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The Cambrian system in the Ordos Basin has a similar development degree of carbonate strata to that in the Sichuan and the Tarim Basins; however, no significant oil and gas breakthroughs similar to those in the latter two basins have been made in the Ordos Basin yet, and the characteristics, genesis, and differences in the reservoir need to be explored. Field outcrop observations reveal that the oil and gas shows are common in the Upper Cambrian Sanshanzi Formation in the eastern Ordos Basin, indicating important oil and gas exploration potential. Analysis of the characteristics and genesis of dolomite reservoirs can greatly support the exploration and development of the Cambrian carbonate oil reservoirs in the Ordos Basin. Based on the field outcrop observations and comprehensive laboratory tests and analyses, the reservoir characteristics and main control factors are systematically discussed. This study reveals that the reservoir lithology mainly comprises crystalline dolomite, from fine crystalline dolomite to coarse crystalline dolomite; this results in reservoirs with low porosity, extreme-low porosity, and ultralow permeability dominated by intergranular denudation, caves, and microfractures. They can be further divided into two types of reservoirs: type I reservoirs that have low porosity, ultralow permeability, and medium pore-throat radii, and type II reservoirs that have extreme-low porosity, ultralow permeability, and small pore-throat radii. The physical properties of fine-medium crystalline and medium crystalline dolomite reservoirs are slightly better, and the throats tend to be larger with increasing grain size. The reservoirs have not experienced deep burial processes; dolomitization mainly occurs in the marine-sourced fluid environment with weak oxidation and weak reduction, influenced by the atmospheric fresh water and thermal fluid transformation during the late period to some extent, whereas the hydrocarbons mainly charged during the late period. The crystalline dolomite in residual grains superimposes the denudation and cataclasis in the epigenetic karst stage that are the main controlling factors of the reservoirs. The crystalline cataclasis of dolomite can aid in the formation and reconstruction of the reservoirs. The spatial and temporal distribution laws of the reservoirs and key formation periods need to be studied further.

Environmental factors affecting the photocatalytic oxidation of volatile organic compounds (VOCs) have previously been studied experimentally, but there are few theoretical studies, especially those on surface intermolecular forces. Because of this, it is unclear how multiple coexisting factors impact photocatalytic processes. Herein, comprehensive multi-factorial impact mechanisms of the photocatalytic oxidation of formaldehyde were assessed using experiments and density functional theory simulations. The influence of humidity, concentration, and intermediate formate was investigated using a nano-TiO2 colloid, followed by adsorption and photocatalytic simulations. The maximum photocatalytic reaction rate and degradation efficiency occurred at 50% humidity due to the initially enhanced and then weakened adsorption and photocatalysis of formaldehyde. This stemmed from the increased number of water molecules and the narrower TiO2 band gap at low humidities, as well as the competitive adsorption between formaldehyde and excess water molecules at high humidities. Upon increasing the formaldehyde concentration, its photocatalytic oxidation rate increased due to enhanced adsorption, but weakened photocatalysis decreased the photocatalytic efficiency. The intermediate formate enhanced the adsorption and inhibited photocatalysis and did not significantly change the photocatalytic oxidation rate of formaldehyde upon changing the irradiation time. These findings provide guidance for the photocatalytic oxidation of VOCs produced by industrial air pollution.

Using fresh core samples, we have determined the origin and formation process of Eocene lacustrine dolomites in the Tibetan Plateau through petrological, mineralogical, and geochemical analyses. Dolomitic rocks were collected from the upper member of the Eocene Niubao Formation in the Lunpola Basin, consisting of dolomitic mudstone, argillaceous dolomite, dolomite-bearing mudstone, and mud-bearing dolomite. These dolomites are dominated by aphanotopic and microcrystalline dolomites, with minor amounts of euhedral or subhedral powder- and fine-crystalline dolomites. Carbon and oxygen stable isotopes, combined with ubiquitous gypsum in study area, indicate a semisaline continental lake under strong evaporative conditions. The revealed relatively high temperature of the dolomitization (33.8°C–119.1°C), combined with hydrothermal minerals such as cerous phosphate and barite, reflect the participation of dolomite from hot fluids. Moreover, the inferred dolomitization temperatures decrease gradually toward the center of the lake basin, suggesting the resurgence of hydrothermal fluids along a fault zone on the lake margin. This proves that frequent thermal events occurred at the boundary fault of the Lunpola Basin margin during early Himalayan orogenesis. In addition, Jurassic carbonates interacting with hydrothermal fluids, as well as strong evaporation conditions, likely provided favorable conditions for the formation of primary lime sediments. A rich source of [Formula: see text] brought by volcanic ash, hydrothermal fluids, and the Jurassic carbonates then created conditions for dolomitization during the depositional period. Strong evaporation under a relatively hot climate enhanced penecontemporaneous dolomitization, thus forming dolomite. Tibetan Plateau was under arid to semiarid climate conditions, and there was a widespread distribution of dolostones in western, central, and northern China during the Eocene period. The hydrothermal dolomites of the upper Niubao Formation testify for active hot springs, whereas lacustrine dolomite imply arid or semiarid climates during the Eocene, in the early stages of Himalayan orogenesis.

Nuclear energy is an integral part of the energy supply required for future space exploration as efficient energy. Although heat pipe reactor is the main development direction of space reactor. Radiation radiator quality accounts for a large proportion of heat pipe reactor quality. Therefore, it is essential to improve the heat dissipation performance of the heat pipe reactor, effectively reducing the quality of the radiator under the condition of ensuring that the radiation heat dissipation power of the radiator is not less than that of the same volume radiator, design the optimal heat pipe cooling scheme and promote the development of space heat pipe reactor. In this paper, based on the finite element multi-physical coupling MOOSE platform, a program is developed to simulate the physical field of the heat pipe reactor radiator. The simulation of the heat pipe, fin and other parts of the radiator end unit is realized, and the combination of heat pipe and fin calculation is completed. At the same time, the temperature field of the new heat pipe radiator unit is obtained. The simulation results for the heat pipe and fin module are verified by the temperature field calculation program and another multi-physical coupling software. Another multi-physical coupling software results are compared with MOOSE simulation results for the combination part. The results show that the MOOSE program can reasonably simulate the heat transfer state in the simulation of heat pipes, fins, and combinations. The temperature field agrees with the verification results.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the malignant tumors with the highest morbidity and mortality worldwide, and its prognosis remains a challenge. Actinidia chinensis Planch (ACP) root has good efficacy against HCC. This study aimed to explore the link between ACP and potential targets of HCC, and to develop a novel immune-based gene signature to predict HCC patient survival. METHODS: Transcriptome data and clinical information on HCC were obtained from The Cancer Genome Atlas (TCGA; HCC: 374, normal: 50) and International Cancer Genome Consortium (ICGC) database (HCC: 243, normal: 202). Combined with the 2,483 immune-related genes from the Immport database, we used the least absolute shrinkage and selection operator (LASSO) to construct a prognostic model. Patients were divided into high-risk and low-risk groups by the median of the risk scores of the TCGA cohort. Kaplan-Meier survival analysis and receiver operating characteristic (ROC) curves were used to estimate the predictability of the model in HCC prognosis, and carried out external validation based on ICGC cohort. We analyzed the correlation of this model with immune cells and immune checkpoint genes. Finally, molecular docking of these genes and the corresponding ACP components. RESULTS: We constructed a prognostic model composed of 3 immune-related genes [epidermal growth factor (EGF), baculoviral inhibitor of apoptosis repeat-containing protein 5 (BIRC5), and secreted phosphoprotein 1 (SPP1)]. And the high-risk group had a lower overall survival (OS) rate compared to the low-risk group (TCGA cohort: P=1.761e-05, ICGC cohort: P=8.716e-04). The outcomes of the AUC of ROC of prognostic risk model to predict for 1-, 2-, and 3-year OS: TCGA cohort: 0.749, 0.710, and 0.653 and ICGC cohort: 0.698, 0.736, and 0.753. Molecular docking results showed that quercetin had good binding activities with SPP1, BIRC5, and EGF, and ursolic acid (UA) and BIRC5 also had this feature. CONCLUSIONS: Our study speculates that ACP root anti-HCC may be involved in the immune regulation of the body by targeting EGF, BIRC5 and SPP1, which possess great potential and value as early warning molecules for HCC. This model may provide a reference for individualized diagnosis and treatment for HCC patients.

Environmental factors affecting the photocatalytic oxidation of volatile organic compounds (VOCs) have previously been studied experimentally, but there are few theoretical studies, especially those on surface intermolecular forces. Because of this, it is unclear how multiple coexisting factors impact photocatalytic processes. Herein, comprehensive multi-factorial impact mechanisms of the photocatalytic oxidation of formaldehyde were assessed using experiments and density functional theory simulations. The influence of humidity, concentration, and intermediate formate was investigated using a nano-TiO

The paper aimed to investigate the effects of up-regulation and down-regulation of Mir-299-3p on the proliferation, migration, invasion and apoptosis of lung adenocarcinoma cell line H1299, and to preliminarily explore the mechanism of Mir-299-3p regulating the biological behavior of lung adenocarcinoma cells. Mir-299-3p inhibitor and Mir-299-3p mimics were transfected into lung adenocarcinoma cell line H1299, and the transfection efficiency was measured by fluorescence microscopy. The successfully transfected lung adenocarcinoma cells were detected of proliferation, migration, invasion, and apoptosis. Mir-299-3p inhibitor and Mir-299-3p mimics were used to down-regulate and up-regulate Mir-299-3p respectively. Western blot was employed to detect the expressions of STAT3, p-STAT3, caspase3, Bcl-2, Bax and MMP-9 proteins in lung adenocarcinoma cells. Small interfering RNA technology was applied to construct a cell line with low expression of PTPRD. WB was used to measure the transfection efficiency to determine whether the down-regulation of PTPRD can partially or completely reverse the proliferation, migration, invasion, and apoptosis of lung adenocarcinoma cells after the down-regulation of Mir-299-3p. It was also determined whether the down-regulation of PTPRD can partially or completely reverse the effect of Mir-299-3p down-regulation on the expressions of p-STAT3, MMP-9, Cleaved-caspase3, Bcl-2 and Bax proteins in lung adenocarcinoma cells. Down-regulation of Mir-299-3p can inhibit the proliferation and invasion of lung adenocarcinoma cell H1299, promote cell apoptosis, inhibit the expression of p-STAT3 and MMP-9, promote the expressions of apoptosis-inducing proteins such as Bax and Cleaved-caspase3, and also inhibit the expression of apoptosis inhibitor protein Bcl-2. The up-regulation of Mir-299-3p worked in the opposite way. PTPRD is the direct target gene of Mir-299-3p. Mir-299-3p may directly target PTPRD to regulate the expressions of p-STAT3, MMP-9, Cleaved-caspase3, Bcl-2 and Bax proteins to affect the biological behavior of lung adenocarcinoma cells.

Firstly, a low operating temperature and high performance sensor for H2S detection based on α-Fe2O3/TiO2 heterojunction nanoparticles (NPs) was developed by a liquid phase reaction with low synthesis temperature. Secondly, the microstructures and chemical compositions of the gas sensing material were analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscope, energy dispersive spectrometer and X-ray photoelectron spectra methods. Thirdly, with the 50 mol% α-Fe2O3 doping amount and operating temperature of 120 °C, the gas sensing performances of the developed α-Fe2O3/TiO2 NPs composite sensor to H2S were obtained: the responses of 3.4–15.6 to 1–50 ppm H2S, a linear relationship between the sensor response and the H2S concentration, the acceptable response/recovery time of 25 s and 48 s to 50 ppm H2S, excellent selectivity (10 times higher than those of the other tested gases) to H2S, and good repeatability and stability in 1-month duration. These excellent H2S gas sensing performances were attributed to the effects of n–n heterojunctions of two metal oxides, which were discussed in detail. Finally, the superior performances of the developed α-Fe2O3/TiO2 NPs composite sensor were compared with the other reported H2S sensors, which the low operating temperature of 120 °C was highlighted.

The elastic and anisotropic properties of BiMg2MO6 (M = P, As and V) ceramics were explored using first-principles calculations. The 3D surface constructions and two dimensional projections of Young's modulus confirm that BiMg2MO6 ceramics exhibit the strong anisotropic properties along the different directions. The minimum thermal conductivity on the different crystal planes for BiMg2MO6 ceramics strongly depended on the direction. Three BiMg2MO6 ceramics are anisotropic in sound velocities due to the different values along the different directions. We expect that the present results will be useful for the further development and applications of BiMg2MO6 ceramics.

It is difficult for papermaking wastewater to reach the discharge standard with only a sequencing batch reactor activated sludge process (SBR). This study developed an advanced wastewater treatment system with nano-TiO2 colloid photoelectrocatalysis and heterogeneous photocatalysis (PEPC). First, the performances of different flocculation processes and their influences on the subsequent PEPC process were studied. The recycling of the nano-TiO2 colloid photocatalyst was further investigated. The results showed that the ternary composite flocculation process using both the inorganic flocculant and the nano-TiO2 colloid (1 × 10-3 wt%) had the best flocculation effect with a suspended solid (SS) removal rate of 93.5% and a chemical oxygen demand (COD) removal rate of 66.9%. It also achieved the best PEPC treatment performance with a COD removal rate of 93.6% in 90 min with the 0.05 wt% dosage of the nano-TiO2 colloid photocatalyst. Moreover, the COD removal rate reached 88.5% after four recyclings of the nano-TiO2 colloid photocatalyst, which demonstrated the excellent reusability of the nano-TiO2 colloid photocatalyst. Finally, based on the PEPC process, an automatic and continuous pilot-scale system was established. Its successful operation suggests the feasibility of operating PEPC technology at an industrial scale.

A cobalt doped free-standing TiO2 nanotube (Co-doped TiNT) array film was firstly synthesized by a one-step anodization followed by immersion method. The characterization analysis results of TiNT with the field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) proved that the doped cobalt ions had entered into the lattice of TiO2. Subsequently, the Co-doped TiNT gas sensors with different concentration of cobalt ions were developed for testing the gas-sensing properties for H2S. Compared with the undoped one, by 0.1 M Co-doping operation, working under the temperature of 300 °C, the Co-doped TiNT gas sensor was demonstrated the following superiorities: the response time and recovery time were 14 s and 4 s, which were shortened by 36.4% and 33.3%, respectively. Moreover, the Co-doped TiNT gas sensor with superior selectivity, stability and repeatability, reached the response value at 199.16 for 50 ppm H2S, which was improved by 7.6 times. Finally, based on the density functional theory (DFT), the calculated band gap of the Co-doped TiO2 decreased from 2.285 eV to 1.418 eV with a 38% decline. The mechanism simulation explained the obtained promotions in the gas sensing properties of the Co-doped TiNT gas sensor.

Refractory pollutants often exist in wastewater after photocatalysis. Here, experiments, gas chromatography-mass spectrometry (GC–MS) analysis and density functional theory (DFT) simulations were used to explain the different levels of photocatalytic degradation of organics in papermaking wastewater associated with two photocatalytic processes with the goal of improving environmental sustainability. The photocatalytic experiments of flocculation and SBR effluents of papermaking wastewater were studied in a reactor with nano-TiO2 colloid, followed by GC–MS analysis, and the different degradation levels of organics were explained based on DFT adsorption and photocatalysis simulations. The experimental results show that the total COD removal rates were 65.8% and 90.8% for the flocculation-photocatalysis and SBR-photocatalysis processes, and the resin acids and fatty acids in wastewater were classified as easily degradable pollutants and esters as refractory pollutants. The adsorption and photocatalysis simulations show that compared with dehydroabietic acid and pentadecanoic acid, the adsorption of glycerol monostearate by nano-TiO2 colloid is difficult, the reaction pathways for photocatalysis are complex and the band gap of TiO2 photocatalyst after adsorption is wide. The experimental and simulation results indicate that the different degradation levels are attributed to the difficulty of the adsorption and photocatalytic reactions of glycerol monostearate compared with the reactions of the other two easily degradable pollutants. Thus, the different photocatalytic degradation levels of organic pollutants in the two photocatalytic processes of papermaking wastewater indicate that sustainable photocatalytic technology could be applied to different types of industrial wastewater.

The refractory benzene is revealed in the gaseous pollutants of pulp mills. Although it can be decomposed by photooxidation, the intermediates impact during benzene photooxidation needs to be studied comprehensively. Herein, the benzene photocatalysis was investigated in a reactor with nano-TiO2 colloid under different reaction conditions. The adsorption behavior of mixed benzene and intermediates on TiO2 (1 0 1) surface was simulated based on density functional theory, and the influencing mechanism of intermediates was also investigated. Experimental results showed that benzene degradation rate firstly stabilized and then decreased at high initial concentration, accompanying the photocatalyst deactivation and conversion of intermediates into aliphatic carboxylates. Adsorption simulations showed that benzene adsorption was promoted firstly and weakened finally due to the formations of several intermediates. Combined experimental results, adsorption simulation and influencing mechanisms showed that, the enhanced benzene adsorption and weakened photocatalysis contributed to a high and stable rate in the initial stage of benzene degradation. Then, the formed intermediate products weakened the adsorption and photocatalytic reaction of benzene, causing the decrease of degradation rate. The formed aliphatic carboxylates occupied almost all adsorption and catalytic sites, leading to the deactivation of nano-TiO2 photocatalyst. This study provides a comprehensive understanding of intermediates impact on benzene photooxidation.

In this research, nanometer size aggregates (clusters) of titanium dioxide (TiO2) quantum dot clusters (QDs) have been successfully prepared via a convenient hydrolysis method at a low temperature (80 °C). Then different amounts (0–5%) of Ag were further decorated on the TiO2 QDs via dipping and annealing under a nitrogen atmosphere. After Ag decoration, the TiO2 QD sensing materials were synthesized, and characterization and NH3 gas sensing performance studies were carried out. Analysis via XRD and EDS was conducted, and the results showed that Ag+ ions were successfully reduced to Ag and decorated on the surface of the anatase TiO2 QDs. Noble metal Ag acted as the sites for adsorbates, catalysts, or promoters during the surface reactions, and as the element improving the thermal stability of the nanostructure. Therefore, the Ag-decorated gas sensor possessed better gas sensing performance than an undecorated gas sensor, and 3% Ag dopant proved to be the optimal amount of addition. The fabricated 3% Ag-decorated TiO2 QDs gas sensor, compared with the undecorated TiO2 QDs sensor, displayed a 6-times-higher sensing response at room temperature and demonstrated excellent gas sensing properties toward 10–100 ppm NH3 gas, good selectivity, gas sensitivity and stability, rapid response/recovery time, and a linear relationship between the response and the target gas concentration. In particular, the excellent performance of the Ag decorated-TiO2 QDs gas sensor was achieved at room temperature, which suggests the great possibility of a prompt gas sensing response, with the use of paper as a substrate, that requires a low operation temperature.

International audience; First, making from eucalyptus cellulose fiber, the influences of different compound enzymolysis conditions on the morphology of cellulose nanocrystals (CNCs) were studied. Under the actions of the compound enzyme composed of cellulase and xylanase with the concentration ratio of 9:1, total enzyme concentrations of 10 and 500 U mL−1 and the hydrolysis time of 12 and 5 h, the rod-like CNCs (length 600 nm, width 30 nm) and the spherical CNCs (40 nm) were obtained, respectively. Subsequently, the crystallinities, chemical structures, and thermal stabilities of the rod-like and spherical CNCs revealed that, the CNCs structures were still similar to those of the eucalyptus cellulose fiber, the thermal decomposition temperatures of the rod-like and spherical CNCs (345, 343 °C) were a little lower than that of the eucalyptus cellulose fiber (364 °C). Lastly, the control mechanism of CNC morphology by the compound enzymatic hydrolysis was also discussed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48407.

Chemical oxygen demand (COD), an important indicative measure of the amount of oxidizable pollutants in wastewater, is often analyzed off-line due to the expensive sensor required for on-line analysis. However, its off-line analysis is time-consuming. An on-line COD estimation method was developed with photoelectrocatalytic (PEC) technology. Based on the on-line data of the oxidation–reduction potential (ORP), dissolved oxygen (DO) and pH of wastewater, four different artificial neural network methods were applied to develop working models for COD estimation. Six different batches of sequence batch reactor (SBR) effluent from a paper mill were treated with PEC oxidation for 90 minutes, and 546 data points were collected from the on-line measurements of ORP, DO and pH, and the off-line COD analysis. After having training and validation with 75% and 25% of data, and evaluation with four statistical criteria (R2, RMSE, MAE and MAPE), the estimation results indicated that the developed radial basis neural network (RBNN) model demonstrated the highest precision. Subsequently, the application of the RBNN model to a new batch of SBR effluent from the paper mill revealed that the RBNN model was acceptable for COD estimation during the PEC advanced treatment process of papermaking wastewater, which implied its possible application in the future.

International audience; In this study, highly ordered TiO2 nanotube arrays (TNAs) with length 1~2 μm were rapidly fabricated via the electrochemical anodic oxidation process, which was specifically used for the photocatalytic degradation of organic pollutants. The effects of the anodization conditions on the nanotube microstructures were investigated with scanning electron microscope (SEM). The crystalline phase and surface element of the as-prepared samples were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. On this basis, the effects of TNAs morphological parameters on the photocatalytic activity were evaluated by the degradation of rhodamine B (RhB) in aqueous solution. The results showed that the diameter and length of the nanotube were linearly related to the anodization voltage in the experimental ranges with 20 wt% water content electrolytes, respectively; the morphological parameter and anodization time were also linearly related. TNAs calcined at 450 °C for 2 h were pure anatase phase and contained Ti3+ element, which were favorable for the photocatalytic reaction. In the study, it was proved that 20 wt% water content electrolytes were suitable for the rapid anodization generating of TNAs with the length 1~2 μm. The assessment experiments for the photocatalytic activity of TNAs demonstrated that, when the actual tube length was near the penetration depth of UV lights, TNAs would exhibit the best photocatalytic activity

In this research, nanometer size aggregates (clusters) of titanium dioxide (TiO

In order to study the thermal and hydraulic characteristics of nuclear reactors under ocean conditions and meet the urgent needs of the design of floating nuclear power plants, the crossflow and heat transfer characteristics of rod bundle with the spacer grid under rolling conditions are studied by using computational fluid dynamics (CFD) code. Firstly, revise and verify CFD codes suitable for rolling conditions. According to CFD results, the influence of heat flux on heat transfer coefficient is greater than that of pressure drops under this condition. And with the spacer grid, the total pressure drop between inlet and outlet is higher. Furthermore, the heat transfer coefficient is also higher due to the mixing effect of spacer grid. Under periodic inlet velocity, the fluctuation amplitude of total pressure, the temperature difference between inlet and outlet and heat transfer coefficient is increased obviously with the spacer grid. Under the condition of nonuniform heat flux, the variation law of crossflow with rolling motion will become more obvious and the spacer grid can enhance the crossflow mixing and improve the heat transfer capacity of the fluid under rolling conditions.

In this paper, we have isolated cellulose nanocrystallines (CNCs) with different morphologies by enzymatic hydrolysis, and prepared flexible and transparent nanocomposite films with PVA matrix via solution casting. By means of SEM, UV–vis, XRD, DTG, FT-IR and mechanical methods, the effects of rod-shaped cellulose nanocrystallines (RCNCs) and spherical cellulose nanocrystallines (SCNCs) on PVA nanocomposite films were compared systematically. The results showed CNCs with different morphologies had little effect on the transparency of the composite films, and the crystallinity fluctuated with the change of CNCs additive amount. Compared with the RCNCs, SCNCs had a better improve ability to the thermal stability of the composite films by promoting pyrolysis temperature 60−80 °C. On the contrary, the maximum mechanical properties of the composite films of RCNCs were much higher than those of SCNCs, and the Young's modulus of the PVA/RCNCs composite film were increased by 120.97 % in comparison with the pure PVA.

Nanometer sized aggregates of titanium dioxide quantum dot clusters (QDs) were used with a convenient low temperature (80 °C) hydrolysis method to prepare a high performance NH3 gas sensor. Using transmission electron microscopy, the synthesized material was found to consist of massive anatase TiO2 QDs (66 nm) with excellent stability and dispersibility (the individual QDs were formed from 2 to 5 nm diameter anatase crystals). The unique preparation method yielded a highly porous TiO2 QDs structure with a huge specific surface area (315.74 m2/g). This provides more potential reaction sites on the surface potential enhancing the performance of the sensor. Testing revealed these NH3 (g) sensors demonstrated excellent gas sensing properties (0.2–10 ppm, room temperature), high sensitivity, selectivity, stability, low detection limit (0.2 ppm), rapid response recovery (88 s/23 s for 0.2 ppm), and a linear response to concentration.

Photo-electro-catalytic (PEC) oxidation has been widely recognized as an effective technology for advanced treatment of papermaking wastewater. To optimize the oxidation process, it is important of monitor continuously the chemical oxygen demand (COD) of inflow and outflow wastewater. However, online COD sensors are expensive difficult to maintain, and therefore COD is usually analyzed off-line in laboratories in most cases. The objective of this study is to develop an inexpensive method for on-line COD measurement. The oxidation-reduction potential (ORP), pH, and dissolved oxygen (DO) of wastewater were selected as the key parameters, which consists of four different types of artificial neural network (ANNs) methods: multi-layer perceptron neural network (MLP), back propagation neural network (BPNN), radial basis neural network (RBNN) and generalized regression neural network (GRNN). These parameters were applied in the development of COD soft-sensing models. Six batches of papermaking wastewater with different pollution loads were treated with PEC technology over a period of 90 minutes, and a total of 546 data points was collected, including the on-line measurements of ORP, pH and DO, as well as off-line COD data. The 546 data points were divided into training set (410 data, 75% of total) and validation set (136 data, 25% of total). Four statistical criteria, namely, root mean square error (RMSE), mean absolute error (MAE), mean absolute relative error (MARE), and determination coefficient (R 2 ) were used to assess the performance of the models developed with the training set of data. The comparison of results for the four ANN models for COD soft-sensing indicated that the RBNN model behaved most favorably, which possessed precise and predictable results with R 2 =0.913 for the validation set. Lastly, the proposed RBNN model was applied to a new batch of PEC oxidation of papermaking wastewater, and the results indicated that the model could be applied successfully for COD soft-sensing for the wastewater.

Volatile organic pollutants such as benzene and formaldehyde are commonly detected in the ambient air of paper mills. To remove these pollutants from the air, a photo-catalytic reactor was developed in this study. The reactor had a series of honeycomb aluminum meshes coated with nanosized titanium dioxide as the catalyst for the degradation reactions of gaseous pollutants. Both formaldehyde and benzene could be completely degraded in the reactor. However, the degrading time for benzene was much longer than that for formaldehyde, and the degradation rate of benzene decreased with increasing initial benzene concentration. It was found that the reaction pathway for formaldehyde in the mixture was different from that in its single component form, and it took about two times longer time to be degraded than that for its single component form. The reaction pathway of benzene was similar in either case although the degradation time for benzene was about 50% shorter in the mixture form.

This paper proposes two strategies for controlling the dissolved oxygen concentration in the sequential batch reactor of the wastewater treatment process in the papermaking industry. Based on a previously developed sequential batch reactor simulation model, a fuzzy logic system and a neural network are integrated with a PID controller separately. According to the criteria defined in benchmark simulation model no. 1 (BSM1), three control strategies, namely, conventional PID, developed BP (back propagation)-PID and fuzzy-PID, applied in two cases with and without noise, have been investigated and assessed. For the cases without noise, both the developed controllers, i.e. BP-PID and fuzzy-PID, are superior to PID, wherein the fuzzy-PID controller not only improves the control performance but also reduces the aeration energy consumption. The results of further simulation with the interference of white noise reveal that the developed fuzzy-PID controller not only has better manipulated and controlled indexes than those of the BP-PID controller, it also demonstrates a good ability for anti-interference. These simulation results reveal the superiority of the developed fuzzy-PID control strategy in the dissolved oxygen control of the sequential batch reactor of the wastewater treatment process in the papermaking industry.

International audience; To reduce pollution emissions and achieve a cleaner production in paper industry, it is essential to understand the inner links between concentrations of gaseous pollutants, types of final products and production techniques. In this study, the concentrations of four potential gaseous pollutants, total volatile organic compounds (TVOC), formaldehyde (HCHO), hydrogen sulfide (H 2 S), and hydrocarbon compounds (C x H y), in the ambient air on thirty sampling points of five pulp and paper mills were detected and analyzed. The results were summarized with respect to the following aspects: (1) Levels of four gaseous pollutants on all the sampling points in five mills. It was obvious that the situation of gaseous pollution from pulp mill was much more serious than those from paper mills. (2) Gaseous pollutant distinctions due to different production processes. The levels of gaseous pollutants from five mills were greatly influenced by the utilized raw materials and the applied paper chemical agents (flavor, coating materials and additives) in mills. (3) Gaseous pollution comparisons at common points. At the two common points in five mills, i.e. the wet end of paper machine and the wastewater treatment process, TVOC and HCHO, C x H y and H 2 S were the main gaseous pollutants, respectively. In addition, some feasible measures to realize a cleaner production in pulping and papermaking process were also put forward in the article.

Being an internationally accepted standard for the activated sludge modeling, the Activated Sludge Model No.1 (ASM1) was used to simulate the treatment of paper mills effluent in an industrial full-scale sequencing batch reactor (SBR). Key characteristic parameters were estimated and corrected with the wastewater temperature: maximum heterotrophic growth rate μH (9.69/day), heterotrophic yield YH (0.625 g cell COD/g COD oxidized) and heterotrophic decay rate bH (1.98/day). The wastewater chemical oxygen demand (COD) was fractionated as slowly biodegradable substrate XS (20%), particulate inert organic matter XI (58%), readily biodegradable substrate SS (18%) and soluble inert organic matter SI (4%). Finally, the SBR operation was simulated with field data from the paper mill. The average relative error of the simulated effluent COD was 12.7%. The results showed that the ASM1 could be reasonably used in the papermaking wastewater treatment simulation.

In this work, the pulp fibers were enzymolyzed to prepare the nanosized cellulose (NC). The as-prepared samples were characterized by optical microscopy, electron microscopy, and Raman spectra. The experimental results indicated that enzymatic hydrolysis of pulp fibers could produce the spherical NC with a mean particle size of about 30nm, which had the excellent monodispersity and uniformity. When the concentration of complex enzymes was 20u/mL (cellulase: xylanase=9: 1), the yield of NC was 13.6%. The single cellulase was used, even if the enzyme concentration reached up to 200u/mL, only a mixture of strip and granular flocculation were obtained. The positive synergistic effect between xylanase and cellulase could be due to the enzymolysis of hemicellulose located on the cellulose microfibers to be favorable of cutting and splitting of the microfibers by the endoglucanase in cellulase.

We studied nitrate control strategies in an activated sludge wastewater treatment process (WWTP) based on the activated sludge model. Two control strategies, back propagation for proportional-integral-derivative (BP-PID) and adaptive-network based fuzzy inference systems (ANFIS), are applied in the WWTP. The simulation results show that the simple local constant setpoint control has poor control effects on the nitrate concentration control. However, the ANFIS (4*1) controller, which considers not only the local constant setpoint control of the nitrate concentration, but also three important indices in the effluent—ammonia concentration, total suspended sludge concentration and total nitrogen concentration—demonstrates good control performance. The results also prove that ANFIS (4*1) controller has better control performance than that of the controllers PI, BP-PID and ANFIS (2*1), and that the ANFIS (4*1) controller is effective in improving the effluent quality and maintaining the stability of the effluent quality.

The first-principle method was used to investigate the elastic anisotropy and thermodynamic properties of Tantalum borides (B–Ta) compounds. The anisotropic indexes, the 3D surface constructions and 2D projections of Young's modulus indicate that B–Ta compounds are anisotropic. The order of elastic anisotropy is B2Ta > BTa2> BTa > B2Ta3>B4Ta3>B6Ta5. Dynamical and thermodynamic properties indicate that B–Ta compounds can keep the dynamical stability at ground state and high temperature. The calculated Debye temperatures of the various B–Ta compounds predict the good mechanical strength at elevated temperatures.

The paper reports a green synthetic route for nanosized hematite colloids with an excellent monodispersity, using green vitriol and ammonia as raw materials. The reaction conditions of the synthetic route were studied and the as-prepared samples were characterized by XRD, TEM, TG-DTA, DLS, and XPS. The results indicated that the key factors for the monodispersity of the colloidal product were preheating reactants and washing repeatedly the intermediate Fe(OH)3. When the initial pH was set as 4 or 5, the transformation product of Fe(OH)3was the pureα-Fe2O3with the minim adsorptive sulfate ions. Contrarily, the mixtures ofα-Fe2O3andα-FeOOH were obtained at the pH 6 or 7, which were related to the mechanism of transformation reaction. In addition, the concentration of Fe(OH)3should be less than or equal to 0.2 mol/L in order to prepare the qualified nanosized hematite colloids. The researches proved that the excellent monodispersity of the colloidal product resulted from a fine dispersion state of the synthetic system during the whole process and that it was a significant way to obtain the nanosized metallic oxide colloids from the corresponding metal hydroxide due to avoidance of hyperspeed centrifugal separation or dialysis operation.

This paper presents a PCA (principal component analysis)-based diagnostic approach, combining the principal component scores with the principal component loadings, to determine the fault location of sensors in a pilot-scale SBR (sequencing batch reactor activated sludge process) wastewater treatment process. The PCA diagnostic model is firstly built with the historical normal data, and the determination of fault location of sensors in wastewater treatment process is further achieved through the combination of the scores with the loadings of principal components. The study results reveal that PCA model can be used to detect faults; the loadings of principal components can well represent the contributions of variables to the principal components; and the scores of principal components give a clear indication of the faulty samples. The feasibility and effectiveness of the application of the combination of score plots with loading plots for sensor fault diagnosis in the wastewater treatment process are well demonstrated in the study.

A method was developed for the determination of glyphosate (GLY) and glufosinate-ammonium (GLUF) in tea using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted with ultrapure water and dichloromethane for 30 min under ultrasonication, followed by a simple cleanup with a C18 solid phase extraction (SPE) cartridge, and then GLY and GLUF were derivatized using 9-fluorenylmethoxycarbonyl (FMOC-Cl) in borate buffer for 2 h. The derivatives of GLY and GLUF were separated on a Waters C18 column (50 mm x 2.1 mm, 1.7 μm) in a gradient elution mode, and finally detected with positive electrospray ionization-mass spectrometry (ESI-MS/MS ) in multiple reaction monitoring (MRM) mode. The quantification analysis was performed by external standard method. The method showed a good linearity (r > 0. 990) in the range of 0.003 125-0.1 mg/L. The limits of detection (LODs) of GLY and GLUF were 0.03 mg/kg. At the spiked levels of 0.375, 1.5 and 4.5 mg/kg, the recoveries of GLY and GLUF were 87.37%-99.11% and 81.44% -86.17% respectively, and the relative standard deviations (RSDs) (n = 6) of GLY and GLUF were 0.68%-1.35% and 1.01%-2.33%, respectively. This method is simple, rapid and characterized with acceptable sensitivity and accuracy to meet the requirements for the analysis of GLY and GLUF simultaneously in tea.

The paper describes features and internal architecture and developing method of SQLite. And then it gives a design and program of meal ordering system. The system realizes the information interaction among the users and embedded devices with SQLite as database system. The embedded database SQLite manages the data and achieves wireless communication by using Bluetooth. A system program based on Qt/Embedded and Linux drivers realizes the local management of environmental data.

Using 4,4′-dibromobenzophenone and 4,4′-diaminoazobenzene as monomers, poly(aryl imino) containing azobenzene unit (PAI-A) was synthesized via palladium-catalyzed amination, and structurally characterized by means of FT-IR, 1H NMR spectra and elemental analysis, the results of which show an agreement with the proposed structure. The UV absorption spectra were tested under different conditions. Additionally, differential scanning calorimetry (DSC) and thermogravimetric (TG) measurements show that PAI-A possesses high glass transition temperature (Tg>176°C) and good thermal stability with high decomposition temperatures in nitrogen atmosphere (TD>410°C).