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161.
162.
Positive-parity doublet bands were reported in ~(120)I. Based on these, we discuss the corresponding experimental characteristics, including rotational alignment, and re-examine the corresponding configuration assignment.The self-consistent tilted axis cranking relativistic mean-field calculations indicate that the doublet bands are built on the configuration πh_(11/2)■νh_(11/2)~(-1). By adopting the two quasiparticles coupled with a triaxial rotor model, the excitation energies, energy staggering parameter S(I), B(M1)/B(E2), effective angles, and K plots are discussed and compared with available data. The obtained results support the interpretation of chiral doublet bands for the positive-parity doublet bands in ~(120)I, and hence identify this nucleus as the border of the A ≈ 130 island of chiral candidates. 相似文献
163.
The level structure in neutron-deficient nucleus 91Ru was investigated via the 58Ni(36Ar,2 plnγ)Ru reaction at a beam energy of 111 MeV.Charged particles,neutrons,and y-rays were emitted in this reaction and detected by the DIAMANT CsI ball,Neutron Wall,and the EXOGAM Ge clover array,respectively.In addition to the previously reported levels in 91Ru,new low-to-medium spin states were observed.Angular correlation and linear polarization measurements were performed to unambiguously determine spins and parities of the excited states in 91 Ru.The low-spin states of 91 Ru exhibit a scheme of multi-quasiparticle excitations,which is very similar to that of the neighboring N=47 isotone.These excitations have been interpreted in terms of the shell model.The calculations performed in the configuration space(p3/2,f5/2,p1/2,g9/2)reproduce the experimental excitation energies reasonably well,supporting the interpretation of the newly assigned positive-parity states in terms of the three quasiparticle configurationsπ(g9/2)^-2v(g9/2^-1 and v(g9/2)^-3. 相似文献
164.
单轴应力下水泥土细观结构的演化特性 总被引:2,自引:0,他引:2
通过单轴压缩条件下不同养护温度及不同土料的水泥土微细结构变化试验,探讨了单轴压缩条件下水泥土微细结构内部变化规律及其与宏观力学响应的关系.利用Geoimage软件定量分析研究了颗粒面积比例、颗粒分布分维、颗粒圆度和孔隙定向度的演化规律,并与全应力应变曲线进行了对比.结果表明,单轴压缩条件下土样细部结构形态和参数均会发生明显变化. 相似文献
165.
运用G03W程序, 在高精度理论水平(B3P86/6-311+G**)下, 对母体转烯(Hypostrophene)及其BCO衍生物的单态、三态、开壳层单态的Cope重排体系进行了理论研究: 对体系进行了相应的结构优化和频率计算, 并进一步计算了体系的重排势垒、反应能量、核独立化学位移值等理论参数. 文中首次提出具有四同芳香性的实例: 转烯的Cope重排过渡态. 计算同时表明BCO取代CH的行为使得进行Cope重排的反应物和过渡态的离域性、芳香性以及稳定性都得到很大的促进, 这可以从前线轨道的成键以及延伸方面得到合理的解释. 所得结果进一步验证了BCO基团的稳定性效应. 相似文献
166.
The title compounds were synthesized from the selectively protected N-acylated d-glucosamine derivatives, containing α-halo carboxylic acid moieties, via intramolecular 3-O-alkylation. It was found that if the starting compound contains asymmetric electrophilic center, isomuramic acid derivatives were mainly formed, regardless of the configuration of the electrophilic carbon atom. An explanation for the observed stereochemical results was proposed on the basis of the analysis of steric interactions in the molecules of the starting compounds, as well as using the concept of anchimeric assistance. It was shown that N-acetylation of the obtained lactam derivatives and subsequent methanolysis under mild conditions led to the selective cleavage of δ-lactam ring resulting in the formation of the corresponding ester derivatives of N-acetylmuramic acid or its analogues in high yields. 相似文献
167.
The title compound, [Mn2·(dinitrobenzoic acid)4·(1,10-phen)2]n, has a linear chain structure containing binuclear [Mn2·(dinitrobenzoic acid)4(1,10-phen)2] repeat units. It crystallizes in the triclinic system, space group P1- with a = 7.9261(8), b = 12.1329(15), c = 14.847(2)(A), α = 103.845(5), β =101.424(5), γ= 92.618(4)°, Mr= 657.37, V= 1352.3(2) (A)3, Z = 2, Dc= 1.614 g/cm3, F(000) = 666, μ =0.567 mm-1, the final R = 0.0407 and wR = 0.1015 for 4081 observed reflections with I > 2σ(Ⅰ). The Mn atom is six-coordinated by two N and four O atoms, forming a slightly distorted octahedral geometry. All Mn-O and Mn-N bond distances range from 2.093(2) to 2.310(2)(A). Two adjacent octahedral units are bridged together by two pairs of bi-monodentate carboxyl groups of different dinitrobenzoic acids to form an eight-membered ring with chair-typed configuration, thus generating a one-dimensional chain along the a axis. 相似文献
168.
利用新手性源,5-(l-孟氧基)-3-氯-2(5H)-呋喃酮4与亲核试剂吗啉通过串联不对称双Michael加成/分子内亲核取代反应合成了一般方法难以得到的含有多个手性中心的螺-环丙烷双内酯化合物C32H50O7NCl.其单晶为C32H50O7NCl(OC3H6)0.5,正交晶系, 空间群为P212121, 晶胞参数a = 17.149(3), b = 20.384(4), c = 10.831(2) , V = 3786.1(12) 3, Z = 4, Dc = 1.097 g/cm3, F(000) = 1352, μ= 0.144 mm-1; 射线类型为MoK?( = 0.71073 ?, 偏离因子R = 0.0755, wR = 0.1956, 独立衍射点3710个, 其中可观测点数2318个.分子中共有六个环, 12个手性中心, 3个六元环呈椅式构象, 两个五员内酯环呈信封式构象, 并分别与环丙烷形成[2.4]螺环和 [3.1.0] 稠环, 4个新生成的手性中心的绝对构型为C(3)(S), C(4)(S), C(5)(R), C(8)(R). 相似文献
169.
170.
偶氮染料结构、光稳定性和光化学降解机理研究 总被引:16,自引:0,他引:16
本文介绍了偶氮染料分子构型、聚集态及其晶体结构的量子化学与实验研究情况, 综述了偶氮染料光稳定性的结构效应和光化学降解机理及其激光闪光光解与时间分辨共振Ram an 光谱近代实验技术的研究进展。 相似文献