全文获取类型
收费全文 | 238篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
化学 | 236篇 |
晶体学 | 1篇 |
力学 | 2篇 |
综合类 | 1篇 |
物理学 | 7篇 |
出版年
2023年 | 3篇 |
2022年 | 22篇 |
2021年 | 19篇 |
2020年 | 16篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 6篇 |
2013年 | 17篇 |
2012年 | 18篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 1篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有247条查询结果,搜索用时 31 毫秒
91.
Grape pomace and grapeseed are agro-industrial by-products, whose inadequate treatment generates socioeconomic and environmental concerns. Nevertheless, it is possible to valorize them by extracting their bioactive compounds, such as antioxidants (phenolic compounds), vitamin E and fatty acids. The bioactive compounds were extracted using solid-liquid extraction. The yields for phenolic compounds were 18.4 ± 0.4% for grape pomace, and 17.4 ± 0.4%, for grapeseed. For the oil, the yields were 13.3 ± 0.2% and 14.5 ± 0.3% for grape pomace and grapeseed. Antioxidant capacity was assessed by the assay with 2,2-diphenyl-1-picrylhydrazyl (DPPH), and showed that phenolic extract has higher antioxidant capacity than the oils. Grape pomace and grapeseed extracts exhibit, correspondingly, values of 90.8 ± 0.8 and 87.5 ± 0.5 of DPPH inhibition and IC50 of 48.9 ± 0.5 and 55.9 ± 0.7 μgextract·mLDPPH−1. The antimicrobial capacity was assessed by the disk diffusion test, and revealed that, phenolic extracts inhibit the growth of Staphylococcus aureus and Staphylococcus epidermidis. The obtained extracts were incorporated in 10 face cream formulations, with slight modifications in quantities of formulation stabilizers. Their stability was studied for 35 days, and this revealed the possibility of incorporating extracts and oils obtained from by-products as antioxidants in cosmetics, and replacing synthetic ones. As a future recommendation, microencapsulation of the extracts should be performed, in order to increase their stability. 相似文献
92.
超高效液相色谱-串联质谱法同时测定化妆品中的22种磺胺类药物 总被引:6,自引:0,他引:6
建立了同时测定化妆品中22种磺胺类药物(磺胺胍、磺胺、磺胺嘧啶、磺胺二甲异嘧啶、磺胺醋酰、磺胺噻唑、磺胺吡啶、磺胺甲基嘧啶、磺胺对甲氧嘧啶、磺胺二甲噁唑、磺胺二甲嘧啶、磺胺甲噻二唑、磺胺甲氧哒嗪、琥珀酰磺胺噻唑、磺胺氯哒嗪、磺胺甲基异噁唑、磺胺间甲氧嘧啶、磺胺邻二甲氧嘧啶、磺胺二甲异噁唑、磺胺间二甲氧嘧啶、磺胺喹噁啉、磺胺硝苯)的超高效液相色谱-串联质谱分析方法。膏霜、水剂、散粉、香波、唇膏等不同类型的化妆品样品经超声提取后,以Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7μm)分离后进行UPLC/MS/MS多反应监测模式下的定性及定量分析。22种磺胺类药物的方法检出限为3.5~14.1μg/kg;在低、中、高的3个添加水平范围内的平均回收率为80.3%~103.6%;日内精密度均小于12%,日间精密度均小于15%。 相似文献
93.
The cosmetics industry is currently looking for innovative ingredients with higher bioactivity and bioavailability for the masses of natural and organic cosmetics. Bioferments are innovative ingredients extracted from natural raw materials by carrying out a fermentation process with appropriate strains of microorganisms. The review was conducted using the SciFinder database with the keywords “fermented plant”, “cosmetics”, and “fermentation”. Mainly bioferments are made from plant-based raw materials. The review covers a wide range of fermented raw materials, from waste materials (whey with beet pulp) to plant oils (F-Shiunko, F-Artemisia, F-Glycyrrhiza). The spectrum of applications for bioferments is broad and includes properties such as skin whitening, antioxidant properties (blackberry, soybean, goji berry), anti-aging (red ginseng, black ginseng, Citrus unshiu peel), hydrating, and anti-allergic (aloe vera, skimmed milk). Fermentation increases the biochemical and physiological activity of the substrate by converting high-molecular compounds into low-molecular structures, making fermented raw materials more compatible compared to unfermented raw materials. 相似文献
94.
95.
建立了毛细管电泳同时分析5种有机酸的间接紫外检测法。优化了背景电解质溶液中表面活性剂十四烷基三甲基溴化铵(TTAB)的浓度和溶液pH。优化后的电泳分析条件如下:含0.4 mmol/L TTAB的15 mmol/L邻苯二甲酸氢钾溶液为背景电解质(pH 5.6);分离电压-15 kV;检测波长254 nm;分离温度25℃;进样压力5 kPa;进样时间5 s。在此条件下,可在6 min内完成5种有机酸的同时分离检测,线性范围为甲酸15~600 mg/L、苹果酸30~800 mg/L、柠檬酸20~700 mg/L、乙醇酸40~500 mg/L和乳酸30~5000 mg/L,线性相关系数为0.9983~0.9998;检出限为0.1~2.0 μg/g。该方法可用于检测水状、乳状、膏状3类化妆品中的5种有机酸。在3个加标水平下,有机酸分析的回收率为95.0%~101.6%,RSD在2.0%以内。该方法操作简单,分析快速,安全环保,灵敏度高,重现性好,有望用于化妆品生产和保存过程中有机酸的监测。 相似文献
96.
97.
The development of personal care formulations incorporates the deliberation of the prerequisite product rheology and the right rheology modifier to deliver these effects. While the effectiveness of the finished product will hinge on the selection and level of active ingredients and excipients, the esthetics and even the penetration of these actives into the stratum corneum will be affected by the product rheology. Rheology modifiers are frequently denoted as thickeners, and while increasing the apparent viscosity should enhance the perception of quality in a formulation, this is only one aspect of rheological control. The product itself can be Newtonian or pseudoplastic, thixotropic, existing as a ringing gel or a stringy flowable liquid. This changes the way that the product appears in the bottle, the ease with which aliquots are poured or scooped from the packaging, the process of rubbing it into the skin or along the hair shaft, and upon using, the rinsing and removal of the product. It will also be vital to select the correct rheological characteristics to guarantee the stability of the finished formulation. By changing the structure of polymeric rheology modifiers, the impact on the sensorial properties and performance characteristics can be investigated. Careful selection of monomers, structure and other co‐ingredients will result in products optimized for use in skin care formulations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
98.
《Journal of separation science》2018,41(11):2441-2452
Dexamethasone‐imprinted polymers were fabricated by reversible addition–fragmentation chain transfer polymerization on the surface of magnetic nanoparticles under mild polymerization conditions, which exhibited a narrow polydispersity and high selectivity for dexamethasone extraction. The dexamethasone‐imprinted polymers were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X‐ray diffraction, energy dispersive spectrometry, and vibrating sample magnetometry. The adsorption performance was evaluated by static adsorption, kinetic adsorption and selectivity tests. The results confirmed the successful construction of an imprinted polymer layer on the surface of the magnetic nanoparticles, which benefits the characteristics of high adsorption capacity, fast mass transfer, specific molecular recognition, and simple magnetic separation. Combined with high‐performance liquid chromatography, molecularly imprinted polymers as magnetic extraction sorbents were used for the rapid and selective extraction and determination of dexamethasone in skincare cosmetic samples, with the accuracies of the spiked samples ranging from 93.8 to 97.6%. The relative standard deviations were less than 2.7%. The limit of detection and limit of quantification were 0.05 and 0.20 μg/mL, respectively. The developed method was simple, fast and highly selective and could be a promising method for dexamethasone monitoring in cosmetic products. 相似文献
99.
建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)同时测定化妆品中13种性激素含量的分析方法。液态水基类、液态油基类、膏霜乳液类(含面膜)化妆品采用50%乙腈超声提取,经C18色谱柱分离,采用动态多反应监测(DMRM)扫描方式测定。结果表明,13种性激素的检出限(LODs)为0.001~0.026μg/g,在0.89~64.80μg/L范围内线性关系良好,相关系数(r)均大于0.995。回收率为80.8%~116.8%,相对标准偏差(RSD,n=6)为0.7%~14.4%。该方法高效、灵敏、准确,填补了化妆品中醋酸氯地孕酮、己酸羟孕酮等化合物的测定方法空白,可作为化妆品中性激素类物质的通用检测方法,适用于多种基质化妆品中性激素的快速筛查。 相似文献
100.
建立了化妆品中8种乙二醇醚类物质的气相色谱-质谱分析方法。样品经甲醇超声提取,提取液经0.45μm微孔滤膜过滤后,采用气相色谱-质谱法分析,外标法定量。在优化的色谱条件下,8种乙二醇醚类物质可实现基线分离,在各自线性范围内线性良好(r20.999)。在0.05、0.5、5 mg/kg 3个加标水平下,平均加标回收率为82.2%~113.0%,相对标准偏差(RSD,n=6)为0.60%~8.5%。方法的检出限为0.10~1.00 mg/kg,定量下限为0.25~2.00 mg/kg。该方法操作简便,准确可靠,重现性好,可用于化妆品中乙二醇醚类物质的测定。 相似文献