全文获取类型
收费全文 | 574篇 |
免费 | 45篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 165篇 |
金属工艺 | 8篇 |
机械仪表 | 13篇 |
建筑科学 | 17篇 |
能源动力 | 31篇 |
轻工业 | 55篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 60篇 |
一般工业技术 | 103篇 |
冶金工业 | 46篇 |
原子能技术 | 3篇 |
自动化技术 | 106篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 16篇 |
2021年 | 19篇 |
2020年 | 13篇 |
2019年 | 22篇 |
2018年 | 23篇 |
2017年 | 24篇 |
2016年 | 20篇 |
2015年 | 28篇 |
2014年 | 38篇 |
2013年 | 44篇 |
2012年 | 40篇 |
2011年 | 54篇 |
2010年 | 35篇 |
2009年 | 28篇 |
2008年 | 30篇 |
2007年 | 20篇 |
2006年 | 20篇 |
2005年 | 15篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 12篇 |
1996年 | 8篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有619条查询结果,搜索用时 11 毫秒
1.
Cataldo Simari Carmelo Lo Vecchio Apostolos Enotiadis Mariano Davoli Vincenzo Baglio Isabella Nicotera 《应用聚合物科学杂志》2019,136(34):47884
Polyethersulphone (PES) is an aromatic thermoplastic, at low environmental impact, evaluated in this work as a promising candidate for new polymer electrolytes in the PEMFCs technology. A sulfonation procedure has been tuned in order to graft sulfonic acid groups on the polymer chains (sPES) and to make it hydrophilic. Homogeneous membranes with different polymer's sulfonation degrees (SD%) have demonstrated excellent mechanical properties and very low permeability toward methanol (important in the DMFCs), even if low proton conductivity. Nanocomposite sPES membranes were prepared by dispersion of highly hydrophilic lamellar particles such as layered double hydroxide (LDH) in the polymer. Deep investigations performed by a combination of PFG-NMR, EIS, XRD, DMA, and scanning electron microscopy have evidenced the exfoliation of the lamellae in polymer matrix. However, a certain anisotropy was evidenced both in the morphology and molecular diffusion, favored in the longitudinal direction (parallel to surface), while completely inhibited in the cross-section. This finding is most likely induced by the polymer structure, therefore particular attention must be paid to the choice of the filler and preparation of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47884. 相似文献
2.
Rodríguez-Pérez Ángel Mariano Pérez-Calañas Cinta Pulido-Calvo Inmaculada 《Water Resources Management》2021,35(6):1977-1990
Water Resources Management - This paper aims to evaluate the possibility of using non-utilized hydraulic energy in urban water distribution systems. For this purpose, the viability and possible... 相似文献
3.
We discuss specific features of Te-based compounds that made them the best materials for the phase-change data storage. It is demonstrated that the phase-change recording is due to a switch of Ge atoms between octahedral and tetrahedral symmetry positions within the Te face-centered cubic lattice. It is this nature of the transition that makes the Te-based media fast and stable. The driving force for this transition is also discussed. The chapter is concluded by introduction of a concept of the super-resolution near-field structure (super-RENS) disc that allows to reduce a bit size well below the diffraction limit and makes 100 GB/disc storage a reality. 相似文献
4.
Alexandre Szklo Giovani Machado Roberto Schaeffer Jacqueline Mariano Janaí na Sala Marina Tavares 《Catalysis Today》2005,106(1-4):123-128
This paper assesses the impacts of a GTL plant on the expansion of Brazil's oil refining segment. The GTL plant (50,000 bpd) was sized to start up operations in 2015, producing diesel and naphtha through the indirect route (FT-synthesis). This plant will consume the non-associated natural gas production from the recent discoveries at the Santos Basin (around 419 Bm3), and the associated gas production from the Campos Basin. Both basins are located in the Southeast of Brazil, the most populated, rich and industrialized region of the country. Two different criteria for refinery expansion were simulated in order to meet oil product demand scenarios. Findings show that depending on the refinery expansion criteria considered GTL will play a fundamental hole to meet the oil product demand forecast to Brazil in the next 10 years. 相似文献
5.
Tom Mariano 《集成电路应用》2008,(11):25-25
在近期一次SEMI产业策略论坛发表的演讲中,Lam Research Corp.的总裁兼CEO Stephen Newberry认为,半导体产业已经进入了“无利的繁荣时代”。2003年以来,每比特/功能的价格已经比每比特/价格的成本下降得更快,使得整个产业的利润遭到侵蚀。这似乎成为了一个无法维继的市场,随着时间的推移必须进行自我修正才行。 相似文献
6.
Challenged by competition pressures and unprecedented pace of change, firms can no longer choose whether to concentrate on the needs of today's customers or on the anticipation of those of tomorrow: they must be excellent in both. This requires managing two related balancing acts: on the one side, being excellent in both exploitation and exploration of their capabilities and, on the other side, being excellent in managing both incremental and radical innovation. These balances are critical since exploitation and exploration, on the one side, and incremental and radical innovation, on the other, require different approaches that have traditionally been considered difficult to combine within the same organization. Working on evidence and discussion from the 7th CINet Conference held in Lucca (Italy) in 2006, this Special Section is aimed at contributing to theory and practice on these two complex balancing acts that today represent a hot issue in innovation management. 相似文献
7.
The Journal of Supercomputing - DNA methylation analysis has become an important topic in the study of human health. DNA methylation analysis requires not only a specific treatment of DNA samples... 相似文献
8.
Rocío Mato-Basalo Miriam Morente-Lpez Onno J Arntz Fons A. J. van de Loo Juan Fafin-Labora María C. Arufe 《International journal of molecular sciences》2021,22(7)
Mesenchymal stem cells have an important potential in the treatment of age-related diseases. In the last years, small extracellular vesicles derived from these stem cells have been proposed as cell-free therapies. Cellular senescence and proinflammatory activation are involved in the loss of therapeutic capacity and in the phenomenon called inflamm-aging. The regulators of these two biological processes in mesenchymal stem cells are not well-known. In this study, we found that p65 is activated during cellular senescence and inflammatory activation in human umbilical cord-derived mesenchymal stem cell. To demonstrate the central role of p65 in these two processes, we used small-molecular inhibitors of p65, such as JSH-23, MG-132 and curcumin. We found that the inhibition of p65 prevents the cellular senescence phenotype in human umbilical cord-derived mesenchymal stem cells. Besides, p65 inhibition produced the inactivation of proinflammatory molecules as components of a senescence-associated secretory phenotype (SASP) (interleukin-6 and interleukin-8 (IL-6 and IL-8)). Additionally, we found that the inhibition of p65 prevents the transmission of paracrine senescence between mesenchymal stem cells and the proinflammatory message through small extracellular vesicles. Our work highlights the important role of p65 and its inhibition to restore the loss of functionality of small extracellular vesicles from senescent mesenchymal stem cells and their inflamm-aging signature. 相似文献
9.
Yuk Ming X. Hung Hung Mariano H. Talou María A. Camerucci 《International Journal of Applied Ceramic Technology》2021,18(5):1466-1477
Alumina ceramic porous structures were shaped by the fused deposition of alumina/polyamide 612 composite granules using an FDM 3D printer with a modified extruder to process granulated powder instead of a filament. The composite granules were prepared via thermally induced phase separation (TIPS). Firstly, in order to determine the proportion of polymer/solvent to be used in the TIPS process, different volume fractions of PA612 in dimethyl sulfoxide (DMSO) were studied (0.01 to 0.20), and the granules obtained were characterized by SEM, DSC, and Raman spectroscopy. Secondly, the addition of different ceramic loadings to the PA612/DMSO solution was studied with the aim of determining the amount to be used for preparing the composite granules by TIPS. In particular, the effect of the alumina content on the morphology and size of the obtained composite granules was studied. In addition, rheological properties (oscillatory and rotational tests) of the feed materials were studied. Finally, the printing conditions, including the nozzle temperature and nozzle diameter, and the extrusion process, were optimized in order to obtain porous structures with good quality. Alumina porous structures were successfully printed, debinded, and sintered. Adequate bonding between layers was achieved, and no defects at interfaces were detected. 相似文献
10.
We present a method for foreground/background video segmentation (change detection) in real-time that can be used, in applications such as background subtraction or analysis of surveillance cameras. Our approach implements a probabilistic segmentation based on the Quadratic Markov Measure Field models. This framework regularizes the likelihood of each pixel belonging to each one of the classes (background or foreground). We propose a new likelihood that takes into account two cases: the first one is when the background is static and the foreground might be static or moving (Static Background Subtraction), the second one is when the background is unstable and the foreground is moving (Unstable Background Subtraction). Moreover, our likelihood is robust to illumination changes, cast shadows and camouflage situations. We implement a parallel version of our algorithm in CUDA using a NVIDIA Graphics Processing Unit in order to fulfill real-time execution requirements. 相似文献