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Modification of activated carbon has the potential to improve its adsorption and separation capacity. Different concentrations of ammonia (6%, 9%, 12%, 15%) and treatment times (4 h, 6 h, 8 h, 10 h) were used to modify jujube shell carbon and coconut shell carbon in ultrasonic washing equipment. Biogas adsorption experiments were carried out with modified activated carbon to study the effect of adsorption and decarbonization on activated carbon surface functional groups. After modification, the surface alkaline functional groups of activated carbon increased, the acidic functional groups decreased, and the adsorption performance of CO2 was enhanced. In addition, the specific surface area and total pore volume of activated carbon decreased, the average pore size increased, and the degree of graphitization increased. In the experimental research range, under ultrasonic conditions, jujube shell carbon impregnated with 12% ammonia water for 4 h and coconut shell carbon impregnated with 9% ammonia water for 10 h had the best modification effect. The adsorption capacity for CO2 was 1.83 and 1.745 mmol/g, respectively, which increased by 0.8 mmol/g and 0.599 mmol/g, respectively, compared with the unmodified sample.

Highways consume a significant amount of electrical energy annually, especially in remote desert regions where the cost of electricity is high. This research explores the utilization of natural resources along desert highways to establish hybrid energy generation systems for service areas. Three service areas along the desert highway in northern Xinjiang, China, serve as case studies. To assess the feasibility of hybrid energy generation systems in these service areas, meteorological data for the three locations were obtained from the NASA platform. The HOMER Pro software was employed for technical, economic, and environmental analyses of the systems. The results indicate the feasibility of Photovoltaic (PV)/Wind/Battery hybrid energy systems in the Huanghuagou, Kelameili, and Wujiaqu service areas. The application of these hybrid energy generation systems across the three service areas could provide 3,349,557 kWh of electrical energy annually for the desert highway. Sensitivity analysis reveals that the Net Present Cost (NPC) and Cost of Energy (COE) values decrease with increasing radiation levels, while NPC shows an increasing trend with growing load demand, and COE exhibits a decreasing trend. Among the three regions, Wujiaqu demonstrates the highest economic viability, with a COE of $0.34/kWh and an NPC of $3,141,641/kWh. Furthermore, Wujiaqu exhibits the lowest environmental impact, with CO2 emissions of 198,387 kg/yr, SO2 emissions of 493 kg/yr, and NOx emissions of 1,711 kg/yr.

Real-time monitoring of canopy chlorophyll content is significant in understanding crop growth status and guiding precision agricultural management. Remote sensing methods have demonstrated great potential in this regard. However, the spatiotemporal heterogeneity of chlorophyll content within crop canopies poses challenges to the accuracy and stability of remote sensing estimation models. Hence, this study aimed to develop a novel method for estimating canopy chlorophyll content (represented by SPAD values) in maize (Zea mays L.) canopies. Firstly, we investigated the spatiotemporal distribution patterns of maize canopy SPAD values under varying nitrogen application rates and different growth stages. The results revealed a non-uniform, “bell-shaped” curve distribution of maize canopy SPAD values in the vertical direction. Nitrogen application significantly influenced the distribution structure of SPAD values within the canopy. Secondly, we achieved satisfactory results by fitting the Lorentz peak distribution function to the SPAD values of different leaf positions in maize. The fitting performance, evaluated using R2 and RMSE, ranged from 0.69 to 0.98 and 0.45 to 3.59, respectively, for the year 2021, and from 0.69 to 0.77 and 2.38 to 6.51, respectively, for the year 2022.Finally, based on the correlation between canopy SPAD values and vegetation indices (VIs) at different growth stages, we identified the sensitive leaf positions for the selected CCCI (Canopy Chlorophyll Index) in each growth stage. The 6th (r = 0.662), 4th (r = 0.816), 12th (r = 0.722), and 12th (r = 0.874) leaf positions exhibited the highest correlations. Compared to the estimation model using canopy wide SPAD values, the model based on sensitive leaf positions showed improved accuracy, with increases of 34%, 3%, 20%, and 3% for each growth stage, respectively. In conclusion, the findings of this study contribute to the enhancement of chlorophyll content estimation models in crop canopies and provide valuable insights for the integration of crop growth models with remote sensing methods.

The wide-bandgap cubic-structure semiconductor In4SnSe4 can be regarded as a product of compositing two typical layered thermoelectric materials SnSe and In4Se3. Remarkably, In4SnSe4 inherited low thermal conductivity from its parent materials. To advance the potential thermoelectric property of In4SnSe4, we systematically investigated its crystal structure and the origin of the intrinsic low thermal conductivity. In4SnSe4 crystallized in a cubic phase (space group Pa3¯), with the lattice parameters of a = b = c = 12.66 Å. The anisotropy of InSe bonds in the lattice determined the complex structure of In4SnSe4 with 72 atoms in the primitive cell. More importantly, sound velocity and elastic properties unclosed the strong anharmonicity in In4SnSe4, which contributed greatly to the low thermal conductivity. With first-principles calculations, it was found that the lone-pair electrons from In+ mainly caused the anharmonicity in the lattice. Additionally, Br was proved to be an effective dopant for In4SnSe4 to improve the electrical transport properties. This work indicated that the complex wide-bandgap semiconductor In4SnSe4 with cubic phase and intrinsic low thermal conductivity was a new promising thermoelectric material with appropriate doping.

The tung tree (Vernicia fordii Hemsl.), as a woody oilseed crop, has been cultivated in China for thousands of years, and its leaves are rich in cellulose and proteins. The tung leaf is an alternative raw material for the traditional ethanol fermentation of food crops. In this work, the effects of the simultaneous saccharification fermentation of tung leaves at different substrate concentrations on gas production characteristics, reducing sugars, pH, oxidation–reduction potential (ORP), and ethanol yield were investigated during bioethanol production. In addition, the effect of the initial fermentation pH on the ethanol fermentation of tung leaves was explored. The results showed that during bioethanol production from tung leaves, the pH of the fermentation broth showed a continuous decreasing trend. Moreover, the ORP showed a decreasing trend and then rebounded, and the concentration of reducing sugars initially increased and then decreased. The optimal ethanol yield of 4.99 g/L was obtained when the substrate concentration was 100 g/L. Changes in the initial pH have little effect on yeast activity, but such changes can affect the yeast cell wall structure and substance transport, leading to differences in the ethanol yield. When the initial pH is 7, the maximum ethanol yield is 5.22 g/L. The experimental results indicate that the utilization of tung leaves for bioethanol production has a good potential for development.

Studying the characteristics and hydrogeochemical evolution processes of groundwater can contribute to the prevention of water-related hazards and ensure sustainable management of groundwater resources. In this study, the hydrogeochemical characteristics and evolution processes of the coal-bearing sandstone aquifer and Carboniferous limestone aquifer of the Taiyuan formation in the Liuqiao coal mine in Huaibei coalfield were assessed using piper diagram, Gibbs diagrams, ionic proportion ratios, and principal component analysis (PCA). The results showed that Na + + K + and SO 4 2− were the dominant cations and anion, respectively, in both aquifers. The coefficients of variation of six hydrochemical parameters increased gradually, reflecting the formation of different water chemical compositions. The formation of hydrochemical compositions was dominated by water-rock interaction, including the dissolution of rock salt, cation exchange adsorption and pyrite oxidation. In addition, the PCA revealed two first components, explaining the highest proportion of variance. Over time, the water sample points were mostly found in the second and third quadrants, indicating the groundwater salinization effect as a result of the gradual increase in the cation alternating adsorption.

The plasma produced by Dielectric Barrier Discharge (DBD) has a very important application in the field of aerodynamics. The plasma generator needs high-voltage and high-frequency power supply. Due to the existence of internal resistance of the power supply, the impedance characteristics of the generator do not match the power supply. The voltage at both ends of the generator is extremely low. Besides, due to the existence of reactive power, most of the energy transported by the power source is reflected, resulting in extremely low energy conversion efficiency of the power source. In the paper, the mechanism of DBD plasma generator is analysed and on the equivalent circuit is received. And then different frequency impedance characteristics of generator and impedance matching circuit by using LR and the LCR respectively is studied. The results show that the equivalent resistance of plasma generator on frequency change is not obvious. The generator is capacitive and tends to 0 with increasing frequency. When LR is matched, resistance increases with the frequency change is not big, and reactance increases gradually, but its value is small, in the range of nΩ. in general the plasma generator impedance is virtually pure resistive. When LCR is matched, the impedance characteristic gradually changes from the inductive to capacitive with the increase of frequency. Keywords: Impedance matching, Dielectric barrier discharge (DBD), LR, LCR

The power frequency high voltage divider is widely used to measure the power frequency high voltage and it is an important measuring instrument for high voltage test. Whether it is accurate or not directly affects the insulation monitoring level of power equipment closely related to the safety of power production, and it is of vital importance for power enterprises to ensure the measurement accuracy of power frequency high-voltage divider. The newly implemented JJG496-2016 recommended three measurement methods: difference comparison, equal power bridge method and voltage ratio method. At present, only some literatures have introduced the measurement method using voltage ratio method and the measurement uncertainty evaluation procedure. This paper introduces a calibration device and measuring method of power frequency high voltage divider using the difference comparison method, and gives the uncertainty of the ratio difference and phase difference of power frequency high voltage divider obtained under the standard test environment. Keywords: High voltage divider, Difference comparison method, Uncertainty, Error value, Calibration device

We thoroughly investigated the electronic structure and various properties of the half-Heusler compound ScRhTe using density functional theory calculations. The electronic structure shows that ScRhTe is a narrow-band-gap semiconductor. Owing to its characteristic conduction-band structure, ScRhTe has a higher Seebeck coefficient and a higher power factor for n-type doping than for p-type doping, with the maximum value of −493 µV K−1 appearing at 900 K. The optimal carrier concentration is approximately 5 × 1019 cm−3–1 × 1020 cm−3. In addition, ZTe is estimated as 0.95 at a doping level of approximately 1019 cm−3. Under pressure, the band structure changes from a direct to an indirect band gap, and the band gap increases as the pressure changes from tensile to compressive. The thermoelectric properties of ScRhTe improve under compressive pressure, whereas the optical properties improve greatly under tensile pressure. By varying the pressure, the electronic structure and various properties of ScRhTe can be effectively adjusted, which signifies that ScRhTe has the potential to become an important optoelectronic or thermoelectric material.

Groundwater outbursts from coal mine goafs, which are widely distributed in China with the increase in the number of abandoned coal mines, demonstrate an impartible relationship with the permeability of goaf overburden strata. A research on rock mass integrity and permeability characteristics of goaf overburden strata is necessary to assess waterinrush risk induced by goaf water. Two goafs in two adjacent coal mines located at the Huaibei mining area in the Anhui Province of China were considered as the research targets. A ground exploration hole was conducted in each goaf. The rock mass integrity and fracture development of goaf overburden strata were determined on the basis of rock quality designation (RQD) and borehole television. The permeability of goaf overburden strata was measured by performing a field packer test. Results are as follows: (1) The fracture development of the borehole wall of the production mine is favorable, and a water drenching phenomenon occurs. The RQD is approximately 20.8–35.6%, which indicates that the integrity of the goaf overburden strata of the production mine is poor. The unit water inflow (q) is 0.133 L/s.m, and the average permeability coefficient is 0.26 m/d, which reveals that the goaf overburden strata of the production mine exhibit medium water abundance and permeable strata. (2) The overburden strata parameters of the abandoned mine goaf are as follows: the q is 0.012–0.014 L/s.m, and the average permeability coefficient is 0.005 m/d, which suggests that the goaf overburden strata exhibit poor water abundance and low permeable strata. The results demonstrate that the overburden strata compaction of the two goafs is different and the results can provide a reference for adjacent mines to access the water inrush risk induced by the goaf water of the abandoned coal mines.

Some studies on the hyperuricemia (HUA) have focused on intestinal bacteria. To better understand the correlation between gut microbiota and HUA, we established a HUA rat model with high-purine diet, and used 16S rRNA genes sequencing to analyze gut microbiota changes in HUA rats. To analyze the potential role played by gut microbiota in HUA, we altered the gut microbiota of HUA rats with antibiotics, and compared the degree of uric acid elevation between HUA and antibiotic-fed HUA rats (Ab+HUA). Finally, we established a recipient rat model, in which we transplanted fecal microbiota of HUA and normal rats into recipient rats. Three weeks later, we compared the uric acid content of recipient rats. As a result, the diversity and abundance of the gut microbiota had changed in HUA rats. The Ab-fed HUA rats had significantly lower uric acid content compared to the HUA rats, and gut microbiota from HUA rats increased uric acid content of recipient rats. The genera Vallitalea, Christensenella and Insolitispirillum may associate with HUA. Our findings highlight the association between gut microbiota and HUA, and the potential role played by gut microbiota in HUA. We hope that this finding will promote the isolation and culture of HUA-related bacteria and orient HUA-related studies from being correlational to mechanistic. These steps will therefore make it possible for us to treat HUA using gut microbiota as the target.

PbS is a latent substitute of PbTe thermoelectric materials, which is on account of its superiority in low cost and earth abundance. Here, the thermoelectric transport properties of p-type PbS by doping alkali metals (Na and Li) are investigated and it is verified that Li is a more effective dopant than Na. By introducing Li, the electrical and thermal transport properties were optimized collectively. The electrical transport properties were boosted remarkably via adjusting carrier concentration, and the maximum power factor (PFmax) of ~11.5 μW/cmK2 and average power factor (PFave) ~9.9 μW/cmK2 between 423 and 730 K in Pb0.99Li0.01S were achieved, which are much higher than those (~9.5 and ~7.7 μW/cmK2) of Pb0.99Na0.01S. Doping Li and Na can weaken the lattice thermal conductivity effectively. Combining the enlarged PF with suppressed total thermal conductivity, a maximum ZT ~0.5 at 730 K and a large average ZT ~0.4 at 423-730 K were obtained in p-type Pb0.99Li0.01S, which are higher than ~0.4 and ~0.3 in p-type Pb0.99Na0.01S, respectively.

We propose the quaternary-compounds CsNb _3 SBr _7 is a nodal-straight-line semimetal candidate based on the first-principles calculations and symmetry analyses. There are a pair of nodal straight lines locate in the k _z = 0 plane of Brillouin zone, which is protected by the crystal symmetry. The topological properties of nodal-straight-line state are characterized by the nontrivial Berry phase and Berry curvature. On the (001) surface of CsNb _3 SBr _7 , Fermi arcs form the belt-like surface state, connecting the nodal straight lines with opposite chirality. Furthermore, the Hofstadter’s butterfly and optical conductivity are investigated using a slab sample. These results not only reveal the symmetric protection mechanism of nodal straight lines, but also pave a way for exploring the electronic and optical properties of CsNb _3 SBr _7 in further condensed matter physics experiments.

We studied the crystal structures, electronic structures and optical properties of Cs 2 AX 2 ′ X 4 (A=Ge,Sn,Pb; X′, X=Cl, Br, I) compounds using the first-principles calculation. Our optimized structures agree well with experimental and theoretical results. Band structure calculations, using the modified Becke-Johnson (mBJ) potential method, indicate that these compounds (with the exception of Cs 2 PbX 2 ′ I 4 ) are semiconductors with the direct band gap ranging from 0.36 to 4.09 eV. We found the compounds Cs2GeBr2I4, Cs2GeCl2I4, Cs2GeI2Br4, Cs2SnI6, and Cs2SnBr2I4 may be good candidates for lead-free solar energy absorber materials.

Labeled graphs are widely used to model complex data in many domains, so subgraph querying has been attracting more and more attention from researchers around the world. Unfortunately, subgraph querying is very time consuming since it involves subgraph isomorphism testing that is known to be an NP-complete problem. In this paper, we propose a novel coding method for subgraph querying that is based on Laplacian spectrum and the number of walks. Our method follows the filtering-and-verification framework and works well on graph databases with frequent updates. We also propose novel two-step filtering conditions that can filter out most false positives and prove that the two-step filtering conditions satisfy the no-false-negative requirement (no dismissal in answers). Extensive experiments on both real and synthetic graphs show that, compared with six existing counterpart methods, our method can effectively improve the efficiency of subgraph querying.

OBJECTIVE: To investigate the potential involvements of E-cadherin and beta-catenin in meningioma. METHODS: Immunohistochemistry staining was performed on samples from patients with meningioma. The results were graded according to the positive ratio and intensity of tissue immunoreactivity. The expression of E-cadherin and beta-catenin in meningioma was analyzed by its relationship with WHO2007 grading, invasion, peritumoral edema and postoperative recurrence. RESULTS: The positive rates of E-cadherin in meningioma WHO I, II, III were 92.69%, 33.33% and 0, respectively, (P

Modification of activated carbon has the potential to improve its adsorption and separation capacity. Different concentrations of ammonia (6%, 9%, 12%, 15%) and treatment times (4 h, 6 h, 8 h, 10 h) were used to modify jujube shell carbon and coconut shell carbon in ultrasonic washing equipment. Biogas adsorption experiments were carried out with modified activated carbon to study the effect of adsorption and decarbonization on activated carbon surface functional groups. After modification, the surface alkaline functional groups of activated carbon increased, the acidic functional groups decreased, and the adsorption performance of CO2 was enhanced. In addition, the specific surface area and total pore volume of activated carbon decreased, the average pore size increased, and the degree of graphitization increased. In the experimental research range, under ultrasonic conditions, jujube shell carbon impregnated with 12% ammonia water for 4 h and coconut shell carbon impregnated with 9% ammonia water for 10 h had the best modification effect. The adsorption capacity for CO2 was 1.83 and 1.745 mmol/g, respectively, which increased by 0.8 mmol/g and 0.599 mmol/g, respectively, compared with the unmodified sample. [ABSTRACT FROM AUTHOR]

Background: Previous studies on polymicrobial Pseudomonas aeruginosa bloodstream infections (Pa-BSIs) are dated, and it is necessary to reanalyze polymicrobial Pa-BSIs. The aim of this study was to investigate clinical characteristics and risk factors for polymicrobial Pa-BSI in comparison with monomicrobial Pa-BSI. Methods: A double-center retrospective observational study was performed between January 1, 2013 and June 30, 2022, in two tertiary hospitals. All patients with Pa-BSI were enrolled, and their clinical data were collected by reviewing electronic medical records. Results: A total of 278 patients with Pa-BSI were enrolled, including 77 patients (27.7%) with polymicrobial Pa-BSI. Compared with monomicrobial Pa-BSI, the main source of polymicrobial Pa-BSI was pneumonia (49.4% vs 31.3%, p < 0.01), whereas the main source of monomicrobial Pa-BSI was primary BSIs (21.9% vs 2.6%, p = 0.04). In multivariate analysis, a history of cerebrovascular accident (CVA) (adjusted odds ratio [OR], 3.62; 95% CI, 1.46-8.92) was independently associated with polymicrobial Pa-BSI. Primary BSI was associated with monomicrobial Pa-BSI (OR, 0.08; 95% CI, 0.02-0.38). Patients with polymicrobial Pa-BSI had a longer intensive care unit (ICU) length of stay after onset of BSI than those with monomicrobial Pa-BSI (2 [2, 16] vs 13 [3.75, 29], p = 0.02). Conclusion: Patients with Pa-BSI and the presence of CVA need to be alert to the possibility of polymicrobial BSI occurrence. Prolonged ICU stay and pneumonia as a source of BSI warrant clinician attention for polymicrobial Pa-BSI, and primary BSIs are likely associated with monomicrobial BSIs. [ABSTRACT FROM AUTHOR]