Moving and fusion of Majorana zero modes in the presence of nonadiabatic transitions

We perform simulations for moving and non-Abelian fusion of Majorana zero modes in topological superconducting quantum wires. We display interesting behaviors of nonadiabatic transition associated with the moving through mini-gate-controlled multiple-segments modulations. Owing to breaking of the initial fermion parity induced by nonadiabatic transitions, deviation from the standard fusion rule is analyzed. Moreover, we develop a measurement scheme to infer the amount of fermion parity breaking and nonadiabatic transition probability to excited states, based on the characteristic spectrum of measurement current by a uantum-point-contact detector, in measuring the charge occupation dynamics in a fusion-outcome-probing quantum dot.Comment: 10 pages, 6 figure

Probing the non-Abelian fusion of a pair of Majorana zero modes

In this work, we perform real time simulations for probing the non-Abelian fusion of a pair of Majorana zero modes (MZMs). The nontrivial fusion outcomes can be either a vacuum, or an unpaired fermion, which reflect the underlying non-Abelian statistics. The two possible outcomes can cause different charge variations in the nearby probing quantum dot (QD), while the charge occupation in the dot is detected by a quantum point contact. In particular, we find that gradual fusion and gradual coupling of the MZMs to the QD (in nearly adiabatic switching-on limit) provide a simpler detection scheme than sudden coupling after fusion to infer the coexistence of two fusion outcomes, by measuring the occupation probability of the QD. For the scheme of sudden coupling (after fusion), we propose and analyze continuous weak measurement for the quantum oscillations of the QD occupancy. From the power spectrum of the measurement currents, one can identify the characteristic frequencies and infer thus the coexistence of the fusion outcomes.Comment: 7 pages, 5 figure

Attribution analysis and forecast of salinity intrusion in the Modaomen estuary of the Pearl River Delta

Under the influence of climate change and human activities, the intensification of salinity intrusion in the Modaomen (MDM) estuary poses a significant threat to the water supply security of the Greater Bay Area of Guangdong, Hong Kong, and Macao. Based on the daily exceedance time data from six stations in the MDM waterway for the years 2016-2020, this study conducted Empirical Orthogonal Function (EOF) and decision tree analyses with runoff, maximum tidal range, and wind. It investigated the variation characteristics and key factors influencing salinity intrusion. Additionally, Long Short-Term Memory (LSTM) networks and Convolutional Neural Networks (CNN) were employed to predict the severity of salinity intrusion. The results indicated that: (1) the first mode (PC1) obtained from EOF decomposition explained 89% of the variation in daily chlorine exceedance time, effectively reflecting the temporal changes in salinity intrusion; (2) the largest contributor to salinity intrusion was runoff (40%), followed by maximum tidal range, wind speed, and wind direction, contributing 25%, 20%, and 15%, respectively. Salinity intrusion lagged behind runoff by 1-day, tidal range by 3 days, and wind by 2 days; North Pacific Index (NPI) has the strongest positive correlation with saltwater intrusion among the 9 atmospheric circulation factors. (3) LSTM achieved the highest accuracy with an R2 of 0.89 for a horizon of 1 day. For horizons of 2 days and 3 days, CNN exhibited the highest accuracy with R2 values of 0.73 and 0.68, respectively. This study provides theoretical support for basin scheduling and salinity intrusion prediction and serves as a reference for ensuring water supply security in coastal areas

Establishment of a new genus, Brephallus Wang et al., gen. nov. (Blattodea, Blaberidae, Epilamprinae) based on two species from Pseudophoraspis, with details of polymorphism in species of Pseudophoraspis

Brephallus Wang et al., gen. n. is established as a genus distinct from Pseudophoraspis Kirby, 1903 because of the lack of a well-developed apical outgrowth on sclerite L2D and substantial genetic differences. Two species are transferred to the new genus from Pseudophoraspis, i.e., Brephallus fruhstorferi (Shelford, 1910), comb. n. and Brephallus tramlapensis (Anisyutkin, 1999), comb. n. We provide a detailed generic diagnosis of Brephallus Wang et al., gen. n. Based on COI data, males, females and nymphs of three Pseudophoraspis species (P. clavellata Wang et al., 2013, P. recurvata Wang et al., 2013 and P. kabakovi Anisyutkin, 1999) were successfully matched. The former two are sexually dimorphic with macropterous males and micropterous females. Photos of the species from China are presented

An Investigation of the Duration of Load of Structural Timber and the Clear Wood

In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood

CSG compressive strength prediction based on LSTM and interpretable machine learning

As a new type of environmentally friendly building material, cemented sand and gravel (CSG) has advantages distinct from those of concrete. Compressive strength is an important mechanical property of CSG. However, his method of testing is mainly by doing experiments. For this reason, a deep learning algorithm, long short-term memory (LSTM) model, was proposed to predict the compressive strength of CSG by using four input variables, namely cement content, sand rate, water-binder ratio, and fly ash content, with a total of 114 sample data. Three metrics – coefficient (R 2), root mean square error (RMSE), and mean absolute error (MAE) – were used to evaluate the model’s performance, and the predicted results were compared with the traditional machine learning algorithm, namely the random forest (RF) model. Finally, SHapley Additive exPlanations can be combined to explain the contribution degree of each input feature in the machine learning inquiry model to the prediction results. The results show that the prediction accuracy and reliability of LSTM are higher. The LSTM model has R 2 = 0.9940, RMSE = 0.1248, and MAE = 0.0960, while the RF model has R 2 = 0.9147, RMSE = 0.4809, and MAE = 0.4397. The LSTM model can accurately predict CSG compressive strength. Cement and sand rate contribute more to the predicted results than other input characteristics

Molecular data resolving the systematics of the related Blattellidae genera Symploce, Episymploce, and Blattella (Blattodea: Blaberoidea)

Members of the morphologically and ecologically diverse Blattellidae provide a dilemma: their systematic assignment, whether morphologically similar or different, is uncertain. We pay special attention to several taxa: the morphologically similar Episymploce Bey-Bienko, 1950 and Symploce Hebard, 1916, which were strongly disputed because of their extremely similar generic diagnosis in the past century, and one brachypterous species of Blattella Caudell, 1903, which can be easily distinguished from other macropterous members, but is at risk of being misassigned to other genera on the basis of morphological characters. We address the phylogeny of Blattellidae using DNA sequences (mitochondrial 12S rRNA, 16S rRNA, COII, nuclear 28S rRNA, histone H3) from a broad sample of taxa. A new genus (Centrocolumna gen. nov.) and four new species (Centrocolumna ericea sp. nov., Symploce nigra sp. nov., Symploce tubercularis sp. nov., Blattella foliolata sp. nov.) are established on the basis of morphological characters combined with the molecular data. The phylogenetic results indicate the relationships ((Episymploce + Blattella) + Centrocolumna gen. nov.) + Symploce. Furthermore, we delimited the taxonomic status of 12 new combinations, which involve Centrocolumna gen. nov., Episymploce, Symploce, and Blattella

Research Progress on Adsorption of Arsenic from Water by Modified Biochar and Its Mechanism: A Review

Arsenic (As) is a non-metallic element, which is widely distributed in nature. Due to its toxicity, arsenic is seriously harmful to human health and the environment. Therefore, it is particularly important to effectively remove arsenic from water. Biochar is a carbon-rich adsorption material with advantages such as large specific surface area, high porosity, and abundant functional groups, but the original biochar has limitations in application, such as limited adsorption capacity and adsorption range. The modified biochar materials have largely enhanced the adsorption capacity of As in water due to their improved physicochemical properties. In this review, the changes in the physicochemical properties of biochar before and after modification were compared by SEM, XRD, XPS, FT-IR, TG, and other characterization techniques. Through the analysis, it was found that the adsorbent dosage and pH are the major factors that influence the As adsorption capacity of the modified biochar. The adsorption process of As by biochar is endothermic, and increasing the reaction temperature is conducive to the progress of adsorption. Results showed that the main mechanisms include complexation, electrostatic interaction, and precipitation for the As removal by the modified biochar. Research in the field of biochar is progressing rapidly, with numerous achievements and new types of biochar-based materials prepared with super-strong adsorption capacity for As. There is still much space for in-depth research in this field. Therefore, the future research interests and applications are put forward in this review