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201.
Kenichi Murata Kazuki Kajiya Megumi Nukaga Yosuke Suga Toshiyuki Watanabe Nobuhumi Nakamura Hiroyuki Ohno 《Electroanalysis》2010,22(2):185-190
A simple method for constructing gold nanoparticle‐modified electrodes with three‐dimensional nanostructures is demonstrated. The electrodes were prepared by casting citrate‐reduced AuNPs onto polycrystalline gold electrodes. The resultant electrodes had a large surface area‐to‐volume ratio, adequate for high protein loading and conferring high stability. The gold nanoparticle electrodes were covered with a self‐assembled monolayer of 11‐mercaptoundecanoic acid for electrostatic immobilization of cytochrome c (cyt c). At the electrode, direct, reversible electron transfer from cyt c was observed with remarkable stability. Moreover, an extremely high surface coverage of electrochemically active cyt c, 167 fully packed monolayers, was obtained through use of the electrode. 相似文献
202.
Shigeo Hayakawa Shinya Matsumoto Mami Hashimoto Kenichi Iwamoto Hirofumi Nagao Michisato Toyoda Yasushi Shigeri Michiko Tajiri Yoshinao Wada 《Journal of the American Society for Mass Spectrometry》2010,21(9):1482-1489
Post-translational modifications (PTMs) of proteins are important in the activation, localization, and regulation of protein
function in vivo. The usefulness of electron capture dissociation (ECD) and electron-transfer dissociation (ETD) in tandem
mass spectrometry (MS/MS) using low-energy (LE) trap type mass spectrometer is associated with no loss of a labile PTM group
regarding peptide and protein sequencing. The experimental results of high-energy (HE) collision induced dissociation (CID)
using the Xe and Cs targets and LE-ETD were compared for doubly-phosphorylated peptides TGFLT(p)EY(p)VATR (1). Although HE-CID using the Xe target did not provide information on the amino acid sequence, HE-CID using the Cs target
provided all the z-type ions without loss of the phosphate groups as a result of HE-ETD process, while LE-ETD using fluoranthene
anion gave only z-type ions from z5 to z11. The difference in the results of HE-CID between the Xe and Cs targets demonstrated that HE-ETD process with the Cs target
took place much more dominantly than collisional activation. The difference between HE-ETD using Cs targets and LE-ETD using
the anion demonstrated that mass discrimination was much weaker in the high-energy process. HE-ETD was also applied to three
other phosphopeptides YGGMHRQEX(p)VDC (2: X = S, 3: X = T, 4: X = Y). The HE-CID spectra of the doubly-protonated phosphopeptides
(= [M + 2H]2+) of 2, 3, and 4 using the Cs target showed a very similar feature that the c-type ions from c7 to c11 and the z-type ions from z7 to z11 were formed via N-Cα bond cleavage without a loss of the phosphate group. 相似文献
203.
Microperforated panels (MPPs) can provide wide-band absorption without fibrous and porous materials and are recognized as next-generation absorption materials. Although the fundamental absorbing mechanism of an MPP absorber is Helmholtz-resonance absorption, sound-induced vibration of an MPP itself can affects the absorption characteristics. There have been some studies considering the effects of the sound-induced vibration and there even is a proposal to widen the absorption bandwidth by positively utilizing the vibration of an MPP itself. On the other hand, in a previous study, the relationship between MPP absorbers and panel-type absorbers was investigated with infinite theory. However, the relationship between Helmholtz-resonance absorption and panel-type absorption in finite flexible MPP absorbers has not been clarified. Herein, from the viewpoint of an absorption-characteristics transition with the perforation ratio, the relationship between Helmholtz-resonance absorption and panel-type absorption including the effects of eigen-mode vibrations of the panel is theoretically and experimentally investigated. The analytical model considers a finite flexible MPP supported in a circular duct, and the predicted data for the absorption coefficient under normal incidence is validated by an experiment using an acoustic tube. From this investigation, it is found that panel-type absorption due to eigen-mode vibrations of the panel occurs independently from Helmholtz-resonance absorption, while panel-type absorption due to a mass-spring resonance of a panel and a back cavity has a trade-off relationship with Helmholtz-resonance absorption with respect to the perforation ratio. 相似文献
204.
Yamanaka M Sada K Miyata M Hanabusa K Nakano K 《Chemical communications (Cambridge, England)》2006,(21):2248-2250
Superhydrophobic surfaces, characterized by water contact angles greater than 150 degrees, can be produced by means of intermediate organogels, which were formed by perfluoroalkyl chain-containing organogelators with volatile organic solvents. 相似文献
205.
Tominaga M Matsumoto M Soejima K Taniguchi I 《Journal of colloid and interface science》2006,299(2):761-765
We demonstrated the fabrication of size-controlled two-dimensional iron oxide nanodots derived from the heat treatment of ferritin molecules self-immobilized on modified silicon surfaces. Ferritin molecules were immobilized onto 3-aminopropyltrimethoxysilane (3-APMS)-modified silicon surfaces by electrostatic interactions between negatively charged amino acids of ferritin molecules and amino terminal functional groups of 3-APMS. Heat treatments were performed at 400 degrees C for 60 min to fabricate two-dimensional nanodots based on ferritin cores. XPS and FT-IR results clearly indicate that ferritin shells were composed of amino acids and 3-APMS modifiers on silicon surfaces were eliminated by heat treatment. Nanodots on substrate surfaces corresponded to iron oxides. The size of nanodots was tunable in the range of 0-5 (+/-0.75) nm by in situ reactions of iron ion chelators with ferritin molecules immobilized on substrates before heat treatment. 相似文献
206.
Tokunaga N Fujiki Y Shinkai S Sada K 《Chemical communications (Cambridge, England)》2006,(34):3617-3618
Face-selective decoration of a single crystal constructed from 1-pyrenemethylammonium chloride by an anionic porphyrin dye is reported. CLSM observations indicated that the {001} face of the single crystal was selectively coated by the anionic porphyrin (TPPS). This novel achievement could be the first step for preparation of multi-component composite materials mediated by anisotropy of organic single crystals toward photochemical devices. 相似文献
207.
Hadamard transform capillary electrophoresis (HTCE) based on electrokinetic injection allows laser-induced fluorescence detection using a small laser, namely the laser-diode-pumped YAG laser, as an excitation source. A small hole is fabricated at the center of a capillary by laser ablation; this hole functions as an inlet port for a sample solution. Therefore, the sample solution can be introduced electrophoretically into the capillary through the small hole. Multiple sample injection is accomplished by introducing a buffer solution from the end of the capillary and the sample solution through the hole. Both solutions are injected using two sets of high-voltage power supplies and migrate toward the opposite end of the capillary. A fluorescent analyte, rhodamine B, is successfully detected in the case of both single and multiple injection according to the Hadamard sequence code. By transforming the data encoded by the Hadamard matrix, the decoded data showed an increase in the signal-to-noise (S/N) ratio by a factor of 9.8. In the case of the sample containing two amino acids labeled with rhodamine B isothiocyanate (RBITC), although the concentration of every component including free RBITC is lower than the concentration limit of detection obtained by single injection, a substantial improvement in the sensitivity is achieved and all components are identified by the Hadamard transform technique. 相似文献
208.
Hisayuki Horai Masanori Arita Shigehiko Kanaya Yoshito Nihei Tasuku Ikeda Kazuhiro Suwa Yuya Ojima Kenichi Tanaka Satoshi Tanaka Ken Aoshima Yoshiya Oda Yuji Kakazu Miyako Kusano Takayuki Tohge Fumio Matsuda Yuji Sawada Masami Yokota Hirai Hiroki Nakanishi Kazutaka Ikeda Naoshige Akimoto Takashi Maoka Hiroki Takahashi Takeshi Ara Nozomu Sakurai Hideyuki Suzuki Daisuke Shibata Steffen Neumann Takashi Iida Ken Tanaka Kimito Funatsu Fumito Matsuura Tomoyoshi Soga Ryo Taguchi Kazuki Saito Takaaki Nishioka 《Journal of mass spectrometry : JMS》2010,45(7):703-714
MassBank is the first public repository of mass spectra of small chemical compounds for life sciences (<3000 Da). The database contains 605 electron‐ionization mass spectrometry(EI‐MS), 137 fast atom bombardment MS and 9276 electrospray ionization (ESI)‐MSn data of 2337 authentic compounds of metabolites, 11 545 EI‐MS and 834 other‐MS data of 10 286 volatile natural and synthetic compounds, and 3045 ESI‐MS2 data of 679 synthetic drugs contributed by 16 research groups (January 2010). ESI‐MS2 data were analyzed under nonstandardized, independent experimental conditions. MassBank is a distributed database. Each research group provides data from its own MassBank data servers distributed on the Internet. MassBank users can access either all of the MassBank data or a subset of the data by specifying one or more experimental conditions. In a spectral search to retrieve mass spectra similar to a query mass spectrum, the similarity score is calculated by a weighted cosine correlation in which weighting exponents on peak intensity and the mass‐to‐charge ratio are optimized to the ESI‐MS2 data. MassBank also provides a merged spectrum for each compound prepared by merging the analyzed ESI‐MS2 data on an identical compound under different collision‐induced dissociation conditions. Data merging has significantly improved the precision of the identification of a chemical compound by 21–23% at a similarity score of 0.6. Thus, MassBank is useful for the identification of chemical compounds and the publication of experimental data. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
209.
210.
5-Methylcytosine was distinguished from cytosine using the large difference of their osmium oxidation rates, and this reaction was applied to detection of the cytosine methylation status at a specific site of a long sequence using the formation of a bulge structure by hybridization with a guide DNA. 相似文献