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1.
With the aid of Riemann–Liouville fractional calculus theory,fractional order Savitzky–Golay differentiation(FOSGD) is calculated and applied to pretreat near infrared(NIR) spectra in order to improve the performance of multivariate calibrations.Similar to integral order Savitzky–Golay differentiation(IOSGD),FOSGD is obtained by fitting a spectral curve in a moving window with a polynomial function to estimate its coefficients and then carrying out the weighted average of the spectral curve in the window with the coefficients.Three NIR datasets including diesel,wheat and corn datasets were utilized to test this method.The results showed that FOSGD,which is easy to compute,is a general method to obtain Savitzky–Golay smoothing,fractional order and integral order differentiations.Fractional order differentiation computation to the NIR spectra often improves the performance of the PLS model with smaller RMSECV and RMSEP than integral order ones,especially for physical properties of interest,such as density,cetane number and hardness.  相似文献   

2.
The availability of whole genome sequence information of Ixodes scapularis (Acari: Ixodidae), an important disease vector of veterinary and public health importance, has opened up new opportunities to explore the vector species at genomic level. Use of acaricides is the mainstay in controlling the disease vector, as effective vaccines are not available for most of the diseases that are transmitted by ticks. The glutathione S-transferase (GST) enzymes are one of the important supergene families that are involved in protecting the organism from oxidative stress and xenobiotics including the acaricides. The analysis of GST supergene family from Ixodes identified all the three broad GST classes, viz. canonical, mitochondrial, and microsomal forms. In total, 35 GST genes belong to five different canonical GST classes, namely Delta (7 genes), Epsilon (5), Mu (14), Omega (3), and Zeta (3 genes) GST classes, and two mitochondrial Kappa class GST genes, and a single microsomal GST gene were found. Interestingly, Delta- and Epsilon-class members, which are thought to be specific to the class Insecta, were also identified in Ixodes. Further, vertebrate/mammalian specific Mu-GSTs (14 genes) were also identified in Ixodes. Analyses of the intron-exon organization revealed higher frequency of phase '0' and phase '2' introns. The comprehensive listing of the GST supergene family members from Ixodes may help in understanding molecular mechanisms of the acaricide resistance in mites and ticks. Cumulatively, these findings may provide an in-depth understanding of the complex evolution of GST supergene family, one of the oldest supergene families that exist in all the domains of life.  相似文献   

3.
The Uygur ethnic minority is the largest ethnic group in the Xinjiang Uygur Autonomous Region of China, and is a precious resource for the study of ethnogeny and forensic biology. Previous studies have focused on the genetic background of the Uygur group, however, the patrilineal descent of the group is still unclear. In this study, we investigated the genetic diversity of 24 Y‐STR loci in the Uygur group and analyzed the population differentiations as well as the genetic relationships between the Uygur group and other previously reported populations using 17 Y‐filer loci. According to haplotypic analysis of the 24 Y‐STR loci in 109 Uygur individuals, 104 different haplotypes were obtained, 99 of which were unique. The haplotypic diversity and discrimination capacity of these 24 Y‐STR loci in Uygur group were 0.9992 and 0.9541, respectively. An additional 7 loci (DYS388, DYS444, DYS447, DYS449, DYS522, and DYS527a,b) showed high genetic diversity and improved the overall discrimination capacity of the 24 Y‐STR system. Pairwise Fst and neighbor‐joining analysis showed that the Uygur group was genetically close to the Han populations from different regions.  相似文献   

4.
铊的环境污染与迁移转化   总被引:6,自引:0,他引:6  
从铊的环境污染途径及其在环境中迁移转化等方面,分析了铊这一分散剧毒元素的表生地球化学行为,环境迁移,分散富集规律和特征,铊的环境污染研究方向和内容。  相似文献   

5.
《中国化学快报》2020,31(7):1970-1973
The biogeochemical transformation of gold (Au), i.e. its dissolution and re-precipitation, is critical in supergene transport of Au and formation of Au granules. Besides biogenic reduction, the formation Au granules can also be driven by chemical processes. Previous studies have showed the formation of Au nanoparticles (AuNPs) from ionic Au(III) can be mediated by dissolved organic matter under sunlight. In this letter, we further demonstrated that these AuNPs can further slowly (in years) grow into visible Au granules. Different sized nano-flower and fractal dendrite-like branched gold structures (from tens of nanometres to over 100 μm) were observed in the Au granule sample. This growth of AuNPs into visible Au granules may play a critical role in the supergene mineralization and enrichment of secondary Au and drive the biogeochemical cycle of Au.  相似文献   

6.
Physicochemical modeling was applied to determine Eh and pH parameters of anthropogenic mineral formation in the Kavalerovskii mining district, study crystallization of supergene minerals from solution, examine the qualitative and quantitative ion compositions of solutions, estimate the role of supergenesis in the pollution of surface and ground water, and assess environmental situation in the district.  相似文献   

7.
8.
The sudden model of atom—molecule vibrotational scattering is generalized to introduce effects of nuclear relaxation. Ab initio corrections are obtained in the form of energy and space differentiations of an off-shell sudden T-matrix. The physical interpretation of the theory and a preliminary numerical application are considered.  相似文献   

9.
A petrochemical study of some rock samples has been carried out using different experimental techniques. The rock samples were collected from the Al-Mizil area, Saudi Arabia. Al-Mizil area consists of Precambrian metasediments which belong to the Halaban Formation. The plutonic rocks later intruded into the Halaban Formation. Major oxides and trace elements in these rocks are presented. The study indicates that the rocks are mainly of granitic composition. The petrochemical data suggest a magmatic origin for Al-Mizil granitic rocks.  相似文献   

10.
The physico-chemical parameters of crystallization (genesis) of 30 supergene minerals from the mine, slime, and drainage waters in the mining technogenic systems of sulfide-containing deposits of the Far East of Russia are presented. The data have been obtained using Selektor software complex allowing modeling the sulfides oxidation under the hypergenesis and technogenesis conditions. We have determined the temperature ranges of formation and association of the primary and secondary minerals.  相似文献   

11.
Isotope effects on the resonance cross sections of preassociative scattering are explicitly studied for the O2, OH and OD systems, based on a semiclassical theory similar to Stückelberg's theory of inelastic scattering. It is found that there are significant isotopic differentiations for the systems studied, which may be exploited in the laboratory for selective photodissociations of the molecules.  相似文献   

12.
A pre-irradiation group separation method has been developed for the neutron activation analysis of rare earth elements (REE) and Ba in silicate rocks. REE and Ba were quantitatively separated from other elements by cation exchange column method. The chemical yield of each separation was monitored with Pr added to the sample powder before decomposition. The accuracy and precision were tested by repeated analyses of JB-1 and one analysis of BCR-1. In addition, it was found that REE distribution in a granitic rock powder was inhomogeneous and therefore special care must be taken for the sampling of granitic rock powders.  相似文献   

13.
张八岭隆起南缘早白垩世火山岩稀土元素对比研究   总被引:2,自引:0,他引:2  
张八岭隆起南缘早白垩世火山岩与北大别山东部、庐枞盆地、鲁西同期火山岩同属于中国东部岩石圈伸展减薄背景下形成的火山岩。然而稀土元素地球化学特征却反映出,张八岭隆起南缘火山岩来源于壳幔过渡带。而北大别山东缘同期火山岩与岩浆上升过程中地壳物质的混染有关,庐枞盆地火山岩岩浆来自与俯冲洋壳有关的富集地幔部分熔融,鲁西地区火山岩岩浆与俯冲的陆壳在地幔源区发生混染和交代形成的富集型地幔部分熔融有关。稀土元素研究的结果与构造背景、微量元素以及Sr,Nd同位索等研究相吻合,进一步表明稀土元素在火山岩岩浆来源方面有很好的示踪作用。岩浆的来源不同以及研究区大型断裂的作用正是张八岭隆起地区成为金矿成矿远景区的重要原因。  相似文献   

14.
The formation of dark patinas has been mainly related with deposition of gases and particles, and sulphation mechanisms particularly in calcareous rocks. However, in granitic monuments located in Galicia (northwest of Spain), especially in rural areas, this origin is unlikely since granite is a very poor calcium-containing rock and the atmospheric pollution in this area is negligible. A biological origin seems to be most probable. In order to know the importance of biological and atmospheric factors in the formation of dark patinas on granitic monuments, a number of analyses using several techniques are needed. The characterization of fatty acids in patinas by gas chromatography has established clear differences among samples. Thus, all of the samples having a biological origin displayed a similar fatty acid pattern, with unsaturated fatty acids predominating, especially oleic and linoleic acids; these were followed in abundance by the branched fatty acid 18:00 anteiso, and palmitic acid. Different patterns of fatty acid allowed establishment of an anthropogenic origin of the some of the patinas analysed.  相似文献   

15.
Several organic acids and bases that are very sparingly soluble in water have been determined by acid-base and redox titrimetry after solubilizing them in micellar suspensions of sodium dodecylsulfate or cetyltrimethylammonium bromide. Thermometric titrations are much more rapid, convenient, accurate, and precise than the corresponding potentiometric ones. Titrations in such media can effect some differentiations that cannot be made in water and are also much more economical than titrations in non-aqueous solvents.  相似文献   

16.
Rare earth elements (REE) and phosphorus (P) in apatite were determined using inductively coupled plasma optical emission spectrometry (ICP-OES) after partial dissolution of the granitic rocks and pure apatite. The dissolution was performed with nitric acid in an open system and the matrix elements were separated by a cation exchange procedure. Samples of pure apatite from granitic rocks were dissolved with, 0.14 mol L−1 nitric acid. The results showed that the release of REE is due to apatite leaching because it could be assessed by comparing the chondrite-normalised pattern corresponding to the rocks and the pure apatite. Similar results were found for absolute REE abundance from the partial dissolution of the rocks and pure apatite.This simple and rapid method can be applied for the determination of REE in apatite as an indicator for mineral exploration, although its use in petrology could be possible.  相似文献   

17.
The results obtained in modeling of drainage waters in tailings dumps of deposits in the Kavalerovsky district in the temperature range from 0 to +45°C are reported. The Eh-pH parameters of the technogenic mineral formation systems at various rock sulfide ratios in the tailings (95: 5, 90: 10, 80: 20, and 60: 40) were determined. The crystallization of supergene minerals from micropore solutions was studied. The qualitative and quantitative ion composition of the minerals and their effect on the surface and ground waters in the district were determined.  相似文献   

18.
AN ANALYSIS OF FOURTH DERIVATIVE SPECTRA   总被引:5,自引:0,他引:5  
Abstract— –Fourth derivative spectra of chloroplast at – 196°C, obtained by four sequential differentiations of the absorption spectrum, were examined to determine the conditions for optimal signal-to-noise ratio and resolution. An appreciable improvement in the signal-to-noise ratio was found when the four differentiating intervals were nearly but not exactly equal. The process of differentiating digitized data with the computer was explored in order to define the rules for optimization of the fourth derivative curves.  相似文献   

19.

Polymeric matrices composed of N,N′-Methylenebis(acrylamide)/glycidyl methacrylate was prepared and modified producing two resins (GMA/MBA/OH and GMA/MBA/SO3H). The adsorption of U(VI) ions onto the modified acrylamide resins was studied from synthetic and granite samples. For better understanding around the uranium mineralization and the rock-forming minerals of the hosted granitic rocks, to facilitate the choice of the appropriate ore-processing techniques, it was necessary to identify the mineral composition and the radiometric specifications of the used granitic rock. The synthesized adsorbents revealed a promising selective adsorption toward the U(VI) ions from its bearing solutions even with the competence of other cations.

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20.
The interaction of granitic biotite with aqueous solutions of La, Nd, Th and U (concentration 10 to 1000 mg·l-1) was studied using instrumental neutron activation analysis (INAA) and 12C-Rutherford backscattering spectroscopy (12C-RBS). For comparison, the sorption of La and Nd by granitic feldspar and natural zeolite heulandite was also investigated. The experimental results showed that biotite exhibits higher sorption ability towards La and Nd, (maximum uptake 2.09 and 7.98 mg/g, respectively) than the feldspar and the heulandite. The interaction of biotite with Th is also intense, the metal being preferably concentrated at the near-surface layers of the crystals. This indicates that other sorption mechanisms (adsorption and surface precipitation) than ion-exchange take place at the solid/solution interface. The same phenomenon was also observed in the case of U, although the corresponding metal uptake was found to be considerably lower.  相似文献   

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