共查询到20条相似文献，搜索用时 437 毫秒
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论述了绿色化学理念和绿色化学的基本原理,重点探讨了绿色化学理念在化学化工过程中的实施,即不断开发新的化学催化过程,提高反应的原子经济性,选用新的合成原料;采用不对称催化剂、分子筛固体酸碱催化剂和生物催化剂等高选择性、高活性的催化剂;采用水、超临界流体、离子液体、氟碳相等无毒无害溶剂和固态反应;重视生物质的利用和化学产品的绿色化等。 相似文献
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双吲哚烷烃衍生物的绿色合成 总被引：1，自引：0，他引：1
李祥 《昭通师范高等专科学校学报》2010,32(5)
双吲哚类化合物主要由吲哚与醛(或酮)在路易斯酸(Lewis 酸)或固体酸条件下反应合成.双吲哚甲烷衍生物也可由吲哚和其它底物反应制备,如:吲哚和希夫碱反应等.但一些催化剂会腐蚀容器、易引发副反应,且使用后的催化剂也不能循环使用;大部分合成所用的溶剂有毒、后处理复杂;有的底物反应时间长;这些都不符合绿色化学的要求.比较各类催化剂和底物的优缺点,寻找绿色溶剂、无毒高效的催化剂及经济的双吲哚烷烃衍生物的合成路线,得出路易斯酸催化剂在离子液体溶剂中,吲哚与醛反应最符合绿色化学的要求. 相似文献
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王建鸣 《商丘师范学院学报》2003,19(5):99-101
从化学反应、原料、催化剂、溶剂和产品的绿色化等方面入手。综述了绿色化学研究与开发的新动向。并展示了我国绿色化学研究的工作概况。 相似文献
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黄思良 《中学生数理化(高中版)》2010,(10):13-13
绿色化学是用化学的技术和方法去减少或消灭那些对人类健康、社区安全、生态环境有害的原料、催化剂、溶剂和试剂、产物、副产物等的使用和产生.绿色化学的核心内容之一体现 相似文献
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综述了绿色合成己二酸的研究现状,主要从催化剂的选择、配体的优化、相转移催化剂的取舍、机理的探索等方面来阐述,最后指出了存在的问题及应用前景. 相似文献
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以水杨酸和乙酸酐为原料、强酸阳离子交换树脂为催化剂合成阿司匹林.探讨了催化剂用量、反应时间、反应温度对阿司匹林收率的影响以及催化剂重复使用情况.结果表明强酸阳离子交换树脂是合成阿司匹林的优良催化剂,是一种绿色催化剂. 相似文献
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绿色化学——环境战略的新认识 总被引：18，自引：1，他引：17
从环境保护出发,论述了绿化学和原子经济性的概念,从化学反应,原料,催化剂,溶剂,生产工艺和产品的绿色化等阐述了绿色化学煌研究方向,介绍了我国绿色化学的发展情况。 相似文献
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陶魏青 《宁波教育学院学报》2013,15(1):69-71,77
颜色词即表示色彩的词。中日两国有丰富的颜色词,红(赤)、黄、绿(青)、白、黑为中日两国的基本色。这些基本颜色词除实指具体的色彩以外又具有一定的抽象感念。本文尝试从"红"、"白"入手,分析其语义特征探究其所反映两国文化内涵的异同。 相似文献
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D. J. Zerbolio 《Learning & behavior》1985,13(3):269-273
Goldfish, trained in the shuttlebox apparatus to avoid shock, acquired a color discrimination between two colors (red/green) and were tested in transfer with a new set of colors (yellow/blue). Transfer color shock-pairing was either consistent with (red=yellow, blue=green) or opposite to (red≠ yellow, green≠blue) categorical color coding seen in pigeons. Groups with transfer shock-pairing consistent with categorical color coding showed positive transfer, and groups with transfer shock-pairing opposite to categorical color coding showed negative transfer, similar to an attenuated reversal learning effect. These results indicate that goldfish, like pigeons, code different colors as behavioral equivalents even though they can easily learn to discriminate between them. As with pigeons, the finding of the categorical color coding phenomenon changes the conclusions drawn from earlier goldfish conditional-discrimination transfer studies using only signal color changes between acquisition and transfer testing, from evidence of concept learning to evidence for categorical color coding, on the grounds of parsimony. It is important to note that this finding affects only the explanation of conditional-discrimination transfer effects, and the fact remains that both pigeons and goldfish can learn to conditionally discriminate—pigeons for positive reinforcement, and goldfish to avoid shock. 相似文献
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王慧丛 《漯河职业技术学院学报》2021,(1)
"青""蓝""绿"这三个颜色词联系密切。基于《说文解字》的视角,分析"青""蓝""绿"这三个颜色词的出现、词义演变及文化内涵。以《汉语大词典》的解释为基础,厘清"青""蓝""绿"三个颜色词的词义演变,了解这三个颜色词的文化内涵,理解服色在历史文化发展中地位的转变以及新兴涵义的出现,以期为汉语颜色词的研究尽绵薄之力。 相似文献
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沈从文在自己的文本世界中有意识地进行了意象的选择和营构,给同时代的中国现代文学保有了一种难得的审美形式。同时其作品中有着丰富的色彩语言和由此形成的色彩意象。传统的红、黄、绿、蓝;白、青、灰、黑在其文本世界中饱含了深刻的寓意性、哲理性,是其借以描摹自然景物、刻画人物形象和体悟人性的重要载体。 相似文献
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Four colors (red, yellow, green, and blue) were arranged in all possible two-color sets to determine if goldfish can discriminate between color sets associated with shock and color sets associated with safety/shock omission in a one-phase (linear presentation) discrimination-learning procedure. The results showed that goldfish learned to discriminate between two-color sets if set colors were natural categorical color-code mates (red = yellow and green = blue). When natural code mates were not in the same set, and therefore were paired with different shock consequents, no discrimination learning occurred, suggesting that goldfish, unlike pigeons, are not able to code colors arbitrarily. The method also allowed a measure of preference between colors within sets associated with safety/shock omission. Original-learning preference measures between colors in sets so associated showed that goldfish chose red over any other color, yellow over blue or green, and green over blue, despite the fact that both colors in any set were procedurally identical, implying that goldfish do discriminate between colors in the absence of explicit discrimination training. The goldfish that failed to discriminate between red/blue and green/yellow sets in original learning were transferred to red/yellow and blue/green color sets. In transfer, the color paired with safety/shock omission in original learning was preferred over the color paired with shock in original learning, which resulted in a reversal of original-learning color preferences for half the goldfish. The transfer color-preference results imply that the goldfish had associated specific colors with specific shock consequents, but the associations were not robust enough to support discrimination learning in the face of categorical color coding. 相似文献
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郝文华 《郧阳师范高等专科学校学报》2010,30(5):43-45
＂青＂是个表示颜色的词。其特殊之处在于,它反映了植物生长过程中颜色的变化：白里透红、浅绿、深绿。同时,它又有自己的发展轨迹,顺着颜色的深浅继续发展,表示浅蓝、深蓝甚至黑色。因此它几乎能表示各种颜色。而在＂白里透红＂的意义上,更是引申出了不少意义。 相似文献
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铂系金属催化剂在醇类氧化中的重要应用 总被引：1，自引：0，他引：1
本文介绍了近年来国外在铂系金属催化醇类的氧化反应中的研究进展,在这些研究中都使用了称为“绿色”氧化剂的分子氧代替传统的氧化剂,因此属于环保型的化工工艺。此催化剂具有高的催化转化率和很好的选择性。 相似文献
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王慧刚 《内江师范学院学报》2009,24(11):88-91
“绿酒”一词经常出现在古典诗词的句子中,一般情况下,绿酒解释为“美酒”,但关键是这种美酒到底有没有可能是绿色的呢。从常见的酒色来看,大多是白酒、红酒等。有论者以为绿酒实际并不存在,其“绿”只是指酒的无色透明。事实上,如果查阅一下相关古代典籍,从酿酒的制作过程进行考察,会发现,无论从原料、酒麴,还是泉水,这三个方面如果使用适当,都有可能酿造出绿色的美酒。 相似文献
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Effect of encoding instructions on children's spatial and color memory: is there evidence for automaticity? 总被引：2，自引：0，他引：2
This experiment is concerned with assessing whether there is evidence for the automatic processing of spatial and color information by children and with the development of control of encoding operations. First, third, and fifth graders viewed pictures of simple objects that varied in color (red or green) and spatial location (left or right). Subjects were instructed to encode (a) only the item, (b) the item and its color, (c) the item and its position, (d) the item, its color, and its position. The data yielded evidence for nonchance incidental memory of spatial, but not color, information. The data also suggested that children at all age levels were able to control their encoding operations similarly, as there was no evidence for an interaction of development with encoding instructions. These findings are discussed with respect to a model for automatic encoding processes and work on memory for central and incidental information. 相似文献
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Selective attention in processing of visual information by pigeons, trained on alternating sessions with two colors (red and
green) and two forms (a diamond and an X shape) differentially associated with a left—right key choice task, was examined.
A color and a form were presented together on probe trials during sessions in which, on other trials, only one of the dimensions,
color or form, was shown. The dimension in effect on the surrounding trials had no influence on choice when the information
provided by the two dimensions on probe trials was in conflict—color correct for one choice and form for the other. When both
color and form redundantly cued the correct choice, there was no increase in accuracy in comparison with that associated with
one dimension. Following separate training on the color and form discriminations, pigeons appeared to base their choices on
color on some trials, on form on other trials, but not on both simultaneously. These findings are discussed in terms of an
exemplar model of information processing. 相似文献