Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application,especially for selection of suita...Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application,especially for selection of suitable dielectric materials for high-power microwave transmission devices and reliable power transmission.Pure magnesium oxide(MgO),a kind of ceramic dielectric material,possesses great application potential in high-power microwave transmission devices due to its high theoretical dielectric strength,low dielectric constant,and low dielectric loss properties,but its application is limited by high sintering temperature during preparation.This work presented the preparation of a new type of multiphase ceramics based on MgO,which was MgO-1%ZrO_(2)-1%CaCO_(3-x)%MnCO_(3)(MZCM_(x),x=0,0.25,0.50,1.00,1.50,in molar),and their phase structures,morphological features,and dielectric properties were investigated.It was found that inclusion of ZrO_(2) and CaCO_(3) effectively inhibited excessive growth of MgO grains by formation of second phase,while addition of MnCO_(3) promoted the grain boundary diffusion process during the sintering process and reduced activation energy for the grain growth,resulting in a lower ceramic sintering temperature.Excellent performance,including high dielectric strength(Eb=92.3 kV/mm)and quality factor(Q×f=216642 GHz),simultaneously accompanying low dielectric loss(<0.03%),low temperature coefficient of dielectric constant(20.3×10^(–6)℃^(–1),85℃)and resonance frequency(–12.54×10^(–6)℃^(–1)),was achieved in MZCM1.00 ceramics under a relatively low sintering temperature of 1350℃.This work offers an effective solution for selecting dielectric materials for high-power microwave transmission devices.展开更多
OBJECTIVE:To observe and compare the effects of Chinese herbal prescriptions for promoting blood circulation,clearing heat,removing toxicity,and dispersing stagnated liver-Qi on cytokines in model rats with experiment...OBJECTIVE:To observe and compare the effects of Chinese herbal prescriptions for promoting blood circulation,clearing heat,removing toxicity,and dispersing stagnated liver-Qi on cytokines in model rats with experimental autoimmune prostatitis(EAP) to provide an experimental basis for the use of Chinese herbal prescriptions in the treatment of chronic prostatitis.METHODS:One-hundred and ten male Wistar rats were randomly divided into 11 groups:blank group;model group;Huoxuehuayu(promoting blood circulation to remove blood stasis) high,middle,and low dose groups;Qingrejiedu(clearing heat and removing toxicity) high,middle,and low dose groups;and Shuganliqi(dispersing stagnated liver-Qi) high,middle,and low dose groups.Except the blank group,rats in all groups were injected subcutaneously in multiple points on days 0 and 30 with prostatic protein extractive solution(60 mg/ml_),and intraperitoneally injected with diphtheria-pertussis and tetanus vaccine(DPT vaccine) to establish the EAP model.Model rats were administrated high,middle,and low doses of Chinese herbal prescriptions and were sacrificed after 4 weeks.Pathological changes in the prostate gland were observed with HE staining and changes in serum interleukin-6(IL-6),interleukin-8(IL-8),and prostaglandin E_2(PGE_2) levels were detected with enzyme-linked immunosorbent assay.RESULTS:Compared with the blank group,serum PGE_2,IL-6,and IL-8 levels in the model group were significantly higher(P < 0.05).Compared with the model group,serum PGE_2,IL-6,and IL-8 levels in the Qingrejiedu low dose and middle dose groups were significantly lower(P < 0.05),with the lower dose having a more obvious effect.Serum PGE_2,IL-6,and IL-8 levels in the Huoxuehuayu high dose group(P < 0.05),IL-6 and IL-8 levels in the Huoxuehuayu middle dose group(P < 0.05),and the IL-8level in the Huoxuehuayu low dose group were significantly lower than those in the model group(P < 0.05).There were significant differences in PGE_2 and IL-6 levels among the different dose groups of Shuganliqi drugs(P < 0.05).Compared with the model group,serum PGE_(2/) IL-6,and IL-8levels in the Shuganliqi high dose group(P <0.05) and IL-8 level in the Shuganliqi low dose group were significantly lower(P < 0.05),while the Shuganliqi middle dose group did not change significantly(P > 0.05).CONCLUSION:Therefore,in TCM treatment of autoimmune prostatitis,different treatment methods should select different doses.For prescriptions that clear heat and remove toxicity,low doses should be used.For prescriptions that promote blood circulation to remove blood stasis and for prescriptions that disperse stagnated liver-Qi,high doses should be used.展开更多
基金Student Training Program for Innovation and Entrepreneurship of Hangzhou Institute for Advanced Study,UCAS(CXCY20230305)Chinese Academy of Sciences Key Project(ZDRW-CN-2021-3-1-18)。
文摘Ceramic dielectric materials with high dielectric strength and mechanisms of their internal factors affecting dielectric strength are significantly valuable for industrial application,especially for selection of suitable dielectric materials for high-power microwave transmission devices and reliable power transmission.Pure magnesium oxide(MgO),a kind of ceramic dielectric material,possesses great application potential in high-power microwave transmission devices due to its high theoretical dielectric strength,low dielectric constant,and low dielectric loss properties,but its application is limited by high sintering temperature during preparation.This work presented the preparation of a new type of multiphase ceramics based on MgO,which was MgO-1%ZrO_(2)-1%CaCO_(3-x)%MnCO_(3)(MZCM_(x),x=0,0.25,0.50,1.00,1.50,in molar),and their phase structures,morphological features,and dielectric properties were investigated.It was found that inclusion of ZrO_(2) and CaCO_(3) effectively inhibited excessive growth of MgO grains by formation of second phase,while addition of MnCO_(3) promoted the grain boundary diffusion process during the sintering process and reduced activation energy for the grain growth,resulting in a lower ceramic sintering temperature.Excellent performance,including high dielectric strength(Eb=92.3 kV/mm)and quality factor(Q×f=216642 GHz),simultaneously accompanying low dielectric loss(<0.03%),low temperature coefficient of dielectric constant(20.3×10^(–6)℃^(–1),85℃)and resonance frequency(–12.54×10^(–6)℃^(–1)),was achieved in MZCM1.00 ceramics under a relatively low sintering temperature of 1350℃.This work offers an effective solution for selecting dielectric materials for high-power microwave transmission devices.
基金Supported by Natural Science Foundation of China(Research on Molecular Biological Mechanisms of the Three Methods,Promoting Blood Circulation to Remove Blood Stasis,Dispersing Stagnated Liver-Qi,and Clearing Heat and Removing Toxicity,for Treatment of Neuralgia Induced by Chronic Prostatitis,No.81060321)
文摘OBJECTIVE:To observe and compare the effects of Chinese herbal prescriptions for promoting blood circulation,clearing heat,removing toxicity,and dispersing stagnated liver-Qi on cytokines in model rats with experimental autoimmune prostatitis(EAP) to provide an experimental basis for the use of Chinese herbal prescriptions in the treatment of chronic prostatitis.METHODS:One-hundred and ten male Wistar rats were randomly divided into 11 groups:blank group;model group;Huoxuehuayu(promoting blood circulation to remove blood stasis) high,middle,and low dose groups;Qingrejiedu(clearing heat and removing toxicity) high,middle,and low dose groups;and Shuganliqi(dispersing stagnated liver-Qi) high,middle,and low dose groups.Except the blank group,rats in all groups were injected subcutaneously in multiple points on days 0 and 30 with prostatic protein extractive solution(60 mg/ml_),and intraperitoneally injected with diphtheria-pertussis and tetanus vaccine(DPT vaccine) to establish the EAP model.Model rats were administrated high,middle,and low doses of Chinese herbal prescriptions and were sacrificed after 4 weeks.Pathological changes in the prostate gland were observed with HE staining and changes in serum interleukin-6(IL-6),interleukin-8(IL-8),and prostaglandin E_2(PGE_2) levels were detected with enzyme-linked immunosorbent assay.RESULTS:Compared with the blank group,serum PGE_2,IL-6,and IL-8 levels in the model group were significantly higher(P < 0.05).Compared with the model group,serum PGE_2,IL-6,and IL-8 levels in the Qingrejiedu low dose and middle dose groups were significantly lower(P < 0.05),with the lower dose having a more obvious effect.Serum PGE_2,IL-6,and IL-8 levels in the Huoxuehuayu high dose group(P < 0.05),IL-6 and IL-8 levels in the Huoxuehuayu middle dose group(P < 0.05),and the IL-8level in the Huoxuehuayu low dose group were significantly lower than those in the model group(P < 0.05).There were significant differences in PGE_2 and IL-6 levels among the different dose groups of Shuganliqi drugs(P < 0.05).Compared with the model group,serum PGE_(2/) IL-6,and IL-8levels in the Shuganliqi high dose group(P <0.05) and IL-8 level in the Shuganliqi low dose group were significantly lower(P < 0.05),while the Shuganliqi middle dose group did not change significantly(P > 0.05).CONCLUSION:Therefore,in TCM treatment of autoimmune prostatitis,different treatment methods should select different doses.For prescriptions that clear heat and remove toxicity,low doses should be used.For prescriptions that promote blood circulation to remove blood stasis and for prescriptions that disperse stagnated liver-Qi,high doses should be used.
