Macleayine,a new alkaloid from Macleaya cordata

Macleayine (1),a new natural occurring alkaloid with a unique spiro[furanone-piperidinedione] framework,was isolated from the aerial parts of Macleaya cordata.Its unusual structure was established by extensive spectroscopic analyses,computer-assisted structure elucidation software (ACD/Structure Elucidator),quantum chemistry calculations and ECD calculation.The result of virtual molecular docking predicted the compound can enhance the effects of insulin,and may be used to treat type II diabetes.     

药物甲氧苄氨嘧啶分子模板聚合物结合作用及选择性研究

采用分子自组装印迹技术合成了对甲氧苄氨嘧啶有高选择性的模板聚合物受体.通过Scatchard分析、¹HNMR和紫外光谱研究了模板聚合物的选择结合特性.结果表明,模板聚合物主要形成一类等价结合位点,通过协同氢键作用专一地结合模板底物,其离解常数为2.22×10^-4mol/L.底物的选择性结合实验表明,这种聚合物对甲氧苄氨嘧啶呈现高的选择性结合能力.     

超高压对枯草杆菌胞外蛋白酶的影响

 以枯草杆菌为研究对象,采用Box-Behnken响应曲面设计,研究了超高压处理对枯草杆菌胞外蛋白酶的影响以及菌体致死与胞外酶的关系。结果表明,超高压能显著抑制枯草杆菌胞外蛋白酶的活性,处理过程中压力和温度是酶失活的主要因素,并且两者之间存在交互作用,超高压处理时温度协同有效。利用Design Expert软件建立了胞外蛋白酶超高压钝化模型,决定系数R₂=0.974 7,调整决定系数R_2,adj=0.942 1。方差分析表明,模型显著,可应用于钝化效果分析与预测。实验结果还表明,超高压处理后枯草杆菌的致死率与胞外蛋白酶活的变化相关性达到极显著水平（R=0.933 0）,胞外酶可作为超高压处理对微生物影响的一个评价指标。     

电晕充电多孔PTFE/PP复合驻极体过滤材料的电荷存储特性

报道采用电晕充电方法，对用高温熔融粘合工艺制备得到的双向拉伸多孔PTFE与PP复合过滤材料进行驻极体改性，并采用热刺激放电和表面电位测量等方法研究了材料的电荷存储稳定性,根据驻极体相关理论，对实验结果进行了解释. 结果表明，电晕充电的多孔PTFE/熔喷或纺粘PP覆膜材料中，既存在空间电荷又存在极化电荷，复合膜的界面是电荷陷阱的主要来源. 从不同面对复合膜材料进行充电时，材料具有完全不同的电荷存储特性. 由于材料体内空间电荷和极化电荷的极性相反、相互补偿，表面电位测定并不能真正反映材料内部电荷的存储状态. 关键词： 驻极体 电晕充电 聚合物复合膜 热刺激放电     

Relative probabilities of breakup channels in reactions of ~(6,7)Li with ~(209)Bi at energies around and above the Coulomb barrier

Coincidence measurements of breakup fragments in reactions of~ (6,7) Li with ~(209)Bi at energies around and above the Coulomb barrier were carried out using a large solid-angle covered detector array. Through the Q values along with the relative energies of the breakup fragments, different breakup components(prompt breakups and delayed breakups) and different breakup modes(α + t, α + d, α + p, and α + α) are distinguished. A new breakup mode, α + t, is observed in ~6Li-induced reactions at energies above the Coulomb barrier. Correlations between breakup modes and breakup components as well as their variations with the incident energy are investigated. The results will help us better understand the breakup effects of weakly bound nuclei on the suppression of a complete fusion, particularly for the above-barrier energies.     

具有优异储氢性能的高质量单壁纳米碳管的合成

高纯度单壁纳米碳管的合成是应用研究和实际应用的基础和关键,提出了一种氢等离子电弧方法,在适当的生长促进剂的作用下,能大量制备出高纯度的单壁纳米碳管。选用宏观数量的单壁纳米碳管,进行适当预处理,在室温及约１００ａｔｍ下进行储氢实验,发现该材料的储氢容量可达（４．２－４．７）ｗｔ％,经过５次循环实验,其储氢容量先略有下降,随后便稳定不变,这些初步实验结果表明,单壁纳米碳管是一种很有前途的储氢材料。     

On bluff body flame stabilization

Summary Several aspects of bluff body flame stabilization are discussed in terms of a theory which focuses attention on the initial mixing region between cool combustible and hot combustion products. Some experiments by Broman and Zukoski on flame stabilization in a deflected jet are correlated in terms of the theory. The characteristic time of Zukoski and Marble is shown to arise as a special case of the theory. The extinction of the propagating flame as the initial event in the blowoff process is discussed qualitatively in terms of the theory. Finally, the results of experiments reported in the literature on injection of gas into the recirculation zone are rationalized in terms of the theory.Nomenclature Á global activation energy - C _p specific heat at constant pressure - D characteristic length - D _r recirculation zone length for bluff body - h combustion chamber height - H heat of combustion - K ₁, K ₂, K ₃, K ₄ constants - l combustion chamber length - l _r recirculation zone length for deflected jet - L a dimensional parameter (L=K ₁ DPrRe ^t+1 Nu ^–2) - m mass flow rate - n constant - Nu Nusselt number (D/) - Pr Prandtl number (C _p /) - q constant - R gas constant - Re Reynolds number (WD/ ₀) - t constant - T _b outlet temperature of localized control volume - T _f adiabatic flame temperature - T _i inlet temperature of localized control volume - T ₀ temperature of main stream - u _r average flow velocity in control volume - v ₀ blowoff speed for deflected jet (experimental) - W main stream velocity - x _i distance from separation point to initial temperature maximum - y _i depth from dividing streamline to initial temperature maximum - ()* quantities evaluated at blowoff - heat transfer coefficient - slot width - thermal conductivity - ₀ kinematic viscosity evaluated in free stream - density - characteristic time D _r /W* - _ch pre-exponential factor in chemical rate law - equivalence ratio of fresh combustible mixture - dynamic viscosity     

NMR spectral assignments of isoprenylated flavanones from Sophora tonkinensis

The phytochemical investigation of extracts from the roots of Sophora tonkinensis yielded three new isoprenylated flavanones, the tonkinochromanes F (2), G (3), and H (5), along with four known compounds. Structural elucidation of the compounds were established on the basis of spectral data, particularly by the use of 1D NMR and several 2D shift-correlated NMR pulse sequences ((1)H-(1)H COSY, HSQC, HMBC, and ROESY).