AutoMLP: Automated MLP for Sequential Recommendations

Sequential recommender systems aim to predict users' next interested item given their historical interactions. However, a long-standing issue is how to distinguish between users' long/short-term interests, which may be heterogeneous and contribute differently to the next recommendation. Existing approaches usually set pre-defined short-term interest length by exhaustive search or empirical experience, which is either highly inefficient or yields subpar results. The recent advanced transformer-based models can achieve state-of-the-art performances despite the aforementioned issue, but they have a quadratic computational complexity to the length of the input sequence. To this end, this paper proposes a novel sequential recommender system, AutoMLP, aiming for better modeling users' long/short-term interests from their historical interactions. In addition, we design an automated and adaptive search algorithm for preferable short-term interest length via end-to-end optimization. Through extensive experiments, we show that AutoMLP has competitive performance against state-of-the-art methods, while maintaining linear computational complexity.Comment: Accepted by WWW'2

An efficient low-density grating setup for monochromatization of XUV ultrafast light sources

Ultrafast light sources have become an indispensable tool to access and understand transient phenomenon in material science. However, a simple and easy-to-implement method for harmonic selection, with high transmission efficiency and pulse duration conservation, is still a challenge. Here we showcase and compare two approaches for selecting the desired harmonic from a high harmonic generation source while achieving the above goals. The first approach is the combination of extreme ultraviolet spherical mirrors with transmission filters and the second approach uses a normal-incidence spherical grating. Both solutions target time- and angle-resolved photoemission spectroscopy with photon energies in the 10-20 eV range but are relevant for other experimental techniques as well. The two approaches for harmonic selection are characterized in terms of focusing quality, efficiency, and temporal broadening. It is demonstrated that a focusing grating is able to provide much higher transmission as compared to the mirror+filter approach (3.3 times higher for 10.8 eV and 12.9 times higher for 18.1 eV), with only a slight temporal broadening (6.8% increase) and a somewhat larger spot size (∼30% increase). Overall, our study establishes an experimental perspective on the trade-off between a single grating normal incidence monochromator design and the use of filters. As such, it provides a basis for selecting the most appropriate approach in various fields where an easy-to-implement harmonic selection from high harmonic generation is needed

Preparation and Performance Characterization of Silver Nanoparticles of Perilla Seed Shell Extract

In order to further improve the utilization value of Perilla resources, this study used Perilla seed shell extract (PSHE) as raw material, through single factor experiments, the effects of silver nitrate concentration, extract concentration, ultrasonic power, ultrasonic temperature and ultrasonic time on the silver ion reduction rate of Perilla seed shell extract silver nanoparticles (PSHE@AgNPs) were investigated, response surface methodology (RSM) was used to optimize the ultrasonic-assisted preparation of PSHE@AgNPs, the structure and properties of PSHE@AgNPs were characterized by X-ray diffraction, fourier transform infrared spectroscopy, thermogravimetric analysis and transmission electron microscope. The results showed that the optimal PSHE@AgNPs preparation process involved a silver nitrate concentration 15 mmol/L, extract concentration 0.4 g/mL, ultrasonic power 480 W, ultrasonic temperature 80 ℃, and ultrasonic time 7 hours. Under these conditions, the silver ion reduction rate of PSHE@AgNPs reached an impressive 92.37%. X-ray diffraction analysis confirmed the presence of a face-centered cubic structure in PSHE@AgNPs. Fourier-transform infrared spectroscopy showed that there were plant chemical substances on the surface of PSHE@AgNPs，and phenolic compounds were involved in the synthesis of nano-silver. Thermal gravimetric analysis demonstrated the exceptional thermal stability of PSHE@AgNPs，with a major mass loss of 46.74% in the range of 276.7~420.3 ℃. Transmission electron microscopy displayed PSHE@AgNPs as highly dispersed near-spherical particles with an average particle size of 27.97 nm. These research findings would provide valuable theoretical guidance for the ultrasound-assisted green synthesis of PSHE@AgNPs with small particle size, superior dispersion, and remarkable thermal stability in a face-centered cubic structure. Furthermore, these results contribute to advancing the application of PSHE@AgNPs in the fields of biomaterials and medicine

Transcriptomic convergence despite genomic divergence drive field cancerization in synchronous squamous tumors

IntroductionField cancerization is suggested to arise from imbalanced differentiation in individual basal progenitor cells leading to clonal expansion of mutant cells that eventually replace the epithelium, although without evidence.MethodsWe performed deep sequencing analyses to characterize the genomic and transcriptomic landscapes of field change in two patients with synchronous aerodigestive tract tumors.ResultsOur data support the emergence of numerous genetic alterations in cancer-associated genes but refutes the hypothesis that founder mutation(s) underpin this phenomenon. Mutational signature analysis identified defective homologous recombination as a common underlying mutational process unique to synchronous tumors.DiscussionOur analyses suggest a common etiologic factor defined by mutational signatures and/or transcriptomic convergence, which could provide a therapeutic opportunity

Enhanced Electric Conductivity Of Polymer-Derived Sicn Ceramics By Microwave Post-Treatment

The effect of microwave treatment on the electric conductivity and structure of a polymer-derived SiCN ceramic is studied. It is found that the conductivity of the microwave-treated sample is about 40 times higher than that of the conventional heat-treated one at the same temperature and dwell time conventionally. The X-ray diffraction patterns show that both samples are amorphous without obvious crystallization. Raman analysis reveals that the microwave-treated sample exhibited a narrower full width at half maximum and upper-shift of G peak. X-ray photoelectron spectroscopy spectra show that there is a significant sp3-to-sp2 transition of free carbon in the microwave-treated sample. These results suggest that the microwave-treatment can induce a distinct structure evolution of the free carbon, which contributes to the remarkable enhancement of the conductivity of the sample

Traditional Chinese Medicine Extract Properties Incorporated Energy Analysis for Membrane Concentration Processes

This work focuses on the energy analysis of the membrane concentration systems that process traditional Chinese medicine extracts with dynamic properties incorporated, particularly for reverse osmosis (RO) and membrane distillation (MD) processes. The evaluation of process energy consumption was achieved by integrating the empirical properties correlations of Brix and other characteristics properties of the feed (e.g., density and heat capacity). The dynamic SEC analysis for RO process was largely dependent on the feed pressure, reported at 50 kWh/m3 at feed pressure of 0.9 MPa with less than 50% water removal. The occurrence of foaming at above 50% water removal caused discrepancies between the simulated flux results and the experimentally acquired results in RO, whereas the estimated dynamic SEC for MD process did not show a strong correlation with the temperatures selected in this study, ranging from 900 to 1000 kWh/m3. This approach can be adapted into the design and zoptimization for the concentration process of other herbal extracts by membrane technologies, allowing comprehensive understanding into the energy analysis in future study

Intentional Carrier Doping to Realize n-Type Conduction in Zintl Phases Eu5−yLayIn2.2Sb6

Due to the tunable electrical transport properties and lower thermal conductivity, Zintl phase compounds have been considered as a promising candidate for thermoelectric applications. Most Sb-based Zintl compounds exhibit essentially p-type conduction as result of the cation vacancy. Herein, n-type Zintl phases Eu5−yLayIn2.2Sb6 has been successfully synthesized via controlling the vacancy defect combined with intentional electron doping. Excess of In would occupy the vacancy while La doping enables the electron to be the major carrier at the measured temperate range, realizing the n-type conduction for Eu5−yLayIn2.2Sb6 (y ≥ 0.04). Meanwhile, the thermal conductivity of Eu5−yLayIn2.2Sb6 reduces from 0.90 W/mK to 0.72 W/mK at 583 K derived from the La doping-induced disorder. The maximum thermoelectric figure of merit zT = 0.13 was obtained. This work firstly realizes the n-type conduction in Eu5In2Sb6, which sheds light on the strategy to synthesize n-type Zintl thermoelectric materials and promotes the practical applications of Zintl thermoelectric devices