The removal of Cs from radioactive wastewater remains a great challenge due to the presence of a large number of coexisting ions. Herein, a novel porous fiber-supported metal tin sulfide named ...PVC-Me2NH22Sn3S7 was designed. Specifically, four tin sulfides were prepared by the one-pot method in different solvents. Water was the most suitable solvent since it was essential for converting amides to cations. When three amides were used as precursors, Me2NH22Sn3S7 prepared with DMF showed the best adsorption performance. Five polymers were then comprehensively evaluated around physicochemical stability, hydrophilicity, and cost to facilitate the engineering application of adsorbents. Finally, polyvinyl chloride (PVC) was selected as the support material. The optimized porous PVC-Me2NH22Sn3S7 fiber with 50 wt% Me2NH22Sn3S7 percentage can reach adsorption equilibrium within 30 min, has a wide active pH range of 2–12, and has a high adsorption capacity of 419.01 mg g−1. When applied to simulated wastewater, the separation coefficients of Cs+ and coexisting ions were above 1 × 104. The Cs + adsorption enthalpy change was obtained by calorimetric study and simulation calculation. Even after 50 consecutive cycles, the removal efficiency barely decayed. The Cs+ concentration could be enriched to 259.93 times that of the geothermal water. The above advantages make PVC-Me2NH22Sn3S7 a promising adsorbent for selective Cs + removal from wastewater.
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•High-performance Me2NH22Sn3S7 was synthesized and applied to the PVC-Me2NH22Sn3S7 fiber.•The porous PVC-Me2NH22Sn3S7 can be large-scale prepared with a commercialized apparatus.•High adsorption performance was maintained even after 50 consecutive adsorption-desorption cycles.•The adsorption enthalpy change of PVC-Me2NH22Sn3S7 toward Cs+ was obtained by calorimetry and simulation calculation.
•Established the quaternary phase diagram FePO4-LiFePO4-NaFePO4-KFePO4 by DFT for the first time.•The competitive mechanism of alkali ions in FePO4 during extraction from a salt lake is ...revealed.•Na2/3FePO4 phase is the main reason for to decreased cyclability of FePO4 for lithium recovery in brines.•Proposed an innovative FePO4 regeneration process to enhance electrode performance and lifespan.
The rapid expansion of lithium battery applications has resulted in a shortage of lithium resources, prompting researchers to focus on the electrochemical extraction of lithium from water resources using FePO4 as the host material. However, a large amount of alkali metal impurity ions in brine leads to irreversible capacity loss, limiting the industrial application of FePO4 materials in lithium extraction. The mechanism of alkali metal ions’ influence on FePO4 materials remains unclear. To address this issue, the quaternary phase diagram of FePO4-LiFePO4-NaFePO4-KFePO4 and the diffusion barriers of lithium/sodium ions in FePO4 were obtained for the first time based on the theoretical calculation of density functional theory (DFT). DFT and X-ray diffraction (XRD) refinement revealed that the inability to remove Na2/3FePO4 from the FePO4 is a critical issue affecting electrode recyclability. An innovative electrode regeneration process was proposed to enhance the lifespan of FePO4 material. The Na2/3FePO4 impurity was converted to LiFePO4 using K2S2O8 abstersion and 0.1 mol/L LiCl lithiation regeneration process. After five rounds of regenerations, the total lithium extraction of the material could still reach 80.18 % of the extraction of the brand-new electrode, demonstrating the multiple reuses of the host material and cost savings. These innovative discoveries can advance the industrial application of electrochemical lithium extraction from FePO4 electrode materials.
Lightweight, strong and broadband microwave absorbents are urgently demanded for practical applications. Exploring magnetic/dielectric composites by anchoring magnetic nanostructures on lightweight ...dielectric carbon is an effective way, due to their possible good impedance matching condition. Herein, one-dimensional FeCo/C nanofibers are fabricated by electrospinning method and subsequent anoxic annealing treatment, which are used as difunctional magnetic/dielectric microwave absorbents. The nanofibers have a large aspect ratio, in which tiny magnetic FeCo nanocrystals are uniformly decorated in the amorphous dielectric C nanofibers. Benefiting from good impedance matching condition, enhanced microwave attenuation ability and synergistic effect between ferromagnetic FeCo and dielectric C, the FeCo/C nanofibers exhibit boosting microwave absorption performance, which is related to the absorber thickness and filling ratio. The optimal FeCo/C/paraffin composites with 40 wt% of functional fillers show a minimum reflection loss value of −59.9 dB with broad effective absorption bandwidth of 6.0 GHz at 13.2 GHz when the absorber thickness is only 2.6 mm. The FeCo/C nanofibers have a small density of only about 1.1 g/cm3, much smaller than the bulk FeCo (7.4–7.6 g/cm3). Owing to the characteristics of low density, strong absorption and broad effective absorption bandwidth, the FeCo/C nanofibers are promised to be good candidates as microwave absorbents.
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•The FeCo/C nanofibers were prepared by electrospinning and annealing treatment.•The carbon nanofibers were uniformly decorated by tiny FeCo nanocrystals.•The FeCo/C nanofibers have a small density of only 1.1 g/cm3.•The absorption bandwidth of FeCo/C reaches 6.0 GHz with a thickness of 2.6 mm.•The FeCo/C composites show a minimum reflection loss value of −59.9 dB at 13.2 GHz.
Objective
To compare the value of the thyroid imaging reporting and data system proposed by Kwak (KWAK TI‐RADS) and the 2015 American Thyroid Association (ATA) guidelines for diagnosis of medullary ...thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC). To confirm the role of cell block (CB)‐assisted fine‐needle aspiration (FNA) in final diagnosis of MTC.
Design
Retrospective hospital‐based cohort study.
Patients
Ninety‐three patients with 29 MTCs, 31 PTCs and 33 thyroid adenomas (TAs) who underwent thyroidectomy from January 2010 to May 2019 were retrospectively reviewed. The KWAK TI‐RADS and ATA guidelines were used to assess each thyroid nodule. FNA, CB‐assisted FNA and core needle biopsy (CNB) were performed in final diagnosis.
Results
Age and ultrasound features (composition, echogenicity and shape) were significantly different between MTC and PTC. Sex and ultrasound features (echogenicity, margin and calcification) were significantly different between MTC and TA. The KWAK TI‐RADS and ATA guidelines showed no significant difference for MTC (area under the curve AUC: 0.812 and 0.808; P = .37‐.85) or PTC (AUC: 0.883 and 0.885; P = .25‐.96). The KWAK TI‐RADS and ATA guidelines showed high specificity and sensitivity for MTC (93.9% and 62.1%, 87.9% and 65.5%) and PTC (93.9% and 67.7%, 87.9% and 77.4%), respectively. For suspicious MTC (7 cases), CB‐assisted FNA provide accuracy preoperative diagnosis.
Conclusions
Although the diagnostic performance of the TI‐RADS and ATA guidelines is worse for MTC than PTC, the difference is not statistically significant. CB‐assisted FNA should be performed in thyroid nodules with 4a or lower suspicion to avoid misdiagnosis of MTC.
Elastography ultrasound (EUS) imaging is a vital ultrasound imaging modality. The current use of EUS faces many challenges, such as vulnerability to subjective manipulation, echo signal attenuation, ...and unknown risks of elastic pressure in certain delicate tissues. The hardware requirement of EUS also hinders the trend of miniaturization of ultrasound equipment. Here we show a cost-efficient solution by designing a deep neural network to synthesize virtual EUS (V-EUS) from conventional B-mode images. A total of 4580 breast tumor cases were collected from 15 medical centers, including a main cohort with 2501 cases for model establishment, an external dataset with 1730 cases and a portable dataset with 349 cases for testing. In the task of differentiating benign and malignant breast tumors, there is no significant difference between V-EUS and real EUS on high-end ultrasound, while the diagnostic performance of pocket-sized ultrasound can be improved by about 5% after V-EUS is equipped.
As the understanding of environmental responsibility deepens among enterprises and the government tightens environmental regulations, the green supply chain becomes trendy. In the present study, an ...investigation is conducted into a two-echelon green product supply chain consisting of one manufacturer and one retailer. Due to the complexity of the dynamic network structure of the supply chain, there are various uncertain factors that cannot be obtained probability distributions, and these parameters are considered as uncertain variables. With the help of the uncertainty theory, we construct chance constrained models for both centralized and decentralized decision-making. The models also consider both the green level and the sensitivity of customers to green. To explore the impact of cost sharing contract on uncertain models, we also establish cost sharing model and bargaining model. According to the results of theoretical analysis, equilibrium decisions can be achieved by solving the models. Finally, numerical experiments have shown that the proposed contract is beneficial for improving the green level of products and the overall profit of the supply chain in uncertain environments. It can also be seen that decision-makers can significantly increase the profits of the manufacturer at a high level of confidence, but the increase in profits for the retailer is not significant. In addition, compared to decentralized decision-making, the bargaining strategy will enable the retailer to gain more profits.
On the morning of July 21, 2017, a localized rainstorm event occurred in the Shijiazhuang area of Hebei Province, with the heavy rain mainly concentrating in the Shijiazhuang urban area and its ...eastern and northern parts. But this rainstorm process was omitted by both numerical and subjective forecasts. In this paper, the triggering mechanisms of the mesoscale convective systems that have caused this localized rainstorm are analyzed by using the intensified surface observation data, Doppler radar data, the four-dimensional variational Doppler radar analysis system (VDRAS), the National Centers for Environmental Prediction (NCEP) reanalysis data and the ERA5 reanalysis. The observation analysis shows that when the heavy rain was occurring, the Shijiazhuang area was controlled by the western Pacific subtropical high, and the high temperature and high humidity environment has provided favorable vapor, thermal and energy conditions for the rainfall. Three key factors are responsible for the triggering of this severe convective weather. First, the strong thunderstorm high pressure and cold pool formed in Qinhuangdao and Tangshan areas in the northeastern Hebei. The surface wind field was affected by the pressure-gradient force generated by the thunderstorm high pressure, and consequently the northeasterly wind gradually strengthened, which guided the tongue-shaped cold pool to gradually move southwestward to the northern Shijiazhuang. Thus, a long lasting cold-warm boundary (the leading edge of the cold tongue) was formed in the key precipitation area, which provided low-level convergence and the ascending motion for the occurrence and development of this severe convective weather. Second, the northeasterly wind in the east side of Taihang Mountain was forced to ascend by the topography of Taihang Mountain, which strengthened the upward motion. Third, as the direction of the Taihang Mountains shifts from a northeast–southwest direction to a northwest–southeast direction in the west side of Shijiazhuang, the surface northeasterly airflow is changed to a northwesterly airflow here, forming a convergence in the key area of precipitation in front of the mountain. Thus, an unstable vertical structure that features low-level convergence and middle-level divergence is formed. The above three factors work together in the region where the severe convections occurred, and triggered the release of the conditional instability energy, finally resulting in this short-time heavy rain. The results indicate that in the forecast of severe convections in midsummer, we should pay extra attention to the complex terrain and the effects of the cold pool.
Herein, NiCoP nanoparticles decorated on reduced graphene oxide (rGO) were synthesized through a two-step hydrothermal-phosphorization route as enhanced microwave absorbers. Microstructure ...investigations indicate that NiCoP nanoparticles are uniformly anchored on the surface of rGO. Compared with the bare NiCoP, NiCoP/rGO nanocomposites reveal clearly improved microwave absorbing performance. The strongest reflection loss (RL) values of NiCoP/rGO hybrid absorber can reach −20.61 dB at 6.43 GHz with a matching thickness of 4.4 mm, and a broad effective absorption bandwidth (RL < −10 dB) of 4.13 GHz (13.87–18 GHz) can be obtained at only 2.0 mm, while the RL values of the pure NiCoP cannot reach −10 dB in the entire measurement frequency range. This improvement of microwave absorption is ascribed to the polarization, interface interaction and synergistic effect between NiCoP and rGO nanosheets. NiCoP/rGO nanocomposites are expected to be novel microwave absorption materials with high microwave absorption properties.
Benefiting from the dipoles polarization, interfacial polarization, conductivity loss and multiple reflection and scattering, the NiCoP/rGO nanocomposites have a broader qualified bandwidth (QB, RL ≤ −10 dB). Display omitted
•NiCoP nanoparticles were in-situ decorated on rGO without using bridging agent.•The effective bandwidth of NiCoP/rGO (RL < −10 dB) covers 13.87–18 GHz at only 2.0 mm.•NiCoP/rGO is novel bifunctional magnetic/dielectric material for absorbing microwave.
In this work, a novel binder-free electrode, in which three-dimensional porous Ni
2
P@Ni(OH)
2
nanosheet arrays were in situ grown on carbon cloth (CC), is rationally designed for supercapacitor ...applications. In comparison with Ni
2
P@CC, the Ni
2
P@Ni(OH)
2
@CC electrode represents superior electrochemical characteristics: the gravimetric capacitance and areal capacitance are boosted to be 632 C g
−1
and 0.73 C cm
−2
at 1 mA cm
−2
, about 2 and 2.7 times larger than those of Ni
2
P@CC (321 C g
−1
and 0.27 C cm
−2
), respectively; the rate capability is improved to be 63.3% from 1 to 10 mA cm
−2
, about 1.5 times larger than Ni
2
P@CC (42.9%); the cycle stability is enhanced to be 81.4% after 1000 cycles, about 1.6 times larger than Ni
2
P/CC (51.8%). The assembly Ni
2
P@Ni(OH)
2
@CC//AC hybrid supercapacitor device shows high energy density of 23.5 Wh kg
−1
at a power density of 1158.0 W kg
−1
and good cycling stability of 75.2% maintenance after 5000 cycles. Benefiting from the combined advantages of high electronic conductivity and large specific capacitance of Ni
2
P, superior anion exchanging/intercalating capacity of Ni(OH)
2
, excellent flexibility of carbon cloth, and special hierarchical architecture with large surface area, the Ni
2
P@Ni(OH)
2
@CC electrode is promised to be a good candidate for supercapacitors.
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