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101.
Nanostructure development in polystyrene‐b‐polybutadiene‐b‐poly(methyl methacrylate) (SBM) thin films by atomic force microscopy: Effect of copolymer composition and solvent 下载免费PDF全文
Loli Martin Lourdes Irusta Alba González Agnieszka Tercjak Galder Kortaberria 《Polymer Engineering and Science》2018,58(3):422-429
Surface morphology development for SBM triblock copolymer thin films has been studied by atomic force microscopy. The effect of copolymer composition and solvent on the final morphology has been investigated. Obtained results indicated that depending on the block ratio (symmetric or asymmetric with minority middle block) and solvent, lamellar, hexagonal, cylindrical, or spheres in lamellae (ls)‐type morphologies can be achieved at film surfaces. The influence of the interaction parameters among blocks and solvents and cohesive energy values of block pairs on the final morphology has been proved. POLYM. ENG. SCI., 58:422–429, 2018. © 2017 Society of Plastics Engineers 相似文献
102.
L. M. Apátiga F. Alba V. M. Castaño R. Vera-Graziano E. Saldaña 《Journal of Materials Science: Materials in Electronics》1996,7(6):381-383
Contact angle studies of pure water droplets were carried out on thin diamond films. The films were deposited on a fresh Si 111 wafer by plasma assisted chemical vapour deposition (PACVD) and confirmed to be diamond by Raman spectroscopy and scanning electron microscopy. Advancing and receding contact angles were measured as a function of droplet volume by using different incident wavelengths: red, green and violet. Large differences in the contact angles were observed, depending on the wavelength of the incident light. These differences are usually related to the existence of illumination-induced surface charges or electromagnetically active inhomogeneities in the diamond films. The results show that this technique is sufficiently sensitive to correlate changes in the contact angle with changes in the wavelength used. 相似文献
103.
Enrique Chirivella-Perez Ricardo Marco-Alaez Alba Hita Ana Serrano Jose M. Alcaraz Calero Qi Wang Pedro M. Neves Giacomo Bernini Konstantinos Koutsopoulos Manuel Gil Pérez Gregorio Martínez Pérez Maria João Barros Anastasius Gavras 《Software》2020,50(5):741-756
This paper presents the design and prototype implementation of the SELFNET fifth-generation (5G) mobile edge infrastructure. In line with the current and emerging 5G architectural principles, visions, and standards, the proposed infrastructure is established primarily based on a mobile edge computing paradigm. It leverages cloud computing, software-defined networking, and network function virtualization as core enabling technologies. Several technical solutions and options have been analyzed. As a result, a novel portable 5G infrastructure testbed has been prototyped to enable the preliminary testing of the integrated key technologies and to provide a realistic execution platform for further investigating and evaluating software-defined networking– and network function virtualization–based application scenarios in 5G networks. 相似文献
104.
Nowadays, it is common to find research problems (in system biology, mobile applications, etc.) that change over time, requiring algorithms which dynamically adapt the search to the new conditions. In most of them, the utilization of some information from the past allows to quickly adapt after a change. This is the idea underlining the use of memory in this field, what involves key design issues concerning the memory content, the process of update, and the process of retrieval. In this article, we focus on global memory schemes, which are the most intuitive and popular ones, and perform an integral analysis of current design variants based on a comprehensive set of benchmarks. Results show the benefits and drawbacks of each strategy, as well as the effect of the algorithm and problem features in the memory performance. 相似文献
105.
Optimisation in changing environments is a challenging research topic since many real-world problems are inherently dynamic. Inspired by the natural evolution process, evolutionary algorithms (EAs) are among the most successful and promising approaches that have addressed dynamic optimisation problems. However, managing the exploration/exploitation trade-off in EAs is still a prevalent issue, and this is due to the difficulties associated with the control and measurement of such a behaviour. The proposal of this paper is to achieve a balance between exploration and exploitation in an explicit manner. The idea is to use two equally sized populations: the first one performs exploration while the second one is responsible for exploitation. These tasks are alternated from one generation to the next one in a regular pattern, so as to obtain a balanced search engine. Besides, we reinforce the ability of our algorithm to quickly adapt after cnhanges by means of a memory of past solutions. Such a combination aims to restrain the premature convergence, to broaden the search area, and to speed up the optimisation. We show through computational experiments, and based on a series of dynamic problems and many performance measures, that our approach improves the performance of EAs and outperforms competing algorithms. 相似文献
106.
A series of designed peptides has been analyzed by 1H-NMR spectroscopy in order to investigate the influence of cross-strand side-chain interactions in beta-hairpin formation. The peptides differ in the N-terminal residues of a previously designed linear decapeptide that folds in aqueous solution into two interconverting beta-hairpin conformations, one with a type I turn (beta-hairpin 4:4) and the other with a type I + G1 beta-bulge turn (beta-hairpin 3:5). Analysis of the conformational behavior of the peptides studied here demonstrates three favorable and two unfavorable cross-strand side-chain interactions for beta-hairpin formation. These results are in agreement with statistical data on side-chain interactions in protein beta-sheets. All the peptides in this study form significant populations of the beta-hairpin 3:5, but only some of them also adopt the beta-hairpin 4:4. The formation of beta-hairpin 4:4 requires the presence of at least two favorable cross-strand interactions, whereas beta-hairpin 3:5 seems to be less susceptible to side-chain interactions. A protein database analysis of beta-hairpins 3:5 and beta-hairpins 4:4 indicates that the former occur more frequently than the latter. In both peptides and proteins, beta-hairpins 3:5 have a larger right-handed twist than beta-hairpins 4:4, so that a factor contributing to the higher stability of beta-hairpin 3:5 relative to beta-hairpin 4:4 is due to an appropriate backbone conformation of the type I + G1 beta-bulge turn toward the right-handed twist usually observed in protein beta-sheets. In contrast, as suggested previously, backbone geometry of the type I turn is not adequate for the right-handed twist. Because analysis of buried hydrophobic surface areas on protein beta-hairpins reveals that beta-hairpins 3:5 bury more hydrophobic surface area than beta-hairpins 4:4, we suggest that the right-handed twist observed in beta-hairpin 3:5 allows a better packing of side chains and that this may also contribute to its higher intrinsic stability. 相似文献
107.
108.
Differential thermal analysis (DTA) was used to study the crystallization phenomena in Y2 O3 -Al2 O3 fibers formed via a melt extraction process. Such fibers are X-ray amorphous and optically transparent regardless of composition in the as-extracted state but can be crystallized to produce various equilibrium phases that depend on the original composition of the ceramic rods used in the extraction process. The activation energy values were calculated using Kissinger and Augis-Bennett equations by measuring the variation of the peak temperature in the differential thermal patterns with heating rate. X-ray diffractometry analysis was used to determine the phase formation in the fibers crystallized after the DTA scan. 相似文献
109.
Elena Yeregui Jenifer Masip Consuelo Vilads Pere Domingo Yolanda M. Pacheco Juli Blanco Josep Mallolas Vernica Alba Montserrat Vargas Graciano García-Pardo Eugnia Negredo Montserrat Olona Judit Vidal-Gonzlez Maria Peraire Anna Martí Laia Revert Frderic Gmez-Bertomeu Manuel Leal Francesc Vidal Joaquim Peraire Anna Rull 《International journal of molecular sciences》2022,23(4)
A significant proportion of people living with HIV (PLHIV) who successfully achieve virological suppression fail to recover CD4+ T-cell counts. Since adipose tissue has been discovered as a key immune organ, this study aimed to assess the role of adipokines in the HIV immunodiscordant response. This is a multicenter prospective study including 221 PLHIV starting the first antiretroviral therapy (ART) and classified according to baseline CD4+ T-cell counts/µL (controls > 200 cells/µL and cases ≤ 200 cells/µL). Immune failure recovery was considered when cases did not reach more than 250 CD4+ T cells/µL at 144 weeks (immunological nonresponders, INR). Circulating adipokine concentrations were longitudinally measured using enzyme-linked immunosorbent assays. At baseline, apelin receptor (APLNR) and zinc-alpha-2-glycoprotein (ZAG) concentrations were significantly lower in INRs than in immunological responders (p = 0.043 and p = 0.034), and they remained lower during all ART follow-up visits (p = 0.044 and p = 0.028 for APLNR, p = 0.038 and p = 0.010 for ZAG, at 48 and 144 weeks, respectively). ZAG levels positively correlated with retinol-binding protein 4 (RBP4) levels (p < 0.01), and low circulating RBP4 concentrations were related to a low CD4+ T-cell gain (p = 0.018 and p = 0.039 at 48 and 144 weeks, respectively). Multiple regression adjusted for clinical variables and adipokine concentrations confirmed both low APLNR and RBP4 as independent predictors for CD4+ T cells at 144 weeks (p < 0.001). In conclusion, low APLNR and RBP4 concentrations were associated with poor immune recovery in treated PLHIV and could be considered predictive biomarkers of a discordant immunological response. 相似文献
110.
Dr. Rob Hoen Dr. Eva Maria Novoa Alba López Noelia Camacho Dr. Laia Cubells Pedro Vieira Prof. Manuel Santos Patricia Marin‐Garcia Prof. Jose Maria Bautista Prof. Alfred Cortés Prof. Lluís Ribas de Pouplana Dr. Miriam Royo 《Chembiochem : a European journal of chemical biology》2013,14(4):499-509
The resistance of malaria parasites to available drugs continues to grow, and this makes the need for new antimalarial therapies pressing. Aminoacyl‐tRNA synthetases (ARSs) are essential enzymes and well‐established antibacterial targets and so constitute a promising set of targets for the development of new antimalarials. Despite their potential as drug targets, apicoplastic ARSs remain unexplored. We have characterized the lysylation system of Plasmodium falciparum, and designed, synthesized, and tested a set of inhibitors based on the structure of the natural substrate intermediate: lysyl‐adenylate. Here we demonstrate that selective inhibition of apicoplastic ARSs is feasible and describe new compounds that that specifically inhibit Plasmodium apicoplastic lysyl‐tRNA synthetase and show antimalarial activities in the micromolar range. 相似文献