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排序方式: 共有166条查询结果,搜索用时 15 毫秒
11.
A microfluidic approach for rapid bioluminescent real-time detection of single nucleotide polymorphism (SNP) is presented. The method is based on single-step primer extension using pyrosequencing chemistry to monitor nucleotide incorporations in real-time. The method takes advantage of the fact that the reaction kinetics differ between matched and mismatched primer-template configurations. We show here that monitoring the initial reaction in real time accurately scores SNPs by comparing the initial reaction kinetics between matched and mismatched configurations. Thus, no additional treatment is required to improve the sequence specificity of the extension, which has been the case for many allele-specific extension assays. The microfluidic approach was evaluated using four SNPs. Three of the SNPs included primer-template configurations that have been previously reported to be difficult to resolve by allele-specific primer extension. All SNPs investigated were successfully scored. Using the microfluidic device, the volume for the bioluminescent assay was reduced dramatically, thus offering a cost-effective and fast SNP analysis method. 相似文献
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Islam Ullah Khan Tehseen Aman Muhammad Asif Iqbal Asrar Ahmad Kazi 《Mikrochimica acta》2000,134(1-2):27-31
Fluoxetine hydrochloride reacts with benzoyl peroxide and potassium iodide, after heating for 1 min at 30 °C, to give a blue
colour having maximum absorbance at 570 nm. The reaction is selective for fluoxetine with 0.01 mg/mL as visual limit of quantitation
and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.1 mg/10 mL to
2.0 mg/10 mL of fluoxetine and the relative standard deviation is 0.68%. The qualitative assessment of tolerable amounts of
other drugs is also studied.
Received September 21, 1998. Revision September 10, 1999. 相似文献
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A Multi‐Addressable Switch Based on the Dimethyldihydropyrene Photochrome with Remarkable Proton‐Triggered Photo‐opening Efficiency
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Dr. Diego Roldan Dr. Saioa Cobo Dr. Frédéric Lafolet Dr. Neus Vilà Dr. Constance Bochot Dr. Christophe Bucher Prof. Dr. Eric Saint‐Aman Dr. Martial Boggio‐Pasqua Dr. Marco Garavelli Prof. Dr. Guy Royal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):455-467
A series of photochromic derivatives based on the trans‐10b,10c‐dimethyl‐10b,10c‐dihydropyrene (DHP, “closed form”) skeleton has been synthesized and their photoisomerization leading to the corresponding cyclophanediene (CPD, “open form”) isomers has been investigated by UV/Vis and 1H NMR spectroscopies. Substitution of the DHP core with electron‐withdrawing pyridinium groups was found to have major effects on the photoisomerization efficiency, the most remarkable examples being to enhance the quantum yield of the opening reaction and to allow fast and quantitative conversions at much lower radiant energies. This effect was rationalized by theoretical calculations. We also show that the reverse reaction, that is, going from the open form to the closed form, can be electrochemically triggered by oxidation of the CPD unit and that the photo‐opening properties of pyridine‐substituted DHPs can be efficiently tuned by protonation, the system behaving as a multi‐addressable molecular switch. These multi‐addressable photochromes show promise for the development of responsive materials. 相似文献
16.
Kulshrestha A Schomaker JM Holmes D Staples RJ Jackson JE Borhan B 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(44):12326-12339
Good to excellent stereoselectivity has been found in the addition reactions of Grignard and organozinc reagents to N-protected aziridine-2-carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl-protected cis, tert-butyloxycarbonyl-protected trans, and tosyl-protected 2,3-disubstituted aziridine-2-carboxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziridines' substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6-31G* level of theory with the SM8 solvation model to account for solvent effects. 相似文献
17.
We present a compact passively q-switched diode end pumped Nd:YAG laser at 1064 nm for 2D micromachining. It consists of a 5.5 cm long plano-concave end pumped resonator carrying a Cr:YAG passive q-switch inside the cavity. With an optical conversion efficiency of 46 and 33% the laser emits 1.4 W in CW and 986 mW in q-switched mode at a current of 2.5 A. After using a 2 mm circular aperture the output is seen in TEM00 mode with a single pulse energy of 5 mJ. The laser produced circular holes of diameter 75 μm in 25 μm thick Tantalum foils. Actual results of 1D and 2D machining are shown along with the diffraction patters of the samples. 相似文献
18.
Bernabé L. Rivas Julio Sánchez S. Amalia Pooley Luis Basaez Eduardo Pereira Christophe Bucher Guy Royal Eric Saint Aman Jean-Claude Moutet 《Macromolecular Symposia》2010,296(1):416-428
Arsenic species can be removed from aqueous solutions using the liquid-phase polymer-based retention, LPR, technique. The LPR technique removes ionic species by functional groups of water-soluble polyelectrolytes (WSP) and then using a ultrafiltration membrane that does not let them pass through the membrane, thus separating them from the solution. The ability of WSP with groups (R)4N+X− to remove arsenate ions using LPR was studied. The interaction and arsenate anion retention capacity depended on: pH, the quaternary ammonium group's counter ion, and the ratio polymer: As(V), using different concentrations of As(V). Water-soluble polychelates were also used for one-step retention of As(III) in solution. The complex of poly(acrylic acid)-Sn, 10 and 20 wt-% of metal gave a high retention of As(III) species at pH 8, although the molar ratio polychelate: As(III) was 400:1. The enrichment method was used to determine the maximum retention capacity (C) for arsenate anions in aqueous solutions at pH 8. In similar conditions, the values of C were 142 mg g−1 for P(ClAETA) and 75 mg g−1 for P(SAETA). The combined treatment of arsenic aqueous solutions by electrocatalytic oxidation (EO) to convert the species of As(III) to As(V) with the LPR technique quantitatively removed arsenic. 相似文献
19.
We present the operation of a diode-pumped high-power electro-optically Q-switched 4 W Nd:LuAG laser operating at 1064 nm. At an absorbed optical power of 20 W, the laser described provides a maximum output of 3.5 W average power at a repetition rate of 50 Hz. The output varies up to a factor of 1.3% for about 1 h operation with a peak power of 280 kW, with the laser beam quality in the TEM00 mode. 相似文献
20.
Anil K. Gupta Xiaopeng Yin Munmun Mukherjee Aman A. Desai Aliakbar Mohammadlou Kelsee Jurewicz William D. Wulff 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3399-3405
A highly diastereo‐ and enantioselective method for the epoxidation of aldehydes with α‐diazoacetamides has been developed with two different borate ester catalysts of VANOL. Both catalytic systems are general for aromatic, aliphatic, and acetylenic aldehydes, giving high yields and inductions for nearly all cases. One borate ester catalyst has two molecules of VANOL and the other only one VANOL. Catalysts generated from BINOL and VAPOL are ineffective catalysts. An application is shown for access to the side‐chain of taxol. 相似文献