In view of the requirements for high-performance epoxy resin(EP)enamelled wire insulating varnish in the rapidly developments of new energy vehicle drive motors,the problems of localised electric field concentration d...In view of the requirements for high-performance epoxy resin(EP)enamelled wire insulating varnish in the rapidly developments of new energy vehicle drive motors,the problems of localised electric field concentration due to the unevenness electric field distribution has to be solved.In this paper,to enhance the corona resistance,insulation,and mechanical properties of EP insulating varnish,the function dielectric gradient structure consists of hyperbranched polyester(HBP)inner layer and silane coupling agent(KH-550)modified graphene oxide(GO)nonlinear layer are proposed.The results show that the introduction of HBP not only adjusts the dielectric constant of the insulating varnish but also increases the breakdown field strength significantly,and with the increase of K-GO,the nonlinear conductivity of K-GO/EP insulating varnish becomes more prominent.Simulation results show that the highest field strength of the structural insulating varnish with different dielectric constant gradients is reduced to 16.7 kV/mm,and the field strength difference of the inner layer is reduced to 0.3 kV/mm,which further reduces the electric field aberration of the neighbouring interfaces as compared to the pure EP insulating varnish.This work provides a new strategy for constructing the dielectric gradient structure to meet the high corona resistance and insulating varnish requirements of high-voltage motor enamelled wire insulating varnish in actual industrial production.展开更多
目的分析3M White Varnish氟保护漆联合激光对牙本质过敏症的治疗效果,旨在探讨该病更有效的疗法,提高患者的临床的诊疗效果。方法80例牙本质过敏症患者(共113颗患牙),根据不同疗法分为A组(56颗患牙)与B组(57颗患牙),各40例。A组予以3M ...目的分析3M White Varnish氟保护漆联合激光对牙本质过敏症的治疗效果,旨在探讨该病更有效的疗法,提高患者的临床的诊疗效果。方法80例牙本质过敏症患者(共113颗患牙),根据不同疗法分为A组(56颗患牙)与B组(57颗患牙),各40例。A组予以3M White Varnish氟保护漆处理,B组予以3M White Varnish氟保护漆联合激光治疗。对比两组临床疗效;治疗前,治疗后即刻及1、3、6个月机械刺激与温度刺激的视觉模拟量表(VAS)评分及吹气刺激敏感评分。结果B组的治疗总有效率85.00%高于A组的65.00%,差异有统计学意义(P<0.05)。治疗后即刻及1、3、6个月,B组的机械刺激VAS评分与温度刺激VAS评分均低于A组,差异有统计学意义(P<0.05)。B组治疗后即刻及1、3、6个月的吹气刺激敏感评分分别为(0.70±0.18)分、(1.01±0.17)分、(1.24±0.35)分、(1.49±0.37)分,均低于A组的(0.83±0.21)分、(1.14±0.15)分、(1.52±0.42)分、(1.78±0.40)分,差异有统计学意义(P<0.05)。结论3M White Varnish氟保护漆联合激光对牙本质过敏症的治疗效果显著,总有效率高,且能明显减轻对患牙刺激时的疼痛程度与敏感度,值得临床推行。展开更多
BACKGROUND： Studies have demonstrated that coating materials used commonly in the interior decoration contain volatile of alkyd varnish, which has obvious effects on the structure of endothelial cells of respiratory ...BACKGROUND： Studies have demonstrated that coating materials used commonly in the interior decoration contain volatile of alkyd varnish, which has obvious effects on the structure of endothelial cells of respiratory tract. OBJECTIVE： To observe the effects of volatile of alkyd varnish in the decoration materials on the expression of neuronal growth associated protein-43 （GAP-43） in mice, and to analyze the influencing mechanism of interior environmental pollutants for brain mechanism. DESIGN： A randomized grouping and controlled experiment. SETTING： College of Life Science, Liaoning Normal University. MATERIALS： This study was carried out in the College of Life Science, Liaoning Normal University between February and December 2006. Twenty one-month-old Kunming mice, weighing （20 ± 2 ） g, male and female in half, were involved in this study. The involved mice were divided into 2 groups by random lot method： chronic poisoning group （n =10） and control group （n =10）. Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Rabbit GAP-43 polyclonal antibody, rat β -actin monoclonal antibody, goat anti-rat IgG-HRP and goat ant-rabbit IgG-HRP were purchased from Boster Company （Wuhan）. ECL was purchased from Amersham Company （Britain）, other related reagents were all purchased from Sigma Company and Promega Company （USA）. All the other reagents were home-made analytical pure. METHODS： ①Poisoning test： The mice were poisoned by static inhalation poisoning method. Mice in the chronic poisoning group were placed in the 0.024 m^3 poisoning cabinet. Alkyd varnish （8 g, 3-time dosage of house decoration） was daily spread once on a 40 cm × 21 cm kraft paper evenly. Mice were poisoned for 14 hours within 3 weeks successively. Mice in the control group were placed in the same environment without alkyd varnish, and the poisoning method was the same as that of chronic poisoning group. ② Experimental evaluation： content of protein in the cortex, cerebellum and hippocampus of mice was measured separately by Bradford method. GAP-43 expression in the hippocampus and cortex was observed separately by SDS-polyacrylamide gel electrophoresis （SDS-PAGE）. MAIN OUTCOME MEASURES： Content of protein and expression of GAP-43 in different brain regions of mice. RESULTS： Twenty mice were involved in the final analysis. ① Content of protein in the cerebellum and hippocampus of mice in the chronic poisoning group was decreased a little, separately （P 〉 0.05）. ② GAP-43 expression in the hippocampus of mice of the chronic poisoning group was significantly lower than that of the control group（P 〈 0.05）. CONCLUSION： Long-term action of volatile of alkyd varnish can inhibit the brain functions of mice by depressing the GAP-43 expression in hippocampus of mice.展开更多
The dielectric constant, the dielectric loss and the power factor of three types of resins namely polyesteramide, alkyd polyesteramide and alkyd resins were measured with in the frequency range of 105 to 107 Hz and th...The dielectric constant, the dielectric loss and the power factor of three types of resins namely polyesteramide, alkyd polyesteramide and alkyd resins were measured with in the frequency range of 105 to 107 Hz and the temperature range of 20 to 50℃. The activation energy of dielectric relaxation and the entropy changes were also calculated using the usual rate equation. The results obtained are recorded and discussed.展开更多
The variation of the dielectric constant e' and the dielectric loss e' of polyesteramide, alkyd polyesteramide and alkyd varnish dry films were measured within the frequency range from 105 to 107 Hz and the te...The variation of the dielectric constant e' and the dielectric loss e' of polyesteramide, alkyd polyesteramide and alkyd varnish dry films were measured within the frequency range from 105 to 107 Hz and the temperature range from 20 to 50℃. The varnish films were subjected to accelerated ageing by heating at 110℃ for diferent durations. The efect of the accelerated ageing on e' and e' were measured. The activation energy and the entropy change of dielectric relaxation for the dry films before and after ageing were also calculated. All the results obtained were recorded and discussed in correlation with the molecular structure of the investigated varnishes.展开更多
This study was performed to determine the effects of varnishing after impregnation with boron compounds on the combustion properties of Scotch pine. For this purpose, test samples prepared from Scotch pine (Pinus sylv...This study was performed to determine the effects of varnishing after impregnation with boron compounds on the combustion properties of Scotch pine. For this purpose, test samples prepared from Scotch pine (Pinus sylvestris Lipsky) wood were impregnated according to ASTM-D 1413-99 standard with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated by cellulosic (Cv), synthetic (Sn), polyurathane (Pu), waterborne (Wb), acrylic (Ac) and acid hardening (Ah) varnishes in accordance with ASTM D-3023 standard and then, combustion temperature was determined. According to material and process type, combustion temperature was the highest in Bx and Wb in flame source combustion (FSC), the lowest in Ba and Ac without flame source combustion (WFSC). According to combustion type, impregnation material and varnish type, combustion temperature was the highest in FSC, borax and cellulosic varnish combination and the lowest in WFSC, boric acid and acid hardening varnish combination. In conclusion, impregnation materials decrease while varnishes increase the combustion temperature of Scotch pine wood.展开更多
基金The National Natural Science Foundation of China(Grant 52107014)China Postdoctoral Science Foundation(Grants 2022M710981 and 2023T160171)Shandong Provincial Natural Science Foundation(Grant ZR2022QE187).
文摘In view of the requirements for high-performance epoxy resin(EP)enamelled wire insulating varnish in the rapidly developments of new energy vehicle drive motors,the problems of localised electric field concentration due to the unevenness electric field distribution has to be solved.In this paper,to enhance the corona resistance,insulation,and mechanical properties of EP insulating varnish,the function dielectric gradient structure consists of hyperbranched polyester(HBP)inner layer and silane coupling agent(KH-550)modified graphene oxide(GO)nonlinear layer are proposed.The results show that the introduction of HBP not only adjusts the dielectric constant of the insulating varnish but also increases the breakdown field strength significantly,and with the increase of K-GO,the nonlinear conductivity of K-GO/EP insulating varnish becomes more prominent.Simulation results show that the highest field strength of the structural insulating varnish with different dielectric constant gradients is reduced to 16.7 kV/mm,and the field strength difference of the inner layer is reduced to 0.3 kV/mm,which further reduces the electric field aberration of the neighbouring interfaces as compared to the pure EP insulating varnish.This work provides a new strategy for constructing the dielectric gradient structure to meet the high corona resistance and insulating varnish requirements of high-voltage motor enamelled wire insulating varnish in actual industrial production.
文摘目的分析3M White Varnish氟保护漆联合激光对牙本质过敏症的治疗效果,旨在探讨该病更有效的疗法,提高患者的临床的诊疗效果。方法80例牙本质过敏症患者(共113颗患牙),根据不同疗法分为A组(56颗患牙)与B组(57颗患牙),各40例。A组予以3M White Varnish氟保护漆处理,B组予以3M White Varnish氟保护漆联合激光治疗。对比两组临床疗效;治疗前,治疗后即刻及1、3、6个月机械刺激与温度刺激的视觉模拟量表(VAS)评分及吹气刺激敏感评分。结果B组的治疗总有效率85.00%高于A组的65.00%,差异有统计学意义(P<0.05)。治疗后即刻及1、3、6个月,B组的机械刺激VAS评分与温度刺激VAS评分均低于A组,差异有统计学意义(P<0.05)。B组治疗后即刻及1、3、6个月的吹气刺激敏感评分分别为(0.70±0.18)分、(1.01±0.17)分、(1.24±0.35)分、(1.49±0.37)分,均低于A组的(0.83±0.21)分、(1.14±0.15)分、(1.52±0.42)分、(1.78±0.40)分,差异有统计学意义(P<0.05)。结论3M White Varnish氟保护漆联合激光对牙本质过敏症的治疗效果显著,总有效率高,且能明显减轻对患牙刺激时的疼痛程度与敏感度,值得临床推行。
文摘BACKGROUND： Studies have demonstrated that coating materials used commonly in the interior decoration contain volatile of alkyd varnish, which has obvious effects on the structure of endothelial cells of respiratory tract. OBJECTIVE： To observe the effects of volatile of alkyd varnish in the decoration materials on the expression of neuronal growth associated protein-43 （GAP-43） in mice, and to analyze the influencing mechanism of interior environmental pollutants for brain mechanism. DESIGN： A randomized grouping and controlled experiment. SETTING： College of Life Science, Liaoning Normal University. MATERIALS： This study was carried out in the College of Life Science, Liaoning Normal University between February and December 2006. Twenty one-month-old Kunming mice, weighing （20 ± 2 ） g, male and female in half, were involved in this study. The involved mice were divided into 2 groups by random lot method： chronic poisoning group （n =10） and control group （n =10）. Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Alkyd varnish used commonly for house decoration was purchased from Furnishing World of Liberation Plaza of Dalian City. Rabbit GAP-43 polyclonal antibody, rat β -actin monoclonal antibody, goat anti-rat IgG-HRP and goat ant-rabbit IgG-HRP were purchased from Boster Company （Wuhan）. ECL was purchased from Amersham Company （Britain）, other related reagents were all purchased from Sigma Company and Promega Company （USA）. All the other reagents were home-made analytical pure. METHODS： ①Poisoning test： The mice were poisoned by static inhalation poisoning method. Mice in the chronic poisoning group were placed in the 0.024 m^3 poisoning cabinet. Alkyd varnish （8 g, 3-time dosage of house decoration） was daily spread once on a 40 cm × 21 cm kraft paper evenly. Mice were poisoned for 14 hours within 3 weeks successively. Mice in the control group were placed in the same environment without alkyd varnish, and the poisoning method was the same as that of chronic poisoning group. ② Experimental evaluation： content of protein in the cortex, cerebellum and hippocampus of mice was measured separately by Bradford method. GAP-43 expression in the hippocampus and cortex was observed separately by SDS-polyacrylamide gel electrophoresis （SDS-PAGE）. MAIN OUTCOME MEASURES： Content of protein and expression of GAP-43 in different brain regions of mice. RESULTS： Twenty mice were involved in the final analysis. ① Content of protein in the cerebellum and hippocampus of mice in the chronic poisoning group was decreased a little, separately （P 〉 0.05）. ② GAP-43 expression in the hippocampus of mice of the chronic poisoning group was significantly lower than that of the control group（P 〈 0.05）. CONCLUSION： Long-term action of volatile of alkyd varnish can inhibit the brain functions of mice by depressing the GAP-43 expression in hippocampus of mice.
文摘The dielectric constant, the dielectric loss and the power factor of three types of resins namely polyesteramide, alkyd polyesteramide and alkyd resins were measured with in the frequency range of 105 to 107 Hz and the temperature range of 20 to 50℃. The activation energy of dielectric relaxation and the entropy changes were also calculated using the usual rate equation. The results obtained are recorded and discussed.
文摘The variation of the dielectric constant e' and the dielectric loss e' of polyesteramide, alkyd polyesteramide and alkyd varnish dry films were measured within the frequency range from 105 to 107 Hz and the temperature range from 20 to 50℃. The varnish films were subjected to accelerated ageing by heating at 110℃ for diferent durations. The efect of the accelerated ageing on e' and e' were measured. The activation energy and the entropy change of dielectric relaxation for the dry films before and after ageing were also calculated. All the results obtained were recorded and discussed in correlation with the molecular structure of the investigated varnishes.
文摘This study was performed to determine the effects of varnishing after impregnation with boron compounds on the combustion properties of Scotch pine. For this purpose, test samples prepared from Scotch pine (Pinus sylvestris Lipsky) wood were impregnated according to ASTM-D 1413-99 standard with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated by cellulosic (Cv), synthetic (Sn), polyurathane (Pu), waterborne (Wb), acrylic (Ac) and acid hardening (Ah) varnishes in accordance with ASTM D-3023 standard and then, combustion temperature was determined. According to material and process type, combustion temperature was the highest in Bx and Wb in flame source combustion (FSC), the lowest in Ba and Ac without flame source combustion (WFSC). According to combustion type, impregnation material and varnish type, combustion temperature was the highest in FSC, borax and cellulosic varnish combination and the lowest in WFSC, boric acid and acid hardening varnish combination. In conclusion, impregnation materials decrease while varnishes increase the combustion temperature of Scotch pine wood.
