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11.
研究一种自制的聚醚改性硅油类新型表面活性剂(代号JCS-001)溶液对煤尘的润湿性能.Walker实验结果表明,JCS-001溶液润湿煤尘的能力非常强,尤其在临界胶束浓度(CMC)范围内,其润湿性能均大大优于SDBS和TX-100;同时研究了加入氯化钠以及与SDBS或TX-100复配等因素对JCS-001溶液润湿性能的影响,实验结果表明,当JCS-001与SDBS以3:2复配(总浓度为0.5g·L-1)时,所得混合溶液对煤尘的润湿效果达到最佳,最大润湿速度为9.84 mg/s. 相似文献
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用硅橡胶平板复合膜处理高浓度含酚废水,测定了体系的总传质系数(Kov),分析了温度、盐离子强度、跨膜压差(△p)、膜厚度对Kov的影响。实验结果表明:Kov随温度的升高而呈线性增加,传质通量与温度的关系符合Arrhenius方程;当△p〈0.1MPa时,Kov与压力无关;当△p〉0.1MPa时,压差升高可提高传质系数,但会导致膜的致密化;离子强度改变了苯酚在相间的分配系数,进而影响传质过程;膜厚度降低能有效提高膜的Kov;在膜活性皮层厚度4μm、pH12.5~13.0、温度323.15K、废水流量1205mL/min、废水中苯酚质量浓度7.78g/L、无压差和离子强度的条件下,运行8h后,Kov为16.1×10^-7m/s。 相似文献
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废硅橡胶二次裂解渣制多孔吸声材料的研究 总被引:1,自引:0,他引:1
采用吸声材料是吸声、降噪、改善声环境的有效手段。本文研究用废旧硅橡胶二次裂解渣和粘结剂为主要原料,采用压制成型的工艺,在常温下制成一种多孔吸声材料。主要考虑残渣里的硅烷类油份和所用发泡剂对试件吸声性能的影响。试验结果表明:所制吸声材料能达到一定的吸声性能,具有对环境无污染,施工方便等优点;且分离出硅烷类油份的灰渣所制试件比原废旧硅橡胶裂解残渣的吸声效果好很多,尤其在共振频率1250Hz下达到吸声峰值0.87。FP-186植物性水泥发泡剂相比FP-180动物性水泥发泡剂对试件吸声性能有所改善,使吸声特性曲线向低频方向移动。 相似文献
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多环芳烃(polycyclic aromatic hydrocarbons,PAHs)对人体危害巨大,目前关于人体暴露于大气环境PAHs研究主要以主动采样方式开展。硅胶腕带作为一种新的大气被动采样装置,具有体积小、价格低、耐磨耐热、无毒无味等优点,适合人体环境暴露监测。国际上研究刚起步,尚未建立完善的腕带被动采样与主动采样技术之间的定量关系。本研究于2019年秋冬季和2021年冬季在西安市城区,同时开展硅胶腕带被动采样与大气主动采样对低分子量(MW<203 g·mol?1)PAHs的对比实验,力求建立两者的联系。2019年和2021年西安冬季大气中低分子量PAHs浓度分别为(52.81±14.76) ng·m?3和(134.59±39.48) ng·m?3,与前人研究相当。相对应的腕带浓度为(183.07±40.43) ng·d?1和(524.99±150.32) ng·d?1。Pearson相关分析发现:萘、苊烯、1-甲基萘、2-甲基萘、荧蒽以及总PAHs的主、被动采样之间显著相关(P<0.05),相关系数均大于0.4,证明硅胶腕带被动采样方法适用于低分子量PAHs的人体暴露监测。 相似文献
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构造了卷绕式及管束式两种膜组件,采用均质硅橡胶膜,以氢氧化钠溶液为萃取液来萃取邻甲酚废水.通过考察邻甲酚初始浓度、两相流动状态、两相压差(△P)和温度等因素对传质过程的影响,研究了邻甲酚废水的膜萃取过程与机制.结果表明,初始质量浓度为21.93 g/L的邻甲酚废水很适合直接进行膜萃取;当△P<0.07 MPa时,总传质系数(Kov)随△P的增大而略有减小.当△P>0.07 MPa时,Kov随△P增大而显著增大,由实验数据拟合得到总的膜萃取传质模型.且该模型的实验值与理论值的相对误差在5%以内,满足工业设计要求. 相似文献
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疏水性污染物的去除是废气生物净化的难点.以硅酮母粒为非水相介质构建两相分配体系处理氯苯废气,结果表明,硅酮母粒对氯苯具有较高的亲和性,无生物毒性和生物降解性,且吸附于硅酮母粒表面的菌体对其相间分配系数没有明显影响.采用气升式生物反应器连续净化氯苯废气,当进气浓度为1000 mg·m~(-3)时,单相体系的去除率为60%;而添加了硅酮母粒的两相体系去除率达到90%,且CO_2矿化率较高,抗冲击负荷能力更好,说明硅酮母粒能有效强化气升式生物反应器净化氯苯废气的效果.该系统的最适硅酮母粒比例和停留时间分别为10%和90 s.以最大传质速率(β~*_s)来衡量氯苯的传质效果,发现硅酮母粒的添加使得β~*_s提升20%以上. 相似文献
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Summary. We describe the use of pieces of silicone tubing
to analyse the mandibular gland components of queen and
worker honeybees and show that these compounds can be
efficiently trapped on bis(trimethylsilyl)trifluoroacetamide
(BSTFA) treated pieces of tubing. The use of this technique
rather than that of solid phase microextraction (SPME) techniques
with commercially available fibres that have been
shown to be efficient at sampling secretions from the cuticle
of insects, is necessitated by a requirement for collection of
large sample numbers in a short space of time or for
sampling in the field. The technique may be generalised for
use with semiochemicals of low volatility in other insect
communciation systems. 相似文献
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Silicones are well-known useful materials varying in structure, reactivity, and chemical and physical properties, but they all contain a covalent bond between the silicon atom and an organic group. Most common of these polymers are those based on polydimethylsiloxane (PDMS) having a siloxane (Si–O–Si) repeat unit and two methyl groups on each silicon atom. All these polymers are manmade, and the organosilicon linkage is not found in nature. It was therefore erroneously assumed that these polymers do not degrade naturally in the environment. It is the purpose of this review to refute this myth and to describe the degradation processes of PDMS in the environment and any potential ecological impact on the terrestrial, aquatic, and atmospheric compartments. Although it was found that minor degradation takes place by hydrolysis of PDMS to dimethylsilandiol followed by oxidation of the methyl group to aldehyde and ultimately to CO2 by Arthobacter and Fusarium oxysporium schlechtendahl, the major degradation processes are abiotic. High molecular weight PDMS are initially depolymerized by soil hydrolysis of the siloxane bonds to yield organosilanol terminated oligomers. These organosilanols and low molecular weight linear PDMS and cyclics are evaporated into the atmosphere and are oxidized there by hydroxyl radicals to benign silica, water, and CO2. 相似文献