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111.
Proteins of the FtsZ (filamentous temperature-sensitive Z) family establish complex polymeric spatial patterns in plastids of the moss Physcomitrella patens. These structures represent a "plastoskeleton" that might contribute to plastid shape and stability. The aim of this work is to develop computer models of FtsZ network connectivity and dynamics. These computer models are developed from green fluorescent protein (GFP) images obtained by Prof. Reski's Plant Biotechnology group at the University of Freiburg by means of laser scanning confocal microscopy. Subsequently, structural reconstruction techniques based on cellular automata algorithm are applied on the raw image data to compensate for any information that is lost in the process of imaging. Segmentation of the processed data will result in the computer model of the targeted structures, which are used for further analysis. Model generation and experimental testing in the moss system is conducted in an iterative process with the aim of both forward and reverse biomimetics. A developed image processing algorithm with the aim of quantification of structural characteristics is utilized to extract structural features of the FtsZ network in Physcomitrella enabling us a statistical analysis on the extracted data. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
112.
Sloshing absorbers work on a similar principle to that of tuned vibration absorbers. A sloshing absorber consists of a tank, partially filled with liquid. The absorber is attached to the structure to be controlled, and relies on the structure's motion to excite the liquid. Consequently, a sloshing wave is produced at the liquid free surface possessing energy dissipative qualities. The primary objective of this paper is to demonstrate the effectiveness of employing liquid sloshing as a structural control mechanism. To this end, simple experimental observations are presented first. Then, numerical predictions obtained using smoothed particle hydrodynamics (SPH) are compared with experimental observations. The objective of this comparison is to demonstrate the modelling technique's ability to approximate the characteristics of such flows.  相似文献   
113.
Tetelbaum  D. I.  Mikhaylov  A. N.  Belov  A. I.  Ershov  A. V.  Pitirimova  E. A.  Plankina  S. M.  Smirnov  V. N.  Kovalev  A. I.  Turan  R.  Yerci  S.  Finstad  T. G.  Foss  S. 《Physics of the Solid State》2009,51(2):409-416
Physics of the Solid State - Photoluminescence, infrared Fourier spectroscopy, Raman scattering, transmission electron microscopy, and electron diffraction were used to study the luminescent,...  相似文献   
114.
Zusammenfassung Der Artikel behandelt die isotherme Verformung eines linear-viskoelastischen Stoffes im einachsigen Spannungszustand. Ein Integralgesetz für die Spannungs-Dehnungsbeziehung wird aufgestellt, in dem der Relaxationsmodul als Summe von Exponentialfunktionen angesetzt wird. Die Möglichkeit, die freie Energie und die Entropieproduktion aus der Kenntnis des Relaxationsmoduls zu bestimmen, wird diskutiert. Im Gegensatz zu früheren Untersuchungen dieses Problems macht der vorliegende Artikel keinen Gebrauch von Modellvorstellungen und stützt sich ausschliesslich auf thermodynamische Überlegungen.

The results communicated in this paper were obtained in the course of research sponsored by the Office of Naval Research under Contract Nonr 562(10), and by Material Research Program, The Advanced Research Projects Agency, Department of Defense.  相似文献   
115.
Aliphatic polycarbonate (PC) copolymer is synthesized by ring opening copolymerization of acrylate‐ and allyl‐functional cyclic carbonate monomers. The post‐polymerization functionalization of the resulting copolymer is performed quantitatively using a variety of thiol compounds via sequential Michael addition and photo‐induced radical thiol‐ene click reactions within relatively short reaction time at ambient temperature. This metal‐free click chemistry methodology affords the synthesis of biocompatible PC copolymer with multifunctional groups. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1581–1587  相似文献   
116.
The single‐electron transfer living radical polymerization (SET‐LRP) of N‐isopropylacrylamide (NIPAM) from silicon wafer modified with an initiator layer composed of 2‐bromopropionyl bromide (2‐BPB) fragments is described. The amount of Cu(0) generated in situ by the disproportination of Cu(I) to Cu(0) and Cu(II) in the presence of 2,2′‐bipyridine (2,2′‐bpy) ligand and N,N‐dimethylformamide (DMF) solvent at 90 °C is dependent on the ratio of [CuBr]/[CuBr2]. By proper selection of the [CuBr]/[CuBr2] ratio, well‐controlled SET‐LRP polymerization of NIPAM was observed such that the thickness of the layer consisting of chains grown from the surface increased linearly with the molecular weight of chains polymerized in solution in identical. In addition, the calculation of grafting parameters, including surface coverage, σ (mg/m2); grafting density, Σ (chain/nm2); and average distance between grafting sites, D (nm), from the number‐average molecular weight, M n (g/mol), and ellipsometric thickness, h (nm), values indicated the synthesis of densely grafted poly(NIPAM) films and allowed us to predict a “brush‐like” conformation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010  相似文献   
117.
Surface‐initiated atom transfer radical polymerization (SI‐ATRP) of N‐isopropylacrylamide (NIPAM) on silicon wafer in the presence of 2‐mercaptoethanol (ME) chain transfer agent was conducted in attempt to create controllable hydroxyl‐terminated brushes. The initiator‐immobilized substrate, was prepared by the esterification of hydroxyl groups on silicon wafer with 2‐bromopropionyl bromide (2‐BPB); followed by the ATRP of NIPAM using a catalyst system, that is, Cu(I)Br/2,2′‐bipyridine (2,2′‐bpy) and a chain transfer agent, that is, ME. The formation of homogeneous tethered poly(N‐isopropylacrylamide) (poly(NIPAM) brushes with hydroxyl end‐group, whose thickness can be tuned by chancing ME concentration, is evidenced by using the combination of grazing angle attenuated total reflectance‐Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, ellipsometry, atomic force microscopy, gel permeation chromatography, and water contact‐angle measurements. The calculation of grafting parameters from experimental measurements indicated the synthesis of densely grafted poly(NIPAM) films with hydroxyl end‐group on silicon wafer and allowed us to predict a ME concentration for forming a “brush” conformation for the chains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3880–3887, 2010  相似文献   
118.
Immobilization of biologically important molecules on myriad nano-sized materials has attracted great attention. Through this study, thermophilic esterase enzyme was obtained using recombinant DNA technology and purified applying one-step His-Select HF nickel affinity gel. The synthesis of chitosan was achieved from chitin by deacetylation process and degree of deacetylation was calculated as 89% by elemental analysis. Chitosan nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. The physicochemical properties of the chitosan and chitosan nanoparticles were determined by several methods including SEM (Scanning Electron Microscopy), FT-IR (Fourier Transform Infrared Spectroscopy) and DLS (Dynamic Light Scattering). The morphology of chitosan nanoparticles was spherical and the nanospheres’ average diameter was 75.3 nm. The purified recombinant esterase was immobilized efficiently by physical adsorption onto chitosan nanoparticles and effects of various immobilization conditions were investigated in details to develope highly cost-effective esterase as a biocatalyst to be utilized in biotechnological purposes. The optimal conditions of immobilization were determined as follows; 1.0 mg/mL of recombinant esterase was immobilized on 1.5 mg chitosan nanoparticles for 30 min at 60°C, pH 7.0 under 100 rpm stirring speed. Under optimized conditions, immobilized recombinant esterase activity yield was 88.5%. The physicochemical characterization of enzyme immobilized chitosan nanoparticles was analyzed by SEM, FT-IR and AFM (Atomic Force Microscopy).  相似文献   
119.
Temperature‐sensitive imprinted and non‐imprinted hydrogels composed of N‐isopropylacrylamide (NIPA) and 2‐acrylamido‐2‐methyl‐propanosulfonic acid (AMPS) have been prepared by free‐radical crosslinking copolymerization in aqueous solution at three different temperatures: 10 °C (below the lower critical solution temperature, LCST), 33 °C (at the LCST), and 40 °C (above the LCST). Myoglobin (Mb, MW 17 kDa) is used as the template biomolecule. The effects of the initial concentration and adsorption time over the Mb adsorption capacity of the hydrogels have been analyzed and found to be strongly dependent on the preparation temperature (Tprep). The maximum Mb adsorption for the imprinted hydrogel prepared at 10 °C is 97.40 ± 2.35 mg Mb · g−1 dry gel in 0.32 mg · mL−1 Mb solution at 22 °C. Moreover, batch adsorption equilibrium and selectivity studies have been performed using a reference molecule, hemoglobin (Hb, MW 65 kDa). The imprinted hydrogels have a 2.8–3.3 times higher adsorption capacity for Mb than the non‐imprinted hydrogels prepared at the same Tpreps, and also have a 1.8–2.7 times higher selectivity for the imprinted molecule.

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120.
SiO2 layer structures with a middle layer containing Ge nanocrystals were prepared by sputtering on n- and p-type Si substrates, and by consecutive annealing. Ge content in the middle layer was varied in the range of 40-100%. Most of the structures exhibited low breakdown voltages. The current through the structures became Schottky-like after breakdown. However, some p-type samples showed a considerable memory effect. It was obtained by spectroscopic ellipsometry that the middle layer contains amorphous Ge phase as well. The results also suggest intermixing of the layers during the sputtering and/or the annealing process.  相似文献   
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