全文获取类型
收费全文 | 1171篇 |
免费 | 57篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 22篇 |
化学工业 | 296篇 |
金属工艺 | 18篇 |
机械仪表 | 31篇 |
建筑科学 | 28篇 |
矿业工程 | 2篇 |
能源动力 | 42篇 |
轻工业 | 186篇 |
水利工程 | 8篇 |
石油天然气 | 6篇 |
无线电 | 80篇 |
一般工业技术 | 157篇 |
冶金工业 | 165篇 |
原子能技术 | 12篇 |
自动化技术 | 176篇 |
出版年
2023年 | 7篇 |
2022年 | 24篇 |
2021年 | 65篇 |
2020年 | 26篇 |
2019年 | 37篇 |
2018年 | 26篇 |
2017年 | 35篇 |
2016年 | 31篇 |
2015年 | 38篇 |
2014年 | 43篇 |
2013年 | 83篇 |
2012年 | 64篇 |
2011年 | 79篇 |
2010年 | 48篇 |
2009年 | 59篇 |
2008年 | 59篇 |
2007年 | 50篇 |
2006年 | 41篇 |
2005年 | 33篇 |
2004年 | 32篇 |
2003年 | 21篇 |
2002年 | 22篇 |
2001年 | 26篇 |
2000年 | 21篇 |
1999年 | 14篇 |
1998年 | 65篇 |
1997年 | 32篇 |
1996年 | 33篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1960年 | 2篇 |
排序方式: 共有1229条查询结果,搜索用时 125 毫秒
1.
Elise Laszlo Gregory De Crescenzo Alfonso Nieto-Argüello Xavier Banquy Davide Brambilla 《Advanced functional materials》2021,31(46):2106061
The noninvasive sampling of dermal interstitial fluid (ISF) for the monitoring of clinical biomarkers is a greatly appealing area of research. The identification of molecular biomarkers in biological fluids has been accelerated with -omics analyses but remains limited in ISF because of its time-consuming and complex extraction process. Here, the generation of microneedle (MN) patches made of superabsorbent acrylate-based hydrogels for the rapid sampling of dermal ISF is described to explore its proteome. In depth, iterative optimization allows the identification of novel acrylate-based compositions with the required chemical, mechanical, and biocompatibility properties allowing proteomic analysis of the extracted ISF for the first time after sampling with swelling MNs. The generated MN arrays show no cytotoxic effect, successfully cross the stratum corneum, and can collect up to 6 µL of dermal ISF in 10 min in vivo. Proteomics lead to the detection of 176 clinically relevant biomarkers in the collected samples validating the use of ISF as a relevant bodily fluid for disease monitoring and diagnostic. Importantly, it is discovered that extraction fingerprint is strongly dependent on the MNs chemistry, and thus specific biomarkers could be selectively extracted by tuning the composition of the patch, making the system versatile and specific. 相似文献
2.
Simone Grassi Oscar Campuzano Mnica Coll Francesca Cazzato Georgia Sarquella-Brugada Riccardo Rossi Vincenzo Arena Josep Brugada Ramon Brugada Antonio Oliva 《International journal of molecular sciences》2021,22(8)
Inherited cardiomyopathies are frequent causes of sudden cardiac death (SCD), especially in young patients. Despite at the autopsy they usually have distinctive microscopic and/or macroscopic diagnostic features, their phenotypes may be mild or ambiguous, possibly leading to misdiagnoses or missed diagnoses. In this review, the main differential diagnoses of hypertrophic cardiomyopathy (e.g., athlete’s heart, idiopathic left ventricular hypertrophy), arrhythmogenic cardiomyopathy (e.g., adipositas cordis, myocarditis) and dilated cardiomyopathy (e.g., acquired forms of dilated cardiomyopathy, left ventricular noncompaction) are discussed. Moreover, the diagnostic issues in SCD victims affected by phenotype-negative hypertrophic cardiomyopathy and the relationship between myocardial bridging and hypertrophic cardiomyopathy are analyzed. Finally, the applications/limits of virtopsy and post-mortem genetic testing in this field are discussed, with particular attention to the issues related to the assessment of the significance of the genetic variants. 相似文献
3.
Alfonso Martín-Bernab Josep Tarrag-Celada Valrie Cunin Sylvie Michelland Roldn Corts Johann Poignant Cyril Boyault Walid Rachidi Sandrine Bourgoin-Voillard Marta Cascante Michel Seve 《International journal of molecular sciences》2021,22(7)
Growing evidence is showing that acetylation plays an essential role in cancer, but studies on the impact of KDAC inhibition (KDACi) on the metabolic profile are still in their infancy. Here, we analyzed, by using an iTRAQ-based quantitative proteomics approach, the changes in the proteome of KRAS-mutated non-small cell lung cancer (NSCLC) A549 cells in response to trichostatin-A (TSA) and nicotinamide (NAM) under normoxia and hypoxia. Part of this response was further validated by molecular and biochemical analyses and correlated with the proliferation rates, apoptotic cell death, and activation of ROS scavenging mechanisms in opposition to the ROS production. Despite the differences among the KDAC inhibitors, up-regulation of glycolysis, TCA cycle, oxidative phosphorylation and fatty acid synthesis emerged as a common metabolic response underlying KDACi. We also observed that some of the KDACi effects at metabolic levels are enhanced under hypoxia. Furthermore, we used a drug repositioning machine learning approach to list candidate metabolic therapeutic agents for KRAS mutated NSCLC. Together, these results allow us to better understand the metabolic regulations underlying KDACi in NSCLC, taking into account the microenvironment of tumors related to hypoxia, and bring new insights for the future rational design of new therapies. 相似文献
4.
The Optically-Coupled Current-Mirror (OCCM) is a novel feedback circuit architecture that allows linear transmission of analog signals via optical fibers. Its most distinctive feature is that the input stage is galvanically isolated and passive, as it consists just on the back-to-back connection of a LED and a photodiode. Only those components are required to be in close contact with the detector, and no power supply is required to be brought to the input stage. All active components are located at a safe distance, therefore saving them from being exposed to radiation, as it is common in most experiments at particle accelerators. We have investigated the properties of the OCCM when its passive input stage is cooled to cryogenic temperatures. Results have been extremely interesting as, for instance, the sharp increase in open-loop gain observed when cooling to 77 K, due to an enhanced LED efficiency. This translates into a higher dynamic range and still better linearity, opening new opportunities for the transmission of current signals generated in cryogenic detectors. 相似文献
5.
Maria E. Amato Antonio Grassi Kenny B. Lipkowitz Giuseppe M. Lombardo Giuseppe C. Pappalardo Claudia Sadun 《Journal of Inorganic and Organometallic Polymers and Materials》1996,6(3):237-253
Suitable parameter sets for the CHARMm force field were derived for the structural units in polychlorophosphazene [P=N, P N, P Cl] using the Dinur Hagler energy second derivative procedure based on quantum mechanical SCI calculations using the 6–31G* basis set. To validate the reliability of the parameter set, structural results obtained with CHARMm for the adopted model compounds (OP2NCl5 and OP3N2Cl5) were compared with those derived fromab initio quantum mechanics using the 6–31G* basis set. Application of molecular dynamics (MD) simulations in combinatioin with the available X-ray diffraction data provided structural and conformational information on the polymer. The calculation made using the periodic boundary conditions (PBC) agree well with the polychlorophosphazene ordered in a monoclinic unit cell (a=5.98,b=12.99,c=4.92 A; β=111.7). This model was stabilized mainly by the image atoms contribution to the electrostatic energy term and had aquasi-planar conformation of the backbone chain (glide symmetry). The MD calculations also provided evidence that the difference between single and double PN bonds is less marked than that measured experimentally. This result is, however, in agreement with more recent and accurate X-ray studies on poly(methylphosphazene). Validation of the polymer model provided a complete picture, otherwise experimentally inaccessible, of the internal fluctuations of the polymeric chains. 相似文献
6.
W Fries SA Grassi L Leone D Giacomin F Galeazzi R Naccarato A Martin 《Canadian Metallurgical Quarterly》1995,30(12):1221-1223
BACKGROUND: Common etiopathogenic factors may explain the association of systemic sarcoidosis with inflammatory bowel disease. METHODS: We report two cases of such an association: one of sarcoidosis that developed 2 years after proctocolectomy for ulcerative colitis and one of sarcoidosis and Crohn's colitis. Factors like increased cellular immunity or circulating immunocomplexes or autoantibodies may have a role. Exogenous agents or familiarity may also be involved. CONCLUSIONS: It is postulated that the association between sarcoidosis and inflammatory bowel disease (both ulcerative colitis and Crohn's disease) does not occur by chance alone and that the two conditions may share some genetic or immunologic alterations. The two diseases, however, follow an independent clinical course. 相似文献
7.
Sebastián Bruque-Cámara Alfonso Vargas-Sánchez M. Jesús Hernández-Ortiz 《欧洲信息系统杂志》2004,13(2):133-146
The aim of this paper is to propose new organizational factors that might explain the differences in the extent and the speed of IT adoption. With this in mind, we carried out an analysis of 16 cases in the pharmaceutical distribution sector in Spain. The results indicate that there are certain intangible assets that favour the introduction and development of IT. Among these are a frank and fluid communication between departments and members of the organization, low levels of conflict, the explicit support of top management towards IT adoption and learning and creative skills of IT-staff. In addition to these factors, we found others that we propose as catalysts of IT adoption. Among these we might mention the special relationship between the member-clients and the company in the case of cooperative firms. 相似文献
8.
Gradient-corrected density functional theory was used to investigate the adsorption of H2S on Pd(1 1 1) surface. Molecular adsorption was found to be stable with H2S binding preferentially at top sites. In addition, the adsorption of other S moieties (SH and S) was investigated. SH and S were found to be preferentially bind at the bridge and fcc sites, respectively. The reaction pathways and energy profiles for H2S decomposition giving rise to adsorbed S and H were determined. Both H2S(ad) → SH(ad) + H(ad) and SH(ad) → S(ad) + H(ad) reactions were found to have low barriers and high exothermicities. This reveals that the decomposition of H2S on Pd(1 1 1) surface is a facile process. 相似文献
9.
10.
Costa Albert; Kovacic Damir; Fedorenko Evelina; Caramazza Alfonso 《Canadian Metallurgical Quarterly》2003,29(6):1270
The authors report 3 picture-word interference experiments in which they explore some properties of the agreement process in speech production. In Experiment 1, Croatian speakers were asked to produce utterances in which the noun's gender value had an impact on the selection of gender-marked freestanding morphemes (pronouns) while ignoring the presentation of same- or different-gender distractor words. In Experiments 2 and 3, Croatian speakers were asked to name the same pictures using noun phrases in which the noun's gender value surfaced as an inflectional suffix. Different-gender distractors interfered more than same-gender distractors (the gender congruency effect) in Experiment 1, but not in Experiments 2 and 3. These contrasting results show that the cause of the gender congruency effect is not at the level where lexical-grammatical information is selected but at the level of selection of freestanding morphemes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献