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121.
Mariana Ramos-Estrada Gustavo A. Iglesias-Silva Kenneth R. Hall F. Kohler 《Fluid Phase Equilibria》2006,240(2):179-185
We use the Clausius–Clapeyron equation to calculate third virial coefficients at low reduced temperatures. This procedure gives an alternative to predict third virial coefficients in a region where the third virial coefficient is difficult to measure. We compare the results of this method with published third virial coefficient data. Calculated third virial coefficients have average percentage deviations within 5% of the experimental values at reduced temperatures between 0.8 and 1.0. 相似文献
122.
123.
The alignment of analytical signals is an important preprocessing step when further analysis (e.g. PCA) requires the same lengths of all of them. Two techniques for alignment of profiles, namely dynamic time warping (DTW) and correlation optimized warping (COW) were tested and compared. The attention was focused on chromatographic and spectroscopic profiles. Simulated and two sets of real data were studied in this study. 相似文献
124.
Summary The possibilities and limitation of automated solute identification via UV/VIS spectroscopy in HPLC are demonstrated and applications in toxicologic analysis are described. A standard isocratic system is used. The influence of various chromatographic parameters on retention time is shown. A retention time window of ±15% is required. In addition to retention time, derived spectral data are calculated (minima and maxima of derivatives, area counts under standardized spectral ranges, absorption at various wavelength) and used for positive solute identification. It is possible to identify solutes with a high degree of certainty in urine and plasma if their concentration is at least 10 ppm. 相似文献
125.
126.
Ross Graham 《Journal of statistical physics》1982,29(2):177-183
We establish the following new correlation inequalities for the truncated twopoint function of an Ising ferromagnet in a positive external field:
j
;
l
T
j
;
k
T
k
;
l
T
, and
j
;
l
T
k K
j
;
k
T
k
l
, whereK is any set of sites which separatesj froml. The inequalities are also valid for the pure phases with zero magnetic field at all temperatures. Above the critical temperature they reduce to known inequalities of Griffiths and Simon, respectively.NSERC Postgraduate Fellow, 1978–1981. Research supported in part by NSF Grant No. PHY-78-25390-A02. 相似文献
127.
Summary The effect of drying conditions on the preservation of chlorophyll pigments in mint and basil have been investigated in order to determine the effects of drying temperature and whether or not there was a prior blanching.Pigments extracted from fresh and dried samples were analyzed by reversed phase high performance liquid chromatography coupled to a photodiode array detector; isocratic separation was performed on a Zorbax ODS C18 column.The purity of the chromatographic peaks of chlorophylls and breakdown products was investigated. The visible spectra of standard samples of chlorophylls and pheophytins were compared, using least squares normalization with those of peaks from the extracts of fresh and dried mint and basil. The study has shown that chlorophylls were better preserved when drying was preceded by a short blanching; if samples were not blanched before drying, the degradation of chlorophylls a and b was best prevented by drying at low temperatures. 相似文献
128.
129.
Xianpeng Yin Hao Dong Shiqiang Wang Yun Liang Ning Gao Wanlin Zhang Li Tian Fuwei Sun Guangtao Li 《中国化学快报》2019,30(1):179-182
In this work, large area gold-nanoparticle-cluster pillar array with a gold mirror as high-performance SERS substrate was facilely fabricated by combined use of nanosphere lithography and self-assembly approach. 相似文献
130.
A rapid and inexpensive method for simultaneous quantification of terbumeton (TER), and its major potential metabolites (TED;
terbumeton-desethyl, TOH; terbumeton-2-hydroxy and TID; terbumeton-deisopropyl) in soil bulk water (SBW) samples is proposed.
The analytical method involves extraction–concentration from SBW samples using a graphitized carbon black (GCB) cartridge
followed by their separation–detection by reversed-phase high-performance liquid chromatography analysis using a C18 column and a diode array detector. A mobile phase of acetonitrile−0.005 mol L−1 phosphate buffer (pH 7.0) (35:65, v/v) at a flow rate of 0.8 mL min−1 in isocratic elution mode has been used. After optimization of the extraction and separation conditions, this method can be
used for the simultaneous determination of investigated compounds in the range of the international limits of 0.1 μg L−1. For TER the detection limit was 0.009 μg L−1 and it was 0.100, 0.550, and 0.480 μg L−1 for TED, TOH, and TID, respectively. The recoveries of TER, TED, TOH, and TID from SBW samples, measured at three levels of
concentration range, were found to be between 48.0 and 102.0%. The intra-day precision measured by relative standard deviation
(RSD) was always lower than 9.0%. 相似文献