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Hfq is an RNA-binding protein, its main function is to participate in post-transcriptional regulation of bacteria and regulate small regulatory RNA (sRNA) and messenger RNA (mRNA) stability, but the Hfq function of Bacillus subtilis (B. subtilis) has not been fully explained. In this study, we used the strains of B. subtilis168 (BS

Perovskites with flexible structures and excellent redox properties have attracted considerable attention in industry, and their denitration activities can be further improved with metal substitution.

Probable surface NH3-SCR reaction mechanism over CuCe/TiO2-ZrO2 catalyst is proposed to follow the E–R mechanism and the L–H mechanism, while the E–R mechanism dominates in the reaction and the oxidation of NO closes the catalytic cycle.

Photoactive Bi/BiOBr/TiO2 NRA composites displayed an efficient visible light response and fast charge transport rate and were used to construct sensitive kanamycin photoelectrochemical aptasensors.

Crystallization of a CaO–Al2O3–MgO–SiO2 (CAMS)–based glass–ceramic with different additives, Fe2O3 and CeO2, was investigated. The compositions of crystals formed in the glass–ceramic were related to the coordination polyhedron of Fe–O and Ce–O in the glass matrix. Fe existed in the glass network in a form of [Fe3+O4–SiO4] (variant of Q2), which facilitated the formation of diopside. CeO2 addition led to the formations of [CeO4] and [CeO6]. [CeO4] was assembled in the diopside crystal, forming a Ce-containing diopside solid-solution. As a glass modifier, [CeO6] consumed Na ions, achieving electric neutrality and increasing the fraction of Q4 (SiO2 O2/2)2−. This enables the precipitation of albite and anorthite. EBSD observation of CaCe4(SiO4)6O crystal

With the constant exploration and development of intelligent manufacturing, the concept of digital twins has been proposed and applied. In view of the complexity and intellectualization of virtual workshop systems, real workshops can link with virtual workshosp based on AR under the structure of digital twins, which allows users to interact with virtual information and perceive the virtual information superimposed on the real world with great immersion. However, the three-dimensionality of virtual workshops and interaction with complex workshop information can be challenging for users. Due to a shortage of input bandwidth and the nontraditional mode of interaction, a more natural interaction technique for virtual workshops is required. To solve such problems, this paper presents a technical framework for 3D eye movement interaction applied to a virtual workshop. An eye movement interaction technique, oriented to implicit interaction and explicit interaction, is developed by establishing behavior recognition and interaction intention understanding. An eye-movement experiment verifies the former’s accuracy is above 90% and had better recognition performance. A better feature vector group of the latter is selected to establish a model and verify its feasibility and effectiveness. Finally, the feasibility of the framework is verified through the development of an application example.

In order to improve the energy performance and mechanical properties of insensitive high-energy propellants, cyclotrimethylenetrinitramine (RDX)-based insensitive high-energy propellant with nitrocellulose (NC) and glycidyl azide polymer-energetic thermoplastic elastomer (GAP-ETPE) blends as the binder was prepared by solvent method. The effects of GAP-ETPE/NC ratio and RDX content on the energy properties of propellants were analyzed by numerical calculations. The effects of GAP-ETPE/NC ratio, RDX particle size and RDX content on the mechanical properties of propellants were studied by compression test, impact test and solid surface properties test. The impact sensitivity and friction sensitivity of all the propellant compositions were tested. The theoretical calculation results showed that the introduction of GAP-ETPE into propellant significantly decreased the explosion temperature and increased the specific volume. The density, compression strength, and surface energy of the propellant were gradually decreased with increasing the GAP-ETPE/NC ratio, and the impact strength was increased gradually as well. The mechanical properties and surface energy of the propellant were improved greatly when the RDX particles were smaller. The studied propellants showed a linear increase in the propellant force and explosion temperature with increasing the RDX content. However, increasing the RDX content significantly reduced the impact strength and surface energy. Mechanical reinforcement with solid fillers increased the compression strength and propellant density to a certain degree. Compared with the standard propellants SF-3, the prepared propellant composition is insensitive to the impact and friction.

CuS/ZnS/sodium alginate/reduced graphene oxide nanocomposites (CZSrG) were prepared by physical crosslinking followed by one-step reduction and were justified as green binder-free hydrogel high-capacitance electrodes. The physical crosslinking was realized simply through the hydrogen-bond interaction between sodium alginate (SA) and graphene oxide (GO), avoiding the usage of traditional Ca2+ crosslinking agent. The hydrogel structure made of CZSrG possessed the most beneficial effect of avoiding large volume change and increasing cycle stability for supercapacitors. When used as electrode, the specific capacitance of CZSrG was 992 F·g−1 (10 mV·s−1) in a three-electrode system. Furthermore, the fabricated supercapacitors had a specific capacitance of 252.1 F·g−1 (5 mV·s−1), and a power density of 1800 Wh·kg−1 at the energy density of 2.05 Wh·kg−1. Thus, the CZSrG has a favorable electrochemical performance and wide application prospects in supercapacitors.

To improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

Polyacrylamide (PAM) has been used as a coagulant aid in water treatment process for past decades, but it has caused great damages to human nervous system. Developing new coagulant aid with high biological safety is urgently demanded. This study provides a natural biomacromolecule coagulant aid with good biosecurity-Enteromorpha prolifera polysaccharide (Ep). Its coagulant aid efficiency and mechanism were investigated in terms of organics removal, floc properties and membrane fouling degree. In addition, contrast experiments were conducted with PAM to evaluate its potential of industrial applications. Results showed that organics removal could be increased by 23% when 0.3 mg/L Ep was used, which exhibited comparable aid effects to PAM. Due to the bridging-sweep aid role of Ep, flocs sizes, growth rate and recovery factor reached 470 μm, 62.6 μm/min and 0.492, respectively, while only 170 μm, 14.0 μm/min and 0.326 were obtained by PAM. Additionally, flocs exhibited more porous and multi-branched structures when Ep was applied, which caused less ultrafiltration membrane fouling (eventual J/J0 value = 0.52). As a result, Ep could be considered as a potential substitute of PAM, since better biosecurity, higher organics removal and lower membrane fouling could be obtained simultaneously by Ep addition.

In the past few years, human-health has been severely impacted from PM2.5 and has thus been a very popular topic of study. Furthermore, monitoring and control of PM2.5 are becoming one of the major environmental problems. In view of this, the present work targets at the establishment of an optimized BP neural network model based on t-distributed control genetic algorithm (BPM-TCG). Subsequently, in order to verify the performance of the proposed BPM-TCG, comparison analyses were performed among the prediction results generated from BPM-TCG, BP neural network model and BP-GA according to hourly data of PM2.5 mass concentration, analysis of corresponding meteorological factors, and gas pollutant concentrations from October 2017 to August 2018 at Qiqihar University monitoring point. The experimental results showed that BPM-TCG had the highest prediction accuracy and the best generalization ability, excellent applicability and commonality. Additionally, it may provide a basis for predicting the mass concentration of PM2.5, and thereby control and prevent the air pollution.

Circular RNAs (circRNAs) are a newly discovered class of endogenously expressed non-coding RNAs (ncRNAs). They are highly stable, covalently closed molecules that frequently exhibit tissue-specific expression in eukaryotes. A small number of circRNAs are abundant and have been remarkably conserved throughout evolution. Numerous circRNAs are known to play important biological roles by acting as microRNAs (miRNAs) or protein inhibitors (‘sponges’), by regulating the function of proteins, or by being translated themselves. CircRNAs have distinct cellular functions due to structural and production differences from mRNAs. Recent advances highlight the importance of characterizing circRNAs and their targets in a variety of insect species in order to fully understand how they contribute to the immune responses of these insects. Here, we focus on the recent advances in our understanding of the biogenesis of circRNAs, regulation of their abundance, and biological roles, such as serving as templates for translation and in the regulation of signaling pathways. We also discuss the emerging roles of circRNAs in regulating immune responses to various microbial pathogens. Furthermore, we describe the functions of circRNAs encoded by microbial pathogens that play in their hosts.

Hypothesis Cellulose aerogels are a new category of high-efficiency adsorbents for treating oil spills and water pollution. However, the hydrophilic properties and recyclability of aerogels after adsorption hamper developments and applications. Combining both hydrophobic and magnetic properties are expected to improve their adsorption capacity and functionality. Experiments In this study, the effect of oleic acid (OA) and nanomagnetite on the preparation of magnetic nanocellulose aerogels (called as NCA/OA/Fe3O4) by a mechanical mixing combined with freeze-drying method have been investigated. Findings It has been found that the optimal condition for fabricating this NCA/OA/Fe3O4 aerogel is 0.4 wt% nanocellulose, 3 mg mL−1 OA and 0.5 wt% Fe3O4 in the aqueous solution. This aerogel has a very low density of 9.2 mg cm−3 and demonstrates a high adsorption capacity of 68.06 g g−1 for cyclohexane. In addition, this aerogel adsorbent demonstrates an excellent magnetic responsivity and can be easily recycled by a permanent magnet after adsorption. As a consequence, this hydrophobic magnetic NCA/OA/Fe3O4 aerogel is promising not only for easy oil and organic solvent adsorption but also potentially for other magnetic related applications.

The nano-oxide materials with special structures prepared by template methods have a good dispersion, regular structures and high specific surface areas. Therefore, in some areas, improved properties are observed than conventional bulk oxide materials. For example, in the treatment of dye wastewater, the treatment efficiency of adsorbents and catalytic materials prepared by template method was about 30 % or even higher than that of conventional samples. This review mainly focuses on the progress of inorganic, organic and biological templates in the preparation of micro- and nano- oxide materials with special morphologies, and the roles of the prepared materials as adsorbents and photocatalysts in dye wastewater treatment. The characteristics and advantages of inorganic, organic and biological template are also summarized. In addition, the applications of template method prepared oxides in the field of sensors, drug carrier, energy materials and other fields are briefly discussed with detailed examples.

Carbon nanotubes (CNT)-cerium oxide (CeO2) nanocomposites were fabricated successfully by one-pot microwave hydrothermal growth of regular CeO2 nanoparticles with a size of 8 nm on hydroxyl-functionalized multi-walled CNTs. These nanocomposite photocatalysts demonstrated an acid orange (AO7) photocatalytic degradation efficiency of above 90% under solar-simulated light irradiation for 3 h, which was much higher than that of the pure CeO2 nanoparticles. The enhanced photocatalytic activity was observed to mainly originate from the ˙O2- and hole traps, while the hydroxyl radical ˙OH played a secondary role.

In this study, carbon dot-sensitized Ti3+ self-doped TiO2 dual-phase (TiO2−x/CDs) composite photocatalytic systems were successfully constructed using a low-temperature hydrothermal method. The TiO2−x photocatalyst showed improved photocatalytic activities for the removal of Cr6+ and RhB under visible light. Remarkably, RhB (10 mg L−1) and Cr6+ (40 mg L−1) solutions were degraded completely in 30 and 120 min, respectively, by the composite photocatalyst (1 g L−1) under visible-light irradiation. These results were much better than those of commercial P25. This fascinating photocatalytic performance was attributed to the improved photogenerated electron–hole separation efficiency from the synergistic effects of rutile and anatase, and the reduced photogenerated charge carrier recombination and facilitated visible-light absorption from the introduced CDs. This study provides a promising approach for the treatment of real wastewater using sunlight.

This study investigates the antioxidant, antibacterial and antiproliferative properties of the ethyl acetate, chloroform, ethanol and n-butanol extracts from Chloranthus henryi. Total flavonoid content (TFC) and total phenol content (TPC) values for the extracts could be investigated. The TPC value for extracts changed from 4.36 to 19.64 milligram gallic acid equivalents per gram of dry material, and the TFC of extracts changed from 3.13 to 9.99 milligram rutin equivalents per gram of dry material. The antioxidant properties were evaluated and their antimicrobial activity was tested against bacterial strains Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, Group A Streptococcus and Monilia albican. The results showed that all extract displayed moderate or great potential of antioxidant and antibacterial activity. Strong correlations were observed between TPC and antioxidant activity. Five compounds could be separated from n-butanol extract, which showed high content of TPC and significant antioxidant activity. They are (1) gallic acid, (2) caffeic acid, (3) 4-hydroxybenzoic acid, (4) rosmarinic acid and methyl rosmarinate (5). Antiproliferative activity was tested using HepG2, Hela and MCF-7 cells. The study suggested that components of Chloranthus henryi possessed fine antioxidant property, therefore can be applied for antioxidant, antibacterial and antiproliferative agents in the food or drug industries.

Bismuth oxychloride (BiOCl) and cerium dioxide (CeO2) composites were successfully synthesized via a facile one-step co-precipitation method. The BiOCl/CeO2 composites were observed to be sheet-like structures with some CeO2 nanoparticles distributed on the surface. The BiOCl/CeO2 composites exhibited higher photodegradation performance (98.8%) of rhodamine B (RhB) than pure BiOCl (80.2%) and CeO2 (9.6%) under solar simulated irradiation. The BiOCl/CeO2 composites with a Bi/Ce molar ratio of 4 : 1 exhibited the highest photocatalytic performance for RhB, and an optimal RhB degradation efficiency of 98.8% was achieved under solar simulated irradiation for 60 min. The photocatalytic performance results were compared with other BiOCl composites. The photocatalytic mechanisms of BiOCl/CeO2 composites were discussed by radical trapping experiments and electron spin resonance (ESR), which indicated that h+ and ˙O2− were the dominant radicals for RhB degradation.

Excess sludge, a carbon-rich valuable by-product from wastewater treatment, is utilized as a carbon precursor for synthesizing porous activated carbon. However, improving specific surface area (SBET) is the main challenge for the sludge derived activated carbon (SAC). In this study, the carbonization process was optimized as following: carbonization temperature of 900 °C, heating rate of 10 °C/min, and dwell time of 30 min. Moreover, the residue heavy metals and bound water remaining in the sludge were demonstrated to be important in the pore formation of the SAC. The metals acted as hard template to form the pores in the SAC after the metals were removed by acid wash. The bound water was found to be soft templates for forming pores due to its evaporation during carbonization. A maximum SBET of 1018.8 m2/g was achieved for the SAC when the bound water content was controlled at 2 wt%.

Practical applications of lithium–sulfur batteries have been impeded by their poor cycling stability that results from the “shuttling” of polysulfides. Herein, we demonstrate a new strategy for developing a hierarchical phosphorus-doped graphene/carbon nanofiber/sulfur aerogel (PGCNF/S) with “network” morphologies, in which sulfur spheres are wrapped with graphene sheets and carbon nanofibers (PGCNFs) with “net” structures and this carbon matrix has greatly improved the electrochemical performances of sulfur spheres. PGCNF nets ensure a uniform loading of sulfur spheres that leads to a high sulfur mass loading of 85 wt%. Also, the good porous structures achieved with this PGCNF/S cathode can provide sufficient space for volume expansion of active sulfur spheres. Due to its structural advantages, this binder-free PGCNF/S cathode exhibits a specific capacity of 1360 mA h g−1 at 0.1C, and a high areal capacity of 21.5 mA h cm−2 based on a high sulfur mass loading of 15.8 mg cm−2. Furthermore, a long term cycling stability of 600 cycles has been achieved by this PGCNF/S cathode with an average coulombic efficiency of ∼99.8%. This work highlights a broadly adaptable strategy of “network” structures for developing scalable and high-energy density electrode materials for energy storage devices.

One major obstacle in the advancement of proton exchange membrane (PEM) technology is the development of highly active and durable electrocatalysts for the oxygen evolution reaction (OER) in an aci...

In this work, natural polysaccharide product sodium alginate (SA) served as templates to prepare porous calcium silicate (CS) hydroxyapatite (HA) composite microspheres (CHCM) with high specific surface area by a new route combining ion exchange and calcination. CHCM played an important role in the fields of environmental protection with its large specific surface area, excellent adsorptive property, high mechanical strength and good regeneration performance. In order to explore its treatment capacity of wastewater, a series of eriochromeblue black R (EBBR) adsorption experiments were carried out. The equilibrium data fitted well with the Langmuir isotherm with a maximum adsorption capacity of 76.80 mg/g. Electrostatic interaction, ionic bonds and physical adsorption were responsible for the interactions between the EBBR and CHCM. Meanwhile, the CHCM maintained complete spherical and almost undamaged in the regeneration experiments, which confirmed its stability for cyclical usage. This paper demonstrates the role of natural polysaccharide product sodium alginate serving as templates to prepare useful products with potential wide applications.

Low-cost natural polymer lignin has been widely used to remove heavy metal ions from polluted water. But it still has some shortcomings, such as poor removal performance, and weak selective adsorption. Thus, in this study, the lignin prepared by Mannich reaction with black liquor was activated with triethylenetetramine (TETA) to achieve a novel adsorbent with high adsorption rates and a strong selectivity for specific oxygen-containing anions. The adsorption capacity of activated lignin (a-CL) on three oxygen-containing anions (i.e. As(V), P(V) and Cr(VI)) was investigated systematically. The adsorption mechanism of a-CL was elucidated theoretically by the density functional theory (DFT) method. Under the same conditions, the selectivity toward oxygen-containing anions by a-CL followed P(V) Cr(VI) As(V). Both FT-IR and DFT simulation results revealed that the hydrogen bond between HAsO

Three-dimensional graphene (3D-GN)/Cu/Fe3O4 composite support materials were synthesized by a modified chemical reduction method using graphene oxide precursor. A 3D-GN/Cu/Fe3O4 biosensor was prepared by coating the electrode with laccase. The electrochemical properties of the biosensor were investigated by cyclic voltammetry (CV) and differential pulse voltammetry using potassium ferricyanide, phosphate-buffered saline (PBS) solution, and bisphenol A (BPA) solution. The current response of 3D-GN/Cu/Fe3O4 biosensors presents a remarkable sensitivity based on CV. The linear range of BPA is 7.2–18 µM using differential pulse voltammetry in PBS solution (pH = 4.0). A linear fitting equation of the laccase biosensor was observed for the current response as a function of BPA concentration. The detection limit was decreased to 1.7 µM. The detection approach herein turns out to be highly sensitive, has a wide linear range, and exhibits excellent stability.

Thermal expansion coefficient (CTE) is a critical parameter of gun propellant because of its major role in fabrication, storage and combustion performance of the propellant. Further, controlling the CTE of the propellant is an effective solution to improve its loading density. Therefore, it is important to understand the thermal expansion of the propellant. To obtain the linear CTE of insensitive gun propellant, different weight percentages of NQ are added to the B# double-base absorbent propellant, the thermal mechanical analyzer (TMA) is employed to estimate their dimensional change over the temperature range of 213–323 K. The pure NQ flaky gun propellant exhibits a negative thermal expansion with a linear CTE of −2.006 × 10−4 mm/mm K−1. The results show that the linear CTE of the B# double-base absorbent propellant is decreased by 53.74% as the concentration of NQ is increased to 30%, whereas the glass transition temperature increases with increasing the NQ content. Keywords: Flaky gun propellant, Coefficient of thermal expansion (CTE), Negative thermal expansion, Nitroguanidine (NQ), Glass transition temperature

The flexible metacomposites with tunable negative permittivity have great potential in wearable cloaks, stretchable sensors, and thin-film capacitors, etc. In this paper, the flexible graphene/poly...

Development of polymer based mid-wavelength infrared (MWIR) optics has been limited mainly due to high optical loss of organic polymers used in general optical components. In this study, a MWIR polarization grating based on a sulfuric polymer poly(sulfur-random-(1,3-diisopropenylbenzene)) with a low loss in the MWIR range was fabricated using a simple two-step process: imprint and metal deposition. Fourier-transform infrared (FTIR) spectroscopy measurement showed that this polymeric MWIR polarizer selectively transmitted the polarized IR in transverse magnetic (TM) mode over the transverse electric (TE) mode at normal incidence. The measured extinction ratios ( η = The ratio of transmissions in TM and TE) were 208, 176, and 212 at the wavelength of 3, 4, and 5 μm, respectively. The computational simulation and analytical model confirmed that the enhanced TM transmission efficiency and η followed a Fabry-Perot (FP) resonance mode within the created sulfuric polymer film. This polymeric MWIR polarizer demonstrated a great potential for broader applications in IR photonics to realize low-cost and durable optical components.

Porous grafted copolymer with excellent thermal stability and swelling capacity was synthesized from water soluble Prunus cerasifera gum polysaccharide (PG) and acrylamide (AM). The monosaccharide compositions and the structure of Prunus cerasifera tree gum were detected by a high-performance anion exchange chromatography (HPAEC) system and 1H NMR and 13C NMR, and the obtained PG-AM copolymer was characterized by Fourier transform infrared (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The results indicated that the water soluble polysaccharides obtained from Prunus cerasifera tree gum were mainly composed of l-arabinose (39.78%) and d-galactose (40.59%) with minor amount of xylose, mannose and uronic acids. The maximum percent and the grafting efficiency of grafting acrylamide (AM) onto PG to form PG-AM were obtained by copolymerization between polysaccharide and 3 times (weight) acrylamide with 3 mmol/L potassium persulfate initiator at 50 °C for 1 h. In addition, lots of isolated and conjoint pores were observed in the prepared PG-AM materials, with a diameters distribution between 2 and 10 μm. Compared with PG, the synthesized copolymer PG-AM showed an excellent performance in thermal stability and swelling capacity. The detailed structural characteristic together with excellent thermal stability and swelling properties will benefit efficient utilization of the synthesized copolymer as a precursor for preparation of large-scale environmentally friendly advanced materials with various potential applications.