全文获取类型
收费全文 | 4370篇 |
免费 | 114篇 |
专业分类
电工技术 | 43篇 |
综合类 | 5篇 |
化学工业 | 750篇 |
金属工艺 | 63篇 |
机械仪表 | 98篇 |
建筑科学 | 198篇 |
矿业工程 | 12篇 |
能源动力 | 144篇 |
轻工业 | 473篇 |
水利工程 | 38篇 |
石油天然气 | 22篇 |
武器工业 | 1篇 |
无线电 | 355篇 |
一般工业技术 | 645篇 |
冶金工业 | 1076篇 |
原子能技术 | 43篇 |
自动化技术 | 518篇 |
出版年
2022年 | 34篇 |
2021年 | 31篇 |
2020年 | 29篇 |
2019年 | 29篇 |
2018年 | 51篇 |
2017年 | 68篇 |
2016年 | 67篇 |
2015年 | 50篇 |
2014年 | 88篇 |
2013年 | 274篇 |
2012年 | 161篇 |
2011年 | 217篇 |
2010年 | 203篇 |
2009年 | 167篇 |
2008年 | 208篇 |
2007年 | 221篇 |
2006年 | 185篇 |
2005年 | 142篇 |
2004年 | 128篇 |
2003年 | 117篇 |
2002年 | 106篇 |
2001年 | 75篇 |
2000年 | 80篇 |
1999年 | 104篇 |
1998年 | 161篇 |
1997年 | 115篇 |
1996年 | 96篇 |
1995年 | 86篇 |
1994年 | 86篇 |
1993年 | 78篇 |
1992年 | 71篇 |
1991年 | 41篇 |
1990年 | 53篇 |
1989年 | 50篇 |
1988年 | 46篇 |
1987年 | 56篇 |
1986年 | 52篇 |
1985年 | 72篇 |
1984年 | 62篇 |
1983年 | 63篇 |
1982年 | 40篇 |
1981年 | 54篇 |
1980年 | 28篇 |
1979年 | 35篇 |
1978年 | 28篇 |
1977年 | 48篇 |
1976年 | 39篇 |
1975年 | 29篇 |
1974年 | 23篇 |
1973年 | 30篇 |
排序方式: 共有4484条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.
Interaction of β‐casein with (−)‐epigallocatechin‐3‐gallate assayed by fluorescence quenching: effect of thermal processing temperature 下载免费PDF全文
Zhiyong He Jie Chen Sydney E. Moser Owen G. Jones Mario G. Ferruzzi 《International Journal of Food Science & Technology》2016,51(2):342-348
The interactions between the flavan‐3‐ol (?)‐epigallocatechin‐3‐gallate (EGCG) and bovine β‐casein in phosphate‐buffered saline (PBS) of pH 6.5 subjected to thermal processing at various temperatures (25–100 °C) were investigated using fluorescence quenching. The results indicated that different temperatures had different effects on the structural changes and EGCG‐binding ability of β‐casein. At temperatures below 60 °C, the β‐casein–EGCG interaction changed little (P > 0.05) with increasing temperature. At temperatures above 80 °C, native assemblies of β‐casein in solution dissociated into individual β‐casein molecules and unfolded, as demonstrated by a red shift of the maximum fluorescence emission wavelength (λmax) of up to 8.8 nm. The highest quenching constant (Kq) and the number of binding sites (n) were 0.92 (±0.01) × 1013 m ?1 s?1 and 0.73 (±0.02) (100 °C), respectively. These results provide insight into the potential of interactions between β‐casein–EGCG that may modulate bioactivity or bioavailability to be altered during thermal process. 相似文献
105.
Elham Khanipour Steve H. Flint Owen J. McCarthy Matt Golding Jon Palmer Mark Tamplin 《International Journal of Food Science & Technology》2014,49(6):1506-1512
The aim of this study was to evaluate the combined effect of salt (sodium chloride, 0–8% w/v), sorbate (potassium sorbate, 0–4.5% w/v), nisin (0–500 ppm) and lysozyme (0–500 ppm) on the survival of Clostridium sporogenes as a non‐toxigenic surrogate of Clostridium botulinum in terms of the probability of growth by using a central composite rotatable design. The results indicated that salt and sorbate were the most effective factors in preventing the growth of Cl. sporogenes in high‐moisture (>95%) and low‐acid conditions. The probability of growth of Cl. sporogenes in broth was reduced by combinations of salt and sorbate. Nisin and lysozyme had insignificant effects on the probability of growth of Cl. sporogenes (P > 0.05). Lysozyme individually and in combination with nisin had no inhibitory effect on Cl. sporogenes. Overall, the addition of sorbate and lysozyme may allow the salt concentration to be reduced while preventing growth. 相似文献
106.
Tim Huber Jörg Müssig Owen Curnow Shusheng Pang Simon Bickerton Mark P. Staiger 《Journal of Materials Science》2012,47(3):1171-1186
Cellulose is a fascinating biopolymer of almost inexhaustible quantity. While being a lightweight material, it shows outstanding
values of strength and stiffness when present in its native form. Unsurprisingly, cellulose fibre has been rigorously investigated
as a reinforcing component in biocomposites. In recent years, however, a new class of monocomponent composites based on cellulosic
materials, so-called all-cellulose composites (ACCs) have emerged. These new materials promise to overcome the critical problem
of fibre–matrix adhesion in biocomposites by using chemically similar or identical cellulosic materials for both matrix and
reinforcement. A number of papers scattered throughout the polymer, composites and biomolecular science literature have been
published describing non-derivatized and derivatized ACCs. Exceptional mechanical properties of ACCs have been reported that
easily exceed those of traditional biocomposites. Several different processing routes have been applied to the manufacture
of ACCs using a broad range of different solvent systems and raw materials. This article aims to provide a comprehensive review
of the background chemistry and various cellulosic sources investigated, various synthesis routes, phase transformations of
the cellulose, and mechanical, viscoelastic and optical properties of ACCs. The current difficulties and challenges of ACCs
are clearly outlined, pointing the way forward for further exploration of this interesting subcategory of biocomposites. 相似文献
107.
108.
Thomas R. Bieler Scott C. Sutton Bret E. Dunlap Zackery A. Keith Philip Eisenlohr Martin A. Crimp Brad L. Boyce 《JOM Journal of the Minerals, Metals and Materials Society》2014,66(1):121-128
The evolution of heterogeneous deformation in a tantalum polycrystal was examined during a three-point bending experiment using electron backscatter pattern mapping. Slip bands formed at strains as low as 1%, and they became more intense with strain. Heterogeneous deformation was evident as intragranular orientation gradients as large as 30° were observed after a strain of about 8%. Nonmonotonic changes in the local average misorientation distribution were observed, implying that dislocation substructure developed in a complex manner. Slip bands were analyzed using plane traces computed from local orientation information. With the assumption of uniaxial stress, Schmid factors for favorable slip systems were identified for each grain and compared with observations, showing evidence for macroscopic activity on both {110} and {112} slip systems. Reconstructed boundary data were used to estimate the geometric potential for slip transfer at grain boundaries. The correlations indicated that when active slip systems were favorably oriented for slip transfer across the boundary, it was often observed in the form of continuous slip bands aligned across the boundary. In boundaries where geometrical alignment and Schmid factors were not favorable for slip transfer, there was a higher likelihood to form ledges (topographic discontinuities) along the grain boundaries. Dislocation pileups at grain boundaries were also correlated with a low potential for slip transfer. 相似文献
109.
110.
International Journal of Coal Science & Technology - A mutualistic relationship between grasses, coal-degrading fungi, and arbuscular mycorrhizal fungi was proposed to account for the... 相似文献