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1.
阿莫西林的荷移光谱测定方法研究   总被引:6,自引:0,他引:6  
在丙酮介质中阿莫西林与 7,7,8,8-四氰基对二次甲基苯醌 (TCNQ)荷移反应 ,形成 1∶ 1络合物 ,在74 4nm和 84 5 nm处有较强光吸收 ,表观摩尔吸光系数分别为 1.2× 10 4L· mol-1· cm-1和 1.8× 10 4L·mol-1· cm-1,阿莫西林的浓度在 10— 15 0 mg· L-1范围内符合比耳定律。在乙醇介质中 ,阿莫西林与对苯醌 (p- BQ)反应 ,形成 1∶ 1络合物 ,最大吸收波长为 4 80 nm,表观摩尔吸光系数为 1.92× 10 3 L· mol-1·cm-1。阿莫西林的浓度在 2 0— 2 0 0 mg·L-1范围内符合比耳定律。两种方法相对标准偏差分别为 1.2 %和1.5 % (n=8) ,用于测定阿莫西林制剂的含量 ,结果与标准方法一致。  相似文献
2.
重金属碲酸盐玻璃中Ho~(3+)的红外辐射特性   总被引:1,自引:0,他引:1  
制备了高折射率Ho3+单掺和Ho3+/Yb3+共掺低声子能量重金属碲酸盐玻璃.根据Judd-Ofelt理论对吸收光谱进行拟合,求得Ho3+强度参数Ωt(t=2,4,6)分别为4.373×10-20,1.906×10-20和1.451×10-20cm2,并进一步计算了Ho3+在红外区各能级跃迁的振子强度、自发辐射跃迁概率、辐射寿命和荧光分支比等光谱参数.982 nm激发下,铋碲酸盐玻璃中Yb3+直接敏化Ho3+,在红外区产生有效红外发射.Ho3+吸收与发射截面在1.95和2.05μm处分别高达5.63×10-21和6.24×10-21cm2,大于Ho3+掺杂磷酸盐和氟化物玻璃,这有利于降低激光抽运阈值,实现高效Ho3+激光输出.较低的声子能量和较大的发射截面表明,Ho3+/Yb3+共掺杂铋碲酸盐玻璃有望成为良好的红外激光工作物质.  相似文献
3.
The difference in temporal structures of retinal ganglion cell spike trains between spontaneous activity and firing activity after contrast adaptation is investigated. The Lempel-Ziv complexity analysis reveals that the complexity of the neural spike train decreases after contrast adaptation. This implies that the behaviour of the neuron becomes ordered, which may carry relevant information about the external stimulus. Thus, during the neuron activity after contrast adaptation, external information could be encoded in forms of some certain patterns in the temporal structure of spike train that is significantly different, compared to that of the spike train during spontaneous activity, although the firing rates in spontaneous activity and firing activity after contrast adaptation are sometime similar.  相似文献
4.
Quasi-classical trajectory(QCT) studies on the stereodynamics of H + Br O → O + HBr reaction have been performed on the X1A′state of ab initio potential energy surface by Peterson [Peterson K A 2000 J. Chem. Phys. 113 4598] in a collision energy range from 0 kcal/mol to 6 kcal/mol. Two of the polarization-dependent generalized differential cross sections(PDDCSs),(2π /σ)( dσ00/ dωt)(PDDCS00) and(2π /σ)( dσ20/ dωt)(PDDCS20) are considered. The rotational polarizations of these products show sensitive behaviors to the calculated collision energy range. Furthermore, in order to gain more knowledge about vector correlations, the product angular distribution, P(θr), and the dihedral angle, P(φr),are calculated, and the results indicate that both the rotational alignment and orientation of the product are enhanced as collision energy increases.  相似文献
5.
A quasi-classical trajectory(QCT) calculation is used to investigate the vector and scalar properties of the D + Br O → DBr + O reaction based on an ab initio potential energy surface(X1A state) with collision energy ranging from 0.1 kcal/mol to 6 kcal/mol. The reaction probability, the cross section, and the rate constant are studied. The probability and the cross section show decreasing behaviors as the collision energy increases. The distribution of the rate constant indicates that the reaction favorably occurs in a relatively low-temperature region(T < 100 K). Meanwhile, three product angular distributions P(θr), P(φr), and P(θr, φr) are presented, which reflect the positive effect on the rotational angular momentum j’ polarization of the DBr product molecule. In addition, two of the polarization-dependent generalized differential cross sections(PDDCSs), PDDCS00 and PDDCS20, are computed as well. Our results demonstrate that both vector and scalar properties have strong energy dependence.  相似文献
6.
In this paper, the stereodynamics of Li + DF → Li F + D reaction is investigated by the quasi-classical trajectory(QCT)method on the ^2A' potential energy surface(PES) at a relatively low collision energy of 8.76 kcal/mol. The scalar properties of the title reaction such as reaction probability and cross section are studied with vibrational quantum number of v = 1–6. The product angular distributions P(θr) and P(φr) are presented in the same vibrational level range. Moreover, two polarization-dependent generalized differential cross sections(PDDCSs), i.e., the PDDCS00 and PDDCS22+are calculated as well. These stereodynamical results demonstrate sensitive behaviors to the vibrational quantum numbers.  相似文献
7.
Calculations on the dynamics of the reaction O( 1 D) + HBr → OH + Br are performed on the ab initio potential energy surfaces (PESs) of the ground state given by Peterson Peterson K A J. Chem. Phys. 113 4598 (2000)using the quasiclassical trajectory (QCT) method. The product distribution of the dihedral angle, P (φ r ), and that of the angle between and , P (θ r ), are presented in three dimensions. Moreover, we also investigate the reagent vibrational excitation effects on the two polarization-dependent generalized differential cross sections (PDDCS), PDDCS 00 and PDDCS 20 , in the center-of-mass frame. The results indicate that the vector properties are sensitive to the reagent vibrational quantum number.  相似文献
8.
采用磁控溅射方法在玻璃衬底上生长了In2O3晶体薄膜.该薄膜具有(111)晶面择优取向,晶粒尺寸达到33 nm.利用光刻工艺制作了以In2O3晶体薄膜为沟道层的底栅式薄膜晶体管.In2O3薄膜晶体管具有良好的栅压调制特性,场效应迁移率达到6.3 cm2/(V·s),开关电流比为3×103,阈值电压为-0.9 V.结果表明,In相似文献
9.
采用气体反应电子束蒸发法,氨气氛下在玻璃上沉积了氮掺杂氧化锌(ZnO)薄膜。AFM观察发现氨气氛下生长的氮掺杂氧化锌薄膜表面比未掺杂样品的粗糙度略高,且随氨气压的增加粗糙度也随之增加,这可能与氨气氛对ZnO生长表面的轻微腐蚀作用有关,但表面依然比较平整。XRD分析显示,(0002)衍射峰位没有发生移动,但是氮掺杂后衍射峰的线宽比未掺杂样品稍有增加,衍射峰的半峰全宽由非掺杂ZnO的0.261°增加到0.427°。氧化锌掺氮后电阻率提高了4~7个数量级,达到了降低ZnO中电子浓度的目的。  相似文献
10.
Complex stimuli are used to probe the response properties of the chicken's retinal ganglion cells (GCs). The correlation dimension method and the nonlinear forecasting method are applied to detect the determinism in the firing activities of the retinal GCs during response to complex stimuli. The inter-spike interval (ISI) series and the first difference of the ISI (DISI) series are analysed. Two conclusions are drawn. Firstly, the first difference operation of the ISI series makes it comparatively easier for determinism detection in the firing activities of retinal GCs. Secondly, the nonlinear forecasting method is more efficient and reliable than the correlation dimension method for determinism detection.  相似文献
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