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Influence of an indefinite causal order on an Otto heat engine

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Communications in Theoretical Physics 2022年第2期74卷 118-122页

作者： jifei Zhao Youyang Xu Faculty of Science Kunming University of Science and TechnologyKunming 650500China

The quantum effect plays an important role in quantum thermodynamics,and recently the application of an indefinite causal order to quantum thermodynamics has attracted much attention.Based on two trapped ions,we propose a scheme to add an indefinite causal order to the isochoric cooling stroke of an Otto engine through reservoir engineering.Then,we observe that the quasi-static efficiency of this heat engine is far beyond the efficiency of a normal Otto heat engine and may reach one.When the power is its maximum,the efficiency is also much higher than that of a normal Otto heat engine.This enhancement may originate from the nonequilibrium of the reservoir and the measurement on the control qubit.

关键词： indefinite causal order Otto engine quantum thermodynamics

Zheng Guangxu's Oil Painting Exhibition 'Nature is My Tutor'

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China & The World Cultural Exchange 2022年第6期88卷 22-26页

作者： Li jifei 不详

Zheng Guangxu's oil paintings are mainly under the theme of nature,presenting consistenee in the selection of theme.He tends to express his admiration for nature and perception of life by painting common scenes in life.

关键词： Painting Zheng painting

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混合型包络跟踪电源技术研究

微电子学 2022年第5期52卷 783-789页

作者：叶康林王晓航桑吉飞宁波大学信息科学与工程学院浙江宁波315211 西安电子科技大学杭州研究院杭州311231

提高功率放大器效率主要有三种方案:Doherty技术、包络线消除与恢复技术和包络跟踪技术。其中,包络跟踪技术在性能和可实现性方面具有显著优势。为了降低包络跟踪技术的电能损耗,以进一步提高包络跟踪系统性能,文章设计了一种混合型包... 详细信息

提高功率放大器效率主要有三种方案:Doherty技术、包络线消除与恢复技术和包络跟踪技术。其中,包络跟踪技术在性能和可实现性方面具有显著优势。为了降低包络跟踪技术的电能损耗,以进一步提高包络跟踪系统性能,文章设计了一种混合型包络跟踪电源电路。测试实验表明,该电源电路的效率达到60%、平均输出功率为1 W,可以在不同频率的输入下,保持稳定的传输效率和良好的输出波形线性度,适用于高效率功率放大器应用。

关键词：包络跟踪功率放大器 Doherty技术包络线消除与恢复 DC-DC变换器

Preliminary single-arm study of brain effects during transcutaneous auricular vagus nerve stimulation treatment of recurrent depression by resting-state functional magnetic resonance imaging

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Journal of Traditional Chinese Medicine 2022年第5期42卷 818-824页

作者： CHEN Limei SUN jifei GUO Chunlei LI Xiaojiao WANG Zhi Hong Yang FANG Jiliang Radiology Department Guang'anmen Hospital of China Academy of Chinese Medical SciencesBeijing 10003China

OBJECTIVE:To examine the brain effects of transcutaneous auricular vagus nerve stimulation(ta VNS)treatment of recurrent depression based on the functional brain network by using resting-state functional magnetic resonance imaging(f MRI).METHODS:Twenty-five patients with recurrent depression were enrolled in a single-arm trial of ta VNS treatment for eight weeks.Clinical results were assessed by 17-item Hamilton Depression Rating Scale(HAMD-17),Hamilton Anxiety Scale(HAMA),Self-Rating Depression Scale(SDS),Self-Rating Anxiety Scale(SAS),and Ruminative Response Scale(RRS)scales.Resting-state f MRI was conducted to explore the brain effects before and after treatment.For the functional connectivity(FC)analysis,the bilateral nucleus accumbens,globus pallidus,caudate,and putamen were selected as seeds.Finally,the correlations between FC and the clinical scale scores were calculated.RESULTS:After treatment,the patients’scores of HAMD-17,HAMA,SDS,SAS,and RRS were significantly decreased(P<0.05).FC was considerably decreased between the following areas:the left globus pallidus and the right postcentral gyrus,inferior parietal gyrus,the right globus pallidus and the left superior marginal gyrus,postcentral gyrus,superior parietal gyrus,inferior parietal gyrus,precuneus,right postcentral gyrus,superior marginal gyrus,and inferior parietal gyrus,between the right caudate and the right lingual gyrus,calcarine gyrus,and cerebellum.Changes in FC between the right globus pallidus and the left inferior parietal gyrus,between the left globus pallidus and the right postcentral gyrus were negatively correlated with HAMD-17 scores change before and after treatment(before,P=0.003,r=-0.6;after,P=0.009,r=-0.54).The change of FC between the right globus pallidus and the right postcentral gyrus was negatively correlated with the change in SDS(P=0.026,r=-0.474).The difference in FC between the right globus pallidus and the right postcentral gyrus was negatively correlated with the change in SAS(P=0.016,r=-0.513).CONCLUSIONS:Recurrent dep

关键词： recurrence depression magnetic resonance imaging basal ganglia default mode network transcutaneous auricular vagus nerve stimulation

基于两种MCDM的四川汶川县农村环境保护和社会经济综合发展评估

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农业工程学报 2023年第15期39卷 228-238页

作者：张帅张继飞水利部/中国科学院成都山地灾害与环境研究所/山区发展研究中心成都610041 中国科学院大学北京101408

科学全面的综合评估,是引导农村环境保护和社会经济综合发展方向的先决条件。该研究通过VIKOR与TOPSIS两种方法,分别对地处生态脆弱且地位重要的川西北汶川县,展开行政村尺度的环境保护和社会经济综合发展评估。结果表明:1)相较于TOPSI... 详细信息

科学全面的综合评估,是引导农村环境保护和社会经济综合发展方向的先决条件。该研究通过VIKOR与TOPSIS两种方法,分别对地处生态脆弱且地位重要的川西北汶川县,展开行政村尺度的环境保护和社会经济综合发展评估。结果表明:1)相较于TOPSIS方法,综合考虑群体效应(整体综合发展水平)和个体遗憾(发展制约因素)的VIKOR评估方法,对本地的综合发展评估更全面、深入;2)VIKOR方法评估得到汶川县整体综合发展水平较高,无论乡镇还是行政村尺度均呈现出显著空间分异特征,综合发展水平高值区沿县域西北-中部-东南一线分布,综合发展水平低值区主要集中于县域东北及中南部。3)TOPSIS方法评估得到汶川县整体综合发展水平处于中等,综合发展水平高值区沿县域西北-中部-西南一线分布,综合发展水平低值区与VIKOR方法评估结果一致。4)就评估结果而言,基于VIKOR方法因综合考虑了整体发展水平与短板因素,可能使部分行政村的综合发展水平差异缩小;TOPSIS方法则因未考虑正、负理想解之间的相对重要性,可能导致“逆序”问题。两种方法评估得到的主要差异聚焦于综合发展优秀区。5)借助VIKOR方法考虑个体遗憾的特点,认识到生态保育及村民自治水平是限制汶川县农村综合发展的两大关键制约因素,其中村民自治能力对于综合发展的提升发挥着重要作用。

关键词：环境保护综合发展评估 VIKOR法 TOPSIS法川西北汶川县

Geographical Space Development Zone Classification:An Essential Guide for Transformation of Mountain Resource Cities

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Chinese Geographical Science 2015年第3期25卷 361-374页

作者： ZHANG jifei DENG Wei LIU Shaoquan Institute of Mountain Hazards and Environment Chinese Academy of Sciences

Sustainable development of mountain areas and resource cities has been a significant issue worldwide. Transformation of mountain resource cities is facing tremendous difficulties. In the context of National Major Function-oriented Zone Planning raised to a national strategic level in China, it is important to effectively implement the planning by studying geographical space development zone classification of prefecture- and county-level cities based on their major function orientation. This research is even more critical for the transformation of mountain resource cities. In this study, we evaluated geographical space development suitability, and classified geographical space development zones for Dongchuan Distric in Kunming City of Yunan Province, China, a typical mountain resource city. A quantitative grid-based evaluation was conducted using key-factor identification and restrictive-supportive comprehensive index determinati based on a geographic information system framework with different source data. The results included a classification of geographical space of Dongchuan into five types: the prohibited development zone, the inappropriate development zone, the controlled development zone, the moderate development zone and the preferential development zone. The distribution characteristics of geographical space development zones showed that the proportion of the prohibited development zone is the highest, while that of the other four development zones is comparatively lower and significantly fragmented. The geographical space development suitability is greatly controlled by the geomorphic pattern. Although Dongchuan is extremely restrained in terms of suitable geographical space for industrialization and urbanization, it still has the certain preferential and moderate development zones with an area of 207.81 km2 with large parts being concentrated and contiguous, which makes these areas the most favorable for development. Only by adapting to this reality and implementing centralized development strategy in t

关键词：资源型城市地理空间开发区城市转型图形分类城市可持续发展可持续发展能力南山

Design and characterisation of the high-current DC breaker driven by explosive

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High Voltage 2023年第3期8卷 466-476页

作者： Cunwen Tang Hua Li Zhiquan Song jifei Ye Meng Xu Xingguang Hu Fu Peng Institute of Plasma Physic s Hefei Institutes of Physical ScienceChinese Academy of SciencesHefeiChina 2University of Science and Technology of ChinaHefeiChina College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhenChina

The development of a high-current DC breaker is very important for the protection of the expensive superconducting magnet.A kind of an economic switch called pyrobreaker,which is driven by explosive detonation waves,has been used as the backup quench protection due to its inherent reliability and fast response.A prototype pyrobreaker with a special structure that can withstand and break 100 kA is discussed.The numerical material model is taken to calculate the fracture demand of contact and the mass demand of explosive.Then,the detonation wave and contact breaking process are simulated by the ANSYS software.The performance of the design and characterisation during dynamic breaking are compared with simulation and no-load experiment test.At the end,the temperature rise test and the breaking test under 100 kA are completed successfully.These results demonstrate that the design of 100 kA pyrobreaker is reliable.

关键词： breaking character high

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胜利滩浅海复杂地层钻井关键技术研究与应用

石油机械 2024年第1期52卷 52-58页

作者：曹继飞中石化胜利石油工程公司钻井工艺研究院

胜利滩浅海地区油气资源储量丰富,老区产量递减快,勘探开发逐渐转向边际和深层,钻井过程中面临密集井网防碰难度大,深部坚硬地层钻速慢、复杂情况多发,油泥岩地层易坍塌,裂缝储层保护及固井质量要求高等难题。为有效解决上述钻井难题,... 详细信息

胜利滩浅海地区油气资源储量丰富,老区产量递减快,勘探开发逐渐转向边际和深层,钻井过程中面临密集井网防碰难度大,深部坚硬地层钻速慢、复杂情况多发,油泥岩地层易坍塌,裂缝储层保护及固井质量要求高等难题。为有效解决上述钻井难题,通过理论研究、专项攻关和集成应用相结合的方法,形成了包括密集井组磁测距主动防碰技术、潜山复杂地层快速穿越技术、油泥岩多元封堵钻井液技术、高强恒定低密度水泥浆技术等关键技术。这些技术累计推广应用于200余口井,形成了重点区域标准优快钻完井施工模式,有效保障了密集井组的施工安全,提高了潜山地层的钻井机械钻速,降低了复杂时效。所得结论可为滩浅海油气资源的高效勘探开发提供技术保障。

关键词：滩浅海密集井组潜山地层油泥岩固井要求

Interaction of single-pulse laser energy with bow shock in hypersonic flow

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Chinese Journal of Aeronautics 2014年第2期27卷 241-247页

作者： Hong Yanji Wang Diankai Li Qian Ye jifei State Key Laboratory of Laser Propulsion & Application Equipment Academy

Pressure sensing and schlieren imaging with high resolution and sensitivity are applied to the study of the interaction of single-pulse laser energy with bow shock at Mach 5. An Nd：YAG laser operated at 1.06 μm, 100 mJ pulse energy is used to break down the hypersonic flow in a shock tunnel. Three-dimensional Navier-Stokes equations are solved with an upwind scheme to simulate the interaction. The pressure at the stagnation point on the blunt body is measured and calculated to examine the pressure variation during the interaction. Schlieren imaging is used in conjunction with the calculated density gradients to examine the process of the interaction, The results show that the experimental pressure at the stagnation point on the blunt body and schlieren imaging fit well with the simulation. The pressure at the stagnation point on the blunt body will increase when the transmission shock approaches the blunt body and decrease with the formation of the rarefied wave. Bow shock is deformed during the interaction. Quasi-stationary waves are formed by high rate laser energy deposition to control the bow shock. The pressure and temperature at the stagna- tion point on the blunt body and the wave drag are reduced to 50%, 75% and 81% respectively according to the simulation. Schlieren imaging has provided important information for the inves- tigation of the mechanism of the interaction.

关键词： Drag Flow control Navier-Stokes equation Shock wave Wind tunnel test