2003年上半年我国染料、有机颜料生产及进出口情况浅析（一）

20 0 2年我国染料及有机颜料生产和进出口数量达到历史最好水平 ,2 0 0 3年上半年虽然经受了SARS的影响 ,但我国染料及有机颜料工业仍然取得了稳定增长的成绩。上半年染料产量总计 19 5 9万t,同比增长 2 4 7%;颜料产量为 4 30万t,同比增长 2 1 6 9%。上半年出口增长幅度减缓 ,染料出口总量为 9 92万t,同比增长 3 1%;有机颜料出口为 4 2万t,同比增长 3 1%。进口基本稳定 ,上半年染料进口量为 3 2 5万t,同比增长 9 1%;有机颜料进口为1 6 9万t,同比增长为 11 5 %。总之 ,上半年主要经济指标完成情况良好 ,进出口数量和经济效益继续保持稳定增长。但染料和纺织品的生产与出口都遇到一定的困难 ,纺织品出口又直接影响染料的内销市场 ,由于内外市场的变化 ,使染料生产和进出口的增长幅度减缓。     

Organic-inorganic hybrid materials from a new octa(2,3-epoxypropyl)silsesquioxane with diamines

Hybrid materials based on a new polyhedral oligomeric silsesquioxane, octa(2,3-epoxypropyl)silsesquioxane (OE) with diamines of 4,4′-methylenedianiline (DDM) and 5-trifluoromethyl-1,3-phenylenediamine (FPA) were prepared and characterized. OE was synthesized from cage-structured octaallylsilsesquioxane (OA) with m-chloroperbenzoicacid. The FTIR studies suggested that the N-H bond in diamines was not completely reacted with epoxy group due to steric hindrance and also extensive hydrogen bonding existed in the hybrid materials. The retention of the cage structure in the prepared hybrid materials was suggested by the FTIR and ²⁹Si NMR studies. The OE/FPA hybrid materials had superior thermal/mechanical characteristics than the OE/DDM due to the higher rigidity of the FPA than that of DDM or the silicon-fluorine interaction enhancing crosslinking reaction or hydrogen bonding. The prepared OE/FPA had a T_g of 170 °C, which was higher than diglycidyl ether of bisphenyl A (DGEBA)/DDM at the same stoichiometric ratio. It also had excellent thermal, mechanical, and dielectric characteristics with high storage modulus of 1.8 GPa (30 °C) and 0.3 GPa (250 °C), low coefficient of thermal expansion of 86 μm/m °C, and dielectric constant of 2.19. Thus, it can be high performance materials with potential applications for electronic packaging.     

Synthesis and Characterization of Al-MCM-41 and Al-MCM-48 Mesoporous Materials

A novel route in the synthesis of Al-MCM-41 and Al-MCM-48, using tetraethoxysilane (TEOS) and sodium aluminate (NaAlO₂) as Si and Al source has been obtained. The effect of surfactant nature and the synthesis conditions such as surfactant/Si ratio and hydrothermal treatment time on the formed mesostructure regularity has been studied. Different methods of template removal have also been evaluated. The samples were characterized by X-ray diffraction, nitrogen physisorption, FT-IR, and solid-state MAS NMR spectroscopy.     

Mullite for Structural, Electronic, and Optical Applications

Mullite (3Al₂O₃·2SiO₂) is becoming increasingly important in electronic, optical, and high-temperature structural applications. This paper reviews the current state of mullite-related research at a fundamental level, within the framework of phase equilibria, crystal structure, synthesis, processing, and properties. Phase equilibria are discussed in terms of the problems associated with the nucleation kinetics of mullite and the large variations observed in the solid-solution range. The incongruent melting behavior of mullite is now widely accepted. Large variations in the solid solubility from 58 to 76 mol% alumina are related to the ordering/disordering of oxygen vacancies and are strongly coupled with the method of synthesis used to form mullite. Similarly, reaction sequences which lead to the formation of mullite upon heating depend on the spatial scale at which the components are mixed. Mixing at the atomic level is useful for low-temperature (<1000°C) synthesis of mullite but not for low-temperature sintering. In contrast, precursors that are segregated are better suited for low-temperature (1250° to 1500°C) densification through viscous deformation. Flexural strength and creep resistance at elevated temperatures are significantly affected by the presence of glassy boundary inclusions; in the absence of glassy inclusions, polycrystalline mullite retains >90% of its room-temperature strength to 1500°C and displays very high creep resistance. Because of its low dielectric constant, mullite has now emerged as a substrate material in high-performance packaging applications. Interest in optical applications mainly centers on its applicability as a window material within the mid-infrared range.     

Synthesis and characterization of porous media produced by a sol-gel method

Mesoporous silica materials were synthesized by sol-gel method using tetraethoxysilane (TEOS) as precursors and surfactants i.e., cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyoxyethylene cetyl ether (Brij 56) as templates. Surfactant templates were completely removed by calcination to form mesoporous structure. The effects of type and amount of surfactants on the characteristics of samples were studied. The textural characteristics such as surface area, pore volume, pore size, and pore size distribution were determined by nitrogen sorption isotherms. Fourier transform infrared (FTIR) spectroscopy was employed to qualitatively identify the chemical functionality and to confirm the removal of surfactant template. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to directly observe surface morphology and mesoporous structure, respectively. The adsorption capacity of the synthesized adsorbent for toluene vapor was examined. We found that the pore volume and pore size of mesoporous materials affected the adsorption capacity. The sample prepared with high content of CTAB under basic condition (pH ∼7) yielded large pore volumes and pore sizes and subsequently possessed the high adsorption capacity for toluene vapor.     

Molten salts/ceramic-foam matrix composites by melt infiltration method as energy storage material

A new type of high temperature energy storage material was obtained through the melt infiltration method, using compounding SiC ceramic foam as matrix and Na₂SO₄ as phase change material. The resulting composite material was measured by XRD, SEM, TG-DSC methods. The experimental results indicate that the composite is composed of silicon carbide, sodium sulfate and square quartz, and no chemical reactions occurs between Na₂SO₄ and SiC matrix. Na₂SO₄ has a good bonding with the SiC ceramic foam matrix. As the composite material is characterized by high thermal energy storage density and high thermal conductivity, it is suit for energy storage under high temperature. Funded by the “863” Hi-Tech Research and Development Program of China (2008AA05Z418)     

Characterization of NOM and THM formation potential in eutrophic reservoir water

Resin adsorption technique with XAD-8 and XAD-4 was used to characterize the raw water from Erlong reservoir in Jilin province of China. The NOM chemical composition sequences of four organic fractions in the raw water,from high to low,are fulvic acid (FA) fraction,hydrophilic non-acid (HPINA) fraction,hydrophilic acid (HPIA) fraction,and humic acid (HA) fraction. Experimental results show that FA is the main precursor of THMFP among the four organic fractions. However,HA or hydrophobic acid exhibits the highest chlorination activity in forming THMs. It is also found that the value of FI/DOC or SUVA and the specific THMFP have better positive correlation. It is implied that certain source water has unique nature of NOM and DBPs.     

电网企业物资集约化管理探讨

分析电网企业的物资集约化管理现状,明确物资集约化管理的重要性和必要性,从而探索研究电网企业物资集约化管理的途径.     

关于体育教学改革的问题探讨

分析体育课教学中的主要任务、教材内容、教学方法、成绩考核等几个问题,并对此进行初步的研究和探讨,提出改革意见和措施,以改善体育课的教学效果。