全文获取类型
收费全文 | 1904篇 |
免费 | 141篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 8篇 |
综合类 | 4篇 |
化学工业 | 849篇 |
金属工艺 | 17篇 |
机械仪表 | 38篇 |
建筑科学 | 49篇 |
矿业工程 | 4篇 |
能源动力 | 40篇 |
轻工业 | 356篇 |
水利工程 | 12篇 |
石油天然气 | 9篇 |
无线电 | 91篇 |
一般工业技术 | 267篇 |
冶金工业 | 49篇 |
原子能技术 | 4篇 |
自动化技术 | 249篇 |
出版年
2024年 | 8篇 |
2023年 | 26篇 |
2022年 | 188篇 |
2021年 | 199篇 |
2020年 | 62篇 |
2019年 | 77篇 |
2018年 | 67篇 |
2017年 | 79篇 |
2016年 | 100篇 |
2015年 | 85篇 |
2014年 | 97篇 |
2013年 | 139篇 |
2012年 | 129篇 |
2011年 | 134篇 |
2010年 | 96篇 |
2009年 | 102篇 |
2008年 | 103篇 |
2007年 | 66篇 |
2006年 | 63篇 |
2005年 | 57篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 17篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1967年 | 1篇 |
排序方式: 共有2046条查询结果,搜索用时 15 毫秒
21.
This paper studies the bilateral teleoperation over communication networks. Specifically, the network-induced random delays are modeled as being from a finite set, each delay in the set having a probability of occurrence. To fully utilize the stochastic information inherent with the delays, a novel design scheme combining the probability information and pole placement is proposed to achieve better tracking performance. The teleoperation problem is first formulated as the stabilization of an error dynamic system where the error is the difference between the states of the master and slave. Then, by constructing a Lyapunov function, a sufficient condition to guarantee the input-to-state stability is established in terms of linear matrix inequalities. The simulation results and comparison show a decrease in tracking error with the new design method. 相似文献
22.
Marina Sala de Medeiros Daniela Chanci Carolina Moreno Debkalpa Goswami Ramses V. Martinez 《Advanced functional materials》2019,29(42)
Multifunctional electronic textiles (e‐textiles) incorporating miniaturized electronic devices will pave the way toward a new generation of wearable devices and human–machine interfaces. Unfortunately, the development of e‐textiles is subject to critical challenges, such as battery dependence, breathability, satisfactory washability, and compatibility with mass production techniques. This work describes a simple and cost‐effective method to transform conventional garments and textiles into waterproof, breathable, and antibacterial e‐textiles for self‐powered human–machine interfacing. Combining embroidery with the spray‐based deposition of fluoroalkylated organosilanes and highly networked nanoflakes, omniphobic triboelectric nanogenerators (RF‐TENGs) can be incorporated into any fiber‐based textile to power wearable devices using energy harvested from human motion. RF‐TENGs are thin, flexible, breathable (air permeability 90.5 mm s?1), inexpensive to fabricate (<0.04$ cm?2), and capable of producing a high power density (600 µW cm?2). E‐textiles based on RF‐TENGs repel water, stains, and bacterial growth, and show excellent stability under mechanical deformations and remarkable washing durability under standard machine‐washing tests. Moreover, e‐textiles based on RF‐TENGs are compatible with large‐scale production processes and exhibit high sensitivity to touch, enabling the cost‐effective manufacturing of wearable human–machine interfaces. 相似文献
23.
Luisa Torsi Francesco Marinelli M. Daniela Angione Antonio Dell’Aquila Nicola Cioffi Elvira De Giglio Luigia Sabbatini 《Organic Electronics》2009,10(2):233-239
Contact effects in organic thin-film transistors (OTFTs) sensors are here investigated specifically respect to the gate field-induced sensitivity enhancement of more than three orders of magnitude seen in a DHα6T OTFT sensor exposed to 1-butanol vapors. This study shows that such a sensitivity enhancement effect is largely ascribable to changes occurring to the transistor channel resistance. Effects, such as the changes in contact resistance, are seen to influence the low gate voltage regime where the sensitivity is much lower. 相似文献
24.
In this paper, we present a Wireless Sensor node implementation which aims at solving two major issues in Wireless Sensor Networks. This solution provides nanosecond-scale synchronization between nodes and high data-rate transmission thanks to cross-layer design and the time-domain properties of UltraWide Band (UWB) modulation schemes. The high data rate is achieved through a specific implementation of a IR-UWB physical layer. Specific algorithms are also implanted into the MAC and physical layers and form a cross-layered synchronization protocol for deterministic Wireless Sensor Networks named WiDeCS (Wireless Deterministic Clock Synchronization). This protocol propagates master time reference to nodes of a cluster tree network. WiDeCS Cross layered scheme is possible thanks to flag signals rising in the physical layer. These signals, owing to the UWB time domain properties, capture precise timestamps of transmission and reception. Hardware level simulations show a clock synchronization precision of 2 ns with a 2 GHz bandwidth signal, and an ASIC demonstrator shows 374 ps synchronization precision and 677 ps of standard deviation with the same bandwidth. In this paper, the physical layer implementation is detailed, and the cross-layered WiDeCS scheme is demonstrated. 相似文献
25.
Selective Functionalization of Microstructured Surfaces by Laser‐Assisted Particle Transfer 下载免费PDF全文
Clemens von Bojnicic‐Kninski Valentina Bykovskaya Frieder Maerkle Roman Popov Andrea Palermo Daniela S. Mattes Laura K. Weber Barbara Ridder Tobias C. Foertsch Alexander Welle Felix F. Loeffler Frank Breitling Alexander Nesterov‐Mueller 《Advanced functional materials》2016,26(39):7067-7073
Microcavity arrays represent millions of different reaction compartments to screen, for example, molecular interactions, exogenous factors for cells or enzymatic activity. A novel method is presented to selectively synthesize different compounds in arrays of microcavities with up to 1 000 000 cavities per cm2. In this approach, polymer microparticles with embedded pre‐activated monomers are selectively transferred into microcavities with laser radiation. After particle patterning, heating of the particle matrix simultaneously leads to diffusion and coupling of the monomers inside each microcavity separately. This method exhibits flexibility, not only in the choice of compounds, but also in the choice of particle matrix material, which determines the chemical reaction environment. The laser‐assisted selective functionalization of microcavities can be easily combined with the intensively growing number of laser applications for patterning of molecules and cells, which is useful for the development of novel biological assays. 相似文献
26.
Silvia Orsi Daniela Guarnieri Paolo A. Netti 《Journal of materials science. Materials in medicine》2010,21(3):1013-1020
The ability to genetically modify cells seeded inside synthetic hydrogel scaffolds offers a suitable approach to induce and
control tissue repair and regeneration guiding cell fate. In fact the transfected cells can act as local in vivo bioreactor,
secreting plasmid encoded proteins that augment tissue regeneration processes. We have realized a DNA bioactivated high porous
poly(ethylene glycol) (PEG) matrix by polyethyleneimine (PEI)/DNA complexes adsorption. As the design of the microarchitectural
features of a scaffold also contributes to promote and influence cell fate, we appropriately designed the inner structure
of gene activated PEG hydrogels by gelatine microparticles templating. Microarchitectural properties of the scaffold were
analysed by scanning electron microscopy. 3D cell migration and transfection were monitored through time-lapse videomicroscopy
and confocal laser scanning microscopy. 相似文献
27.
The inactivation kinetics at 4 degrees C of Bifidobacterium bifidum, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, cultured alone or consociated in a laboratory medium (modified MRS broth), were modelled through the Weibull model and a second-order polynomial equation. The initial cell number of S. thermophilus and L. delbrueckii subsp. bulgaricus was approximately 6-7log (CFU/ml); the viability loss after 30 days of storage was 2.87 and 1.99log (CFU/l) for L. delbruckii subsp. bulgaricus and S. thermophilus, cultured alone, respectively; whereas the consociation of lactobacilli and streptococci with bifidobacteria reduced viability loss during storage (0.28 and 0.54log CFU/l for lactobacilli and streptococci, respectively). Finally, the consociation of lactobacilli and streptococci with B. bifidum improved their oxygen uptake. 相似文献
28.
29.
30.
Marieli Rosseto Cesar Vinicius Toniciolli Rigueto Karolynne Sousa Gomes Daniela Dal Castell Krein Raquel Aparecida Loss Aline Dettmer Neila Silvia Pereira dos Santos Richards 《Journal of the science of food and agriculture》2024,104(6):3185-3196
In the cheese industry, whey, which is rich in lactose and proteins, is underutilized, causing adverse environmental impacts. The fractionation of its components, typically carried out through filtration membranes, faces operational challenges such as membrane fouling, significant protein loss during the process, and extended operating times. These challenges require attention and specific methods for optimization and to increase efficiency. A promising strategy to enhance industry efficiency and sustainability is the use of enzymatic pre-treatment with the enzyme transglutaminase (TGase). This enzyme plays a crucial role in protein modification, catalyzing covalent cross-links between lysine and glutamine residues, increasing the molecular weight of proteins, facilitating their retention on membranes, and contributing to the improvement of the quality of the final products. The aim of this study is to review the application of the enzyme TGase as a pretreatment in whey protein filtration. The scope involves assessing the enzyme's impact on whey protein properties and its relationship with process performance. It also aims to identify both the optimization of operational parameters and the enhancement of product characteristics. This study demonstrates that the application of TGase leads to improved performance in protein concentration, lactose permeation, and permeate flux rate during the filtration process. It also has the capacity to enhance protein solubility, viscosity, thermal stability, and protein gelation in whey. In this context, it is relevant for enhancing the characteristics of whey, thereby contributing to the production of higher quality final products in the food industry. © 2023 Society of Chemical Industry. 相似文献