全文获取类型
收费全文 | 24937篇 |
免费 | 1863篇 |
国内免费 | 1179篇 |
专业分类
电工技术 | 258篇 |
综合类 | 1210篇 |
化学工业 | 10456篇 |
金属工艺 | 4310篇 |
机械仪表 | 353篇 |
建筑科学 | 715篇 |
矿业工程 | 518篇 |
能源动力 | 1468篇 |
轻工业 | 2728篇 |
水利工程 | 136篇 |
石油天然气 | 1354篇 |
武器工业 | 92篇 |
无线电 | 576篇 |
一般工业技术 | 2322篇 |
冶金工业 | 1168篇 |
原子能技术 | 225篇 |
自动化技术 | 90篇 |
出版年
2024年 | 89篇 |
2023年 | 536篇 |
2022年 | 637篇 |
2021年 | 809篇 |
2020年 | 822篇 |
2019年 | 815篇 |
2018年 | 733篇 |
2017年 | 809篇 |
2016年 | 735篇 |
2015年 | 695篇 |
2014年 | 1116篇 |
2013年 | 1334篇 |
2012年 | 1394篇 |
2011年 | 1725篇 |
2010年 | 1278篇 |
2009年 | 1511篇 |
2008年 | 1305篇 |
2007年 | 1598篇 |
2006年 | 1445篇 |
2005年 | 1240篇 |
2004年 | 1053篇 |
2003年 | 928篇 |
2002年 | 792篇 |
2001年 | 729篇 |
2000年 | 654篇 |
1999年 | 424篇 |
1998年 | 399篇 |
1997年 | 324篇 |
1996年 | 338篇 |
1995年 | 220篇 |
1994年 | 213篇 |
1993年 | 200篇 |
1992年 | 183篇 |
1991年 | 161篇 |
1990年 | 141篇 |
1989年 | 81篇 |
1988年 | 58篇 |
1987年 | 57篇 |
1986年 | 52篇 |
1985年 | 49篇 |
1984年 | 48篇 |
1983年 | 21篇 |
1982年 | 42篇 |
1981年 | 36篇 |
1980年 | 31篇 |
1979年 | 20篇 |
1978年 | 24篇 |
1977年 | 18篇 |
1976年 | 17篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Hanna Harrysson Birgitta Swolin Michael Axelsson Ingrid Undeland 《International Journal of Food Science & Technology》2020,55(6):2462-2471
Whole body saline-perfused rainbow trout (Oncorhynchus mykiss) was ice-stored for 4 weeks and compared with unwashed/washed minces from unbled and bled trout in terms of rancid odour, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and redness loss. Muscle from saline-perfused fish, which had 72% less total haem, was deficient in rancid odour during the whole storage, while bled (54% less haem) and unbled samples developed rancid odour already after ~4 and 2 days; higher intensity without bleeding. PV/TBARS also developed in the order unbled > bled > perfused samples; however, PV/TBARS were not as completely prevented as rancid odour after perfusion. Saline washing (3 × 3 volumes) of unbled mince removed 84% haem and yielded the second most stable sample while saline washing (1 × 1 volumes) destabilised unbled mince, despite 64% haem removal. Concurrent antioxidant removal during washing of minces obviously counteracted the effect of blood removal and washing fish mince with small volumes of solution should be used with great care. 相似文献
972.
973.
In a photocatalytic reaction, maintaining the high efficiency of photocatalyst under a low concentration of pollutants is a key challenge. In this work, a new 2D sodium titanate nanosheet encapsulated Ag2O-TiO2 (2D NTO/Ag2O-TiO2) p-n heterojunction photocatalyst is proposed to deal with this dilemma. Through a simple plasma electrolytic oxidation (PEO) treatment and ion exchange treatment, a classic Ag2O-TiO2 p-n heterojunction structure is prepared and used as the photoelectric conversion unit in the photocatalyst. Then, through a subsequent hydrothermal treatment, a 2D NTO film that serves as the adsorption unit in the photocatalyst can be produced on the surface of the Ag2O-TiO2 p-n heterojunction layer. Finally, the desired 2D NTO/Ag2O-TiO2 structure is formed. The photocatalyst exhibits superior photocatalytic performance including high degradation rate as well as excellent catalytic stability and durability by combining the high sunlight utilization efficiency and high photoelectric utilization efficiency of the Ag2O-TiO2 p-n heterojunction and the outstanding adsorption performance of the 2D NTO film. Therefore, the problem of photocatalytic slow kinetics under low pollutants concentration is perfectly solved. This work provides a new strategy for the structural design of high-performance photocatalysts. 相似文献
974.
Development of a long‐life vacuum‐packaged ready‐to‐eat meat product based on a traditional Portuguese seasoned meat
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Marta Laranjo Ana Gomes Maria Eduarda Potes Maria José Fernandes Maria João Fraqueza Miguel Elias 《International Journal of Food Science & Technology》2016,51(5):1150-1158
Carne do alguidar is a Portuguese traditional pork fried meat, usually manufactured for self‐consumption purposes. This study developed a ready‐to‐eat (RTE) meat product, to meet today's consumers’ convenience, manufactured at the industrial scale evaluating its quality and shelf life, assessing the effect of vacuum packaging and the use of an antioxidant (50 ppm BHT) to enhance oxidative stability. Physicochemical and microbiological parameters were assessed, and a sensory analysis was performed. Interestingly, no significant differences were recorded between control (non‐BHT) and antioxidant (BHT) samples. Microbiological counts remained at low levels throughout the storage period, ensuring the product's required microbiological quality. At later storage stages, higher values of thiobarbituric acid‐reactive substances arose and off flavours and aromas were perceived. Still, overall appreciation was not affected until 12 months of storage and a significant depreciation was perceived only after 15 months. Fibrousness and rising of off flavours were negatively correlated with overall appreciation. 相似文献
975.
Anna F. Horn Nina S. Nielsen Charlotte Jacobsen 《International Journal of Food Science & Technology》2012,47(5):1097-1108
The objective of this study was to investigate the protective effect of five different emulsifiers on iron‐mediated lipid oxidation in 70% fish oil‐in‐water emulsions. The emulsifiers were either based on protein (whey protein isolate and sodium caseinate) or based on phospholipid (soy lecithin and two milk phospholipids with different phospholipid contents, MPL20 and MPL75). Lipid oxidation was studied at pH 4.5 and 7.0, and results were compared to lipid oxidation in neat fish oil. Results showed that all emulsions oxidised more than neat oil. Furthermore, emulsions prepared with proteins oxidised more at low pH than at high pH, and casein emulsions oxidised the least (Peroxide value (PV) at day 7 was 0.5–0.7 meq kg?1). Among emulsions prepared with phospholipids, emulsions with MPL75 were the most oxidised followed by emulsions prepared with lecithin and MPL20. Thus, PV in MPL75 emulsions was 5.0–5.5 meq kg?1 at day 7 compared with 0.9–1.9 meq kg?1 in MPL20 emulsions. 相似文献
976.
none 《Canadian Metallurgical Quarterly》2013,52(2):221-234
AbstractNucleation of ferrite either at austenite grain boundaries or within them on deformation defects has been examined experimentally and analyzed on the basis of the theory of heterogeneous nucleation. Low-carbon low-alloy steels were deformed by controlled rolling schedules to a total reduction of 50 or 68% in finish rolling at 730-800 °C. Deformation accelerates the kinetics of the γ→∞ transformation and strongly activates ferrite nucleation at grain boundaries. Both experimental and theoretical estimations showed that the rate of intragranular nucleation is much less compared to nucleation at grain boundaries. Intragranular nuclei develop notably only in the final stages of transformation in deformed austenite and affect the formation of structure only in the small separated areas.On a examiné expérimentalement et analysé la nucléation de la ferrite, soit aux joints de grain de l'faustenite, ou à l'finterieur de ceux-ci, aux défauts de déformation, en se basant sur la théorie de la nucléation hétérogéne. On a déformé des aciers peu alliés à faible carbone, en suivant des plans de laminage contrôlé, jusqu'fa une réduction totale de 50 ou 68% pour le laminage final a 800-730 °C. La déformation accélère la cinétique de transformation de γ→α et active fortement la nucleation de la ferrite aux joints de grains. Tant les évaluations expérimentales que theoriques ont montré que le taux de nucléation intragranulaire était beaucoup moins élevé en comparaison avec la nucleation aux joints de grain. Les noyaux intragranulaires se développent particuliérement seulement lors des étapes finales de transformation de l'faustenite déformée et affectent la formation de la structure seulement dans de petites zones séparées. 相似文献
977.
Remediation of diesel‐contaminated soil using in situ chemical oxidation (ISCO) and the effects of common oxidants on the indigenous microbial community: a comparison study
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
978.
979.
The stability of vitamin A in fortified palm olein during extended storage and thermal treatment
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dewi Kristina Natalia Silalahi Dewi Yuliyanti Monica da Silva Isti Christianti Karyanto Mulyono Paul Wassell 《International Journal of Food Science & Technology》2017,52(8):1869-1877
The stability of vitamin A in Refined Bleached Deodorised Palm Olein (RBDPOL) was studied for 24 months. Vitamin A decreased with time, temperature and thermal treatment (frying/cooking). RBDPOL fortification was observed over several temperature ranges, using PET, nylon and HDPE commercial packaging materials. After 24 months, the following vitamin A contents of 39–43 IU g?1 (39–45%) at 16–20 °C; 35–40 IU g?1 (43–49%) at 24–29 °C; and 28–39 IU g?1 (45–73%) at 24–45 °C were detected at the respective temperature ranges. Results showed stability of vitamin A fortified RBDPOL vegetable oil was not stable over typical shelf life (12 months). Depletion of vitamin A accelerated when the RBDPOL vegetable oil was subjected to high temperature thermal treatment. 相似文献
980.