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321.
Mara Mirasoli Angela Buragina Luisa Stella Dolci Massimo Guardigli Patrizia Simoni Angel Montoya Elisabetta Maiolini Stefano Girotti Aldo Roda 《Analytica chimica acta》2012
Simple, rapid and highly sensitive assays, possibly allowing on-site analysis, are required in the security and forensic fields or to obtain early signs of environmental pollution. Several bioanalytical methods and biosensors based on portable devices have been developed for this purpose. Among them, Lateral Flow ImmunoAssays (LFIAs) offer the advantages of rapidity and ease of use and, thanks to the high specificity of antigen–antibody binding, allow greatly simplifying and reducing sample pre-analytical treatments. However, LFIAs usually employ colloidal gold or latex beads as labels and they rely on the formation of colored bands visible by the naked eye. With this assay format, only qualitative or semi-quantitative information can be obtained and low sensitivity is achieved. Recently, the use of enzyme-catalyzed chemiluminescence detection in LFIA has been proposed to overcome these problems. In this work, we describe the development of a quantitative CL-LFIA assay for the detection of 2,4,6-trinitrotoluene (TNT) in real samples. Thanks to the use of a portable imaging device for CL signal measurement based on a thermoelectrically cooled CCD camera, the analysis could be performed directly on-field. A limit of detection of 0.2 μg mL−1 TNT was obtained, which is five times lower than that obtained with a previously described colloidal gold-based LFIA developed employing the same immunoreagents. The dynamic range of the assay extended up to 5 μg mL−1 TNT and recoveries ranging from 97% to 111% were obtained in the analysis of real samples (post blast residues obtained from controlled explosion). 相似文献
322.
Carmen Festa Simona De Marino Maria Valeria D’Auria Maria Chiara Monti Mariarosaria Bucci Valentina Vellecco Cécile Debitus Angela Zampella 《Tetrahedron》2012,68(13):2851-2857
DCCC chromatography followed by HPLC purification on the polar extract of marine sponge Theonella swinhoei resulted in the isolation of five new cyclopeptides, perthamides G–K. The new structures, featuring unprecedented amino acid units, were determined by interpretation of extensive spectroscopic and spectrometric data (MS, 1H and 13C NMR, COSY, HSQC, HMBC, and ROESY). Pharmacological analysis demonstrated that these natural cyclopeptides are endowed with anti-inflammatory potential as assessed by their ability to reduce carrageenan-induced mouse paw oedema. 相似文献
323.
Musah RA Vuong AL Henck C Shepard JR 《Journal of the American Society for Mass Spectrometry》2012,23(5):996-999
The spermicide nonoxynol-9 is actually a complex mixture of dozens of closely related amphiphilic compounds, and the chemical
properties of this assortment significantly hamper its characterization by GC-MS. The inability to perform routine GC-MS testing
on nonoxynol-9 has limited its evidentiary value in forensic casework, which relies heavily on this technique for analysis.
A disturbing trend in sexual assault is the use of condoms by assailants, to avoid leaving behind DNA evidence that can connect
a perpetrator to a victim. This observation necessitates the development of alternative methods for the analysis of trace
evidence that can show causal links between a victim and a suspect. Detection of lubricants associated with sexual assault
is one such way to establish this connection. The development of GC-MS methods that permit facile detection of both nonoxynol-9
alone and nonoxynol-9 extracted from other complex matrices that have potential as trace evidence in sexual assault is reported.
A detection limit of 2.14 μg of nonoxynol-9 is demonstrated, and a detailed mass spectral profile that elaborates on what
is known of its structure is provided. 相似文献
324.
Weiss VU Subirats X Pickl-Herk A Bilek G Winkler W Kumar M Allmaier G Blaas D Kenndler E 《Electrophoresis》2012,33(12):1833-1841
During infection, enteroviruses, such as human rhinoviruses (HRVs), convert from the native, infective form with a sedimentation coefficient of 150S to empty subviral particles sedimenting at 80S (B particles). B particles lack viral capsid protein 4 (VP4) and the single-stranded RNA genome. On the way to this end stage, a metastable intermediate particle is observed in the cell early after infection. This subviral A particle still contains the RNA but lacks VP4 and sediments at 135S. Native (150S) HRV serotype 2 (HRV2) as well as its empty (80S) capsid have been well characterized by capillary electrophoresis. In the present paper, we demonstrate separation of at least two forms of subviral A particles on the midway between native virions and empty 80S capsids by CE. For one of these intermediates, we established a reproducible way for its preparation and characterized this particle in terms of its electrophoretic mobility and its appearance in transmission electron microscopy (TEM). Furthermore, the conversion of this intermediate to 80S particles was investigated. Gas-phase electrophoretic mobility molecular analysis (GEMMA) yielded additional insights into sample composition. More data on particle characterization including its protein composition and RNA content (for unambiguous identification of the detected intermediate as subviral A particle) will be presented in the second part of the publication. 相似文献
325.
Single crystal polarized Raman and infrared spectra of the series Na(5)[MO(2)][X] with M = Co(I), Ni(I), and Cu(I) and X = S(2-) and CO(3)(2-), are reported. All phonon modes are assigned to the lattice eigenmodes based on the group theory analysis and first principles lattice dynamics calculations. The energies of the fundamental symmetric and asymmetric vibrations of the [MO(2)](3-) complex are discussed on the basis of their electronic structure and variation in M-O interatomic distances. Electronic Raman scattering and luminescence are observed for the magnetic members of the series (Co(I), d(8), and Ni(I), d(9)). Ligand field theory is employed to account for the electronic effects which originate from states split by spin-orbit coupling. 相似文献
326.
Angela Šurca Vuk Boris Orel Goran Dražič 《Journal of Solid State Electrochemistry》2001,5(7-8):437-449
In this paper we generalize the IR spectroscopic properties of M3+VO4 (M=Fe, In) orthovanadate and Fe2V4O13 films. The films were prepared using the sol-gel synthesis route from M3+ nitrates and vanadium oxoisopropoxide. The vibrational bands in the IR absorbance spectra of the films are classified in
terms of terminal V-O stretching (1050–880 cm–1), bridging V-O...Fe and V...O...Fe stretching (880–550 cm–1), mixed V-O-V deformations and Fe-O stretching (<550 cm–1) modes. Ex situ IR spectra of films were measured after consecutive charging/discharging to various intercalation coefficients x and correlated to the current peaks in the cyclic voltammetry curves measured in 1 M LiClO4/propylene carbonate electrolyte. We classified the ex situ IR spectra of charged/discharged films according to their vibrational
band changes. The results reveal that, for small values of the intercalation coefficient, crystalline FeVO4, InVO4 and Fe2V4O13 films exhibit a simultaneous decrease in the intensity of all IR bands while the band frequencies remain unaffected. For
the higher intercalation levels, IR mode frequencies are shifted, signaling the presence of reduced vanadium. Further charging
leads to an amorphization of the film structure, which was established from the similarity of the IR spectra of charged films
with those of amorphous films prepared at lower annealing temperatures. The results confirm that ex situ IR spectroelectrochemical
measurement is an effective way to assess the structural changes in films with different levels of intercalation.
Electronic Publication 相似文献
327.
Jeremy M. Kaminski Angela Rodríguez-Serrano Fabian Dinkelbach Hector Miranda-Salinas Andrew P. Monkman Christel M. Marian 《Chemical science》2022,13(23):7057
Quantum chemical studies employing combined density functional and multireference configuration interaction methods suggest five excited electronic states to be involved in the prompt and delayed fluorescence emission of TpAT-tFFO. Three of them, a pair of singlet and triplet charge transfer (CT) states (S1 and T1) and a locally excited (LE) triplet state (T3), can be associated with the (Me → N) conformer, the other two CT-type states (S2 and T2) form the lowest excited singlet and triplet states of the (Me → Ph) conformer. The two conformers, which differ in essence by the shearing angle of the face-to-face aligned donor and acceptor moieties, are easily interconverted in the electronic ground state whereas the reorganization energy is substantial in the excited singlet state, thus explaining the two experimentally observed time constants of prompt fluorescence emission. Forward and reverse intersystem crossing between the singlet and triplet CT states is mediated by vibronic spin–orbit interactions involving the LE T3 state. Low-frequency vibrational modes altering the distance and alignment of the donor and acceptor π-systems tune the S1 and T3 states (likewise S2 and T3) into and out of resonance. The enhancement of intersystem crossing due to the interplay of vibronic and spin–orbit coupling is considered a general feature of organic through-space charge-transfer thermally activated delayed fluorescence emitters.DFT/MRCI quantum chemical studies suggest five excited electronic states to be involved in the prompt and delayed fluorescence emission of TpAT-tFFO. 相似文献
328.
329.
Angela P. Blum David A. Nelles Francisco J. Hidalgo Mollie A. Touve Deborah S. Sim Assael A. Madrigal Gene W. Yeo Nathan C. Gianneschi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(44):15793-15796
The scarcity of effective means to deliver functional proteins to living cells is a central problem in biotechnology and medicine. Herein, we report the efficient delivery of an active DNA‐modifying enzyme to human stem cells through high‐density cell penetrating peptide brush polymers. Cre recombinase is mixed with a fluorophore‐tagged polymer carrier and then applied directly to induced pluripotent stem cells or HEK293T cells. This results in efficient delivery of Cre protein as measured by activation of a genomically integrated Cre‐mediated recombination reporter. We observed that brush polymer formulations utilizing cell penetrating peptides promoted Cre delivery but oligopeptides alone or oligopeptides displayed on nanoparticles did not. Overall, we report the efficient delivery of a genome‐modifying enzyme to stem cells that may be generalizable to other, difficult‐to‐transduce cell types. 相似文献
330.
Dr. Sen Ye Dr. Nir Hananya Dr. Ori Green Dr. Hansen Chen Angela Qian Zhao Prof. Dr. Jiangang Shen Prof. Dr. Doron Shabat Prof. Dr. Dan Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14432-14436
Selective and sensitive molecular probes for hydrogen peroxide (H2O2), which plays diverse roles in oxidative stress and redox signaling, are urgently needed to investigate the physiological and pathological effects of H2O2. A lack of reliable tools for in vivo imaging has hampered the development of H2O2 mediated therapeutics. By combining a specific tandem Payne/Dakin reaction with a chemiluminescent scaffold, H2O2-CL-510 was developed as a highly selective and sensitive probe for detection of H2O2 both in vitro and in vivo. A rapid 430-fold enhancement of chemiluminescence was triggered directly by H2O2 without any laser excitation. Arsenic trioxide induced oxidative damage in leukemia was successfully detected. In particular, cerebral ischemia-reperfusion injury-induced H2O2 fluxes were visualized in rat brains using H2O2-CL-510 , providing a new chemical tool for real-time monitoring of H2O2 dynamics in living animals. 相似文献