全文获取类型
收费全文 | 771篇 |
免费 | 40篇 |
专业分类
电工技术 | 14篇 |
综合类 | 6篇 |
化学工业 | 251篇 |
金属工艺 | 6篇 |
机械仪表 | 40篇 |
建筑科学 | 21篇 |
能源动力 | 23篇 |
轻工业 | 90篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 33篇 |
一般工业技术 | 95篇 |
冶金工业 | 28篇 |
原子能技术 | 11篇 |
自动化技术 | 187篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 58篇 |
2021年 | 59篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 21篇 |
2017年 | 24篇 |
2016年 | 37篇 |
2015年 | 17篇 |
2014年 | 31篇 |
2013年 | 58篇 |
2012年 | 59篇 |
2011年 | 48篇 |
2010年 | 40篇 |
2009年 | 32篇 |
2008年 | 30篇 |
2007年 | 29篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 14篇 |
2003年 | 22篇 |
2002年 | 22篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 6篇 |
1997年 | 20篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有811条查询结果,搜索用时 15 毫秒
21.
Danilo Tardioli Luis Riazuelo Domenico Sicignano Carlos Rizzo Francisco Lera Jos L. Villarroel Luis Montano 《野外机器人技术杂志》2019,36(6):1074-1101
The work reported in this article describes the research advances and the lessons learned by the Robotics, Perception and Real‐Time group over a decade of research in the field of ground robotics in confined environments. This study has primarily focused on localization, navigation, and communications in tunnel‐like environments. As will be discussed, this type of environment presents several special characteristics that often make well‐established techniques fail. The aim is to share, in an open way, the experience, errors, and successes of this group with the robotics community so that those that work in such environments can avoid (some of) the errors made. At the very least, these findings can be readily taken into account when designing a solution, without needing to sift through the technical details found in the papers cited within this text. 相似文献
22.
Experimental exchange rates for Cl-/SO=4 exchange on strictly comparable anion resins in 0.006N solution confirm the unfavorable correlation between kinetics and selectivity.Furthermore, evaluation of the influence of other physico-chemical properties of the resins (i.e., nature of matrix, type of amine, etc) seems to support the hypothesis that chemical interactions, and not only diffusional effects, in the resin phase play a leading role on rate control. 相似文献
23.
Rishi Raj Luca Pederiva Masaki Narisawa Gian Domenico Soraru 《Journal of the American Ceramic Society》2019,102(3):924-929
Silicon-based polymers evolve into refractory ceramics when heated gradually up to ~1000°C. The conversion is accompanied by the loss of gaseous species, and by a two-fold increase in density. The shrinkage can produce microcracks if the heating rate is too high, or if the specimen is too thick. This communication builds on earlier work whereby the measurement of gas evolution, and its relationship with viscous flow, are related to the onset of fracture in disk-shaped green (polymer) samples. The onset is determined as a function of the thickness of the disks, and of the heating rate. The results are presented in the form of a processing map. The overlay with gas evolution, and strain-rate measurements, suggest that fracture initiates with the release of hydrogen and methane, starting at temperatures near 750°C. 相似文献
24.
Gian Domenico Sorarù Lakshminath Kundanati Balanand Santhosh Nicola Pugno 《Journal of the American Ceramic Society》2019,102(3):907-913
Silicon oxycarbide (SiOC) glasses in the form of thin, dense, and crack-free samples were fabricated according to the polymer pyrolysis route starting from cross-linked polysiloxane. The amount of free carbon in the final SiOC materials was varied in the range 18-60 vol%. The mechanical properties of the SiOC glasses were measured by nanoindentaion technique and revealed that both the Young's modulus and the hardness decrease with increase in the free carbon content and follow a simple rule of mixtures model. 相似文献
25.
Pietro Russo Giorgio Simeoli Domenico Acierno Valentina Lopresto 《Polymer Composites》2015,36(11):2022-2029
Polyolefin‐based composite laminates reinforced with jute fabric were prepared by compression molding and investigated in terms of flexural properties and impact behavior. The use of a virgin polypropylene as the matrix was compared with two polyolefin matrices coming from discarded car bumpers and selected packaging wastes, respectively, and mainly constituted by mixtures of polyethylene and polypropylene resins. The influence of a coupling agent (maleated polypropylene) was always considered in order to improve the interfacial adhesion and, consequently, the composite strength. The effect of this coupling agent, clearly dependent on the amount of polypropylene phase in the overall mixture, was found to be satisfactory only in the case of virgin polypropylene‐based systems. These latter, in presence of maleated polypropylene, have shown higher flexural parameters, lower propagation energy and higher breaking impact load with respect to uncompatibilized ones. Results were supported by morphological observations of impact surfaces, always highlighting a poor adhesion at the reinforcement–matrix interface except in compatibilized virgin polypropylene‐based laminates. POLYM. COMPOS., 36:2022–2029, 2015. © 2014 Society of Plastics Engineer 相似文献
26.
We show the results of an experimental campaign to study the pressure drop during the restart of a core-annular flow from a stratified configuration. In normal core annular flow operations, due to fouling or pump failures, a core flow may not be sustained anymore and hence it stratifies. Since the pressure drops connected to the stratified flow regime are much larger than the ones of core annular, the flow suddenly stops. To restart it there are two possibilities: one is to try to provide a higher pressure gradient trying to restore the flow of water and oil, the other is to clean the pipe using water only: in both cases an attachment of a thin layer of oil on the pipe internal wall occurs and the pressure drop for water only or oil–water are higher than the previous ones with clean pipe wall. We focused our attention on the cleaning by water only and we provide experimental data on the evolution of the pressure drop as function of time in order to find when the pipe could be considered as perfectly cleaned or, at least, when the pressure drop are low enough to restart the oil flow. The experimental results are finally compared with a two-fluid model available in literature. 相似文献
27.
Dr. Rosaria Ciriminna Dr. Alexandra Fidalgo Dr. Francesco Meneguzzo Dr. Alessandro Presentato Dr. Antonino Scurria Dr. Domenico Nuzzo Prof. Rosa Alduina Prof. Laura M. Ilharco Dr. Mario Pagliaro 《ChemMedChem》2020,15(23):2228-2235
First reported in the late 1930s and partly explained in 1970, the antibacterial activity of pectin remained almost ignored until the late 1990s. The concomitant emergence of research on natural antibacterials and new usages of pectin polysaccharides, including those in medicine widely researched in Russia, has led to a renaissance of research into the physiological properties of this uniquely versatile polysaccharide ubiquitous in plants and fruits. By collecting scattered information, this study provides an updated overview of the subtle factors affecting the behaviour of pectin as an antimicrobial. Less-degraded pectin extracted by acid-free routes, we argue in the conclusions, will soon find applications from new treatments for polymicrobial infections to use as an implantable biomaterial in tissue and bone engineering. 相似文献
28.
Dr. Jessica Ceramella Dr. Annaluisa Mariconda Dr. Camillo Rosano Dr. Domenico Iacopetta Dr. Anna Caruso Prof. Pasquale Longo Prof. Maria Stefania Sinicropi Prof. Carmela Saturnino 《ChemMedChem》2020,15(23):2306-2316
Cancer is going to be the first cause of mortality worldwide in the 21th century. It is considered a multifactorial disease that results from the combined influence of many genetic aberrations, leading to abnormal cell proliferation. As microtubules are strongly implicated in cellular growth, they represent an important target for cancer treatment. The well-known microtubule-targeting agents (MTAs) including paclitaxel, colchicine and vinca alkaloids are commonly used in the treatment of various cancers. However, adverse effects and drug resistance are major limitations in their clinical use. To find new candidates able to induce microtubule alteration with reduced toxic effects or drug resistance, we studied a small new series of derivatives that present imidazolinic, guanidinic, thioureidic and hydrazinic groups ( 1 – 9 ). All the compounds were tested for their antitumor activity against a panel of six tumoral cell models. In particular, compound 8 (nonane-1,9-diyl-bis-S-amidinothiourea dihydrobromide) showed the lowest IC50 value against HeLa cells, together with a low cytotoxicity for normal cells. This compound was able to induce the apoptotic mitochondrial pathway and inhibited tubulin polymerization with a similar efficacy to vinblastine and nocodazole. Taken together, these promising biological properties make compound 8 useful for the development of novel therapeutic approaches in cancer treatment. 相似文献
29.
Identification and estimation of outliers in time series is proposed by using empirical likelihood methods. Theory and applications are developed for stationary autoregressive models with outliers distinguished in the usual additive and innovation types. Some other useful outlier types are considered as well. A simulation experiment is used for studying the behaviour of the empirical likelihood‐based method in finite samples and indicates that the proposed methods are preferable when dealing with the non‐Gaussian data. Our simulations suggest that the usual sequential procedure for multiple outlier detection is suitable also for the methods based on empirical likelihood. 相似文献
30.
Yingwei Di Domenico Acierno Alberto D'Amore Rossella Nobile Luigi Nicolais 《应用聚合物科学杂志》1997,65(5):951-958
The capillary extrusion flow properties of novel engineering thermoplastic phenolphthalein poly(ether-ether-sulphone) (PES-C) have been investigated using capillary rheometer. The dependence of viscosity on the wall shear rate and temperatures were obtained. The flow activation energy was found to decrease with shear rate but to be constant with shear stress. The entrance effect was calculated and from which the extensional behavior was estimated using Cogswell's method. From the extrudate swell ratio the principal normal stress was evaluated and a temperature-independent correlation was observed when they were plotted against shear stress. The melt fracture phenomena were checked and discussed also. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:951–958, 1997 相似文献