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An Improved Binary Wolf Pack Algorithm Based on Adaptive Step Length and Improved Update Strategy for 0-1 Knapsack Problems
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作者 Liting Guo Sanyang Liu 《国际计算机前沿大会会议论文集》 2017年第2期105-106,共2页
Binary wolf pack algorithm (BWPA) is a kind of intelligence algorithm which can solve combination optimization problems in discrete spaces.Based on BWPA, an improved binary wolf pack algorithm (AIBWPA) can be proposed... Binary wolf pack algorithm (BWPA) is a kind of intelligence algorithm which can solve combination optimization problems in discrete spaces.Based on BWPA, an improved binary wolf pack algorithm (AIBWPA) can be proposed by adopting adaptive step length and improved update strategy of wolf pack. AIBWPA is applied to 10 classic 0-1 knapsack problems and compared with BWPA, DPSO, which proves that AIBWPA has higher optimization accuracy and better computational robustness. AIBWPA makes the parameters simple, protects the population diversity and enhances the global convergence. 展开更多
关键词 BINARY WOLF PACK ALGORITHM 0-1 knapsack problem ADAPTIVE step length Update strategy
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Appraisal of Existing HIV/AIDs Prevention and Control Measures and Presentation of Innovative Strategies to End HIV/AIDS Epidemic by 2030
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作者 Mathias Tumwebaze John Rubaihayo Mpairwe Harold 《Open Journal of Epidemiology》 2023年第3期178-194,共17页
Background: Globally, UNAIDS report 2022 shows, there are 84.2 million people affected by HIV/AIDS and 40.1 million deaths from AIDS since the start of epidemic. In sub-Saharan Africa, women and girls accounted for 63... Background: Globally, UNAIDS report 2022 shows, there are 84.2 million people affected by HIV/AIDS and 40.1 million deaths from AIDS since the start of epidemic. In sub-Saharan Africa, women and girls accounted for 63% of all new HIV infections in 2021 with, six in seven new HIV infections among adolescents aged 15 - 19 years being girls. Key populations accounted for 70% of HIV infections globally in 2021, with 51% of these new HIV infections in sub-Saharan Africa. Reflecting on the 4 decades’ journey of HIV epidemic amidst local, national and international efforts, the UN target of ending AIDS as a public health threat by 2030 remains questionable unless new innovative ways are used. This study aimed at analyzing existing HIV/AIDS interventions, discuss UN interventions in line with ending HIV/AIDS by 2030 then, suggest and discuss new innovative ways of ending HIV scourge by 2030. Methods: Systematic literature review methodology was used to extract existing published information on HIV prevention strategies from 1981 to 2023. The articles were previewed by 2 experts for quality and grouped by intervention. Of the 637 articles accessed, on HIV prevention/control only 45 met the inclusion criteria. Data were synthesized using a narrative synthesis approach following standard guidelines on synthesis without meta-analysis. Descriptive analysis was done, strength and limitations were identified. UNAIDS recommendations for ending HIV/AIDS by 2030 identified and analyzed. New Innovations in HIV/AIDS were presented and discussed. The scope of the reviewed literature was limited to HIV preventive strategies practiced between 1981 and 2023. Results: Findings show that, Uganda’s HIV prevalence was at a peak in 1991 of 15% (30% among pregnant women in urban areas). ABC strategy is claimed to have turned sharply downward the prevalence through the mid-1990s and reached 5% (14% for pregnant urban women) by 2001. Analysis of the strategy showed that the achievements of the strategy could not be sustained, subsequently HIV prevalence rose again. This is because none of the ABC components can independently reduce HIV problem. In the real world, 100% abstinence has failed, condom use only reduces infection by 90% (WHO), and lifelong monogamy is impractical. Such limitations weaken ABC strategy. The study established that Post-exposure prophylaxis (PEP) i.e. taking HIV medicines within 72 hours (3 days) after a possible exposure to HIV infection is a safe, effective and a globally practiced HIV preventive intervention in emergency situations of HIV exposure. However, PEP is limited to care sought within 72 hours after exposure and yet timely access especially in rural areas and for key populations remains a big challenge. Oral PrEP was also identified as effective HIV preventive measure that can reduce HIV risk from sex by about 99% and from injection drug users by 74%. However, like PEP, timely access especially in rural areas and for key populations remains a big challenge. The UNAIDS 95-95-95 strategy (i.e. 95% of people know their HIV status, 95% with +HIV status be on sustained ART and 95% on ART get viral load suppression) formed the basis for setting the target of ending HIV/AIDS epidemic by 2030. However, our analysis shows that this target is unrealistic given the above highlighted limitations/ barriers in preventive measures and the unlikely perfect adherence (100%) to ART by all enrolled HIV positive persons. Conclusion: Ending HIV/AIDS by 2030 cannot be achieved by implementing the current preventing strategies and control measures. This study established that most of the existing HIV preventive strategies and control measures have a number of limitations. However, with sustained UN 95-95-95 strategy supplemented with additional innovative ways, there is hope that the UN dream of ending HIV/AIDS though not necessarily by 2030, can in the long run be achieved. 展开更多
关键词 HIV Prevention Innovative HIV Strategies UNAIDS 95-95-95 Ending HIV by 2030 ABC strategy
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跨情境词汇学习的偏态学习优势效应
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作者 石宇婧 黄艳利 +1 位作者 谢久书 刘书云 《心理科学》 CSCD 北大核心 2024年第3期538-545,共8页
词频分布对跨情境词汇学习至关重要。然而,以往研究主要考察了基于均匀分布的跨情境词汇学习,相对忽视了真实情境中基于Zipfian分布等偏态分布的跨情境词汇学习,而仅有的研究对Zipfian分布究竟促进还是抑制跨情境词汇学习争论激烈。为此... 词频分布对跨情境词汇学习至关重要。然而,以往研究主要考察了基于均匀分布的跨情境词汇学习,相对忽视了真实情境中基于Zipfian分布等偏态分布的跨情境词汇学习,而仅有的研究对Zipfian分布究竟促进还是抑制跨情境词汇学习争论激烈。为此,这项研究率先建立了学习机制的宏观视角,提出单个词汇的学习效果取决于学习环境中其他词汇的整体学习效果,据此首次提出基于互斥性策略的偏态学习优势效应,认为互斥性策略的有效使用是产生Zipfian频率促进效应的关键。 展开更多
关键词 跨情境词汇学习 语言学习 宏观学习视角 偏态学习 互斥性策略 词汇爆炸
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Strategy of Vodafone in New Service
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作者 王晖 《商情》 2009年第20期106-107,共2页
关键词 沃达丰 通信行业 服务策略 外部环境
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基于PESTEL模型的国产民用飞机制造产业链环境分析
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作者 李庆 《现代工业经济和信息化》 2024年第3期21-22,26,共3页
从政治、经济、社会、科技、生态环境和法律因素等宏观环境要素出发,对各个要素的动态变量进行分析,并与国外同行业竞争者进行对比,探索国产民用飞机产业链在各个宏观环境要素影响下面临的主要矛盾、风险和发展机会.
关键词 国产民用飞机 飞机制造产业链 PESTEL模型 宏观环境分析 发展规划 SWOT战略
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Generalized CAPP and synthetic evaluation strategy for production line of accuracy welding
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作者 孔谅 吴毅雄 《China Welding》 EI CAS 2007年第1期25-31,共7页
This paper presents generalized CAPP (G-CAPP) method which deals with macro process planning for multiobjective in the planning stage of production line of accuracy welding (PLAW) based on the features of accuracy... This paper presents generalized CAPP (G-CAPP) method which deals with macro process planning for multiobjective in the planning stage of production line of accuracy welding (PLAW) based on the features of accuracy welding production ( AWP ). G-CAPP offers foundations for prototype design and general equipment sorting, production capacity predication and production analysis by means of simulation and optimization. A synthetic hierarchy evaluation (SHE) model for G-CAPP established according to the planning objective is utilized to estimate the alternate processing plans by using membership function and analytic hierarchy process (AHP) of operational theory. The assembly welding line of hydraulic torque converter (HTC) is as an example of typical A WP to explicate G-CAPP and synthetic evaluating strategy of PLAW. The feasible and rational process configuration strategies of HTC assembly welding line are pointed oat under different planning objective. 展开更多
关键词 generalized CAPP accuracy welding production line macro planning synthetic evaluation strategy
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The Characteristics of Putaohua Reservoir and Development Strategies in Xujiaweizi Baxin Oilfield
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作者 GUO Qingxia(Exploration and Development Research Institute of Daqing Oilfield, Heilongjiang 163453, P. R.China)YANG Haibo( The Advanced Personnel Training Center of Daqing Oilfield, Heilongjiang 163453, P,R, China) 《Global Geology》 2002年第1期89-95,共7页
With the using of new full 3 - D interpretative technology, the carefully interpretation of the micro - amplitude structures and faults by the reprocessed 3 -D seismic data in IES (Interactive Exploration System) inte... With the using of new full 3 - D interpretative technology, the carefully interpretation of the micro - amplitude structures and faults by the reprocessed 3 -D seismic data in IES (Interactive Exploration System) interpretative system of Sun workstation is obtained. Because of the application of the well - advanced predictive technique for reservoir lithological changes, the predictive accuracy rate of drilling for 31 wells drilled in 1996 achieved 100 % and the economic and social benefits are desirable. 展开更多
关键词 Full 3 - D MICRO - AMPLITUDE structure strategy
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语篇模式视角下提升高中学生语篇宏观理解能力的案例分析与教学建议--以2021年高考英语(天津卷)为例
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作者 李留建 高翔 +2 位作者 姚卫盛 刘欣 杨琳 《考试研究》 2022年第2期1-15,共15页
从课堂中关注语篇的宏观视角——语篇模式出发,以2021年高考英语(天津卷)3月及6月考试阅读理解及阅读表达分测试各项数据为例,探讨语篇模式研究的重要性,在厘清语篇、语篇分析与语篇模式分析内涵基础上,例析两次考试分测试的典型语篇及... 从课堂中关注语篇的宏观视角——语篇模式出发,以2021年高考英语(天津卷)3月及6月考试阅读理解及阅读表达分测试各项数据为例,探讨语篇模式研究的重要性,在厘清语篇、语篇分析与语篇模式分析内涵基础上,例析两次考试分测试的典型语篇及试题,提出基于语篇模式的阅读教学策略,以提升一线教师的教学效率。 展开更多
关键词 语篇模式 宏观理解 策略
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Vitamin A supplement: a key strategy to prevent vitamin A deficiency among young children in Afghanistan
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作者 Ahmad Mujtaba Barekzai Abdullah Sahar Naseer Ahmad Shinwari 《Food Therapy and Health Care》 2022年第2期4-9,共6页
Background:Vitamin A deficiency is the main problem of public health worldwide demonstrated that 190 million population of preschool children and 122 countries(in Africa and South-East Asia)have vitamin A deficiency,a... Background:Vitamin A deficiency is the main problem of public health worldwide demonstrated that 190 million population of preschool children and 122 countries(in Africa and South-East Asia)have vitamin A deficiency,according to recent estimated research.In Afghanistan,vitamin A supplementation is a key strategy to prevent vitamin A deficiency among young children.Children receive vitamin A supplements as part of National Immunization Days(NID)campaigns.Methods:In this case study,the data was collected from June 15/2015 to February 23/2016,and the final report of the Afghanistan Demographic Health Survey(AfDHS)2015 was released on February 15/2017.All 27,209 children aged 6-59 months who are living with their mothers were included in this study.Who consumed foods rich in vitamin A was not included in this study.Results:The percentages who were given vitamin A supplements in the last 6 months among all children 6-59 months aged.A total of 1,572 children aged among 6-8 months were given vitamin A supplements 670(42.6%)children and comparison with the total community of the study(27,209)children(2.46%).A total of 1,148 children aged among 9-11 months were given vitamin A supplements to 465(40.5%)children and comparison with the total community of the study(27,209)children(1.70%).Conclusion:After following up on more studies,we found that vitamin A deficiency is a public problem,thus it is better to use wheat flour fortification,vitamin A capsule(VAC)supplementation,nutrition education,source of vitamin A,and training of primary healthcare workers on the clinical to prevent and treat the vitamin A deficiency among children.Therefore,we aimed to determine the given vitamin A supplementation among children aged 6-59 months in 33 provinces in Afghanistan,in 2015. 展开更多
关键词 vitamin A deficiency SUPPLEMENT children age 6-59 months key strategy
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抖音短视频对城市形象的传播及优化策略以盐城市为例 被引量:2
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作者 姚永明 《盐城师范学院学报(人文社会科学版)》 2023年第3期116-124,共9页
随着新媒体的快速发展,短视频作为一种新兴的传播方式,为民众参与社会话题讨论提供了途径,也为民众在城市的建设中争取了越来越多的话语权。抖音作为短视频播放的主流平台之一,已影响到人们生活的方方面面。无论是从官方还是民众的角度... 随着新媒体的快速发展,短视频作为一种新兴的传播方式,为民众参与社会话题讨论提供了途径,也为民众在城市的建设中争取了越来越多的话语权。抖音作为短视频播放的主流平台之一,已影响到人们生活的方方面面。无论是从官方还是民众的角度,合理使用抖音都可以对城市形象的传播起到积极作用。对盐城城市形象进行分析,了解官方与民众在城市传播形象中的话语体系,可以优化抖音在城市形象传播中的策略。 展开更多
关键词 微宏观视角 抖音 短视频 城市形象 传播策略
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Synergetic Alkoxy Side-Chain and Chlorine-Contained End Group Strategy toward High Performance Ultra-Narrow Bandgap Small Molecule Acceptors 被引量:1
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作者 Qingya Wei Songting Liang +6 位作者 Beibei Qiu Wei Liu Xiang Xu Xinhui Lu Yuang Fu Jun Yuan Yingping Zou 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第20期2664-2670,共7页
Ultra-narrow bandgap(ultra-NBG)small molecule acceptors(SMAs)show great potential in organic solar cells(OSCs)due to the extended near-infrared(NIR)absorption.In this work,a synergetic alkoxy side-chain and chlorine-c... Ultra-narrow bandgap(ultra-NBG)small molecule acceptors(SMAs)show great potential in organic solar cells(OSCs)due to the extended near-infrared(NIR)absorption.In this work,a synergetic alkoxy side-chain and chlorine-contained end group strategy is employed to achieve A-DA'D-A type ultra-NBG SMAs by introducing alkoxy chains with oxygen atom at the second position into the thiopheneβposition as well as replacing the F atoms with Cl atoms in the end group.As a result,the heptacyclic BZO-4F shows a redshifted absorption onset(960 nm)compared with Y11(932 nm)without oxygen atoms in the side chains.Then,the fluorinated end groups are substituted with the chlorinated ones to synthesize BZO-4Cl.The absorption onset of BZO-4Cl is further redshifted to 990 nm,corresponding to an optical ultra-NBG of 1.25 eV.When blending with the polymer donor PBDB-T,the binary devices based on PBDB-T:BZO-4F and PBDB-T:BZO-4Cl deliver power conversion efficiencies(PCEs)over 12%.Furthermore,ternary devices with the addition of BZ4F-O-1 into PBDB-T:BZO-4Cl system achieve the optimal PCE of 15.51%.This work proposes a synergetic alkoxy side-chain and chlorine-contained end group strategy to achieve A-DA'D-A type ultra-NBG SMAs,which is important for future molecular design. 展开更多
关键词 Organic solar cells A-DA'D-A type small molecule acceptors Ultra-narrow bandgap Alkoxy side chains Ternary strategy π-πstacking
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基于改进TICC聚类算法的智能博弈宏观策略生成技术
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作者 周盼 程健庆 初阳 《舰船电子工程》 2023年第2期69-74,共6页
随着军事智能技术的发展,采用智能博弈技术构建决策智能体已成为热点研究方向。当前,以深度强化学习算法为主构建的决策智能体输出主要是基于实时态势的微观决策指令,而作战决策人员需要的往往是未来一段时间内的宏观策略。针对智能博... 随着军事智能技术的发展,采用智能博弈技术构建决策智能体已成为热点研究方向。当前,以深度强化学习算法为主构建的决策智能体输出主要是基于实时态势的微观决策指令,而作战决策人员需要的往往是未来一段时间内的宏观策略。针对智能博弈中微观决策指令周期短,战场态势数据规模大、维度高,导致难以对智能博弈中宏观策略进行提取的问题,提出了一种基于时间序列的改进TICC分割聚类算法,对智能博弈形成的数据进行分割聚类,生成宏观策略,为作战方案的制作提供支撑。 展开更多
关键词 聚类分析 智能博弈 宏观策略
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宏微空间机械臂运动控制方法综述 被引量:1
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作者 尹旺 王翔 +1 位作者 王为 刘冬雨 《中国空间科学技术》 CSCD 北大核心 2023年第4期13-23,共11页
由于单一的机械臂不能满足日益增长的空间任务需求,为了提升机械臂的综合性能如快速响应、高精度和大负载,世界各航天大国开展了宏微机械臂的研制工作。综述了国际空间站和中国空间站上宏微机械臂的发展现状,分别从分时独立控制和协调... 由于单一的机械臂不能满足日益增长的空间任务需求,为了提升机械臂的综合性能如快速响应、高精度和大负载,世界各航天大国开展了宏微机械臂的研制工作。综述了国际空间站和中国空间站上宏微机械臂的发展现状,分别从分时独立控制和协调控制两种操作模式下对宏微机械臂系统的运动控制进行了归纳总结。当宏微机械臂采用分时独立的控制模式时,可将其等效为柔性基座机械臂,并从反作用最优控制、主动阻尼控制和末端轨迹跟踪控制三方面对柔性基座机械臂的控制算法进行了分析研究,为中国空间组合机械臂的在轨操作提供了借鉴意义。最后,对空间宏微机械臂的动力学建模和运动控制进行了展望。 展开更多
关键词 宏微机械臂 柔性基座 运动控制 振动抑制 操作策略
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基于CiteSpace国内连续油管研究知识图谱分析
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作者 高纪超 邵尚奇 陈军 《广东石油化工学院学报》 2023年第3期50-54,共5页
连续油管技术涉及多领域、多学科,采用传统文献调研方式对中国连续油管技术进行全面系统的总结难度较大,急需一种新方法来探索连续油管技术发展的规律。利用CiteSpace可视化文献分析工具对1984—2022年CNKI数据库的2119篇文献进行分析,... 连续油管技术涉及多领域、多学科,采用传统文献调研方式对中国连续油管技术进行全面系统的总结难度较大,急需一种新方法来探索连续油管技术发展的规律。利用CiteSpace可视化文献分析工具对1984—2022年CNKI数据库的2119篇文献进行分析,建立作者和机构合作关系共现、关键词共现的知识结构图谱,将中国连续油管技术发展划分为接触期、萌发期、发展期和高峰期四个阶段。对重要性高、突现性强的学者文献和关键词进行研读,了解各时期研究主题的变化趋势。研究结果表明,国家宏观战略对于行业发展具有明显的促进和指导作用,研究能力的提高缩短了研究时长,连续油管在页岩气、超深水平井、海洋油气开发中的应用逐渐成为研究热点和前沿。 展开更多
关键词 连续油管 CITESPACE 知识图谱 宏观战略 研究前沿 研究热点
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“大思政课”视域下高校思政课教师领导力提升策略 被引量:2
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作者 唐忠英 《重庆文理学院学报(社会科学版)》 2023年第4期130-140,共11页
思政课教师领导力指在特定的教育教学情景(思政课)中,思政课教师为实现立德树人根本任务,以尊重自身和他人人格完整为前提,以受众学习生活和成长发展为时空维度,系统地挖掘、整合和运用在学校和社会中获取的、具有思想政治教育功能属性... 思政课教师领导力指在特定的教育教学情景(思政课)中,思政课教师为实现立德树人根本任务,以尊重自身和他人人格完整为前提,以受众学习生活和成长发展为时空维度,系统地挖掘、整合和运用在学校和社会中获取的、具有思想政治教育功能属性的资源和素材,通过多边合作,形成思政教育领导合力,有效协同他人和谐发展,共同实现思政课教育活动中各参与者在个体思想道德素养和品性等方面的全面提升。思政课教师领导力主要包括思政课教师的政治领导力、教育领导力、团队领导力和社会领导力。通过对思政课教师领导力内涵的界定,应用深度访谈和文本分析的研究方法,借助多种信息来源互补,从社会环境、学校环境、教师团队和教师个体四个变量来分析“大思政课”视域下思政课教师领导力的提升策略。 展开更多
关键词 大思政课 教师领导力 教师团队 提升策略
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基于自抗扰的宏微复合驱动器宏动控制策略研究 被引量:1
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作者 喻曹丰 肖志豪 +3 位作者 吴干 杨坤 魏益军 陶雪枫 《制造技术与机床》 北大核心 2023年第7期100-107,共8页
面向高速精密定位领域设计了以音圈电机为宏动部分,超磁致伸缩驱动器为微动部分的同轴式宏微复合驱动器。为实现宏动部分的驱动控制,基于电磁驱动原理建立了宏动部分的动力学模型,设计了自抗扰控制(active disturbance rejection contro... 面向高速精密定位领域设计了以音圈电机为宏动部分,超磁致伸缩驱动器为微动部分的同轴式宏微复合驱动器。为实现宏动部分的驱动控制,基于电磁驱动原理建立了宏动部分的动力学模型,设计了自抗扰控制(active disturbance rejection control,ADRC)系统,其包括4阶扩张状态观测器及非线性状态误差反馈控制率,采用5阶S型位移曲线作为路径规划,并搭建了实验测试平台进行验证。实验结果显示:定位过程中,ADRC算法控制下其最大跟随误差约为0.155 mm,最终定位误差约为9μm,在负载工况下,最大跟随误差约为0.277 mm,最终定位误差约为11μm。研究结果表明:ADRC算法较于PID算法跟随误差更低,超调更小,且最终定位误差处于宏微复合驱动器微动的定位范围内,满足整体设计要求。 展开更多
关键词 宏微复合驱动器 音圈电机 自抗扰控制 精密定位 控制策略
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The Dynamics and Macro Strategy of Structural Reform in Higher Education in China:Case Study of Two Critical Periods(1949-1960 and 1998-2009)
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作者 SHI Jinghuan JO Lyeong +1 位作者 HU Maobo LI Jiayi 《Frontiers of Education in China》 2018年第2期245-266,共22页
The development of the higher education system in China has experienced huge changes alongside the transitions in the socio-economic milieu since the establishment of the People’s Republic of China in 1949.Among the ... The development of the higher education system in China has experienced huge changes alongside the transitions in the socio-economic milieu since the establishment of the People’s Republic of China in 1949.Among the major structural transformations of higher education,the reform during the 1950s and the one from 1998 to 2009 can be seen as two typical cases and manifestations of macro strategy modulation.Both reforms were driven by the need of strengthening and empowering the nation as a whole through the advancement of higher education.But the 1950s reforms featured the perpetuation of state control,highly centralized resource allocation,and authoritarian administration,while the 1998-2009 period reflected the transition from a planned to a market economy in higher education,manifested in an increased weight given to market forces,the enlarged autonomy of higher education institutions(HEIs)and expanded government guidance instead of mere state control.The paper will take the two periods as cases to show why and how the reforms were formulated and what directions they are leading towards. 展开更多
关键词 higher education macro strategy 1950’s college reform 1998–2009 reform
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雨水资源合理利用及其宏观调控 被引量:12
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作者 张正斌 黄占斌 山仑 《水土保持通报》 CSCD 北大核心 1999年第2期52-56,共5页
从多降天上雨,多蓄地上流,南水北调,节水灌溉,高效利用有限降水等方面,系统地论述了雨水资源开发利用的战略思想和宏观调控措施,对我国当前旱地和节水农业的持续发展具有重要指导意义。
关键词 雨水资源 宏观调控 资源利用 水资源 农田水利
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宏观经济政策下的水利投融资策略分析 被引量:8
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作者 乔根平 王瑜 张康波 《中国水利》 2008年第12期55-56,60,共3页
通过分析2008年宏观经济政策的取向和主要内容,针对当前水利面临的形势及宏观经济政策对水利行业各领域投融资的影响程度,提出制定水利建设投融资政策的建议。
关键词 宏观调控 水利发展 投融资 策略
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东南地区土壤养分的空间变异性与取样策略I.土壤属性与大量元素 被引量:5
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作者 陈防 刘冬碧 +2 位作者 熊桂云 鲁剑巍 张过师 《湖北农业科学》 北大核心 2006年第4期432-435,444,共5页
在我国东南6省(市)选择代表性区域(自然村),采用ASI和地统计学等方法对耕作土壤的pH值、有机质、有效氮、磷和钾的空间变异性与合理取样数量进行了研究。结果表明,①pH值和有机质是相对稳定的土壤属性,在整个研究区域其变异较小,近似于... 在我国东南6省(市)选择代表性区域(自然村),采用ASI和地统计学等方法对耕作土壤的pH值、有机质、有效氮、磷和钾的空间变异性与合理取样数量进行了研究。结果表明,①pH值和有机质是相对稳定的土壤属性,在整个研究区域其变异较小,近似于正态分布;施肥元素的变异则较大,表现出明显的负偏峰分布特征。②尽管某些土壤属性或大量元素的总体变异性相似,但在各研究区域,其实际半方差结构并不相同。③对于明显偏峰分布的土壤养分来说,建议采用最适分配法确定合理取样数量。纯随机合理取样数量可在一定程度作为参考。 展开更多
关键词 空间变异 取样策略 地统计学 大量元素
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