酶法获得的多肽库用于新型手性固定相的制备

采用胰蛋白酶酶解牛血清白蛋白,将制备的酶解液超滤,得到相对分子质量小于6000的小分子多肽库。应用羰基咪唑法将该多肽库键合至多孔硅胶,得到一种新型手性固定相。应用该新型手性固定相成功地拆分了两种氨基酸对映体。     

Dirac Equation and Its Solution Around Schwarzschild–de Sitter Black Hole

This paper aims to solve the radial parts of Dirac equation between the inner and the outer horizon in Schwarzschild–de Sitter geometry numerically. A logarithm approximation which almost has the same nature with the modified tortoise coordinate r* even close to the two horizons is found. It is used to replace the modified tortoise coordinate r*, this leads to a simple analytically invertible relation between r* and the radius r. Then, the potential V (r*) is replaced by a collection of step functions. By a quantum mechanical method, the solution of the wave equation as well as the reflection and transmission coefficients are computed. The resulting wave turns out to be not close to that of a harmonic wave globally.     

Zeeman laser-scanning confocal microscopy in turbid media

A novel Zeeman laser-scanning confocal microscope (ZLSCM) is proposed. It has the same configuration as the conventional laser-scanning confocal microscope (LSCM) in which a Zeeman laser in conjunction with a Glan-Thompson analyzer is used. In our system, the analyzer with the bandpass filter, which act simultaneously as a polarization gate and a coherence gate, enhance the collection efficiency of the weak-scattering photons and simultaneously suppress the multiple-scattering photons. The improvement in depth resolution of a ZLSCM in a scattering medium compared with that of a conventional LSCM is discussed and demonstrated experimentally.     

LD Pumped Q-Switching and Self-starting Mode-locked All Fiber Laser

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Drug carrying hydrogel base wound dressing

A special drug carrying hydrogel base wound dressing by radiation preparation is developed for hospital uses. The dressing possesses high water absorption property. Radiation preparation is carried out using a Van de Graaff Accelerator as an electron radiation source. The effect of absorbed dose and cmount of crosslinking agent on the gel fraction and swelling ratio of the hydrogel were determined respectively. As a bio-medical material, standard tests were made. Results showed properties conforming with requirements for clinical applications. Results obtained from clinical tests were good.     

Noninvasive determination of absorption coefficient and reduced scattering coefficient of human skin tissues in vivo with oblique-incidence reflectometry

A spatial distribution of diffuse reflectance produced by obliquely incident light is not centered about the point of light entry. The value of shift in the center of diffuse reflectance is directly related to the absorption coefficient μa and the effective attenuation coefficient μeff. μa and the reduced scattering coefficient μ's of human skin tissues in vivo are measured by oblique-incidence reflectometry based on the two-source diffuse theory model. For ten Chinese volunteers aged 15-63 years, μa and μ's are noninvasively determined to be 0.029 - 0.075 and 0.52 - 0.97 mm-1, respectively.     

Efficient electrocatalytic oxygen evolution at ultra-high current densities over 3D Fe,N doped Ni(OH)2 nanosheets

Developing highly efficient nickel or iron based hydroxide electrocatalysts is primary essential but challenging for oxygen evolution reaction (OER) at ultra-high current densities. Herein, we developed a facile method to prepare nitrogen and iron doped nickel(II) hydroxide nanosheets on self-supported conductive nickel foam (denoted as Fe,N-Ni(OH)₂/NF) through ammonia hydrothermal and impregnation methods. Owing to the optimization of the electronic structure by nitrogen doping and the strong synergistic effect between Fe and Ni(OH)₂, the three-dimensional (3D) Fe,N-Ni(OH)₂/NF nanosheets delivered superior electrocatalytic OER performances in basic solution with low potentials of 1.57 V and 1.59 V under 500 mA/cm² and 1000 mA/cm² respectively and robust operation for 10 h with ignored activity decay, comparing well with the potentials of previously reported NiFe based electrocatalysts as well as the benchmark commercial Ir/C/NF. In-situ Raman spectroscopy revealed that the main active species were NiOOH during the OER process. The present results are expected to provide new insights into the study of OER process towards ultra-high current densities.     

Experimental study on the effect of pyrolysis temperature on the NO emission and conversion during combustion

Journal of Thermal Analysis and Calorimetry - For realizing the coupling pyrolysis of coal and combustion of semi-coke, this paper explored the effect of pyrolysis temperature on the combustion...     

Sustainable Chromium (VI) Removal from Contaminated Groundwater Using Nano-Magnetite-Modified Biochar via Rapid Microwave Synthesis

This study developed a nano-magnetite-modified biochar material (m-biochar) using a simple and rapid in situ synthesis method via microwave treatment, and systematically investigated the removal capability and mechanism of chromium (VI) by this m-biochar from contaminated groundwater. The m-biochar was fabricated from reed residues and magnetically modified by nano-Fe₃O₄. The results from scanning electron microscopy (SEM) and X-ray diffraction (XRD) characterisations confirmed the successful doping of nano-Fe₃O₄ on the biochar with an improved porous structure. The synthesised m-biochar exhibited significantly higher maximum adsorption capacity of 9.92 mg/g compared with that (8.03 mg/g) of the pristine biochar. The adsorption kinetics followed the pseudo-second-order model and the intraparticle diffusion model, which indicated that the overall adsorption rate of Cr(VI) was governed by the processes of chemical adsorption, liquid film diffusion and intramolecular diffusion. The increasing of the pH from 3 to 11 significantly affected the Cr(VI) adsorption, where the capabilities decreased from 9.92 mg/g to 0.435 mg/g and 8.03 mg/g to 0.095 mg/g for the m-biochar and pristine biochar, respectively. Moreover, the adsorption mechanisms of Cr(VI) by m-biochar were evaluated and confirmed to include the pathways of electrostatic adsorption, reduction and complexation. This study highlighted an effective synthesis method to prepare a superior Cr(VI) adsorbent, which could contribute to the effective remediation of heavy metal contaminations in the groundwater.     

Imaging the Reaction Dynamics of O(3P)+CH4→OH+CH3

The title reaction was studied in a crossed‐beam experiment, in which the ground‐state methyl products were probed using a time‐sliced velocity‐imaging technique. By taking images over the energy range of chemical significance, from the threshold to about 15 kcal mol^?1, the reactive excitation function as well as the dependences of product angular distributions and of the energy disposal on initial collision energies were determined. All experimental data are consistent with the picture that the ground‐state reaction of O(³P)+CH₄ proceeds via a direct abstraction rebound‐type mechanism with a narrow cone of acceptance. Deeper insights into the underlying mechanism and the key feature of the potential‐energy surface are elucidated by comparing the results with the corresponding observables in the analogous Cl+CH₄ reaction.