Study of MO2N catalyst activity and stability in CO oxidation

Unsupported molybdenum nitride powder with S_g of 115 m²g⁻¹ (passivated) has been prepared by the temperature-programmed reaction of MoO₃ in H₂/N₂ mixture. It exhibited high catalytic activity in CO oxidation. DTA experiments in the air flow and O₂ temperature-programmed pulse reaction (TPPR) showed that the optimal oxidation temperature for the Mo₂N catalyst was under 450°C because of its instability at high temperature in the presence of O₂.     

含DMIT配体配合物的结构与导电性

本文描述了含DMIT(4,5-二硫基-1,3-二硫杂环戊烯-2-硫酮)配体配合物的含成和导电性,讨论了其各个结构层次及其与导电性的关系。Ni、Pd、Pt、的DMIT导电配合物的分子结构特征是平面构型和离域π电子态,晶体结构特征是配位阴离子堆砌成各种形式的、导电能力不同的分子柱和分子层,作为非导电组元的平衡离子对导电性也有重要影响。     

液相色谱－电致化学发光检测系统的检测性能研究

使用几种常见的反相液相色谱介质和４种多环化合物对液相色谱交流电致化学发光检测系统的性能进行了测试，结果表明：检测器对４种化合物的检测限均可达到２．０ｎｇ，线性范围达３个数量级。     

The behaviour of the negative-branch unstable resonator with an aperture inside

The negative-branch unstable resonator with an aperture inside the cavity at one conjugate image point is studied. The analysis shows that there is only one unique wave existing. The behaviour of the cavity depends only on the magnification and Fresnel numberN ₁.     

Novel Photoinduced Electron Transfer Reaction of N-methylphenothiazine in Carbon Tetrachloride

PhenothiazinederivativeshaveattractedmuchinterestforalongtimeduetotheirdiversechemicalandbioIogicalproperties,aswellasmedicalaPplicationsl.Theradicalcationofphenothiazinesisbelievedtobeinvolvedinthebiotransformationofphenothiazinedrugs2andnumerousstudieshavethusfocusedonthegenerationandreactionsofphenothiazineradicalcations3-6.WereporthereinanovelphotochemicalreactionofN-methylphenothiazineincarbontetrachloridewhichcoupIestwoparentmoleculeswitheliminationofonemethylgroup(Schemel).Resultsandd…     

Progress in Molecular Chaperone Regulation of Heat Shock Protein 90 and Cancer

Heat shock protein 90 (HSP90) is a member of genetically conserved heat shock protein family. As an important molecular chaperone in eukaryotic cells, HSP90 plays a key regulatory role in maintaining cellular protein homeostasis. HSP90 clients encompass a wide range of proteins, thus HSP90 is involved in diverse biological process. With the deeper study, it is found that HSP90 takes an important part in the development and metastasis of cancer, and has become a promising target for the study of anticancer biology. In this review, the progress of HSP90 as molecular chaperone and its relationship with cancer are discussed.     

Non-constant Diffusion Behavior for CO<Subscript>2</Subscript> Diffusion into Brine: Influence of Density-Driven Convection

A graphically-based analysis method used to characterize the diffusion process of carbon dioxide (CO₂) into brine conventionally assumes a constant diffusion coefficient. However, this study found that the assumption is not valid: an inflection point appeared in the calculated dimensionless pressure versus time curve separating the whole diffusion process into unsteady and steady stages, with each stage corresponding to different mechanisms. The unsteady stage, which accounts for the majority of the dissoluble CO₂ diffused into the brine, has hitherto always been neglected in calculating the diffusion coefficient. In this study, a pseudo-diffusion coefficient, which considers both the natural convection effect caused by fluid circulation due to density difference and molecule diffusion driven by the dissolved CO₂ concentration gradient, is proposed to characterize the unsteady stage of the diffusion process. Results from 21 pressure decay experiments indicate that the pseudo-diffusion coefficient of the unsteady stage varies directly with environment’s temperature and inversely with the brine concentration and pressure. The pseudo-diffusion coefficient varied in the range of 10^?8–10^?7 m²·s^?1, while the diffusion coefficient reported in the literature vary in the lower range of 10^?10–10^?8 m²·s^?1. The up to three orders of magnitude difference in the diffusion coefficients representing different diffusive mechanisms testifies to the importance of the unsteady stage in the diffusion of CO₂ in brine. This higher range of variation for the pseudo-diffusion coefficient now incorporating the unsteady stage has also the side effect of introducing higher uncertainties into the prediction of the concentration distribution in CO₂ sequestration calculations.     

PPC-based Reactive Hot Melt Polyurethane Adhesive(RHMPA)——Efficient Glues for Multiple Types of Substrates

Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly(propylene carbonate)(PPC) is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive(RHMPA) based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics(PC, PMMA, ABS) and metals(aluminium, steel), which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process(up to 270 °C). The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.