Europium doped LiNiPO4 and undoped LiNiPO4 were prepared by Pechini method. Compound formation temperature was confirmed from thermogravimetry and differential thermal analysis （TG/DTA）. Powder X-ray diffraction （...Europium doped LiNiPO4 and undoped LiNiPO4 were prepared by Pechini method. Compound formation temperature was confirmed from thermogravimetry and differential thermal analysis （TG/DTA）. Powder X-ray diffraction （XRD） pattern confirmed the formation of pure LiNiPO4 compound with an orthorhombic structure. The conductivity and modulus analyses of the samples were carried out at different temperatures and frequencies using the complex impedance spectroscopy technique. The conductivity parameters such as ion hopping frequency and the charge cartier concentration term were calculated using Almond and West formalisms. An increase of one order of magnitude in the ionic conductivity has been observed for 1.0% Eu-doped LiNiPO4. （mole fraction）. The complex modulus studies suggest the presence of non-Debye type of relaxation in the materials.展开更多
This letter proposes a novel design of a Micro Electro Mechanical System （MEMS） device featuring a metal grating vibratory mierostructure driven by electrostatic force to sense the spatial electric field. Due to the...This letter proposes a novel design of a Micro Electro Mechanical System （MEMS） device featuring a metal grating vibratory mierostructure driven by electrostatic force to sense the spatial electric field. Due to the advantages in slide-film damping and large vibration amplitude, such a device makes atmospheric packaging a low-cost option for practical manufacture. In this letter, we present the operating principles and specifications, the design structure, as well as the finite element simulation. Computational analysis shows that our design obtains good results in device parameters setting, while its simplicity and low-cost features make it an attractive solution for applications.展开更多
The permeation flux or the resistance in the ultrafiltration process is mainly limited by osmotic pressure, and it may originate from various kinds of polymer interactions. However, the real origin of permeation resis...The permeation flux or the resistance in the ultrafiltration process is mainly limited by osmotic pressure, and it may originate from various kinds of polymer interactions. However, the real origin of permeation resistance hasn＇t been clarified yet in the light of polymer solution nature. The removal of nitrate contamination by polyelectrolytes was carried out with stirred batch ultrafiltration. The polyelectrolyte concentrations both in permeate and retentate were analyzed with total organic carbon analyzer and permeate mass was acquired by electronic balance connected with computer. The total resistance was calculated and interpreted based on the osmotic pressures in three concentration regimes. In the dilute region, the resistance was proportional to polymer concentration; in the semidilute region, the resistance depended on polymer concentration in the parabolic relationship; in the highly concentrated solution regime, the osmotic pressure factor （OPF） would dominate the total resistance; and the deviation from OPF control could come from the electrostatic repulsion between the tightly compacted and charged polyelectrolyte particles at extremely concentrated solution regime. It was first found that dilute and semidilute concentration regions can be easily detected by plotting the leg-log curves of the polymer concentration versus the ratio of the total resistance to polymer concentration. The new concept OPF was defined and did work well at highly concentrated regime.展开更多
文摘Europium doped LiNiPO4 and undoped LiNiPO4 were prepared by Pechini method. Compound formation temperature was confirmed from thermogravimetry and differential thermal analysis （TG/DTA）. Powder X-ray diffraction （XRD） pattern confirmed the formation of pure LiNiPO4 compound with an orthorhombic structure. The conductivity and modulus analyses of the samples were carried out at different temperatures and frequencies using the complex impedance spectroscopy technique. The conductivity parameters such as ion hopping frequency and the charge cartier concentration term were calculated using Almond and West formalisms. An increase of one order of magnitude in the ionic conductivity has been observed for 1.0% Eu-doped LiNiPO4. （mole fraction）. The complex modulus studies suggest the presence of non-Debye type of relaxation in the materials.
基金Supported by the National Natural Science Foundation of China (No.60172001).
文摘This letter proposes a novel design of a Micro Electro Mechanical System （MEMS） device featuring a metal grating vibratory mierostructure driven by electrostatic force to sense the spatial electric field. Due to the advantages in slide-film damping and large vibration amplitude, such a device makes atmospheric packaging a low-cost option for practical manufacture. In this letter, we present the operating principles and specifications, the design structure, as well as the finite element simulation. Computational analysis shows that our design obtains good results in device parameters setting, while its simplicity and low-cost features make it an attractive solution for applications.
文摘The permeation flux or the resistance in the ultrafiltration process is mainly limited by osmotic pressure, and it may originate from various kinds of polymer interactions. However, the real origin of permeation resistance hasn＇t been clarified yet in the light of polymer solution nature. The removal of nitrate contamination by polyelectrolytes was carried out with stirred batch ultrafiltration. The polyelectrolyte concentrations both in permeate and retentate were analyzed with total organic carbon analyzer and permeate mass was acquired by electronic balance connected with computer. The total resistance was calculated and interpreted based on the osmotic pressures in three concentration regimes. In the dilute region, the resistance was proportional to polymer concentration; in the semidilute region, the resistance depended on polymer concentration in the parabolic relationship; in the highly concentrated solution regime, the osmotic pressure factor （OPF） would dominate the total resistance; and the deviation from OPF control could come from the electrostatic repulsion between the tightly compacted and charged polyelectrolyte particles at extremely concentrated solution regime. It was first found that dilute and semidilute concentration regions can be easily detected by plotting the leg-log curves of the polymer concentration versus the ratio of the total resistance to polymer concentration. The new concept OPF was defined and did work well at highly concentrated regime.
