In recent years, the development of artificial intelligence technology and theory has been rapid, and the application in language science has been gradually comprehensive and diversified, especially ...the accuracy rate of artificial intelligence for Chinese language is up to 90%. In the era of artificial intelligence, the effect of different structures and parameters of arithmetic models on Chinese language recognition varies greatly. Language science is an important research area for realizing machine-human communication, and accurate comprehension of the meaning of linguistic expressions is the key to realize communication. In this paper, we construct a speech system that is different from the traditional stable time series for the irreplaceable characteristics of artificial intelligence technology to improve Chinese language ability. A dynamic Bayesian network (DBN) is used for modeling and analysis, and a DBN construction method is investigated to import a hidden Markov model in a speech recognition system to reveal the interactions between nodes within multiple time slices. The accuracy of dynamic Bayesian networks in Chinese dialect inference algorithms is demonstrated using Matlab simulations to characterize the reliability of speech features using a speech spectrogram. It proves that artificial intelligence technology and Chinese language science are complementary and mutually reinforcing, showing a good and rapid development trend.
Nanoplastics as emerging pollutants have caused growing concerns and posed potential threats to the environment. Nonetheless, only few studies investigated transport behaviors of nanoplastics in ...natural soils. In this study, column experiments were conducted to investigate the effect of soil properties, ionic strength and cation type on the transport of polystyrene nanoplastics (PSNPs) in a desert soil (DS), a black soil (BS) and a red soil (RS). The effluent recovery of PSNPs in three soils followed the order of DS (0%–96.8%) > BS (0%–87.5%) > RS (0%). The retention of PSNPs was positively correlated with Fe/Al oxides contents (DS: Fe-2.69%, Al-12.6%; BS: Fe-4.04%, Al-15.9%; RS: Fe-6.57%, Al-26.9%), whereas negatively correlated with soil pH (DS: 9.75; BS: 6.57; RS: 4.97). Soil minerals and pH were thus identified as the crucial soil properties determining transport of PSNPs, due to their coupled effects on surface charges to affect electrostatic interactions between soils and PSNPs. In addition, increasing solution ionic strength strongly inhibited the transport of PSNPs in the DS (0%–96.8%) and BS (0%–87.5%). Ca2+ (IS: 1–5 mM) was more pronounced in enhancing PSNP retention than Na+ (IS: 1–20 mM). Our findings highlight that the transport and fate of PSNPs in natural soils are highly sensitive to soil physicochemical properties, ionic strength and cation type, and reveal that nanoplastics have strong mobility ability in soils with high pH and low Fe/Al oxides contents, which may pose potential risks to the soil and groundwater environment.
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•PSNPs retention in soils was positively correlated with Fe/Al oxides contents.•PSNPs retention in soils was negatively correlated with soil pH.•PSNPs transport decreased with increasing ionic strength in soils.•Ca2+ was more pronounced in inhibiting PSNPs transport than Na+ in soils.
A tubular g‐C3N4 isotype heterojunction (TCNH) photocatalyst was designed for cooperative manipulation of the oriented transfer of photogenerated electrons and holes to pursue high catalytic ...performance. The adduct of cyanuric acid and melamine (CA·M) is first hydrothermally treated to assemble into hexagonal prism crystals; then the hybrid precursors of urea and CA·M crystals are calcined to form tubular g‐C3N4 isotype heterojunctions. Upon visible‐light irradiation, the photogenerated electrons transfer from g‐C3N4 (CA·M) to g‐C3N4 (urea) driven by the conduction band offset of 0.05 eV, while the photogenerated holes transfer from g‐C3N4 (urea) to g‐C3N4 (CA·M) driven by the valence band offset of 0.18 eV, which renders oriented transfer of the charge carriers across the heterojunction interface. Meanwhile, the tubular structure of TCNH is favorable for oriented electron transfer along the longitudinal dimension, which greatly decreases the chance of charge carrier recombination. Consequently, TCNH exhibits a high hydrogen evolution rate of 63 μmol h−1 (0.04 g, λ > 420 nm), which is nearly five times of the pristine g‐C3N4 and higher than most of the existing g‐C3N4 photocatalysts. This study demonstrates that isotype heterojunction structure and tubular structure can jointly manipulate the oriented transfer of electrons and holes, thus facilitating the visible‐light photocatalysis.
A novel tubular g‐C3N4 isotype heterojunction photocatalyst is explored for cooperative manipulation of the oriented transfer of photogenerated electrons and holes, as well as for the separation of electron–hole pairs, leading to a high visible‐light catalytic activity.
•Biomass wastes-derived activated carbon were prepared by one-step method.•The properties of precursors were characterized by thermogravimetric analysis.•The surface acidic functional groups were ...determined by NH3-TPD.•The characterization and adsorption properties of both carbons were compared.
As biomass wastes, Arundo donax Linn and pomelo peel were used as precursors for activated carbons (ALAC and PPAC) preparation by phosphoric acid activation. The pore structure and surface acidic functional groups of both carbons were characterized by nitrogen adsorption/desorption experiment, NH3-temperature-programmed desorption (NH3-TPD) and Fourier transform infrared spectroscopy (FTIR). A batch of experiments was carried out to investigate the adsorption performances of ciprofloxacin under different conditions. Results showed that PPAC exhibited larger surface area (1252m2/g) and larger portion of mesoporous, while ALAC was typical of microporous materials. Results from NH3-TPD suggested that ALAC was characteristic of more acidic functional group than PPAC. The maximum monolayer adsorption capability was 244mg/g for ALAC and 400mg/L for PPAC. Kinetics studies showed intra-particle diffusion was not the unique rate-controlling step. Boundary layer resistance existed between adsorbent and adsorbate.
Quercetin has potential pharmacological values in various carcinomas including oral squamous cell carcinoma (OSCC). Moreover, the anti-tumor effect of quercetin is correlated with WNT/β-catenin ...pathway and miRNA dysregulation. In the present study, we aimed to further investigate whether quercetin can exert its anti-tumor function by regulating miR-22 together with miR-22 downstream pathway WNT1/β-catenin in OSCC. The results of Cell Counting Kit-8 (CCK-8) and flow cytometry analyses showed that quercetin treatment and miR-22 overexpression resulted in the reduction of cell viability and the increase of cell apoptotic rate in OSCC. WNT1 was a target of miR-22, which was confirmed by bioinformatics, luciferase reporter and RNA immunoprecipitation (RIP) assays. RT-qPCR assay showed that quercetin promoted miR-22 expression and suppressed WNT1 and β-catenin expression in OSCC cells, whereas this effect was abrogated by miR-22 inhibitor. Moreover, miR-22 depletion weakened quercetin-mediated viability inhibition and apoptosis increase in OSCC cells. Quercetin inhibited the growth of OSCC xenograft tumors by inducing miR-22 expression and repressing WNT1/β-catenin pathway in vivo. Taken together, quercetin hampered OSCC tumorigenesis by regulating miR-22/WNT1/β-catenin pathway in OSCC, providing a deep insight into the molecular targets of quercetin in the treatment of OSCC.
The bioaccessibility and human health risks of As and heavy metals (Cu, Pb, Zn, Ni, Co, Cr, Cd and Mn) in total suspended particulates (TSP) and fine particulate matter (PM2.5) in Nanjing, China were ...investigated. The average mass concentration ratios of PM2.5 to TSP were 0.61 for Gulou sampling site and 0.50 for Pukou sampling site, respectively. Zn, Pb, Mn and Cu were the most abundant elements among the studied metal(loid)s in both TSP and PM2.5. The results of a simple bioaccessibility extraction test of the studied metal(loid)s varied among elements, with Cd, Zn, Mn, Pb and As showing the higher bioaccessibility. The carcinogenic risks of As, Cd, Co, Cr and Ni in both TSP and PM2.5 via dermal contact and inhalation exposure were within the acceptable level (<1 × 10−4) for both children and adults, but there was potential carcinogenic risk posed by Pb via ingestion to children and adults. The hazard index values for all of the studied elements suggested no non-carcinogenic health risks via ingestion and dermal contact, but a potential non-carcinogenic health risk via inhalation to adults. Values of hazard quotient and hazard index indicated the non-carcinogenic risks from the studied metal(loid)s to children via ingestion, dermal contact and inhalation pathways in Nanjing given the present air quality.
► Bioaccessibility of metal(loid)s in aerosols (TSP and PM2.5) were analyzed using SBET. ► Zn, Pb, Mn and Cu were the most abundant contaminants in both TSP and PM2.5. ► Pb, As and Co in TSP/PM2.5 were the main exposure contaminants for children. ► Main risks for adults resulted from inhalation exposure of TSP and PM2.5. ► Health risk from metal(loid)s in PM2.5 is higher than that in TSP.
Photocatalytic CO2 reduction into fuels has been an attractive research topic. Herein, Ag and TiO2 nanoparticles co-loaded zeolite TS-1 (Ag–TiO2/TS-1) were synthesized by the ion-exchange and ...subsequently in-situ photodeposition method. The obtained Ag–TiO2/TS-1 sample has a high surface area and rich Ti3+-Vo defects and as well as highly dispersed Ag nanoparticles. As expected, the sample Ag–TiO2/TS-1 not only shows high CO2 adsorption capacity, but also improves the separation efficiency of photogenerated electron-hole pairs. As a result, only CO and CH4 can be detected on the sample Ag–TiO2/TS-1 in the photocatalytic CO2 conversion, and the competing H2 evolution can be completely suppressed, suggestive of its high selectivity. The super photocatalytic activity toward CO2 reduction can be ascribed to the synergistic effect among highly dispersed Ag nanoparticle, the support zeolite TS-1 and TiO2 with highly exposed {101} planes.
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•A novel Ag and TiO2 nanoparticles co-loaded zeolite TS-1 (Ag–TiO2/TS-1) was prepared.
•Ag–TiO2/TS-1 has highly exposed {101} planes and rich Ti3+-Vo defects.
•Ag–TiO2/TS-1 exhibits high CO2 adsorption capacity.
•Ag–TiO2/TS-1 exhibits super separation efficiency of photogenerated charges.
•Only CO and CH4 can be detected on the sample Ag–TiO2/TS-1 in the CO2 reduction.
•The lignin-based activated carbon was prepared by physical activation with steam.•The influences of various process parameters were investigated.•The optimum preparation conditions were ...determined.•The lignin-based carbon prepared by steam activation exhibited a mesoporous structure.•The static adsorption experiment and adsorption isotherms were studied.
Black liquor lignin obtained from pulp and paper industry was employed as the precursor for preparing activated carbon by physical activation with steam. The preparation was carried out with a two-step approach, firstly carbonized in an oxygen-free atmosphere and subsequently activated with steam. Experiments were performed to investigate the influences of different preparation parameters such as carbonization temperature, activation temperature and activation time on the pore texture characteristics of the products in detail by nitrogen adsorption analysis. The analysis results demonstrated that the optimized lignin-based activated carbon (LAC) obtained at a carbonization temperature of 450°C, carbonization time of 60min, activation temperature of 725°C and activation time of 40min. The microstructures of the raw lignin, the carbonized lignin and LAC were examined by SEM, whereas, surface chemistry was probed through FTIR. In the adsorption study, LAC was applied to remove methylene blue (MB) from aqueous solution. In the isotherms study, the Langmuir and Freundlich isotherms were applied to analyze the equilibrium data for the adsorption of MB onto LAC. It was found that the equilibrium data could be fit well by the Langmuir equation, and the maximum adsorption capacity was 92.51mg/g. The considerable maximum adsorption capacity indicated that the LAC could afford a noteworthy potential for dye wastewater treatment. Consequently, the procedure of physical activation with steam demonstrated its environmental and practical value for producing lignin-based adsorbent.
In this paper, a novel indirect adaptive interval type-2 fuzzy tracking control is proposed. Strategy with impulsive and Lyapunov synthesis approach, it handles the training data corrupted by noise ...or rule uncertainties for linear and nonlinear systems involving external disturbances. In comparison with conventional methods, the advocated approach guarantees closed-loop stability. The output tracking error of the overall system will converge to zero asymptotically by the generalized Barbalat's lemma. Numerical simulations are given to illustrate the effectiveness of the proposed techniques.
In gold(
i
) catalysis, the activation of Au(
i
) chloride catalysts
via
chloride abstraction and noncovalent interactions has become a research focus in organometallic catalysis. In this work, ...taking halogen bond donors (C
4
H
2
INO
2
, C
6
F
5
I, C
8
H
9
O
2
I) as activators for a Au(
i
) chloride catalyst (Ph
3
PAuCl), the mechanism of the cyclization reaction of propargylic amide was investigated. It was found that there are two activation modes as design principles to obtain the catalytically active species Ph
3
PAu
+
: the halogen bond donors activate the Cl atoms of Ph
3
PAuCl to form X-I Cl (X = C, N) classical halogen bonds and activate the Au atoms of Ph
3
PAuCl to form X-I Au (X = C, N) metal-involved halogen bonds. For the two activation modes, the mechanism of the cyclization reaction of propargylic amide has pathways: the chloride abstraction process of the first step and the 5-
exo
/6-
endo
cyclization process of the second step. Both activation modes show good activity for the cyclization reaction with the activation ability of classical halogen bonds being slightly stronger than that of the metal-involved halogen bonds, which is consistent with the strength of the X-I Cl halogen bonds being slightly stronger than that of the X-I Au halogen bonds. Therefore, both metal-involved halogen bonds and classical halogen bonds have important development prospects for the activation of catalysts in gold(
i
) catalysis.
Both metal-involved halogen bond activation and classical halogen bond activation are investigated in gold(
i
) catalysis of the propargylic amide cyclization reaction.
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