Journal of Theoretical and Applied Sciences

Longevity has always been a desire and expectation since ancient times. Exploring the influencing factors of longevity is the goal of many scholars. Longevity has spatial aggregation. The influence of natural geographical environment on longevity is the focus of research. The content and distribution of elements in environmental media are one of the important factors affecting longevity. At present, there is still a lack of systematic exposition of regional health and longevity, and a lack of overall grasp of the relationship between elements in environmental media and health and longevity. Based on the research of environmental elements and longevity in typical longevity areas, this paper explores the key dominant elements affecting longevity and provides scientific basis for improving the health level of the elderly population.

There is a large amount of enrichment of rare earth elements in Zhungeer coal and coal ash, making it possible to use fly ash as a source for industrial production of rare earth elements. In order to optimize the leaching process of rare earth elements in fly ash and increase the leaching rate, the circulating fluidized bed fly ash of Zhungeer Power Plant was used as the material, and the single factor test and orthogonal test were used to influence the leaching rate of rare earth elements in the acid leaching process of fly ash The factors were discussed, and the results showed that when fly ash and 3mol/L hydrochloric acid were leached at a ratio of 1:10 for 2h at 130 0C, the element leaching effect was the best, and the leaching rate could reach 97%.

Gravity is redefined by drawing on the author’s works and inputting quark physics in a way consistent with it ; it allows to better understand black hole dynamics, black hole eruptions and some constellation patterns in the sky (the Scorpio, Ursa Minor and Ursa Major as well as Cassiopea for instance). The concept of gravitational lensing is rapidly differenciated from black hole eruptions. Some final remarks underline a possible threat for missions to the Moon.

With the increasing of mining depth, intensity, scale and speed, Ordovician limestone water has become the biggest threat to the safety production of the low group seam. Based on the existing geological data, the hydrogeological characteristics of Ordovician limestone water are analyzed; the risk of Ordovician limestone water inrush is evaluated by using the method of “five maps and double coefficients” and considering the importance of effective protective thickness of floor protective layer in the evaluation results. The results show that there are no non straight through relative safety area (Area I) and non straight type relative risk area (Area II), only non straight type water inrush risk area (Area III) and straight through water inrush risk area (Area IV). According to the evaluation results, the floor grouting reinforcement is directly adopted in Area IV, and the Ordovician limestone may need to be modified in the strong water rich area; in Area III, the grouting transformation of the floor is carried out after the area with water inrush is identified first, but the Ordovician limestone is not needed. Other prevention and control measures should be subsidiary.

Blasting flying stone is one of the six hazards in rock and soil blasting construction. In order to determine the risk level of blasting flying stone, 3 first-grade indexes such as blasting design and construction are selected, and 11 second-grade indexes such as warning range are not set, so as to establish the blasting flying stone safety evaluation model of AHP-GRA. The analytic hierarchy process (AHP) was used to calculate the weight of the evaluation index. The grey correlation method was used to determine the correlation degree between the blasting flying stone and the safety level of an airport. The risk level of an airport was calculated based on the weight of the evaluation index, and the engineering verification was carried out. The results show that there is no warning signal, no notice before detonation and the warning range is too small, which are the main factors of the flying stone accident. The model presented in this paper is used to evaluate the blasting flying stones in an airport, and the evaluation results are basically consistent with the reality. It can be seen that the evaluation model can scientifically and reasonably evaluate the risk level of blasting flying stones, which has important practical significance.

Wheat is one of the major staple crops in Ethiopia in terms of both production and consumption. Even though it is such an important cereal crops in Ethiopia, it is giving low yield due to many production constraints such as lack of improved varieties, poor agronomic practice (inappropriate seeding rate and row spacing), diseases, weeds and low soil fertility in Ethiopia in general and in Guji zone in particular. Therefore, field experiment was conducted during the 2015-2017 main cropping season at Bore and Ana sora to assess the effect of seeding rate and row spacing on yield components and yield of bread wheat; and to determine appropriate seeding rates row spacing for bread wheat. The experiment was laid out RCBD in a factorial arrangement with three replications using a wheat variety known as ‘Huluka’ as a test crop. The treatments consisted of four levels of seeding rate (100, 125, 150 and 175 kg ha-1) and four levels of row spacing (15, 20, 25 and 30 cm) consisting a total of 16 treatments. Analysis of the results revealed that all parameters were significantly (P

This paper focuses on the application of nonlinear programming in solving the optimal selection strategy of generator. A nonlinear programming model for optimal scheme selection was established. Comparative analysis, numerical combination analysis and sensitivity analysis were used to solve the problem, and MATLAB, LINGO and other software were used to assist the calculation. According to the actual background provided in this paper, it can be concluded that the minimum cost of this factory in a week of power failure is 1868443.7 yuan without charging. If the remaining 20% of the battery is taken into account, the minimum charge is 2575502.0 yuan. After obtaining the results, the sensitivity analysis was carried out to improve the practicability of the results.

Seafood provides essential nutrients to the body. A study funded by CDC found that eating seafood for essential Omega-3 fatty acids can prevent 84,000 deaths each year [1-3]. According to a Harvard study, 3-ounce servings of fatty fish a week reduces the risk of dying from heart disease by nearly 40% [4]. Eating 8 two servings of fish per week during pregnancy can improve baby’s IQ, cognitive development, and eye health [5,6]. Older adults with the highest fish consumption live and average of 2.2 years longer [7]. But all these statements possess another side of the coin. Food-born poisoning, mercury-lead-arsenic-cadmium poisoning, exposure to polycyclic aromatic hydrocarbons (PAHs) raised the issue of safety with aberrant consumption of seafoods. Seafood choices that are very low in mercury include: salmon, sardines, pollock, flounders, cod, tilapia, shrimp, oysters, clams, scallops and crab. The U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) have developed directions to help consumers minimize risks that could be associated with several pollutants (specially mercury) in seafood.

Calculating the modes of cylindrical shell, then embed them into ideal perfect cylindrical pressure-resistant shell as the initial geometric imperfections to form the modal. According to the characteristics of each mode, the first 30 modes can be classified into four types, and it is found that the mode of the first type is the worst defect form. By calculation, the cylinder shell has the minimum ultimate strength when the 23rd mode happened. The sensitivity analysis of cylindrical shells with initial geometric defects shows that the critical buckling load has approximate linear relationship with different thickness radius ratio and defect amplitude. Six cylindrical shells of different materials are selected for research, and it is found that although the modal orders of the worst geometric defects of various materials are not the same, they all belong to the first type of mode. The comparison showed that the 921 steel and 909 steel materials are economic.

As the social economy develops faster and faster, the functions of commercial complex buildings become more and more diverse. It is not only a place to shop, but also a place to gather a place of popularity. Therefore, in addition to providing a shopping place, it also has the function of providing a gathering place for leisure and entertainment, and can become a landmark building of a city. Therefore, we hope that through the analysis of the design features of this work, a complete and detailed architectural design idea for the design of such commercial complexes can be proposed.