全文获取类型
收费全文 | 898篇 |
免费 | 52篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 496篇 |
金属工艺 | 19篇 |
机械仪表 | 6篇 |
建筑科学 | 21篇 |
矿业工程 | 9篇 |
能源动力 | 32篇 |
轻工业 | 159篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 94篇 |
冶金工业 | 13篇 |
原子能技术 | 1篇 |
自动化技术 | 70篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 104篇 |
2021年 | 139篇 |
2020年 | 28篇 |
2019年 | 43篇 |
2018年 | 24篇 |
2017年 | 31篇 |
2016年 | 36篇 |
2015年 | 39篇 |
2014年 | 51篇 |
2013年 | 46篇 |
2012年 | 51篇 |
2011年 | 61篇 |
2010年 | 32篇 |
2009年 | 25篇 |
2008年 | 31篇 |
2007年 | 27篇 |
2006年 | 31篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 19篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有950条查询结果,搜索用时 15 毫秒
81.
The Impact of Zeta Potential and Physicochemical Properties of TiO2‐Based Nanocomposites on Their Biological Activity 下载免费PDF全文
Agnieszka Maria Jastrzębska Patrycja Kurtycz Andrzej Olszyna Ewa Karwowska Ewa Miaśkiewicz‐Pęska Monika Załęska‐Radziwiłł Nina Doskocz Dariusz Basiak 《International Journal of Applied Ceramic Technology》2015,12(6):1157-1173
The aim of this research was to observe the relationship between zeta potential, morphology, surface area, porosity, chemical composition, and ecotoxicity of nanocomposite powders such as Au/TiO2, Ag2O/TiO2, PdO/TiO2, Ag/TiO2/SiO2, Ag/N(C)TiO2, and SiO2/TiO2 from which Ag2O/TiO2, Ag/N(C)/TiO2, and Ag/TiO2/SiO2 were exhibiting good antimicrobial properties. It was observed, that nanomaterials characterized by similar morphology and zeta potential revealed the similar toxic behavior. The samples of higher agglomeration and higher zeta potential, especially Ag/TiO2/SiO2 xerogel and TiO2/SiO2 aerogel were generally less ecotoxic to water organisms and plants. They were also not genotoxic in concentrations up to 500 and 250 mg/L, respectively. 相似文献
82.
Nanoengineered biodegradable constructs based on synthetic and natural polymers enriched with hydroxyapatite (HA) nanoparticles have been found to mimic the extracellular matrix of bone tissue. The main objective of this study was to create biocomposite nanostructured scaffolds by incorporating collagen and HA nanoparticles into poly(L-lactic acid)-co-poly(?-caprolactone) by electrospinning. The fiber diameter of the composite PLCL/Col and PLCL/Col/HA fibers was smaller compared to PLCL. In vitro biocompatibility of the scaffolds studied using human fetal osteoblasts and EDX analysis showed high deposition of calcium on PLCL/Col/HA. The results shows that PLCL/Col/HA nanofibrous constructs have huge potential as substrates for bone regeneration. 相似文献
83.
Natalia Pawlik Barbara Szpikowska-Sroka Ewa Pietrasik Tomasz Goryczka Wojciech A. Pisarski 《中国稀土学报(英文版)》2019,37(11):1137-1144
In the present work,the transparent oxyfluoride glass-ceramic samples containing GdF_3:RE~(3+)(RE=Tb,Eu) nanocrystals(nGCs) were fabricated via controlled heat-treatment of precursor xerogels prepared using a sol-gel method.The formation of GdF_3 nanocrystalline phase from gadolinium(III) trifluoroacetate was verified based on XRD measurements.The average crystal sizes calculated from Scherrer formula were estimated to~10 nm as well as~6 nm for Tb~(3+)-and Eu~(3+)-doped samples,respectively.The optical behavior of prepared sol-gel samples was evaluated based on photoluminescence excitation(PLE) and emission spectra(PL) as well as luminescence decay analysis.Obtained samples exhibit the ~5D_4→~7F_J(J=6-3,Tb~(3+))and the ~5D_0→~7F_J(J=0-4,Eu~(3+)) emission bands recorded within the visible spectral area under excitation at near-UV(393 nm(Eu~(3+)),351,369,378 nm(Tb~(3+))) as well as middle-UV illumination(273 nm(Gd~(3+))).Additionally,based on recorded decay curves,the luminescence lifetimes(τ_m) for the ~5D_4(Tb3+) and the ~5D_0(Eu~(3+))excited states were also evaluated.In general,recorded luminescence spectra and double-exponential character of decay curves for nGCs indicate a successful migration of Tb~(3+) and Eu~(3+) dopant ions from amorphous silicate framework to lowphonon energy GdF_3 nanocrystal phase. 相似文献
84.
Beata Zielińska Ewa Borowiak-PalenBarbara Grzmil Ryszard J. Kalenczuk 《Journal of Alloys and Compounds》2011,509(17):5414-5419
Titanate nanorods with high photocatalytic activity was successfully synthesized through a simple catalyst-free hydrothermal method. The photocatalytic degradation of a model organic dye (Reactive Red 198) was accelerated by the calcination of the nanorods prior the reaction. The calcination of nanorods did not modify their morphology, however the crystallinity of the samples was significantly improved. Therefore, the quality of the samples is a key parameter determining their activity in the investigated photocatalytic process. The as-produced and annealed catalysts were characterized by high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Diffuse Reflectance (DR) UV-Vis and resonance Raman spectroscopy. 相似文献
85.
The effect of different cooking times on the GLS content in white cabbage (Brassica oleracea L. var. capitata f. alba) was determined. Cooking of cabbage for 5-30 min caused a gradual decrease in the GLS content. The most efficient reduction of the GLS content (by about 35%) occurred during the first minutes of cooking. As the cooking time was extended by another 5 min, each time the GLS content decreased by 10-15%. Higher losses in indole GLS, as compared to those of aliphatic ones, resulted from more efficient diffusion of those compounds to cooking water. The GLS content in cooking water, irrespective of the cooking time of white cabbage, remained rather stable, whereas the content of indole GLS was between 3.5- and 4-fold higher in comparison to that of aliphatic GLS. Taking into consideration the rate of changes in the content of particular GLS in cabbage and the GLS content in cooking water, it can be stated that glucoiberin was more thermolabile than other GLS. 相似文献
86.
Ewa Jakubczyk Ewa Ostrowska‐Ligeza Ewa Gondek 《International Journal of Food Science & Technology》2010,45(12):2515-2523
The aim of this study was to characterise the influence of different foam‐mat‐drying methods on the moisture sorption characteristics and glass transition temperatures of apple puree powder. Apple puree was foamed with the addition of 2.5% egg albumin and 0.5% methylcellulose. Convective air‐drying and microwave‐drying techniques were used. Also foamed puree with and without maltodextrin (6% or 15% w/w) was freeze‐dried. Moisture equilibrium data of powders were determined by using a static desiccator method in a water activity range of 0.0–0.903. Modulated differential scanning calorimetry (MDSC) was used to obtain the glass transition temperature. No effect of drying method on sorption properties and glass transition temperatures of apple puree powders was observed. The addition of maltodextrin to the apple puree caused an increase in Tg by 10–30 °C depending on the amount of incorporated additive. Addition of maltodextrin significantly reduced the hygroscopicity of apple puree powders. 相似文献
87.
Ryszard Siuda Andrzej Grabowski Leszek Lenc Maria Ralcewicz Ewa Spychaj‐Fabisiak 《International Journal of Food Science & Technology》2010,45(12):2596-2604
The paper aims to enlarge the current knowledge about the dependence of technological traits of wheat grain on its degree of infestation (DI) with fusariosis. Samples of grain of four wheat cultivars were obtained from naturally grown crops (control) and from crops inoculated with Fusarium culmorum from which three degrees of kernel infestation were selected. Samples were determined for thousand kernels weight (TKW), total protein, starch and wet gluten (WG) contents, Hagberg falling number (HFN) and sedimentation value (SV). Content of protein and wet gluten showed higher values for moderately infested kernels (up to 15 and 25%, respectively, when compared to control grain) than for kernels lightly or heavily infested. All the remaining traits had values lower than that for control grain and showed a decrease with increasing DI. Decrease for the heaviest infestation was on average: 8, 29, 31 and 34% for starch, TKW, HFN and SV, respectively. 相似文献
88.
The influence of thermal treatment, pickling and fermentation on the content of glucobrassicin and its selected breakdown products in broccoli and cauliflower was investigated. The highest content of glucobrassicin and the lowest content of its breakdown products were found in vegetables which underwent thermal treatment such as boiling and steam cooking. The lowest content of glucobrassicin and the highest content of its breakdown products were present in raw, pickled and fermented vegetables in which the myrosinase remained active. Ascrobigen was the major glucobrassicin breakdown product and its content was negatively correlated with glucobrassicin content in broccoli and cauliflower. After heating of vegetables in 60 °C for 20 min (causing thermal deactivation of epithiospecific protein) no presence of indole-3-acetonitrile was found. 相似文献
89.
Study of self-stratifying compositions 总被引:2,自引:0,他引:2
Helena Kuczyńska Ewa Langer Elżbieta Kamińska-Tarnawska Dmitry A. Kulikov Eugene A. Indeikin 《Journal of Coatings Technology and Research》2009,6(3):345-352
Paint applied as a single layer, and its spontaneous separation to form a primer and a top coat, is one of the newest concepts
of the effective and economical application of two layers in one step. The influence of the molecular weight of epoxy oligomer
and acrylic polymer and their ratio on self-stratification was investigated. The degree of stratification depending on molecular
weight and their mutual ratio was determined using ATR-FTIR spectroscopy, differential scanning calorimetry, microscopy techniques,
adhesion tests, and surface tension measurements. Phase separation and self-stratification of two-component homogenous mixtures
were followed using FTIR technique and surface tension measurements. As a result of these investigations, optimal oligomeric/polymeric
composition was selected. The obtained coating system showed good mechanical properties, gloss, and interlayer adhesion. 相似文献
90.
The peroxide-initiated copolymerisation of an unsaturated polyester with zinc acrylate, diallyl phthalate prepolymer and a solid vinyl ester resin was investigated. The curing was followed by means of gelation curves and differential scanning calorimetry. The studies showed that zinc acrylate has the highest reactivity. 相似文献