Abstract
Ambient sunlight-driven CO
2
methanation cannot be realized due to the temperature being less than 80 °C upon irradiation with dispersed solar energy. In this work, a selective light ...absorber was used to construct a photothermal system to generate a high temperature (up to 288 °C) under weak solar irradiation (1 kW m
−2
), and this temperature is three times higher than that in traditional photothermal catalysis systems. Moreover, ultrathin amorphous Y
2
O
3
nanosheets with confined single nickel atoms (SA Ni/Y
2
O
3
) were synthesized, and they exhibited superior CO
2
methanation activity. As a result, 80% CO
2
conversion efficiency and a CH
4
production rate of 7.5 L m
−2
h
−1
were achieved through SA Ni/Y
2
O
3
under solar irradiation (from 0.52 to 0.7 kW m
−2
) when assisted by a selective light absorber, demonstrating that this system can serve as a platform for directly harnessing dispersed solar energy to convert CO
2
to valuable chemicals.
An ocean of studies have pointed to abnormal brain laterality changes in patients with bipolar disorder (BD). Determining the altered brain lateralization will help us to explore the pathogenesis of ...BD. Our study will fill the gap in the study of the dynamic changes of brain laterality in BD patients and thus provide new insights into BD research. In this work, we used fMRI data from 48 BD patients and 48 normal controls (NC). We constructed the dynamic laterality time series by extracting the dynamic laterality index (
) at each sliding window. We then used k-means clustering to partition the laterality states and the Arenas-Fernandez-Gomez (AFG) community detection algorithm to determine the number of states. We characterized subjects' laterality characteristics using the mean laterality index (MLI) and laterality fluctuation (LF). Compared with NC, in all windows and state 1, BD patients showed higher MLI in the attention network (AN) of the right hemisphere, and AN in the left hemisphere showed more frequent laterality fluctuations. AN in the left hemisphere of BD patients showed higher MLI in all windows and state 3 compared to NC. In addition, in the AN of the right hemisphere in state 1, higher MLI in BD patients was significantly associated with patient symptoms. Our study provides new insights into the understanding of BD neuropathology in terms of brain dynamic laterality.
The adsorption characteristics of protoxin and toxin from Bacillus thuringiensis by sepiolite were studied. The kinetic results showed that the protoxin and toxin could be adsorbed by sepiolite ...rapidly, and the equilibrium was reached within 1 h. The adsorption isotherms of both proteins followed Langmuir equation (R2>0.98) and the curves belonged to L type. The adsorption capacity, adsorption rate and the insecticidal activity of toxin were higher than those of protoxin. The results of ultraviolet irradiation showed that sepiolite could protect the toxin from ultraviolet irradiation damage, but it accelerated the damage of protoxin. Therefore, the toxin is suitable for preparing long-term formulations of B. thuringiensis using the carrier of sepiolite. The results of Fourier transform infrared, X-ray diffraction, and scanning electron microscopy indicated that toxin did not influence the structure of sepiolite and the adsorption of toxin only on the surface of sepiolite. The adsorption of toxin by sepiolite was enhanced by metal ions in the range of concentration from 0 to 4.0 mmol L−1, and the enhancement extent of metal ions on the adsorption of toxin was in the order: Ca2+>Mg2+>K+>Na+. The higher the loading of toxin per mass sepiolite, the lower the 50% of the larvae of sepiolite–toxin complex. The zeta potential of sepiolite suspension increased with the addition of metal ions, indicating that the driving forces of the adsorption of toxin to negatively charged sepiolite was electrostatic interaction.
With the large-scale cultivation of transgenic crops expressing Bacillus thuringiensis (Bt) insecticidal toxin in the world, the problem of environmental safety caused by these Bt crops has received ...extensive attention. The effects of soil organic matter (SOM) on the adsorption and insecticidal activity of Bt toxin in variable- and constant-charge soils (red and brown soils, respectively) were studied. Organic carbon in the soils was removed using hydrogen peroxide (H2O2). After H2O2 treatment, the SOM in the red and brown soils decreased by 71.26% and 82.82%, respectively. Mineral composition of the H2O2-treated soils showed no significant changes, but soil texture showed a slight change. After SOM removal, the cation exchange capacity (CEC) and pH decreased, while the specific surface area (SSA), point of zero charge (PZC), and zeta potential increased. The adsorption isotherm experiment showed that the Bt toxin adsorption on the natural and H2O2-treated soils fitted both the Langmuir model (R2≥ 0.985 7) and the Freundlich model (R2≥ 0.984 1), and the amount of toxin adsorbed on the H2O2-treated soils was higher than that on the natural soils. There was a high correlation between the maximum adsorption of Bt toxin and the PZC of soils (R2 = 0.935 7); thus, Bt toxin adsorption was not only influenced by SOM content, but also by soil texture, as well as the SSA, CEC, PZC, and zeta potential. The LC50 (lethal concentration required to kill 50% of the larvae) values for Bt toxin in the H2O2-treated soils were slightly lower than those in the natural soils, suggesting that the environmental risk from Bt toxin may increase if SOM decreases. As the measurement of insecticidal activity using insects is expensive and time consuming, a rapid and convenient in vitro method of enzyme-linked immunosorbent assays is recommended for evaluating Bt toxin degradation in soils in future studies.
The adsorption of hexavalent chromium (Cr(VI)) was improved by using organic bentonite (OB) modified with iron(III) chloride. The adsorption mechanisms and characteristics of OB and organic bentonite ...modified by FeCl3 (FMOB) were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDS). It was found that hydroxyl-iron replaced some of the calcium and magnesium contained in the FMOB, but no significant change in its structure was shown even though the adsorption experiments proved that FMOB had a better Cr(VI) adsorption ability compared to OB. The coated material was prepared by mixing FMOB and 4A molecular sieves in a coated pot for the adsorption experiments in the test column. The relevant results showed that the adsorption of the coated material retained its high adsorption ability and maintained that ability after desorption and regeneration, which implied a potential for further application.
The calculation of equilibrium constant from the Langmuir model is widely used in the literature. However, the dimensional problem of the equilibrium constant has often been ignored. For example, a ...recent publication on the strong properties of the new adsorbent for tetracycline. Nevertheless, this used an improper calculation of the standard equilibrium constant, confusing solute and solution. This creates dimension for K0 obtained from Eq. (13). Unfortunately, K0 should be dimensionless. In this comment, the origin and background of this kind of error is analyzed and the method for correcting the error is presented. Specifically, we establish a clear relationship between the Langmuir constant (KL) and the standard equilibrium constant (K0). We hope this comment clarifies the essence of calculating the standard equilibrium constant by using the Langmuir model, so others avoid the propagation of this kind of error.
The thermodynamic parameters are usually used to analyze the spontaneity, thermal and random change of the adsorption process, therefore, it is important to obtain these parameters accurately. ...Recently, Saeed et al. (2022) published a high academic paper to reveal the adsorption properties and mechanism of dyes onto the chitosan composite of the iron metal-organic framework (CS/MOF-235). However, the thermodynamic parameters of ΔG and ΔS need to be corrected because their results affected the analyzed conclusions. In the present study, the thermodynamic parameters were recalculated by using the correct method through the Langmuir isotherm model. The recalculated thermodynamic parameters indicated that the change in free energy (ΔG) for the removal of methylene blue (MB) and methyl orange (MO) onto CS/MOF-235 is negative but not positive, meaning that the adsorption of dyes (MB and MO) is spontaneous but not non-spontaneous. The change in entropy (ΔS) is positive but not negative, implying that the randomness increases but not decreases during the adsorption process. The enthalpy (ΔH) maintained negative value and the entropy (ΔS) obtained positive value indicate that both of them are the driving forces of the adsorption.
In this work, carbon fiber reinforced biomass carbon aerogel composites (CF/CA) were prepared by ionothermal synthesis using fructose as the raw material and oxidized polyacrylonitrile fiber as the ...reinforcing agent. During the preparation process, we have mixed fructose with oxidized polyacrylonitrile fibers and subjected them to a carbonization process under the conditions of hot ionic liquids. By controlling the reaction conditions, we successfully prepared fiber-reinforced carbon aerogel composites with excellent properties. The CF/CA has a high compressive strength (3.306 MPa). At the same time, the original low thermal conductivity (0.106 W·m−1·K−1) and low density (0.2976 g/cm2) of the carbon aerogel are maintained. In this work, the mechanical properties of carbon aerogel are improved to 230 % without changing the thermal insulation properties of CA, which makes a certain progress compared with the similar research. These excellent properties make CF/CA a promising engineering material. Moreover, we found that about 95 % of the ionic liquid can be recovered by evaporating under reduced pressure, and the recovered ionic liquid is still usable. This discovery provides a possibility for the green and sustainable development of the preparation process of carbon aerogels. This study provides new ideas and methods to further optimize the properties and applications of biomass carbon aerogels and their composites.
It is widely recognized that carbonic anhydrase (CA) participates in silicate weathering and carbonate formation. Nevertheless, it is still not known if the magnitude of the effect produced by CA on ...surface rock evolution changes or not. In this work, CA gene expression from Bacillus mucilaginosus and the effects of recombination protein on wollastonite dissolution and carbonate formation under different conditions are explored. Real-time fluorescent quantitative PCR was used to explore the correlation between CA gene expression and sufficiency or deficiency in calcium and CO₂ concentration. The results show that the expression of CA genes is negatively correlated with both CO₂ concentration and ease of obtaining soluble calcium. A pure form of the protein of interest (CA) is obtained by cloning, heterologous expression, and purification. The results from tests of the recombination protein on wollastonite dissolution and carbonate formation at different levels of CO₂ concentration show that the magnitudes of the effects of CA and CO₂ concentration are negatively correlated. These results suggest that the effects of microbial CA in relation to silicate weathering and carbonate formation may have increased importance at the modern atmospheric CO₂ concentration compared to 3 billion years ago.
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