全文获取类型
收费全文 | 19022篇 |
免费 | 553篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 231篇 |
综合类 | 14篇 |
化学工业 | 2613篇 |
金属工艺 | 226篇 |
机械仪表 | 327篇 |
建筑科学 | 920篇 |
矿业工程 | 43篇 |
能源动力 | 464篇 |
轻工业 | 2000篇 |
水利工程 | 273篇 |
石油天然气 | 32篇 |
无线电 | 1732篇 |
一般工业技术 | 2399篇 |
冶金工业 | 5507篇 |
原子能技术 | 144篇 |
自动化技术 | 2668篇 |
出版年
2023年 | 75篇 |
2021年 | 276篇 |
2020年 | 153篇 |
2019年 | 217篇 |
2018年 | 299篇 |
2017年 | 270篇 |
2016年 | 298篇 |
2015年 | 276篇 |
2014年 | 408篇 |
2013年 | 703篇 |
2012年 | 715篇 |
2011年 | 967篇 |
2010年 | 670篇 |
2009年 | 695篇 |
2008年 | 734篇 |
2007年 | 703篇 |
2006年 | 598篇 |
2005年 | 569篇 |
2004年 | 520篇 |
2003年 | 489篇 |
2002年 | 411篇 |
2001年 | 326篇 |
2000年 | 291篇 |
1999年 | 414篇 |
1998年 | 1927篇 |
1997年 | 1167篇 |
1996年 | 784篇 |
1995年 | 487篇 |
1994年 | 474篇 |
1993年 | 458篇 |
1992年 | 205篇 |
1991年 | 198篇 |
1990年 | 190篇 |
1989年 | 194篇 |
1988年 | 194篇 |
1987年 | 123篇 |
1986年 | 131篇 |
1985年 | 180篇 |
1984年 | 138篇 |
1983年 | 100篇 |
1982年 | 108篇 |
1981年 | 115篇 |
1980年 | 91篇 |
1979年 | 90篇 |
1978年 | 77篇 |
1977年 | 134篇 |
1976年 | 144篇 |
1975年 | 79篇 |
1974年 | 71篇 |
1973年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
1.
Stumpo Vittorio Sebök Martina van Niftrik Christiaan Hendrik Bas Seystahl Katharina Hainc Nicolin Kulcsar Zsolt Weller Michael Regli Luca Fierstra Jorn 《Magma (New York, N.Y.)》2022,35(1):29-44
Magnetic Resonance Materials in Physics, Biology and Medicine - Innovative physiologic MRI development focuses on depiction of heterogenous vascular and metabolic features in glioblastoma. For this... 相似文献
2.
Victoria L. Gremminger Charlotte L. Phillips 《International journal of molecular sciences》2021,22(9)
Bone and muscle are highly synergistic tissues that communicate extensively via mechanotransduction and biochemical signaling. Osteogenesis imperfecta (OI) is a heritable connective tissue disorder of severe bone fragility and recently recognized skeletal muscle weakness. The presence of impaired bone and muscle in OI leads to a continuous cycle of altered muscle–bone crosstalk with weak muscles further compromising bone and vice versa. Currently, there is no cure for OI and understanding the pathogenesis of the skeletal muscle weakness in relation to the bone pathogenesis of OI in light of the critical role of muscle–bone crosstalk is essential to developing and identifying novel therapeutic targets and strategies for OI. This review will highlight how impaired skeletal muscle function contributes to the pathophysiology of OI and how this phenomenon further perpetuates bone fragility. 相似文献
3.
Mohammad Hossein
Abbasi Laura Iapichino Sajad Naderi Lordejani Wil Schilders Nathan van de Wouw 《International journal for numerical methods in engineering》2020,121(23):5178-5199
To circumvent restrictions of conventional drilling methods, such as slow control actions and inability to drill depleted reservoirs, a drilling method called managed pressure drilling (MPD) has been developed. In MPD, single-phase flow processes can be modeled as a feedback interconnection of a high-order linear system and a low-order nonlinear system. These nonlinearities appear locally both inside and at the boundaries of the computational domain. To obtain a fast simulation platform for real-time purposes (eg, online model-based controller implementation), model order reduction is required for MPD. However, the local nonlinearities render applying model order reduction techniques challenging. In this study, a new approach is proposed to deal with such nonlinearities within the reduced basis (RB) context and it is successfully tested on a model for MPD. Contrary to the classical RB technique, the proposed approach not only does not generate nonphysical spikes at the locations of these local nonlinearities but also yields high speedup factors. The obtained reduced-order model can be used for efficient online simulation and controller design for drilling systems with MPD. 相似文献
4.
Davalos Monteiro Raul van de Wetering Jan Krawczyk Benjamin Engelberg Dirk L. 《Metals and Materials International》2020,26(5):630-640
Metals and Materials International - The corrosion behaviour of type 316L stainless steel in aqueous 30–50 wt%. NaOH at temperatures up to 90 °C has been elucidated.... 相似文献
5.
Cecilia Arriagada Viviana A. Cavieres Charlotte Luchsinger Alexis E. Gonzlez Vanessa C. Muoz Jorge Cancino Patricia V. Burgos Gonzalo A. Mardones 《International journal of molecular sciences》2020,21(22)
Protein trafficking is altered when normal cells acquire a tumor phenotype. A key subcellular compartment in regulating protein trafficking is the Golgi apparatus, but its role in carcinogenesis is still not well defined. Golgi phosphoprotein 3 (GOLPH3), a peripheral membrane protein mostly localized at the trans-Golgi network, is overexpressed in several tumor types including glioblastoma multiforme (GBM), the most lethal primary brain tumor. Moreover, GOLPH3 is currently considered an oncoprotein, however its precise function in GBM is not fully understood. Here, we analyzed in T98G cells of GBM, which express high levels of epidermal growth factor receptor (EGFR), the effect of stable RNAi-mediated knockdown of GOLPH3. We found that silencing GOLPH3 caused a significant reduction in the proliferation of T98G cells and an unexpected increase in total EGFR levels, even at the cell surface, which was however less prone to ligand-induced autophosphorylation. Furthermore, silencing GOLPH3 decreased EGFR sialylation and fucosylation, which correlated with delayed ligand-induced EGFR downregulation and its accumulation at endo-lysosomal compartments. Finally, we found that EGF failed at promoting EGFR ubiquitylation when the levels of GOLPH3 were reduced. Altogether, our results show that GOLPH3 in T98G cells regulates the endocytic trafficking and activation of EGFR likely by affecting its extent of glycosylation and ubiquitylation. 相似文献
6.
Production planning and control (PPC) systems that employ aspects from both make-to-order (MTO) and make-to-stock (MTS) production control are known as hybrid MTS/MTO systems. While both MTO and MTS separately have been studied extensively, their combined use has received less attention. However, the literature on this topic is growing and this paper shows that the review performed in this paper is an important addition to the field. We categorise relevant literature according to a novel taxonomy and show that hybrid MTS/MTO production control can be used in different contexts. In addition, an overview of the modelling techniques and methods used in these papers is provided. Based on the reviewed literature, relevant research questions and directions for future research are identified. Finally, it is shown that hybrid MTS/MTO production control is prevalent in practice by discussing research with industrial applications. The paper contains an overview of research on hybrid MTS/MTO production control to be used as reference for researchers active in the field, and provides managerial insights and directions for future research on this topic. 相似文献
7.
Bianca B.M. Keers Paul C. van Fenema 《International Journal of Project Management》2018,36(6):861-875
While sourcing by means of Public-Private Partnerships has been lauded over recent years, increasingly risks appear to jeopardise public organisations' unique societal tasks. Integrated Risk Management has not yet been applied to public organisations getting involved in PPP in the sense of understanding risk management capabilities. This article explores risk awareness and risk management practices underpinning maintenance partnership formation by means of a dual case study of two PPP projects and a short industry survey. The results suggest that organisations face several “intolerable risks” linked to project governance and project management responsibilities: insufficient representation of qualified employees, absence of a shared performance system, assignment of responsibilities and decision-making authority, impractical or inappropriate partnership agreement, and timing of the partnership initiative. Cross-case analysis revealed the role of different levels of risk awareness and senior management involvement. Drawing on these findings, a framework for risk management for PPP formation projects is developed. 相似文献
8.
Ronen Gottesman Angang Song Igal Levine Maximilian Krause A. T. M. Nazmul Islam Daniel Abou‐Ras Thomas Dittrich Roel van de Krol Abdelkrim Chemseddine 《Advanced functional materials》2020,30(21)
A new method for enhancing the charge separation and photo‐electrochemical stability of CuBi2O4 photoelectrodes by sequentially depositing Bi2O3 and CuO layers on fluorine‐doped tin oxide substrates with pulsed laser deposition (PLD), followed by rapid thermal processing (RTP), resulting in phase‐pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing of similar films for 72 h at 500 °C do not result in phase‐pure CuBi2O4. The combined PLD and RTP approach allow excellent control of the Bi:Cu stoichiometry and results in photoelectrodes with superior electronic properties compared to photoelectrodes fabricated through spray pyrolysis. The low photocurrents of the CuBi2O4 photocathodes fabricated through PLD/RTP in this study are primarily attributed to their low specific surface area, lack of CuO impurities, and limited, slow charge transport in the undoped films. Bare (without protection layers) CuBi2O4 photoelectrodes made with PLD/RTP shows a photocurrent decrease of only 26% after 5 h, which represents the highest stability reported to date for this material. The PLD/RTP fabrication approach offers new possibilities of fabricating complex metal oxides photoelectrodes with a high degree of crystallinity and good electronic properties at higher temperatures than the thermal stability of glass‐based transparent conductive substrates would allow. 相似文献
9.
10.
Event sequences and time series are widely recorded in many application domains; examples are stock market prices, electronic health records, server operation and performance logs. Common goals for recording are monitoring, root cause analysis and predictive analytics. Current analysis methods generally focus on the exploration of either event sequences or time series. However, deeper insights are gained by combining both. We present a visual analytics approach where users can explore both time series and event data simultaneously, combining visualization, automated methods and human interaction. We enable users to iteratively refine the visualization. Correlations between event sequences and time series can be found by means of an interactive algorithm, which also computes the presence of monotonic effects. We illustrate the effectiveness of our method by applying it to real world and synthetic data sets. 相似文献