降低介耗 提高精煤产率

针对河南禹州地区煤质煤泥含量高、浮选精煤粒度组成过细、细粒级颗粒偏多等极难选特征,为了优化极难选高细泥含量原煤洗选加工工艺、提高精煤产率、降低介耗,河南永锦选煤有限公司通过应用3GDMC1100/780AI型无压给料三产品重介旋流器,采取提高精煤产率措施与降低介耗途径,实现精煤产率提高2%,原煤介耗由2.5 kg/t降至1.21 kg/t,降低了材料消耗,增加经济收益1 347万元。     

Refractory Ceramic Fiber and the Products GB/T 3003-2006

正GB/T 3003-20061 Scope This standard specifies the terms,definitions,classifications,brands,technical requirements,test methods,quality appraisal procedure,packing,marking,transportation,storage and quality certificate of     

中专化学“复习方法”初探

根据教材特点和教学对象的特性,采用行之有效的"化学复习方法",既可提高学生的学习效率也能增强学生的学习兴趣。从而进一步提高中专生的综合能力和专业素质。     

Hydrogenated silicon oxycarbonitride films. Part II. Physicochemical and functional properties

The optical, and electrophysical characteristics of hydrogenated silicon oxycarbonitride films synthesized by the plasma enhanced chemical vapor decomposition of the mixtures of 1,1,1,3,3,3-hexamethyldisilazane with oxygen and nitrogen in the temperature range of 373–973 K have been studied. It has been shown that the obtained films are highly transparent (transmittance is ～92–99%) in the UV, visible, and IR ranges of the spectrum; they have refractive indices in the range of 1.43–2.25, a low reflection coefficient of visible light (nearly 3%), and low dielectric permittivity.     

Preparation and Characterization of C10–C14 Alkyl Cellulose Ester Sulfate Surfactant

The aim of this work is to synthesize surfactants based on cellulose with different molecular weights. Raw cotton cellulose was tailored into cellulose segments with different molecular weights by a hydrothermal process, then the average degree of polymerization (DP) was determined by viscosimetry and the molecular weight distribution was estimated by gel permeation chromatography. The C₁₀–C₁₄ alkyl cellulose ester sulfate surfactants were prepared by hydrophilic sulfonation and hydrophobic esterification. The surface tension of the surfactants solution was obtained by the Wilhelmy plate method. Results showed that the cellulose segments presented a broader distribution compared with the raw material. The critical micelle concentration (CMC) value decreased from 1.08 to 0.86 wt% as the hydrophobic chain length was increased from 10 to 14. The CMC values of cellulose surfactants with C₁₄-acyl chloride hydrophobization decreased from 1.32 to 0.86 wt% as the DP was decreased from 2,700 to 296.     

Performance evaluation of asphalt containing layered double hydroxides with different zinc ratio in the host layer

The effects of five layered double hydroxides (LDHs) with different zinc ratio on the physical and rheological properties, chemical components, and anti-UV aging performance of asphalt were evaluated. Results show that LDHs improve the deformation resistance of asphalt at high temperature. After UV aging, LDH-modified asphalts show the smaller changes of physical and rheological properties and chemical components in comparison with asphalt, indicating the improved UV aging resistance. By comparison, the LDHs with higher ratio of zinc in the layers have the more outstanding UV reflection ability, leading to a beneficial effect in improving UV aging resistance of asphalt.     

An Unexpected Construction of 2‐Arylquinolines from N‐Cinnamylanilines through sp3 C?H Aerobic Oxidation Induced by a Catalytic Radical Cation Salt

An unexpected reaction of cinnamylanilines was achieved through the radical cation salt‐induced aerobic oxidation of sp³ C H bonds, providing a series of 2‐arylquinolines. The mechanistic study shows that the cinnamylaniline was oxidized to an imine, which was attacked by the aniline generated through decomposition of the corresponding imine. After further intramolecular cyclization and aromatization, 2‐arylquinolines were obtained. This reaction provides a new method to construct 2‐arylquinolines from readily accessible starting materials.

     

Copper‐Catalyzed Aerobic Formation of Unstable Sulfinyl Radicals for the Synthesis of Sulfinates and Thiosulfonates

Copper‐catalyzed aerobic coupling of thiols and alcohols affords sulfinates and thiosulfonates. These products are assumed to form via sulfinyl radicals which are not commonly found in oxidative coupling reactions of thiols. A reaction mechanism involving sulfinyl radicals is proposed, and mass and electron paramagnetic resonance (EPR) experimental results are provided.