~(55)Mn(α,n)~(58m,g)Co,~(55)Mn(α,2n)~(57)Co和~(55)Mn(α,α′n)~(54)Mn反应的激发函数

用活化法和迭靶技术,在入射α粒子能量从10.4到26.5MeV范围内,测量了~(55)Mn(α,n)~(58m,g)Co、~(55)Mn(α,2n)~(57)Co和~(55)Mn(α,α′n)~(54)Mn反应的截面,并同激子模型理论计算作了比较,结果表明在上述反应中存在平衡前发射反应机制。     

31.2MeV α粒子在B核上的(α,t)、(α,d)和(α,p)反应的研究

我们用粒子鉴别系统测量了31.2MeV的α粒子在^11,10B核上的(α,t)、(α,d)和(α,p)反应的角分布; 由出射粒子的能谱, 我们分别得到了剩余核处于基态和不同激发态的十个角分布. 从角分布的形状看, 在¹¹B(α,t₀)¹²C_g﹒s, ¹¹B(α,d₀)¹³C_g﹒s, ¹⁰B(α,d₀)¹²C_g﹒s, ¹⁰B(α,d₁)¹²C_1st, ¹¹B(α,p₀)¹⁴C_g﹒s等反应中均有不同程度的后角上翘; 并且(α,t₀)和(α,p₀)的后角上翘的同位素效应似乎与(α, α)的反常散射的同位素效应相反.     

关于介分子离子(αp,μ~-)和(αp,2μ~-)

应用ACQM理论和方法研究介分子离子(αp,μ~-)和(αp,2μ~-).发现(αp,μ~-)的基态(X~2Σ~+)为排斥态;(αp,2μ~-)为束缚态,平衡核间距R_e=0.0078bohr,能量极小值E=-551.78a.u.     

~(20)Mg β衰变谱学与~(15)O(α,γ)~(19)Ne反应（英文）

~(15)O(α,γ)~(19)Ne(p,γ)~(20)Na反应链是高温CNO循环向快速质子俘获过程突破的一条关键路径,相关的反应率输入量可通过~(20)Mg的β衰变可布居~(19)Ne共振态并测量其衰变性质来获得。通过高效率高精度地测量~(20)Mgβ衰变中产生的质子与γ射线得到了~(20)Mg衰变的详细信息,并构建了完整的衰变纲图,还进行了~(19)Ne 4 033 keV共振态衰变性质的探索,获得了该态在~(20)Mgβ衰变中被布居的分支比上限。通过比~(20)Mg和~(20)O镜像能级跃迁的结果确认了同位旋非对称性,为检验相关理论模型提供了精确的实验数据。对于突破路径中有重要影响的~(19)Ne 4 033 keV共振态的性质,有待更高统计的实验进一步研究。     

Tighter sum uncertainty relations via(α, β, γ) weighted Wigner–Yanase–Dyson skew information

We establish tighter uncertainty relations for arbitrary finite observables via(α, β, γ) weighted Wigner–Yanase–Dyson((α, β, γ) WWYD) skew information. The results are also applicable to the(α, γ) weighted Wigner–Yanase–Dyson((α, γ) WWYD) skew information and the weighted Wigner–Yanase–Dyson(WWYD) skew information. We also present tighter lower bounds for quantum channels and unitary channels via(α, β, γ) modified weighted Wigner–Yanase–Dyson((α, β, γ) MWWYD) skew information. Detailed examples ...     

快中子(n,α)和(n,p)反应的研究

快中子核反应数据,不论对反应堆和聚变堆的设计,还是对核反应机制和核结构的研究及其理论的发展均有着重要的意义．由于屏栅电离室的诸多特点,被用于快中子核反应截面、能谱及双微分截面的测量．作为系统研究的一部分,利用屏栅电离室在北京大学４．５ＭＶ静电加速器上和在４～７ＭｅＶ能区内,对４０Ｃａ、６４Ｚｎ、５８Ｎｉ、５４Ｆｅ、３９Ｋ的（ｎ,α）反应进行了成功的测量,并对５８Ｎｉ的（ｎ,ｐ）反应进行了初步的测量．实验给出了反应中出射粒子的微分能谱、角分布和反应截面．从测量结果来看,在所测能区内,角分布大致是９０°对称的,说明在此能区复合核反应机制起主要作用．The study of the charged particle emission reactions induced by 3～7 MeV fast neutrons is of considerable interest for both nuclear applications and the understanding of basic nuclear problems. For its many merits, twin gridded ionization chamber is used in the studies of (n,α) and (n,p) reactions. As a part of systematic investigation, the (n,α) reactions for some nuclei, such as 40 Ca, 64 Zn, 58 Ni, 54 Fe, 39 K have been studied. Cross sections...     

The SU(3) β-functionat large β

MCRG results are presented for the SU(3) β-function obtained from optimized blockspin transformations at β = 6.9 and 7.2. At both couplings for the shiftΔβ, corresponding to a change of length scale by a factor 2, Δβ = 0.51 is found. Although the error is large, deviations from asymptotic scaling seem to be larger than expected on the basis of earlier calculations.     

(n,p)和(n,α)激发函数半经验计算方法

在En≤20MeV的情况下,忽略了粒子的二次发射过程,认为复合系统的形成截面是能量相关的,得到了理论模型清晰、公式形式简单的半经验计算方法.在靶核23≤A≤209的范围内,利用大量(n,p)和(n,α)反应的截面实验数据对可调参数进行了研究,得到了参数对靶核的N和Z以及入射能量的依赖关系.对得到的参数做了定性的解释,利用普适参数对(n,p)和(n,α)反应的激发函数做了预言,预言值在其误差范围内与实验数据一致. To simplify the calculation, some assumptions are considered at present work. The preequilibrium emission is the first step in the equilibrium process, which is characterized by exciton n=3 and "never come back" are considered at the preequilibrium emission process; the proton and alpha emissions are only competed with the neutron emission, the second particle emission is neglected. A semiempirical method of the cross section for (n, p ) and (n, α) reactions were obtained on the basis of evaporatio...     

Synthesis and properties of β-modifiedmesotetra(aryl, heteryl)porphyrins

A series of chemical conversions of formyl derivatives of tetraphenylporphyrin is implemented, including the dimerization under the action of low-valence titanium, formation of a vinyl derivative by Wittig's reaction, and also the intramolecular cyclization with formation of isomeric verdins. By means of radical nitration, nitro derivatives of heterylporphyrins are obtained, which are exposed to a reaction of vicarious nucleophilic substitution of hydrogen with formation of 2,3-disubstituted derivatives. The previously unknown derivatives of the above-named porphyrins are obtained, and means for synthesis of well-known compounds are considerably improved. Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998. I. I. Mechnikov Odessa State University, 2, Dvoryanskaya Str., Odessa, 270026, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 512–515, July–August, 1999.     

(α, n) reactions in cascade γ-transitions

The ratios of the cross sections for the formation of the ground and isomeric states in reactions on¹⁰⁷Ag,¹⁰⁹Ag, and¹¹³In are calculated based on the assumption that at low energies the (, n) reaction proceeds via a) formation of the compound nucleus, b) evaporation of a neutron, and c) cascade -transitions. The number of cascade -quanta and the distribution of the excitation energy between the -quanta and the neutron is not postulated beforehand (as is usually done), but is calculated based on the statistical theory. By comparing with experiment, the parameter of the spin-dependence of the density of nuclear states is found. It is shown that the average number of -quanta in the cascade increases approximately linearly with the energy of the particles. The energy spectrum of the -quanta in the (, n) reaction is calculated. The distribution of -quanta has a maximum at low energies (1 MeV), which, as the energy of the primary particles is increased, moves slowly into the higher energy range while broadening at the same time.Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Fizika, No. 8, pp. 77–81, August, 1984.     

~(59)Co(n,p)~(59)Fe,~(59)Co(n,α)~(56)Mn,~(59)Co(n,2n)~(58)Co反应截面的测量

本实验用活化法测量了中子能量在12.8MeV到17.8MeV的~(59)Co(n,p)~(59)Fe,~(59)Co(n,α)~(56)Mn,~(59)Co(n,2n)~(58)Co三个反应道的反应截面值,实验的测量误差在3.3％—6.9％范围内. 本文还计算了反应截面测量误差的协方差矩阵,并将实验测量值与理论计算值进行了比较.另外,还对上述三个反应道的截面进行编评,给出了推荐的激发曲线.     

The 3He(α, γ)7Be and 3He(α, γ)7Li reactions at astrophysical energies

The radiative capture cross sections for ³He(α, γ)⁷Be and ³He(α, γ)⁷Li at astrophysical energies have been studied microscopically in terms of the resonating group method. It was found that the astrophysical S-factors correlate strongly to the nuclear size and deformation of ⁷Be and ⁷Li. With the help of measured nuclear properties of these nuclei, a safety range of the absolute values of the S-factor was determined; the most recommended S(0)-values are 0.50 ± 0.03 keV · b for the ³He(α, γ)⁷Be reaction and 0.098 ± 0.006 keV · b for the ³H(α, γ)⁷Li reaction.     

Investigation of α-nucleus interaction in the 27Al (α,α)27Al scattering and 27Al (α, d )29Si reaction

Full finite-range macroscopic calculations in the distorted-wave Born approximation have been performed using the molecular and Michel α-nucleus potentials to analyze the angular distributions of cross-sections of the ²⁷Al(α, d)²⁹Si reaction, at 26.5 and 27.2 MeV incident energies, leading to seven transitions up to the excitation energy E _X = 4.08 MeV of the final nucleus. The parameters of the two types of the α-nucleus potentials are determined from the elastic-scattering data. Both the molecular and Michel potentials, without any adjustment to the parameters needed to fit the elastic-scattering data, are able in most cases to reproduce, simultaneously, the absolute cross-sections particularly at large angles, where the previous calculations failed to reproduce by orders of magnitude, and the gross pattern of angular distributions of the reaction. The deuteron-cluster spectroscopic factors for most of the seven transitions, deduced using the two α-²⁷Al potentials, differ from those obtained in earlier works. The spectroscopic factor for the ground-state transition, deduced in the present work for the 25.8 MeV data, agrees well with the shell model prediction. Received: 15 July 2002 / Accepted: 8 August 2002 / Published online: 10 December 2002 RID="a" ID="a"e-mail: akbasak2001@Yahoo.com Communicated by G. Orlandini     

在独立α集团模型下对敲出反应16O(p,pα)12C和16O(α,2α)12C的研究

在独立α集团模型下,利用扭曲波冲量近似(DWIA),计算了实验室系下入射能量为101.5MeV的敲出反应16O(p,pα)12C和实验室系下入射能量分别为90MeV和140MeV的敲出反应16O(α,2α)12C.得到的反应截面和谱因子与实验数据基本符合,比用壳模型的结果有了一定的改进,表明独立α集团模型能较好地描述α集团敲出反应的机理.     

几个(n,d),(n,t)和(n,n'α)反应截面的测量

本文报告了En～14MeV中子以²⁷Al(n,α)²⁴Na或⁹³Nb(n,2n)^92mNb反应截面为中子注量标准测得的⁹²Mo(n,d*)^91mNb,¹⁰⁶Cd(n,d*)¹⁰⁵Ag;⁵⁴Fe(n,t)^52m+gMn,⁵⁸Ni(n,t)⁵⁶Co;⁵¹V(n,n'α)⁴⁷Sc和⁹²Mo(n,n'α)⁸⁸Zr的反应截面.文中还列举了能收集到的数据以作比较,中子能量是用铌锆截面比法测定的.     

Cross Section Measurements for (n,d*)(n,t) and (n,n'α) Reactions

Cross sections for some (n,d*),(n,t) and (n,n'α)reactions have been measured by using the activation method relative to cross sections of ²⁷Al(n,α)²⁴Na or ⁹³Nb(n,2n)^92mNb reactions in neutron energies around 14MeV.In this paper some of the published cross section data have also been listed and compared with our results.The neutron energies were determined by the method of cross section ratios for the reactions of ⁹⁰Zr(n,2n) ^89m+gZr and ⁹³Nb(n,2n)^92mNb.     

8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide分子的晶体结构

运用层析法、结晶法从狭苞橐吾全草中分离得到艾里莫芬烷型倍半萜8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide化合物,并通过质谱、核磁共振氢谱和碳谱、氢核-氢核相关谱、异核多量子相干谱和异核多键相干谱进行结构鉴定．其单晶经X射线衍射测试表明,其晶体属正交晶系,空间群为P212121,晶胞参数为: a=6．8519(5),b=10．7191(8),c=18．5942(14)A,V=1365．67(18) A3,Z=4,Dc=1．354 mg／m3．F(000)=592,μ=0．101 mm-1     

Thermonuclear ~(19)F(p,α_0)~(16)O reaction rate

The thermonuclear~(19)F(p,α_0)16O reaction rate in the temperature region 0.007–10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical R-matrix extrapolations.Our new rate deviates by up to about 30% compared to the previous results, although all rates are consistent within the uncertainties. At very low temperature(e.g. 0.01 GK) our reaction rate is about 20% lower than the most recently published rate, because of a difference in the low energy extrapolated S-factor and a more accurate estimate of the reduced mass used in the calculation of the reaction rate. At temperatures above ~1 GK, our rate is lower, for instance, by about 20% around 1.75 GK, because we have re-evaluated the previous data(Isoya et al., Nucl. Phys.7, 116(1958)) in a meticulous way. The present interpretation is supported by the direct experimental data. The uncertainties of the present evaluated rate are estimated to be about 20% in the temperature region below 0.2 GK,and are mainly caused by the lack of low-energy experimental data and the large uncertainties in the existing data.Asymptotic giant branch(AGB) stars evolve at temperatures below 0.2 GK, where the~(19)F(p,α)16O reaction may play a very important role. However, the current accuracy of the reaction rate is insufficient to help to describe, in a careful way, the fluorine over-abundances observed in AGB stars. Precise cross section(or S factor) data in the low energy region are therefore needed for astrophysical nucleosynthesis studies.     

~(100)Mo(n,2n)~(99)Mo,~(96)Mo(n,p)~(96)Nb和~(92)Mo(n,α)~(89m+g)Zr反应截面测量

本文报告了在E_n=13.40—14.79MeV中子能区用活化法以~(27)Al(n,α)~(24)Na截面为中子注量标准测得的~(100)Mo(n,2n)~(99)Mo,~(96)Mo(n,p)~(96)Nb和~(92)Mo(n,α)~(89m+g)Zr的反应截面,中子能量是用铌锆截面比法测定的。文中将实验测量值与理论计算值进行了比较,还对上述三个反应的截面进行了编评,给出了推荐的激发曲线。     

几个(n,d~*),(n,t)和(n,n′α)反应截面的测量

本文报告了En～14MeV中子以~(27)Al(n,a)~(24)Na或~(93)Nb(n,2n)~(92m)Nb反应截面为中子注量标准测得的~(92)Mo(n,d~*)~(91m)Nb,~(106)Cd(n,d~*)~(105)Ag;~(54)Fe(n,t)~(25m+g)Mn,~(58)Ni(n,t)~(56)Co;~(51)V(n,n'a)~(47)Sc和~(92)Mo(n,n'a)~(88)Zr的反应截面。文中还列举了能收集蓟的数据以作比较,中子能量是用铌锆截面比法测定的。