Importance of oxygen-containing functionalities and pore structures of biochar in catalyzing pyrolysis of homologous poplar

Biochar and bio-oil are produced simultaneously in one pyrolysis process,and they inevitably contact and may interact,influencing the composition of bio-oil and modifying the structure of biochar.In this sense,biochar is an inherent catalyst for pyrolysis.In this study,in order to investigate the influence of functionalities and pore structures of biochar on its capability for catalyzing the conversion of homologous volatiles in bio-oil,three char catalysts(600C,800C,and 800AC)produced via pyrolysis of poplar wood at 600 or 800℃or activated at 800℃,were used for catalyzing pyrolysis of homologous poplar wood at 600℃,respectively.The results indicated that the 600C catalyst was more active than 800C and 800AC for catalyzing cracking of volatiles to form more gas(yield increase by 40.2%)and aromatization of volatiles to form more light or heavy phenolics,due to its abundant oxygen-containing functionalities acting as active sites.The developed pores of the 800AC showed no such catalytic effect but could trap some volatiles and allow their further conversion via sufficient aromatization.Nevertheless,the interaction with the volatiles consumed oxygen on 600C(decrease by 50%),enhancing the aromatic degree and increasing thermal stability.The dominance of deposition of carbonaceous material of a very aromatic nature over 800C and 800AC resulted in net weight gain and blocked micropores but formed additional macropores.The in situ diffuse reflectance infrared Fourier transform spectroscopy characterization of the catalytic pyrolysis indicated superior activity of 600C for removal of -OH,while conversion of the intermediates bearing C=O was enhanced over all the char catalysts.

Enhanced and asymmetric signatures of hybridization at climatic margins: Evidence from closely related dioecious fig species

Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. Ficus heterostyla and F. squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene flow.Signatures of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.

Cryptic divergences and repeated hybridizations within the endangered “living fossil” dove tree(Davidia involucrata) revealed by whole genome resequencing

The identification and understanding of cryptic intraspecific evolutionary units(lineages) are crucial for planning effective conservation strategies aimed at preserving genetic diversity in endangered species.However, the factors driving the evolution and maintenance of these intraspecific lineages in most endangered species remain poorly understood. In this study, we conducted resequencing of 77 individuals from 22 natural populations of Davidia involucrata, a “living fossil” dove tree endemic to central and southwest China. Our analysis revealed the presence of three distinct local lineages within this endangered species, which emerged approximately 3.09 and 0.32 million years ago. These divergence events align well with the geographic and climatic oscillations that occurred across the distributional range.Additionally, we observed frequent hybridization events between the three lineages, resulting in the formation of hybrid populations in their adjacent as well as disjunct regions. These hybridizations likely arose from climate-driven population expansion and/or long-distance gene flow. Furthermore, we identified numerous environment-correlated gene variants across the total and many other genes that exhibited signals of positive evolution during the maintenance of two major local lineages. Our findings shed light on the highly dynamic evolution underlying the remarkably similar phenotype of this endangered species. Importantly, these results not only provide guidance for the development of conservation plans but also enhance our understanding of evolutionary past for this and other endangered species with similar histories.

Scale-space effect and scale hybridization in image intelligent recognition of geological discontinuities on rock slopes

Geological discontinuity(GD)plays a pivotal role in determining the catastrophic mechanical failure of jointed rock masses.Accurate and efficient acquisition of GD networks is essential for characterizing and understanding the progressive damage mechanisms of slopes based on monitoring image data.Inspired by recent advances in computer vision,deep learning(DL)models have been widely utilized for image-based fracture identification.The multi-scale characteristics,image resolution and annotation quality of images will cause a scale-space effect(SSE)that makes features indistinguishable from noise,directly affecting the accuracy.However,this effect has not received adequate attention.Herein,we try to address this gap by collecting slope images at various proportional scales and constructing multi-scale datasets using image processing techniques.Next,we quantify the intensity of feature signals using metrics such as peak signal-to-noise ratio(PSNR)and structural similarity(SSIM).Combining these metrics with the scale-space theory,we investigate the influence of the SSE on the differentiation of multi-scale features and the accuracy of recognition.It is found that augmenting the image's detail capacity does not always yield benefits for vision-based recognition models.In light of these observations,we propose a scale hybridization approach based on the diffusion mechanism of scale-space representation.The results show that scale hybridization strengthens the tolerance of multi-scale feature recognition under complex environmental noise interference and significantly enhances the recognition accuracy of GD.It also facilitates the objective understanding,description and analysis of the rock behavior and stability of slopes from the perspective of image data.

Manipulating d-d orbital hybridization induced by Mo-doped Co_(9)S_(8) nanorod arrays for high-efficiency water electrolysis

Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.

Asymmetric orbital hybridization in Zn-doped antiperovskite Cu_(1-x)Zn_(x)NMn_(3)enables highly efficient electrocatalytic hydrogen production

Rational design of efficient and robust earth-abundant alkaline hydrogen evolution reaction(HER)catalysts is a key factor for developing energy conversion technologies.Currently,antiperovskite nitride CuNMn_(3)has garnered significant interest due to its remarkable properties such as negative/zero thermal expansion and magnetocaloric effects.However,when utilized as hydrogen evolution catalysts,it encounters large challenge resulting from excessively strong/weak interactions with adsorbed H on Mn/Cu active sites,which leads to low HER activity.In this study,we introduce an asymmetric orbital hybridization strategy in Zn-doped Cu_(1-x)Zn_(x)NMn_(3)by leveraging the localization of Zn electronic states to reconfigure the electronic structures of Cu and Mn,thereby reducing the energy barrier for water dissociation and optimizing Cu and Mn active sites for hydrogen adsorption and H_(2)production.Electrochemical evaluations reveal that Cu_(0.85)Zn_(0.15)NMn_(3)with x=0.15 demonstrates exceptional electrocatalytic activity in alkaline electrolytes.A low overpotential of 52 mV at 10 mA cm^(-2)and outstanding stability over a 150-h test period are achieved,surpassing commercial Pt/C.This research offers a novel strategy for enhancing HER performance by modulating asymmetric hybridization of electron orbitals between multiple metal atoms within a material structure.

Enhanced Redox Electrocatalysis in High‑Entropy Perovskite Fluorides by Tailoring d–p Hybridization

High-entropy catalysts featuring exceptional properties are,in no doubt,playing an increasingly significant role in aprotic lithium-oxygen batteries.Despite extensive effort devoted to tracing the origin of their unparalleled performance,the relationships between multiple active sites and reaction intermediates are still obscure.Here,enlightened by theoretical screening,we tailor a high-entropy perovskite fluoride(KCoMnNiMgZnF_(3)-HEC)with various active sites to overcome the limitations of conventional catalysts in redox process.The entropy effect modulates the d-band center and d orbital occupancy of active centers,which optimizes the d–p hybridization between catalytic sites and key intermediates,enabling a moderate adsorption of LiO_(2)and thus reinforcing the reaction kinetics.As a result,the Li–O2 battery with KCoMnNiMgZnF_(3)-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability,preceding majority of traditional catalysts reported.These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst.

Cryptic diversity and rampant hybridization in annual gentians on the Qinghai-Tibet Plateau revealed by population genomic analysis

Understanding the evolutionary and ecological processes involved in population differentiation and speciation provides critical insights into biodiversity formation. In this study, we employed 29,865 single nucleotide polymorphisms(SNPs) and complete plastomes to examine genomic divergence and hybridization in Gentiana aristata, which is endemic to the Qinghai-Tibet Plateau(QTP) region. Genetic clustering revealed that G. aristata is characterized by geographic genetic structures with five clusters(West, East, Central, South and North). The West cluster has a specific morphological character(i.e., blue corolla) and higher values of FSTcompared to the remaining clusters, likely the result of the geological barrier formed by the Yangtze River. The West cluster diverged from the other clusters in the Early Pliocene;these remaining clusters diverged from one another in the Early Quaternary. Phylogenetic reconstructions based on SNPs and plastid data revealed substantial cyto-nuclear conflicts. Genetic clustering and D-statistics demonstrated rampant hybridization between the Central and North clusters,along the Bayankala Mountains, which form the geological barrier between the Central and North clusters. Species distribution modeling demonstrated the range of G. aristata expanded since the Last Interglacial period. Our findings provide genetic and morphological evidence of cryptic diversity in G. aristata, and identified rampant hybridization between genetic clusters along a geological barrier.These findings suggest that geological barriers and climatic fluctuations have an important role in triggering diversification as well as hybridization, indicating that cryptic diversity and hybridization are essential factors in biodiversity formation within the QTP region.

Identification and Control of Several Leaf Diseases of Poplar

This paper introduces the identification characteristics,occurrence regularity and control methods of several leaf diseases of poplar,including poplar angular leaf spot,poplar large spot,poplar leaf blight and poplar rust,in order to provide the basis for the healthy growth of poplar and the technical support for the sustainable development of forestry industry.

Factors affecting poplar wetwood characteristics

Wet wood is an abnormal phenomenon in growing trees,which adversely affects growth,subsequent wood processing and economic values of wood products.In this study,the influences of factors such as clones,afforestation methods,site conditions and climate conditions on the characteristics of poplar wetwood were studied through field investigations in 27 clones from 48 sample plots in 28 counties.Results showed that the incidences of wetwood were almost 100%in all plots.Ratios of wetwood area among the48 plots differed from 15.1 to 90.2%.Wetwood area ratios,moisture contents and pH differed significantly between the 27 clones.Wetwood area ratios of the clones ranged from18.7 to 62.3%.Ratios of wetwood areas were positively correlated with wet wood moisture content and pH,tree age,and negatively correlated with pH of sap wood.The repeatability of wet wood area ratios was 0.52,moderately controlled by genetics.Wetwood moisture content and pH were highly controlled by genetics,indicated by the repeatability of 0.91 and 0.89,respectively.There were significant differences in wetwood area ratios,moisture content and pH between different site conditions,afforestation methods,and geographical regions.Sloping land had the lowest wetwood area ratios and moisture content among four types of sites.Afforestation by direct seeding and rooted cuttings had the lowest wetwood area ratios and moisture content,respectively.In the three geographical regions,the Yellow River Basin had the lowest wetwood values of all three factors.

PtrDJ1C,an atypical member of the DJ-1 superfamily,is essential for early chloroplast development and lignin deposition in poplar

The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woody plants.As a model material of woody plants,poplar not only has very significant value of research,but also possesses economic and ecological properties.This study reports the Populus trichocarpa DJ-1C(PtrDJ1C)factor,encoded by a nuclear gene,and a member of the DJ-1 superfamily.PtrDJ1C knock-out with the CRISPR/Cas9 system resulted in different albino phenotypes.Chlorophyll fluorescence and immunoblot analyses showed that the levels of photosynthetic complex proteins decreased significantly.Moreover,the transcript level of plastid-encoded RNA polymerase-dependent genes and the splicing efficiency of several introns were affected in the mutant line.Furthermore,rRNA accumulation was abnormal,leading to developmental defects in chloroplasts and affecting lignin accumulation.We concluded that the PtrDJ1C protein is essential for early chloroplast development and lignin deposition in poplar.

Selecting the Technology of Sodium Silicate Modified Poplar with the Highest Performance by Fuzzy Orthogonal Method

Sodium silicate modification can improve the overall performance of wood.The modification process has a great influence on the properties of modified wood.In this study,a new method was introduced to analyze the wood modification process,and the properties of modified wood were studied.Poplar wood was modified with sodium silicate by vacuum-pressure impregnation.After screening using single-factor experiments,an orthogonal experiment was carried out with solution concentration,impregnation time,impregnation pressure,and the cycle times as experimental factors.The modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM,FT-IR,XRD and TG.The results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate,and the orderly crystal area of poplar became disorderly,resulting in the reduction of crystallinity of the modified poplar wood.FT-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood,and structural analysis revealed the formation of Si-O-Si and Si-O-C,indicating that sodium silicate reacted with fibers on the wood cell wall.TG-DTG curves showed that the final residual mass of modified poplar wood increased from 25%to 67%,and the temperature of the maximum loss rate decreased from 343℃ to 276℃.The heat release and smoke release of modified poplar wood decreased obviously.This kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.

Function identification of miR159a,a positive regulator during poplar resistance to drought stress

Drought seriously affects the growth and development of plants.MiR159 is a highly conserved and abundant microRNA family that plays a crucial role in plant growth and stress responses.However,studies of its function in woody plants are still lacking.Here,the expression of miR159a was significantly upregulated after drought treatment in poplar,and the overexpression of miR159a(OX159a)significantly reduced the open area of the stomata and improved water-use efficiency in poplar.After drought treatment,OX159a lines had better scavenging ability of reactive oxygen species and damage of the membrane system was less than that in wild-type lines.MYB was the target gene of miR159a,as verified by psRNATarget prediction,RT-qPCR,degradome sequencing,and 5′rapid amplification of cDNA ends(5′RACE).Additionally,miR159a-short tandem target mimic suppression(STTM)poplar lines showed increased sensitivity to drought stress.Transcriptomic analysis comparing OX159a lines with wild-type lines revealed upregulation of a series of genes related to response to water deprivation and metabolite synthesis.Moreover,drought-responsive miR172d and miR398 were significantly upregulated and downregulated respectively in OX159a lines.This investigation demonstrated that miR159a played a key role in the tolerance of poplar to drought by reducing stomata open area,increasing the number and total area of xylem vessels,and enhancing water-use efficiency,and provided new insights into the role of plant miR159a and crucial candidate genes for the molecular breeding of trees with tolerance to drought stress.

Experimental Study of Mode-I and Mode-II Interlaminar Fracture Characteristics of Poplar LVL

Fracture is a common failure form of poplar laminated veneer lumber(LVL).In the present work,we performed an experimental study on the mode-I along-grain interlaminar fracture,mode-I cross-grain interlaminar fracture,and mode-II interlaminar fracture of poplar LVL.We investigated stress mechanisms,failure modes,and fracture toughness values of the different fracture types.The experimental results revealed that the crack in the mode-I along-grain interlaminar fracture specimen propagated along the prefabricated crack direction,and the crack tip broke.The mode-I cross-grain interlaminar fracture specimen had cracks in the vertical direction near the prefabricated crack.In the mode-II interlaminar fracture specimen,cracks appeared along the initial prefabricated crack direction.The load–displacement curves of these three specimens were linear in the early stage of loading.With the increase in the load,a nonlinear segment appeared before crack propagation and a descending segment appeared after crack propagation.The nonlinear segments of the mode-I along-grain interlaminar fracture and mode-II interlaminar fracture were very short,and cracks expanded quickly after their initiation,resulting in brit-tle fracture.The nonlinear segment of the mode-I cross-grain interlaminar fracture was long,resulting in plastic failure.The average toughness values of the mode-I along-grain interlaminar fracture,mode-I cross-grain inter-laminar fracture,and mode-II interlaminar fracture were 15.43,270.15,and 39.72 MPa·mm^(1/2),respectively.

Evaluation of Water Transfer Capacity of Poplar with Pectinase Treated under the Solar Interface Evaporation

Poplar wood,which was used as the absorption material for the solar-driven interfacial evaporation,was treated for 3 days,6 days and 9 days with the pectinase,and then was simulated for photothermal evaporation test at one standard solar radiation intensity(1 kW⋅m^(−2)).The effects of pectinase treatment on cell passage and water migration capacity of poplars were analyzed by the mercury intrusion porosimetry,the scanning electron microscope and fractal theory.It was found that the pit membrane and the ray parenchyma cells of poplar wood were degraded and destroyed after pectinase treatment.Compared with the untreated poplar wood,the evaporation rate of three sections of the specimen was changed.Especially the evaporation rate of radial and tangential direction was significantly increased.At the same time,based on the experimental data and fractal dimension deduction,fractal characteristics could be found in that the structure of poplars treated with pectinase.The porosity decreased with the increase of the fractal dimension in a certain range.It was shown that it is feasible to evaluate solar-driven water migration capacity by using fractal theory.

An optimized protocol using Steedman’s wax for high-sensitivity RNA in situ hybridization in shoot apical meristems and flower buds of cucumber

In situ mRNA hybridization(ISH)is a powerful tool for examining the spatiotemporal expression of genes in shoot apical meristems and flower buds of cucumber.The most common ISH protocol uses paraffin wax;however,embedding tissue in paraffin wax can take a long time and might result in RNA degradation and decreased signals.Here,we developed an optimized protocol to simplify the process and improve RNA sensitivity.We combined embedding tissue in low melting-point Steedman’s wax with processing tissue sections in solution,as in the whole-mount ISH method in the optimized protocol.Using the optimized protocol,we examined the expression patterns of the CLAVATA3(CLV3)and WUSCHEL(WUS)genes in shoot apical meristems and floral meristems of Cucumis sativus(cucumber)and Arabidopsis thaliana(Arabidopsis).The optimized protocol saved 4–5 days of experimental period compared with the standard ISH protocol using paraffin wax.Moreover,the optimized protocol achieved high signal sensitivity.The optimized protocol was successful for both cucumber and Arabidopsis,which indicates it might have general applicability to most plants.

Plasmonic hybridization properties in polyenes octatetraene molecules based on theoretical computation

Relationship of plasmonic properties of multiple clusters to molecular interactions and properties of a single cluster or molecule have become increasingly important due to the continuous emergence of molecular and cluster devices or systems.A hybrid phenomenon similar to plasmonic nanoparticle hybridization exists between two molecules with plasmon excitation modes.We use linear-response time-dependent density functional theory,real-time propagation time-dependent density functional theory,the plasmonicity index,and transition contribution maps(TCMs)to identify the plasmon excitation modes for the linear polyenes octatetraene with–OH and–NH_(2)groups and analyze the hybridization characteristics using charge transitions.The results show that molecular plasmon hybridization exists when the two molecules are coupled.The TCM analysis shows that the plasmon modes and hybridization result from collective and single-particle excitation.The plasmon mode is stronger,and the individual properties of the molecules are maintained after coupling when there is extra charge depose in the molecules because the electrons are moving in the molecules.This study provides new insights into the molecular plasmon hybridization of coupled molecules.

Early differentiation in biomass production and carbon sequestration of white poplar and its two hybrids in Central Iran

We assessed the potential of white poplar（Populus alba L.） and its inter-sectional hybridization with euphrates poplar（P. euphratica Oliv.） for carbon storage and sequestration in central Iran. Trials were established at planting density of 2,500 trees per hectare in block randomized design with three replicates. After 6 years, we measured the above-ground biomass of tree components（trunk, branch, bark, twig and leaf）, and assessed soil carbon at three depths. P. alba 9 euphratica plantation stored significantly more carbon（22.3 t ha-1） than P. alba（16.7 t ha-1） and P. euphratica 9 alba（13.1 t ha-1）.Most of the carbon was accumulated in the above-ground biomass（61.1 % in P. alba, 72.4 % in P. alba 9 euphratica and 56.0 % in P. euphratica 9 alba）. There was no significant difference in soil carbon storage. Also, biomass allocation was different between white poplar P. alba and its inter-sectional hybridization. Therefore, there was a yield difference due to genomic imprinting, which increased the possibility that paternally and maternally inherited wood production alleles would be differentially expressed in the new crossing.

The rehybridization of electronic orbitals in carbon nanotubes

Rehybridization of electronic orbitals in carbon nanotubes contains tilting angles of π orbital, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, etc. In this paper, we have obtained analytical formulas of tilting angle of π orbital relative to tube surface, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, separately, as well as the numerical results.

Improved Nucleic Acid Spot Hybridization Technique for Detection of Potato Spindle Tuber Viroid(PSTVd)

Potato spindle tuber viroid(PSTVd)disease is one of the major diseases that threatens potato production.Therefore,an advanced,rapid and sensitive detection technology is needed to detect the disease for better control.In order to establish an easier nucleic acid spot hybridization(NASH)method,some studies were tried as the followings:(1)the pre-hybridization step of nucleic acid spot hybridization(NASH)was omitted compared with ordinary way;(2)RNA extraction(phenol extraction and Ames buffer extraction)methods were compared;(3)fixed RNA by UV lamp and oven compared with UV cross-linker;(4)hybridized the RNA in shaking incubator and so on.The results showed that RNA extracted by Ames buffer was more effective than by the phenol extraction method.Besides,the result of hybridization without pre-hybridization step was better than that with 1.5 h of pre-hybridization.The more important discovery was that the shaking incubator could replace the hybridization oven and the ordinary UV lamp could replace the UV cross-linker.After a long term repeated research and testing,a new hybridization system that could rapidly detect the PSTVd by improved NASH technique merely using common instruments and equipment was established.