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As a key device for solar energy conversion, solar absorbers play a critical role in improving the operating temperature of concentrated solar power (CSP) systems. However, solar absorbers with high spectral selectivity and good thermal stability at high temperatures in air are still scarce. This study presents a novel surface reconstruction strategy to improve the spectral selectivity of La0.5Sr0.5CoO3-δ (LSC5) for enhanced CSP application. The strategy could efficiently enhance the solar absorptance due to the existence of a high-absorption thin layer composed of nanoparticles on the LSC5 surface. Meanwhile, the crystal facet with low emittance on the LSC5 surface was exposed. Thus, the LSC5 that underwent surface reconstruction achieved a higher solar absorptance (â¼0.75) and lower infrared emittance (â¼0.19) compared to the original LSC5 (0.63/0.21), representing an improvement of nearly 32%. Additionally, the surface reconstructed LSC5 demonstrated a lower infrared thermographic temperature and a higher solar-thermal conversion equilibrium temperature compared to those of LSC5 and SiC. Moreover, the reconstructed LSC5 could maintain stable performance up to 800 °C in air, which might simplify the complexity of the CSP systems. The surface reconstruction strategy provided a new method to optimize the spectral selectivity of high-temperature stable ceramics, contributing to advancements in solar energy conversion technologies.
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Resource-based water shortages, uncoordinated irrigation, and fertilization are prevalent challenges in agricultural production. The scientific selection of appropriate water and fertilizer management methods is important for improving the utilization efficiency of agricultural resources and alleviating agricultural non-point source pollution. This study focused on wolfberry and compared the effects of four irrigation levels [full irrigation (W0, 75%-85% θf), slight water deficit (W1, 65%-75% θf), moderate water deficit (W2, 55%-65% θf), and severe water deficit (W3, 45%-55% θf)] and four nitrogen application levels [no nitrogen application (N0, 0 kg·ha-1), low nitrogen application (N1, 150 kg·ha-1), medium nitrogen application (N2, 300 kg·ha-1), and high nitrogen application (N3, 450 kg·ha-1)] on soil nitrate nitrogen (NO3 --N) transport, plant nitrogen allocation, and soil nitrous oxide (N2O) emissions during the harvest period of wolfberry. And this study used CRITIC-entropy weights-TOPSIS model to evaluate 16 water and nitrogen regulation models comprehensively. The results revealed the following: (1) The NO3 --N content of the soil decreased with increasing horizontal distance from the wolfberry. It initially decreased, then increased, and finally decreased with an increase in soil depth. The average NO3 --N content in the 0-100 cm soil layer ranged from 3.95-13.29 mg·kg-1, indicating that W0 > W1, W2, W3, and N3 > N2 > N1 > N0. (2) The soil NO3 --N accumulation ranged from 64.45-215.27 kg·ha-1 under varying water and nitrogen levels, demonstrating a decreasing trend with increasing horizontal distance. The NO3 --N accumulation at each horizontal distance increased with increasing irrigation and nitrogen application. The NO3 --N accumulation of W0N3 treatment increased by 5.55%-57.60% compared with the other treatments. (3) The total nitrogen content and nitrogen uptake in all wolfberry organs were W1 > W0 > W2 > W3, and N2 > N3 > N1 > N0. The maximum total nitrogen content and nitrogen uptake in W1N2 treatment were 3.25% and 27.82 kg·ha-1 in the roots, 3.30% and 57.19 kg·ha-1 in the stems, 3.91% and 11.88 kg·ha-1 in the leaves, and 2.42% and 63.56 kg·ha-1 in the fruits, respectively. (4) The emission flux and total emission of N2O increased with increasing irrigation and nitrogen application. The emission flux exhibited a transient peak (116.39-177.91 ug·m-2·h-1) after irrigation. The intensity of N2O emissions initially decreased and then increased with an increase in the irrigation amount. It also initially increased with increasing nitrogen application amount, then decreased, and finally increased again. The maximum emission intensity was observed under the W3N3 treatment (0.23 kg·kg-1). The N2O emission coefficients ranged from 0.17%-0.39%, in the order of W0 > W1 > W2 > W3 (except for N1) and N1 > N2 > N3. (5) Under varying water and nitrogen concentrations, N2O emission flux showed a positive linear correlation with soil pore water content and NO3 --N content and a negative linear correlation with soil temperature. The comprehensive evaluation revealed that a slight water deficit (65%-75% θf) combined with medium nitrogen application (300 kg·ha-1) decreased soil NO3 --N leaching, increased nitrogen uptake, and reduced N2O emission. These findings can serve as a reference for improving the efficiency and reducing emissions of wolfberry in the Yellow River irrigation region of Gansu Province and in similar climate zones.
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In the production of economic forests, there are common issues such as excessive application of water and fertilizer, redundant plant growth, and low economic benefits. Reasonable water and fertilizer management can not only help address these problems but also improve the absorption and use efficiency of water and fertilizer resources by plants, promoting the green and efficient development of the fruit and forestry industry. In order to explore a suitable water and nitrogen management mode for Lycium barbarum, field experiments were conducted in this study from 2021 to 2022. Specifically, four irrigation modes (according to the proportion ratio of soil moisture content to field moisture capacity θf, 45-55% θf (W1, severe water deficiency), 55-65% θf (W2, moderate water deficiency), 65-75% θf (W3, mild water deficiency), and 75-85% θf (W4, sufficient irrigation)) and four nitrogen application levels (0 kg·ha-1 (N0, no nitrogen application), 150 kg·ha-1 (N1, low nitrogen application level), 300 kg·ha-1 (N2, medium nitrogen application level), and 450 kg·ha-1 (N3, high nitrogen application level)) were set up to analyze the influences of water and nitrogen control on the plant height, stem diameter, chlorophyll content, photosynthetic characteristics and yield, and economic benefits of Lycium barbarum in the Lycium barbarum + Alfalfa system. The study results show that the plant height and stem diameter increment of Lycium barbarum increase with the irrigation amount, increasing first and then decreasing with the increase in the nitrogen application level. Meanwhile, the chlorophyll contents in Lycium barbarum continuously increase throughout their growth periods, with Lycium barbarum treated with W4N2 during all growth periods presenting the highest contents of chlorophyll. In a Lycium barbarum + Alfalfa system, the daily variation curve of the Lycium barbarum net photosynthetic rate presents a unimodal pattern, with maximum values of the daily average net photosynthetic rate and daily carboxylation rate appearing among W4N2-treated plants (19.56 µmol·m-2·s-1 and 157.06 mmol·m-2·s-1). Meanwhile, the transpiration rates of Lycium barbarum plants continuously decrease with the increased degree of water deficiency and decreased nitrogen application level. W1N2-treated plants exhibit the highest leaf daily average water use efficiency (3.31 µmol·s-1), presenting an increase of 0.50-10.47% in efficiency compared with plants under other treatments. The coupling of water and nitrogen has significantly improved the yields and economic benefits of Lycium barbarum plants, with W4N2-treated and W3N2-treated plants presenting the highest dried fruit yield (2623.07 kg·ha-1) and net income (50,700 CNY·ha-1), respectively. Furthermore, compared with other treatment methods, these two treatment methods (W4N2 and W3N2) exhibit increases of 4.04-84.08% and 3.89-123.35% in dried fruit yield and net income indexes, respectively. Regression analysis shows that, in a Lycium barbarum + Alfalfa system, both high yields and economic benefits of Lycium barbarum plants can be achieved using an irrigation amount of 4367.33-4415.07 m3·ha-1 and a nitrogen application level of 339.80-367.35 kg·ha-1. This study can provide a reference for improving the productivity of Lycium barbarum plants and achieving a rational supply of water and nitrogen in Lyciun barbarum + Alfalfa systems in the Yellow River Irrigation Area of Gansu, China, and other similar ecological areas.
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To solve the problems of the lack of property research in organic synthesis experiments and the relative independence of instrumental analytical methods in experiments, we designed a comprehensive undergraduate experiment based on mechanofluorochromic materials. In this project, 4-[bis(4-methylphenyl)amino] benzaldehyde was synthesized via the Vilsmeier-Haack reaction using 4,4'-dimethyltriphenylamine as the raw material. The product was then characterized by mass spectrometry, infrared absorption spectroscopy, and nuclear magnetic resonance spectroscopy. The solvatofluorochromism and mechanofluorochromism of the target material were studied using ultraviolet-visible absorption spectroscopy, fluorescence spectroscopy, etc. Furthermore, the mechanism of mechanofluorochromism was determined using powder X-ray diffraction. Organic synthesis and a series of instrumental analytical methods were combined to form an integrated experiment. The experiment is interesting, scientific, and comprehensive for undergraduates as a creative exercise; moreover, it can inspire their interest in chemical research, cultivate a variety of experimental operation abilities, improve creative-thinking skills, and encourage the development of effective solutions to existing problems in chemical experiments.
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To address the problems of extensive field management, low productivity, and inefficient water and fertilizer utilization in wolfberry (Lycium barbarum L.) production, an appropriate water and nitrogen regulation model was explored to promote the healthy and sustainable development of the wolfberry industry. Based on a field experiment conducted from 2021 to 2022, this study compared and analyzed the effects of four irrigation levels [75%-85% θf (W0, full irrigation), 65%-75% θf (W1, slight water deficit), 55%-65% θf (W2, moderate water deficit), and 45%-55% θf (W3, severe water deficit)] and four nitrogen application levels [0 kg·ha-1 (N0, no nitrogen application), 150 kg·ha-1 (N1, low nitrogen application), 300 kg·ha-1 (N2, medium nitrogen application), and 450 kg·ha-1 (N3, high nitrogen application)] on soil water distribution, soil nitrate nitrogen (NO3 --N) migration, yield, and water-nitrogen use efficiency of wolfberry. The soil moisture content of the 40-80 cm soil layer was higher than those of 0-40 cm and 80-120 cm soil layer. The average soil moisture content followed the order of W0 > W1 > W2 > W3 and N3 > N2 > N1 > N0. The NO3 --N content in the 0-80 cm soil layer was more sensitive to water and nitrogen regulation, and the cumulative amount of NO3 --N in the soil followed the order of W0 > W1> W2 > W3 and N3 > N2 > N1 > N0 during the vegetative growth period. There was no evidently change in soil NO3 --N accumulation between different treatments during the autumn fruit. The yield of wolfberry under the W1N2 treatment was the highest (2623.09 kg·ha-1), which was 18.04% higher than that under the W0N3 treatment. The average water consumption during each growth period of wolfberry was the highest during the full flowering period, followed by the vegetative growth and full fruit periods, and the lowest during the autumn fruit period. The water use efficiency reached a peak value of 6.83 kg·ha-1·mm-1 under the W1N2 treatment. The nitrogen uptake of fruit and nitrogen fertilizer recovery efficiency of fruit first increased and then decreased with increasing irrigation and nitrogen application. The treatment of W1N2 obtained the highest nitrogen uptake of fruit and nitrogen recovery efficiency of fruit, which were 63.56 kg·ha-1 and 8.17%, respectively. Regression analysis showed that the yield and water-nitrogen use efficiency of wolfberry improved when the irrigation amount ranged from 315.4 to 374.3 mm, combined with nitrogen application amounts of 300.0 to 308.3 kg·ha-1. Additionally, the soil NO3 --N residue was reduced, making it an optimal water and nitrogen management model for wolfberry planting. The present findings contribute novel insights into the production of wolfberry with saving water and reducing nitrogen, which helps to improve the level of wolfberry productivity in the Yellow River irrigation region of Gansu Province and other areas with similar climate.
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Permeable reactive barrier (PRB) is potentially effective for groundwater remediation, especially using environmentally friendly mixed fillers in representative areas, such as semi-arid loess region in northwestern China. The mixed materials, including corn straw (agricultural wastes), fly ash (industrial wastes), zeolite synthesized from fly ash (reutilized products), and iron-manganese nodule derived from loess (materials with regional characteristics) in northwestern China, were chosen as PRB media to reduce the contents of lead and cadmium in simulated groundwater. A series of lab-scale column experiments were investigated, and the response surface methodology (RSM) was used to optimize the working process; Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) were applied to further reveal the reaction mechanism. It shows that the purification efficiencies are more acceptable when the concentrations of lead and cadmium are approximately 7 and 0.7 mg/L, respectively, at 25 °C in weakly acidic solution, and functional groups of -OH and C=C play an important role for contaminants removal. The mixed adsorbents used are effective to remove lead and cadmium in groundwater. This is the first report on the removal of lead and cadmium from groundwater in loess region in northwestern China using PRB filled with environmentally friendly mixed adsorbents.
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Cadmio/aislamiento & purificación , Conservación de los Recursos Naturales , Agua Subterránea/química , Plomo/aislamiento & purificación , Purificación del Agua/métodos , Cadmio/química , China , Hierro/química , Plomo/química , Manganeso/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Zeolitas/químicaRESUMEN
CD73 is a glycosylphosphatidylinositol (GPI) anchored cell surface protein that is encoded by NT5E gene, plays multiple roles in tumor processes. Previous studies have presented a potential value of CD73 served as a detectable biomarker for prognosis of several solid tumors, but the results were more controversially. A comprehensive meta-analysis was conducted to precisely evaluate the prognostic role of CD73 in solid tumors. The included studies were searched in PubMed, Web of Science and EBSCO from Jan 1990 to Jan 2016. Pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI) for overall survival (OS), disease free survival (DFS) were carried out using a fixed or random effects model. Totally, 13 studies about 12,533 patients were included. CD73-high expression was correlating with poor OS (pooled HR = 1.28, 95% CI = 1.19-1.37). In addition, CD73 expression had borderline association with worse DFS (pooled HR = 1.28, 95% CI = 1.01-1.62). Egger's tests indicated that there was no evidence of significant publication bias. CD73 is an efficient prognostic biomarker in solid tumors, and over-expression of CD73 is associated with inverse OS or DFS. But this predictive value and target therapy for clinical practice yet needs advanced research.
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Phytoremediation is a novel method with great potential for site remediation contaminated by heavy metals in future. The cell wall of plant roots is significant to affect the remediation efficiency, for it is related to the multi-interface of heavy metals, pedosphere and plant. The relationship between cell wall of plant and heavy metals is complicated, containing the reaction behavior of physical chemistry, physiology and biochemistry. At present, the spectral technologies are not adequately used to investigate the in-situ response characteristics between cell wall of plant roots and heavy metals. The Calendula officinalis seedlings, the remediation plant in loess, were used as experimental sampleswhile the root characteristic variation was revealed on cell wall. The approaches of X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra were applied to analyze the response effect of cell wall to lead/cadmium stress. The results showed: the cell wall appears to be shrinking, and certain amounts of dark particles appear on cell wall. The contents of lead/cadmium increase greatly as shown from XRF, while the representative crystals of lead/cadmium are hardly detected. The absorbance peak at 3 416 cm-1 indicates the coordination effect between lead/cadmium and OH in FTIR, and the movement of absorbance peaks, from 1 701 to 1 736 cm-1 and 1 593 to 1 618 cm-1, respectively, indicates the different characteristics of protein in cell wall of Calendula officinalis seedlings roots under lead/cadmium stress. The Raman intensity of absorbance peak at 2 960 cm-1 increases under lead/cadmium stress, and it proves the changes on arranging directions of cellulose molecules in cell wall samples. The components (Pectin, protein, cellulose, etc.) and functional groups (OH, NH, CO, etc.) of cell wall play an important role in the resistance process of cell wall derived from Calendula officinalis seedlings roots to the stress of lead/cadmium in loess.
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Calendula , Biodegradación Ambiental , Cadmio , Pared Celular , Restauración y Remediación Ambiental , Plomo , Raíces de Plantas , Plantas , Plantones , Contaminantes del Suelo , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
The soil washing technology is commonly used to remediate contaminated soils because of its advantages of low cost, ease handling and environmental-friendly. However, it should be noticed that the nutrient might leach simultaneously from soil in the washing process, and the technical solution of the issue will greatly accelerate the application process of washing technology in site remediation. This paper aims to reveal the regulating mechanism of synthesized anion adsorbent from straw on nutrient leaching potential through approaches of adsorption equilibrium models (isotherms and kinetics) and spectral analysis instruments (SEM and FTIR). The results showed: the Langmuir isotherm and pseudo second order kinetic equation fit better the adsorption behavior of nitrate and phosphate. The maximum adsorption capacity (qm), calculated with Langmuir isotherm, are 7.507 5 and 4.194 6 mg·g-1, respectively, and the reaction belongs to the monolayer and favorable adsorption with chemical adsorption the rate-determining step. The activation energy of adsorption for nitrate and phosphate at 298 K are 42.25 and 39.38 kJ·mol-1, respectively, and the reaction is spontaneous and endothermic. The purified water and KOH solution are effective for the regeneration of anion adsorbent, the desorption effect is better for the assistance of ultrasonic sound and longer desorption time. The surface of anion adsorbent after adsorption is covered with particles, while less spray-like component appears after desorption with purified water. The movement of vibration peaks in FTIR spectra indicates the effect of electrostatic interaction in the reaction. The adsorption of nitrate and phosphate on anion adsorbent involves simultaneously the effects of physical and chemical adsorption.
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As an environmentally-friendly technology attracting great attention from current researchers, phytoremediation is significant for site remediation contaminated by heavy metals. The plant will appear related physiological response to reduce direct harm caused by the stress of heavy metals. The microscale behavior is always multi-dimensional and difficult to detect. The advanced instruments are effective to resolve the scientific issues, while the related researches are seldom investigated. Taking calendula officinalis seedlings as experimental samples, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) were applied to compare the surface characteristics and functional groups variation, respectively. The response process and tolerance mechanism of calendula officinalis seedlings to lead and cadmium stress were further analyzed. The results showed: with the increasing concentration of lead and cadmium in loess, the calyptra of calendula officinalis seedlings become bending and wilting; the amount of root hairs decreases greatly while no significant variations of aerial parts are found on surface characteristics. The stress of lead and cadmium are responsible for the difference of FTIR spectra of Calendula officinalis seedlings. The peak absorbance at 3 573 cm-1 decreases and the peak becomes more complex with the increasing contents of lead and cadmium. It might be the coordination effect between lead/cadmium and hydroxyl, which affects the synthesis and secretion of organic matters. The movement of CH vibration peak is associated with the lipid oxidationwhile the changes at 1 631 and 1 574 cm-1 suggest the protein component differences. The shifting peak at 1 385 cm-1 might be associated with the methylation of pectin and lipid, and the behavior is positive for the adaption process of calendula officinalis seedlings to lead and cadmium stress. The FTIR spectra are effective to reveal the phytoremediation mechanism on heavy metals contamination in pedosphere.
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Calendula , Biodegradación Ambiental , Cadmio , Restauración y Remediación Ambiental , Plomo , Plantones , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Atomic absorption spectrometry (AAS) is widely used in the analysis and detection of heavy metals. The optimal operation conditions on metals detection are important for the stabilization and repeatability of scientific research, which affects the expected investigation objectives greatly. Thus, it becomes a key issue to establish appropriate detection methods in scientific works. Calendula officinalis was used for lead/cadmium remediation in contaminated loess, and the flame atomic absorption spectrometry (FAAS) with wet digestion was applied to analyze the contents of lead/cadmium in Calendula officinalis seedlings. The investigation data was further studied to reveal the bioaccumulation efficiency of lead/cadmium in Calendula officinalis seedlings. The results showed: the limits of detection are 0.104 and 0.007 mg·L-1 for lead and cadmium; the recovery rates of lead and cadmium are from 94.33% to 110.78% and 97.73% to 107.50% respectively. The relative standard deviations (RSD) are between 4.11% and 4.75% for lead while between 1.11% and 2.77% for cadmiumï¼and It's been proved that the method is accurate and reliable. The low accumulation efficiency of lead with Calendula officinalis seedlings might be related to the electronegativity of lead while the growth period of calendula officinalis seedlings and environmental factors. The accumulation content of cadmium is 104.85 mg·kg-1 with cadmium concentration of 50 mg·kg-1. The co-existing of lead in loess is positive for cadmium accumulation by Calendula officinalis seedlings, and the synergistic effect might work in the process. The established detection method is effective for quantitative analysis of lead and cadmium in calendula officinalis seedlings and significant for future research.
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Biodegradación Ambiental , Calendula , Cadmio , Plomo , Plantones , Espectrofotometría AtómicaRESUMEN
OBJECTIVE: To investigate the effect of phthalates exposure from drinking water on children's intelligence and secretion of thyroid hormone. METHODS: Two villages in S County were selected randomly as polluted area and control area according to the distance from the Shaying river basin. Phthalates including DEP, DBP, DMP, DEHP were measured both in the river water and drinking water using HPLC method. Children aged 8 to 13 years old studying in the village primary school were recruited by cluster sampling (n = 154). The combined Reven Test was used to test children intelligence and ELISA method was used to determined thyroid hormone levels. RESULTS: The concentrations of phthalates (DEP, DBP) were exceeding standards of surface water quality in any of the three sections of the river. Compared to the control area, the concentration of DEP and DBP in drinking water were significant higher in the polluted area than that in control area (P < 0.05). Children from polluted area had significant higher FT4 concentration compared to children from control area (P < 0.05). Intelligence level in children from polluted area was lower than that from control area (P < 0.05). CONCLUSION: The drinking water has been polluted by Shaying river and thyroid hormones levels of children were affected in the polluted areas. It is necessary to verify if this change is related to the phthalates.