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Optical modification of nonlinear crystals for quasi-parametric chirped-pulse amplification

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Fundamental Research 2024年第1期4卷 43-50页

作者： Qian Lin Jingui Ma zhe yin Peng Yuan Jing Wang Guoqiang Xie Liejia Qian Key Laboratory for Laser Plasmas(MOE) Collaborative Innovation Center of IFSASchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

Quasi-parametric chirped-pulse amplification(QPCPA),which features a theoretical peak power much higher than those obtained with Ti:sapphire laser or optical parametric chirped-pulse amplification,is promising for future ultra-intense *** doped rare-earth ion used for idler dissipation is critical for effective QPCPA,but is usually not compatible with traditional *** far,only one dissipative crystal of Sm^(3+)-doped yttrium calcium oxyborate has been grown and *** we introduce optical means to modify traditional crystals for QPCPA *** theoretically demonstrate two dissipation schemes by idler frequency doubling and sum-frequency generation with an additional *** contrast to absorption dissipation,the proposed nonlinear dissipations ensure not only high signal efficiency but also high small-signal *** demonstrated ability to optically modify crystals will facilitate the wide application of QPCPA.

关键词： Quasi-parametric amplifier Second-harmonic generation Sum-frequency generation Back conversion Idler dissipation

CsPbX_(3)钙钛矿纳米晶中Mn(Ⅱ)离子的可控掺杂及其发光性能研究

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发光学报 2024年第2期45卷 185-194页

作者：陈洁訚哲王立瑾李宇王帅冰林欧阳唐爱伟滕枫北京交通大学物理科学与工程学院北京100044

Mn离子掺杂策略被广泛用于提高CsPbX3钙钛矿纳米晶(Nanocrystals,NCs)的稳定性和调控Pb的含量,但离子掺杂反应速率极快,不易控制。本文分别采用一步和两步热注射法对Mn^(2+)的掺杂含量进行大范围和精确调控,制备出具有不同Mn^(2+)掺杂... 详细信息

Mn离子掺杂策略被广泛用于提高CsPbX3钙钛矿纳米晶(Nanocrystals,NCs)的稳定性和调控Pb的含量,但离子掺杂反应速率极快,不易控制。本文分别采用一步和两步热注射法对Mn^(2+)的掺杂含量进行大范围和精确调控,制备出具有不同Mn^(2+)掺杂含量的CsPbCl_(3)∶Mn^(2+)NCs。通过对其结构及发光性能的研究,将其区分为合金结构和掺杂结构,并进一步揭示了一步法和两步法进行Mn^(2+)调控时的不同机制,明确了在相同Pb∶Mn投料比的情况下,一步法合成的合金结构纳米晶具有更高的Mn^(2+)掺杂量,使得纳米晶在610nm左右与Mn相关的发射峰更为强烈,最高光致发光量子产为77%,而两步法合成的掺杂结构纳米晶在较少的Mn^(2+)情况下同样具有较高的光致发光量子产率。同时,Mn^(2+)的可控掺杂使得钙钛矿纳米晶的稳定性有效提升,放置四周后形貌和发光性能仍稳定。值得注意的是,合金结构对于本征激子发光稳定性的提升比掺杂结构更加有利。此外,还合成了具有优异发光性能的CsPb(Cl_(x)Br_(3-x))∶Mn^(2+)钙钛矿纳米晶,其荧光光谱可在404~640nm之间调控;但当Br-含量较高时,与Mn相关的发射峰消失,这是由于CsPbBr_(3)的能带与Mn^(2+)的^(4)T_(1-)^(6)A_(1)能级不匹配所致。本文强调了在CsPbCl_(3)∶Mn^(2+)钙钛矿制备过程中Mn^(2+)可控掺杂的重要性,对于实现纳米晶的可控合成具有重要意义。

关键词：全无机钙钛矿 CsPbCl_(3):Mn^(2+) 组分调控

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食品安全检验检测质量管理与策略研究

现代食品 2024年第4期30卷 172-174页

作者：尹喆姚惠芳唐山市食品药品综合检验检测中心河北唐山063000

目前,我国食品安全检测存在技术落后、监督管理体系不健全、检测效率不高等问题,需要食品安全监督管理部门引进先进的检测技术、提升检测效率,以保证食品安全。基于此,本文分析了食品安全检验检测质量管理的重要意义以及食品安全检验检... 详细信息

目前,我国食品安全检测存在技术落后、监督管理体系不健全、检测效率不高等问题,需要食品安全监督管理部门引进先进的检测技术、提升检测效率,以保证食品安全。基于此,本文分析了食品安全检验检测质量管理的重要意义以及食品安全检验检测的问题,并提出了相应的质量控制对策,以期促进食品安全检验技术的进步。

关键词：食品安全质量管理建议

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Implicit finite difference method for fractional percolation equation with Dirichlet and fractional boundary conditions

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Applied Mathematics and Mechanics(English Edition) 2016年第3期37卷 403-416页

作者： Boling GUO Qiang XU zhe yin Institute of Applied Physics and Computational Mathematics Beijing 100088 China School of Mathematical Sciences Shandong Normal University Jinan 250014 China

An implicit finite difference method is developed for a one-dimensional frac- tional percolation equation （FPE） with the Dirichlet and fractional boundary conditions. The stability and convergence are discussed for two special cases, i.e., a continued seep- age flow with a monotone percolation coefficient and a seepage flow with the fractional Neumann boundary condition. The accuracy and efficiency of the method are checked with two numerical examples.

关键词： fractional percolation equation (FPE) Riemann-Liouville derivative frac-tional boundary condition finite difference method stability and convergence Toeplitzmatrix

适应新型电力系统多类灵活性资源日前-实时协同优化模型

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上海理工大学学报 2024年第4期46卷 440-451页

作者：梁燕吉喆樊伟尹哲赵海波王尧刘红丽侯昱丞华北电力大学电气与电子工程学院北京102206 国网山西省电力公司经济技术研究院太原030000 华北电力大学经济与管理学院北京102206

在高比例新能源并网背景下,为了保证新型电力系统运行的安全稳定,挖掘多类灵活性资源的调节潜力至关重要。为此,提出多类灵活性资源日前–实时两阶段协同优化模型。首先,通过场景模拟和场景削减技术模拟新能源发电不确定性,并分析了电... 详细信息

在高比例新能源并网背景下,为了保证新型电力系统运行的安全稳定,挖掘多类灵活性资源的调节潜力至关重要。为此,提出多类灵活性资源日前–实时两阶段协同优化模型。首先,通过场景模拟和场景削减技术模拟新能源发电不确定性,并分析了电源侧、用户侧、储能侧灵活性资源的类型及优势。然后,设计日前–实时两阶段优化框架并建立风险经济调度模型,在日前阶段,根据新能源预测功率确定启停计划、发电计划等,以最小运行成本达到功率平衡。在实时阶段,根据新能源实际模拟功率确定调整功率、调用备用容量、需求响应程度,以最小期望成本达到功率再平衡。为了刻画新能源不确定性,在目标函数中引入条件风险价值来度量风险。最后,以区域系统为例进行算例分析。研究结果表明:在两阶段优化框架下,多类型电源实现互济,共同满足系统负荷需求,电源侧、用户侧、储能侧的灵活性资源发挥了协同调节功能,增强了系统灵活性;此外,两阶段风险经济调度模型通过条件风险价值刻画不确定性,较好地均衡了系统运行的经济性和安全性。

关键词：新型电力系统灵活性资源两阶段优化调度模型条件风险价值

Static balancing of planar articulated robots

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Frontiers of Mechanical Engineering 2015年第4期10卷 326-343页

作者： QUAGLIA zhe yin Department of Mechanical and Aerospace Engineering Politecnico diTorino Torino 10129 Italy

Static balancing for a manipulator＇s weight is necessary in terms of energy saving and performance improvement. This paper proposes a method to design balancing devices for articulated robots in industry, based on robotic dynamics. Full design details for the balancing system using springs are presented from two aspects： One is the optimization for the position of the balancing system; the other is the design of the spring parameters. As examples, two feasible balancing devices are proposed, based on different robotic structures： The first solution consists of linkages and springs; the other consists of pulleys, cross mechanisms and （hydro-） pneumatic springs. Then the two solutions are compared. Pneumatic, hydro-pneumatic and mechanical springs are discussed and their parameters are decided according to the requirements of torque compensation. Numerical results show that with the proper design using the methodology presented in this paper, an articulated robot can be statically balanced perfectly in all configurations. This paper therefore provides a design method of the balancing system for other similar structures.

关键词： robotics static balancing pneumatic spring,mechanical spring torque compensation

历史街区的文化重塑——以文殊坊一体化项目实践为例

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当代建筑 2024年第3期 43-47页

作者：高锐尹喆杨艳梅四川省建筑设计研究院有限公司A2建筑工作室

本文以文殊坊一体化规划设计实践为例,依托文化本底,聚焦文化脉络、空间场景和业态运营的活力再生,对地域文化与空间整合、历史保护与有机更新、街巷脉络与空间格局、传统形制与现代空间、商业运营与场景营造等多个层面进行探索,并针对... 详细信息

本文以文殊坊一体化规划设计实践为例,依托文化本底,聚焦文化脉络、空间场景和业态运营的活力再生,对地域文化与空间整合、历史保护与有机更新、街巷脉络与空间格局、传统形制与现代空间、商业运营与场景营造等多个层面进行探索,并针对历史文化街区的有机更新及规划设计总结经验,提出策略与建议。

关键词：地域重塑新旧共生活力再生

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肩关节脱位伴肩袖巨大撕裂镜下修复1例

中国骨伤 2024年第8期37卷 792-795页

作者：严正马佳金哲峰崔胤哲展嘉文司江涛王毅韩雪崔莹中国中医科学院望京医院运动医学三科北京100102 中国中医科学院望京医院放射科北京100102

患者,女,70岁,主因“右肩伤后疼痛伴活动受限2个月”于2022年9月13日入院。患者2个月前不慎自行摔伤致右肩关节脱位,至医院急诊就诊,经X线检查后诊断:右肩关节脱位(图1a)。手法复位后颈腕吊带悬吊固定。1个月后右肩肿痛明显伴活动受限,... 详细信息

患者,女,70岁,主因“右肩伤后疼痛伴活动受限2个月”于2022年9月13日入院。患者2个月前不慎自行摔伤致右肩关节脱位,至医院急诊就诊,经X线检查后诊断:右肩关节脱位(图1a)。手法复位后颈腕吊带悬吊固定。1个月后右肩肿痛明显伴活动受限,经查体及MRI(图1b-1c),诊断为右肩袖巨大撕裂(冈上肌腱、冈下肌腱、肩胛下肌撕裂),右肱二头肌长头腱脱位,右肩骨关节炎,遂由门诊收入院进一步诊治。专科情况:右肩局部肤色、皮温、感觉均正常,锁骨走行正常。关节主动活动度:外展,左170°,右60°;中立位内收,左40°,右0°;前屈,左180°,右100°;后伸,左30°,右20°;0°外旋,左50°,右20°;被动活动与主动活动无明显差别(图1d)。右肩Neer征阳性、Neer加强试验阳性、外展抗阻力试验阳性、0°内外旋抗阻力试验阳性、Hawkins征阳性、O'Brien试验阳性、熊抱试验阳性、肱二头肌抗阻力试验阳性、Speed试验阳性、落臂试验阴性、外旋迟滞试验阴性、内旋迟滞试验阳性、双上肢感觉正常对称,上肢肌力、肌张力未见明显异常,颈椎无明显压痛,生理曲度正常,压颈试验阴性。

关键词：肩关节脱位肩袖巨大撕裂肩关节镜逗号征

Forecasts of cosmological constraints from HI intensity mapping with FAST,BINGO and SKA-I

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Research in Astronomy and Astrophysics 2019年第12期19卷 343-360页

作者： Elimboto Yohana Yi-Chao Li yin-zhe Ma Astrophysics and Cosmology Research Unit School of MathematicsStatistics&Computer ScienceUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa Dar Es Salaam University College of Education A Constituent College of the University of Dar Es SalaamP.O.Box 2329 Dar Es SalaamTanzania Astrophysics and Cosmology Research Unit School of Chemistry and PhysicsUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa NAOC-UKZN Computational Astrophysics Centre(NUCAC) University of KwaZulu-NatalDurban4000South Africa

We forecast the cosmological constraints of the neutral hydrogen(HI) intensity mapping(IM)technique with radio telescopes by assuming 1-year of observational time. The current and future radio telescopes that we consider here are Five-hundred-meter Aperture Spherical radio Telescope(FAST), Baryon acoustic oscillations In Neutral Gas Observations(BINGO), and Square Kilometre Array phase Ⅰ(SKA-Ⅰ) single-dish experiments. We also forecast the combined constraints of the three radio telescopes with Planck. We find that the 1σ errors of(w0, wa) for BINGO, FAST and SKA-Ⅰ with respect to the fiducial values are respectively,(0.9293, 3.5792),(0.4083, 1.5878) and(0.3158, 0.4622). This is equivalent to(56.04%, 55.64%) and(66.02%, 87.09%) improvements in constraining(w0, wa) for FAST and SKA-Ⅰ respectively relative to BINGO. Simulations further show that SKA-Ⅰ will put more stringent constraints than both FAST and BINGO when each of the experiments is combined with Planck measurements. The 1σ errors for(w0, wa), BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck covariance matrices are respectively(0.0832, 0.3520),(0.0791, 0.3313) and(0.0678, 0.2679) implying there is an improvement in(w0, wa) constraints of(4.93%, 5.88%) for FAST + Planck relative to BINGO + Planck and an improvement of(18.51%, 23.89%) in constraining(w0, wa) for SKA-Ⅰ + Planck relative to BINGO + Planck. We also compared the performance of Planck data plus each single-dish experiment relative to Planck alone,and find that the reduction in(w0, wa) 1σ errors for each experiment plus Planck, respectively, imply the(w0, wa) constraints improvement of(22.96%, 8.45%),(26.76%, 13.84%) and(37.22%, 30.33%) for BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck relative to Planck alone. For the nine cosmological parameters in consideration, we find that there is a trade-off between SKA-Ⅰ and FAST in constraining cosmological parameters, with each experiment being more superior in constraining a particular set of parameter

关键词： surveys galaxies:statistics cosmology:observations large-scale structure of Universe galaxies:kinematics and dynamics