全文获取类型
收费全文 | 495篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 11篇 |
综合类 | 1篇 |
化学工业 | 120篇 |
金属工艺 | 17篇 |
机械仪表 | 13篇 |
建筑科学 | 19篇 |
能源动力 | 25篇 |
轻工业 | 52篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 34篇 |
一般工业技术 | 71篇 |
冶金工业 | 19篇 |
原子能技术 | 4篇 |
自动化技术 | 130篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 35篇 |
2021年 | 35篇 |
2020年 | 14篇 |
2019年 | 19篇 |
2018年 | 16篇 |
2017年 | 18篇 |
2016年 | 12篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 49篇 |
2012年 | 32篇 |
2011年 | 32篇 |
2010年 | 29篇 |
2009年 | 27篇 |
2008年 | 16篇 |
2007年 | 23篇 |
2006年 | 24篇 |
2005年 | 18篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有522条查询结果,搜索用时 15 毫秒
141.
A numerical assessment of the load bearing capacity of externally pressurized moderately thick tubes
Leone Corradi Valentino Di Marcello Lelio Luzzi Fulvio Trudi 《International Journal of Pressure Vessels and Piping》2009,86(8):525-532
The collapse behavior of cylindrical shells pressurized from outside is examined. Attention is focused on tubes of moderate thickness, as required by very deep water pipelines or some innovative nuclear power plant proposals. Their collapse is expected to be dominated by yielding but, because of the decreasing nature of the post-collapse evolution, interaction with instability is likely to be significant enough to demand consideration. At present, no quantitative assessment of such effect is available, because little study has been devoted to tubes in this thickness range.Plasticity–instability interaction is activated by imperfections and to assess their influence on a systematic numerical study is undertaken. Computations produce a meaningful measure of the collapse pressure and it is proposed that the allowable pressure be determined on its basis, by introducing a suitable safety factor. This is chosen so that results reproduce those provided by presently accepted procedures in the well explored and reliable range of medium-thin tubes. When the same factor is applied to thicker tubes, the resulting allowable pressure is significantly higher than the values suggested by codes, which apparently react to the present lack of knowledge by assuming an extremely conservative attitude. 相似文献
142.
Viviana Costa Marcello De Fine Valeria Carina Alice Conigliaro Lavinia Raimondi Angela De Luca Daniele Bellavia Francesca Salamanna Riccardo Alessandro Giovanni Pignatti Milena Fini Gianluca Giavaresi 《International journal of molecular sciences》2021,22(5)
Osteoarthritis (OA) is a degenerative bone disease that involved micro and macro-environment of joints. To date, there are no radical curative treatments for OA and novel therapies are mandatory. Recent evidence suggests the role of miRNAs in OA progression. In our previous studies, we demonstrated the role of miR-31-5p and miR-33a families in different bone regeneration signaling. Here, we investigated the role of miR-31-5p and miR-33a-5p in OA progression. A different expression of miR-31-5p and miR-33a-5p into osteoblasts and chondrocytes isolated from joint tissues of OA patients classified in based on different Kellgren and Lawrence (KL) grading was highlighted; and through a bioinformatic approach the common miRNAs target Specificity proteins (Sp1) were identified. Sp1 regulates the expression of gap junction protein Connexin43 (Cx43), which in OA drives the modification of (i) osteoblasts and chondrocytes genes expression, (ii) joint inflammation cytokines releases and (iii) cell functions. Concerning this, thanks to gain and loss of function studies, the possible role of Sp1 as a modulator of CX43 expression through miR-31-5p and miR-33a-5p action was also evaluated. Finally, we hypothesize that both miRNAs cooperate to modulate the expression of SP1 in osteoblasts and chondrocytes and interfering, consequently, with CX43 expression, and they might be further investigated as new possible biomarkers for OA. 相似文献
143.
144.
Marco Pedrazzi Silvia Vercellone Elettra Barberis Michela Capraro Roberta De Tullio Federico Cresta Rosaria Casciaro Carlo Castellani Mauro Patrone Emilio Marengo Paola Lecca Paola Melotti Claudio Sorio Marcello Manfredi Monica Averna 《International journal of molecular sciences》2021,22(8)
The aim of this study was the identification of specific proteomic profiles, related to a restored cystic fibrosis transmembrane conductance regulator (CFTR) activity in cystic fibrosis (CF) leukocytes before and after ex vivo treatment with the potentiator VX770. We used leukocytes, isolated from CF patients carrying residual function mutations and eligible for Ivacaftor therapy, and performed CFTR activity together with proteomic analyses through micro-LC–MS. Bioinformatic analyses of the results obtained revealed the downregulation of proteins belonging to the leukocyte transendothelial migration and regulation of actin cytoskeleton pathways when CFTR activity was rescued by VX770 treatment. In particular, we focused our attention on matrix metalloproteinase 9 (MMP9), because the high expression of this protease potentially contributes to parenchyma lung destruction and dysfunction in CF. Thus, the downregulation of MMP9 could represent one of the possible positive effects of VX770 in decreasing the disease progression, and a potential biomarker for the prediction of the efficacy of therapies targeting the defect of Cl− transport in CF. 相似文献
145.
Tesfaye Yonatan Tariku Zemene Eyasu Prati Andrea Pelillo Marcello Shah Mubarak 《International Journal of Computer Vision》2019,127(9):1303-1320
International Journal of Computer Vision - In this paper, a unified three-layer hierarchical approach for solving tracking problem in a multiple non-overlapping cameras setting is proposed. Given a... 相似文献
146.
In this article we question the utility of the distinction between conceptual and nonconceptual content in cognitive science,
and in particular, in the empirical study of visual perception. First, we individuate some difficulties in characterizing
the notion of “concept” itself both in the philosophy of mind and cognitive science. Then we stress the heterogeneous nature
of the notion of nonconceptual content and outline the complex and ambiguous relations that exist between the conceptual/nonconceptual
duality and other pairs of notions, such as top–down/bottom-up and modular/nonmodular. Finally we look in greater detail at
the proposal developed by Jacob and Jeannerod (Ways of seeing. The scopes and limits of visual cognition. Oxford, UK: Oxford
University Press, 2003), who apply the notion of nonconceptual content to empirical research on visual perception. After reconstructing their point
of view on concepts, we try to reject their major arguments in support of the conceptual/nonconceptual distinction, i.e. the
compositionality of thought and the fineness of grain of percepts. 相似文献
147.
148.
Prof. Marcello Leopoldo Dr. Marialessandra Contino Prof. Francesco Berardi Prof. Roberto Perrone Prof. Nicola Antonio Colabufo 《ChemMedChem》2014,9(1):38-42
PET radiotracer development to target in vivo P‐glycoprotein (P‐gp) could be an important strategy for the early diagnosis of neurodegenerative disorders such as Alzheimer’s disease (AD). Indeed, as a dysfunction of P‐gp is responsible for the accumulation of β‐amyloid plaques (a hallmark of AD) in brain parenchyma, P‐gp is the cause of AD onset. P‐gp substrates and inhibitors are useful for imaging the activity or expression of this protein, respectively; herein we discuss the in vivo evaluation of some 11C radiotracers with P‐gp‐inhibitory activity, such as [11C]MC18 and [11C]MC113, as well as P‐gp substrates [11C]MC266 and [11C]MC80. Moreover, the radiosynthesis of all these P‐gp probes is reported. 相似文献
149.
The growing dispersion of ICs’ parameters poses relevant uncertainties on gate output conductances and logic thresholds which
play a main role in bridging fault detection. In this evolving context, the quality of fault simulation and test generation
tools making use of nominal parameters should be verified. To analyze this problem we have studied bridging fault detection
in combinational ICs in the presence of growing variations of IC’s parameters. Results show that a single test is not sufficient
to ensure acceptable escape probabilities. Conversely, the minimal number of test vectors required to provide a null escape
probability is upper bounded with respect to variations in the standard deviation of IC’s parameters. This result has been
verified by means of Monte Carlo electrical level simulation. We propose a method to derive these minimal test sets in the
case of low frequency tests. A fault simulator and a test generator have been developed supporting the search of minimal test
sets targeting a null escape probability. These tools have been applied to a set of combinational benchmarks.
Michele Favalli received the Dr. Eng. degree in Electronic Engineering from the University of Bologna in 1987 and the Ph. D. in Electronic Engineering and Computer Science in 1993. From 1993 he has worked at the Department of Electronics at the University of Bologna as a Researcher. From 1998 he is Associate Professor of Computer Science at the University of Ferrara. His research interests are in the area of digital IC’s design and testing. They include fault modeling, fault simulation, test generation, on-line testing and fault tolerant circuits. Marcello Dalpasso received the B.S. degree (summa cum laude) in electrical engineering, in 1990, and the Ph.D. degree in computer science, in 1994, from the University of Bologna, Italy. Since 2004, he has been an Associate Professor at the University of Padova, Italy, where he teaches computer science. His research interests include the areas of fault modeling and simulation for digital IC design and CAD frameworks and tools for intellectual-property protection in EDA. 相似文献
Michele FavalliEmail: |
Michele Favalli received the Dr. Eng. degree in Electronic Engineering from the University of Bologna in 1987 and the Ph. D. in Electronic Engineering and Computer Science in 1993. From 1993 he has worked at the Department of Electronics at the University of Bologna as a Researcher. From 1998 he is Associate Professor of Computer Science at the University of Ferrara. His research interests are in the area of digital IC’s design and testing. They include fault modeling, fault simulation, test generation, on-line testing and fault tolerant circuits. Marcello Dalpasso received the B.S. degree (summa cum laude) in electrical engineering, in 1990, and the Ph.D. degree in computer science, in 1994, from the University of Bologna, Italy. Since 2004, he has been an Associate Professor at the University of Padova, Italy, where he teaches computer science. His research interests include the areas of fault modeling and simulation for digital IC design and CAD frameworks and tools for intellectual-property protection in EDA. 相似文献
150.