全文获取类型
收费全文 | 551篇 |
免费 | 33篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 172篇 |
金属工艺 | 8篇 |
机械仪表 | 11篇 |
建筑科学 | 22篇 |
矿业工程 | 1篇 |
能源动力 | 27篇 |
轻工业 | 106篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 36篇 |
一般工业技术 | 92篇 |
冶金工业 | 29篇 |
原子能技术 | 5篇 |
自动化技术 | 71篇 |
出版年
2023年 | 11篇 |
2022年 | 44篇 |
2021年 | 55篇 |
2020年 | 30篇 |
2019年 | 22篇 |
2018年 | 27篇 |
2017年 | 18篇 |
2016年 | 19篇 |
2015年 | 22篇 |
2014年 | 22篇 |
2013年 | 41篇 |
2012年 | 25篇 |
2011年 | 35篇 |
2010年 | 27篇 |
2009年 | 18篇 |
2008年 | 29篇 |
2007年 | 20篇 |
2006年 | 14篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1998年 | 4篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1947年 | 1篇 |
排序方式: 共有590条查询结果,搜索用时 0 毫秒
151.
Gloria Huerta-Ángeles Kateřina Knotková Petr Knotek Ondrej Židek Martina Brandejsová Marek Pokorný Hana Vagnerová Ipsita Roy Vladimir Velebný 《Journal of materials science. Materials in medicine》2018,29(3):32
In this work, a hybrid copolymer consisting of poly(3-hydroxybutyrate) grafted to hyaluronic acid (HA) was synthesised and characterised. Once formed, the P(3HB)-g-HA copolymer was soluble in water allowing a green electrospinning process. The diameters of nanofibres can be tailored by simply varying the Mw of polymer. The optimization of the process allowed to produce fibres of average diameter in the range of 100–150?nm and low polydispersity. The hydrophobic modification has not only increased the fibre diameter, but also the obtained layers were homogenous. At the nanoscale, the hybrid copolymer exhibited an unusual hairy topography. Moreover, the hardness and tensile properties of the hybrid were found to be superior compared to fibres made of unmodified HA. Particularly, this reinforcement was achieved at the longitudinal direction. Additionally, this work reports the use in the composition of a water-soluble copolymer containing photo cross-linkable moieties to produce insoluble materials post-electrospinning. The derivatives as well as their nanofibrous mats retain the biocompatibility of the natural polymers used for the fabrication. 相似文献
152.
Cyclic torsion (twisting in a forward clockwise direction followed by twisting in the reverse direction) of high purity Al
wires under the simultaneous application of a small tensile load (P) was found to increase the torsional ductility considerably. The number of twists in each direction (N) varied between 5 and 50 andP ranged between 0.1 and 0.78 kg mm−2. The average shear strain
increased considerably asN and/orP decreased. Specimens with a fine grain size showed higher ductility than those with a coarse grain size. By suitable combination
ofN, P and grain size,
exceeding 3000%, indicating superplastic behaviour, was obtained. The accompanying electrical resistivity changes were small
and did not exceed 1%. The results are discussed in terms of recovery mechanisms and possible dislocation interactions occurring
during this complex mode of deformation. 相似文献
153.
Diop Lamine Samadianfard Saeed Bodian Ansoumana Yaseen Zaher Mundher Ghorbani Mohammad Ali Salimi Hana 《Water Resources Management》2020,34(2):733-746
Water Resources Management - Rainfall, as one of the key components of hydrological cycle, plays an undeniable role for accurate modelling of other hydrological components. Therefore, a precise... 相似文献
154.
Hana Sehadova Radka Zavodska Lenka Rouhova Michal Zurovec Ivo Sauman 《International journal of molecular sciences》2021,22(24)
Filippi’s glands (FGs), formerly also called Lyonet’s glands, are accessory secretory structures of the labial (silk) glands of lepidopteran caterpillars, which were implicated to play an important role in the maturation of the silk material and the construction of the cocoon. In our previous study, we have identified several species of giant silk moths that completely lack the FGs. Interestingly, the absence of FGs in these species correlates with the construction of a loose cocoon architecture. We investigated the functions of FGs by their surgical extirpation in the last instar larvae of the silkworm, Bombyx mori. We found that the absence of FGs altered the structure of the resulting cocoon, in which the different layers of silk were separated. In further experiments, we found no effects of the absence of FGs on larval cocoon formation behavior or on changes in cocoon mass or lipid content. Differential proteomic analysis revealed no significant contribution of structural proteins from FGs to silk cocoon material, but we identified several low abundance proteins that may play a role in posttranslational modifications of some silk proteins. Proteomic analysis also revealed a difference in phosphorylation of the N-terminal sequence of fibroin-heavy chain molecule. Thus, FGs appear to affect silk stickiness during spinning by regulating posttranslational modifications. This could also explain the link that exists between the absence of these glands and the formation of loose cocoons in some giant silk moth species. 相似文献
155.
Neamul H. Khansur Udo Eckstein Matej Sadl Hana Ursic Kyle G. Webber 《Journal of the American Ceramic Society》2020,103(1):43-47
A novel technique for the rapid room-temperature deposition of porous ceramic, glass, or metal thick films using the aerosol deposition (AD) method is presented. The process is based on the co-deposition of the desired film material and a second water-soluble constituent, resulting in a ceramic-ceramic composite. Following the subsequent removal of water-soluble end member, a network of pores is retained. To demonstrate the process, porous BaTiO3 thick films were fabricated through co-deposition with NaCl. Microstructural images show the clear development of a porous structure, which was found to enhance the dielectric properties over dense thick films, possibly related to the lower extent of internal residual stress. This simple but highly effective porous structure fabrication can be applied to any film and substrate material stable in water and is promising for the application of AD-processed films in gas sensors, solid oxide fuel cells, and humidity sensors. 相似文献
156.
Dispersing agents are used during the manufacture of disperse dyes to ensure standard dyeing properties. Polymeric dispersing agents have advantages over classical dispersants in that they are are colourless and easily degraded and do not have to be present in such large quantities. Redispersibility is a potential problem and we have therefore investigated the redispersibility of CI Disperse Red 60 (pure colorant) achieved with classical and polymeric dispersants. We have developed a calculation procedure that will provide some basis characteristics of the studied system and make it possible to choose the composition of mixture of components used for preparation of disperse dye at which the relative coefficient of redispersibility (Kr) is optimised. We found that the Krof dye prepared with classical dispersants was 10–40 while that of dye prepared with polymeric dispersant was 0.05–7.0. 相似文献
157.
Marian Rupert Anirban Bhattacharya Vendula Tvrdonova Stillerova Marie Jindrichova Audrey Mokdad Eric Bou-Grabot Hana Zemkova 《International journal of molecular sciences》2020,21(22)
Activation of the P2X7 receptor results in the opening of a large pore that plays a role in immune responses, apoptosis, and many other physiological and pathological processes. Here, we investigated the role of conserved and unique residues in the extracellular vestibule connecting the agonist-binding domain with the transmembrane domain of rat P2X7 receptor. We found that all residues that are conserved among the P2X receptor subtypes respond to alanine mutagenesis with an inhibition (Y51, Q52, and G323) or a significant decrease (K49, G326, K327, and F328) of 2′,3′-O-(benzoyl-4-benzoyl)-ATP (BzATP)-induced current and permeability to ethidium bromide, while the nonconserved residue (F322), which is also present in P2X4 receptor, responds with a 10-fold higher sensitivity to BzATP, much slower deactivation kinetics, and a higher propensity to form the large dye-permeable pore. We examined the membrane expression of conserved mutants and found that Y51, Q52, G323, and F328 play a role in the trafficking of the receptor to the plasma membrane, while K49 controls receptor responsiveness to agonists. Finally, we studied the importance of the physicochemical properties of these residues and observed that the K49R, F322Y, F322W, and F322L mutants significantly reversed the receptor function, indicating that positively charged and large hydrophobic residues are important at positions 49 and 322, respectively. These results show that clusters of conserved residues above the transmembrane domain 1 (K49–Y51–Q52) and transmembrane domain 2 (G326–K327–F328) are important for receptor structure, membrane expression, and channel gating and that the nonconserved residue (F322) at the top of the extracellular vestibule is involved in hydrophobic inter-subunit interaction which stabilizes the closed state of the P2X7 receptor channel. 相似文献
158.
Hana Mtnkov Gilles Mailhot Jaromír Jirkovský Josef Krýsa Michle Bolte 《Applied catalysis. B, Environmental》2005,57(4):257-265
Kinetics of oxidative photodegradation of Monuron (3-(4-chlorophenyl)-1,1-dimethylurea) in different photocatalytic systems (iron, TiO2 and combined system iron + TiO2) were investigated and compared. The influence of iron addition on TiO2 photocatalyst and of TiO2 on the photocatalytic cycle Fe(III)/Fe(II) were carefully studied. A very positive effect of iron addition was observed. This phenomenon was more and more pronounced when TiO2 concentration was lower. In a suspension of TiO2 (24 mg L−1) with addition of Fe(III) (3 × 10−4 mol L−1) the measured rate constant was similar to that obtained in a suspension of TiO2 with a concentration more than 20 times higher (500 mg L−1). The mechanistic approach carried out in this study allows us to identify the main reactions governing the combined system and a photochemical cycle was proposed. The optimisation of the photocatalytic systems was obtained when each photocatalyst plays a specific role: Fe(III) as a main OH radicals source and TiO2 as an oxidizing agent of Fe(II). 相似文献
159.
Dora Hrestak Mario Matijai Hana ip
i Paljetak Daniela Ledi Drvar Suzana Ljubojevi Hadavdi Mihaela Peri 《International journal of molecular sciences》2022,23(7)
The skin microbiota represents an ecosystem composed of numerous microbial species interacting with each other, as well as with host epithelial and immune cells. The microbiota provides health benefits to the host by supporting essential functions of the skin and inhibiting colonization with pathogens. However, the disturbance of the microbial balance can result in dysbiosis and promote skin diseases, such as atopic dermatitis (AD). This review provides a current overview of the skin microbiota involvement in AD and its complex interplay with host immune response mechanisms, as well as novel therapeutic strategies for treating AD focused on restoring skin microbial homeostasis. 相似文献
160.
S. Souentie A. Hammad S. Brosda G. Foti C. G. Vayenas 《Journal of Applied Electrochemistry》2008,38(8):1159-1170
The reduction of NO by C2H4 in high excess of O2 and temperatures 200−300 °C was investigated using a monolithic electropromoted reactor (MEPR) with twenty-two Rh/YSZ/Pt
parallel plate elements. It was found that at 220–240 °C and 10% O2 the selective catalytic reduction (SCR) of NO can be electropromoted by 450% with near 100% selectivity to N2 and ΛNO values up to 2.4. The corresponding rate enhancement ratio of complete C2H4 oxidation is up to 900% with Faradaic efficiency,
, values up to 350. The system appears promising for practical applications. 相似文献