For the Sylvester continued fraction expansions of real numbers,FAN et al.(2007)proved that,for almost all real numbers,the nth partial quotient grows exponentially with respect to the product of the first n-1 partial...For the Sylvester continued fraction expansions of real numbers,FAN et al.(2007)proved that,for almost all real numbers,the nth partial quotient grows exponentially with respect to the product of the first n-1 partial quotients.In this paper,we establish the Hausdorff dimension of the exceptional set where the growth rate is a general function.展开更多
An essential prerequisite of any genetherapy technique is the efficient and stable de-livery of transferred DNA into the target cell.Avariety of techniques are available for directly in-troducing DNA into eukaryotic c...An essential prerequisite of any genetherapy technique is the efficient and stable de-livery of transferred DNA into the target cell.Avariety of techniques are available for directly in-troducing DNA into eukaryotic cells,includingcoprecipitation with calcium phosphate,electroporation and microinjection. The efficien-cy of most of these physical transfection tech-niques is less than one in ten thousand, and展开更多
Teratogenic effect: HYTRIN was not teratogenic in either rats or rabbits when administered at oral doses up to 1330 and 165 times,zespectively,the maximum recommended human dose.Fetal resoaptions occured in rats dcsed...Teratogenic effect: HYTRIN was not teratogenic in either rats or rabbits when administered at oral doses up to 1330 and 165 times,zespectively,the maximum recommended human dose.Fetal resoaptions occured in rats dcsed with 480 mg/kg/day,appzoximately 1330 times the maximum recommened human dose.Increased fetal resorptions,decreased fetal weight and an increased humber of supernumerary ribs were observed in offspring展开更多
Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especial...Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especially continuous wave(CW)THz near-field scanning microscopy(THz-SNOM)with its nanoscale reso⁃lution,can be promising in biomedical imaging.In addition,compared with traditional THz time-domain spec⁃troscopy(TDS),portable solid-state source as the emission has higher power and SNR,lower cost,and can ob⁃tain more precise imaging.In this study,we employ CW THz-SNOM to further break the resolution limitations of conventional THz imaging techniques and successfully achieve the near-field imaging of demineralized enamel at the nanoscale.We keenly observe that the near-field signal of the enamel significantly lowers as demineralization deepens,mainly due to the decrease in permittivity.This new approach offers valuable insights into the micro⁃scopic processes of enamel demineralization,laying the foundation for further research and treatment.展开更多
The insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aq...The insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aquatic organisms,indicating the need for effective remediation strategies.Thus,we investigated the feasibility of treating water contaminated with NQ in continuous-flow columns packed with zero-valent iron(ZVI)or iron sulfide(FeS).Initially,the impact of pH on NQ transformation by ZVI or FeS was evaluated in batch experiments.The pseudo first-order rate constant for NQ transformation(k_(1,NQ))by ZVI was 8-10 times higher at pH 3.0 compared to pH 5.5 and 7.0,whereas similar k_(1,NQ)values were obtained for FeS at pH 5.5-10.0.Based on these findings,the influent p H fed to the ZVIand Fe S-packed columns was adjusted to 3.0 and 5.5,respectively.Both reactors transformed NQ into nitrosoguanidine(Nso Q).Further transformation of Nso Q by ZVI produced aminoguanidine,guanidine,and cyanamide,whereas Nso Q transformation by Fe S produced guanidine,ammonium,and traces of urea.ZVI outperformed Fe S as a reactive material to remove NQ.The ZVI-packed column effectively removed NQ below detection even after 45 d of operation(490 pore volumes,PV).In contrast,NQ breakthrough(removal efficiency<85%)was observed after 18 d(180 PV)in the Fe S-packed column.The high NQ removal efficiency and long service life of the ZVI-packed column(>490 PV)suggest that the technology is a promising approach for NQ treatment in packed-bed reactors and in situ remediation.展开更多
High-overload shocks are very likely to cause damage to the microstructure of MEMS devices, especially the continuous multiple high-overload shocks generated by the penetration of the multilayer target environment pos...High-overload shocks are very likely to cause damage to the microstructure of MEMS devices, especially the continuous multiple high-overload shocks generated by the penetration of the multilayer target environment pose more stringent challenges to its protective structure. In this study, the kinetic response model of the protective structure under single-pulse and continuous double-pulse impact is established,and a continuous double-pulse high overload impact test impact platform based on the sleeve-type bullet is constructed, and the protective performance of the multi-layer structure under multi-pulse is analyzed based on the acceleration decay ratio, and the results show that the protective performance of the structure has a positive correlation with its thickness, and it is not sensitive to the change of the load of the first impact;the first impact under double-pulse impact will cause damage to the microstructure through the superposition of the second impact. The first impact under double-pulse impact will cause an increase in the overload amplitude of the second impact through superposition;compared with the single-layer structure, the acceleration attenuation ratio of the double-layer structure can be increased by up to 26.13%, among which the epoxy-polyurethane combination has the best protection performance, with an acceleration attenuation ratio of up to 44.68%. This work provides a robust theoretical foundation and experimental basis for the reliable operation of MEMS devices, as well as for the design of protective structures in extreme environments.展开更多
Range-azimuth imaging of ground targets via frequency-modulated continuous wave(FMCW)radar is crucial for effective target detection.However,when the pitch of the moving array constructed during motion exceeds the phy...Range-azimuth imaging of ground targets via frequency-modulated continuous wave(FMCW)radar is crucial for effective target detection.However,when the pitch of the moving array constructed during motion exceeds the physical array aperture,azimuth ambiguity occurs,making range-azimuth imaging on a moving platform challenging.To address this issue,we theoretically analyze azimuth ambiguity generation in sparse motion arrays and propose a dual-aperture adaptive processing(DAAP)method for suppressing azimuth ambiguity.This method combines spatial multiple-input multiple-output(MIMO)arrays with sparse motion arrays to achieve high-resolution range-azimuth imaging.In addition,an adaptive QR decomposition denoising method for sparse array signals based on iterative low-rank matrix approximation(LRMA)and regularized QR is proposed to preprocess sparse motion array signals.Simulations and experiments show that on a two-transmitter-four-receiver array,the signal-to-noise ratio(SNR)of the sparse motion array signal after noise suppression via adaptive QR decomposition can exceed 0 dB,and the azimuth ambiguity signal ratio(AASR)can be reduced to below-20 dB.展开更多
The'International Workshop on e+e-collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This ...The'International Workshop on e+e-collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008)。展开更多
The'International Workshop on e+e-collisions fromtoψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is ...The'International Workshop on e+e-collisions fromtoψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10 th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008),Beijing(2009),展开更多
The'International Workshop on e^+e^- collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.Th...The'International Workshop on e^+e^- collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk。展开更多
The'International Workshop on e^+e^-collisions fromφtoψ'(PHIPSI15),was held at University of Science and Technology o{China(USTC),He{el,China,{rom Wednesday,September 23 to Saturday,September 26,2015.This is...The'International Workshop on e^+e^-collisions fromφtoψ'(PHIPSI15),was held at University of Science and Technology o{China(USTC),He{el,China,{rom Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008),展开更多
At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack be...At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack began less than 19 hours after the expiration of the UN-mandated deadline. From the following day to the end of the month, the U.S.-led allied air forces continued massive bombing&against targets in Iraq and occupied Kuwait. From展开更多
基金Supported by Projects from Chongqing Municipal Science and Technology Commission(CSTB2022NSCQ-MSX0445)。
文摘For the Sylvester continued fraction expansions of real numbers,FAN et al.(2007)proved that,for almost all real numbers,the nth partial quotient grows exponentially with respect to the product of the first n-1 partial quotients.In this paper,we establish the Hausdorff dimension of the exceptional set where the growth rate is a general function.
文摘An essential prerequisite of any genetherapy technique is the efficient and stable de-livery of transferred DNA into the target cell.Avariety of techniques are available for directly in-troducing DNA into eukaryotic cells,includingcoprecipitation with calcium phosphate,electroporation and microinjection. The efficien-cy of most of these physical transfection tech-niques is less than one in ten thousand, and
文摘Teratogenic effect: HYTRIN was not teratogenic in either rats or rabbits when administered at oral doses up to 1330 and 165 times,zespectively,the maximum recommended human dose.Fetal resoaptions occured in rats dcsed with 480 mg/kg/day,appzoximately 1330 times the maximum recommened human dose.Increased fetal resorptions,decreased fetal weight and an increased humber of supernumerary ribs were observed in offspring
基金Supported by the National Natural Science Foundation of China(61988102,62401113,92463308)。
文摘Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especially continuous wave(CW)THz near-field scanning microscopy(THz-SNOM)with its nanoscale reso⁃lution,can be promising in biomedical imaging.In addition,compared with traditional THz time-domain spec⁃troscopy(TDS),portable solid-state source as the emission has higher power and SNR,lower cost,and can ob⁃tain more precise imaging.In this study,we employ CW THz-SNOM to further break the resolution limitations of conventional THz imaging techniques and successfully achieve the near-field imaging of demineralized enamel at the nanoscale.We keenly observe that the near-field signal of the enamel significantly lowers as demineralization deepens,mainly due to the decrease in permittivity.This new approach offers valuable insights into the micro⁃scopic processes of enamel demineralization,laying the foundation for further research and treatment.
基金financially supported by the Strategic Environmental Research and Development Program(Grant No.ER19-1075)。
文摘The insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aquatic organisms,indicating the need for effective remediation strategies.Thus,we investigated the feasibility of treating water contaminated with NQ in continuous-flow columns packed with zero-valent iron(ZVI)or iron sulfide(FeS).Initially,the impact of pH on NQ transformation by ZVI or FeS was evaluated in batch experiments.The pseudo first-order rate constant for NQ transformation(k_(1,NQ))by ZVI was 8-10 times higher at pH 3.0 compared to pH 5.5 and 7.0,whereas similar k_(1,NQ)values were obtained for FeS at pH 5.5-10.0.Based on these findings,the influent p H fed to the ZVIand Fe S-packed columns was adjusted to 3.0 and 5.5,respectively.Both reactors transformed NQ into nitrosoguanidine(Nso Q).Further transformation of Nso Q by ZVI produced aminoguanidine,guanidine,and cyanamide,whereas Nso Q transformation by Fe S produced guanidine,ammonium,and traces of urea.ZVI outperformed Fe S as a reactive material to remove NQ.The ZVI-packed column effectively removed NQ below detection even after 45 d of operation(490 pore volumes,PV).In contrast,NQ breakthrough(removal efficiency<85%)was observed after 18 d(180 PV)in the Fe S-packed column.The high NQ removal efficiency and long service life of the ZVI-packed column(>490 PV)suggest that the technology is a promising approach for NQ treatment in packed-bed reactors and in situ remediation.
基金supported by Fund of the National Natural Science Foundation of China (Grant No. 52375553)。
文摘High-overload shocks are very likely to cause damage to the microstructure of MEMS devices, especially the continuous multiple high-overload shocks generated by the penetration of the multilayer target environment pose more stringent challenges to its protective structure. In this study, the kinetic response model of the protective structure under single-pulse and continuous double-pulse impact is established,and a continuous double-pulse high overload impact test impact platform based on the sleeve-type bullet is constructed, and the protective performance of the multi-layer structure under multi-pulse is analyzed based on the acceleration decay ratio, and the results show that the protective performance of the structure has a positive correlation with its thickness, and it is not sensitive to the change of the load of the first impact;the first impact under double-pulse impact will cause damage to the microstructure through the superposition of the second impact. The first impact under double-pulse impact will cause an increase in the overload amplitude of the second impact through superposition;compared with the single-layer structure, the acceleration attenuation ratio of the double-layer structure can be increased by up to 26.13%, among which the epoxy-polyurethane combination has the best protection performance, with an acceleration attenuation ratio of up to 44.68%. This work provides a robust theoretical foundation and experimental basis for the reliable operation of MEMS devices, as well as for the design of protective structures in extreme environments.
基金supported by the National Natural Science Foundation of China under Grant 62301051.
文摘Range-azimuth imaging of ground targets via frequency-modulated continuous wave(FMCW)radar is crucial for effective target detection.However,when the pitch of the moving array constructed during motion exceeds the physical array aperture,azimuth ambiguity occurs,making range-azimuth imaging on a moving platform challenging.To address this issue,we theoretically analyze azimuth ambiguity generation in sparse motion arrays and propose a dual-aperture adaptive processing(DAAP)method for suppressing azimuth ambiguity.This method combines spatial multiple-input multiple-output(MIMO)arrays with sparse motion arrays to achieve high-resolution range-azimuth imaging.In addition,an adaptive QR decomposition denoising method for sparse array signals based on iterative low-rank matrix approximation(LRMA)and regularized QR is proposed to preprocess sparse motion array signals.Simulations and experiments show that on a two-transmitter-four-receiver array,the signal-to-noise ratio(SNR)of the sparse motion array signal after noise suppression via adaptive QR decomposition can exceed 0 dB,and the azimuth ambiguity signal ratio(AASR)can be reduced to below-20 dB.
文摘The'International Workshop on e+e-collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008)。
文摘The'International Workshop on e+e-collisions fromtoψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10 th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008),Beijing(2009),
文摘The'International Workshop on e^+e^- collisions from Ф to ψ'(PHIPSI15),was held at University of Science and Technology of China(USTC),Hefei,China,from Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk。
文摘The'International Workshop on e^+e^-collisions fromφtoψ'(PHIPSI15),was held at University of Science and Technology o{China(USTC),He{el,China,{rom Wednesday,September 23 to Saturday,September 26,2015.This is the 10th workshop in a series,which started in Karlsruhe in 1996 and continued in Novosibirsk(1999),SLAC(2001),Pisa(2003),Novosibirsk(2006),Frascati(2008),
文摘At 02:30 am Baghdad time on January 17, the U. S. and allied forces carried out 1000 sorties air and 100 ship-launcnea cruise missile strikes, blasting Iraqi targets to free Kuwait from Iraqi occupation. The attack began less than 19 hours after the expiration of the UN-mandated deadline. From the following day to the end of the month, the U.S.-led allied air forces continued massive bombing&against targets in Iraq and occupied Kuwait. From
