Feasibility of optical computerized tomography for measuring the species concentration distribution of flow fields

In this paper, the feasibility of using optical computerized tomography (OCT) methods for measuring the distribution of species concentration for flow fields is analyzed and discussed. First, feasible methods are chosen for two or three objects composed flow fields from the perspective of the measurable principle. Second, both common gas and plasma are chosen as two typical examples for specific analysis and discussion. The results show that the feasibility and applicable range of OCT methods are related to the temperature, pressure, and species composition of the measured flow fields. Finally, the study indicates that OCT methods are more suitable for measuring the distribution of species composition for common gas rather than plasma. In a word, this study could be helpful for extending the applicable range of OCT methods, which are based on the measurement of the refractive index.     

Diagnostic de l'état agropédologique des sols acides de la province de Kinshasa en république démocratique du Congo (RDC)

This study is a part of the research methods for sustainable management of sandy soils of the province of Kinshasa (DRC).The intended aim is to characterize the soil sites with high agricultural activity in Kinshasa and to identify the main constraints to productivity. The diagnosis revealed that soils of three sites investigated studied are sandy and characterized by low retention capacity in the field (< 45 %) present an acid reaction (pH <5.5), have very low TOC contents (≤ 1 %), N_tot (≤ 0.1 %), P_ass (< 20 mg.kg⁻¹), inexchangeable bases and are saturated to more than 60 % Al. Microbiological characteristics are weak in terms of microbial carbon, basal and induced respiration, and enzymatic activities. These characteristics are influenced by the organic matter and are the limitations on the productivity of these soils.     

Support vector machine with a Pearson VII function kernel for discriminating halophilic and non-halophilic proteins

Understanding of proteins adaptive to hypersaline environment and identifying them is a challenging task and would help to design stable proteins. Here, we have systematically analyzed the normalized amino acid compositions of 2121 halophilic and 2400 non-halophilic proteins. The results showed that halophilic protein contained more Asp at the expense of Lys, Ile, Cys and Met, fewer small and hydrophobic residues, and showed a large excess of acidic over basic amino acids. Then, we introduce a support vector machine method to discriminate the halophilic and non-halophilic proteins, by using a novel Pearson VII universal function based kernel. In the three validation check methods, it achieved an overall accuracy of 97.7%, 91.7% and 86.9% and outperformed other machine learning algorithms. We also address the influence of protein size on prediction accuracy and found the worse performance for small size proteins might be some significant residues (Cys and Lys) were missing in the proteins.     

Retrieval of the vertical column of an atmospheric constituent from data fusion of remote sensing measurements

Techniques of data fusion are presently being considered with increasing interest for application to atmospheric observations from space because of their capability to optimally exploit the complementary information provided by different instruments operating aboard on-going and future satellite missions. The task of combining measurements of the same target, when carried out at the level of the retrieved state vectors, faces with two major problems: the need to interpolate the products represented on different retrieval grids which determines a loss of information and the presence of a priori information in the products that can determine a bias in the product of the data fusion. The measurement space solution method avoids these problems. Based on this method we present a novel approach to retrieve the vertical column of an atmospheric constituent from data fusion of remote sensing measurements. We apply the method to retrieve the ozone column from the fusion of simulated measurements of the IASI nadir-viewing spectrometer onboard the METOP-A platform and of the MIPAS limb sounder onboard the ENVISAT satellite. The performance of the method is evaluated in terms of retrieval errors and averaging kernels of the products. The results show the evidence of improved retrieval quality when comparing the outcome of data fusion with that of the inversion process applied to spectra from either of the two instruments.     

Constructions of optimal GDRP’s of type

Generalized doubly resolvable packings (GDRPs) represent a combinatorial characterization of constant composition codes (CCCs). In this paper, we develop a number of general constructions of GDRPs of type λ¹μ^m−1. As a consequence, a new series of optimal CCCs is obtained.     

On the equality of interfacial and critical composition

It is shown that interfacial composition of the liquid–liquid interfaces is equal to the critical composition. The idea has been rigorously proven for binary regular solutions and has been reasonably supported for non-regular multicomponents, making use of the experimental mutual solubility data and the available information on titration, pulsed gradient spin-echo NMR, and differential scanning calorimetry of some W/O and O/W microemulsions. Using this finding, we, moreover, developed a simple equation for prediction of plait point concentration, having known just one tie-line data. The equation suggests a simple consistency test for measured solubility data, which is shown reliable for a large number of ternary systems. A molecular dynamic simulation also has been performed to support the idea.     

The average carbon oxidation state of thermally modified wood as a marker for its decay resistance against Basidiomycetes

It has recently been reported that the oxygen to carbon-ratio (O/C) of thermally modified wood is a reliable indicator for the resistance against attack by Basidiomycete fungi. The present theoretical study is an attempt to clarify causality between the O/C-ratio of thermally modified wood and its fungal resistance, as measured by standardized laboratory test procedures. It is shown that different wood species, with varying degree of thermal modification, reveal a remarkable correlation in elemental composition when plotted in a van Krevelen state diagram, suggesting a common modification chemistry shared by these species. The overall chemical reaction types responsible for the composition changes appear to be mainly dehydration, with some decarboxylation. The latter reaction decreases the mean overall oxidation state of carbon atoms present in thermally modified wood, leading to an inherently improved resistance against oxidation of the material. A known general correlation, between the average oxidation state of organic matter and the Gibbs free energy of the oxidation half-reaction, was found quantitatively consistent with the observed trend in the fungal resistance of thermally modified wood with the O/C-ratio.     

MgO晶须的物相组成和微观形貌多样性

采用适当MgO-Al比例物料,压制成型后放入气氛炉中于1500℃烧制6h,最终在样块表面得到 MgO晶须.晶须的物相组成为方镁石,显微结构研究表明多数呈细长的柱状,顶端尖锐,长约600～800μm ,长径比100～200;晶须发育的纹理特征有多种,晶须的横截面有扁六边形、正六边形、菱形和正四边形以及不规则形状等多种,能谱分析表明晶须的形貌与化学组成有关.     

全氟甲基乙烯基醚和其它含氟单体乳液共聚合的竞聚率测定

分别通过气相色谱法测定了全氟甲基乙烯基醚 (PMVE)与偏氟乙烯 (VDF)以及PMVE与四氟乙烯(TFE)二元乳液共聚反应中的气相单体组成和共聚物组成 ,然后用非线性回归法 (RREVM )计算得TFE PMVE及VDF PMVE乳液共聚合反应的表观竞聚率分别为γTFE =3 89和γPMVE =0 0 5以及γVDF =1 0 6和γPMVE =0 11.结合已经测定的TFE VDF二元乳液共聚的表观竞聚率 ,计算了由VDF TFE PMVE三元乳液共聚合反应合成的共聚物组成 ,后者与由1 9F NMR实测的共聚物组成吻合     

Factorizations of root-based polynomial compositions

Let denote the finite field of order q=p^r, p a prime and r a positive integer, and let f(x) and g(x) denote monic polynomials in of degrees m and n, respectively. Brawley and Carlitz (Discrete Math. 65 (1987) 115–139) introduce a general notion of root-based polynomial composition which they call the composed product and denote by fg. They prove that fg is irreducible over if and only if f and g are irreducible with gcd(m,n)=1. In this paper, we extend Brawley and Carlitz's work by examining polynomials which are composed products of irreducibles of non-coprime degrees. We give an upper bound on the number of distinct factors of fg, and we determine the possible degrees that the factors of fg can assume. We also determine when the bound on the number of factors of fg is met.