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Abstract Rapid detection and absorption of 99TcO4⁻ contamination in the environment are critical due to its high radioactivity, long half‐life, and significant environmental mobility. Resins have been demonstrated effective bifunctional properties for both the detection and separation of 99TcO4⁻. However, the poor stability of these compounds limits their practical application. Here, a chemical grafting strategy is presented to synthesize ultra‐stable plastic scintillation resin, in which 4‐vinylpyridine and divinylbenzene are cross‐linked as matrix polymer to withstand extreme conditions and a fluorophore “shield” to convert beta radiation into detectable signals. As expected, the as‐obtained resin exhibits a high adsorption capacity of 549.2 mg g⁻¹ for 99TcO4⁻ with a rapid kinetic response of just 10 min as well as superior selectivity at 1000 times excess of interfering ions and full reusability. Moreover, it showed remarkable stability under 800 kGy, 3.0 mol L−1 HNO3 or 2.5 L solution continuous leaching, consistently maintaining high separation and detection efficiency after recycling 10 times. This strategy paves a new way to develop stable resin for the rapid capture and accurate measurement of 99TcO4⁻, which owns great potential for practical application.

Background and objectHeart failure is one of the common complications in patients with end-stage renal disease (ESRD) and a major cause of death in these patients. The choice of dialysis modality for ESRD patients with congestive heart failure (CHF) is still inconclusive. The purpose of this study was to compare the prognosis of hemodialysis (HD) and peritoneal dialysis (PD) among ESRD patients with CHF and provide a basis for clinical decision-making.Materials and methodsThis was a retrospective study conducted at Guangdong Provincial Hospital of Traditional Chinese Medicine that included patients with CHF requiring long-term renal replacement therapy between January 1, 2012 and December 31, 2017. The end of follow-up was December 31, 2020. All patients were divided into HD and PD groups and sub grouped by age, and we used univariate and multifactorial Cox regression analyses to calculate the relative hazard ratios (HR) of the different dialysis types and adjusted for differences in baseline data using propensity score matching (PSM).ResultA total of 121 patients with PD and 156 patients with HD were included in this study. Among younger ESRD patients (≤65 years of age) with CHF, the prognosis of HD was worse than that of PD [HR = 1.84, 95% confidence interval (CI) = 1.01–3.34], and this disadvantage remained significant in the fully adjusted model [sex, age at dialysis initiation, Charlson comorbidities index, body mass index, prealbumin, hemoglobin, and left ventricular ejection fraction (LVEF)] and after PSM. In the older group (>65 years of age), the prognosis of HD was better than that of PD (HR = 0.46, 95% CI = 0.25–0.85), and the protective effect remained in the fully adjusted model and after PSM. The aforementioned survival differences across the cohort were maintained in patients with preserved LVEF (>55%), but could not be reproduced in patients with reduced LVEF (≤55%).ConclusionIn southern China, PD is a better choice for younger patients with ESRD, CHF and preserved LVEF, and HD is the better option for older patients.

In 2018, a flash flood occurred in the Zhongdu river, which lies in Yibin, Sichuan province of China. The flood caused many casualties and significant damage to people living nearby. Due to the difficulty in predicting where and when flash floods will happen, it is nearly impossible to set up monitors in advance to detect the floods in detail. Field investigations are usually carried out to study the flood propagation and disaster-causing mechanism after the flood’s happening. The field studies take the relic left by the flash flood to deduce the peak level, peak discharge, bed erosion, etc. and further revel the mechanism between water and sediment transport during the flash flood This kind of relic-based study will generate bigger errors in regions with great bed deformation. In this study, we come up with numerical simulations to investigate the flash flood that happened in the Zhongdu river. The simulations are based on two-dimensional shallow water models coupled with sediment transport and bed deformation models. Based on the real water level and discharge profile measured by a hydrometric station nearby, the numerical simulation reproduced the flash flood in the valley. The results show the flood coverage, water level variation, and velocity distribution during the flood. The simulation offers great help in studying the damage-causing process. Furthermore, simulations without considering sediment transport are also carried out to study the impact of bed erosion and sedimentation. The study proved that, without considering bed deformation, the flood may be greatly underestimated, and the sediment lying in the valley has great impact on flood power.

Selective extraction of low-concentration thorium (Th(IV)) from wastewater is a very important research topic. In this paper, amidoxime cellulose was synthesized, and its composition and structure were characterized by FT-IR, SEM, XPS, and elemental analysis. The adsorption experiment results showed that the adsorption reaction was a spontaneous exothermic process. When the solid–liquid ratio was 0.12 g/L and the pH value was 3.5, the adsorption percentage of the Th(IV) in water onto amidoxime-functionalized cellulose (AO-CELL) could reach over 80%. The maximum adsorption capacity can reach to 450 mg/g. At the same time, the adsorption selectivity, desorption process and reusability of the material were also studied. The results showed that the AO-CELL had a good selectivity for Th(IV) in the system with Sr2+, Cu2+, Mg2+, Zn2+, Pb2+, Ni2+, and Co2+ as co-ions. In the nitric acid concentration of 0.06 mol/L system, the AO-CELL desorption rate of Th(IV) can reach 95%, and the adsorption rate of Th(IV) in aqueous solution of AO-CELL is still above 60% when the AO-CELL is reused four times. The above results show that the amidoxime cellulose adsorption material synthesized by our research group has good selective adsorption performance for Th(IV) of a low concentration in an aqueous solution and has a good practical application value.

Graphene oxide (GO) and its composite membranes have exhibited great potential for application in water purification and desalination. This article reports that a novel graphene oxide membrane (GOM) of ~5 µm thickness was fabricated onto a nylon membrane by vacuum filtration and cross-linked by amino acids (L-alanine, L-phenylalanine, and serine). The GOM cross-linked by amino acids (GOM-A) exhibits excellent stability, high water flux, and high rejection to metal ions. The rejection coefficients to alkali and alkaline earth metal ions through GOM-A were over 94% and 96%, respectively. The rejection coefficients decreased with an increasing H+ concentration. Metal ions (K+, Ca2+, and Fe3+) can be inserted into GOM-A layers, which enlarges the interlayer spacing of GOM-A and neutralizes the electronegativity of the membrane, resulting in the decease in the rejection coefficients to metal ions. Meanwhile, GOM-A showed quite high antibacterial efficiency against E. coli. With the excellent performance as described above, GOM-A could be used to purify and desalt water.

There is continuously increasing interest in research on multi-sensor data fusion technology. Because Dempster’s rule of combination can be problematic when dealing with conflicting data, there are numerous issues that make data fusion a challenging task, including the exponential explosion, Zadeh Paradox, and one-vote veto. These issues lead to a great difference between the fusion results and real results. This paper applies the idea of analyzing distance-based evidence conflicts, introduces the concept of vector space, and proposes a new cosine theorem-based method of identifying and expressing conflicting data. In addition, this paper proposes a new data fusion algorithm based on the degree of mutual support between beliefs, which is based on the Jousselme distance-based combination rule proposed by Deng et al. Simulation results demonstrate that the presented algorithm achieves great improvements in both the accuracy of identifying conflicting data and that of fusing conflicting data.

Dempster-Shafer evidence theory (DSET) is a flexible and popular paradigm for multisource data fusion in wireless sensor networks (WSNs). This paper presents a novel and easy implementing method computing masses from the hundreds of pieces of data collected by a WSN. The transfer model is based on the Mahalanobis distance (MD), which is an effective method to measure the similarity between an object and a sample. Compared to the existing methods, the proposed method concerns the statistical features of the observed data and it is good at transferring multi-dimensional data to belief assignment correctly and effectively. The main processes of the proposed method, which include the calculation of the intersection classes of the power set and the algorithm mapping MDs to masses, are described in detail. Experimental results in transformer fault diagnosis show that the proposed method has a high accuracy in constructing masses from multidimensional data for DSET. Additionally, the results also prove that higher dimensional data brings higher accuracy in transferring data to mass.

The cation transport behavior of thermally treated reduced graphene oxide membranes (GOMs) is reported. The GOMs were reduced by heat treatment at 25, 80, and 120 °C and then characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy to determine oxygen group content, C/O ratio, and layer spacing. The permeation rates of various cations with different sizes and charge numbers through these membranes were measured to understand the effect of the cations on transport behavior. The results indicated that the cation transport through the membranes depended on the layer spacing of the membrane and ion size and charge. Cations of the same valence permeating through the same GOM could be differentiated by their hydration radius, whereas the same type of cation passing through different GOMs could be determined by the spacing of the GOM layers. The cation valence strongly affected permeation behavior. The GOM that was prepared at 120 °C exhibited a narrow layer spacing and high separation factors for Mg/Ca, Mg/Sr, K/Ca, and K/Fe. The cations moving through the membrane could insert into the membrane lamellas, which neutralized the negative charge of the membrane, enlarged the layer spacing of the GOMs, and affected cation permeation.

Sediment transport and bed morphology at channel confluences with different confluence angles and discharge ratios are analyzed through a series of flume experiments. Bed topography and sediment transport rate are measured and results are compared among different conditions. Sediment transport is intermittent and pulsating as the tributary flow mixes with the mainstream, and the sediment transport rate goes up with the increase in discharge ratio and confluence angle. With no sediment supplied from upstream of the flume, a central scour hole will form along the shear plane and develop toward the right bank, and the depth of the central scour hole increases as the confluence angle and discharge ratio increase. With heavy upstream sediment supplement, deposition will happen in the separation zone and upstream of the confluence area because of the tributary. And the deposition height is related to the discharge ratio and confluence angle. Results indicate the significant impact of confluence geometry, sediment, and flow factors on fluvial processes.

To better eliminate the impact of radioactive elements on the environment, we synthesized a terpolymer of acrylonitrile, acrylic acid, and hydroxyapatite (AN/AA-co-HAP) as an adsorption material for separating uranyl ions in aqueous solution, which was based on our previous work. We used Fourier-transform infrared spectroscopy, scanning electron microscopy, elemental analysis, N2 sorption/desorption isotherm, thermogravimetric analysis and X-ray diffraction methods to characterize the material’s structure, and studied the effect of equilibrium time, pH, ionic strength, solid–liquid ratio, initial concentration, and temperature on the adsorption process. Finally, it is concluded that adsorption equilibrium can be reached within 60 min at room temperature, and the maximum adsorption capacity is 343.3 mg/g. Thermodynamic analysis indicates that the adsorption process is a spontaneous endothermic process. In the system with a nitric acid concentration of 0.05 mol/L (pH value: 1.3), the desorption rate of U(VI) can reach 91%, while the adsorption rate of U(VI) in aqueous solution onto AN/AA-co-HAP is still remains >60% even after the material is has been reused 6 times. These results suggest that AN/AA-co-HAP is highly valuable for treating U(VI) ions in aqueous solution. [ABSTRACT FROM AUTHOR]

Amidoxime functionalized hydroxyapatite (HAP) composites were prepared and characterized by means of Fourier-transform infrared spectroscopy, scanning electron microscopy and X-ray powder diffraction. The adsorption characteristics of the adsorbent on uranyl ions were studied, and the effects of solid–liquid ratio, pH value, ionic strength, temperature, equilibrium time and other factors on the adsorption process were investigated. Under the optimum conditions, the adsorption capacity of the modified HAP material can reach 889.7 mg/g. The adsorption thermodynamics and kinetics data show that the adsorption of U(VI) by amidoxime (AO) functionalized hydroxyapatite is a spontaneous exothermic process, and the adsorption equilibrium can be reached within 30 min, which is in line with the Langmuir isothermal adsorption model. AO-co-HAP has a very good selectivity for U(VI). The desorption rate of U(VI) can reach 97.88% in 0.15 M acid solution. Compared with the traditional separation method, this adsorbent has a wider range of raw materials and a lower cost of waste liquid treatment, so it has an excellent practical application value. [ABSTRACT FROM AUTHOR]

The copolymer of poli(acrylic acid- co-hydroxyapatite) (PAA-HAP) was prepared and characterized by means of FT-IR and SEM analysis. The adsorptive features of PAA-HAP for $$ {{\text{UO}}_{ 2}}^{{ 2 { + }}} $$ was studied as a function of pH, adsorbent dosage, initial metal ion concentration and temperature. The adsorption isotherm data fitted well to the Langmuir isotherm model. The adsorbed $$ {{\text{UO}}_{ 2}}^{{ 2 { + }}} $$ can be desorbed effectively by 0.1 M HNO. The maximum adsorption capacities for $$ {{\text{UO}}_{ 2}}^{{ 2 { + }}} $$ of the dry PAA-HAP was 1.86 × 10 mol/g. The high adsorption capacity and kinetics results indicate that PAA-HAP can be used as an alternative adsorbent to remove $$ {{\text{UO}}_{ 2}}^{{ 2 { + }}} $$ from aqueous solution. [ABSTRACT FROM AUTHOR]

Poly( N,N-diethylacrylamide- co-acrylicacid) (P(DEA- co-AA)) was synthesized by Free-Radical polymerization. The effects of contact time, solid/liquid ratio, pH value, and initial concentration on the adsorption of Th ions onto P(DEA- co-AA) were investigated. The adsorption was highly dependent on the initial pH and initial metal ions concentration of the solvent. The adsorption kinetic data indicated that the chemical adsorption is a swiftness processes, the adsorption equilibrium could be achieved within 20 min. The adsorption isotherm of the microgels for Th is fitted to the Langmuir isotherm model. Gibbs free enthalpy change was ∆ G < 0 indicating that the adsorption process was spontaneous. The enthalpy and entropy changes of the process of the adsorbents for Th were greater than zero showing that the overall process was endothermic. After five times of repeated tests for the P(DEA- co-AA) microgels it still remained its excellent adsorption. [ABSTRACT FROM AUTHOR]

We prepared poly(N, N-diethylacrylamide- co-acrylic acid) (P(DEA- co-AA)) microgels which could efficiently remove UO from aqueous solutions. In this study, the effect of adsorption parameters such as pH value, adsorbent dose, shaking time, and temperature has investigated. It is found that the pseudo-second-order model is more suitable for our experiment. The adsorption kinetic data indicated that the chemical adsorption was the swiftness processes, the adsorption equilibrium could be achieved within 30 min. And there are very good correlation coefficients of linearized equations for Langmuir isotherm model, which indicated that the sorption isotherm of the hydrogel for UO can be fitted to the Langmuir isotherm model. The adsorption process was spontaneous (∆ G < 0) and exothermic (∆ H < 0). The adsorbed UO can be desorbed effectively by 0.1 M HNO and the adsorption capacity is not significantly reduced after five cycles. Present study suggests that this P(DEA- co-AA) can be used as a potential adsorbent for sorption UO and also provide a simple, fast separation method for removal of UO ions from aqueous solution. [ABSTRACT FROM AUTHOR]

The copolymers of styrene and maleic anhydride resin (PSt/MA) was synthesized by free radical polymerization and characterized by means of FTIR. It is shown that the PSt/MA copolymer has rather strong coordination ability to UO ions by chelation with the carboxylate group, and the microstructures of the U(VI)-PSt/MA complexes can be well controlled. The influence factors on UO ions were also investigated and described in detail, such as contact time, solid/liquid ratio, pH value, ethanol content, and initial concentration. It was found that the maximum adsorption quantity of UO was 831 mg/g. Experiments show that PSt/MA can recover UO ions with high adsorption selectively from a simulated industry solution containing Ca and Mg as impurities. The adsorption kinetic data were best described by the pseudo-second-order equation, indicating that the chemical adsorption was the rate-limiting step. And there are very good correlation coefficients of linearized equations for Langmuir model, which indicated that the sorption isotherm of the PSt/MA for UO can be fitted to the Langmuir model. After five times of repeated tests for the hydrogel it still remained its excellent adsorption. [ABSTRACT FROM AUTHOR]