全文获取类型
收费全文 | 4098篇 |
免费 | 551篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 6篇 |
综合类 | 69篇 |
化学工业 | 216篇 |
金属工艺 | 4篇 |
机械仪表 | 28篇 |
建筑科学 | 24篇 |
矿业工程 | 6篇 |
轻工业 | 3999篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
武器工业 | 2篇 |
无线电 | 18篇 |
一般工业技术 | 84篇 |
冶金工业 | 116篇 |
原子能技术 | 3篇 |
自动化技术 | 78篇 |
出版年
2024年 | 53篇 |
2023年 | 137篇 |
2022年 | 208篇 |
2021年 | 245篇 |
2020年 | 309篇 |
2019年 | 244篇 |
2018年 | 207篇 |
2017年 | 207篇 |
2016年 | 210篇 |
2015年 | 216篇 |
2014年 | 203篇 |
2013年 | 210篇 |
2012年 | 277篇 |
2011年 | 290篇 |
2010年 | 171篇 |
2009年 | 145篇 |
2008年 | 128篇 |
2007年 | 153篇 |
2006年 | 112篇 |
2005年 | 121篇 |
2004年 | 108篇 |
2003年 | 89篇 |
2002年 | 95篇 |
2001年 | 56篇 |
2000年 | 45篇 |
1999年 | 28篇 |
1998年 | 39篇 |
1997年 | 30篇 |
1996年 | 41篇 |
1995年 | 35篇 |
1994年 | 37篇 |
1993年 | 41篇 |
1992年 | 48篇 |
1991年 | 22篇 |
1990年 | 20篇 |
1989年 | 18篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1984年 | 3篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1966年 | 3篇 |
1964年 | 11篇 |
1963年 | 2篇 |
1959年 | 2篇 |
1958年 | 3篇 |
1956年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有4663条查询结果,搜索用时 9 毫秒
151.
对七种天然木塞(分别编号为1#~7#)的综合性能进行研究,通过检测木塞外观质量及物理特性,监测瓶贮期间是否漏酒、胀塞,酒液浸塞高度,瓶内游离氧,酒液中溶解氧、游离SO2、色度、色调,感官评价等多项指标,分析不同天然木塞的优缺点及对瓶装葡萄酒品质的影响。结果表明,2#木塞表面光洁、端面平整、色泽均一;木塞密封性能2#>7#>6#>5#>4#>3#>1#。2#木塞塞孔径最小、皮孔深度最浅、皮孔条数最少,尺寸误差最小、回弹能力最强,瓶贮36个月后,瓶内顶端空间游离氧最低(0.13 mg/L),酒液中溶解氧最低(0.19 mg/L),游离SO2最高(14 mg/L),色度最低(5.6),色调最低(0.96),感官品质最高(92分)。因此,2#木塞的性能指标及密封酒液的品质最好。 相似文献
152.
目的 通过风味分析确定花露烧酒新品中银杏果的最佳添加量。方法 采用固相微萃取-气质联用(solid phase microexteaction-gas chromatography-mass spectrometry, SPME-GC-MS)和感官评价技术测定比较了不同银杏果添加量的花露烧酒的挥发性风味成分。结果 共鉴定出49种挥发性风味成分,各样品中香气成分的种类和含量有明显差异;经与糯米混合发酵后,银杏果中青草风味成分如壬醛、正己醛等显著下降或未检出;采用主成分分析法得出银杏花露烧酒香气与辛醇、八甲基四硅氧烷、乳酸乙酯、乙酸异戊酯等风味成分有关。由感官分析可知银杏果添加量为25%的样品C整体感官品质最佳,尤其是香气方面,产生了令人愉悦的正己酸乙酯、乙酸异戊酯等风味成分。结论 添加25%银杏果的花露烧酒的风味较好,为传统特色产品花露烧酒的创新提供了新思路,对银杏花露烧酒的风味控制提供了理论依据。 相似文献
153.
Marialuisa Aragona Caterina Porcino Maria Cristina Guerrera Giuseppe Montalbano Rosaria Laur Marzio Cometa Maria Levanti Francesco Abbate Teresa Cobo Gabriel Capitelli Jos A. Vega Antonino German 《International journal of molecular sciences》2022,23(5)
The brain-derived neurotrophic factor (BDNF) was discovered in the last century, and identified as a member of the neurotrophin family. BDNF shares approximately 50% of its amino acid with other neurotrophins such as NGF, NT-3 and NT-4/5, and its linear amino acid sequences in zebrafish (Danio rerio) and human are 91% identical. BDNF functions can be mediated by two categories of receptors: p75NTR and Trk. Intriguingly, BDNF receptors were highly conserved in the process of evolution, as were the other NTs’ receptors. In this review, we update current knowledge about the distribution and functions of the BDNF-TrkB system in the sensory organs of zebrafish. In fish, particularly in zebrafish, the distribution and functions of BDNF and TrkB in the brain have been widely studied. Both components of the system, associated or segregated, are also present outside the central nervous system, especially in sensory organs including the inner ear, lateral line system, retina, taste buds and olfactory epithelium. 相似文献
154.
Tun Patricia A.; Benichov Jonathan; Wingfield Arthur 《Canadian Metallurgical Quarterly》2010,25(3):730
Older adults with good hearing and with mild-to-moderate hearing loss were tested for comprehension of spoken sentences that required perceptual effort (hearing speech at lower sound levels), and two degrees of cognitive load (sentences with simpler or more complex syntax). Although comprehension accuracy was equivalent for both participant groups and for young adults with good hearing, hearing loss was associated with longer response latencies to the correct comprehension judgments, especially for complex sentences heard at relatively low amplitudes. These findings demonstrate the need to take into account both sensory and cognitive demands of speech materials in older adults' language comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
155.
156.
Utilisation possibility of Enterococcus faecalis isolates from neonate's faeces for production of fermented sausages as starter cultures 下载免费PDF全文
Hoa Van Ba Hyun‐Woo Seo Soo‐Hyun Cho Yoon‐Seok Kim Jin‐Hyoung Kim Beom‐Young Park Hyun‐Wook Kim Jun‐Sang Ham Pil‐Nam Seong 《International Journal of Food Science & Technology》2017,52(7):1660-1669
This study aimed at assessing the utilisation possibility of Enterococcus faecalis as starter cultures for production of fermented sausages. The E. faecalis isolates isolated from faeces samples of 5‐day‐old healthy newborn babies, identified by 16SrDNA sequencing and free from virulence determinants as proven by genomic sequencing, were used for fermented sausages production as starter culture. Six treatments (four inoculated with four different E. faecalis isolates, one with commercial starter culture and one control) were prepared. The inoculation with E. faecalis showed a stronger acidification compared with the control. The treatments with E. faecalis showed significantly higher flavour and acceptability scores in comparison with the control or commercial starter culture. Both of commercial starter culture and E. faecalis were positive with tyramine. Apart from the amine production, the inoculation with E. faecalis generally improved the acidifying activity and flavour of the products, suggesting their application potentials in fermented sausages production as starter cultures. 相似文献
157.
Jack A. Neal Betsy Booren Luis Cisneros-Zevallos Rhonda K. Miller Lisa M. Lucia Joseph E. Maxim Alejandro Castillo 《Journal of food science》2010,75(6):S319-S326
Abstract: The use of ionizing radiation for the control of foodborne pathogens and extending the shelf life of fresh iceberg lettuce and fresh spinach has recently been approved by the U.S. Food and Drug Administration. The efficacy of electron beam irradiation for controlling foodborne pathogens has been reported. For this experiment, the effectiveness of electron beam irradiation on the microbiological and sensory characteristics of fresh spinach was studied. Total aerobic plate counts were reduced by 2.6 and 3.2 log CFU/g at 0.7 and 1.4 kGy, respectively. Lactic acid bacteria were reduced at both doses of e-beam but grew slowly over the 35 d of the experiment. Yeasts and molds were not reduced in samples exposed to 0.7 kGy whereas 1.4 kGy significantly reduced microbial counts. Gas compositions (O2 and CO2) were significantly different than controls. Oxygen levels inside the spinach sample bags decreased over time; however, O2 levels did not drop below 1% that can induce anaerobic fermentation. CO2 levels for all treatments increased through day 4; yet 7 d after irradiation, CO2 level differences were not significant in both control and irradiated samples. Irradiation dose did not affect the basic tastes, aromatics, or mouth feels of fresh spinach, however; hardness attributes decreased as irradiated dose increased and slimy attributes of fresh spinach were higher in control samples compared to irradiated samples. 相似文献
158.
He Wang Ruijin Yang Yanning Liu Weibin Zhang Wei Zhao Yanpeng Zhang Xiao Hua 《International Journal of Food Science & Technology》2010,45(6):1088-1096
Changes in microbiological, physicochemical and sensory properties of shrimp gamma irradiated with 60Co at doses of 0, 1, 3, 6, 9 kGy were investigated. Irradiation at 6 kGy eliminated most of the spoilage microorganisms and did not affect sensory quality. The L* value increased as irradiation dose increased, while a* value decreased as irradiation dose increased. Irradiation had no significant effect on the texture of shrimp samples; however, increasing the dose up to 9 kGy significantly increased the amount of volatile compounds, such as, alcohols, ketones, aldehydes, furans, and oxides. According to the total sensory points, the appearance and flavour of the shrimp product was considered as acceptable by sensory evaluation when irradiated at doses of 0–6 kGy. These results showed that gamma irradiation processing (<6 kGy) had the potential to extend the shelf life of fried shrimp. 相似文献
159.
160.
A. Hernández J. Ureña M. Mazo J. J. García A. Jiménez J. A. Jiménez M. C. Pérez F. J. Álvarez C. De Marziani J. P. Dérutin J. Sérot 《Journal of Intelligent and Robotic Systems》2009,55(1):81-106
An advanced adaptive sonar module is described, capable of being configured to different circumstances and distances according
to reflectors found in the environment. Thanks to the sensory distribution, it is possible to identify three basic types of
reflector (planes, edges and corners). Furthermore, a heuristic map of the environment is built. The proposed methods have
been computationally optimized, and implemented in a real-time system based on a Field-Programmable Gate Array (FPGA) and
a Digital Signal Processor (DSP). Results have been obtained in the detection, classification and mapping of obstacles; and
finally testing has been carried out on a commercial vehicle. 相似文献