Study on the corrosion behavior and mechanical response of weakly cemented sandstone in alkaline solutions.

This study examines the corrosion characteristics of weakly cemented sandstone under alkaline conditions, evaluating the effects of varying pH levels on its macroscopic degradation, micro-porosity, and mechanical properties, notably uniaxial compressive strength. Findings reveal that heightened alkalinity exacerbates rock damage, although a temporary alleviation in mass loss occurs between pH 9 and 11 due to pore clogging by complexes formed from cations like Ca2+ and Mg2+.Increased alkalinity induces marked changes in pore features, with an observed rise in pore numbers, transformation of pore shapes from elongated to more spherical, and adjustments in porosity, pore size, and roundness.

Special economic zone and infant mortality: Evidence from China.

By exploiting the development of special economic zones (SEZs) in China as a quasi-natural experiment, this paper evaluates how such zones affect infant mortality. Difference-in-differences analysis reveals that SEZs significantly decrease the local infant mortality rate, and the impact is larger for male infants and infants with less-educated mothers. Further studies show that the SEZs, which acts as an economic growth shock, improve infant survival by increasing the local income.

Case report: Minimally invasive removal of a dislodged thoracoamniotic shunt with an integral cystoscope in a preterm infant.

Introduction: Fetal pleural effusion is a rare condition that is associated with significant mortality. Although the insertion of fetal thoracoamniotic shunts can improve perinatal outcomes, there are several associated complications, such as intrathoracic dislodgement of the shunts. The optimal neonatal treatment for retained shunts remains uncertain.

All-Organic Composite Films for High Flexibility and Giant Nonlinear Optical Limiting Responses.

Given the substantial π-electron delocalization observed in 4--dimethylamino-4--methyl-stilbazolium tosylate (DAST), a high third-order nonlinear optical response can be expected that might manifest itself in various ways for potential applications. To probe the possibility and assess its potential, all-organic DAST-polymethyl methacrylate (PMMA) composite films were prepared by a simple solution casting method, and their nonlinear absorption performances were measured by an open-aperture Z-scan system. The results reveal that under irradiation by a 380 fs laser pulse at 520 nm or a 6 ns laser pulse at 532 nm, the DAST-PMMA composite films with a DAST concentration of 0.

Porous and nanowire-structured NiO/AgNWs composite electrodes for significantly-enhanced supercapacitive and electrochromic performances.

NiO/AgNWs composite films which specially contain both porous and one-dimensional (1D) nanowire structures are prepared uniformly via a simple chemical bath deposition method. The supercapacitive electrodes constructed by the as-prepared NiO/AgNWs composite films exhibit a high specific capacitance (980 F gat 1 A g), much higher than that of the pure NiO films. Particularly, a large optical modulation (84.

Stimuli-responsive behavior of naphthyl acylhydrazone derivative and its application in information security protection.

Acylhydrazone derivatives containing naphthyl group, namely, 3,5-bis-octyloxy-benzoic acid naphthalen-1-ylmethylene-hydrazide (NTH-mB8) and 4-methoxy-benzoic acid naphthalen-1-ylmethylene-hydrazide (NTH-P1) were synthesized. π-π interactions between naphthalene groups and -N-H···O=C- intermolecular hydrogen bondings were observed in NTH-P1 single crystal, in which -C=N- bonds exhibited trans-isomer. NTH-mB8 showed photo-responsive behavior due to photo-induced trans-cis isomerizations of -C=N- bonds.

Salisbury Screen Terahertz Absorber Formed with an Insulator: 4-,-Dimethylamino-4'-'-methyl-stilbazolium Tosylate (DAST).

A novel Salisbury screen absorber (SSA) based on a 4-,-dimethylamino-4'-'-methyl-stilbazolium tosylate (DAST) crystalline film was designed and fabricated. Different from the conventional SSA, an insulating organic DAST film replaced the normally highly conductive top surface metal layer. The absorption spectra and the structure of this SSA were optimized with a transmission line model to correspond to the DAST absorption peak at 1.

A colorimetric and fluorescent sensor for the detection of both fluoride ions and trifluoroacetic acid based on acylhydrazone derivatives.

An acylhydrazone-based colorimetric and fluorescent sensor (PAH-8) for the detection of fluoride ions (F-) and trifluoroacetic acid (TFA)/triethylamine (TEA) has been studied. PAH-8 solution and organogel are highly selective and sensitive to F- among various tested anions (F-, Cl-, Br-, AcO-, and H2PO4-) in DMSO. Upon addition of F-, the maximum absorption wavelength of PAH-8 in DMSO solution shows a big red shift from 377 nm to 464 nm with a marked color change from colorless to yellow, and the fluorescence emission also displays a red shift from 438 nm to 532 nm with its fluorescence emission switching from blue to yellow.

Electrochemical oxygen reduction mechanism on FeN-graphene.

Metal-coordinated nitrogen-doped carbons are highly active in promoting electrochemical oxygen reduction reactions (ORR). The detailed kinetic and thermodynamic ORR behavior on three different FeN-graphene [FeN-G (A), (B) and (C)] structures was investigated in this work. The results show that formation of these FeN-G configurations is energetically favorable; however, not all of them are effective for ORR.

E-Z isomerization of the -C[double bond, length as m-dash]N- bond in anthracene-based acylhydrazone derivatives under visible light.

The photoresponsive behaviour of AHP-mB8 upon irradiation by visible light was demonstrated to be due to the E-Z isomerizations of the -C[double bond, length as m-dash]N- group, rather than the photodimerization of anthracene groups. In addition, the Z-isomer of AHP-mB8 was stable at room temperature. AHP-mB8 organogels showed visible light induced gel-sol transition and its mechanism was proposed.

Reductive Removal of Selenate in Water Using Stabilized Zero-Valent Iron Nanoparticles.

Polysaccharide-stabilized zero-valent iron (ZVI) nanoparticles were synthesized using sodium carboxymethyl cellulose (CMC) or starch as stabilizer, and tested for reductive removal of selenate in water. Batch kinetic tests showed that the stabilized ZVI nanoparticles offer much faster selenate removal than bare ZVI particles at both pH 6.0 and pH 8.

[Analysis of XPS in the removal of Se(IV) from groundwater with pyrite].

Selenium (Se) is an elementary trace nutrient element for human but there is a very narrow range between deficit and toxic levels. Furthermore, excessive intake of Selenium is harmful for human. The product species of selenite which was removal by pyrite particles was studied in the present research In the experiments, the pyrite particles were prepared by the wet ball mill method, and surface analyses of pyrite before and after contact with Se(IV) were conducted using X-ray photoelectron spectroscopy (XPS).

Microwave-assisted hydrothermal synthesis of Cu/Cu2O hollow spheres with enhanced photocatalytic and gas sensing activities at room temperature.

Cu/Cu2O nano-heterostructure hollow spheres with a submicron diameter (200-500 nm) were prepared by a microwave-assisted hydrothermal method using Cu(OAc)2·H2O, PVP and ascorbic acid solution as the precursors. The morphology of the products could evolve with the hydrothermal time from solid spheres to thick-shell hollow spheres, then to thin-shell hollow spheres, and finally to nanoparticles. Moreover, the content of Cu in the products could be controlled by adjusting the hydrothermal time.

Absence of Ligamentum Teres in Developmental Dysplasia of the Hip.

Background: Ligamentum teres is hypertrophied and should be resected in developmental dysplasia of the hip (DDH). We have observed a relatively high prevalence of absence of ligamentum teres (ALT) in severe DDH. The purpose of this study was to determine: (1) the percentage of ALT in DDH; (2) the risk factors correlating with ALT; and (3) the pathologic characteristics of DDH with ALT.

[One-stage anteroposterior hemi-vertebra resection and segmental internal fixation for young children with congenital scoliosis].

Objective: to discuss the feasibility and efficacy of one-stage anteroposterior hemi-vertebra resection and segmental internal fixation for young children with congenital scoliosis.

Methods: thirty-five patients undergoing one-stage anteroposterior hemi-vertebra resection and segmental internal fixation were retrospectively studied. The mean followed-up period was 5.