全文获取类型
收费全文 | 2435篇 |
免费 | 146篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 2篇 |
综合类 | 80篇 |
化学工业 | 271篇 |
金属工艺 | 2篇 |
机械仪表 | 21篇 |
建筑科学 | 4篇 |
能源动力 | 10篇 |
轻工业 | 2133篇 |
水利工程 | 3篇 |
石油天然气 | 8篇 |
无线电 | 5篇 |
一般工业技术 | 38篇 |
冶金工业 | 1篇 |
原子能技术 | 1篇 |
自动化技术 | 10篇 |
出版年
2024年 | 14篇 |
2023年 | 40篇 |
2022年 | 87篇 |
2021年 | 114篇 |
2020年 | 134篇 |
2019年 | 116篇 |
2018年 | 107篇 |
2017年 | 116篇 |
2016年 | 105篇 |
2015年 | 100篇 |
2014年 | 93篇 |
2013年 | 147篇 |
2012年 | 202篇 |
2011年 | 176篇 |
2010年 | 114篇 |
2009年 | 97篇 |
2008年 | 92篇 |
2007年 | 117篇 |
2006年 | 94篇 |
2005年 | 81篇 |
2004年 | 68篇 |
2003年 | 58篇 |
2002年 | 51篇 |
2001年 | 33篇 |
2000年 | 29篇 |
1999年 | 34篇 |
1998年 | 21篇 |
1997年 | 22篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 17篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 2篇 |
1987年 | 11篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有2589条查询结果,搜索用时 15 毫秒
31.
32.
Yuan Yuan Dongyan Chen Huangyou Liu Sijia Wu Haiyang Yan 《Journal of food science》2016,81(8):T2114-T2121
Furan, a typical food contaminant formed by heating process, is classified as a possible carcinogen to humans. Many factors lead to the formation of furan in food processing. In our present study, 3 potato varieties, white potato, sweet potato, and purple potato were selected to investigate the effect of thermal processing temperature and time on furan formation. The results showed that the formation of furan was highly correlated with frying temperature and time. Among the 3 potato varieties, sweet potato resulted in the highest furan concentration when fried at 200 °C for 5 min. In addition, the frying temperature and time also influenced the water activity and the color of the 3 kinds of potato slices, which had significant correlation with the formation of furan. Furan concentration decreased along with the increasing of water activity in the 3 potato varieties and the changes presented regression relationships. Meanwhile, there was an inverse correlation between furan content and color changes in the 3 potato varieties. The level of furan decreased as total color changes (ΔE) increased and the changes also presented regression relationships. These results could be used to estimate the possibility of furan formation in the 3 varieties of potato slices systems. 相似文献
33.
The amino acid composition,solubility and emulsifying properties of sweet potato protein 总被引:5,自引:0,他引:5
A protein was purified from the high-protein type sweet potato variety 55-2 available in China. The amino acid composition, solubility and emulsifying properties of the sweet potato protein (SPP) were studied. The SPP was rich in aspartic acid (18.5%) and glutamic acid (9.30%) while essential acid amino acids made up approximately 40.7% of the SPP. The SPP was highly soluble in distilled water over a wide range of pH. However, solubility of the SPP in 1.0 M NaCl and 1.0 M CaCl2 solutions was low especially at pH below the pI of the SPP. The SPP in CaCl2 demonstrated emulsifying activity index (EAI) and emulsion stability index (ESI) many folds higher than those in distilled water and NaCl solution (P < 0.05). 相似文献
34.
Substituent distribution within cross-linked and hydroxypropylated sweet potato starch and potato starch 总被引:2,自引:0,他引:2
Jianwei Zhao Henk A. Schols Zhenghong Chen Zhengyu Jin Piet Buwalda Harry Gruppen 《Food chemistry》2012
Revealing the substituents distribution within starch can help to understand the changes of starch properties after modification. The distribution of substituents over cross-linked and hydroxypropylated sweet potato starch was investigated and compared with modified potato starch. The starches were cross-linked with sodium trimetaphosphate and/or hydroxypropylated with propylene oxide. The native and modified starches were gelatinized and hydrolysed by pullulanase, β-amylase, α-amylase and a combination of pullulanase, α-amylase and amyloglucosidase. The hydrolysates were analysed by HPSEC, HPAEC and MALDI-TOF mass spectrometry. Cross-linking had only a slight effect on the enzymatic hydrolysis, where hydroxypropylation evidently limited the enzymatic hydrolysis. The results obtained suggest that the hydroxypropyl substituents are not distributed regularly over the starch chains. Although the average substitution was around 2 hydroxypropyl groups per 10 glucose units, in the enzyme digests of hydroxypropylated starches, oligomer fragments of 10–15 glucose units, carrying 5–8 hydroxypropyl groups, were identified. It is hypothesised that higher levels of substituents are present in the amorphous regions and periphery of clusters of starch granules. This is the first time that the location of hydroxypropyl groups within sweet potato starch has been examined in this detail. Despite significant differences in granule architecture between starches from potato and sweet potato, similar patterns of hydroxypropylation have been found. 相似文献
35.
甘薯多糖的抗肿瘤研究 总被引:1,自引:1,他引:1
采用水提醇沉法从“广薯98”中提取甘薯粗多糖,通过灌胃给药,研究了甘薯多糖对荷瘤小鼠(H22)的抑瘤率、存活期和脾脏指数、胸腺指数、腹腔巨噬细胞活性的影响。其研究结果显示:甘薯多糖对H22实体瘤小鼠具有明显的抑瘤作用(P<0.05),对H22腹水瘤小鼠具有明显的延长存活期作用(P<0.05);甘薯多糖能明显增加H22实体瘤小鼠的脾脏指数、胸腺指数(P<0.05或P<0.01),能明显增强H22实体瘤小鼠的腹腔巨噬细胞活性(P<0.01)。表明甘薯多糖对H22荷瘤小鼠具有明显的抗肿瘤作用。 相似文献
36.
Involvement of Anthocyanins and other Phenolic Compounds in Radical-Scavenging Activity of Purple-Fleshed Sweet Potato Cultivars 总被引:7,自引:0,他引:7
T. Oki M. Masuda s. Furuta y. Nishiba N. Terahara I. Suda 《Journal of food science》2002,67(5):1752-1756
ABSTRACT: The 80% ethanol extracts of 5 purple-fleshed sweet potato cultivars were separated into 2 fractions, anthocyanins- and phenolic compounds-rich fractions, to clarify the contribution of these constituents to the radical-scavenging activity. The separation was accomplished with an ethyl acetate liquid/liquid extraction. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity in each fraction and the contributors varied according to the cultivars. The dominant DPPH radical-scavengers in "Ayamurasaki" and "Kyushu-132" were anthocyanins rather than phenolic compounds, while those in "Miyanou-36" and "Bise" were phenolic compounds, such as chlorogenic acid. Furthermore, the high-performance liquid chromatography analysis of anthocyanins showed that "Ayamurasaki" and "Kyushu-132" were rich in anthocyanins with peonidin aglycon, whereas "Miyanou-36,""Bise," and "Tanegashimamurasaki" contained cyanidin aglycon. 相似文献
37.
对马铃薯的预糊化实验结果揭示,在各种加热方法中,马铃薯经蒸煮25min后的糊化效果最好.正交试验结果表明,奶粉含量和黄油含量对冷冻调理马铃薯饼的感官指标有高度显著的影响.对冷冻调理马铃薯饼的油脂的测试结果显示,未经油炸的马铃薯饼的脂肪含量为4.24%,而经过油炸后的马铃薯饼的脂肪含量为11.18%.经过一个月的冻藏后,未经油炸的冷冻调理马铃薯饼的油脂的过氧化值为1.94%,而经过油炸的冷冻调理马铃薯饼的油脂的过氧化值为7.79%. 相似文献
38.
以机械性能(抗张强度、断裂拉伸应变)和透湿性为指标,研究食品胶对甘薯淀粉膜性能的优化。结果表明:羟丙基羧甲基纤维素(HPCMC)添加量为3.5~4.0g/100g 淀粉、甘油添加量小于2.0g/100g 淀粉及黄原胶添加量小于2.0g/100g 淀粉时,膜的机械性能较好;HPCMC 添加量小于2.0g/100g 淀粉、甘油添加量大于4.0g/100g 淀粉和黄原胶添加量小于1.5g/100g 淀粉时,膜的透湿性较小。由于不同性能的优化值范围不完全相同,在实际应用中可根据对不同性能的要求进行选择。 相似文献
39.
新型保健食品——土豆面包的研制 总被引:4,自引:1,他引:4
研究了用土豆淀粉生产面包的较佳原料配比方案,分析了土豆淀粉对面包品质和面团品质的影响规律。结果表明,以土豆淀粉为主生产土豆面包是可行的,其生产用原料的较佳配比为:土豆淀粉60%、谷朊粉18%、小麦面粉22%。土豆淀粉的添加比例与面包的体积显著负相关;当添加比例小于50%时,随着土豆淀粉的添加比例的增大,面包的其它表观性状均有不同程度的好转。土豆淀粉的加入对面团品质影响较大:随着土豆淀粉比例的增大,评价值增大,吸水率下降,软化度先升后降。当土豆淀粉添加比例达90%时,不能形成面团。 相似文献
40.
S. Djordjevic S. Kovacevic LJ. Nikolic M. Miljkovic D. Djordjevic 《Journal of Natural Fibers》2014,11(3):212-224
Synthesis and characterization of copolymer obtained by grafting acrylamide onto hydrolyzed potato starch and its application in cotton yarn sizing were presented in this work. Some process parameters of starch hydrolysis and grafting, like as hydrolysis yield, grafting yield, grafting percentage, graft efficiency, and monomer to polymer conversion were determinated. Molar mass values of hydrolyzed starch and copolymer samples are located in a narrow range of 1 × 105 to 1 × 107 and 1 × 102 to 1 × 104. Grafted hydrolyzed starch, as a sizing agent, gives better results than nongrafted, particularly in terms of sizing uniformity, yarn mechanical parameters, and easier removal in subsequent desizing process. 相似文献