Effect of Different Mixed Fertilizer on Yield, Quality and Economic Benefits in Stevia rebaudiana Bertoni

Abstract: The effect of different mixed fertilizer on yield, quality and economic benefits in Stevia rebaudiana Bertoni had been studied in open field. The result showed that organic cultivation and the common had some remarkable difference in yield, quality, as well as the economic benefits. Leaf production of treatment that incorporating organic fertilizer with decomposed Stevia rebaudiana dregs lower than the one that incorporating organic fertilizer with inorganic fertilizer, yet higher than applying organic fertilizer only and inorganic fertilizer only; organic cultivation enable Stevia rebaudiana produced more Stevioside (STV) in leaf blade compared with common cultivation, especially in the content of Rebaudioside A (RA); and incorporating organic fertilizer with decomposed Stevia rebaudiana dregs led to a significantly higher economic benefit compared with others

Theory of ARPES in Graphene-Based Moiré Superlattices

Graphene-based moir´e superlattices are now established as an interesting platform for strongly- correlated many-electron physics, and have so far been characterized mainly by transport and scan- ning tunneling microscopy (STM) measurements. Motivated by recent experimental progress, we present a theoretical model study whose aim is to assess the potential of angle-resolved photoemis- sion spectroscopy (ARPES) to resolve some of the many open issues in these systems. The theory is developed specifically for graphene on hexagonal boron nitride (G/hBN) and twisted bilayer graphene (TBG) moir´e superlattices, but is readily generalized to any system with active degrees of freedom in graphene sheets.This research was primarily supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF MRSEC under Cooper- ative Agreement No. DMR-1720595. We acknowledge helpful interactions with Dan Dessau, Eli Rotenberg and Simon Moser.Center for Dynamics and Control of Material

Robust Finite-Time Control for Guidance Law with Uncertainties in Missile Dynamics

In this paper, the robust !nite-time control for impact angle guidance of missile dynamic system with uncertainties is investigated by combining linear extended state observer (LESO) and adaptive non-singular fast terminal sliding mode method. Specially for dealing with existing uncertainties including time-varying parametric perturbation and nonparametric disturbances in high order line-of-sight rates and target acceleration, a robust LESO strategy is proposed for designing sliding mode-based impact angle guidance, which can guarantee that estimation error converges to the neighborhood of the origin in finite-time. Based on the proposed LESO framework, an adaptive non-singular fast terminal sliding mode guidance law is considered for realizing interception of maneuvering targets, which can guarantee asymptotically stability of the system. Simulation results are shown for confirming effectiveness of the proposed guidance strategy of this paper. Compared with former methods, accuracy of estimation is increased by nearly two times, and miss distance is reduced by nearly two times

Acidification oxidation reagent system optimization on coal seams and stimulation effect evaluation

China has abundant coalbed methane (CBM) resources, and most of them are low-permeability and tight reservoirs, with generally low production rate and small recovery factor. Existing technologies face great challenges to meet the demand on CBM in China. It is desirable to develop new methods to improve the production rate and enhance recovery factor. In addition to physical stimulation methods such as hydraulic fracturing and open-hole cave completion, the use of chemical methods to improve physical properties of coal reservoirs has also been a hot research topic in recent years. Coal reservoir acidification and oxidation technology can promote desorption of gas and enlarge permeability of reservoir. But for different coal rank coal reservoirs, the acidification and oxidation agents need to be optimized and their performance evaluated. Laboratory experiments are conducted to compare and analyze the physical properties coal samples from Baode, Mu’ai, and Xinjiang blocks, including coal rank, texture, macroscopic characteristics, quality, porosity, permeability, element, and mineral composition. The optimal concentration of hydrochloric acid is determined through pre-dissolution experiment of coal powder in acid solution. Then a five-factor and three-level orthogonal experiment for acid solution optimization is designed and performed by using Design-Expert software, which identifies the sensitive factors affecting the dissolution. For the coal samples in Baode, Mu’ai, and Xinjiang blocks, the oxidant types and the corresponding acidification and oxidation agent systems are optimized. Applying these acidification and oxidation agent systems to coal samples from Baode, Mu’ai, and Xinjiang blocks, the change of porosity, permeability, and wettability are compared and analyzed. Finally, through numerical simulation, the gas production is predicted for acidification and oxidation in typical well group in Block Mu’ai. Results show that the acid solution has the best dissolution at a concentration of hydrochloric acid of 3 mol/L to 4 mol/L; Top factors played in the experiment are soaking time, acid type, soaking temperature, coal sample type, and acid concentration, in descending order of importance; The optimal oxidant is a hydrogen peroxide solution with a concentration of 3%; the mixed acidification oxidant formula in Baode block is 10% HCl + 2% CH3COOH + 2% HF + 3% H2O2; The optimal mixed acidification oxidant formula in Mu’ai block is 8% HCl + 2% CH3COOH + 4% HF + 3% H2O2; the optimal mixed acidification oxidant formula in Xinjiang block is 12% HCl + 1% CH3COOH + 1% HF + 3% H2O2; The higher the coal rank, the greater the HF content in the optimal acidification oxidant system. Both acidification and oxidation improve the porosity and permeability of coal samples to some extent, and the improvement in low-rank coal is more significant than that in high-rank coal. Acidification and oxidation have different effects on the wettability of coal: Acidification increases the hydrophilicity of coal, whereas oxidation reduce the hydrophilicity of coal; and the hydrophilicity of coal samples treated by the optimized acidification and oxidation system is weakened. Reservoir simulation results show that acidification and oxidation lead to a recovery factor of 64.64% after 10 years of production, which is 19.72% higher than that without acidification and oxidation. The advantage of acidification and oxidation is 0.97% after 18 years of production. However, the acidification and oxidation saved 8 years of production time to achieve a close final recovery factor, which greatly reduces the operating costs. The optimized acidizing oxidation agent systems for CBM reservoirs with low, medium, and high ranks improved the desorption and permeability of the target reservoirs, and increase well production and recovery factor. This research provides technical support for stimulation practices of CBM reservoirs in the aforementioned blocks in China, as well as similar coal reservoirs in the world

Effect of Different Harvest Stages on Nutritional Components of Purple Yam

Abstract: The effect of different harvest stages on nutritional components of purple yam had been studied in the open field. The results showed that the content of anthocyanins in purple yam turberous root was the highest, while the content of dietary fiber and starch moderate during the first harvest stage; the content of anthocyanins, dietary fiber and starch began to decline during the second harvest stage; the content of all three gained some instead during the third harvest stage and the content of dietary fiber and starch was the highest; the content of β-carotene and selenium in purple yam turberous root was stable during all harvest stages. In summary, the date between September 30 th and October 15 th which purple yam turberous root containing higher levels of nutrients and is the best harvest stage