边加载径向三腔渡越时间振荡器设计

 提出了一种边加载结构的径向三腔渡越时间振荡器。通过1维单粒子理论研究了直流渡越角和电压调制系数对束-波互作用效率的影响,并进行了2.5维数值模拟验证。数值模拟研究表明:该器件具有低阻抗、高效率、输出微波频率单一稳定等特点。在400 kV,60 kA无外加引导磁场的条件下,获得了平均功率为8 GW,频率为3.9 GHz的微波输出,效率达33.3%,阻抗仅为6.7 Ω。     

Synthesis of graphene-supported LiFePO4/C materials via solid-state method using LiFePO4(OH) as precursors

Journal of Solid State Electrochemistry - The solid-state method is a mainly adopted large-scale preparation of LiFePO4 cathode materials for Li-ion batteries but suffers from a challenge of...     

A [4+1] Cyclative Capture Approach to 3H‐Indole‐N‐oxides at Room Temperature by Rhodium(III)‐Catalyzed C?H Activation

The rhodium(III)‐catalyzed [3+2] C H cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N‐hydroxyindoles and 3H‐indole‐N‐oxides. Reported herein is the first rhodium(III)‐catalyzed [4+1] C H oxidative cyclization of nitrones with diazo compounds to access 3H‐indole‐N‐oxides. More significantly, this reaction proceeds at room temperature and has been extended to the synthesis of N‐hydroxyindoles and N‐hydroxyindolines.     

A [4+1] Cyclative Capture Approach to 3H‐Indole‐N‐oxides at Room Temperature by Rhodium(III)‐Catalyzed CH Activation

The rhodium(III)‐catalyzed [3+2] C? H cyclization of aniline derivatives and internal alkynes represents a useful contribution to straightforward synthesis of indoles. However, there is no report on the more challenging synthesis of pharmaceutically important N‐hydroxyindoles and 3H‐indole‐N‐oxides. Reported herein is the first rhodium(III)‐catalyzed [4+1] C? H oxidative cyclization of nitrones with diazo compounds to access 3H‐indole‐N‐oxides. More significantly, this reaction proceeds at room temperature and has been extended to the synthesis of N‐hydroxyindoles and N‐hydroxyindolines.     

Chemical Constituents of Tripterygium wilfordii

The two new triterpenoids, (5β,8α,9β,10α,13α,14β)‐5,9,13‐trimethyl‐4‐oxo‐3,24,25,26‐tetranor‐2,3‐secooleanane‐2,29‐dioic acid (=4‐oxo‐D:A‐friedo‐3‐nor‐2,3‐secooleanane‐2,29‐dioic acid; 1 ) and (2α,3β,4β,5β,8α,9tlsb=‐2%>β,10α,13α,14β,24R)‐3,24‐epoxy‐24‐ethoxy‐2‐hydroxy‐5,9,13‐trimethyl‐24,25,26‐trinoroleanan‐29‐oic acid (=3β,24‐ epoxy‐24α‐ethoxy‐2α‐hydroxy‐D:A‐friedooleanan‐29‐oic acid; 2 ) (absolute configurations tentative), together with a novel bi‐2H‐benzopyran, namely (rel‐(3R,3′S,4R,4′S)‐3,3′,4,4′‐tetrahydro‐6,6′‐dimethoxy[3,3′‐bi‐2H‐benzopyran]‐4,4′‐diol ( 3 ), were isolated from Tripterygium wilfordii Hook . f. Their structures were established by chemical and spectroscopic studies and by X‐ray crystallography.     

大骨节病活跃严重病区和邻近非病区儿童尿硒与尿羟脯氨酸关系研究

通过测定尿硒、尿羟脯氨酸含量,研究了大骨节病活跃严重病区和邻近非病区儿童尿硒含量和尿羟脯氨酸含量的变化及其相关性.结果表明,大骨节病活跃严重病区组儿童尿硒含量和尿羟脯氨酸含量均明显低于邻近非病区组（P＜0.01）,处于病区中较低水平.两组的尿硒含量与尿羟脯氨酸含量均显著正相关（r=0.582,P＜0.01;r=0.383,P＜0.05）.这些结果提示,体硒水平是影响尿羟脯氨酸排泄量的原因之一,大骨节病活跃严重病区儿童的低硒状态,是导致其尿羟脯氨酸减少的一个重要因素.     

发光搪瓷釉料研究

铕激活的铝酸锶系列超长余辉发粉具有起始亮度高、余辉时间长、无放射性毒害等突出优点,成为当前一类极具发展前途的发光材料,本项目采用该系列发光材料,研究了蓄能发光搪瓷釉料,并制备了性能稳定的发光搪瓷制品。     

新型高温超导扭绞缆线的临界电流评估方法及其特性研究

高温超导缆线是研究各种大电流高温超导应用的基础.将超导材料通过不同方式组合成复合导体,不仅可以让缆线的载流量得到提升,更可以在机械强度和电磁特性等方面得到改善.在国内外众多研究缆线的团队中,上海交通大学超导团队提出了一种基于YBCO高温超导带材的新型高温超导扭绞缆线结构.这种结构在理论上不仅实现了载流量和机械强度的平衡,还通过扭绞改善了电磁特性[4-5].但是目前对于这种缆线的研究还处于起步阶段,特别是对其临界电流特性的研究.因此为了研究新型高温超导扭绞缆线的临界电流特性,本文从新型高温超导扭绞缆线的结构出发,通过仿真和实验两个角度对新型高温超导扭绞缆线的临界电流特性进行研究.在仿真方面,用H方程法计算缆线的临界电流,并探究扭绞节距是否会对临界电流的衰减产生影响.在实验方面,研究出了一种最适合于该缆线结构的临界电流评估方法“SVWE-copperwire-TU”.并用该方法测量了新型高温超导扭绞缆线的临界电流特性.本研究的结论对于后续制作更大电流的新型高温超导扭绞缆线具有重要意义.     

Charge transfer at biotic/abiotic interfaces in biological electrocatalysis

In this opinion paper, we discuss the charge transfer at biotic/abiotic interfaces in man-made and biological electrochemical systems. Specifically, we will first introduce the heterogeneous charge transfer at the bioelectrode interface, followed by the intramolecular change transfer in peptide and protein structures, and finally discuss the extracellular charge transfer in electrogenic microorganisms. In addition to discussion of charge transfer mechanisms and synthetic structures/scaffolds required for it, a particular focus will be given to novel experimental designs that are able to bring new concepts and boost mechanism understanding and applications development. There are also discussions on the combination of modern computational techniques and experimental characterizations.     

Rhodium(III)‐Catalyzed Intramolecular Redox‐Neutral Annulation of Tethered Alkynes: Formal Total Synthesis of (±)‐Goniomitine

A Rh^III‐catalyzed intramolecular redox‐neutral atom‐economic annulation of a tethered alkyne has been developed to efficiently construct 2‐amidealkyl indoles with completely reversed regioselectivity by a C?H activation pathway. Furthermore, using the Rh^III‐catalyzed C?H activation/annulation as a key step, a one‐pot synthesis of pyrido[1,2‐a]indoles has also been developed and applied to a highly efficient formal total synthesis of (±)‐goniomitine.