全文获取类型
收费全文 | 208篇 |
免费 | 9篇 |
学科分类
工业技术 | 217篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 16篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 8篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 9篇 |
1997年 | 16篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1991年 | 1篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有217条查询结果,搜索用时 15 毫秒
1.
Sante Camo 《Canadian Metallurgical Quarterly》2003,8(5):297-311
Cable reliability analysis involves the combined evaluation of cable capacity and cable load in a probabilistic manner. Assessment of cable capacity is only possible through visual inspections of the wires, field sampling, laboratory analysis of the degraded wire populations, and analytical techniques. In addition to a brief presentation of cable mechanics and deterministic models that approximate cable strength, this paper discusses inspection methodologies and statistical methods of estimation of the sizes of the degraded wire populations, and wire properties, leading to cable capacities. These capacities are described by probability distributions. The paper also discusses fundamentals of reliability analysis as they apply to bridge cables. Load criteria of present standard specifications (such as AASHTO or other international codes) are not applicable to long-span suspension bridges. The paper discusses criteria of bridge loading and reliability indices for bridge cables. More work is needed in the evaluation of loading for long-span bridges. 相似文献
2.
Sueva Cantalupo Vito Alessandro Lasorsa Roberta Russo Immacolata Andolfo Giuseppe DAlterio Barbara Eleni Rosato Giulia Frisso Pasquale Abete Gian Marco Cassese Giuseppe Servillo Ivan Gentile Carmelo Piscopo Matteo Della Monica Giuseppe Fiorentino Giuseppe Russo Pellegrino Cerino Carlo Buonerba Biancamaria Pierri Massimo Zollo Achille Iolascon Mario Capasso 《International journal of molecular sciences》2021,22(10)
Genome-wide association studies (GWAS) found locus 3p21.31 associated with severe COVID-19. CCR5 resides at the same locus and, given its known biological role in other infection diseases, we investigated if common noncoding and rare coding variants, affecting CCR5, can predispose to severe COVID-19. We combined single nucleotide polymorphisms (SNPs) that met the suggestive significance level (P ≤ 1 × 10−5) at the 3p21.31 locus in public GWAS datasets (6406 COVID-19 hospitalized patients and 902,088 controls) with gene expression data from 208 lung tissues, Hi-C, and Chip-seq data. Through whole exome sequencing (WES), we explored rare coding variants in 147 severe COVID-19 patients. We identified three SNPs (rs9845542, rs12639314, and rs35951367) associated with severe COVID-19 whose risk alleles correlated with low CCR5 expression in lung tissues. The rs35951367 resided in a CTFC binding site that interacts with CCR5 gene in lung tissues and was confirmed to be associated with severe COVID-19 in two independent datasets. We also identified a rare coding variant (rs34418657) associated with the risk of developing severe COVID-19. Our results suggest a biological role of CCR5 in the progression of COVID-19 as common and rare genetic variants can increase the risk of developing severe COVID-19 by affecting the functions of CCR5. 相似文献
3.
S. De Rosa F. FrancoD. Capasso S. Costagliola 《Mechanical Systems and Signal Processing》2011,25(4):1192-1203
This work is aimed at the numerical analysis of the vibration response of a plate, carrying one or more concentrated masses, under a stochastic, and convective load. The pressure load is a typical turbulent boundary layer excitation (TBL) and the structural configurations reproduce common experimental situations because the concentrated masses can be considered similar to accelerometer sensors.The models adopt the Corcos TBL model and the concentrated masses are simulated with the Dirac singularity function. The approximations, introduced with the above assumptions on the concentrated masses, and the necessary numerical accuracy, in calculating the structural responses, are discussed.The added masses do not lead to a relevant modification of the global structural response but, on the contrary, the results show that the local effects can be relevant: the paper highlights the differences of the vibration responses from the analogous structural configurations under a stochastic load without convective characteristics. 相似文献
4.
5.
Simple calculation in the high field regime show that ballistic motion is competitive with intervalley scattering processes in determining electron dynamics in GaAs along the 〈100〉 and 〈110〉 orientations. On the other hand, in the 〈111〉 orientation, the dynamics of electrons are controlled primarily by intervalley phonon scattering. These considerations, and the different threshold conditions for the three orientations are used to explain why significant orientational effects and related band structure dependent phenomena can be observed in GaAs avalanche diodes. 相似文献
6.
Sonnenfroh DM Rawlins WT Allen MG Gmachl C Capasso F Hutchinson AL Sivco DL Baillargeon JN Cho AY 《Applied optics》2001,40(6):812-820
Distributed-feedback quantum-cascade (QC) lasers are expected to form the heart of the next-generation mid-IR laser absorption spectrometers, especially as they are applied to measurements of trace gases in a variety of environments. The incorporation of room-temperature-operable, single-mode QC lasers should result in highly compact and rugged sensors for real-world applications. We report preliminary results on the performance of a laser absorption spectrometer that uses a QC laser operating at room temperature in a quasi-cw mode in conjunction with balanced ratiometric detection. We have demonstrated sensitivities for N(2)O [10 parts in 10(6) volume-mixing ratio for a 1-m path (ppmv-m)] and NO [520 parts in 10(9) volume-mixing ratio for a 1-m path (ppbv-m)] at 5.4 mum. System improvements are described that are expected to result in a 2 orders of magnitude increase in sensitivity. 相似文献
7.
Ozcan A. Cubukcu E. Bilenca A. Bouma B.E. Capasso F. Tearney G.J. 《IEEE journal of selected topics in quantum electronics》2007,13(6):1721-1729
In this paper, we introduce a new aperture-type near-Held scanning optical microscopy (NSOM) imaging concept that relies on specially designed large-area (e.g. >200 nm times 200 nm) aperture geometries having sharp corners. Unlike in conventional NSOM, the spatial resolution of this near-field imaging modality is not determined by the size of the aperture, but rather by the sharpness of the corners of the large aperture. This approach significantly improves the light throughput of the near-field probe and, hence, increases the SNR. Here, we discuss the basic concepts of this near-field microscopy approach and illustrate both theoretically and experimentally how an array of detectors can be utilized to further improve the SNR of the near-field image. The results of this work are particularly relevant for imaging of biological samples at a spatial resolution of < 50 nm with significantly improved image quality. 相似文献
8.
Palmieri GF Cantalamessa F Di Martino P Nasuti C Martelli S 《Drug development and industrial pharmacy》2002,28(10):1241-1250
Solid dispersions of lonidamine in PEG 4000 and PVP K 29/32 were prepared by the spray-drying method. Then, the binary systems were studied and characterized using differential scanning calorimetry, hot stage microscopy, and x-ray diffractometry. In vitro dissolution studies of the solid dispersed powders were performed to verify if any lonidamine dissolution rate or water solubility improvement occurred. In vivo tests were carried out on the solid dispersions and on the cyclodextrin inclusion complexes to verify if this lonidamine water solubility increase was really able to improve the in vivo drug plasma levels. Drug water solubility was increased by the solid dispersion formation, and the extent of increase depended on the polymer content of the powder. The greater increase of solubility corresponded to the highest content of polymer. Both the solid dispersions and the cyclodextrin complexes were able to improve the in vivo bioavailability of the lonidamine when administered per os. Particularly, the AUC of the drug plasma levels was increased from 1.5 to 1.9-fold depending on the type of carrier. 相似文献
9.
Giovanni Filippo Palmieri Depalmo Galli-Angeli Gaetana Giovannucci Sante Martelli 《Drug development and industrial pharmacy》1997,23(1):27-37
Interactions between methoxybutropate and β-cyclodextrin or hydroxypropyl β-cyclodextrin and the possibility of obtaining inclusion complexes have been evaluated by phase solubility diagram, HPLC, DSC, and x-ray diffractometry. Solid inclusion complexes were prepared by spray drying, kneading, and solid dispersion. The dissolution profiles of the obtained powders were studied in order to define the most appropriate cyclodextrin preparation method and molar ratio to use in the production of methoxybutropate inclusion complexes 相似文献
10.