For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)M...For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc.展开更多
Low profile antenna in communication is a new methodology. Fractal geometry is a methodology through which size reduction is achieved. A Self-similar fractal antenna using multicantor technique is proposed and experim...Low profile antenna in communication is a new methodology. Fractal geometry is a methodology through which size reduction is achieved. A Self-similar fractal antenna using multicantor technique is proposed and experimentally studied. Space-filling cantors and self-similarity properties of fractal geometry have been adopted in the proposed antenna to miniaturize the size of antenna. The antenna is designed in such a way to operate at MICS band (Medical Implant communication Service) for wireless telemedicine application. The prototype antenna exhibits wideband characteristics and provides a good agreement of return loss (S11). Experimental return loss has been compared with that which is obtained using method of moments. The objective of using self-similar concept in antenna makes it flexible in terms of controlling the resonance and bandwidth. In this paper, the Self-similar property of fractal geometry is examined by maintaining return loss (S11) more than –30 dB approximately in all the iterations (n) and the prototype antenna has return loss greater than –10 dB and exhibits wideband characteristics.展开更多
In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiat...In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.展开更多
Intestinal cancers are developed from intestinal epithelial stem cells(ISCs)in intestinal crypts through a multi-step process involved in genetic mutations of oncogenes and tumor suppressor genes.ISCs play a key role ...Intestinal cancers are developed from intestinal epithelial stem cells(ISCs)in intestinal crypts through a multi-step process involved in genetic mutations of oncogenes and tumor suppressor genes.ISCs play a key role in maintaining the homeostasis of gut epithelium.In 2009,Sato et al established a three-dimensional culture system,which mimicked the niche microenvironment by employing the niche factors,and successfully grew crypt ISCs into organoids or Mini-guts in vitro.Since then,the intestinal organoid technology has been used to delineate cellular signaling in ISC biology.However,the cultured organoids consist of heterogeneous cell populations,and it was technically challenging to introduce genomic changes into three-dimensional organoids.Thus,there was a technical necessity to develop a twodimensional ISC culture system for effective genomic manipulations.In this study,we established a conditionally immortalized mouse intestinal crypt(ciMIC)cell line by using a piggyBac transposon-based SV40 T antigen expression system.We showed that the ciMICs maintained long-term proliferative activity under two-dimensional niche factor-containing culture condition,retained the biological characteristics of intestinal epithelial stem cells,and could form intestinal organoids in three-dimensional culture.While in vivo cell implantation tests indicated that the ciMICs were non-tumorigenic,the ciMICs overexpressing oncogenic b-catenin and/or KRAS exhibited high proliferative activity and developed intestinal adenoma-like pathological features in vivo.Collectively,these findings strongly suggested that the engineered ciMICs should be used as a valuable tool cell line to dissect the genetic and/or epigenetic underpinnings of intestinal tumorigenesis.展开更多
基金funded by the financial support from National Natural Science Foundation of China(Grant No 21805014 and No82102635)Science and Technology Research Project of Chongqing Education Board(Grant No.KJQN201901428)。
文摘For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc.
文摘Low profile antenna in communication is a new methodology. Fractal geometry is a methodology through which size reduction is achieved. A Self-similar fractal antenna using multicantor technique is proposed and experimentally studied. Space-filling cantors and self-similarity properties of fractal geometry have been adopted in the proposed antenna to miniaturize the size of antenna. The antenna is designed in such a way to operate at MICS band (Medical Implant communication Service) for wireless telemedicine application. The prototype antenna exhibits wideband characteristics and provides a good agreement of return loss (S11). Experimental return loss has been compared with that which is obtained using method of moments. The objective of using self-similar concept in antenna makes it flexible in terms of controlling the resonance and bandwidth. In this paper, the Self-similar property of fractal geometry is examined by maintaining return loss (S11) more than –30 dB approximately in all the iterations (n) and the prototype antenna has return loss greater than –10 dB and exhibits wideband characteristics.
基金Supported by National Key R&D Program of China(2019YFA0405400)。
文摘In recent years,heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy.Usually,a very high uniformity in the irradiation area is required for the extracted ion beams,which is crucial because it directly affects the experimental precision and therapeutic effect.Specifically,ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design.In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure(SESRI),proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals.In order to achieve the required large irradiation area of 320 mm×320 mm,horizontal and vertical scanning magnets are used in the extraction beam line.However,considering the various requirements for beam species and energies,the tracking accuracy of power supplies(PSs),the eddy current effect of scanning magnets,and the fluctuation of ion bunch structure will reduce the irradiation uniformity.To mitigate these effects,a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI.In the experiment,the uniformity is successfully optimized from 75%to over 90%after five iterations of adjustment to the PS waveforms.In this paper,the method and experimental results were introduced.
文摘Intestinal cancers are developed from intestinal epithelial stem cells(ISCs)in intestinal crypts through a multi-step process involved in genetic mutations of oncogenes and tumor suppressor genes.ISCs play a key role in maintaining the homeostasis of gut epithelium.In 2009,Sato et al established a three-dimensional culture system,which mimicked the niche microenvironment by employing the niche factors,and successfully grew crypt ISCs into organoids or Mini-guts in vitro.Since then,the intestinal organoid technology has been used to delineate cellular signaling in ISC biology.However,the cultured organoids consist of heterogeneous cell populations,and it was technically challenging to introduce genomic changes into three-dimensional organoids.Thus,there was a technical necessity to develop a twodimensional ISC culture system for effective genomic manipulations.In this study,we established a conditionally immortalized mouse intestinal crypt(ciMIC)cell line by using a piggyBac transposon-based SV40 T antigen expression system.We showed that the ciMICs maintained long-term proliferative activity under two-dimensional niche factor-containing culture condition,retained the biological characteristics of intestinal epithelial stem cells,and could form intestinal organoids in three-dimensional culture.While in vivo cell implantation tests indicated that the ciMICs were non-tumorigenic,the ciMICs overexpressing oncogenic b-catenin and/or KRAS exhibited high proliferative activity and developed intestinal adenoma-like pathological features in vivo.Collectively,these findings strongly suggested that the engineered ciMICs should be used as a valuable tool cell line to dissect the genetic and/or epigenetic underpinnings of intestinal tumorigenesis.
