大功率辐照加速器的研制

介绍了10MeV/20kW大功率辐照加速器的设计.该加速器采用返波型行波加速结构加速管,综合了常规行波加速结构微波反射小、频率稳定性好和驻波加速结构分流阻抗高的优点.加速器工作于S波段,中心频率为2856MHz.利用自编的模拟程序AccDesign进行物理设计,设计输出电子束能量为1OMeV,脉冲流强300mA,加速管总长1.5m,模拟计算结果显示微波至电子束的转换效率为66%.同时利用计算机仿真程序对加速腔的温度和应力分布进行了计算,得到了微波功率损耗对加速腔频率的影响.     

碳纳米管宏观条带的原位制备

采用化学气相沉积法(CVD),以二甲苯为碳源,二茂铁为催化剂,在涂有SiO₂薄膜的不锈钢基底上,原位制备出了碳纳米管宏观条带。使用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和拉曼光谱(Raman)对样品形貌和结构进行了表征。结果显示：合成的碳纳米管条带宽度为20～100 μm,厚度10～30 μm,长度可达6 mm;条带由大量多壁碳纳米管沿轴向密实排列组成。对其形成机制进行了初步探讨。     

A new N-type organic semiconductor synthesized by knoevenagel condensation of truxenone and ethyl cyanoacetate

A novel n-type organic semiconductor, Et-TITC, was synthesized by Knoevenagel condensation of truxenone and ethyl cyanoacetate. Ultrasonication improved the yield of Et-TITC by more than 10 times. The molecular structure of Et-TITC was determined by X-ray analysis. Et-TITC possesses a large electron affinity and excellent solubility in many organic solvents. A positively charged xerographic photoreceptor with an excellent photosensitivity (E 1/2) of 0.32 microJ cm(-2) was prepared using Et-TITC as the charge-transport material. [structure: see text]     

Synthesis and Crystal Structure of 4-(2-Methylene-1-ethyl-3,3-dimethylindoline-2'-yl)-6,8-dibromo- 1'-ethyl-3',3'-dimethylspiro-[3,4-dihydro-2H-1-benzopyran-2,2'-indoline]

The title compound of 4-(2-methylene-1-ethyl-3,3-dimethylindoline-2'-yl)-6,8-dibro-mo-1'- ethyl-3',3'-dimethylspiro[3,4-dihydro-2H-1-benzopyran-2,2'-indoline],C33H36Br2N2O,as a dicondensed spiropyran (DC) has been synthesized by indoline in ethanol with 3,5-dibromo-salicyaldehyde.The compound was characterized by elemental analysis and IR spectra.Meanwhile,the crystal of the compound was obtained and determined by X-ray single-crystal diffraction.Crystal data: monoclinic system,space group P21/n,a=12.9699(15),b=12.5196(13),c=19.327(2) (A),β=106.493(3)°,Mr=636.46,V= 3009.1(6) (A)3,Z=4,F(000)=1304,Dc=1.405 g/cm3,μ=2.722 mm-1,R=0.0554 and wR=0.1176 for 6892 independent reflections (Rint=0.0354) and 5699 observed reflections (I>2σ(I)).