The propagation of a probe field through a four-level Y-type atomic system is described in the presence of two additional coherent radiation fields,namely,the control field and the coupling field.An expression for the...The propagation of a probe field through a four-level Y-type atomic system is described in the presence of two additional coherent radiation fields,namely,the control field and the coupling field.An expression for the probe response is derived analytically from the optical Bloch equations under steady state condition to study the absorptive properties of the system under probe field propagation through an ensemble of stationary atoms as well as in a Doppler broadened atomic vapor medium.The most striking result is the conversion of electromagnetically induced transparency(EIT)into electromagnetically induced absorption(EIA)as we start switching from weak probe regime to strong probe regime.The dependence of this conversion on residual Doppler averaging due to wavelength mismatch is also shown by choosing the coupling transition as a Rydberg transition.展开更多
Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to conne...Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to connect the ground level with the intermediate level whereas a coherent control beam is supposed to act between the intermediate energy level and the uppermost level. Optical Bloch equations（OBE） for a three-level Ξ type system and a four-level Ξ type system are derived by using density matrix formalism. These equations are solved by an analytic method to determine the probe response, which not only depends on the wavelength difference between the control（pump） field and the probe field but shows substantially different features depending on whether the wavelength of the control field is greater than that of the probe field or the reverse. The effect of temperature on probe response is also shown. Enhancement in probe absorption and additional features are noticed under a strong probe limit at room temperature. The four-level Ξ type system has two ground levels and this leads to substantial modification in the simulated probe absorption as compared to the three-level system.展开更多
Objective Benzophenone semicarbazone(BSC) was synthesized and characterized to identify compounds with anticancer activities. Methods Anticancer activities were studied against Ehrlich Ascites Carcinoma(EAC) cells in ...Objective Benzophenone semicarbazone(BSC) was synthesized and characterized to identify compounds with anticancer activities. Methods Anticancer activities were studied against Ehrlich Ascites Carcinoma(EAC) cells in Swiss albino mice by monitoring parameters such as tumor weight measurement,survival time of tumor bearing mice,tumor cell growth inhibition,and so on.Some hematological parameters,such as red blood cells,white blood cells,and hemoglobin content,were also measured. Results The results showed that BSC has a positive effect against EAC cells.An assessment was conducted by comparing these results with those obtained using the standard drug bleomycin. Conclusions The BSC compound can be considered as a potent anticancer agent.展开更多
基金UGC (ERO) for granting a minor research project (F. No. PSW: 050(2015–16), date-16/11/2016)UGC (New Delhi) for providing research fellowship (JRF-NET, vide sanction No. F.17-124/2008(SAI) dated 22/08/2014)+1 种基金SERB for granting a project under Teaching Associateship for Research Excellence (TARE) scheme (sanction no. TAR/2018/000710)the University Grants Commission (New Delhi) for sanctioning a major research project (F. No-43–527/2014(SR) dated 28/09/2015).
文摘The propagation of a probe field through a four-level Y-type atomic system is described in the presence of two additional coherent radiation fields,namely,the control field and the coupling field.An expression for the probe response is derived analytically from the optical Bloch equations under steady state condition to study the absorptive properties of the system under probe field propagation through an ensemble of stationary atoms as well as in a Doppler broadened atomic vapor medium.The most striking result is the conversion of electromagnetically induced transparency(EIT)into electromagnetically induced absorption(EIA)as we start switching from weak probe regime to strong probe regime.The dependence of this conversion on residual Doppler averaging due to wavelength mismatch is also shown by choosing the coupling transition as a Rydberg transition.
文摘Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to connect the ground level with the intermediate level whereas a coherent control beam is supposed to act between the intermediate energy level and the uppermost level. Optical Bloch equations（OBE） for a three-level Ξ type system and a four-level Ξ type system are derived by using density matrix formalism. These equations are solved by an analytic method to determine the probe response, which not only depends on the wavelength difference between the control（pump） field and the probe field but shows substantially different features depending on whether the wavelength of the control field is greater than that of the probe field or the reverse. The effect of temperature on probe response is also shown. Enhancement in probe absorption and additional features are noticed under a strong probe limit at room temperature. The four-level Ξ type system has two ground levels and this leads to substantial modification in the simulated probe absorption as compared to the three-level system.
基金supported by a grant from the National Science and Information and Communication Technology of Bangladesh
文摘Objective Benzophenone semicarbazone(BSC) was synthesized and characterized to identify compounds with anticancer activities. Methods Anticancer activities were studied against Ehrlich Ascites Carcinoma(EAC) cells in Swiss albino mice by monitoring parameters such as tumor weight measurement,survival time of tumor bearing mice,tumor cell growth inhibition,and so on.Some hematological parameters,such as red blood cells,white blood cells,and hemoglobin content,were also measured. Results The results showed that BSC has a positive effect against EAC cells.An assessment was conducted by comparing these results with those obtained using the standard drug bleomycin. Conclusions The BSC compound can be considered as a potent anticancer agent.
