利用改进的Gamow-like模型研究原子核的α衰变和质子放射性

通过引入离心势和静电屏蔽效应对Gamow-like模型进行了改进，并将其用于α衰变和质子放射性研究，发现改进的Gamow-like模型能更好地符合实验数据。另外，还利用改进的Gamow-like模型预言了16个丰质子核的质子放射性的半衰期以及7个$Z=120$超重核素($^{296-308}120$)α衰变链上原子核的α衰变的半衰期，为将来在大科学装置上合成和鉴别这些新核素提供重要的理论参考。     

Conversion of carbohydrates into furfural and 5-hydroxymethylfurfural using furfuryl alcohol resin-based solid acid as catalyst

Cellulose - A furfuryl alcohol resin-based solid acid (SC-FAR-800) was prepared and applied in the conversion of carbohydrates into furan platform compounds in microwave. The results showed that...     

Asymmetric Ring‐Opening of Cyclopropyl Ketones with Thiol,Alcohol, and Carboxylic Acid Nucleophiles Catalyzed by a Chiral N,N′‐Dioxide–Scandium(III) Complex

A highly efficient asymmetric ring‐opening reaction of cyclopropyl ketones with a broad range of thiols, alcohols and carboxylic acids has been first realized by using a chiral N,N′‐dioxide–scandium(III) complex as catalyst. The corresponding sulfides, ethers, and esters were obtained in up to 99 % yield and 95 % ee. This is also the first example of one catalytic system working for the ring‐opening reaction of donor–acceptor cyclopropanes with three different nucleophiles, let alone in an asymmetric version.     

Asymmetric Synthesis of Furo[3,4‐b]indoles by Catalytic [3+2] Cycloaddition of Indoles with Epoxides

A highly efficient N,N′‐dioxide–Ni^II catalyst system for the catalytic [3+2] cycloaddition of indoles with epoxides through C?C cleavage of oxiranes was accomplished under mild conditions. It provided a promising approach for chiral furo[3,4‐b]indoles in up to 98 % yield with up to 91 % enantiomeric excess (ee) and >95:5 diastereomeric ratio (d.r.).     

RP-HPLC法测定黑顺片中6种酯型生物碱的含量

建立黑顺片中6种酯型生物碱含量的高效液相测定方法。采用岛津C18色谱柱(250 mm×4.6 mm,5μm),以乙腈–四氢呋喃(体积比为25∶15)为流动相A,以0.1 mol/L乙酸铵溶液(每1 000 m L加冰乙酸0.5 m L)为流动相B梯度洗脱,流量为1.0 ml/min,检测波长为235 nm,柱温为35℃。苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱进样量分别在0.222~4.430,0.060~1.119,0.144~2.878,0.015~0.297,0.025~0.496,0.011~0.229μg范围内与色谱峰面积线性呈良好的线性关系,相关系数r均大于0.999 5,检出限分别为2.10,2.70,2.20,2.60,1.60,3.10 ng,样品在12 h内稳定。苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱的加标回收率分别为98.7%~102.2%,98.6%~102.3%,99.0%~101.9%,102.0%~97.3%,102.1%~98.3%,95.7%~103.5%,测定结果的相对标准偏差分别为2.5%,2.5%,2.2%,2.3%,2.2%,1.7%(n=6)。该方法简便,测定结果准确、可靠,可为黑顺片的质量评价和质量控制提供参考。     

Catalytic Asymmetric Intramolecular Homologation of Ketones with α‐Diazoesters: Synthesis of Cyclic α‐Aryl/Alkyl β‐Ketoesters

A catalytic asymmetric intramolecular homologation of simple ketones with α‐diazoesters was firstly accomplished with a chiral N,N′‐dioxide–Sc(OTf)₃ complex. This method provides an efficient access to chiral cyclic α‐aryl/alkyl β‐ketoesters containing an all‐carbon quaternary stereocenter. Under mild conditions, a variety of aryl‐ and alkyl‐substituted ketone groups reacted with α‐diazoester groups smoothly through an intramolecular addition/rearrangement process, producing the β‐ketoesters in high yield and enantiomeric excess.     

Regio‐ and Enantioselective Aza‐Diels–Alder Reactions of 3‐Vinylindoles: A Concise Synthesis of the Antimalarial Spiroindolone NITD609

An asymmetric aza‐Diels–Alder reaction of 3‐vinylindoles with isatin‐derived ketimines has been developed. A series of spiroindolone derivatives were thus obtained in good to excellent yields with excellent enantioselectivity (up to 96 % yield and 99 % ee). Furthermore, the antimalarial compound NITD609 could be obtained in three steps with an overall yield of 40.6 %. Control experiments and operando IR experiments imply a concerted reaction pathway. The regioselectivity and exo selectivity result from π–π interactions between the two indoline rings of the two reactants.     

可可西里-金沙江地震带震级频度关系及其参数的相关性分析

本文通过可可西里-金沙江地震带震级频度关系的确定及其参数b值与a值、ν值(地震年平均发生率)和Mmax(最大震级a/b)之间的相关性分析, 以说明地震危险性概率分析中的地震活动性参数ν值与b值也应有某种相关性。当地震带未来一定时期内地震活动震级上限Muz和b值被确定后, 未来地震活动的ν值的取值范围似将受到一定的限制。如假设可可西里-金沙江地震带的Muz为8级, b值为0.73后, 相应的ν值若取13.943, 可能偏小。