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Ethanol-assisted direct synthesis of wafer-scale nitrogen-doped graphene for III-nitride epitaxial growth
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作者 WEI Wen-ze GAO Xiang +4 位作者 YU Chao-jie SUN Xiao-li WEI Tong-bo JIA Li SUN Jing-yu 《新型炭材料(中英文)》 北大核心 2025年第3期678-687,共10页
Among the synthesis techniques for graphene,chemical vapor deposition(CVD)enables the direct growth of graphene films on insulating substrates.Its advantages include uniform coverage,high quality,scalability,and compa... Among the synthesis techniques for graphene,chemical vapor deposition(CVD)enables the direct growth of graphene films on insulating substrates.Its advantages include uniform coverage,high quality,scalability,and compatibility with industrial processes.Graphene is chemically inert and has a zero-bandgap which poses a problem for its use as a functional layer,and nitrogen doping has become an important way to overcome this.Post-plasma treatment has been explored for the synthesis of nitrogen-doped graphene,but the procedures are intricate and not suitable for large-scale production.We report the direct synthesis of nitrogen-doped graphene on a 4-inch sapphire wafer by ethanol-assisted CVD employing pyridine as the carbon feedstock,where the nitrogen comes from the pyridine and the hydroxyl group in ethanol improves the quality of the graphene produced.Additionally,the types of nitrogen dopant produced and their effects on III-nitride epitaxy were also investigated,resulting in the successful illumination of LED devices.This work presents an effective synthesis strategy for the preparation of nitrogen-doped graphene,and provides a foundation for designing graphene functional layers in optoelectronic devices. 展开更多
关键词 III-nitride epitaxy direct synthesis Ethanol-assisted CVD LED devices Nitrogen-doped graphene
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Cyclic behavior of root-loess composites under direct simple shear test conditions and insights from discrete element method modeling
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作者 SUN Yuan LI Hui CHENG Zhifeng 《水利水电技术(中英文)》 北大核心 2025年第S1期665-680,共16页
Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various f... Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability.However,whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied.The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess.The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated.After that,cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC^(3D))to investigate the effects of root geome-try,mechanical traits and root-soil bond strength on the cyclic strength of rooted loess.It was discovered that the roots could effectively improve the cyclic resistance of loess.The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress,then increases,and improves with the increase of the frequency.The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites,and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°. 展开更多
关键词 root-soil composite cyclic direct simple shear tests PFC^(3D)
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Infrared small target detection algorithm via partial sum of the tensor nuclear norm and direction residual weighting
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作者 SUN Bin XIA Xing-Ling +1 位作者 FU Rong-Guo SHI Liang 《红外与毫米波学报》 北大核心 2025年第2期277-288,共12页
Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small targe... Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed.Based on converting the infrared image into an infrared patch tensor model,from the perspective of the low-rank nature of the background tensor,and taking advantage of the difference in contrast between the background and the target in different directions,we designed a double-neighborhood local contrast based on direction residual weighting method(DNLCDRW)combined with the partial sum of tensor nuclear norm(PSTNN)to achieve effective background suppression and recovery of infrared small targets.Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target. 展开更多
关键词 infrared small target detection infrared patch tensor model partial sum of the tensor nuclear norm direction residual weighting
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Observed-based adaptive neural tracking control for nonlinear systems with unknown control directions and input delay
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作者 DENG Yuxuan WANG Qingling 《Journal of Systems Engineering and Electronics》 2025年第1期269-279,共11页
Enhancing the stability and performance of practical control systems in the presence of nonlinearity,time delay,and uncertainty remains a significant challenge.Particularly,a class of strict-feedback nonlinear uncerta... Enhancing the stability and performance of practical control systems in the presence of nonlinearity,time delay,and uncertainty remains a significant challenge.Particularly,a class of strict-feedback nonlinear uncertain systems characterized by unknown control directions and time-varying input delay lacks comprehensive solutions.In this paper,we propose an observerbased adaptive tracking controller to address this gap.Neural networks are utilized to handle uncertainty,and a unique coordinate transformation is employed to untangle the coupling between input delay and unknown control directions.Subsequently,a new auxiliary signal counters the impact of time-varying input delay,while a Nussbaum function is introduced to solve the problem of unknown control directions.The leverage of an advanced dynamic surface control technique avoids the“complexity explosion”and reduces boundary layer errors.Synthesizing these techniques ensures that all the closed-loop signals are semi-globally uniformly ultimately bounded(SGUUB),and the tracking error converges to a small region around the origin by selecting suitable parameters.Simulation examples are provided to demonstrate the feasibility of the proposed approach. 展开更多
关键词 adaptive neural network dynamic surface control unknown control direction input delay
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Improved microstructure and mechanical properties of A517Q steel fabricated via laser directed energy deposition assisted by ultrasonic vibration combined with tempering treatment
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作者 LI Jian-liang REN He +6 位作者 WANG Qi-chen CHEN Zu-bin JIANG Guo-rui SUN Wen-yao SU Ye-tong GUO Chun-huan JIANG Feng-chun 《Journal of Central South University》 2025年第3期760-775,共16页
In this work,ultrasonic energy field assistance combined with tempering treatment is proposed to improve the microstructure and mechanical properties of A517Q alloy steel fabricated by laser directed energy deposition... In this work,ultrasonic energy field assistance combined with tempering treatment is proposed to improve the microstructure and mechanical properties of A517Q alloy steel fabricated by laser directed energy deposition(LDED).The effects of ultrasonic vibration(UV)and tempering treatment on microstructure evolution,microhardness distribution and mechanical properties of deposition layer were studied in detail.The microstructure of UV assisted LDED sample after tempering is mainly composed of tempered sorbite(TS).Due to the improvement of microstructure inhomogeneity and grains refinement,UV assisted LDED sample with tempering treatment obtains excellent mechanical properties.The ultimate tensile strength(UTS),yield strength(YS)and elongation after breaking(EL)reach 765 MPa,657 MPa and 19.5%,the increase ratios of UTS and YS are 14.5%and 33.8%while maintaining plasticity compared to original LDED sample,respectively.It is obvious that ultrasonic vibration combined with tempering is a potential and effective method to obtain uniform microstructure and excellent mechanical properties in metal laser directed energy deposition field. 展开更多
关键词 laser directed energy deposition ultrasonic vibration TEMPERING microstructure mechanical property A517Q steel
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Electrical properties of PVDF/PZT composite films prepared by direct ink writing
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作者 ZHOU Run-kai YANG Hong +4 位作者 PENG Chao-qun WANG Ri-chu ZHANG Dou FANG Guang-qiang WANG Xiao-feng 《Journal of Central South University》 2025年第1期71-81,共11页
Polyvinylidene fluoride/lead zirconate titanate(PVDF/PZT)composite films have been prepared by direct ink writing and the effect of PZT content on crystallization behavior and electrical properties of film were system... Polyvinylidene fluoride/lead zirconate titanate(PVDF/PZT)composite films have been prepared by direct ink writing and the effect of PZT content on crystallization behavior and electrical properties of film were systematically investigated.The composite films were characterized by scanning electron microscope(SEM),X-ray diffractometer(XRD),Flourier transform infrared spectroscope(FTIR)and differential scanning calorimeter(DSC).The results show that,surface modified PZT powder(PZT@PDA)is successfully coated by polydopamine(PDA),resulting in a large number of polar groups that interact with the-CF_(2)-groups in PVDF,inducing the generation of polarβphase due to hydrogen bonding formed in the interaction.Theβphase content in composite film increases with increasing PZT@PDA content,up to 28.09%as with 5 wt.%PZT@PDA.PZT@PDA plays a role of nucleating agent to promote the generation of polar phases in the film and also acts as an impurity hindering the growth of nuclei to reduce crystallinity.Moreover,the presence of PZT@PDA in interfaces provides more sites for the occurrence of interfacial polarization and thus improving the electrical properties of films.The composite film with 5 wt.%PZT@PDA possesses the highest dielectric constant(8.61)and residual polarization value(0.6803μC/cm^(2)). 展开更多
关键词 polyvinylidene fluoride(PVDF) lead zirconate titanate(PZT) direct ink writing crystallization behaviour electrical properties
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Research on power improvement of a LD directly-pumped mid-infrared pulse solid-state laser
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作者 ZHANG Meng YANG Xi +5 位作者 GUO Jia-Wei CAI He WU Xin-Yang HAN Ju-Hong WANG Shun-Yan WANG You 《红外与毫米波学报》 CSCD 北大核心 2024年第6期820-826,共7页
An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)... An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)lasers in the 3-5µm band.However,the quantum defect of LD directly-pumped MIR solid-state lasers will be much larger than that of ordinary near-infrared LD pumped solid-state lasers,which may lead to thermal damage and limit their development.In order to solve this problem,the methods of reducing the specific surface area of the crystal and improving the thermal energy released by the crystal structure are discussed,and the opti⁃mal length of the laser crystal is determined.The cooling structures of barium yttrium fluoride laser crystals(Ho^(3+):BY_(2)F_(8))of different lengths were studied by thermal simulation using COMSOL software.The experimen⁃tal results show that the output power can be increased and the thermal stress in the laser crystal can be alleviated by using the laser crystal whose length is slightly shorter than that of the cooler.The final experiment shows that when the pump repetition rate is 15 Hz and the pulse width is 90µs,the single pulse energy is 7.28 mJ at the out⁃put wavelength of 3.9µm,which is about 3 times as large as that of the crystal with the length of 10 mm(2.81 mJ).Such results should be another breakthrough of our team since the first directly-pumped solid-state MIR laser was realized more than a year ago.It might pave the way for the construction of a feasible MIR laser in the near future. 展开更多
关键词 mid-infrared laser LD directly pumping solid state laser Ho:BYF laser crystal
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Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform
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作者 Xinwei Wang Xiaopeng Yan +2 位作者 Tai An Qile Chen Dingkun Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期352-363,共12页
Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suf... Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suffers from significant performance degradation owing to the limited number of physical elements.To improve the underdetermined DOA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DOA estimation method.Using the motion of the UAV platform,the echo signal is sampled at different positions.Then,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DOFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal DOFs.Under the condition of no increase in the aperture of the physical array,the proposed method obtains a high DOF with fewer sampling runs and greatly improves the underdetermined DOA estimation performance of ULA.The results of numerical simulations conducted herein verify the superior performance of the proposed method. 展开更多
关键词 Unmanned aerial vehicle(UAV) Uniform linear array(ULA) direction of arrival(DOA) Difference co-array Nonuniform linear motion sampling method
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中国银矿成矿规律与百年勘查成果及新一轮找矿突破行动建议--《中国矿产地质志·银矿卷》研编 被引量:3
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作者 江彪 王登红 +13 位作者 王岩 刘榆 黄凡 王成辉 李楠 武利文 张彤 唐增才 叶泽富 秦海燕 靳皇玉 冯德臣 缪仁谷 张荣臻 《地球学报》 北大核心 2025年第1期35-51,共17页
银是人类最早开发利用的元素之一,随着社会的发展和科技的进步,银的新材料属性日益突出。中国是银矿资源相对丰富的国家之一,自1990年以来,尤其是自2010年以来,中国银矿找矿勘查取得较大突破,新增银资源储量超过55000 t,新发现银矿产地... 银是人类最早开发利用的元素之一,随着社会的发展和科技的进步,银的新材料属性日益突出。中国是银矿资源相对丰富的国家之一,自1990年以来,尤其是自2010年以来,中国银矿找矿勘查取得较大突破,新增银资源储量超过55000 t,新发现银矿产地超过53处,探获了包括双尖子山超大型银矿在内的大量银矿。中国银矿有7个主要矿床类型,以热液型和陆相火山-次火山型最为重要,资源储量分别为161271 t和48870 t,分别占总量的49.5%和15%。中国银矿主要产于中生代,查明银资源储量为266476 t,占比达74.25%;空间上呈“东多西少”的分布格局。大兴安岭成矿带及其邻区查明银资源储量超过86000 t,是中国最重要的银矿产区和找矿潜力区。运用成矿系列理论,寻找新矿区或新类型银矿、老银矿区外围和深部以及在成银带内找银矿等是中国银矿找矿勘查的重要方向。 展开更多
关键词 银矿 成矿规律 勘查成果 找矿方向
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Direction finding of bistatic MIMO radar in strong impulse noise
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作者 CHEN Menghan GAO Hongyuan +2 位作者 DU Yanan CHENG Jianhua ZHANG Yuze 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期888-898,共11页
For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in ... For bistatic multiple-input multiple-output(MIMO)radar,this paper presents a robust and direction finding method in strong impulse noise environment.By means of a new lower order covariance,the method is effective in suppressing impulse noise and achieving superior direction finding performance using the maximum likelihood(ML)estimation method.A quantum equilibrium optimizer algorithm(QEOA)is devised to resolve the corresponding objective function for efficient and accurate direc-tion finding.The results of simulation reveal the capability of the presented method in success rate and root mean square error over existing direction-finding methods in different application situations,e.g.,locating coherent signal sources with very few snapshots in strong impulse noise.Other than that,the Cramér-Rao bound(CRB)under impulse noise environment has been drawn to test the capability of the presented method. 展开更多
关键词 bistatic multiple-input multiple-output(MIMO)radar impulse noise direction finding lower order covariance quan-tum equilibrium optimizer algorithm(QEOA) maximum likeli-hood estimation method Cramér-Rao bound(CRB)
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论数据管辖权的冲突与协调 被引量:5
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作者 张晓君 《政法论丛》 北大核心 2025年第1期95-109,共15页
随着数字经济的快速发展,数据流动的跨国性和复杂性使得数据管辖权的冲突日益凸显,如何协调各国数据管辖权,已成为国际上亟待解决的关键议题。在厘清数据管辖权的性质与内涵属性的基础上,结合数据管辖权冲突的诸多表征进行分析,揭示出... 随着数字经济的快速发展,数据流动的跨国性和复杂性使得数据管辖权的冲突日益凸显,如何协调各国数据管辖权,已成为国际上亟待解决的关键议题。在厘清数据管辖权的性质与内涵属性的基础上,结合数据管辖权冲突的诸多表征进行分析,揭示出数据管辖权价值取向的博弈、国家权力结构的力量对比、数据主权与长臂管辖的对抗等因素,是构成数据管辖权冲突的内在根源。通过自我约束、依赖双边与区域合作机制以及遵循传统国际法原则等已有方式协调数据管辖权存在着效用的局限与规则的缺位等问题。因此,需要通过国家层面自我协调的优化区域合作的深化、全球治理机制的构建等多维进路,舒缓和解决国家之间数据管辖权的冲突,以保障数据管辖权的行使与平衡,推动构建公平合理的全球数据治理体系。 展开更多
关键词 数据管辖权 数据主权 冲突与协调 跨境数据流动 全球数据治理
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湿直播模式下水稻种子丸化包衣处理对主要病虫害防治效果及产量的影响 被引量:2
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作者 于居龙 张国 +7 位作者 张新凤 朱阿秀 张海波 王晓琳 缪康 张建华 束兆林 姚克兵 《植物保护》 北大核心 2025年第2期339-345,351,共8页
为了明确水稻利用药剂丸化包衣后对主要病虫害的防治效果及对产量的影响,为种子丸化包衣技术推广及应用提供技术支撑。在湿直播播种模式下,以常规拌种包衣和裸种播种作为对照,研究了种子处理药剂丸化包衣后对水稻出苗安全性、茎蘖动态... 为了明确水稻利用药剂丸化包衣后对主要病虫害的防治效果及对产量的影响,为种子丸化包衣技术推广及应用提供技术支撑。在湿直播播种模式下,以常规拌种包衣和裸种播种作为对照,研究了种子处理药剂丸化包衣后对水稻出苗安全性、茎蘖动态、病虫害防效、缓释增效及产量的影响。结果表明,用三氟苯嘧啶、氯虫苯甲酰胺和噻呋酰胺丸化包衣水稻种子后,比拌种包衣和裸种处理出苗率分别提高2.25百分点和3.00百分点,田间出苗成苗数、分蘖数及最终有效穗数均显著高于对照处理;水稻种子药剂丸化包衣播种后45 d,对田间稻飞虱、稻纵卷叶螟和纹枯病的防效分别为84.29%、89.98%和90.86%,播种后76 d,对田间稻飞虱、稻纵卷叶螟和纹枯病的防效分别为85.24%、83.69%和81.69%,防效优于拌种包衣处理;播种后45 d药剂残留检测结果表明,丸化包衣处理后氯虫苯甲酰胺在水稻叶片中、三氟苯嘧啶和噻呋酰胺在水稻茎秆中分布量均显著高于拌种包衣处理,药剂利用率得到提升;水稻成熟时,丸化包衣处理田间有效穗达到384.0穗/m^(2),千粒重为28.96 g,实测产量达到9321.30 kg/hm^(2),单位面积有效穗数、千粒重及实测产量均显著高于裸种对照。因此,利用三氟苯嘧啶、氯虫苯甲酰胺和噻呋酰胺丸化包衣处理水稻种子,可显著提高种子出苗率、增加分蘖数,提升药剂利用率,增强对病虫害防治效果,且对水稻具有一定增产作用,可为水稻湿直播安全生产提供一条新的解决方案。 展开更多
关键词 湿直播 丸化包衣 种子包衣 防治效果 产量
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工作家庭冲突与引航员工作行为:有调节的中介模型 被引量:1
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作者 庄元 兰承宇 +2 位作者 马小聪 雷胡根 刘钊 《安全与环境学报》 北大核心 2025年第3期1026-1035,共10页
为探究工作家庭冲突与引航员工作行为(组织公民行为和反生产行为)之间的作用机制以及组织支持感的调节作用,随机对长江引航员进行调查,利用SPSS和AMOS实证研究理论假设模型。结果表明:(1)引航员的工作家庭冲突在年龄、婚姻状况上存在显... 为探究工作家庭冲突与引航员工作行为(组织公民行为和反生产行为)之间的作用机制以及组织支持感的调节作用,随机对长江引航员进行调查,利用SPSS和AMOS实证研究理论假设模型。结果表明:(1)引航员的工作家庭冲突在年龄、婚姻状况上存在显著差异;(2)引航员的工作家庭冲突负向预测其组织公民行为且正向预测其反生产行为;(3)引航员的工作家庭冲突通过情绪耗竭的完全中介作用对其组织公民行为产生负向影响,对其反生产行为产生正向影响;(4)组织支持感在引航员的工作家庭冲突与情绪耗竭间起到了负向调节作用。关注引航员群体差异,降低工作家庭冲突,提升引航员个体的组织支持感,缓解情绪耗竭,能够改善引航员工作行为,推动引航事业安全健康发展。 展开更多
关键词 安全社会科学 引航员 工作家庭冲突 工作行为 情绪耗竭 组织支持感
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生成式人工智能赋能学习分析:价值内涵、实践框架及发展路向 被引量:8
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作者 叶俊民 尹兴翰 +2 位作者 于爽 刘清堂 罗晟 《电化教育研究》 北大核心 2025年第1期86-92,共7页
生成式人工智能正在教育领域崭露头角,其在数据处理、分析和生成方面的出色表现,为解决学习分析面临的利益相关者素养不足、技术可信性不强等问题提供了重要机遇,对深化教育评价改革意义深远。然而,关于生成式人工智能赋能学习分析的价... 生成式人工智能正在教育领域崭露头角,其在数据处理、分析和生成方面的出色表现,为解决学习分析面临的利益相关者素养不足、技术可信性不强等问题提供了重要机遇,对深化教育评价改革意义深远。然而,关于生成式人工智能赋能学习分析的价值内涵、实践框架及发展路向尚不清晰。因此,研究首先从“术用”与“器用”的双重角度剖析生成式人工智能赋能学习分析的价值内涵。其次,从确立目标、数据采集、数据处理与分析、智慧应用四个主要方面构建并阐释了生成式人工智能赋能学习分析的实践框架,以为学习分析实践提供参考。最后,立足于生成式人工智能赋能学习分析的现状,研究认为未来应该关注智能素养培育,以转向人智协同的学习分析范式;注重多种技术兼容,以促进分析变革培养的创新发展;重视分析伦理规范,以推动可信学习分析生态的构建。 展开更多
关键词 生成式人工智能 学习分析 价值内涵 实践框架 发展路向
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知识冲突:大语言模型教育应用的挑战与应对 被引量:2
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作者 陈向东 周春红 +1 位作者 刘泽民 张靖沅 《中国电化教育》 北大核心 2025年第3期1-10,共10页
大语言模型在教育应用领域所呈现的知识冲突问题,表现为概念定义、事实陈述和逻辑推理等层面的认知不一致性,这种认知断裂严重制约了其在跨学科探究学习、深度认知任务和个性化教学等场景中的适用性和支持能力。该文系统分析了知识冲突... 大语言模型在教育应用领域所呈现的知识冲突问题,表现为概念定义、事实陈述和逻辑推理等层面的认知不一致性,这种认知断裂严重制约了其在跨学科探究学习、深度认知任务和个性化教学等场景中的适用性和支持能力。该文系统分析了知识冲突的技术成因,包括训练数据中的噪声、参数化知识表示的局限、推理机制的缺陷、模型架构的先天不足以及外部知识的偏差,并探讨了这些因素对大语言模型教育应用的深层影响。针对这一挑战,论文提出了多维度的解决路径:通过数据增强优化知识表示,利用提示强化上下文的连贯,开发量规完善模型评估。同时,研究从社会文化的宏观视角进一步剖析了知识冲突的外部驱动因素,探讨如何在多元异质、动态演进的社会建构语境中,构建开放进取、兼容融通的智能教育应用体系。知识冲突的有效化解不仅可以显著提升大语言模型在教育场景中的应用价值,更将为人工智能在更广泛领域的可持续发展奠定坚实基础。研究旨在为解决这一问题提供理论洞见与实践指引,促进教育人工智能技术的可靠性、适应性和普及性的不断提升。 展开更多
关键词 大语言模型 知识冲突 教育应用 训练数据 社会建构
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新时代推动基层矛盾治理现代化的现实样态与实践机理 被引量:1
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作者 赵聚军 庞尚尚 《河海大学学报(哲学社会科学版)》 北大核心 2025年第2期74-85,共12页
基层矛盾治理是国家治理的基础,是基层社会安全稳定和良性运行的“压舱石”。党的十八大以来,在顶层设计的引领下,地方围绕基层矛盾纠纷的预防与化解,进行了大量的实践创新。然而,现有研究多以单案例的形式呈现,未能对基层矛盾治理形成... 基层矛盾治理是国家治理的基础,是基层社会安全稳定和良性运行的“压舱石”。党的十八大以来,在顶层设计的引领下,地方围绕基层矛盾纠纷的预防与化解,进行了大量的实践创新。然而,现有研究多以单案例的形式呈现,未能对基层矛盾治理形成完整的构象与分析。采用程序化扎根方法,基于25个典型案例,构建了一个以“结构-过程-功能”为核心内容的解释框架,力图深入展现新时代推动基层矛盾治理现代化的现实样态与实践机理。研究发现,在问题导向与高位推动的双重动力驱动下,以党政统合为主、多元主体协同参与的基层矛盾治理结构初步成型。在此基础上,沿着“资源-能力-工具”3个维度推进的治理过程,最终有效保障了治理效能释放、社会稳定有序与党政领导力提升等治理功能的实现。为进一步解释新时代基层矛盾治理实践,基于对现实样态的深描,从结构、过程、功能等方面归纳基层矛盾治理的主体间赋能、治理制度化、破除“悬浮化”等深层次实践机理。在全面推动基层矛盾治理现代化的过程中,为保障治理功能的有效发挥,既要继续强化提升党政领导力,也应重视完善各类过程机制。 展开更多
关键词 基层社会安全 矛盾治理 基层治理现代化 结构-过程-功能
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吉林省成矿规律与百年勘查成果及新一轮找矿突破行动建议--《中国矿产地质志·吉林卷》研编 被引量:2
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作者 姜福平 靳皇玉 +5 位作者 李楠 马超 宋小磊 臧兴运 赵华伟 冯德臣 《地球学报》 北大核心 2025年第1期251-272,共22页
吉林省的地质历史演化复杂,构造岩浆活动强烈,矿产资源丰富。其中油页岩、硅藻土、油砂、火山渣等矿产资源量位居中国前列。本研究通过研编《中国矿产地质志·吉林卷》,总结了吉林省矿产资源禀赋特征和区域成矿规律。在5个III级成... 吉林省的地质历史演化复杂,构造岩浆活动强烈,矿产资源丰富。其中油页岩、硅藻土、油砂、火山渣等矿产资源量位居中国前列。本研究通过研编《中国矿产地质志·吉林卷》,总结了吉林省矿产资源禀赋特征和区域成矿规律。在5个III级成矿区带的基础上,将吉林省进一步划分了11个IV级成矿亚带,29个矿集区,并总结了各IV级成矿亚带和重要矿集区的矿产分布规律。根据区域地质构造发展历史与成矿作用演化过程,吉林省地壳演化经历了新太古代-中元古代、新元古代-晚三叠世、晚三叠世-新生代3个构造演化阶段,10个构造演化旋回,形成了3个成矿域,24个矿床成矿系列,70个矿床式。据此构建了吉林省区域成矿谱系图。在此基础上,针对大宗紧缺矿产和战略性矿产资源金、铁、钼、镍、油页岩等矿种,提出了吉林省实施新一轮找矿突破战略行动的建议。 展开更多
关键词 勘查成果 成矿区带 矿床成矿系列 找矿方向 吉林省
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一种新型面肩肱肌营养不良症小鼠模型的建立
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作者 陈昊 孟茹 +6 位作者 蒋凌东 刘雯雯 安君 吴思惠 张沁欣 张军 胡平 《中国实验动物学报》 北大核心 2025年第7期968-979,共12页
目的利用Myf6-CreERT2小鼠与FLExDUX4小鼠构建面肩肱肌营养不良症(facioscapulohumeral muscular dystrophy,FSHD)转基因小鼠,并采用他莫昔芬诱导构建FSHD疾病小鼠模型。方法利用Myf6-CreERT2半合子小鼠与FLExDUX4半合子小鼠杂交获得双... 目的利用Myf6-CreERT2小鼠与FLExDUX4小鼠构建面肩肱肌营养不良症(facioscapulohumeral muscular dystrophy,FSHD)转基因小鼠,并采用他莫昔芬诱导构建FSHD疾病小鼠模型。方法利用Myf6-CreERT2半合子小鼠与FLExDUX4半合子小鼠杂交获得双转基因杂合子小鼠(M6D4/+),在3周龄时使用他莫昔芬诱导该小鼠表达全长DUX4(DUX4-fl),通过9周龄时小鼠体质量变化、四肢抓力、倒置网格实验、骨骼肌占体质量比、骨骼肌石蜡切片苏木素-伊红(HE)染色、天狼星红染色及免疫荧光、实时荧光定量PCR、骨骼肌RNA-seq等实验评估该疾病模型。结果成功获得双转基因杂合子小鼠(M6D4/+),9周龄时该小鼠与对照组相比,在生理方面表现出体质量增加下降、四肢抓力及耐力下降、骨骼肌比重下降;组织病理方面出现中央核肌纤维增多、肌束纤维化程度增高等骨骼肌受损表现;实时荧光定量PCR分析发现DUX4及其靶向基因在骨骼肌中表达明显上调;RNA-seq结果显示免疫调节、IL-6、肿瘤坏死因子相关基因的表达上调,骨骼肌发育和分化相关基因的表达下调。结论M6D4/+小鼠很好地模拟了FSHD的骨骼肌表型,是一种良好的FSHD动物模型,可用于FSHD的致病机制及干预、治疗研究。 展开更多
关键词 面肩肱肌营养不良症 DUX4 Myf6 骨骼肌 小鼠模型
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文化冲突:大语言模型教育应用中的张力与调适 被引量:1
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作者 陈向东 卢淑怡 易乐湘 《远程教育杂志》 北大核心 2025年第3期3-15,43,共14页
凭借其卓越的知识处理能力和个性化学习支持,大语言模型正逐步重塑教育生态。然而,这一技术创新同样伴随着深层次的文化冲突,尤其在跨文化或多元文化的教育环境中,神经网络和大模型固有的文化偏差与多样化教育需求之间的错位,已成为制... 凭借其卓越的知识处理能力和个性化学习支持,大语言模型正逐步重塑教育生态。然而,这一技术创新同样伴随着深层次的文化冲突,尤其在跨文化或多元文化的教育环境中,神经网络和大模型固有的文化偏差与多样化教育需求之间的错位,已成为制约其教育效能的重要因素。研究通过对大语言模型在教育应用中的多维度分析,从技术与文化的双重视角,系统探讨了三类典型的文化冲突:内容层面的“教什么”,过程层面的“怎么教”,以及技术层面的“用什么教”。基于此分析,研究提出了一系列缓解文化冲突的策略:充分发掘大语言模型的“世界知识”、有效利用模型的参数化知识特征、汲取不同文化和群体的语料、构建跨文化评估和检测机制以及规范大语言模型教育应用的伦理。在此基础上,研究进一步探讨了目前应对文化冲突的一种截然不同的策略——主权AI,以反映大模型教育推进过程中全球化与本土化之间的复杂纠结。文化冲突是大语言模型教育应用中不可回避的挑战,亟须在全球教育实践中得到有效应对。通过应对这一挑战,大语言模型有望为全球教育提供更加包容、有效的支持,在推动技术创新的同时,促进文化共融与理解。 展开更多
关键词 大语言模型 教育应用 文化冲突 教育公平 主权人工智能
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2025年国际原油价格分析与趋势预测 被引量:1
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作者 赵鲁涛 曲直 +1 位作者 孙嘉伟 何泽轩 《北京理工大学学报(社会科学版)》 北大核心 2025年第2期7-11,共5页
2024年,全球经济温和复苏,在政策转向分化、供需博弈加剧、局部冲突频发等多重因素叠加作用下,国际油价跌宕起伏,年均值下降。展望2025年,从基本面和非基本面着手,分析全球经济、能源转型、供应、库存、美元、市场投机、黄金和地缘政治... 2024年,全球经济温和复苏,在政策转向分化、供需博弈加剧、局部冲突频发等多重因素叠加作用下,国际油价跌宕起伏,年均值下降。展望2025年,从基本面和非基本面着手,分析全球经济、能源转型、供应、库存、美元、市场投机、黄金和地缘政治等因素的未来动向,结合预测模型客观计算和专家的主观判断,对2025年国际原油价格走势进行整体研判和预测。预计2025年国际原油价格中枢延续下行态势,市场供需偏紧,但需求增速不及供应,地缘冲突仍是重要风险因素,短期内将增强不确定性,Brent、WTI原油均价将在67~77美元/桶和62~72美元/桶。 展开更多
关键词 原油价格 价格预测 市场分析 能源转型 地缘政治冲突
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