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Super Quantum Discord and Inferior “Geometric Discord” Based on Weak Measurement in Noninertial Frames
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作者 Maohuai Xiang Jiliang Jing 《Journal of Quantum Information Science》 2014年第1期54-63,共10页
Instead of projective measurement, we use weak measurement to define quantum and geometric discords, and compare them with the normal quantum and geometric discords based on the projective measurement in noninertial f... Instead of projective measurement, we use weak measurement to define quantum and geometric discords, and compare them with the normal quantum and geometric discords based on the projective measurement in noninertial frames. We find that using weak measurement to define quantum discord we can capture more quantum correlations compared with the projective measurement, so calling it super quantum discord. However, we note that the geometric discord based on the weak measurements becomes smaller, so we name it inferior “geometric discord”. We also show that, although both the super quantum discord and the inferior “geometric discord” decrease with the increase of observer’s acceleration, the super quantum discord/inferior “geometric discord” increases/decreases as the measurements become weak. These differences reveal that the definitions of the quantum and geometric discords are not too concordant with each other. 展开更多
关键词 WEAK measurement super QUANTUM DISCORD INFERIOR GEOMETRIC DISCORD
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Dynamics of super-quantum discord and direct control with weak measurement in open quantum system
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作者 嵇英华 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第12期209-214,共6页
Super-quantum discord(SQD) with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord(QD), and qua... Super-quantum discord(SQD) with weak measurement is regarded as a kind of quantum correlation in quantum information processing. We compare and analyze the dynamical evolutions of SQD, quantum discord(QD), and quantum entanglement(QE) between two qubits in the correlated dephasing environmental model. The results indicate that(i) owing to the much smaller influence of weak measurement on the coherence of the system than that of von Neumann projection measurement, SQD with weak measurement is larger than QD, and(ii) dynamical evolution of QD or QE monotonically goes to zero with time, while SQD monotonically tends to a stable value and a freezing phenomenon occurs. The stable value after freezing mainly depends on the measurement strength and the purity of the initial quantum state. 展开更多
关键词 super-quantum discord(SQD) weak measurement CONTROL
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Difficulties and measures of driving super long piles in Bohai Gulf
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作者 Shuwang Yan Jia Li +1 位作者 Liqiang Sun Guomin Sun 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2015年第2期69-73,共5页
Long piles of the ocean oil platform are usually manufactured as the integration of several segments, which have to be assembled one by one during installation. During pile driving, excessive pore pressure will build ... Long piles of the ocean oil platform are usually manufactured as the integration of several segments, which have to be assembled one by one during installation. During pile driving, excessive pore pressure will build up in such a high level that hydraulic fracturing in the soil round the pile may take place, which will cause the soil to consolidate much faster during pile extension period. Consequently, after pile extension, the soil strength will recover to some extent and the driving resistance will increase considerably, which makes restarting driving the pile very difficult and even causes refusal. A finite element (FE) analysis procedure is presented for judging the risk of refusal by estimating the blow counts after pile extension, in which the regain of soil strength is considered. A case analysis in Bohai Gulf is performed using the proposed orocedure to exolain the nile refusal phenomenon. 展开更多
关键词 super long pile driving Refusal Excessive pore pressure Hydraulic fracture Finite element analysis Prevent measures
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ABSOLUTE CONTINUITIES OF EXIT MEASURES AND TOTAL WEIGHTED OCCUPATION TIME MEASURES FOR SUPER-α-STABLE PROCESSES
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作者 张静 任艳霞 《Acta Mathematica Scientia》 SCIE CSCD 2006年第2期358-370,共13页
Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measur... Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measure and the total weighted occupation time measure of X in a bounded smooth domain D, respectively. The absolute continuities of Xγ and Yγ are discussed. 展开更多
关键词 super-α-stable process absolute continuity exit measure total weighted occupation time measure
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Martingales and Super-Martingales Relative to a Convex Set of Equivalent Measures
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作者 Nicholas S. Gonchar 《Advances in Pure Mathematics》 2018年第4期428-462,共35页
In the paper, the martingales and super-martingales relative to a convex set of equivalent measures are systematically studied. The notion of local regular super-martingale relative to a convex set of equivalent measu... In the paper, the martingales and super-martingales relative to a convex set of equivalent measures are systematically studied. The notion of local regular super-martingale relative to a convex set of equivalent measures is introduced and the necessary and sufficient conditions of the local regularity of it in the discrete case are founded. The description of all local regular super-martingales relative to a convex set of equivalent measures is presented. The notion of the complete set of equivalent measures is introduced. We prove that every bounded in some sense super-martingale relative to the complete set of equivalent measures is local regular. A new definition of the fair price of contingent claim in an incomplete market is given and the formula for the fair price of Standard Option of European type is found. The proved Theorems are the generalization of the famous Doob decomposition for super-martingale onto the case of super-martingales relative to a convex set of equivalent measures. 展开更多
关键词 Random Process CONVEX Set of EQUIVALENT measures Optional Doob Decomposition Local Regular super-Martingale MARTINGALE Fair Price of CONTINGENT CLAIM
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Challenges and Thoughts on Risk Management and Control for the Group Construction of a Super-Long Tunnel by TBM 被引量:16
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作者 Mingjiang Deng 《Engineering》 2018年第1期112-122,共11页
The total length of the second stage of the water supply project in the northern areas of the Xinjiang Uygur Autonomous Region is 540 km, of which the total length of the tunnels is 516 km. The total tun- neling milea... The total length of the second stage of the water supply project in the northern areas of the Xinjiang Uygur Autonomous Region is 540 km, of which the total length of the tunnels is 516 km. The total tun- neling mileage is 569 km, which includes 49 slow-inclined shafts and vertical shafts. Among the tunnels constructed in the project, the Ka-Shuang tunnel, which is a single tunnel with a length of 283 kin, is cur- rently the longest water-conveyance tunnel in the world. The main tunnel of the Ka-Shuang tunnel is divided into 18 tunnel-boring machine (TBM) sections, and 34 drilling-and-blasting sections, with 91 tunnel faces. The construction of the Ka-Shuang tunnel has been regarded as an unprecedented challenge for project construction management, risk control, and safe and efficient construction; it has also pre- sented higher requirements for the design, manufacture, operation, and maintenance of the TBMs and their supporting equipment. Based on the engineering characteristics and adverse geological conditions, it is necessary to analyze the major problems confronted by the construction and systematically locate disaster sources. In addition, the risk level should be reasonably ranked, responsibility should be clearly identified, and a hierarchical-control mechanism should be established. Several techniques are put for- ward in this paper to achieve the objectives mentioned above; these include advanced geological prospecting techniques, intelligent tunneling techniques combined with the sensing and fusion of infor- mation about rock parameters and mechanical parameters, monitoring and early-warning techniques, and modern information technologies. The application of these techniques offers scientific guidance for risk control and puts forward technical ideas about improving the efficiency of safe tunneling. These techniques and ideas have great significance for the development of modern tunneling technolo- gies and research into major construction equipment. 展开更多
关键词 super-long tunnelsGroup construction by TBMRisk management and controlTechnical measures
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基于Super-SBM模型的四川省地市州科技成果转化效率测算与分析
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作者 吴佳玲 丁奕芳 李亚丹 《竞争情报》 2023年第6期41-49,共9页
科学评价四川省地市州科技成果转化效率能够有效促进区域高新技术的发展,提高区域经济效益。以2015—2020年四川省21个地市州的混合截面数据为样本,采用数据包络分析(DEA)方法构建Super-SBM模型,对科技成果转化效率进行测算,并分析其区... 科学评价四川省地市州科技成果转化效率能够有效促进区域高新技术的发展,提高区域经济效益。以2015—2020年四川省21个地市州的混合截面数据为样本,采用数据包络分析(DEA)方法构建Super-SBM模型,对科技成果转化效率进行测算,并分析其区域异质性。研究表明,四川省21个地市州整体科技成果转化效率较高,但规模效率低于纯技术效率,制约了部分地区的综合效率有效;各地市州具有较为明显的区域异质性,其中,成都平原经济区和川东北经济区科技成果转化效率两极分化较为严重,川南、川西北和攀西经济区技术转化效率差异较小。最后根据效率测算与分析结果提出相应的对策建议。 展开更多
关键词 科技成果转化效率 效率测算 super-SBM模型 区域异质性
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ON THE WEIGHTED OCCUPATION TIME AND SUPPORT OF SUPER-BROWNIAN MOTION CONDITIONED ON NON-EXTINCTION
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作者 李炳章 余旌胡 《Acta Mathematica Scientia》 SCIE CSCD 1999年第3期272-278,共7页
This paper investigates the property of super-Brownian motion conditioned on non-extinction. The authors obtain a representation of Laplace functional for the weighted occupation time of this class of processes. By th... This paper investigates the property of super-Brownian motion conditioned on non-extinction. The authors obtain a representation of Laplace functional for the weighted occupation time of this class of processes. By this, they get a result about the distribution of the support of it. 展开更多
关键词 super-Brownian motion non-extinction weighted occupation the support of measure
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中国式现代化背景下超老龄农村的乡村振兴 被引量:5
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作者 杜鹏 李子洋 《中国农业大学学报(社会科学版)》 CSSCI 北大核心 2024年第2期68-82,共15页
中国式现代化是人口规模巨大的现代化,也是全体人民共同富裕的现代化,适应人口变化趋势是中国式现代化与乡村振兴的应然选择和必然之路。当前人口老龄化程度持续加深,叠加长期存在的“城乡倒置”现象,使得农村地区已有近1/4的区域率先... 中国式现代化是人口规模巨大的现代化,也是全体人民共同富裕的现代化,适应人口变化趋势是中国式现代化与乡村振兴的应然选择和必然之路。当前人口老龄化程度持续加深,叠加长期存在的“城乡倒置”现象,使得农村地区已有近1/4的区域率先进入超老龄社会,其共同面临劳动力与人才老化、乡村发展能力弱化以及养老服务需求增加的现实挑战。为应对挑战,超老龄农村依靠尚存的人口机会窗口与内生的资源禀赋维系发展。在此基础上,乡村振兴战略通过外部资源输入的方式支持乡村发展,以解决农村发展不充分的矛盾、弥合区域发展不平衡的差距。然而,内生资源形塑的区域差异与乡村振兴推进过程中“整齐划一”的发展模式导致的匹配“错位”现象屡见不鲜。因此,为促进区域协同发展、实现超老龄农村的乡村振兴并最终达成共同富裕与中国式现代化,本研究从保障基本、深入发展和城乡融合三个阶段契合超老龄农村不同的发展基础,探索适合超老龄农村的乡村振兴道路。 展开更多
关键词 超老龄农村 乡村振兴 人口挑战 区域差异 因地制宜
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Super Efficiency and Misallocation: Evidence from Vietnamese Electric-Computer Industry
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作者 Nguyen Khac Minh Pham Van Khanh Nguyen Thi Phuong 《American Journal of Operations Research》 2018年第2期63-81,共19页
Misallocation means that the source is not distributed efficiently. This leads to an important question of how the relationship between misallocation and efficiency is (see [1]). The purpose of this study is to addres... Misallocation means that the source is not distributed efficiently. This leads to an important question of how the relationship between misallocation and efficiency is (see [1]). The purpose of this study is to address the empirical relationship between misallocation and efficiency in the electric and computer industry in Vietnam during the 2005-2015 periods. To do this, we built a model that allowed us to evaluate the impact of misallocation and other factors on efficiency. The slack-based measured efficiency (SBM) model (Tone [2]), and the super-efficient model (Tone [3]) are used to estimate the firms’ efficiency. The approach of Hsieh and Klenow [4] is used to measure misallocation in the study area. Estimated results of the model about the relationship between misallocation and efficiency show that the variable representing the misallocation has a negative sign and statistical significance in all models. In other words, the misallocation negatively affects efficiency. The bigger the misallocation, the lower the efficiency. 展开更多
关键词 Misallocation super-Efficient Slack-Based measurED EFFICIENCY
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Super-Resolution Stress Imaging for Terahertz-Elastic Based on SRCNN
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作者 Delin Liu Zhen Zhen +4 位作者 Yufen Du Ka Kang Haonan Zhao Chuanwei Li Zhiyong Wang 《Optics and Photonics Journal》 CAS 2022年第11期253-268,共16页
Limited by diffraction limit, low spatial resolution is one of the shortcomings of terahertz imaging. Low spatial resolution is also one of the reasons limiting the development of stress measurement using terahertz im... Limited by diffraction limit, low spatial resolution is one of the shortcomings of terahertz imaging. Low spatial resolution is also one of the reasons limiting the development of stress measurement using terahertz imaging. In this paper, the full-field stress measurement using Terahertz Time Domain Spectroscopy (THz-TDS) is combined with Super-Resolution Convolutional Neural Network (SRCNN) algorithm to obtain stress fields with high spatial resolution. A modulation model from a plane stress state to a THz-TDS signal is constructed. A large number of simulated sets are obtained to train the SRCNN model. By applying the trained SRCNN model to imaging the numerical and physical stress fields, the improved spatial resolution of stress field calculated from the captured THz-TDS signal is obtained. 展开更多
关键词 THZ-TDS Stress measurement super-Resolution Convolutional Neural Network
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超效率SBM-Malmquist模型在燃气管道完整性管理效能评价中的应用
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作者 岑康 陈思宇 +3 位作者 陈开 李琦 朱林 沈娇 《安全与环境学报》 CAS CSCD 北大核心 2024年第8期3144-3153,共10页
为解决燃气管道完整性管理效能评价时,无法准确对比各评价单元完整性管理水平的差异,以及无法动态测算同一评价单元完整性管理效能的问题,提出了一种基于超效率松弛值测算(Slacks-Based Measure, SBM)的模型和Malmquist模型相结合的方法... 为解决燃气管道完整性管理效能评价时,无法准确对比各评价单元完整性管理水平的差异,以及无法动态测算同一评价单元完整性管理效能的问题,提出了一种基于超效率松弛值测算(Slacks-Based Measure, SBM)的模型和Malmquist模型相结合的方法,对管道完整性管理效能评价进行研究。首先,综合考虑完整性管理实施过程、效果与效益,并结合专家意见和相关规范标准,构建效能评价指标体系,该指标体系由3项一级指标和14项二级指标进行表征。其次,采用考虑非期望产出的超效率SBM模型解决各评价单元的比较与排序问题,再将Malmquist模型与超效率SBM模型相结合,测算各评价单元效能的动态变化趋势。最后,针对5家燃气公司在2019—2022年的完整性管理效能,采用所提出的效能评价模型开展评价。结果表明,超效率SBM模型和Malmquist模型相结合是实现管道完整性管理效能客观定量评价的有效方法,通过横向对比和动态测度发现短板并提出针对性的改进意见,其分析结果与实际工程相吻合,证明该方法能够有效评估完整性管理效能,为管道完整性管理提供了一种评价思路。 展开更多
关键词 安全工程 燃气管道 效能评价 超效率松弛值测算(SBM)模型 MALMQUIST指数
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基于两阶段DEA-SFA模型的科学数据平台资源提供者服务效率研究——以国家生态科学数据中心为例
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作者 严素梅 王庆 +1 位作者 陈荣 李建霞 《科技管理研究》 CSSCI 2024年第17期77-84,共8页
服务绩效评价是衡量国家科学数据平台发展质量的重要指标,效率测算为其提供重要依据。将国家生态科学数据中心资源提供者的服务过程分为资源服务和知识转化前后相关联的两个阶段,从投入产出要素的使用效率、科学资源的利用程度和用户感... 服务绩效评价是衡量国家科学数据平台发展质量的重要指标,效率测算为其提供重要依据。将国家生态科学数据中心资源提供者的服务过程分为资源服务和知识转化前后相关联的两个阶段,从投入产出要素的使用效率、科学资源的利用程度和用户感知的服务质量3个维度构建指标体系,利用两阶段数据包络分析-随机前沿方法(DEA-SFA)模型对43个资源提供者进行服务效率测算,并运用超效率模型对有效DMU做进一步区分和排名。结果表明:国家生态科学数据中心资源提供者在资源服务和知识转化阶段平均纯技术效率值分别为0.794和0.838,DEA有效站点数分别为12个和16个;在43个决策单元中,优秀资源提供者约占16%,一般资源提供者约占70%,较差资源提供者约占14%;另外,资源提供者的服务效率和地区经济发展水平具有一定关联性,东部地区表现优于中西部地区。基于上述研究结果,进而提出推动我国国家科学数据平台发展建设的相关对策建议。 展开更多
关键词 科学数据平台 效率测算 绩效评价 两阶段DEA模型 SFA模型 超效率模型
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超高层建筑钢结构施工的关键技术和措施 被引量:1
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作者 张俏 《智能城市应用》 2024年第1期45-47,共3页
随着城市化的不断推进,超高层建筑的兴建成为城市发展的一种趋势。在超高层建筑中,钢结构因其轻质、高强度等特点,成为超高层建筑的首选方案。文中通过对钢结构特征的分析,深入剖析了超高层建筑中的钢结构施工流程及影响因素。在此基础... 随着城市化的不断推进,超高层建筑的兴建成为城市发展的一种趋势。在超高层建筑中,钢结构因其轻质、高强度等特点,成为超高层建筑的首选方案。文中通过对钢结构特征的分析,深入剖析了超高层建筑中的钢结构施工流程及影响因素。在此基础上,详细讨论了柱基础检查、钢柱吊装和钢柱连接等关键技术与应用措施,包括了施工过程中的质量监控、安全管理和技术检测等方面,旨在为超高层建筑钢结构施工提供可行的解决方案。 展开更多
关键词 超高层建筑 钢结构 施工流程 关键技术 措施
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考虑投入产出的常规公交调度绩效回溯性动态评价
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作者 吴娇蓉 田子立 刘安娜 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第5期778-787,821,共11页
实时调度因其灵活性在公交运营组织中发挥着重要决策作用。现行调度(员)绩效评价虽然能够考核行车计划执行情况,却忽略了在乘客体验和企业投入产出层面对调度效果考查,也不支持回溯过往调度实施效果。为使调度员能够精准提升调度技能和... 实时调度因其灵活性在公交运营组织中发挥着重要决策作用。现行调度(员)绩效评价虽然能够考核行车计划执行情况,却忽略了在乘客体验和企业投入产出层面对调度效果考查,也不支持回溯过往调度实施效果。为使调度员能够精准提升调度技能和绩效、解决调度决策滞后造成的运能浪费等问题并提高乘客满意度,从投入产出及回溯性动态评价2个维度提出基于三阶段Super-SBM(super-efficiency slack-based measurement)模型的常规公交调度绩效评价方法,考虑路况及客流对调度效果的影响,在现行指标基础上从乘客角度增加运营速度、候车时间变化率及满载率标准差3项产出指标,构建评价体系。对2条上海公交线路的实际调度进行回溯性评价,验证了本文评价方法能准确区分调度效果差异。结果表明,高峰时段灵活的调度策略比在平峰能产生更明显的效益,且调度策略在不同时空场景呈现差异化适用性。通过回溯分析历史调度记录的绩效,一方面可以针对各场景为调度员提供调度决策支持,另一方面可为基于机器学习的公交实时调度策略生成技术挑选合适的学习样本,从而提升常规公交运营组织效率。 展开更多
关键词 交通工程 公交调度 回溯性动态评价 投入产出 三阶段super-SBM模型
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丝绸之路经济带能源生态效率测度及影响因素
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作者 张超 鲁健 宋瑶 《沈阳工业大学学报(社会科学版)》 2024年第1期47-54,共8页
党的十八大以来,生态文明建设被提升到前所未有的战略高度,能源生态效率研究也备受关注。丝绸之路经济带作为我国重要的能源基地和对外开放新前沿,对我国经济发展具有重要意义。基于丝绸之路经济带沿线省份2006—2019年数据,运用Super-... 党的十八大以来,生态文明建设被提升到前所未有的战略高度,能源生态效率研究也备受关注。丝绸之路经济带作为我国重要的能源基地和对外开放新前沿,对我国经济发展具有重要意义。基于丝绸之路经济带沿线省份2006—2019年数据,运用Super-SBM和ML指数对能源生态效率分别进行静态和动态测度,并运用Tobit模型对其影响因素进行研究。实证结果显示:丝绸之路经济带能源生态效率未达到有效水平,在趋势上有所下降;人口规模、产业结构、科学技术水平对能源生态效率具有积极的推动作用;而能源消费结构和对外开放水平则起到了抑制作用。据此,提出促进产业结构优化升级、大力发展清洁能源、调整进出口商品结构、完善创新驱动发展战略等建议。 展开更多
关键词 丝绸之路经济带 能源生态效率 super-SBM ML指数 TOBIT模型
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数字经济促进城市绿色发展的碳排放效应与影响因素研究
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作者 田泽 张瀚亓 +1 位作者 徐兴武 任阳军 《工业技术经济》 CSSCI 北大核心 2024年第7期70-80,共11页
本文基于2010~2021年我国284个地级市面板数据,采用超效率SBM模型等方法,研究数字经济对城市绿色发展的碳排放效率及其影响机制。研究结果显示,数字经济发展有助于提升城市的碳排放效率。其中,财政支出绩效和环境规制强度起到中介作用;... 本文基于2010~2021年我国284个地级市面板数据,采用超效率SBM模型等方法,研究数字经济对城市绿色发展的碳排放效率及其影响机制。研究结果显示,数字经济发展有助于提升城市的碳排放效率。其中,财政支出绩效和环境规制强度起到中介作用;数字经济在经济发展速度和人力资本水平的调节下,更显著地促进城市的碳排放效率;同时,数字经济对城市碳排放效率的影响存在明显的异质性。因此,本文提出了加强数字经济发展与碳排放效率协同增长、优化政府财政支出、加快数字城市建设等建议。 展开更多
关键词 数字经济 城市绿色发展 超效率SBM模型 智慧降碳 效率测度 碳排放效率 环境规制 数字城市建设
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城镇化推进模式与我国农业低碳全要素生产率——来自双源夜间灯光证据 被引量:1
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作者 方芳 赵军 +1 位作者 黄宏运 苏旭峰 《统计研究》 CSSCI 北大核心 2024年第4期111-125,共15页
本文利用卫星监测的数据构造夜间灯光复合指数表征城镇化水平,运用Superefficiency Ray Slacks-Based Measure(Super-RSBM)模型和Global Malmquist-Luenberger(GML)指数测算2000—2021年我国农业低碳全要素生产率(TFP),实证检验城镇化... 本文利用卫星监测的数据构造夜间灯光复合指数表征城镇化水平,运用Superefficiency Ray Slacks-Based Measure(Super-RSBM)模型和Global Malmquist-Luenberger(GML)指数测算2000—2021年我国农业低碳全要素生产率(TFP),实证检验城镇化对我国农业低碳TFP的影响及其作用机制,并考察紧凑集约型和规模扩张型两种城镇化推进模式对农业低碳TFP的异质性影响。研究发现,从全国来看,城镇化推进与农业低碳TFP之间具有显著的U型关系,且邻近地区农业低碳TFP的提升对本地区产生示范效应;分区域来看,这种U型关系主要体现在农业适度发展区,而农业优化发展区的城镇化与农业低碳TFP之间呈现显著的正向线性关系,表明农业优化发展区应发挥“领头羊”作用,带动适度发展区早日跨越U型曲线的拐点,实现城镇化带动农业绿色发展;紧凑集约型的城镇化深度推进模式能够显著提升农业低碳TFP,而规模扩张型的城镇化广度推进模式降低了农业低碳TFP;农业低碳技术进步、农村劳动力转移、规模效应、农业产业链延伸和农村居民可支配收入增加是城镇化影响农业低碳TFP的主要途径。 展开更多
关键词 城镇化 农业低碳TFP super-RSBM模型 夜间灯光数据 动态空间杜宾模型
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台风作用下深圳新世界中心风致响应实测与风洞试验研究
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作者 林旭盛 张乐乐 +2 位作者 谢壮宁 王飞 石碧青 《振动工程学报》 EI CSCD 北大核心 2024年第8期1359-1367,共9页
依据近10年来监测到的5次强台风过境期间深圳新世界中心的实测响应数据,分析了该建筑结构在台风影响下的响应特点和模态参数变化特性,并将实测结果与粗糙度指数α分别为0.22,0.30和0.35地形下的风洞试验结果进行了比较。结果表明:历次... 依据近10年来监测到的5次强台风过境期间深圳新世界中心的实测响应数据,分析了该建筑结构在台风影响下的响应特点和模态参数变化特性,并将实测结果与粗糙度指数α分别为0.22,0.30和0.35地形下的风洞试验结果进行了比较。结果表明:历次台风影响下实测建筑达到最大振幅附近时均表现为明显的横风向振动,且最大振动方向均为南北方向;实测最大峰值加速度为17.28 cm/s^(2),满足舒适度要求;台风过境时,建筑结构模态频率表现出明显的振幅依赖性和时变特性,采用“时变”方式描述更加合理,几次台风过程的结构模态频率均是随时间先减小,在最大风速时达到最小值,然后增大并恢复到常态值;结构模态阻尼比在中低振幅区域分布较为离散,随着振幅的增加,阻尼比有所增大,顺风向和横风向的阻尼比最大分别为1.9%和1.2%;实测结果更接近于α为0.35地貌的风洞试验结果,显示C类地貌的风洞试验结果偏于保守。 展开更多
关键词 超高层建筑 现场实测 风洞试验 参数识别 地貌粗糙度
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相衬光学相干弹性成像的超分辨应变测量
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作者 张展华 曹鑫 +3 位作者 詹伟浩 董博 谢胜利 白玉磊 《光学精密工程》 EI CAS CSCD 北大核心 2024年第12期1812-1823,共12页
相衬光学相干弹性成像的相位分辨率受限于系统的光源带宽,导致层析应变成像质量低。这严重制约了相衬光学相干弹性成像的实际应用与发展。为此,本文提出一种基于数据驱动的超分辨应变测量方法,以解决相位分辨率受限下的应变重构困难问... 相衬光学相干弹性成像的相位分辨率受限于系统的光源带宽,导致层析应变成像质量低。这严重制约了相衬光学相干弹性成像的实际应用与发展。为此,本文提出一种基于数据驱动的超分辨应变测量方法,以解决相位分辨率受限下的应变重构困难问题。首先,根据相衬光学相干弹性成像原理,搭建了层析应变测量模型,用于获取网络训练所需的数据集,解决实际测量过程中超分辨应变标签难以获取的问题。其次,构建深度卷积神经网络,通过带有层析分辨率受限特点的数据驱动方式,让网络学习低分辨相位与高分辨应变之间的映射关系,从而实现相衬光学相干弹性成像的超分辨应变测量。最后,采用数值验证和压缩变形加载实验对本文方法的性能进行验证。实验结果表明本文方法在窄带宽输出下能重构出宽带宽的应变测量效果,并且其信噪比相比于矢量方法和传统应变计算深度神经网络,分别提高了18.4 dB和1.45 dB。本文方法可以突破系统光源的带宽限制,在低分辨相位输入条件下实现超分辨应变测量,从而加快相衬光学相干弹性成像在力学性能表征、内部早期损伤探测等方面的应用前景。 展开更多
关键词 光学弹性成像 相衬技术 应变测量 深度神经网络 超分辨重构
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