全文获取类型
收费全文 | 1005篇 |
免费 | 92篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 1篇 |
综合类 | 22篇 |
化学工业 | 77篇 |
机械仪表 | 13篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 1篇 |
轻工业 | 891篇 |
石油天然气 | 11篇 |
无线电 | 8篇 |
一般工业技术 | 54篇 |
冶金工业 | 8篇 |
原子能技术 | 3篇 |
自动化技术 | 9篇 |
出版年
2024年 | 7篇 |
2023年 | 23篇 |
2022年 | 28篇 |
2021年 | 52篇 |
2020年 | 50篇 |
2019年 | 47篇 |
2018年 | 52篇 |
2017年 | 64篇 |
2016年 | 55篇 |
2015年 | 57篇 |
2014年 | 50篇 |
2013年 | 90篇 |
2012年 | 72篇 |
2011年 | 86篇 |
2010年 | 50篇 |
2009年 | 42篇 |
2008年 | 30篇 |
2007年 | 41篇 |
2006年 | 32篇 |
2005年 | 34篇 |
2004年 | 24篇 |
2003年 | 19篇 |
2002年 | 23篇 |
2001年 | 10篇 |
2000年 | 15篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有1104条查询结果,搜索用时 31 毫秒
141.
采用夹持水果果梗的方法,设计一套能够适应当前水果在线检测分级需求的水果检测分级机,主要包括水果果梗夹持装置、输送装置、旋转装置以及分级卸果装置。其中果梗夹持装置是本设计的核心部件,它不仅能够独立完成果梗的夹持功能,还能够在其他辅助装置的配合下完成水果的输送、旋转及卸果功能。该果梗夹持装置实现了水果夹持部分与水果的共同旋转,有效避免了水果与机械装置之间的摩擦,使得整个水果检测分级机对水果的机械损伤大大降低,能够很好地满足水果在线检测分级的需求,具有较高参考价值和应用前景。 相似文献
142.
鲜切水果保鲜研究进展 总被引:7,自引:3,他引:7
鲜切水果是国外新兴的水果加工制品,具有新鲜、营养、方便等特点,市场前景广阔。综述了国外鲜切水果保鲜研究现状及发展趋势。 相似文献
143.
The purpose of this study was to determine the reducing power, metal chelating, and radical scavenging capabilities of water and ethanol extracts of sumac (Rhus coriaria L.), comparatively. The water and ethanol extracts of sumac were evaluated for their radical scavenging activities by means of the DPPH and DMPD assays. Water extract of sumac (R. coriaria L.) scavenged radicals effectively with EC50 values of 36.4 ??g/ml for DPPH free radical and 44.7 ??g/ml for DMPD cation radical. Similarly, the total reducing power of water extract was found higher than ethanol extract in both potassium ferricyanide reduction (FRAP) and cupric ions reduction capacity methods (CUPRAC). 2,2′-Bipyridine was used to determine the metal chelating activity and the result of water extract was found higher than ethanol extract. Total phenolic and total flavonoid contents of both extracts were studied as well. The values of water extract were found to be higher than that of ethanol extract. The present study found that water extracts of sumac (R. coriaria L.) have effective antioxidant and radical scavenging activities as compared to ethanol extracts. 相似文献
144.
145.
阐述了联合干燥的定义和技术特点,介绍了各种联合干燥方式在国内外的研究和应用现状,探讨了该技术在果蔬干燥加工中存在的问题和应用前景. 相似文献
146.
Changes of Quality in the Fruits of Prunus mume during Deacidification by Fermentation with Lactobacillus Fermentium
下载免费PDF全文
![点击此处可从《Journal of food science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yuanshan Yu Gengsheng Xiao Yujuan Xu Jijun Wu Yousheng Zhang Weidong Chen 《Journal of food science》2015,80(2):M405-M410
The aim of this study was to investigate the changes of quality attributes of Prunus mume fruits during deacidification using the fermentation of Lactobacillus fermentium. Results of HPLC analysis showed that the sucrose and glucose were dominant sugars, and citric acid was dominant organic acids in P. mume fruits. The level of citric acid reaches 39.3 g/kg, and yet the sucrose and glucose content in the P. mume fruits was very lower, which were 2.16 and 0.66 g/L, respectively. After 8 d of fermentation, sugar and citric acid in the P. mume fruits was completely consumed, and the total phenolics, antioxidant activity (oxygen radical absorbance capacity value), and sarcocarp firmness retained 64.4%, 70.0%, 62.6%, respectively. Also, the viability counts of L. fermentium in fermentation broth increased slowly, which were near 8.0 lg CFU/mL after 8 d of fermentation at 30 °C. Overall, fermentation with L. fermentium can be applied in deacidification of P. mume fruits, and also the fermented P. mume fruits can meet the standard to be further processed into prune or sauces, and the fermentation broth of P. mume fruits with L. fermentium have a good prospect in the development of probiotic beverage. 相似文献
147.
Antioxidant actions and phenolic and vitamin C contents of common Mauritian exotic fruits 总被引:1,自引:0,他引:1
Amitabye Luximon‐Ramma Theeshan Bahorun Alan Crozier 《Journal of the science of food and agriculture》2003,83(5):496-502
Seventeen commonly consumed exotic fruits from Mauritius were analysed for their antioxidant capacity, total phenolics, proanthocyanidins, flavonoids and vitamin C content. Two independent methods were used to evaluate the antioxidant potential of total fruit extracts. The antioxidant activities of the fruits ranged from 1 to 47 µmol Trolox equivalent antioxidant capacity (TEAC) g?1 fresh weight and from 0.3 to 34 micro/mol g fresh weight (FRAP) g?1 fresh weight. Total phenolics in the fruits ranged from 118 to 5638 µg g?1 fresh weight, proanthocyanidins from 7 to 2561 µg g?1 fresh weight, flavonoids from 21 to 712 µg g?1 fresh weight and vitamin C content from 8 to 1426 µg g?1 fresh weight. There were strong correlations between antioxidant activity (assessed by both TEAC and FRAP) and total phenolics and proanthocyanidins. Flavonoids seemed to contribute less to the antioxidant potential of the fruits, while very poor correlations were observed between ascorbate content and antioxidant activity. The highest antioxidant capacities were observed in red and yellow Psidium cattleianum Sabine ‘Chinese guava’, sweet and acid Averrhoa carambola L ‘starfruit’, Syzygium cumini L Skeels ‘jamblon’ and white Psidium guajava L ‘guava’. These fruits were also characterised by high levels of total phenolics. Mauritian exotic fruits are thus a significant source of phenolic antioxidants, which may have potential beneficial effects on health. Copyright © 2003 Society of Chemical Industry 相似文献
148.
149.
目的 以气相色谱-串联质谱(gas chromatography tandem mass spectrometry, GC-MS/MS)为检测条件, 考察61种农药在30种常见蔬果中的基质效应, 探索利用替代基质配制标准溶液进行定量分析的可行性。方法 利用乙腈分别提取30种供试基质, 经分散固相萃取净化后, 配制基质标准工作曲线和溶剂标准工作曲线, 经GC-MS/MS测试, 分析基质效应。结果 所有供试农药在10~200 μg/L线性范围良好, 线性相关系数(r2)>0.99。在未净化基质中, 绝大多数农药表现为较强的基质增强效应, 仅有14种农药表现为可忽略的弱基质效应。QuEChERS净化可减小农药在供试基质中的基质效应, 但水胺硫磷、p,p’-DDT、氟虫腈、莠灭净、氟啶脲、异菌脲在各供试基质中仍然表现为强基质增强效应。以西葫芦作为代表基质分析其他供试基质的基质效应, 95%以上数量的农药均表现为中、弱基质效应, 且在25种供试基质中, 80%以上数量的农药表现为可忽略的弱基质效应。采用添加回收的方式对本研究结果进行验证, 当添加水平为0.08 mg/kg时, 利用西葫芦基质配制标准溶液进行定量, 水胺硫磷、氟虫腈、莠灭净的回收率为73.8%~115.8%。结论 在利用GC-MS/MS结合QuEChERS法检测蔬菜水果中的农药残留过程中, 以西葫芦作为代表基质配制基质标准曲线可以有效校正待测农药在其他基质中的基质效应。 相似文献
150.
基于果蔬原料的食品3D打印技术及其应用 总被引:1,自引:0,他引:1
作为新兴数字化生产技术,3D打印技术已在许多领域中被广泛应用。其在食品领域中的应用可满足人们对食品定制化、个性化营养和数字化营养的需求,能进一步简化食品供应链体系,拓宽食材来源。水果和蔬菜富含多种营养素,是人类饮食的重要组成部分。相对于面团、巧克力、肉糜等食材,水果和蔬菜具有含水量高、难成形、易褐变的特点,因此很难实现直接3D打印。为了更好地了解水果和蔬菜在食品3D打印领域的应用情况,本文从食品3D打印的原料特性要求、果蔬原料特性以及3D打印果蔬材料的加工技术等方面进行了综述,并对其发展趋势作出展望。 相似文献