全文获取类型
收费全文 | 985篇 |
免费 | 51篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 3篇 |
综合类 | 2篇 |
化学工业 | 343篇 |
金属工艺 | 12篇 |
机械仪表 | 11篇 |
建筑科学 | 51篇 |
能源动力 | 12篇 |
轻工业 | 202篇 |
水利工程 | 6篇 |
石油天然气 | 2篇 |
无线电 | 50篇 |
一般工业技术 | 153篇 |
冶金工业 | 58篇 |
原子能技术 | 4篇 |
自动化技术 | 129篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 43篇 |
2021年 | 42篇 |
2020年 | 38篇 |
2019年 | 18篇 |
2018年 | 29篇 |
2017年 | 26篇 |
2016年 | 31篇 |
2015年 | 31篇 |
2014年 | 42篇 |
2013年 | 72篇 |
2012年 | 64篇 |
2011年 | 70篇 |
2010年 | 63篇 |
2009年 | 60篇 |
2008年 | 56篇 |
2007年 | 54篇 |
2006年 | 46篇 |
2005年 | 49篇 |
2004年 | 33篇 |
2003年 | 21篇 |
2002年 | 22篇 |
2001年 | 11篇 |
2000年 | 22篇 |
1999年 | 12篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1934年 | 3篇 |
排序方式: 共有1038条查询结果,搜索用时 15 毫秒
61.
Igor V. Levkov Stephanie Cassel Zoia V. Voitenko Nathalie Saffon Armand Lattes Isabelle Rico-Lattes 《Journal of surfactants and detergents》2014,17(1):101-109
In this work, we present the synthesis of cationic surfactants based on 1-aminoisoindole. The physico-chemical properties were studied by conductometry, tensiometry, dynamic light scattering and transmission electron microscopy in water and in formamide. The reactivity of these novel surfactants has been studied at concentrations below and above critical aggregation concentrations (CAC) and it was found that reactions can proceed in structured media without the addition of other catalysts. 相似文献
62.
Steffen Vojacek Lukas Schulig Nathalie Wössner Norman Geist Prof. Dr. Walter Langel Prof. Dr. Manfred Jung Prof. Dr. Dennis Schade Prof. Dr. Andreas Link 《ChemMedChem》2019,14(8):853-864
Indoles are privileged structures in medicinal and bioorganic chemistry that are particularly well suited to serve as platforms for diversity. Among many other therapeutic areas, the indole scaffold has been used to design aromatic compounds useful to interfere with enzymes engaged in the regulation of substrate acylation status, such as sirtuins. However, the planarity of the indole ring is not necessarily optimal for all target enzymes, especially when functionalization with aromatic side chains is required. Replacement of flat scaffolds by nonplanar molecular cores dominated by sp3 hybridization is a common strategy to avoid the disadvantages associated with poor solubility and high promiscuity, while covering less-well-explored areas of chemical space. Thus, we synthesized fragment-like tetrahydroindoles suitable for fragment-based drug discovery as well as a well-characterized small library intended as multipurpose screening compounds. For proof of principle, these compounds were screened against sirtuins 1–3, enzymes known to be addressable by indoles. We found that 2,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamides are potent and selective SIRT2 inhibitors. Compound 16 t displayed an IC50 value of 0.98 μm and could serve as exquisite starting point for hit-to-lead profiling. 相似文献
63.
集装箱码头装卸作业的调度控制模型及算法设计 总被引:1,自引:0,他引:1
对集装箱码头上装卸作业的调度控制直接影响码头的整体运营效率.本文研究了集装箱码头装卸作业的调度控制问题,提出了一个基于柔性化flow shop的集成化控制模型.该问题具有非线性规划(NP:non- polynomial)难度,因此本文开发设计了两类基于优先级规则的启发式调度算法.利用该模型来对码头中多种装卸设备进行总体调度可以提高设备之间的协调性,提高码头效率,降低成本.实验研究证明算法能有效地解决该问题. 相似文献
64.
Gambling versus Designing: Organizing for the Design of the Probability Space in the Energy Sector 下载免费PDF全文
Sophie Hooge Olga Kokshagina Pascal Le Masson Kevin Levillain Benoit Weil Vincent Fabreguettes Nathalie Popiolek 《Creativity & Innovation Management》2016,25(4):464-483
The objective of this paper is to elucidate an organizational process for the design of generic technologies (GTs). While recognizing the success of GTs, the literature on innovation management generally describes their design according to evolutionary strategies featuring multiple and uncertain trials, resulting in the discovery of common features among multiple applications. This random walk depends on multiple market and technological uncertainties that are considered exogenous: as smart as he can be, the ‘gambler’ must play in a given probability space. However, what happens when the innovator is not a gambler but a designer, i.e., when the actor is able to establish new links between previously independent emerging markets and technologies? Formally speaking, the actor designs a new probability space. Building on a case study of two technological development programmes at the French Center for Atomic Energy, we present cases of GTs that correspond to this logic of designing the probability space, i.e. the logic of intentionally designing common features that bridge the gap between a priori heterogeneous applications and technologies. This study provides another example showing that the usual trial‐and‐learning strategy is not the only strategy to design GTs and that these technologies can be designed by intentionally building new interdependences between markets and technologies. Our main result is that building these interdependences requires organizational patterns that correspond to a ‘design of exploration’ phase in which multiple technology suppliers and application providers are involved in designing both the probability space itself and the instruments to explore and benefit from this new space. 相似文献
65.
Topology identification of complex networks is an important problem. Existing research shows that the synchronization of network nodes is an obstacle in the identification of network topology. Identification of the structure of the network presents an interesting challenge during the synchronization of complex networks. We developed a new method using the sinusoidal disturbance to identify the topology when the complex network achieves synchronization. Compared with the disturbance of all the nodes, the disturbance of the key nodes alone can achieve a very good effect. Finally, numerical simulation data are provided to validate our hypothesis. 相似文献
66.
Gilles Celeux Author VitaeFlorence ForbesAuthor Vitae Nathalie Peyrard Author Vitae 《Pattern recognition》2003,36(1):131-144
Image segmentation using Markov random fields involves parameter estimation in hidden Markov models for which the EM algorithm is widely used. In practice, difficulties arise due to the dependence structure in the models and approximations are required. Using ideas from the mean field approximation principle, we propose a class of EM-like algorithms in which the computation reduces to dealing with systems of independent variables. Within this class, the simulated field algorithm is a new stochastic algorithm which appears to be the most promising for its good performance and speed, on synthetic and real image experiments. 相似文献
67.
Bertrand Nathalie Konnov Igor Lazić Marijana Widder Josef 《International Journal on Software Tools for Technology Transfer (STTT)》2021,23(5):797-821
International Journal on Software Tools for Technology Transfer - Randomized fault-tolerant distributed algorithms pose a number of challenges for automated verification: (i) parameterization in... 相似文献
68.
We discuss how the standard Cost-Benefit Analysis should be modified in order to take risk (and uncertainty) into account. We propose different approaches used in finance (Value at Risk, Conditional Value at Risk, Downside Risk Measures, and Efficiency Ratio) as useful tools to model the impact of risk in project evaluation. After introducing the concepts, we show how they could be used in CBA and provide some simple examples to illustrate how such concepts can be applied to evaluate the desirability of a new project infrastructure. 相似文献
69.
Francillette Yannick Boucher Eric Bier Nathalie Lussier Maxime Bouchard Kévin Belchior Patricia Gaboury Sébastien 《User Modeling and User-Adapted Interaction》2020,30(5):895-947
User Modeling and User-Adapted Interaction - Intelligent environments may improve the independence and quality of life of persons with mild cognitive impairment (MCI) or Alzheimer’s disease... 相似文献
70.
In this article, an extension of the spatial filter method to study Fabry‐Perot antennas with homogeneous or inhomogeneous partially reflecting surface (PRS) of finite size is proposed. This tool was subsequently validated through the study of different Fabry‐Perot antennas, with homogeneous PRS and inhomogeneous GRadient‐INdex (GRIN) PRS that present very high side lobe level (SLL). Since they are due to structure truncation, a new inhomogeneous PRS to reduce the SLL is designed with the new analytical tool. The new inhomogeneous PRS for Fabry‐Perot antenna is characterized by simulations and measurements. Compared to the homogeneous PRS antenna, the proposed PRS allows a SLL reduction of 5 dB without decreasing the 14 dBi directivity. 相似文献