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131.
Using atom probe tomography, the partitioning of alloying elements between α and β in the alloy Ti metal-5553 (Ti–5Al–5Mo–5V–3Cr–0.5Fe) has been investigated as a function of heat-treatment. It has been shown that β-solutionizing followed by step-quenching to a higher temperature (700°C) or slow-cooling leads to substantial partitioning of the alloying elements, including an enrichment of slow-diffusing Mo at the α/β interfaces. In contrast, it was found that the combination of β-solutionizing, quenching to room temperature and aging at 400°C leads to rather limited partitioning of these alloying elements. 相似文献
132.
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134.
Amiya Kumar Panda Phil Wojciechowski Kaushik Nag Fred Possmayer Nils O. Petersen 《Journal of Dispersion Science and Technology》2013,34(9):1255-1261
Studies on the interaction of cholesterol (CHOL) with palmitoyl-oleoyl phosphatidylcholine (POPC) and sphingomyelin (SPM) are considered to be important because of the occurrence of strong interactions between sphingolipids and CHOL, which lead to the formation of microdomains or rafts within biological membranes. In the present investigation, studies on the surface pressure (π)-area ( A ) measurements and fluorescence microscopic studies on monolayers of the above mentioned system have been reported. Ideality/nonideality of mixing, excess area, and free energy changes during the formation of the monolayers at different surface pressures for the mixed lipid systems were evaluated from the π– A data. Interactions were found to be repulsive at lower CHOL content, which became associative at higher CHOL content. Condensing effects of CHOL on the mixed monolayers were found. Fluorescence studies on the systems revealed similar overall results. 相似文献
135.
Terpene esters of fatty acids have potential applications in food, cosmetic, and pharmaceutical industries. The present study
focuses on the synthesis of terpene esters of long chain fatty acids catalyzed by Candida antarctica lipase B. Different parameters like temperature, solvent, and enzyme concentration for the esterification of terpene alcohols
(geraniol and citronellol) with oleic acid were studied. Maximum conversion (98 %) was found for both terpene esters at 60°C
in 2,2,4-trimethylpentane as well as in dry hexane and around 95–97 % in other tested solvents. The reaction was also carried
out using stearic and linoleic acid in hexane to study the effects of unsaturation in the substrate in which stearic acid
showed the maximum conversion. The reaction was monitored by 1H nuclear magnetic resonance spectroscopy. Using the peak integration values of methylene protons of terpene and terpene ester
of δ = 3.6 and 4.0 for citronellol and δ = 4.2 and 4.6 for geraniol, respectively, percentage conversions of each of the esters
were calculated. 相似文献
136.
Habibul Arfin Jagjit Kaur Tariq Sheikh Sudip Chakraborty Angshuman Nag 《Angewandte Chemie (International ed. in English)》2020,59(28):11307-11311
Bi3+ and lanthanide ions have been codoped in metal oxides as optical sensitizers and emitters. But such codoping is not known in typical semiconductors such as Si, GaAs, and CdSe. Metal halide perovskite with coordination number 6 provides an opportunity to codope Bi3+ and lanthanide ions. Codoping of Bi3+ and Ln3+ (Ln=Er and Yb) in Cs2AgInCl6 double perovskite is presented. Bi3+‐Er3+ codoped Cs2AgInCl6 shows Er3+ f‐electron emission at 1540 nm (suitable for low‐loss optical communication). Bi3+ codoping decreases the excitation (absorption) energy, such that the samples can be excited with ca. 370 nm light. At that excitation, Bi3+‐Er3+ codoped Cs2AgInCl6 shows ca. 45 times higher emission intensity compared to the Er3+ doped Cs2AgInCl6. Similar results are also observed in Bi3+‐Yb3+ codoped sample emitting at 994 nm. A combination of temperature‐dependent (5.7 K to 423 K) photoluminescence and calculations is used to understand the optical sensitization and emission processes. 相似文献
137.
Okhil K. Nag Ji-Eun Jeong Van Sang Le Eunkeu Oh Han Young Woo James B. Delehanty 《Photochemistry and photobiology》2020,96(4):834-844
We report a Förster resonance energy transfer (FRET)-based imaging ensemble for the visualization of membrane potential in living cells. A water-soluble poly(fluorene-cophenylene) conjugated polyelectrolyte (FsPFc10) serves as a FRET donor to a voltage-sensitive dye acceptor (FluoVolt™). We observe FRET between FsPFc10 and FluoVolt™, where the enhancement in FRET-sensitized emission from FluoVolt™ is measured at various donor/acceptor ratios. At a donor/acceptor ratio of 1, the excitation of FluoVolt™ in a FRET configuration results in a three-fold enhancement in its fluorescence emission (compared to when it is excited directly). FsPFc10 efficiently labels the plasma membrane of HEK 293T/17 cells and remains resident with minimal cellular internalization for ~ 1.5 h. The successful plasma membrane-associated colabeling of the cells with the FsPFc10-FluoVolt™ donor-acceptor pair is confirmed by dual-channel confocal imaging. Importantly, cells labeled with FsPFc10 show excellent cellular viability with no adverse effect on cell membrane depolarization. During depolarization of membrane potential, HEK 293T/17 cells labeled with the donor-acceptor FRET pair exhibit a greater fluorescence response in FluoVolt™ emission relative to when FluoVolt™ is used as the sole imaging probe. These results demonstrate the conjugated polyelectrolyte to be a new class of membrane labeling fluorophore for use in voltage sensing schemes. 相似文献
138.
Sweetman A Jarvis S Danza R Bamidele J Gangopadhyay S Shaw GA Kantorovich L Moriarty P 《Physical review letters》2011,106(13):136101
We reversibly switch the state of a bistable atom by direct mechanical manipulation of bond angle using a dynamic force microscope. Individual buckled dimers at the Si(100) surface are flipped via the formation of a single covalent bond, actuating the smallest conceivable in-plane toggle switch (two atoms) via chemical force alone. The response of a given dimer to a flip event depends critically on both the local and nonlocal environment of the target atom-an important consideration for future atomic scale fabrication strategies. 相似文献
139.
We show how to treat the dynamics of an asymmetric three-body system consisting of one heavy and two identical light particles
in simple coordinate space variational approach. The method is constructive and gives an efficient way of resolving a three-body
system to an effective two-body system. It is illustrated by explaining the structural properties of some nuclei of current
interest, namely halo nuclei and double-λ hypernuclei. The ansatz used here may be of value in a number of three particle
problems of similar nature. 相似文献
140.