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991.
993.
离子交换膜间水的电离及其应用 总被引:1,自引:0,他引:1
王方 《精细与专用化学品》2002,10(21):22-24
本文通过分析纯水的电离,讨论了普通电渗析(ED)和填充床电渗析(EDI)中水的电离现象及其相关 机理。EDI过程中水电离产生的H+和OH-离子可以自再生离子交换树脂。文中简单介绍了已得到产业化的EDI 技术和正在推广中的离子交换树脂的电再生技术。 相似文献
994.
995.
This review paper summarizes current research efforts toward a comprehensive view of wet material dewatering, considering the binding energy as the strength to hold water, and rupture energy given to remove moisture from materials. 相似文献
996.
Nuran Iiklan 《应用聚合物科学杂志》2006,99(4):1310-1319
Interpenetrating network polymeric beads of sodium alginate (NaAlg) and its blend with gelatin (gels) or sodium carboxymethyl cellulose (NaCMC) have been prepared by crosslinking with a common crosslinking agent, glutaraldehyde (GA), for the release of insecticide carbaryl (Carb). The prepared beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Scanning electron microscopy confirmed the spherical nature and surface morphology of the particles. Bead characteristics, such as carbaryl entrapment efficiency, particle size, equilibrium swelling degree, and carbaryl release kinetics, were determined. The effects of the preparation conditions, such as Carb/NaAlg ratio, time of exposure to GA, blend ratio, and temperature of release medium on the carbaryl release, were investigated for 25 days at 25°C. It was observed that the carbaryl release decreased with increase in crosslinking of network, while it increased with increase in Carb/NaAlg ratio and temperature. The release of carbaryl also increased with increase in Gel or NaCMC content in the blend beads. The highest carbaryl release was found to be 100%, for the beads that were prepared with 1 : 1 NaAlg/Gel at 16 days. The diffusion coefficients have been calculated for the transport of insecticide through the polymeric beads, using initial time approximation method. These values were also consistent with the carbaryl release data. The carbaryl release from most of the bead formulations followed the Fickian trend. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1310–1319, 2006 相似文献
997.
The effects of moisture absorption on the dielectric properties of a rubber‐modified, mineral‐filled, epoxy resin based on the diglycidyl ether of bisphenol A cured with dicyandiamide are reported. Samples of the resin were aged by immersing in deionized water, or 5% w/w NaCl solution, at elevated temperatures. Dielectric measurements were carried out over the frequency range 10?1 to 6 × 105 Hz. A featureless dielectric spectrum was observed with both real and imaginary dielectric permittivity increasing with the amount of absorbed water. The change in the dielectric properties with absorption of water was independent of presence of salt, temperature of exposure, and aging history, although a hysteresis of the hydration–dehydration process was observed at low frequencies. Two types of absorbed water were observed—water molecularly dispersed within the epoxy matrix and clustered water in spherical microcavities. The time dependence of the real dielectric permittivity measured at 10 kHz was found to closely resemble that of the water absorption, which allowed the activation energy of diffusion to be calculated from both dielectric and gravimetric data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1011–1024, 2002; DOI 10.1002/app.10368 相似文献
998.
999.
汽水循环状况对废热锅炉系统的安全运行、稳定操作和延长使用寿命都有重要的意义,通过对甲醇厂废热锅炉系统汽水循环过程进行计算和研究,判断废热锅炉系统循环回路的工作状态,并对现有系统存在的问题提出建议,为稳定工艺生产提供借鉴。 相似文献
1000.
Soybean oil (900 g) was heated by deep frying at 200°C for 1 h with the addition of 0, 50, 100, 150 and 200 mL water, and
then stored at 55°C for 26 weeks. Soybean oil, corn oil and lard were heated by stir frying and then stored at 55°C for 30
weeks. The volatiles and peroxide values of these samples were monitored. All samples contained aldehydes as major volatiles.
During heating and storage, total volatiles increased 260-1100-fold. However, aldehyde content decreased from 62–87% to 47–67%,
while volatile acid content increased from 1–6% to 12–33%; especially hexanoic acid which increased to 26–350 ppm in the oils
after the storage period was completed. Water addition to the oils heated by deep frying tended to retard the formation of
volatile compounds. The total amount of volatile constituents of lard heated by stir frying increased more during storage
than that of corn oil or soybean oil. Peroxide values did not reflect the changes of volatile content in the samples. 相似文献