全文获取类型
收费全文 | 80篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
林业 | 11篇 |
农学 | 4篇 |
基础科学 | 3篇 |
15篇 | |
综合类 | 32篇 |
农作物 | 8篇 |
水产渔业 | 1篇 |
畜牧兽医 | 7篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2000年 | 4篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
排序方式: 共有86条查询结果,搜索用时 15 毫秒
21.
拟三元相图在高效氯氰菊酯水乳剂配方筛选中的应用 总被引:1,自引:0,他引:1
以高效氯氰菊酯为例,通过拟三元相图系统研究了非离子与阴离子表面活性剂及其不同复配比例、不同有机溶剂、油相中有效成分不同含量及不同水质下高氯溶液/表面活性剂/水体系的相行为。研究结果表明:非离子表面活性剂与阴离子表面活性剂在质量比1:1时与非离子表面活性剂单用形成的相圈中水乳区的面积相差不大。而非离子表面活性剂与阴离子表面活性剂在质量比2:1、3:1时水乳区的面积无明显变化,但二者较质量比在1:1时水乳区面积明显增大。溶剂的不同对水乳区面积影响很大,而油相中有效成分的含量及水硬度的增加,水乳区面积有所增加,但影响不大。 相似文献
22.
表面活性剂“粤辅1号”提高水稻植株对赤霉素的吸收和利用研究 总被引:6,自引:0,他引:6
与GA3单独处理相比.GA3与表面活性剂粤辅1号 (YF-1)混合使用,可降低GA3的表面张力及其受雨水冲刷程度,部分地溶解叶表面的硅质、蜡质和角质,使秧苗对GA3的吸附量增加2~4倍,吸收量增加1~3倍;且能增加水稻幼苗的株高,增加不育系秆长,降低包颈程度。 相似文献
23.
几种表面活性剂和色素物质对氯苯嘧啶醇光化学降解的影响 总被引:2,自引:0,他引:2
以高压汞灯和太阳光为试验光源,研究了不同种类的表面活性剂和几种色素对氯苯嘧啶醇在固体表面和水中光解的影响。结果表明,高压汞灯下十二烷基苯磺酸钠(SDBS)和表面活性剂吐温-60(T-60)对氯苯嘧啶醇的表面光化学降解有很强的敏化作用,而十二烷基磺酸钠(sos)和十六烷基三甲基溴化铵(CrAB)对氯苯嘧啶醇的光解则具有一定的猝灭作用,且作用效应与剂量成正相关性;司班-20(Soan-20)对氯苯嘧啶醇的光解影响比较复杂,在剂量比为1:1时,表现为微弱的光敏作用,而当剂量比为5:1时则表现为较强的猝灭作用。太阳光下,表面活性剂十六烷基三甲基溴化铵(CTAB)对氯苯嘧啶醇水中光解有较强的敏化作用,而Span-20和SDS则表现出一定的猝灭作用;几种色素对氯苯嘧啶醇水中光解有一定的影响,低浓度时,亚甲基兰、核黄素对氯苯嘧啶醇光化学降解有一定的敏化作用,高浓度时反而表现出极强的猝灭作用;结晶紫对氯苯嘧啶醇的光解表现出一定的光猝灭作用效应,且与剂量成正相关。 相似文献
24.
European tarnished plant bug, Lygus rugulipennis, is a serious pest on late season strawberries in the UK. Feeding by the pest on the developing fruits causes severe malformation, and over 50% of fruit may be downgraded as a result of capsid feeding in unsprayed crops. A range of compounds was tested against the pest over two years at East Malling Research. In 2008 experiments were conducted on weed plots with high L. rugulipennis populations, and in 2009 were conducted on an everbearer strawberry planting. The 2008 experiments showed that etoxazole had no effect on L. rugulipennis and that although flonicamid and indoxacarb significantly reduced populations they were not as effective as thiacloprid, either with or without a surfactant, or acetamiprid. In the 2009 experiment on strawberry thiacloprid + surfactant, applied twice, was more effective than this treatment applied once, which in turn was more effective than thiacloprid alone. In both years the most effective treatment was the pyrethroid bifenthrin. There was no suggestion that different developmental stages of the pest were more susceptible to the tested insecticides. Thus there was no evidence to suggest that timing applications against specific life stages would significantly improve pest control. 相似文献
25.
It is well known that environmental conditions have an important influence on herbicide efficacy. In particular, the effect of humidity on herbicide uptake has been attributed to changes in cuticle hydration and droplet drying. As early as the 1950s, it was hypothesized that humectants such as glycerol would enhance herbicide uptake by not letting droplets dry, thus maintaining the herbicide in solution, and hence making it available for uptake. Shortly thereafter, evidence was found to support this hypothesis and humectants were used successfully in warm, dry areas to increase herbicide efficacy. However, by the mid-1980s, there was little use of humectants as research on humectants gave way to investigations on the effect of ethylene oxide (EO) content on surfactant performance to improve herbicide uptake and efficacy. While ethoxylated surfactants effectively increase the uptake of both lipophilic and hydrophilic herbicides, the suggestion that long EO chains have humectant properties is misleading, since the studies that led to this suggestion were performed at high humidity, which would prevent rapid droplet drying. Furthermore, current evidence suggests that highly water-soluble, ionic herbicides may be more sensitive to low humidity and rapid drop drying than lipophilic herbicides. Therefore, an overview is presented on the interaction of water-soluble herbicides with surfactants, the cuticle, and humidity, with particular emphasis on the impact of low humidity and humectants on herbicide uptake. It was found that when one focuses on research performed at low humidity the importance of humectants emerges, which is not in keeping with what is now commonly accepted. 相似文献
26.
J.D. Hansen M.L. Heidt L.G. Neven E.A. Mielke J. Bai P.M. Chen R.A. Spotts 《Postharvest Biology and Technology》2006,40(3):221-229
Surface arthropods on pome fruits can cause export problems and disrupt commercial markets. Eliminating insects and mites on the packing line would be the last opportunity to provide for pest-free produce. In this study, an experimental packing line was used to evaluate techniques using different surfactant baths, pressurized water sprays, and styles of rotating brushes to remove field-collected and laboratory-reared grape mealybug, Pseudococcus maritimus (Ehrhorn) (Homoptera: Pseudococcidae), the diapausing two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and the woolly apple aphid, Eriosoma lanigerum (Hausman) (Homoptera: Aphididae). The organosilicone Silwet L-77 was no more effective than a silicone-based food grade defoamer in aiding removal. Mechanical methods, such as the style of rotating brushes and pressurized sprays, were significantly effective in removing surface arthropods. No improvement in removal occurred when pressure was increased beyond 420 kPa. These techniques can be easily adapted to commercial facilities and will reduce the incidence of surface arthropods on marketed fresh fruits. 相似文献
27.
表面活性剂辅助钾肥喷施对烤烟叶片润湿性能、生理指标及品质的影响 总被引:2,自引:0,他引:2
为提高烟叶钾肥利用率及改善烟叶品质,以烤烟品种‘K326’为材料,利用接触角法测定了烟叶的临界表面张力;选取蔗糖脂肪酸酯、茶皂素、洗衣粉3种表面活性剂,利用表面张力法确定其临界胶束浓度;以喷施清水和单独喷施钾肥为对照,分别在钾肥中加入3种表面活性剂进行大田喷施试验(CK:喷施清水;CK1:喷施钾肥;T1:喷施钾肥+蔗糖脂肪酸酯;T2:喷施钾肥+茶皂素;T3:喷施钾肥+洗衣粉),测定不同生育期不同处理烟叶钾含量、抗氧化酶活性以及质体色素含量,并对烤后烟叶进行化学成分测定,研究了表面活性剂辅助钾肥喷施对烤烟润湿性能、生理指标及烤后烟叶品质的影响。结果表明:1)烟叶临界表面张力为30.41 mN?m~(-1),属于临界表面张力较低的叶片,较难被液体润湿。表面活性剂蔗糖脂肪酸酯和茶皂素的临界胶束浓度为1 000 mg?L~(-1)、5 000 mg?L~(-1),对应的表面张力值为32.64 mN?m~(-1)、40.33 mN?m~(-1),而洗衣粉浓度2 000 mg?L~(-1)时的表面张力最接近烟叶的临界表面张力,对应的表面张力值为30.30 mN?m~(-1)。加入表面活性剂后,钾肥溶液表面张力显著降低,润湿性能增加。2)表面活性剂促进了烟叶对钾肥的吸收。与单独喷施钾肥相比,加入表面活性剂后,烟叶生长过程中钾含量提高,其中T1、T2处理4个生育期烟叶钾含量均高于CK1处理。表面活性剂辅助钾肥喷施不同程度提高了烟叶SOD、POD酶活性,降低了MDA含量,烟叶抗氧化能力增强,膜脂过氧化程度降低,烟株抗逆性增强。此外,加入表面活性剂后,烟叶功能盛期叶绿素含量、类胡萝卜素含量提高,进而增强了烟叶的光合作用,有利于光合产物的合成和积累。3)加入表面活性剂后,烤后烟叶总氮和烟碱含量降低,钾含量和总糖、还原糖含量升高,化学成分更协调,烟叶品质更加优异。综合来看,添加蔗糖脂肪酸酯处理在提高烟叶润湿性能、促进钾肥吸收以及改善烟叶生理指标、提升品质方面效果最佳。 相似文献
28.
去氢枞酸合成两性表面活性剂及其性质 总被引:4,自引:0,他引:4
从歧化松香中分离出去氢枞酸,并以此为原料合成了三种新型的两性表面活性剂,N-(3-去氢枞酰氧-2-羟)丙基-N-甲基氨基乙酸钠,N-{N'-[(3-去氢枞酰氧-2-羟)丙基]胺乙基}氨基乙酸钠。N-{N'-[(3-去氢枞酰氧-2-羟)丙基]双胺乙基}氨基乙酸钠。其结构通过波谱和元素分析得以证实,并测定了其表面物理化学性质如克拉夫特点,临界胶束浓度和分子横断面积。此外还根据相分离模型计算得出胶束化过 相似文献
29.
30.