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BACKGROUND: Psychological factors are a risk factor for the incidence of breast cancer and have a significant impact on patient prognosis. OBJECTIVE: The present study aims to investigate the effects of personalised graded psychological intervention on negative emotion and quality of life in patients with breast cancer. METHODS: A total of 200 patients with breast cancer were randomly divided into two groups: an experimental group (n = 100) and control group (n = 100). Both groups received routine nursing care. The experimental group received personalised graded psychological intervention care, and the control group received routine nursing measures. After 2 months of standard treatment, the patients' quality of life and negative emotions were evaluated using the self-rating depression scale (SDS), self-rating anxiety scale (SAS), social support rating scale (SSRS) and quality of life measurement scale (FACT-B) scoring criteria. RESULTS: There were no significant differences in the general data between the two groups (p > 0.05). Furthermore, there were no significant differences in the SDS, SAS, SSRS and FACT-B scores between the two groups before personalised graded psychological intervention (p > 0.05). After the intervention, the experimental group exhibited an improved nursing effect compared with the control group. The SDS and SAS scores were lower in the experimental group than in the control group (p < 0.05); after the intervention, the SDS and SAS scores were significantly lower in the experimental group than in the control group (p < 0.05). The SSRS and FACT-B scores were higher in the experimental group than in the control group (p < 0.05), and the experimental group's post-intervention SSRS and FACT-B scores were significantly higher than before the intervention (p < 0.05). CONCLUSIONS: The use of personalised graded psychological intervention for the nursing of patients with breast cancer in clinical practice can significantly reduce patients' negative emotions as well as improve positive emotions and quality of life; thus, this method can be popularised in the nursing process. [ABSTRACT FROM AUTHOR]

The study of dynamic brittleness and failure characteristics is of guiding significance for promoting the full exploitation and utilization of deep sandstone reservoirs. At present, there have been more comprehensive studies on the mechanical properties of deep sandstone reservoirs, but the study of mineral composition on the dynamic brittleness and failure characteristics of deep sandstone reservoirs is relatively weak. In this paper, XRD mineral composition analysis, uniaxial compression experiment, and Brazilian splitting are used to study the influence of mineral composition on mechanical properties and failure characteristics of deep sandstone reservoirs. It was concluded that (1) the mineral compositions of deep sandstone reservoirs are mainly three kinds of oxides: SiO2, Al2O3, and CaO. The failure modes of deep sandstone reservoir samples under uniaxial compression are more complicated, with tension failure and shear failure each accounting for half. In the Brazilian split test, the failure modes of sandstone samples are mainly shear failure. (2) The compressive strength decreases obviously with the increase of CaO content. The contents of SiO2, Al2O3, and CaO all have a great influence on the residual strength of deep sandstone reservoirs. The deformation modulus decreases gradually with the increase of Al2O3 content. (3) The brittleness increases slightly when the content of SiO2 increases, while the brittleness decreases slightly when the content of Al2O3 increases. Considering factors such as strength, modulus, brittleness, and failure characteristics, SiO2 content has the greatest influence on the mechanical properties of deep sandstone reservoirs, followed by Al2O3 content, and CaO content has the least influence. The research results have a guiding role in the utilization and development of oil and gas resources in deep sandstone reservoirs and promote oil and gas development from the middle to deeper layers. [ABSTRACT FROM AUTHOR]

Brittleness is one of the most significant properties of geomaterials. However, very few studies have been conducted on factors influencing the rock brittleness indices. In this paper, conventional triaxial compression tests were carried out to investigate the effects of confining pressure and bedding angle on the brittleness of slate. From the perspective of energy, brittleness is an index that could reflect the release rate of energy that accumulated in the slate under the effect of external energy after reaching peak strength. Therefore, a new brittleness index of slate based on postpeak energy release is proposed herein. The applicability of this index is illustrated by comparing with other five existing brittleness indices. The following results can be obtained. (1) The confining pressure exerts a great influence on the brittleness of slate. With the increase of confining pressure, the brittleness of slate decreases significantly. The dispersion of brittleness values of slate declines with increasing confining pressure. (2) There is a parabolic relationship between slate brittleness and bedding angle. As bedding angle increases, the brittleness is intensified and reaches its maximum at a bedding angle of about 45° and then decreases gradually. (3) In contrast to the previous indices, the brittleness index proposed in this paper can describe the whole process of the postpeak stage through an index of the energy release, which makes this measure more suitable for rock that has the characteristics of step-drop or bench-drop at the postpeak stage. [ABSTRACT FROM AUTHOR]

• An integrated study of physical and numerical modelling is conducted. • Unloading rates affect both crack patterns and depths. • Low-speed unloading produces closed arc-shaped cracks on both sides of the tunnel. • Crack depth caused by low-speed unloading is larger than high-speed unloading. Excavation of tunnel is the unloading process of surrounding rock, and the unloading rate is one of the important factors affecting the stability of underground tunnel. Through the combination of large-scale physical model test and numerical simulation, combined with the water bag filling technology to simulate high-speed unloading excavation, the influence of unloading rate and unloading magnitude on the stability of surrounding rock of underground tunnel is quantitatively analysed according to the crack depth, displacement and stress concentration of surrounding rock. The results show that low-speed unloading produces closed arc-shaped cracks on both sides of the tunnel, while high-speed unloading produces closed circular cracks around the tunnel surrounding rock. Tunnels excavated with low-speed form wedge-shaped cracks and flaky destruction. The cracks distribute on the left and right sides of the tunnel, and form closed arcs. Tunnels excavated with high-speed form wedge-shaped closed cracks, which are circularly distributed around the tunnel. The crack depth of tunnel surrounding rock caused by low-speed unloading is larger than that caused by high-speed unloading, and the local stress concentration of low-speed unloading is also more obvious in the sidewall of the tunnel. However, the overall stress of the surrounding rock of the high-speed unloading is more significant, which means it accumulates much energy, and dynamic disasters may occur. High-speed unloading is more suitable for projects in low ground stress or soft rock mass stratum, which may cause less damage to the surrounding rock. In contrast, low-speed unloading can reduce the possibility of dynamic disaster for projects in high ground stress or hard, brittle rock mass. [ABSTRACT FROM AUTHOR]

• 32 loading levels in 3 physical models with different σ max direction are conducted. • The smaller the angle of σ max direction and tunnel axial, the tunnel is more stable. • If σ max direction is perpendicular to the tunnel axial, spalling is occurred. • If σ max direction is parallel, ring-like failure is occurred when σ max is large. • With increase of σ max , the effect of its direction increases. The major principal stress direction of the tunnel is one of the most important factors affecting the stability of an underground tunnel. This paper is devoted to the quantitative analysis of the effect of the major principal stress direction respect to the tunnel long axis on the stability of an underground tunnel. A total of thirty-two loading levels with three physical models combined with the numerical simulation were conducted. The results indicated that, with the decrease of the angle between the major principal stress direction and the long axis of the tunnel, the tunnel becomes more stable. For the load at which cracks begin to occur in the tunnel, when the major principal stress direction is parallel to the tunnel axis, there are no cracks in the tunnel until the load reaches approximately twice as much that of perpendicular. When the major principal stress direction is perpendicular to the tunnel axis, the failure involves spalling. The cracks initially occur at the corner of the tunnel, and then propagate along the sidewall in the form of a parabola. When the major principal stress direction is parallel to the tunnel axis, the failure involves ring-like damages. Cracks appear at the top and bottom of the tunnel, and connect with the cracks on the sidewall. With the increase of the principal stress, the effect of the major principal stress direction increases. [ABSTRACT FROM AUTHOR]

• 74 specimens with seven bedding angles and five confining pressures were tested. • The lowest strength occurs at bedding angle of 45°–60° and greatest below 15°. • The fracture angle of slate presents a U-shaped curve. • The lowest modulus occurs at bedding angle of 45°–60°, and greatest at 75°–90°. • Even if confining pressure is small, the modulus is significantly increased. The physical properties of slate in buildings are affected by its bedding angle and confining pressure. A total of 74 slate specimens with seven bedding angles and five levels of confining pressure were tested in uniaxial and triaxial compression tests. The effects of bedding angle and confining pressure on the mechanical behaviour of the brittle slate were quantified. The test results showed that, with the increase of confining pressure, the compressive strength of rock increased significantly. The variation in compressive strength of slate under confining pressure could be described by the parabolic Mohr-Coulomb strength criterion. The strength of slate is the lowest when the bedding angle is 45°–60°, and greatest when it is below 15°. When unconfined, the fracture angle of slate is 65°–90°. With increased confining pressure, the fracture angle of slate tends to 45° from above. As the bedding angle increases from 0° to 90°, the fracture angle of slate presents a U-shaped curve. When the bedding angle is 75°–90°, the deformation modulus of slate is greatest, and is minimised when the bedding angle is 45°–60°. Even if the confining pressure is low, the deformation modulus of slate is significantly increased compared to that in unconfined conditions. It proves that shotcrete treatment of the rock surrounding a tunnel will greatly improve the supporting effect thereon. [ABSTRACT FROM AUTHOR]

In order to study the influence of bedding angle and loading rate on the initiation fracture toughness (IFT) of coal, notched semi-circular bending (NSCB) specimens were made by using a split Hopkinson pressure bar (SHPB) system. The dynamic IFT of NSCB coal specimens with various bedding angles and crack lengths under different loading rates were analyzed and discussed. A high-speed high-resolution digital camera was used to record the processes of cracking initiation and propagation in coal specimens. The experimental results indicate that the effects of bedding plane on the cracking pattern decreases with the increase of both loading rate and crack length in the specimens. The impact velocity dominates the evolution of the dynamic IFT of coal, and the anisotropy caused by bedding planes in the specimens plays a more critical role in the evolution of dynamic IFT than the crack length. The effects of bedding angles on the dynamic IFT decrease with the increase of impact velocity. The growth behavior of dynamic IFT of coal distinctly changes after the loading rate exceeds a critical value. In addition, a model of rate dependency was established to describe the dynamic IFT of coal. [ABSTRACT FROM AUTHOR]

The reactive-transportation of radioactive elements in fractured rock mass is critical to the storage of radioactive elements. To describe the reactive-transportation and distribution morphology of a uranium-containing solution, a stress-dependent reactive transport model was developed, and the simulator of FLAC3D-CFD was employed. The uranium transport experiment subjected to the variation of confining stress of 5–19 MPa and hydraulic pressure of 0.5–3.5 MPa was conducted in fractured rock mass. The results show that the uranium-containing solution transport and distribution is significantly dependent on the evolution of the connected channel in rough-walled fracture, which is significantly influenced by the confining stress and hydraulic pressure. In more detail, the increase of confining stress resulted in the anisotropic of seepage channel in aperture, and corresponding turbulence flow and uranium retention were presented at the fracture aperture of 2–5 μm. As the increase of hydraulic pressure, flow regime evolved from the inertial flow to vortex flow, and the transformation region is 16 MPa confining stress and 1.5 MPa hydraulic pressure. The evolution of loading paths also dominates the flow and solute transport, and high seepage speed and strong solute transport were presented at the k = 1 (ratio of vertical stress loading to horizontal stress unloading), and a laminar flow and weak solute transport were presented at k = 0. [ABSTRACT FROM AUTHOR]