煤焦与水蒸气的气化实验及表观反应动力学分析

在Thermax500型热重分析仪上对褐煤煤焦与水蒸气的气化反应进行了实验研究，并采用n级速率方程和Langmuir-Hinshelwood(L-H)速率方程考察了反应气体分压的影响。实验系统压力为0.1和0.6MPa，其中0.1MPa下水蒸气浓度分别为5%，10%和20%，0.6MPa下的水蒸气浓度为20%。气化反应在恒温条件下进行，温度分别为850、875、 900、925、950和1 000 ℃。实验发现，反应速率随温度和压力的增大而加快，900 ℃以下为化学反应控制区，不同压力下的表观活化能数值接近，而900 ℃以上由于受到扩散阻力的作用，表观活化能不同程度降低。采用n级速率方程计算得到褐煤煤焦与水蒸气的反应级数n为0.34，活化能E为153.7 kJ×mol-1，采用L-H方程得到活化能为207.1 kJ×mol-1，其速率方程可更精确地描述水蒸气压力的影响。     

Transient changes in the power output from the concentration difference cell (dialytic battery) between seawater and river water

Experimental study on the concentration difference cell between seawater and river water (dialytic battery) has been made with special attention to the transient change in the power output. The cell consists of 59 compartments made with 29 ion-exchange membrane pairs, each of which has an effective area of 80 cm² per sheet. It has been found that the voltage drop across the load decreases exponentially with two different short and long time constants, of which values are about 50 and 800 s, respectively. Accordingly the power also decreased to about one fourth (from 259 to 68.9 mW/m² pair) after sufficient time passed. These transient behaviors have been successfully interpreted by the capacitor-type equivalent circuit model. From comparisons between the experimental and the model results, values of the internal resistance and two kinds of capacitor were determined, of which values were 114 Ω, 1.35 and 66.4 F, respectively. It was suggested that the short and long time constants came from charge double layers formed at the cathode and the anode, respectively. Measurements of potential difference between saline water compartments in the case with and without external current by reference electrodes showed that voltage losses occurred due to the concentration polarization near the ion-exchange membranes and the activation polarization at the electrode surfaces.     

Cell Profiling Based on Sugar-Chain–Cell Binding Interaction and Its Application to Typing and Quality Verification of Cells

Developing methods to determine cell type and cell state has been a significant challenge in the field of cancer diagnosis as well as in typing and quality verification for cultured cells. Herein, we report a cell profiling method based on binding interactions between cell-surface sugar-chain-binding proteins and sugar-chain-immobilized fluorescent nanoparticles (SFNPs), together with a method for cell typing and cell quality verification. Binding profiles of cells against sugar chains were analyzed by performing flow cytometry analysis with SFNPs. Discrimination analysis based on binding profiles could classify cell type and evaluate the quality of cultured cells. By applying our method to differentiated cells originating from conventional cell lines and also to mouse embryotic stem cells, we could detect the cells before and after differentiation. Our method can be utilized not only for the biofunctional analysis of cells but also for diagnosis of cancer cells and quality verification of cultured cells.     

Phase Transformation Behavior of a Pyrochlore‐Type CeO2–ZrO2 Binary Compound

The phase transformation behavior of the superlattice structure of a CeO₂–ZrO₂ pyrochlore‐type binary compound (CP) was investigated so as to better understand how to improve the thermal stability of such a system. CP was synthesized through high‐temperature reduction of a conventional CeO₂–ZrO₂ solid solution with a 1:1 molar ratio of Ce and Zr. High‐resolution transmission electron microscopy and selected‐area electron diffraction clearly revealed that the pyrochlore structure of CP transformed to the standard disordered cubic fluorite or tetragonal zirconia structure after having been subjected to a high‐temperature durability test; moreover, it was determined that this phase transformation moves inward from the crystallite surface. This discovery suggests a new method by which to improve upon this material for practical applications.     

Synthesis of acrylamide/acrylic acid‐based aluminum flocculant for dye reduction and textile wastewater treatment

Aluminum hydroxide‐poly[acrylamide‐co‐(acrylic acid)], AHAMAA, was synthesized with a redox initiator by solution polymerization in which the effects of reactant contents were optimized. The effects of pH, temperature, and initial dye concentration on Congo red reduction were investigated. A mixture of Congo red and direct blue 71, and the composite textile dye wastewater were investigated. Adsorptions of both dyes were more effective in the nonbuffered solution than those in the buffered solution, and Congo red adsorbed more than direct blue 71 at all pHs. The adsorption of Congo red increased with increasing temperature and its initial concentration. Both dyes obeyed the Freundlich adsorption isotherm. The maximum adsorptions in 100 mg dm^?3 solution were 109 ± 0.5 mg g^?1 and 62 ± 6.6 mg g^?1 for Congo red and direct blue 71, respectively. At 150 mg dm^?3 of the mixed Congo red and direct blue 71, the adsorption was 142 ± 2 mg g^?1 by 643 ± 3 mg dm^?3 AHAMAA. The 40 mg g^?1 dyes of the textile effluent wastewater were adsorbed by 500 mg dm^?3 AHAMAA. AHAMAA could decrease turbidity of the composite wastewater containing a mixture of reactive and direct dyes from 405 to 23 NTU. POLYM. ENG. SCI., 50:1535–1546, 2010. © 2010 Society of Plastics Engineers     

Synthesis of poly(methyl methacrylate) nanoparticles initiated by azobisisobutyronitrile using a differential microemulsion polymerization technique

Nanosized poly(methyl methacrylate) (PMMA) particles with a high molecular weight of 10⁶ g mol^?1 and a polydispersity index of about 1–2 were synthesized, for which 2,2′‐azobisisobutyronitrile was used as the initiator and a differential microemulsion polymerization technique was employed. The kinetics of the polymerization, the glass transition temperature, tacticity, the particle size distribution, and the morphology of the nanosized PMMA synthesized were investigated. The dependence of the number of the polymer particles (N_p) and the number of the micelles (N_m) on the concentration of the surfactant was discussed. The molecular weight distribution was found to be nearly constant over the polymerization time, which was attributed to the significance of micellar polymerization. The resultant nanosized PMMA has a rich syndiotactic configuration (53–57% rr triads) with a glass transition temperature of about 125°C. A beneficial operation condition was discovered where the conversion reached a maximum at a high monomer‐to‐water ratio. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Plasma nano-modification of poly(ethylene terephthalate) fabric for pigment adhesion enhancement

Poly(ethylene terephthalate) (PET) fabrics were modified by treating with radio frequency (RF) plasma of different gases, including argon (Ar), nitrogen (N2), oxygen (O2) and sulfur hexafluoride (SF6), under varied power (50-150 watt) and time period (0.5-20 min). Observations indicated that plasma has affected the morphology and roughness of PET fiber surface in the nano-scale level. After plasma treatment, test patterns were printed by inkjet printer directly onto the sample surface. The enhancement of color printing performance on PET fabric by plasma treatment was evaluated by color spectroscopy. The surface nano-modified PET fabrics by Ar, N2, O2, and SF6 plasmas all exhibited enhanced color yield. AFM, SEM, FTIR-ATR and XPS results suggested that the improved pigment color yield was neither clearly contributed by the wettability of the fabrics nor the polar group induced onto the fiber surfaces but rather mainly by the alteration of surface roughness.     

16S rRNA gene-based analysis of microbial community by whole-genome amplification and minigel-single-strand conformation polymorphism technique

We have developed an analytical technique for the 16S rRNA gene that comprises whole-genome amplification and the polymerase chain reaction (PCR)-minigel-single-strand conformation polymorphism technique (WGA-SSCP). Under optimal conditions, SSCP bands could be detected when genomic DNA from bacteria of interest comprised 0.5% or more of the specimen. This method will be effective for the identification of nonculturable bacteria in a microbial community.