Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was resp...Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of heat treatment that make thin film resistance stable were obtained. The experimental result indicates that the most stable thin film resistance can be obtained when it is heat-treated under protection of SiO2 and N2 at 673 K for 1 h, and then kept at 473 K for 24 h. Pressure sensor chips of high precision for harsh environments can be manufactured by this process.展开更多
Stability of tea catechins and the antioxidant properties of green tea extracts as affected by boiling-treatment from 1 to 5h were studied.Green tea catechins were partially epimerized from epi-form to nonepi-form und...Stability of tea catechins and the antioxidant properties of green tea extracts as affected by boiling-treatment from 1 to 5h were studied.Green tea catechins were partially epimerized from epi-form to nonepi-form under boiling-treatment.Total phenolic compounds of the samples under the boiling-treatment for 1 to 4h showed the same statistically significant(P > 0.05) comparing with the untreated samples and there was no significant reduction(P > 0.05) of total catechins when the green tea extracts were boiling-treated for 1h.There were no significant(P > 0.05) reduction of the antioxidant capacity when the samples were boiling-treated for 1h,no significant(P> 0.05) reduction of the scavenging ability against DPPH and O-·2when treated for 2h,and no difference on scavenging ability against OH when treated even for 5h.The results indicated that boiling-treatment for 1h had limited effect on total catehins and phenols content in green tea extracts.Green tea extracts still remained excellent in antioxidant properties and free radical scavenging activity after boiling-treated for 1 h.展开更多
Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),...Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),pH and rotation speed(N)on the interception of Hg^2+were investigated.The interception could reach 99.7%at pH 7.0,P/M 6 and N less than 1890 r/min.The shear stability of PMA-Hg complex was studied by RDM.The critical rotation speed,at which the interception starts to decrease,was 1890 r/min,and the critical shear rate,the smallest shear rate at which PMA-Hg complex begins to dissociate,was 2.50×10^5s^-1 at pH 7.0.Furthermore,the critical radii were obtained at different rotation speeds and pHs.The results showed that the critical radius decreased with the rotation speed and increased with pH.Shear induced dissociation coupling with ultra?ltration(SID-UF)was efficiently used to recover Hg^2+and PMA.展开更多
The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490,650 and 800 mm.The experimental results without and with the magnetic field are compared in ...The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490,650 and 800 mm.The experimental results without and with the magnetic field are compared in terms of the shaped charge jet form,stability and penetration ability.A theoretical model based on one-dimension fluid dynamics is then developed to assess the depth of penetration of the shaped charge at those three standoffs and magnetic conditions.The results show that the penetration capability can be enhanced in more than 70%by the magnetic field.The theoretical calculations are compared with the experimental results with reasonably good correlation.In addition,the parameters introduced in the theory are discussed together with the experiments at three standoffs studied.展开更多
文摘Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of heat treatment that make thin film resistance stable were obtained. The experimental result indicates that the most stable thin film resistance can be obtained when it is heat-treated under protection of SiO2 and N2 at 673 K for 1 h, and then kept at 473 K for 24 h. Pressure sensor chips of high precision for harsh environments can be manufactured by this process.
文摘Stability of tea catechins and the antioxidant properties of green tea extracts as affected by boiling-treatment from 1 to 5h were studied.Green tea catechins were partially epimerized from epi-form to nonepi-form under boiling-treatment.Total phenolic compounds of the samples under the boiling-treatment for 1 to 4h showed the same statistically significant(P > 0.05) comparing with the untreated samples and there was no significant reduction(P > 0.05) of total catechins when the green tea extracts were boiling-treated for 1h.There were no significant(P > 0.05) reduction of the antioxidant capacity when the samples were boiling-treated for 1h,no significant(P> 0.05) reduction of the scavenging ability against DPPH and O-·2when treated for 2h,and no difference on scavenging ability against OH when treated even for 5h.The results indicated that boiling-treatment for 1h had limited effect on total catehins and phenols content in green tea extracts.Green tea extracts still remained excellent in antioxidant properties and free radical scavenging activity after boiling-treated for 1 h.
基金Project(21476265)supported by the National Natural Science Foundation of China。
文摘Copolymer of acrylic acid and maleic acid(PMA)was used to remove Hg^2+from aqueous solution by complexation-ultrafiltration(C-UF)through rotating disk membrane(RDM).The effects of P/M(mass ratio of PMA to metal ions),pH and rotation speed(N)on the interception of Hg^2+were investigated.The interception could reach 99.7%at pH 7.0,P/M 6 and N less than 1890 r/min.The shear stability of PMA-Hg complex was studied by RDM.The critical rotation speed,at which the interception starts to decrease,was 1890 r/min,and the critical shear rate,the smallest shear rate at which PMA-Hg complex begins to dissociate,was 2.50×10^5s^-1 at pH 7.0.Furthermore,the critical radii were obtained at different rotation speeds and pHs.The results showed that the critical radius decreased with the rotation speed and increased with pH.Shear induced dissociation coupling with ultra?ltration(SID-UF)was efficiently used to recover Hg^2+and PMA.
基金National Natural Science Foundation of China(Grant No.11972196)Youth fund of Jiangsu Natural Science Foundation(Grant Nos.BK20190433)National Natural Science Funds for Distinguished Young Scholar of China(Grant No.11702144)to provide fund for conducting experiments.
文摘The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490,650 and 800 mm.The experimental results without and with the magnetic field are compared in terms of the shaped charge jet form,stability and penetration ability.A theoretical model based on one-dimension fluid dynamics is then developed to assess the depth of penetration of the shaped charge at those three standoffs and magnetic conditions.The results show that the penetration capability can be enhanced in more than 70%by the magnetic field.The theoretical calculations are compared with the experimental results with reasonably good correlation.In addition,the parameters introduced in the theory are discussed together with the experiments at three standoffs studied.
