Acyclic diene metathesis (ADMET) of vinylsilanes over Re2O7–Al2O3 catalyst

Tetravinylsilane and divinylsilanes have been successfully metathesized for the first time over Re₂O₇/Al₂O₃ catalyst promoted with tetrabutyltin under mild reaction conditions. All of the products were acyclic oligomers via intermolecular metathesis; the cyclic products via intramolecular metathesis were not formed.     

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。     

Nuclear spin dynamics of nuclear-ordered solid<Superscript>3</Superscript>He in the low field phase

Pulsed NMR was used to investigate nuclear spin dynamics of nuclear-ordered solid³He in the low field phase. The nuclear spin motion became unstable under certain conditions. Under stable conditions the spin motion can be described by the OCF equations. The tipping-angle-dependent frequency shift and multiple spin echoes were observed, which are similar to the case of superfluid³He. The onset of the instability of spin motion is attributed to the stimulated emission mechanism through the three-magnon relaxation process, which is similar to the Suhl instability in electronic magnetism. We derived the magnon life time from the analysis of the instability. During the instability, a largenegative frequency shift was observed. This negative shift is explained by the extension of Fomin-Ohmi's theory to include the state of decayed magnon and this explanation is consistent with the instability model.     

Nonequilibrium relaxation method — an alternative simulation strategy

One well-established simulation strategy to study the thermal phases and transitions of a given microscopic model system is the so-called equilibrium method, in which one first realizes the equilibrium ensemble of a finite system and then extrapolates the results to infinite system. This equilibrium method traces over the standard theory of the thermal statistical mechanics, and over the idea of the thermodynamic limit. Recently, an alternative simulation strategy has been developed, which analyzes the nonequilibrium relaxation (NER) process. It is called theNER method. NER method has some advantages over the equilibrium method. The NER method provides a simpler analyzing procedure. This implies less systematic error which is inevitable in the simulation and provides efficient resource usage. The NER method easily treats not only the thermodynamic limit but also other limits, for example, non-Gibbsian nonequilibrium steady states. So the NER method is also relevant for new fields of the statistical physics. Application of the NER method have been expanding to various problems: from basic first- and second-order transitions to advanced and exotic phases like chiral, KT spin-glass and quantum phases. These studies have provided, not only better estimations of transition point and exponents, but also qualitative developments. For example, the universality class of a random system, the nature of the two-dimensional melting and the scaling behavior of spin-glass aging phenomena have been clarified.     

A heterometal single-molecule magnet of [MnIII2NiII2Cl2(salpa)2

The tetranuclear complex [MnIII2NiII2Cl2(salpa)2] (salpa = N-(2-hydroxybenzyl)-3-amino-1-propanol) has a spin ground state of S = 6 and was confirmed to be an SMM based on a steplike feature of the magnetization hysteresis loop at 0.55 K.     

Vacuum ultraviolet luminescence-excitation spectra of RPO4 : Eu3+ (R = Y,La, Gd and Lu)

Measurements of luminescence-excitation spectra and diffuse reflection spectra are performed with rare-earth orthophosphate phosphors, RPO₄ (R = Y, La, Gd, and Lu) activated mainly with Eu³⁺ ions, in the vacuum ultraviolet region, 120–300 nm. A rather narrow excitation band at the absorption edge (145–160 nm) of the hosts is assigned to an intramolecular transition of PO^3-₄ anions.     

ESR-Untersuchung der Prim?rprozesse bei strahlungsinduzierten Reaktionen. 6. Mitt. Isopren und 1,3-Pentadien in Matrizes aus Alkylhalogeniden

Ohne Zusammenfassung     

Thermal expansion anomaly of MnB

The thermal expansion of MnB has been measured in the temperature range from 0 to 420°C. An Invar type thermal expansion is observed. The thermal expansion coefficient is ?42×10^-6 deg.^-1 at 295°C(≈T_c).     

Insertion of a strongly pi-pi stacked chloranilate pair into an M4 arrangement preorganized within a large macrocyclic ligand (M = Zn2+ and Cu2+)

Four Zn(II) ions arranged within a pyridine-modified large phenolate-containing macrocyle Lpy2- encapsulate two chloranilate ions in a double bis-didentate bridging fashion; the ligands are strongly pi-pi stacked with each other with a short distance of 3.27 A and are electrochemically reduced at the same potential of -1.00 V to produce a reasonably stable biradical species with T1/2 = 60 min at 25 degrees C.