全文获取类型
收费全文 | 265篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 106篇 |
金属工艺 | 7篇 |
机械仪表 | 3篇 |
建筑科学 | 7篇 |
轻工业 | 14篇 |
水利工程 | 6篇 |
石油天然气 | 3篇 |
无线电 | 18篇 |
一般工业技术 | 58篇 |
冶金工业 | 5篇 |
原子能技术 | 2篇 |
自动化技术 | 46篇 |
出版年
2023年 | 6篇 |
2022年 | 26篇 |
2021年 | 23篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 20篇 |
2017年 | 29篇 |
2016年 | 22篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 27篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1987年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有276条查询结果,搜索用时 15 毫秒
61.
The authors present a suite to assist in the creation of musical pieces, whose foundation lies on fractals, fuzzy logic and expert systems. Even though algorithmic music has been explored, some gaps still exist. The favored approach has consisted in mapping numbers to notes to create appealing pieces. This, we contend, is a necessary but not a sufficient condition. Our suite, besides the necessary mapping, possesses the following advantages. First, it is possible to define notes, tempos, and notes durations. Notes evolve according to the selected fractal. Tempos and durations can remain fixed or they also can follow a fractal. Second, it is possible to translate the resultant fractal notes into notes belonging to a musical scale. This is done by firing appropriate rules in a rule base. Third, interpretation templates are provided. Also, melodies or harmonies are available. The suite currently contains several known fractal systems, and we also proposed one dynamical, recursive computation based on Mamdani fuzzy rule bases. The suite we present helps promoting and monitoring the creative process of composing musical scores. The actual implementation of the suite was done on the Java language. 相似文献
62.
Ioana Stefan Pia Hurmelinna-Laukkanen Wim Vanhaverbeke 《International Journal of Project Management》2021,39(2):139-153
This study aims to elevate the current understanding of value creation and value capture tensions that emerge in open innovation projects and of their potential solutions. In contrast with prior studies that often suggest specific solutions to individual tensions, our study takes an integrative approach by considering complex (bundles of) tensions and potential solutions to these. The study employs qualitative methods and builds on interview data from six case companies and a group of expert informants. We investigate unfolding events from the point when value creation – value capture tensions are identified in open innovation projects, to the search for their solutions. We label such sequences of unfolding events as trajectories. Our findings reveal two types of trajectories: resolution paths, which are trajectories from initial tensions to solutions, and tension loops, where initial tensions persist and/or new tensions emerge after solutions are enforced. We analyze a total of 17 trajectories, of which seven are marked as resolution paths, and ten represent tension loops. For the majority of the tension loops in our data (eight out of ten) the tensions remain unresolved. We further categorize the types of tensions and discuss the implications of our results for researchers and practitioners. 相似文献
63.
Sagana Thamboo Adrian Najer Andrea Belluati Claudio von Planta Dalin Wu Ioana Craciun Wolfgang Meier Cornelia G. Palivan 《Advanced functional materials》2019,29(40)
Subcellular compartmentalization of cells, a defining characteristic of eukaryotes, is fundamental for the fine tuning of internal processes and the responding to external stimuli. Reproducing and controlling such compartmentalized hierarchical organization, responsiveness, and communication is important toward understanding biological systems and applying them to smart materials. Herein, a cellular signal transduction strategy (triggered release from subcompartments) is leveraged to develop responsive, purely artificial, polymeric multicompartment assemblies. Incorporation of responsive nanoparticles—loaded with enzymatic substrate or ion channels—as subcompartments inside micrometer‐sized polymeric vesicles (polymersomes) allowed to conduct bioinspired signaling cascades. Response of these subcompartments to an externally added stimulus is achieved and studied by using confocal laser scanning microscopy (CLSM) coupled with in situ fluorescence correlation spectroscopy (FCS). Signal triggered activity of an enzymatic reaction is demonstrated in multicompartments through recombination of compartmentalized substrate and enzyme. In parallel, a two‐step signaling cascade is achieved by triggering the recruitment of ion channels from inner subcompartments to the vesicles' membrane, inducing ion permeability, mimicking endosome‐mediated insertion of internally stored channels. This design shows remarkable versatility, robustness, and controllability, demonstrating that multicompartment polymer‐based assemblies offer an ideal scaffold for the development of complex cell‐inspired responsive systems for applications in biosensing, catalysis, and medicine. 相似文献
64.
Gabriela Elena Dumitran Liana Ioana Vuta 《Simulation Modelling Practice and Theory》2011,19(4):1235-1242
In the actual economical and ecological context the rehabilitation of aquatic ecosystems represents one of the most important concerns all over the world. The physical, chemical and biological processes that take place inside a lake are very complex. A simple analysis of the field data is not enough. Even if those dates offers an appreciation of the global functioning of the ecosystem under the influence of certain factors, it does not allow to predict the system evolution, the optimization of the water arrangement, in order to respect and to assure the water quality criteria or to propose solutions for diminishing the lakes eutrophication.In the recent years, Lake Izvorul Muntelui, which is the largest artificial lake on the interior waters of Romania, experienced eutrophication problems. This paper analyzes the apparition condition, its effects onto water quality in the lake and the solutions for the rehabilitation of the ecosystem. Since systematic measured data are not available for this ecosystem, the mathematical modelling it is used.The simulation is done by considering the ecosystem dynamic and the stipulation of the spatial and temporal variation domains for the natural processes to appear and act onto perturbation factors to modify the ecological succession.Thus, different scenarios will be created allowing us to offer solutions for the eutrophication phenomenon and, in the same time, to identify solutions for the rehabilitation of the Izvorul Muntelui Lake. 相似文献
65.
Adriana Grozav Luiza Ioana G?in? Valentina Pileczki Ovidiu Crisan Luminita Silaghi-Dumitrescu Bruno Therrien Valentin Zaharia Ioana Berindan-Neagoe 《International journal of molecular sciences》2014,15(12):22059-22072
New and known arylidene-hydrazinyl-thiazole derivatives have been synthesized by a convenient Hantzsch condensation. All compounds were evaluated for their in vitro cytotoxicity on two carcinoma cell lines, MDA-MB231 and HeLa. Significant antiproliferative activity for 2-(2-benzyliden-hydrazinyl)-4-methylthiazole on both MDA-MB-231 (IC50: 3.92 µg/mL) and HeLa (IC50: 11.4 µg/mL) cell lines, and for 2-[2-(4-methoxybenzylidene) hydrazinyl]-4-phenylthiazole on HeLa (IC50: 11.1 µg/mL) cell line is reported. Electrophoresis experiments showed no plasmid DNA (pTZ57R) cleavage in the presence of the investigated thiazoles. 相似文献
66.
Zhang J.J. Papandreou-Suppappola A. Gottin B. Ioana C. 《Signal Processing, IEEE Transactions on》2009,57(8):2973-2985
We investigate a frequency-domain characterization of shallow water environments based on normal-mode models of acoustic mediums. The shallow water environment can be considered as a time-dispersive system whose time-varying impulse response can be expressed as a superposition of time-frequency components with dispersive characteristics. After studying the dispersive characteristics, a blind time-frequency processing technique is employed to separate the normal-mode components without knowledge of the environment parameters. This technique is based on first approximating the time-frequency structure of the received signal and then designing time-frequency separation filters based on warping techniques. Following this method, we develop two types of receivers to exploit the diversity inherent in the shallow water environment model and to improve underwater communication performance. Numerical results demonstrate the dispersive system characterization and the improved processing performance of the receiver structures. 相似文献
67.
Ben van Berkel Caroline Bos Astrid Piber Hannes Pfau Markus van Aalderen Juliane Maier Marc Salemink Andreas Bogenschuetz Marina Bozukova Brendon Carlin Miklos Deri Gary Freedman Juergen Heinzel Alexander Hugo Abhijit Kapade Marcin Koltunski Fernie Lai James Leng Tom Minderhoud Peter Moerland Rudi Nieveen Hans-Peter Nuenning Hyunil Oh Steffen Riegas Rikjan Scholten Ioana Sulea Christian Veddeler Rein Werkhoven Georg Willheim 《城市环境设计》2010,(1):36-39
杭州Raffles城发展坐落于浙江省省会杭州市的钱塘江边,是嘉德置地继新加坡、上海、北京、成都和巴林之后的第六栋,将零售店、办公楼、住户和酒店设施融于一体,成为新城区的文化地标。 相似文献
68.
Cornu C. Stankovic S. Ioana C. Quinquis A. Stankovic L. 《Signal Processing, IEEE Transactions on》2007,55(10):4831-4838
This paper introduces a new generalized complex-lag moment which produces joint time-"phase derivatives" distributions. For the choice of the time-"first-order phase derivative," which stands for time-frequency representation, this distribution can be seen as a form of the Wigner-Ville distribution. Moreover, this generalization leads to distributions with highly reduced inner interferences caused by the nonlinearity of the signal's phase. It can also be seen as a polynomial distribution since the Nth-order distribution produces no inner interferences for polynomial phase law of order N. Implementation of these distributions is addressed. The results are illustrated by examples. 相似文献
69.
70.
Ioana Fechete Philippe Caullet Emil Dumitriu Vasile Hulea Henri Kessler 《Applied Catalysis A: General》2005,280(2):245-254
(Al,Ga)EMT-type zeolites (Al:Ga = 1:0, 0.75:0.25 and 0.5:0.5) were prepared and tested as catalysts in the gas-phase toluene–methanol alkylation and toluene–trimethylbenzene transalkylation. Various techniques including XRD, N2 sorption, MAS NMR and SEM were used to monitor the physico-chemical properties of these solids. The results revealed a high purity and crystallinity of the materials, and that the Ga atoms are entirely incorporated into the framework. The ammonia TPD measurements indicated that the isomorphous substitution of aluminium by gallium leads to a decrease of both acidic strength and acid sites concentration. The catalytic performances of the EMT-type solids in the conversion of methylaromatic hydrocarbons were correlated with their acid properties. Thus, the less acidic (Al,Ga)EMT samples exhibited a lower activity, but a higher selectivity towards the xylenes formation by comparison with (Al)EMT. 相似文献