It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence （SGC）, the gain without inversion （GWI） is very sensitive to the variation of the relative phase ...It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence （SGC）, the gain without inversion （GWI） is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate （R0） and the ratio （S） of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case.展开更多
It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase betw...It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case.展开更多
A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one...A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one-photon inversion does not occur but two-photon inversion is present, in a closed A-type three-level system with incoherent pumping. It is shown that when the driving field is resonant but the probe field is not, in a certain range of Doppler width, for the case of the lower degree of frequency up-conversion, generally, pure gain without inversion increases monotonically and non-pure gain without inversion does not monotonically increase or decrease with increasing Doppler width; for the case of the higher degree of frequency up-conversion, pure gain without inversion decreases monotonically but non-pure gain without inversion cannot be produced. In the case of two-photon resonance, in some range of Doppler width, pure gain without inversion does not monotonically increase or decrease while non-pure gain without inversion decreases monotonically with Doppler width increasing. Finally, an experimental scheme for examining our theoretical result is given.展开更多
This study was conducted to examine the nutritional content, contamination levels, and biological effects of 3 local prepared formulas. Formula (1) contained mixed nuts;formula (2) contained moghat, honey and royal je...This study was conducted to examine the nutritional content, contamination levels, and biological effects of 3 local prepared formulas. Formula (1) contained mixed nuts;formula (2) contained moghat, honey and royal jelly, while formula (3) contained honey, fenugreek and royal jelly. Groups of albino rats (90 rats) were randomly allocated to diets of control group or 1 - 3 treatment groups. The tested diets contained 15% carbohydrate. The weight and food intake were recorded. Blood tests were conducted to determine total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, urea, creatinine, white blood cell count (WBC), red blood cell count (RBC), haemoglobin (HB), mean corpuscular volume (MCV), and haematocrit (HCT). Results showed that bacterial contamination was found in formula (1) and formula (3). Fungal contamination was detected in formula (2) and formula (3). Body weight increased significantly in the rats fed treatment formulas compared to the control group. The blood tests indicated significant increases in the levels of glucose, WBC, HCT, total cholesterol, LDL cholesterol, and triglycerides as well as a significant decrease in HDL level in the group (2) was fed formula (1) the control. In conclusion, these findings indicate that these local formulas may not be safe, and further studies are required to understand the consequences of a long-term consumption of these formulas.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No. 11175105）.
文摘It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence （SGC）, the gain without inversion （GWI） is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate （R0） and the ratio （S） of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11175105)
文摘It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case.
基金Project supported by the Natural Science Foundation of Shandong Province,China (Grant No Y2006A21)the National Natural Science Foundation of China (Grant No 10675076)
文摘A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one-photon inversion does not occur but two-photon inversion is present, in a closed A-type three-level system with incoherent pumping. It is shown that when the driving field is resonant but the probe field is not, in a certain range of Doppler width, for the case of the lower degree of frequency up-conversion, generally, pure gain without inversion increases monotonically and non-pure gain without inversion does not monotonically increase or decrease with increasing Doppler width; for the case of the higher degree of frequency up-conversion, pure gain without inversion decreases monotonically but non-pure gain without inversion cannot be produced. In the case of two-photon resonance, in some range of Doppler width, pure gain without inversion does not monotonically increase or decrease while non-pure gain without inversion decreases monotonically with Doppler width increasing. Finally, an experimental scheme for examining our theoretical result is given.
文摘This study was conducted to examine the nutritional content, contamination levels, and biological effects of 3 local prepared formulas. Formula (1) contained mixed nuts;formula (2) contained moghat, honey and royal jelly, while formula (3) contained honey, fenugreek and royal jelly. Groups of albino rats (90 rats) were randomly allocated to diets of control group or 1 - 3 treatment groups. The tested diets contained 15% carbohydrate. The weight and food intake were recorded. Blood tests were conducted to determine total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, urea, creatinine, white blood cell count (WBC), red blood cell count (RBC), haemoglobin (HB), mean corpuscular volume (MCV), and haematocrit (HCT). Results showed that bacterial contamination was found in formula (1) and formula (3). Fungal contamination was detected in formula (2) and formula (3). Body weight increased significantly in the rats fed treatment formulas compared to the control group. The blood tests indicated significant increases in the levels of glucose, WBC, HCT, total cholesterol, LDL cholesterol, and triglycerides as well as a significant decrease in HDL level in the group (2) was fed formula (1) the control. In conclusion, these findings indicate that these local formulas may not be safe, and further studies are required to understand the consequences of a long-term consumption of these formulas.
