凸体的曲率映象与仿射表面积

本文研究了一些特殊凸体与其极体的曲率仿射表面积乘积的下界.对任意两个凸体,建立了它们的投影体的混合体积与其仿射表面积的一个不等式（见文[1-15]）.     

k-order Slant Toeplitz Operators on the Bergman Space

In this paper κ-order slant Toeplitz operator on the Bergman space is defined. Some properties like spectrum, commuting are discussed.     

N,N-二(2-苯并咪唑亚甲基)甲胺高氯酸盐的晶体和电子结构

合成了三齿配体N,N-二(2-苯并咪唑亚甲基)甲胺(MN3)的高氯酸盐.对该化合物进行了元素分析、紫外和红外表征;采用X射线衍射方法测定了该化合物的晶体结构,依据晶体结构数据使用G98程序对配体(MN3)进行了量子化学计算.     

富勒烯掺杂有机光电导材料的光电导性

富勒烯掺杂有机光电导材料的光电导性徐铸德，陈万喜，冷拥军，许小平，李文铸（浙江大学化学系，物理系，杭州，３１００２７）汪茫（浙江大学高分子科学与工程学系）关键词富勒烯，光化学，光物理，光电导体光电导材料在现代静电成像领域中有极广泛的应用，近年来，有机...     

Synthesis of a Tweezer—like Bis（Phenylthiapropoxy）calix[4]—arene as a Cation／π Enhanced Sensor for Ion—Selective Electrodes

Two novel 25,27-dihydroxy-26,28-bis(3-phenylthiapropxy)-calix[4]arene(3) and 25,27-dihydroxy-26,28-bis(3-phenylthiapropoxy)-5,11,17,23-tetra-tert-butylcalix[4] arene (4) were synthesized for the evaluation of their ion-selectivity in ion-selective electrodes(ISEs).ISEs based on 3 and 4 as neutral ionophores were prepared,and their selectivity coefficients for Ag^ (lg KAg,M^pot)were investigated against other alkali metal,alkaline-earth metal,aluminum,thallium(Ⅰ）,Lead and some transition metal ions using the separate solution method (SSM).These ISEs showed excellent Ag^ seletivity over most of the interfering cations examined,except for Hg^2 and Fe^2 having relative smaller interference(lg KAg,M^pot≤-2.1).     

蛋白芯片法同时检测食品中克伦特罗与莱克多巴胺的残留量

建立了食品中克伦特罗和莱克多巴胺残留含量同时检测的微阵列蛋白芯片法。结果显示:克伦特罗的线性范围为0.07～1.2 ng/g;莱克多巴胺的线性范围为0.05～0.8 ng/g。猪肉、猪肝中上述两种物质的加标回收率为74%～132%,相对标准偏差均小于10%。将所建立的方法与HPLC-MS方法进行对比,两者检测结果一致。该方法简单、快速、通量高,可用于实际样品中克伦特罗和莱克多巴胺残留量的检测。     

A research study on the spallation strength of LY12 aluminum under the pre-compression condition

Science China Physics, Mechanics & Astronomy - To pre-compress the disk-shaped LY12 samples along the radial direction can be done with the aid of overstress assembly by heating or by...     

Synthesis, Crystal Structure and Antibacterial Activity of Two Hydrazones Derived from 2-Fluorobenzhydrazide

Two new Schiff base benzoyl hydrazone compounds, C14H10FN3O3 (Ⅰ) and C14H10F2N2O (Ⅱ), have been synthesized and characterized by elemental analysis, IR, UV and X-ray single-crystal diffraction. Both compounds crystallize in monoclinic, space group P21/c with a = 7.0514(14), b = 25.928(5), c = 7.7099(15), β = 111.823(2)°, V = 1308.6(4)3, Z = 4, C14H10FN3O3, Mr = 287.25, Dc = 1.458 g/cm3, μ(MoKα) = 0.115 mm-1, F(000) = 592, the final R = 0.0841 and wR = 0.2489 for 1901 observed reflections (I > 2σ(I)) for I; a = 11.232(3), b =12.735(4), c = 8.612(2) , β = 90.869(3)°, V = 1231.7(6)3, Z = 4, C14H10F2N2O, Mr = 260.24, Dc = 1.403 g/cm3, μ(MoKα) = 0.111 mm-1, F(000) = 536, the final R = 0.0453 and wR = 0.1085 for 1317 observed reflections (I > 2σ(I)) for Ⅱ. The antibacterial activities of both compounds against two bacteria were first studied and one compound showed considerable antibacterial activity against K. Pneumonia and S. aureus.     

匀浆提取-超高效液相色谱-串联质谱法测定烟草中亚硝胺含量

提出了超高效液相色谱-串联质谱法测定烟草中N-亚硝基降烟碱(NNN)、N-亚硝基新烟草碱(NAT)、N-亚硝基假木贼碱(NAB)和4-甲基亚硝基吡啶基丁酮(NNK)等4种亚硝胺含量的方法。烟草样品经0.1mol.L-1乙酸铵溶液匀浆提取,离心分离取上清液过Waters AcquityUPLC BEH C18色谱柱(2.1mm×100mm,1.7μm)分离,以乙腈和0.01mol.L-1乙酸铵溶液按不同体积混合作流动相梯度洗脱。串联质谱测定中采用电喷雾离子源正离子模式和多反应监测模式检测,同位素内标法定量。NNK、NNN、NAB和NAT的检出限(3s)分别为0.06,0.17,0.15,0.053μg.L-1。方法的加标回收率在92.1%～104%之间;日内和日间相对标准偏差(n=7)分别为2.7%～3.3%和3.5%～4.2%。     

电化学还原预处理对BiVO_4薄膜电极光电化学氧化水性能的提高

在酸性水溶液中(pH=2.0),采用电化学还原(ER)方法对BiVO4薄膜电极进行预处理,并探讨了其对薄膜电极光电化学氧化水性能的影响.结果表明,这种预处理可显著提高电极的光电化学氧化水的性能,且具有良好的光电化学稳定性.利用扫描电子显微镜、X射线衍射、拉曼光谱、光电子能谱、紫外-可见漫反射光谱、荧光光谱、电化学阻抗谱及Mott-Schottky等方法对ER处理前后的电极进行了表征.结果表明,ER预处理使电极粗糙度增大,表面积增大约1.4倍;电极材料的晶型无明显变化,但V—O对称伸缩振动略有红移;表面Bi,V和O结合能变小,Bi3+部分被还原,Bi/V原子比增大;ER处理导致电极平带电位负移,光生载流子在薄膜电极/溶液界面转移速率加快,表面复合速率降低.这些变化和表面积增加是BiVO4电极光电化学性能提高的主要原因.