反,反-和顺,反-2,4-己二烯的简正振动分析

为研究聚乙炔(PA)的分子结构及振动光谱,对反,反-2,4-己二烯(TTHF)和顺,反-2,4-己二烯(CTHE)进行了红外(IR)和拉曼(Raman)光谱的检测和简正振动分析。主要结果如下: (1) TTHE的C_2h分子对称性,导致真观测谱带严格遵守IR-Raman相互排斥规则。而CTHE的分子不对称性,使其并无此现象发生。(2) TTHE和CTHE的简正振动分析都得到了42个非零的计算频率,这是符合3N-6规则的。(3) 计算所得TTHE和CTHE的位能分布值,与我们听做的经验指认吻合得较好。伹TTHE和CTHE的大部分骨架的简正振动模式都是由多个经验模式的贡献,这表明了平面和共轭结构所造成的骨架振动的复杂性。(4) 对TTHE和CTHE进行力场精化,所得计算频率与观测值的平均绝对偏差为14cm~(-1),平均相对偏差为1.8%。     

ИЗМЕРЕНИЕ ЦИКРУЛЯРН ОЙ ПОЛЯРИЗАЦИИ γ-КВАН ТОВ, ИСПУСКАЕМЫХ ЯДРАМИ П ОСЛЕ ЗАХВАТА ПОЛЯРИЗ ОВАННЫХ ТЕПЛОВЫХ НЕЙТРОНОВ

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Measurement of the circular polarization of gamma-quanta emitted from the nuclei after the capture of polarized thermal neutrons

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Phonon density of states in γ-, β-, and α-AgCuS

The ternary superionic conductor AgCuS was studied by means of inelastic neutron scattering at temperatures of 150 to 398 K. The experimental time-of-flight spectra were recalculated into the generalized phonon density of states G(ɛ) in an incoherent approximation. It is shown that G(ɛ) of AgCuS has a nontrivial temperature dependence over the low-energy range. The relation between the temperature dependence of G(ɛ) and the existence of a low-energy mode in AgCuS is discussed. The text was submitted by the authors in English.     

2-巯基-5-甲基-1, 3, 4-噻二唑分子的拉曼、红外光谱和简正振动分析

实验测量了2-巯基-5-甲基-1, 3, 4-噻二唑分子的拉曼和红外光谱, 采用B3LYP混合泛函和6-31+G(d, p)基函数组, 计算了该分子的最稳定构型和振动频率。以实验频率为标准采用简正振动分析方法得到了该分子各振动频率的势能分布, 从而对其振动频率归属做出了全面地指认。     

Magnetic circular dichroism and absorption spectra of d° tetrahedral oxyanions and thioanions: MoS4 2-, MoO4 2-, WS4 2-, ReS4 -, VS4 3-, VO4 3- and OsO4

Absorption and magnetic circular dichroism spectra have been measured for the tetrahedral d° ions MoS₄ ^2-, MoO₄ ^2-, WS₄ ^2-, ReS₄ ^-, VS₄ ^3-, VO₄ ^3- and OsO₄ in the visible and ultra-violet spectral range. Comparison of the experimentally obtained MCD parameters with regard to their relative signs leads to the conclusion that probably the first two allowed longest wavelength electronic transitions of all these species have the same assignment (i.e., t ₁ →2e and 3t ₂ →2e, which seems likely on energetic grounds). An estimation of the MCD parameters by using eigenvectors from recently published molecular orbital treatments gave contradictory results.     

Wei Mo-an, 1921-1996

ProfessorWeiMo-an,theHonoraryPresidentoftheInstituteofAcoustics,supervisorofDoctorStudentsofTonaiiUniversity,HonoraryPresidentoftheAcousticalSocietyofChina,theChairmanoftheFirstandSecondSessionoftheAcousticalSocietyofShanghai,theEditor-in-chiefoftheprofessionaImagazinesTechnicalAcousticsandtheAssociateEditor-in-chiefofAPPliedAcoustics,MemberoftheEditorialBoardofChineseJournalojAcoustics,theDeputyoftheEighthSessionoftheShanghaiPeople'sCongress,theMemberoftheparty'Jiu-san'Xuesh…     

原子阱,氪-81,撒哈拉的地下水

自放射性碳年龄测定法在1949年首次在实验中得以证实以来,长寿命的由宇宙射线产生的放射性核素痕量分析这一领域,无论是在分析技术还是在可利用的核素种类上,都取得了长足的进步.它所产生的影响已经渗透到广泛的科学和技术领域.文章介绍了一种新的痕量分析方法——原子阱痕量分析(atomtraptraceanalysis,ATTA).这种方法已经用于分析环境样品中的氪-81(半衰期为23万年;同位素含量约为1×10-12)和氪-85(半衰期为10.8年;同位素含量约为2×10-11)核素.氪-81主要由宇宙射线产生于大气层上部.它是理想的测定年代范围从5万年到100万年的水和冰样品的放射性核素.另一方面,氪-85是铀-235和钋-239的核裂变产物.对氪-85的同位素含量测定可以用于监督国际核公约的执行情况.在ATTA中,一个由激光光束和磁场共同产生的原子阱可以有选择地捕陷特定核素的原子.被囚禁的原子可以通过观察其荧光来进行探测.作为ATTA技术的第一次实际应用,一个国际合作小组确定了撒哈拉沙漠地区Nubian含水土层中地下水的寿命.利用ATTA对地下水寿命的成功测定,标志着放射性氪年龄测定法在地球科学中的广泛应用已经具备了可行性.     

2, 4, 8, 10-四卤代-6-硫-12-H-双苯并[d,g] [1, 3,,3]-二氧磷杂八环的1H和13C NMR研究

通过2D NMR技术对5个2, 4, 8, 10-四卤代-6-硫-12-H-双苯并[d, g] [1, 3, 2]-二氧磷杂八环的¹H和¹³C NMR信号进行了准确的归属,获得了所有芳环碳原子的P-C和部分质子的P-H偶合常数,3/9质子的⁵J_PH属于折线型偶合,偶合常数为0.9～1.0 Hz.     

Phase stability of α-, γ-, and ε-Ce: DFT+DMFT study

We present the total energy calculation of α-, γ-, and ε-Ce phases in the frame of GGA, GGA+U, and DFT+DMFT methods. It has been shown that taken into account of Coulomb correlations in the frame of dynamical mean-field theory allows reproducing the phase diagram of Ce in correct way. Equilibrium volume calculated within the DFT+DMFT method for face-centered cubic (fcc) structure agrees with experimental Ce-γ cell volume. With temperature decrease energy minimum shifts toward α cell volume. Moreover, the DFT+DMFT total energy for body-centered tetragonal (bct) structure becomes smaller than for fcc one with increase in pressure in agreement with experimental phase diagram. Importance of accounting of Coulomb correlation in the frame of DMFT is discussed.     

Спектр поглощения Kcl Ca, о Блученного γ-излучением и рентге новскими лучами

В статъе описывается расщепление F-полосы (м аксимум 0,55 μ) на полосы с максимума ми 0,54 μ и 0,56 μ которые наб людаются при облучении рентгенов ым и γ-иэлучением в мал ых дозах или после обл учения светом с длиной волны 0,54 μ. При повторном облу чении и прогреве при опреде ленной температуре п роисходит необратим ый переход F →Z ₂ до опреде ленного значения при насыщении. Величина коэффициента поглощ ения k_m F-полосы зависит от качества облучающ его излучения и от общей д озы облучения и не зав исит от мощности дозы.     

Исследование оснóвного водородного обмена ароматических СН-связей некоторых азотистых гетероциклов, их N-окисей и четвертичных солей

A tube generator of fast neutrons (14·1 MeV) is discussed with neutron output of 2·10⁷ n/s working in pulsed operation with the frequency of 400 Hz and with the pulse width of 100 μs. The accelerating voltage is 90 kV. The generator has been constructed in the form of a geophysical probe used for oil prospecting by means of n – γ logging. The time dependence of gamma ray intensity is measured by means of four channel analyser together with a photo-recorder. The accuracy is sufficient owing to simultaneous monitoring of the fast-neutron flux. Maximum operation temperature of the prototype is 80 °C.     

2, 4, 8, 10-四卤代-6-硫-12-H-双苯并[d, g] [1, 3,,3]-二氧磷杂八环的1H和13C NMR研究

通过2D NMR技术对5个2, 4, 8, 10-四卤代-6-硫-12-H-双苯并[d, g] [1, 3, 2]-二氧磷杂八环的¹H和¹³C NMR信号进行了准确的归属,获得了所有芳环碳原子的P-C和部分质子的P-H偶合常数,3/9质子的⁵J_PH属于折线型偶合,偶合常数为0.9～1.0 Hz.