Fabrication of TiO 2

The TiO2 photoelectrodes fabricated on the substrate of Ti foils by Ti ions implantation and subsequent annealing at different temperatures were applied for water splitting. The size of TiO2 nanoparticles increased with annealing temperatures, and the GIXRD patterns and Raman spectra demonstrate that the phase of TiO2 turns to rutile at high temperature. The photoelectrochemical (PEC) and X-ray photoelectron spectroscopy (XPS) spectra of the valence band demonstrate that the samples annealed at 400 and 500°C show the n-type property. The sample annealed at 600°C shows the weak p-type TiO2 property. For the sample annealed at 700°C, the negative photocurrent is main, which mainly performs the p-type property of TiO2. The IPCE values indicate that the absorption edges are red shifted with the increase of annealing temperatures

Enhanced photocatalysis by coupling of anatase TiO2 film to triangular Ag nanoparticle island

In order to overcome the low utilization ratio of solar light and high electron-hole pair recombination rate of TiO(2), the triangular Ag nanoparticle island is covered on the surface of the TiO(2) thin film. Enhancement of the photocatalytic activity of the Ag/TiO(2) nanocomposite system is observed. The increase of electron-hole pair generation is caused by the enhanced near-field amplitudes of localized surface plasmon of the Ag nanoparticles. The efficiently suppressed recombination of electron-hole pair caused by the metal-semiconductor contact can also enhance the photocatalytic activity of the TiO(2) film

An innovative approach for pseudoboehmite precipitation from seeded sodium aluminate solutions

Precipitation of boehmite from seeded sodium aluminate (SA) solutions for production of smelter grade alumina by calcination is in the early stage of development. However, the reported boehmites are usually well crystallized and actually most boehmites for activated aluminas are poorly crystallized and less ordered forms, which is also called pseudoboehmite. In the present study, an attempt has been made to find the appropriate precipitation conditions of pseudoboehmite from seeded SA solutions by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), and transmission electron microscopy (TEM). It was found that pure pseudoboehmite showing minor morphology difference with the pseudoboehmite seed can be easily obtained under hydrothermal conditions at 373 K not less than 10 h or at 398 K not less than 3 h. The hydrothermal seed precipitation is a dynamic inhibited process that approximately consists of three stages, namely a fast precipitation stage, a slow precipitation stage and an analogously apparent equilibrium stage. However, the seeded precipitation under circulation reflux at approximate 0.1 MPa is not suitable for preparing pure pseudoboehmite because of by-products formation, such as gibbsite, nordstrandite, diaspore, etc. This work demonstrates that pseudoboehmite can be efficiently precipitated from seeded SA solutions under certain hydrothermal conditions. (C) 2009 Elsevier Ltd. All rights reserved

Enhancement on Synthesis of Boehmite Through a Precarbonization-assisted Hydrogen Peroxide Route in Highly Alkaline Sodium Aluminate Solutions

Hydrogen peroxide (H(2)O(2)) precipitation from sodium aluminate (SA) solution at close-ambient temperature is an efficient method to synthesize boehmite and its derived alumina with high surface area, but the precipitation yield of Al(2)O(3) is usually below 50% in highly alkaline SA solutions. Here the synthesis of boehmite is enhanced through a precarbonization-assisted H(2)O(2) route in highly alkaline SA solutions. It is found that the crystal structure of the precipitation product is evidently influenced by the precipitation conditions. As the precipitation temperature increases from 273 to 325 K, a small amount of gibbsite by-product is formed. As the aging temperature increases from 301 to 333 K, the crystallinity of boehmite decreases and part of the boehmite dissolves due to an increase in the pH value. Based on the above results, a precarbonization-assisted H(2)O(2) route is proposed to obtain pure boehmite with more complete recovery of Al(2)O(3) from highly alkaline SA solutions. The route includes a controllable precarbonization step of SA solutions with a molar ratio of Na(2)O to Al(2)O(3) higher than 2 : 1, followed by the H(2)O(2)-precipitated step with a molar ratio of H(2)O(2) to Al(2)O(3) less than 7 : 1. Because of its facile operation conditions, no extraneous impurity, time saving and a possible recycle of the filtrate, the route has great potential to be an alternative method for preparation of boehmite and its derived alumina

Enhancement on Synthesis of Boehmite Through a Precarbonizationassisted Hydrogen Peroxide Route in Highly Alkaline Sodium Aluminate Solutions

Hydrogen peroxide (H 2 O 2 ) precipitation from sodium aluminate (SA) solution at close-ambient temperature is an efficient method to synthesize boehmite and its derived alumina with high surface area, but the precipitation yield of Al 2 O 3 is usually below 50% in highly alkaline SA solutions. Here the synthesis of boehmite is enhanced through a precarbonization-assisted H 2 O 2 route in highly alkaline SA solutions. It is found that the crystal structure of the precipitation product is evidently influenced by the precipitation conditions. As the precipitation temperature increases from 273 to 325 K, a small amount of gibbsite by-product is formed. As the aging temperature increases from 301 to 333 K, the crystallinity of boehmite decreases and part of the boehmite dissolves due to an increase in the pH value. Based on the above results, a precarbonization-assisted H 2 O 2 route is proposed to obtain pure boehmite with more complete recovery of Al 2 O 3 from highly alkaline SA solutions. The route includes a controllable precarbonization step of SA solutions with a molar ratio of Na 2 O to Al 2 O 3 higher than 2 : 1, followed by the H 2 O 2 -precipitated step with a molar ratio of H 2 O 2 to Al 2 O 3 less than 7 : 1. Because of its facile operation conditions, no extraneous impurity, time saving and a possible recycle of the filtrate, the route has great potential to be an alternative method for preparation of boehmite and its derived alumina

Corrosion Reason Analysis of 13Cr110 Tubing in an Injection and Production Well of the Suqiao Gas Storage Group

Natural gas as a clean energy, its extensive use can alleviate energy crisis and environmental pollution and other problems. The storage and transportation of natural gas are of great significance to the standard use of natural gas. Suqiao gas storage reservoir is responsible for seasonal peak adjustment and emergency gas supply in the Beijing-Tianjin-Hebei region, and the corrosion of tubular goods is the most important issue. In this paper, the tubing composition analysis, metallographic structure analysis, mechanical property analysis, simulated corrosion test, corrosion morphology, and product analysis were carried out to analyze and study the corrosion behavior under the conditions, and suggestions were put forward to control the corrosion of the outer surface of the tubing

Enantiomeric Effect of d-Amino Acid Substitution on the Mechanism of Action of α-Helical Membrane-Active Peptides

V13K, a 26-residue peptide, has been shown to have strong antimicrobial activity, negligible hemolytic activity, and significant anticancer activity. In the present work, V13K was used as the framework to investigate the influence of helicity, as influenced by d-amino acid substitutions in the center of the peptide polar and non-polar faces of the amphipathic helix, on biological activity. The antibacterial and anticancer activities of the peptides were investigated. Atomic force microscopy and other biophysical methods were used to investigate the effect of peptide helicity on biological activity. The results showed the importance of suitable and rational modification of membrane-active peptides, based on helicity, in optimizing potential biological activity

Whole-genome DNA methylation and DNA methylation-based biomarkers in lung squamous cell carcinoma

Summary: Exploring early detection methods through comprehensive evaluation of DNA methylation for lung squamous cell carcinoma (LUSC) patients is of great significance. By using different machine learning algorithms for feature selection and model construction based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, five methylation biomarkers in LUSC (along with mapped genes) were identified including cg14823851 (TBX4), cg02772121 (TRIM15), cg10424681 (C6orf201), cg12910906 (ARHGEF4), and cg20181079 (OR4D11), achieving extremely high sensitivity and specificity in distinguishing LUSC from normal samples in independent cohorts. Pyrosequencing assay verified DNA methylation levels, meanwhile qRT-PCR and immunohistochemistry results presented their accordant methylation-related gene expression statuses in paired LUSC and normal lung tissues. The five methylation-based biomarkers proposed in this study have great potential for the diagnosis of LUSC and could guide studies in methylation-regulated tumor development and progression

Construction and validation of a 15-gene ferroptosis signature in lung adenocarcinoma

Background Ferroptosis is a novel form of programmed cell death characterized by the excessive accumulation of intracellular iron and an increase in reactive oxygen species. Emerging studies have shown that ferroptosis plays a vital role in the progression of lung adenocarcinoma, but the effect of ferroptosis-related genes on prognosis has been poorly studied. The purpose of this study was to explore the prognostic value of ferroptosis-related genes. Methods Lung adenocarcinoma samples were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The least absolute shrinkage and selection operator (LASSO) Cox regression algorithm was used to establish a predictive signature for risk stratification. Kaplan–Meier (K–M) survival analysis and receiver operating characteristic (ROC) curve analysis were conducted to evaluate the signature. We further explored the potential correlation between the risk score model and tumor immune status. Results A 15-gene ferroptosis signature was constructed to classify patients into different risk groups. The overall survival (OS) of patients in the high-risk group was significantly shorter than that of patients in the low-risk group. The signature could predict OS independent of other risk factors. Single-sample gene set enrichment analysis (ssGSEA) identified the difference in immune status between the two groups. Patients in the high-risk group had stronger immune suppression, especially in the antigen presentation process. Conclusions The 15-gene ferroptosis signature identified in this study could be a potential biomarker for prognosis prediction in lung adenocarcinoma. Targeting ferroptosis might be a promising therapeutic alternative for lung adenocarcinoma