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91.
Geoffrey Cottenet Carine Blancpain Véronique Sonnard Poh Fong Chuah 《Analytical and bioanalytical chemistry》2013,405(21):6831-6844
Considering the increase of the total cultivated land area dedicated to genetically modified organisms (GMO), the consumers’ perception toward GMO and the need to comply with various local GMO legislations, efficient and accurate analytical methods are needed for their detection and identification. Considered as the gold standard for GMO analysis, the real-time polymerase chain reaction (RTi-PCR) technology was optimised to produce a high-throughput GMO screening method. Based on simultaneous 24 multiplex RTi-PCR running on a ready-to-use 384-well plate, this new procedure allows the detection and identification of 47 targets on seven samples in duplicate. To comply with GMO analytical quality requirements, a negative and a positive control were analysed in parallel. In addition, an internal positive control was also included in each reaction well for the detection of potential PCR inhibition. Tested on non-GM materials, on different GM events and on proficiency test samples, the method offered high specificity and sensitivity with an absolute limit of detection between 1 and 16 copies depending on the target. Easy to use, fast and cost efficient, this multiplex approach fits the purpose of GMO testing laboratories. Figure
A broad multiplex real‐time PCR method for the detection and identification of GMOs 相似文献
92.
The palladium-catalysed coupling of bromofurans with activated alkenes and of furanoyl chlorides with either terminal alkynes or alkynyl stannanes gave good yields of the corresponding vinyl furans and alkynyl ketones. These studies culminated in a short synthesis of the antifungal agent dihydrowyerone. 相似文献
93.
Anurag Krishna Cosmin Laslau Geoffrey I. N. Waterhouse Zoran D. Zujovic Jadranka Travas-Sejdic 《Chemical Papers》2013,67(8):995-1001
This study investigates the effect of the ionic liquid 1-butyl-3-methyl imidazolium chloride ([bmim]Cl) on the morphological, structural, and electronic properties of polyaniline (PANI) products synthesised by the falling-pH method. Products were characterised by SEM, FT-IR, UVVIS, N2-physisorption, and conductivity measurements. The [bmim]Cl addition strongly influenced the PANI morphology, specific surface area, porosity, and conductivity. Depending on the [bmim]Cl: ANI ratio and the synthesis pH, a wide range of PANI nanostructures could be prepared, with rod-like, and fibre-like elongated structures being the dominant morphology under most experimental conditions. Samples prepared in the presence of [bmim]Cl exhibit specific areas of ca 22–35 m2 g?1. The conductivity of the final products depends on the [bmim]Cl: ANI ratio. Temperature dependence of conductivity in the temperature range from 77 K to 300 K was also studied. 相似文献
94.
Noel Kong Rong Yi Sarah Zhao Jasmeet Sandhu Geoffrey Lam Devan Loganathan Barbara Morrissey 《Journal of separation science》2014,37(21):3015-3023
A sensitive hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry method was developed and validated for the simultaneous detection and quantification of etilefrine and oxilofrine in equine blood plasma and urine. The method is highly sensitive and specific with good precision and accuracy. In plasma the limit of detection and limit of quantification are 0.03 and 0.1 ng/mL, respectively, for both analytes. In urine the limit of detection and limit of quantification are 0.3 and 1 ng/mL, respectively, for both analytes. The suitability of the method for doping control analysis in equine species is demonstrated by analyzing postadministration samples collected after a single intravenous administration of 50 mg etilefrine to a standardbred mare. Etilefrine was detected up to 120 h in urine and up to 48 h in plasma. Etilefrine is highly conjugated in equine urine whereas it exists in the free form in equine plasma. Therefore, enzyme hydrolysis prior to sample preparation is recommended for the detection and quantification of etilefrine and oxilofrine in equine urine. 相似文献
95.
96.
Fast Proton Exchange in Histidine: Measurement of Rate Constants through Indirect Detection by NMR Spectroscopy 下载免费PDF全文
Akansha Ashvani Sehgal Dr. Luminita Duma Prof. Geoffrey Bodenhausen Dr. Philippe Pelupessy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(21):6332-6338
Owing to its imidazole side chain, histidine participates in various processes such as enzyme catalysis, pH regulation, metal binding, and phosphorylation. The determination of exchange rates of labile protons for such a system is important for understanding its functions. However, these rates are too fast to be measured directly in an aqueous solution by using NMR spectroscopy. We have obtained the exchange rates of the NH3+ amino protons and the labile NHε2 and NHδ1 protons of the imidazole ring by indirect detection through nitrogen‐15 as a function of temperature (272 K<T<293 K) and pH (1.3<pH<4.9) of uniformly nitrogen‐15‐ and carbon‐13‐labeled L ‐histidine ? HCl ? H2O. Exchange rates up to 8.5×104 s?1 could be determined (i.e., lifetimes as short as 12 μs). The three chemical shifts δHi of the invisible exchanging protons Hi and the three one‐bond scalar coupling constants 1J(N,Hi) could also be determined accurately. 相似文献
97.
Exploring Weak Ligand–Protein Interactions by Long‐Lived NMR States: Improved Contrast in Fragment‐Based Drug Screening 下载免费PDF全文
Roberto Buratto Daniele Mammoli Dr. Elisabetta Chiarparin Dr. Glyn Williams Prof. Geoffrey Bodenhausen 《Angewandte Chemie (International ed. in English)》2014,53(42):11376-11380
Ligands that have an affinity for protein targets can be screened very effectively by exploiting favorable properties of long‐lived states (LLS) in NMR spectroscopy. In this work, we describe the use of LLS for competitive binding experiments to measure accurate dissociation constants of fragments that bind weakly to the ATP binding site of the N‐terminal ATPase domain of heat shock protein 90 (Hsp90), a therapeutic target for cancer treatment. The LLS approach allows one to characterize ligands with an exceptionally wide range of affinities, since it can be used for ligand concentrations [L] that are several orders of magnitude smaller than the dissociation constants KD. This property makes the LLS method particularly attractive for the initial steps of fragment‐based drug screening, where small molecular fragments that bind weakly to a target protein must be identified, which is a difficult task for many other biophysical methods. 相似文献
98.
Benjamin A. Ellingson Matthew T. Geballe Stanislaw Wlodek Christopher I. Bayly A. Geoffrey Skillman Anthony Nicholls 《Journal of computer-aided molecular design》2014,28(3):289-298
Several submissions for the SAMPL4 hydration free energy set were calculated using OpenEye tools, including many that were among the top performing submissions. All of our best submissions used AM1BCC charges and Poisson–Boltzmann solvation. Three submissions used a single conformer for calculating the hydration free energy and all performed very well with mean unsigned errors ranging from 0.94 to 1.08 kcal/mol. These calculations were very fast, only requiring 0.5–2.0 s per molecule. We observed that our two single-conformer methodologies have different types of failure cases and that these differences could be exploited for determining when the methods are likely to have substantial errors. 相似文献
99.
Jérémy Vuilleumier Geoffrey Gaulier Raphaël De Matos Yannick Mugnier Gabriel Campargue Jean-Pierre Wolf Luigi Bonacina Sandrine Gerber-Lemaire 《Helvetica chimica acta》2020,103(1):e1900251
While chemotherapy is one of the most used treatments in oncology, the systemic administration of chemotherapeutics generally results in undesired damages to healthy tissues and cells, side effects such as severe nausea and leukopenia, and reduced efficacy due to multidrug resistance and poor target accessibility. The limitations of conventional chemotherapy formulation have prompted the development of alternative nanomaterials-based strategies to achieve targeted and stimuli sensitive payload delivery to reach optimal local drug concentration at tumor sites. In this study, the anticancer drug chlorambucil (Clb) was conjugated to the surface of silica coated lithium niobate (LNO) harmonic nanoparticles (HNPs) using a photocaging tether based on coumarin-4-yl methyl derivative. Upon laser pulsed femtosecond irradiation at 790 nm, the second harmonic emission from the metal oxide core induced the efficient release of Clb, with concomitant contribution from the nonlinear absorption of the coumarin (CM)-based moiety. 相似文献
100.
Juan-Ramón Jiménez Jana Glatz Amina Benchohra Geoffrey Gontard Lise-Marie Chamoreau Jean-François Meunier Azzedine Bousseksou Rodrigue Lescouëzec 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(21):8166-8170
A mixed-valence {MnII3MnIIIFeII2FeIII2} cyanide-bridged molecular cube hosting a caesium cation, Cs⊂{Mn4Fe4}, was synthesized and structurally characterized by X-ray diffraction. Cyclic-voltammetry measurements show that its electronic state can be switched between five different redox states, which results in a remarkable electrochromic effect. Magnetic measurements on fresh samples point to the occurrence of a spin-state change near room temperature, which could be ascribed to a metal-to-metal electron transfer converting the {FeII−CN−MnIII} pair into a {FeIII−CN−MnII} pair. This feature was only previously observed in the polymeric MnFe Prussian-blue analogues (PBAs). Moreover, this novel switchable molecule proved to be soluble and stable in organic solvents, paving the way for its integration into advanced materials. 相似文献