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In response to the shortage of water resources, multiple processes have been applied to turn wastewater secondary effluent (SE) into potable water. However, trace organic contaminants (TOrCs) and high concentrations of organic matter contained in SE pose a significant challenge to the reclamation. In this manuscript, combined UV-based and biofilm processes were used to treat the SE spiked with ibuprofen (IBU) and clofibric acid (CA). The efficiency of these sequential treatments was characterized in terms of changes in dissolved organic carbon (DOC), absorbance at 254 nm (A254), fluorescence excitation-emission matrix (FEEM), the concentration of IBU and CA, and molecular weight of SE. Parallel factor (PARAFAC) was applied as the analysis method for FEEM of the samples and two fluorescent components were successfully identified: humic-like substances (C1) and protein-like matter (C2). Large reductions in A254, C1, C2, IBU, and CA were observed during the UV-based processes, especially with the addition of H2O2. Nearly 50% of A254, 80% of the component C1 were decreased and almost complete removal of the component C2 and TOrCs was achieved by UV/2.0 mM H2O2 after 90-min treatment. During the oxidation processes, the formation of lower molecular weight (LMW) compounds was detected, and the biodegradability of the organic matters was greatly increased. Although no significant DOC reduction was obtained in UV-based processes, an obvious further DOC reduction (30~60%) was achieved by biofilm treatment following UV-based processes, especially after UV/H2O2 treatments. In the meantime, large amounts of LMW were removed in the biofilm treatment process. This manuscript provides an effective advanced treatment of SE for the removal of DOC and TOrCs, facilitating the wastewater reclamation.

To improve the utilization of sucrose for 2,3-butanediol (2,3-BD) production, four combinations of heterologous energy-conserving sucrose utilization pathways were introduced into Bacillus subtilis Δtet strain (a derivative from B. subtilis 168) and B. subtilis FJ-1 strain (a new isolate in our lab). Results demonstrated that the combination of cscB (encoding sucrose permease) from Escherichia coli and gtfA (encoding sucrose phosphorylase) from Streptococcus mutans showed the most remarkable enhancement for the 2,3-BD production. With sucrose and sugar cane juice as substrate, respectively, the Δtet-CEG strain (B. subtilis Δtet strain containing the energy-conserving sucrose utilization pathway as referred above) showed 36.5% and 24.7% increase in 2,3-BD production than the control Δtet strain, and the FJ-1-CEG strain also produced 23.8% and 44.5% more 2,3-BD than the control FJ-1 strain. The metabolic engineering strategy demonstrated in this study can be extensively applied to other microorganisms for r...

In this paper, we prove the following results: (1) Let f : G → H be a continuous d-open surjective homomorphism; if G is an R -factorizable paratopological group, then so is H. This improves a result by Peng and Zhang [4, Theorem 1.7] , and (2) let G be a regular (so G is completely regular by a theorem of Banakh and Ravsky) R -factorizable paratopological group; then every subgroup H of G is R -factorizable if and only if H is z-embedded in G. This result gives a partial answer to a question of M. Sanchis and M. Tkachenko [8, Problem 5.3] .

2,3-Butanediol (2,3-BD), especially when it exists in the chirally pure form, is a valuable chemical feedstock with numerous applications in various industries. However, in most cases, the 2,3-BD naturally produced by the microorganism is a mixture of two of the three isomers (d-2,3-BD, l-2,3-BD, and meso-2,3-BD), which has restricted applications and thus a much lower value than the chirally pure one. In this study, we report a new isolate Bacillus spp. FJ-4 strain, which can produce highly chirally pure d-2,3-BD (>99.9%) to high levels, with very high productivity and yield. The composition of the fermentation medium for the strain was sequentially optimized using statistical experimental methodologies. During a fed-batch experiment, 100.0 g/L of d-2,3-BD was produced from 226.8 g/L glucose, with a yield of 0.44 g/g (88.2% of the theoretical maximum). Acetoin was the primary byproduct, and no other byproduct such as lactate, acetate, or ethanol was detected, which would be advantageous for the downstrea...

In this paper, a novel image encryption algorithm based on coarse-grained chaotic signals in which scrambling and diffusion are both covered. First, the chaotic signals are handled with unfixed coarse-grained key instead of been utilized directly. Second, both original image and derived chaotic signals are divided into bit signals form pixel values. In addition, high bits and low bits are also separated. Third, the high bits and low bits are scrambled with different methods at the same time and combined bit signals after scrambling are used to get the final results by global diffusion. At last, the image is encrypted and a corresponding decryption is designed to recover the encrypt image. In the simulation, properties including key space, information entropy, correlation analysis, key sensitivity and resistance to differential attack are provided to show the effectiveness and robustness of the high secure image encryption algorithm.

Understanding the impact of temperature variations (i.e., maximum, minimum, and diurnal temperature ranges [DTRs]) on ecosystems is now recognized as being of paramount importance in global change ecology; the roles of different aspects of these temperature variations in influencing plant photosynthesis remain under‐studied. Here, we investigated the photosynthetic responses of two local dominant wetland plants to two simulated air‐warming scenarios (+2° ± 0.5°C and +3.5° ± 0.5°C) by using open‐top chambers in the northwest Yunnan plateau. During the growing season from 2014 to 2016, we explored photosynthetic parameters and the relationships linking photosynthesis to temperature variations. We found that open‐top chambers had increased the daily maximum temperature as well as DTRs. The photosynthetic responses of two plant species to warming were species‐specific during the first two years but species‐independent in the third year. The two warming scenarios did not significantly alter the linear relationships linking maximum net photosynthetic rate (Amax) to stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (Tr), despite changes in slopes and intercepts of the fitted lines. The DTRs between 0°C and 30°C were positively correlated with photosynthesis, while DTRs over 30°C were negatively correlated with photosynthesis. Our results provide experimental evidence that temperature variations play a greater role than increasing average temperature in explaining plant photosynthesis, and more attention should be paid to temperature variations when assessing the impact of climate warming on wetland ecosystem.

Compared with numerous X-ray dominant active galactic nuclei (AGNs) without emission-line signatures in their optical spectra, the X-ray selected AGNs with optical emission lines are probably still in the high-accretion phase of black hole growth. This paper presents an investigation on the fraction of these X-ray detected AGNs with optical emission-line spectra in 198 galaxy groups at $z0.5$, most member AGNs are X-ray bright, optically dull, which results in a lower AGN fractions at higher redshifts. The AGN fraction in isolated fields also exhibits a rising trend with redshift, and the slope is consistent with that in groups. The environment of galaxy groups seems to make no difference in detection probability of the AGNs with emission lines. Additionally, a larger AGN fractions are found in poorer groups, which implies that the AGNs in poorer groups might still be in the high-accretion phase, whereas the AGN population in rich clusters is mostly in the low-accretion, X-ray dominant phase., Comment: 11 pages, 7 figures, 2 tables

In this paper, the class of weakly ω-admissible paratopological groups is introduced. We mainly show that: (1) Every bounded set in a weakly ω-admissible paratopological group is p-bounded for each free ultrafilter p on ω; (2) every C-compact set in a weakly ω-admissible paratopological group is strongly r-pseudocompact. The class of weakly ω-admissible paratopological groups contains all totally ω-narrow, precompact, locally feebly compact, weakly Lindelof and saturated, and ω-admissible paratopological groups. It is worth mentioning that all the aforementioned spaces are not to satisfy any separation axiom. Some Sanchis, Sanchez and Tkachenko's results are improved.

Dissolved organic matter (DOM) in wastewater can be characterized using fluorescence excitation-emission matrix and parallel factor (EEM-PARAFAC) analysis. Wastewater from animal farms or pharmaceutical plants usually contains high concentration of antibiotics. In this study, the quenching effect of antibiotics on the typical components of DOM was explored using fluorescence EEM-PARAFAC analysis. Four antibiotics (roxarsone, sulfaquinoxaline sodium, oxytetracycline, and erythromycin) at the concentration of 0.5∼4.0 mg/L and three typical components of DOM (tyrosine, tryptophan, and humic acid) were selected. Fluorescence quenching effects were observed with the addition of antibiotics. Among these four antibiotics, roxarsone (2.9∼20.2 %), sulfaquinoxaline sodium (0∼32.0 %), and oxytetracycline (0∼41.8 %) led to a stronger quenching effect than erythromycin (0∼8.0 %). From the side of DOM, tyrosine and tryptophan (0.5∼41.8 %) exhibited a similar quenching effect, but they were higher than humic acids (0∼20.2 %) at the same concentration of antibiotics. For humic acid, a significant quenching effect was observed only with the addition of roxarsone. This might be the first report about the fluorescence quenching effect caused by antibiotics. The results from this study confirmed the interference of antibiotics on the fluorescence intensity of the main components of DOM and highlighted the importance of correcting fluorescence data in the wastewater containing antibiotics.