Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission wit...Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.展开更多
The thermal shift of 5d energy level of Eu^(2+) doped in Sr_5(PO_4)_3Cl have been measured in 10～ 700 K.A simulation calculation was worked out with a modified theoretical equation.
By taking into account all the irreducible representations and their components in t he electron-phononinteraction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 elect ronic config...By taking into account all the irreducible representations and their components in t he electron-phononinteraction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 elect ronic configuration,the values of all the parameters in the expressions of thermal shift (TS) and thermal broadening (TB) due to EPI forthe ground level, R level and R line of MgO:Cr3+ have microscopically been evaluated; and then, TS and TB of R lineand various contributions to them have uniformly been calculated. The results arc in very good agreement with theexperimental data. It is found that all the three terms of TS due to EPI are red shifts; the Raman term is the largestone, and the optical-branch term and neighbor-level term are important for TS; the contribution to TS from thermalexpansion is bluc shift, which is also important. The R-line TS of MgO:Cr3+ comes from the first-order term of EPI. Theelastic Raman scattering of acoustic phonons plays a dominant role in R-line TB of MgO:Cr3+. For both TS and TB,it is very important to take into account all the admixtures of basic wavefunctions within d3 electronic configuration.展开更多
A great improvement on a previous work (Phys. Rev. B48 (1993) 14067) has been made. By taking intoaccount all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as al...A great improvement on a previous work (Phys. Rev. B48 (1993) 14067) has been made. By taking intoaccount all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as allthe levels and the admixtures of basic wavefunctions within d3 electronic configuration, the values of all the parametersin the expressions of thermal shift (TS) and thermal broadening (TB) from EPI for the ground level, R level and R lineof MgO:V2+ have microscopically been evaluated; and then, both the TS and TB of R line and various contributions tothem have uniformly been calculated. The results are in very good agreement with the experimental data. It is foundthat all the three terms of TS from EPI are red shifts; the term of the contribution to TS from thermal expansion is blueshift. The Raman term is the largest, and the other terms are also important for TS. The R-line TS of MgO:V2+ comesfrom the first-order term of EPI. The elastic Raman scattering of acoustic phonons plays a dominant role in R-line TBof MgO:V2+. For calculations of both the TS and TB, it is very important to take into account all the admixtures ofwavefunctions.展开更多
Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy).By means of improved li...Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy).By means of improved ligand-field theory,the R line,t_2^(32)T_1 and t_2^(32)T_2 lines,t_2~2(~3T_1)e^4T_2,t_2~2(~3T_1)e^4T_1 and t_2e^2(~4A_2)~4T_1 bands,g factors of t_2~3 ~4A_2 and t_2^(32)E,four strain-induced level-splittings and R-line thermal shift of MgO:V^(2+) have been calculated.The results are in very good agreement with the experimental data.It is found that for MgO:V^(2+),the contributions due to electron- phonon interaction (EPI) come from the first-order term;the contributions from the second-order and higher terms are insignificant.In thermal shift of R line of MgO:V^(2+),the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.展开更多
Quantum chemical calculations on some possible equilibrium geometries of C24O2 isomers derived from C24 （D6） and C24O have been performed using density functional theory （DFT） method. The geometric and electronic ...Quantum chemical calculations on some possible equilibrium geometries of C24O2 isomers derived from C24 （D6） and C24O have been performed using density functional theory （DFT） method. The geometric and electronic structures as well as the relative energies and thermal stabilities of various C24O2 isomers at the ground state have been calculated at the B3LYP/6-31G（d） level of theory. And the 1,4,2,5-C24O2 isomer was found to be the most stable geometry where two oxygen atoms were added to the longest carbon-carbon bonds in the same pentagon from a thermodynamic point of view. Based on the optimized neutral geometries, the vertical ionization potential and vertical electron affinity have been obtained. Meanwhile, the vibrational frequencies, IR spectrum, and 13C chemical shifts of various C24O2 isomers have been calculated and analyzed.展开更多
Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with dat...Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the perimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geopressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of dissolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.展开更多
Background: Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine(CQ) has played an i...Background: Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine(CQ) has played an indispensable role, however, its mechanism of action(MoA) is not fully understood.Methods: We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling(ABPP) and mass spectrometry-coupled cellular thermal shift assay(MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays.Results: We developed a novel clickable, photo-affinity chloroquine analog probe(CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photocrosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods.Conclusions: We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled(ABPP)and label-free(MS-CETSA) methods.展开更多
With the rapid development of cryptography, the strength of security protocols and encryption algorithms consumedly relies on the quality of random number. In many cryptography applications, higher speed is one of the...With the rapid development of cryptography, the strength of security protocols and encryption algorithms consumedly relies on the quality of random number. In many cryptography applications, higher speed is one of the references required. A new security random number generator architecture is presented. Its philosophy architecture is implemented with FPGA, based on the thermal noise and linear feedback shift register(LFSR). The thermal noise initializes LFSRs and is used as the disturbed source of the system to ensure the unpredictability of the produced random number and improve the security strength of the system. Parallel LFSRs can produce the pseudo-random numbers with long period and higher speed. The proposed architecture can meet the requirements of high quality and high speed in cryptography.展开更多
基金Project supported by Estahban Branch,Islamic Azad University
文摘Spectroscopic properties of flashlamp pumped Nd^3＋：YAG laser are studied as a function of temperature in a range from-30℃ to 60℃. The spectral width and shift of quasi three-level 946.0-nm inter-Stark emission within the respective intermanifold transitions of ^4F3/2→^4I9/2are investigated. The 946.0-nm line shifts toward the shorter wavelength and broadens. In addition, the threshold power and slope efficiency of the 946.0-nm laser line are quantified with temperature.The lower the temperature, the lower the threshold power is and the higher the slope efficiency of the 946.0-nm laser line is,thus the higher the laser output is. This phenomenon is attributed to the ion-phonon interaction and the thermal population in the ground state.
基金The project supported by the National Natural Science Foundation of China
文摘The thermal shift of 5d energy level of Eu^(2+) doped in Sr_5(PO_4)_3Cl have been measured in 10～ 700 K.A simulation calculation was worked out with a modified theoretical equation.
文摘By taking into account all the irreducible representations and their components in t he electron-phononinteraction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 elect ronic configuration,the values of all the parameters in the expressions of thermal shift (TS) and thermal broadening (TB) due to EPI forthe ground level, R level and R line of MgO:Cr3+ have microscopically been evaluated; and then, TS and TB of R lineand various contributions to them have uniformly been calculated. The results arc in very good agreement with theexperimental data. It is found that all the three terms of TS due to EPI are red shifts; the Raman term is the largestone, and the optical-branch term and neighbor-level term are important for TS; the contribution to TS from thermalexpansion is bluc shift, which is also important. The R-line TS of MgO:Cr3+ comes from the first-order term of EPI. Theelastic Raman scattering of acoustic phonons plays a dominant role in R-line TB of MgO:Cr3+. For both TS and TB,it is very important to take into account all the admixtures of basic wavefunctions within d3 electronic configuration.
文摘A great improvement on a previous work (Phys. Rev. B48 (1993) 14067) has been made. By taking intoaccount all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as allthe levels and the admixtures of basic wavefunctions within d3 electronic configuration, the values of all the parametersin the expressions of thermal shift (TS) and thermal broadening (TB) from EPI for the ground level, R level and R lineof MgO:V2+ have microscopically been evaluated; and then, both the TS and TB of R line and various contributions tothem have uniformly been calculated. The results are in very good agreement with the experimental data. It is foundthat all the three terms of TS from EPI are red shifts; the term of the contribution to TS from thermal expansion is blueshift. The Raman term is the largest, and the other terms are also important for TS. The R-line TS of MgO:V2+ comesfrom the first-order term of EPI. The elastic Raman scattering of acoustic phonons plays a dominant role in R-line TBof MgO:V2+. For calculations of both the TS and TB, it is very important to take into account all the admixtures ofwavefunctions.
文摘Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy).By means of improved ligand-field theory,the R line,t_2^(32)T_1 and t_2^(32)T_2 lines,t_2~2(~3T_1)e^4T_2,t_2~2(~3T_1)e^4T_1 and t_2e^2(~4A_2)~4T_1 bands,g factors of t_2~3 ~4A_2 and t_2^(32)E,four strain-induced level-splittings and R-line thermal shift of MgO:V^(2+) have been calculated.The results are in very good agreement with the experimental data.It is found that for MgO:V^(2+),the contributions due to electron- phonon interaction (EPI) come from the first-order term;the contributions from the second-order and higher terms are insignificant.In thermal shift of R line of MgO:V^(2+),the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.
文摘Quantum chemical calculations on some possible equilibrium geometries of C24O2 isomers derived from C24 （D6） and C24O have been performed using density functional theory （DFT） method. The geometric and electronic structures as well as the relative energies and thermal stabilities of various C24O2 isomers at the ground state have been calculated at the B3LYP/6-31G（d） level of theory. And the 1,4,2,5-C24O2 isomer was found to be the most stable geometry where two oxygen atoms were added to the longest carbon-carbon bonds in the same pentagon from a thermodynamic point of view. Based on the optimized neutral geometries, the vertical ionization potential and vertical electron affinity have been obtained. Meanwhile, the vibrational frequencies, IR spectrum, and 13C chemical shifts of various C24O2 isomers have been calculated and analyzed.
基金Projects 1212010535416 supported by the Geological Investigation Bureau of China2005D03 by the Shaanxi Natural Science Foundation
文摘Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the perimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geopressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of dissolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.
基金suppor ted by the National Key Research and Development Program of China(2020YFA0908000)the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-C-202002)+2 种基金the National Natural Science Foundation of China(82074098,82003814)the CACMS Innovation Fund(CI2021A05101)the Fundamental Research Funds for the Central public welfare research institutes(ZZ14-YQ-050,ZZ14-YQ-051,ZZ14-ND-010,ZZ15-ND-10 and ZZ14-FL-002)。
文摘Background: Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine(CQ) has played an indispensable role, however, its mechanism of action(MoA) is not fully understood.Methods: We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling(ABPP) and mass spectrometry-coupled cellular thermal shift assay(MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays.Results: We developed a novel clickable, photo-affinity chloroquine analog probe(CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photocrosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods.Conclusions: We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled(ABPP)and label-free(MS-CETSA) methods.
基金National Natural Science Foundation of China(60373087 and 90104005) Foundation for Doctoral SpecialBranch by Ministry of Education of China(20020486046)
文摘With the rapid development of cryptography, the strength of security protocols and encryption algorithms consumedly relies on the quality of random number. In many cryptography applications, higher speed is one of the references required. A new security random number generator architecture is presented. Its philosophy architecture is implemented with FPGA, based on the thermal noise and linear feedback shift register(LFSR). The thermal noise initializes LFSRs and is used as the disturbed source of the system to ensure the unpredictability of the produced random number and improve the security strength of the system. Parallel LFSRs can produce the pseudo-random numbers with long period and higher speed. The proposed architecture can meet the requirements of high quality and high speed in cryptography.
