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To alleviate the metal corrosion problem caused by incomplete acid discharge during pickling or acidification, a corrosion inhibitor, long chain fatty hydrazides (LCFH), with a significant corrosion inhibition effect was synthesized from natural grease. The corrosion inhibition and adsorption properties of LCFH on carbon steel in 1 M HCl solution were studied by static sample weight loss test, electrochemical impedance spectroscopy, and potentiodynamic polarization curve. The results showed that LCFH exhibits excellent corrosion inhibition performance in HCl solution. The inhibition efficiency increases with the increase of inhibitor concentration. When the concentration of LCFH is 40 mg/L, the inhibition efficiency can reach 97.9%. The potentiodynamic polarization curve shows that LCFH is a corrosion inhibitor that mainly inhibits the cathodic reaction. The corrosion inhibitor is spontaneously adsorbed on the surface of low-carbon steel in physical form, which conforms to the Langmuir isothermal adsorption model.

The purpose of this study was to investigate the cross-lagged relationships between academic procrastination and test anxiety. A sample of Chinese adolescents from a high school in Changsha City, HuNan Province, China participated in this study. The participants completed the Aitken Procrastination Inventory and the Test Anxiety Scale at two times during a semester. Pearson correlation analysis showed academic procrastination and test anxiety to be positively correlated. Cross-lagged panel analyses demonstrated that academic procrastination at Time 1 predicted test anxiety at Time 2, while test anxiety at Time 1 did not predict academic procrastination at Time 2. Within the limits of the design, we found that academic procrastination may lead to an increase in test anxiety, but test anxiety did not predict the future level of academic procrastination. It is recognised that the relationship between anxiety and procrastination is complicated. It is suggested that a focus on interventions for academic procrastination may help to reduce students' test anxiety, but not necessarily vice versa.

The identification of styrene-butadiene-styrene (SBS) content is crucial in engineering applications since the key to assessing the performance of aged-modified asphalt is the SBS content. Six types of modified asphalts with various SBS contents were prepared, and physical, rheological, and Fourier-transform infrared spectroscopy (FTIR) tests were conducted. The fitting relationship between aged-modified asphalt indexes and SBS content was established, and the three methods] accuracy, simplicity, and efficiency were compared and analyzed. The results showed that the fitting relationship between SBS content and viscosity could exceed 0.83 after aging. However, the linear and quadratic fittings deviated from the measured values, and the softening point had no apparent law with the SBS content. The rheological index method significantly correlated with SBS content and is highly automated. However, FTIR was established based on the direct detection of SBS characteristic peaks compared with the physical and rheological indexes methods. It could directly reflect the SBS content and was not easily disturbed by SBS substitutes. In addition, after long-term aging, the linear relationship between SBS characteristic peak index, [A.sub.966]/[A.sub.811], and SBS content could exceed 0.97. The FTIR test exhibited high accuracy and fast detection speed and is the best detection method for SBS content. KEYWORDS aging, FTIR spectrum, modified asphalt, physical and rheological properties, SBS content, 1 | INTRODUCTION Styrene-butadiene-styrene (SBS) modified asphalt is essential, accounting for more than 60% of the global asphalt demand. It has excellent anti-fatigue performance and wear resistance and is widely [...]

Objective: To explore the application value of high performance liquid chromatography (HPLC) and erythrocyte parameters for screening of thalassemia in Shanghai. Methods: The hemoglobin of 1 029 samples from patients with suspected thalassemia and with suspected hemolytic anemia were analyzed using HPLC. Genetic analysis of the globin were performed simultaneously with GAP-PCR,reverse dot blot(RDB) and DNA sequencing. Results: Among 1029 samples, 591（57.43%） were diagnosed as having thalassemia and 14 (1.36%) having structural hemoglobin variants.Compared with results of genetic analysis,the sensitivity,specificity,positive predictive value and negative predictive value of HbA2 >3.9% by HPLC as cut-off value for diagnosing β-thalassemia were 95.84%, 96.87%, 95.40%, 97.20%,with AUC of 0.962. When HbA2≤2.1% by HPLC as the cutoff value combined with presence of rapid band were taken for diagnosing α-thalassemia moderate（HbH disease）, sensitivity, specificity, positive predictive value, negative predictive value were 96.32%, 52.60%, 100.00 %, with AUC of 0.990. If f HbA2 ≤3.2% by HPLC was taken as the cutoff value for diagnosing minor α-thalassemia or α-thalassemia trait, the corresponding indice were 97.76%, 53.11%, 24.0%, 99.4%,and AUC was 0.753. If MCV≤73.3 fl,MCH≤23.5 pg,MCHC≤324g/L were taken as the cutoff value alone for diagnosing thalassemia, sensitivity and specificity were 87.98%,77.51%, 93.73% and 69.86%, 89.20%,47.61%,respectively. Conclusions: Based on RBC parameters analysis,results of HPLC technology have a good consistence with the resluts of gene detection in the diagnosis of β-thalassemia, HbH disease and structural hemoglobin variant, while a low specificity and positive predictive value may occur in the diagnosis of minor α-thalassemia orα-thalassemia trait.

Metal–organic frameworks (MOFs) with ordered organic linkers and inorganic nodes/clusters possess laudable catalytic properties and underpin the reactivity and selectivity that are not observed in other manifolds by integrating various active components into one network. However, MOFs with a three-dimensional (3D) structure suffer from pore size limitation, slow electron communication and substrate diffusion, which limit their photocatalytic performance and application. Ultrathin two-dimensional (2D) monolayer metal–organic framework nanosheets with more accessible active sites, faster electron communication and substrate diffusion provide a tunable platform to overcome these limitations. In this work, by in situ exfoliation of 3D layered MOFs, an ultrathin 2D copper-based MOF nanosheet containing photoactive anthraquinone groups was successfully constructed for activating the inert C(sp3)–H bonds and oxygen by integrating the energy transfer (EnT), ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) events together into one network. A large number of Cu2(Ac)4 paddlewheel clusters are uniformly distributed on the surface of the ultrathin 2D copper-based MOF nanosheets, which provide a wealth of coordination sites with the highly electrophilic radical precursor chloride ions to form Cu–Cl chromophores. Under multiphoton excitation, in situ formed Cu–Cl chromophores and anthraquinone ligands are triggered simultaneously to form the highly active chlorine radical (Cl˙) and reactive oxygen species (ROS) by LMCT and EnT events for the activation and oxidation of C(sp3)–H bonds through a HAT process. This ultrathin 2D MOF nanosheet with a short electron transfer distance and rich active sites not only inherits the versatility of MOFs, but also combines the unique advantages of 2D catalytic materials. Benefiting from the synergistic effects of two active sites and the flexibility of the ultrathin 2D MOF-based nanosheets with high surface utilization, the observed activities are obviously superior to that of bulk 3D MOF crystals in photocatalysis. This work not only highlights the potential of 2D MOF-based nanosheets in various photocatalytic transformations, but also presents opportunities to use nanostructured MOFs to handle the synergy of multiple molecular catalysts. [ABSTRACT FROM AUTHOR]

Nanoparticles have been widely applied to treat emulsion-containing wastewater in the form of chemical demulsifiers, such as SiO2, Fe3O4, and graphene oxide (GO). Owing to their asymmetric structures and selective adsorption, Janus nanoparticles show greater application potential in many fields. In the present work, the novel magnetic Janus graphene oxide (MJGO) nanoparticle was successfully prepared by grafting magnetic Fe3O4 to the surface of the JGO, and its demulsifying ability to treat a crude oil-in-water emulsion was evaluated. The MJGO structure and its magnetic intensity were verified by Fourier-transform infrared spectra (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and magnetization saturation (MS) tests. Compared with GO and JGO, MJGO displayed the superior efficiency (>96%) to demulsify the crude oil-in-water emulsion, which can be attributed to the reduced electrostatic repulsion between MJGO and the emulsion droplets. Furthermore, the effects of pH and temperature on the demulsification performance of MJGO were also studied. Lastly, the recyclability of MJGO largely reduced the cost of demulsifiers in separating crude oil and water. The current research presents an efficient and recyclable demulsifier, which provides a new perspective for the structural design of nanomaterials and their application in the field of demulsification. [ABSTRACT FROM AUTHOR]