利用断裂反应合成1,3-二(2-羟基-3,5-二叔丁基苄基)咪唑鎓氯盐

4,6-tBu2-1-(HO)C6H2CH2Cl与1,1'-羰基二咪唑反应成功地合成双阴离子芳氧功能化的氮杂环卡宾前体[[2-HO-3,5-tBu2-C6H2CH2]2{CH(NCHCHN)}]CI(I),结果表明在反应过程中发生了断裂反应。化合物I通过元素分析,1HNMR和X-ray衍射进行表征。晶体结构表明其晶体属三斜晶系,空间群为P-1,化学式为C33H49ClN2O2,晶胞参数为a=12.014(3),b=16.757(3),c=19.191(4),α=94.836(4)deg,β=92.658(4)deg,γ=92.631(4)deg,V=3840.8(14)3,Z=2,最终R=0.092,wR=0.291。     

大豆黄素的电化学行为及其循环伏安测定

在pH 7.5的三羟甲基氨基甲烷-盐酸(Tris-盐酸)缓冲溶液的底液中,采用循环伏安法测定大豆黄素,得到一良好的氧化峰,其峰电位在0.53 V处;峰电流与大豆黄素的浓度在1.2×10-7～9.6×10-6mol·L-1范围内呈线性关系.该方法的检出限(3S/N)为8.0×10-8mol·L-1.用此法测定红车轴草中大豆黄素含量,加标平均回收率为98.0%;对1.6×10-6mol·L-1大豆黄素平行测定8次,进行精密度试验,相对标准偏差为0.81%.根据大豆黄素在玻碳电极上的电化学行为,表明大豆黄素的电极过程具有吸附性和不可逆性.     

300 kA直线型变压器驱动源模块实验研究

介绍了14支路并联的300 kA百ns直线型变压器驱动源单级模块的结构和关键部件。模块通过采用双端引出电极电容器以及小型多间隙串联气体火花开关,可以并联更多的支路数,减小回路电感,提高储能密度;通过采用非晶磁芯,减小磁芯损耗,提高模块耦合效率。实验研究了初级气体开关工作系数对模块输出的影响,实验结果表明:模块开关电压工作系数达到0.7,多间隙串联开关才能较好同步放电;给出了快直线型变压器模块的初步调试实验结果,在模块充电90 kV,开关气压0.32 MPa情况下,匹配负载电流峰值可达到302 kA,上升时间约100 ns,负载上获得的峰值功率为23 GW。     

直线变压器驱动源感应腔电路建模方法

参照研制成功的300 kA直线变压器驱动源单级感应腔的物理设计和电气参数,在考虑气体开关火花通道电阻、放电支路间电磁耦合、磁芯磁滞及饱和特性、次级功率传输的情况下,建立了较完备的单级感应腔电路模型。实验验证了模型的有效性,感应腔正常输出和单支路开关自放电时模拟结果与实验波形均吻合较好,表明模型可以模拟腔内电气元件异常时感应腔的工作特性。     

Synthesis, Crystal Structure and Catalytic Behavior of 1-Ethyl-3-benyl-imidazolyl Tetranuclear N-Heterocyclic Carbene Silver Bromide

The title complex [Ag(carbene)2]2[Ag2Br4] has been synthesized by the reaction of Ag2O with 1-ethyl-3-benyl-imidazolium bromide in DMSO at room temperature, and characterized by elemental analysis, 1H NMR and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P with a = 10.1597(10), b =11.0646(11), c = 13.0245(14) , α = 102.230(2), β = 90.606, γ = 113.9250(10)o, V = 1300.3(2) 3, Mr = 748.06, Z = 2, Dc = 1.911 g/cm3, μ(MoKα) = 4.60 mm-1 and F(000) = 728. The structure was refined to R = 0.0316 and wR = 0.0835 for 3744 observed reflections with I > 2σ(I). The title compound crystallizes as a centrosymmetric tetranuclear compound. One half of the molecule comprises the asymmetric unit of the structure. The Ag(1) atom is nearly linear or T-shaped when the Ag(1)-Ag(2) interaction is taken into consideration, which is bi-coordinated by two carbene carbon atoms. The Ag(2) atom adopts tetrahedral geometry. The catalytic behavior of the title complex has been investigated, and the results indicate it has a highly catalytic activation for L-lactide polymerization.     

Enhancement and suppression of spatial splitting four-wave mixing in atomic medium

We experimentally report on the evolution from singly-dressed to doubly-dressed four-wave mixing (FWM) process by controlling the powers of the probe, the pump and the dressing fields respectively. The differences in the enhancement and the suppression of FWM signal between the two-level and cascade three-level atomic systems are observed and explained by the multi-dressed effect theoretically. Both the x direction and the y direction spatial splittings of the degenerate-FWM (DWFM) beams are obtained. We also investigate the switch between the enhancement and the suppression of the DWFM signals and between its spatial splittings in x direction and y direction. The spatial splittings in x direction and y direction can be controlled by the relative position and the intensity of the involved laser beams. Such a study can be useful for optimizing the efficiency of the FWM process and providing potential applications in spatial signal processing.     

桥联杂环卡宾前体[CH3CH（NCHCHN）CH2]2Br2的合成

甲基咪唑与1,2-二溴乙烷在THF(四氢呋喃)中以2∶1(摩尔比)反应合成了一种新型桥联氮杂环卡宾前体[CH3CH(NCHCHN)CH2]2Br-2,产物通过核磁和X射线衍射表征.晶体结构显示其晶体属单斜晶系P21/c,a=0.847 5(3) nm,b=0.891 6(3) nm,c=0.923 4(3) nm,α=90°,β=108.214°,γ=90°,V=0.662 8(4) nm3,Z=2,Dc=1.764 mg/m3,μ=6.097 mm-1,F(000)=348.产物分子结构中存在的大量氢键是其形成空间网状结构的主要原因.     

氮杂环卡宾迁移产物[O-4，6-di—^t Bu—C6H2—2-CH2{C（MeNCHCHNH）}]2Li2（THF）2的合成

通过亲核反应合成了芳氧功能化的氮杂环卡宾前体[HO-4,6-di-C(CH3)3-C6H2-2-CH2{CH(NCHCHN)CH3}]Cl(1),1再与正丁基锂(n-BuLi)按照摩尔比2∶1常温反应生成芳氧功能化的氮杂环卡宾迁移产物[O-4,6-di-tBu-C6H2-2-CH2{C(MeNCHCHNH)}]2Li2(THF)2(2).化合物1和2均通过核磁、元素分析和X射线衍射表征.晶体结构显示化合物1属单斜晶系,空间群为C2/c,化学式为C19H29ClN2O,晶胞参数a=3.203 4(14) nm,b=0.863 0(4) nm,c=1.469 5(7) nm,α=90 °,β=106.305(10) °,γ=90 °,V=3.899(3) nm3,Z=8,R=0.170 5, wR=0.176 6.化合物2也属三斜晶系P1,a=0.942 64(13) nm,b=0.987 21(15) nm,c=1.405 58(16) nm,α=79.040(10)°,β=73.928(9)°,γ=85.804(11)°,V=1.233 7(3)nm3,Z=1,Dc=1.116 mg/m3,μ=0.070 mm-1,F(000)= 452.同时,发现温度是影响氮杂环卡宾迁移的主要原因.     

高效毛细管电泳安培法测定芦荟中芦荟苷的含量

建立了芦荟中芦荟苷含量的高效毛细管电泳安培检测方法. 探讨了缓冲溶液种类、浓度、酸碱度,工作电位,有机改性剂及其操作电压、进样时间等对检测的影响. Na2B4O7-NaOH(Na2B4O7浓度为30 mmol/L)为缓冲液,工作电位为-0.8 V,体积分数为2.5%甲醇为有机添加剂,进样时间为10 s,在15 kV分离高压,pH=9.5的碱性条件下柱端安培法检测了芦荟苷的含量. 该法的线性范围为50～0.05 mg/L,线性方程Y=856.2+123.3c,相关系数r=0.999 4,检出限为0.01 mg/L.     

深部开采对覆岩破坏移动规律的实验研究

根据淮南矿业集团潘一矿2171（1）工作面开采实践,采用相似材料模拟实验。利用电子经纬仪与数字散斑相关方法相结合监测位移,分析研究了采场上覆岩层的“三带”特征及分布规律,上覆岩层移动发展趋势、演化规律、存在范围及形态,以及与开采宽度的关系。结果表明：一定采宽后顶板垮落规律显著,断层下顶板周期断裂步距减小;岩层下沉系数与岩层高度和采厚比成线性关系,上覆岩层沉降具有非对称性;离层裂隙的发生、扩展、闭合受关键岩层的影响和控制。数据分析还表明,数字散斑相关方法具有较高的精度,这一新的研究方法引入,丰富了上覆岩层活动规律的研究手段。本文结果可为指导工程实践提供重要理论依据。