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Bimetallic lined pipe (BLP) has been increasingly used in offshore and subsea oil and gas structures, but how to identify the invisible inner defects such as liner wall thinning and interface debonding is a challenge for future development. A nondestructive testing (NDT) method based on pulsed eddy current testing (PECT) has been proposed to face these difficulties. The inspection of the BLP specimen (AISI1020 base tube and SS304 liner) is implemented from outside of the pipe by using a transmitter–receiver-type PECT probe consisting of two induction coils. By simplifying the BLP specimen to stratified conductive plates, the electromagnetic field interaction between the PECT probe and specimen is analytically modeled, and the probe inspection signals due to liner wall thinning and interface debonding are calculated. In order to highlight the weak response (in microvolts) from the liner, the inspection signals are subtracted by the signal, which is calculated in the case of only having a base tube, yielding differential PECT signals. The peak voltage of the differential signal is selected to characterize the liner wall thinning and interface debonding due to its distinguishable and linear variation. Experiment verification is also carried out on a double-walled specimen simulated by a combination of a Q235 casing pipe and SS304 tubes of different sizes. The experimental results basically agree with the analytical predictions. The peak value of the PECT signal has an ascending and descending variation with the increase in the remaining liner wall thickness and debonding gap, respectively, while the negative peak value shows opposite changes. The peak value exhibits a larger sensitivity than the negative peak value. The proposed method shows potential promise in practical applications for the evaluation of the inner defects in BLP lines. [ABSTRACT FROM AUTHOR]

The over-extraction of groundwater has resulted in seawater intrusion and the southward migration of the saltwater interface, gradually deteriorating the groundwater quality in the Weibei Plain. In this research, groundwater samples were gathered from 46 monitoring wells for shallow groundwater during the years 2006, 2011, 2016, and 2021. The hydrochemical features of regional groundwater and the factors influencing the issue were subjected to statistical analysis. Additionally, the assessment of spatiotemporal variations in groundwater quality was conducted using the customized entropy-weighted water quality index (EWQI) method. The relationship between groundwater over-extraction and the southward intrusion of the saltwater interface was compared and analyzed. The results of this paper revealed that the Weibei Plain has been in a state of long-term over-extraction of groundwater from 2000 to 2021, with an average annual over-extraction of 118.49 million m3. The groundwater depression cone areas in the northern part of the study area increased from 3,247.37 to 4,581.34 km2 from 2006 to 2021, with the center of the cone experiencing a drop in groundwater level from -22 to -85 m. The saltwater interface shifted southward by 711.71 km2 from 2006 to 2021. In groundwater, the high concentrations of TH, TDS, and Cl- were primarily related to the seawater intrusion, while higher concentrations of NO3- were mainly determined by frequent agricultural production, industrial wastewater, and domestic sewage discharges. The groundwater hydrochemical types in the study area transitioned from predominantly HCO3 Ca-Mg type in 2006 to HCO3-Na type and SO4 Cl-Ca Mg type in 2021 due to seawater intrusion. The results of PCA and HCA show the effects of seawater intrusion, human activities, and rock weathering on groundwater hydrochemistry. The evaluation results based on the EWQI revealed that the average value of the samples in 2021 was 101.36, which belonged to Class IV water quality standards, representing the poorest water quality among the 4 years. The southward migration of the saltwater interface led to the deterioration of groundwater quality in the groundwater depression cone areas, which gradually worsened from 2006 to 2021. The maximum increase in EWQI value was 174.68 during the period, shifting from Class III water quality to Class V water quality. Groundwater quality remained relatively better in the western and southern regions which were less affected or unaffected by seawater intrusion. The results of the study can provide a certain reference value for the sustainable management of groundwater resources and the management of groundwater pollution and seawater intrusion in the Weifang City area in the future. [ABSTRACT FROM AUTHOR]

Desalination and power generation through solar energy harvesting is a crucial technology that can effectively address freshwater shortages and energy crises. However, owing to the complexity of the actual water environment, the thermal output capability of the photothermal material and the functional integration of the evaporation system need urgent improvement, to obtain high‐quality fresh water and sufficient electricity. Herein, a 2D/2D cesium tungsten bronze/copper sulfide (2D/2D Cs0.32WO3/CuS) nano‐heterojunction is developed and it is loaded into a cellulose‐based hybrid hydrogel to construct a multifunctional evaporator. Benefiting from the more nonradiative recombination centers from deep‐level defects, as well as shorter carrier migration distances and higher redox potentials in the Cs0.32WO3/CuS nano‐heterojunction, this evaporator has a significant improvement in thermal output capacity, enabling both super‐efficient seawater evaporation (4.22 kg m−2 h−1) and photodegradation of organic pollutants (removal rate ≈ 99%). Moreover, the evaporator exhibits long‐term stability and sustainable self‐cleaning property against salt accumulation. Remarkably, the thermoelectric module based on the Cs0.32WO3/CuS nano‐heterojunction shows promising electricity generation performance (4.85 W m−2), which can power small appliances durably and stably, exceeding previously reported similar devices. This 2D/2D heterojunction‐based solar evaporation system will provide a more reliable solution for efficient and sustainable freshwater‐electricity co‐generation in resource‐limited areas. [ABSTRACT FROM AUTHOR]

Low-cost and highly electroactive nickel-based materials are important electrodes for the development of supercapacitors. The precise modulation of the morphology and microstructure has been a crucial measure to further enhance the electrochemical performance. Herein, a three-dimensional porous nanocage NixS6/Ni(OH)2 hybrid formed by NixS6 nanoparticles anchored on Ni(OH)2 nanoflakes was creatively synthesized via a simple and scalable approach, which was based on two-time ion exchange reactions of the Mg(OH)2 precursor. Significantly, in asymmetric supercapacitors, the NixS6/Ni(OH)2 hybrid exhibits a high specific capacitance of 2726 F g−1 at a current density of 1 A g−1 and an excellent energy density of 31.31 Wh kg−1 at a power density of 62.56 W kg−1, which are superior to those of the currently reported nickel sulfide electrode materials. Compared with the nanoflower-like Mg(OH)2 and Ni(OH)2 precursors, the NixS6/Ni(OH)2 hybrid possesses hollow, abundant porous morphology and better electrical conductivity, which could provide a large contact surface area, shorter ion diffusion path and excellent charge transport, resulting in a dramatic improvement in electrochemical performance, making the NixS6/Ni(OH)2 hybrid a superb cathode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Desalination and power generation through solar energy harvesting is a crucial technology that can effectively address freshwater shortages and energy crises. However, owing to the complexity of the actual water environment, the thermal output capability of the photothermal material and the functional integration of the evaporation system need urgent improvement, to obtain high-quality fresh water and sufficient electricity. Herein, a 2D/2D cesium tungsten bronze/copper sulfide (2D/2D Cs 0.32 WO 3 /CuS) nano-heterojunction is developed and it is loaded into a cellulose-based hybrid hydrogel to construct a multifunctional evaporator. Benefiting from the more nonradiative recombination centers from deep-level defects, as well as shorter carrier migration distances and higher redox potentials in the Cs 0.32 WO 3 /CuS nano-heterojunction, this evaporator has a significant improvement in thermal output capacity, enabling both super-efficient seawater evaporation (4.22 kg m -2 h -1 ) and photodegradation of organic pollutants (removal rate ≈ 99%). Moreover, the evaporator exhibits long-term stability and sustainable self-cleaning property against salt accumulation. Remarkably, the thermoelectric module based on the Cs 0.32 WO 3 /CuS nano-heterojunction shows promising electricity generation performance (4.85 W m -2 ), which can power small appliances durably and stably, exceeding previously reported similar devices. This 2D/2D heterojunction-based solar evaporation system will provide a more reliable solution for efficient and sustainable freshwater-electricity co-generation in resource-limited areas., (© 2023 Wiley-VCH GmbH.)

The further bioapplications of sonodynamic therapy (SDT) were hindered by the inadequate efficiency and poor degradability of sonosensitizers and the hypoxic tumor microenvironment (TME). Therefore, it is ideal to develop pH-sensitive sonosensitizers that generate abundant reactive oxygen species (ROS) and rapidly degrade in a neutral environment while slowly degrading in an acidic environment to reduce their long-term toxicity. Herein, the defective tungsten oxide nanobelts (WO x NBs) were developed as a type of pH-sensitive and biodegradable sonosensitizers with a high SDT efficiency and low toxicity for enhanced SDT. The defective oxygen sites of WO x NBs could inhibit the recombination of electrons and holes, making WO x NBs promising sonosensitizers that could generate abundant ROS under ultrasound (US) irradiation. Enhanced by the catalase (CAT) that reacted with H 2 O 2 to generate O 2 , the WO x NBs exhibited better SDT performance against 4T1 cells in both normoxic and hypoxic environments. In addition, the WO x NBs could degrade by releasing protons (H + ), resulting in intracellular acidification and inhibited cell motility that further enhanced the therapeutic effects of SDT. Assisted with CAT and ALG for hypoxia refinement and better retention, the WO x NBs enabled effective SDT and antimetastasis against 4T1 tumors in vivo . Most importantly, the WO x NBs could degrade rapidly in normal tissues but slowly in an acidic TME, which was favorable for their fast clearance, without any obvious long-term toxicity. Our work developed defective WO x NBs with a high SDT efficiency and pH-sensitive degradation for enhanced SDT, which extended the biomedical application of tungsten-based nanomaterials and the further development of SDT.

A series of novel transition metal ion-substituted Zn 1- x A x WO 4 (A = Co, Mn, and Fe, 0 < x ≤ 0.1) inorganic pigments with blue, yellow, brown, and pale green colors have been prepared by a solution combustion method and exhibit extremely high near-infrared reflectance ( R > 85%). X-ray energy-dispersive spectroscopy analysis makes it clear that transition metal ions have already been incorporated into the host ZnWO 4 lattice and do not change the lattice's initial wolframite structure. The optical absorption spectrum in the UV region of the ZnWO 4 pigment calcined at 800 °C for 3 h is a ligand-to-metal charge transfer from O 2p nonbonding orbits to antibonding W 5d orbits. On account of the doping Co 2+ (3d 7 ), Mn 2+ (3d 5 ), and Fe 3+ (3d 5 ) transition metal ions, these chromophore ions have occupied the distorted octahedral site of Zn 2+ , leading to d-d transition and metal-to-metal charge transfer from the occupied 3d orbits of A 2+ to unoccupied W 5d orbits in UV and visible ranges and generating some bright colors. Significantly, these inorganic pigments are also endowed with excellent thermal and chemical stability and are conducive to harsh working conditions. All of the analysis results have offered some design strategies for various colorful inorganic pigments with high near-infrared reflectance.