Effects of Magnesium Compound with Fertilizer on Daylily (Hemerocallis citrina Baroni) Growth and Soil Nutrients

Effects of two kinds of magnesium compound with fertilizer on Daylily （Hemerocallis citrina Baroni） growth, yield, and soil nutrients in red soil were studied. The results indicated that significant effects of magnesium applied to soils were observed in increasing Daylily （Hemerocallis citrina Baroni） yield, improving its growth, and strengthening its antivirus property as well as increasing the amount of exchangeable Mg, N, P, and K in red soil. In particular, the effects of magnesium compound fertilizer Ⅱ （MCF2） with higher Mg content were better than that of the others, which increased Daylily （Hemerocallis citrina Baroni） yield by 57.4, 32.8, and 14.5% compared to that of control treatment （CK）, chemical fertilizer with nitrogen, phosphorus, potassium treatment （CF）, and magnesium compound fertilizer Ⅰ treatment （MCF1） with lower Mg content. It increased soil Alkali N, available P, exchangeable K, and exchangeable Mg by 94.9, 46.5, 31.1, and 35.3%, respectively, compared with that of CK treatment. Therefore, the application of magnesium compound with fertilizer is an optimum method for improving red soil quality.

First-principles Calculations of Strengthening Compounds in Magnesium Alloy： A General Review

First-principles computation methods play an important role in developing and designing new magnesium alloys.In this article,we present an overview of the first-principles modeling techniques used in recent years to simulate ideal models of the structure of strengthening compounds in Mg alloys.For typical Mg compounds,structural stability,mechanical properties,electronic structure and thermodynamic properties have been discussed.Specifically,the elastic anisotropies of these compounds are examined,which is highly correlated with the possibility of inducing micro-cracks.Furthermore,some heterogeneous nucleation interfaces investigated by first-principles method are reviewed.Some of the theoretical results are compared with available experimental observations.We hope to illustrate that the first-principles computation can help to accelerate the design of new Mg-based materials and the development of materials genome initiative.Remaining problems and future directions in this research field are considered.

Diffusion behavior and reactions between Al and Ca in Mg alloys by diffusion couples

The diffusion behavior and reactions between AI and Ca in Mg alloys by diffusion couple method were investigated. Results demonstrate that Al2Ca is the only phase existing in the diffusion reaction layers. The volume fraction of Al2Ca in diffusion reaction layers increases linearly with temperature. The standard enthalpy of formation for intermetallic compounds was rationalized on the basis of the Miedema model. Al-Ca intermetallic compounds were preferable to form in the Mg-Al-Ca ternary system under the same conditions. Over the range of 350-400℃, the structure of Al2Ca is more stable than that of Al4Ca, Al14Ca13and Al3Ca8, The growth constants of the layer I, layer II and entire diffusion reaction layers were determined. The activation energies for the growth of the layer I, layer II and entire diffusion reaction layers were （80.74 ± 3.01 ） kJ/mol, （93.45 ±2.12） kJ/mol and （83.52 ±1.50） kJ/mot, respectively. In layer I and II, AI has higher integrated interdiffusion coefficients D^i^Int,layer layer than Ca. The average effective interdiffusion coefficients D^Al^eff values are higher than D^Ca^eff in the layer I and II.