Effects of V and Gd doping on novel positive colossal electroresistance and quantum transport in PbPdO2 thin films with (002) preferred orientation.

In this work, PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films with (002) preferred orientation were prepared using a pulsed laser deposition technique. The temperature dependence of resistivities ρI(T) was investigated under various applied DC currents. Colossal electroresistance (CER) effects were found in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2. It was found that the positive CER values of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 reach 3816% and 154% for I = 1.00 µA at 10 K, respectively. In addition, the ρI(T) cycle curves of PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 thin films showed a critical temperature similar to that of PbPdO2 (Tc = 260 K). Particularly, charge transfer between O1- and O2- was confirmed by in situ XPS. Additionally, based on first-principles calculations and internal electric field models, the CER and magnetic sources in PbPd0.9V0.1O2 and PbPd0.9Gd0.1O2 can be well explained. Finally, it was found that thin film samples doped with V and G ions exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport properties. Ion doping leads to a transition from WAL to WL. The study results indicate that PbPdO2, one of the few oxide topological insulators, can exhibit novel quantum transport behavior after ion doping.

Effects of Mn doping on electronic and quantum transport in PbPdO2 thin films.

PbPdO2, a gapless semiconductor, can be transformed into a spin gapless semiconductor structure by magnetic ion doping. This unique band-gap structure serves as the foundation for its distinctive physical properties. In this study, PbPd1-xMnxO2 (x = 0.05, 0.1, 0.15) thin films with (002) preferred orientation were prepared by laser pulse deposition (PLD). The structural, electroresistive and magnetoresistive properties were systematically characterized, and the results suggest that films with different Mn doping ratios exhibit a current-induced positive colossal electroresistance (CER), and the CER values of PbPd1-xMnxO2 thin films increase with the increase of Mn doping concentration. The CER values are several fold magnitudes higher compared to those of the previously reported PbPdO2 films possessing identical (002) orientation. Combined with first-principles calculation, the underlying influence mechanism of Mn doping on CER is elucidated. In situ X-ray photoelectron spectroscopy (XPS) demonstrates a close correlation between the positive CER and the band gap change induced by oxygen vacancies in PbPd1-xMnxO2. Additionally, it is observed that Mn-doped films exhibit weak localization (WL) and weak anti-localization (WAL) quantum transport. Moreover, it is found that Mn doping can lead to a transition from WAL to WL; a small amount of Mn doping significantly enhances the weak anti-localization effect. However, with increasing Mn concentration, the WAL effect is conversely weakened. The results of studies suggest strongly that PbPdO2, one of the few oxide topological insulators, can display novel quantum transport behavior by ion doping.

Artificial intelligence optimization and controllable slow-release iron sulfide realizes efficient separation of copper and arsenic in strongly acidic wastewater.

Iron sulfide (FeS) is a promising material for separating copper and arsenic from strongly acidic wastewater due to its S2- slow-release effect. However, uncertainties arise because of the constant changes in wastewater composition, affecting the selection of operating parameters and FeS types. In this study, the aging method was first used to prepare various controllable FeS nanoparticles to weaken the arsenic removal ability without affecting the copper removal. Orthogonal experiments were conducted, and the results identified the Cu/As ratio, H2SO4 concentration, and FeS dosage as the three main factors influencing the separation efficiency. The backpropagation artificial neural network (BP-ANN) model was established to determine the relationship between the influencing factors and the separation efficiency. The correlation coefficient (R) of overall model was 0.9923 after optimizing using genetic algorithm (GA). The BP-GA model was also solved using GA under specific constraints, predicting the best solution for the separation process in real-time. The predicted results show that the high temperature and long aging time of FeS were necessary to gain high separation efficiency, and the maximum separation factor can reached 1,400. This study provides a suitable sulfurizing material and a set of methods and models with robust flexibility that can successfully predict the separation efficiency of copper and arsenic from highly acidic environments.

Selective separation of metals from wastewater using sulfide precipitation: A critical review in agents, operational factors and particle aggregation.

Extensive research has been conducted on the separation and recovery of heavy metals from wastewater through the targeted precipitation of metal sulfides. It is necessary to integrate various factors to establish the internal correlation between sulfide precipitation and selective separation. This study provides a comprehensive review of the selective precipitation of metal sulfides, considering sulfur source types, operating factors, and particle aggregation. The controllable release of H2S from insoluble metal sulfides has garnered research interest due to its potential for development. The pH value and sulfide ion supersaturation are identified as key operational factors influencing selectivity precipitation. Effective adjustment of sulfide concentration and feeding rate can reduce local supersaturation and improve separation accuracy. The particle surface potential and hydrophilic/hydrophobic properties are crucial factors affecting particle aggregation, and methods to enhance particle settling and filtration performance are summarized. The regulation of pH and sulfur ion saturation also controls the zeta potential and hydrophilic/hydrophobic properties on the particles surface, thereby affecting particle aggregation. Insoluble sulfides can decrease sulfur ion supersaturation and improve separation accuracy, but they can also promote particle nucleation and growth by acting as growth platforms and reducing energy barriers. The combined influence of sulfur source and regulation factors is vital for achieving precise separation of metal ions and particle aggregation. Finally, suggestions and prospects are proposed for the development of agents, kinetic optimization, and product utilization to promote the industrial application of selective precipitation of metal sulfides in a better, safer, and more efficient way.

Substituent effect of ancillary ligands on the luminescence of bis[4,6-(di-fluorophenyl)-pyridinato-N,C2']iridium(III) complexes.

Two series of (dfppy)(2)Ir(L(N^O)) with different substituents were designed and successfully synthesized and the effect of substitution at the ancillary ligand on the photophysical and electrochemical properties of (dfppy)(2)Ir(L(N^O)) were investigated. The results indicate that the electron-donating group of -OMe at L(N^O) increases the PL quantum efficiencies of (dfppy)(2)Ir(L(N^O)) and the electron-withdrawing groups of -CF(3) and -F lower the PL quantum efficiencies.

Imaging characteristics of bronchopulmonary Lophomonas blattarum infection: case report and literature review.

Bronchopulmonary Lophomonas blattarum infection is a new form of disease, for which the clinical features are not fully understood. The present article is a retrospective review and analysis of clinical manifestations, chest x-ray, and computed tomography imaging findings in 15 cases of bronchopulmonary L. blattarum infection reported in China, including 1 case diagnosed and treated in our hospital. Imaging presentation of bronchopulmonary L. blattarum infection varies with individual patients. The most common manifestations were pneumonia or migratory pneumonia, and occasional findings included bronchiectasis, pulmonary abscess, and hydrothorax. Diagnosis of L. blattarum mainly depends on sputum smear examination, bronchoscopic examination, and bronchoalveolar lavage.

[Bronchopulmonary Lophomonas blattarum infection: two cases report and literature review].

OBJECTIVE: To improve the recognition and diagnosis of pulmonary Lophomonas blattarum infection. METHODS: Two cases of bronchopulmonary Lophomonas blattarum diagnosed in this hospital were reported. The clinical features of 13 cases in the literature during the period of 1993 to 2006, 1 case with sinus infection and 12 cases with bronchopulmonary infection, were also analyzed. RESULTS: For the 2 cases diagnosed in this hospital, severe asthma and bronchiectasis with prolonged infection were the underlying diseases, respectively. The diagnosis of these 2 cases and the 13 cases reported in the literature were all confirmed by the presence of parasites in airway samples. The most common symptoms included fever (64.3%), cough and expectoration (71.4%). Fifty percent of the patients showed increased eosinophils in peripheral blood. Chest radiograph and CT scan showed changes similar to pneumonia (83.3%). Chronic cases were manifested with asthma attack, bronchiectasis or lung abscess. Smear preparations of sputum or specimen by bronchoscopy were direct methods for diagnosis. CONCLUSION: Pulmonary Lophomonas blattarum infection is an emerging infectious disease caused by protozoon of hypermastigote parasitized in the bronchus or the lung. Epidemiological characteristics including host, route of transmission and susceptible population of Lophomonas blattarum infection are not fully understood. The optimal treatment also needs further investigation.