Author Keywords: Chemometrics; Modelling; Fitting; Polynomial analytical function; Linear regression; Experimental design 相似文献
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151.
本文紧紧围绕发展我国化纤新品种的现状和展望,提出由“产品先导型”向“技术先导型”、由“市场开发型”向“发展型”过渡的发展展望。按化纤新品种几种主要发展途径,侧重就我国化纤新品种的成就,如:合成新的高聚物,化学、物理(包括结构)改性和纱线、织物后整理等,特别对共聚、共混、多种复合技术改性等,进行了重点讨论。 相似文献
152.
The application of solid layer crystallization techniques in industry is arousing ever more interest. One reason is the increasing demand for ultrapure products, and another is the energysaving potential of this separation technology.This article examines solid layer melt crystallization as concerns its purification efficiency. The crystallization process was carried out in two different modes, whereby the process parameters were varied and post-crystallization treatments were additionally applied. The experimental results were used as the basis for a mathematical fit of a semi-empirical expression which predicts the purification efficiency. It was used for a design of different multistage plants, which operate with different crystallization strategies. One result is that a comparable product quality is attainable with a simple process technique in combination with post-crystallization treatments, instead of a more complicated and therefore more expensive process technique.The authors wish to acknowledge support by the EU (JOULE program), which helped attainment of some results presented here. 相似文献
153.
研究了利用电感耦合等离子体质谱仪测定无尘产品中的痕量杂质元素氯含量的方法,检测下限0.06 ng/mL,精密度RSD<5%(n=7),回收率93.7%~110.0%。 相似文献
154.
Stationary phase crosslinking conditions for fused silica capillary columns were optimized with the use of a factorial design experiment. This experimental strategy was chosen because it provided for the determination of two-factor interactions. A predictive model was developed for the desired chromatographic performance parameters as a function of the variables of the crosslinking reaction. Confirmatory experiments proved the usefulness of the mathematical model which resulted in the production of capillary columns of superior performance with significant improvements in reproducibility. 相似文献
155.
Kiyokawa T Kanaori K Tajima K Kawaguchi M Mizuno T Oku J Tanaka T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(14):3548-3554
The alpha-helical coiled coils have a representative amino acid sequence of (abcdefg)(n) heptad repeats. We previously reported that two peptides named IZ-2A and IZ-2W formed an (IZ-2A)(2)/IZ-2W heterotrimer with an Ala-Ala-Trp interaction in the hydrophobic core. In this paper, we describe the selective formation of AAB- and ABC-type heterotrimers. To increase the selectivity of the AAB-type heterotrimeric formation, Lys residues at the f position were mutated to either an Ala or a Gln residue to form IZ-2A(fA) or IZ-2W(fQ). Separately, both IZ-2A(fA) and IZ-2W(fQ) have a random structure at pH 7 and 20 degrees C. However, together IZ-2A(fA) and IZ-2W(fQ) form a 2:1 complex with a thermal transition midpoint (Tm) of 48 degrees C. This procedure was applied to prepare the ABC-type heterotrimer, in which two sets of Ala-Ala-Trp interactions were designed in the hydrophobic core. Interhelical interaction between the e and g positions and the alpha-helical propensity of the amino acid at the f position were also considered in the design. The resultant three peptides selectively formed the ABC-type heterotrimer with a Tm of 51 degrees C. Other peptide combinations had random coil properties. 相似文献
156.
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158.
The total synthesis of the polyenoyltetramic acid polycephalin C is described. Key steps of the synthesis include a double Swern oxidation, double Takai reaction and a double Stille reaction. In addition, the absolute stereochemistry of the ring junction has been determined by synthesis of both isomers and comparison of their CD spectra with natural polycephalin C. 相似文献
159.
An algorithm for searching the best polynomial analytical function for describing different experimental systems is presented. It is based
1. (1)on the generation of all possible analytical functions of a given order, with a given number of terms and with a given number of independent variables, and
2. (2)on the calculation of the parameters of all selected functions using the linear regression method.
To show the ability of the program two different examples are given:
1. (1) searching the best univariate polynomial model, and
2. (2) modelling of the stability of a two-component mixture as a function of three factors.
160.
Fernando J. S. Oliveira Francisca P. De França 《Applied biochemistry and biotechnology》2005,122(1-3):593-603
A 23 full factorial experimental design was adopted to estimate the effects of three variables on the biodegradation of oil during
soil bioremediation: bioaugmentation seeding a mixed culture, addition of fertilizer or mineral media, and correction of initial
pH of the soil to 7.0. The tests were carried out in polyvinyl chloride reactors with 5.0 kg of crude oil-contaminated soil
at 14 g/kg. After screening the variables, soil bioremediation tests were conduced with varied C:N ratios, yielding an increase
in biodegradation of the oil heavy fraction from 24 to 65%, consumption of total n-paraffins, and a remarkable decrease in the concentration of residual polycyclic aromatic hydrocarbons of the soil. 相似文献