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Relative molar responses (RMRs) of some straight-chain aliphatic alkanes, ketones, aldehydes, alcohols, carboxylic acids, primary amines, aniline, and nitrobenzene derivatives were investigated related to naphthalene. Most of the respective compounds have not been investigated yet due to their high polarity or high boiling point. The earlier cross section data for oxygenated compounds were changed to RMRs which are more utilizable from an analytical aspect. A linear correlation was found between the RMRs and the carbon atom numbers in primary amines. In the cases of aniline and nitrobenzene derivatives the RMRs were also determined; however, no functional relationship was found. The measurement conditions, i.e., the type of column affect the apparent RMRs of aliphatic primary amines. A midpolar column having a higher maximum operating temperature provides a more sensitive apparent RMR (Rtx-1701) than the basic polar column having a lower maximum temperature (Stabilwax-DB), because a high temperature allows setting a higher injector temperature and a higher amount of compound can reach the ion source. Knowing correlations the quantitative analysis passes into easier and fewer reference materials are needed to investigate a sample having many components, because the sensitivities can be determined from the correlations studied in this paper. This is also valid for aromatic compounds, even though no functional relationship exists. 相似文献
3.
Viera Mrázová Ján Mocák Adriána Bednárová Ján Balla 《Central European Journal of Chemistry》2010,8(6):1216-1222
The objective of this work was a correct statistical comparison of two assay methods for determination of glycated haemoglobin
HbA1c. The immunoturbidimetric determination of HbA1c was performed in two ways: using an automatic analyser Hitachi 912,
calibrated according to the IFCC reference system (International Federation of Clinical Chemistry and Laboratory Medicine)
and using an analyser Advia 1200 and the NGSP reference system (National Glycohaemoglobin Standardization Program). For statistical
comparison of these two analytical methods several advanced regression methods were used, which respect random errors of both
compared methods. Specifically, Deming regression with and without weights, orthogonal regression, and Passing-Bablok regression
were employed. The results demonstrate that the investigated analytical assay methods do not correspond to each other. The
summarized results indicate usefulness of better harmonisation of two existing reference systems. 相似文献
4.
Summary A new type of gas sampling device was constructed to improve the analysis of the gas in halogen lamps. Low levels of gases such as O2, CH4, C2H4 and CH3Br could be determined by the techniques worked out. 相似文献
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Summary The effect of adding an electrolyte and increasing the temperature on the preconcentration of volatile compounds in headspace
analysis has been investigated. Quantification of the interactive effects of temperature and addition of salt on the vapor
concentration is of interest for the determination of trace organic impurities in pharmaceutical base materials. This study
was undertaken to investigate the quantitative effects of the addition of salts alcohols, and acetone, and of increasing the
temperature on the vapor concentrations and distribution coefficients of volatile aromatic compounds (benzene, toluene, ando-xylene). It was found that the concentration of aromatic compound residues in the headspace could be increased by adding
an inert salt to the water, but this effect was not very significant because of the low orginal solubility of the aromatic
compounds in water. The reverse effect can be achieved by use of polar organic additives; this can be explained by the high
polarizability of aromatic compounds and their greater solubility in the presence of these solvents.
Presented at Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 1–3, 1999. 相似文献
6.
Hyder H. Balla Shahrir Abdullah Wan Mohd Faizal WanMahmood M. Abdul Razzaq Rozli Zulkifli Kamaruzaman Sopian 《Research on Chemical Intermediates》2013,39(6):2801-2815
A metallic nanofluid is a suspension of metallic nanoparticles in a base fluid. Multi-metallic nanoparticles are a combination of two or more types of metallic particles. Such multi-metallic nanoparticles were suspended in water using an ultrasonic vibrator for different total volume fractions and different ratios of metallic/metallic nanoparticles. A transient hot wire setup was built to measure the thermal conductivity of the nanofluid at different temperatures. The experimental results were in good agreement with the results in the literature. Then, the experimental results were used as input data for an adaptive neural fuzzy inference system (ANFIS) to predict the thermal conductivity of the multi-metallic nanofluid. The maximum deviation between the ANFIS results and experimental measurements was 1 %. The predicted results and the experimental data were compared with other models. The ANFIS model was found to have good ability to predict the thermal conductivity of the multi-metallic nanofluid over the range of the experimental results. 相似文献
7.
Summary Hydrogen flame-ionization detectors (FIDs) are the most widely used type of detector in gas chromatography. The FID signals
is proportional to the number of carbon atoms in a hydrocarbon molecule; the presence of heteroatoms usually reduces the signal.
If the extent of the signal-reducing effect of heteroatoms were known, it would be possible to measure compounds which are
not available as pure standards, or cannot be prepared, or their preparation is very expensive. The sensitivity of a detector
to an organic molecule containing heteroatoms is referred to normal hydrocarbons by means of the effective carbon-atom number
(ECN) value. By use of the values of increments inECN for heteroatoms and functional groups, theECN can be calculated for any organic molecule. For this, exact values of theECN increments are needed, and the effects of different factors on the increments must be known. In this study a wide range of
homologues of normal paraffins, alcohols, amines, and esters was investigated, with emphasis on differences between the behaviour
of lower and higher homologues. Studies were extended to theECN values of ketones, and aromatic and halogenated compounds. For all types of compound investigated the difference between
the actual carbon number and the calculated effective carbon number (dECN) was compared with literature data, and an attempt was made to interpret the differences. 相似文献
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