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This paper independently developed a set of experimental equipment that can approximately simulate the service working environment of unsaturated bentonite buffer. By conducting heat and moisture transfer experiments on unsaturated bentonite under the combined action of heating-cooling path and water erosion conditions, the evolution laws of temperature, humidity, electrical conductivity at different locations away from the heat source, as well as the heat and moisture coupling migration behavior were studied. The results show that during the heating-cooling process, the temperature evolution laws is similar at different positions away from the heat source. Although the temperature of the heat source reaches 100 °C, its impact range is relatively small. The evolution law of humidity varies greatly at different positions, and is significantly influenced by the temperature field, as well as the coupling effect of hydraulic field. The change in electrical conductivity is basically consistent with the change in humidity, and is also subject to the combined coupling effect of temperature field and hydraulic field. Under the condition of no water erosion and increasing heating/cooling rate, the amplitude of temperature change decreases, and humidity and electrical conductivity show a trend of migration away from the heat source throughout the heating cooling stage.

Abstract A gas breakthrough in saturated bentonite is relevant to the safety of high-level radioactive waste repositories. The study of gas transport mechanisms in saturated bentonite is very important for the safety assessment of repositories. This paper proposed a coupled fluid-mechanical interaction model for predicting and simulating the path of gas transport and gas breakthrough in saturated Gaomiaozi bentonite. The model considered the effect of deformation and damage of bentonite on its permeability and introduced pore pressure into the deformation equation of bentonite. The damage coefficient was also introduced into the permeability evolution equation by combining the Mohr–Coulomb criterion, the maximum tensile stress criterion and the damage evolution. In addition, considering the heterogeneity of the soil, the Weibull distribution function was introduced to assign differential values to material parameters of the cells in the model. The numerical simulation of the bentonite stress field and seepage field was realized by the joint MATLAB and COMSOL secondary development, and the evolution law of the pore path in bentonite was explored under a flexible boundary. The gas breakthrough pressure and permeability pressures were calculated at various gas injection from a gas injection experiment into bentonite with flexible boundaries. Finally, the rationality and applicability of the model were verified by comparing the numerically calculated gas breakthrough pressure and permeability with experimental values.

Media coverage can greatly impact the spread of infectious diseases. Taking into consideration the impacts of media coverage, we propose an SEIR model with a media coverage mediated nonlinear infection force. For this novel disease model, we identify the basic reproduction number using the next generation matrix method and establish the global threshold results: If the basic reproduction number $ \mathcal{R}_{0} < 1 $, then the disease-free equilibrium $ P_{0} $ is stable, and the disease dies out. If $ \mathcal{R}_{0} > 1 $, then the endemic equilibrium $ P^{*} $ is stable, and the disease persists. Sensitivity analysis indicates that the basic reproduction number $ \mathcal{R}_{0} $ is most sensitive to the population recruitment rate $ \Lambda $ and the disease transmission rate $ \beta _{1} $.

Abstract Lactiplantibacillus plantarum X7022 is a novel strain isolated from stinky tofu brine. Its constipation amelioration potential was evaluated on two different constipation types (acute and subacute) in mice induced by loperamide hydrochloride in present work. L. plantarum X7022 could significantly decrease the first black stool defecation time, and increase black fecal weight, number, and the gastrointestinal transit ratio in both models. High‐dose treatment of L. plantarum X7022 (2 × 1010 CFU/kg BW) was more significant in improving constipation condition than low‐dose (2 × 107 CFU/kg BW). Furthermore, 16S rDNA sequencing of the intestinal flora showed that the treatment with the strain X7022 could increase the α diversity in both constipation models. Meanwhile, the abundance of Bacteroidetes increased, and Firmicutes decreased, which was more effective in acute constipated mice. In addition, X7022 treatment could enhance the relative abundance of beneficial flora, such as Bacteroides, Ruminococcus, and depressed Adlercreutzia and Odoribacter in acute model mice. In subacute constipated mice, X7022 treatment could enhance Alloprevotell, Rikenellaceae_RC9, and decreased Lachnospiraceae_NK4A136 and Desulfovibrio. Therefore, L. plantarum X7022 is a prospect probiotic strain for the amelioration of constipation.

In this paper, we consider a boundary value problem of impulsive fractional differential equations with the nonlinear p-Laplacian operator, where impulses are non-instantaneous. By converting the given problem into an equivalent integral form and applying the Schauder fixed point theorem, we obtain some sufficient conditions for the existence of solutions. An illustrative example is presented to demonstrate the validity of our results.

Abstract This paper investigates the existence of solutions for a coupled system of fractional differential equations. The existence is proved by using the topological degree theory, and an example is given to show the applicability of our main result.

Lactic acid bacteria are a kind of microorganisms that can ferment carbohydrates to produce lactic acid, and are currently widely used in the fermented food industry. In recent years, with the excellent role of lactic acid bacteria in the food industry and probiotic functions, their microbial metabolic characteristics have also attracted more attention. Lactic acid bacteria can decompose macromolecular substances in food, including degradation of indigestible polysaccharides and transformation of undesirable flavor substances. Meanwhile, they can also produce a variety of products including short-chain fatty acids, amines, bacteriocins, vitamins and exopolysaccharides during metabolism. Based on the above-mentioned metabolic characteristics, lactic acid bacteria have shown a variety of expanded applications in the food industry. On the one hand, they are used to improve the flavor of fermented foods, increase the nutrition of foods, reduce harmful substances, increase shelf life, and so on. On the other hand, they can be used as probiotics to promote health in the body. This article reviews and prospects the important metabolites in the expanded application of lactic acid bacteria from the perspective of bioengineering and biotechnology.

Defining the trajectory of hydraulic fractures crossing bedding planes and other fractures is a significant issue in determining the effectiveness of the stimulation. In this work, a damage evolution law is used to describe the initiation and propagation of the fracture. The model couples rock deformation and gas seepage using the finite element method and is validated against classical theoretical analysis. The simulation results define four basic intersection scenarios between the fluid-driven and preexisting fractures: (a) inserting—the hydraulic fracture inserts into a bedding plane and continues to propagate along it; (b) L-shaped crossing—the hydraulic fracture approaches the fracture/bedding plane then branches into the plane without crossing it; (c) T-shaped crossing—the hydraulic fracture approaches the fracture/bedding plane, branches into it, and crosses through it; (d) direct crossing—the hydraulic fracture crosses one or more bedding planes without branching into them. The intersection scenario changes from (a) → (b) → (c) → (d) in specimens with horizontal bedding planes when the stress ratio β (β=σy/σx) increases from 0.2 to 5. Similarly, the intersection type changes from (d) → (c) → (a) with an increase in the bedding plane angle α (0° → 90°). Stiffness of the bedding planes also exerts a significant influence on the propagation of hydraulic fractures. As the stiffness ratio E1¯/E2¯ increases from 0.1 to 0.4 and 0.8, the seepage area decreases from 22.2% to 41.8%, and the intersection type changes from a T-shaped crossing to a direct crossing.

In this paper, we study a Leslie–Gower predator-prey model with harvesting effects. We carry out local bifurcation analysis and stability analysis. Under certain conditions, the model is shown to undergo a supercritical Hopf bifurcation resulting in a stable limit cycle. Numerical simulations are presented to illustrate our theoretic results.

A series of multistage creep tests under different confining pressures with acoustic emission monitoring have been performed to investigate the deformation characteristic and failure process of cracked granite during creep. The critical axial strain of cracked sample showed an increasing tendency with the increase of confining pressure. In contrast, critical lateral strain experienced a process of descending first at low confinement and then remaining nearly constant at high confinement. Compared with loading-cracked specimen, smaller critical axial strain, greater critical lateral strain, and higher lateral creep strain rate were found for unloading-cracked specimen. Based on the spatial and temporal distribution of acoustic emission events, the cracking process during creep was analysed. The AE events with high energy are mainly concentrated at the final fracture area of the specimen. The higher the confining pressure, the more the AE events with low energy. Compared with the loading-cracked specimen, the percentage of AE events with high energy is relatively small for the unloading-cracked specimen.

In this paper, we investigate a class of integral boundary value problems of fractional differential equations with a p-Laplacian operator. Existence of solutions is obtained by using the fixed point theorem, and an example is given to show the applicability of our main result.

According to the preliminary concept of the high-level radioactive waste (HLW) repository in China, a large-scale mock-up facility, named China-Mock-Up was constructed in the laboratory of Beijing Research Institute of Uranium Geology (BRIUG). A heater, which simulates a container of radioactive waste, is placed inside the compacted Gaomiaozi (GMZ)-Na-bentonite blocks and pellets. Water inflow through the barrier from its outer surface is used to simulate the intake of groundwater. The numbers of water injection pipes, injection pressure and the insulation layer were determined based on the numerical modeling simulations. The current experimental data of the facility are herein analyzed. The experiment is intended to evaluate the thermo-hydro-mechano-chemical (THMC) processes occurring in the compacted bentonite-buffer during the early stage of HLW disposal and to provide a reliable database for numerical modeling and further investigation of engineered barrier system (EBS), and the design of HLW repository.

The water-soluble protein from Phascolosoma esculenta was hydrolyzed by pepsin to obtain the hydrolysate with angiotensin I-converting enzyme (ACE) inhibitory activity. The hydrolysate (PEPH) was then further separated by membrane bioreactor system, ion-exchange chromatography, gel filtration, and reversed phase high-performance liquid chromatography (RP-HPLC) and a novel ACE inhibitory peptide named as PeP with the IC50 value of 135 M was isolated. The amino acid sequence, Ala-Trp-Leu-His-Pro-Gly-Ala-Pro-Lys-Val-Phe, was identified by matrix-assisted laser desorption ionization-time of flight/time of flight (MALDI-TOF/TOF). Inhibitory kinetics study suggested that PeP acted as competitive inhibitor against ACE. Single oral administration of synthesized PeP at 10 mg/kg dose in spontaneously hypertensive rats could reduce the systolic blood pressure around 30 mmHg and the effect could last for more than 8 h. The results suggest that peptide from P. esculenta could be a potent natural ingredient for functional foods or pharmaceuticals against hypertension.

Three sulfated polysaccharides from Bullacta exarata were isolated, purified, and named BEP1, BEP2 and BEP3, respectively. The antitumor and antioxidant activities, in vitro, of three polysaccharides were investigated, including inhibition of cells proliferation, hydroxyl radical scavenging effect, superoxide radical scavenging capacity and reducing power assay. The results suggested that three polysaccharides possessed antioxidant activities in a dose-dependent manner, and BEP3 exhibited stronger antioxidant activities than BEP1 and BEP2. Furthermore, BEP3 showed significant inhibitory effects on growth of Bcap37 breast cancer cells, SW1990 pancreatic cancer cells and HeLa cervical cancer cells, and the IC50 were 135.3, 147.5 and 172.6 μg/ml, respectively. The highest inhibition rates of BEP1 and BEP2 were approximately 10% against three cancer cells. The data obtained in vitro models indicates that polysaccharides from B. exarata could be explored as novel and potential natural antioxidants and cancer prevention agents for use in functional foods.

This paper is concerned with the existence of homoclinic solutions for a class of the second order impulsive Hamiltonian systems. By employing the Mountain Pass Theorem, we demonstrate that the limit of a 2kT-periodic approximation solution is a homoclinic solution of our problem.

We study the existence of solutions to a boundary value problem of a second-order impulsive Sturm-Liouville equation with a control parameter . By employing some existing critical point theorems, we find the range of the control parameter in which the boundary value problem admits at least three solutions. It is also shown that, under certain conditions, there exists an interval of the control parameter in which the boundary value problem possesses infinitely many solutions. Some examples are given to demonstrate the main results in this paper.

The methods of lower and upper solutions and monotone iterative technique are employed to the study of integral boundary value problems for a class of first-order impulsive functional differential equations. Sufficient conditions are obtained for the existence of extreme solutions.