下软流圈地幔上涌导致的早中元古代下地壳物质部分熔融所形成。 展开更多
关键词 锆石U-PB定年 地球化学 S型花岗岩 薄竹山 滇东南
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教育硕士产教融合“U-G-S&E”育人模式探析
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作者 赵兴碧 章光洁 董红梅 《西南林业大学学报(社会科学)》 2024年第4期104-109,共6页
产教融合是教育与产业的深度合作,我国产教融合的政策经历了从职业教育到普通教育的发展。产教融合符合教育硕士人才培养的逻辑,“U-G-S&E”育人模式以高校为主导,政府提供政策引导和资金支持,中小学和企业协同参与教育硕士的培养... 产教融合是教育与产业的深度合作,我国产教融合的政策经历了从职业教育到普通教育的发展。产教融合符合教育硕士人才培养的逻辑,“U-G-S&E”育人模式以高校为主导,政府提供政策引导和资金支持,中小学和企业协同参与教育硕士的培养。通过实践探索发现,“U-G-S&E”模式可以更好地激发学生提升职业能力的动力,助力学生职业生涯规划和就业,提升以赛赋能的效果,帮助高校校内导师、中小学和企业的校外导师加深对教育链、人才链与产业链、创新链有机衔接的理解,助力孵化本地企业参与遴选国家产教融合型企业,推动本地企业更好的融入国家现代教育体系建设。 展开更多
关键词 教育硕士 产教融合 U-G-S&E 职业能力
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U-G-S模式下现代大学附属学校建设的路径思考
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作者 郭长江 《现代基础教育研究》 2024年第3期23-26,共4页
U-G-S(大学-政府-学校)三方联动是上海师范大学近年来建设现代大学附属学校的主要模式,上海师范大学、各区政府与中小学校高效协同合作,发挥各方优势,主动服务上海市政府建设“五个新城”的城市战略,办老百姓家门口的好学校。大学附属... U-G-S(大学-政府-学校)三方联动是上海师范大学近年来建设现代大学附属学校的主要模式,上海师范大学、各区政府与中小学校高效协同合作,发挥各方优势,主动服务上海市政府建设“五个新城”的城市战略,办老百姓家门口的好学校。大学附属学校分为挂牌学校和新建学校两种类型,研究从内在机制、实践路径和建设成效三个方面对两类学校的变革发展进行深度剖析,以期为大学附属学校建设提供宝贵经验。 展开更多
关键词 U-G-S模式 建设路径 大学附属学校
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U-G-S协同推进创新人才早期培养的国际经验与启示
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作者 陆超 金辉召 黄雪君 《教育参考》 2024年第6期43-52,84,共11页
本文选取美国、澳大利亚、新加坡等创新人才机制相对成熟的国家,探究其创新人才多主体早期培育项目经验,分析、归纳得出主要培养路径有四:首先,“丰富和加速”是主要培养手段,以高阶课程助力超前学习、以缩短学制促进加速学习、以暑期... 本文选取美国、澳大利亚、新加坡等创新人才机制相对成熟的国家,探究其创新人才多主体早期培育项目经验,分析、归纳得出主要培养路径有四:首先,“丰富和加速”是主要培养手段,以高阶课程助力超前学习、以缩短学制促进加速学习、以暑期项目丰富课程学习;其次,以信息技术搭建资优教育平台,扩展资源网络渠道,推进创新人才培养的机会均等;再次,注重教育体系衔接,以大中小衔接体系为创新人才接续培养枢纽,确保培养质量;最后,以分类培养理念创新人才和技术创新人才为目标,建立针对性培养体系。据此,本文提出改进我国创新人才早期培养U-G-S协作机制的建议:加强政策顶层设计、扶持校企联合、增强创新人才网络资源建设、推进校本创新人才培养项目建设等。 展开更多
关键词 创新人才 早期培养 U-G-S
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“U-S”合作中高校教师与中小学教师的跨界知识互动探究
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作者 陆超 《现代基础教育研究》 2024年第3期27-31,共5页
对于“U-S”合作情境中高校教师与中小学教师如何进行知识互动这一重要问题,鲜有实证研究涉及。通过对高校与中小学合作的多个案例进行质性研究,发现高校教师与中小学教师的知识互动存在三种不同的模式:一是高校教师主导下的知识迁移模... 对于“U-S”合作情境中高校教师与中小学教师如何进行知识互动这一重要问题,鲜有实证研究涉及。通过对高校与中小学合作的多个案例进行质性研究,发现高校教师与中小学教师的知识互动存在三种不同的模式:一是高校教师主导下的知识迁移模式,二是内化与重构后的知识转化模式,三是基于研究伙伴关系的知识生产模式。基于此,自我定位与地位关系、知识互动的聚焦性和持续性、卷入程度及跨界互动能力,是影响高校教师与中小学教师知识互动效果的重要因素。 展开更多
关键词 “U-S”合作 跨界知识互动 知识生产
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湘西沃溪金锑钨矿床燕山期幕式成矿作用:来自原位白钨矿U-Pb定年与黄铁矿元素-同位素的约束 被引量:1
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作者 李彬 许德如 +5 位作者 柏道远 陈旭 邹少浩 代俊峰 马文 曾广乾 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第1期215-240,共26页
沃溪矿床位于江南造山带中段,是一座同时具有金、锑、钨大规模成矿的大型金矿,近年的研究揭示其主要形成于燕山期,但该矿的成矿物质源区及矿床成因尚存争议。基于此,本文利用SEM、EPMA、LA-MC-IF-ICP-MS等原位分析技术,对该矿床多世代... 沃溪矿床位于江南造山带中段,是一座同时具有金、锑、钨大规模成矿的大型金矿,近年的研究揭示其主要形成于燕山期,但该矿的成矿物质源区及矿床成因尚存争议。基于此,本文利用SEM、EPMA、LA-MC-IF-ICP-MS等原位分析技术,对该矿床多世代黄铁矿的结构、成分及同位素组成和成矿期白钨矿的U-Pb年代学进行了研究。在沃溪矿床中,识别出3个世代5种类型黄铁矿(Py),即成矿前Py1,成矿第二阶段Py2和第三阶段的Py3a、Py3b和Py3c。黄铁矿微区成分及围岩蚀变特征指示,成矿期Au、As和Cu耦合,Au主要以固溶体(Au+)的形式存在于Py3b的晶格中;As-取代S-进入黄铁矿是促进晶格金富集的主要因素;而强烈的水-岩反应是导致成矿期热液黄铁矿Co/Ni<1的原因。黄铁矿的原位微量元素和S-Pb同位素组成(δ34 S V-CDT值:Py2为-4.33‰~-1.61‰,Py3a为-6.36‰~3.59‰,Py3b为-4.36‰~3.59‰,Py3c为-2.21‰~-0.65‰;206 Pb/204 Pb、207 Pb/204 Pb、208 Pb/204 Pb值:Py2分别为18.029、15.618和38.653,Py3a分别为18.047~18.341、15.594~15.698、38.781~39.394)及其在环带结构中的变化,指示第二及第三成矿阶段流体性质存在显著差异。成矿第三阶段白钨矿的LA-ICP-MS U-Pb定年结果为132.7±7.9Ma(1σ,n=31,MSWD=0.43)。结合前人研究成果,我们认为沃溪金锑钨矿床主要形成于燕山期148~140Ma的黑钨矿(少量白钨矿、黄铁矿和金)和~130Ma的金-锑-白钨矿两阶段幕式成矿作用。早阶段成矿为下伏基底岩石重熔岩浆演化出的相对高温的还原性流体;晚阶段金-锑-白钨矿成矿以脉冲性幔源流体为主,金主要具地幔来源,而锑和钨可能来源于壳源与幔源流体混合演化出的富矿热液,成矿的脉动性可能与深部断层阀机制有关。金的主要沉淀机制为水岩反应和硫化作用,流体混合是辉锑矿与白钨矿的沉淀机制。富集交代的岩石圈地幔活化和古太平洋板块俯冲后撤、拆沉导致的岩石圈大规模伸展是江南造山带中段(湖南)燕山晚期金多金属大规模成矿的关键因素及构造背景,区域上具有进一步寻找陆内弧后伸展背景金多金属矿床的潜力。 展开更多
关键词 江南造山带 沃溪Au-Sb-W矿 白钨矿U-Pb定年 黄铁矿 S-Pb同位素
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