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Empirical modeling of dopability in diamond-like semiconductors
摘要： Carrier concentration optimization has been an enduring challenge when developing newly discovered semiconductors for applications (e.g., thermoelectrics, transparent conductors, photovoltaics). This barrier has been particularly pernicious in the realm of high-throughput property prediction, where the carrier concentration is often assumed to be a free parameter and the limits are not predicted due to the high computational cost. In this work, we explore the application of machine learning for high-throughput carrier concentration range prediction. Bounding the model within diamond-like semiconductors, the learning set was developed from experimental carrier concentration data on 127 compounds ranging from unary to quaternary. The data were analyzed using various statistical and machine learning methods. Accurate predictions of carrier concentration ranges in diamond-like semiconductors are made within approximately one order of magnitude on average across both p- and n-type dopability. The model fit to empirical data is analyzed to understand what drives trends in carrier concentration and compared with previous computational efforts. Finally, dopability predictions from this model are combined with high-throughput quality factor predictions to identify promising thermoelectric materials.
关键词： dopability,machine learning,diamond-like semiconductors,thermoelectrics,carrier concentration
更新于2025-09-04 15:30:14
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Remote Estimation of Chlorophyll-a in Inland Waters by a NIR-Red-Based Algorithm: Validation in Asian Lakes
摘要： Satellite remote sensing is a highly useful tool for monitoring chlorophyll-a concentration (Chl-a) in water bodies. Remote sensing algorithms based on near-infrared-red (NIR-red) wavelengths have demonstrated great potential for retrieving Chl-a in inland waters. This study tested the performance of a recently developed NIR-red based algorithm, SAMO-LUT (Semi-Analytical Model Optimizing and Look-Up Tables), using an extensive dataset collected from five Asian lakes. Results demonstrated that Chl-a retrieved by the SAMO-LUT algorithm was strongly correlated with measured Chl-a (R2 = 0.94), and the root-mean-square error (RMSE) and normalized root-mean-square error (NRMS) were 8.9 mg?m?3 and 72.6%, respectively. However, the SAMO-LUT algorithm yielded large errors for sites where Chl-a was less than 10 mg?m?3 (RMSE = 1.8 mg?m?3 and NRMS = 217.9%). This was because differences in water-leaving radiances at the NIR-red wavelengths (i.e., 665 nm, 705 nm and 754 nm) used in the SAMO-LUT were too small due to low concentrations of water constituents. Using a blue-green algorithm (OC4E) instead of the SAMO-LUT for the waters with low constituent concentrations would have reduced the RMSE and NRMS to 1.0 mg?m?3 and 16.0%, respectively. This indicates (1) the NIR-red algorithm does not work well when water constituent concentrations are relatively low; (2) different algorithms should be used in light of water constituent concentration; and thus (3) it is necessary to develop a classification method for selecting the appropriate algorithm.
关键词： Asian lakes,blue-green algorithms,chlorophyll-a concentration,accuracy assessment,NIR-red algorithms
更新于2025-09-04 15:30:14
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Langmuir–Hinshelwood and Light-Intensity Dependence Analyses of Photocatalytic Oxidation Rates by Two-Dimensional-Ladder Kinetic Simulation
摘要： Though photocatalytic reactions gather enormous attention, dependences of light intensity and reactant concentration have not been concurrently expressed clearly. In the previously reported studies, a quadratic formula equation obtained from the conventional analysis using the concentration of electron?hole pairs has been modified. In this report we numerically simulated the reaction with a two-dimensional(2D)-ladder kinetics without using electron?hole concentrations. In fundamental processes, (i) photoabsorption, (ii) reduction, (iii) oxidation, and (iv) recombination, were treated as the transitions between the states of each powder characterized by the numbers of possessing negative and positive charges. Through the numerical 2D-ladder simulation with various rate constants, the light-intensity (I) dependence of the oxidation rate was found to be fully expressed by involving the square of the intrinsic quantum yield into the square root part of the well-known quadratic formula equation. The square root dependence of the reaction rate, r ∝ I1/2, could be expected only when the rate of the reduction is extremely smaller than the recombination rate at the normal light intensity. Then, the resultant equations obtained with this 2D-ladder simulation were transformed to the equation for Langmuir?Hinshelwood kinetics with two parameters, rL and KL, which correspond to the intrinsic oxidation rate and the adsorption equilibrium constant of the reactant, respectively. Light-intensity dependence of KL was expressed by adding two terms proportional to I2 to both the adsorption and desorption rate constants. The reported experimental data sets of the decomposition rates for phenol and 4-chlorophenol were fitted with the proposed equation, and then from the obtained parameter values the formation rate of (cid:129)O2? could be estimated and found to be compatible to that which has been experimentally measured. Thus, the present analytical treatment is actually the simple and useful method to understand the dependencies of reactant concentration and light-intensity on the photocatalytic oxidation rates.
关键词： reactant concentration,photocatalytic reactions,light intensity,Langmuir?Hinshelwood kinetics,two-dimensional-ladder kinetics
更新于2025-09-04 15:30:14
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Salt-Dependent Rheology and Surface Tension of Protein Condensates Using Optical Traps
摘要： An increasing number of proteins with intrinsically disordered domains have been shown to phase separate in buffer to form liquidlike phases. These protein condensates serve as simple models for the investigation of the more complex membraneless organelles in cells. To understand the function of such proteins in cells, the material properties of the condensates they form are important. However, these material properties are not well understood. Here, we develop a novel method based on optical traps to study the frequency-dependent rheology and the surface tension of P-granule protein PGL-3 condensates as a function of salt concentration. We find that PGL-3 droplets are predominantly viscous but also exhibit elastic properties. As the salt concentration is reduced, their elastic modulus, viscosity, and surface tension increase. Our findings show that salt concentration has a strong influence on the rheology and dynamics of protein condensates suggesting an important role of electrostatic interactions for their material properties.
关键词： surface tension,rheology,protein condensates,salt concentration,optical traps
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - Krakow, Poland (2018.10.16-2018.10.18)] 2018 IEEE International Conference on Imaging Systems and Techniques (IST) - An Integrated ECT and Electrostatic Sensor for Particulate Flow Measurement
摘要： An integrated electrical capacitance tomography (ECT) and electrostatic sensor has been developed for measurement of volume flow rate in particulate processes. Unlike the traditional methods for mass/volume flow rate measurement, this integrated sensor can measure particle concentration and velocity at the same cross section instead of different cross sections. Experiment was carried out to measure particle concentration, velocity and volume flow rate using the developed sensor. Experimental results show that the integrated sensor can measure the parameters in particulate processes. The relative error of the measured volume flow rate is less than 10%.
关键词： volume flow rate,cross correlation,ECT,concentration,particle flow,electrostatic
更新于2025-09-04 15:30:14