全文获取类型
收费全文 | 267篇 |
免费 | 6篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 41篇 |
金属工艺 | 18篇 |
机械仪表 | 2篇 |
建筑科学 | 3篇 |
能源动力 | 2篇 |
轻工业 | 39篇 |
水利工程 | 7篇 |
石油天然气 | 1篇 |
无线电 | 21篇 |
一般工业技术 | 50篇 |
冶金工业 | 62篇 |
原子能技术 | 4篇 |
自动化技术 | 21篇 |
出版年
2023年 | 3篇 |
2022年 | 9篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 18篇 |
2012年 | 20篇 |
2011年 | 13篇 |
2010年 | 17篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 17篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有273条查询结果,搜索用时 15 毫秒
1.
A Lanza S Tornaletti C Rodolfo MC Scanavini AM Pedrini 《Canadian Metallurgical Quarterly》1996,271(12):6978-6986
DNA topoisomerases have been proposed as the proteins involved in the formation of the DNA-protein cross-links detected after ultraviolet light (UV) irradiation of cellular DNA. This possibility has been investigated by studying the effects of UV-induced DNA damage on human DNA topoisomerase I action. UV lesions impaired the enzyme's ability to relax negatively supercoiled DNA. Decreased relaxation activity correlated with the stimulation of cleavable complexes. Accumulation of cleavable complexes resulted from blockage of the rejoining step of the cleavage-religation reaction. Mapping of cleavage sites on the pAT153 genome indicated UV-induced cleavage at discrete positions corresponding to sites stimulated also by the topoisomerase I inhibitor camptothecin, except for one. Subsequent analysis at nucleotide level within the sequence encompassing the UV-specific cleavage site revealed the precise positions of sites stimulated by camptothecin with respect to those specific for UV irradiation. Interestingly, one of the UV-stimulated cleavage sites was formed within a sequence that did not contain dimerized pyrimidines, suggesting transmission of the distortion, caused by photodamage to DNA, into the neighboring sequences. These results support the proposal that DNA structural alterations induced by UV lesions can be sufficient stimulus to induce cross-linking of topoisomerase I to cellular DNA. 相似文献
2.
3.
Modeling guided wave propagation with application to the long-range defect detection in railroad tracks 总被引:2,自引:0,他引:2
Ivan Bartoli Francesco Lanza di Scalea Mahmood Fateh Erasmo Viola 《NDT & E International》2005,38(5):325-334
The aim of this work is to demonstrate the use of a commercial finite element package, ABAQUS EXPLICIT, to model ultrasonic guided waves in structural components. The particular application of interest is modeling the interaction of a broadband vertical bending mode with transverse-type defects in railroad tracks. This topic is part of a broader project on high-speed defect detection in rails by long-range ultrasonic inspections. Reflection coefficient spectra in the 20–45 kHz range are obtained for four different sizes and three different orientations of transverse head flaws. A preliminary study of Lamb waves in a free plate helps drawing modeling guidelines for the rail. 相似文献
4.
M. F. Stroosnijder N. Zheng W. J. Quadakkers R. Hofman A. Gil F. Lanza 《Oxidation of Metals》1996,46(1-2):19-35
The effect of niobium implantation (2×1016 and 1017 ions/cm2) on the oxidation behavior of a -TiAl-based intermetallic alloy Ti–48Al–2Cr in air at 800°C has been examined. Isothermal studies with exposure times up to 200 hr and cyclic-oxidation tests up to 800 hr revealed a negligible effect for the low implantation dose. However, a remarkable decrease in oxidation rates was observed for the material implanted with 1017 Nb ions/cm2. The improvement in the oxidation resistance appeared to be similar to that obtained by alloying of the intermetallic with a few atomic percent niobium. Possible mechanisms for the effect of niobium on the oxidation resistance of TiAl-base intermetallics are discussed in view of the results obtained for the implanted material. 相似文献
5.
The objectives of this study are to provide detailed information about green roof performance in the Mediterranean climate (retained volume, peak flow reduction, runoff delay) and to identify a suitable modelling approach for describing the associated hydrologic response. Data collected during a 13-month monitoring campaign and a seasonal monitoring campaign (September-December 2008) at the green roof experimental site of the University of Genova (Italy) are presented together with results obtained in quantifying the green roof hydrologic performance. In order to examine the green roof hydrologic response, the SWMS_2D model, that solves the Richards' equation for two-dimensional saturated-unsaturated water flow, has been implemented. Modelling results confirm the suitability of the SWMS_2D model to properly describe the hydrologic response of the green roofs. The model adequately reproduces the hydrographs; furthermore, the predicted soil water content profile generally matches the observed values along a vertical profile where measurements are available. 相似文献
6.
Wurster Marco Michel Marius May Marvin Carl Kuhnle Andreas Stricker Nicole Lanza Gisela 《Journal of Intelligent Manufacturing》2022,33(2):575-591
Journal of Intelligent Manufacturing - Remanufacturing includes disassembly and reassembly of used products to save natural resources and reduce emissions. While assembly is widely understood in... 相似文献
7.
Metrics are essential in object-oriented software engineering for several reasons, among which quality assessment and improvement of development team productivity. While the mathematical nature of metrics calls for clear definitions, frequently there exist many contradicting definitions of the same metric depending on the implementation language. We suggest to express and define metrics using a language-independent metamodel based on graphs. This graph-based approach allows for an unambiguous definition of generic object-oriented metrics and higher-order metrics. We also report on some prototype tools that implement these ideas.We thank Kim Mens, Roel Wuyts and the anonymous reviewers for their comments on drafts of this paper. 相似文献
8.
Abstract The main topic of this paper is the nondestructive inspection of adhesively bonded lap joints by using ultrasonic guided (plate) waves. A noncontact, couplant-free method that employs capacitive air-coupled transducers is demonstrated for the inspection of thin aluminum joints with dimensions typical of aircraft fuselage and wing panels. Two types of bond defects, disbonded regions and regions of poorly cured (low-cohesive-strength) adhesive, are successfully detected by measuring the amplitude decrease of selected plate waves leaking from one adherend to the other one through the bondline. It is shown that proper choice of the vibrating mode structure, in terms of cross-sectional displacement distributions, is needed in order to maximize the sensitivity of the inspection to the presence of the low-cohesive-strength bond. Results from a dynamic photoelasticity study are also presented to visualize fundamental behavior of propagating plate waves and study their interaction with bond defects in glass lap joints. The photoelastic results confirm in a clear, pictorial manner certain assumptions on plate wave leakage through the bond, including the influence of vibrating mode structure on the detection of low-strength bonds. 相似文献
9.
10.
Piero Portincasa Leonilde Bonfrate Mirco Vacca Maria De Angelis Ilaria Farella Elisa Lanza Mohamad Khalil David Q.-H. Wang Markus Sperandio Agostino Di Ciaula 《International journal of molecular sciences》2022,23(3)
Gut microbiota encompasses a wide variety of commensal microorganisms consisting of trillions of bacteria, fungi, and viruses. This microbial population coexists in symbiosis with the host, and related metabolites have profound effects on human health. In this respect, gut microbiota plays a pivotal role in the regulation of metabolic, endocrine, and immune functions. Bacterial metabolites include the short chain fatty acids (SCFAs) acetate (C2), propionate (C3), and butyrate (C4), which are the most abundant SCFAs in the human body and the most abundant anions in the colon. SCFAs are made from fermentation of dietary fiber and resistant starch in the gut. They modulate several metabolic pathways and are involved in obesity, insulin resistance, and type 2 diabetes. Thus, diet might influence gut microbiota composition and activity, SCFAs production, and metabolic effects. In this narrative review, we discuss the relevant research focusing on the relationship between gut microbiota, SCFAs, and glucose metabolism. 相似文献