全文获取类型
收费全文 | 118419篇 |
免费 | 10494篇 |
国内免费 | 6190篇 |
学科分类
工业技术 | 135103篇 |
出版年
2024年 | 355篇 |
2023年 | 1766篇 |
2022年 | 2939篇 |
2021年 | 4587篇 |
2020年 | 3536篇 |
2019年 | 3013篇 |
2018年 | 3452篇 |
2017年 | 3850篇 |
2016年 | 3323篇 |
2015年 | 4692篇 |
2014年 | 5878篇 |
2013年 | 7245篇 |
2012年 | 7730篇 |
2011年 | 8484篇 |
2010年 | 7710篇 |
2009年 | 7391篇 |
2008年 | 7192篇 |
2007年 | 6886篇 |
2006年 | 6764篇 |
2005年 | 5836篇 |
2004年 | 4149篇 |
2003年 | 3753篇 |
2002年 | 3620篇 |
2001年 | 3201篇 |
2000年 | 2916篇 |
1999年 | 2780篇 |
1998年 | 2207篇 |
1997年 | 1767篇 |
1996年 | 1724篇 |
1995年 | 1436篇 |
1994年 | 1133篇 |
1993年 | 893篇 |
1992年 | 688篇 |
1991年 | 507篇 |
1990年 | 408篇 |
1989年 | 301篇 |
1988年 | 266篇 |
1987年 | 161篇 |
1986年 | 130篇 |
1985年 | 110篇 |
1984年 | 65篇 |
1983年 | 43篇 |
1982年 | 55篇 |
1981年 | 38篇 |
1980年 | 28篇 |
1979年 | 17篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1959年 | 5篇 |
1951年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Correlation between instrumental texture and colour quality attributes with sensory analysis of selected cheeses as affected by fat contents 下载免费PDF全文
A. Półtorak J. Wyrwisz M. Moczkowska M. Marcinkowska‐Lesiak A. Stelmasiak U. Ulanicka M. Zalewska A. Wierzbicka Da‐Wen Sun 《International Journal of Food Science & Technology》2015,50(4):999-1008
This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (r = 0.766, r = 0.75 and r = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (r = 0.722) and moderately correlated with the elasticity from penetration test (r = 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese. 相似文献
72.
73.
74.
Neural Processing Letters - The beta processes (BP) is a powerful nonparametric tool in feature learning, which is often used as the prior of Bernoulli process for choosing features from a feature... 相似文献
75.
Yong Pan Chen Zhu Wen Bin Zeng Pei Fu Chi Chen Bao Ming Xu Zhong Feng Gao 《Chembiochem : a European journal of chemical biology》2021,22(24):3431-3436
Rapid and sensitive point-of-care testing (POCT) is an extremely critical mission in practical applications, especially for rigorous military medicine, home health care, and in the third world. Here, we report a visual POCT method for adenosine triphosphate (ATP) detection based on Taylor rising in the corner of quadratic geometries between two rod surfaces. We discuss the principle of Taylor rising, demonstrating that it is significantly influenced by contact angle, surface tension, and density of the sample, which are controlled by ATP-dependent rolling circle amplification (RCA). In the presence of ATP, RCA reaction effectively suppresses Taylor-rising behavior, due to the increased contact angle, density, and decreased surface tension. Without addition of ATP, untriggered RCA reaction is favorable for Taylor rising, resulting in a significant height. With this proposed method, visual sensitive detection of ATP without the aid of other instruments is realized with only a 5 μL droplet, which has good selectivity and a low detection limit (17 nM). Importantly, this visual method provides a promising POCT tool for user-friendly molecular diagnostics. 相似文献
76.
77.
78.
79.
340管线矫直机是太原重工成熟产品,在国内占有较大市场,并出口印度、印尼、缅甸、埃及等国际市场。出口印度矫直机在质保期内出现主缸裂纹问题,为探明问题原因并杜绝类似情况发生,快开机构设计静强度分析、疲劳强度分析及生产加工过程等方面探查裂纹原因并提出几点预防措施。 相似文献
80.