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• The internal control quality of enterprises has a positive impact on stock liquidity. • Earnings quality plays an intermediary transmission role in listed firms' internal control, affecting stock liquidity. • The quality of internal control of non-state-owned enterprises enhances the stock liquidity effect more significantly. This paper examines the correlation between corporate internal control and stock liquidity by utilizing data from China's A-share listed companies spanning the period from 2012 to 2022. It is observed that a higher quality of internal control positively signals to the capital market, thereby enhancing the stock liquidity of the enterprise. Furthermore, compared to state-owned enterprises, earnings quality serves as a partial intermediary in the process where internal control influences stock liquidity. However, for non-state-owned enterprises, the improvement in the quality of internal control is more notably effective in augmenting stock liquidity. [ABSTRACT FROM AUTHOR]

Highlights • A nonpolarizing GMRF with different grating periods along the x and y axes was designed for oblique incidence. • A tunable nonpolarizing GMRF incorporating an electrically driving liquid crystal cell was fabricated. • Nonpolarizing resonance spectra tuned by electrically driving the refractive index of liquid crystal cell were measured. Abstract A tunable nonpolarizing guided-mode resonance filter (GMRF) incorporating an electrically driving polymer-dispersed liquid crystal (PDLC) cell is designed, fabricated and demonstrated. By studying the dependence of the resonance wavelength on the grating period, the two-dimensional (2D) nonpolarizing GMRF is designed using different grating periods along the x and y axes at oblique incidence. The 2D electrically driving GMRF sample is fabricated through thin-film deposition, electron beam lithography and PDLC injection. Moreover, the resonance spectra of the fabricated sample are measured by a spectrometer and the measured results are consistent with the theory. Thus the nonpolarizing resonance spectra can be tuned by electrically driving the refractive index of PDLC cell in real time. [ABSTRACT FROM AUTHOR]

Considering the variations of optimal light intensity required by microalgae cells along with growth phases, growth-phase light-feeding strategies were proposed and verified in this paper, aiming at boosting microalgae lipid productivity from the perspective of light conditions optimization. Experimental results demonstrate that under an identical time-averaged light intensity, the light-feeding strategies characterized by stepwise incremental light intensities showed a positive effect on biomass and lipid accumulation. The lipid productivity (235.49 mg L −1  d −1 ) attained under light-feeding strategy V (time-averaged light intensity: 225 μmol m −2  s −1 ) was 52.38% higher over that obtained under a constant light intensity of 225 μmol m −2  s −1 . Subsequently, based on light-feeding strategy V, microalgae lipid productivity was further elevated to 312.92 mg L −1  d −1 employing a two-stage based light-feeding strategy V 560 (time-averaged light intensity: 360 μmol m −2  s −1 ), which was 79.63% higher relative to that achieved under a constant light intensity of 360 μmol m −2  s −1 . [ABSTRACT FROM AUTHOR]

2,11,20,29-Tetra- tert -butyl-2,3-naphthalocyanine (TTBNc) was used as an alternative host to support magnesium (Mg) nanoparticles. After deposition and decomposition of dibutylmagnesium on TTBNc, Mg nanoparticles of around 4 nm supported on TTBNc were observed by TEM. These TTBNc stabilized Mg nanoparticles were found to absorb hydrogen at 100 °C and release hydrogen from 75 °C. The Mg-TTBNc material showed good hydrogen cycling properties and structural stability. Kinetic measurements showed fast hydrogen absorption within 2 min at 150 °C. The hydrogen desorption kinetics were slower at the same temperature but faster at 250 °C with 80% of the hydrogen desorbed within 1 h. Enthalpy and entropy for hydrogen uptake and release in Mg-TTBNc determined from PCT measurements were found to be of 52.7 ± 4.9 kJ mol −1 H 2 and 107.8 ± 9.4 J K −1 mol −1 H 2, respectively. These values are much lower than those of bulk Mg. [ABSTRACT FROM AUTHOR]

Aiming at alleviating the adverse effect of poor light penetrability on microalgae growth, planar waveguide modules functioned as diluting and redistributing the intense incident light within microalgae culture more homogeneously were introduced into a lab-scale open raceway pond (ORP) for Nannochloropsis oculata cultivation. As compared to the conventional ORP, the illumination surface area to volume ratio and effective illuminated volume percentage in the proposed ORP were respectively improved by 5.53 times and 19.68–172.72%. Consequently, the superior light distribution characteristics in the proposed ORP contributed to 193.33% and 443.71% increase in biomass concentration and lipid yield relative to those obtained in conventional ORP, respectively. Subsequently, the maximum biomass concentration (2.31 g L −1 ) and lipid yield (1258.65 mg L −1 ) was obtained when the interval between adjacent planar waveguide modules was 18 mm. The biodiesel produced in PWM-ORPs showed better properties than conventional ORP due to higher MUFA and C18:1 components proportions. [ABSTRACT FROM AUTHOR]

Interval between adjacent planar waveguides and light intensity emitted from waveguide surface were the primary two factors affecting light distribution characteristics in the planar waveguide flat-plate photobioreactor (PW-PBR). In this paper, the synergy effect between light and nitrate in the PW-PBR was realized to simultaneously enhance microalgae growth and lipid accumulation. Under an interval of 10 mm between adjacent planar waveguides, 100% of microalgae cells in regions between adjacent waveguides could be illuminated. Chlorella vulgaris growth and lipid accumulation were synchronously elevated as light intensities emitted from planar waveguide surface increasing. With an identical initial nitrate concentration of 18 mM, the maximum lipid content (41.66% in dry biomass) and lipid yield (2200.25 mg L −1 ) were attained under 560 μmol m −2 s −1 , which were 86.82% and 133.56% higher relative to those obtained under 160 μmol m −2 s −1 , respectively. The PW-PBR provides a promising way for microalgae lipid production. [ABSTRACT FROM AUTHOR]

Industrially manufactured planar waveguides doped with light scattering nanoparticles, which can dilute and redistribute the intense incident light within microalgae suspension more uniformly, were introduced into a flat-plate photobioreactor (PBR) with a width of 25 cm to alleviate the adverse effect of poor light penetrability on microalgae growth. Compared with the flat-plate PBR without waveguides, the illumination surface area per unit volume in the proposed PBR was increased by 10.3 times. During the whole cultivation period, the illuminated volume fractions in the proposed PBR were 21.4–410% higher than those in the flat-plate PBR without waveguides. Consequently, attributed to the optimized light distribution in the proposed PBR, a 220% improvement in biomass production was obtained relative to that in the flat-plate PBR without waveguides. Furthermore, higher light output intensities emitted from the planar waveguide surfaces and increased microalgae growth rates were achieved by decreasing the length of planar waveguides. [ABSTRACT FROM AUTHOR]

To improve light penetrability and biomass production in batch cultivation, a cultivation mode that periodically pre-harvesting partial microalgae cells from suspension with culture medium recycling was proposed. By daily pre-harvesting 30% microalgae cells from the suspension, the average light intensity in the photobioreactor (PBR) was enhanced by 27.05–122.06%, resulting in a 46.48% increase in total biomass production than that cultivated in batch cultivation without pre-harvesting under an incident light intensity of 160 μmol m −2 s −1 . Compared with the semi-continuous cultivation with 30% microalgae suspension daily replaced with equivalent volume of fresh medium, nutrients and water input was reduced by 60% in the proposed cultivation mode but with slightly decrease (12.82%) in biomass production. No additional nutrient was replenished when culture medium recycling. Furthermore, higher pre-harvesting ratios (40%, 60%) and lower pre-harvesting frequencies (every 2, 2.5 days) were not advantageous for the pre-harvesting cultivation mode. [ABSTRACT FROM AUTHOR]

To offset the adverse effects of light attenuation on microalgae growth, hollow polymethyl methacrylate (PMMA) tubes were embedded into a flat-plate photobioreactor (PBR) as light guides. In this way, a fraction of incident light could be transmitted and emitted to the interior of the PBR, providing a secondary light source for cells in light-deficient regions. The average light intensity of interior regions 3–6 cm from surfaces with 70 μmol m −2 s −1 incident light was enhanced 2–6.5 times after 3.5 days cultivation, resulting in a 23.42% increase in biomass production to that cultivated in PBR without PMMA tubes. The photosynthetic efficiency of microalgae in the proposed PBR was increased to 12.52%. Moreover, the installation of hollow PMMA tubes induced turbulent flow in the microalgae suspension, promoting microalgae suspension mixing. However, the enhanced biomass production was mainly attributed to the optimized light distribution in the PBR. [ABSTRACT FROM AUTHOR]

[Display omitted] • Suspended microalgal growth are confronted with poor availability of light and CO 2. • Enhancing light and CO 2 transfer are crucial to the design of high-efficiency PBRs. • Built-in illuminants and light-guiding materials can realize internal illumination. • Size and residence time of bubbles exhibit significant impact on CO 2 mass transfer. • More efforts are needful to achieve a breakthrough on microalgal biomass density. Inhomogeneous light distribution and poor CO 2 transfer capacity are two critical concerns impeding microalgal photosynthesis in practical suspended photobioreactors (PBRs). To provide valuable guidance on designing high-performance PBRs, recent progress on enhancing light and CO 2 availabilities is systematically summarized in this review. Particularly, for the first time, the strategies on elevating light availability are classified and discussed from the perspectives of increasing incident light intensity, introducing internal illumination, optimizing flow field, regulating biomass concentrations, and enlarging illumination surface areas. Meanwhile, the strategies on enhancing CO 2 light availability are outlined from the aspects of generating smaller bubbles, extending bubbles residence time, and facilitating CO 2 dissolution using extra additives. Given the microalgal biomass production using current PBRs are still suffering from low productivity and economic feasibility, the possible future directions for PBRs implementation and development are presented. Altogether, this review is beneficial to furthering development of PBRs as a practical technology. [ABSTRACT FROM AUTHOR]

Porous carbons produced using poplar sawdust are promising CO 2 adsorbent applied under ambient conditions due to the low-cost preparation approach. CO 2 uptake capability of the porous carbons produced from poplar sawdust can be effectively enhanced via doping an approximate amount of microalgae. The N-doped porous carbon produced from poplar sawdust using microalgae as N-doping source (microalgae/poplar sawdust=0.5:1) possesses an excellent capacity of 4.14 mmol·g−1 for CO 2 uptake, nearly over 1.7 times that of the carbon without N-doping. The improved performance for CO 2 uptake of porous carbons is mainly ascribed to the two-fold effect of microalgae doping: (i) generating extensive narrow pores and channels within the porous carbons owe to co-pyrolysis; (ii) introduction of N-containing moieties derived from the intrinsic N of microalgae increasing the surface polarity and alkalinity. The N-doped porous carbon granules derived from poplar sawdust are inferior to the powdered porous carbons for CO 2 adsorption due to the destroyed structure. They still maintain the relatively desirable capability for CO 2 adsorption (~3.0 mmol·g−1 during 5 cycles) and good mechanical property (10.96 ± 1.43 Mpa). Comprehensively considering the advantaged properties (low-pressure drop, high bulk density) required for practical application, the N-doped porous carbon granules derived from poplar sawdust with low-doping of renewable microalgae possess strong practicability. [Display omitted] • Microalgae replaces the chemical N-containing reagents as the N-doping source. • Microalgae doping plays a two-fold role in enhancing CO 2 adsorption for porous carbon. • N-doped, sawdust-derived porous carbons exhibit desirable CO 2 adsorption capacity. • N-doped, sawdust-derived porous carbon extrudates possess superior practicability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Algae inoculation is not the essential requirement for algal-bacterial granules. • Formation of algal-bacterial granules with various inocula are summarized. • Multi-scale transfer phenomena involved in bioreactors are analyzed. • Advances in algal-bacterial granule-based bioreactors are reviewed. • Future development directions of algal-bacterial granules systems are outlined. Aiming at deepening the understanding of the formation and evolution of emerging microalgal-bacterial granule (MBG)-based wastewater treatment systems, the recent advances regarding the formation processes, transfer phenomena, innovative bioreactors development and wastewater treatment performance of MBG-based systems are comprehensively reviewed in this work. Particularly, the successful establishments of MBG-based systems with various inocula are summarized. Besides, as the indispensable factors for biochemical reactions in MBGs, the light and substrates (organic matters, inorganic nutrients, etc) need to undergo complicated and multi-scale transfer processes before being assimilated by microorganisms within MBGs. Therefore, the involved transfer phenomena and mechanisms in MBG-based bioreactors are critically discussed. Subsequently, some recent advances of MBG-based bioreactors, the application of MBG-based systems in treating various synthetic and real wastewater, and the future development directions are discussed. In short, this review helps in promoting the development of MBG-based systems by presenting current research status and future perspectives. [ABSTRACT FROM AUTHOR]

Aiming at alleviating the adverse effects on attached microalgae biofilm growth caused by heterogeneous spatial light distributions within the attached cultivation photobioreactors (PBRs), an innovative PBR integrated with stacked horizontal planar waveguide modules (SHPW-PBR) was proposed in this work. Different from the conventional PBR, the emergent light from the external LED light bars were guided and evenly redistributed within the SHPW-PBR by the planar waveguides and hence provided light energy for microalgae cells photoautotrophic growth. In comparison with the control PBR, the average light intensity illuminating the attached Chlorella vulgaris biofilm in the SHPW-PBR was elevated by 204.11% and contributed to a 145.20% improvement on areal C. vulgaris biofilm production. Thereafter, responses of attached C. vulgaris biofilm growth in the SHPW-PBR to various light intensities were evaluated and the maximum areal C. vulgaris biofilm density reached 90.43 g m−2 under the light intensity of 136 μmol m−2 s−1 after 9 days cultivation. Furthermore, the SHPW-PBR can be easily scaled-up by increasing the quantity of the stacked planar waveguide modules and thus shows great potential in biofilm-based biomass production. Unlabelled Image • An attached PBR integrated with stacked planar waveguide modules was proposed. • Uniform spatial light intensity distribution inside the SHPW-PBR was realized. • A 145.20% improvement on areal Chlorella vulgaris biofilm density was achieved. • The maximum areal Chlorella vulgaris biofilm density reached 90.43 g m−2. • The SHPW-PBR can be easily scaled-up and exhibits great potential. [ABSTRACT FROM AUTHOR]

Microalgae biofilm photobioreactors (PBRs) have been gaining more and more attention worldwide attributed to their advantages of lower water requirement and simpler harvesting process. In this work, aiming at enhancing microalgae biofilm growth and gas-liquid mass transfer based on previous biofilm PBRs, a gas-permeable membrane PBR integrated with additional rough surface (GMPBR-RS) was designed. By attaching an additional piece of stainless steel mesh onto the upper surface of the newly prepared gas-permeable membrane, the roughness of the substratum surface for Scenedesmus obliquus biofilm adhesion was enhanced and therefore resulted in a 28.27% improvement in areal biomass density of S. obliquus relative to the control PBR. Moreover, responses of S. obliquus biofilm adsorption growth and CO 2 fixation in the GMPBR-RS to various liquid flow rates and gas flow rates were investigated. Notably, the maximum areal biomass density of S. obliquus biofilm and CO 2 removal efficiency of the GMPBR-RS reached 31.44 g m−2 and 65.05%, respectively. • Roughness of substratum surface for S. obliquus biofilm adhesion was improved. • A novel waterproof gas-permeable membrane was designed. • 28.27% improvement in areal biomass density of S. obliquus biofilm was achieved. • The maximum CO 2 removal efficiency in the designed GMPBR-RS reached 65.05%. [ABSTRACT FROM AUTHOR]

In this study, Zn2+-substituted Li 2 MgSiO 4 ceramics (Li 2 (Mg 1-x Zn x)SiO 4 , x = 0.00, 0.05, 0.10, 0.15, and 0.20) were synthesized using a traditional solid-state method. A fixed amount of LiF sintering aid (1.5 wt%) was added to the ceramics for decreasing the sintering temperature and adjusting their microwave dielectric properties. X-ray diffraction (XRD) results revealed no secondary phases, and scanning electron microscopy (SEM) data suggest that the Zn2+ ion substitution increased the size and uniformity of the grains, thereby affecting the densification of the prepared ceramics. The maximum bulk density (2.94 g/cm3) was found in a Zn2+ ion-substituted ceramic with x = 0.10 at a relative density of 94.2% (compared with the XRD theoretical density). Excellent microwave dielectric properties (ε r = 6.28, Q × f = 50400 GHz, and τ f = −145 ppm/°C) can also be obtained at this zirconium content. We believe that the developed ceramics are promising for use as antenna substrates or transmit/receive modules in low-temperature co-firing ceramic applications. [ABSTRACT FROM AUTHOR]

• Distribution feature among the different status of PV arrays is revealed. • New indicators are introduced to comprehensive evaluation operating status of PV arrays. • Reference status array is selected based on the improved objective weight TOPSIS method. • The proposed method can effectively identify the operation status of PV arrays. In the context of rapid development of photovoltaic (PV) power generation, as an aspect of the key equipment that undertakes the photoelectric conversion in PV power plants, the operation status of PV arrays directly affects the power generation efficiency and economic benefits of PV power plants. An accurate evaluation of the PV array operation status can quickly locate operational weak points and provide the benchmark array for fault diagnosis, which has important engineering application value. So, a new method for selecting the operating reference status of PV arrays is proposed in the paper. First, the array Performance Ratio (PR) probability distribution model was established using the non-parametric estimation method, and the comprehensive evaluation indicators of the PV array were determined using the model characteristic indices and output power of the PV array. The technique for order preference by similarity to ideal solution (TOPSIS) method was improved, the reference PV array was selected, and a graded evaluation of the operation status of the PV arrays was designed. This study provides a novel method to evaluate the operation status of PV arrays from the perspectives of power deviation and stability. The effectiveness of the proposed method was verified through empirical analysis. [ABSTRACT FROM AUTHOR]

An oxime extractant of HBL101 was used to directly extract molybdenum (VI) from a strong acid leach solution of Ni–Mo ore. The organic system was optimized in terms of its organic composition and the conditions of extraction and stripping and further characterized in terms of the extraction and stripping kinetics and distribution isotherms and phase separation. More than 99.8% of the molybdenum was extracted by two-stage counter current extraction using an organic system of 10%HBL101 + 5%TBP + 85% sulfonated kerosene and a feed containing 14.7 g/L of Mo and 4 mol/L H + with an A/O ratio of 1:1.5 at 30 °C for 5 min. The loaded organic was stripped using ammonia solutions after scrubbing with de-ionized water. The stripping of molybdenum was completed by three-stage counter current stripping using 6 mol/L of NH 3 ·H 2 O with an A/O ratio of 1:4 at 30 °C for 20 min, resulting in the separation of molybdenum over nickel, iron, calcium, magnesium, aluminum, copper and zinc, and the enrichment and transformation of the molybdenum. The concentration of molybdenum in the strip liquor of pure (NH 4 ) 2 MoO 4 solutions reached 33.42 g/L and increased to as high as 143.67 g/L after reflux stripping. The extractant of HBL101 exhibited good performance and stability for reuse. [ABSTRACT FROM AUTHOR]

Highlights: [•] Addition of template in synthesized Al2O3 resulted in the difference in pore textures. [•] All studied Al2O3 behaved as philic adsorbents for formaldehyde. [•] HCHO adsorption capacity was directly with the surface area and pore volume. [•] The smaller pore size resulted in the higher desorption active energy (E d ). [•] The surface hydroxyl was favorable to the chemical adsorption of HCHO. [ABSTRACT FROM AUTHOR]

This work presents a study on the properties of upgraded agro-pellets produced by torrefaction and co-pelletization process, where starch-rich food waste was used as a pellet binder. The impact of blending coal cutting waste (CCW), torrefaction pre-treatment and the use of starch binder on the mechanical properties of agro-pellets were examined. The resulting physical properties of agro-pellets were significantly improved. Thermal decomposition of corn straw (CS) can be divided into three stages. Co-pelleting with a small amount of CCW promote the combustion of CS showing an improved thermodynamic characteristic of torrefied corn straw (TCS). Torrefaction reduces the difference of heat distribution, improving the adaptability of pellet fuel in operation. Both co-pelletization and torrefaction processes lead to reduced concentrations of NO x and SO 2 , increased calorific value of fuel and elevated CO 2 emission per unit mass, which are conducive to pollutants reduction and thermodynamic qualities of agro-pellets. Moreover, life cycle assessment (LCA) analysis indicated that more energy input was required for co-pelletization and torrefaction pre-treatment, consequently leading to an enhanced energy return ratio. [ABSTRACT FROM AUTHOR]

The use of heterogeneous catalysts in the transesterification reaction is an eco-friendly and cost-effective approach for biodiesel production as compared to the homogeneous catalyst-based processes. In this study, a heterogeneous cobalt doping Zn/Al complex oxide was prepared by a simple birch-templating method, and successfully applied to the transesterification of jatropha oil with methanol. The catalyst had strong diffraction peaks of ZnAl 2 O 4 spinel crystal with substitutional doping of amorphous cobalt atom. It had a tendency to achieve a high base strength whilst increasing the specific surface area in the presence of cobalt. By contrast to the impregnation and coprecipitation methods, the crystalline particles from templating method were uniformly distributed on the catalyst surface, thus forming a well-defined tiled network with large amounts of grain-free pores. The exposure of available activity sites resulted in a biodiesel yield of 91.4%. After used several times and recycled, the regenerated catalyst also exhibited good catalytic potency without obvious deactivation. The transesterification kinetics satisfied the Pseudo first order model that controlled by the reaction temperature and catalyst dosage. The thermodynamic parameters of Δ H of 16.7 kJ/mol, Δ S of −284.6 J/mol/K, and Δ G of 140.0 kJ/mol suggested an endothermic, endergonic, and non-spontaneous nature of the reaction. [Display omitted] • Co doped Zn-Al spinel was prepared for biodiesel production by different methods. • Templating method had high specific surface area with pores evenly distributed. • Efficient biodiesel yield above 90% was achieved with low levels of residual metal. • The catalyst exhibited good catalytic potency and reusability after reactivation. • Kinetic and thermodynamic properties of biodiesel production were assessed. [ABSTRACT FROM AUTHOR]

New high-performance materials have attracted much attention due to ever-increasing demands for advanced communication technologies. In present work, Ge-doped Li 3+x Mg 2 Nb 1-x Ge x O 6 (0 ≤ x ≤ 0.08) ceramics are prepared via solid-state reaction route. Microstructural analysis and crystal structure refinement reveal that moderate substitution can promote grain growth and modify crystal structure, thus enhancing microwave dielectric properties of composites. In that sense, special attention is paid to the behavior of dielectric constant ε r , quality factor Q×f , and frequency temperature coefficient τ f of final products. In these systems, ε r parameter depends on the density, miscellaneous phases, and polarizability; Q×f value is shown to be influenced by Nb-O bond energy, grain size, and bulk density; finally, τ f characteristic refers to Nb-O bond valence and NbO 6 octahedral distortion. Among above ceramics, Li 3.02 Mg 2 Nb 0.98 Ge 0.02 O 6 composite sintered at 1250 °C exhibits outstanding microwave absorption performance with ε r = 15.32, Q×f = 969 88 GHz, and τ f = −8.25 ppm/°C. [ABSTRACT FROM AUTHOR]

Highlights • Lignin was successfully depolymerized with in situ hydrogen from isopropanol. • PtRe/TiO 2 exhibited excellent catalytic performance on disrupting C O bonds. • 18.71 wt% monophenols were achieved for acid extracted birch lignin. • The presence of H 2 hindered the depolymerization of lignin. • Yields of monophenols were highly related to the β-O-4 contents in lignin. Abstract Using isopropanol as an in situ hydrogen donor, catalytic transfer hydrogenolysis of lignin into monomeric phenols was studied at mild conditions. The performance of catalysts and the effects of H 2 , temperature, and time on depolymerization of acid extracted birch lignin (ABL) were extensively examined. Platinum-rhenium supported on titanium dioxide (PtRe/TiO 2) exhibited much higher activity on disrupting C O bonds than Pd/C, HZSM-5, Pt/TiO 2 , and Re/TiO 2. 18.71 wt% monophenols was achieved for depolymerization of ABL over PtRe/TiO 2 at 240 °C for 12 h with He. 4-Propylsyringol had the highest yield of 7.48 wt%. 2D HSQC NMR analysis reveals that β-O-4 bonds have been fully disrupted during depolymerization. Addition of H 2 led to less monophenols, likely due to the competitive adsorption of active sites on catalysts. Structure-reactivity analysis based on six representative lignins shows that the total yields of monophenols were highly linearly correlated with the β-O-4 contents (R2 = 0.97). [ABSTRACT FROM AUTHOR]

Highlights • Microwave assissted wet torrefaction with aqueous ammonia was employed on corn stalk. • A significant physicochemical modification was achieved with combined pretreatment. • Pyrolysis of pretreated corn stalk gave more ketones and aldehydes, and less acids. • This study provides a promising way for enhancing bio-oil quality. Abstract The physicochemical characteristics and pyrolysis performance of corn stalk (CS) torrefied in water and aqueous ammonia by microwave heating were investigated. Physicochemical characterization revealed that both microwave water torrefied CS (MCS) and microwave ammonia torrefied CS (MACS) showed low hemicellulose content, disrupted macrostructure, improved porous properties, and low ash content. MACS exhibited a significantly lower crystallinity degree of 44.34% than CS (79.55%) and MCS (89.50%). MACS also showed increased methyl/methylene groups intensity, and complete acetyl groups disrupture. Pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) revealed that compared with CS and MCS, MACS exhibited higher peak areas for ketones, aldehydes, furans and esters, and significantly lower peak areas for acids and phenols. A possible mechanism was proposed for the effects of wet torrefaction with aqueous ammonia on changes in physicochemical structure and pyrolysis behavior of corn stalk. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A perforated inverted arc trough internals was proposed to promote CO 2 bio-fixation. • Gas–liquid contact time was prolonged from 0.448 s to 256 s by the PIAT internals. • Dissolved CO 2 concentration in microalgae culture of PIAT-PBR increased by 26.0%. • 20.9% and 26.2% increase in biomass productivity and CO 2 fixation rate were obtained. • The maximum CO 2 fixation rate by Chlorella vulgaris reached to 36.6 mg L−1 h−1. Abstract Flat-plate photobioreactor (PBR) with perforated inverted arc trough (PIAT) internals was proposed to promote CO 2 bio-fixation by microalgae. The PIAT internals can enhance CO 2 transfer from gas to culture medium by prolonging CO 2 gas–liquid contact time and generate periodic aeration in the suspension upper side the PIAT providing suspension mixing. Experimental results showed gas–liquid contact time was prolonged from 0.448 s to 256 s and the CO 2 partial pressure inside the PIAT internals was about 15.5 kPa during microalgae cultivation. Consequently, the dissolved CO 2 concentration in the microalgae suspension of the proposed PBR was increased by 26.0% compared to that in the PBR without PIAT internals when 15% CO 2 (v/v) was aerated at a rate of 15 mL min−1. The elevated CO 2 transfer contributed to a 20.9% increment in biomass concentration (3.35 g L−1) and a 26.2% increment in CO 2 fixation rate (36.6 mg L−1 h−1). [ABSTRACT FROM AUTHOR]

[Display omitted] • Binary catalysts of Ru/C and H 2 WO 4 promote native lignin depolymerization efficiently. • 40.4 wt% monophenols were afforded from birch lignin at 200℃ upon Ru/C and H 2 WO 4. • H 2 WO 4 promotes the solvolysis of lignin, and Ru/C enhances the reductive cracking. • β-O-4 bonds in the soluble lignin fragments were fully disrupted. • The binary catalysts can be readily recovered for reuse. Herein, using Ru/C and H 2 WO 4 as the catalysts, native lignin in biomass was efficiently depolymerized into monophenols following the lignin-first strategy at mild conditions. Upon the co-presence of Ru/C and H 2 WO 4 , birch lignin afforded monophenols in 40.4 wt% yield at 200 °C, which was 2.5 times that upon Ru/C and 7.5 times that upon H 2 WO 4. 4-Propylsyringol and 4-propylguaiacol were two major products with a combined selectivity of 73%. 2D HSQC NMR of liquid product reveals that β-O-4 bonds in the soluble lignin fragments had been thoroughly disrupted. H 2 WO 4 dissolving at high temperatures promoted the solvolysis of lignin from the biomass matrix, and Ru/C enhanced the following reductive depolymerization. The solid catalysts can be readily recovered for reuse at room temperature after the hydrolysis of carbohydrates, and the catalysts exhibited high activity after four recycles. [ABSTRACT FROM AUTHOR]

Attachment of cells to substrate surface is the premise for biofilm formation. To shelter microalgae cells from fluid shear stress and offer larger areas for microalgae attachment, the inerratic microgrooves, which can act as anchor points that offer larger areas for microalgae attachment and induce vortex to protect cells from hydraulic shear stress, were designed and fabricated into substrate surface. The results indicated that the shear stress on the surface with V-grooves was weaker than that on the surface with U-grooves, and 45° V-grooves with the width of 200 μm were benefit for cells attachment. The initial attachment time was shortened to 50 min under the hydraulic shear stress of 0.02 Pa compared to that of 135 min on the surface without microgrooves. Subsequently, the biofilm biomass concentration on the surface with 45° V-grooves increased by 14.29% to 165.84 g m −2 compared with that on flat substrates. [ABSTRACT FROM AUTHOR]

S, N-codoped porous carbons (NSPCs) were synthesized from 4-cyanophenol, thiourea and formaldehyde based on benzoxazine chemistry with KOH chemical activation at different temperatures. The textural and chemical properties of NSPCs were characterized in detail by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N 2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy (XPS) and elemental analysis. The resulting porous carbons possess high volume of pores smaller than 1.5 nm, which exhibit good adsorptive desulfurization performance with high maximum adsorptive capacity of dibenzothiophene (DBT) from 69.81 to 83.34 mg S/g. Furthermore, NSPC-2 shows good selectivity in adsorptive process for aromatic-containing model fuel, due to its abundant surface functionalities. More than 77% adsorption capacity of NSPC-2 can still be recovered after 5 times adsorptive experiments. [ABSTRACT FROM AUTHOR]

Different from current harvesting methods, the aim of this study was to concentrate microalgae by removing the medium with polyacrylic superabsorbent polymers (PSAPs). This method can concentrate freshwater microalgae Chlorella sp. at a relatively high biomass concentration of 90.23 g L −1 . Without further dewatering, the concentrated microalgae can be directly used to produce biofuels by oil extraction or fermentation. The kinetic characteristics of PSAPs swelling in different solutions were investigated. The results indicate that the negative influence on absorbency caused by ionic strength was greater than microalgae concentration. Compared with the diffusion part, water absorbed by the relaxation of PSAPs was dominant and accounted for over 97%. Equilibrium absorbed water equations under different microalgae concentration were fitted and could provide guide to quantifiably concentrate microalgae. Increasing temperature decreased the absorbency of PSAPs, while, the absorption and desorption rate were increased. Moreover, the absorbency remained at 91.45% after recycling three times. [ABSTRACT FROM AUTHOR]

An eco-friendly and efficient process for extractive and biomimetic catalytic oxidative desulfurization in fuel oil under mild conditions with H 2 O 2 as oxidant, ionic liquids as extractant and Fe(III) porphyrins as catalysts was reported. The catalytic reactivity of different Fe(III) porphyrins had been investigated in ionic liquids, and the catalysts showed good stability and performance in [Bmim]PF 6 . The possible mechanism seemed that sulfur-containing compound was oxidized to corresponding sulfone with [(Porp)Fe III -OOH] or/and [(Porp)Fe III (O) +· ], which generated in ionic liquids phase. The different reaction conditions such as temperature, mole ratio of H 2 O 2 and sulfur compounds were investigated in the catalytic system with Fe(III)(p-CH 3 TPP)Cl (catal. III) and [Bmim]PF 6 . The system could be recycled 6 times without obvious decrease of desulfurization efficiency. The reaction system was also applied for the desulfurization of a real diesel fuel. [ABSTRACT FROM AUTHOR]