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
OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly di...OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly divided into five groups(n=10in each group).Group 1served as vehicle control with injection of saline(vehicle control group),and the other groups of rats received daily subcutaneously injected with D-galactose(aged model group)at dose of 100mg·kg-1 for ten weeks,respectively.At the same time,rats in groups 3-5were intragastrically administered SBG 〔extracted twice with 60%(V/V)ethanol〕at doses of 50,100 and 200mg·kg-1 for ten weeks,and the rats of groups 1 and 2 were administrated an equal volume of the vehicle.At the tenth week,the learning and memory abilities were examined by Morris water maze.The urine was collected using metabolic cages and analyzed by high-resolution 1HNMR spectroscopy combined with multivariate statistical analyses.Principal component analysis(PCA)was utilized to classify and reveal the differences between the model group and control group.Then,the concentration of these differences was analyzed with t-test to determine whether SBG was possible to influence the metabolic pattern induced by D-galactose.RESULTS Compared with the vehicle control group,the D-galactose-treated aged model group markedly spent longer time(P<0.05)in finding the platform on days 3-5 in the spatial learning acquisition training of Morris water maze test.However,the escape latency was significantly reduced(P<0.05)by long-term administration of SBG(50,100 and 200mg·kg-1)compared with the D-galactose-treated aged model group on days 3-5.In the probe test,the D-galactose-treated aged model group made fewer(P<0.05)platform crossings and distance travelled in target quadrant(P<0.05)than the vehicle control group,and the SBG at doses of 50,100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the number of times of crossing over the platform site.The SBG at doses of100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the distance travelled in target quadrant compared with the D-galactose-treated aged model group.In addition,the significant difference in metabolic profiling was observed from model group compared with drug-dose group by using PCA,indicating the recovery effect of SBG on D-galactose induced aging rats.Some significantly changed metabolites like glycine,glucose and hexadecanoic acid have been identified.These biochemical changes are related to the the disturbance in aimno acid metabolism,energy metabolism and glycometabolism,which are helpful to further understanding the D-galactose induced aging rats and the therapeutic mechanism of SBG.CONCLUSION These results demonstrate that SBG extract has protective effect on the D-galactose-induced aging in rats.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
It is common for datasets to contain both categorical and continuous variables. However, many feature screening methods designed for high-dimensional classification assume that the variables are continuous. This limit...It is common for datasets to contain both categorical and continuous variables. However, many feature screening methods designed for high-dimensional classification assume that the variables are continuous. This limits the applicability of existing methods in handling this complex scenario. To address this issue, we propose a model-free feature screening approach for ultra-high-dimensional multi-classification that can handle both categorical and continuous variables. Our proposed feature screening method utilizes the Maximal Information Coefficient to assess the predictive power of the variables. By satisfying certain regularity conditions, we have proven that our screening procedure possesses the sure screening property and ranking consistency properties. To validate the effectiveness of our approach, we conduct simulation studies and provide real data analysis examples to demonstrate its performance in finite samples. In summary, our proposed method offers a solution for effectively screening features in ultra-high-dimensional datasets with a mixture of categorical and continuous covariates.展开更多
The core-shell metastable intermolecular composites(MIC)have attracted much attention in the past few years due to their unique properties.Here,the preparation of Al-Core heterojunction fibers using PVP as a template ...The core-shell metastable intermolecular composites(MIC)have attracted much attention in the past few years due to their unique properties.Here,the preparation of Al-Core heterojunction fibers using PVP as a template is proposed.The nano-Al was directly added to the precursor solution of cupric acetate monohydrate(CAM)/Polyvinylpyrrolidone(PVP),and the initial Al@CAM/PVP fibers were obtained via electrospinning.The core-shell MIC fibers are then obtained by calcining the initial fibers.The morphology,structure,and composition of Al-core MIC fibers were characterized,that the energetic fibers calcined at 300℃,350℃,and 400℃have a core-shell structure with shell compositions CuxO and PVP,CuxO and Cu O,respectively.The energy release characteristics of Al-core MIC were investigated,and preliminary ignition tests were performed using an ignition temperature measuring instrument and a pulsed laser.The energetic fibers calcined at 300℃exhibited unique properties.The decomposition of PVP in the shell layer promoted exotherm,and a low-temperature exothermic peak was shown at 372-458℃.Lower ignition temperatures and higher flame heights were observed in the combustion tests than calcination at 350℃and 400℃.An unexpected result was that PVP can play a positive role in Al/CuO nanothermites.Simultaneously,this preparation method provided an idea for the integrated preparation of core-shell Al-Core MIC fibers and tuning the properties of MIC.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.
基金The project supported by the Construction Plan for Basic Condition Platform of Shanxi(2014091022)Program of Science and Technology of Shanxi Province(20140313008-14)
文摘OBJECTIVE Behavior research and urinary metabolomics method were applied to evaluate the anti-aging effects of Scutellaria baicalensis Georgi extract(SBG)in D-galactose-induced rats.METHODS Fifty rats were randomly divided into five groups(n=10in each group).Group 1served as vehicle control with injection of saline(vehicle control group),and the other groups of rats received daily subcutaneously injected with D-galactose(aged model group)at dose of 100mg·kg-1 for ten weeks,respectively.At the same time,rats in groups 3-5were intragastrically administered SBG 〔extracted twice with 60%(V/V)ethanol〕at doses of 50,100 and 200mg·kg-1 for ten weeks,and the rats of groups 1 and 2 were administrated an equal volume of the vehicle.At the tenth week,the learning and memory abilities were examined by Morris water maze.The urine was collected using metabolic cages and analyzed by high-resolution 1HNMR spectroscopy combined with multivariate statistical analyses.Principal component analysis(PCA)was utilized to classify and reveal the differences between the model group and control group.Then,the concentration of these differences was analyzed with t-test to determine whether SBG was possible to influence the metabolic pattern induced by D-galactose.RESULTS Compared with the vehicle control group,the D-galactose-treated aged model group markedly spent longer time(P<0.05)in finding the platform on days 3-5 in the spatial learning acquisition training of Morris water maze test.However,the escape latency was significantly reduced(P<0.05)by long-term administration of SBG(50,100 and 200mg·kg-1)compared with the D-galactose-treated aged model group on days 3-5.In the probe test,the D-galactose-treated aged model group made fewer(P<0.05)platform crossings and distance travelled in target quadrant(P<0.05)than the vehicle control group,and the SBG at doses of 50,100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the number of times of crossing over the platform site.The SBG at doses of100 and 200mg·kg-1 treatments groups could significantly increase(P<0.05)the distance travelled in target quadrant compared with the D-galactose-treated aged model group.In addition,the significant difference in metabolic profiling was observed from model group compared with drug-dose group by using PCA,indicating the recovery effect of SBG on D-galactose induced aging rats.Some significantly changed metabolites like glycine,glucose and hexadecanoic acid have been identified.These biochemical changes are related to the the disturbance in aimno acid metabolism,energy metabolism and glycometabolism,which are helpful to further understanding the D-galactose induced aging rats and the therapeutic mechanism of SBG.CONCLUSION These results demonstrate that SBG extract has protective effect on the D-galactose-induced aging in rats.
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.
文摘It is common for datasets to contain both categorical and continuous variables. However, many feature screening methods designed for high-dimensional classification assume that the variables are continuous. This limits the applicability of existing methods in handling this complex scenario. To address this issue, we propose a model-free feature screening approach for ultra-high-dimensional multi-classification that can handle both categorical and continuous variables. Our proposed feature screening method utilizes the Maximal Information Coefficient to assess the predictive power of the variables. By satisfying certain regularity conditions, we have proven that our screening procedure possesses the sure screening property and ranking consistency properties. To validate the effectiveness of our approach, we conduct simulation studies and provide real data analysis examples to demonstrate its performance in finite samples. In summary, our proposed method offers a solution for effectively screening features in ultra-high-dimensional datasets with a mixture of categorical and continuous covariates.
文摘The core-shell metastable intermolecular composites(MIC)have attracted much attention in the past few years due to their unique properties.Here,the preparation of Al-Core heterojunction fibers using PVP as a template is proposed.The nano-Al was directly added to the precursor solution of cupric acetate monohydrate(CAM)/Polyvinylpyrrolidone(PVP),and the initial Al@CAM/PVP fibers were obtained via electrospinning.The core-shell MIC fibers are then obtained by calcining the initial fibers.The morphology,structure,and composition of Al-core MIC fibers were characterized,that the energetic fibers calcined at 300℃,350℃,and 400℃have a core-shell structure with shell compositions CuxO and PVP,CuxO and Cu O,respectively.The energy release characteristics of Al-core MIC were investigated,and preliminary ignition tests were performed using an ignition temperature measuring instrument and a pulsed laser.The energetic fibers calcined at 300℃exhibited unique properties.The decomposition of PVP in the shell layer promoted exotherm,and a low-temperature exothermic peak was shown at 372-458℃.Lower ignition temperatures and higher flame heights were observed in the combustion tests than calcination at 350℃and 400℃.An unexpected result was that PVP can play a positive role in Al/CuO nanothermites.Simultaneously,this preparation method provided an idea for the integrated preparation of core-shell Al-Core MIC fibers and tuning the properties of MIC.
