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1.
利用北京谱仪在北京正负电子对撞机上采集的350万(2S)事例,通过(2S)→γπ-和γK+K-反应道测量了Xc0的总宽度.由MonteCarlo模拟给出的质量分辨函数,利用拟合Xc2谱形得到的质量分辨作标定后,用于Xc0宽度的拟合,得到Xc0的宽度为(15.0)MeV.同时定出了XcJ(J=0,2)到π+π=和K+K-的衰变分支比.结果为B(Xc0→π+π-)=(4.27±0.23±O.60)×10-3;B(Xc0→K+K-)=(3.44±0.21±0.47×10-3;B(Xc2→π+π-)=(1.52±0.17±0.29)×10-3和B(Xc2→K+K-)=(5.2±1.1±1.8)×10-4,其中第一项误差为统计误差,第二项为系统误差。  相似文献   

2.
自由基分子CN(A^2Пi—X^2Σ^+)的光谱研究   总被引:1,自引:1,他引:0  
利用塞曼调制磁旋转光谱技术对自由基分子CN(A^2ΠI-x^2Σ^+)(12,6)带、(7,2)带进行了测量,标识了光谱并拟合了A^2Πi太分子常数,从而得到V=7T V=12振转谱带的Tv、Av、Bv、Dv等参数,还获得A双分裂参数Pv和qv,两个带的总拟合方差分别为0.039和0.046cm^-1。  相似文献   

3.
本研究高Tc大块超导体YBa2Cu3O7-b(Fx)(其中x=0.0,0.5,0.75,1.0,1.5,2.0,2.5)的磁性。X射线衍射实验表明相当多的F进入了YBaCuO(123)晶格并被O空位俘获。用振动样品磁强计(VSW)测试这些样品的质量比磁矩σ与温度T的关系,以及抗磁性磁滞回线。未掺氟样品的Tc为89K,掺F(x=0.75)的样品具有最高的Tc0=93K和最强的抗磁性。在150K样品  相似文献   

4.
制备了四氯四铜酸苯铵盐(C6H5NH3)2CuCl4单晶,Mr=187.26,由四园衍射数据确定了晶体结构,晶体属单斜晶系,空间群P21/a,a=0.7184(1),b=0.7448(2),c=1.5070(4)nm,β=100.67(2)°,V=0.7924nm^3,Z=2,Dx=1.650gcm^-3,(Mo,Ka)=0.071069nm,μ=4.056mm^-1,F(000)=389,R=0  相似文献   

5.
在77—300K温度范围内用正电子湮没方法测量了Y1-xPrxBa2Cu3O7-δ(x=0.2,0.1,0.0)三个超导样品中正电子湮没寿命随温度的变化,细致地研究了正常志异常现象.X为0.0和0.1的二个样品分别在较Tc高40K和30K处观察到了正常态异常现象x=0.2样品(Tc<80K)没有观察到正常态异常现象.实验观察到的正常态异常现象可能是发生超导转变的前奏,由结构不稳定产生的类相交所致.  相似文献   

6.
测量了Tl系2223相银包套超导带(J_c=1.5×10 ̄4A*cm ̄(-2),77K,0T)在0-0.8T磁场下电阻转变展宽,实验结果引用热激活磁通蠕动模型加以解释。磁场平行于带面(Hab面)和磁场垂直于带面(HJ⊥ab面)两种情况下,激活能与磁场之间满足幂指数关系:U_(0)=0.21,其中H的单位为kG。对Hab面,HI时出现的与宏观洛仑兹力无关的耗散进行了讨论。  相似文献   

7.
本文研究了Hg0.7Cr0.3Sr2Ca2Cu3Oy,HgBa2Ca2Cu2.9Re0.1Oy,HgSr2Ca3Cu3.8Re0.2Oy的磁性,发现Re的掺入会改变UJ关系.由驰豫测量结果分析得到Hg(Re)1223,Hg(Re)1234具有对数钉扎势U=U0H-nln(Jc0/J),其中对Hg(Re)1223在20K~60K范围里U0和Jc0近似与温度无关;对Hg(Re)1234,U0和Jc0与磁场和温度有关.而Hg1223具有幂次方钉扎势U=U0(Jc0/J)μ.另外,由磁化曲线M(H)的测量得到临界电流密度随磁场的变化关系.结果表明Hg(Re)1223在20K~90K、Hg(Re)1234在20K~70K的温度范围内,临界电流密度随磁场的变化关系均可以用由对数钉扎势得出的Jc(H)关系很好地描述.我们认为Re掺入引起的体系的各向异性的减小和岛状钉扎中心,使得材料钉扎能力增强并引起UJ关系的变化  相似文献   

8.
用对称透射法,收集在室温下不同拉伸比的非晶聚酯(PET)纤维之二有X射线散射(WAXS)强度函数I(κ,α),采用自编MPS96型全谱分峰程序,将不同方位角α测得的WAXS强度曲线上的4个非晶重叠峰进行分解,获得分子链间原子 射引起的2个峰为:KA=0.141nm^-1,KB=0.172nm^-1;分子链内原子 射引起的2个峰为;KC=0.311nm^-1,KD=0.555nm^-1,详细分析了  相似文献   

9.
于扬  金新 《低温物理学报》1994,16(2):119-122
本介绍了用熔融法制备Bi2.2Sr1.8Ca1.05Cu2.15-xNaxO8+y(x=0,0.4~0.8)样品,发现诸样品零电阻温度都在90K左右,其中x=0.7,Tc0达到92.5K。在81K较高温区,该类样品仍然表现出良好的超导电性,其临界电流密度还达到10^3A/cm^2量级。  相似文献   

10.
采用傅里叶变换光谱技术(FTS)记录了CH^35Cl3和它的同位素分子CH^35Cl2^37Cl的V=3的高分辨光谱,由于0.02m^-1分经不足以分辨K结构,我们将所观察到的谱线近似归属为K=0的转动能级,归属了CH^35Cl3岔子4〈J〈73,CH^35Cl^37Cl分子6〈J〈53的转动级。最后采用最小二乘法拟合,得到了关于J的转动常数和振动带心。  相似文献   

11.
The (1, 0), (0, 1) and (0, 2) bands ofD→X system of lead monoxide have been excited in RF discharge source and photographed in the seventh order of a 2-meter PGS. Intensity records of the rotational lines have been obtained. Rotational constants and the intensity measurements ofQ andP branch lines of the above three bands andJ numbering are used to calculate the effective rotational temperature of the source emitting the spectrum of208Pb16O molecule.  相似文献   

12.
After theβ-decay of Kr85 in solid Krypton the Rb+-ion, resulting from this decay, is excited in 4p5 5p(J=0)-states with a certain probability. The photon-spectrum, due to dipole-transitions from these excited states, selected with narrow-band-filters and measured in coincidence with the emittedβ-particles, shows narrow bands (“lines”) and broad bands. The “lines” are not shifted with respect to the atomic Rb+-lines, whereas each broad band can be interpreted as a component of each “line”, being shifted about 800 cm?1 to the blue end of the spectrum. The measured lifetime of the excited states is (7.5±0.5) ns in the “lines” and (5±0.5) ns in the bands, the measured excitation-probability is (8±1) · 10?2 perβ-decay. A calculation of the magnitude of the spectral shift and the excitation-probability with the LCAO-approximation is made under the following assumptions: the “lines” are due to Rb+-ions on regular crystal-sites; the shifted bands are caused by Rb+-ions, trapped at octaedral interstitial-sites, after being displaced from their original regular crystal-sites by theβ-recoil. A comparison between the experimental and calculated values confirms these assumptions.  相似文献   

13.
The cw dye laser excitation spectrum of the (110)-(000) and (021)-(000) vibronic bands of the system of DNO was observed between 16530 and 16860 cm−1 with Doppler-limited resolution. A rotational analysis of the two bands gave values for the rotational constants and centrifugal distortion constants. DNO was produced by the pyrolysis method and more than 1200 lines were observed in the two bands. A total of 1112 of these lines could be assigned to 9 and 11 subbands of the (110)-(000) and (021)-(000) bands, respectively. The molecular constants determined reproduce the observed transition frequencies with an average deviation of 0.011 and 0.008 cm−1, respectively. Extensive perturbations in the excited state were found in most of the subbands. “Extra” lines were observed in connection with several of these perturbations. Accurate determination of the dissociation energy has been obtained; D0 = 17010 ± 10 cm−1.  相似文献   

14.
A dispersed fluorescence study of the FeH radical at near ambient (~450 K) temperature has identified the g6Φ-a 6δ (0, 2) and g6Φ-b6II (0, 1) bands in the orange region of the spectrum. The corresponding bands with upper state e6II are located at about 640nm in the red. High resolution measurements in LIF have enabled the assignment of around 275 lines to these four transitions. Analysis of these bands has provided a second vibrational interval for the a6δ state and a first vibrational interval for the b6II state as 1536cm?1 and 1542cm?1, respectively. Term values have also been measured for a set of levels with a tentative assignment to c4Φ9/2 (ν = 1).  相似文献   

15.
杨平  田莲花  田荣 《发光学报》2009,30(6):768-772
采用高温固相法制备了Eu3+离子激活的Ca9R(VO4)7(R = Y, La, Gd)红色发光粉,并利用荧光光谱对发光粉的特性进行研究。激发光谱中,Ca9Y(VO4)7 : Eu3+ , Ca9La(VO4)7 : Eu3+和Ca9Gd(VO4)7 : Eu3+都有两个宽的VO3-4激发带和Eu3+的特征激发峰。发射光谱中,在Ca9Y(VO4)7 : Eu3+ 和Ca9La(VO4)7 : Eu3+中的350~550 nm范围内出现VO3-4的发射带,而在Ca9Gd(VO4)7 : Eu3+中却没有观察到VO3-4的发射。在这三种发光粉中,Ca9Gd(VO4)7 : Eu3+的发光强度远远高于其它两种,这是由于Gd3+的存在有效地使能量通过Gd3+ →VO3-4 → Eu3+及Gd3+ → Eu3+的两种方式进行能量传递,从而提高了Eu3+发光效率。  相似文献   

16.
The infrared transmission spectrum has been studied on the mixed medicine sample composed of sildenafil citrate (SDF or Viagra) and traditional Chinese medicine(TCM). The measured infrared spectra are composed of several broad absorption bands and many sharp absorption lines. Then the broad absorption bands are changed from sample to sample. It is identified that the sharp and broad absorption bands are from the Viagra and TCM, respectively. A numerical best fitting process has been used to extract the absorption spectrum from the spectrum of mixed sample. Combined with the numerical analysis, the Viagra component can be extracted from the mixed material even with a changeable broad absorption bands' background. It shows that the infrared transmission spectroscopy is a useful method to extract the component of chemical medicine from the mixed medicine.  相似文献   

17.
High resolution transmission electron microscopy, X-ray diffraction and photoluminescence measurements are carried out in order to study the defects in CdS quantum dots (QDs), synthesized in cubic phase by chemical co-precipitation method. The nanotwinning structures in CdS quantum dots (∼2.7 nm) are reported for the first time. Mostly CdS QDs are characterized by existence of nanotwin structures. The twinning structures are present together with stacking faults in some QDs while others exist with grain boundaries. Raman spectroscopy analysis shows intense and broad peaks corresponding to fundamental optical phonon mode (LO) and the first over tone mode (2LO) of CdS at 302 cm−1 and 605 cm−1 respectively. A noticeable shift is observed in Raman lines indicating the effect of phonon confinement. Fourier transform infrared spectroscopy analysis confirms the presence of Cd–S stretching bands at 661 cm−1 and 706 cm−1. The photoluminescence spectrum shows emission in yellow and red regions of visible spectrum. The presence of stacking faults and other defects are explained on the basis of X-rays diffraction patterns and are correlated with photoluminescence spectrum. These nanotwinning and microstructural defects are responsible for different emissions from CdS QDs.  相似文献   

18.
The 4f65d6s2 → 4f7 6s2 emission spectrum of Eu atoms isolated in an argon matrix shows (a) zero-phonon lines and (b) Stokes vibrational sidebands due to resonance modes in the Ar: Eu phonon spectrum. In addition, unexpected anti-Stokes vibrational side bands are observed, which might be due to “hot luminescence”.  相似文献   

19.
The Raman spectrum of the symmetric stretching vibration (ν1) of liquid carbon tetrachloride observed at 295 K and reported repeatedly over the last 80 years clearly shows four of the five more abundant isotopomers at 440–470 cm−1. At the lower energy end of this spectrum, additional intensity due to isotopomeric contributions from the symmetric stretch for v = 1 → 2 (hotbands) partially overlaps the prominent v = 0 → 1 features, and accounts for about 18% of the integrated intensity at 295 K in agreement with theory. When these two patterns are modeled and subtracted from the experimental spectrum, a feature underlying almost exactly the C35Cl4 (v = 0 → 1) band at 462.5 cm−1 becomes apparent. We propose that this feature is the ν3 − ν4 difference band. Observations at lower temperatures, and of the combination bands, and the polarized Raman spectra are consistent with this hypothesis. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

20.
The electronic spectra of CrO2?4 ions embedded in cesium halide lattices show two well defined bands due to dipole allowed transitions along with some weak bands due to forbidden transitions. All the above bands are interpreted in terms of transitions within molecu ar orbital levels using the Ballhausen and Liehr scheme. It is observed that superposed on the electronic transitions there is a vibrational fine structure which arises due to the coupling between the electronic transitions and the totally symmetric stretching frequency of the ion. IR absorption spectrum of Analar grade CsI :CrO2?4 shows seven lines, whereas Specpure CsI :CrO2?4 shows five lines. The above spectra are interpreted on the basis of different local symmetries of CrO2?4 ions in the lattice.  相似文献   

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