Studies on Rheological Behaviors of Bismaleimide Resin System for Resin Transfer Molding

AbstractThe rheological behavior of bismaleimide resin for resin transfer molding(RTM) was studied with DSC analysis and viscosity experiments. A rheological model based on the dual-Arrhenius equation was established and used to simulate the rheological behavior of the resin. The model predictions determined from the dual-Arrhenius equation were in good agreement with experimental data. The processing window of the resin system can be well determined based on the developed model. The rheological model is important for processing simulation and quality control of RTM processing for high performance composites

The Relation between Initial Returns and Audits by the Big Four Accounting Firms

This paper mainly explores the relation between initial returns and audits by the big four accounting firms (the Big Four) in China. The sample period is from January 2007 to December 2012 (the new accounting standards in China is implemented after January 2007 for integrating with the international standards), and selected 1,069 IPO firms listed in the Shanghai Stock Exchange and Shenzhen Stock Exchange in this paper.Many previous studies have proposed the Informational Hypothesis, which states that the initial returns of IPOs being audited by the Big Four are lower than those IPOs being audited by other accounting firms. Oppositely, this paper proposes the Snap-up Hypothesis due to consider the IPOs in mainland China are characterized by “three lows,”: the low reliability of audits being performed by non-Big Four, low proportion of IPOs audits being performed by the Big Four, and low balling ratio. These “three lows” features indicate that the Snap-up Hypothesis applies in the IPOs market of mainland China. In other words, the initial returns of the IPOs being audited by the Big Four are higher than those IPOs being audited by other accounting firms due to the Big Four have the superior reputations.This paper further collects the trading volumes and the turnover ratio on the first day, and selects the Big Four audited IPOs by snap-up tide. As above mentioned, because the snap-up tide and raised stock prices on the first-day listing, investors may purchase the shares when offering and sell them on the first-day listing to obtain considerable profits

Nanomedicine‐boosting icaritin-based immunotherapy of advanced hepatocellular carcinoma

Traditional treatments for advanced hepatocellular carcinoma (HCC), such as surgical resection, transplantation, radiofrequency ablation, and chemotherapy are unsatisfactory, and therefore the exploration of powerful therapeutic strategies is urgently needed. Immunotherapy has emerged as a promising strategy for advanced HCC treatment due to its minimal side effects and long-lasting therapeutic memory effects. Recent studies have demonstrated that icaritin could serve as an immunomodulator for effective immunotherapy of advanced HCC. Encouragingly, in 2022, icaritin soft capsules were approved by the National Medical Products Administration (NMPA) of China for the immunotherapy of advanced HCC. However, the therapeutic efficacy of icaritin in clinical practice is impaired by its poor bioavailability and unfavorable in vivo delivery efficiency. Recently, functionalized drug delivery systems including stimuli-responsive nanocarriers, cell membrane-coated nanocarriers, and living cell-nanocarrier systems have been designed to overcome the shortcomings of drugs, including the low bioavailability and limited delivery efficiency as well as side effects. Taken together, the development of icaritin-based nanomedicines is expected to further improve the immunotherapy of advanced HCC. Herein, we compared the different preparation methods for icaritin, interpreted the HCC immune microenvironment and the mechanisms underlying icaritin for treatment of advanced HCC, and discussed both the design of icaritin-based nanomedicines with high icaritin loading and the latest progress in icaritin-based nanomedicines for advanced HCC immunotherapy. Finally, the prospects to promote further clinical translation of icaritin-based nanomedicines for the immunotherapy of advanced HCC were proposed

Dynamic MRI Reconstruction Combining Tensor Nuclear Norm and Casorati Matrix Nuclear Norm

Low-rank tensor models have been applied in accelerating dynamic magnetic resonance imaging (dMRI). Recently, a new tensor nuclear norm based on t-SVD has been proposed and applied to tensor completion. Inspired by the different properties of the tensor nuclear norm (TNN) and the Casorati matrix nuclear norm (MNN), we introduce a novel dMRI reconstruction method combining TNN and Casorati MNN, which we term as TMNN. Moreover, we convert the the TMNN dMRI reconstruction problem into a simple tensor completion problem, which can be efficiently solved by the alternating direction method of multipliers (ADMM)

rPPG-MAE: Self-supervised Pre-training with Masked Autoencoders for Remote Physiological Measurement

Remote photoplethysmography (rPPG) is an important technique for perceiving human vital signs, which has received extensive attention. For a long time, researchers have focused on supervised methods that rely on large amounts of labeled data. These methods are limited by the requirement for large amounts of data and the difficulty of acquiring ground truth physiological signals. To address these issues, several self-supervised methods based on contrastive learning have been proposed. However, they focus on the contrastive learning between samples, which neglect the inherent self-similar prior in physiological signals and seem to have a limited ability to cope with noisy. In this paper, a linear self-supervised reconstruction task was designed for extracting the inherent self-similar prior in physiological signals. Besides, a specific noise-insensitive strategy was explored for reducing the interference of motion and illumination. The proposed framework in this paper, namely rPPG-MAE, demonstrates excellent performance even on the challenging VIPL-HR dataset. We also evaluate the proposed method on two public datasets, namely PURE and UBFC-rPPG. The results show that our method not only outperforms existing self-supervised methods but also exceeds the state-of-the-art (SOTA) supervised methods. One important observation is that the quality of the dataset seems more important than the size in self-supervised pre-training of rPPG. The source code is released at https://github.com/linuxsino/rPPG-MAE

Bis(1,10-phenanthroline-κ2 N,N′)[2-(4-sulfonato­anilino)acetato-κO]copper(II) dihydrate

In the title compound, [Cu(C8H7NO5S)(C12H8N2)2]·2H2O, the CuII ion is coordinated by four N atoms from two 1,10-phenanthroline (phen) ligands and one O atom from a 2-(4-sulfonato­anilino)acetate (spia) ligand in a distorted square-pyramidal geometry. Inter­molecular N—H⋯O and O—H⋯O hydrogen bonds, as well as π–π inter­actions between phen ligands and between phen and spia ligands [centroid–centroid distances = 3.663 (3), 3.768 (3) and 3.565 (3) Å], result in a three-dimensional supra­molecular structure

A piezoelectric motor driven by a single-phase signal

This paper aims to present a proof-of-concept for a novel piezoelectric motor using a single-phase driving signal. The stator is constructed by bonding a Terfenol-D plate and a piezoelectric ceramic (PZT) plate onto the outer surface of a metal base. The PZT plate based on d31 effect is used to simultaneously excite two in-plane bending modes of the stator. Similarly, the Terfenol-D plate can also be used to excite the two bending modes. By superposition of the two bending modes, elliptical motions of the stator surface points are generated. The working modes and vibration characteristics of the motor are analyzed by finite element analysis software. The resonance frequencies of the two bending modes are tuned to be close by additional mass. The dimensions of the stator are optimized to maximize the output displacement. To confirm the feasibility of the proposed design, a prototype motor is fabricated and tested. The size of the prototype motor is about 11.2×10.7×28.0 mm3. The tested resonance frequencies of the two bending modes are 16.0820 kHz and 16.3476 kHz respectively. The maximum no-load speed is 85 rpm. The applied driving voltage is 100 Vo-p (peak voltage) at a frequency of 16.34 kHz

2,3,5,6-Tetra­fluoro-1,4-bis­(2-pyridylmethyl­eneamino­meth­yl)benzene

The title compound, C20H14F4N4, is a flexible bis-pyridine-type ligand with an extended fluorinated spacer group between the two pyridyl functions. The centroid of the central aromatic ring is situated on a crystallographic center of inversion. The dihedral angle between the pyridine ring and the central benzene ring is 63.85 (9)°. The crystal structure exhibits inter­molecular C—H⋯F hydrogen-bonding inter­actions