A Large Conformational Change of a Bridged b-Cyclodextrin Dimer in Aqueous Solution

As artificial enzymes, the binding constants of cyclodextrins (CDs) and their substrates are expected to be high1. For this purpose, many kinds of bridged cyclodextrin dimers2 whose two cyclodextrins are linked by various spacers have been constructed. It was of interest to make the dimers, whose binding constants would exceed 108dm3/mol3. Up to date, the bridged cyclodextrin dimers have been extensively studied as enzyme models and as molecular receptors4-6. Recently, we synthesized a brid…     

30J能量驱动类镍银X光激光的理论研究

 在1.2×10¹³W·cm^－2低功率密度下，对基频激光预主短脉冲驱动类镍银X光激光机理进行了数值模拟和理论分析。证实了在靶长23 mm范围内X光激光都能获得有效放大，取得了和实验相符合的结果。考虑了单柱面镜线聚焦沿靶长度方向功率密度的非均匀性对X光激光放大的影响，采用弯曲靶能有效克服折射以及单柱面镜线聚焦功率密度非均匀带来的不利影响。理论模拟给出的类镍银X光激光的出光下限泵浦功率密度也与实验符合得很好。理论模拟还表明，采用1%左右的预脉冲强度并对预主脉冲时间间隔进行优化，X光激光的输出能量和能量转换效率将获得大幅度提高。     

Zn(BTZ)2白色有机电致发光材料的合成及其器件制备

以PCl₃为脱水剂,将邻氨基硫酚与水杨酸脱水环化合成出2-(2-羟基苯基)苯并噻唑,并进一步将所得产物与乙酸锌反应合成出2-(2-羟基苯基)苯并噻唑螯合锌(Zn(BTZ)₂)材料。以该配合物作为发光层制备出结构为ITO/PVK:TPD/Zn(BTZ)₂/Al近白色电致发光器件,其色坐标位于白场之内(x=0.242,y=0.359),在驱动电压为16V时,亮度达3200cdm²,对应的量子效率为0.32%。进一步在Zn(BTZ)₂中掺入橙红色染料Rubrene,制成ITO/PVK:TPD/Zn(BTZ)₂:Rubrene/Al结构器件,实现了纯白色发光(色坐标值:x=0.324,y=0.343),非常接近于白色等能点,且量子效率达0.47%。最后对上述器件的发光和电学性能进行了深入的研究和探讨。     

19.6nm波长类氖锗X光激光光源理论模拟

 波长19.6nm的类氖锗X光激光适合作为诊断激光等离子体界面不稳定性的光源。用经过实验检验的系列程序对预-主短脉冲驱动类氖锗进行了系统的优化设计和理论分析。采用2%~3%的预脉冲强度，6~8ns的预-主脉冲时间间隔，在4×10¹³W/cm²功率密度驱动下, 波长19.6nm增益区的宽度可以超过60μm，增益区的维持时间可以达到90ps。对于16mm长的平板靶，增益系数可达11.8/cm；弯曲靶增益系数可达13.3/cm；单靶小增益长度积可达21.3，单靶就可以获得饱和增益。采用双靶对接，其小讯号增益可达38.4，可以获得深度饱和增益，能满足应用演示所需的X光激光光源。     

衍/折射光学元件消二级光谱的设计

 采用衍/折射光学元件结合的方法，使用两种玻璃设计了星载用长焦距望远物镜，对其二级光谱进行了校正。具体介绍了衍/折透镜望远透镜消二级光谱方法、步骤。计算机模拟结果表明：校正后的望远物镜轴上位置色差小于0.08mm，满足使用要求，并且设计方法步骤简单。     

钌(Ⅱ)卟啉催化顺式二苯乙烯类化合物的选择性合成

由芳醛制得的腙盐在钌(Ⅱ)卟啉催化下发生自身偶合，以较高收率合成了二苯乙烯类化合物(～90％的顺式选择性)。部分中间体及目标化合物的结构经^1H NMR，^13C NMR和MS表征。     

Hydrothermal Synthesis and Characterization of a Novel Two-dimensional Framework Materials Constructed from Polyoxometalate and Coordination Groups: [H_2Mo_(5.5)V_(10.5)O_(40)(PO_4)][Cu(en)_2]_4·7H_2O

IntroductionPolyoxometalatesarewidelystudiedfortheirin terestingapplicationsincatalysis ,electronicconduc tivity ,magnetism ,nonlinearopticsandmedicine[1— 4 ] .Whilethemechanismofthesynthesisofpolyoxometalatesremainselusiveandisoftende scribedasself assembly ,thereseemstobeanincreas inguseofthecombinationofthehydrothermalmethodandthestructure directingtemplate .There searchwiththismethodhasdemonstratedthatanum beroftransitionmetaloxides ,typicallyreducedmolybdenumoxides ,mixedvalancevanadiumo…     

Synthesis of New 13-O-Acylavermectin Bl Aglycones

Six new 13-O-acylavermectin Bl aglycones(3-8) were synthesized from avermectin B1 aglycone and their bioactivities were evaluated against Spodoptera exigua, Spodoptera eridania, Tetranychus urticae and Aphis fabae.     

BIFURCATIONS OF ROUGH 3—POINT—LOOP WITH HIGHER DIMENSIONS

The authors study the bifurcation problems of rough heteroclinic loop connecting three saddle points for the case β1 > 1, β2 > 1, β3 < 1 and β1β2β3 < 1. The existence, number, coexistence and incoexistence of 2-point-loop, 1-homoclinic orbit and 1-periodic orbit are studied. Meanwhile, the bifurcation surfaces and existence regions are given.     

Additive Maps Preserving Nilpotent Operators or Spectral Radius

Let X be a （real or complex） Banach space with dimension greater than 2 and let B0（X） be the subspace of B（X） spanned by all nilpotent operators on X. We get a complete classification of surjective additive maps Ф on B0（X） which preserve nilpotent operators in both directions. In particular, if X is infinite-dimensional, we prove that Ф has the form either Ф（T） = cATA^-1 or Ф（T） = cAT＇A^-1, where A is an invertible bounded linear or conjugate linear operator, c is a scalar, T＇ denotes the adjoint of T. As an application of these results, we show that every additive surjective map on B（X） preserving spectral radius has a similar form to the above with ｜c｜ = 1.