This paper presents a generalized Gronwall inequality with singularity. Using the inequality, we study the dependence of the solution on the order and the initial condition of a fractional ...differential equation.
This study focuses on the blended cement containing ground granulated blast furnace slag (GGBFS) and waste clay brick (CBP), with 30% and 50% Portland cement contents. The compressive strength, ...hydration kinetics, hydration products and microstructure of blended cement up to 365 d were investigated to explore GGBFS and CBP interaction in the blended cement. The results show that both GGBFS and CBP reduce the hydration heat of blended cement, but the GGBFS will accelerate the C3A hydration more significantly due to consuming more sulfate than CBP. The improvement effect of GGBFS on compressive strength mainly occurs before 90 d, while the reaction of CBP continues to improve the compressive strength after its drastic reduction at early age. The X-ray diffraction and thermogravimetry results prove that the blended cement containing both GGBFS and CBP shows a high hydration degree at early age and will continue to hydrate. Furthermore, the chemically bound water content and porosity in blended cement containing both GGBFS and CBP at 365 d are almost the same as those in Portland cement.
Recycled clay brick powder (RCBP) was used to replace partially cement to prepare composite cementitious materials, and the hydration kinetics and microstructure evolution of the composite ...cementitious materials were investigated by measuring the types of hydration products, hydration heat and microstructure. The results show that RCBP has little effect on the types of hydration products. However, at the later stage of cement hydration, the pozzolanic reaction occurs between RCBP and Ca(OH)
2
. Meanwhile, RCBP promotes the dispersion and dissolution of cement and provides many nucleation sites for C–S–H gel, increases the effective water-binder ratio and accelerates the heat release of cement hydration, however, the cumulative heat release decreases with the dosage of RCBP. In addition, RCBP can increase porosity at early stage of hydration, but the pozzolanic reaction between RCBP and Ca(OH)
2
at the later stage of hydration would produce more hydration products, filling the pores, refining the pore diameter and improving the pore structure. Furthermore, RCBP affects the formation and microstructure of C–(A)–S–H gel, and promotes the formation of spherical C–(A)–S–H gel.
Sex chromosomes evolved from autosomes many times across the eukaryote phylogeny. Several models have been proposed to explain this transition, some involving male and female sterility mutations ...linked in a region of suppressed recombination between X and Y (or Z/W, U/V) chromosomes. Comparative and experimental analysis of a reference genome assembly for a double haploid YY male garden asparagus (Asparagus officinalis L.) individual implicates separate but linked genes as responsible for sex determination. Dioecy has evolved recently within Asparagus and sex chromosomes are cytogenetically identical with the Y, harboring a megabase segment that is missing from the X. We show that deletion of this entire region results in a male-to-female conversion, whereas loss of a single suppressor of female development drives male-to-hermaphrodite conversion. A single copy anther-specific gene with a male sterile Arabidopsis knockout phenotype is also in the Y-specific region, supporting a two-gene model for sex chromosome evolution.
The modification of fly ash based SBA-15 enables the selective adsorption of REE(III) with a high capacity.
Display omitted
•The species distribution of rare earth elements ions was ...simulated.•DTPADA-SBA-15 owned high adsorption efficiency and selectivity for REE (III).•DTPADA-SBA-15 owned preferable reusability in acidic solution.
Rare earth elements (REE) are strategic resources and the recycling of REE in alternative resources is urgent and gets increasingly attention. However, the separation of REE in these alternative resources is still a challenge due to the low concentration of REE and multi coexisted ions in acidic system. In this study, the species distribution of REE within the pH 0–8.0 was calculated. The SBA-15 originated from coal fly ash was modified by two steps with (3-aminopropyl) triethoxysilane (APTES) and diethylenetriaminepentaacetic dianhydride (DTPADA) to obtain DTPADA-SBA-15 adsorbent, which was applied to the selective adsorption of REE. The results showed that DTPADA-SBA-15 possessed excellent adsorption performance on the selective adsorption of REE, including Eu, Gd, Tb, Nd and Sm, in acidic solution (pH 2) with multi competing ions. The FT-IR and Zeta potential characterization verified that the chemical adsorption through the coordination of O in DTPADA-SBA-15 with REE was dominant at lower pH value. The study of adsorption kinetics indicated that the adsorption of rare earth metal ions followed pseudo-second-order kinetic, of which the adsorption process followed the Langmuir isotherm model.
In this work, we demonstrated the EG-assisted solvothermal synthesis of 3-D microspherical BiOBr architectures assembled by nanosheets. The morphology and compositional characteristics of the 3-D ...architectures were investigated by various microscopy techniques. The possible formation mechanism for the architectures was discussed. The band gap of the obtained BiOBr materials was estimated to be 2.54 eV by UV–vis. The specific surface area and porosity of the BiOBr 3-D architectures also were investigated by using nitrogen adsorption and desorption isotherms. Because of the narrow bandgap and the novel 3-D micro-/nanostructure, the BiOBr architectures show a more excellent photocatalytic activity under visible light irradiation than the BiOBr bulk plates. Several possible reasons for the higher photocatalytic activity have been taken into consideration. In addition, the photocatalyst is stable during the reaction and can be used repeatedly.
As an important component of N-linked glycoproteins, the core pentasaccharide is highly crucial to the potential application prospect of glycoprotein. However, the gas phase conformation study is a ...challenging one due to the size and complexity of the molecule, together with the necessity to rely on quantum chemistry modeling for relevant energetics and structures. In this paper, the structures of the trisaccharides and core pentasaccharides in N-linked glycans in the gas phase were constructed by a three-step tree-based (TSTB) sampling. Since single point energies of all the conformers are calculated at the temperature of zero, it is necessary to evaluate the stability at a high temperature. We calculate the Gibbs free energies using the standard thermochemistry model (T = 298.15 K). For trimannose, the energetic ordering at 298.15 K can be strongly changed compared to 0 K. Moreover, two structures of trimannose with high energies at 0 K are considered to provide a much better match of IR vibration signatures with the low Gibbs free energies. On this basis, the core pentasaccharide was constructed in three ways. The building configurations of core pentasaccharide were optimized to obtain reasonable low-energy stable conformers. Fortunately, the lowest-energy structure of core pentasaccharide is eventually the minimum at 0 K and 298.15 K. Furthermore, spectrum analysis of core pentasaccharide was carried out. Although poorly resolved, its contour from the experiment was in qualitative correspondence with the computed IR spectrum associated with its minimum free energy structure. A large number of strongly and weakly hydrogen-bonded hydroxyl and acetylamino groups contribute to a highly congested set of overlapping bands. Compared with traditional conformation generators, the TSTB sampling is employed to efficiently and comprehensively obtain preferred conformers of larger saccharides with lower energy.
Calcium sulfate hemihydrate whiskers (CSHW), a multi-functional and high value-added building material, were prepared with flue gas desulfurization (FGD) gypsum by hydrothermal method, which could be ...a reasonable disposal of FGD gypsum. In order to obtain CSHW of a high aspect ratio, a series of manufacturing parameters such as reaction temperature, stirring speed, material-water ratio, and reaction time were investigated. The effect of stabilizing treatment and glycerol concentration on CSHW morphology were also studied by environmental scanning electron microscopy (ESEM) and statistical analysis. The results showed that the optimum preparing conditions of reaction temperature, stirring speed, water-material ratio, and reaction time were 160 °C, 200~300 rpm, 11:1 and 1 h, respectively. Furthermore, stabilizing treatment with octodecyl betaine was necessary for the preparation of CSHW. The final prepared whiskers had smooth surface, uniform morphology, a diameter of 260 nm, and a corresponding aspect ratio of 208.2. Moreover, the addition of glycerol reduced the activity of water, contributing to a lower reaction temperature and much smaller diameter.
This paper presents retarded integral inequalities of Henry–Gronwall type. Applying these inequalities, we study certain properties of solutions to fractional differential equations with delay.
PDF
