Enhanced Electrical Performance and Stability of Solution-Processed Thin-Film Transistors with In2O3/In2O3:Gd Heterojunction Channel Layer.

The use of the semiconductor heterojunction channel layer has been explored as a method for improving the performance of metal oxide thin-film transistors (TFTs). The excellent electrical performance and stability of heterojunction TFTs is easy for vacuum-based techniques, but difficult for the solution process. Here, we fabricated In2O3/In2O3:Gd (In2O3/InGdO) heterojunction TFTs using a solution process and compared the electrical properties with single-layer In2O3 TFTs and In2O3:Gd (InGdO) TFTs. The In2O3/InGdO TFT consisted of a highly conductive In2O3 film as the primary transmission layer and a subconductive InGdO film as the buffer layer, and exhibited excellent electrical performance. Furthermore, by altering the Gd dopant concentration, we obtained an optimal In2O3/InGdO TFT with a higher saturation mobility (µ) of 4.34 cm2V-1s-1, a near-zero threshold voltage (Vth), a small off-state current (Ioff) of 1.24×10-9 A, a large on/off current ratio (Ion/Ioff) of 3.18×105, a small subthreshold swing (SS), and an appropriate positive bias stability (PBS). Finally, an aging test was performed after three months, indicating that In2O3/InGdO TFTs enable long-term air stability while retaining a high-mobility optimal switching property. This study suggests that the role of a high-performance In2O3/InGdO heterojunction channel layer fabricated by the solution process in the TFT is underlined, which further explores a broad pathway for the development of high-performance, low-cost, and large-area oxide electronics.

Experimental and numerical studies of the impact breakage of granite with high ejection velocities.

The impact-induced fragmentation of rock is widely and frequently encountered when natural hazards occur in mountainous areas. This type of fragmentation is an important and complex natural process that should be described. In this study, laboratory impact tests under different impact velocities were first conducted using a novel gas-driven rock impact apparatus. The three-dimensional digital image correlation (3D DIC) technique was used to monitor the dynamic fragmentation process upon impact. Then, coupled 3D finite-discrete element method (FDEM) numerical simulations were performed to numerically investigate the energy and damage evolutions and fragmentation characteristics of the sample under different impact velocities. The laboratory test results show that as the impact velocity increases, the failure pattern of the rock sample gradually changes from shear failure to splitting failure, and the fragmentation intensity increases obviously. The strain localization area gradually increases as the impact velocity increases and as the location gradually deviates away from the impacting face. In the numerical simulation, the proposed model is validated by quasi-static uniaxial compression tests and impact tests. The numerical simulations clearly show the progressive fracture process of the samples, which agrees well with the experimental observations. The evolutions of energy and damage variables were also derived based on the simulation results, which are markedly affected by the impact velocity. The fragment size distributions based on mass and number can be well fitted using a generalized extreme value law. Finally, the distribution of the fragment flying velocity and angle are analyzed.

Numerical Study on the Dynamic Fracture Energy of Concrete Based on a Rate-Dependent Cohesive Model.

As an important parameter for concrete, fracture energy is difficult to accurately measure in high loading rate tests due to the limitations of experimental devices and methods. Therefore, the utilization of numerical methods to study the dynamic fracture energy of concrete is a simple and promising choice. This paper presents a numerical investigation on the influence of loading rate on concrete fracture energy and cracking behaviors. A novel rate-dependent cohesive model, which was programmed as a user subroutine in the commercial explicit finite element solver LS-DYNA, is first proposed. After conducting mesh sensitivity analysis, the proposed model is calibrated against representative experimental data. Then, the underlying mechanisms of the increase in fracture energy due to a high strain rate are determined. The results illustrate that the higher fracture energy during dynamic tension loading is caused by the wider region of the damage zone and the increase in real fracture energy. As the loading rate increases, the wider region of the damage zone plays a leading role in increasing fracture energy. In addition, as the strain rate increases, the number of microcracks whose fracture mode is mixed mode increases, which has an obvious effect on the change in real fracture energy.

Elucidating the Calcium-Binding Site, Absorption Activities, and Thermal Stability of Egg White Peptide-Calcium Chelate.

With the current study, we aimed to determine the characteristics and calcium absorption capacity of egg white peptide-calcium complex (EWP-Ca) and determine the effect of sterilization on EWP-Ca to study the possibility of EWP-Ca as a new potential calcium supplement. The results of SEM and EDS showed a high calcium chelating ability between EWP and calcium, and the structure of EWP-Ca was clustered spherical particles due its combination with calcium. The FTIR and Raman spectrum results showed that EWP could chelate with calcium by carboxyl, phosphate, and amino groups, and peptide bonds may also participate in peptide-calcium binding. Moreover, the calcium absorption of EWP-Ca measured by the intestinal everted sac model in rats was 32.38 ± 6.83 µg/mL, significantly higher than the sample with CaCl2, and the mixture of EWP and Ca (p < 0.05) revealed appropriate calcium absorption capacity. The fluorescence spectra and CD spectra showed that sterilization caused a decrease in the content of α-helix and ß-sheet and a significant increase in ß-turn (p < 0.05). Sterilization changed the EWP-Ca structure and decreased its stability; the calcium-binding capacity of EWP-Ca after sterilization was decreased to 41.19% (p < 0.05). Overall, these findings showed that EWP could bind with calcium, form a peptide-calcium chelate, and serve as novel carriers for calcium supplements.

Nanoliposomes for encapsulation and calcium delivery of egg white peptide-calcium complex.

Nanoliposomes and crude liposomes loaded with egg white peptide-calcium complex (EWP-Ca) were fabricated by thin-film dispersion with or without dynamic high-pressure microfluidization. Their physiochemical properties, in vitro stability, and calcium release profiles were investigated in this study. Results showed that the EWP-Ca-loaded nanoliposomes exhibited spherical structures with a lower particle size and polydispersity index as well as a higher thermal stability as compared to the corresponding crude liposomes. Further investigations revealed that EWP-Ca was embedded into the liposomes mainly through hydrogen bonding and present in an amorphous form within the liposomes. Additionally, the EWP-Ca-loaded nanoliposomes effectively slowed the release of calcium in gastric digestion, allowing more soluble calcium to enter the intestinal tract; in the subsequent intestinal digestion, the EWP-Ca-loaded nanoliposomes were more electrically and physically stable than the crude liposomes. Therefore, the EWP-Ca-loaded nanoliposomes could be used as a favorable dietary calcium delivery system to promote calcium bioavailability. PRACTICAL APPLICATION: Nanoliposomes were fabricated in this study to encapsulate the egg white peptide-calcium complex (EWP-Ca) for calcium delivery. The EWP-Ca-loaded nanoliposomes effectively slowed the release of calcium in gastric digestion, allowing more soluble calcium to enter the intestinal tract, and were more electrically and physically stable in the subsequent intestinal digestion. Therefore, the EWP-Ca-loaded nanoliposomes may be incorporated in calcium-fortified food to enhance calcium delivery for maintaining bone health.

Herring egg phosphopeptides as calcium carriers for improving calcium absorption and bone microarchitecture in vivo.

Phosphorylation may enhance the functional properties of proteins/peptides. Herring egg phosphopeptides (HEPPs) have been found to be more effective than the non-phosphorylated variant in calcium-binding activities due to the introduced phosphate groups. However, whether HEPPs as calcium carriers will be superior to herring egg peptides (HEPs) in improving calcium bioavailability in vivo, for the equivalent calcium intake prerequisite, remains to be clarified. This study aimed to evaluate the effect of HEPPs-calcium complex and HEPs-calcium complex on calcium absorption and bioavailability in calcium-deficient mice. Results showed that the remarkably lower calcium absorption and bone calcium deposition induced by long-term calcium deficiency were accompanied by deterioration of the trabecular bone microarchitecture (P < 0.05). The HEPPs-Ca supplements significantly improved the apparent calcium absorption, increased the serum calcium level, decreased the alkaline phosphatase activity, strengthened the bone biomechanical property, and increased bone volume/tissue volume (BV/TV) and trabecular number (Tb·N) in calcium-deficient mice (P < 0.05), as determined by micro-computed tomography (micro-CT) assay. The effect of HEPPs-Ca on calcium absorption and bioavailability was comparable to that of CPPs-Ca, but better than that of HEPs-Ca and CaCO3. This study brings new insights into the potential of HEPPs as an alternative to CPPs for use in calcium supplements.

Nickel-Catalyzed Highly Selective Hydroalkenylation of Alkenyl Boronic Esters to Access Allyl Boron.

Allyl boron derivatives are valuable building blocks in the synthesis of natural products and bioactive molecules. Herein, a practical strategy of nickel-catalyzed highly selective hydroalkenylation of alkenyl boronic esters was developed. Under the mild reaction conditions, a variety of allyl boronic esters were accessed with excellent chemo- and regioselectivity. The mechanism of this transformation was illustrated by control experiments and kinetic studies.

Cu-Catalyzed highly regioselective 1,2-hydrocarboxylation of 1,3-dienes with CO2.

A practical copper-catalyzed highly regioselective 1,2-hydrocarboxylation of terminal 1,3-diene with carbon dioxide has been developed. Under mild reaction conditions, this chemistry afforded 2-benzyl-ß,γ-unsaturated acid derivatives as products, which are a kind of important unit for bio-active molecules and versatile precursors for organic synthesis, with good functional group tolerance. The key intermediate in this transformation is illustrated by control experiments.

Apparent mass of the seated human body during vertical vibration in the frequency range 2-100 Hz.

We studied the apparent mass during vertical whole-body vibration in the frequency range 2-100 Hz at four magnitudes (sinusoidal sweep signals, 1.0, 1.5, 2.0 and 2.5 ms-2 r.m.s.) in 12 males and 12 females with upright and relaxed sitting postures. The first two peaks of apparent mass decreased with increasing vibration magnitude with both postures. The non-linearity characteristics became obscured at the two largest magnitudes and were less transparent with relaxed sitting posture. The peak frequencies and the normalised apparent masses were similar between males and females with both postures. The standardised three degrees-of-freedom parametric model with modified parameters was proposed to predict well the apparent mass of seated human body during vertical vibration in the frequency range 2-100 Hz and in the magnitude range 1.0-2.5 ms-2 r.m.s. Practitioner summary: This study shows the frequency-dependence and magnitude-dependence of biodynamic responses in the frequency range of 2-100 Hz. The magnitude of apparent mass at frequencies above 20 Hz may not be negligible. The proposed 3 DOF model with modified parameters would help with understanding and developing the human-seat system. Abbreviations: WBV: whole-body vibration; DOF: degrees-of-freedom; CMIFs: complex mode indicator functions.

Pd-Catalyzed Stereoselective 1,2-Aryboration of Alkenylarenes.

The palladium-catalyzed highly regio- and diastereoselective arylboration of alkenylarenes has been developed. This chemistry afforded the benzylic boronic esters with a broad substrate scope, which are valuable synthetic intermediates for organic synthesis. The chiral anion phase-transfer strategy was designed for this transformation to realize the regio-, diastereo-, and enantioselective control of this reaction simultaneously.

Cu-Catalyzed highly selective reductive functionalization of 1,3-diene using H2O as a stoichiometric hydrogen atom donor.

A copper-catalyzed highly regio- and diastereo-selective reductive reaction of terminal 1,3-diene with water and aldehyde has been developed. This chemistry afforded a product containing a terminal alkenyl group, which is a versatile kind of precursor for organic synthesis, with the scope for various substrates. The present reaction system could realize the catalytic transfer of hydrogen to diene using water as a stoichiometric H atom donor. In this transformation, B2Pin2, a mild and practical kind of reductant was used as the mediator. The reaction pathway of this practical strategy was illustrated by a control experiment.

Subjective discomfort caused by vertical whole-body vibration in the frequency range 2-100 Hz.

Current standards assume the same frequency weightings for discomfort at all magnitudes of vibration, whereas biodynamic and psychological studies show that the frequency-dependence of objective and subjective responses of the human body depends on the magnitude of vibration. This study investigated the discomfort of seated human body caused by vertical whole-body vibration over the frequency range 2-100 Hz at relatively high magnitudes from 1.0 to 2.5 ms-2 r.m.s. Twenty-eight subjects (15 males and 13 females) judged the discomfort using the absolute magnitude estimation method. The rate of growth of discomfort with increasing vibration magnitude was highly dependent on the frequency, so the shapes of the equivalent comfort contours depended on the magnitude of vibration and no single frequency weighting would be appropriate for all magnitudes. The equivalent comfort contours indicated that the standards and previous relevant studies underestimated the vibration discomfort at frequencies greater than about 30 Hz. Practitioner Summary: The discomfort caused by vertical vibration at relatively high frequencies can be severe, particularly at relatively great magnitudes in transport. This study provides the frequency-dependence of vibration discomfort at 2-100 Hz, and shows how the frequency weightings in the current standards can be improved at relatively high frequencies.

Preparation and Characterization of Solution-Processed Nanocrystalline p-Type CuAlO2 Thin-Film Transistors.

The development of p-type metal oxide thin-film transistors (TFTs) is far behind the n-type counterparts. Here, p-type CuAlO2 thin films were deposited by spin coating and annealed in nitrogen atmosphere at different temperature. The effect of post-annealing temperature on the microstructure, chemical compositions, morphology, and optical properties of the thin films was investigated systematically. The phase conversion from a mixture of CuAl2O4 and CuO to nanocrystalline CuAlO2 was achieved when annealing temperature was higher than 900 °C, as well as the transmittance, optical energy band gap, grain size, and surface roughness of the films increase with the increase of annealing temperature. Next, bottom-gate p-type TFTs with CuAlO2 channel layer were fabricated on SiO2/Si substrate. It was found that the TFT performance was strongly dependent on the physical properties and the chemical composition of channel layer. The optimized nanocrystalline CuAlO2 TFT exhibits a threshold voltage of - 1.3 V, a mobility of ~ 0.1 cm2 V-1 s-1, and a current on/off ratio of ~ 103. This report on solution-processed p-type CuAlO2 TFTs represents a significant progress towards low-cost complementary metal oxide semiconductor logic circuits.

Mechanically Robust and Thermally Stable Colorful Superamphiphobic Coatings.

Colorful super anti-wetting coatings are receiving growing attention, but are challenging to invent. Here, we report a general method for preparing mechanically robust and thermally stable colorful superamphiphobic coatings. A composite of palygorskite (PAL) nanorods and iron oxide red (IOR) was prepared by solid-state grinding or hydrothermal reaction, which was then modified by hydrolytic condensation of silanes to form a suspension. Superamphiphobic coatings were prepared by spray-coating the suspension onto substrates. The superamphiphobicity depends upon the surface microstructure and chemical composition, which are controllable by the PAL/IOR concentration and the solid-state grinding time. The colorful coatings show excellent superamphiphobicity with high contact angles and low sliding angles for water and various organic liquids of low surface tension, e.g., toluene and n-decane. The coatings also feature high mechanical, chemical and thermal stability, which is superior to all the reported colorful super anti-wetting coatings. Moreover, superamphiphobic coatings of different colors can be prepared via the same procedure using the other metal oxides instead of IOR. We believe the colorful superamphiphobic coatings may find applications in many fields like anti-climbing of oils and restoration of cultural relics, as the coatings are applicable onto various substrates.

Total Synthesis of Lycopodium Alkaloids Palhinine A and Palhinine D.

The first total syntheses of Lycopodium alkaloids palhinine A, palhinine D, and their C3-epimers have been divergently achieved through the use of a connective transform to access a pivotal hexacyclic isoxazolidine precursor. A microwave-assisted regio- and stereoselective intramolecular nitrone-alkene cycloaddition was tactically orchestrated as a key step to install the crucial 10-oxa-1-azabicyclo[5.2.1]decane moiety embedded in the conformationally rigid isotwistane framework, demonstrating the feasibility of constructing the highly strained medium-sized ring by introduction of an oxygen bridging linker to relieve the transannular strain in the polycyclic scaffold. Subsequent N-O bond cleavage provided the synthetically challenging nine-membered azonane ring system bearing the requisite C3 hydroxyl group. Late-stage transformations featuring a chemo- and stereoselective reduction of the pentacyclic ß-diketone secured the availability of our target molecules.

Matching of feature points based on TSSC method from MR images of nonrigid deformed tissues.

Due to the nonlinear and nonuniform local deformation of nonrigid tissues, it is difficult to match a number of feature points distributing somewhat uniform in the tissues from MR images for deformation measurement. This paper proposes TSSC (TPS-SURF-SAC-Clustering) based method of feature point matching and elimination of mismatching. First, Fast-Hessian and Harris operator are utilized to extract the feature points in the initial MR image, and the matching region is identified by TPS transformation model for every query point in the deformed image. Then the SURF descriptors and the proposed Spatial Association Correspondence (SAC) method are combined to match the feature points. Finally, by clustering the coordinate differences between the matching points obtained by TPS-SURF-SAC and the matching points calculated by TPS model, most incorrectly matched points are eliminated. After every iterative processing of matching and mismatching elimination, the updated TPS model becomes more accurate and more correctly so that the matched points can be identified than those of last iteration. The experimental results show that the proposed SAC was efficient and that TSSC based method outperformed the single SURF or SIFT method.

Composite match index with application of interior deformation field measurement from magnetic resonance volumetric images of human tissues.

Whereas a variety of different feature-point matching approaches have been reported in computer vision, few feature-point matching approaches employed in images from nonrigid, nonuniform human tissues have been reported. The present work is concerned with interior deformation field measurement of complex human tissues from three-dimensional magnetic resonance (MR) volumetric images. To improve the reliability of matching results, this paper proposes composite match index (CMI) as the foundation of multimethod fusion methods to increase the reliability of these various methods. Thereinto, we discuss the definition, components, and weight determination of CMI. To test the validity of the proposed approach, it is applied to actual MR volumetric images obtained from a volunteer's calf. The main result is consistent with the actual condition.