Dual ambient plasma source ionization mass spectrometry for the rapid detection of trace sterols in urban water

A direct analytical method based on dual ambient plasma ion source tandem mass spectrometry was used for the simultaneous determination of four sterols in the environment. This technology has very high sensitivity and the method detects the four sterols in methanol–water (1:3) solutions with limits of detection (LOD) and limits of quantification (LOQ) ranging from 1.2 ng/L to 6.9 ng/L and 7.6 ng/L to 10.0 ng/L, respectively. The method was also used to test water quality at three locations within the city and successfully detected all four sterols at very low concentrations. The dual plasma source tandem mass spectrometry technique is extremely simple, rapid, sensitive and highly efficient compared to other traditional methods, providing a useful screening tool for sterols in water.     

Analytical Solution of the Bending Problem for Rectangular Orthotropic Plates with a Variable in-Plane Stiffness

Mechanics of Composite Materials - The analytical solution of the bending problem for a clamped rectangular plate with a variable in-plane stiffness is found by using the method of superposition....     

Structured FISTA for image restoration

In this paper, we propose an efficient numerical scheme for solving some large‐scale ill‐posed linear inverse problems arising from image restoration. In order to accelerate the computation, two different hidden structures are exploited. First, the coefficient matrix is approximated as the sum of a small number of Kronecker products. This procedure not only introduces one more level of parallelism into the computation but also enables the usage of computationally intensive matrix–matrix multiplications in the subsequent optimization procedure. We then derive the corresponding Tikhonov regularized minimization model and extend the fast iterative shrinkage‐thresholding algorithm (FISTA) to solve the resulting optimization problem. Because the matrices appearing in the Kronecker product approximation are all structured matrices (Toeplitz, Hankel, etc.), we can further exploit their fast matrix–vector multiplication algorithms at each iteration. The proposed algorithm is thus called structured FISTA (sFISTA). In particular, we show that the approximation error introduced by sFISTA is well under control and sFISTA can reach the same image restoration accuracy level as FISTA. Finally, both the theoretical complexity analysis and some numerical results are provided to demonstrate the efficiency of sFISTA.     

Catalyst-Free Intermolecular Sulfonyl/Fluoromethyl Heteroarylation of Vinyl Ethers via Visible-Light-Induced Charge Transfer

We report a visible-light-induced three-component sulfonyl-heteroarylation of vinyl ethers with sulfinates and five-membered heteroaryl chlorides. This protocol proceeds via electron-donor-acceptor (EDA) complexes between sulfinates and heteroaryl chlorides, giving β-sulfonyl alkyl five-membered heteroarenes with high efficiency and excellent regioselectivity under mild and catalyst-free conditions. Utilization of CF₃SO₂Na or CF₂HSO₂Na as coupling partners further achieves three-component fluoromethyl-arylation of vinyl ethers, furnishing a series of valuable CF₃/CF₂H-incorporated alkyl heterocycles under mild conditions.     

Relaxor-like dielectric behavior and its effect on energy storage performance in P(TFE-HFP-VDF) terpolymers

Capacitors are critical components in many advanced electronic and electrical systems,such as pulse power systems,due to their fast charging-discharging speed and high power density[1-4].The ever-increasing demand for compact energy storage devices requires the dielectrics,which are the energy storage materials in capacitors,to have a higher energy density and low dielectric loss[2,3].Furthermore,a stable high-temperature performance is another important parameter to be considered for some applications in which high-temperature conditions are present,such as hybrid vehicles[4-7].     

Optimization and effect of wall conduction on natural convection in a cavity with constant temperature heat source: Using lattice Boltzmann method and neural network algorithm

Journal of Thermal Analysis and Calorimetry - In this paper, the natural convection (NC) of the Al2O3–H2O nanofluids (NFs) in a cavity with a heat source in its center is numerically...     

Synthesis and electrochemical performance of poly(vinylidene fluoride)/SiO2 hybrid membrane for lithium-ion batteries

Journal of Solid State Electrochemistry - In this work, a series of rationally designed hybrid membranes composed of poly(vinylidene fluoride) (PVDF) as polymer matrix and silica nanoparticles...     

Chiral P,N‐ligands for the highly enantioselective addition of diethylzinc to aromatic aldehydes

A new sterically hindered chiral P,N‐ligand was synthesized and successfully applied to copper catalyzed asymmetric addition of diethylzinc to aromatic aldehydes. Various aromatic aldehydes can react smoothly to give the corresponding addition products with good to excellent enantioselectivities, which provides a readily accessible method for the preparation of chiral secondary alcohols.