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Variation of Membrane Electrode Assembly Catalyst Layer in Unitized Regenerative Fuel Cell
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作者 Yollanda Nurcholifah Dedi Rohendi +4 位作者 Edy Herianto Majlan Nirwan Syarif Addy Rachmat Dwi Hawa Yulianti Nyimas Febrika S 《电化学(中英文)》 北大核心 2025年第4期32-43,共12页
A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefo... A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2. 展开更多
关键词 unitized regenerative fuel cell Round trip efficiency Pt-Ru/C Membrane electrode assembly Electrochemical surface area
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Glassmaking Units and Glass Feeders Production -- a New Production Development Stage at JSC "Krastsvetmet"
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作者 MALTSEV E. V. MAMONOV S. N. DMITRIEV V. A. KHORIKOV P. A. 《贵金属》 CAS CSCD 北大核心 2012年第A01期117-120,共4页
JSC "Krastsvetmet" has launched the production of glass melting units(GU) and glass feeders(GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide forming a... JSC "Krastsvetmet" has launched the production of glass melting units(GU) and glass feeders(GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide forming and reinforcing elements.The proprietary technology for dispersion-stabilized material of PtRh10DS composition having high strength and performance properties has been developed and applied.Combined products production was launched where bushings made of PtRh-20 alloy are welded to the plate of the dispersion-stabilized PtRh10DS material.The manufacture of seamless spinning assemblies has been organized. 展开更多
关键词 glass-melting units glass feeders platinum-rhodium alloys dispersion-stabilized material
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Fuzzy data envelopment analysis approach based on sample decision making units 被引量:11
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作者 Muren Zhanxin Ma Wei Cui 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第3期399-407,共9页
The conventional data envelopment analysis (DEA) measures the relative efficiencies of a set of decision making units with exact values of inputs and outputs. In real-world prob- lems, however, inputs and outputs ty... The conventional data envelopment analysis (DEA) measures the relative efficiencies of a set of decision making units with exact values of inputs and outputs. In real-world prob- lems, however, inputs and outputs typically have some levels of fuzziness. To analyze a decision making unit (DMU) with fuzzy input/output data, previous studies provided the fuzzy DEA model and proposed an associated evaluating approach. Nonetheless, numerous deficiencies must still be improved, including the α- cut approaches, types of fuzzy numbers, and ranking techniques. Moreover, a fuzzy sample DMU still cannot be evaluated for the Fuzzy DEA model. Therefore, this paper proposes a fuzzy DEA model based on sample decision making unit (FSDEA). Five eval- uation approaches and the related algorithm and ranking methods are provided to test the fuzzy sample DMU of the FSDEA model. A numerical experiment is used to demonstrate and compare the results with those obtained using alternative approaches. 展开更多
关键词 fuzzy mathematical programming sample decision making unit fuzzy data envelopment analysis EFFICIENCY α-cut.
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Research on virtual entity decision model for LVC tactical confrontation of army units 被引量:4
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作者 GAO Ang GUO Qisheng +3 位作者 DONG Zhiming TANG Zaijiang ZHANG Ziwei FENG Qiqi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第5期1249-1267,共19页
According to the requirements of the live-virtual-constructive(LVC)tactical confrontation(TC)on the virtual entity(VE)decision model of graded combat capability,diversified actions,real-time decision-making,and genera... According to the requirements of the live-virtual-constructive(LVC)tactical confrontation(TC)on the virtual entity(VE)decision model of graded combat capability,diversified actions,real-time decision-making,and generalization for the enemy,the confrontation process is modeled as a zero-sum stochastic game(ZSG).By introducing the theory of dynamic relative power potential field,the problem of reward sparsity in the model can be solved.By reward shaping,the problem of credit assignment between agents can be solved.Based on the idea of meta-learning,an extensible multi-agent deep reinforcement learning(EMADRL)framework and solving method is proposed to improve the effectiveness and efficiency of model solving.Experiments show that the model meets the requirements well and the algorithm learning efficiency is high. 展开更多
关键词 live-virtual-constructive(LVC) army unit tactical confrontation(TC) intelligent decision model multi-agent deep reinforcement learning
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Design of 32 kbit one-time programmable memory for microcontroller units 被引量:1
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作者 JEON Hwang-gon CHOI In-hwa +1 位作者 HA Pan-bong KIM Young-hee 《Journal of Central South University》 SCIE EI CAS 2012年第12期3475-3483,共9页
A 32 kbit OTP(one-time programmable)memory for MCUs(micro-controller units)used in remote controllers was designed.This OTP memory is used for program and data storage.It is required to apply 5.5V to BL(bit-line)and 1... A 32 kbit OTP(one-time programmable)memory for MCUs(micro-controller units)used in remote controllers was designed.This OTP memory is used for program and data storage.It is required to apply 5.5V to BL(bit-line)and 11V to WL(word-line)for a OTP cell of 0.35μm ETOX(EEPROM tunnel oxide)type by MagnaChip.We use 5V transistors on column data paths to reduce the area of column data paths since they require small areas.In addition,we secure device reliability by using HV(high-voltage)transistors in the WL driver.Furthermore,we change from a static logic to a dynamic logic used for the WL driver in the core circuit.Also,we optimize the WD(write data)switch circuit.Thus,we can implement them with a small-area design.In addition,we implement the address predecoder with a small-area logic circuit.The area of the designed 32 kbit OTP with 5V and HV devices is 674.725μm×258.75μm(=0.1745mm2)and is 56.3% smaller than that using 3.3V devices. 展开更多
关键词 one-time programmable memory micro controller unit EEPROM tunnel oxide small-area
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Coordination properties and structural units distribution of Q_T^i in calcium aluminosilicate melts from MD simulation 被引量:1
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作者 吴永全 蒋国昌 +2 位作者 尤静林 侯怀宇 陈辉 《Journal of Central South University of Technology》 2004年第1期6-14,共9页
The distribution of Al (j) and the structural units distribution of Qi T in calcium aluminosilicate melts were studied by means of molecular dynamics simulation. The results show that provided there exists lower-fie... The distribution of Al (j) and the structural units distribution of Qi T in calcium aluminosilicate melts were studied by means of molecular dynamics simulation. The results show that provided there exists lower-field strength cation relative to Al3+, such as alkaline and alkaline earth metals, Al will be four-coordinated but not six-coordinated. Meanwhile, if there exist a large number of higher-field strength cations such as Si4+ and little lower-field strength cation, six-coordinated aluminum will be formed. The relation of structural units distribution of Qi T with chemical composition shift was also extracted, showing that as Ca2+ exists, the distributions of Qi Si, Qi Al or Qi T have the similar changing trend with the variation of component. Because of high-temperature effect, the Al-tetrahedral units in melts are greatly active and unstable and there exist dynamic transforming equilibria of Al(3)Al(4) and (Al(5))Al(4). The three-coordinated oxygen and charge-compensated bridging oxygen are proposed to explain phenomena of the negative charge redundancy of AlO4 and location of network modifier with charge-compensated function in aluminosilicate melts. 展开更多
关键词 Molecular dynamics simulation calcium aluminosilicate melt coordination number structural unit of tetrahedra
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Classification of Coalbed Methane Enrichment Units of Qinshui Basin Based on Geological Dynamical Conditions
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作者 Gang Xu,Wenfeng Du,Xubiao Deng State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(Beijing),Beijing 100083, China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期155-155,共1页
Coalbed methane enrichment will be controlled by many good macro geological dynamical conditions; there is evident difference of enrichment grade in different area and different geological conditions.This paper has st... Coalbed methane enrichment will be controlled by many good macro geological dynamical conditions; there is evident difference of enrichment grade in different area and different geological conditions.This paper has studied tectonic dynamical conditions, thermal dynamical conditions and hydraulic conditions, which affect coalbed methane enrichment in Qinshui basin.Coalbed methane enrichment units have been divided based on tectonic dynamical conditions of Qinshui basin,combined with thermal dynamical conditions and hydraulic conditions. 展开更多
关键词 GEOLOGICAL DYNAMICAL CONDITIONS Qinshui basin coalbed methane ENRICHMENT units CLASSIFICATIONS
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Aerial target threat assessment based on gated recurrent unit and self-attention mechanism 被引量:3
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作者 CHEN Chen QUAN Wei SHAO Zhuang 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期361-373,共13页
Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties ... Aerial threat assessment is a crucial link in modern air combat, whose result counts a great deal for commanders to make decisions. With the consideration that the existing threat assessment methods have difficulties in dealing with high dimensional time series target data, a threat assessment method based on self-attention mechanism and gated recurrent unit(SAGRU) is proposed. Firstly, a threat feature system including air combat situations and capability features is established. Moreover, a data augmentation process based on fractional Fourier transform(FRFT) is applied to extract more valuable information from time series situation features. Furthermore, aiming to capture key characteristics of battlefield evolution, a bidirectional GRU and SA mechanisms are designed for enhanced features.Subsequently, after the concatenation of the processed air combat situation and capability features, the target threat level will be predicted by fully connected neural layers and the softmax classifier. Finally, in order to validate this model, an air combat dataset generated by a combat simulation system is introduced for model training and testing. The comparison experiments show the proposed model has structural rationality and can perform threat assessment faster and more accurately than the other existing models based on deep learning. 展开更多
关键词 target threat assessment gated recurrent unit(GRU) self-attention(SA) fractional Fourier transform(FRFT)
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基于Unity3D的油田抽油机三维可视化监控系统设计 被引量:13
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作者 刘立强 孙文磊 +1 位作者 王一 王炳楷 《系统仿真学报》 CAS CSCD 北大核心 2024年第2期463-475,共13页
针对抽油机监测形式单一、三维可视化程度低和联动性差的缺陷,引入信息―物理实时映射思想,开发了油田抽油机三维可视化监控系统。设计了抽油机数字空间,搭建虚实交互层设计架构;搭建三维可视化系统数据组成及关系框架;结合逆运动学,构... 针对抽油机监测形式单一、三维可视化程度低和联动性差的缺陷,引入信息―物理实时映射思想,开发了油田抽油机三维可视化监控系统。设计了抽油机数字空间,搭建虚实交互层设计架构;搭建三维可视化系统数据组成及关系框架;结合逆运动学,构建数学模型,基于五维模型和Unity 3D平台设计抽油机三维可视化系统总体架构;以游梁式抽油机为对象进行实验验证,实现了实时动态监测、虚实混合控制、运动轨迹追踪和在线预警等服务功能。为三维可视化监控在石油机械领域的落地应用和数字孪生系统的开发提供借鉴。 展开更多
关键词 抽油机 三维可视化 实时动态监测 虚实混合控制 unitY3D
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Distributed Mo del Predictive Control Based on Multi-agent Mo del for Electric Multiple Units 被引量:12
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作者 LI Zhong-Qi 《自动化学报》 EI CSCD 北大核心 2014年第11期2625-2631,共7页
关键词 分布式电源 电动车组 多代理 预测控制 多单元 协调控制算法 多AGENT 功率单元
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Semantic Units Based Event Detection in Soccer Videos 被引量:1
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作者 TONGXiao-Feng LIUQing-Shan LUHan-Qing JINHong-Liang 《自动化学报》 EI CSCD 北大核心 2005年第4期523-529,共7页
A semantic unit based event detection scheme in soccer videos is proposed in this paper.The scheme can be characterized as a three-layer framework. At the lowest layer, low-level featuresincluding color, texture, edge... A semantic unit based event detection scheme in soccer videos is proposed in this paper.The scheme can be characterized as a three-layer framework. At the lowest layer, low-level featuresincluding color, texture, edge, shape, and motion are extracted. High-level semantic events aredefined at the highest layer. In order to connect low-level features and high-level semantics, wedesign and define some semantic units at the intermediate layer. A semantic unit is composed of asequence of consecutives frames with the same cue that is deduced from low-level features. Based onsemantic units, a Bayesian network is used to reason the probabilities of events. The experiments forshoot and card event detection in soccer videos show that the proposed method has an encouragingperformance. 展开更多
关键词 事件探测 语言单位 BAYESIAN网络 视频语仪分析
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大国战略竞争背景下美国在联合国的对华政策 被引量:2
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作者 毛瑞鹏 《太平洋学报》 北大核心 2025年第1期11-25,共15页
多边机构是美国实施大国战略竞争政策的重要一环。美国在联合国对华实施打压遏制政策,是其大国竞争战略的延伸,也是其奉行“美国例外主义”和将联合国“战场化”的突出体现。美国行政当局、国会及战略界均参与到有关在联合国对华打压遏... 多边机构是美国实施大国战略竞争政策的重要一环。美国在联合国对华实施打压遏制政策,是其大国竞争战略的延伸,也是其奉行“美国例外主义”和将联合国“战场化”的突出体现。美国行政当局、国会及战略界均参与到有关在联合国对华打压遏制政策的设计之中,对中国在联合国影响力的提升作出系统性反应,并重点寻求打击中国的规范倡导、阻遏中国的人才输送、抹黑中国的国家形象、瓦解中国的伙伴关系。美国的大国竞争政策破坏了联合国正常的合作氛围和运作秩序,加剧了联合国的动荡和分裂,阻碍了全球治理的进程和效能。面对美国压力,中国坚持真正的多边主义,坚定维护发展中国家的合法权益,推动构建公正合理的国际秩序。展望未来,更好地发挥联合国对大国关系的调节功能对于维护国际和平与稳定具有重要意义和价值。 展开更多
关键词 美国 中国 联合国 大国竞争 多边主义
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基于纵轴流开式玉米脱粒装置的优化设计与试验 被引量:3
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作者 张红梅 胡经营 +5 位作者 何勋 屈哲 杨立权 李世龙 刘冰杰 张静 《河南农业大学学报》 北大核心 2025年第1期122-135,共14页
【目的】解决现阶段玉米籽粒收获过程中籽粒破碎率和未脱净率高的问题,满足黄淮海地区玉米籽粒收获的要求。【方法】设计了纵轴流开式玉米脱粒装置,搭配钉齿式脱粒元件,将其按螺旋等间距排列的方式分布在辐条上。通过EDEM软件对脱粒装... 【目的】解决现阶段玉米籽粒收获过程中籽粒破碎率和未脱净率高的问题,满足黄淮海地区玉米籽粒收获的要求。【方法】设计了纵轴流开式玉米脱粒装置,搭配钉齿式脱粒元件,将其按螺旋等间距排列的方式分布在辐条上。通过EDEM软件对脱粒装置进行仿真分析,确定较佳的滚筒转速参数。以滚筒转速、喂入量、含水率为试验因素对脱粒装置进行单因素试验,得到较优的参数组合:滚筒转速为350.00 r⋅min^(-1)、喂入量为8.00 kg⋅s^(-1)、含水率为25.90%±1%。【结果】正交试验确定了影响的主次因素,先后依次为含水率、滚筒转速、喂入量。当滚筒转速为400 r⋅min^(-1)、喂入量为8.66 kg⋅s^(-1)、含水率为15.90%时,破碎率为3.99%、未脱净率为0.39%,脱粒装置台架验证试验得出该参数组合下破碎率和未脱净率分别为4.27%和0.51%,其中破碎率与理论优化值相差0.28%、未脱净率与理论优化值相差0.12%,试验结果与理论优化值非常接近。【结论】符合国家玉米籽粒直收的标准要求,为玉米籽粒收获机的研制提供了理论依据和新的研究思路。 展开更多
关键词 玉米脱粒 开式 脱粒装置 钉齿结构
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麻醉恢复室预约系统应用于术后患者管理的效果评价 被引量:2
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作者 张晨 何苗 +1 位作者 果旭 康百慧 《中国护理管理》 北大核心 2025年第2期180-184,共5页
目的 :分析麻醉恢复室预约系统应用于术后患者管理的效果,以加快患者周转,并保障患者安全。方法 :以医院麻醉排班系统为支撑,构建麻醉恢复室预约系统,2023年6月将该系统应用于麻醉恢复室,比较系统应用前(2022年5月至2023年5月)及应用后(... 目的 :分析麻醉恢复室预约系统应用于术后患者管理的效果,以加快患者周转,并保障患者安全。方法 :以医院麻醉排班系统为支撑,构建麻醉恢复室预约系统,2023年6月将该系统应用于麻醉恢复室,比较系统应用前(2022年5月至2023年5月)及应用后(2023年6月至2024年6月)患者平均等候时长、预约内容错误率、医护人员满意度。结果 :应用麻醉恢复室预约系统后,患者平均等候时长由(13.26±3.44)min缩短至(8.89±2.83)min(P<0.05),预约错误率由0.84%降至0.37%(P<0.05),医护人员满意度由(2.70±0.81)分上升至(4.68±0.62)分(P<0.05)。结论 :麻醉恢复室预约系统优化了麻醉恢复室预约方式,有助于保障患者安全,加速患者周转,提高护理工作效率。 展开更多
关键词 麻醉恢复室 预约系统 信息化 闭环管理
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我国废弃/关闭煤矿瓦斯抽采现状及发展趋势 被引量:2
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作者 华心祝 秦浩 +4 位作者 郝定溢 石必明 林柏泉 赵志根 张苗 《煤炭科学技术》 北大核心 2025年第4期15-28,共14页
在“双碳”目标的驱动下,我国能源结构迎来高质量发展。截至目前,已累计淘汰落后煤炭产能10亿t,废弃/关闭煤矿数量快速增加,据研究预计到2030年,我国废弃/关闭矿井将达到1.5万处,其中赋存非常规天然气近5000亿m3。为构建清洁低碳、安全... 在“双碳”目标的驱动下,我国能源结构迎来高质量发展。截至目前,已累计淘汰落后煤炭产能10亿t,废弃/关闭煤矿数量快速增加,据研究预计到2030年,我国废弃/关闭矿井将达到1.5万处,其中赋存非常规天然气近5000亿m3。为构建清洁低碳、安全高效的能源体系,加快发展新质生产力,亟需加大我国对废弃/关闭煤矿遗留瓦斯的抽采与开发力度。系统性地总结分析了我国现阶段废弃煤矿瓦斯地面抽采理论、技术及工艺设备的研究进展与存在问题,提出了未来研究的关键方向与潜在热点。首先,总结了废弃/关闭煤矿瓦斯赋存规律,归纳对比了遗留瓦斯资源量评估方法,分析了废弃煤矿地面抽采过程中瓦斯渗流及运移规律。其次,总结了2种常见的废弃/关闭煤矿瓦斯地面抽采技术,以及采用的钻井抽采工艺设备,对比分析了与生产矿井地面钻井瓦斯抽采工艺的异同。然后,从废弃/关闭煤矿瓦斯抽采理论、技术和工艺设备等方面分析了研究中存在的不足:①瓦斯资源赋存空间和机理不明;②瓦斯资源量评估不精准;③瓦斯次生运移及动态积聚规律不清;④瓦斯抽采渗流及运移规律研究不充分;⑤瓦斯抽采关键技术不成熟;⑥地面钻井工艺设备不全面;⑦瓦斯抽采系统不完善。最后,凝练提出了未来的研究方向:揭示不同影响因素下的遗留瓦斯资源赋存特征与运移机理,构建废弃煤矿瓦斯储量与资源精准预测理论模型,阐明遗留瓦斯次生运移聚集范围分布特征及演化过程,丰富完善地面抽采过程中遗留瓦斯渗流及运移规律研究理论,逐步优化废弃煤矿地面瓦斯抽采技术体系,系统升级废弃煤矿瓦斯地面钻井工艺设备,逐步实现废弃煤矿地面钻井工艺智能化,深入改进废弃煤矿地面瓦斯抽采工艺设备。废弃/关闭煤矿瓦斯资源的精准与安全开发研究,对于提升废弃/关闭煤矿安全水平、促进能源结构调整、保障国家能源安全和推动经济持续健康发展具有重大意义。 展开更多
关键词 废弃/关闭煤矿 遗留瓦斯 赋存特征 瓦斯抽采 工艺设备
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南海主要断裂(带)与构造分区 被引量:1
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作者 邱燕 杜文波 +3 位作者 鞠东 韩冰 马浩明 胡小三 《海洋地质与第四纪地质》 北大核心 2025年第1期136-153,共18页
构造分区是区域构造演化研究的基础。由于区域性构造分区的界线基本上都以深大断裂(带)为依据,因此在划分构造单元之前,研究区域内规模较大的主要断裂(带)是必不可少的。本文在分析南海主要断裂(带)的基础上,以板块构造理论为指导,完善... 构造分区是区域构造演化研究的基础。由于区域性构造分区的界线基本上都以深大断裂(带)为依据,因此在划分构造单元之前,研究区域内规模较大的主要断裂(带)是必不可少的。本文在分析南海主要断裂(带)的基础上,以板块构造理论为指导,完善了南海的构造分区。南海主要断裂(带)分为以俯冲带、碰撞带、大型逆冲带、大型走滑带为特征的一级断裂带;切穿沉积基底与上地壳、延伸至下地壳的二级断裂带;错断沉积基底的三级断裂。本区一级构造单元为“南海次板块”,其边界基本以一级断裂带,个别以二级断裂带为界;二级构造单元有微板块、断阶带、隆起区、深坳带、深坳区、碰撞带等;三级构造单元在微板块之内划分为隆坳带和微地块。 展开更多
关键词 主要断裂(带) 构造活动 构造分区 南海
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美国舞蹈教育与体育教育的百年共生发展研究 被引量:1
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作者 胡曦 毕鑫 +1 位作者 陈芳 李芳 《成都体育学院学报》 北大核心 2025年第1期115-127,共13页
美国舞蹈教育深深植根于体育教育,100多年来,无论是在高等学校还是中小学,舞蹈教育与体育教育一直相互依存、斗争妥协,体现出“共生效应”。文章基于社会共生论的视角,从共同的身体活动形式起源,到舞蹈高等教育在体育教育中的发端、脱... 美国舞蹈教育深深植根于体育教育,100多年来,无论是在高等学校还是中小学,舞蹈教育与体育教育一直相互依存、斗争妥协,体现出“共生效应”。文章基于社会共生论的视角,从共同的身体活动形式起源,到舞蹈高等教育在体育教育中的发端、脱离与新联系的建立,再到中小学舞蹈教育和体育教育的“体艺融合”历史与现实,系统梳理了美国舞蹈教育和体育教育百年共生的历程。高等教育中舞蹈类专业课程的设置、舞蹈类跨学科专业的开设以及中小学舞蹈教育与体育教育的“体艺融合”等方面值得我们借鉴。 展开更多
关键词 美国 体育教育 舞蹈教育 百年共生 融合发展
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融合寿命信息与多性能退化信息的元动作单元可靠性评估 被引量:1
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作者 冉琰 吉昱 朱晓 《湖南大学学报(自然科学版)》 北大核心 2025年第2期109-121,共13页
针对机床可靠性建模困难、可靠性数据匮乏等问题,从元动作单元出发,提出一种融合寿命信息与多性能退化信息的可靠性评估方法.利用“功能—运动—动作”(functionmotion-action,FMA)分解法将机床分解至最小运动单元,即元动作单元,机床的... 针对机床可靠性建模困难、可靠性数据匮乏等问题,从元动作单元出发,提出一种融合寿命信息与多性能退化信息的可靠性评估方法.利用“功能—运动—动作”(functionmotion-action,FMA)分解法将机床分解至最小运动单元,即元动作单元,机床的可靠性水平通过准确评估关键元动作单元的可靠性来保证.建立随机效应下非线性Wiener过程的性能退化模型,刻画试验样本退化过程存在的个体差异性、共同属性以及退化过程的非线性,在此基础上针对退化数据不足的问题,利用贝叶斯方法建立融合失效寿命信息的可靠性模型.考虑多性能退化失效相关性,基于Copula函数建立多性能退化可靠性评估模型,利用MCMC-Gibbs抽样算法实现参数估计.以某型号数控滚齿机的蜗杆转动元动作单元为研究对象,通过实例分析以及验证对比表明所提可靠性评估方法的可行性和优越性. 展开更多
关键词 可靠性 信息融合 随机过程 元动作单元 贝叶斯方法
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大作业观视角下的生物学单元作业设计与实践 被引量:1
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作者 张凌霞 张锋 《生物学教学》 北大核心 2025年第4期54-57,共4页
以“遗传信息的传递”单元为例,阐述单元作业设计与实践路径包括:以概念进阶为线索,通过制订素养指向的单元作业目标,实现单元作业的大取向;基于真实性的大情境及多重情境编制,形成课前、课中和课后作业链,实现单元作业的大设计;在完成... 以“遗传信息的传递”单元为例,阐述单元作业设计与实践路径包括:以概念进阶为线索,通过制订素养指向的单元作业目标,实现单元作业的大取向;基于真实性的大情境及多重情境编制,形成课前、课中和课后作业链,实现单元作业的大设计;在完成作业的过程中,通过融入以学习化评估为主导的学本评估,实现单元作业的大评价。旨在学生深刻理解与运用生物学概念性知识,发展科学思维能力与科学探究能力。 展开更多
关键词 大作业观 单元作业 概念进阶 遗传信息 情境
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我国水稻大面积单产提升面临的现实困境与出路 被引量:1
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作者 徐春春 纪龙 +2 位作者 陈中督 李丹 方福平 《中国稻米》 北大核心 2025年第4期1-4,共4页
我国水稻年度间、品种间、区域间生产水平存在明显差异,水稻单产还有较大提升空间。当前,我国水稻单产提升面临重大突破性品种短缺、轻简型高产技术储备不足、标准化技术落实难到位难、灾害防控技术创新不足等突出问题,需要从品种选育... 我国水稻年度间、品种间、区域间生产水平存在明显差异,水稻单产还有较大提升空间。当前,我国水稻单产提升面临重大突破性品种短缺、轻简型高产技术储备不足、标准化技术落实难到位难、灾害防控技术创新不足等突出问题,需要从品种选育、技术集成、技术推广和防灾减灾等四方面协同发力,切实将科技潜力转化为现实产量、区试产量转化为农民产量,推动稻谷产能持续提升。 展开更多
关键词 水稻 大面积单产 品种选育 技术集成 防灾减灾
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