Preparation of sodium molybdate from molybdenum concentrate by microwave roasting and alkali leaching

The preparation process of sodium molybdate has the disadvantages of high energy consumption,low thermal efficiency,and high raw material requirement of molybdenum trioxide,in order to realize the green and efficient development of molybdenum concentrate resources,this paper proposes a new process for efficient recovery of molybdenum from molybdenum concentrate and preparation of sodium molybdate by microwave-enhanced roasting and alkali leaching.Thermodynamic analysis indicated the feasibility of oxidation roasting of molybdenum concentrate.The effects of roasting temperature,holding time,and power-to-mass ratio on the oxidation product and leaching product sodium molybdate (Na_(2)MoO_(4)·2H_(2)O) were investigated.Under the optimal process conditions:roasting temperature of 700℃,holding time of 110 min,and power-to-mass ratio of 110 W/g,the molybdenum state of existence was converted from MoS_(2) to Mo O3.The process of preparing sodium molybdate by alkali leaching of molybdenum calcine was investigated,the optimal leaching conditions include a solution concentration of 2.5 mol/L,a liquid-to-solid ratio of 2 mL/g,a leaching temperature of 60℃,and leaching solution termination at pH 8.The optimum conditions result in a leaching rate of sodium molybdate of 96.24%.Meanwhile,the content of sodium molybdate reaches 94.08wt%after leaching and removing impurities.Iron and aluminum impurities can be effectively separated by adjusting the pH of the leaching solution with sodium carbonate solution.This research avoids the shortcomings of the traditional process and utilizes the advantages of microwave metallurgy to prepare high-quality sodium molybdate,which provides a new idea for the highvalue utilization of molybdenum concentrate.

Giant efficiency and color purity enhancement in multicolor inorganic perovskite light-emitting diodes via heating-assisted vacuum deposition

Inorganic perovskites(Cs Pb X3(X=I,Br,Cl))have broad prospection in the field of high-definition displaying due to its excellent optoelectronic characteristics.The vacuum deposition process possesses advantages and competitiveness in the industrialized production.However,the performance of light emitting diodes(LEDs)based on vacuum-deposited is incredibly low.Herein,we proposed a heating-assisted vacuum deposition(HAVD)method to construct inorganic perovskite LEDs(Pe LEDs)with enhanced performance.The roughness and crystallinity of perovskite film were improved by regulating the heating treatment of substrates.And the perovskite film exhibited largely rise in luminescence,with decreasing defect density.Consequently,with the optimized temperature,the green Pe LEDs exhibited 100-fold improvement of external quantum efficiency(EQE)with the luminance of up to 11941 cd/m2,and the full width at half-maximum(FWHM)of the electroluminescence(EL)spectra was decreased from 25 to 17 nm.At the same time,the red and blue Pe LEDs also exhibited obvious enhancement in EQE and luminance by HAVD method,and both the FWHM of EL spectra dropped below 20 nm,exhibiting excellent high color purity.HAVD strategy has a huge potential to be a new commonly used method for low-cost fabrication of displays and lighting.

Significant change of sensitivity index d' in sensory processing of human brain during wake-sleep transition

The sensor area in the brain remains active during the wake-sleep transition. However, the behavioral mechanisms of sensor sensitivity involved in the transition from a state of wakefulness to a sleep state remain poorly understood. To detect sensitivity index （d） changes during the wake-sleep transition, the present study recorded response times of wakefulness versus wake-sleep transition in 14 healthy undergraduate volunteers. During wake-sleep transition testing, morphological changes in the time courses of behavior response revealed 2 typical phases （stages A and B）. In stage A, subject behavior responses exhibited temporal fluctuations, and all subjects displayed a high accuracy rate. In stage B, subjects did not exhibit behavioral responses. The sensitivity index d＇ during the wake-sleep transition （stage A） was significantly weaker than during wakefulness. Results demonstrated that at the behavioral level, sensation capacity for transfer information from the external world into the internal system significantly decreased during the transition to sleep.

Aloe Royal Jelly Powder Contributes to Maintain Normal Immunity: a Randomized Clinical Trial

Objective: To study the safety and the function of maintaining normal immunity of product with royal jelly lyophilized powder and whole-leaf aloe drying powder as main raw materials. Methods: Selected 125 subjects qualified for inclusion/exclusion criteria for a trial test.(The trial group lost 9 subjects. The control group lost 6 subjects.54 effective subjects of trial group includes 12 men and 42 women. 56 effective subjects of control group including 9 men and 47 women.) The trial group was evaluated by self-control and inter-group comparison, after 90 days of continuous use of aloe royal jelly. Results: There are significant differences in the overall feeling, physiological feeling, psychological feeling and comprehensive evaluation of the individuals in the trial group after 90 days (P<0.001), which are higher than before. The control group has no statistically significant difference in the comprehensive evaluation before and after the trial (P>0.05). The ratio of CD4/CD8, IgG, IgA and IgM in the trial group and the placebo control group are above the normal low-limit. There is no obvious abnormality in indicators of blood test, blood biochemistry, liver and kidney function and other clinical tests. Conclusion: Aloe royal jelly powder contributes to maintain normal immune function and has no harmful effect to the health of subjects.

Efficient control of root-knot nematodes by expressing Bt nematicidal proteins in root leucoplasts

Root-knot nematodes(RKNs)are plant pests that infect the roots of host plants.Bacillus thuringiensis(Bt)nematicidal proteins exhibited toxicity to nematodes.However,the application of nematicidal proteins for plant protection is hampered by the lack of effective delivery systems in transgenic plants.In this study,we discovered the accumulation of leucoplasts(root plastids)in galls and RKN-induced giant cells.RKN infection causes the degradation of leucoplasts into small vesicle-like structures,which are responsible for delivering proteins to RKNs,as observed through confocal microscopy and immunoelectron microscopy.We showed that different-sized proteins from leucoplasts could be taken up by Meloidogyne incognita female.To further explore the potential applications of leucoplasts,we introduced the Bt crystal protein Cry5Ba2 into tobacco and tomato leucoplasts by fusing it with a transit peptide.The transgenic plants showed significant resistance to RKNs.Intriguingly,RKN females preferentially took up Cry5Ba2 protein when delivered through plastids rather than the cytosol.The decrease in progeny was positively correlated with the delivery efficiency of the nematicidal protein.In conclusion,this study offers new insights into the feeding behavior of RKNs and their ability to ingest leucoplast proteins,and demonstrates that root leucoplasts can be used for delivering nematicidal proteins,thereby offering a promising approach for nematode control.

The PIWI-specific insertion module helps load longer piRNAs for translational activation essential for male fertility

PIWI-clade proteins harness pi RNAs of 24–33 nt in length.Of great puzzles are how PIWI-clade proteins incorporate pi RNAs of different sizes and whether the size matters to PIWI/pi RNA function.Here we report that a PIWI-Ins module unique in PIWIclade proteins helps define the length of pi RNAs.Deletion of PIWI-Ins in Miwi shifts MIWI to load with shorter pi RNAs and causes spermiogenic failure in mice,demonstrating the functional importance of this regulatory module.Mechanistically,we show that longer pi RNAs provide additional complementarity to target m RNAs,thereby enhancing the assembly of the MIWI/e IF3f/Hu R super-complex for translational activation.Importantly,we identify a c.1108C>T(p.R370W)mutation of HIWI(human PIWIL1)in infertile men and demonstrate in Miwi knock-in mice that this genetic mutation impairs male fertility by altering the property of PIWI-Ins in selecting longer pi RNAs.These findings reveal a critical role of PIWI-Ins-ensured longer pi RNAs in fine-tuning MIWI/pi RNA targeting capacity,proven essential for spermatid development and male fertility.

Perovskite light-emitting/detecting bifunctional fibres for wearable LiFi communication

Light fidelity(LiFi),which is emerging as a compelling technology paradigm shifting the common means of highcapacity wireless communication technologies,requires wearable and full-duplex compact design because of its great significance in smart wearables as well as the‘Internet of Things’.However,the construction of the key component of wearable full-duplex LiFi,light-emitting/detecting bifunctional fibres,is still challenging because of the conflicting process between carrier separation and recombination,as well as the highly dynamic film-forming process.Here,we demonstrate light-emitting/detecting bifunctional fibres enabled by perovskite QDs with hybrid components.The hybrid perovskite inks endow fibres with super-smooth QD films.This,combined with the small exciton binding energy and high carrier mobility of perovskite QDs,enables successful integration of electroluminescence and photodetection into monofilaments.The bifunctional fibres possess the narrowest electroluminescence full width at half maximum of ~19 nm and,more importantly,the capability for simultaneously transmitting and receiving information.The successful fabrication of narrow emission full-duplex LiFi fibres paves the way for the fabrication and integration of low crosstalk interoperable smart wearables.

Stabilizing electroluminescence color of blue perovskite LEDs via amine group doping

Voltage loading-induced change in the electroluminescence(EL)wavelength of mixed halide perovskite light-emitting diodes(PeLEDs),so-called color-shift,has become an inevitable phenomenon,which is seriously unfavorable to their applications in lighting and display.Here,we achieve color-stable blue PeLEDs via a hydrogen-bonded amine-group doping strategy.Selecting guanidine(GA)or formamidinium(FA)as amine-group(-NH_(2))doping source for CsPbBr_(x)Cl_(3-x)quantum dots(QDs),experimental and theoretical results reveal that the strong N-H…X(X=Br/Cl)bonding can be produced between-NH_(2)dopants and Pb-X lattices,thereby increasing the migration barrier of halide anions.Resultantly,color-stable sky-blue devices were realized with emission peaks fixed at 490.5(GA)and 492.5(FA)nm without any obvious shift as the voltage increases,in sharp contrast devices without N-H…X producing a 15 nm red-shift from 487 to 502 nm.Not only that,maximum external quantum efficiency is improved to 3.02%and 4.14%from the initial 1.3%.This finding offers a convenient boulevard to achieve color-stable PeLEDs with high efficiency.

Recent advances and prospects toward blue perovskite materials and light-emitting diodes

Perovskite based light-emitting diodes(PeLEDs)have become a powerful candidate for next-generation solid-state lightings and high-definition displays due to their high photoluminescence quantum yield(PLQY),tunable emission wavelength over the visible spectrum,and narrow emission linewidths.Over the past few years,the development of red-and green-emissive PeLEDs has rapidly increased,and the corresponding external quantum efficiencies(EQE)have exceeded 20%.However,the research progress of blue-emitting PeLEDs is limited by its poor material quality and inappropriate device structure.Currently,the maximum EQE of blue PeLED is only 6.2%,which is far from the industrialization requirements.In order to promote the development of blue PeLEDs,we summarize the recent research progress of blue perovskite materials and LEDs and discuss several fatal challenges,mainly embodied in low efficiency and poor stability.In order to overcome these challenges,detailed analysis and strategies are put forward in terms of the materials and devices.For the former,we summarize the feasible strategy for the preparation of efficient and stable blue-emissive perovskites using component engineering.For the latter,we analyze the advantages and limitations of the different strategies for blue-emissive perovskite in LEDs.At the end of the review,a comprehensive outlook is detailed,including future development directions and several technical problems to be solved.Thus,we aim to highlight the significance and promote the industrialization of PeLEDs.

Arbuscular mycorrhizal fungi enhance the growth of the exotic species Ambrosia artemisiifolia

Arbuscular mycorrhizal fungi(AMF)can increase host plant nutrient uptake via their mycelium,thus promoting plant growth.AMF have always been associated with successful invasion of most exotic plant species.However,knowledge regarding how AMF affect the success of plant invasion remains limited.Exotic Ambrosia artemisiifolia is an invasive and mycorrhizal plant species.A long-term field experiment was conducted to examine the differences in AMF diversity and composition in the roots of A.artemisiifolia and Setaria viridis subjected to interspecific competition during growth.A greenhouse experiment was also performed to test the effect of Funneliformis mosseae on the growth of these two species.Ambrosia artemisiifolia invasion caused AMF diversity to change in native S.viridis roots.Meanwhile,the relative abundance of F.mosseae was significantly higher in the roots of A.artemisiifolia than in those of S.viridis.The higher AMF colonization rate in the exotic species(A.artemisiifolia)than in the native species(S.viridis)was found in both the field and greenhouse experiments.The greenhouse experiment possibly provided that AMF advantaged to the growth of A.artemisiifolia,by influencing its photosynthetic capacity as well as its phosphorus and potassium absorption.These observations highlight the important relationship of AMF with the successful invasion of A.artemisiifolia.

Bacillus promotes invasiveness of exotic Flaveria bidentis by increasing its nitrogen and phosphorus uptake

The effect of exotic plants on Bacillus diversity in the rhizosphere and the role of Bacilli in exotic or native plant species remain poorly understood.Flaveria bidentis is an invasive grass in China.Setaria viridis is a native grass and occurs in areas invaded by F.bidentis.Our objectives were(i)to examine the differences in the Bacillus communities between F.bidentis and S.viridis rhizospheres soil,and(ii)to compare the effects of Bacilli from F.bidentis and S.viridis rhizospheres on the competitiveness of the invasive species.Flaveria bidentis monoculture,mixture of F.bidentis and S.viridis and S.viridis monoculture were designed in the field experiment.Bacillus diversity in their rhizosphere was analyzed using 16S rRNA.One of the dominant Bacilli in the rhizosphere soil of F.bidentis was selected to test its effect on the competitive growth of F.bidentis in a greenhouse experiment.Bacillus diversity differed in F.bidentis and S.viridis rhizosphere.Brevibacterium frigoritolerans was the dominant Bacilli in the rhizosphere of both F.bidentis and S.viridis;however,its relative abundance in the F.bidentis rhizosphere was much higher than that in the S.viridis rhizosphere.In addition,B.frigoritolerans in the F.bidentis rhizosphere enhanced the growth of the plant compared with that of S.viridis by improving the nitrogen and phosphorus levels.This study showed that F.bidentis invasion influenced Bacillus communities,especially B.frigoritolerans,which,in turn,facilitated F.bidentis growth by increasing the levels of available nitrogen and phosphorus.

Selectivity mechanism of Anoplophora glabripennis on four different species of maples

Anoplophora glabripennis(Motsch.)is a wood-boring beetle that is native to China.For a long time,it caused great losses in the economy and ecology of northwest China.Attractants are often used to control insects.The volatiles emitted from the host plant play an important role for insects in finding their target.To explore the mechanism of selec-tivity to different host plants,the response of Anoplophora glabripennis to four different host plants was investigated,which included Acer negundo L.,Acer mono Maxim.,Acer truncatum Bunge.and Acer platanoides L.,and the com-pounds in the profiles of volatiles were identified from these species.The olfactory responses of Anoplophora glabripennis to the odors of different plants showed preference for certain host plants:Acer negundo,Acer mono and Acer truncatum.The attraction of Acer negundo and Acer mono was signifi-cantly different(p<0.05).The attraction of Acer negundo to the insects was stronger than to Acer mono.Acer platanoides neither attracted nor repelled the insects.Compounds in the profiles of volatiles from the above four species were identified and quantified by gas chromatography-mass spec-trometry(GC-MS)equipped with a CP-4020 termodesorp-tion and cold trap(TCT)device.The constituents of volatiles and the relative concentrations were different in the four host species.The amount of ketones,alcohols and aldehydes in the four plants showed the same order:Acer negundo<Acer mono<Acer truncatum<Acer platanoides,while that of alkanes and esters was quiet different:Acer negundo L.>Acer mono Maxim.>Acer truncatum Bunge.>Acer platanoides L..1-penten-3-ol,ocimene and trans-Germanylacetone were repellent to Anoplophora glabripennis.1-penten-3-ol and trans-gerranylacetone were identified in Acer platanoides,and Ocimene was the most attractive to Anoplophora glabripennis among these species.The extent of feeding damage caused by Anoplophora glabripennis differed among four species.The sequences was Acer negundo>Acer mono>Acer truncatum>Acer platanoides.The epidermal hairs of the four host plants revealed that the extent of damage was related to the physical characteristics of the host plants.