全文获取类型
收费全文 | 8733篇 |
免费 | 348篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 66篇 |
综合类 | 2篇 |
化学工业 | 1703篇 |
金属工艺 | 159篇 |
机械仪表 | 189篇 |
建筑科学 | 359篇 |
矿业工程 | 26篇 |
能源动力 | 231篇 |
轻工业 | 951篇 |
水利工程 | 47篇 |
石油天然气 | 51篇 |
无线电 | 753篇 |
一般工业技术 | 1329篇 |
冶金工业 | 1985篇 |
原子能技术 | 63篇 |
自动化技术 | 1183篇 |
出版年
2023年 | 68篇 |
2022年 | 133篇 |
2021年 | 225篇 |
2020年 | 138篇 |
2019年 | 165篇 |
2018年 | 238篇 |
2017年 | 209篇 |
2016年 | 222篇 |
2015年 | 196篇 |
2014年 | 227篇 |
2013年 | 800篇 |
2012年 | 320篇 |
2011年 | 391篇 |
2010年 | 326篇 |
2009年 | 376篇 |
2008年 | 316篇 |
2007年 | 292篇 |
2006年 | 288篇 |
2005年 | 254篇 |
2004年 | 226篇 |
2003年 | 184篇 |
2002年 | 193篇 |
2001年 | 207篇 |
2000年 | 193篇 |
1999年 | 224篇 |
1998年 | 279篇 |
1997年 | 205篇 |
1996年 | 156篇 |
1995年 | 143篇 |
1994年 | 128篇 |
1993年 | 131篇 |
1992年 | 93篇 |
1991年 | 49篇 |
1990年 | 93篇 |
1989年 | 93篇 |
1988年 | 80篇 |
1987年 | 92篇 |
1986年 | 77篇 |
1985年 | 87篇 |
1984年 | 91篇 |
1983年 | 80篇 |
1982年 | 75篇 |
1981年 | 86篇 |
1980年 | 59篇 |
1979年 | 76篇 |
1978年 | 70篇 |
1977年 | 59篇 |
1976年 | 50篇 |
1975年 | 48篇 |
1974年 | 53篇 |
排序方式: 共有9097条查询结果,搜索用时 0 毫秒
1.
2.
Towards a Better Prediction of Cell Settling on Nanostructure Arrays—Simple Means to Complicated Ends 下载免费PDF全文
Nina Buch‐Månson Sara Bonde Jessica Bolinsson Trine Berthing Jesper Nygård Karen L. Martinez 《Advanced functional materials》2015,25(21):3246-3255
Vertical arrays of nanostructures (NSs) are emerging as promising platforms for probing and manipulating live mammalian cells. The broad range of applications requires different types of interfaces, but cell settling on NS arrays is not yet fully controlled and understood. Cells are both seen to deform completely into NS arrays and to stay suspended like tiny fakirs, which have hitherto been explained with differences in NS spacing or density. Here, a better understanding of this phenomenon is provided by using a model that takes into account the extreme membrane deformation needed for a cell to settle into a NS array. It is shown that, in addition to the NS density, cell settling depends strongly on the dimensions of the single NS, and that the settling can be predicted for a given NS array geometry. The predictive power of the model is confirmed by experiments and good agreement with cases from the literature. Furthermore, the influence of cell‐related parameters is evaluated theoretically and a generic method of tuning cell settling through surface coating is demonstrated experimentally. These findings allow a more rational design of NS arrays for the numerous exciting biological applications where the mode of cell settling is crucial. 相似文献
3.
4.
5.
6.
Özge Seçmeler Özlem Güçlü Üstündağ 《International Journal of Food Science & Technology》2019,54(5):1609-1616
The partitioning of predominant lipophilic olive bioactives (squalene, β-sitosterol and α-tocopherol) in olive oil processing was studied for the first time using common integrated olive milling plant. 7% of the oil and 5% of the squalene present in the olives was lost in the last pomace. β-sitosterol and α-tocopherol, which are mainly concentrated in the seed of the olive fruit, was recovered in virgin olive oil to a lesser extent (66%, 67%) while 10% were lost in last pomace. Thus, the loss of β-sitosterol and α-tocopherol was higher than that of squalene and oil, due to nonrecovered bound forms. 19% of the α-tocopherol and 21% of the β-sitosterol loss was unaccounted for, which can be attributed to degradation of α-tocopherol and incomplete recovery of sterols from the olive and pomace matrices. This study provides a basis for process development studies. 相似文献
7.
8.
Lawrence K. Forbes Graeme C. Hocking Simon Wotherspoon 《Journal of Engineering Mathematics》2004,48(1):69-91
Rainwater can collect in a lens-shaped region within the rock of a tropical island, and may be separated from the underlying salt water by a sharp interface. This paper presents a nonlinear theory for determining the shape of this interface. The island is assumed to be saturated with rain, and provision is made for the outflow of rain-water through the sides of the island. The effect of a bore well on the shape of the interface is investigated, and the problem is solved using a spectral method. An integral-equation method is also presented for the case when the island has infinite width. 相似文献
9.
Physically based simulation of human hair is a well studied and well known problem. But the “pure” physically based representation of hair (and other animation elements) is not the only concern of the animators, who want to “control” the creation and animation phases of the content. This paper describes a sketch-based tool, with which a user can both create hair models with different styling parameters and produce animations of these created hair models using physically and key frame-based techniques. The model creation and animation production tasks are all performed with direct manipulation techniques in real-time. 相似文献
10.
Vladimir Katkovnik Jaakko Astola Karen Egiazarian 《IEEE transactions on image processing》2008,17(6):833-846
The local polynomial approximation (LPA) is a nonparametric regression technique with pointwise estimation in a sliding window. We apply the LPA of the argument of cos and sin in order to estimate the absolute phase from noisy wrapped phase data. Using the intersection of confidence interval (HCI) algorithm, the window size is selected as adaptive pointwise varying. This adaptation gives the phase estimate with the accuracy close to optimal in the mean squared sense. For calculations, we use a Gauss-Newton recursive procedure initiated by the phase estimates obtained for the neighboring points. It enables tracking properties of the algorithm and its ability to go beyond the principal interval [-pi, pi] and to reconstruct the absolute phase from wrapped phase observations even when the magnitude of the phase difference takes quite large values. The algorithm demonstrates a very good accuracy of the phase reconstruction which on many occasion overcomes the accuracy of the state-of-the-art algorithms developed for noisy phase unwrap. The theoretical analysis produced for the accuracy of the pointwise estimates is used for justification of the HCI adaptation algorithm. 相似文献