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991.
改性木质素作BIIR交联剂 总被引:1,自引:0,他引:1
研究了羟甲基化木质素(HKL)对BIIR的交联。结果表明,在165℃或以上的温度下,BIIR/HKL混炼胶转矩随硫化时间的延长而上升,这是由于木质素与BIIR形成了交联网状结构所致。10份HKL在165℃交联BIIR达t90所需的时间为650s;当温度升至175℃,达t90的时间则为418s。随羟甲基化木质素质量分数提高,达到t90时间缩短。硫化胶主要物理机械性能同样表明这一体系已形成了三维网状结构。改性木质素在这一体系中,不仅有增强作用,而且可使BIIR橡胶交联。 相似文献
992.
993.
Intel SoC处理器E6x5C系列产品,作为多芯片的封装芯片,具有出色的灵活性。本文基于该处理器,利用Altera新一代集成开发工具Qsys,描述了I2 C总线IP核的设计过程,给出了IP核的系统接口和各个子模块的设计方法,并进行仿真和验证,最后将该IP核应用于模拟视频解码芯片SAA7113的配置及初始化。 相似文献
994.
基于DDS直接数字频率合成技术原理,采用凌阳SPCE061A单片机作为人机界面控制单元和参数形成处理单元,首先以一片AD9851芯片为核心产生频率在10Hz~30 MHz可调、幅度稳定的正弦波、方波和三角波信号,然后通过一路可控模拟开关(使用AD7502芯片)选择波形输出。再通过外接键盘按键控制输出频率及频率步进,并通过LCD显示输出波类型、频率及电压幅度。该系统除具有基本函数信号发生器的主要功能外,还可控制输出频率在10Hz~1MHz之间变化的波型信号,同时还能够保障输出电平满足Vpp=(0~5V)±0.1V。在输出为50Ω负载的条件下,可实现频率在10Hz~1kHz范围内步进10Hz,在10kHz~1MHz范围内步进1kHz。在实验教学、生产等应用中,有一定的使用和推广价值。 相似文献
995.
Iván Jachmanián Lucía Margenat Ana I. Torres Maria A. Grompone 《Journal of the American Oil Chemists' Society》2007,84(6):597-601
The solubility of different ethyl esters derivatized from hake liver oil in supercritical carbon dioxide was studied. A selectivity
factor was used to determine optimal conditions to fractionate the ethyl ester mixture. A strong influence of solvent pressure
and temperature was observed within 8.63–18.04 MPa and 40–70 °C. The lowest total solubility of the ethyl ester mixture was
obtained when using supercritical carbon dioxide at the lowest density (the lowest pressure and the highest temperatures value
tested). The highest discrimination against long-chain polyunsaturated fatty acids (e.g. EPA and DHA) was also obtained at
these above conditions. Conversely, higher solubility and lower selectivity were obtained when solvent density increased.
Considering this inverse correlation between selectivity and solubility, a single-step batch-fractionation process was designed
to increase the 22:6 ethyl ester content from an initial value of 17.5% in the starting material to 55% in the final extract. 相似文献
996.
Min-Jae Yoon Yoan-Sang Bae Sang-Ha Son Jae-Wook Lee Chang-Ha Lee 《Korean Journal of Chemical Engineering》2007,24(5):877-880
Luminescent yttrium aluminum garnet (YAG, Y3Al5O12) nanoparticles doped with Eu (10 at%) were synthesized in batch-type and continuous-type supercritical water (SCW) reactors.
In the case of the continuous-type SCW method, the particles of YAG: Eu phosphors were much smaller and demonstrated a uniform
spherical-like shape. Inversely, in the case of the batch-type SCW method, a needle-like or elliptical-like shape was formed
because a finite amount of time was required to reach SCW conditions from ambient conditions. However, the emission intensity
of YAG: Eu phosphors synthesized by using the batch-type SCW method was stronger. Therefore, it is concluded that the continuous-type
SCW method is superior to the batch-type SCW method from the viewpoint of the particle size and shape, but the luminescence
property of phosphors in the continuous-type SCW method needs to be improved. In addition, a calcination process slightly
improved the luminescence intensities of YAG: Eu phosphors generated by using either the batch-type or continuous-type SCW
methods. 相似文献
997.
998.
999.
Colloidal suspensions containing salts of poly(methacrylic acid) which exhibit high electrorheological (ER) activity were synthesized by inverse emulsion polymerization. Factors influencing the ER effect were studied. The results showed that maximum yield stress occurred at optimum amounts of both polymeric stabilizer and crosslinking agent used in the inverse emulsion polymerization as well as a certain water content of the particles, while yield stress increased with electric field strength, average diameter of the particles below 0.9 μm, or the molar ratio of the salt to the acid. The ER activity for the suspensions containing different monovalent counter ions decreased in the following order: Li+ > Na+ > K+ > NH4+. The phenomena were discussed with the ionic polarization mechanism. © 1995 John Wiley & Sons, Inc. 相似文献
1000.
Results are reported of experiments and modelling of cathodic Pb and anodic PbO2 electrodeposition, aimed at developing a process using both reactions simultaneously for treating aqueous effluents from lead–acid battery recycling plants. Pb(II) solubilities and equilibrium potentials were calculated as functions of pH and sulfate activities. Using kinetic parameters from the literature or determined experimentally, models were developed for current density–potential and current efficiency–potential relationships, together with the current density dependence of specific electrical energy consumptions for Pb(II) recovery. Experimental current density–potential and charge efficiency–potential relationships were in broad agreement with model predictions, with near unity current efficiencies for mass transport controlled PbO2 deposition from electrolytes containing 1 mol Pb(II) m–3 at pH 12. However, charge efficiencies for cathodic deposition of lead were typically 0.2 for 1 mol Pb(II) m–3 + 1 mol O2 (aq) m–3; removal of dissolved oxygen was predicted and determined to increase current efficiencies to near unity. Pb(II) concentrations were depleted to <60 ppb in a batch recycle reactor system with graphite felt anodes and graphite or titanium felt cathodes. Simultaneous cathodic Pb and anodic PbO2 electrodeposition resulted in more rapid Pb(II) depletion than for either reaction separately. 相似文献