As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manuf...
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As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high ***, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.
Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil...
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Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3,10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene.
A novel storage and extraction method was developed for biofluids. Plasma spiked with four types of minor ginsenosides (Rg(2), Rg(3), Rh-1 and Rh-2) was used as a model biofluid to evaluate this method. The method was...
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A novel storage and extraction method was developed for biofluids. Plasma spiked with four types of minor ginsenosides (Rg(2), Rg(3), Rh-1 and Rh-2) was used as a model biofluid to evaluate this method. The method was based on solid-phase adsorption and ultrasonic-assisted nebulization coupled with solid phase extraction (SPA-UANE-SPE). Diatomaceous earth was used as an adsorbent to store the plasma for long periods of time at room temperature. Ultrasonic-assisted nebulization system-solid phase extraction was used to extract the four minor ginsenosides from the plasma. Some experimental parameters, such as the type and amount of the adsorbent, the ultrasonic-assisted nebulization extraction time, the pH of the extraction solution, the concentration of ZnSO4, the amount of C-18, and the type and volume of the eluent were investigated and optimized. Under the optimized conditions, the recoveries of four minor ginsenosides were in the range of 78.5-91.4%, and the RSDs are in the range of 3.5-4.4%. For the storage stability test, the stability of the method was better than that of 4 degrees C storage and was similar to that of -20 degrees C storage. Compared with other methods, the proposed method had a better extraction performance and was advantageous in terms of ease of operation, stable long term storage, and minimal requirements for storage conditions. Thus, this method may be effective for sample preparation in biofluid analysis.
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