Gadolinium zirconate（Gd2Zr2O7） nanocrystals were prepared via two different combustion methods： citric acid combustion（CAC） and stearic acid combustion（SAC）. The effects of the different preparation methods on ...Gadolinium zirconate（Gd2Zr2O7） nanocrystals were prepared via two different combustion methods： citric acid combustion（CAC） and stearic acid combustion（SAC）. The effects of the different preparation methods on the phase composition, microtopography, and sintering densification of the resulting Gd2Zr2O7 nanopowders were investigated by thermal-gravimetric and differential thermal analysis（TG-DTA）, Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, and transmission electron microscopy（TEM） techniques. The results indicated that both methods could produce Gd2Zr2O7 nanopowders with an excellent defective fluorite structure. The reaction time was reduced by the SAC method, compared with the CAC method. The nanopowders synthesized by the two methods were different in grain size distribution. The resulting nanoparticle diameter was about 50 nm for CAC and 10 nm for SAC. After vacuum sintering, the sintered bodies also had a different relative density of about 93% and 98%, respectively. Thus the preparation of Gd2Zr2O7 nanopowders by SAC was the first choice to achieve the desired sintering densification.展开更多
Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus...Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus[R.(B.)microplus]and the adult of Haemaphrysalis bispinosa(H.bispinosa).Methods:The lyophilized C.gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH_2)(10 mM)and magnetically stirred for 6 h.Synthesized TiO_2 NPs were characterized by X-ray diffraction(XRD).Fourier transform infrared spectroscopy(FTIR),Scanning electron microscopy(SEM),and Energy dispersive X-ray spectroscopy(EDX).The synthesised TiO_2 NPs were tested against the larvae of R(B.)microplus and adult of H.bispinosa were exposed to filter paper impregnated method.Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm.The functional groups for synthesized TiO_2NPs were 1405.19,and 1053.45 cm^(-1)for-NH_2 bending,primary amines and amides and 1053.84and 1078.45 cm^(-1)for C-O.SEM micrographs of the synthesized TiO_2 NPs showed the aggregated and spherical in shape.The maximum efficacy was observed in the aqueous flower extract of C.gigantea and synthesized TiO_2 NPs against R.(B.)microplus(LC_(50)=24.63 and 5.43 mg/L and r^2=0.960 and 0.988)and against H.bispinosa(LC_(50)=35.22 and 9.15 mg/L and r^2=0.969 and 0.969).respectively.Conclusions:The synthesized TiO_2 NPs were highly stable and had significant acaricidal activity against the larvae of R.(B.)microplus and adult of H.bispinosa.This study provides the first report of synthesized TiO_2 NPs and possessed excellent anti-parasitic activity.展开更多
The abrasive crystalline phases in Colgate Regular, Aquafresh , and Macleans tcothpaste were identifiedby X-ray powder diffractometry to be calcium ortho-phaphate hydrate (CaHPO_4 . 2H_2O),calcite (CaCO_3) ,and aragon...The abrasive crystalline phases in Colgate Regular, Aquafresh , and Macleans tcothpaste were identifiedby X-ray powder diffractometry to be calcium ortho-phaphate hydrate (CaHPO_4 . 2H_2O),calcite (CaCO_3) ,and aragonite and calcite (beth CaCO_3), respectively.展开更多
文摘Gadolinium zirconate（Gd2Zr2O7） nanocrystals were prepared via two different combustion methods： citric acid combustion（CAC） and stearic acid combustion（SAC）. The effects of the different preparation methods on the phase composition, microtopography, and sintering densification of the resulting Gd2Zr2O7 nanopowders were investigated by thermal-gravimetric and differential thermal analysis（TG-DTA）, Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, and transmission electron microscopy（TEM） techniques. The results indicated that both methods could produce Gd2Zr2O7 nanopowders with an excellent defective fluorite structure. The reaction time was reduced by the SAC method, compared with the CAC method. The nanopowders synthesized by the two methods were different in grain size distribution. The resulting nanoparticle diameter was about 50 nm for CAC and 10 nm for SAC. After vacuum sintering, the sintered bodies also had a different relative density of about 93% and 98%, respectively. Thus the preparation of Gd2Zr2O7 nanopowders by SAC was the first choice to achieve the desired sintering densification.
文摘Objective:To assess the acaricidal activity of titanium dioxide nanoparticles(TiO_2 NPs)synthesized from flower aqueous extract of Calotropis gigantea(C.gigantea)against the larvae of Rhipicephalus(Boophilus)microplus[R.(B.)microplus]and the adult of Haemaphrysalis bispinosa(H.bispinosa).Methods:The lyophilized C.gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH_2)(10 mM)and magnetically stirred for 6 h.Synthesized TiO_2 NPs were characterized by X-ray diffraction(XRD).Fourier transform infrared spectroscopy(FTIR),Scanning electron microscopy(SEM),and Energy dispersive X-ray spectroscopy(EDX).The synthesised TiO_2 NPs were tested against the larvae of R(B.)microplus and adult of H.bispinosa were exposed to filter paper impregnated method.Results:XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm.The functional groups for synthesized TiO_2NPs were 1405.19,and 1053.45 cm^(-1)for-NH_2 bending,primary amines and amides and 1053.84and 1078.45 cm^(-1)for C-O.SEM micrographs of the synthesized TiO_2 NPs showed the aggregated and spherical in shape.The maximum efficacy was observed in the aqueous flower extract of C.gigantea and synthesized TiO_2 NPs against R.(B.)microplus(LC_(50)=24.63 and 5.43 mg/L and r^2=0.960 and 0.988)and against H.bispinosa(LC_(50)=35.22 and 9.15 mg/L and r^2=0.969 and 0.969).respectively.Conclusions:The synthesized TiO_2 NPs were highly stable and had significant acaricidal activity against the larvae of R.(B.)microplus and adult of H.bispinosa.This study provides the first report of synthesized TiO_2 NPs and possessed excellent anti-parasitic activity.
