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In this paper, DSA-AAD-DA and DSA-TPDH-DA were prepared to effectively remove metal ions and cationic dyes from aqueous solution. The hydrazone structure was prepared by hydrazide-modified SA which captured metal ions selectively, and the remaining functional groups were used as active adsorption sites for cationic dyes. The thermodynamic parameter for the sorption demonstrated the process is endothermic and spontaneous. In single process, the adsorption of metal ions by DSA-AAD-DA and DSA-TPDH-DA correlated well with the Freundlich model through the hydrazone structure coordination and ion exchange which was mainly chemical adsorption, and cationic dyes adsorption correlated well with the Langmuir model which was shown monolayer adsorption was dominant by hydrogen bonding, electrostatic interaction, and π-π interaction. In binary system, the mixed adsorption shown significant antagonism effect in high concentration, but cationic dyes and metal ions in low concentration were efficiently and simultaneously removed, the adsorption ability of DSA-TPDH-DA was much better than DSA-AAD-DA. Moreover, adsorption efficiency can still maintain more than 80% after five times adsorption-desorption recycle. Therefore, DSA-AAD-DA and DSA-TPDH-DA possessed great potential for wastewater treatment.

Herein, a novel magnetic cross-linked chitosan CS-BA@Fe3O4 was rationally synthesized by cross-linked with epichlorohydrin and coated with Fe3O4 to the acylated chitosan, which was prepared by the reaction of chitosan with benzenetricarboxylic anhydride. The as-obtained absorbent was characterized by FTIR, XRD, VSM, TGA, TEM, BET, SEM and EDS. The results showed that the maximum adsorption capacities of CR and CV were 471.46 ± 16.97 mg/g and 515.91 ± 25.12 mg/g at 318.15 K, respectively. The main adsorption mechanisms were H-bonding and electrostatic interaction. The kinetic data were in good agreement with the pseudo-second-order model and closed to adsorption equilibrium at 30 min. Thermodynamic studies showed that the adsorption on CS-BA@Fe3O4 were spontaneous and endothermic. More importantly, the adsorbent exhibited excellent regeneration properties after 6 cycles and remarkable stability under harsh environments including strong acid, strong alkali, multi-salt and mixed dyes conditions. Therefore, abundant efforts revealed a broad application prospect of CS-BA@Fe3O4 in water remediation.

Preform shape design for complex forging is an important and intractable aspect in the design of forging process. This paper presents an integrated methodology based on elliptic Fourier analysis (EFA), finite element method (FEM) and genetic algorithms (GA) to determine optimal preform shape. Firstly, an elliptic Fourier analysis, which has the advantages of wide versatility and short design cycle, is adopted as the transformation rule for the first time in this paper. The similarity between elliptic Fourier analysis and plastic forming process is demonstrated theoretically. Meanwhile, the main steps for using elliptic Fourier analysis module to design preform shape are introduced: two-dimensional slice, elliptic Fourier analysis and three-dimensional reconstruction. The preform shapes generated by elliptic Fourier analysis module can be simulated directly in finite element method module. Next, in order to control the deformation amount and material distribution of preform, two sets of design parameters, i.e., shape factor and triaxial scaling factors, are employed to control the preform shape before entering the finite element method module simulation. Then, these design parameters are optimized using the genetic algorithm module. Finally, taking a heavy forging with complex shapes as an example, its optimized design scheme is carried out in real forging production. The results show that the forging is produced without problems of crack, folds, underfilling and unreasonable flash distribution, which validates the effectiveness of the presented methodology. Furthermore, this integrated methodology could be extended to other complex forgings.

Abnormal Cu(II) ions levels may affect many biological functions, and it is of great importance to detect Cu(II) ions in organisms.Herein, we report a near-infrared (NIR) fluorescent probe EtRh-N-NH

For a forging with complex shape, it is necessary to design one or more pre-forging shapes before the final forging to avoid forging defects and improve forging performance. In this paper, a novel method of using conformal mapping to design the pre-forging shape is proposed to achieve a reasonable three-dimensional (3D) shape of the pre-forging. Firstly, the 3D final forging was two-dimensionally (2D) sliced to simplify the design problem. The new profile of each slice was calculated based on the conformal mapping method. Then, the discrete points on all new profiles were combined into a 3D point cloud for surface reconstruction to obtain 3D model of the pre-forging. Next, four parameters (conformal factor and triaxle scaling factors) were applied to describe the pre-forging shape. Finite element analysis was used to simulate the forging process of the designed pre-forging. Finally, this method was applied to design the pre-forging shapes of different forgings. Through reasonable parameter values, a satisfactory pre-forging shape can be obtained. This method is effective, easy to implement, and has universal adaptation.

The emergence of coronavirus disease 2019 (COVID-19) pandemic led to an urgent need to develop therapeutic interventions. Among them, neutralizing antibodies play crucial roles for preventing viral infections and contribute to resolution of infection. Here, we describe the generation of antibody libraries from 17 different COVID-19 recovered patients and screening of neutralizing antibodies to SARS-CoV-2. After 3 rounds of panning, 456 positive phage clones were obtained with high affinity to RBD (receptor binding domain). Then the positive clones were sequenced and reconstituted into whole human IgG for epitope binning assays. After that, all 19 IgG were classified into 6 different epitope groups or Bins. Although all these antibodies were shown to have ability to bind RBD, the antibodies in Bin2 have more superiority to inhibit the interaction between spike protein and angiotensin converting enzyme 2 receptor (ACE2). Most importantly, the antibodies from Bin2 can also strongly bind with mutant RBDs (W463R, R408I, N354D, V367F and N354D/D364Y) derived from SARS-CoV-2 strain with increased infectivity, suggesting the great potential of these antibodies in preventing infection of SARS-CoV-2 and its mutations. Furthermore, these neutralizing antibodies strongly restrict the binding of RBD to hACE2 overexpressed 293T cells. Consistently, these antibodies effectively neutralized pseudovirus entry into hACE2 overexpressed 293T cells. In Vero-E6 cells, these antibodies can even block the entry of live SARS-CoV-2 into cells at only 12.5 nM. These results suggest that these neutralizing human antibodies from the patient-derived antibody libraries have the potential to become therapeutic agents against SARS-CoV-2 and its mutants in this global pandemic.

Many researchers focus on the conversion of waste into reusable materials in recent years. In this study, waste expanded polystyrene foam (WEPS) and 1,2,4-benzenetricarboxylic anhydride (BTA) were used as raw materials to prepare recyclable acylating waste expanded polystyrene adsorbent (WEPS-BTA) by Friedel-Crafts reaction and to recover dyes effectively. The WEPS-BTA was characterized by FT-IR, TGA, BET and SEM. WEPS-BTA showed good performance in a wide range of pH (2–12) and high concentration brine (0.2 M). The maximum adsorption capacity to methylene blue, safranine T, and malachite green were 859.9, 1036.7, and 1197.3 mg/g, respectively. It was found that Freundlich model and pseudo-second-order kinetics could describe the adsorption behavior. This is a heterogeneous, endothermic, and spontaneous multiple adsorption process. The plausible adsorption mechanism was explained by kinetic model, thermodynamic discussion, SEM-EDS, XPS and FT-IR. In addition, WEPS-BTA showed satisfactory reusability without significant loss of the removal efficiency of the three dyes after 5 cycles. Therefore, WEPS-BTA has the advantages of simple synthesis, efficient adsorption, easy recycling and reuse, and stable performance in a harsh environment. Converting waste polystyrene foam to an adsorbent is an economic way of handling waste and providing material for wastewater remediation simultaneously.

The purpose of this study is to quantitatively analyze the effect of strain path on roughness evolution of free surface during plastic deformation. Firstly, the crystal plastic finite element model for a representative volume element (RVE) of polycrystalline is established, including the polycrystalline geometric model and initial topography model. Next, based on two groups of strain path including five typical strain paths, i.e., uniaxial tension (UT), biaxial tension (BT), plane strain tension (PST), plane strain compression (PSC) and in-plane pure shear (PPS), the 3D surface roughness of free surface after the plastic deformation is presented quantitatively. The total change of surface topography can be divided into two parts, which relate to the homogenous deformation and inhomogeneous deformation. In a simple manner, the homogenous deformation and inhomogeneous deformation can correspond with the elastic deformation and plastic deformation respectively. As in the elastic deformation, the effect of the misorientation of the adjacent grains and strain localization in the polycrystalline material on the surface topography has no chance to exert on the very small strain. So the inhomogeneity of polycrystalline material has been ignored in the elastic deformation. For the effect of homogeneous deformation, the relationship between the surface roughness of the deformed surface, initial roughness and strain path is analytically derived. For the contribution of the inhomogeneous deformation to surface roughening, the quantitative relationship between surface roughness of the deformed surface and the strain path is acquired by the mathematical fitting based on hundreds of crystal plasticity finite element simulations. The final surface roughness of the deformed surface is obtained by combining these two parts. Then the experiment of biaxial tension on 6061 aluminum alloy sheet is taken as an example to verify the accuracy of surface roughness calculation. The comparison of experimental results and calculated results shows good consistency. Thereafter the surface roughening phenomena in the plastic deformation are observed at three different scales. The homogeneous deformation does not form additional peaks and valleys but changes the spacing and height of peaks and valleys of the initial surface topography, which brings about the surface roughening at macroscale level. In inhomogeneous deformation, the misorientation of the adjacent grains in the polycrystalline material is taken into consideration, which leads to the grain rotation and generates the additional peaks and valleys of the initial surface topography. The surface roughening due to this part can be seen at the mesoscopic scale. And the step phenomenon caused by slip bands inner the grains is the microscopic scale roughening behavior. This work is beneficial to understand the roughness evolution of free surface quantitatively with the effect of strain path and make out the surface roughening phenomena at different scales.

A recombinant laccase from Trametes versicolor in Pichia methanolica was produced constitutively in a defined medium. The recombinant laccase was purified using ultrafiltration, anion-exchange chromatography, and gel filtration. The molecular weight of the purified laccase was estimated as 64 kDa by SDS-PAGE. The purified recombinant laccase decolorized more than 90% of Remazol Brilliant Blue R (RBBR) initially at 80 mg l(-1) after 16 h at 45 degrees C and pH 5 when 25 U laccase ml(-1) was used. The purified recombinant laccase could efficiently decolorize RBBR without additional redox mediators.