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Background Depression is a common psychiatric disorder associated with the defects in GABAergic neurotransmission. α-Dystroglycan (α-DG), a cell adhesion molecule known to be essential for skeletal muscle integrity, is also present at inhibitory synapses in the central nervous system and forms a structural element in certain synapses. However, the role of α-DG in the regulation of depressive-like behaviors remains largely unknown. Methods Depressive-like behaviors were induced by chronic social defeat stress (CSDS). Surface protein was extracted by a biotin kit and the expression of protein was detected by western blotting. Intra-hippocampal microinjection of the lentivirus or adeno-associated virus or agrin intervention were carried out using a stereotaxic instrument and followed by behavioral tests. The miniature inhibitory postsynaptic currents (mIPSCs) were recorded by whole-cell patch-clamp techniques. Results The expression of α-DG and glycosylated-α-DG (GLY-α-DG) in the ventral hippocampus (vHip) was significantly lower in CSDS susceptible male mice than that in controls, accompanied with a decreased surface expression of GABAAR γ2 and reduced GABAergic neurotransmission. RNAi-mediated knockdown of dystroglycan encoding gene dystroglycan 1 (DAG1) increased the susceptibility of mice to sub-threshold stress. Both in vivo administration of agrin and overexpression of like-acetylglucosaminyltransferase (LARGE) ameliorated depressive-like behaviors and restored the decrease in surface expression of GABAAR γ2 and the amplitude of mIPSCs in CSDS-treated mice. Conclusions Our findings demonstrate that GLY-α-DG plays a role in the pathophysiological process of depressive-like behaviors by regulating the surface expression of GABAAR γ2 and the GABAergic neurotransmission in the vHip.

Adding phase change materials in building walls or roofs can help control the inner temperature of buildings. A kind of composite phase change material, sulphoaluminate cement-based polyethylene glycol (SPEG), can be prepared by blending polyethylene glycol (PEG)-water solution with sulphoaluminate cement. This study aims at improving the heat storage capacity of SPEG using five water-cement ratios (i.e., 0.2, 0.3, 0.4, 0.5 and 0.6). The microstructure, chemical composition, phase change characteristic, thermal and mechanical properties of the SPEGs were investigated, respectively. The results showed that with the increase of water-cement ratio, more hydration products were generated, and the precipitated PEG adhered to the surfaces of the hydration products. Although PEG did not change the hydration product types, it slowed the hydration process. When the water-cement ratio was 0.5, the heat enthalpy of SPEGs could reach up to 40.31 J/g. All the prepared SPEGs could keep their thermal stability under the temperature of 300 °C. After 200 thermal cycles the phase change enthalpy and temperature of SPEGs changed in a very small range. The thermal conductivity, compressive and flexural strength all increased with the increase of water-cement ratio, although the addition of PEG negatively affected the above indicators. The findings in this study are expected to help prepare cement-based phase change materials with high heat storage capacity.

Explorations in the stereolithography fabricated polymer-derived ceramics are still far from maturity. Herein, a novel preceramic slurry, which consists of a photocurable epoxy-acrylic siloxane and particle-size gradated ZrO2 fillers, was digital light processing shaped into 3D preceramic precursors. By taking advantage of the high reactivity of in-situ formed silica from the polysiloxane, 3D-zircon product can be synthesized through the sintering reaction between the polysiloxane and ZrO2 particles in the precursor at a low temperature. During the sintering process, ZrSiO4 phase starts to appear at the temperature of 1200 °C. A proper particle-size distribution of the ZrO2 filler, 20 wt% of micropartciles and 4 wt% of nanoparticles, not only endowed the ceramic slurry with a low viscosity but also increase the purity of the zircon products. Besides, the addition of sintering aid NaF can promote the sintering reaction between the polysiloxane and ZrO2 particles while increase the crystalize degree of the 3D-zircon products.

Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical redox agents. Indirect electrolysis employing a redox catalyst has received tremendous attention, since it provides various advantages compared to direct electrolysis. With indirect electrolysis, overpotential of electron transfer can be avoided, which is inherently milder, thus wide functional group tolerance can be achieved. Additionally, chemoselectivity, regioselectivity, and stereoselectivity can be tuned by the redox catalysts used in indirect electrolysis. Furthermore, electrode passivation can be avoided by preventing the formation of polymer films on the electrode surface. Common redox catalysts include N-oxyl radicals, hypervalent iodine species, halides, amines, benzoquinones (such as DDQ and tetrachlorobenzoquinone), and transition metals. In recent years, great progress has been made in the field of indirect organic electrosynthesis using transition metals as redox catalysts for reaction classes including C–H functionalization, radical cyclization, and cross-coupling of aryl halides-each owing to the diverse reactivity and accessible oxidation states of transition metals. Although various reviews of organic electrosynthesis are available, there is a lack of articles that focus on recent research progress in the area of indirect electrolysis using transition metals, which is the impetus for this review.

Nowadays, 3D polymer-derived silicon oxycarbide ceramics (SiOC) can be fabricated by the stereolithography method successfully. However, due to their intrinsically poor ceramic content and the large thermal shrinkage during the pyrolysis, it is difficult for the bulk 3D polysiloxane precursors to be pyrolyzed into dense 3D-ceramics. Herein, the ceramic content of the photocurable polysiloxane precursors was increased by adding a large amount of SiO2 powders into the low solid content epoxy-acrylic siloxane. After being added with proper dispersant, the viscosity of the high solid loading polysiloxane/SiO2 slurry can reach a proper level. Bulk 3D-silica ceramics with the wall-thickness around 8 mm can be conveniently fabricated from the polysiloxane/SiO2 slurry by stereolithography and a two-step sintering process. The addition of a proper sintering aid NaF can promote the 3D-PSO/SiO2 precursor to be converted into dense and crack-free 3D-silica ceramics with good mechanical proprieties.

By taking advantage of the low sintering temperatures of the preceramic polymers, stereolithography printed mullite components derived from preceramic polymer precursor containing alumina particles can be sintered at low temperatures. However, due to their high specific surface, nano alumina particles are difficult to be dispersed into the photocurable polysiloxane. Herein, to prepare mullite slurry, a photosensitive hydroxysiloxane was employed as the preceramic polymer matrix while γ-Al2O3 nanoparticle was added as the active filler. The introduction of photocurable hydroxysiloxane not only improved the homogeneity and rheological properties of mullite slurry but also shorted the ionic diffusion distance of Si-ion and Al-ion during the sintering process. Therefore, 3D mullite preceramic precursor stereolithography printed from hydroxysiloxane-Al2O3 slurry was endowed with a low sintering temperature around 1400 °C. During the sintering process of preceramic precursor, sintering aid AlF3 can participate in the reaction and further promote the formulation of mullite grains.

In recent years, deep reinforcement learning (DRL) algorithm has been widely used in algorithmic trading. Many fully automated trading systems or strategies have been built using DRL agents, which integrate price prediction and trading signal generation in one system. However, the previous agents extract the current state from the market data without considering the long-term market historical trend when making decisions. Besides, plenty of related and useful information has not been considered. To address these two problems, we propose a novel model named Parallel Multi-Module Deep Reinforcement Learning (PMMRL) algorithm. Here, two parallel modules are used to extract and encode the feature: one module employing Fully Connected (FC) layers is used to learn the current state from the market data of the traded stock and the fundamental data of the issuing company; another module using Long Short-Term Memory (LSTM) layers aims to detect the long-term historical trend of the market. The proposed model can extract features from the whole environment by the above two modules simultaneously, taking the advantages of both LSTM and FC layers. Extensive experiments on China stock market illustrate that the proposed PMMRL algorithm achieves a higher profit and a lower drawdown than several state-of-the-art algorithms.

Magnesium phosphate cement (MPC) has been applied in grouting engineering due to its features of quick setting, high early-strength, and perfect volume stability. The rheological properties (RPs) of MPC, being vitally important for site operation, need to be studied further. Sodium tripolyphosphate (STP) is one type of high-efficiency retarders used in MPC. This study investigated the effects of STP content on the RPs of MPC pastes, and the mechanisms were studied by characterizing the zeta potential, 1H NMR relaxation signal, water film thickness, mineral changes, and electrical impedance. Experimental results indicate that the plastic viscosity (η) increases gradually and the yield stress (τ0) decreases firstly and then increases with increasing the STP content. The influencing mechanisms of STP need to be distinguished by analyzing η and τ0 respectively. The water film thickness and the amount of intermediate hydration products within 15 min of hydration is directly related to the change in η. The porosity and distribution of free water obtained from 1H NMR in MPC slurry are the dominant factor for τ0, and followed by the diffused double layer. It is noteworthy that zeta potential is not an effective measure for studying the RPs of MPC. Results of electrical impedance also explain the mechanisms of STP retarding the hydration and improving the early-term strength of MPC.

Pursuing material development for next-generation batteries, organic electrode materials have shown great potential for lithium-ion batteries. However, their widespread adopting is plagued by intrinsic problems such as poor electronic conductivity, high dissolution inside electrolytes and unstable chemical peculiarity. Recently, nanostructured-strategies promoted organic electrodes with exotic properties for enhancing electron and ion transport together with the stability during electrochemical process, have received increasing attention and have been extensive applied in boosting the organic lithium-ion based energy storage. In this review, we summarize the applications of nanostructures to improve the performance of both organic anodes and cathodes, including (i) nanoscale design of zero-dimensional organic electrode materials, (ii) strategies of one-dimensional nanostructured organic electrode materials, (iii) construction of two-dimensional nanosized organic composite electrodes, and (iv) three-dimensional exploration of nanosized organic electrodes. We hope to stimulate high-quality applied research on understanding and handling the relationship between the nanostructure and performance of organic lithium-ion batteries that might speed up the commercialization of organic lithium ion batteries.

The high energy consumption of the microalgae dewatering process results in microalgae being less economically feasible as a new bioenergy material. As an energy-saving method, forward osmosis (FO) filtration can be applied in microalgae dewatering to reduce membrane fouling and energy consumption. In this study, a novel hybrid dead-end/cross-flow FO system was proposed to obtain highly efficient microalgae dewatering. The effects of agitation speed, draw solution concentration, and pH on microalgae and membrane flux reduction volume concentration factors were investigated using Box-Behnken design (BBD) of response surface methodology (three factors and three levels). The results demonstrated that the higher the draw solution concentration and agitation speed, the higher the volume concentration factors. When the draw solution concentration and agitation speed reached their maximums (5 M and 500 r, respectively), the maximum volume concentration factor was obtained (3.73). pH exhibited the greatest influence on flux reduction. The flux reduction decreased more with an increase in pH (pH > 7). When the pH was neutral or acidic, the influence of pH on flux was insignificant. This study provided a more efficient method for dewatering and reduced energy consumption by applying a BBD to optimize the operation parameters of a novel hybrid dead-end/cross-flow FO system for microalgae dewatering.

Utilizing phase change materials (PCMs) in building envelope has been proved to be able to effectively reduce the indoor temperature variations, of which the preparation of composite PCMs is rather important due to the leakage of PCMs. This work proposed a novel fabrication approach of cement-based composite phase change materials (CCPCMs) by means of the water solubility of polyethylene glycol (PEG) and the hydraulicity of cement. The microstructure, mineral component and latent heat storage capacity of CCPCMs were characterized by a series of experiments, including scanning electron microscopy (SEM), Fourier transform infrared rheometer (FTIR), X-ray diffraction (XRD), differential scanning calorimeter (DSC), thermal gravimetric analyzer (TGA) and leakage test. The potential cooling effect of the CCPCMs was also verified using an indoor irradiation test. The result of SEM test shows that PEG was well incorporated into cementitious matrix, which was also confirmed by the leakage test. The FTIR and XRD results indicate that PEG did not react with cement. In the DSC test, the prepared CCPCMs were observed to have phase transition enthalpy as high as 37.47 J/g. The TGA test reveals that CCPCMs had excellent thermal stability below the temperature of 300 °C. Furthermore, compared to control cement paste, the surface temperature of CCPCMs sample reduced by a maximum of 6.2 °C, showing that CCPCMs had a good thermal storage capacity. The findings of the paper indicate that the prepared CCPCMs have great potentials to be applied in thermal energy storage buildings.

Because of the sparse reward and the sequence of the complex multi-step task, there is a big challenge in reinforcement learning, that is, the agent needs to implement several consecutive sequential steps to complete the whole task without the intermediate reward. Reward Shaping and Curriculum Learning algorithms are always used to solve this challenge, but Reward Shaping is prone to sub-optimal policies and Curriculum Learning easily suffers from the catastrophic forgetting problem. In this paper, we propose a novel algorithm called Parallel Multi-Environment Shaping (PMES), where several sub-environments are built based on human knowledge to make the agent aware of the importance of intermediate steps, each of which corresponds to a key intermediate step. Specifically, the learning agent is trained under these parallel multiple environments including the original environment and several sub-environments by synchronous advantage actor-critic algorithm. And the PMES algorithm has the mechanism of adaptive reward shaping to adjust the reward function. In this way, PMES algorithm effectively incorporates human experience by multiple different environments rather than only shaping the reward function, which combines the benefits of Reward Shaping and Curriculum Learning algorithms while avoiding their drawbacks. Extensive experiments on the mini-game ‘Build Marines’ of StarCraft II environment show that our proposed algorithm is more effective than Reward Shaping, Curriculum Learning, and PLAID algorithms, which is almost close to the level of human Grandmaster. And compared with the existing work, it takes less time and computing resources to reach a good result.

Regularization is a very effective algorithm to solve overfitting problem in neural network, which improves the generalization ability of the model. However, their working mechanisms and the impact on the model performance have not been fully explored. In this paper, we study and analyze them using information bottleneck theory and one theory from human brain sensory system. We propose a metric to characterise the encoding length of hidden layers, named as AEntry value. Then, we implement extensive experiments on MNIST and FashionMNIST datasets with several commonly used regularization algorithms, and calculate the corresponding AEntry values. We analyze these results and obtain three conclusions. (1) The introduction of regularization influences the encoding of relative features with prediction task in neural network. The early stopping technique avoids introducing unrelated information with the task into the model by stopping the training process as an appropriate iterations. Laplace, Gaussian and Sparse Response regularizations compress the related representation and improve the performance of neural network by introducing the prior information into the model. In contrast, Dropout, Batch Normalization, and Layer Normalization increase the encoding length of features by adopting redundant representation to improve the performance. (2) The encoding of neural network does not satisfy the data processing inequality of information theory, which is mainly caused by redundant coding of extracted features. (3) The overfitting is caused by introducing irrelative information with the target. These results can give us insight into building more efficient regularization algorithm to improve the performance of neural network model.

A novel gravity sedimentation - forward osmosis (G-FO) hybrid reactor was built up for separating and concentrating the biomass from the algal-rich water (microalgal dewatering). The extracellular organic matter (EOM) from Chlorella vulgaris (C. vulgaris) was divided into dissolved EOM (dEOM) and bound EOM (bEOM). Water flux, flux recovery rate and moisture content (MC) were investigated. Through sedimentation rate, zeta potential and hydrophilicity/hydrophobicity to analyze the experimental results. Scanning electronic microscopy (SEM) was used to observe the different morphologies of accumulated algae cells and EOM on the surface of the membrane. The results showed that cell + bEOM solution had the fastest sedimentation rate and fewest negative charge, so the pollutants accumulated more easily on the membrane surface, resulting in the highest flux decline. Its algal cake layer was the densest from the view of SEM. Cell + bEOM + dEOM solution had the lowest flux decline and the cake layer was the loosest. Cell + bEOM solution had the most severe irreversible fouling and the lowest flux recovery rate (FRR). The membrane fouling of cell solution was lower than that of cell + bEOM + dEOM solution, and the FRR of cell solution was almost 100%. According to the nonionic macro-porous resin fraction results of EOM, cell + bEOM + dEOM solution contained more hydrophilic components, resulting in the lowest MC. On the contrary, cell + bEOM solution showed the highest MC, which contained more hydrophobic components. Effects of bEOM and dEOM on microalgae dewatering performance of a novel gravity sedimentation - forward osmosis (G-FO) hybrid system were investigated, which provided a theoretical basis for large-scale application of FO technology for microalgae dewatering.

Membrane fouling and wetting limit the applications of membrane distillation (MD) for wastewater treatment, especially when treating the wastewater with a high concentration of low surface tension substances such as oil and surfactants. In this paper, virgin polyvinylidene fluoride (PVDF) membrane was modified by polydimethylsiloxane (PDMS) to enhance anti-wetting ability. Then a thin polydopamine (PDA) layer was coated as a reaction platform for further modification. Polyethyleneimine (PEI) was cross-linked with PDA to form a uniform and stable layer, through hydrogen bonds and electrostatic interaction to immobilize hydrophilic MXene, which formed a Janus MXene-PVDF membrane. The MXene layer was the key for superoleophobicity and high liquid entry pressure (LEP) of membrane, capable of mitigating membrane fouling and wetting when dealing with low surface tension wastewater (LSTW). From the experiments results, pristine PVDF membrane showed severe fouling and wetting with flux decline and salt leakage during treatment of LSTW (surfactants containing water, oil-in-water emulsion and sodium dodecyl sulfate stabilized oil-in-water emulsion). However, under the same conditions, the Janus MXene-PVDF membrane exhibited remarkably stable flux (9.3 kg m

In this study, the isothermal calorimetry was employed to measure the heat release rate and total heat release of cement composites incorporated with expanding agent, viscosity modifier and nano-SiO2 at low temperatures. The results indicate that expanding agent and viscosity modifier decrease the maximal heat release rate of cement composites and make the arrival time of the maximal heat release rate in advance. The addition of nano-SiO2 can shorten the induction period and increase the maximal heat release rate at different temperatures. The influencing regularity of expanding agent and viscosity modifier on hydration process remains unchanged with temperature, and the effect of nano-SiO2 is more significant under lower temperature. The use of expanding agent and viscosity modifier accelerates the nucleation process significantly and decreases the growth rate of hydration products to some degrees. In comparison to the admixtures, temperature is the dominant factor for growth rate of hydration products.

In order to understand the influencing mechanisms of curing temperature on the performances of steam cured concrete further, the microhardness characteristics of the interfacial transition zone between cement paste and coarse aggregate under different curing temperatures were studied through microhardness measurements, backscattered electronic microscopy (BSEM) and mathematical statistical analysis. The experimental results indicate that the microhardness of the hardened cement paste presents a significant statistical distribution characteristic. That is to say, there are two microhardness characteristic values which reflect the hydrated products and unhydrated cement particles, respectively. The curing temperature has a significant effect on the microhardness of interfacial transition zone. In other words, the microhardness decreases, and the thickness range of interfacial transition zone increases with increasing the curing temperature. The relationship of the microhardness value of the interfacial transition zone to the distance from the aggregate surface conforms to the Peal function.

A GO-TiO2 membrane was fabricated using a layer-by-layer method to assemble graphene oxide (GO) on a polyacrylonitrile (PAN) support, interconnecting GO nanosheets with polyethylenimine (PEI). The surfaces of the GO nanosheets were modified by depositing titanium dioxide (TiO2) nanoparticles on them using an ethanol/ultraviolet (UV) post-treatment, that enhanced their photocatalytic and self-cleaning properties. The GO-TiO2 membrane showed good photocatalytic performance with a 58.8% removal rate of methylene blue (MB) under UV for 250 min. The self-cleaning properties were illustrated via the flux recovery by UV irradiation and the effect of UV irradiation before membrane filtration. The experimental results indicated that the J/J0 ratio of the GO-TiO2 membrane increased from 41% to 54% after the fouled membrane was exposed to UV irradiation for 30 min. When UV irradiated the GO-TiO2 membrane for 40 min prior to filtration, the flux increased from 1.67 to 1.88 L/m2•h. This may be a result of the photo-induced superhydrophilicity of TiO2.

The free arc thermal excitation were adopted to rapidly disperse the mixed system that composed of carbon nanotubes and Fe3O4 particles, and the microscopic statistical methods of image recognition were adopted to compare the free arc dispersion of working fluid content and dispersant and ultrasonic dispersion with different particle size and quantity; the structural continuity of Fe3O4 before and after dispersion was characterized by Raman spectroscopy and the macroscopic dispersion of the two materials was analyzed by mapping mode. The free arc with the medium working fluid content was of the best dispersion effect, and the two nanomaterials were well dispersed by scanning electron microscopy and mapping signals, and there were interpenetration effects at the micro level.

Within-image co-saliency detection is to detect/highlight the common saliency (similar-appearance salient objects) in a single image. Ideally, it can be solved by detecting each individual salient object first and then comparing them, which is possible for some images with simple representations. However, in practice, this way is not accurate and robust for some images with complex representations. In this paper, we propose an easy-to-hard learning strategy to solve this problem. By directly localizing and comparing salient objects in simple images, superpixel confidences as co-salient objects are inferred by an easy learning method, which provide promising but also noisy supervisions for complex images. Therefore, within-image co-saliency detection in complex images can be modeled as a hard learning problem with noisy labels. A multi-scale Multiple Instance Learning (MIL) model together with a new sampling method is proposed to solve this hard learning problem with noisy labels. Experimental results show that the proposed method achieves the best performance on a public benchmark dataset and two synthetic datasets.

In the present study, 13 endocrine disrupting compounds (EDCs) and their transformation products (TPs) were monitored in Jiulong River and its estuary, China in different seasons. The analytes included antimicrobials [triclosan (TCS) and triclocarbon (TCC)]; estrogens [estrone (E1), estradiol (E2), estriol (E3) and ethinylestradiol (EE2)]; alkylphenol ethoxylates [4-n-nonylphenol (NP) and 4-n-octylphenol (OP)] and the TPs [methyl triclosan (MeTCS), carbanilide (NCC), dichlorocarbanilide, 4-hydroxy estrone (4-OH E1) and 4-hydroxy estradiol (4-OH E2)]. A significant seasonal variation was observed for most EDCs. Approximately, 79% of the total E2 residues were detected in the normal season in comparison with the wet season to indicate recalcitrant behavior of E2 during the normal season. Risk assessment revealed that E2 was most potent among the EDCs to cause highest risk to both vertebrate and invertebrate aquatic species, whereas, E1, EE2, MeTCS and TCS also showed relatively high risk for some surface water aquatic species.

The precast structures prepared by steam-cured concrete have been increasingly used in order to speed up the construction of China’s High-Speed Rail and passenger dedicated lines in recent years. In the high-cold regions, such as Harbin, the precast concrete structures are exposed to continuous subfreezing temperature for several months every year. However, the influence of continuous subfreezing condition on mechanical properties of concrete has not been systematically investigated yet. According to the Laplace Equation and Gibbs-Duhem Equation, the theoretical size of minimal frozen pores and ice content in water-saturation concrete at −20 °C can be calculated. It is discovered that the change ratios of mechanical properties are related to the theoretical ice content in concrete. Phenomenological models between change ratios and ice content are established based on hyperbolic equations. Finally, the mechanism of phase transition of free water on mechanical properties is explained by means of classical fracture theory of concrete. In this research, a contrastive research was carried out under two temperature conditions of 20 °C and −20 °C on mechanical properties of steam cured concrete at 28 days, including compressive strength, flexural strength, dynamic modulus of elasticity and damping ratio. Experimental results obtained at −20 °C indicate that compressive strength, flexural strength and dynamic modulus of elasticity increase to some extent and damping ratio decreases. And the application of supplementary cementitious materials (fly ash and GGBS) on concrete has a significant impact on the variation ratio of mechanical properties under freezing temperatures. The results of micro structure by quantitative test reveal that the pore distribution was greatly optimized and the percent of harmful pore were substantially reduced by the supplementary materials of fly ash or GGBS.

One-part geopolymer similar to conventional Portland cement by just adding water is a new type of green cementitious material. Na2SiO3-anhydrous is an excellent powder activator for preparing one-part geopolymer, but its CO2-e emission and alkalinity are very high. In this study, the Na2CO3 was used to replace a portion of Na2SiO3-anhydrous, and the properties of one-part geopolymer with composite activators were investigated systematically. The possible influencing mechanism of the complex use of activators in one-part geopolymer was proposed. Test results indicate that the replacement level of Na2CO3 has slight impact on the fluidity and increases the final setting time significantly. This is directly related to the initial heat release rate and the type of network structures formed. The compressive strength decreases with increasing the Na2CO3 content. On the one hand, the quantity of gelatinous products reduces and calcite is produced as the new phase after replacing Na2SiO3-anhydrous by Na2CO3. On the other hand, the gathering of calcite and low-crystalline CaCO3 in some regions leads to the generation of many large micro-cracks, which explains the change in the porosity of the unfavorable pores. Judged from the cost per MPa and total CO2-e emission for a cubic meter of cementitious materials, one-part geopolymer activated by composite activators is cleaner than that activated by single Na2SiO3-anhydrous or Na2CO3. This study provides a guidance for preparing one-part geopolymer with lower alkalinity and potential environmental impact.

Periodic withdrawal and replenishment of powdered activated carbon (PAC) hybrid membrane bioreactor (MBR) is required for stable performance. The influence of the replenishment of powdered activated carbon (PAC) on sludge filterability and microbial community in hybrid MBRs was investigated. Results showed that the removal of organic matter and nitrogen were not significantly affected by the PAC refreshment, while soluble microbial products (SMP) concentration decreased and extracellular polymeric substance (EPS) increased with increasing PAC replacement ratio. MBR system with PAC replenishment exhibited low fouling propensity and prolonged filtration agreed well with fouling rate and resistance analysis. Molecular weight distribution of SMP in MBR confirmed the synergistic effects of PAC adsorption/biodegradation and membrane interception on organics removal. Microbial activity was positive associated with the PAC replenishment ratio. Moreover, the high-throughput sequencing indicated that due to fresh PAC added, the increased abundance of Proteobacteria, Bacteroidetes and Nitrospira guaranteed the pollutant removal, and the membrane fouling caused by Planctomycetes and Betaproteobacteria decreased. An optimal PAC replenishment ratio at 1.67% achieved the effective membrane fouling mitigation and enhanced dominant bacterial structure. PAC refreshment is considered to be a promising way to advance the application of MBR.

The CDs were used as the ratiometric probe for detection of curcumin and Fe3+. The fluorescence of CDs at 420 nm was quenched through inner filter effect (IFE) while the fluorescence of curcumin at 525 nm was enhanced after adding curcumin. The value of ln(I525/I420) increased linearly with the curcumin concentration in the range of 5–30 μM, the limit of detection was 21.79 nM. After adding Fe3+ into the system of CDs-curcumin, curcumin complexed with Fe3+ leading to the quenching of the fluorescence of curcumin at 525 nm, which declined the spectra overlap between curcumin and CDs. The process of IFE was inhibited, the fluorescence of CDs at 420 nm was recovered. The value of ln(I525/I420) linearly decreased with the increasing of Fe3+ in the range of 2-14 μM, the limit of detection is 18.11 nM. The CDs-curcumin system was successfully applied for H1299 cell imaging and has potential applications in the fields of fluorescent labeling and inhibition of tumor cells. The CDs-curcumin system was furtherly used for PVDF membrane fouling research of iron flocculants in wastewater treatment.

One-part geopolymeric binders which are considered as cleaner non-Portland cementitious materials are prepared by first mixing the aluminosilicate materials with the solid alkaline activators before adding water, which makes the mixing method of the geopolymer being the same as Portland cement. In this paper, sinking spherical beads (SSB) is introduced into the raw materials containing fly ash (CFA) and ground granulated blast furnace slag (GGBS) to synthesize a ternary one-part geopolymer. A systematic investigation of the effect of SSB on the geopolymer pastes and mortars is performed through measuring the fluidity, final setting time, compressive strength and flexural strength. It is found that SSB can significantly improve the fluidity and mechanical properties of geopolymer due to its high reactive effect and remarkable morphological effect. The action mechanism of SSB for improving the performance of the geopolymer was also dissected. It is interesting to note that SSB has little influence on the initial heat flow and increases the cumulative heat relating to the strength development. The changes in the formation of C-A-S H and N-A-S H gels after the introduction of SSB are well captured by the XRD and EDX analysis. It clearly appears that the N-A-S H gel with the optimal Na/Si ratio of 0.5 can be generated by optimizing the rational proportion of raw materials and alkaline activators. This study not only demonstrates the superiority of SSB in synthesizing a ternary one-part geopolymer, but also develops a method to design the novel non-Portland cement only by using industrial wastes.