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Phenylhydrazone anions excitation for the photochemical carbonylation of aryl iodides with aldehydes

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Chinese Chemical Letters 2024年第4期35卷 346-351页

作者： Lei shen Yang Zhang Linlin Zhang Chuanwang Liu zhixian Ma Kangjiang Liang Chengfeng Xia Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of EducationYunnan Provincial Center for Research&Development of Natural ProductsSchool of PharmacyYunnan UniversityKunming 650500China

Spectroscopic investigations discovered that the in-situ generated phenylhydrazone anion was significantly bathochromically shifted to visible light region for photoactivation under irradiation. The photoexcited phenylhydrazone anion was potential to reduce aryl iodides via single electron transfer process for the subsequent radical chain reaction. A redox-neutral photochemical carbonylation of aryl iodides was developed on basis of the special spectroscopic features of phenylhydrazone anion. This protocol provided a convenient and efficient synthetic tool for accessing carbonylation products under redox neutral conditions without the need of transition-metals.

关键词： Organic anion Hydrazone Carbonylation Visible light Single electron transfer

马克思主义法律思想中国化的新成果(上篇)——江泽民的法治思想初探

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政治与法律 2008年第1期 41-49页

作者：沈志先上海市第二中级人民法院上海200070

马克思主义法律思想的中国化,是伴随着马克思主义中国化的进程而实现的。党的十三届四中全会以后,江泽民继承并发展了毛泽东、邓小平的法制思想,提出了许多关于社会主义民主法治建设的新思想、新观点、新论断,形成了作为"三个代表"重要... 详细信息

马克思主义法律思想的中国化,是伴随着马克思主义中国化的进程而实现的。党的十三届四中全会以后,江泽民继承并发展了毛泽东、邓小平的法制思想,提出了许多关于社会主义民主法治建设的新思想、新观点、新论断,形成了作为"三个代表"重要思想组成部分的江泽民的法治思想。江泽民的法治思想,是马克思主义法律思想中国化的崭新的理论成果。认真学习《江泽民文选》,深入研究江泽民的法治思想,对于当前贯彻科学发展观,构建社会主义和谐社会,不断推进我国法治建设的进程,具有重大的实践意义和理论意义。

关键词：江泽民法治思想马克思主义法律思想马克思主义中国化

Transient Characteristics and Accommodative Current Limiting Strategy for Bidirectional Interlinking Converters in Hybrid AC/DC Microgrids

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1575-1588页

作者： Xia shen Zhikang Shuai Wen Huang Chao shen Yang shen Z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616 USA

Bidirectional interlinking converter(BIC)is the core equipment in a hybrid AC/DC microgrid connected between AC and DC ***,the variety of control modes and flexible bidirectional power flow complicate the influence of AC faults on BIC itself and on DC sub-grid,which potentially threaten both converter safety and system *** study first investigates AC fault influence on the BIC and DC bus voltage under different BIC control modes and different pre-fault operation states,by developing a mathematical model and equivalent sequence ***,based on the analysis results,a general accommodative current limiting strategy is proposed for BIC without limitations to specific mode or operation *** amplitude is predicted and constrained according to the critical requirements to protect the BIC and relieving the AC fault influence on the DC bus *** with conventional methods,potential current limit failure and distortions under asymmetric faults can also be ***,experiments verify feasibility of the proposed method.

关键词： Bidirectional interlinking converter current limiting fault characteristic hybrid AC/DC microgrid variation/oscillation of DC bus voltage

Rational Solutions of First Order Algebraic Ordinary Differential Equations

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Journal of Systems Science & Complexity 2024年第2期37卷 567-580页

作者： FENG Shuang shen Liyong School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Let f(t,y,y')=∑ _(i=0)^(n )a_(i)(t,y)y'^(i)=0 be an irreducible first order ordinary differential equation with polynomial *** in 1998 proved that there exists a constant C such that every rational solution of f(t,y,y')=0 is of degree not greater than *** show that this degree bound C depends not only on the degrees of f in t,y,y' but also on the coefficients of f viewed as the polynomial in t,y,y'.In this paper,the authors show that if f satisfies deg(f,y)0,then the degree bound C only depends on the degrees of f in t,y,y',and furthermore we present an explicit expression for C in terms of the degrees of f in t,y,y'.

关键词： Degree bound first order AODE height rational solution

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晋代“璇玑图”织锦的探索和研制

丝绸 2014年第4期51卷 1-5,14页

作者：钱小萍沈之娴苏州市钱小萍古丝绸复制研究所江苏苏州215001

"璇玑图"织锦由前秦时期才女苏蕙创作并织就,是一件绝世之作。根据文献资料对诗文内容及图形文字的记载,探讨了"璇玑图"织锦的由来,并通过推断当年的纺织科技水平及织锦的结构、材质,还原了当时的制作技艺。在调查分析的基础上,最后确... 详细信息

"璇玑图"织锦由前秦时期才女苏蕙创作并织就,是一件绝世之作。根据文献资料对诗文内容及图形文字的记载,探讨了"璇玑图"织锦的由来,并通过推断当年的纺织科技水平及织锦的结构、材质,还原了当时的制作技艺。在调查分析的基础上,最后确定了采用五重经锦来进行表现的设计方案。经过多年反复试验和改进,终于将失传1 600余年的晋代"璇玑图回文诗织锦"试制成功。复原品不仅仿制得形似、神似,而且创新研制了不同技法、不同结构和不同风格的"璇玑图"丝绸作品,以适应现代人的喜爱和应用。

关键词：璇玑图回文诗五重经锦织锦复原品宋锦挂轴晋代丝绸

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黎锦的结构与织造工艺及其龙被刺绣技法研究

丝绸 2021年第11期58卷 1-4页

作者：钱小萍沈芝娴方婷玉苏州市钱小萍古丝绸复制研究所江苏苏州215001

“黎族传统纺染织绣技艺”是联合国教科文组织首批急需保护的非物质文化遗产名录之一,也是海南黎族传统工艺的典型代表。为使人们对黎锦技艺有更深入、全面的认识,文章重点对黎锦的织物结构和织造原理,以及对黎锦龙被的刺绣技法展开深... 详细信息

“黎族传统纺染织绣技艺”是联合国教科文组织首批急需保护的非物质文化遗产名录之一,也是海南黎族传统工艺的典型代表。为使人们对黎锦技艺有更深入、全面的认识,文章重点对黎锦的织物结构和织造原理,以及对黎锦龙被的刺绣技法展开深入研究,通过对海南黎锦龙被先后两次的复制实践,论述了黎锦独特的技术原理,剖析了黎锦的组织结构和织造技艺的巧妙之处,同时研究了黎锦龙被刺绣技法,以期黎族这一代表性的传统纺织技艺能得到更好的传承和弘扬。

关键词：海南黎族纺染织绣纺织技艺黎锦龙被非遗腰机滴针绣

Influence of erosion voids and traffic loads on buried large-diameter reinforced concrete pipes

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Underground Space 2024年第4期17卷 120-131页

作者： Ming Xu Dawei shen Department of Civil Engineering Tsinghua UniversityBeijing 100084China Beijing Institute of Technology Beijing 100081China

Geotechnical centrifuge tests were conducted to examine the influence of invert voids and surface traffic loads on 1400 mm diameter reinforced concrete pipes buried with a shallow soil cover depth of 700 *** formation beneath the pipe was simulated during centrifuge *** test results revealed that before void formation,the surface load directly above the middle of the pipe caused a significant increase in not only the circumferential bending moments but also the longitudinal bending moments,the latter of which was considerable and could not be *** formation beneath the middle of the pipe led to a reduction in both the circumferential bending moments and longitudinal bending moments at all measuring positions,i.e.,crown,springline,and *** most significant reduction occurred at the invert,and there was even a reversal in the sign of the invert longitudinal bending moment.A comparison was made between centrifuge tests with erosion voids and surface loads at different horizontal positions,which had a marked influence even when the positions differed by half a pipe *** rotation played an important role in relieving large bending moments of pipe barrels in a jointed pipeline when the void and surface load were located at the joint.

关键词： Centrifuge test Erosion void Reinforced concrete pipe Traffic loading Longitudinal bending moment Joint rotation

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齿轮磨损故障动态响应特征与诊断指标研究

机械工程学报 2021年第17期57卷 120-131页

作者：沈智宪乔百杰罗巍杨来浩陈雪峰西安交通大学机械工程学院西安710049 西安交通大学机械制造系统工程国家重点实验室西安710049

齿轮磨损属于典型的早期故障,为监测齿轮磨损状态,开展齿轮磨损故障机理与诊断指标研究。采用解析建模的方法,定量研究了齿轮磨损对时变啮合刚度和无负载静态传递误差动力学参数的影响规律:采用Archard磨损模型计算齿轮齿面磨损深度,获... 详细信息

齿轮磨损属于典型的早期故障,为监测齿轮磨损状态,开展齿轮磨损故障机理与诊断指标研究。采用解析建模的方法,定量研究了齿轮磨损对时变啮合刚度和无负载静态传递误差动力学参数的影响规律:采用Archard磨损模型计算齿轮齿面磨损深度,获得沿齿廓方向的非均匀磨损分布;采用势能法计算齿轮啮合刚度,揭示了齿轮磨损对啮合刚度幅值影响的定量规律;将齿轮磨损等效为轮齿齿廓偏差,揭示了齿轮磨损对无负载静态传递误差影响的定量规律。采用集中参数法建立齿轮传动的动力学模型,通过两级直齿轮疲劳寿命试验对比验证了齿轮磨损动态响应特征。结果表明,齿轮磨损主要影响齿轮啮合频率及其谐波成分,同时啮合频率及其谐波的边频带以转频为主,且随磨损增加出现明显变化。基于获得的磨损动态响应特征,构造了四个基于振动信号啮合频率边带的诊断指标,该指标对磨损状态变化敏感,通过仿真和试验验证了指标的有效性和鲁棒性。

关键词：齿轮磨损动力学模型时变啮合刚度传递误差动态响应诊断指标

Large reversible magnetocaloric effect in antiferromagnetic Er_(3)Si_(2)C_(2) compound

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Journal of Rare Earths 2024年第8期42卷 1555-1559,I0005页

作者： Hao Sun Lu Tian Xinqiang Gao Zhaojun Mo Jun shen Baogen shen School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341000China Department of Energy and Power Engineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing100081China

The magnetic properties,magnetic phase transition and magnetocaloric effects(MCE) of Er_(3)Si_(2)C_(2) compound were investigated based on theoretical calculations and experimental *** on the first principles calculations,the antiferromagnetic(AFM) ground state type in Er_(3)Si_(2)C_(2) compound was predicted and its electronic structure was *** experimental results show that Ei_(3)Si_(2)C_(2) compound is an AFM compound with the Neel temperature(T_(N) of 7 K and undergoes a field-induced firstorder magnetic phase transition from AFM to ferromagnetic(FM) under magnetic fields exceeding 0.6 T at 2 *** magnetic transition process of Er_(3)Si_(2)C_(2) compound was investigated and *** values of the maximum magnetic entropy change(-ΔS_(M)^(max)) and the refrigeration capacity(RC) are 17 J/(kg·K)and 193 J/kg under changing magnetic fields of 0-5 T,*** a potential cryogenic magnetic refrigerant,the Er_(3)Si_(2)C_(2) compound also provides an interesting research medium to study the magnetic phase transition process.

关键词： Magnetic materials Magnetocaloric Metamagnetic transitions Magnetic phase transition Rare earths