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991.
研究了痂囊腔菌素A(EA)与肌红蛋白(Mb)的相互作用.通过紫外-可见吸收光谱研究发现痂囊腔菌素A与肌红蛋白在避光与光照两种条件作用模式存在明显差异;痂囊腔菌素A对肌红蛋白的内源荧光有猝灭作用,形成了新的配合物,属于静态猝灭;热力学计算结果表明痂囊腔菌素A与肌红蛋白之间以疏水作用力结合.同步荧光光谱研究了痂囊腔菌素A对... 相似文献
992.
通过拟合Mg的晶格能、晶格常数、弹性常数,并将其与前人的结果相比较后获得了描述Mg的最优长程Finnis-Sinclair(F-S)势函数参数,使用同样方法并引入修正因子后得到了Zn的长程F-S势参数.基于单质Zn,Mg的F-S势参数,进一步拟合合金Mg21Zn25,MgZn2,Mg2Zn11的晶格常数、晶格能获得Zn-Mg原子对的F-S势参数,构建了整套描述Zn-Mg合金的长程F-S势参数.在此
关键词:
长程Finnis-Sinclair势
Zn-Mg合金
分子动力学模拟 相似文献
993.
采用超分子单双迭代(包括非迭代三重激发)耦合簇理论CCSD(T)方法,选择由原子中心高斯函数和高斯键函数3s3p2d1f组成的大基组,计算了He-H2(D2,T2)碰撞体系的H2分子取不同键长时的相互作用势能面.运用Tang-Toennies势模型和非线性最小二乘法拟合构造了He与同位素分子H2(D2,T2)在质心坐标系下的振转相互作用势.通过密耦计算得
关键词:
高斯键函数
Tang-Toennies势函数
分波截面
碰撞参数 相似文献
994.
995.
Magnetic properties and magnetocaloric effects of amorphous and crystalline TbCuAl ribbons are investigated by measuring their ac susceptibilities including a nonlinear term and dc magnetizations. The in-phase third harmonic ac susceptibility is found to be negative. It can be well fitted by the expression at high temperatures, indicating a spin-glass behavior in amorphous TbCuAl alloy. ΔTf(ω)/[Tf(ω)Δlog10ω], a possible distinguishing criterion to judge the presence of a spin-glass behavior is ∼0.011. The frequency-dependent data can be well fitted by the conventional critical slowing down law and the spin-glass transition temperature is obtained to be 20.1 K. The maximum of magnetic entropy change reaches 4.5 J kg−1 K−1 for a field change of 0-50 000 Oe, while the crystalline TbCuAl compound experiences a simple ferromagnetic-to-paramagnetic phase transition. The peak value of magnetic entropy change is obtained at the Curie temperature and reaches 14.4 J kg−1 K−1 for the same field change, which is much larger than that of amorphous TbCuAl alloy. 相似文献
996.
The results of an experimental study of quantum correction of electron-electron interaction (EEI) to the conductivity of two-dimensional electron gas (2DEG) in an undoped heterostructure are reported. A small but significant decrease of the Hall slope with the increase of temperature was discovered. This is not due to the increase of electron concentration as temperature increases but to the EEI effect. Both diffusion and ballistic contributions of EEI to the conductivity of 2DEG were observed. As the temperature increases, the negative diffusion EEI correction to the conductivity increases in an absolute value while the ballistic EEI correction reduces to a renormalization of the transport mobility. 相似文献
997.
Nonlinear absorption (NLA) of hydrogenated nanocrystalline silicon (nc-Si:H) has been investigated through the open aperture Z-scan method for the photon energy of the incident irradiance slightly less than the bandgap of the sample. NLA responses have been observed to be highly sensitive to the wavelength and intensity of the incident irradiance as well as to the bandgap of the sample, indicating greatly tunable NLA of nc-Si:H. The band tail of nc-Si:H appears to play a crucial role in such NLA responses. 相似文献
998.
We report on the high-power and high-efficiency operation of a polycrystalline Ho:YAG ceramic laser in-band pumped by a Tm fiber laser at ~1907 nm. Lasing characteristics of a 1.5 at.% and a 2.0 at.% Ho3?-doped YAG ceramic were investigated and compared. Using an output coupler of 6% transmission, over 21.4 W of cw output power at 2097 nm has been generated with the 1.5 at.% doped Ho:YAG ceramic under 35 W of incident pump power, corresponding to an average slope efficiency with respect to the incident pump power of 63.6% and an optical-to-optical conversion efficiency of 61.1%. 相似文献
999.
We present an ultrafine tunable single-frequency Brillouin fiber laser in which the fiber Brillouin gain also acts as a high-precision tunable filter. Controlling the strain on the fiber, the Stokes frequency shift may be precisely changed, and thus the lasing frequency can be tuned. Assisted by the frequency pulling effect, this method provides continuous ultrafine tuning ability for ~30% of the free spectral range without mode hopping, and can cover 271 MHz. The experiments showed that the laser achieves tuning step of 60 kHz. 相似文献
1000.
Feng JiangHonglie Shen Chao GaoBing Liu Long LinZhou Shen 《Applied Surface Science》2011,257(11):4901-4905
SnS films have been prepared by a novel two-stage process. It involved sputtering of Sn film on glass substrate and sulfurization of the thin metallic tin precursor layers in a vacuum furnace. The X-ray diffraction results showed that the SnS layers had orthorhombic structure and (0 4 0) preferential growth is more and more obvious with the increase of sulfurization time. The SnS film obtained by this work shows high optical absorption efficiency, and the film has a direct optical band gap of about 1.3 eV. The films show p-type conductivity and the resistivity of SnS film decreased obviously under illumination. 相似文献