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111.
Silvestro A. Ruffolo Mauro F. La Russa Piergiorgio Aloise Cristina M. Belfiore Andrea Macchia Antonino Pezzino Gino M. Crisci 《Applied Physics A: Materials Science & Processing》2014,114(3):753-758
Salt crystallisation process is one of the most powerful weathering agents in stone materials, especially in the coastal areas, where sea-spray transports large amount of salts on the stone surface. The consolidation of such degraded stone material represents a critical issue in the field of restoration of cultural heritage. In this paper, the nanolime consolidation behaviour in limestone degraded by salt crystallization has been assessed. For this purpose, a stone material taken from a Sicilian historical quarry and widely used in the eastern Sicilian Baroque architecture has been artificially degraded by the salt crystallization test. Then degraded samples have been treated with NanoRestore®, a suspension of nanolime in isopropyl alcohol. To evaluate the consolidating effectiveness, the peeling test and point load test were performed. Moreover, mercury intrusion porosimetry has been executed to evaluate the variations induced by treatment, while colorimetric measurements have been aimed to assess aesthetical issues. 相似文献
112.
The purpose of this paper is twofold: (1) to examine strengths and weaknesses of recently developed optimization methods for selecting radiation treatment beam angles and (2) to propose a simple and easy-to-use hybrid framework that overcomes some of the weaknesses observed with these methods. Six optimization methods—branch and bound (BB), simulated annealing (SA), genetic algorithms (GA), nested partitions (NP), branch and prune (BP), and local neighborhood search (LNS)—were evaluated. Our preliminary test results revealed that (1) one of the major drawbacks of the reported algorithms was the limited ability to find a good solution within a reasonable amount of time in a clinical setting, (2) all heuristic methods require selecting appropriate parameter values, which is a difficult chore, and (3) the LNS algorithm has the ability to identify good solutions only if provided with a good starting point. On the basis of these findings, we propose a unified beam angle selection framework that, through two sequential phases, consistently finds clinically relevant locally optimal solutions. Considering that different users may use different optimization approaches among those mentioned above, the first phase aims to quickly find a good feasible solution using SA, GA, NP, or BP. This solution is then used as a starting point for LNS to find a locally optimal solution. Experimental results using this unified method on five clinical cases show that it not only produces consistently good-quality treatment solutions but also alleviates the effort of selecting an initial set of appropriate parameter values that is required by all of the existing optimization methods. 相似文献
113.
The great revolution in theoretical fluid mechanics (brought along by the advent of computers in the middle of the century) that replaced search for a formal solution of a general problem with the analysis of evolutions, is in turn threatened by consumerism replacing physical thought with easy, uncontrolled output.Sommario. La grande rivoluzione nello studio della meccanica dei fluidi (conseguente alla nascita dei calcolatori a metà del secolo) consistette nel sostituire alla ricerca formale di una soluzione generale, l'analisi delle evoluzioni fisiche; ma il consumismo imperante minaccia ora di sostituire l'interpretazione fisica con la facile produzione di risultati incontrollati. 相似文献
114.
This article describes the synthesis of new peptomers through a simple and efficient route using a one-pot Ugi four-component reaction. The synthesis started from either carboxylic acids or protected amino acids, primary amines, aldehydes, and isocyanides in anhydrous methanol and proceeded under stirring at room temperature. The reaction produced several functionalized peptomers in good yields (67–80%). These compounds are versatile multifunctional intermediates that can be further unprotected or functionalized to generate new molecules with numerous applications in the field of biomedicine. 相似文献
115.
Nicolò Dossi Rosanna Toniolo Evandro Piccin Sabina Susmel Andrea Pizzariello Gino Bontempelli 《Electroanalysis》2013,25(11):2515-2522
A simple method is described to discriminate between analytes comigrating under on‐plate separation conditions, whose electrochemical behavior displays different reversible characters. It is based on the use of dual electrode detectors pencil‐drawn at the end of paper‐based fluidic channels defined by hydrophobic barriers. Simultaneous detection of comigrating species is achieved by applying to the upstream pencil‐drawn working electrode a potential for the oxidation (or reduction) of both analytes, while to the downstream pencil‐drawn working electrode a potential is imposed for the reverse process involving the product of the sole analyte undergoing a reversible enough electrochemical process. The performance of these inexpensive devices was preliminarily optimized by adopting hexacyanoferrate(II) as prototype species undergoing a reversible anodic process at carbon electrodes. They were then used as dual electrode detectors for thin‐layer chromatographic runs conducted on paper‐based microfluidic devices. Two types of synthetic solutions, one containing different contents of dopamine (DA) and ascorbic acid (AA) and the other of paracetamol (PA) and AA, were chosen as model samples. This choice was prompted us by the fact that in both cases these analytes comigrated under the adopted experimental conditions and required similar enough oxidation potentials. Nevertheless, DA and PA underwent reversible enough anodic processes while an irreversible electrochemical reaction is involved in the AA oxidation. Satisfactory results were found for both couples of target analytes, whose simultaneous detection was achieved within 230 s and was characterized by good enough repeatability and sensitivity. In particular, this approach appears to be well suited for the rapid and inexpensive assembling of electrochemical detectors for flow analysis systems. 相似文献
116.
Rosanna Toniolo Nicolò Dossi Andrea Pizzariello Alice Casagrande Gino Bontempelli 《Analytical and bioanalytical chemistry》2013,405(11):3571-3577
A prototype of a fast-response task-specific amperometric gas sensor based on paper-supported room-temperature ionic liquids (RTILs) is proposed here for improved analysis of volatile acid species. It consists of a small filter paper foil soaked with a RTIL mixture containing an ionic liquid whose anion (acetate) displays a basic character, upon which three electrodes are screen printed by carbon ink profiting from a suitable mask. It takes advantage of the high electrical conductivity and negligible vapour pressure of RTILs and of their easy immobilization into a porous and inexpensive supporting material such as paper. The performance of this device, used as a wall-jet amperometric detector for flow injection analyses of headspace samples in equilibrium with aqueous solutions at controlled concentrations, was evaluated for phenol and 1-butanethiol vapours which were adopted as model acid gaseous analytes. The results obtained showed that the quite high potentials required for the detection of these analytes are lowered significantly, thanks to the addition of the basic acetate RTIL. In such a way, overlap with the medium discharge is avoided, and the possible adverse effect of interfering species is minimised. The sensor performance was quite satisfactory (detection limits, ca. 0.3 μM; dynamic range, ca. 1–200 μM, both referred to solution concentrations; correlation coefficients in the range 0.993–0.997; repeatability, ± 6 % RSD; long-term stability, 9 %); thus suggesting the possible use of this device for manifold applications. Figure
Layout and cross-section of the RTIL-PED sensor adopted in flow injection analyses. R pseudo-reference electrode, W working electrode, C counter electrode 相似文献
117.
The present paper has three closely related aims. We first argue that Agazzi’s scientific realism about Quantum Mechanics
is in line with Selleri’s and Tarozzi’s proposal of Quantum Waves. We then go on to formulate rigorously different metaphysical
principles such as property compositional determinateness and mereological extensionalism. We argue that, contrary to widespread
agreement, realism about Quantum Mechanics actually refutes only the former. Indeed we even formulate a new quantum mechanical
argument in favor of extensionalism. We conclude by noting that, given the results of the work, Agazzi’s particular attitude
towards Quantum Mechanics is still one of the most promising theoretical perspectives. 相似文献
118.
Amperometric Sniffer for Volatile Amines Based on Paper‐Supported Room Temperature Ionic Liquids Enabling Rapid Assessment of Fish Spoilage 下载免费PDF全文
Rosanna Toniolo Nicolò Dossi Rossella Svigely Sabina Susmel Innocenzo G. Casella Gino Bontempelli 《Electroanalysis》2014,26(9):1966-1974
A gas sensors based on a room temperature ionic liquid (RTIL) supported on paper is proposed as amperometric sniffer for monitoring volatile amines (VAs) released from fish samples, in order to gain indication of their state of turning spoiled. It was used as a paper electrochemical detector (PED) for a flow injection system in which controlled headspace volumes in equilibrium with ice‐stored fish samples were directly injected. The performance of this RTIL‐PED sensor was preliminarily tested on synthetic samples of trimethylamine (TMA), dimethylamine (DMA), methylamine (MA) and ammonia (i.e. the main species responsible for the typical flavor of spoiled fish), thus verifying that only TMA, DMA and MA can be detected because NH3 oxidation occurred beyond the solvent discharge. This notwithstanding, detection of the sole TMA, DMA and MA as a whole turned out to be well suited for the rapid assessment of fish spoilage, since during storage the release enhancement for these amines is largely predominant over that of NH3. Repeatable (8 % RSD) sharp peaks were detected for all amines above over a wide range (5–1000 nmol) and a detection limit of a little more than 3 nmol was inferred for a signal‐to‐noise ratio of 3. This approach was applied to the detection of VAs released from real fish samples (sardines), in parallel to the determination of their total volatile basic nitrogen (TVBN), which is a conventional indicator frequently adopted for the chemical quality assessment of fish. A substantially satisfactory agreement was found by comparing the data achieved by these two approaches. 相似文献
119.