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Carbon spheres, prepared by hydrothermally treating fresh potato starch, is employed as the sulfur host to configure a high-performance cathode substrate candidate for Li–S batteries. As confirmed by experimental results, both the improved the rate and cycle performances of Li–S batteries cathode with gradient sulfur immobilization, are mainly attributed to the confining, adsorption and conduction multi-functions of as-prepared carbon spheres toward polysulfides. Specifically, on starting the discharging/charging cycles, the active material α-S8 is irreversibly converted to polysulfides and then transformed between β-S8 and polysulfides during the next charge/discharge cycles. After initialization at 0.1C for 3 cycles, the initial reversible discharge capacities of the Li–S batteries cathode with optimized sulfur amount are 1072.5, 831.3, 780.4, 726.8, 714.3, 702.7 mAh g−1sulfur at 0.1, 0.5, 1, 2, 3 and 4 C, which is superior to those of the most previously reported reports. Besides that, as-designed potato-derived carbon based composite cathodes exhibits remarkable rate performance and cycling stability even at wide temperature ranging from −40 to 60 °C, which evidently supports the dominant role of as-prepared 3D carbon spheres in boosting the cathode performance for Li–S batteries.

Sweet potato-derived carbon with a unique solid core/porous layer core/shell structure is used as a conductive substrate for gradually immobilizing sulfur to construct a cathode for Li-S batteries. The first discharge specific capacity of the Li-S batteries with the C-10K@2S composite cathode at 0.1C is around 1645 mAh g-1, which is very close to the theoretical specific capacity of active sulfur. Especially, after 175 cycles at 0.5C, the maintained specific discharge capacities of the C-10K@2S cathode at -20, 0, 25, and 40 °C are about 184.9, 687.2, 795.5, and 758.3 mAh g-1, respectively, and the cathode is superior to most of the classical carbon form matrices. Working mechanisms of the cathodes under different temperatures are confirmed based on X-ray photoelectron spectroscopy (XPS) and in situ X-ray diffraction (XRD) characterizations. Distinctively, during the discharge stage, the widely proposed two-step cathodic reactions occur simultaneously rather than sequentially. In addition, the largely accelerated phase conversion efficiency of the cathode at a higher temperature (from room temperature to 40 °C) contributes to its enhanced charge/discharge specific capacity, while the byproduct Li2S2O7 or Li3N irreversibly formed during the cycles limits its application performance at 0 °C. These conclusions would be very significant and useful for designing cathodes for Li-S batteries with excellent wide working temperature performance.

Only a few studies have described the use of H+-attacking S-EDA in nucleophilic substitution reactions to bind frameworks and sulfur in cathode materials, which is also known as the ion-exchange method. The pros and cons of this method are still unclear in relation to lithium–sulfur battery applications. Here, the influences of two synthetic routes, a melt-diffusion method and H+ reacting with S-EDA via nucleophilic substitution, on the morphologies and electrochemical properties of cathode materials are discussed in detail based on in situ XRD and other advanced technologies. Accordingly, high S-loading is achieved when H+ reacts with S-EDA via ion exchange on the surface of acetylene black, and capacities of 693.8, 644.5, and 638.9 mA h g−1 are obtained over the first three cycles when the C/S composite is used as a cathode in coin cells without the conductive additive Super P. In situ XRD data confirm that poor electrochemical properties can mainly be attributed to the conversion rate of S species being too rapid to thoroughly utilize the S molecules that are immobilized, which means that more fixed sulfur can form during the charge/discharge process when using the ion-exchange method to make the C/S composite. In addition, a long-chain polysulfide shuttling effect is directly noticed via AFM in tapping-KPFM mode in the C/S composite that was synthesized via the melt-diffusion method, even though polar S–O bonds exist in the composite. The increase in the cathodic surface potential from 102.8 to 141.1 mV and the increase in the morphological height from 547.7 to 829.7 nm during the discharge/charge process can be attributed to the process of S loss.

To effectively avoid the shuttle effect of polysulfides between the cathode and anode, a boron nitride (BN)-Ketjenblack-xKOH@S composite (x means 1, 2, and 3 M) cathode for lithium–sulfur batteries...

The structure and property evolution of graphene oxide (GO) during low-temperature (≤200 °C) reduction is related to the economically effective production and many behaviors of graphene-based materials, such as property tuning and long-term stability at high working temperatures. The interfacial effects on the physiochemical processes are yet to be quantified experimentally. Here, combining scanning polarization force microscopy with UV–vis absorption spectra, the formation and expansion of sp2 domains on individual single-layered GO sheets and the opto-electronic behaviors of GO films on average at low temperatures are in situ monitored. Kinetics of the interfacial evolutions are examined. Surprisingly, unexpected faster evolution of GO sheets at interfaces than that in bulk water is observed. We find this discrepancy can be addressed if the water atmosphere is taken into account and the humidity dependence of evolution is verified. Environmental water and asymmetric moisturizing of GO are believed to play important roles in the process. Based on this, the evolution rate is modulated via adjusting the humidity. The findings shed light on the interfacial structure and property evolution processes of GO and open a new avenue to manipulate the evolution rates at low temperatures.

A sodium acetate trihydrate (SAT)-urea binary eutectic mixture was developed as a phase change material (PCM). Using the differential scanning calorimetry (DSC) experiment and synthetic visual meth...

This paper systematically studied the extraction process of total flavonoids from quinoa and the kinetics of macroporous resin purification. On the basis of single-factor experiments, the optimum extraction and purification process of total flavonoids from quinoa was studied by orthogonal experiments. The results showed that the optimum extraction conditions were as follows: ultrasonic time 25 min, temperature 200 °F, solid-liquid ratio 1:10 (g/mL), reflux time 2 h, and ethanol concentration 90%. Under this condition, the total flavonoids extracted from quinoa was 3.859 mg/g. Fifteen percent NaCl was added to salt out protein from flavonoid solution. The best macroporous resin purification process was as follows: pH 2, flow rate 2 BV/h, 0.3 mg/mL flavonoid solution loading, 8 BV water wash with acetone elution. Under this condition, the adsorption rate of purified flavonoids was 80.89%. The purity can be increased from 7.09% of the initial extract to 28.48%.

In this study, a Ni-Co-Mn-Cd-based precursor was synthesized using a solvothermal method and the Li(Ni0.6Co0.2Mn0.2O2)xCd1-xO2 cathode materials were prepared using a high-temperature solid-phase method. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to determine the morphology, structure, elemental composition, and electronic state of the pristine and Cd-doped cathode materials. The electrochemical tests indicated that the Cd-doped samples exhibited better electrochemical performance than the pristine material; specifically, at a doping amount of 0.01 mol, the initial discharge capacity was 186.3 mAh g−1 with a capacity retention of 87.49% after 200 cycles at a current rate of 0.5 C and a capacity retention of 72.43% after 300 cycles at a current rate of 2 C, whereas the pristine material only had an initial capacity of 173.2 mAh g−1 and a capacity retention of 61.25% and 41.09% for the same current rate and cycle number, respectively. In addition, at 8 C, the discharge capacity was 129.8 mAh g−1 for the Cd-doped samples but only 119.6 mAh g−1 for the pristine material. The enhanced electrochemical performance was attributed to the in situ doping modification during the synthesis process of the precursor. This approach effectively stabilized the crystal structure, improved the electronic conductivity of the material, and reduced the impact of the hydrofluoric acid (HF) on the electrode surface due to the generation of CdF2 during the cycle process.

Background: Common buckwheat (Fagopyrum esculentum) is an important staple food crop in southwest China, where drought stress is one of the largest limiting factors that lead to decreased crop production. To reveal the molecular mechanism of common buckwheat in response to drought stress, we performed a comprehensive transcriptomics study to evaluate gene expression profiles of common buckwheat during PEG-mediated drought treatment. Results: In total, 45 million clean reads were assembled into 53,404 unigenes with an average length of 749 bp and N50 length of 1296 bp. A total of 1329 differentially expressed genes (DEGs) were identified by comparing well-watered and drought-treated plants, out of which 666 were upregulated and 663 were downregulated. Furthermore, we defined the functional characteristics of DEGs using GO and KEGG classifications. GO enrichment analysis showed that the DEGs were significantly overrepresented in four categories, namely, “oxidoreductase activity,” “oxidation–reduction process,” “xyloglucan:xyloglucosyl transferase activity,” and “apoplast.” Using KEGG pathway analysis, a large number of annotated genes were overrepresented in terms such as “plant hormone signal transduction,” “phenylpropanoid biosynthesis,” “photosynthesis,” and “carbon metabolism.” Conclusions: These results can be further exploited to investigate the molecular mechanism of common buckwheat in response to drought treatment and could supply with valuable molecular sources for abiotic-tolerant elite breeding programs in the future.How to cite: Wu Q, Zhao G, Bai X et al. Characterization of the transcriptional profiles in common buckwheat (Fagopyrum esculentum) under PEG-mediated drought stress. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.03.005. Keywords: Abiotic stress, Aluminum, Chlorophyll-binding proteins, Common buckwheat (Fagopyrum esculentum), Differentially expressed genes (DEGs), Drought stress, RNA sequencing, Transcription factor, Transferase, Triticum

Taking the importance and significance of wastewater treatment into consideration, mono-dispersed Mn2O3 powders with sphere-like morphology and mesopore features has been firstly synthesized from the thermal decomposition of MnCO3 which is prepared via a modified carbonization method using CO2 gas as the sole carbonate source. The measured isoelectric point, the pH value at which the ζ-potential is zero, of uniformly dispersed Mn2O3 particles is 9.13. Benefiting from the surface electrostatic interaction, as-prepared Mn2O3 microparticles has high adsorption capacity up to 135.5 mg/g toward Congo red dye in aqueous solution. Accordingly, the adsorption process of Congo red by Mn2O3 microspheres could be explained by Langmuir isotherm model and the pseudo-second-order kinetic model. Especially, it is necessary to point out that the removal efficiency of Mn2O3 toward Congo red dye still be well maintained at about 90.78% even after five cycles. Therefore, as-prepared Mn2O3 powders has potential application in large-scale wastewater treatment.

In this study, we have successfully coated the CeO2 nanoparticles (CeONPs) layer onto the surface of the Ni-rich layered LiNi0.7Co0.2Mn0.1O2 cathode materials by a wet chemical method, which can effectively improve the structural stability of electrode. The X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) are used to determine the structure, morphology, elemental composition and electronic state of pristine and surface modified LiNi0.7Co0.2Mn0.1O2. The electrochemical testing indicates that the 0.3 mol% CeO2-coated LiNi0.7Co0.2Mn0.1O2 demonstrates excellent cycling capability and rate performance, the discharge specific capacity is 161.7 mA h g−1 with the capacity retention of 86.42% after 100 cycles at a current rate of 0.5 C, compared to 135.7 mA h g−1 and 70.64% for bare LiNi0.7Co0.2Mn0.1O2, respectively. Even at 5 C, the discharge specific capacity is still up to 137.1 mA h g−1 with the capacity retention of 69.0%, while the NCM only delivers 95.5 mA h g−1 with the capacity retention of 46.6%. The outstanding electrochemical performance is assigned to the excellent oxidation capacity of CeO2 which can oxidize Ni2+ to Ni3+ and Mn3+ to Mn4+ with the result that suppress the occurrence of Li+/Ni2+ mixing and phase transmission. Furthermore, CeO2 coating layer can protect the structure to avoid the occurrence of side reaction. The CeO2-coated composite with enhanced structural stability, cycling capability and rate performance is a promising cathode material candidate for lithium-ion battery.

Figure S1. Dated phylogeny of Saussurea. Figure S2. Dated phylogeny showing the diversification time of three clades of Saussurea. Figure S3. Posterior probability of each shift rate in the BAMM analysis. Figure S4. Rate-through-time plot from the TESS analysis. Figure S5. Speciation rates of four morphology-based subgenera of Saussurea estimated by DR statistic. Figure S6 Paleoenvironment-dependent diversification processes in Saussurea. Figure S7. Multistate trait dependent diversification of Saussurea estimated from MuSSE analysis. Figure S8. PCA results of eight bioclimatic variables representing climate lability of Saussurea species. Table S1. Summary of diversification analyses Table S2. Sample information in the present study. Table S3. Traits coding regime in the present study. Table S4. HiSSE models used in the present study. Table S5. Speciation rates of Saussurea species estimated from BAMM and DR statistic. Table S6. Results of RPANDA analyses. Table S7. Results of the diversity-dependence diversification analyses for Saussurea. Table S8. Model comparison of HiSSE analysis for four binary traits of Saussurea. Table S9. Summary table of the mean rate values for four binary traits in HiSSE and FiSSE analysis. Table S10. Model comparison of MuSSE analysis for multistate traits of Saussurea. Table S11. Summary table of ecological factors for correlation with diversification rates of Saussurea species. Table S12. Model comparison of QuaSSE analysis for correlation between ecological factors and speciation rates of Saussurea. Table S13. Results of ES-sim tests for correlation between speciation rate and continuous ecological factors. Supplementary Data S1. GBIF-mediated data citations.

With the increasing application of nanomaterials, evaluation of the phytotoxicity of nanoparticles has attracted considerable interest. Buckwheat is an economically pseudocereal crop, which is a potential model for investigating the response of plants to hazardous materials. In this study, the response of buckwheat to graphene oxide (GO) was investigated by integrating physiological and transcriptome analysis. GO can penetrate into buckwheat root and stem, and high concentrations of GO inhibited seedlings growth. High concentration of GO improved ROS production and regulated the activities and gene expression of oxidative enzymes, which implying GO may affect plant growth via regulating ROS detoxification. Root and stem exhibit distinct transcriptomic responses to GO, and the GO-responsive genes in stem are more enriched in cell cycle and epigenetic regulation. GO inhibited plant hormone biosynthesis and signaling by analyzing the expression data. Additionally, 97 small secreted peptides (SSPs) encoding genes were found to be involved in GO response. The gene expression of 111 transcription factor (TFs) and 43 receptor-like protein kinases (RLKs) were regulated by GO, and their expression showed high correlation with SSPs. Finally, the TFs-SSPs-RLKs signaling networks in regulating GO response were proposed. This study provides insights into the molecular responses of plants to GO.

This paper systematically studied the extraction process of total flavonoids from quinoa and the kinetics of macroporous resin purification. On the basis of single-factor experiments, the optimum extraction and purification process of total flavonoids from quinoa was studied by orthogonal experiments. The results showed that the optimum extraction conditions were as follows: ultrasonic time 25 min, temperature 200 °F, solid-liquid ratio 1:10 (g/mL), reflux time 2 h, and ethanol concentration 90%. Under this condition, the total flavonoids extracted from quinoa was 3.859 mg/g. Fifteen percent NaCl was added to salt out protein from flavonoid solution. The best macroporous resin purification process was as follows: pH 2, flow rate 2 BV/h, 0.3 mg/mL flavonoid solution loading, 8 BV water wash with acetone elution. Under this condition, the adsorption rate of purified flavonoids was 80.89%. The purity can be increased from 7.09% of the initial extract to 28.48%.

The relationship between ζ-potential and surface defects of micro-nano sized hexagram-like α-Al2O3 particles was investigated in this paper. The 2D α-Al2O3 particles was prepared by the phase transformation of gibbsite precursor by the following steps during calcination in air: Al(OH)3 → AlOOH→a-Al2O3 → θ-Al2O3 → α-Al2O3. Resulting from the varied intensities of surface defects, as-prepared α-Al2O3 samples have different Eg values around 4.5 eV, which is much narrower than that of bulk α-Al2O3. While benefiting from the interface reaction between surface > AlOH0 and water (>AlOH0 + OH−⇋ > AlO− + H2O), as-prepared α-Al2O3 suspensions can reach their specific pHE values after stirring for 8 h at room temperature. And the measured IEP values of Al2O3-1250°C-2 h, Al2O3-1250°C-3 h, and Al2O3–1300 °C-3 h, which remain 2D morphology, are 7.96, 8.67, and 8.86, respectively. This study is significant and useful for making the industrial applications of α-Al2O3 valid.

Herein, we present the use of lithium tetrafluoroborate (LiBF4) as an electrolyte salt for wide-temperature electrolytes in lithium-ion batteries. The research focused on the application of blend salts to exhibit their synergistic effect especially in a wide temperature range. In the study, LiCoO2 was employed as the cathode material; LiBF4 and lithium difluoro(oxalate)borate (LiODFB) were added to an electrolyte consisting of ethylene carbonate (EC), propylene carbonate (PC), and ethyl methyl carbonate (EMC). The electrochemical performance of the resulting electrolyte was evaluated through various analytical techniques. Analysis of the electrical conductivity showed the relationship among solution conductivity, the electrolyte composition, and temperature. Cyclic voltammetry (CV), charge-discharge cycling, and AC impedance measurements were used to investigate the capacity and cycling stability of the LiCoO2 cathode in different electrolyte systems and at different temperatures. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were applied to analyze the surface properties of the LiCoO2 cathode after cycling. The results indicated that the addition of a small amount of LiODFB into the LiBF4-based electrolyte system (LiBF4/LiODFB of 8:2) may enhance the electrochemical performance of the LiCoO2 cell over a relatively wide temperature range and improve the cyclability of the LiCoO2 cell at 60 °C.

The present study introduces a facile triethanolamine-assisted combustion method, wherein stoichiometric hydrate transition metal acetate with and without the addition of triethanolamine (TEA) were dissolved and mixed uniformly in deionized water and heated to burn. The ashes were then grinded and calcinated to synthesize layered LiNi1/3Co1/3Mn1/3O2 cathode materials. The structure, morphology, and electrochemical performance of two kinds of LiNi1/3Co1/3Mn1/3O2 materials were investigated and compared systematically. The results indicate that the sample with TEA possesses smaller particles and exhibits less aggregation and a better hexagonal layered structure. On the contrary, the sample with TEA exhibits lower polarization, a better cycling ability, a significantly improved rate performance, and better electronic conductivity. The enhanced electronic conductivity and electrochemical performance may be ascribed to a higher combustion enthalpy and better dispersion in the solvent following the introduction of TEA. This simple synthetic strategy presents a promising synthetic model for the enhancement of electrochemical performance cathode materials for lithium-ion batteries.

Li1.6Mn1.6O4 (LMO) is deemed as the most promising candidate for Li+ extraction from brine. However, it suffers from structural collapses and capacity fading during lithium adsorption/desorption cycles. To solve this problem, an effortless one-step dry method was adopted to prepared surface-fluorinated Mn-based ion-sieve materials using NH4F at low temperatures. XRD, FIB-SEM, HRTEM, XPS, and chemical analyses were used to characterize the crystal structure, morphology, surface information, chemical composition, and adsorption properties of the materials. The surface-fluorinated LMO showed an adsorption capacity of up to 31.86 mg g−1, a low dissolution loss ratio of Mn, and remarkable long cycle stability with a capacity retention rate of 91.29%. The main reason for the improved adsorption capacity was that the surface fluorination eroded the material outside and increased the specific surface area. Furthermore, the bond energy and structural stability of the material were enhanced by the F–Mn bond, which partially replaced the surface O–Mn bond. In addition, DFT simulation was theoretically performed to understand the improvement mechanism of the material properties by fluorination. These results provide insights into the surface fluoridation effect in the optimization of Mn-based adsorbents, and the proposed simple modification strategy has the potential to be applied to large-scale production.

Surface evolution of eutectic salt hydrate phase change materials (PCMs) plays an important role in progressive degradation, and its tracking and control are crucial to the cycle stability in latent heat storage. In this study, we combined Peak Force quantitative nanomechanics with differential scanning calorimetry to monitor the topography evolution, nanomechanical performances, and corresponding thermal properties of the eutectic MgCl2·6H2O-Mg(NO3)2·6H2O PCM (EPCM). Topography of the EPCM was highly similar to those of the corresponding single crystallohydrates, accounting for its congruent melting and solidifying behavior. Surface evolution-induced initial phase separation at the nanoscale level was directly imaged. This deterioration is rooted in adsorption/evaporation of the surface water molecules, and can be restored accurately. Based on this, a universal strategy to eradicate phase segregation was proposed, with no significant degradation after 1500 thermal cycles. Moreover, evolution of the EPCM containing thickener hydroxyethyl cellulose and its effects on local supercooling due to the formed crosslinking networks were explored, and stable supercooling inhibition (≤0.6 °C) was achieved. This study provides a better understanding of the evolution mechanism and its effects on the thermal behavior, and can be used as an effective guide for improving the long-term stability of low-cost salt hydrate-based latent heat storage materials.

In this study, Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 cathode materials for lithium-ion battery have been successfully synthesized by triethanolamine(TEA) and ethylene glycol solution assisted co-precipitation technology and solid-state sintering method. Relevant tests (XRD, ICP, SEM) were used to determine the structure, composition and morphology of the Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 cathode materials. The electrochemical tests were performed to evaluate the electrochemical performance of the materials. The results show that the initial discharge capacity is 263.8 mAh g −1 at 0.1C rate in a half battery. Furthermore, this cathode material retains a final capacity of 186 mAh g −1 at 0.5C after 200 cycles and displays an outstanding capacity retention of 98.5%. And all tests prove that the Li 1.2 Ni 0.13 Co 0.13 Mn 0.54 O 2 lithium-rich materials synthesized with TEA and ethylene glycol solution assisted co-precipitation method have excellent electrochemical properties.

Gold as a precious metal resource has high recycling significance. However, the current extraction methods cannot achieve the both efficiency and environmental friendliness. In this paper, we propose a new gold leaching agent, which can leach gold under light condition by mixing iodoform (CHI3) with 1-butyl-3-methylimidazolium dicyanamide (BmimN(CN)2) ionic liquid. Under 25 °C and 13 W incandescent lamp irradiation, the leaching yield of gold can achieve 100 wt%, and the average leaching rate is 945 mg Au/(h·mol·CHI3) (18.9 times of that of the cyanidation method). Through the analysis of the results of radical inhibition experiment, UV-Vis and XPS, a possible leaching mechanism is proposed: the iodine radical generated by light oxidizes Au0 to Au+, and then forms AuN(CN)2 by coordinating with N(CN)2−. Subsequently, the ionic liquid and Au N(CN)2 form a stable [Bmim]·[Au(N(CN)2)2] ion pair structure, further promoting the dissolution reaction. The leaching yield of gold can reach 81.9 wt% and 100 wt%, respectively, when applied to ore and waste electrical and electronic equipment (WEEE), the leaching yield of gold can also reach 100 wt% when applied to a waste catalyst by adding a Soxhlet extraction. The results show that this method is not only efficient, mild, and environmentally friendly, but also has strong adaptability and wide application prospects.

Scanning polarization force microscopy (SPFM) is a useful surface characterization technique to visually characterize and distinguish nanomaterial with different local dielectric properties at nanometer scale. In this paper, taking the individual one-atom-thick graphene oxide (GO) and reduced graphene oxide (rGO) sheets on mica as examples, we described the influences of environmental humidity on SPFM imaging. We found that the apparent heights (AHs) or contrast of SPFM imaging was influenced significantly by relative humidity (RH) at a response time of a few seconds. And this influence rooted in the sensitive dielectric constant of mica surface to the RH change. While dielectric properties of GO and rGO sheets were almost immune to the humidity change. In addition, we gave the method to determine the critical humidity at which the contrast conversion happened under different conditions. And this is important to the contrast control and repeatable imaging of SPFM through RH adjusting. These findings suggest a strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM, which is critically important for further distinguishment, manipulation, electronic applications, etc.

A facile, convenient, and mild method has been developed for large-scale synthesis of uniformly dispersed 2D six-pointed star-like gibbsite micro–nano crystals with lateral size around 2.5 μm and thickness around 100 nm, through a replacement reaction between Al powder and water. Investigation of the influence of solvent in a series allows for conclusion that replacing the reactant solvent water with ethylene glycol not only effectively moderates the reaction, but also benefits control of shape, crystal structure, and dispersibility. In contrast, besides decreasing the reaction speed, the same function cannot be attributed to another inorganic solvent candidate absolute ethanol. This conclusion was supported by XRD, FE-SEM, TEM, FT-IR, TGA and PSD measurements. Moreover, the band gap of as-prepared gibbsite powder in EG–H2O mixture is 5.78 eV, which is mainly attributed to its surface low coordinated O2−. Theoretically, scale-up of this simple synthetic procedure for large-scale production of gibbsite powder with high crystallinity and purity should be very easy.

Background Inflorescence architecture is denoted by the spatial arrangement of various lateral branches and florets formed on them, which is shaped by a complex of regulators. Unveiling of the regulatory mechanisms underlying inflorescence architecture is pivotal for improving crop yield potential. Quinoa (Chenopodium quinoa Willd), a pseudo cereal originated from Andean region of South America, has been widely recognized as a functional super food due to its excellent nutritional elements. Increasing worldwide consumption of this crop urgently calls for its yield improvement. However, dissection of the regulatory networks underlying quinoa inflorescence patterning is lacking. Results In this study, we performed RNA-seq analysis on quinoa inflorescence samples collected from six developmental stages, yielding a total of 138.8 GB data. We screened 21,610 differentially expressed genes (DEGs) among all the stages through comparative analysis. Weighted Gene Co-Expression Network Analysis (WGCNA) was performed to categorize the DEGs into ten different modules. Subsequently, we placed emphasis on investigating the modules associated with none branched and branched inflorescence samples. We manually refined the coexpression networks with stringent edge weight cutoffs, and generated core networks using transcription factors and key inflorescence architecture related genes as seed nodes. The core networks were visualized and analyzed by Cytoscape to obtain hub genes in each network. Our finding indicates that the specific occurrence of B3, TALE, WOX, LSH, LFY, GRAS, bHLH, EIL, DOF, G2-like and YABBY family members in early reproductive stage modules, and of TFL, ERF, bZIP, HD-ZIP, C2H2, LBD, NAC, C3H, Nin-like and FAR1 family members in late reproductive stage modules, as well as the several different MADS subfamily members identified in both stages may account for shaping quinoa inflorescence architecture. Conclusion In this study we carried out comparative transcriptome analysis of six different stages quinoa inflorescences, and using WGCNA we obtained the most highly potential central hubs for shaping inflorescence. The data obtained from this study will enhance our understanding of the gene network regulating quinoa inflorescence architecture, as well will supply with valuable genetic resources for high-yield elite breeding in the future. Electronic supplementary material The online version of this article (10.1186/s12864-019-6027-0) contains supplementary material, which is available to authorized users.

Solid-phase reactions were used for the synthetization of the spinel Li1.6Mn1.6O4 powder and the lithium ion-sieve MnO2·0.5H2O was subsequently obtained by the leaching of the lithium. The physical characterization showed that the polycrystalline precursor and the MnO2·0.5H2O were nearly pure spinel, as well as that during the process of the adsorption-desorption, the structural stability was high. The Langmuir isotherm and pseudo second-order kinetics model showed consistency with the adsorption behavior, which indicated the presence of homogeneous adsorption sites for the lithium adsorption and that its process was chemisorption. Adsorbents were found to remain being characterized with a relatively high Li+ uptake (26.13 ​mg ​g−1) with low manganese extracted (1.71%) after the circulation experiment was performed up to 5 times, proving a significant repeatability and stability for the lithium ion-sieve. The concentration factors exhibited the highly selective adsorption capacity for absorbent from Qarhan raw brine with high concentrations of Na+, K+, Ca2+, Mg2+. The adsorbents could be efficiently used for Li+ recovery from Salt Lake brine as well as its excellent potential for further application.

Based on the control hardware in-loop simulation technique, the article built the SVG control hardware in-loop electromagnetic transient real-time simulation platform, and completed the simulation analysis of the transient reactive response characteristics of the SVG controller under the ideal grid. Relying on the SVG control hardware in-loop simulation platform, using code encapsulation cryptography, a pure digital model of the SVG control system dynamic link library was established. The feasibility of the SVG control hardware in-loop real-time simulation platform and DLL model was verified by “three-line check” of the control hardware in-loop simulation model - DLL model - field experimental data curve, which provides a simulation analysis solution for the analysis of SVG transient response characteristics of large-scale offshore wind bases.

The 'Fuji' line includes many varieties with a similar genetic background and consistent inducement factors with epigenetic occurrence, thus it may be considered an ideal candidate for epigenetic research. In this study, 91 bud mutations of 'Fuji' apple were used as the test materials. Using the genetic variation within 'Fuji' as the control, the characteristics of epigenetic variation at different levels in both varieties and mutant groups were examined. The results showed that: (1) the global genomic DNA methylation level of the 91 bud mutants of 'Fuji' ranged from 29.120%-45.084%, with an average of 35.910%. Internal cytosine methylation was the main DNA methylation pattern. Regarding the variation of methylation patterns of 'Fuji' mutants, the vast majority of loci maintained the original methylation pattern existed in 'Fuji'. CHG methylation variation was the main type of variation; (2) the variation in methylation patterns between the mutant groups was greater than that of methylation levels. Among these patterns, the variation in CHG methylation patterns (including CHG hypermethylation and CHG demethylation) was expected to be dominant. The observed variation in methylation levels was more important in the Color mutant group; however, the variation in methylation patterns was more obvious in both the early maturation and Spur mutant groups. Moreover, the range of variation in the Early-maturation group was much wider than that in the Spur mutant group; (3) epigenetic diversity and genetic diversity were both low between the mutant groups. In the 'Fuji' mutant groups, there was few correlation between genetic and epigenetic variation, and epigenetic differentiation resulted in more loci with moderate or greater differentiation; (4) the purifying selection seemed to play a major role in the differentiation of different groups of 'Fuji' mutants (65.618%), but epigenetic diversity selection still occurred at nearly 35% of loci. Sixteen epigenetic outlier loci were detected.

This study synthesizes pristine and Nb-doped lithium-rich manganese-based cathode materials by solvothermal and high-temperature solid-phase methods. Analysis by focused ion beam scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy indicates successful Nb doping into the material's bulk structure. Electrochemical evaluation reveals that electrochemical performance is significantly enhanced by Nb doping. The discharge capacity of Nb-0.02 can maintain 271.7 mAh·g−1, and its cycle retention rate is up to 98.50% after 300 cycles at 0.2C; however, under the same parameters, the pristine material's discharge capacity and cycle retention rate are 212.8 mAh·g−1 and 86.68%. The initial coulombic efficiency and initial discharge capacity of Nb-0.02 is 86.94% and 287.5 mAh·g−1, while that of the pristine material is 73.59% and 234.2 mAh·g−1. Density functional theory calculations demonstrate that Nb doping accelerates Li-ion diffusion and stabilizes material structure due to stronger Nb–O bonds from reduced Li-ion migration barrier energy. Thus, the proposed modification strategy for Nb doping can illuminate the structural design of lithium-rich manganese-based cathode materials.

The extraction of precious metals is of significant importance for recycling valuable precious metal resources, however, most of the current methods for extraction are inefficient, energy-intensive, or environmentally unfriendly. Herein, we report a new chemical dissolution system for precious metals employing the trichloroisocyanuric acid (TCCA) as an oxidant and tributyl monomethyl ammonium chloride (N4441Cl) as a complexant. The leaching yield was achieving 100 wt% for the metals of Au, Pd, Cu, and Ag at 25 &deg, C, and the average dissolution rate of gold was reaching 375 mg/h, 107.1 times higher than that of traditional cyanide method. Based on the analysis of UV-Vis and XPS results, a possible reaction mechanism was proposed: the precious metals were probably oxidized by TCCA, then the formed precious metal ions coordinate with N4441Cl strongly to promote the dissolution process. Applied to gold dissolution from ores, waste electronic and electrical equipment (WEEE) and waste catalysts, the leaching yield of the TCCA-N4441Cl coordinative composite reached 97, 100, and 100 wt%, respectively, demonstrating that this method is not only efficient and environmentally friendly, but also with great adaptability and high potential for real applications.

Nickel-rich ternary material LiNi0.8Co0.1Mn0.1O2 is the promising cathode for lithium ion battery, but it has the disadvantage of structural instability. The common method for modifying its electrochemical performance is element doping, such as sodium, aluminum, magnesium and other elements, because the elements with different types and valences have varied ionic radii and binding energies to oxygen. They are incorporated into the layered nickel-rich ternary material to play the distinct roles. In this work, we investigate the effect of Na and Mg co-doping on Li(Ni0.8Co0.1Mn0.1)O2. Our results suggest that the mixed doping has no effect on the crystal structure and morphology of the material. The Rietveld refinement results demonstrated that cation mixing reduced. The electrochemical test results show that the proper amount of Na and Mg mixed doping improves the cyclic reversibility and reduces the resistance of the material. Na and Mg elements can promote each other to improve the electrochemical performance of the material. At the same time we note that high doping concentrations might mitigate the Li diffusion rates.

The structure of KCaCO3F is reinvestigated to unambiguously determine the K and Ca sites by neutron powder diffraction. The powder neutron diffractions at temperatures (295 K, 373 K, 473 K, 573 K and 673 K) are also performed to reveal the thermal expansions for this compound. No structural transition in this compound is found in the experimental temperature range. The Rietveld refinements indicate that the unit cell parameters and the cell volume of the compound increase linearly with the increasing temperature. Large anisotropic thermal expansions are found in this compound. The thermal expansion coefficient along a (b) axis is over two times as large as that parallel to the c-axis. The possible reasons for the large anisotropic thermal expansions are briefly discussed. (c) 2005 Elsevier B.V. All rights reserved.