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71.
Scaglia E Sockalingum GD Schmitt J Gobinet C Schneider N Manfait M Thiéfin G 《Analytical and bioanalytical chemistry》2011,401(9):2919-2925
Assessment of liver fibrosis is of paramount importance to guide the therapeutic strategy in patients with chronic hepatitis
C (CHC). In this pilot study, we investigated the potential of serum Fourier transform infrared (FTIR) spectroscopy for differentiating
CHC patients with extensive hepatic fibrosis from those without fibrosis. Twenty-three serum samples from CHC patients were
selected according to the degree of hepatic fibrosis as evaluated by the FibroTest: 12 from patients with no hepatic fibrosis
(F0) and 11 from patients with extensive fibrosis (F3–F4). The FTIR spectra (ten per sample) were acquired in the transmission
mode and data homogeneity was tested by cluster analysis to exclude outliers. After selection of the most discriminant wavelengths
using an ANOVA-based algorithm, the support vector machine (SVM) method was used as a supervised classification model to classify
the spectra into two classes of hepatic fibrosis, F0 and F3–F4. Given the small number of samples, a leave-one-out cross-validation
algorithm was used. When SVM was applied to all spectra (n = 230), the sensitivity and specificity of the classifier were 90.1% and 100%, respectively. When SVM was applied to the
subset of 219 spectra, i.e., excluding the outliers, the sensitivity and specificity of the classifier were 95.2% and 100%,
respectively. This pilot study strongly suggests that the serum from CHC patients exhibits infrared spectral characteristics,
allowing patients with extensive fibrosis to be differentiated from those with no hepatic fibrosis. 相似文献
72.
Favier I Castillo AB Godard C Castillón S Claver C Gómez M Teuma E 《Chemical communications (Cambridge, England)》2011,47(27):7869-7871
Chiral carbohydrate-based diphosphites were used for Pd-catalysed asymmetric allylic substitution (alkylation, amination, phosphination) in neat ionic liquids (ILs). Pyrrolidinium-based IL led to the best activities, allowing an efficient catalyst immobilization. In the allylic amination (TOF > 3100 h(-1)), the catalyst could be recycled nine times preserving both activity and enantioselectivity. 相似文献
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Dr. Sébastien Thiery Dr. Denis Tondelier Bernard Geffroy Dr. Olivier Jeannin Dr. Joëlle Rault‐Berthelot Dr. Cyril Poriel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10136-10149
This work reports a detailed structure–property relationship study of a series of efficient host materials based on the donor–spiro–acceptor (D‐spiro‐A) design for green and sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs). The electronic and physical effects of the indoloacridine (IA) fragment connected through a spiro bridge to different acceptor units, namely, fluorene, dioxothioxanthene or diazafluorene moiety, have been investigated in depth. The resulting host materials have been easily synthesised through short, efficient, low‐cost, and highly adaptable synthetic routes by using common intermediates. The dyes possess a very high triplet energy (ET) and tuneable HOMO/LUMO levels, depending on the strength of the donor/acceptor combination. The peculiar electrochemical and optical properties of the IA moiety have been investigated though a fine comparison with their phenylacridine counterparts to study the influence of planarisation. Finally, these molecules have been incorporated as hosts in green and sky‐blue PhOLEDs. For the derivative SIA‐TXO2 as a host, external quantum efficiencies as high as 23 and 14 % have been obtained for green and sky‐blue PhOLEDs, respectively. 相似文献
77.
We describe the first effective H/D exchange reaction with acidic substrates in CDCl(3) at room temperature. The particularly mild reaction conditions involved (solvent, base, and temperature) allow the chemoselective deuteration of ketones over esters. An NMR study was conducted with the aim of rationalizing the results obtained in the presence of TBD as catalyst. 相似文献
78.
Clean Donor Oxidation Enhances the H2 Evolution Activity of a Carbon Quantum Dot–Molecular Catalyst Photosystem 下载免费PDF全文
Benjamin C. M. Martindale Evelyne Joliat Dr. Cyril Bachmann Prof. Dr. Roger Alberto Dr. Erwin Reisner 《Angewandte Chemie (International ed. in English)》2016,55(32):9402-9406
Carbon quantum dots (CQDs) are new‐generation light absorbers for photocatalytic H2 evolution in aqueous solution, but the performance of CQD‐molecular catalyst systems is currently limited by the decomposition of the molecular component. Clean oxidation of the electron donor by donor recycling prevents the formation of destructive radical species and non‐innocent oxidation products. This approach allowed a CQD‐molecular nickel bis(diphosphine) photocatalyst system to reach a benchmark lifetime of more than 5 days and a record turnover number of 1094±61 molH2 (molNi)?1 for a defined synthetic molecular nickel catalyst in purely aqueous solution under AM1.5G solar irradiation. 相似文献
79.
Cover Picture: Fast‐Geomimicking using Chemistry in Supercritical Water (Angew. Chem. Int. Ed. 34/2016) 下载免费PDF全文
80.
Samuel F. Cousin Dr. Pavel Kadeřávek Baptiste Haddou Dr. Cyril Charlier Thorsten Marquardsen Jean‐Max Tyburn Dr. Pierre‐Alain Bovier Dr. Frank Engelke Dr. Werner Maas Prof. Dr. Geoffrey Bodenhausen Dr. Philippe Pelupessy Prof. Dr. Fabien Ferrage 《Angewandte Chemie (International ed. in English)》2016,55(34):9886-9889
Nuclear magnetic resonance (NMR) studies have benefited tremendously from the steady increase in the strength of magnetic fields. Spectacular improvements in both sensitivity and resolution have enabled the investigation of molecular systems of rising complexity. At very high fields, this progress may be jeopardized by line broadening, which is due to chemical exchange or relaxation by chemical shift anisotropy. In this work, we introduce a two‐field NMR spectrometer designed for both excitation and observation of nuclear spins in two distinct magnetic fields in a single experiment. NMR spectra of several small molecules as well as a protein were obtained, with two dimensions acquired at vastly different magnetic fields. Resonances of exchanging groups that are broadened beyond recognition at high field can be sharpened to narrow peaks in the low‐field dimension. Two‐field NMR spectroscopy enables the measurement of chemical shifts at optimal fields and the study of molecular systems that suffer from internal dynamics, and opens new avenues for NMR spectroscopy at very high magnetic fields. 相似文献