全文获取类型
收费全文 | 254篇 |
免费 | 13篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 75篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 8篇 |
能源动力 | 4篇 |
轻工业 | 17篇 |
水利工程 | 8篇 |
无线电 | 13篇 |
一般工业技术 | 28篇 |
冶金工业 | 47篇 |
原子能技术 | 2篇 |
自动化技术 | 54篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 2篇 |
2014年 | 10篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 26篇 |
2010年 | 17篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 9篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 16篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 10篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有267条查询结果,搜索用时 12 毫秒
31.
The melting behavior of two 1‐octene linear low‐density polyethylene (LLDPE) copolymers is investigated. One made using Dow′s INSITE constrained geometry catalyst technology (LLDPE‐A) and the other using titanium‐based Ziegler–Natta catalysts (LLDPE‐B). Both have similar comonomer content as well as melt flow index. Differential scanning calorimetry (DSC) was used throughout the work. Isothermal crystallizations in the DSC for several times were carried out at various temperatures between 90 and 100°C for LLDPE‐A and between 105 and 112.5°C for LLDPE‐B. As a result of the isothermal crystallizations for both copolymers, multiple melting peaks are found in the DSC traces on subsequent heating. The melting behavior was also examined as a function of heating rate (1, 2.5, 5, 10, and 20°C/min). The multiple melting behavior indicates that they are inhomogeneous. In addition, a melting–recrystallization process was shown to be responsible for the appearance of one of the melting peaks in LLDPE‐B. A lowering in heating rate from the crystallization temperature favors the occurrence of melting–recrystallization during the dynamic experiment. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2022–2028, 2001 相似文献
32.
S Puig Ll Corominas A Traore J Colomer M D Balaguer J Colprim 《Water science and technology》2006,53(4-5):171-178
A pilot plant sequencing batch reactor (SBR) was applied in a wastewater treatment plant treating urban wastewater focused on carbon and nitrogen removal. From an initial predefined step-feed cycle definition, the evolution of the on-line monitored pH and calculated oxygen uptake rate (OUR) were analysed in terms of knowledge extraction. First, the aerobic phases of the SBR cycle were operated using an On/Off dissolved oxygen (DO) control strategy that concluded with a sinusoidal pH profile that made detecting the "ammonia valley" difficult. After changing to fuzzy logic control of the dissolved oxygen and by adding an air flow meter to the pilot plant, the pH evolution and on-line calculated OUR showed a clearer trend during the aerobic phases. Finally, a proposed algorithm for adjusting the aerobic phases of the SBR for carbon and ammonia removal is presented and discussed. 相似文献
33.
Gibert M Abellán P Benedetti A Puig T Sandiumenge F García A Obradors X 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(23):2716-2724
Assembling arrays of ordered nanowires is a key objective for many of their potential applications. However, a lack of understanding and control of the nanowires' growth mechanisms limits their thorough development. In this work, an appealing new path towards self-organized epitaxial nanowire networks produced by high-throughput solution methods is reported. Two requisites are identified to generate the nanowires: a thermodynamic driving force for an unrestricted elongated equilibrium island shape, and a very fast effective coarsening rate. These requirements are met in anisotropically strained Ce(1-x)Gd(x)O(2-y) nanowires with the (011) orientation grown on the (001) surface of LaAlO(3) substrates. Nanowires with aspect ratios above ≈100 oriented along two mutually orthogonal axes are obtained leading to labyrinthine networks. A very fast effective nanowire growth rate (≈60 nm min(-1)) for ex-situ thermally annealed nanostructures derives from simultaneous kinetic processes occurring in a branched network. Ostwald ripening and anisotropic dynamic coalescence, both promoted by strain-driven attractive nanowire interaction, and rapid recrystallization, enabled by fast atomic diffusion associated with a high concentration of oxygen vacancies, contribute to such an effective growth rate. This bottom-up approach to self-organized nanowire growth has a wide potential for many materials and functionalities. 相似文献
34.
Phenyl‐γ‐valerolactones,flavan‐3‐ol colonic metabolites,protect brown adipocytes from oxidative stress without affecting their differentiation or function 下载免费PDF全文
35.
Pettersson S Pérez-Nueno VI Ros-Blanco L Puig de La Bellacasa R Rabal MO Batllori X Clotet B Clotet-Codina I Armand-Ugón M Esté J Borrell JI Teixidó J 《ChemMedChem》2008,3(10):1549-1557
HIV cell fusion and entry have been validated as targets for therapeutic intervention against infection. Bicyclams were the first low-molecular-weight compounds to show specific interaction with CXCR4. The most potent bicyclam was AMD3100, in which the two cyclam moieties are tethered by a 1,4-phenylenebis(methylene) bridge. It was withdrawn from clinical trials owing to its lack of oral bioavailability and cardiotoxicity. We have designed a combinatorial library of non-cyclam polynitrogenated compounds by preserving the main features of AMD3100. At least two nitrogen atoms on each side of the p-phenylene moiety, one in the benzylic position and the other(s) in the heterocyclic system were maintained, and the distances between them were similar to the nitrogen atom distances in cyclam. A selection of diverse compounds from this library were prepared, and their in vitro activity was tested in cell cultures against HIV strains. This led to the identification of novel potent CXCR4 coreceptor inhibitors without cytotoxicity at the tested concentrations. 相似文献
36.
Helena de Puig Stefania Federici Salmaan H. Baxamusa Paolo Bergese Kimberly Hamad‐Schifferli 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(17):2477-2484
A study is presented of the nanomechanical phenomena experienced by nanoparticle‐conjugated biomolecules. A thermodynamic framework is developed to describe the binding of thrombin‐binding aptamer (TBA) to thrombin when the TBA is conjugated to nanorods. Binding results in nanorod aggregation (viz. directed self‐assembly), which is detectable by absorption spectroscopy. The analysis introduces the energy of aggregation, separating it into TBA–thrombin recognition and surface‐work contributions. Consequently, it is demonstrated that self‐assembly is driven by the interplay of surface work and thrombin‐TBA recognition. It is shown that the work at the surface is about ?10 kJ mol?1 and results from the accumulation of in‐plane molecular forces of pN magnitude and with a lifetime of <1 s, which arises from TBA nanoscale rearrangements fuelled by thrombin‐directed nanorod aggregation. The obtained surface work can map aggregation regimes as a function of different nanoparticle surface conditions. Also, the thermodynamic treatment can be used to obtain quantitative information on surface effects impacting biomolecules on nanoparticle surfaces. 相似文献
37.
Sealing system and bottle storage position effects on the evolution of white and red wines were analyzed. The sealing systems were natural‐cork stopper, colmated‐cork stopper, agglomerated‐cork stopper, polyurethane‐powdered‐cork (PPC) stopper, plastic stopper, and metal screw‐top. Chemical analysis and sensory analysis showed that wine is better preserved when the bottles are kept horizontally. The sealing systems that allowed the most suitable evolution were the natural‐cork stopper, the colmated‐cork stopper, and the PPC stopper. The agglomerated cork produced faster wine oxidation when the bottles were kept vertically. The plastic cork and the screw‐top allowed oxidation in the wine more quickly than the other systems. 相似文献
38.
O. Esquivel M. E. Treviño H. Saade J. E. Puig E. Mendizábal R. G. López 《Polymer Bulletin》2011,67(2):217-226
The synthesis by semicontinuous heterophase polymerization and the characterization of mesoporous crosslinked polystyrene
particles in the nanometer range (ca. 30 nm) are reported here. The particles have pores between 6 and 8 nm in diameter and
pore volume around 0.40 cm3/g. In spite that the polymerization was not carried out at highly monomer-starved conditions, particles with narrow size
distribution were obtained, which is ascribed to inter-particle hetero-coagulation at latter stages of polymerization, due
to lack of enough surfactant to cover all the particles even before 45% global conversion. 相似文献
39.
Hugo Martínez‐Gutiérrez Víctor M. Ovando‐Medina René D. Peralta Eduardo Mendizábal Jorge E. Puig 《Polymer Engineering and Science》2013,53(9):1990-1995
Vinyl acetate (VAc) was polymerized by a seeded semicontinuous heterogeneous process. Stable latexes with a polymer/surfactant weight ratio of 65 were obtained, which is comparable with the highest value reported in the literature for emulsion polymerization but with the advantage of obtaining smaller particles (average diameter, Dp = 53 nm) which are similar to those obtained by microemulsion polymerization. The surfactant (sodium dodecylsulfate, SDS) concentration used in the recipe (0.32 wt%) is much lower than those typically used in microemulsion polymerization. Although molar masses increased during the continuous monomer addition period, they were small at the end of the reaction (Mn = 69 × 103 g·mol–1) and this was attributed to bimolecular termination inside the particles. The values of polymerization rate (Rp) and monomer addition rate (Fm) were nearly the same, indicating that polymerization was performed under monomer starved conditions. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers 相似文献
40.
Domenec Puig Author Vitae Miguel Angel Garcia Author Vitae 《Pattern recognition》2006,39(11):1996-2009
Pixel-based texture classifiers and segmenters are typically based on the combination of texture feature extraction methods that belong to a single family (e.g., Gabor filters). However, combining texture methods from different families has proven to produce better classification results both quantitatively and qualitatively. Given a set of multiple texture feature extraction methods from different families, this paper presents a new texture feature selection scheme that automatically determines a reduced subset of methods whose integration produces classification results comparable to those obtained when all the available methods are integrated, but with a significantly lower computational cost. Experiments with both Brodatz and real outdoor images show that the proposed selection scheme is more advantageous than well-known general purpose feature selection algorithms applied to the same problem. 相似文献