共查询到20条相似文献,搜索用时 109 毫秒
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钾和硅是农作物生长必需的主要元素,仅次于氮和磷,我国土壤调查结果显示土壤缺钾和硅的现象十分严重,矿质钾肥和硅肥的需要量很大。但我国目前用于钾肥和硅肥生产的可溶性钾盐和硅盐十分缺乏,而全国不溶性钾矿和硅矿资源却十分丰富。如何充分发掘这些矿产资源,把钾矿... 相似文献
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过磷酸钙与窑灰钾混合制含钾过磷酸钙的探讨邬仙明(浙江省龙游化工厂)我国的钾资源比较缺乏,只能依靠大量进口来满足农业的需要。而水泥生产中可以回收利用的窑灰钾数量相当可观,约占水泥产量的1%~2%。但是,由于它存在着钾含量较低(约8%左右)、碱性重(pH... 相似文献
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13C cross-polarization and magic-angle spinning (CP/MAS) nuclear magnetic resonance (n.m.r.) experiments are reported on two fusinites, three vitrinites, one micrinite, one sample of attrite, one exinite, one resinite and one lignite. With one exception, the maceral spectra show no more fine structure than the CP/MAS n.m.r. results for whole coals. The maceral spectra are discussed in relation to each other and to the corresponding spectra of whole coals. 相似文献
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C. L. Deeds 《Journal of the American Ceramic Society》1931,14(10):770-772
Twelve whiteware bodies were made, consisting of 51.41%, clay, 10.69% North Carolina feldspar, and 37.9% flint, one clay being used in each body. Twelve clays were studied. The specimens made from these bodies were fired in the regular tunnel bisque kiln to cone 9, glazed on one side, and fired to cone 4 in the glost kiln. The trial pieces were then subjected to the autoclave test, with the steam at a pressure of 100 pounds per square inch, maintained for a period of 3 hours. Of three American ball clays none was found to have caused crazing. In the case of four domestic kaolin bodies, one crazed in part, two were noncrazing, and one shivered. Of five imported kaolins, one of the bodies was noncrazing. While lower absorptions bring about a craze-resisting condition, it was shown that of two single clay bodies with practically the same absorption, one may resist the steam action and one may not. The structure of the clay is an important factor in this connection. 相似文献
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简述我国炼胶机的发展过程。对进口与国产的同类型GK400N大容量密炼机及配套上辅机进行技术性能和投资比较,认为国产机完全能替代进口机且有价格优势。 相似文献
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2009年国外上市或登记的杀菌剂品种共有5个,其中酰胺类化合物2个,三唑类化合物1个,含甲氧基丙烯酸酯类复配制剂1个,二苯酮类化合物1个。 相似文献