丰中子核63,65,67Mn的在束γ谱学研究

利用放射性束68Fe轰击液氢靶引起的敲出反应,研究了极端丰中子核63,65,67Mn的激发态,指认了它们的自旋宇称,建立了这三个原子核的能级纲图。纲图包含11/2–、9/2–和 7/2– 三个激发态以及$5/2_{rm{g.s.}}^{-}$基态,它们由三条$Delta I !=! 1$的$gamma$跃迁连接。这种能级结构与$K !=! 5/2$时强耦合转动带的特征一致。使用改进的LNPS有效相互作用(LNPSm)的大规模壳模型计算能很好地重现观测到的能级。计算表明,65,67Mn的低位激发态都主要包含处于$4p{text -}4h$的中子组态和$1p{text -}1h$的质子组态。基于实验结果发现,在吸积中子星壳中,与质量数$A !=! 63$相关的Urca中微子冷却效果比预期的要强很多,而$A !=! 65, 67$的冷却效果比预期的更弱。     

New generation and cycloaddition of α-(n-tert-butylimino)-o-quinodimethane

CsF induced 1,4-elimination of ammonium bromide 7, prepared by quaternization of N-tert-butyl o-(dimethylaminomethyl)benzimidoylsilane 6, provides a new generation of α-(N-tert-butylimino)-o-quinodimethane (3a), which gives benzocyclobutenone N-tert-butylimine (8) in the absence of dienophile. Trapping of 3a with electron deficient olefins affords Diels-Alder adducts regioselectively.     

Low-temperature 15N NMR spectra of reduced 1,3-heterocyclic systems

The ¹⁵N NMR spectra of the O-inside cis-fused conformer of perhydropyrido[1,2-c][1,3]thiazine shows a shielding of the nitrogen of 23.0 ppm relative to the trans-fused conformer. In contrast, ¹⁵N shifts for the cis-and trans-fused conformers of perhydro-oxazolo[3,4-a]pyridine and perhydrothiazolo[3,4-a]pyridine show corresponding shieldings of only 0.6 and 2.5 ppm, respectively.     

A mobile computerized laser radar system for observing rapidly varying meteorological phenomena

A high repetition, mobile laser radar system with a computerized real-time data acquisition and display system is described. Signal-to-noise levels of the system are compared with theoretical values, and it is found that they are affected by the shot noise in the system. An example of a stack plume observation is also presented to show the performance of the system.