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Cosmology-Independent Photon Mass Limits from Localized Fast Radio Bursts by Using Artificial Neural Networks
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作者 冉景遇 王宝 魏俊杰 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第5期177-183,共7页
A hypothetical photon mass m_(γ) can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed di... A hypothetical photon mass m_(γ) can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure and redshift measurements of fast radio bursts(FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard ΛCDM cosmological context. In order to alleviate the circularity problem induced by the presumption of a specific cosmological model based on the fundamental postulate of the masslessness of photons, here we employ a new model-independent smoothing technique, artificial neural network(ANN), to reconstruct the Hubble parameter H(z) function from 34 cosmic-chronometer measurements.By combining observations of 32 well-localized FRBs and the H(z) function reconstructed by ANN, we obtain an upper limit of m_(γ) ≤ 3.5 × 10^(-51)kg, or equivalently m_(γ) ≤ 2.0 × 10^(-15)eV/c^(2)(m_(γ) ≤ 6.5 × 10^(-51)kg, or equivalently m_(γ) ≤ 3.6 × 10^(-15)eV/c_(2)) at the 1σ(2σ) confidence level. This is the first cosmology-independent photon mass limit derived from extragalactic sources. 展开更多
关键词 DISPERSION LIMIT independent
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A Constrained Local Neighborhood Approach for Efficient Markov Blanket Discovery in Undirected Independent Graphs
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作者 Kun Liu Peiran Li +4 位作者 Yu Zhang JiaRen Ming Li Xianyu Wang Cong Li 《Computers, Materials & Continua》 SCIE EI 2024年第8期2535-2555,共21页
When learning the structure of a Bayesian network,the search space expands significantly as the network size and the number of nodes increase,leading to a noticeable decrease in algorithm efficiency.Traditional constr... When learning the structure of a Bayesian network,the search space expands significantly as the network size and the number of nodes increase,leading to a noticeable decrease in algorithm efficiency.Traditional constraint-based methods typically rely on the results of conditional independence tests.However,excessive reliance on these test results can lead to a series of problems,including increased computational complexity and inaccurate results,especially when dealing with large-scale networks where performance bottlenecks are particularly evident.To overcome these challenges,we propose a Markov blanket discovery algorithm based on constrained local neighborhoods for constructing undirected independence graphs.This method uses the Markov blanket discovery algorithm to refine the constraints in the initial search space,sets an appropriate constraint radius,thereby reducing the initial computational cost of the algorithm and effectively narrowing the initial solution range.Specifically,the method first determines the local neighborhood space to limit the search range,thereby reducing the number of possible graph structures that need to be considered.This process not only improves the accuracy of the search space constraints but also significantly reduces the number of conditional independence tests.By performing conditional independence tests within the local neighborhood of each node,the method avoids comprehensive tests across the entire network,greatly reducing computational complexity.At the same time,the setting of the constraint radius further improves computational efficiency while ensuring accuracy.Compared to other algorithms,this method can quickly and efficiently construct undirected independence graphs while maintaining high accuracy.Experimental simulation results show that,this method has significant advantages in obtaining the structure of undirected independence graphs,not only maintaining an accuracy of over 96%but also reducing the number of conditional independence tests by at least 50%.This significant performance improvement is due to the effective constraint on the search space and the fine control of computational costs. 展开更多
关键词 Bayesian network structure learning Markov blanket conditional independence
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Origin of the Dashuigou independent tellurium deposit at Qinghai–Xizang Plateau: constraints from the light stable isotopes C, O, and H
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作者 Jianzhao Yin Yuhong Chao +2 位作者 Haoyu Yin Hongyun Shi Shoupu Xiang 《Acta Geochimica》 EI CAS CSCD 2024年第2期385-398,共14页
By studying the light isotopic compositions of carbon,oxygen,and hydrogen,combined with previous research results on the ore-forming source of the deposit,the authors try to uncover its metallogenic origin.The δ^(18)... By studying the light isotopic compositions of carbon,oxygen,and hydrogen,combined with previous research results on the ore-forming source of the deposit,the authors try to uncover its metallogenic origin.The δ^(18)O and δ^(13)C isotope signatures of dolomite samples vary between 10.2 and 13.0‰,and between−7.2 and−5.2‰,respectively,implying that the carbon derives from the upper mantle.δD and δ^(18) O of quartz,biotite,and muscovite from diff erent ore veins of the deposit vary between−82 and−59‰,and between 11.6 and 12.4‰,respectively,implying that the metallogenic solutions are mainly magmatic.According to the relevant research results of many isotope geologists,the fractionation degree of hydrogen isotopes increases as the depth to the Earth’s core increases,and the more diff erentiated the hydrogen isotopes are,the lower their values will be.In other words,mantle-derived solutions can have extremely low hydrogen isotope values.This means that the δD‰ value−134 of the pyrrhotite sample numbered SD-34 in this article may indicate mantle-derived oreforming fl uid of the deposit.The formation of the Dashuigou tellurium deposit occurred between 91.71 and 80.19 Ma. 展开更多
关键词 Carbon oxygen and hydrogen isotopes ORIGIN independent tellurium deposit The Qinghai–Xizang Plateau
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Are cities greener because of innovation?Independent innovation policy and green economic efficiency
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作者 Zhuoji Zheng Xueqin Li +3 位作者 Mengjie Yu Yuan Li Xianfeng Han Yuping Yin 《Chinese Journal of Population,Resources and Environment》 2024年第2期118-126,共9页
The national independent innovation demonstration zone(NIIDZ)is an independent innovation policy that plays a crucial role in implementing strategies.Given the importance of the NIIDZ,this study uses panel data of 278... The national independent innovation demonstration zone(NIIDZ)is an independent innovation policy that plays a crucial role in implementing strategies.Given the importance of the NIIDZ,this study uses panel data of 278 prefecture-level cities in China from 2006 to 2020 and empirically examines the effect and internal mechanism of the NIIDZ on green economic efficiency(GEE)using the difference-in-difference model(DID).The results show that the NIIDZ effectively enhances the growth of GEE,and the results remain valid through several robustness tests,such as year-by-year propensity score matching.The transmission mechanism suggests that the NIIDZ indirectly drives GEE by accelerating scientific and technological investment,promoting talent concentration,and optimizing the industrial structure.Moreover,heterogeneity analysis reveals that the promotion effect of the NIIDZ on GEE is more prominent in the eastern region and high green development level areas.The study’s findings can serve as a reference for China to further utilize the policy effectiveness of the NIIDZ and accelerate the high-quality development of the green economy in the future. 展开更多
关键词 National innovation independent demonstration Zone(NIIDZ) Green economy efficiency(GEE) Difference-in-difference model(DID)
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Study on Independent Supervision Function of Design Assurance System
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作者 SUI Lijun MA Congyao WANG Jianyuan 《International Journal of Plant Engineering and Management》 2024年第3期185-192,共8页
The effective operation of a design assurance system cannot be achieved without the effective performance of the independent supervision function.As one of the core functions of the design assurance system,the purpose... The effective operation of a design assurance system cannot be achieved without the effective performance of the independent supervision function.As one of the core functions of the design assurance system,the purpose of the independent supervision function is to ensure that the system operates within the scope of procedures and manuals.At present,the function of independent supervision is a difficult and confusing issue for various original equipment manufacturers as well as suppliers,and there is an urgent requirement to put forward relevant requirements and form relevant methods.Based on the above mentioned objective,the basic requirements of the independent supervision function of design assurance system were studied,the problems and deficiencies in the organization,staffing,and methods existing in the current independent supervision function were analyzed,the improvement suggestions and measures for the performance of the independent supervision function from the aspects of the organization,staffing,procedures,and suppliers were put forward.The present work and conclusions provide guidance and direction for the effective operation of the design assurance system. 展开更多
关键词 design of assurance systems independent supervision functions system operation internal audits SUPPLIERS
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Analysis of the Role of Problem-Based Independent Learning Model in Teaching Cerebral Ischemic Stroke First Aid in Emergency Medicine
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作者 Hua Liu 《Journal of Contemporary Educational Research》 2024年第6期16-21,共6页
Objective:To analyze the effect of using a problem-based(PBL)independent learning model in teaching cerebral ischemic stroke(CIS)first aid in emergency medicine.Methods:90 interns in the emergency department of our ho... Objective:To analyze the effect of using a problem-based(PBL)independent learning model in teaching cerebral ischemic stroke(CIS)first aid in emergency medicine.Methods:90 interns in the emergency department of our hospital from May 2022 to May 2023 were selected for the study.They were divided into Group A(45,conventional teaching method)and Group B(45 cases,PBL independent learning model)by randomized numerical table method to compare the effects of the two groups.Results:The teaching effect indicators and student satisfaction scores in Group B were higher than those in Group A(P<0.05).Conclusion:The use of the PBL independent learning model in the teaching of CIS first aid can significantly improve the teaching effect and student satisfaction. 展开更多
关键词 Problem-based independent learning model Emergency medicine Ischemic stroke First aid teaching SATISFACTION
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MPC-based Torque Distribution for Planar Motion of Four-wheel Independently Driven Electric Vehicles:Considering Motor Models and Iron Losses 被引量:3
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作者 Yiyan Su Deliang Liang Peng Kou 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第1期45-53,共9页
The most critical obstacle for four-wheel independently driven electric vehicles(4WID-EVs)is the driving range.Being the actuators of 4WID-EVs,motors account for its major power consumption.In this sense,by properly d... The most critical obstacle for four-wheel independently driven electric vehicles(4WID-EVs)is the driving range.Being the actuators of 4WID-EVs,motors account for its major power consumption.In this sense,by properly distributing torques to minimize the power consumption,the driving range of 4WID-EV can be effectively improved.This paper proposes a model predictive control(MPC)-based torque distribution scheme,which minimizes the power consumption of 4WID-EVs while guaranteeing its tracking performance of planar motions.By incorporating the motor model considering iron losses,the optimal torque distribution can be achieved without an additional torque controller.Also,for this reason,the proposed control scheme is computationally efficient,since the power consumption term to be optimized,which is expressed as the product of the motor voltages and currents,is much simpler than that derived from the efficiency map.With reasonable simplification and linearization,the MPC problem is converted to a quadratic programming problem,which can be solved efficiently.The simulation results in MATLAB and CarSim co-simulation environments demonstrate that the proposed scheme effectively reduces power consumption with guaranteed tracking performance. 展开更多
关键词 four-wheel independently driven electric vehicles Model predictive control Motor models Iron losses
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Functional magnetic resonance imaging study of group independent components underpinning item responses to paranoid-depressive scale 被引量:1
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作者 Drozdstoy Stoyanov Rositsa Paunova +3 位作者 Julian Dichev Sevdalina Kandilarova Vladimir Khorev Semen Kurkin 《World Journal of Clinical Cases》 SCIE 2023年第36期8458-8474,共17页
BACKGROUND Our study expand upon a large body of evidence in the field of neuropsychiatric imaging with cognitive,affective and behavioral tasks,adapted for the functional magnetic resonance imaging(MRI)(fMRI)experime... BACKGROUND Our study expand upon a large body of evidence in the field of neuropsychiatric imaging with cognitive,affective and behavioral tasks,adapted for the functional magnetic resonance imaging(MRI)(fMRI)experimental environment.There is sufficient evidence that common networks underpin activations in task-based fMRI across different mental disorders.AIM To investigate whether there exist specific neural circuits which underpin differ-ential item responses to depressive,paranoid and neutral items(DN)in patients respectively with schizophrenia(SCZ)and major depressive disorder(MDD).METHODS 60 patients were recruited with SCZ and MDD.All patients have been scanned on 3T magnetic resonance tomography platform with functional MRI paradigm,comprised of block design,including blocks with items from diagnostic paranoid(DP),depression specific(DS)and DN from general interest scale.We performed a two-sample t-test between the two groups-SCZ patients and depressive patients.Our purpose was to observe different brain networks which were activated during a specific condition of the task,respectively DS,DP,DN.RESULTS Several significant results are demonstrated in the comparison between SCZ and depressive groups while performing this task.We identified one component that is task-related and independent of condition(shared between all three conditions),composed by regions within the temporal(right superior and middle temporal gyri),frontal(left middle and inferior frontal gyri)and limbic/salience system(right anterior insula).Another com-ponent is related to both diagnostic specific conditions(DS and DP)e.g.It is shared between DEP and SCZ,and includes frontal motor/language and parietal areas.One specific component is modulated preferentially by to the DP condition,and is related mainly to prefrontal regions,whereas other two components are significantly modulated with the DS condition and include clusters within the default mode network such as posterior cingulate and precuneus,several occipital areas,including lingual and fusiform gyrus,as well as parahippocampal gyrus.Finally,component 12 appeared to be unique for the neutral condition.In addition,there have been determined circuits across components,which are either common,or distinct in the preferential processing of the sub-scales of the task.CONCLUSION This study has delivers further evidence in support of the model of trans-disciplinary cross-validation in psychiatry. 展开更多
关键词 Paranoid-depressive scale Functional magnetic resonance imaging Cross-validation Group independent component analysis Schizophrenia Depression
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Solving the k-Independent Sets Problem of Graphs by Gröbner Bases
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作者 Junyu Luo Shengzhen Ding 《Open Journal of Discrete Mathematics》 2023年第3期86-94,共9页
The aim of this paper is to given an algebraic computational method for finding maximal independent sets as well as the independent number of an arbitrary finite graph of n vertices G by strengthening the problem of f... The aim of this paper is to given an algebraic computational method for finding maximal independent sets as well as the independent number of an arbitrary finite graph of n vertices G by strengthening the problem of finding maximal independent sets of G to the problem of finding k-independent sets in G for. It is shown that the existence of k-independent sets in G is equivalent to the existence of solutions of a system of multivariate polynomial equations. It follows that the problem of finding k-independent sets can be realized by using Gröbner bases of polynomial ideals. Since the number of k-independent sets is finite, the triangular equations composed by Gröbner bases are easier to be solved. Consequently, the maximal independent sets and the independent number of G are obtained after solving at most n such equations. Finally, the numerical example is presented to illustrate the effectiveness of this algebraic computational method. 展开更多
关键词 k-independent Set Maximal independent Set Gröbner Bases
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Free Vibration Analysis of Rectangular Plate with Cutouts under Elastic Boundary Conditions in Independent Coordinate Coupling Method
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作者 Qiuhong Li Wenhao Huang +3 位作者 Joey Sanchez Ping Wang Qiang Ding Jiufa Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第3期2093-2121,共29页
Based on Kirchhoff plate theory and the Rayleigh-Ritz method,the model for free vibration of rectangular plate with rectangular cutouts under arbitrary elastic boundary conditions is established by using the improved ... Based on Kirchhoff plate theory and the Rayleigh-Ritz method,the model for free vibration of rectangular plate with rectangular cutouts under arbitrary elastic boundary conditions is established by using the improved Fourier series in combination with the independent coordinate coupling method(ICCM).The effect of the cutout is taken into account by subtracting the energies of the cutouts from the total energies of the whole plate.The vibration displacement function of the hole domain is based on the coordinate system of the hole domain in this method.From the continuity condition of the vibration displacement function at the cutout,the transition matrix between the two coordinate systems is constructed,and the mass and stiffness matrices are completely obtained.As a result,the calculation is simplified and the computational efficiency of the solution is improved.In this paper,numerical examples and modal experiments are presented to validate the effectiveness of the modeling methods,and parameters related to influencing factors of the rectangular plate are analyzed to study the vibration characteristics. 展开更多
关键词 Rectangular plate with cutouts the independent coordinate coupling method elastic boundary conditions free vibration analysis
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海外电力建设项目Independent Engineer工作模式探讨
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作者 刘畅 《科学与信息化》 2023年第21期109-111,共3页
在一些海外电力建设项目中,Independent Engineer是不可或缺的。Independent Engineer的角色不同于国内电力建设五方中的任何一方。本文以巴基斯坦某燃煤电站为例,探讨Independent Engineer的工作模式,并将Independent Engineer与国内... 在一些海外电力建设项目中,Independent Engineer是不可或缺的。Independent Engineer的角色不同于国内电力建设五方中的任何一方。本文以巴基斯坦某燃煤电站为例,探讨Independent Engineer的工作模式,并将Independent Engineer与国内电力建设参建方进行对比分析。 展开更多
关键词 independent Engineer 海外电力建设 工作模式
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Tianmen textile machinery:Independently developed the drawing frame equipment
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《China Textile》 2023年第3期68-68,共1页
Hubei Tianmen Textile Machinery Co.,Ltd.is a well-known enterprise and key high-tech enterprise in China textile industry.The company's leading product,drawing frame,has completely independent intellectual propert... Hubei Tianmen Textile Machinery Co.,Ltd.is a well-known enterprise and key high-tech enterprise in China textile industry.The company's leading product,drawing frame,has completely independent intellectual property rights,among which TM 11 is well received by users and has a high market share in China. 展开更多
关键词 independent DRAWING Tian
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中国教育学自主建构的广义认识论条件 被引量:3
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作者 刘庆昌 《西北师大学报(社会科学版)》 CSSCI 北大核心 2024年第1期86-97,共12页
中国教育学的自主建构不只是教育学学科发展不可回避的问题,也是中国社会进一步发展的必然需求,在某种意义上,也是全球化时代更好地服务于国家教育发展的理性选择。然而,中国教育学的自主建构以至中国教育学自主性的实现,并不只是一个... 中国教育学的自主建构不只是教育学学科发展不可回避的问题,也是中国社会进一步发展的必然需求,在某种意义上,也是全球化时代更好地服务于国家教育发展的理性选择。然而,中国教育学的自主建构以至中国教育学自主性的实现,并不只是一个愿望上的或认识上的问题,还需要做相关的条件上的准备。不过,所谓条件归根到底都是关联着认识活动的,可以称之为广义认识论条件。简而言之,中国教育学的自主建构需要具备三个层面的广义认识论条件:一是教育学学者的精神自立。其操作性的内涵是学者须具有求真至善的学者精神和务实创新的学术精神。二是教育学研究的认识论自觉。研究者不仅须知教育学兼有思想性和科学性,而且须有研究方法论上的理性。三是教育学建构的文化自信。只有这样,中国教育学研究才能够摆脱以往被国外教育学研究带路的局面,进而步入自主发展的阶段。 展开更多
关键词 教育学 中国教育学 自主建构 精神自立 认识论自觉 文化自信
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自主探究性实验课程的教学模式探讨 被引量:3
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作者 彭宇 余世策 钱匡亮 《实验室研究与探索》 CAS 北大核心 2024年第2期169-174,共6页
基于多年实践并辅以学生调查问卷,讨论了3种模式,即教师主导、研究生主导与本科生主导模式的适应性及其优缺点,提出“本科生为中心、教师为辅、研究生支持3种模式综合运用”的多层次实验教学体系与教学思路,并通过引入学生互评因子优化... 基于多年实践并辅以学生调查问卷,讨论了3种模式,即教师主导、研究生主导与本科生主导模式的适应性及其优缺点,提出“本科生为中心、教师为辅、研究生支持3种模式综合运用”的多层次实验教学体系与教学思路,并通过引入学生互评因子优化了考核体系。结果表明,该体系丰富了实验实践类课程教学模式,不仅有利于自主探究类创新实验的教学,又能充分利用实验室资源,且最大程度以本科生为中心,提升其创新思维以及动手、团体合作等能力。 展开更多
关键词 新工科 自主探究性 创新实验 教学模式 本科生为中心
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Designing for Independent Living:The Case Study of an Inclusive Apartment for Persons with Disabilities
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作者 Michela Dalprà 《Journal of Civil Engineering and Architecture》 2023年第10期493-501,共9页
Independent living and freedom of choice are closely linked to the social inclusion of PwD(Persons with Disabilities)in society.The paper reports on a recent study focused on investigating and understanding the needs ... Independent living and freedom of choice are closely linked to the social inclusion of PwD(Persons with Disabilities)in society.The paper reports on a recent study focused on investigating and understanding the needs and desires of persons with intellectual disabilities,with reduced mobility and with visual impairments while performing daily activities in order to design user-friendly and inclusive home environments for their life project.The case study concerns an apartment on the ground floor of a building well embedded in a neighborhood urban and social context.It was selected by Anffas Trentino Onlus to train young adults in independent living.Anffas is the National Association of Families of People Intellectual and/or Relational Disabilities,present and operating throughout Italy.Since 2008,important projects have been promoted by Anffas Trentino Onlus aimed at stimulating a personal and housing autonomy in PwD for“during and after us”,or rather when there are no more family members to take care of them.The design process involved a representative focus group of end users.With them and some Anffas staff components,it was possible to implement a participatory design process by sharing and verifying needs,desires,expectations.This approach was adopted in order to jointly develop a design proposal for a new inclusive apartment changing the paradigm from design for to design with,and building awareness both in the end users and designers. 展开更多
关键词 PwD independent living participatory design inclusive home environments
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Research on the Impact of Independent R&D and Collaborative Innovation on Economic Performance in China’s pharmaceutical Industry
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作者 Li Wanting Qiao Jiahui +1 位作者 Wang Su Chen Yuwen 《Asian Journal of Social Pharmacy》 2023年第4期315-325,共11页
Objective To study the impact of independent R&D and collaborative innovation on economic performance in the pharmaceutical industry.Methods A panel regression model was established by selecting the panel data of ... Objective To study the impact of independent R&D and collaborative innovation on economic performance in the pharmaceutical industry.Methods A panel regression model was established by selecting the panel data of China’s pharmaceutical industry from 2009 to 2019.Results and Conclusion Independent R&D and collaborative innovation of the pharmaceutical industry in eastern,central and western regions of China had a positive effect on economic performance.Besides,the promotion effect of independent R&D was greater than that of collaborative innovation.The positive driving effect of economic performance is the largest among the three regions,followed by the central and western regions.The collaborative innovation has the greatest positive effect on economic performance in the central region,followed by the eastern and western regions. 展开更多
关键词 independent R&D collaborative innovation economic performance pharmaceutical industry
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论中国教育学自主知识体系建设 被引量:7
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作者 刘贵华 孟照海 《华东师范大学学报(教育科学版)》 CSSCI 北大核心 2024年第2期1-17,共17页
中国教育学学科成熟、学术繁荣和话语自觉的标志,是形成了自主的知识体系。百余年来,作为“西学东渐”产物的中国教育学经历了多次推倒重来的发展,但始终将民族性与继承性作为自主知识建构的主线,将时代性与原创性作为学科知识发展的动... 中国教育学学科成熟、学术繁荣和话语自觉的标志,是形成了自主的知识体系。百余年来,作为“西学东渐”产物的中国教育学经历了多次推倒重来的发展,但始终将民族性与继承性作为自主知识建构的主线,将时代性与原创性作为学科知识发展的动力,将系统性与专业性作为学科获得认同的基础。新中国成立70多年来,教育的民生属性、战略属性和政治属性随时代变迁而日益凸显。中国教育学自主知识体系由学科体系、学术体系、话语体系、教材体系、治理体系构成。具体而言,在内容形态上由标识性概念、核心知识和前沿知识构成;在生产机制上由学科、学派、学会和学术刊物构成;在转化应用上由实践知识、政策知识和教育思想构成。教育学的中国特色源于中国教育传统、中国教育实践和中国教育问题,建基于学科自觉、学术自律和文化自信。要处理好中国特色与普遍知识的辩证关系,夯实学科体系的基座,激发学术体系的原创性,增强教材体系的导向性,提高治理体系的有效性,让中国教育学“说得出”“用得上”“传得开”“叫得响”,为教育强国建设提供思想先导和理论支撑。 展开更多
关键词 中国教育学 自主知识体系 学科体系 学术体系 话语体系
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Experimental Study of Primary School Students’Independent Reading Based on the Network Teaching Platform
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作者 TANG Hui XU Min 《Journalism and Mass Communication》 2023年第2期60-65,共6页
The development of information technology, especially the rise of online teaching platforms, has changed the way people read and the methods they use. Under this influence, primary school students’ independent readin... The development of information technology, especially the rise of online teaching platforms, has changed the way people read and the methods they use. Under this influence, primary school students’ independent reading has also been changed. However, due to limited self-control and understanding, primary school students face certain difficulties when using online teaching platforms for independent reading. Advantages and disadvantages of distance learning based on the network teaching platform were summarized in this paper. A one-year experiment study was carried out on our school fifth-grade students in independent reading using WeChat campus platform considering their current situation and existing problems of independent reading. In experiment study an independent reading mode was introduced. The results show that this reading mode can significantly improve students’ independent reading ability. 展开更多
关键词 independent reading Primary school student Network teaching platform Experimental study
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如何防止企业堕入“扶持悖论”陷阱 被引量:3
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作者 王淑英 张远芳 《管理工程学报》 CSSCI CSCD 北大核心 2024年第1期145-161,共17页
本文通过使用机器学习算法中Boosting回归树模型,以中国2010—2019年A股上市企业作为研究对象,探寻政府扶持和企业内部创新激励政策对企业研发活动影响情况。研究结果表明,政府扶持和企业内部激励机制均能够影响企业研发投入强度,但企... 本文通过使用机器学习算法中Boosting回归树模型,以中国2010—2019年A股上市企业作为研究对象,探寻政府扶持和企业内部创新激励政策对企业研发活动影响情况。研究结果表明,政府扶持和企业内部激励机制均能够影响企业研发投入强度,但企业创新更依赖政府扶持,尤其是政府补贴,在企业内部创新激励政策中,普通员工晋升激励对企业研发投入影响最强。无论政府对行业扶持集中度高或低,企业研发活动都更依靠政府扶持,企业内部激励机制对其研发活动影响具有差异性,企业普通员工晋升激励和企业高管晋升激励分别在扶持集中度低和扶持集中度高的行业中影响最大。企业员工薪酬在行业处于较高水平时,政府扶持对企业研发活动影响最大,此时管理者晋升激励在企业内部激励机制中对企业研发活动影响最大。国营企业以及私营企业研发活动都更易受政府扶持影响,在企业内部激励机制中,两类企业副总裁层级晋升激励作用最强。本文研究结论丰富了政策激励企业创新的理论成果,也为今后中国企业如何独立自主创新提供指导建议。 展开更多
关键词 政策扶持 扶持悖论 自主创新 机器学习
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银行数字化转型对小微企业自主创新的影响——兼论数字金融的协同作用 被引量:11
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作者 蔡栋梁 王海军 +1 位作者 黄金 黄宇虹 《南开管理评论》 CSSCI 北大核心 2024年第3期39-49,I0007,I0008,共13页
银行数字化转型提高了金融服务质量与效率,这能否缓解实体经济融资约束,助力小微企业牵住自主创新的“牛鼻子”?本文构建理论模型刻画银行数字化转型对小微企业自主创新的影响,并采用爬虫技术获得超过18万条有关商业银行报道的新闻文本... 银行数字化转型提高了金融服务质量与效率,这能否缓解实体经济融资约束,助力小微企业牵住自主创新的“牛鼻子”?本文构建理论模型刻画银行数字化转型对小微企业自主创新的影响,并采用爬虫技术获得超过18万条有关商业银行报道的新闻文本,创新地构造了地级市层面的银行数字化转型指数,将中国小微企业调查(CM ES)数据和银行数字化转型指数相匹配,实证检验银行数字化转型对小微企业自主创新的影响及其机制,并据此分析银行数字化转型与数字金融的协同作用。研究发现,银行数字化转型通过缓解企业融资约束的中介机制,显著驱动了小微企业自主创新。进一步研究发现,银行数字化转型与数字金融在驱动小微企业自主创新方面具有协同效应,数字金融水平越高,银行数字化转型的创新驱动效应越强。本文将制度环境划分为产权保护、产研结合、政策环境,通过异质性分析发现,在知识产权保护环境较好、社会平台协作度较高及经济政策不确定性较小的地区,银行数字化转型对小微企业自主创新的驱动作用更为显著。本研究为赋能银行数字化转型战略提供了支持证据,也为解决实体经济融资难问题、驱动自主创新、促进经济高质量发展提供了解决方案。 展开更多
关键词 银行数字化转型 小微企业 自主创新 数字金融 融资约束
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