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亚马逊棋中评估函数的研究 预览
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作者 陈萱华 杨玲 《电脑知识与技术:学术版》 2019年第3Z期224-226,共3页
机器博弈是人工智能的重要领域,国内外普遍采用棋类作为研究机器博弈技术的载体。以亚马逊棋为载体,总结了实现亚马逊棋机器博弈的几个基本部分,并着重对亚马逊棋对局中用于评定招法优劣的评估函数做了初步研究。在处理评估函数时用到... 机器博弈是人工智能的重要领域,国内外普遍采用棋类作为研究机器博弈技术的载体。以亚马逊棋为载体,总结了实现亚马逊棋机器博弈的几个基本部分,并着重对亚马逊棋对局中用于评定招法优劣的评估函数做了初步研究。在处理评估函数时用到了领地评估特征territory、位置特征position、灵活度特征mobility三个评估特征,并提出使用关于回合数的一次函数加权的计算模型,最后通过实验进行了调参和检验。 展开更多
关键词 亚马逊棋 评估函数 TERRITORY POSITION MOBILITY
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Improving Mobility on Segments with Closely Spaced Intersections in Urban Areas 预览
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作者 Stephen A. Arhin Adam Gatiba +2 位作者 Melissa Anderson Melkamsew Ribbisso Babin Manandhar 《土木工程期刊(英文)》 2019年第1期46-56,共11页
In this research, a strategy to improve mobility and reduce delay on road segments is explored via modeling and simulation. Thirty selected corridors with combination of signalized and unsignalized intersections were ... In this research, a strategy to improve mobility and reduce delay on road segments is explored via modeling and simulation. Thirty selected corridors with combination of signalized and unsignalized intersections were identified for this study. Each segment consists of at least one AWSC and two signalized intersections at which field data were obtained (lane configurations, signal timing, traffic volumes, etc.). The selected AWSC intersections on the segments were within 305 m (1000 feet) from the upstream or downstream signalized intersections. Synchro software program was utilized to model the existing condition of the segments based on which the strategy for mobility improvement was explored. The field data were used as input in Synchro software application to model two scenarios: existing or the “before” scenario, and the “after” scenario. The unsignalized intersections were signalized (and optimized) in the “after” scenario. The measures of effectiveness used to assess the efficiency of the strategy were average travel speed, control delay and 95th percentile queue length. The analyses were conducted for both the morning (AM) and evening (PM) peak periods. The results of the analyses showed reductions in control delay and 95th percentile queue lengths that were statistically significant, while the average travel speed of vehicles significantly increased at 5% level of significance. The evaluation determined that the signalization of some unsignalized intersections (which are 305 m or less from existing signalized intersections) may improve mobility despite the fact that these locations do not meet the MUTCD warrants for signalization. These findings would aid transportation engineers and planners to consider and evaluate this option when making decisions on signalization of intersections in urban areas. 展开更多
关键词 MOBILITY THROUGHPUT Control Delay AVERAGE System TRAVEL Speed Level of Service
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Practical Application of a Tongue-Operated Joystick Device with Force Feedback Mechanism 预览
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作者 Shinya Kajikawa Taku Ohba 《智能控制与自动化(英文)》 2019年第3期90-106,共17页
The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs an... The human tongue has superior movement and tactile sensations. For individuals with severe disabilities, a tongue operated interface device can be used to operate life-support equipment, such as powered wheelchairs and robotic manipulators. A joystick-type device can directly translate various tongue motions to external equipment behavior. In addition, the user can interactively communicate with the equipment by tactile feedback. This helps the user to control the equipment safely and skillfully. Considering these factors, in a previous study [1], we developed a novel tongue-operated joystick device with reaction force feedback mechanism. We described the design process including the analysis of human tongue movement and tactile sensations and showed fundamental performances of reaction force feedback with the prototype device. In this study, we discuss the shape of the operational part that is used by the tongue. Two types of operational tools are prepared and their operability and perception of reaction force feedback are compared. Furthermore, we confirm the effectiveness of reaction force feedback to operate the joystick device safely and skillful controlling a mobile robot in an unknown environment. 展开更多
关键词 TONGUE JOYSTICK TACTILE SENSATION MOBILITY Reaction Force FEEDBACK
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迈向流动性治理:新地域空间的理论重构及其行动策略
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作者 吴越菲 《学术月刊》 CSSCI 北大核心 2019年第2期86-95,共10页
流动社会的来临不仅在根本上冲击着传统的地域假定和治理模式,更是将'地域性'和'流动性'之间的关系问题推向了全球治理变革的前沿地带。20世纪80年代以来,流动性与地域性在地域空间理论的变革中相互关联,并在地域实践... 流动社会的来临不仅在根本上冲击着传统的地域假定和治理模式,更是将'地域性'和'流动性'之间的关系问题推向了全球治理变革的前沿地带。20世纪80年代以来,流动性与地域性在地域空间理论的变革中相互关联,并在地域实践中交织出了全新的治理模式-流动性治理。地域空间理论重新赋予了地域以全面的流动属性,并促动了地域治理的实践变革。流动性治理并非是对'地域'这一治理空间单元的根本性解构,而是形成了一套全新的地域治理范式。 展开更多
关键词 流动性 流动性治理 新地域空间 地域治理
航天试验信息网络战时生存能力研究 预览
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作者 黄雅琳 王宇 《计算机与网络》 2019年第10期62-65,共4页
航天试验信息网络主要面向常规航天科研试验任务,战时生存能力相对有限,不能适应未来战争环境。分析了未来战争的发展趋势,提出航天试验信息网络面对的战场威胁模型,对航天试验信息网络现状及战时生存能力综合分析的基础上,综合运用传... 航天试验信息网络主要面向常规航天科研试验任务,战时生存能力相对有限,不能适应未来战争环境。分析了未来战争的发展趋势,提出航天试验信息网络面对的战场威胁模型,对航天试验信息网络现状及战时生存能力综合分析的基础上,综合运用传输技术、交换技术、网络管理技术和安全保密技术,提出了满足战场环境需求的航天试验信息网络体系架构。 展开更多
关键词 航天试验信息网络 战时生存能力 机动性 抗毁性 抗干扰
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泌阳凹陷页岩油富集及可动性探讨 预览
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作者 冯国奇 李吉君 +3 位作者 刘洁文 章新文 余志远 谭静娟 《石油与天然气地质》 EI CAS CSCD 北大核心 2019年第6期1236-1246,共11页
中国陆相页岩油资源丰富,但近年来的开发实践并没有取得预期的效果。针对这一问题,本文应用显微镜薄片观察、岩石热解、低温氮气吸附、页岩油吸附实验、高压压汞和核磁共振等实验对泌阳凹陷页岩油富集及可动性主控因素进行了研究。结果... 中国陆相页岩油资源丰富,但近年来的开发实践并没有取得预期的效果。针对这一问题,本文应用显微镜薄片观察、岩石热解、低温氮气吸附、页岩油吸附实验、高压压汞和核磁共振等实验对泌阳凹陷页岩油富集及可动性主控因素进行了研究。结果表明:页岩油富集层段TOC含量较高,无机大孔隙较为发育。页岩油富集时饱和烃含量较高,沥青质含量较低,由此页岩油的可动性较好。粘土矿物是页岩比表面积的主要贡献者,是页岩油吸附的主要载体,粘土矿物含量越低,页岩油的可动性越好。泌阳凹陷纵向上页岩油富集的最佳深度为2 800 m,页岩油在3 000 m以深API度较高,粘度较低,具较好的可动性。泌页HF1井、安深1井深度为2 400~2 500 m,还未达到页岩油富集、可动的最佳深度段,不利于页岩油的开采。高温条件下小分子烃吸附能力较弱,深层(3 000 m以深)是该区未来的有利勘探目标。泌阳凹陷地层压力系数较小,高声波时差主要是高TOC的反映。 展开更多
关键词 可动性 储集能力 油气富集 页岩油 泌阳凹陷 南襄盆地
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Mobility impact on compensation performance of AMOLED pixel circuit using IGZO TFTs 预览
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作者 Congwei Liao 《半导体学报:英文版》 EI CAS CSCD 2019年第2期33-38,共6页
The suitability of indium gallium zinc oxide(IGZO) thin-film transistors(TFT) for implementation of active matrix display of organic light emitting diodes(AMOLED) compensation pixel circuits is addressed in this paper... The suitability of indium gallium zinc oxide(IGZO) thin-film transistors(TFT) for implementation of active matrix display of organic light emitting diodes(AMOLED) compensation pixel circuits is addressed in this paper. In particular, the impact of mobility on compensating performance for the implementation in AMOLED pixel circuits is investigated. Details of the effective mobility modeling using the power law of gate-to-source voltage are provided, and parameters are extracted according to the measured current-to-voltage data of IGZO TFT samples. The investigated AMOLED pixel circuit consists of 4 switching TFTs, 1 driving TFT, and 1 capacitor. A 'source-follower' structure is used for the threshold voltage extraction of the driving transistor. A new timing diagram is proposed;thus the current error of the pixel circuit is almost independent of the effective mobility. But, to improve the precision of the threshold voltage extraction of the driving transistor, the mobility is required to be greater than5 cm2 V-1 s-1. On the other hand, the optimized storage capacitance is reversely proportional to the effective mobility. Thus, the layout area of the pixel circuit can be decreased from 100 × 100 to 100 × 68 μm2, with the effective mobility increased from 10 to50 cm2 V-1 s-1. Therefore, IGZO TFT is a good alternative backplane technology for AMOLED displays, and a higher effective mobility is preferred for high compensation performance and compact layout. 展开更多
关键词 IGZO TFT PIXEL circuit MOBILITY
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Fe-substituted Ba-hexaaluminate with enhanced oxygen mobility for CO2 capture by chemical looping combustion of methane 预览
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作者 Fei Huang Ming Tian +5 位作者 Yanyan Zhu Xiaodong Wang Aiqin Wang Lin Li Jian Lin Junhu Wang 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第2期50-57,共8页
While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur afte... While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba FexAl12– xO19,denoted as BFxA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BFxA-C,x = 1 and 2) but also high CO2 selectivity above 92% during the nearly whole reduction from Fe3+ to Fe2+.Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe5(O–Fe5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BFxA-H. 展开更多
关键词 CO2 CAPTURE Chemical LOOPING CH4 conversion Oxygen MOBILITY FE-BASED HEXAALUMINATE
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文化反恐的基本特点研究 预览
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作者 李明 艾恒平 《辽宁公安司法管理干部学院学报》 2019年第1期18-23,共6页
文化反恐是指运用文化进行反恐或者在文化领域进行的反恐斗争,是各种形态反恐斗争的基本构成部分之一。文化恐怖主义具有隐蔽性强和欺骗性大等特点,因此有必要基于理论高度,围绕文化反恐的特点进行深入研究,使人们能够进一步理解文化反... 文化反恐是指运用文化进行反恐或者在文化领域进行的反恐斗争,是各种形态反恐斗争的基本构成部分之一。文化恐怖主义具有隐蔽性强和欺骗性大等特点,因此有必要基于理论高度,围绕文化反恐的特点进行深入研究,使人们能够进一步理解文化反恐的本质,从而筑牢底线,有效防范敌对势力利用文化在意识形态领域进行渗透和破坏,提高人们运用文化进行反恐斗争的能力。 展开更多
关键词 文化反恐 特点 行动力
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右美托咪定复合罗哌卡因甲钴胺混合液治疗肩周炎疗效观察
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作者 任丹凤 曹敏芳 +1 位作者 王冬燕 王芳 《中国预防医学杂志》 CAS CSCD 2019年第4期308-311,共4页
目的观察B超引导下局部注射右美托咪定+罗哌卡因治疗肩周炎的治疗效果。方法选取2015年11月至2017年3月,杭州市萧山区第一人民医院收治的100例肩周炎患者,随机分为治疗组和对照组,每组50例,均采用在B超引导下混合液分别注射于肩岬上神... 目的观察B超引导下局部注射右美托咪定+罗哌卡因治疗肩周炎的治疗效果。方法选取2015年11月至2017年3月,杭州市萧山区第一人民医院收治的100例肩周炎患者,随机分为治疗组和对照组,每组50例,均采用在B超引导下混合液分别注射于肩岬上神经和喙突、岗下肌、小圆肌。治疗组混合液为0.5mg/L右美托咪定+0.1%罗哌卡因+甲钴胺1mg;对照组混合液为0.1%罗哌卡因+甲钴胺1mg。观察治疗后效果从注入药物起开始计时,注射后15min、24h、 1周、1月的效果。比较两组的疗效、NRS疼痛评分、运动阻滞评分、肩关节活动度评分、血流动力学、复发率和再治疗率、不良反应。结果治疗组与对照组相比,治疗组总有效率较高(χ^2=6.06,P<0.05),治疗组NRS疼痛评分低于对照组(P<0.05),关节活动度评分高于治疗组(P<0.05)。治疗组运动阻滞情况优于对照组(Z=12.34,P<0.01)。治疗组复发3例,再治疗3例,对照组复发10例,再治疗11例,对照组复发率和再治疗率均高于治疗组(P<0.05)。两组不良反应发生率比较差异无统计学意义(P>0.05)。结论在疼痛改善,活动度改善等方面右美托咪定组疗效优于对照组,且无明显血流动力学影响。 展开更多
关键词 B超引导 右美托咪定 罗哌卡因 联合治疗 肩周炎 疼痛 活动度
数字地面广播移动接收场景下层分复用技术性能分析 预览
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作者 张宇 刘润楠 解伟 《广播与电视技术》 2019年第6期115-120,共6页
随着视频内容的解析度不断提高,视频数据流量成倍增长。现有的单信道传输能力已经接近香农理论极限,基于时空编码的信道复用技术不适合广播行业大尺度覆盖场景,因此需要寻找新的信道复用技术大幅提高信道容量满足新的广播传输需求。层... 随着视频内容的解析度不断提高,视频数据流量成倍增长。现有的单信道传输能力已经接近香农理论极限,基于时空编码的信道复用技术不适合广播行业大尺度覆盖场景,因此需要寻找新的信道复用技术大幅提高信道容量满足新的广播传输需求。层分复用技术在能量这个新的维度上进行信道复用,能够在现有技术的基础上大幅提升广播传输速率与频谱利用率,成为下一代广播技术的研究重点。但是该技术在接收机高速移动场景下性能明显下降,需要针对性地消除由于接收机的移动而引入的干扰。本文介绍并分析了两种不同的干扰消除方法,给出了未来的研究方向。 展开更多
关键词 层分复用 频谱效率 移动性 干扰消除
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High mobility group box-1 release from H2O2-injured hepatocytes due to sirt1 functional inhibition 预览
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作者 Ting-Jie Ye Yan-Lin Lu +2 位作者 Xiao-Feng Yan Xu-Dong Hu Xiao-Ling Wang 《世界胃肠病学杂志:英文版》 SCIE CAS 2019年第36期5434-5450,共17页
BACKGROUND High mobility group box-1 (HMGB1), recognized as a representative of damageassociated molecular patterns, is released during cell injury/death, triggering the inflammatory response and ultimately resulting ... BACKGROUND High mobility group box-1 (HMGB1), recognized as a representative of damageassociated molecular patterns, is released during cell injury/death, triggering the inflammatory response and ultimately resulting in tissue damage. Dozens of studies have shown that HMGB1 is involved in certain diseases, but the details on how injured hepatocytes release HMGB1 need to be elicited. AIM To reveal HMGB1 release mechanism in hepatocytes undergoing oxidative stress. METHODS C57BL6/J male mice were fed a high-fat diet for 12 wk plus a single binge of ethanol to induce severe steatohepatitis. Hepatocytes treated with H2O2 were used to establish an in vitro model. Serum alanine aminotransferase, liver H2O2 content and catalase activity, lactate dehydrogenase and 8-hydroxy-2- deoxyguanosine content, nicotinamide adenine dinucleotide (NAD+) levels, and Sirtuin 1 (Sirt1) activity were detected by spectrophotometry. HMGB1 release was measured by enzyme linked immunosorbent assay. HMGB1 translocation was observed by immunohistochemistry/immunofluorescence or Western blot. Relative mRNA levels were assayed by qPCR and protein expression was detected by Western blot. Acetylated HMGB1 and poly(ADP-ribose)polymerase 1 (Parp1) were analyzed by Immunoprecipitation. RESULTS When hepatocytes were damaged, HMGB1 translocated from the nucleus to the cytoplasm because of its hyperacetylation and was passively released outside both in vivo and in vitro. After treatment with Sirt1-siRNA or Sirt1 inhibitor (EX527), the hyperacetylated HMGB1 in hepatocytes increased, and Sirt1 activity inhibited by H2O2 could be reversed by Parp1 inhibitor (DIQ). Parp1 and Sirt1 are two NAD+-dependent enzymes which play major roles in the decision of a cell to live or die in the context of stress . We showed that NAD+ depletion attributed to Parp1 activation after DNA damage was caused by oxidative stress in hepatocytes and resulted in Sirt1 activity inhibition. On the contrary, Sirt1 suppressed Parp1 by negatively regulating its gene expression and deace 展开更多
关键词 Sirtuin1 Poly ADP-RIBOSE POLYMERASE 1 High MOBILITY group box-1 HEPATOCYTES Hydrogen PEROXIDE
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图书馆移动服务使用意愿影响因素实证研究——基于信息安全感知和移动性等变量的技术接受模型 预览 被引量:2
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作者 徐向东 何丹丹 《图书馆》 CSSCI 北大核心 2019年第2期79-85,共7页
文章根据当今移动互联网环境下用户使用图书馆移动服务的具体情景和感知行为深入分析,在TAM理论基础上,充分关注用户泛在化和信息安全感知等新一代信息技术背景下的互联网相关情景因素,并通过实证研究证明了信息安全感知和移动性对用户... 文章根据当今移动互联网环境下用户使用图书馆移动服务的具体情景和感知行为深入分析,在TAM理论基础上,充分关注用户泛在化和信息安全感知等新一代信息技术背景下的互联网相关情景因素,并通过实证研究证明了信息安全感知和移动性对用户感知易用性和感知有用性有重要影响,同时得出了与以往研究不同的观点:网络外部性对感知易用性影响不显著,感知成本对使用意愿影响不显著等。 展开更多
关键词 图书馆移动服务 TAM 信息安全感知 移动性
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Integrating GPS trajectory and topics from Twitter stream for human mobility estimation
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作者 Satoshi MIYAZAWA Xuan SONG +2 位作者 Tianqi XIA Ryosuke SHIBASAKI Hodaka KANEDA 《中国计算机科学前沿:英文版》 SCIE EI CSCD 2019年第3期460-470,共11页
Understanding urban dynamics and large-scale human mobility will play a vital role in building smart cities and sustainable urbanization. Existing research in this domain mainly focuses on a single data source (e.g., ... Understanding urban dynamics and large-scale human mobility will play a vital role in building smart cities and sustainable urbanization. Existing research in this domain mainly focuses on a single data source (e.g., GPS data, CDR data, etc.). In this study, we collect big and heterogeneous data and aim to investigate and discover the relationship between spatiotemporal topics found in geo-tagged tweets and GPS traces from smartphones. We employ Latent Dirichlet Allocation-based topic modeling on geo-tagged tweets to extract and classify the topics. Then the extracted topics from tweets and temporal population distribution from GPS traces are jointly used to model urban dynamics and human crowd flow. The experimental results and validations demonstrate the efficiency of our approach and suggest that the fusion of cross-domain data for urban dynamics modeling is more practical than previously thought. 展开更多
关键词 GPS TRAJECTORY HUMAN MOBILITY SNS locationbased social network (LBSN) TOPIC modeling data mining SPATIOTEMPORAL TOPIC
Effect of defects properties on InP-based high electron mobility transistors
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作者 孙树祥 常明铭 +6 位作者 李梦珂 马刘红 钟英辉 李玉晓 丁芃 金智 魏志超 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期529-533,共5页
The performance damage mechanism of InP-based high electron mobility transistors(HEMTs) after proton irradiation has been investigated comprehensively through induced defects.The effects of the defect type, defect ene... The performance damage mechanism of InP-based high electron mobility transistors(HEMTs) after proton irradiation has been investigated comprehensively through induced defects.The effects of the defect type, defect energy level with respect to conduction band ET, and defect concentration on the transfer and output characteristics of the device are discussed based on hydrodynamic model and Shockley–Read–Hall recombination model.The results indicate that only acceptorlike defects have a significant influence on device operation.Meanwhile, as defect energy level ETshifts away from conduction band, the drain current decreases gradually and finally reaches a saturation value with ETabove 0.5 eV.This can be attributed to the fact that at sufficient deep level, acceptor-type defects could not be ionized any more.Additionally,the drain current and transconductance degrade more severely with larger acceptor concentration.These changes of the electrical characteristics with proton radiation could be accounted for by the electron density reduction in the channel region from induced acceptor-like defects. 展开更多
关键词 InP-based high electron mobility transistor PROTON radiation DEFECTS PROPERTIES output and transfer characteristics
Waveflex半刚性内固定治疗腰椎间盘突出症的生物力学优势 预览
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作者 甘东浩 乔全来 +3 位作者 陈德强 谭国庆 薛海鹏 徐展望 《中国组织工程研究》 CAS 北大核心 2019年第36期5830-5835,共6页
背景:腰椎动态固定多为早期临床研究,但其中期疗效及力学机制分析研究较少。目的:评价Waveflex内固定系统的临床疗效,分析其生物力学优势,为临床应用及动态固定理论研究奠定基础。方法:回顾性分析2015年9月至2018年10月于山东中医药大... 背景:腰椎动态固定多为早期临床研究,但其中期疗效及力学机制分析研究较少。目的:评价Waveflex内固定系统的临床疗效,分析其生物力学优势,为临床应用及动态固定理论研究奠定基础。方法:回顾性分析2015年9月至2018年10月于山东中医药大学附属医院骨科行髓核摘除Waveflex半刚性内固定治疗并随访的腰椎间盘突出症患者,所有患者对治疗方案均知情同意,且得到医院伦理委员会批准。统计分析患者术前、术后及末次随访的目测类比评分和Oswestry功能障碍指数、腰椎前凸角、椎间隙高度、椎间孔高度和椎间隙退变UCLA分级,评价置入半刚性内固定的临床疗效。构建完整及置入Waveflex半刚性内固定腰椎模型,进行有限元分析,评价Waveflex半刚性内固定模型的生物力学性能,结合临床统计观察验证其安全、有效性。结果与结论:①Waveflex半刚性固定可有效改善患者临床症状,维持腰椎稳定性和活动度,临床疗效肯定;②Waveflex系统可承担较大应力,有效减轻手术节段椎间盘应力,延缓腰椎退变;③总的来说,Waveflex半刚性内固定既可维持固定节段的稳定性,又有一定的活动度,可有效减缓固定节段退变。 展开更多
关键词 腰椎间盘突出症 Waveflex 半刚性内固定 腰椎稳定性 活动度 有限元分析 应力
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对游动性的反思——评《游牧的终结?——内亚地区社会、国家与环境》 预览
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作者 阿妮尔 《内蒙古社会科学》 CSSCI 北大核心 2019年第2期204-212,共9页
在游牧大量消失的今天,汉弗莱与斯尼思在《游牧的终结?》一书中开创性地提出,作为草原畜牧业的关键技能,保持高度的游动性不仅可以避免草场退化,还可以与现代化、机械化与市场化相结合。汉弗莱等的观点虽然被广泛引述,却一直没有得到深... 在游牧大量消失的今天,汉弗莱与斯尼思在《游牧的终结?》一书中开创性地提出,作为草原畜牧业的关键技能,保持高度的游动性不仅可以避免草场退化,还可以与现代化、机械化与市场化相结合。汉弗莱等的观点虽然被广泛引述,却一直没有得到深入探究。在讨论汉弗莱等所提出的主要观点的同时,结合笔者的田野资料,指出汉弗莱等的研究存在忽略产权与草场退化的深层关联等多方面的局限,并总结了其对后续研究的启示。 展开更多
关键词 草原畜牧业 游动性 草场退化 现代化
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基于移动化安全监察管理新模式 预览
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作者 张智俊 李黎 《科技创新与应用》 2019年第31期195-196,共2页
国家对电力建设投入了更大的力度,促进其飞速发展。对于电力企业来说,移动化、信息化已成为其发展的主要趋势,同时也是在新经济形势下的重要发展机遇。所谓移动化,简而言之就是在移动通信网络和移动互络网的基础上构建综合通信平台,从... 国家对电力建设投入了更大的力度,促进其飞速发展。对于电力企业来说,移动化、信息化已成为其发展的主要趋势,同时也是在新经济形势下的重要发展机遇。所谓移动化,简而言之就是在移动通信网络和移动互络网的基础上构建综合通信平台,从而吸收利用更多的信息资源,在安全监察管理工作中加入多媒体、语音等服务功能,开发基于移动化的电力企业安全监察管理新模式。文章对此进行深入的探讨和分析,结合电力企业内、外部环境和影响因素,提出可靠的建议措施,为我国电力企业的发展和电力事业的进步,提供重要的支持和帮助。 展开更多
关键词 移动化 安全 监察管理
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Will Germany move into a situation with unsecured power supply?
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作者 Harald SCHWARZ 《能源前沿:英文版》 CSCD 2019年第3期551-570,共20页
Together with a huge number of other countries, Germany signed the Paris Agreements in 2015 to prevent global temperature increase above 2℃. Within this agreement, all countries defined their own national contributio... Together with a huge number of other countries, Germany signed the Paris Agreements in 2015 to prevent global temperature increase above 2℃. Within this agreement, all countries defined their own national contributions to CO2 reduction. Since that, it was visible that CO2 emissions in Germany decreased, but not so fast than proposed in this German nationally determined contribution to the Paris Agreement. Due to increasing traffic, CO2 emissions from this mobility sector increased and CO2 emission from German power generation is nearly constant for the past 20 years, even a renewable generation capacity of 112 GW was built up in 2017, which is much higher than the peak load of 84 GW in Germany. That is why the German National Government has implemented a commission (often called "The German Coal Commission") to propose a time line: how Germany can move out of coal-fired power stations. This "Coal Commission" started its work in the late spring of 2018 and handed over its final report with 336 pages to the government on January 26th, 2019. Within this report the following proposals were made:①Until 2022: Due to a former decision of the German Government, the actual remaining nuclear power generation capacity of about 10 GW has to be switched off in 2022. Besides, the "Coal Commission" proposed to switch off additionally in total 12.5 GW of both, hard coal and lignite-fired power plants, so that Germany should reduce its conventional generation capacity by 22.5 GW in 2022.②Until 2030: Another 13 GW of German hard coal or lignite-fired power plants should be switched off.③Until 2038:The final 17 GW of German hard coal or lignitefired power plants should be switched off until 2038 latest. Unfortunately the "Coal Commission" has not investigated the relevant technical parameter to ensure a secured electric power supply, based on German's own national resources. Because German Energy Revolution mainly is based on wind energy and photovoltaic, this paper will describe the negligible contribution of these sources 展开更多
关键词 CO2 reduction mobility sector RENEWABLE GENERATION coal COMMISSION secured POWER GENERATION capacity reliable POWER supply power-to-gas power-to-heat
Terahertz emission from layered GaTe crystal due to surface lattice reorganization and in-plane noncubic mobility anisotropy
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作者 Jiangpeng Dong Kevin-P. Gradwohl +5 位作者 Yadong Xu Tao Wang Binbin Zhang Bao Xiao Christian Teichert Wanqi Jie 《光子学研究:英文版》 CSCD 2019年第5期518-525,共8页
In this work, a model based on the optical rectification effect and the photocurrent surge effect is proposed to describe the terahertz emission mechanism of the layered GaTe crystal. As a centrosymmetric crystal, the... In this work, a model based on the optical rectification effect and the photocurrent surge effect is proposed to describe the terahertz emission mechanism of the layered GaTe crystal. As a centrosymmetric crystal, the optical rectification effect arises from the breaking of the inversion symmetry due to lattice reorganization of the crystal’s surface layer. In addition, the photocurrent surge originating from the unidirectional charge carrier diffusion-due to the noncubic mobility anisotropy within the layers-produces terahertz radiation. This is confirmed by both terahertz emission spectroscopy and electric property characterization. The current surge perpendicular to the layers also makes an important contribution to the terahertz radiation, which is consistent with its incident angle dependence. Based on our results, we infer that the contribution of optical rectification changes from 90%under normal incidence to 23% under a 40° incidence angle. The results not only demonstrate the terahertz radiation properties of layered GaTe bulk crystals, but also promise the potential application of terahertz emission spectroscopy for characterizing the surface properties of layered materials. 展开更多
关键词 GATE CRYSTAL surface lattice REORGANIZATION IN-PLANE noncubic MOBILITY
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