We study the dynamical evolution of cold atoms in crossed optical dipole trap theoretically and experimentally. The atomic transport process is accompanied by two competitive kinds of physical mechanics, atomic loadin...We study the dynamical evolution of cold atoms in crossed optical dipole trap theoretically and experimentally. The atomic transport process is accompanied by two competitive kinds of physical mechanics, atomic loading and atomic loss.The loading process normally is negligible in the evaporative cooling experiment on the ground, while it is significant in preparation of ultra-cold atoms in the space station. Normally, the atomic loading process is much weaker than the atomic loss process, and the atomic number in the central region of the trap decreases monotonically, as reported in previous research. However, when the atomic loading process is comparable to the atomic loss process, the atomic number in the central region of the trap will initially increase to a maximum value and then slowly decrease, and we have observed the phenomenon first. The increase of atomic number in the central region of the trap shows the presence of the loading process, and this will be significant especially under microgravity conditions. We build a theoretical model to analyze the competitive relationship, which coincides with the experimental results well. Furthermore, we have also given the predicted evolutionary behaviors under different conditions. This research provides a solid foundation for further understanding of the atomic transport process in traps. The analysis of loading process is of significant importance for preparation of ultra-cold atoms in a crossed optical dipole trap under microgravity conditions.展开更多
Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithiu...Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.展开更多
Using two series of de novo designed antimicrobial peptides,we studied the effects of peptide length and hydrophobicity/charge(H/C) ratio on the antimicrobial activities.For these peptides,a correlation was establishe...Using two series of de novo designed antimicrobial peptides,we studied the effects of peptide length and hydrophobicity/charge(H/C) ratio on the antimicrobial activities.For these peptides,a correlation was established between their antimicrobial efficacy and the leakage,aggregation,and fusion activities on artificial membrane.The results showed that peptides with an H/C ratio of 1.3,and a length of about half of the membrane thickness caused most potent membrane leakage,and negligible membrane aggregation and fusion.In addition,such peptide also exhibited the highest antimicrobial activity.Analysis of the hydrophobic and electrostatic interactions showed that the strength,the order and the position of these interactions determined the activities of the peptides on the artificial membrane and thus the antimicrobial efficacy.Further analyses on the tilt angle of the peptides on the membrane surface indicated that the peptides distorted the membrane in a dynamic mode,instead of being fixed in the membrane at a constant angle.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.92365208,11934002,and 11920101004)the National Key Research and Development Program of China(Grant Nos.2021YFA0718300 and 2021YFA1400900)+1 种基金the Science and Technology Major Project of Shanxi(Grant No.202101030201022)the Space Application System of China Manned Space Program。
文摘We study the dynamical evolution of cold atoms in crossed optical dipole trap theoretically and experimentally. The atomic transport process is accompanied by two competitive kinds of physical mechanics, atomic loading and atomic loss.The loading process normally is negligible in the evaporative cooling experiment on the ground, while it is significant in preparation of ultra-cold atoms in the space station. Normally, the atomic loading process is much weaker than the atomic loss process, and the atomic number in the central region of the trap decreases monotonically, as reported in previous research. However, when the atomic loading process is comparable to the atomic loss process, the atomic number in the central region of the trap will initially increase to a maximum value and then slowly decrease, and we have observed the phenomenon first. The increase of atomic number in the central region of the trap shows the presence of the loading process, and this will be significant especially under microgravity conditions. We build a theoretical model to analyze the competitive relationship, which coincides with the experimental results well. Furthermore, we have also given the predicted evolutionary behaviors under different conditions. This research provides a solid foundation for further understanding of the atomic transport process in traps. The analysis of loading process is of significant importance for preparation of ultra-cold atoms in a crossed optical dipole trap under microgravity conditions.
基金The authors are indebted to the National Key Research and Development Program of China(No.2019YFE0122500)the National Natural Science Foundation of China(Nos.21878185 and 51772188)the Natural Science Foundation of Shanghai(No.21ZR1434800).
文摘Solid lithium-sulfur batteries(SLSBs)show potential for practical application due to their possibility for high energy density.However,SLSBs still face tough challenges such as the large interface impedance and lithium dendrite formation.Herein,a highperformance SLSB is demonstrated by using a fiber network reinforced Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)based composite solid electrolyte(CSE)in combination with sulfurized polyacrylonitrile(SPAN)cathode.The CSE consisting of an electrospun polyimide(PI)film,LLZTO ionically conducting filler and polyacrylonitrile(PAN)matrix,which is named as PI-PAN/LLZTO CSE,possesses high room-temperature ionic conductivity(2.75×10^(-4)S/cm),high Li^(+)migration number(tLi+)of 0.67 and good interfacial wettability.SPAN is utilized due to its unique electrochemical properties:reasonable electronic conductivity and no polysulfides shuttle effect.The CSE enables a highly stable Li plating/stripping cycle for over 600 h and good rate performance.Moreover,the assembled SLSB exhibits good cycle performance of accomplishing 120 cycles at 0.2 C with the capacity retention of 474 mAh/g,good rate properties and excellent long-term cycling stability with a high capacity retention of 86.49%from 15^(th)to 1,000^(th)cycles at 1.0 C.This work rationalizes our design concept and may guide the future development of SLSBs.
基金supported by the National Natural Science Foundation of China(21574002,21174007)the Beijing Natural Science Foundation(5132015)the Nantong Jianghai Talent Program
文摘Using two series of de novo designed antimicrobial peptides,we studied the effects of peptide length and hydrophobicity/charge(H/C) ratio on the antimicrobial activities.For these peptides,a correlation was established between their antimicrobial efficacy and the leakage,aggregation,and fusion activities on artificial membrane.The results showed that peptides with an H/C ratio of 1.3,and a length of about half of the membrane thickness caused most potent membrane leakage,and negligible membrane aggregation and fusion.In addition,such peptide also exhibited the highest antimicrobial activity.Analysis of the hydrophobic and electrostatic interactions showed that the strength,the order and the position of these interactions determined the activities of the peptides on the artificial membrane and thus the antimicrobial efficacy.Further analyses on the tilt angle of the peptides on the membrane surface indicated that the peptides distorted the membrane in a dynamic mode,instead of being fixed in the membrane at a constant angle.
