全文获取类型
收费全文 | 206篇 |
免费 | 2篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 42篇 |
金属工艺 | 4篇 |
机械仪表 | 15篇 |
建筑科学 | 1篇 |
能源动力 | 1篇 |
轻工业 | 9篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 37篇 |
冶金工业 | 46篇 |
原子能技术 | 2篇 |
自动化技术 | 29篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 2篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 19篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有208条查询结果,搜索用时 31 毫秒
11.
Sandor Balog Urs Gasser Kell Mortensen Hicham Ben youcef Lorenz Gubler Günther G. Scherer 《Polymer》2012,53(1):175-182
We report on correlations between the proton conductivity, the water swelling and the dry-state morphology of ETFE-g-poly(sulfonated styrene-co-DVB) proton-exchange membranes (PEMs). We focus on the influence of the systematically varied monomer composition. Especially, the impact of the DVB cross-linker on the ion-rich phase aggregated in the dry PEM is studied by small-angle X-ray scattering. A modified hard-sphere fluid model describing the ion-rich phase is applied to interpret the observed scattering function. We find hereby that the size and number density of the ion-rich domains decrease with increasing cross-link level. Consequently, the distance between the ion-rich domains is proportional to the cross-link level. The total volume fraction of water in the hydrated membrane is proportional to the overall volume fraction of the ion-rich phase, and the number of water molecules per ion-rich aggregate is inversely proportional to the level of cross-linking. We show that there is a clear correlation between the structure of the ion-rich phase formed in the dry state and the proton conductivity of the hydrated membrane: beyond a threshold, indicating the onset of percolation of the aqueous network, the conductivity is proportional to the hydration level and inversely proportional to the mean distance between the ion-rich domains. 相似文献
12.
Estelle Durantie Dimitri Vanhecke Laura Rodriguez-Lorenzo Flavien Delhaes Sandor Balog Dedy Septiadi Joel Bourquin Alke Petri-Fink Barbara Rothen-Rutishauser 《Particle and fibre toxicology》2017,14(1):49
Background
The lung represents the primary entry route for airborne particles into the human body. Most studies addressed possible adverse effects using single (nano)particles, but aerosolic nanoparticles (NPs) tend to aggregate and form structures of several hundreds nm in diameter, changing the physico-chemical properties and interaction with cells. Our aim was to investigate how aggregation might affect the biodistribution; cellular uptake and translocation over time of aerosolized NPs at the air-blood barrier interface using a multicellular lung system.Results
Model gold nanoparticles (AuNPs) were engineered and well characterized to compare single NPs with aggregated NPs with hydrodynamic diameter of 32 and 106 nm, respectively. Exposures were performed by aerosolization of the particles onto the air-liquid interface of a three dimensional (3D) lung model. Particle deposition, cellular uptake and translocation kinetics of single and aggregated AuNPs were determined for various concentrations, (30, 60, 150 and 300 ng/cm2) and time points (4, 24 and 48 h) using transmission electron microscopy and inductively coupled plasma optical emission spectroscopy. No apparent harmful effect for single and aggregated AuNPs was observed by lactate dehydrogenase assay, nor pro-inflammation response by tumor necrosis factor α assessment. The cell layer integrity was also not impaired. The bio-distribution revealed that majority of the AuNPs, single or aggregated, were inside the cells, and only a minor fraction, less than 5%, was found on the basolateral side. No significant difference was observed in the translocation rate. However, aggregated AuNPs showed a significantly faster cellular uptake than single AuNPs at the first time point, i.e. 4 h.Conclusions
Our studies revealed that aggregated AuNPs showed significantly faster cellular uptake than single AuNPs at the first time point, i.e. 4 h, but the uptake rate was similar at later time points. In addition, aggregation did not affect translocation rate across the lung barrier model since similar translocation rates were observed for single as well as aggregated AuNPs.13.
Sandor Kokenyesi Dezso L. Beke Kanatinkal S. Sangunni Viktor Takats Attila Csik Lajos Daroczi 《Journal of Materials Science: Materials in Electronics》2009,20(Z1):107-110
Photo-stimulated interdiffusion in a-Se/As2S3 amorphous chalcogenide nano-multilayers (ANML) is known as a useful method for amplitude-phase optical relief formation besides
the known amorphous–amorphous or amorphous–crystalline photo-induced structural transformations (PST) in homogeneous chalcogenide
layers, but it has a relatively narrow sensitivity spectral range and small amplitude modulation. Experimental evidences of
improvement of optical recording processes were obtained in Te-, Bi-, Sb-containing nano-layered structures based on As2S3 matrix. The influence of nano-structuring and combination of components on the sensitivity, type of the recorded relief is
discussed. 相似文献
14.
Sandor RL Bettelheim EC Swingland IR 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2002,360(1797):1607-1620
This paper describes the convergence of environmental and financial markets, reviews the evolution of market-based environmental programmes as an example of the seven-stage evolutionary process witnessed in a variety of markets and summarizes the emergence of greenhouse-gas-mitigation markets and their potential role in advancing land stewardship, biodiversity and other environmental services. Emissions trading has been developed to meet the demand to reduce pollution while avoiding economic disruption. Consistent with the seven-stage pattern of market evolution, the US programme to reduce the damage from acid rain established a standardized environmental commodity, developed 'evidence of ownership' necessary for financial instruments and provided the infrastructure to efficiently transfer title. The success of the system in reducing pollution at low cost has provided a model for other market-based environmental protection initiatives. The demand for cost-effective action to reduce the threat of climate change has initiated the same evolutionary process for markets to reduce greenhouse-gas emissions. Many of the land- and forest-management practices that can capture and store atmospheric CO(2) can also provide other environmental benefits, such as biodiversity preservation and enhanced water quality. The presence of a carbon-trading market will introduce a clear financial value for capture and mitigation of CO(2) emissions, thus introducing a new source of funding for land stewardship and forest rehabilitation. The market is now emerging through a variety of 'bottom-up' developments being undertaken through governmental, multilateral, private-sector and non-governmental-organization initiatives. The extension of markets to other emerging environmental issues is now underway, and the linkages between environmental sustainability and capital markets are being more deeply understood. The early evidence indicates that environmental sustainability can be compatible with maximization of shareholder value. 相似文献
15.
A joint compression-discrimination neural transformation applied to target detection. 总被引:1,自引:0,他引:1
Alex Lipchen Chan Sandor Z Der Nasser M Nasrabadi 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2005,35(4):670-681
Many image recognition algorithms based on data-learning perform dimensionality reduction before the actual learning and classification because the high dimensionality of raw imagery would require enormous training sets to achieve satisfactory performance. A potential problem with this approach is that most dimensionality reduction techniques, such as principal component analysis (PCA), seek to maximize the representation of data variation into a small number of PCA components, without considering interclass discriminability. This paper presents a neural-network-based transformation that simultaneously seeks to provide dimensionality reduction and a high degree of discriminability by combining together the learning mechanism of a neural-network-based PCA and a backpropagation learning algorithm. The joint discrimination-compression algorithm is applied to infrared imagery to detect military vehicles. 相似文献
16.
We present a general method using kernel canonical correlation analysis to learn a semantic representation to web images and their associated text. The semantic space provides a common representation and enables a comparison between the text and images. In the experiments, we look at two approaches of retrieving images based on only their content from a text query. We compare orthogonalization approaches against a standard cross-representation retrieval technique known as the generalized vector space model. 相似文献
17.
Vittorio Sgrigna Francesco Altamura Simone Ascani Roberto Battiston Raffaele Bencardino Sandor Blasko Aurora Buzzi Marco Casolino Livio Conti Stefano Lucidi Mauro Minori Andrea Papi Piergiorgio Picozza Stefano Rossi Carlo Stagni David Zilpimiani 《Microgravity science and technology》2007,19(5-6):70-74
EGLE is a wide frequency band search- coil magnetometer designed and built at the Roma Tre University. It has been installed onboard the ISS by the Italian astronaut Roberto Vittori on April 25, 2005 within the LAZIO- EGLE experiment carried out during the ENEIDE Soyuz mission. The scope of the experiment is to test EGLE in space and to investigate geomagnetic field variations. The main applications of EGLE are the study of electromagnetic environment inside the ISS, the correlation of magnetic field data with particle fluxes detected by LAZIO particle detector, and the monitoring of ionospheric perturbations possibly caused by Earth seismic activity. Since continuous electromagnetic field measurements on board the ISS are important for diverse space applications, a magnetometer with a suitable design is requested. Appropriate solutions for these applications, which have been adopted by EGLE, are in particular the use of 1- Wire technology and the possibility to detect by means of a search- coil magnetometer a large portion of the ULF frequency band, usually measured by flux- gate probes. To investigate the topside ionosphere electromagnetic environment and stability of Van Allen radiation belts in relation with seismic and anthropogenic electromagnetic emissions, a specific satellite mission (the ESPERIA project) has been designed for the Italian Space Agency (ASI), and up to now a few instruments of its payload have been built and tested in space. One of them is exactly the EGLE search- coil magnetometer. The first magnetic observations performed by this instrument reveal to be promising and demand for a further and deeper analysis based on a longer time series of data. 相似文献
18.
George N Sandor Research Professor Director E Raghavacharyulu Assistant Professor Arthur G Erdman Professor of Mechanical Engineering 《Mechanism and Machine Theory》1982,17(6):405-414
One of the pitfalls in current methods of acceleration analysis of planar mechanisms is the difficulty in identifying the different types of acceleration components such as the “sliding” acceleration and the Coriolis contribution. Furthermore, the latter is often missed by the analyst altogether which then leads to completely false results in dynamic analysis. Even distinguished authors have on the record actual numerical examples where the wrong angular velocity was used in computing the Coriolis component. The present article demonstrates the acceleration analysis of planar mechanisms using complex-number algebra. This technique, when programmed for digital computation using complex-arithmetic, or using hand calculation, provides the magnitude and direction of all the acceleration components, including the Coriolis term, automatically without resort to such crutches as a “rule of thumb” for determining whether or not the latter is present, “traditional sign conventions”, and without the risk of using the wrong angular velocity. The procedure, derived here, is illustrated by examples. 相似文献
19.
Toth Gergely; Murphy Richard F.; Lovas Sandor 《Protein engineering, design & selection : PEDS》2001,14(8):543-547
Weakly polar interactions between the side-chain aromatic ringsand hydrogens of backbone amides (ArHN) and CHn of aliphaticgroups ( 相似文献
20.