Studies on marine natural products. IV The stereochemistry of 13-membered carbocyclic cembranolide diterpenes from the soft coral lobophytum pauciflorum (Ehrenberg)

The relative and absolute stereochemistry of two 13-membered carbocyclic cembranolides was determined as shown in $\text{1}$ and $\text{2}$ on the basis of NMR spectral evidence.     

Sublevel echoes induced by resonant light pulses: Quantum beat echoes

We predict and observe a new class of echoes of atomic sublevel coherences induced by two impact excitations with resonant light pulses which may be either coherent or incoherent. The Zeeman-sublevel echoes in 3 ²S_{$\text{1}\text{2}$} of sodium were observed by using polarization selective detection technique under the excitation condition that the optical T₂ (5 × 10^-11 s) was much shorter than the pulse width (5 ns). Theoretical analysis also predicts the echoes involving coherence transfer between ground and excited states.     

Generic singularity studies revisited

Intermittency and chaos are shown to occur in a single-mode laser driven on resonance by an external constant amplitude electric field and a periodically modulated inversion. Numerically the strange attractor of the system is found to be approximately a two-dimensional manifold in an appropriate three-dimensional phase space.     

Solvolysis of 2-m-chlorobenzoyloxy-4-isopropyl-2h-1,4-thiazin-3-one generation of a stable carbocation

The title compound $\text{2b}$ undergoes nucleophilic substition reactions with exclusive aklyl-oxygen bond fission and its rate of solvolysis is highly sensitive toward change in polarity of solvents, as is shown by its highest m-value of all reported so far in logK - logk₀ = mY.     

等离子体的光电转换以及激光刻蚀金纳米颗粒(英文)

Anewtechnologyforthedevelopmentofop icandphotonicdevicesandsystemstakingad antagesofextraordinaryenhancementandlocal ationofsurfaceplasmonmaybecalledas“plas onics”.Anoteworthycharacteristicofgold anoparticlesisthattheyshowstrongabsorption andsinthevisib…     

Mössbauer study on the photolysis of pentacarbonyliron isolated in low temperature nitrogen matrix by continuous or pulsed deposition

The UV photolysis of pentacarbonyliron isolated in low temperature nitrogen matrix by continuous or pulsed deposition was studied by means of Mössbauer technique. Unstable species such as Fe/CO/_n /n=2–4/ were produced by UV irradiation and their Mössbauer parameters were measured. The yields of unstable species were found to be influenced by the deposition method of nitrogen matrix.