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YU YanLi BAI Wei ZHAO KongShuang& ZHOU YunLong College of Chemistry Beijing Normal University Beijing China College of Life Science 《中国科学:化学》2010,(3)
Dielectric spectroscopy(DS) was utilized to investigate the toxicity of the Cu2+ solution to Microcystis aeruginosa.It was found that 0.04 mM Cu2+ had no effect on dielectric increment,whereas the Cu2+ concentrations above 0.1 mM decreased the value of Δε/Δε intact.The toxic effect of Cu2+ on M.aeruginosa cells was time-dependent and concentration-dependent.There was a threshold concentration between 0.04 mM and 0.1 mM,which affected the cell membrane,suggesting that Cu2+ at the concentrations higher than 0... 相似文献
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The electric field of the microtubule is calculated according to its dipole distribution. The conformationalchange of a molecular motor is described by the rotation ofa dipole which interacts with the microtubulc. The mricalsimulation for the particle current shows that this interaction helps to produce a directional motion along the microtubule.And tte average displacement executes step changes that resemble the experimental result for kinesin motors. 相似文献
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We study a class of semilinear Schrdinger equation with electromagnetic fields and the nonlinearity term involving critical growth.We assume that the potential of the equation includes a parameter λ and can be negative in some domain.Moreover,the potential behaves like potential well when the parameter λ is large.Using variational methods combining Nehari methods,we prove that the equation has a least energy solution which,as the parameter λ becomes large,localized near the bottom of the potential well.Our result is an extension of the corresponding result for the Schrodinger equation which involves critical growth but does not involve electromagnetic fields. 相似文献
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Based on atmospheric chemical kinetics, the rate constant of overall pseudo-first order oxidation re-moval of gaseous pollutants (Kpor,T) is proposed to characterize the atmospheric oxidation capacity in troposphere. Being a quantitative parameter, Kpor,T can be used to address the issues related to at-mospheric oxidation capacity. By applying this method, the regional oxidation capacity of the atmos-phere in Pearl River Delta (PRD) is numerically simulated based on CBM-IV chemical mechanism. Re-sults show the significant spatio-temporal variation of the atmospheric oxidation capacity in PRD. It is found that OH initiated oxidations, heterogeneous oxidation of SO2, and photolysis of aldehydes are the three most important oxidation processes influencing the atmospheric oxidation capacity in PRD. 相似文献
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JiaGao Cheng WeiLiang Zhu YanLi Wang XiuHua Yan Zhong Li Yun Tang HuaLiang Jiang 《中国科学B辑(英文版)》2008,51(8):768-775
The M2 protein from influenza A virus is a tetrameric ion channel. It was reported that the permeation of the ion channel is correlated with the hydrogen bond network among His37 residues and the cation-π interactions between His37 and Trp41. In the present study,the hydrogen bonding network of 4-methyl-imidazoles was built to mimic the hydrogen bonds between His37 residues,and the cation-π interactions between 4-methyl-imidazolium and indole systems were selected to represent the interac-tions between His37 and Trp41. Then,quantum chemistry calculations at the MP2/6-311G level were carried out to explore the properties of the hydrogen bonds and the cation-π interactions. The calcula-tion results indicate that the binding strength of the N-H···N hydrogen bond between imidazole rings is up to -6.22 kcal·mol-1,and the binding strength of the strongest cation-π interaction is up to -18.8 kcal·mol-1(T-shaped interaction) or -12.3 kcal·mol-1(parallel stacking interaction). Thus,the calcu-lated binding energies indicate that it is possible to control the permeation of the M2 ion channel through the hydrogen bond network and the cation-π interactions by altering the pH values. 相似文献
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Dielectric spectroscopy (DS) was utilized to investigate the toxicity of the Cu2+ solution to Microcystis aeruginosa. It was found that 0.04 mM Cu2+ had no effect on dielectric increment, whereas the Cu2+ concentrations above 0.1 mM decreased the value of Δ?/Δ? intact. The toxic effect of Cu2+ on M. aeruginosa cells was time-dependent and concentration-dependent. There was a threshold concentration between 0.04 mM and 0.1 mM, which affected the cell membrane, suggesting that Cu2+ at the concentrations higher than 0.1 mM caused serious plasmalemma damage to M. aeruginosa cells. The addition of 1 mM Ca2+ or Mg2+ did not protect M. aeruginosa cells from 1 mM Cu2+ toxicity. The study demonstrates that DS monitors cell biomass facilitating observation of the toxic effects of metal ions. 相似文献
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Radiation Temperature Scaling Law for Gold Hohlraum Heated with Lasers at 0.35 mm Wavelength 下载免费PDF全文
We have carried out the hohlraum experiments about radiation temperature scaling on the Shenguang-Ⅱ (SG- Ⅱ) laser facility with eight laser beams of 0.35#m, pulse duration of about 1.0ns and total energy of 2000J. The reradiated x-ray flux through the laser entrance hole was measured using a soft x-ray spectrometer. The measured peak radiation temperature was 170eV for the standard hohlraum and 150 eV for the 1.5-scaled one. We have derived the radiation temperature scaling law, in which the laser hohlraum coupling efficiency is included. With an appropriate coupling efficiency, the coincidences between experimental and scaling hohlraum radiation temperatures are rather good. 相似文献