排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
水热条件下,合成了钴(Ⅱ)配位聚合物{[Co(L)(chdc)].2H2O}n(1)(L=1,3-二(苯并咪唑-1-甲基)苯,H2chdc=1,4-环己烷二酸)。结构分析表明,配合物1的晶体属于单斜晶系,C2/c空间群,晶胞参数为a=1.4504(1)nm,b=1.834 9(2)nm,c=2.128 7(2)nm,β=94.325(1)°,V=5.649 2(9)nm3,Z=4。该配合物为一维环状链结构,并进一步通过链间的π-π作用自组装成二维超分子结构。配合物1作为类芬顿反应的催化剂降解刚果红显示较高的活性。 相似文献
2.
3.
4.
The resonance effect of microcrystalline cellulose/castor oil electrorheological (ER) suspensions was studied in a compressed oscillatory squeeze flow under external electric fields. The resonance frequency first increases linearly with increasing external field, and then shift to high-field plateau. The amplitudes of resonance peak increase sharply with the applied fields in the range of 0.17-1.67 kV/mm. The phase difference of the reduced displacement relative to the excitation force inverses in the case of resonance. A viscoelasticity model of the ER suspensions, which offers both the equivalent stiffness and the viscous damping, should be responsible for the appearance of resonance. The influence of the electric field on the resonance frequency and the resonance hump is consistent qualitatively with the interpretation of our proposed model. Storage modulus G' was presented for the purpose of investigating this influence. 相似文献
5.
6.
借助《几何画板》,笔者近日在学习和教学中发现了圆锥曲线中一组漂亮的统一性质,现与大家分享.性质1若抛物线y2=2px(p>0)上某点P的法线与x轴交于点G,过点G作焦半径PF的垂线l,垂足为L,则|PL|=p. 相似文献
7.
水热条件下,合成了钴(Ⅱ)配位聚合物{[Co(L)(chdc)]·2H2O}n (1) (L=1,3-二(苯并咪唑-1-甲基)苯,H2chdc=1,4-环己烷二酸)。结构分析表明,配合物1的晶体属于单斜晶系,C2/c空间群,晶胞参数为a=1.4504(1) nm,b=1.834 9(2) nm,c=2.128 7(2) nm,β=94.325(1)°,V=5.649 2(9) nm3,Z=4。该配合物为一维环状链结构,并进一步通过链间的π-π作用自组装成二维超分子结构。配合物1作为类芬顿反应的催化剂降解刚果红显示较高的活性。 相似文献
8.
Single-walled carbon nanotubes (SWNTs) were synthesized by pyrolyzing
methane (CH4) at a temperature of 900℃ on SiO2 substrates
pre-coated with iron nano-particles. Electrical contacts were fabricated
onto one of the SWNTs by using an electron beam lithography process. Coulomb
blockade and single-electron tunnelling characters were found at low
temperatures, indicating that the SWNT in-between the electrodes forms a
quantum dot. It is found that the Coulomb gap of the quantum dot is about
8.57 meV, and the factor \alpha , which converts the gate voltage to the
true electrostatic potential shift, is around 200 for this device. 相似文献
9.
Bistable switch modules are among the most important fundamental motifs in signal-transduction pathways. To better understand their spatial signal transduction, we model the diffusion process in the one-dimensional (1–D) domain. We find that when none of the elements diffuse, the response of the system exhibits a spatial switch–like property. However, when one of the elements is highly diffusible, the response of the system does not show any spatial switching behavior. Furthermore, we observe that the spatial responses of the system are more sensitive to the time constant of the switch when none of the elements are diffusible. Further, a slow loop keeps the system in the high steady state more positions than that in the fast loop. Finally, we consolidate our numerical results analytically by performing a mathematical method. 相似文献
10.
We investigate the resistance and magnetoresistance (MR) of an entangled single-walled carbon nanotube (SWNT) network. The temperature dependence of conductance is fitted by formula G(T) = Go exp[-(To/T)^1/2] with To = 15.8 K at a wide temperature range from 4 K to 300K. The MR defined by [R(T, H) - R(T, 0)]/ R(T, 0) as a function of temperature and magnetic field perpendicular to the tube axis is negative at low temperatures. The MR amplitude increases as the temperature decreases at relative high temperature, but becomes decrease when temperature below 4 K. The results are explained in terms of the coherent hopping of carriers in the presence of a Coulomb gap at low temperature. 相似文献