The anti-sublimation CO2 capture technology has attracted the attention of researchers due to its advantages such as no pollution and high product purity. The anti-sublimation process is the core link of this technology, so the study of this process is of great significance to the low-temperature capture system. At present, there are few research works on the CO2 anti-sublimation process. In order to study the influence of key parameters on the capture performance during CO2 anti-sublimation, a one-dimensional steady-state of CO2 anti-sublimation process in a double pipe heat exchanger was established based on the mixture gas of N2 and CO2. The effects of cooling nitrogen inlet temperature, mixture gas velocity and pressure on the CO2 volume fraction, deposition rate distribution, capture rate and valid capture length are investigated. Optimal operation parameters are obtained, which could be used to provide guidance for parameter setting and design of anti-sublimation heat exchanger
CO<sub>2</sub>+HFC binary mixtures have good performance and environmental friendliness and are considered good alternative working fluids in cooling and power cycle systems. The vapor-liquid phase equilibrium properties are key to the calculation of the enthalpy and entropy of mixtures, which is critical for the analysis of cooling and power cycle systems. To accurately predict the vapor-liquid equilibrium of CO<sub>2</sub> and HFC (R23, R32, R41, R125, R134a, R143a, R152a, R161, and R227ea) binary mixtures, a group contribution model based on the excess free energy (<i>G</i><sup>E</sup>) mixing rules (PR+MHV1+UNIFAC and PR+LCVM+UNIFAC) is established in this paper. The interaction parameters between groups such as -CO<sub>2</sub>, -Alkane, -CHF, and -CHF<sub>3</sub> are obtained by the vapor-liquid phase equilibrium experiment of CO<sub>2</sub> and HFC refrigerants, and these group parameters are critical for predicting their vapor-liquid phase equilibrium properties (the pressures and vapor phase molar fractions). The AARD<i>p</i> value calculated by the PR+LCVM+UNIFAC model is 5.53%, the value of AAD<i>y</i><sub>1</sub> is 0.0132, and the AARD<i>p</i> and AAD<i>y</i><sub>1</sub> values of the PR+MHV1+UNIFAC model are 7.40% and 0.0229, respectively. However, for the CO<sub>2</sub>+R32 system, the PR+MHV+UNIFAC prediction model can reproduce the experimental data with lower deviations, and the values of AARD<i>p</i> and AAD<i>y</i><sub>1</sub> are 1.53% and 0.0045, respectively. In summary, for CO<sub>2</sub>+HFC binary mixtures, the PR+LCVM+UNIFAC group contribution model can reproduce the experimental data with lower deviations, but for individual CO<sub>2</sub> binary mixtures (such as CO<sub>2</sub>+R32), the PR+MHV1+UNIFAC model also has unique advantages. According to the prediction results of the group contribution model, the PR+LCVM+UNIFAC model has significantly improved the calculation progress compared with the PR+MHV1+UNIFAC model used in the previous system.
This thesis makes an analysis and research into the open experimental teaching for biotechnological majors in colleges and discusses the content, teaching method and pattern, specific process and final assessment and mechanism of open experiments.The content of the open experiment plays a decisive role in the experimental teaching.Three aspects are very important.They are the innovation, practicality and synthesis of the experimental content.Assessment method and mechanism includes the integrity of experimental implementation, experiment with reasonable progress, the reliability of the experimental project report and papers and rewards.It provides reference for the cultivation of innovative talents with high capacity for scientific research, as well as the establishment of open experiment for biotechnological majors and the improvement of system.
Abstract Organic self‐assembled molecules (OSAMs) based hole‐transporting materials play a pivotal role in achieving highly efficient and stable inverted perovskite solar cells (IPSCs). However, the reported carbazol‐based OSAMs have serious drawbacks, such as poor wettability for perovskite solution spreading due to the nonpolar surface, worse matched energy arrangement with perovskite, and limited molecular species, which greatly limit the device performance. To address above problems, a novel OSAM [4‐(3,6‐glycol monomethyl ether‐9H‐carbazol‐9‐yl) butyl]phosphonic acid (GM‐4PACz) was synthesized as hole‐transporting material by introducing glycol monomethyl ether (GM) side chains at carbazolyl unit. GM groups enhance the surface energy of Indium Tin Oxide (ITO)/SAM substrate to facilitate the nucleation and growth of up perovskite film, suppress cation defects, release the residual stress at SAM/perovskite interface, and evaluate energy level for matching with perovskite. Consequently, the GM‐4PACz based IPSC achieves a champion PCE of 25.52 %, a respectable open‐circuit voltage ( V OC ) of 1.21 V, a high stability, possessing 93.29 % and 91.75 % of their initial efficiency after aging in air for 2000 h or tracking at maximum power point for 1000 h, respectively.
The proper addition of additives to pure CO2 can improve the performance of CO2 as a working fluid. By working fluid, we mean a fluid used for the CO2-based transcritical power cycle characterized by the addition of R134a to CO2. Hence, an experimental investigation of the pressure drop characteristics of a supercritical CO2/R134a mixture in a rectangular microchannel was conducted. For this purpose, an accurate and stable CO2/R134a mixture thermal-hydraulic experimental system was designed and built. The experimental results show that the pressure drop of the CO2/R134a mixture is lower than that of pure CO2 under the same conditions. The proportion of friction resistance to the total pressure drop decreases with an increase in R134a composition. Finally, a frictional resistance correlation that fully considers the effects of CO2/R134a mixture components and thermophysical property variations is proposed, which can guide the design of mixture heat transfer devices.
The rapidly increased efficiency of perovskite solar cells (PSCs) indicates their broad commercial prospects, but the commercialization of perovskite faces complex optimization processes and stability issues. In this work, a simple optimized strategy is developed by the addition of trimethylgermanium chloride (TGC) into FACsPbI
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