The impact of volunteer service on moral education performance and mental health of college students.

BACKGROUND: Moral education in colleges and universities is an important part of the talent training system, including moral education curriculum, moral education practice, mental health education. Volunteer service is a public welfare act in which volunteers volunteer their time, knowledge, property, technology, with the ultimate goal of helping others and serving the society without personal compensation. As an innovative form of moral education practice in colleges and universities, college students' voluntary service is of great significance in promoting the reform and innovation of moral education, enhancing the affinity, appeal and influence of moral education, and building a positive psychology for college students. SUBJECTS AND METHODS: As an effective carrier of moral education practice in colleges and universities, voluntary service is helpful to enhance the effectiveness of moral education practice and construct the positive psychology of college students. This project is based on the actual situation of college students participating in volunteer services, and collected the volunteer services of 4545 college students in Zhejiang Province. Through model construction and data modeling, the correlation between college students' participation in volunteer service and their moral education performance and mental health was analyzed, and the basic path and guarantee measures to promote the role of volunteer service in moral education and positive psychological construction were deeply explored. RESULTS: From the correlation analysis of students' voluntary service participation, moral education performance and voluntary service motivation, students' attributes are determined according to their voluntary service participation, so as to predict their moral education performance and mental health level. CONCLUSION: College students' voluntary service is partially positively related to their moral education performance and mental health. In order to improve students' moral education performance and mental health, we can optimize the participation frequency, participation duration, participation ways and type structure of voluntary service, constantly increase the participation frequency of voluntary service, increase the duration of voluntary service, broaden the participation ways of voluntary activities, and enrich the types of voluntary service activities.

Auxin and abscisic acid play important roles in promoting glucose metabolism of reactivated young kernels of maize (Zea mays L.).

In maize, young kernels that are less competitive and have poor sink activity often abort. Studies have indicated that such poor competitiveness depends, in part, on the regulation by auxin (IAA) and abscisic acid (ABA). However, the mechanisms for such effects remain unclear. We used pollination-blocking and hand-pollination treatments accompanied by multi-omics and physiological tests, to identify underlying mechanism by which IAA and ABA, along with sugar signaling affect kernel development. Results showed that preventing pollination of the primary ears reactivated kernels in the secondary ears and altered both sugar metabolism and hormone signaling pathways. This was accompanied by increased enzyme activities in carbon metabolism and concentrations of glucose and starch, as well as increased levels of IAA and decreased levels of ABA in the reactivated kernels. Positive and negative correlations were observed between IAA, ABA contents and cell wall invertase (CWIN) activity, and glucose contents, respectively. In vitro culture revealed that the expression of genes involved in glucose utilization was upregulated by IAA, but downregulated by ABA. IAA could promote the expression of ABA signaling genes ZmPP2C9 and ZmPP2C13 but downregulated the expression of Zmnced5, an ABA biosynthesis gene, and ZmSnRK2.10, which is involved in ABA signal transduction. However, these genes showed opposite trends when IAA transport was inhibited. To summarize, we suggest a regulatory model for how IAA inhibits ABA metabolism by promoting the smooth utilization of glucose in reactivated young kernels. Our findings highlight the importance of IAA in ABA signaling by regulating glucose production and transport in maize.

Global Existence and Fixed-Time Synchronization of a Hyperchaotic Financial System Governed by Semi-Linear Parabolic Partial Differential Equations Equipped with the Homogeneous Neumann Boundary Condition.

Chaotic nonlinear dynamical systems, in which the generated time series exhibit high entropy values, have been extensively used and play essential roles in tracking accurately the complex fluctuations of the real-world financial markets. We are concerned with a system of semi-linear parabolic partial differential equations supplemented by the homogeneous Neumann boundary condition, which governs a financial system comprising the labor force, the stock, the money, and the production sub-blocks distributed in a certain line segment or planar region. The system derived by removing the terms involved with partial derivatives with respect to space variables from our concerned system was demonstrated to be hyperchaotic. We firstly prove, via Galerkin's method and establishing a priori inequalities, that the initial-boundary value problem for the concerned partial differential equations is globally well posed in Hadamard's sense. Secondly, we design controls for the response system to our concerned financial system, prove under some additional conditions that our concerned system and its controlled response system achieve drive-response fixed-time synchronization, and provide an estimate on the settling time. Several modified energy functionals (i.e., Lyapunov functionals) are constructed to demonstrate the global well-posedness and the fixed-time synchronizability. Finally, we perform several numerical simulations to validate our synchronization theoretical results.

Signal-in-space range error and positioning accuracy of BDS-3.

Being the first mixed-constellation global navigation system, the global BeiDou navigation system (BDS-3) designs new signals, the service performance of which has attracted extensive attention. In the present study, the Signal-in-space range error (SISRE) computation method for different types of navigation satellites was presented. The differential code bias (DCB) correction method for BDS-3 new signals was deduced. Based on these, analysis and evaluation were done by adopting the actual measured data after the official launching of BDS-3. The results showed that BDS-3 performed better than the regional navigation satellite system (BDS-2) in terms of SISRE. Specifically, the SISRE of the BDS-3 medium earth orbit (MEO) satellites reached 0.52 m, slightly inferior compared to 0.4 m from Galileo, marginally better than 0.59 m from GPS, and significantly better than 2.33 m from GLONASS. The BDS-3 inclined geostationary orbit (IGSO) satellites achieved the SISRE of 0.90 m, on par with that (0.92 m) of the QZSS IGSO satellites. However, the average SISRE of BDS-3 geostationary earth orbit (GEO) satellites was 1.15 m, which was marginally inferior to that of the QZSS GEO satellite (0.91 m). In terms of positioning accuracy, the new signals B1C and B2a are considered together with the transition signals B1I and B3I. The overall three-dimensional single-frequency standard point positioning (SPP) accuracy of BDS-3 B1C, B2a, B1I, and B3I gained an accuracy level better than 5 m. Moreover, the B1I signal exhibited the best positioning accuracy in the Asian-Pacific region, while the B1C signal set forth the best positioning accuracy in the other regions. Owing to the advantage in signal frequency, the dual-frequency SPP accuracy of B1C + B2a surpassed that of the transitional signal of B1I + B3I. Since there are more visible satellites in Asia-Pacific, the positioning accuracy of BDS-3 was moderately superior to that of GPS. The precise point positioning (PPP) accuracy of BDS-3 B1C + B2a or B1I + B3I converged to the order of centimeters, marginally inferior to that of the GPS L1 + L2. However, these three combinations had a similar convergence time of approximately 30 min.

Maize ear growth is stimulated at the fourth day after pollination by cell wall remodeling and changes in lipid and hormone signaling.

BACKGROUND: Stimulating maize ear development is an effective way of improving yield. However, limited information is available regarding the regulation of sink strength change from weak to strong at the same position of maize plants. Here, a novel method for stimulating development combined with physiological assays and proteomics was applied to explore the regulation of ear strengthened development. RESULTS: By blocking pollination of the upper ear of maize hybrid Suyu 41, the adjacent lower ear was dramatically stimulated at 4 days after pollination (DAP). Tandem mass tag (TMT)-based proteomics identified 173 differentially expressed proteins (fold change >1.2 or <0.83, P < 0.05) from 7793 total proteins. Gene ontology annotations indicated that several pathways showed noticeable changes, with a preferential distribution to cell wall remodeling, hormone signals and lipid metabolism in the stimulated kernels. Cell wall remodeling was highly mediated by chitinase, exhydrolase II and xyloglucan enotransglucosylase/hydrolase, and accompanied by increased sucrose and glucose content. A series of lipoxygenase proteins were significantly upregulated, causing a significant alteration in lipid metabolism. Hormone signals were influenced by the expression of the proteins involved in indole-3-acetic acid (IAA) transport, zeatin (ZT) biosynthesis and abscisic acid (ABA) signal response, and increased IAA, ZT and ABA content. CONCLUSION: The critical time for understanding the mechanism by which ear growth is stimulated is 4 DAP. Comparative proteomics and physiological analysis revealed that lipid metabolism enhancement, cell wall remodeling and changes in hormone signaling (IAA, ZT and ABA) were all important in stimulating early ear development. Proper regulation of these pathways may improve ear development, resulting in increased maize yield. © 2022 Society of Chemical Industry.

Associations of Genetic Polymorphisms of mTOR rs2295080 T/G and rs1883965 G/A with Susceptibility of Urinary System Cancers.

BACKGROUND: Genetic polymorphisms in mammalian target of rapamycin (mTOR) signaling axis can influence the susceptibility of cancer. The relationship between mTOR gene variants rs2295080 T/G and rs1883965 G/A and the risk of cancer remains inconsistent. The present study is aimed at comprehensively investigating the association between mTOR polymorphisms and susceptibility to cancer. METHODS: We conducted a comprehensive assessment using odds ratios (ORs), corresponding 95% confidence intervals (CIs), and in silico tools to evaluate the effect of mTOR variations. Immunohistochemical staining (IHS) and GSEA analysis were used to investigate the expression of mTOR in urinary system cancer. RESULTS: The pooled analysis involved 22 case-control studies including 14,747 cancer patients and 16,399 controls. The rs2295080 T/G polymorphism was associated with the risk of cancer (G-allele versus T-allele, OR = 0.89, 95%CI = 0.80-0.98, P = 0.023; GT versus TT, OR = 0.88, 95%CI = 0.81-0.96, P = 0.004; GG+GT versus TT, OR = 0.87, 95%CI = 0.78-0.96, P = 0.008), especially for cancers of the urinary system, breast, and blood. Variation rs1883965 G/A was associated with cancer susceptibility, especially for digestive cancer. IHS analysis showed that mTOR was upregulated in prostate and bladder cancer. GSEA revealed that the insulin signaling pathway, lysine degradation pathway, and mTOR signaling pathway were enriched in the high mTOR expression group. CONCLUSIONS: The mTOR rs2295080 T/G polymorphism may be associated with susceptibility of urinary cancer. The expression of mTOR is positively correlated with tumor malignancy in prostate cancer.

Theoretical Design of Novel Boron-Based Nanowires via Inverse Sandwich Clusters.

Borophene has important application value, boron nanomaterials doped with transition metal have wondrous structures and chemical bonding. However, little attention was paid to the boron nanowires (NWs). Inspired by the novel metal boron clusters Ln2B n - (Ln = La, Pr, Tb, n = 7-9) adopting inverse sandwich configuration, we examined Sc2B8 and Y2B8 clusters in such novel structure and found that they are the global minima and show good stability. Thus, based on the novel structural moiety and first-principles calculations, we connected the inverse sandwich clusters into one-dimensional (1D) nanowires by sharing B-B bridges between adjacent clusters, and the 1D-Sc4B24 and 1D-Y2B12 were reached after structural relaxation. The two nanowires were identified to be stable in thermodynamical, dynamical and thermal aspects. Both nanowires are nonmagnetic, the 1D-Sc4B24 NW is a direct-bandgap semiconductor, while the 1D-Y2B12 NW shows metallic feature. Our theoretical results revealed that the inverse sandwich structure is the most energy-favored configuration for transition metal borides Sc2B8 and Y2B8, and the inverse sandwich motif can be extended to 1D nanowires, providing useful guidance for designing novel boron-based nanowires with diverse electronic properties.

Research on the method of designing cap lens using ant colony algorithm.

It is necessary to select the appropriate parameters defining a aspheric lens for coupling the light from a laser diode into the optical fiber by cap aspheric lenses. In this paper, the ant colony optimization algorithm is applied to the optimization of structural parameters of the cap aspheric lens, and the merit function defining the optimization problem and detailed design steps are given. A cap aspheric lens with center thickness of 1.1019 mm and effective focal length of 1.10331 mm is designed using a self-made MATLAB program of ant colony optimization algorithm, which can couple the light emitting from a laser diode into a single mode fiber with a diameter of 9 um, the light-emitting surface of the LD is 3 µm × 2 µm, and beam-divergence angle in the X and Y directions are ± 35° and ± 23.58°, respectively. The theoretical coupling efficiency is 89.8%, and the experiment shows that the maximum coupling efficiency and average coupling efficiency are 88.63% and 79.39%, respectively. Design and experimental results prove that the design method in this paper is feasible and effective.

Effect of interleukin-8 receptor B (IL8RB) rs1126579 C>T variation on the risk to cancer.

Chemokines are a type of cytokine that participate in the migration of macrophages and monocytes to inflammatory cells. In particular, CXC chemokines are involved in the development of many cancers. Evidence for the association between interleukin-8 receptor B (IL8RB) rs1126579 C > T variation and cancer risk remains contradictory. Here, we utilized a comprehensive analysis containing odds ratios (ORs), regression, and in silico tools to evaluate the effect of IL8RB polymorphism on cancer risk. We further employed Gene set enrichment analysis combined with ELISA to evaluate the IL8RB expression in patients with prostate cancer (PRAD). A total of 5,187 cancer cases and 6,691 controls were included in the present analysis. Individuals with the TT genotype were associated with an increased risk of cancer compared to those with the TC+CC genotype. In a subgroup analysis by type of cancer, individuals with the TT genotype had a 39% increased risk of urinary cancer compared to those with the CC genotype. A subgroup analysis by ethnicity showed that Asians carrying the TC genotype had a 26% lower risk of cancer than those carrying the CC genotype. We found that the expression of IL8RB was down-regulated in PRAD. Compared to that in PRAD subjects carrying the CC genotype, the expression of IL8RB was decreased in patients with the TT+TC genotype. In conclusion, the IL8RB rs1126579 C > T variation may be associated with cancer risk, especially in Asian populations and patients with PRAD.

Effects of FGFR4 G388R, V10I polymorphisms on the likelihood of cancer.

The correlation between G388R or V10I polymorphisms of fibroblast growth factor receptor (FGFR) 4 gene and the risk of carcinoma has been investigated previously, but the results are contradictory. Odds ratios (ORs) with 95% confidence intervals (95%CIs), in silico tools, and immunohistochemical staining (IHS) were adopted to assess the association. In total, 13,793 cancer patients and 16,179 controls were evaluated in our pooled analysis. Summarization of all the studies showed that G388R polymorphism is associated with elevated susceptibility to cancer under homozygous comparison (OR = 1.21, 95%CI = 1.03-1.43, P = 0.020) and a recessive genetic model (OR = 1.21, 95%CI = 1.04-1.41, P = 0.012). In the stratification analysis by cancer type and ethnicity, similar findings were indicated for prostate cancer, breast cancer, and individuals of Asian descendant. Polyphen2 bioinformatics analysis showed that the G388R mutation is predicted to damage the protein function of FGFR4. IHS analysis indicated that FGFR4 expression is increased in advanced prostate cancer. These findings may guide personalized treatment of certain types of cancers. Up-regulation of FGFR4 may be related to a poor prognosis in prostate cancer.

How long-term exposure of environmentally relevant antibiotics may stimulate the growth of Prorocentrum lima: A probable positive factor for red tides.

Antibiotics have been widely detected in the ocean and have various impacts on the environment, while knowledge of their chronic influence on phytoplankton, especially red tide algae, is still limited. Dinoflagellates and green algae are common phytoplankton in marine ecosystems. The former is the main red tide algae, and the latter is an important primary producer. We investigated the long-term responses of two representative algae, Prorocentrum lima and Chlorella sp., to two common antibiotics (sulfamethoxazole (SMX) and norfloxacin (NFX)) at environmentally relevant levels (10 and 100 ng/L) during simulated natural conditions. The cell density and activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)) were analyzed. The results showed that the influence of each antibiotic on Chlorella sp. was not significant (p > 0.05) during the first 10 days, but the influence of the antibiotics later began to show significant inhibition (p < 0.05) compared with the control group, especially during mixed exposure. P. lima was not inhibited, but its cell density increased. SMX had a superior stimulation effect on P. lima. The three enzymes activities of P. lima increased, and the antioxidant mechanism was not seriously impacted. However, for Chlorella sp., the activity of SOD increased while the activities of CAT and POD decreased, suggesting that this algae's antioxidant system was unbalanced due to oxidative stress. Based on our results, the growth of P. lima was different from green algae Chlorella sp. as well as other inhibited marine algae (such as diatom, golden algae) studied in previous studies. Therefore, as a typical pollutant in the ocean, antibiotics may play a positive role in the bloom of dinoflagellate red tides.

NanoFe3O4 accelerates anoxic biodegradation of 3, 5, 6-trichloro-2-pyridinol.

3, 5, 6-trichloro-2-pyridinol (TCP) is a widespread organic pollutant with persistent, mobile and high antimicrobial effects. Here, nanoFe3O4 was firstly introduced into the anoxic biodegradation of TCP. It was found that nanoFe3O4 significantly accelerated TCP biodegradation. The removal rate of TCP (100 mg L-1) increased from 83.03% to 98.74% within 12 h in the presence of nanoFe3O4, and the addition of nanoFe3O4 also promoted the accumulation of CO2. Reductive dechlorination mechanism was involved in anoxic biodegradation of TCP. Molecular approaches further revealed that nanoFe3O4 distinctly induced the shifts of bacterial community. The dominant genus Ochrobactrum was converted to genus Delftia in nanoFe3O4 treatment, and the relative abundance of Delftia increased from 10.26% to 44.62%. Meanwhile, the total relative abundance of bacteria related to TCP dechlorination and degradation significantly increased in the presence of nanoFe3O4. These results indicated that nanoFe3O4 induced the enrichment of TCP-degrading bacteria to promote the anoxic biodegradation of TCP.

Degradation of 3,5,6-trichloro-2-pyridinol by a microbial consortium in dryland soil with anaerobic incubation.

Biodegradation of 3,5,6-trichloro-2-pyridinol (TCP) in drylands is an important biological process of detoxification. Flooding in drylands can result in the formation of anaerobic habitats. However, little is known about the microbial metabolism of TCP in dryland soil under anaerobic conditions. Here, chlorpyrifos-contaminated dryland soil was incubated to enrich the TCP-degrading microbial consortium under anaerobic conditions. Chloridion and CO2 were released with TCP degradation, and the enrichment cultures of dryland soil could metabolize 97% of TCP (100 mg/L) within 20 h. Both reductive and hydrolysis dechlorination mechanisms were involved in TCP biodegradation under anaerobic conditions. Bacterial taxonomic analysis revealed that the aerobic TCP-degrading bacteria Ochrobactrum and dechlorination bacteria Delftia were the dominant genera. Anaerobic and facultative bacteria; i.e., Bacteroides, Bacillus, and Cupriavidus had lower relative abundances, but they were significantly enriched following treatment with TCP. These results indicate that the enrichment cultures of dryland soil dominated by aerobic bacteria could dechlorinate and degrade TCP under anaerobic conditions.

Ecological risk assessment of microcystin-LR in the upstream section of the Haihe River based on a species sensitivity distribution model.

The eutrophication of surface water has been the main problem of water quality management in recent decades, and the ecological risk of microcystin-LR (MC-LR), which is the by-product of eutrophication, has drawn more attention worldwide. The aims of our study were to determine the predicted no effect concentration (PNEC) of MC-LR and to assess the ecological risk of MC-LR in the upstream section of the Haihe River. HC5 (hazardous concentration for 5% of biological species) and PNEC were obtained from a species sensitivity distribution (SSD) model, which was constructed with the acute toxicity data of MC-LR on aquatic organisms. The concentrations of MC-LR in the upstream section of the Haihe River from April to August of 2015 were analysed, and the ecological risk characteristics of MC-LR were evaluated based on the SSD model. The results showed that the HC5 of MC-LR in freshwater was 17.18 µg/L and PNEC was 5.73 µg/L. The concentrations of MC-LR ranged from 0.68 µg/L to 32.21 µg/L and were obviously higher in summer than in spring. The values of the risk quotient (RQ) ranged from 0.12 to 5.62, suggesting that the risk of MC-LR for aquatic organisms in the river was at a medium or high level during the study period. Compared with other waterbodies in the world, the pollution level of MC-LR in the Haihe River was at a moderate level. This research could promote the study of the ecological risk of MC-LR at the ecosystem level.

Occurrence and distribution of antibiotic resistance genes in water supply reservoirs in Jingjinji area, China.

Jingjinji area occupies important position in developing of the Chinese economy, while there exists a sharp conflict between economic growth and limited water resources in this area. To ensure the safety of water consumption of cities in Jingjinji area, we investigated the abundance of three classes of antibiotic resistance genes (ARGs) in water and sediment of six water supply reservoirs in this area. The results showed that the detection frequency of sul1, tetM and ermB were 100%. However, the content ranges of these genes were different (10-5 to 10-2/16S gene copies for sul1, 10-5 to 10-3/16S gene copies for ermB, and 10-5 to 10-3/16S gene copies for tetM). The content of ribosome protection proteins (RPP) genes were the highest in all selected tet genes. The highest abundance of ARGs in water and sediment samples was sampled from Panjiakou reservoir and Guanting reservoir, respectively. Except COD, chla and tetM, there are no significant correlation between water quality parameters and ARGs. Overall, this study provides integrated profiles of the three types of ARGs in water supply reservoirs of Jingjinji area and thus helps to re-evaluate the effects of human activities to water supply reservoirs.

Did municipal solid waste landfill have obvious influence on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air: A case study in East China.

Municipal solid waste (MSW) landfill was a main way to disposal of MSW and almost 95% of MSW was disposed by landfills in the world. In order to understand the influence of MSW landfill on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in surrounding atmosphere, 42 ambient air samples were collected and analyzed from surrounding sites, background site, upwind site and downwind site of a MSW landfill in East China. The results of present study were summarized as follows. (1) The total concentrations of PCDD/Fs (∑PCDD/Fs) in ambient air from surrounding sites, background site, upwind site and downwind site were 2.215±1.004, 2.058±0.458, 2.617±1.092 and 1.822±0.566pgNm-3, respectively. (2) The toxic equivalent concentrations (TEQ) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 0.103±0.017, 0.096±0.015, 0.120±0.024 and 0.108±0.014pg I-TEQNm-3, respectively. (3) The congener profiles, ∑PCDD/Fs and TEQ between background atmosphere and surrounding atmosphere of landfill did not show statistically significant difference. (4) The ∑PCDD/Fs and TEQ in ambient air of downwind site were not higher than that of upwind site, suggesting that studied landfill did not have obvious influence on PCDD/Fs in ambient air from downwind site. (5) The 95th percentile carcinogenic risk (CR) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 8.03×10-9, 7.57×10-9, 9.69×10-9 and 8.15×10-9, respectively, which were much lower than the threshold value of CR (10-6), suggesting that studied landfill did not influence the CR of PCDD/Fs in surrounding atmosphere and negligible cancer risk occurred. (6) The non-carcinogenic risk (non-CR) analysis indicated that landfill did not have influence on the non-CR of PCDD/Fs in surrounding atmosphere and no obvious non-carcinogenic effects developed.

Orbital angular momentum mode division filtering for photon-phonon coupling.

Stimulated Brillouin scattering (SBS), a fundamental nonlinear interaction between light and acoustic waves occurring in any transparency material, has been broadly studied for several decades and gained rapid progress in integrated photonics recently. However, the SBS noise arising from the unwanted coupling between photons and spontaneous non-coherent phonons in media is inevitable. Here, we propose and experimentally demonstrate this obstacle can be overcome via a method called orbital angular momentum mode division filtering. Owing to the introduction of a new distinguishable degree-of-freedom, even extremely weak signals can be discriminated and separated from a strong noise produced in SBS processes. The mechanism demonstrated in this proof-of-principle work provides a practical way for quasi-noise-free photonic-phononic operation, which is still valid in waveguides supporting multi-orthogonal spatial modes, permits more flexibility and robustness for future SBS devices.

Emission characteristic of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from medical waste incinerators (MWIs) in China in 2016: A comparison between higher emission levels of MWIs and lower emission levels of MWIs.

Emission characteristic of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from 12 medical waste incinerators (MWIs) which have a total yearly capacity of 523 440 ton medical waste and accounted for 8.1% of total yearly capacity of 246 MWIs in China were studied. The congeners profile, emissions and toxic equivalent concentrations (TEQ) indicators of PCDD/Fs in stack gas from two groups of MWIs were researched, and the possible formation mechanisms of PCDD/Fs from MWIs were preliminarily discussed. The results of present study were summarized as follows. (1) The total concentrations and TEQ of PCDD/Fs in stack gas from MWIs were 0.516-122.803 ng Nm-3 and 0.031-3.463 ng I-TEQ Nm-3, respectively. (2) 1,2,3,4,6,7,8-H7CDF, O8CDD, O8CDF and 1,2,3,4,6,7,8-H7CDD were the indicatory PCDD/Fs of MWI source, which could be used to apportion the sources of PCDD/Fs in environmental medium in China. (3) The emission factors of PCDD/Fs from MWIs ranged from 32.7 to 4900.0 ng I-TEQ ton-1 with a mean of 1923.6 ng I-TEQ ton-1. (4) The gas emissions of PCDD/Fs from researched 12 MWIs and all of MWIs in China in 2016 were 37.742 and 465.951 mg I-TEQ year-1, respectively. (5) 1,2,3,7,8,9-H6CDF and 1,2,3,4,7,8-H6CDF were effective TEQ indicators for the real-time monitoring of the PCDD/Fs emission. (6) The congeners profile and factor composition of PCDD/Fs in stack gas from two groups of MWIs were researched based on positive matrix factorization (PMF) model, and the possible formation mechanisms of PCDD/Fs from MWIs were preliminarily discussed.

Stormwater infiltration and surface runoff pollution reduction performance of permeable pavement layers.

In this paper, the laboratory-scale permeable pavement layers, including a surface permeable brick layer, coarse sand bedding layers (thicknesses = 2, 3.5, and 5 cm), and single-graded gravel sub-base layers (thicknesses = 15, 20, 25, and 30 cm), were built to evaluate stormwater infiltration and surface runoff pollution reduction performance. And, the infiltration rate (I) and concentrations of suspended solids (SS), total phosphorus (TP), chemical oxygen demand (COD), ammonia nitrogen, and total nitrogen (TN) were measured under the simulated rainfall intensity of 72.4 mm/h over duration of 60 min. The results indicate that the thickness factor primarily influences the infiltration rate and pollutant removal rate. The highest steady infiltration rate was for surface brick layer 51.0 mm/h, for 5-cm sand bedding layer 32.3 mm/h, and for 30-cm gravel sub-base layer 42.3 mm/h, respectively. The SS average removal rate was relative higher (79.8 ∼ 98.6 %) for all layers due to the interception and filtration. The average removal rates of TP and COD were for surface layer 71.2 and 24.1 %, for 5-cm bedding layer 54.8 and 9.0 %, and for 20-cm sub-base layer 72.2 and 26.1 %. Ammonia nitrogen and TN cannot steadily be removed by layers according to the experiment results. The optimal thickness of bedding sands was 5 cm, and that of sub-base gravels was 20 ∼ 30 cm.

Enhanced surface hydrophilicity of thin-film composite membranes for nanofiltration: an experimental and DFT study.

In the current study, thin-film composite (TFC) nanofiltration membranes desirable for water softening were successfully developed through interfacial polymerization using N-(2-hydroxyethyl)ethylenediamine (HEDA) as the amine monomer in the aqueous phase. The hydrophilicity of the membrane surface was greatly enhanced with the introduction of the residual hydroxyl groups during the fabrication process. The TFC membranes possessed a permeate flux of 15.8 L m(-2) h(-1) under 0.6 MPa, with a rejection of 85.9%, 73.8%, and 99.8% for Na2SO4, MgSO4 and Congo red, respectively. The interplays of the solvent, solute and polymer matrix on the separation performance were investigated by means of the solubility parameter study. Moreover, density functional theory was employed to calculate the Fukui function by the Hirshfeld charge, which gave the global and local softness values to predict the reactivity of the atomic sites in the HEDA molecule. The findings of this study support the possible forming mechanism of the barrier layer for the first time. The TFC membrane was found to be stable and displayed good separation ability over a week-long filtration process. The combined results of this work suggest that these HEDA/TMC TFC nanofiltration membranes are promising candidates for various applications, such as desalination and dye removal from wastewater.