全文获取类型
收费全文 | 87篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
综合类 | 4篇 |
化学工业 | 46篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 37篇 |
石油天然气 | 5篇 |
出版年
2025年 | 2篇 |
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 11篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有94条查询结果,搜索用时 0 毫秒
81.
S. Fuzeau-Braesch E. Genin R. Jullien E. Knowles C. Papin 《Journal of chemical ecology》1988,14(3):1023-1033
Volatile substances in the atmosphere surrounding gregarious locustsSchistocerca gregaria andLocusta migratoria were captured and investigated by combined gas chromatography-mass spectrometry. Three aromatic derivates have been identified: phenol, guaiacol, and veratrole. Their relative percentages differ for different ages and species. Behavioral tests show that essentially phenol, guaiacol, and the mixture of the three products tend to increase the aggregation behavior in both species and thus act as cohesion pheromones. 相似文献
82.
Pyrolysis of kraft lignin was carried out using small reactors with an added ZnCl2-KCl mixture at three levels of temperature, 500°C, 550°C and 600°C, and three levels of salt-to-lignin ratio (SR), 1, 2 and 3. Nineteen kinds of phenolic compound were identified and their quantitative determinations were made by gas chromatography. The yield of gaseous products determined gravimetrically exhibited a strong dependence on the added amount of salt mixture, and its lowest value was obtained at SR of 1. The formation of gaseous products, apparently stemming from decomposition of liquid products and tar, was observed at reaction times longer than 30 min. At SR of 1 and a temperature of 550°C, all phenolic compounds attained their maximum yields almost synchronously at a reaction time of 15 min. Cresol's formation was slightly increased with the amount of added salt mixture. At a temperature of 550°C, cresols and guaiacols decomposed according to a pseudo-first-order lumping model, while catechols did not follow the similar model. 相似文献
83.
用水蒸汽蒸馏法提取收集烟熏腊猪肉的香味成分,在蒸馏过程中,接受瓶加入200ml无水乙醚并用冰浴冷却。用无水乙醚萃取馏出物,用无水硫酸钠干燥,用高纯氮吹去溶剂浓缩至10ml。所得到的成分用气相色谱/质谱(GC/MS)法分离并分析鉴定其成分及相对含量,共鉴定出43个化合物,所鉴定的组分占挥发性成分总峰面积的98.89%,烟熏腊猪肉的关键香味成分是:愈创木酚、苯酚、5-甲基-2-甲氧基苯酚、2-甲基苯酚、4-乙基愈创木酚、2,4-二甲基苯酚、丁子香酚等。 相似文献
84.
以廉价的硅藻土和偏铝酸钠为原料,采用水热法制备Beta沸石。通过软模板法、有机碱(尿素)处理法、无机碱(Na OH)处理法对沸石的酸性和孔结构进行了调节,合成了多级孔Beta分子筛,通过超声辅助浸渍法负载非贵金属Ni、Mo制备了双金属负载Beta沸石(NiMo/Beta)催化剂。利用XRD、SEM、N2吸附-脱附、NH3-TPD、H2-TPR对催化剂晶体结构、微观形貌、孔结构、酸性和金属还原性进行了表征。考察了改性处理方式和工艺条件(反应温度、H2压力、溶剂正十二烷用量、反应时间)对催化剂催化愈创木酚加氢脱氧反应性能的影响。结果表明,在300℃、H2压力4 MPa、反应时间3 h、溶剂正十二烷20 mL的条件下,在6.0 g硅藻土中加入3.0g十六烷基三甲基溴化铵(CTAB)改性后的NiMo/Beta-3.0CB表现出最佳的催化活性,愈创木酚转化率为99.8%,环己烷选择性为92.7%。NiMo/Beta-3.0CB循环使用3次后,愈创木酚转化率为85.7%。 相似文献
85.
5-硝基愈创木酚钠的合成研究 总被引:3,自引:0,他引:3
研究了以愈创木酚为起始原料,经乙酰化、硝化、水解合成5 硝基愈创木酚钠的最佳反应条件。以乙酐作酰化剂,120℃反应;硝酸加冰乙酸为硝化剂,50℃硝化;水解在氢氧化钠溶液中进行。5 硝基愈创木酚钠收率86%。 相似文献
86.
在圆柱型光催化反应器中,以UV-A light(功率11W,波长253.7,nm)作为光源,对含有紫丁香醇模型物的木素类有机废水进行光催化降解实验,研究讨论了悬浮体系中TiO2光催化降解紫丁香醇木素的反应特性.实验结果表明,紫丁香醇结构中部分双甲氧基在光照的条件下,与苯环发生了断裂,生成了具有单甲氧基结构的中间体——愈创木酚和一些其他低分子有机物;通过联立公式对降解过程中的紫丁香醇和愈创木酚的浓度进行定量分析. 相似文献
87.
88.
A.L. FUDGE M. SCHIETTECATTE R. RISTIC Y. HAYASAKA K.L. WILKINSON 《Australian Journal of Grape and Wine Research》2012,18(3):302-307
Background and Aims: Fermentation of smoke‐affected grapes can lead to wines that exhibit objectionable smoke‐related sensory attributes, i.e. smoke taint. Fining agents are routinely used at different stages of the winemaking process to address constituents that are considered to adversely affect juice or wine quality. This study aimed to evaluate the efficacy of commercial fining agents in reducing the concentration of volatile phenols and the intensity of sensory attributes associated with smoke‐tainted wine. Methods and Results: Smoke‐affected wines were treated with a range of fining agents, two of which, an activated carbon and a synthetic mineral, were found to appreciably ameliorate the taint. Treated wines contained a significantly lower level of smoke‐derived volatile phenols and exhibited less intense ‘smoke’ and ‘cold ash’ aromas, ‘smoky’ flavour and ‘ashy’ aftertaste, compared with that of untreated (control) wines; with little or no impact on wine colour. Conclusions: Selected fining agents can ameliorate smoke taint in wine. Whereas most fining agents showed poor specificity towards the wine components responsible for smoke taint, some, an activated carbon in particular, were highly effective. Significance of the Study: This research identifies a treatment that can be used to mitigate the impact of grapevine exposure to smoke on wine composition and sensory properties. 相似文献
89.
90.
《石油化工》2016,45(5):536
以愈创木酚为生物油模型化合物,正丁醇为共裂解物,利用GC-MS等方法研究了共裂解产物中的有机物含量、油相产物的热值和含水量,分析了共裂解物原料比和原料含水量对共裂解反应的影响,探究了以愈创木酚为代表的生物油模型化合物的催化共裂解机理。实验结果表明,共裂解法可提高油相产物的品质及烃类收率,当m(愈创木酚)∶m(正丁醇)从2∶1降至1∶2时,油相产物中含氧化合物相对含量(w)从35.7%降至12.7%,但烃类总收率从19.5%降至15.0%,油相产物热值最高为43.1 MJ/kg、含水量(w)从2.73%降至0.91%。共裂解物的烃类总收率随原料含水量的增大而快速降低,油相产物中的含氧化合物含量逐渐增大,品质快速下降。生物油高含水量是阻碍生物油通过共裂解法提质改性的主要原因。 相似文献