Study on Mechanical Problems of Complex Rock Mass by Composite Material Micromechanics Methods: A Literature Review

The mechanical analysis of complex rock mass is a difficult problem, which often occurs in scientific research and practical engineering. Many achievements have been made in the study of rock mass composite problems by composite material micromechanics method, but it has not been well summarized so far. This paper summarizes in detail the research status of complex rock mass problems by composite material micromechanics method at home and abroad, including the application of the Eshelby equivalent inclusion theory and self-consistent model in rock mass composite problems, and the application of the homogenization method in jointed rock mass and other rock mass composite problems such as anchored rock mass, layered rock mass, and salt rock mass with impurities. It is proposed that the structural similarity and mechanical analysis similarity should be satisfied when the composite material micromechanics method is used to study the complex rock mass. Finally, the problems that need to be further studied are put forward. The research results provide a valuable reference for the study of complex rock mass by the composite material micromechanics method.

Analysis, Design and Experimental Research of a Novel Bilateral Patient Transfer Robot

Patient transfer has always been a difficult problem in the hospital. For medical staff, there are problems including high risk of infection, heavy physical labor and low efficiency of transfer; for patients, there are problems including poor comfort and secondary injury. In this paper, a novel bilateral patient transfer robot is investigated and designed. The following tasks are conducted: (1) Based on the process of patient transfer, a transfer model, which consists of two degrees of freedom, is proposed, and the working principle of bilateral patient transfer robot is obtained and analyzed in detail. (2) Force analysis of the patient transfer robot is conducted. The corresponding relationship between the patient comfort and the insertion angle is proposed, and the optimal sizes of mechanical structure are obtained. (3) Based on the theoretical analysis, the mechanical structure and the control system of the robot are designed, and the prototype is manufactured. (4) Experimental research is conducted. The results show that the prototype can complete the required motion performance with a carrying capacity up to 150 kg and patient comfort is excellent. The results of this paper prove that this kind of patient transfer robot has good performance, it can also reduce the burden on medical staff.

Optimization of Mechanically Assembled Van Der Waals Heterostructure Based On Solution Immersion and Hot Plate Heating

Layers of two-dimensional material are bonded together by van der Waals force, as a result, there is no need to take into consideration of the lattice mismatch in the formation of heterojunction, which is endowed with the characteristics of simple stacking in method, free of limitation to the type of materials and diverse changes. However, although the Van Der Waals heterojunction is relatively easy to stack, it is still difficult to generate inter-layer coupling between the thin crystal layers that form the Van Der Waals heterojunction. In most cases, the stacked heterojunction is simply stacked together without any new effects. Therefore, the realization of heterojunction coupling is a difficult problem to be considered in the process of preparing Van Der Waals heterojunction. In this paper, a method based on solution immersion and hot plate heating is proposed to optimize the mechanical stacking of Van Der Waals heterojunctions. It is found that the heterojunctions prepared by normal mechanical stacking method are usually uncoupled before treatment, but they can be stably coupled after treatment. Our method, simple, fast with low-cost, has been repeatedly verified to have a high success rate of coupling, which is suitable for most experimental groups to use and reproduce.

Application Research of BP Neural Network Algorithm in Power Line Loss Calculation

In recent years, it is still a difficult problem to calculate the line loss of distribution system. The main reason is that China’s power system data is not perfect, the components are huge, the management function does not exist, the network structure is directly connected. Therefore, reducing the loss rate of power system has become an urgent problem for energy companies to solve. Developing effective methods for line loss reduction evidence and line loss assessment requires careful calculation and analysis of line loss, which ultimately contributes to and guides line loss management.

Plasmonic Bi NPs-accelerated interfacial charge transfer for enhanced solar-driven ciprofloxacin mineralization

High-efficient mineralization of refractory organic pollutants is an admittedly difficult problem for most photocatalytic processes. Herein, a hierarchical type-II heterojunction of Bi2MoO6/Bi/BiOBr-x (BMO/Bi/BOB-x) was successfully fabricated via one-pot solvothermal method....

SPATIAL PROBLEMS OF DYNAMIC STABILITY OF FRAME STRUCTURES

Periodic longitudinal forces in structural elements caused by operational or seismic influences, at certain values of the parameters of these forces can cause the occurrence and growing of transverse oscillations of these elements. This phenomenon is called parametric resonance or loss of dynamic stability. In the works of N. M. Belyaev, N. M. Krylov, М. М. Bogolyubov, E. Mettler, V. N. Chelomey, V. V. Bolotin flat problems of dynamic stability of frame structures were investigated. In this paper the modified Bolotin’s method, proposed to solve flat problems of dynamic stability of frames, is used. Instead of the deformation method used by V. V. Bolotin to construct analytical expressions of deflections of frame rods, in the modified method the numerical-analytical method of boundary elements is used. The article proposes a method for constructing domains of dynamic instability of frames in the space of parameters (frequency and amplitude) of seismic and operational dynamic influences that cause longitudinal forces in the rods, which periodically change over time and lead to unlimited growth of transverse oscillations amplitudes in the domains of instability. The proposed method is demonstrated in example, which considers the spatial problem of dynamic stability of a П-shaped frame with two concentrated masses located on it, which are under the action of vertical periodic forces. These forces create periodic longitudinal forces in the vertical rods of the frame. Areas of dynamic instability of the frame were constructed. Taking into account the destructive effect of oscillations is important for practical application. The most dangerous destructive effect of oscillations is observed in earthquakes and explosions. The study of this action makes it possible to avoid undesirable consequences of oscillations by limiting their level and to solve important practical problems of the dynamics of structures. Solving dynamics problems is a difficult problem. Dynamic calculation of structures provides their bearing capacity under the combined action of static and dynamic loads.

An Empirical Study Based on the Impact of Smart Sensor System on Rural Relative Poverty

Solving the problem of rural poverty is a difficult problem for the country to enter a well-off society in an all-round way. Therefore, this paper conducts an experimental analysis based on the impact of smart sensor systems on the relative poverty in rural areas. This article is aimed at studying the related factors of rural poverty and improving relative poverty in rural areas. In this regard, this article proposes an intelligent processing function based on smart sensors. Multiple sensors work together to process relatively complex things. Then, through the experimental analysis of GH efficiency, the data collected in the experimental area is used as the data. Combining the Lorentz curve and Gini coefficient analysis to determine the influencing factors of rural relative poverty. This article also selected 10 areas for experimentation. The experimental results show that the proportion of middle school education from 2014 to 2020 is between 24.3% and 34%, and the number of poor people has also declined, indicating that education level is a factor affecting rural poverty. Therefore, based on the intelligent sensor system, the factors of relative poverty in rural areas can be found, and related measures can be analyzed. By implementing the rural poverty alleviation strategy, the relative poverty situation in rural areas can be effectively improved.

Using Determinants for Determining Extreme Values of a Function of One Variable, Two Variables and Three Variables

Finding the maximum and minimum values of a function is essential in high school math. However, Vietnamese high school students have only been taught how to find the extreme values of a function of 1 variable. Seeing the extreme values of a function of 2 and 3 variables is a difficult problem for students. Using the determinants, our aim in this paper is to show the necessary and sufficient conditions for a continuous and differentiable function (1 variable, two variables, and three variables) to reach its maximum over a specified domain. Furthermore, our method can be used to find the extremes of n-variable differentiable functions.

Quantum Entanglement of Monochromatic and Non-Monochromatic Photons on a Waveguide Beam Splitter

It is well known that the waveguide beam splitter can be used as a source for the quantum entanglement of photons. The analysis of such quantum entanglement is a difficult problem even for monochromatic photons, since the system under study is multiparametric. This paper will show that quantum entanglement can be represented in a simple form not only for monochromatic photons but also for non-monochromatic ones. It will be shown that quantum entanglement for non-monochromatic photons can be very different from monochromatic photons, which can be used to create large quantum entanglement.