Theoretical Herman-Wallis coefficients for C70 and D70 and the dipole-moment function of HCl

Theoretical expressions for the Herman-Wallis coefficients C⁷₀ and D⁷₀ and a correction term of order 2B_e/ω_e times the leading term for C⁶₀ have been derived in terms of the Dunham potential-energy parameters and series dipole-moment expansion coefficients by the method of computer algebra. After reviewing previous work on the extraction of the dipole-moment function for HCl from experimental data, the present results are applied to a determination of the series representation up to seventh order in the reduced displacement from the equilibrium internuclear separation. Coefficients for an alternate representation in terms of a Padé approximant are also obtained; this model dipole-moment function should enable one to estimate more accurately the higher overtone and highly excited hot-band intensities since it circumvents the divergence difficulties of the series expansion and has the correct asymptotic behavior at both small and large internuclear separations.     

烟草(Nicotiana tabacum)原生质体再生成植株及影响植株分化的某些因素

从烟草(品种革新一号)单倍体花粉植株的叶和茎产生的愈伤组织,结合悬浮培养,获得的细胞分离出原生质体。在液体培养基中静置培养,12小时后原生质体开始变为卵圆形,细胞壁明显可见,24小时后完成第一次细胞分裂。以后继续分裂形成浅黄色的愈伤组织,在培养四星期后可达1毫米大小,再放到转床上进行旋转培养18天左右,愈伤组织可达3—4毫米大小。当转移到分化培养基后,分别分化出苗及根,长成完整的植株。 原生质体再生细胞的分裂与分化,不仅受不同器官来源的愈伤组织及其年龄的影响;还受分化培养基的基本成份及所用细胞分裂素的类型等的影响。     

Fragmentation of gold projectiles: From evaporation to total disassembly

We have studied the fragmentation of Au projectiles interacting with targets of C, Al and Cu at an incident energy ofE/A=600 MeV. The employed inverse kinematics allowed a nearly complete detection of projectile fragments with chargeZ≧2. The recorded fragmentation events were sorted according to three observables, the multiplicityM _lp of light charged particles, the largest atomic numberZ _max within an event, and a new observable,Z _bound, representing the sum of the atomic numbersZ of all fragments withZ≧2. Using these observables, the impact parameter dependence of the fragmentation process was investigated. For all three targets, a maximum mean multiplicity of 3 to 4 intermediate mass fragments (IMFs) is observed. The corresponding impact parameters range from central collisions for theC target to increasingly peripheral collisions for the heavier targets. It is found that the correlation between the IMF multiplicity andZ _bound, extending from evaporation type processes (largeZ _bound) to the total disassembly of the projectile (smallZ _bound), is independent of the target nucleus. This universal behaviour may suggest an — at least partial — equilibration of the projectile fragment prior to its decay.     

叶轮机械设计自变数在内外环壁面上的限制条件及轴流式叶轮机械S1流面的翘曲

本文利用中心流面法的概念,指出叶轮机械的设计白变数在内、外环壁面上应有附加的限制条件,并导得其具体简明方程。同时,还定性地分析了S₁流面的翘曲情况。     

超导临界温度理论(Ⅰ)

本文求出了Eliashberg方程在T=T_c时的解,得到了下面的临界温度级数表示式: 其中α₀(μ^*),α₁(μ^*)等系数是μ^*的函数.此式表明,T_c不仅依赖于λ,〈ω²〉和μ^*,而且依赖于有效声子谱α²F(ω)的各级矩〈ω²n〉.这是区别于前人的T_c公式最重要的一点。这说明像McMillan以及Allen和Dynes的T_c公式不仅是近似的,而主要是他们没有能正确地概括出α²F(ω)对T_c的影响.     

Dunham potential energy coefficients of the hydrogen halides and carbon monoxide

The Dunham potential energy coefficients a_i, 0 ≤ i ≤ 6 (except 4 for HI) have been derived from spectroscopic data of hydrogen halides HF, HCl, HBr, and HI, and carbon monoxide in their ground electronic states. A full error analysis has produced standard deviations of both these a_i and further energy coefficients Y_lj. Comparison with experimental data shows good agreement; trends in the hydrogen halide series are discussed.     

The methyl group as phosphate protecting group in nucleotide syntheses

A novel method is described for the removal of a methyl protecting group from phosphotriesters in oligonucleotides.     

Dunham energy parameters of isotopic carbon monoxide,hydrogen halide,and hydroxyl radical molecules

Dunham potential energy coefficients a₁-a₆ for ¹²C¹⁶O, ¹³C¹⁶O, ¹²C¹⁸O, H⁸¹Br, HI, and OH have been calculated, including error limits, from published experimental spectroscopic data. There is no indication of deviation from Born-Oppenheimer behavior for a₁-a₆ of the carbon monoxide molecules, and the mass-independent internuclear separation R_e and force constants k_e and a₀ have also been calculated.     

Radial Functions of AIH X 1∑+ from Vibration-Rotational Spectra ana Spectral Properties of the Group 13 Hydrides

The coefficients C_j , j ≤ 9, defining the potential-energy V(z) and coefficients of two other radial functions related to adiabatic and nonadiabatic effects have been determined for AlH in the electronic ground state X ¹∑⁺ by a direct fit to the published frequencies and wavenumbers of vibration-rotational transitions of ²⁷Al¹H and ²⁷Al²H. The functions are valid in the range of internuclear distance/10^?10 m [1.24, 2.60]. Some trends in the spectral properties of the group 13 hydrides AlH, GaH, InH and TlH are discussed. The possibility of determining the rotational magnetogyric factor g_j from the available data of only wavenumbers of vibration-rotational transitions is considered; an approximate value g_j ～ ?2.25 is deduced for ²⁷Al¹H.