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A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality 被引量:8
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作者 谭伟 张安明 An-ming 《Agricultural Science & Technology》 CAS 2010年第5期182-186,共5页
Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pione... Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District. 展开更多
关键词 Mountainous area Eco-friendly Land use Qianjiang District
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基于纯硬件电路的轴角-数字解码系统研究
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作者 王浩 牛伟 卢玉芳 《计算机技术与发展》 2024年第11期9-13,共5页
针对旋转变压器解码系统需要软硬件协同合作及系统结构复杂的问题,提出了一种基于纯硬件电路的轴角-数字解码系统,主要包括解调模块和解算模块。解调模块基于与激励信号同步的脉冲信号控制采样/保持电路来得到低频的解调信号;为避免使... 针对旋转变压器解码系统需要软硬件协同合作及系统结构复杂的问题,提出了一种基于纯硬件电路的轴角-数字解码系统,主要包括解调模块和解算模块。解调模块基于与激励信号同步的脉冲信号控制采样/保持电路来得到低频的解调信号;为避免使用AD转换、昂贵的压控振荡器等复杂硬件,解算模块采用了负反馈结构,主要基于计数器实现,通过正余弦LUT查找表将计数值转换为旋转变压器角度的线性输出,计数值表示解算角度;当解算角度与实际角度不一致时,解算模块会控制计数值增加或者减少,直到解算角度与实际角度一致。为验证该方法的有效性,在Matlab/Simulink中搭建系统模型进行多工况仿真验证,结果表明,纯硬件解码方法在角度阶跃变化、匀速变化及系统存在噪声时均能稳定正常工作,并且误差不超过0.2°,响应时间不超过2 ms,优于常规软件解码方法。最后进一步制作了验证板卡进行了实物验证,验证结果表明该系统具有较好的稳定性及精度。 展开更多
关键词 旋转变压器 轴角-数字变换 计数器 仿真 角度测量
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Environmental Issues of Geothermal Development in Yangbajing, Tibet and the Countermeasures 被引量:4
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作者 LiHui-xia HeXiao-rong +1 位作者 HuXian-cai DuoJi 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期965-974,共10页
The pollution source and pollution state of surface water is respectively assessed with equal-standard-pollution-load index and Nemero index, and the habitans' health is assessed as well by comparison with pre-dev... The pollution source and pollution state of surface water is respectively assessed with equal-standard-pollution-load index and Nemero index, and the habitans' health is assessed as well by comparison with pre-development of geo-thermal field. Results show that: 1) Three pollutive factors obviously fail to attain the required standards and their order sorted by impact degree is As>F- >S2-. 2) The Nemero index of Donggua cross section of Duilongqu River is 0. 725 and the water quality is at mildly-polluted level. 3) In Lhasa River, the Nemero indexes of cross sections affected by geo-thermal fields are much higher than that of the unaffected one, which shows the present and potential impacts of geo-thermal development. 4) Much more inhabitants nearby got trichomadesis sickness after geothermal development, which shows that the surface water pollution in this area has threatened the inhabitants' health. In addition, other environmental issues caused by Yangbajing geothermal development are analyzed and some countermeasures are proposed. 展开更多
关键词 Yangbajing of Tibet geothermal energy resources equal-standard-pollution-load index Nemero index counter measures
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A "Declining" Power and Its Counter measures
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作者 Shi Yinhong is a Professor of the School of International Relations and Director of theCenter for American Studies, Remin University of China. 《Contemporary International Relations》 2004年第12期1-7,共7页
关键词 DECLINING Power and Its counter measures
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The Opening of China's Securities: Challenge, Opportunities and Counter Measures
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作者 Bao Daiqin Zhao Huaiyong 《China's Foreign Trade》 1999年第12期15-18,共4页
No matter what is the outcome,as long as China is linked with theworld economy and enjoys thebenefits brought about by variouscountries that have opened theirsecurities market, China’s securities market will open soo... No matter what is the outcome,as long as China is linked with theworld economy and enjoys thebenefits brought about by variouscountries that have opened theirsecurities market, China’s securities market will open sooner or later. 展开更多
关键词 CHALLENGE Opportunities and counter measures
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On China's Accession to the WTO: Many Entrepreneurs Are Optimistic, But Few Have Counter Measures
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作者 Yang Wei 《China's Foreign Trade》 2000年第3期39-39,共1页
关键词 On China’s Accession to the WTO view But Few Have counter measures Many Entrepreneurs Are Optimistic
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江西水利文化遗产保护开发研究--以赣抚平原岗前渡槽工程为例
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作者 廖艳彬 赖青延 《老区建设》 2023年第10期59-65,共7页
江西赣抚平原岗前渡槽工程是新中国成立初期地方水利建设的重要代表之一,具有丰富的时代文化价值内涵,既是中国特色社会主义制度优越性和党的精神的重要体现,也是现代水利技术和建筑审美价值的体现,成为地方社会经济效益的推力和生态环... 江西赣抚平原岗前渡槽工程是新中国成立初期地方水利建设的重要代表之一,具有丰富的时代文化价值内涵,既是中国特色社会主义制度优越性和党的精神的重要体现,也是现代水利技术和建筑审美价值的体现,成为地方社会经济效益的推力和生态环境效应的借鉴。目前其保护开发存在着文化挖掘不完整、文化功能管理薄弱、文化宣传薄弱、文化管理人才不足、文化保护机制缺乏等问题。加强岗前渡槽工程文化保护与开发,需要坚持完整性保护开发原则,注重文化关联性保护,推进岗前渡槽文化建设,加强水利文化保护管理人才培养,做好总体保护开发规划。 展开更多
关键词 岗前渡槽工程 文化价值 保护开发 对策思考
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Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated martian atmosphere 被引量:4
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作者 Xin Lin Xi-Long Yu +3 位作者 Fei Li Shao-Hua Zhang Jian-Guo Xin Xin-Yu Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第5期1296-1302,共7页
Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- reso... Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- resolved spectra of the Av = 0 sequence of the B^2∑^+ → X^2∑^+ electronic transition of CN have been observed through optical emission spectroscopy (OES). A new method, which is based on fitting high resolution spectrum for rotational and vibrational temperatures measurement, is proposed to diag- nose temperature distribution behind the shock wave. It is estimated that the current scheme has the maximum deviation less than 8% (lσ) for vibrational temperature measurement through detailed analysis of the influence of the uncertainties of spectroscopic constants and spectral resolution. Radiation structure of the shock layer, including induction, relaxation and equilibrium process, and corresponding rotational and vibrational temperatures are obtained through time gating OES diagnostics with sub-microsecond temporal resolution. The present extensive results will strongly benefit the reaction rate estimation and computational fluid dynamics (CFD) code validation in high enthalpy Mars reentry chemistry. 展开更多
关键词 Radiation measurements - Shock wave Marsre-entry Rotational temperature Vibrational temperature
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MIMO Channel Measurement and Characterization at 6.0-6.4 GHz Under Typical Classroom Environment 被引量:3
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作者 Ji-Liang Zhang Yang Wang +2 位作者 Li-Qin Ding Xiao-Min Huang Nai-Tong Zhang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第1期69-76,共8页
An extensive 4 x 4 MIMO channel measurement is carried out at 6. 0-6. 4 GHz under a typical classroom environment with channel sounder based on vector network analyzer. Both LOS and NLOS scenarios are considered. The ... An extensive 4 x 4 MIMO channel measurement is carried out at 6. 0-6. 4 GHz under a typical classroom environment with channel sounder based on vector network analyzer. Both LOS and NLOS scenarios are considered. The results on path loss, delay spread and spatial correlation are presented. The measurement shows that, for corridor coverage, 2x2 MIMO is more economical than 4x4 MIMO due to high correlation. In order to identify the unique characteristics at the high frequency band, the measured channel parameters at 6. 0-6.4 GHz are compared with those at 2. 45 GHz. The comparison shows that the shortened wavelength of this higher frequency band results in a great difference of channel characteristics. Therefore, our measurement results provide new gnidance for the design and development of the system working on 6. 0-6.4 GHz band. 展开更多
关键词 6. 0-6.4 GHz muhi-input multi-output (MIMO) channel measurement channel characteristics
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Carrier fringe method of moire interferometry for tiny strain measurements in micro-field 被引量:2
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作者 Yudong Cao Shibin Wang +1 位作者 Shuangxi Qi Jingwei Tong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第1期101-106,共6页
In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of carrier fringes of moire interferometry. A cross-line grating with frequency of 1200 lp/mm is replicated on the... In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of carrier fringes of moire interferometry. A cross-line grating with frequency of 1200 lp/mm is replicated on the specimen surface, and the strain can be deduced from the changes in carrier fringes before and after the deformation of an object. Four coherent laser beams are used to obtain the carrier fringe patterns of field U and V. Both theoretical analysis and numerical simulation indicate that the ideal accuracy of strain can be controlled within a range of ±1με. Case study of a plane extension experiment shows that the measurement accuracy of strain can be controlled within the range of ±10με. The average strain values of every row of field U and every column of field V can be obtained by using this method, and approximated strain of every pixel in the whole-field can be further acquired, and thus it is possible to measure tiny strains occurred in a micro-field. The technology in this paper can provide comprehensive information for analyzing related mechanical content in the field of MEMS. 展开更多
关键词 Moire interferometry - Carrier fringe Micro-field Tiny strain. measured accuracy
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Measurement and simulation of the two-phase velocity correlation in sudden-expansion gas-particle flows 被引量:3
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作者 Li-Xing Zhou.Yang Liu.Yi Xu Department of Engineering Mechanics,Tsinghua University,100084 Beijing,China Marine Engineering College,Dalian Maritime University,116026 Dalian,China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第4期494-501,共8页
In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer (PDPA) and simulated the system behavior by ... In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer (PDPA) and simulated the system behavior by using both a Reynolds-averaged Navier-Stokes (RANS) model and a large-eddy simulation (LES). The results of the measurements yield the axial and radial time-averaged velocities as well as the fluctuation velocities of gas and three particle-size groups (30μm, 50μm, and 95μm) and the gasparticle velocity correlation for 30μm and 50μm particles. From the measurements, theoretical analysis, and simulation, it is found that the two-phase velocity correlation of sudden-expansion flows, like that of jet flows, is less than the gas and particle Reynolds stresses. What distinguishes the two-phase velocity correlations of sudden-expansion flow from those of jet and channel flows is the absence of a clear relationship between the two-phase velocity correlation and particle size in sudden-expansion flows. The measurements, theoretical analysis, and numerical simulation all lead to the above-stated conclusions. Quantitatively, the results of the LES are better than those of the RANS model. 展开更多
关键词 PDPA measurement - Simulation Two-phasevelocity correlation Sudden expansion gas-particle flows
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Predicament and Countermeasure Analysis of Intellectual Property Management for Strategic Emerging Industry 被引量:2
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作者 Zhang Lingwei Liu Dunhu 《学术界》 CSSCI 北大核心 2014年第7期303-307,共5页
Intellectual property is the core support and important driving force for the sound development of strategic emerging industry. This paper makes an analysis on the current predicament of intellectual property manageme... Intellectual property is the core support and important driving force for the sound development of strategic emerging industry. This paper makes an analysis on the current predicament of intellectual property management for strategic emerging industry from the four stages of the process,including creation and development management,business management,revenue management and disposal management on intellectual property,and finally explores the solutions and gives some countermeasures. 展开更多
关键词 知识产权管理 新兴产业 业务管理 收入
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Auto-measuring System of 3-Dimensional Human Body
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作者 李勇 尚保平 +1 位作者 付小莉 尚会超 《Journal of Donghua University(English Edition)》 EI CAS 2001年第3期110-112,共3页
To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge C... To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge Coupled Devices (CCD) and infrared sensors is presented in this paper. The system can measure the bare size of human body that excludes the effect of clothing quickly and accurately. 展开更多
关键词 3- D measurement HUMAN BODY measurement.
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Analysis and counter measure in blood grouping errors of volunteers’donating blood
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《中国输血杂志》 CAS CSCD 2001年第S1期378-,共1页
关键词 Analysis and counter measure in blood grouping errors of volunteers
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3-Dimensional Body Measurement Technology
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作者 周旭东 李艳梅 《Journal of Donghua University(English Edition)》 EI CAS 2002年第4期138-140,共3页
3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body... 3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body measurement technology, and recounts the principle and primary structure of some types of 3 - dimensional automatic body measurement system. With this understanding, it discusses prospect of 3- dimensional CAD and virtual technology used in apparel industry. 展开更多
关键词 3 - DIMENSIONAL BODY measurement technology digital apparel industry quick response virtual fitting apparel NAD
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Fundamental Properties and Optimal Gains of a Steady-State Velocity Measured <i>α</i>-<i>β</i>Tracking Filter
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作者 Kenshi Saho 《Advances in Remote Sensing》 2014年第2期61-76,共16页
This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filt... This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filter. We first derive the stability condition and steady-state predicted errors as fundamental properties of the VM-α-β filter. The optimal gains for representative motion models are then derived from the Kalman filter equations. Theoretical and numerical analyses verify that VM-α-β filters with these optimal gains realize more accurate tracking than conventional α-β filters when the filter gains are relatively large. Our study reveals the conditions under which the predicted errors of the VM-α-β filters are less than those of conventional α-β filters. Moreover, numerical simulations clarify that the variance of the tracking error of the VM-α-β filters is approximately 3/4 of that of the conventional α-β filters in realistic situations, even when the accuracy of the position/velocity measurements is the same. 展开更多
关键词 α-β FILTER Moving Target Tracking VELOCITY measurement KALMAN FILTER OPTIMAL Gain
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Test of Normality of Waist Measurement Data of Young Male and Female Adults based on the Quantile - Quantile Plot
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作者 F. Z. Okwonu J. N. Igabari 《Journal of Statistical Science and Application》 2017年第3期118-126,共9页
This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q... This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q plot is used to determine the normality or otherwise of the data set. In this regards, the probabilities of the quantiles were computed, modified and plotted. Thereafter the correlation coefficients for the quantile - quantile plots were obtained. Results indicate that at 0.1 level of significance, the data for young adult males of the sample were not normally distributed, and had a mean value that is within the range of low risk, healthwise, whereas the distribution of the data for young female adults showed reasonable normality, but also with a mean value that is within the range of low risk in terms of health condition. 展开更多
关键词 Correlation coefficient probability plot quantile - quantile plot test of normality waist measurement young adults.
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A Steady-State Errors Correction Method for Eliminating Measurement Errors
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作者 田新良 杨苹 《Journal of Donghua University(English Edition)》 EI CAS 2013年第4期298-304,共7页
This paper proposes a steady-state errors correction(SSEC)method for eliminating measurement errors.This method is based on the detections of error signal E(s)and output C(s)which generate an expected output R(s).In c... This paper proposes a steady-state errors correction(SSEC)method for eliminating measurement errors.This method is based on the detections of error signal E(s)and output C(s)which generate an expected output R(s).In comparison with the conventional solutions which are based on detecting the expected output R(s)and output C(s)to obtain error signal E(s),the measurement errors are eliminated even the error might be at a significant level.Moreover,it is possible that the individual debugging by regulating the coefficient K for every member of the multiple objectives achieves the optimization of the open loop gain.Therefore,this simple method can be applied to the weak coupling and multiple objectives system,which is usually controlled by complex controller.The principle of eliminating measurement errors is derived analytically,and the advantages comparing with the conventional solutions are depicted.Based on the SSEC method analysis,an application of this method for an active power filter(APF)is investigated and the effectiveness and viability of the scheme are demonstrated through the simulation and experimental verifications. 展开更多
关键词 measurement errors steady-state errors correction (SSEC) active power filters (APF)CLC number:TM77Document code:AArticle ID:1672-5220(2013)04-0298-07
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利用数字化仪实现放射性气体85Kr核素活度浓度的绝对测量
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作者 拓飞 路天翔 +3 位作者 张明 周倩倩 郭贵银 王硕 《计量学报》 CSCD 北大核心 2024年第10期1570-1575,共6页
基于中国计量科学研究院建立的长度补偿法充气正比计数器绝对测量系统,利用CAEN公司开发的DT5730型数字化仪替代多套传统模拟电子学插件,并通过数字化仪对β信号进行采集、重建和数据离线分析,开展85Kr放射性惰性气体活度浓度的绝对测... 基于中国计量科学研究院建立的长度补偿法充气正比计数器绝对测量系统,利用CAEN公司开发的DT5730型数字化仪替代多套传统模拟电子学插件,并通过数字化仪对β信号进行采集、重建和数据离线分析,开展85Kr放射性惰性气体活度浓度的绝对测量。实验研究了各种条件的影响,通过对正比计数器端效应、正比计数器壁效应、本底、噪声、死时间漏计数和阈值以下计数进行修正,最终得到85Kr活度浓度绝对测量结果。在相同阈值、主放大倍数100倍、气压50.5 kPa,工作电压1675 V和1700 V的条件下,数字化仪测量和电子学插件测量^(85)Kr放射性活度浓度的相对偏差分别为0.83%和0.74%。测量结果在不确定度范围内一致,证明数字化仪可有效替代传统电子学插件实现放射性惰性气体^(85)Kr活度浓度的绝对测量。 展开更多
关键词 电离辐射计量 数字化仪 85Kr 正比计数器 放射性活度浓度 绝对测量
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教育数字化转型中高校课程思政的困境和对策研究
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作者 贺祖松 《北京经济管理职业学院学报》 2024年第3期65-71,共7页
教育数字化转型是对传统教育模式、教学方法、教学内容等进行创新、改造和升级,极大地推动了教育理念的革新。在教育数字化转型大背景下,高校应加强课程思政数字化教学资源的建设及课程思政与数字技术的融合创新,创设高效的思政育人环境... 教育数字化转型是对传统教育模式、教学方法、教学内容等进行创新、改造和升级,极大地推动了教育理念的革新。在教育数字化转型大背景下,高校应加强课程思政数字化教学资源的建设及课程思政与数字技术的融合创新,创设高效的思政育人环境,增强课程思政的吸引力,完善课程思政多元化评价体系,提升师生的数字化素养,强化师生互动,构建数字化思政学习共同体。确保课程思政的数字化转型能够顺利进行并取得实效,为培养具有创新精神和实践能力的高素质人才做出更大贡献。 展开更多
关键词 教育数字化 转型 课程思政 对策
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