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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method normalized solution
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Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
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作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
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Rate-frequency dependent shear behavior of rough rock joint experiencing normal load oscillations
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作者 DANG Wen-gang LI Xing-ling +1 位作者 TAO Kang FU Jin-yang 《Journal of Central South University》 2025年第5期1873-1886,共14页
Dynamic disturbances certainly reduce shear strength of rock joints,yet the mechanism needs deeper explanation.We investigate the shear behavior of a rough basalt joint by conducting laboratory shear experiments.Const... Dynamic disturbances certainly reduce shear strength of rock joints,yet the mechanism needs deeper explanation.We investigate the shear behavior of a rough basalt joint by conducting laboratory shear experiments.Constant and superimposed oscillating normal loads are applied at the upper block.Meanwhile,the bottom block moves at a constant shear rate.We investigate the shear behavior by:1)altering the normal load oscillation frequency with a same shear rate,2)altering the shear rate with a same normal load oscillation frequency,and 3)altering the normal load oscillation frequency and shear rate simultaneously with a constant ratio.The results show that the oscillating normal load reduces the coefficient of friction(COF).The reduce degree of COF increases with higher shear rate,decreases when increasing normal load oscillation frequency,and keeps constant if the special ratio,v/f(shear rate divided by normal oscillation frequency),is constant.Moreover,we identify a time lag between peak normal load and peak shear load.And the lagging proportion increases with higher shear rate,and decreases with larger static COF.Our results imply that a lower creep rate with a higher normal load oscillation frequency easily destabilizes the creeping fault zones. 展开更多
关键词 normal load oscillation shear rate oscillation frequency friction reduction time lag
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High-thermal free vibration analysis of functionally graded microplates using a new finite element formulation based on TSDT and MSCT
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作者 Huu Trong Dang Nhan Thinh Hoang +2 位作者 Quoc Hoa Pham Trung Thanh Tran Huy Gia Luong 《Defence Technology(防务技术)》 2025年第2期131-149,共19页
Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis r... Recent advancements in additive manufacturing(AM)have revolutionized the design and production of complex engineering microstructures.Despite these advancements,their mathematical modeling and computational analysis remain significant challenges.This research aims to develop an effective computational method for analyzing the free vibration of functionally graded(FG)microplates under high temperatures while resting on a Pasternak foundation(PF).This formulation leverages a new thirdorder shear deformation theory(new TSDT)for improved accuracy without requiring shear correction factors.Additionally,the modified couple stress theory(MCST)is incorporated to account for sizedependent effects in microplates.The PF is characterized by two parameters including spring stiffness(k_(w))and shear layer stiffness(k_(s)).To validate the proposed method,the results obtained are compared with those of the existing literature.Furthermore,numerical examples explore the influence of various factors on the high-temperature free vibration of FG microplates.These factors include the length scale parameter(l),geometric dimensions,material properties,and the presence of the elastic foundation.The findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the findings significantly enhance our comprehension of the free vibration of FG microplates in high thermal environments.In addition,the results of this research will have great potential in military and defense applications such as components of submarines,fighter aircraft,and missiles. 展开更多
关键词 Microplates Functionally graded material Finite element method Modified couple stress theory new TSDT High-thermal free vibration Pasternak foundation
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交互式数字叙事:加拿大Writing New Body Worlds阅读治疗新探索 被引量:2
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作者 牟晓青 于志涛 《图书馆论坛》 CSSCI 北大核心 2024年第4期222-230,F0003,共10页
文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性... 文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性健康干预。基于数据与计算的精准化阅读治疗是数字人文视角下的新变革,更具推广应用价值;以在线阅读平台建设为依托,推进实施平台化的阅读和治疗应成为未来发展方向之一;基于阅读形态与体验因技术赋能而改变的现状,图书馆应发挥引领作用,积极收集、创建或协助创建数字故事,推进阅读推广、服务与治疗的融合性发展,成为社区建设促进者、历史欣赏者和社区参与倡导者,也使阅读借助交互式数字叙事这一新载体,更好地发挥变革的力量,促进健康与幸福。 展开更多
关键词 交互式数字叙事 阅读治疗 Writing new Body Worlds 加拿大
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New normalized LMS adaptive filter with a variable regularization factor 被引量:9
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作者 LI Zhoufan LI Dan +1 位作者 XU Xinlong ZHANG Jianqiu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第2期259-269,共11页
A new normalized least mean square(NLMS) adaptive filter is first derived from a cost function, which incorporates the conventional one of the NLMS with a minimum-disturbance(MD)constraint. A variable regularization f... A new normalized least mean square(NLMS) adaptive filter is first derived from a cost function, which incorporates the conventional one of the NLMS with a minimum-disturbance(MD)constraint. A variable regularization factor(RF) is then employed to control the contribution made by the MD constraint in the cost function. Analysis results show that the RF can be taken as a combination of the step size and regularization parameter in the conventional NLMS. This implies that these parameters can be jointly controlled by simply tuning the RF as the proposed algorithm does. It also demonstrates that the RF can accelerate the convergence rate of the proposed algorithm and its optimal value can be obtained by minimizing the squared noise-free posteriori error. A method for automatically determining the value of the RF is also presented, which is free of any prior knowledge of the noise. While simulation results verify the analytical ones, it is also illustrated that the performance of the proposed algorithm is superior to the state-of-art ones in both the steady-state misalignment and the convergence rate. A novel algorithm is proposed to solve some problems. Simulation results show the effectiveness of the proposed algorithm. 展开更多
关键词 adaptive filtering normalized least mean SQUARE (NLMS) minimum-disturbance (MD) constraint VARIABLE REGULARIZATION VARIABLE STEP-SIZE NLMS
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Discussion on Social Governance Mode under New Normal Concept 被引量:1
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作者 Dai Jianzhong 《学术界》 CSSCI 北大核心 2016年第5期269-275,共7页
"New Normal"is the basic transition modality existing in the Chinese society to the historical development stage and the new normal mode has special pattern of manifestation in political,economic,cultural,so... "New Normal"is the basic transition modality existing in the Chinese society to the historical development stage and the new normal mode has special pattern of manifestation in political,economic,cultural,social,legal and military fields.Recognizing,adapting to and leading new normal should become the basic content in the work of the party and the country in the coming period. 展开更多
关键词 社会存在 治理 军事领域 正常模
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Schur Forms and Normal-Nilpotent Decompositions 被引量:1
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作者 LI Zhen 《应用数学和力学》 CSCD 北大核心 2024年第9期1200-1211,共12页
Real and complex Schur forms have been receiving increasing attention from the fluid mechanics community recently,especially related to vortices and turbulence.Several decompositions of the velocity gradient tensor,su... Real and complex Schur forms have been receiving increasing attention from the fluid mechanics community recently,especially related to vortices and turbulence.Several decompositions of the velocity gradient tensor,such as the triple decomposition of motion(TDM)and normal-nilpotent decomposition(NND),have been proposed to analyze the local motions of fluid elements.However,due to the existence of different types and non-uniqueness of Schur forms,as well as various possible definitions of NNDs,confusion has spread widely and is harming the research.This work aims to clean up this confusion.To this end,the complex and real Schur forms are derived constructively from the very basics,with special consideration for their non-uniqueness.Conditions of uniqueness are proposed.After a general discussion of normality and nilpotency,a complex NND and several real NNDs as well as normal-nonnormal decompositions are constructed,with a brief comparison of complex and real decompositions.Based on that,several confusing points are clarified,such as the distinction between NND and TDM,and the intrinsic gap between complex and real NNDs.Besides,the author proposes to extend the real block Schur form and its corresponding NNDs for the complex eigenvalue case to the real eigenvalue case.But their justification is left to further investigations. 展开更多
关键词 Schur form normal matrix nilpotent matrix tensor decomposition vortex identification
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Shear mechanical properties and frictional sliding responses of rough joint surfaces under dynamic normal displacement conditions 被引量:1
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作者 ZHU Qiang YIN Qian +9 位作者 TAO Zhi-gang HE Man-chao ZHENG Bo-wen JING Hong-wen REN Shu-lin ZHANG Qiang MENG Bo BAI Dong-feng WU Sai-sai WU Jiang-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2393-2410,共18页
A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating... A comprehensive understanding of the dynamic frictional characteristics in rock joints under high normal load and strong confinement is essential for ensuring the safety of deep engineering construction and mitigating geological disasters.This study conducted shear experiments on rough rock joints under displacement-controlled dynamic normal loads,investigating the shear behaviors of joints across varying initial normal loads,normal loading frequencies,and normal loading amplitudes.Experimental results showed that the peak/valley shear force values increased with initial normal loads and normal loading frequencies but showed an initial increase followed by a decrease with normal loading amplitudes.Dynamic normal loading can either increase or decrease shear strength,while this study demonstrates that higher frequencies lead to enhanced friction.Increased initial normal loading and normal loading frequency result in a gradual decrease in joint roughness coefficient(JRC)values of joint surfaces after shearing.Positive correlations existed between frictional energy dissipation and peak shear forces,while post-shear joint surface roughness exhibited a negative correlation with peak shear forces through linear regression analysis.This study contributes to a better understanding of the sliding responses and shear mechanical characteristics of rock joints under dynamic disturbances. 展开更多
关键词 dynamic normal displacement shear strength variations phase lag phenomenon STICK-SLIP
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Boehmeria nivea var. strigosa (Urticaceae), a new variety from Southwest China 被引量:1
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作者 ZHAO Ying Richard I.MILNE +2 位作者 LI Zhipeng Amos KIPKOECH WU Zengyuan 《广西植物》 CAS CSCD 北大核心 2024年第9期1617-1624,I0001-I0006,共14页
Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly charact... Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly characterized by its green abaxial leaf blade,partly connate stipules,and densely patent strigose hairs on stems and potioles.The phylogenetic analysis based on rbc L,nrDNA and rbc L+nrDNA datasets,revealed that all individuals of B.nivea var.strigosa formed a monophyletic group.The conservation status of B.nivea var.strigosa is assessed as“Near Threatened”(NT)according to IUCN evaluation criteria.The discovery of this new variety is not only crucial for the taxonomy of ramie,but also provides reference for the exploration and utilization of ramie. 展开更多
关键词 Boehmeria nivea MORPHOLOGY molecular phylogeny new variety Southwest China YUNNAN
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Cloud edge integrated security architecture of new cloud manufacturing system 被引量:1
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作者 ZHAO Longbo LI Bohu YUAN Haitao 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1177-1189,共13页
With the rapid development of cloud manufacturing technology and the new generation of artificial intelligence technology,the new cloud manufacturing system(NCMS)built on the connotation of cloud manufacturing 3.0 pre... With the rapid development of cloud manufacturing technology and the new generation of artificial intelligence technology,the new cloud manufacturing system(NCMS)built on the connotation of cloud manufacturing 3.0 presents a new business model of“Internet of everything,intelligent leading,data driving,shared services,cross-border integration,and universal innovation”.The network boundaries are becoming increasingly blurred,NCMS is facing security risks such as equipment unauthorized use,account theft,static and extensive access control policies,unauthorized access,supply chain attacks,sensitive data leaks,and industrial control vulnerability attacks.Traditional security architectures mainly use information security technology,which cannot meet the active security protection requirements of NCMS.In order to solve the above problems,this paper proposes an integrated cloud-edge-terminal security system architecture of NCMS.It adopts the zero trust concept and effectively integrates multiple security capabilities such as network,equipment,cloud computing environment,application,identity,and data.It adopts a new access control mode of“continuous verification+dynamic authorization”,classified access control mechanisms such as attribute-based access control,rolebased access control,policy-based access control,and a new data security protection system based on blockchain,achieving“trustworthy subject identity,controllable access behavior,and effective protection of subject and object resources”.This architecture provides an active security protection method for NCMS in the digital transformation of large enterprises,and can effectively enhance network security protection capabilities and cope with increasingly severe network security situations. 展开更多
关键词 new cloud manufacturing system(NCMS) integrated cloud-edge-terminal security system architecture zero trust
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Constructing Public Participation Mechanism in Social Public Management' s New Normal
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作者 Li Hongxun 《学术界》 CSSCI 北大核心 2015年第12期267-272,共6页
The construction and development of social public management's new normal depend on the scientific transformation of government functionalization orientation and highlighting the role of grassroots public's ex... The construction and development of social public management's new normal depend on the scientific transformation of government functionalization orientation and highlighting the role of grassroots public's extensive illustrations on social issues and social conditions.Based on this situation,in the process of public participation mechanism construction,it is necessary to emphasize that the construction of joint elements should be carried out systematically and comprehensively,and to dig deep into the relations and functions of all elements.When the stability of public participation mechanism construction is fully guaranteed,it will extensively supervise and evaluate the development of government's social public management cause,help achieve the final goal of coordinating social development environment and social development elements,ensure that the intrinsic value of public participation mechanism can be thoroughly displayed. 展开更多
关键词 社会条件 公共管理 机制建设 公共参与 公众参与机制 社会问题 社会发展 协调发展
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Three new records of lycopsids and ferns from Vietnam
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作者 LU Yu WANG Bo +2 位作者 LIN Guoliang JIANG Rihong WANG Zhenxing 《广西植物》 CAS CSCD 北大核心 2024年第10期1943-1946,共4页
Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specim... Three new records from Vietnam,Phlegmariurus guangdongensis Ching,Adiantum longzhouensis A.H.Wang,F.G.Wang&F.W.Xing,and Lepisorus bicolor Ching,are reported.The identification characteristics,information of specimen,and geographical distribution of the species are described.The discovery of new records not only enriches the study of plant diversity in Vietnam,but also provides important information for biodiversity conservation and botanical research in the region.The voucher specimens are kept in the Herbarium of Kunming Institute of Botany,Chinese Academy of Sciences(KUN),Herbarium of Institute of Botany,Chinese Academy of Sciences(PE)and Herbarium of Guangxi Forestry Research Institute(GXFI). 展开更多
关键词 Phlegmariurus guangdongensis Adiantum longzhouensis Lepisorus bicolor new record VIETNAM
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Severe hyperhomocysteinemia due to MTHFR deficiency caused by a new mutation:A case report and literature review
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作者 YIN Qing YUAN Tianxiang +3 位作者 MA Jie TANG Jianguang TAN Xuling YANG Li 《中南大学学报(医学版)》 CAS CSCD 北大核心 2024年第8期1363-1374,共12页
Methylenetetrahydrofolate reductase(MTHFR)deficiency is a rare autosomal recessive genetic disorder caused by mutations in the MTHFR gene,leading to a variety of clinical manifestations.In October 2022,the Second Xian... Methylenetetrahydrofolate reductase(MTHFR)deficiency is a rare autosomal recessive genetic disorder caused by mutations in the MTHFR gene,leading to a variety of clinical manifestations.In October 2022,the Second Xiangya Hospital of Central South University admitted a 21-year-old male patient with neuropsychiatric disorders,presenting primarily with cognitive decline,limb tremors,abnormal mental and behavioral symptoms,seizures,and gait disturbances.These symptoms had gradually developed over 5 years,worsening significantly in the past year.The patient’s plasma homocysteine levels were 10 times higher than normal,and brain MRI revealed brain atrophy and significant abnormal signals in the bilateral paraventricular nuclei and heads of the bilateral caudate nuclei.Further genetic testing identified a paternal mutation c.1604G>A(p.R535Q)and a maternal mutation c.227T>G(p.L76R)of the MTHFR gene.After betaine supplementation,the plasma homocysteine levels decreased within a week,and the symptoms improved.The patient was ultimately diagnosed with severe hyperhomocysteinemia due to MTHFR deficiency.The c.227T>G(p.L76R)mutation represents a novel missense mutation in the MTHFR gene associated with MTHFR deficiency,but further research is needed to confirm its potential pathogenicity.Early treatment with betaine can fully reverse the symptoms. 展开更多
关键词 methylenetetrahydrofolate reductase deficiency MTHFR gene HYPERHOMOCYSTEINEMIA genetic metabolism new mutation neuropsychiatric disorders
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中国上市企业新质生产力指数编制暨发展报告(2011-2022年) 被引量:6
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作者 徐子尧 申程程 +1 位作者 张雪兰 王剑 《金融经济学研究》 北大核心 2025年第3期3-18,共16页
发展新质生产力是习近平新时代中国特色社会主义思想的理论创新,是推进中国式现代化的根本动力。新质生产力的理论研究与实践发展需要以新质生产力指数与发展评价为基础。基于2011—2022年中国上市企业数据,从新质劳动者、新质劳动资料... 发展新质生产力是习近平新时代中国特色社会主义思想的理论创新,是推进中国式现代化的根本动力。新质生产力的理论研究与实践发展需要以新质生产力指数与发展评价为基础。基于2011—2022年中国上市企业数据,从新质劳动者、新质劳动资料、新质劳动对象、优化组合等四个维度编制企业新质生产力指数,并从整体、个体、行业等层面对新质生产力发展状况予以分析评价。研究发现,2011—2022年中国企业新质生产力指数按时间脉络可划分为萌芽期、发展期和成长期三个阶段,总体平稳进步,2022年略有回调。相较于小规模企业、国有企业、非初创企业与非专精特新企业而言,大规模企业、非国有企业、初创企业与专精特新企业新质生产力发展迅速。从区域视角来看,不同省份之间的新质生产力指数总体上呈现增长态势,但增长速度和发展水平存在明显差异。从产业视角来看,技术密集型产业的企业新质生产力指数最高,资本密集型产业次之,劳动密集型产业最低;高新技术服务业的企业新质生产力指数最高,高新技术制造业次之,非高新技术产业最低。因此,有必要坚持创新驱动发展战略,加快劳动要素协同融合,优化产业体系建设,以此稳步推进企业新质生产力发展。 展开更多
关键词 企业新质生产力 新质劳动者 新质劳动资料 新质劳动对象 要素优化组合
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危中寻机:战略联盟对民营企业韧性的影响研究 被引量:1
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作者 连燕玲 孙汉 高皓 《南开管理评论》 北大核心 2025年第7期161-172,共12页
在面临外部市场环境危机加剧和内部财务困境的双重威胁时,民营企业通过战略联盟进行“抱团取暖”式的变革方式能否提升自身的韧性?以2009~2021年沪深A股非金融上市企业发布的战略合作协议公告为基础,本文系统检验了战略联盟对民营企业... 在面临外部市场环境危机加剧和内部财务困境的双重威胁时,民营企业通过战略联盟进行“抱团取暖”式的变革方式能否提升自身的韧性?以2009~2021年沪深A股非金融上市企业发布的战略合作协议公告为基础,本文系统检验了战略联盟对民营企业韧性的驱动机制及作用机理。研究发现,战略联盟能够显著提升民营企业韧性。在缓解反向因果、样本选择等一系列内生性问题后,上述结论依旧成立。影响路径检验显示,战略联盟通过增强风险承担能力、激发创新关注以及改善资金融通渠道,进而提升民营企业韧性。区分市场环境层面和企业内部危机因素,高市场环境动态性、高市场环境复杂性和高财务困境风险会强化战略联盟对民营企业韧性的促进效应。基于战略联盟主体异质性和联盟对象特征的拓展性分析发现,当联盟主体属于高科技行业、小规模企业和后发企业,以及联盟合作伙伴包含国有企业特别是获得高科技称号时,战略联盟对民营企业韧性的正向作用更为明显。本文认为在依赖内生式增长动力不足的现实背景下,应当充分关注民营企业参与战略联盟的增量价值,从而为促进我国民营企业高质量发展注入强大动能。 展开更多
关键词 战略联盟 组织韧性 风险抵御 创新关注 新常态危机
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基于上浮力正态分布的盾构管片上浮变形半解析方法研究 被引量:2
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作者 刘维正 师嘉文 +2 位作者 谭际鸣 董军 豆小天 《中南大学学报(自然科学版)》 北大核心 2025年第3期1039-1052,共14页
针对盾构管片上浮计算中上浮力变化的假设形式与实际存在差异,导致上浮量计算不准确,从而引发管片错台、渗水等工程问题,建立三维管片上浮数值模型,基于数值模拟结果与已有试验结果,提出一种符合实际的上浮力正态分布函数,并将上浮力作... 针对盾构管片上浮计算中上浮力变化的假设形式与实际存在差异,导致上浮量计算不准确,从而引发管片错台、渗水等工程问题,建立三维管片上浮数值模型,基于数值模拟结果与已有试验结果,提出一种符合实际的上浮力正态分布函数,并将上浮力作用范围视为置信水平为99.7%的置信区间。假设盾构隧道为置于Pasternak地基上的Euler-Bernoulli梁,考虑土体剪切变形,建立基于上浮力正态分布的管片上浮变形半解析方法,将解析结果与实测结果及已有方法计算结果进行对比,验证本文方法的适用性,并采用该方法分析地层参数、浆液参数对管片上浮及内力的影响。研究结果表明:在单次注浆作用下,瞬时上浮量先增大后减小,最大值出现在距盾尾21m处,弯矩最大值出现在盾尾处;剪力先增大后减小,在距盾尾9m处达到最大;在持续注浆作用下,累计上浮量、弯矩及剪力不断增大,距盾尾54m处上浮量达到最大值并趋于稳定,弯矩与剪力分别在距盾尾36m、54m处达到最大值;管片上浮量随埋深h、地层等效弹性模量Es增大而减小,随浆液初凝时间t延长呈非线性增大,随注浆压力P的变化呈线性变化;增大h与Es、减小P与t能有效减小管片上浮量、上浮范围及内力;距离盾尾36m至54m为管片最易发生错台区域,Es、t增大会使错台区域首端更接近盾尾。研究成果可为盾构隧道施工参数选取及管片上浮预测与控制提供理论依据。 展开更多
关键词 正态分布 上浮力 盾构隧道 管片上浮 半解析解
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新质生产力的地域性与布局规律研究--因地制宜发展新质生产力的地理科学探讨 被引量:4
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作者 樊杰 陈东 +2 位作者 李佳洺 郭锐 陈卓 《地理科学》 北大核心 2025年第1期47-60,共14页
在讨论生产力三要素劳动者、劳动资料、劳动对象具有显著的空间分异,且国家间生产力要素的差异性不断扩大的基础上,系统分析了新质生产力出现带来的地域属性和空间结构的变化,包括:非物质性要素在新质生产力中的重要性不断增强,新型劳... 在讨论生产力三要素劳动者、劳动资料、劳动对象具有显著的空间分异,且国家间生产力要素的差异性不断扩大的基础上,系统分析了新质生产力出现带来的地域属性和空间结构的变化,包括:非物质性要素在新质生产力中的重要性不断增强,新型劳动者逐步成为影响新质生产力布局中关键性的稀缺要素,创新模式呈现层级化、网络化、跨区域的特征,流空间的崛起弱化地理空间距离对于新质生产力的影响,创新效能的提升要求创新要素的高效流动,并由此产生新的不平衡。进而,从新质生产力新要素、地域综合体、国家网络系统3个方面讨论了新质生产力布局的基本规律,并通过资源环境承载力约束作用、以人为本的发展目标取向、集聚效率的内在要求、国际开放合作和区域分工协作的效能等分析,揭示了新质生产力布局演变趋势。研究认为:(1)体现“知识”价值及利益分享合理化、数字化、智能化引发的劳动者关系变化与适应性管理以及科技创新能力引发区域非均衡与空间公平的权衡,是生产关系“新转型”的机理所在;(2)重新定位主体功能、重新审视地区资源比较优势和发展路径、重新建构不同功能区域之间的相互作用关系,是基于主体功能区战略建构适应新型生产关系的制度的主要方面;(3)因地制宜发展新质生产力的配套改革重点包括:聚焦提高科技创新能力,形成各具地方特色的科技-教育-人才一体化的体制机制;聚焦科技创新驱动发展,形成创新链和产业链在空间上耦合和协同发展的体制机制;聚焦国家“一盘棋”的系统谋划,形成发挥各地比较优势形成新质生产力生产网络和体系的体制机制;聚焦开放的经济格局,形成开放的具有竞争力、安全性和韧性的新质生产力体制机制。 展开更多
关键词 新质生产力 新型生产关系 地域属性 因地制宜发展 新质生产力布局 地理科学基础
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无人机图像中耕期甘蔗植株检测计数方法——基于改进YOLOv5s 被引量:1
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作者 李尚平 唐丹 +1 位作者 文春明 李凯华 《农机化研究》 北大核心 2025年第10期138-145,共8页
以中耕期甘蔗作物的无人机图像为研究对象,针对植株叶片互相遮挡、目标粘连和背景信息复杂等问题,设计了一种基于改进YOLOv5s的甘蔗检测计数模型。首先,通过在网络中使用基于归一化的注意力模块,加强对图像中中耕期甘蔗植株的特征学习... 以中耕期甘蔗作物的无人机图像为研究对象,针对植株叶片互相遮挡、目标粘连和背景信息复杂等问题,设计了一种基于改进YOLOv5s的甘蔗检测计数模型。首先,通过在网络中使用基于归一化的注意力模块,加强对图像中中耕期甘蔗植株的特征学习和特征提取,并且减弱与甘蔗植株相似的蔗地杂草背景对检测效果的干扰。其次,原始YOLOv5s网络中的耦合头替换为改进过的高效解耦头,用以进行分类和回归分支的解耦计算,提升甘蔗植株检测模型的性能。最后,更改边界框损失函数为动态非单调聚焦机制WIoU,提高模型收敛速度。同时,采用多尺度训练在一定程度上提高改进模型对物体大小的鲁棒性,最终使模型可以输入任意大小的图片。试验结果表明:改进的YOLOv5s模型准确率、召回率和平均精度均值分别为97.72%、91.7%和96.2%,较原始YOLOv5s模型分别提高3.82、4.5、2.5个百分点。统计表明:测试集的30幅甘蔗图像中,甘蔗植株真实值为1104,改进YOLOv5s模型生成的甘蔗植株数为1086,漏检个数为18,漏检率为1.6%,改进模型对无人机图像中的甘蔗植株计数误差较小,可为甘蔗的检测计数、长势评估提供技术支撑。 展开更多
关键词 甘蔗计数 无人机 图像处理 YOLOv5s 解耦头 归一化
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新质生产力视域下职业教育数字化转型的动力机制与实践进路 被引量:9
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作者 郭福春 许嘉扬 《中国职业技术教育》 北大核心 2025年第1期105-112,共8页
新一代数字技术的广泛应用驱动生产力的变革,职业教育数字化转型是数字经济时代顺应新质生产力发展要求的重要趋势和战略选择。以“生产力—科技—教育”理论为逻辑起点,在新一轮科技革命和产业变革下,以技术赋能职业教育综合改革为主线... 新一代数字技术的广泛应用驱动生产力的变革,职业教育数字化转型是数字经济时代顺应新质生产力发展要求的重要趋势和战略选择。以“生产力—科技—教育”理论为逻辑起点,在新一轮科技革命和产业变革下,以技术赋能职业教育综合改革为主线,基于新质技术技能人才培养理念,构建“数据驱动—技术迭代—产业升级—制度革新”四维动力模型,揭示新质生产力赋能职业教育数字化转型的机理。基于此,指明新质生产力引领职业教育数字化转型的实践进路:加速数字要素融合渗透,强化优质教育资源供给;创新数字技术应用场景,构建更具韧性的教学生态;建立数字孪生融创平台,促进产科教融合模式转型;优化人机协同治理机制,推动教育治理体系现代化。 展开更多
关键词 新质生产力 职业教育 数字化转型 新质人才 技术技能
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