全文获取类型
收费全文 | 1325篇 |
免费 | 32篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 271篇 |
金属工艺 | 13篇 |
机械仪表 | 33篇 |
建筑科学 | 42篇 |
矿业工程 | 10篇 |
能源动力 | 21篇 |
轻工业 | 127篇 |
水利工程 | 9篇 |
石油天然气 | 2篇 |
无线电 | 119篇 |
一般工业技术 | 224篇 |
冶金工业 | 279篇 |
原子能技术 | 17篇 |
自动化技术 | 174篇 |
出版年
2022年 | 18篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 10篇 |
2018年 | 30篇 |
2017年 | 17篇 |
2016年 | 24篇 |
2015年 | 22篇 |
2014年 | 34篇 |
2013年 | 66篇 |
2012年 | 44篇 |
2011年 | 61篇 |
2010年 | 38篇 |
2009年 | 40篇 |
2008年 | 44篇 |
2007年 | 30篇 |
2006年 | 30篇 |
2005年 | 34篇 |
2004年 | 38篇 |
2003年 | 22篇 |
2002年 | 23篇 |
2001年 | 14篇 |
2000年 | 26篇 |
1999年 | 18篇 |
1998年 | 66篇 |
1997年 | 40篇 |
1996年 | 33篇 |
1995年 | 37篇 |
1994年 | 32篇 |
1993年 | 32篇 |
1992年 | 22篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 19篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 12篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1977年 | 24篇 |
1976年 | 26篇 |
1974年 | 14篇 |
1973年 | 10篇 |
1971年 | 9篇 |
排序方式: 共有1358条查询结果,搜索用时 15 毫秒
31.
T. Kraus L. Malaquin E. Delamarche H. Schmid N.D. Spencer H. Wolf 《Advanced materials (Deerfield Beach, Fla.)》2005,17(20)
The cover shows 100 μm diameter glass spheres covered by a grid of hexagonally packed polystyrene beads. Wolf and co‐workers placed the 500 nm diameter polystyrene beads onto the larger spheres using the self‐assembly, transfer, and integration (SATI) process that they report on p. 2438. The cover illustrates the capability of SATI to process uneven surfaces in addition to the planar substrates discussed in the article. The carrier that holds the smaller beads deforms during their transfer onto the larger spheres, so that on the larger spheres patterned “caps” are formed. Using this process, which is compatible with standard microfabrication techniques, a variety of particle assemblies can be achieved. 相似文献
32.
Kapila V. Haddad W.M. Erwin R.S. Bernstein D.S. 《Automatic Control, IEEE Transactions on》1998,43(7):1003-1007
Parameterized Lyapunov bounds and shifted quadratic guaranteed cost bounds are merged to develop shifted parameter-dependent quadratic cost bounds for robust stability and robust performance. Robust fixed-order (i.e., full- and reduced-order) controllers are developed based on new shifted parameter-dependent bounding functions. A numerical example is presented to demonstrate the effectiveness of the proposed approach 相似文献
33.
There is an implicit assumption in electronic commerce that induces the buyers to believe that their deals will be handled appropriately. However, after a seller has already committed to a buyer, he may be tempted by several requests though he will not be able to supply them all. We analyze markets in which a finite set of automated buyers interacts repeatedly with a finite set of automated sellers. These sellers can satisfy one buyer at a time, and they can be tempted to break a commitment they already have. We have found the perfect equilibria that exist in markets with a finite horizon, and with an unrestricted horizon. A significant result stemming from our study reveals that sellers are almost always tempted to breach their commitments. However, we also show that if markets' designers implement an external mechanism that restricts the automated buyers actions, then sellers will keep their commitments. 相似文献
34.
Rakauskas ME Ward NJ Boer ER Bernat EM Cadwallader M Patrick CJ 《Accident; analysis and prevention》2008,40(5):1742-1749
Although alcohol and distraction are often cited as significant risk factors for traffic crashes, most research has considered them in isolation. It is therefore necessary to consider the interactions between alcohol and distraction impairment sources, especially when examining the relationship between behavior and crash risk. In a driving simulator, the primary goal was to maintain a safe headway to a lead vehicle and the secondary goal was to maintain stable lane position. All participants engaged in distractions that represented different levels of resource competition and half of the participants consumed alcohol (target BAC 0.08 g/dl). Specific comparisons were made between sober driving while distracted and driving intoxicated without distraction. Distraction tasks produced more changes in driving behavior than did alcohol for both longitudinal (primary) and lateral (secondary) driving goals. Alcohol impairment was evident only in relation to lateral driving performance, however there was an amplification of impairment when alcohol and distraction conditions were combined. Distraction resulted in a general level of impairment across all driving goals, whereas participants with alcohol appeared to shed secondary driving goals to “protect” primary driving goals. Drivers’ strategies to cope with alcohol (and distraction) may not be sufficient to offset the increased crash risk. 相似文献
35.
Ajay Matta Muhammad Zia Karim Hoda Gerami Bettina Zoe Benigno Ivan Cheng Arne Mehrkens William Mark Erwin 《International journal of molecular sciences》2022,23(10)
Background: Tissue sources of pain emanating from degenerative discs remains incompletely understood. Canine intervertebral discs (IVDs) were needle puncture injured, 4-weeks later injected with either phosphate-buffered saline (PBS) or NTG-101, harvested after an additional fourteen weeks and then histologically evaluated for the expression of NGFr, BDNF, TrkB and CALCRL proteins. Quantification was performed using the HALO automated cell-counting scoring platform. Immunohistochemical analysis was also performed on human IVD tissue samples obtained from spinal surgery. Immunohistochemical analysis and quantification of neurotrophins and neuropeptides was performed using an in vivo canine model of degenerative disc disease and human degenerative disc tissue sections. Discs injected with NTG-101 showed significantly lower levels of Nerve Growth Factor receptor (NGFr/TrkA, p = 0.0001), BDNF (p = 0.009), TrkB (p = 0.002) and CALCRL (p = 0.008) relative to PBS injections. Human IVD tissue obtained from spinal surgery due to painful DDD show robust expression of NGFr, BDNF, TrkB and CALCRL proteins. A single intradiscal injection of NTG-101 significantly inhibits the expression of NGFr, BDNF, TrkB and CALCRL proteins in degenerative canine IVDs. These results strongly suggest that NTG-101 inhibits the development of neurotrophins that are strongly associated with painful degenerative disc disease and may have profound effects upon the management of patients living with discogenic pain. 相似文献
36.
Kollmann Immel Holdheide M. Antonoff H. Mayer-Wegelin Frey-Wyssling Eidmann Thiele J. S. Cammerer A. v. Wacek Klauditz Scheer A. Nowak Gumz Vorreiter Finkbeiner Müller Munds E. Becker A. Kraus Fessel Keylwerth A. Troche Graf B. Thunell Tiemann Bäseler 《Holz als Roh- und Werkstoff》1942,5(10):363-371
Ohne Zusammenfassung 相似文献
37.
38.
v. Pohl R. Trendelenburg Zimmermann E. Brüche S. Nickel Zycha Liese Schulz Graf A. Troche T. Perkitny M. Lüdtke Frey-Wyssling K. Storch Otto Kratky A. v. Wacek Finkbeiner K. Storch Munds Paula Sarten Ernst Tschanter A. Kraus R. Lechner Schaile Thiele W. Küch Kräß Hengerer Kollmann A. Nowak 《Holz als Roh- und Werkstoff》1940,3(4):128-136
Ohne Zusammenfassung 相似文献
39.
R. Trendelenburg Botteri Schulz Zimmermann Schulz Gustav G. Klem Frey-Wyssling O. Kratky A. v. Wacek O. Kratky G. Becker Egner Graf B. Thunell M. Lüdtke S. Nickel A. Kraus Klar Finkbeiner Müller E. Becker Zimmermann v. Pohl Lechner Richard Huber L. Metz Thiele Schlüter Egner W. Wenhart Graf Kinberg Kraemer 《Holz als Roh- und Werkstoff》1940,3(5):165-174
Ohne Zusammenfassung 相似文献
40.
Eugene Shi Guang Choo Erwin Peng Reshmi Rajendran Prashant Chandrasekharan Chang‐Tong Yang Jun Ding Kai‐Hsiang Chuang Junmin Xue 《Advanced functional materials》2013,23(4):496-505
This study proposes a new method to generate positive contrast in magnetic resonance imaging (MRI) using superparamagnetic contrast agents. Superparamagnetic nanostructures consisting of octahedron manganese ferrite nanoparticles embedded in spherical nanogels are fabricated using a bottom‐up approach. The composite nanoparticles are strongly magnetized in an external magnetic field and produce a unique NMR frequency shift in water protons, which can be demonstrated in MR spectroscopy and imaging to be different from the bulk pool. Moreover, the particles exhibit excellent colloidal stability in aqueous media and good cell biocompatibility. Hence, these particles are potentially useful as biomarkers by taking advantage of the positive contrast effects produced in MRI. 相似文献