Electron beam lithography(EBL)involves the transfer of a pattern onto the surface of a substrate byfirst scanning a thin layer of organicfilm(called resist)on the surface by a tightly focused and precisely controlled el...Electron beam lithography(EBL)involves the transfer of a pattern onto the surface of a substrate byfirst scanning a thin layer of organicfilm(called resist)on the surface by a tightly focused and precisely controlled electron beam(exposure)and then selectively removing the exposed or nonexposed regions of the resist in a solvent(developing).It is widely used for fabrication of integrated cir-cuits,mask manufacturing,photoelectric device processing,and otherfields.The key to drawing circular patterns by EBL is the graphics production and control.In an EBL system,an embedded processor calculates and generates the trajectory coordinates for movement of the electron beam,and outputs the corresponding voltage signal through a digital-to-analog converter(DAC)to control a deflector that changes the position of the electron beam.Through this procedure,it is possible to guarantee the accuracy and real-time con-trol of electron beam scanning deflection.Existing EBL systems mostly use the method of polygonal approximation to expose circles.A circle is divided into several polygons,and the smaller the segmentation,the higher is the precision of the splicing circle.However,owing to the need to generate and scan each polygon separately,an increase in the number of segments will lead to a decrease in the overall lithography speed.In this paper,based on Bresenham’s circle algorithm and exploiting the capabilities of afield-programmable gate array and DAC,an improved real-time circle-producing algorithm is designed for EBL.The algorithm can directly generate cir-cular graphics coordinates such as those for a single circle,solid circle,solid ring,or concentric ring,and is able to effectively realizes deflection and scanning of the electron beam for circular graphics lithography.Compared with the polygonal approximation method,the improved algorithm exhibits improved precision and speed.At the same time,the point generation strategy is optimized to solve the blank pixel and pseudo-pixel problems that arise with Bresenham’s circle algorithm.A complete electron beam deflection system is established to carry out lithography experiments,the results of which show that the error between the exposure results and the preset pat-terns is at the nanometer level,indicating that the improved algorithm meets the requirements for real-time control and high precision of EBL.展开更多
The fracture modes of low alloy steels and cast irons under tensile and fatigue conditions were identified by electron back-scattered diffraction（EBSD） misorientation analysis in this research. The curves of grain r...The fracture modes of low alloy steels and cast irons under tensile and fatigue conditions were identified by electron back-scattered diffraction（EBSD） misorientation analysis in this research. The curves of grain reference orientation deviation（GROD） distribution perpendicular to the fracture surface were obtained by EBSD observation, and the characteristics of each fracture mode were identified. The GROD value of the specimen fractured in tension decreases to a constant related to the elongation of corresponding specimen in the far field（farther than 5 mm away from the fracture surface）. The peak exhibits in GROD curves of two smooth specimens and a notched specimen near the fracture surface（within 5 mm away from the fracture surface）, and the formation mechanisms were discussed in detail based on the influences of specimen geometries（smooth or notched） and material toughness. The GROD value of fatigue fractured specimen is close to that at undeformed condition in the whole field, except the small area near the crack path. The loading conditions（constant stress amplitude loading or constant stress intensity factor range K loading） and the EBSD striation formation during fatigue crack propagation were also studied by EBSD observation parallel to the crack path.展开更多
Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe...Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.展开更多
Three dimensional（3D） displacements, which can be translated further into 3D strain, are key parameters tor design, manufacturing and quality control. Using different optical setups, phase-shift methods, and algorit...Three dimensional（3D） displacements, which can be translated further into 3D strain, are key parameters tor design, manufacturing and quality control. Using different optical setups, phase-shift methods, and algorithms, several different 3D electronic speckle pattern interferometry（ESPl） systems for displacement and strain measurements have been achieved and commercialized. This paper provides a review of the recent developments in ESPI systems for 3D displacement and strain measurement. After an overview of the fundamentals of ESP! theory, temporal phase-shift, and spatial phase-shift techniques, 3D deformation measurements by the temporal phase-shift ESPI system, which is suited well for static measurement, and by the spatial phase-shift ESPI system, which is particularly useful for dynamic measurement, are discussed. For each method, the basic theory, a brief derivation and different optical layouts are presented. The state of art application, potential and limitation of the ESPI systems are shown and demonstrated.展开更多
Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed t...Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed that the simulated ED pattern of γ'-FexC(Ⅱ) model proposed by the present authors is in good agreement with experimentally observed ED pattern.It was also confirmed that the incommensurate superperiod stems from the coexistence of several γ'-Fe_xC(H) phases with different superperiods.The Fe(144)C(24)(Fe6C) model proposed by Uwakweh et al.generated ED patterns remarkably different from the experimental ones.展开更多
Using the Lindemann criterion,we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional(2D)semiconductor moirépatterns.We show that the finite 2D screenin...Using the Lindemann criterion,we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional(2D)semiconductor moirépatterns.We show that the finite 2D screening of the atomically thin material can suppress(enhance)the inter-site Coulomb(dipolar)interaction strength,thus inhibits(facilitates)the formation of the electronic(excitonic)crystal.Meanwhile,a strong enough moiréconfinement is found to be essential for realizing the crystal phase with a wavelength near 10 nm or shorter.From the calculated Lindemann ratio which quantifies the fluctuation of the site displacement,we estimate that the crystal will melt into a liquid above a critical temperature ranging from several tens Kelvin to above 100 K(depending on the system parameters).展开更多
We theoretically investigate the effects of different electronic states as the initial state on the vortex patterns in photoelectron momentum distributions(PMDs)from numerical solutions of the two-dimensional(2D)time-...We theoretically investigate the effects of different electronic states as the initial state on the vortex patterns in photoelectron momentum distributions(PMDs)from numerical solutions of the two-dimensional(2D)time-dependent Schrodinger equation(TDSE)of He^(+)with a pair of counter-rotating circularly polarized attosecond pulses.It is found that the number of spiral arms in vortex patterns is equal to the number of the absorbed photons when the initial state is the ground state.However,the number of spiral arms in vortex patterns is always two more than the number of the absorbed photons when the initial state is the excited state.This sensitivity is attributed to the initial electron density distribution.In addition,we have demonstrated the PMDs for different initial electronic states with the same wavelengths and analyzed their corresponding physical mechanisms.It is illustrated that the method presented can be employed to effectively control the distribution of the electron vortices.展开更多
Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were cha...Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were characterized by scanning electron microscopy （SEM）,X-ray diffraction（XRD）,and atomic force microscopy （AFM）.The efficient electron field emission with low turn-on field of about 3.5V/μm was obtained at current density of 0.1μA/cm^2.The electron field emission current density from the patterned PS films reached 1mA/cm^2 under and applied field of about 12.5V/μm.The experimental results show that the patterned PS films are of certain practical significance and are valuable for flat panel displays.展开更多
With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic a...With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic architectural drawing and perspective. AUTOCAD drawing soRware because of its versatility and easy entry, in engineering has broad user base, but also because of the basis of general drawing software, often cannot directly use of the existing order efficiently complete professional drawing. We modify the current pattern and introduce our proposed pattern for advancement. The experiment proves the effectiveness of the pattern. In addition, we will conduct more insightful research in the future to nolish the current anoroach.展开更多
The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered A...The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered Au1-xCux alloys. From characteristic atom occupation （CAO） patterns of L12-Au3Cu, L12-AuCu3 and Llo-AuCu compounds, their electronic structures, volumetric and energetic properties were calculated. The CAO pattern of Johasson-Linde（J-L） model shows that the transition AuCuI→AuCulI is an exothermic and volume contraction reaction, which is opposite from experimental phenomena. According to CAO pattern of Guymont-Feutelais-Legendre（G-F-L） model, the AuCulI cell consists of two periodic antidirection （PAD） AuCuI regions and two PAD boundary regions. The equations derived from CAO pattern of G-F-L model can be used to calculate energetic properties, volumetric properties and ordering degrees of the PAD AuCuI region and PAD boundary region, as well as corresponding average properties of the AuCulI phase. The results are consistent with experimental phenomena.展开更多
CONSPECTUS:Solution-processed electronics have shown promise in cost-effective manufacturing,but face challenges in precisely and accurately placing electronic materials.Traditional methods,such as photolithography wi...CONSPECTUS:Solution-processed electronics have shown promise in cost-effective manufacturing,but face challenges in precisely and accurately placing electronic materials.Traditional methods,such as photolithography with photoresists,involve complex steps that can damage electronic materials.Alternatives such as orthogonal patterning and inkjet printing are limited by the difficulty of finding compatible chemicals that do not dissolve underlying layers,while nanoimprinting lacks compatibility with high-throughput processes and suffers from poor chemical robustness.Conventional photo-cross-linking approaches have used organic or polymeric agents to pattern electronic layers,but the consecutive application of photo-cross-linking processes for patterning and stacking of multiple electronic materials typically led to degradation of the intrinsic properties of the materials.展开更多
Aluminum hydroxide adjuvant exhibits a poorly crystalline boehmite(PCB)structure,which demonstrates instability during prolonged storage.In the present study,we systematically investigated the quality alterations of t...Aluminum hydroxide adjuvant exhibits a poorly crystalline boehmite(PCB)structure,which demonstrates instability during prolonged storage.In the present study,we systematically investigated the quality alterations of the adjuvant stored at roo m temperature by analyzing its crystal structure,particle size distribution,electron microscopic characteristics,pH,isoelectric point(pI),and adsorption capacity.These assessments aimed to ensure the effectiveness and safety of vaccine production.Three batches of adjuvants were stored at room temperature for 15 months,and their changes were monitored using X-ray diffraction patterns,transmission electron microscopy(TEM),pH measurements,pI determination,and adsorption capacity analysis.X-ray diffraction revealed that the crystalline phases of aluminum hydroxide initially exhibited a PCB structure,which became progressively more ordered during storage.Notably,after 12 months,a new diffraction peak emerged at 18.2°2θ,with its intensity increasing over time.This corresponded to the formation of highly crystalline gibbsite and bayerite,which compromised the stability of the adjuvant.Furthermore,the pH and pI values decreased during storage,reflecting a decline in the chemical stability of the adjuvant.Comprising nanoparticles with a mean diameter of 130 nm,the adjuvant maintained a high surface area and excellent adsorption capacity.The adsorption rate at 8 mg BSA/mg Al3+consistently exceeded 97%,with no statistically significant differences observed between the adsorption capacities at 1 and 15 months(P>0.05).This indicated that the nanoparticle aluminum hydroxide adjuvant sustained high adsorption efficiency throughout the storage period,underscoring its reliability as a vaccine adsorbent.However,in the later stages of storage,the emergence of highly crystalline gibbsite and bayerite,coupled with declines in pH and pI,negatively impacted the adjuvant’s stability.Based on these findings,we recommended that aluminum hydroxide adjuvants should not be stored at room temperature for longer than 12 months to preserve their quality and efficacy.展开更多
本文设计了一种专用的图形文件格式(CPF:Pattern format for CETC48),旨在优化电子束光刻设备中的图形数据存储与传输。详细阐述了CPF文件格式的文件结构、数据组成及所采用的多种图形压缩算法。实验结果表明,CPF格式在文件存储效率及...本文设计了一种专用的图形文件格式(CPF:Pattern format for CETC48),旨在优化电子束光刻设备中的图形数据存储与传输。详细阐述了CPF文件格式的文件结构、数据组成及所采用的多种图形压缩算法。实验结果表明,CPF格式在文件存储效率及处理性能上均优于现有格式,该格式已通过了实验证,满足了设计要求及电子束光刻设备的需求。展开更多
基金supported by the Focused Ion Beam/Electron Beam Double Beam Microscopy(Grant No.2021YFF0704702).
文摘Electron beam lithography(EBL)involves the transfer of a pattern onto the surface of a substrate byfirst scanning a thin layer of organicfilm(called resist)on the surface by a tightly focused and precisely controlled electron beam(exposure)and then selectively removing the exposed or nonexposed regions of the resist in a solvent(developing).It is widely used for fabrication of integrated cir-cuits,mask manufacturing,photoelectric device processing,and otherfields.The key to drawing circular patterns by EBL is the graphics production and control.In an EBL system,an embedded processor calculates and generates the trajectory coordinates for movement of the electron beam,and outputs the corresponding voltage signal through a digital-to-analog converter(DAC)to control a deflector that changes the position of the electron beam.Through this procedure,it is possible to guarantee the accuracy and real-time con-trol of electron beam scanning deflection.Existing EBL systems mostly use the method of polygonal approximation to expose circles.A circle is divided into several polygons,and the smaller the segmentation,the higher is the precision of the splicing circle.However,owing to the need to generate and scan each polygon separately,an increase in the number of segments will lead to a decrease in the overall lithography speed.In this paper,based on Bresenham’s circle algorithm and exploiting the capabilities of afield-programmable gate array and DAC,an improved real-time circle-producing algorithm is designed for EBL.The algorithm can directly generate cir-cular graphics coordinates such as those for a single circle,solid circle,solid ring,or concentric ring,and is able to effectively realizes deflection and scanning of the electron beam for circular graphics lithography.Compared with the polygonal approximation method,the improved algorithm exhibits improved precision and speed.At the same time,the point generation strategy is optimized to solve the blank pixel and pseudo-pixel problems that arise with Bresenham’s circle algorithm.A complete electron beam deflection system is established to carry out lithography experiments,the results of which show that the error between the exposure results and the preset pat-terns is at the nanometer level,indicating that the improved algorithm meets the requirements for real-time control and high precision of EBL.
基金financially supported by Mitsubishi Heavy Industries,Ltd.,Japanthe National Natural Science Foundation of China(Nos.11572171,11632010 and U1533134)the opening project(No.KFJJ15-12M)of State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology)
文摘The fracture modes of low alloy steels and cast irons under tensile and fatigue conditions were identified by electron back-scattered diffraction（EBSD） misorientation analysis in this research. The curves of grain reference orientation deviation（GROD） distribution perpendicular to the fracture surface were obtained by EBSD observation, and the characteristics of each fracture mode were identified. The GROD value of the specimen fractured in tension decreases to a constant related to the elongation of corresponding specimen in the far field（farther than 5 mm away from the fracture surface）. The peak exhibits in GROD curves of two smooth specimens and a notched specimen near the fracture surface（within 5 mm away from the fracture surface）, and the formation mechanisms were discussed in detail based on the influences of specimen geometries（smooth or notched） and material toughness. The GROD value of fatigue fractured specimen is close to that at undeformed condition in the whole field, except the small area near the crack path. The loading conditions（constant stress amplitude loading or constant stress intensity factor range K loading） and the EBSD striation formation during fatigue crack propagation were also studied by EBSD observation parallel to the crack path.
基金supported by the Guangdong High Level Innovation Research Institute(Grant No.2021B0909050006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the National Natural Science Foundation of China(Grant No.12205008)support from the National Science Fund for Distinguished Young Scholars(Grant No.12225501)。
文摘Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.
基金supported by National Natural Science Foundation of China(Grant Nos.51275054,51075116)
文摘Three dimensional（3D） displacements, which can be translated further into 3D strain, are key parameters tor design, manufacturing and quality control. Using different optical setups, phase-shift methods, and algorithms, several different 3D electronic speckle pattern interferometry（ESPl） systems for displacement and strain measurements have been achieved and commercialized. This paper provides a review of the recent developments in ESPI systems for 3D displacement and strain measurement. After an overview of the fundamentals of ESP! theory, temporal phase-shift, and spatial phase-shift techniques, 3D deformation measurements by the temporal phase-shift ESPI system, which is suited well for static measurement, and by the spatial phase-shift ESPI system, which is particularly useful for dynamic measurement, are discussed. For each method, the basic theory, a brief derivation and different optical layouts are presented. The state of art application, potential and limitation of the ESPI systems are shown and demonstrated.
文摘Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed that the simulated ED pattern of γ'-FexC(Ⅱ) model proposed by the present authors is in good agreement with experimentally observed ED pattern.It was also confirmed that the incommensurate superperiod stems from the coexistence of several γ'-Fe_xC(H) phases with different superperiods.The Fe(144)C(24)(Fe6C) model proposed by Uwakweh et al.generated ED patterns remarkably different from the experimental ones.
基金support by the National Natural Science Foundation of China(Grant No.12274477)the Department of Science and Technology of Guangdong Province of China(Grant No.2019QN01X061)。
文摘Using the Lindemann criterion,we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional(2D)semiconductor moirépatterns.We show that the finite 2D screening of the atomically thin material can suppress(enhance)the inter-site Coulomb(dipolar)interaction strength,thus inhibits(facilitates)the formation of the electronic(excitonic)crystal.Meanwhile,a strong enough moiréconfinement is found to be essential for realizing the crystal phase with a wavelength near 10 nm or shorter.From the calculated Lindemann ratio which quantifies the fluctuation of the site displacement,we estimate that the crystal will melt into a liquid above a critical temperature ranging from several tens Kelvin to above 100 K(depending on the system parameters).
基金Project supported by the National Natural Science Foundation of China(Grant No.12074142)the Natural Science Foundation of Jilin Province of China(Grant No.20180101225JC)the Graduate Innovation Fund of Jilin University,China(Grant No.101832020CX337)。
文摘We theoretically investigate the effects of different electronic states as the initial state on the vortex patterns in photoelectron momentum distributions(PMDs)from numerical solutions of the two-dimensional(2D)time-dependent Schrodinger equation(TDSE)of He^(+)with a pair of counter-rotating circularly polarized attosecond pulses.It is found that the number of spiral arms in vortex patterns is equal to the number of the absorbed photons when the initial state is the ground state.However,the number of spiral arms in vortex patterns is always two more than the number of the absorbed photons when the initial state is the excited state.This sensitivity is attributed to the initial electron density distribution.In addition,we have demonstrated the PMDs for different initial electronic states with the same wavelengths and analyzed their corresponding physical mechanisms.It is illustrated that the method presented can be employed to effectively control the distribution of the electron vortices.
基金National Natural Science Foundation of China (60476004) Foundation of Graduate Students of East ChinaNormal University(ECNU2005) Foundation of State Key Laboratory of Advanced Technology for MaterialsSynthesis and Processing( Wuhan University of Tech
文摘Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were characterized by scanning electron microscopy （SEM）,X-ray diffraction（XRD）,and atomic force microscopy （AFM）.The efficient electron field emission with low turn-on field of about 3.5V/μm was obtained at current density of 0.1μA/cm^2.The electron field emission current density from the patterned PS films reached 1mA/cm^2 under and applied field of about 12.5V/μm.The experimental results show that the patterned PS films are of certain practical significance and are valuable for flat panel displays.
文摘With the progress of computer technology, CAD technique is urgent needed. In this paper, we conduct numerical and theoretical analysis and research on computer aided design technique and novel pattern for electronic architectural drawing and perspective. AUTOCAD drawing soRware because of its versatility and easy entry, in engineering has broad user base, but also because of the basis of general drawing software, often cannot directly use of the existing order efficiently complete professional drawing. We modify the current pattern and introduce our proposed pattern for advancement. The experiment proves the effectiveness of the pattern. In addition, we will conduct more insightful research in the future to nolish the current anoroach.
基金Project (50711181) supported by the National Natural Science Foundation of China Project (2009FJ4016) supported by Natural Science Foundation of Hunan Province,China
文摘The potential energies, volumes and electronic structures of characteristic atoms coordinated by neighboring configurations were obtained from the experimental heats of formation and lattice parameters of disordered Au1-xCux alloys. From characteristic atom occupation （CAO） patterns of L12-Au3Cu, L12-AuCu3 and Llo-AuCu compounds, their electronic structures, volumetric and energetic properties were calculated. The CAO pattern of Johasson-Linde（J-L） model shows that the transition AuCuI→AuCulI is an exothermic and volume contraction reaction, which is opposite from experimental phenomena. According to CAO pattern of Guymont-Feutelais-Legendre（G-F-L） model, the AuCulI cell consists of two periodic antidirection （PAD） AuCuI regions and two PAD boundary regions. The equations derived from CAO pattern of G-F-L model can be used to calculate energetic properties, volumetric properties and ordering degrees of the PAD AuCuI region and PAD boundary region, as well as corresponding average properties of the AuCulI phase. The results are consistent with experimental phenomena.
基金supported by the Samsung Research Funding&Incubation Center of Samsung Electronics under project number SRFC-MA1901-51by the National Research Foundation of Korea(NRF)grant funded by the Ministry of Science,ICT,and Future Planning under project number(NRF 2023R1A2C3006550,RS-2023-00244309).
文摘CONSPECTUS:Solution-processed electronics have shown promise in cost-effective manufacturing,but face challenges in precisely and accurately placing electronic materials.Traditional methods,such as photolithography with photoresists,involve complex steps that can damage electronic materials.Alternatives such as orthogonal patterning and inkjet printing are limited by the difficulty of finding compatible chemicals that do not dissolve underlying layers,while nanoimprinting lacks compatibility with high-throughput processes and suffers from poor chemical robustness.Conventional photo-cross-linking approaches have used organic or polymeric agents to pattern electronic layers,but the consecutive application of photo-cross-linking processes for patterning and stacking of multiple electronic materials typically led to degradation of the intrinsic properties of the materials.
文摘Aluminum hydroxide adjuvant exhibits a poorly crystalline boehmite(PCB)structure,which demonstrates instability during prolonged storage.In the present study,we systematically investigated the quality alterations of the adjuvant stored at roo m temperature by analyzing its crystal structure,particle size distribution,electron microscopic characteristics,pH,isoelectric point(pI),and adsorption capacity.These assessments aimed to ensure the effectiveness and safety of vaccine production.Three batches of adjuvants were stored at room temperature for 15 months,and their changes were monitored using X-ray diffraction patterns,transmission electron microscopy(TEM),pH measurements,pI determination,and adsorption capacity analysis.X-ray diffraction revealed that the crystalline phases of aluminum hydroxide initially exhibited a PCB structure,which became progressively more ordered during storage.Notably,after 12 months,a new diffraction peak emerged at 18.2°2θ,with its intensity increasing over time.This corresponded to the formation of highly crystalline gibbsite and bayerite,which compromised the stability of the adjuvant.Furthermore,the pH and pI values decreased during storage,reflecting a decline in the chemical stability of the adjuvant.Comprising nanoparticles with a mean diameter of 130 nm,the adjuvant maintained a high surface area and excellent adsorption capacity.The adsorption rate at 8 mg BSA/mg Al3+consistently exceeded 97%,with no statistically significant differences observed between the adsorption capacities at 1 and 15 months(P>0.05).This indicated that the nanoparticle aluminum hydroxide adjuvant sustained high adsorption efficiency throughout the storage period,underscoring its reliability as a vaccine adsorbent.However,in the later stages of storage,the emergence of highly crystalline gibbsite and bayerite,coupled with declines in pH and pI,negatively impacted the adjuvant’s stability.Based on these findings,we recommended that aluminum hydroxide adjuvants should not be stored at room temperature for longer than 12 months to preserve their quality and efficacy.
文摘本文设计了一种专用的图形文件格式(CPF:Pattern format for CETC48),旨在优化电子束光刻设备中的图形数据存储与传输。详细阐述了CPF文件格式的文件结构、数据组成及所采用的多种图形压缩算法。实验结果表明,CPF格式在文件存储效率及处理性能上均优于现有格式,该格式已通过了实验证,满足了设计要求及电子束光刻设备的需求。
