An all-optical phase detector by amplitude modulation of the local field in a Rydberg atom-based mixer

Recently,a Rydberg atom-based mixer was developed to measure the phase of a radio frequency(RF)field.The phase of the signal RF(SIG RF)field is down-converted directly to the phase of a beat signal created by the presence of a local RF(LO RF)field.In this study,we propose that the Rydberg atom-based mixer can be converted to an all-optical phase detector by amplitude modulation(AM)of the LO RF field;that is,the phase of the SIG RF field is related to both the amplitude and phase of the beat signal.When the AM frequency of the LO RF field is the same as the frequency of the beat signal,the beat signal will further interfere with the AM of the LO RF field inside the atom,and then the amplitude of the beat signal is related to the phase of the SIG RF field.The amplitude of the beat signal and the phase of the SIG RF field show a linear relationship within the range of 0 toπ/2 when the phase of the AM is set with a differenceπ/4 from the phase of the LO RF field.The minimum phase resolution can be as small as 0.6°by optimizing the experimental conditions according to a simple theoretical model.This study will expand and contribute to the development of RF measurement devices based on Rydberg atoms.

Controlling fusarium head blight of wheat (triticum aestivum L.) with genetics

Fusarium head blight, one of the most destructive diseases of wheat (Triticum aestivum L.), results in significant economic losses from reduced grain yield and quality. In recent decades, the disease has been frequently recorded, especially under warm and wet climatic conditions. Genetic resistance has engaged plant breeders because the use of resistant cultivars is the most economical, effective, and environmentally friendly method of control. In the present paper, we summarize the research on resistance genetics of Fusarium head blight, suggest a new method for evaluating Fusarium head blight resistance, and recommend strategies for creating and developing new sources of resistance to Fusarium head blight through the use of alien genes and chromosomal segments.

Three-segment control theory of MgO/Al2O3 ratio based on viscosity experiments and phase diagram analyses at 1500℃

In recent years, more and more high Al2O3 iron ores were used in East Asia, especially in China, which increased the Al2O3 content in blast furnace (BF) slag and resulted in poor metallurgical properties of slag. Adding MgO-bearing flux is one of the methods to improve the metallurgical properties of slag with high Al2O3. However, there is lack of theoretical basis for the proper MgO/Al2O3 ratio. Therefore, the properties of slag in SiO2-CaO-MgO-Al2O3 system were investigated based on viscosity experiments and phase diagram analyses at 1500℃, and the proper MgO/Al2O3 ratio was explored according to the Al2O3 content in slag. The experimental results show that: (1) in the case of Al2O3 content less than 14mass%, there is no limitation of the MgO/Al2O3 ratio, and the amount of MgO in slag can be determined according to the hearth tempera-ture and desulfurization;(2) in the case of Al2O3 content between 15 and 17mass%, the proper MgO/Al2O3 ratio should be 0.40-0.50;(3) in the case of Al2O3 content between 18 and 20mass%, the proper MgO/Al2O3 ratio should be 0.45-0.55. Consequently, the three-segment control theory of MgO/Al2O3 for BF slag was built, and the actual BF performances proved the validity and applicability of this theory. The research contents and results can give theoretical guidelines for stable BF operation in a wide range of Al2O3 content of 12-20mass%.