全文获取类型
收费全文 | 13968篇 |
免费 | 1133篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 96篇 |
综合类 | 8篇 |
化学工业 | 5471篇 |
金属工艺 | 164篇 |
机械仪表 | 349篇 |
建筑科学 | 500篇 |
矿业工程 | 21篇 |
能源动力 | 389篇 |
轻工业 | 3395篇 |
水利工程 | 126篇 |
石油天然气 | 88篇 |
无线电 | 536篇 |
一般工业技术 | 1884篇 |
冶金工业 | 567篇 |
原子能技术 | 42篇 |
自动化技术 | 1475篇 |
出版年
2024年 | 53篇 |
2023年 | 199篇 |
2022年 | 936篇 |
2021年 | 1101篇 |
2020年 | 483篇 |
2019年 | 494篇 |
2018年 | 542篇 |
2017年 | 557篇 |
2016年 | 610篇 |
2015年 | 485篇 |
2014年 | 644篇 |
2013年 | 1002篇 |
2012年 | 908篇 |
2011年 | 1037篇 |
2010年 | 815篇 |
2009年 | 773篇 |
2008年 | 665篇 |
2007年 | 632篇 |
2006年 | 479篇 |
2005年 | 351篇 |
2004年 | 307篇 |
2003年 | 279篇 |
2002年 | 252篇 |
2001年 | 156篇 |
2000年 | 110篇 |
1999年 | 136篇 |
1998年 | 115篇 |
1997年 | 117篇 |
1996年 | 109篇 |
1995年 | 79篇 |
1994年 | 62篇 |
1993年 | 64篇 |
1992年 | 68篇 |
1991年 | 46篇 |
1990年 | 41篇 |
1989年 | 36篇 |
1988年 | 36篇 |
1987年 | 34篇 |
1986年 | 41篇 |
1985年 | 37篇 |
1984年 | 31篇 |
1983年 | 25篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1980年 | 19篇 |
1979年 | 21篇 |
1978年 | 22篇 |
1977年 | 14篇 |
1976年 | 10篇 |
1975年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Deborah Oliveira De Fusco Leonardo Lucas Madaleno Vanildo Luiz Del Bianchi Aline da Silva Bernardo Rafael Roberto Assis Gustavo Henrique de Almeida Teixeira 《International Journal of Food Science & Technology》2019,54(7):2416-2424
Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L−1), osmolality (mOsmol kg−1), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L−1 gallic acid), reducing and total sugars (%) and Na and K contents (mg L−1). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences. 相似文献
2.
3.
Cheese fortification using saturated monoglyceride self‐assembly structures as carrier of omega‐3 fatty acids 下载免费PDF全文
Sonia Calligaris Alexandra Ignat Marialuisa Biasutti Nadia Innocente Maria Cristina Nicoli 《International Journal of Food Science & Technology》2015,50(9):2129-2134
The purpose of this research was to study the capacity of emulsions containing saturated monoglyceride self‐assembly structures to deliver omega‐3 fatty acids in fresh soft cheese. To this aim, fortified emulsions containing different ratios of milk, saturated monoglycerides (MGs) and cod liver oil were added to milk before cheese‐making. These emulsions were characterised by distinct microstructural features observed by polarised light microscopy and apparent viscosity values. The omega‐3 delivery performance of MG emulsions highlighted that this strategy allowed a good retention of the omega‐3‐rich oil in the curd (up to 75%). The fortified cheeses showed yield value and fat content higher than those of control samples. The enriched cheese showed hardness and cohesiveness obtained by texture profile analysis similar to those of the unfortified product. Only a slight decrease in gumminess was detected in fortified cheese. 相似文献
4.
5.
6.
Gina Cavaliere Giovanna Trinchese Nadia Musco Federico Infascelli Chiara De Filippo Vincenzo Mastellone Valeria Maria Morittu Pietro Lombardi Raffaella Tudisco Micaela Grossi Vincenzo Monda Monica I. Cutrignelli Antonietta Messina Serena Calabrò Heleena B. Moni Luigi Stradella Giovanni Messina Marcellino Monda Maria Pina Mollica 《Journal of dairy science》2018,101(3):1843-1851
Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism. 相似文献
7.
8.
9.
An approach is presented to satisfy the demand for simple criteria, guidelines and models for the preliminary sizing of horizontal subsurface flow (SF) constructed wetland systems. This approach eliminates time-consuming calculations and iterations by providing graphical solutions for wetland system sizing. Therefore, it can be used for the preliminary assessment of new or performance evaluation of existing subsurface flow constructed wetland systems. The validity of this methodology is checked with data from existing systems and is found to be quite satisfactory. This methodology is combined with simple equations predicting the maximum wetland capacity in summer, so as to assist designers in sizing installations in tourist areas with increased summer populations. Furthermore, based on this methodology, a sensitivity analysis is performed of the area requirements for wastewaters of various strengths and various design conditions and performance criteria. The results provide a useful overview to engineers and further simplify the design methodology of new subsurface flow constructed wetland systems. 相似文献
10.
In this work it is presented a study on the residence time distribution (RTD) of particles in a co-current pilot-plant spray dryer operated with a rotary atomization system. A nuclear technique is applied to investigate the RTD responses of spray dryers. The methodology is based on the injection of a radioisotope tracer in the feed stream followed by the monitoring of its concentration at the outlet stream. The experiments were performed during the drying of aqueous suspensions of gadolinium oxide. The RTD responses obtained experimentally presented good reproducibility, indicating that the technique applied is well suited to investigating fluid-dynamics of spray dryers. In addition to the experimental investigation, a mathematical model was used to describe the RTD experimental curves. 相似文献