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排序方式: 共有373条查询结果,搜索用时 31 毫秒
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Hitoshi Osawa Toshiaki IwazumiHiroko Tokoro Shin-ichi OhkoshiKazuhito Hashimoto Hironobu ShojiEiju Hirai Tetsuya NakamuraSusumu Nanao Yasuhito Isozumi 《Solid State Communications》2003,125(5):237-241
The thermal phase transition of RbMnFe(CN)6 has been observed by Mn and Fe 3p-1s X-ray emission spectroscopy (XES) and 1s X-ray absorption spectroscopy (XAS). The thermal variations of the spin states and the valences of Mn and Fe were determined to be Mn2+(S=5/2)-NC-Fe3+(S=1/2) for the high-temperature (HT) phase and Mn3+(S=2)-NC-Fe2+(S=0) for the low-temperature (LT) phase. These transitions are thus caused by charge transfer between Mn and Fe. The temperature dependences of Mn and Fe 3p-1s XES and 1s XAS were observed as the composition of the spectra of the HT and LT phases. The ratios of the HT component in each spectrum show good agreement with the thermal transition curves observed with magnetic susceptibility measurements. 相似文献
44.
György Bázár Zoltan Kovacs Mariko Tanaka Akane Furukawa Airi Nagai Manami Osawa Yukari Itakura Hiroshi Sugiyama Roumiana Tsenkova 《Analytica chimica acta》2015
Near infrared spectroscopy is an overtone spectroscopy regarded as a quick and non-destructive method that provides analytical solutions for components that represent approximately 1% or more of the total mass of the investigated composite samples. Aquaphotomics offers the possibility for disentanglement of information remaining hidden in the spectra when conventional data evaluation methods are used, since this concept utilizes changes of the water structure induced by the measured solute as specific molecular vibrations at water bands. Here, near infrared technique and aquaphotomics are applied for non-destructive identification and quantification of mono- and di-saccharide solutes at 100–0.02 mM concentration that is accepted as unachievable with near infrared spectroscopy. The results presented in this study support the aquaphotomics' water molecular mirror concept that explores spectral changes related to water molecular rearrangements caused by minute changes of the solutes in the aqueous systems. The method provides quick and accurate alternative for classical analytical measurements of saccharides even at millimolar concentration levels. 相似文献
45.
Fraction collection of selected components from a complex mixture plays a critical role in biomedical research, environmental analysis, and biotechnology. Here, we introduce a novel electrophoretic chip device based on a signal processing theorem that allows simultaneous space sampling for fractionation of ssDNA target fragments. Ten parallel extraction channels, which covered 1.5-mm-long sampling ranges, were used to facilitate the capturing of fast-moving fragments. Furthermore, the space sampling extraction made it possible to acquire pure collection, even from partly overlapping fragments that had been insufficiently separated after a short electrophoretic run. Fragments of 180, 181, and 182 bases were simultaneously collected, and then the recovered DNA was PCR amplified and assessed by CE analysis. The 181-base target was shown to be isolated in a 70-mm-long separation length within 10 min, in contrast to the >50 min required for the 300-mm-long separation channel in our previous study. This method provides effective combination of time and space, which is a breakthrough in the traditional concept of fraction collection on a chip. 相似文献
46.
Contamination of the exterior surface of vials of cytostatic drugs by the drugs themselves is a potential hazard to human health. This study developed a validated method using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the determination of contamination of the exteriors of vials of cisplatin and carboplatin. Large Alpha® sampling swabs were employed to wipe the vial exterior. Cisplatin or carboplatin and gold(III) as an internal standard were derivatized by N,N-diethyldithiocarbamate (DDTC). Pt(DDTC)3+ and Au(DDTC)2+ were monitored by the respective transitions of m/z 639.3-490.9 and 493.0-345.0, respectively. Each separation was completed within 9 min using a 3 μm particle ODS-column. Calibration curves for cisplatin and carboplatin were linear over concentration ranges of 30-10,000 and 30-30,000 pg vial−1, respectively. The accuracies and precisions were 96.1-102.5% and within 8.2% for intra-assay and 99.6-103.3% and within 7.6% for inter-assay, respectively. Their lower limit of quantification was 30 pg vial−1. Amounts of 0.17-17.0 ng vial−1 as cisplatin and 0.48-794 ng vial−1 as carboplatin were detected from the exterior surface of the vials. This validated method using LC-ESI-MS/MS for the determination of platinum anticancer drugs is helpful for monitoring contamination of the exterior surface of drug vials. 相似文献
47.
Namba K Osawa A Ishizaka S Kitamura N Tanino K 《Journal of the American Chemical Society》2011,133(30):11466-11469
An efficient and versatile method was established for the preparation of 1,3a,6a-triazapentalenes. The 1,3a,6a-triazapentalene skeleton without an additional fused ring system was discovered to be a compact and highly fluorescent chromophore, which exhibited various interesting fluorescent properties such as a noteworthy correlation of luminescent wavelength with the Hammett σ(p) value and a strongly positive solvatofluorochromism. 相似文献
48.
On-chip fraction collection for multiple selected ssDNA fragments using isolated extraction channels
Li Z Sun K Sunayama M Matsuo Y Mizeikis V Araki R Ueno K Abe M Misawa H 《Journal of chromatography. A》2011,1218(7):997-1003
High efficiency and high-purity fraction collection is highly sought in analysis of fragments-of-interest from selective polymerase chain reaction (PCR) products generated by High Coverage Gene Expression Profiling (HiCEP) methods. Here we demonstrate a new electrophoretic chip device enabling automatic high-efficient fractionation of multiple ssDNA target fragments during a run of separation. We used thoroughly isolated extraction channels for each selected target to reduce the risk of cross-contamination between targets due to cross-talk of extraction channels. Fragments of 35, 108 and 138 b, were successfully isolated, then the recovery was PCR-amplified and assessed by capillary electrophoresis (CE) analysis. Total impurity level of the targets due to unwanted fragments of 0.7%, 2% and 6% respectively, was estimated. Difficulties in collecting multiple target factions are due to band diffusion and DNA adsorption to the walls for the fragments in the separation channel, which is generated by transferring the DNA target fraction from the extraction section to the target reservoir. Therefore, we have carefully measured band broadening and analyzed its influence on the separation resolution due to the delay. 相似文献
49.
Masubuchi M Toyota T Yamada M Seki M 《Chemical communications (Cambridge, England)》2011,47(29):8433-8435
Molecular self-assemblies exhibiting automatic motions have received much attention as potential artificial models of living organisms. We have developed a microfluidic picolitre nozzle-array device to form multilamellar lipid tubes (MLTs) under fluidic shear stress, which transformed into different two patterns (yarn-balls and double-helixes) and also exhibited unique self-actuation behaviors. 相似文献
50.
An improved method of sample injection was demonstrated for introducing ultra-low volume liquid on a microfabricated device. In our previous study, a pressure-driven injection method has been introduced and was applied to on-chip electrophoresis. In this study, the need for control of the air vent, which was indispensable for sample injection in the previous study, was completely eliminated, facilitating sample injection with great simplicity and high accuracy. This was realized by altering the topology of the air vent channel, which is connected to a hydrophobic and narrow channel (called a passive valve). Several types of air vent channels were designed and their injection performances were tested. In addition, by modifying the shape and the position of air vent channel and passive valve, the residual liquid volume inside the passive valve after sample injection was decreased to approximately 0.5% of the injected volume, a value which showed high reproducibility. 相似文献