The microstructures of Mg96.17Zn3.15Y0.50Zr0.18 alloys solidified under 2-6 GPa high pressure were investigated by employing SEM(EDS) and TEM.The strengthening mechanism of experimental alloy solidified under high pre...The microstructures of Mg96.17Zn3.15Y0.50Zr0.18 alloys solidified under 2-6 GPa high pressure were investigated by employing SEM(EDS) and TEM.The strengthening mechanism of experimental alloy solidified under high pressure is also discussed by analyzing the compressive properties and compression fracture morphology.The results show that the microstructure of experimental alloy becomes significantly fine-grained with increasing GPa level high pressure during solidification process,and the secondary dendrite arm spacing reduces from 40 μm at atmospheric pressure to 10 μm at 6 GPa pressure.The morphology of the second phases changes from the net structure by the lamellar-type eutectic structure at atmospheric pressure to discontinuous thin rods or particles at 6 GPa pressure.Besides,the solid solubility of Zn in the Mg matrix is improved with the increase of the solidification pressure.Compared with atmospheric-pressure solidification,high-pressure solidification can improve the strength of the experimental alloy.The compressive stre ngth is improved from 263 to 437 MPa at 6 GPa.The fracture mechanism of the experimental alloy changes from cleavage fracture at atmospheric pressure to quasi-cleavage fracture at high pressure.The main mechanism of the strength improvement of the experimental alloy includes the grain refinement strengthening caused by the refinement of the solidification microstructure,the second phase strengthening caused by the improvement of the morphology and distribution of the second phases,and solid solution strengthening caused by the increase of the solid solubility of Zn in the Mg matrix.展开更多
Objectives: To compare ocular surface changes induced via glaucoma treatment in patients using fixed combinations of bimatoprost 0.03%/timolol 0.50%, timolol 0.50% or bimatoprost 0.01% eye drops. Methods: This is a pr...Objectives: To compare ocular surface changes induced via glaucoma treatment in patients using fixed combinations of bimatoprost 0.03%/timolol 0.50%, timolol 0.50% or bimatoprost 0.01% eye drops. Methods: This is a prospective, one center, open-label clinical trial. It was performed on 60 glaucoma patients between 01-01-2012 and 12-31-2012. These patients were randomly divided in three subgroups: bimatoprost 0.03%/timolol 0.50% fixed combination, timolol 0.50% and bimatoprost 0.01%. The Ocular Surface Disease Index (O.S.D.I.) was evaluated in all the glaucomatous patients of the three subgroups at basal time and after 6 and 12 months. All the results were statistically evaluated by Student t-test and one-way ANOVA. The results were considered statistically significant if p < 0.05. Results: All of the patients ended the clinical trial. There was no statistical significant difference between patients treated with the bimatoprost 0.03%/timolol 0.50% fixed combination and timolol 0.50% eye drops alone (p = 0.845). Instead, there was a statistically significant difference between bimatoprost 0.01% and bimatoprost 0.03%/timolol 0.50% patients (p = 0.05) and between bimatoprost 0.01% and timolol 0.50% eye drops alone (p = 0.049). Conclusions: This is a clinical trial based not on the hypotonising effect of these drugs but on their tolerability. The drug which showed the best tolerability is bimatoprost 0.01%.展开更多
Lithium-rich layered oxides(LLOs)have been extensively studied as cathode materials for lithium-ion batteries(LIBs)by researchers all over the world in the past decades due to their high specific capacities and high c...Lithium-rich layered oxides(LLOs)have been extensively studied as cathode materials for lithium-ion batteries(LIBs)by researchers all over the world in the past decades due to their high specific capacities and high charge-discharge voltages.However,as cathode materials LLOs have disadvantages of significant voltage and capacity decays during the charge-discharge cycling.It was shown in the past that fine-tuning of structures and compositions was critical to the performances of this kind of materials.In this report,LLOs with target composition of Li1.17Mn0.50Ni0.24Co0.09O2 were prepared by carbonate co-precipitation method with different pH values.X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscope(TEM),and electrochemical impedance spectroscopies(EIS)were used to investigate the structures and morphologies of the materials and to understand the improvements of their electrochemical performances.With the pH values increased from 7.5 to 8.5,the Li/Ni ratios in the compositions decreased from 5.17 to 4.64,and the initial Coulombic efficiency,cycling stability and average discharge voltages were gained impressively.Especially,the material synthesized at pH=8.5 delivered a reversible discharge capacity of 263 mAhg−1 during the first cycle,with 79.0%initial Coulombic efficiency,at the rate of 0.1 C and a superior capacity retention of 94%after 100 cycles at the rate of 1 C.Furthermore,this material exhibited an initial average discharge voltage of 3.65 V,with a voltage decay of only 0.09 V after 50 charge-discharge cycles.The improved electrochemical performances by varying the pH values in the synthesis process can be explained by the mitigation of layered-to-spinel phase transformation and the reduction of solid-electrolyte interface(SEI)resistance.We hope this work can shed some light on the alleviation of voltage and capacity decay issues of the LLOs cathode materials.展开更多
文摘Submicron CMOS IC technology, including triple layer resist lithography technology, RIE, LDD, Titanium Salicide, shallow junction, thin gate oxide, no bird's beak isolation and channel's multiple implantation doping technology have been developed. 0.50μm. CMOS integrated circuits have been fabricated using this submicron CMOS process.
基金the National Natural Science Foundation of China(51675092,51775099)the Natural Science Foundation of Hebei Province(E2018501032,E2018501033)。
文摘The microstructures of Mg96.17Zn3.15Y0.50Zr0.18 alloys solidified under 2-6 GPa high pressure were investigated by employing SEM(EDS) and TEM.The strengthening mechanism of experimental alloy solidified under high pressure is also discussed by analyzing the compressive properties and compression fracture morphology.The results show that the microstructure of experimental alloy becomes significantly fine-grained with increasing GPa level high pressure during solidification process,and the secondary dendrite arm spacing reduces from 40 μm at atmospheric pressure to 10 μm at 6 GPa pressure.The morphology of the second phases changes from the net structure by the lamellar-type eutectic structure at atmospheric pressure to discontinuous thin rods or particles at 6 GPa pressure.Besides,the solid solubility of Zn in the Mg matrix is improved with the increase of the solidification pressure.Compared with atmospheric-pressure solidification,high-pressure solidification can improve the strength of the experimental alloy.The compressive stre ngth is improved from 263 to 437 MPa at 6 GPa.The fracture mechanism of the experimental alloy changes from cleavage fracture at atmospheric pressure to quasi-cleavage fracture at high pressure.The main mechanism of the strength improvement of the experimental alloy includes the grain refinement strengthening caused by the refinement of the solidification microstructure,the second phase strengthening caused by the improvement of the morphology and distribution of the second phases,and solid solution strengthening caused by the increase of the solid solubility of Zn in the Mg matrix.
文摘Objectives: To compare ocular surface changes induced via glaucoma treatment in patients using fixed combinations of bimatoprost 0.03%/timolol 0.50%, timolol 0.50% or bimatoprost 0.01% eye drops. Methods: This is a prospective, one center, open-label clinical trial. It was performed on 60 glaucoma patients between 01-01-2012 and 12-31-2012. These patients were randomly divided in three subgroups: bimatoprost 0.03%/timolol 0.50% fixed combination, timolol 0.50% and bimatoprost 0.01%. The Ocular Surface Disease Index (O.S.D.I.) was evaluated in all the glaucomatous patients of the three subgroups at basal time and after 6 and 12 months. All the results were statistically evaluated by Student t-test and one-way ANOVA. The results were considered statistically significant if p < 0.05. Results: All of the patients ended the clinical trial. There was no statistical significant difference between patients treated with the bimatoprost 0.03%/timolol 0.50% fixed combination and timolol 0.50% eye drops alone (p = 0.845). Instead, there was a statistically significant difference between bimatoprost 0.01% and bimatoprost 0.03%/timolol 0.50% patients (p = 0.05) and between bimatoprost 0.01% and timolol 0.50% eye drops alone (p = 0.049). Conclusions: This is a clinical trial based not on the hypotonising effect of these drugs but on their tolerability. The drug which showed the best tolerability is bimatoprost 0.01%.
基金Supported by the National Natural Science Foundation of China (10774030)the Guangdong Provincial Natural Science Foundation of China (8151009001000003)
基金the National Natural Science Foundation of China(No.21271145)the National Science Foundation of Hubei Province(No.2015CFB537)+1 种基金the Science and Technology Innovation Committee of Shenzhen Municipality(No.JCYJ20170306171321438)the financial support for this investigation.
文摘Lithium-rich layered oxides(LLOs)have been extensively studied as cathode materials for lithium-ion batteries(LIBs)by researchers all over the world in the past decades due to their high specific capacities and high charge-discharge voltages.However,as cathode materials LLOs have disadvantages of significant voltage and capacity decays during the charge-discharge cycling.It was shown in the past that fine-tuning of structures and compositions was critical to the performances of this kind of materials.In this report,LLOs with target composition of Li1.17Mn0.50Ni0.24Co0.09O2 were prepared by carbonate co-precipitation method with different pH values.X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscope(TEM),and electrochemical impedance spectroscopies(EIS)were used to investigate the structures and morphologies of the materials and to understand the improvements of their electrochemical performances.With the pH values increased from 7.5 to 8.5,the Li/Ni ratios in the compositions decreased from 5.17 to 4.64,and the initial Coulombic efficiency,cycling stability and average discharge voltages were gained impressively.Especially,the material synthesized at pH=8.5 delivered a reversible discharge capacity of 263 mAhg−1 during the first cycle,with 79.0%initial Coulombic efficiency,at the rate of 0.1 C and a superior capacity retention of 94%after 100 cycles at the rate of 1 C.Furthermore,this material exhibited an initial average discharge voltage of 3.65 V,with a voltage decay of only 0.09 V after 50 charge-discharge cycles.The improved electrochemical performances by varying the pH values in the synthesis process can be explained by the mitigation of layered-to-spinel phase transformation and the reduction of solid-electrolyte interface(SEI)resistance.We hope this work can shed some light on the alleviation of voltage and capacity decay issues of the LLOs cathode materials.
