全文获取类型
收费全文 | 188篇 |
免费 | 10篇 |
学科分类
工业技术 | 198篇 |
出版年
2023年 | 3篇 |
2021年 | 15篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 8篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 14篇 |
2010年 | 15篇 |
2009年 | 12篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 12篇 |
2003年 | 4篇 |
2002年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1993年 | 5篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有198条查询结果,搜索用时 15 毫秒
81.
GAT: a Graphical Annotation Tool for semantic regions 总被引:1,自引:1,他引:0
Xavier Giro-i-Nieto Neus Camps Ferran Marques 《Multimedia Tools and Applications》2010,46(2-3):155-174
This article presents GAT, a Graphical Annotation Tool based on a region-based hierarchical representation of images. The proposed solution uses Partition Trees to navigate through the image segments which are automatically defined at different spatial scales. Moreover, the system focuses on the navigation through ontologies for a semantic annotation of objects and of the parts that compose them. The tool has been designed under usability criteria to minimize the user interaction by trying to predict the future selection of regions and semantic classes. The implementation uses MPEG-7/XML input and output data to allow interoperability with any type of Partition Tree. This tool is publicly available and its source code can be downloaded under a free software license. 相似文献
82.
The adsorption/desorption kinetics of adenine on Au(1 1 1) electrodes is studied by Electrochemical Impedance Spectroscopy (EIS) in 0.5 M NaF solutions at four adenine concentrations. The experimental procedure is designed in order to obtain impedance data unaffected by surface reconstruction on the entire potential region of adsorption. The frequency dispersion of the impedance at potentials of the adsorption region has been analysed according to the Frumkin-Melik-Gaykazyan adsorption theory without any “a priori” assumption about the potential dependence of the adsorption rate constant. The analysis provides the values of the adsorption capacitance, Cad, adsorption resistance, Rad and the Warburg coefficient, σad, at every potential, and from them the relaxations times τH and τD. A mixed adsorption-diffusion control has been detected and the specific rate constant of adsorption has been obtained in a wide potential region. 相似文献
83.
María Jos Mansilla Iigo Gonzlez-Larreategui Neus Figa-Martín Jaume Barallat Federico Fondelli Ares Sells-Rius Bibiana Quirant-Snchez Aina Teniente-Serra Eva Martínez-Cceres 《International journal of molecular sciences》2021,22(14)
The use of autologous tolerogenic dendritic cells (tolDC) has become a promising strategy to re-establish immune tolerance in autoimmune diseases. Among the different strategies available, the use of vitamin D3 for the generation of tolDC (VitD3-tolDC) has been widely tested because of their immune regulatory properties. To identify molecules and pathways involved in the generation of VitD3-tolDC, we established an easy and fast gene silencing method based on the use of Viromer blue to introduce siRNA into monocytes on day 1 of culture differentiation. The analysis of the effect of CD209 (DC-SIGN) and CD115 (CSF1R) down-modulation on the phenotype and functionality of transfected VitD3-tolDC revealed a partial role of CD115 in their tolerogenicity. Further investigations showed that CSF1R-CSF1 signaling is involved in the induction of cell metabolic reprogramming, triggering glycolysis to produce high amounts of lactate, a novel suppressive mechanism of T cell proliferation, recently found in autologous tolerogenic dendritic cells (ATDCs). 相似文献
84.
Marta Izquierdo Carmen Gabaldón Paula Marzal Feliu Sempere 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(2):165-172
BACKGROUND: The performance of peat for copper sorption was investigated in batch and fixed‐bed experiments. The effect of pH was evaluated in batch experiments and the experimental data were fitted to an equilibrium model including pH dependence. Hydrodynamic axial dispersion was estimated by tracing experiments using LiCl as a tracer. Six fixed‐bed experiments were carried out at copper concentrations between 1 and 60 mg dm?3 and the adsorption isotherm in dynamic mode was obtained. A mass transport model including convection–dispersion and sorption processes was applied for breakthrough curve modelling. RESULTS: Maximum uptake capacities in batch mode were 22.0, 36.4, and 43.7 mg g?1 for pH values of 4.0, 5.0, and 6.0, respectively. Uptake capacities in continuous flow systems varied from 36.5 to 43.4 mg g?1 for copper concentrations between 1 and 60 mg dm?3. Dynamic and batch isotherms showed different shapes but a similar maximum uptake capacity. Sorbent regeneration was successfully performed with HCl. A potential relationship between dispersion coefficient and velocity was obtained with dispersion coefficients between 5.00 × 10?8 and 2.95 × 10?6 m2 s?1 for water velocities ranging between 0.56 × 10?4 and 5.03 × 10?4 m s?1. The mass transport model predicted both the breakpoints and the shape of the breakthrough curves. CONCLUSIONS: High retention capacities indicate that peat can be used as an effective sorbent for the treatment of wastewater containing copper ions. Copyright © 2009 Society of Chemical Industry 相似文献
85.
AC chip calorimetry is used to study the phase separation behavior of 100 nm thin poly(vinyl methyl ether)/poly(styrene) (PVME/PS) blend films. Using the on-chip heaters, very short (10 ms-10 s) temperature jumps into the temperature window of phase separation are applied, simulating laser heating induced patterning. These temperature pulses produce a measurable shift in the glass transition temperature, evidencing phase separation. The effect of pulse length and height on phase separation can be studied. The thus phase separated PVME/PS thin films remix rapidly, in contrast with measurements in bulk. AC chip calorimetry seems to be a more sensitive technique than atomic force microscopy to detect the early stages of phase separation in polymer blend thin films. 相似文献
86.
Possibilities and problems of in situ techniques for measuring steel corrosion rates in large reinforced concrete structures 总被引:2,自引:0,他引:2
In situ measurements of steel corrosion rate in large reinforced concrete structures face difficulties of different types. The paper discusses some of the problems connected with the determination of the true value of the polarisation resistance from (i) the time constant value associated with the corrosion process, and (ii) the use of a guard ring for confining the electrical signal to a definite reinforcement area. In (i), results corroborate the assumption of a time constant value independent of the area affected by the electrical signal, albeit with some exceptions. In (ii), it is shown the great importance of achieving a critical ratio between the current intensities that flow from the guard ring and counter-electrode. 相似文献
87.
The availability of on-site methods of diagnosis of the deterioration rate in reinforced concrete structures is a pressing technical need all over the world. Two new methods are proposed in this paper which are derived from the polarization resistance method, but which, differing from this method, are applicable to full-size structures, in spite of the non-uniform distribution of the electric signals in them. The two proposed procedures are of a simplicity and reliability comparable with those offered by direct measurement of polarization resistance. 相似文献
88.
Hormeño S Bastús NG Pietsch A Weller H Arias-Gonzalez JR Juárez BH 《Nano letters》2011,11(11):4742-4747
Optical and hydrodynamic-size studies on single bare thermo-responsive microspheres, and microspheres covered either with Au nanoparticles, CdSe/CdS quantum dots, or a combination of both have been performed by optical tweezers. The photothermal heating of water in the focal region boosts the shrinkage of the microspheres, an effect that is intensified in the presence of Au nanoparticles. In contrast, bigger microspheres are measured when they are covered with quantum dots. Plasmon-exciton interactions are observable in the trap in the combined Au and quantum dots hybrid systems. 相似文献
89.
The effectiveness of the strain CPA-2 of Pantoea agglomerans alone or in combination with a curing treatment at 33 degrees C for 65 h to control green mold was evaluated on lemons stored at ambient temperature and in cold storage. An application of P. agglomerans at 2 x 10(8) CFU/ml effectively reduced green mold incidence on recently inoculated lemons stored at temperatures from 5 to 25 degrees C. Moreover, a 30-s immersion of lemons in a P. agglomerans suspension at 2 x 10(8) CFU/ml significantly reduced green mold incidence, even when delayed up to 15 h after inoculation with Penicillium digitatum at either 20 degrees C or while in cold storage. However, it failed to control established infections of P. digitatum of more than 24 h. Curing P. agglomerans-treated lemons at 33 degrees C for 65 h completely controlled 24-h-old infections on artificially inoculated lemons stored at 20 degrees C for 14 days and on naturally infected lemons stored at 10 degrees C for 3 weeks plus 7 additional days at 20 degrees C. When applied before curing, population growth of P. agglomerans in wounds was similar to that within wounds of control fruits at 20 degrees C. In contrast, when it was applied immediately after curing treatment, P. agglomerans populations within wounds did not increase. 相似文献
90.