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71.
72.
运用矩阵光学的方法对多棒串接固体激光器的谐振腔参数及其在平平腔时的热稳条件进行了研究,并计算了六棒串接平平腔固体激光器的稳定区.结果证明:多棒串接固体激光器的稳定区和非稳区相互间隔,在平平腔总腔长、激光棒数量n和棒间距L一定的条件下,当采用对称结构时(L1=L2),则谐振腔的每段稳定区均达到最大;且只要 平平腔满足L1=L2=L/2以及热焦距f在大于某个下限值fm时,稳定性条件01<
关键词:
多棒串接固体激光器
稳定区
热稳条件 相似文献
73.
本文测定了几种二茂铁有机锡衍生物的119Sn,13C NMR谱。对其中几种衍生物的13C NMR谱进行了归属,从而进一步验证了这类化合物的结构。着重讨论了结构如化合物中取代基X的改变对119Sn化学位移的影响。并对结构如
类化合物N→Sn异侧配位的问题进行了讨论。 相似文献
74.
Mitsuru Ueda Tetsuya Abe Mitsuo Oda 《Journal of polymer science. Part A, Polymer chemistry》1992,30(9):1993-1998
Aromatic poly(thioether ketone)s were prepared by the direct polycondensation of aromatic dicarboxylic acids with aryl compounds containing ether or sulfide structures using phosphorus pentoxide/methanesulfonic acid (PPMA) as a condensing agent and solvent. Polycondensation proceeded smoothly and produced aromatic poly(thioether ketone)s with inherent viscosities up to 0.73 dL/g. The synthesis of substituted aryl ketones by the reaction of substituted benzoic acids with aryl compounds in PMMA was studied in detail to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(thioether ketone)s showed a 10% weight loss in air and nitrogen at around 450 and 460°C, respectively. © 1992 John Wiley & Sons, Inc. 相似文献
75.
杨慧 《原子与分子物理学报》2002,19(4):411-416
以二维复式晶格作为有限系统的集团模型,在紧束缚近似下,计算了π电子在最近邻及次近邻跳跃集团的态密度.讨论了不同结构参数对态密度及带宽的影响. 相似文献
76.
Protonation constant of an unsymmetrical Schiff base, salicylidene(N-benzoyl)glycyl hydrazone (SalBzGH), and formation constants
of its complexes have been determined potentiometrically at different temperatures in aqueous dioxane medium. Complexes of
SalBzGH with VO(IV), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) have been prepared. Elemental analyses, pH-metric,
molar conductance, magnetic susceptibility, electronic, IR, ESR, XRD (powder) and NMR studies have been carried out to study
the coordination behaviour of SalBzGH toward these metal ions. pH-metric and 1H NMR studies show the presence of two dissociable
protons in the ligand. IR and NMR spectra suggest the tridentate nature of the ligand, coordinating as a uninegative species
in the Mn(II) complex and as a dinegative species in all the other complexes. Presence of two different conformers of the
ligand at room temperature and stabilization of a single conformer upon complex formation have been established from1H NMR spectra of the metal-free ligand, Zn(II) and Hg(II) complexes recorded at 296 K. Electronic and ESR spectra indicate
highly distorted tetragonal geometry for VO(IV) and Cu(II) complexes. XRD powder patterns of the Zn(II) complexes are indexed
for an orthorhombic crystal system. 相似文献
77.
78.
采用循环伏安法,对SPEPt电极以及SPEAu-Pt电极上还原态CO2的电化学氧化行为研究表明,此类电极的电化学特性与光滑Pt电极一致:CO2在氢原子吸附电位区0~250mV(vs.RHE)处,可与电极上化学吸附的氢反应,生成还原态的CO2,通过线性扫描,还原态CO2即发生一不可逆电化学氧化过程(阳极剥离).在SPEPt系列及SPEAu-Pt系列上CO2的电化学行为表明,当SPEPt系列上Pt的载量为2.5mL的0.01mol·L-1H2PtCl6的Pt时,对还原态CO2的电催化活性最好,当Pt的载量相同时,在SPEAu-Pt上,催化剂对还原态CO2的电化学氧化行为比SPEPt电极更强,这是由于预先沉积的Au对后沉积的Pt有调制作用. 相似文献
79.
V.M. Khulugurov V.N. Salomatov I.M. Kalogeras A. Vassilikou-Dova I. Christakis 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,28(1):91-101
Thermally Stimulated Depolarisation Current (TSDC) and optical methods are applied to a range of alkali-fluoride crystals
in order to establish a model for the stable F
2
+
- like colour centres in LiF:OH-. The experimental results for LiF:OH- suggest that the OH- defects are partially destroyed under ionising irradiation or during crystal growth. The low-temperature dielectric relaxation
signals in LiF:OH- and LiF:Mg2+,OH- are attributed to highly interacting hydroxide ions and products of their destruction located in extended lattice defects.
In LiF:OH-, in contrast to other alkali halides, the results advocate for a defect-structure model, which considers a neutral defect
(ND, probably O2 or H2) sited at the anion vacancy of the O2--V
a
+
dipole and which possibly is the “nucleus” for the F
2
+
centre. The proposed F
2
+
(ND, O-) model seems to better explain the dielectric results, compared to the older F
2
+
(O2-) and F
2
+
(O-) models. The estimate for the electric dipole moment derived from the experimental TSDC bands, gives a value for the F
2
+
- like centre in LiF:OH- between those of the F
2
+
(O-) and F
2
+
(O2-) defects, in good agreement with the proposed F
2
+
(ND,O-) model. The reduction of the activation energy barrier of the (re)orientation process of the Mg2+V
c
-
(OH-) complexes in LiF:Mg2+,OH-, and the low-temperature shift of their TSDC band, compared to the single Mg
2
+
V
c
-
peak in LiF:Mg2+, are tentatively ascribed to an increase in the crystal-lattice parameters owing to the presence of OH- and/or products of its destruction.
Received 31 August 2001 / Received in final form 30 March 2002 Published online 9 July 2002 相似文献
80.
A three-dimensional Ising-like model doped with anti-ferromagnetic (AFM) bonds is proposed to investigate the magnetic properties
of a doped triangular spin-chain system by using a Monte-Carlo simulation. The simulated results indicate that a steplike
magnetization behavior is very sensitive to the concentration of AFM bonds. A low concentration of AFM bonds can suppress
the stepwise behavior considerably, in accordance with doping experiments on Ca3Co2O6. The analysis of spin snapshots demonstrates that the AFM bond doping not only breaks the ferromagnetic ordered linear spin
chains along the hexagonal c-axis but also has a great influence upon the spin configuration in the ab-plane.
相似文献