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BackgroundIn the process of in-situ leaching of uranium, pore blockage greatly limits the leaching efficiency of uranium, and the pore blockage is mainly due to the complex physical and chemical action of minerals and leaching agents in in-situ leaching of uranium.PurposeThis study aims at the influence mechanism of each mineral composition on pore blockage under the action of leaching agent in the process of in-situ leaching of uranium to realize the efficient exploitation of uranium resources.MethodsFirst of all, sandstones of uranium mine in Xinjiang were taken as the experimental samples, the relationship between the mineral composition and porosity in the process of acid in-situ leaching of uranium was studied through acid in-situ leaching experiment, and nuclear magnetic resonance experiment was employed every other period of time to obtain the porosity change curve in the process of uranium sandstone leaching. Then, the mineral characteristics of uranium sandstone were analyzed by X-ray diffractometer to find the changes of the mineral composition during uranium sandstone leaching. Finally, the influence of different minerals on porosity change was analyzed with the help of gray relational theory.ResultsThe results show that the pore blockage in the leaching process is mainly due to the complex physical and chemical action of many kinds of minerals, which will affect the solute transport process of other minerals in uranium sandstone and not only lead to the change of mineral composition but also affect the leaching of uranium. Through grey correlation analysis, it is found that calcium sulfate and magnesium silicate as plugging materials have a correlation degree of over 0.781 for porosity and uranium leaching rate. The physical adsorption of clay minerals can block the micropores of uranium sandstone, so its correlation with porosity and uranium leaching is 0.831 and 0.842 respectively, indicating that pore plugging has an impact on uranium leaching.ConclusionsAccording to the relationship between the change of mineral composition and pore blockage in the process of leaching, making appropriate adjustment can solve the problem of pore blockage, so as to realize the efficient exploitation of uranium resources.

A series of methacrylate-acrylonitrile-butadiene-styrene (MABS) resins was prepared using bulk polymerization. The polarity of the continuous phase and the compatibility of two phases were changed by adjusting the methyl methacrylate (MMA) content, choosing values that were close to styrene-butadiene rubber solubility value. The possibility of controlling the microstructure of the MABS resin by changing the polarity of the components and the compatibility of two phases was assessed. The dynamic mechanical analysis shows that the compatibility of two phases varies with the MMA content. The morphological analysis shows that increasing MMA contents results in a gradual decrease in the sub-inclusion structure with a network skeleton of rubber particles, and that all the particles become solid rubber when the MMA content reaches 75%. The sub-inclusion structure reappears but does not have a network skeleton when the MMA content is 90%. The impact strength and morphological analysis indicate that the solid rubber particles and the sub-inclusion structure with a network skeleton provide excellent toughness, while the sub-inclusion structure without a network skeleton does not. In contrast, the transmittance of the ABS resin first increased and then decreased with increasing MMA content. KEYWORDS bulk polymerization, microstructure, sub-inclusion, the compatibility of two phases, transparent MABS resin, 1 | INTRODUCTION Recent developments in industrial design have introduced a natural style and a culture of soft colors. This style requires the use of transparent materials so that the [...]

Pollination dynamics was studied in a first-generation Platycladus orientalis (L.) Franco seed orchard with pedigree reconstruction using eight nuclear and four chloroplast SSRs. The pedigree reconstruction assigned 371 of 448 studied seeds to one of the orchard's 192 candidate male parents and showed a high level of outcrossing and pollen contamination in the orchard's seed crop. While the orchard's seed population showed greater allelic richness compared with the parental population, a few alleles present in the parental population were missing in the seed crop. Additionally, we detected no significant correlation between male reproductive energy (pollen yield) and male reproductive success; however, uneven parental contribution was also observed. Pollen management practices were recommended to ensure the maintenance of genetic diversity in the seed crops and increase in genetic gain. Key words: seed orchard, pedigree reconstruction, gametic contribution, pollen contamination, selfing rate, genetic diversity. La dynamique de la pollinisation a ete etudiee dans un verger a graines de premiere generation de Platycladus orientalis (L.) Franco a l'aide de la reconstruction de pedigree se basant sur huit marqueurs SSRs de type nucleaire et quatre de type chloroplastique. La reconstruction de pedigree a permis d'assigner 371 des 448 graines etudiees a l'un des 192 parents males candidats du verger, tout en indiquant un niveau eleve d'exogamie et de contamination pollinique parmi la recolte de graines du verger. Alors que la population de graines du verger avait une richesse allelique plus elevee comparativement a la population parentale, certains des alleles presents dans la population parentale etaient absents des graines recoltees. De plus, une correlation significative a ete detectee entre l'energie des males consacree a la reproduction (production de pollen) et leur succes reproducteur; toutefois, des contributions parentales inegales ont aussi ete observees. Des pratiques de gestion du pollen sont recommandees afin d'assurer le maintien de la diversite genetique des recoltes de graines et d'augmenter le gain genetique. [Traduit par la Redaction] Mots-cles: verger a graines, reconstruction de pedigree, contribution gametique, contamination pollinique, taux d'autofecondation, diversite genetique., Introduction Platycladus orientalis (L.) Franco, the only member of the family Cupressaceae, is native to northwestern China, Korea, and the Russian far east (Cheng and Fu 1978). As a pioneer [...]