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Purpose: To analyse and compare the clinical characteristics and treatment outcomes of patients with acute angle closure (AAC) who presented before the COVID-19 pandemic, during the COVID-19 management and after their downgrading. Methods: Consecutive AAC patients were recruited from our hospital and divided into three groups: those treated before the COVID-19 pandemic (Group1), during the COVID-19 management (Group2) and after the management downgrade (Group3). The demographic variables, clinical characteristics, treatment methods and therapeutic outcomes of the groups were compared. Results: When compared to Groups1 and 2, Group3 showed a significantly higher incidence of AAC (0.27%, P < 0.001), a longer time from symptoms to treatment (TST; 160.88 ± 137.05 h, P = 0.031) and worse uncorrected visual acuity (P = 0.009) at presentation. In Group3, 68.9% had a history of COVID-19 and 28.5% developed ocular symptoms of AAC after taking medication for COVID-19 symptoms. The average time from the onset of COVID-19 to the appearance of eye symptoms was 3.21 ± 4.00 days. Conclusions: The COVID-19 has had a multifaceted impact on the incidence of AAC. Therefore, it is crucial to strengthen health education on glaucoma, especially AAC. The prevention and timely treatment of AAC should be emphasised to combat global blindness. [ABSTRACT FROM AUTHOR]

As a potential electrode material for lithium-ion batteries, Ga2O3 has high theoretical specific capacity and low lithium storage potential. Still, the bulk expansion efficiency and poor reaction kinetics during the reaction process hinder performance improvement. This paper successfully synthesised the Ga2O3 NPs@CF composite electrode with network core–shell structure using the electrospinning method. Carbon coating effectively alleviates the volume expansion of Ga2O3 during the reaction process. The carbon fibre network structure provides more transport channels for ions, and the Ga2O3 NPs@CF composite electrode shows excellent performance. In the long cycle test, after 500 cycles of 0.5 A/g, the discharge capacity reached 611.04mAh/g, and the capacity retention was 99.8%. At the current density of 0.1 ~ 2A/g, after a periodic cycle, when restored to 0.1A/g, the capacity remains at a high reversible capacity of 677.8mAh/g. [ABSTRACT FROM AUTHOR]

In this study, amorphous SiO2 is used to coat GaIn nanodroplets (GaIn NDs) to construct the core-shell structure of GaIn@SiO2 nanodroplets (GaIn@SiO2 NDs). We found that the amorphous SiO2 shell (~12 nm) formed a stable solid electrolyte interface (SEI) film, alleviated the volume expansion, and provided electron/ion transport channels to achieve excellent cycling performance and high specific capacity. The resulting GaIn@SiO2 NDs exhibited high capacities of 562, 541, 523, 502, 494, and 456 mAh g−1 at 0.1, 0.2, 0.5, 1, 2, and 5 C, respectively. The capacity of 330 mAh g−1 at 1 C was observed after more than 500 cycles. In situ X-ray diffraction (in situ XRD) was used to explore the lithiation mechanism of the GaIn anode during discharge. This study elucidates the design of advanced liquid alloy-based anode materials for high-performance lithium batteries. [ABSTRACT FROM AUTHOR]

In non-dense solid electrolytes, the arrangements of closed pores are rarely periodical repeating, while a periodical repeating assumption would save the cost of modeling and structural interpreting. In this paper, we have made a partially delocalized model to describe the non-periodical repeating pores, where the deviation of pores was confined inside the "cell" finally assembling the whole non-dense solid electrolyte. The quantitative measurement, order parameter S , depicting the degree of order, has also been clearly defined in this paper. The order parameter was defined to be within the range of [0,1]; with the increment of it, the arrangement of closed pores of the whole system was more ordering (i.e., pores arrangement is closer to the periodical repeating structure). Furthermore, with the aid of the finite element modeling (FEM) method, the ionic conductivity has been related to the degree of ordering of the pores: though ordering could enhance the ionic conductivity, it is still possible to model the solid electrolyte by the periodical repeating structure which might impart additional 1% error. Finally, the probability and effect on ionic conductivity of disordering assisted pore impingement have been investigated, indicating that the impingement orientation can ameliorate the ionic conductivity, which could be a guidance for the further functional design of the solid electrolyte structure. [ABSTRACT FROM AUTHOR]

The large capacity production and low utilization rate increase the difficulty of fruit and vegetable wastes (FVW) treatment. Efficient and targeted recovery strategies can solve these problems. This study investigated and proposed combined strategies via pH and organic loading rate (OLR) to target and enhance ethanol- and butyrate-dominant acidogenic production in the FVW mixed culture fermentation. Under pH 4.0, OLR 18 gCOD/(L∙d), and mesophilic (35 °C), ethanol-dominant fermentation was formed. The long-term operation (168 days) showed that the highest ethanol yield was 0.33 g/gCOD which was greater than that in other studies. Also, the hydrolysis rate of ethanol-type fermentation reached 74.5%. Besides, butyrate-type fermentation was stable at yield 0.39 g/gCOD following conditions: pH 6.0, OLR 28 gCOD/(L∙d), and 35 °C, of which hydrolysis and acidogenic rate were 78.0% and 62.0%, respectively. The high relative abundance of Lactobacillus, Olsenella, and Bifidobacterium played positive role in achieving ethanol, butyrate, and lactate production among various metabolic pathways. The results revealed the pH value together with OLR was the valid parameter to affect product formation and composition during FVW fermentation. [ABSTRACT FROM AUTHOR]

The effects of pores in the non-dense solid electrolyte on the ionic conductivity were performed via finite element modeling (FEM). As the basis, the convergence was studied for the low-density model to ensure accuracy and minimize the computational complexity. The pore distribution parameters (relative density, pore size, and the probability density function of the pore size) were systematically investigated based on the converged model. Relative density, the variable mostly researched, was determined to have a linear improvement on the ionic conductivity, quantitatively justifying that the densification process can enhance the ionic-conducting behavior of solid electrolytes. By contrast, at a given relative density for one-point distributed pores, pore size rarely affects ionic conductivity. For non-uniformly distributed solid electrolytes, the ionic conductivity showed a strong dependence on the probability density function (PDF) of the pore size distribution, which could be either improved or reduced. Beyond the traditional method aiming to the densification of solid electrolyte, this paper provides a novel guide to ameliorate the ionic conductivity through the optimization of the pore distribution function. [ABSTRACT FROM AUTHOR]

The fabrication of low-cost, recyclable, reusable, and heterogeneous catalysts is of considerable significance for green chemistry. In this study, a nanocomposite catalyst, MCM-41-supported Zn–Co double metal cyanide (MCM-41@DMC), was prepared using the synchronous dropping method. Thereafter, the composition, crystal structure, complexing state, morphology, and thermal stability of the catalyst were characterised using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, and thermogravimetry. The effects of different organic ligands on the catalytic activity of samples were evaluated, and the results showed that ethyl acetoacetate exhibited the best catalytic activity owing to its ketone coordination. The use of the MCM-41 support was beneficial for improving the catalytic activity because it reduced the crystallinity and substantially increased the external specific surface area of the catalyst. The experimental results pertaining to the use of the MCM-41@DMC catalyst in the fabrication of polypropylene glycol showed that the conversion of propylene oxide and molecular weight reached 90.6% and 2900, respectively. This study provides a new strategy for the green synthesis of poly(propylene glycol) products. [ABSTRACT FROM AUTHOR]

Among the currently studied nitrogen-doped Pt-C catalysts, the environmental friendliness of the nitrogen source and the stability of Pt-C catalysts for fuel cells are urgent issues to be solved. In this study, nitrogen-doped platinum-based catalyst (CSC/BP-Pt) with excellent stability for the ORR is prepared by a self-doping method based on chitosan (CS), a green biomass material with both nitrogen and carbon sources, in combination with conductive carbon black (BP2000). Finally, the N content of the catalyst is as high as 5.8 wt%, which is higher than most comparable catalysts (3–5 wt%). And electrochemical tests show that the CSC/BP-Pt electrochemical active surface area (ECSA) = 154.1 m2/gPt, half-wave potential (E1/2 = 0.85 VRHE) has a better electrochemical performance than the commercial Pt/C (20 wt%), while the half-wave potential is reduced at 10,000 cycles of cyclic voltammetry with almost no attenuation (only 7 mVcompared to 31 mV of Pt/C). Besides, possible mechanisms to improve the activity and stability of CSC/BP-Pt are preliminarily proposed. [ABSTRACT FROM AUTHOR]

The necessity to mitigate the environmental impact of recalcitrant organic residues (RORs) and harness the valuable bio-energy products has stimulated investigations on the application of pyrolysis technology in the treatment and recycling of RORs. In this study, based on the thermogravimetric analysis results, the ROR temperature requirement for the final decomposition was higher than 450 °C and ranged between 500–650 °C. Experiments on the ROR pyrolysis were conducted in a fixed-bed pyrolysis reactor at temperatures of 600–900 °C and a heating rate of 20 °C min−1. Beneficial products such as char, gas, and bio-oil were obtained during the pyrolysis process. The analyzed biochar average pore diameter of 11.01 nm and surface area of 73.54 m2 g−1 reflect features than can enhance bioprocess technology performance and agronomy application potential. The pyrolytic oil analysis revealed a low heating value (LHV) of 28.4 MJ kg−1 at 600 °C, offering the possibility to address the bio-energy challenges. The results showed that pyrolysis of the ROR from a food waste (FW) treatment facility is a beneficial approach offering waste-to-resources opportunity. [ABSTRACT FROM AUTHOR]

Triallyl isocyanurate (TAIC, C12H15N3O3) has featured in wastewater treatment as a refractory organic compound due to the significant production capability and negative environmental impact. TAIC degradation was enhanced when an ozone(O3)/ultraviolet(UV) process was applied compared with the application of an independent O3 process. Although 99% of TAIC could be degraded in 5 min during both processes, the O3/UV process had a 70%mineralization rate that was much higher than that of the independent O3 process (9%) in 30 min. Four possible degradation pathways were proposed based on the organic compounds of intermediate products identified during TAIC degradation through the application of independent O3 and O3/UV processes. pH impacted both the direct and indirect oxidation processes. Acidic and alkaline conditions preferred direct and indirect reactions respectively, with a pH of 9 achieving maximum Total Organic Carbon (TOC) removal. Both CO32– and HCO3– decreased TOC removal, however only CO32– negatively impacted TAIC degradation. Effects of Cl– as a radical scavenger became more marked only at high concentrations (over 500 mg/L Cl–). Particulate and suspended matter could hinder the transmission of ultraviolet light and reduce the production of HO$ accordingly. [ABSTRACT FROM AUTHOR]

The requirements for enhanced technologies, such as pyrolysis and anaerobic digestion, are crucial to improve food waste and sewage sludge and address the difficulty in disposing of hardly biodegradable residues. The pyrolysis process was applied to two waste streams, namely hardly biodegradable residues and sewage sludge, at 500 °C with a heating rate of 25 °C min−1 to obtain hardly biodegradable residues biochar (DBR-Char) and sewage sludge biochar (SS-Char). The two biochars were then used as additives during anaerobic digestion of food waste treatment to enhance biogas production and reactor robustness to achieve average methane contents in biogas up to 75% compared with the control. Biochar addition also improved process stability, with the Methanosaeta/Methanothrix 99.55% in the CK1 (reactor with inoculum, food waste, and DBR-Char) and 98.13% in the CK2 (reactor with inoculum, food waste, and SS-Char) as the dominant genera among the anaerobic consortia. This study averted the hardly biodegradable residues and sewage sludge disposal challenges via pyrolysis and offered biochar utilization to promote reactor stability and biogas production in food waste fermentation. [ABSTRACT FROM AUTHOR]

The influences of flow patterns (mixed-flow and plug-flow) and fermentation pretreatment on aerobic granular sludge (AGS) formation with various substrate availability levels were investigated by running four identical laboratory-scale sequencing batch reactors (R1-R4), comparing two anaerobic feeding strategies and three kinds of substrates. R1 achieved faster granulation with a fast influent fill step followed by a modified anaerobic mixed-flow phase, but the AGS showed poorer stability with a cracked structure and a high suspended solids concentration in the effluent. The anaerobic plug-flow feeding mode (with influent fed slowly from the bottom) in R2 provided deeper penetration depth for the substance to reach the core of AGS and accordingly strengthen AGS stability. An acidogenic up-flow sludge bed reactor was introduced as a pretreatment to improve the AGS performance by enhancing glucose pre-fermentation (R4). AGS fed with mixed volatile fatty acids (VFA) after glucose fermentation showed similar performance compared with the reactor fed with acetate in the aspects of stability, structure, size distribution and nitrogen removal efficiency, and 74% similarity in the microbial community. For actual wastewater with low VFA concentrations, fermentation treatment was suggested as a promising pretreatment for stable AGS granulation and operation. [ABSTRACT FROM AUTHOR]

Layered double hydroxide (LDH) has been recognized as one type of the most promising shell material. In this contribution, SiO2@Mg-Al-LDH core-shell nanocomposites with different shell morphologies were prepared and characterized via XRD, SEM, TEM, FT-IR, TG-DTA, and BET in detail. The as-prepared SiO2@LDHs exhibit different base catalysis for the synthesis of propylene glycol monomethyl ether (PGME). The results indicate that LDH shell oriented vertically on the core could be generated by the sol-gel method (SG-SiO2@LDH) and displays the highest catalytic activity and stability among three materials. The horizontally oriented shell morphology tends to be formed by the self-assembly method (SA-SiO2@LDH), which maintains the original LDH structure but unstable. The formation of a third morphology called mixed platelet is contributed to the coexistence of horizontally and vertically platelets. It has been seen in the case of co-precipitation (CP-SiO2@LDH). Integrating the experimental result analysis, synthesis methods can significantly influence the nucleation rate, which would fabricate different shell morphologies. Furthermore, core-shell nanomaterials with special morphology may have certain application prospects in solid catalysis. [ABSTRACT FROM AUTHOR]

Continuous observation of wastewater treatment plants is very crucial to keep them safe for proper use and protection from pathogenic contamination. Illumina sequencing technology was used for microbiome structuring from various samples taken from different portions of the wastewater treatment plant, including influent, activated, return sludge and effluent, where different microbial compositions were found. The effluent section was found to have pathogenic microbes such as viruses, Alpha- and deltaproteobacteria, Actinobacteria, Bacteroidetes, clostridia, and bacilli in various concentrations. The presence of viruses, Mycobacterium sp., Mycobacterium fortuitum, bacteroidia, and bacilli was investigated. The species Mycobacterium was found to be higher in quantity in the effluent section. Viruses, including hepatitis A and E, were detected in higher quantity in the effluent part of the sludge in comparison with the influent part of the plant. Our discovery reveals the significance and observation of wastewater treatment plants for the existence of water-borne pathogens in the effluent, principally due to the effect on humans while reusing the water. [ABSTRACT FROM AUTHOR]

Anaerobic digestion, a recently hot technology to produce biogases especially methane generation for biofuel from wastewater, is considered an effective explanation for energy crisis and global pollution threat. A complex microbiome population is present in sludge, which plays an important role in the digestion of complex polymer into simple monomers. 16S rRNA approaches simply are not enough for amplification due to the involvement of extreme complex population. However, Illumina sequencing is a recent powerful technology to reveal the entire microbiome structure and methane generation pathways in anaerobic digestion. Metagenomic sequencing was tested to reveal the microbial structure of a digested sludge from a local wastewater treatment plant in Beijing. The Illumina HiSeq program was used to extract about 5 GB of data for metagenomic analysis. The classification investigation revealed about 97.64% dominancy of bacteria while 1.78% were detected to be archaea using MG-RAST server. The most abundant bacterial communities were reported to be Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. Furthermore, the important microbiome involved in methane generation was revealed. The dominant methanogens were detected (Methanosaeta and Methanosarcina), with affiliation of dominant genes involved in acetoclastic methanogenesis in a digesting sludge. The metagenomic analysis showed that microbial structure and methane generation pathways were successfully dissected in an anaerobic digester. [ABSTRACT FROM AUTHOR]

Organic acid production including lactate and acetate is an economically attractive technology that has gained momentum worldwide over the past years. These series of action need to be performed by an esoteric and complex microbial community, in which different members have distinct roles in the establishment of a collective organization. In this study, we analyzed the bioma from bioreactors with various pH conditions of 4.0, 5.0 and 6.0 (R1, R2 and R3), respectively, involved in acidogenic digestion for stable production of various organic acids by means of high-throughput Illumina sequencing, disclosing thousands of genes and extracting more than 53 microbial genomes. At pH 5.0, the hydrolysis reaction was enhanced and thus the lactic acid fermentation was stably improved to 45.96 mm/L and acetic acid to 73.77 mm/L. R2 was found with the most suitable pH condition for stable organic acids production as Lactobacilli and Bifidobacteria were the major members. Both the members have the key roles in heterofermentation and produce higher transcripts of key encoding enzymes involved in the dominant heterofermentation pathways. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) have been extensively studied for applications in biomedical sciences. AuNPs have exceptional advantages in cells studies include good biocompatibility and very low cytotoxicity. The eco-friendly synthesis of AuNPs with various physical characteristics is simple, and led to the fabrication of nanomaterials showing different biological functions routing cellular physiology. A growing number of recent studies focused on the promoting effect of AuNPs on stem cells osteogenic differentiation. This includes the ability of the AuNP to activate Wnt/β-catenin pathway, ERK/MAPK pathway and p38 MAPK pathway, resulting in the activation of the transcription factors for the osteogenic differentiation. This technology represents a promising therapeutic strategy to heal patients with bone injury, by regenerating bone cells using stem cells therapy. In this review, recent applications of AuNPs in stem cells osteogenic differentiation, along with the related inducing mechanism are discussed. We also provide recent updates on the AuNP synthesis methods. [ABSTRACT FROM AUTHOR]

Methanosaeta strains are frequently involved in the granule formation during methanogenic wastewater treatment. To investigate the impact of Methanosaeta on granulation and performance of upflow anaerobic sludge blanket (UASB) reactors, three 1-L working volume reactors noted as R1, R2, and R3 were operated fed with a synthetic wastewater containing sodium acetate and glucose. R1 was inoculated with 1-L activated sludge, while R2 and R3 were inoculated with 200-mL concentrated pre-grown Methanosaeta harundinacea 6Ac culture and 800 mL of activated sludge. Additionally, R3 was daily dosed with 0.5 mL/L of acetyl ether extract of 6Ac spent culture containing its quorum sensing signal carboxyl acyl homoserine lactone (AHL). Compared to R1, R2 and R3 had a higher and more constant chemical oxygen demand (COD) removal efficiency and alkaline pH (8.2) during the granulation phase, particularly, R3 maintained approximately 90 % COD removal. Moreover, R3 formed the best granules, and microscopic images showed fluorescent Methanosaeta-like filaments dominating in the R3 granules, but rod cells dominating in the R2 granules. Analysis of 16S rRNA gene libraries showed increased diversity of methanogen species like Methanosarcina and Methanospirillum in R2 and R3, and increased bacteria diversity in R3 that included the syntrophic propionate degrader Syntrophobacter. Quantitative PCR determined that 6Ac made up more than 22 % of the total prokaryotes in R3, but only 3.6 % in R2. The carboxyl AHL was detected in R3. This work indicates that AHL-facilitated filaments of Methanosaeta contribute to the granulation and performance of UASB reactors, likely through immobilizing other functional microorganisms. [ABSTRACT FROM AUTHOR]

The effect of pH (4.0, 5.0, and 6.0) on acidification and fermentation of fruit and vegetable wastes was investigated using batch and semi-continuous experiments under mesophilic condition. Results showed that fermentation types change with pH variation. The pH of acidification system containing fruit and vegetable wastes could automatically decrease to 3.0 ~ 4.0. At this pH range, a stable ethanol production was observed, at which ethanol-type fermentation was obtained. Based on the results, the fermentation types were classified into ethanol-type, mixed acid-type, propionic acid-type, and butyric acid-type fermentations, which occurred at pH 4.0 ~ 4.5, 4.5 ~ 5.0, 5.0 ~ 5.5, and 5.5 ~ 6.5, respectively. [ABSTRACT FROM AUTHOR]

Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed (EGSB) reactors shows that most EGSB reactors do not behave as expanded bed reactors, as is widely perceived. Rather, these reactors behave as fluidized bed reactors based on the classic chemical reactor theory. In this paper, four bed expansion modes, divided as static bed, expanded bed, suspended bed, and fluidized bed, for bioreactors are proposed. A high-rate anaerobic suspended granular sludge bed (SGSB) reactor was then developed. The SGSB reactor is an upflow anaerobic reactor, and its expansion degree can be easily controlled within a range to maintain the suspended status of the sludge bed by controlling upflow velocity. The results of the full-scale reactor confirmed that the use of SGSB reactors is advantageous. The full-scale SGSB reactor runs stably and achieves high COD removal efficiency (about 90%) at high loading rates (average 40 kg-COD·m·d, maximum to 52 kg-COD·m·d) based on the SGSB theory, and its expansion degree is between 22% and 37%. [ABSTRACT FROM AUTHOR]

Self-made cation exchange resin supported nanoscale zero-valent iron (R-nZVI) was used to remove phosphorus in rainwater runoff. 80% of phosphorus in rainwater runoff from grassland was removed with an initial concentration of 0.72 mg·L phosphorus when the dosage of R-nZVI is 8 g per liter rainwater, while only 26% of phosphorus was removed when using cation exchange resin without supported nanoscale zero-valent iron under the same condition. The adsorption capacity of R-nZVI increased up to 185 times of that of the cation exchange resin at a saturated equilibrium phosphorous concentration of 0.42 mg·L. Various techniques were implemented to characterize the R-nZVI and explore the mechanism of its removal of phosphate. Scanning electron microscopy (SEM) indicated that new crystal had been formed on the surface of R-nZVI. The result from inductive coupled plasma (ICP) indicated that 2.1% of nZVI was loaded on the support material. The specific surface area was increased after the load of nanoscale zero-valent iron (nZVI), according to the measurement of BET-N method. The result of specific surface area analysis also proved that phosphorus was removed mainly through chemical adsorption process. X-ray photoelectron spectroscopy (XPS) analysis showed that the new product obtained from chemical reaction between phosphate and iron was ferrous phosphate. [ABSTRACT FROM AUTHOR]

A self-developed sewer health assessment system using the fuzzy comprehensive evaluation and analytical hierarchy process was applied to give a comprehensive health condition evaluation on part of the local sewers in a southern Chinese city based on the sewer video data collected by a sewer inspection closed circuit television (CCTV) robot. Aside from the overall condition evaluation, the structure, function, and stability status of the sewer were also analyzed using the method. A comprehensive index H was proposed to give the overall health condition of pipes with different defects, and H, H, and H were used to quantify the defects affecting the tightness, stability, and function of the pipe, respectively. Results show that 48% of the inspected pipes were in good condition (0< H<0.25), and about 33% of the sewer pipes analyzed were categorized to be at severe or urgent condition levels ( H>0.5), although most of the pipes were installed only within five years. Frequent sedimentation affects the function of the sewer, and deformation and joint damage affect the structure of the sewer. [ABSTRACT FROM AUTHOR]

Annually laminated sediments in Lake Xiaolongwan, northeast China, contain a suite of n-alkanes (C-C) with a strong odd over even carbon number predominance. Biomarker n-alkane proxies (average chain length, Paq ratio, grass/tree ratio, carbon preference index and compound-specific δC values) were used to reconstruct climate changes that occurred over the last millennium. Compound-specific δC values show large differences between the distinctive chain length groups of n-alkanes that originate from algae, aquatic macrophytes and terrestrial plants. Long-chain n-alkanes (C-C) are predominantly derived from leaf wax lipids in the forest. Variations in long-chain n-alkane δC values may mainly record water-use efficiency, inasmuch as the contribution from C4 plants is negligible in the Lake Xiaolongwan catchment. Short- and middle-chain n-alkanes are mainly from algae and aquatic plants. They are strongly depleted in C. This feature may be linked to a methane-derived, negative δC pool and lake overturn, which regulates dinoflagellate blooms. Parallel fluctuations are observed in δC values, Paq, and the grass/tree ratio throughout the record. Variations in δC values and Paq are in agreement with historical documents on summer and winter climate conditions. They support earlier suggestions that δC values in the long-chain n-alkanes and Paq may be useful indicators of effective precipitation or drought stress in this forested area. The δC index and Paq show distinct decadal variations. Periods with high δC values and a low Paq index correspond with the warm phases of the Pacific Decadal Oscillation (PDO). Values are reversed during PDO cool phases. At the decadal timescale, summer monsoon rainfall in northeast China over the last millennium may have been regulated mainly by the PDO. [ABSTRACT FROM AUTHOR]

When solving many practical problems, we not only need sample labels given by a clustering algorithm, but also rely on the recognition of far-near relations of clusters. Under the difficult condition of many clusters in a high-dimensional data set, the clustering visualization methods based on dimension reductions usually produce the phenomena, e.g., some clusters are overlapping, interlacing, or pushed away; as a result, the far-near relations of some clusters are displayed wrongly or cannot be distinguished. The existing inter-cluster distance methods cannot determine whether two clusters are far away or near. The geometric double-entity model method (GDEM) is proposed to describe far-near relations of clusters, and the methods such as the relative border distance, absolute border distance and region dense degree are designed to measure far-near degrees between clusters. GDEM pays attention to both the absolute distance between nearest sample sets and the dense degrees of border regions of two clusters, and it is able to uncover accurately far-near relations of clusters in a high-dimensional space, especially under the difficult condition mentioned above. The experimental results on four real data sets show that the proposed method can effectively recognize far-near relations of clusters, while the conventional methods cannot. [ABSTRACT FROM AUTHOR]

Frequent flow cutoff has a serious effect on the eco-environment of the region along the Lower Yellow River. The authors study the impact on lateral seepage quantity and groundwater cycling caused by cutoff of the Yellow River and compare it with that of the year 1999 through the numerical simulation model of groundwater flow system of the affected zone. The lateral seepage quantity decreased 53.8% on flow cutoff stage from Huayuankou to the river entrance and breaking time of 300 d. The lateral seepage quantity will decrease 46.3% if flow cutoff is from Jiahetan to the river entrance and breaking time is 300 d, and it will decrease 75.2% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 19.8% if flow cutoff is from Luokou to the river entrance and breaking time is 300 d, and it will decrease 25.1% if flow cutoff occurs throughout the year. The lateral seepage quantity will decrease 4.7% if flow cutoff is from Lijin to the river entrance and flow cutoff occurs throughout the year. Flow cutoff of the Yellow River has a minor effect on the shape of groundwater flow domain of the affected zone. Thus, the boundary condition of the shallow groundwater system will not change. Although flow cutoff has a major influence on the riverside source fields in the Lower Yellow River, it will not have a significant effect on groundwater resources macroscopically in the affected zone of the Yellow River due to its large storage capacity. [ABSTRACT FROM AUTHOR]

A dynamic Bayesian network (DBN) is one of popular approaches for relational knowledge discovery such as modeling relations or dependencies, which change over time, between variables of a dynamic system. In this paper, we propose an adaptive learning method (autoDBN) to learn DBNs with changing structures from multivariate time series. In autoDBN, segmentation of time series is achieved first through detecting geometric structures transformed from time series, and then model regions are found from the segmentation by designed finding strategies; in each found model region, a DBN model is established by existing structure learning methods; finally, model revisiting is developed to refine model regions and improve DBN models. These techniques provide a special mechanism to find accurate model regions and discover a sequence of DBNs with changing structures, which are adaptive to changing relations between multivariate time series. Experimental results on simulated and real time series show that autoDBN is very effective in finding accurate/reasonable model regions and gives lower error rates, outperforming the switching linear dynamic system method and moving window method. [ABSTRACT FROM AUTHOR]

Low-strength municipal wastewater is considered to be a recoverable nutrient resource with economic and environmental benefits. Thus, various technologies for nutrient removal and recovery have been developed. In this paper, powdered ion exchange resin was employed for ammonia removal and recovery from imitated low-strength municipal wastewater. The effects of various working conditions (powdered resin dosage, initial concentration, and pH value) were studied in batch experiments to investigate the feasibility of the approach and to achieve performance optimization. The maximum adsorption capacity determined by the Langmuir model was 44.39 mg/g, which is comparable to traditional ion exchange resin. Further, the effects of co-existing cations (Ca2+,Mg2+,K+) were studied. Based on the above experiments, recovery of ammonia as struvite was successfully achieved by a proposed two-stage crystallization process coupled with a powdered resin ion exchange process. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) results revealed that struvite crystals were successfully gained in alkaline conditions (pH = 10). This research demonstrates that a powdered resin and two-stage crystallization process provide an innovative and promising means for highly efficient and easy recovery from low-strength municipal wastewater. [ABSTRACT FROM AUTHOR]

The article presents a letter to the editor concerning the health effects resulting from exposure to radio frequency (RF) fields from mobile telephones.