Efficient cyclopropanation of aryl/heteroaryl acetates and acetonitriles with vinyl diphenyl sulfonium triflate

A convenient method was developed for the cyclopropanation of aryl acetates and aryl acetonitrile using vinyl diphenyl sulfonium triflate salt. The newly developed conditions are simple, mild, and compatible with a wide range of functional groups, without the need to apply an inert atmosphere, or alkali bases.     

N─甲基吡咯烷酮两相闭式热虹吸管传热特性的实验研究

本文报道了用Ｎ—甲基吡咯烷酮（Ｃ５Ｈ９ＮＯ３）为工质以光滑管与三维内翅片管为管壳制成的两相闭式逆流热虹吸管的传热特性。实验结果表明在工作温度为２２０～３５０℃，热负荷为８．２～１７．３ｋＷ／ｍ２范围内光滑热虹吸管蒸发段与凝结段换热系数的积分平均值分别约为１７００Ｗ／ｍ２·℃和１６００Ｗ／ｍ２·℃。由于三维翅片的强化传热作用，使三维内翅片热虹吸管蒸发段与凝结段换热系数分别比光滑管增大了２０％～４０％和７０％～１６０％。实验表明Ｎ—甲基吡咯烷酮综合传热性能优于萘，可望作为中温热管工质使用。     

Synthesizing monochromatic 3-D images by multiple-exposure rainbow holography with vertical area-partition approach

We report for the first time the theoretical analysis and experimental results of a white-light reconstructed monochromatic 3-D image synthesizing tomograms by multiple rainbow holography with vertical-area partition (VAP) approach. The theoretical and experimental results show that 3-D monochromatic image can be synthesized by recording the master hologram by VAP approach without any distortions either in gray scale or in geometrical position. A 3-D monochromatic image synthesized from a series of medical tomograms is presented in this paper for the first time     

Ab initio multireference configuration-interaction theoretical study on the low-lying spin states in binuclear transition-metal complex: magnetic exchange of [(NH3)5Cr(mu-OH)Cr(NH3)5]5+ and [Cl3FeOFeCl3]2-

The magnetic exchange interaction behavior and energy spectrum of low-lying spin states are investigated by using ab initio multireference configuration-interaction method for the representative binuclear transition-metal complexes [(NH(3))(5)Cr(mu-OH)Cr(NH(3))(5)](5+) and [Cl(3)FeOFeCl(3)](2-). Our calculations for the nonmodeling real title complexes found that under the appropriate basis sets and active space, ab initio method at multireference configuration-interaction level of theory is able to give accurate energy spectrum of low-lying spin states within reachable computation demand nowadays and the deviation of magnetic exchange interaction to Lande interval rule can be described by the biquadratic correction in terms of Heisenberg spin Hamiltonian. As a methodology comparison, density-functional theory combined with broken-symmetry approach provides an alternative yet efficient approach to produce accurate numerical results, but there are dependences on the particular chosen exchange-correlation functionals and system dependent. The spin population analyses at complete active space self-consistent-field level of the theory provide an instructively understanding and prediction for the magnetic interaction mechanism.     

一种具有温度校正功能的新型手持式农药残留检测仪

介绍了一种采用基于酶动力学分析法，以发光二级管(LED)作为单色光源，以电池供电的新型手持式有机磷和氨基甲酸酯类农药残留检测仪。仪器以单片机系统为核心，体积小，重量轻；采用多点采样线性回归与光强直读等技术，保证了测量结果的稳定可靠；采用了温度校正技术，简化了分析操作，使得农药残留的现场快速分析成为可能。     

原发性三叉神经痛患者伴发焦虑抑郁及睡眠障碍的临床研究

目的调查首次诊断为原发性三叉神经痛患者伴发抑郁焦虑情况及睡眠质量,并初步探讨疼痛评分与焦虑抑郁程度的相关性。方法收集61例首次诊断为原发性三叉神经痛并未经正规治疗患者以及55例年龄、性别相匹配的健康体检者（正常对照组）的人口学资料,应用视觉模拟量表（VAS）进行疼痛评分,采用汉密尔顿焦虑量表（HAMA）、汉密尔顿抑郁量表（HAMD）及匹兹堡睡眠指数量表（PSQI）分别进行焦虑、抑郁及睡眠质量的评估,采用简易智能精神状态量表（MMSE）和蒙特利尔认知评估量表（MoCA）进行研究对象认知功能评定,对评分结果及各量表的相关性进行分析。结果两组患者在性别、年龄、受教育年限、吸烟饮酒比率方面的差异均无统计学意义（均P＞0.05）;原发三叉神经痛患者中存在抑郁症状22例（36.1%）,焦虑症状17例（27.8%）,睡眠障碍15例（24.6%）。原发性三叉神经痛患者MoCA评分明显低于正常对照组,HAMA评分、HAMD评分和PSQI评分均高于对照组,差异均有统计学意义（均P＜0.01）;而两组间MMSE评分的差异无统计学意义（P＞0.05）。三叉神经痛患者的疼痛评分与HAMA评分、HAMD评分均呈正相关（均P＜0.01）。结论三叉神经痛患者伴随较高比例的抑郁和焦虑,且与疼痛评分成正相关,更容易发生睡眠障碍。     

Hydrogen Bonding Enables Polymer Hydrogels with pH-Induced Reversible Dynamic Responsive Behaviors

Poly(acrylic acid-co-N-vinylcaprolactam) (PAN) hydrogels containing multiple hydrogen bonds can exhibit pH-induced reversible dynamic responsive behaviors. When placing a transparent hydrogel in an acid bath, as hydrogen bonds between comonomer units involving protonated COOH groups are formed faster than water diffusion, a nonequilibrium light-scattering state is formed to turn the hydrogel opaque, while as the swelling equilibrium is reached over time, the hydrogel regains its transparency. Likewise, when the transparent, hydrogen-bonded hydrogel is subsequently immersed in DI water, faster water absorption occurs in where more COOH groups are deprotonated, which also generates a light-scattering state leading to opacity, while the transparency is slowly recovered after equilibrium. Using such two-way dynamic transparency evolution, a PAN-based hydrogel material is prepared to demonstrate a dynamic memory system for information memorizing-forgetting and recalling-forgetting.     

Facile N‐Alkylation/N′‐Arylation Process: A Direct Approach to Aromatic Aminoalkyl Amines

An intriguing C?N transformation involving a catalyst‐free N‐alkylation/N′‐arylation process in a multicomponent reaction with secondary amines, cyclic tertiary amines and electron‐deficient aryl halides has been described. In this case, the N‐alkylation of secondary amines, utilizing cyclic tertiary amines as alkyl group sources, is enabled by a facile C?N cleavage. Such an operationally simple method could facilitate access to aromatic aminoalkyl amines, nitrogen‐containing bioactive molecules, in good to excellent yields.     

Dehydrogenative etherification homocoupling of heterocyclic N-oxides

A novel approach was developed for the dehydrogenative etherification homocoupling of heterocyclic N-oxides in the presence of silver oxide and PyBroP. Various substrates were well tolerated and the desired products were obtained in moderate to good yields. Generally, this reaction features excellent functional group compatibility, broad substrate scope and good regioselectivity.