[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue cultur...[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue culture method with Houttuynia cordata Thunb.as the research object.Different concentrations of 1-naphthalene acetic acid(NAA),auxin(indole-3-acetic acid,IAA)and gibberellin acid(GA_(3))were added to the group culture medium of H.cordata to investigate the effects of exogenous plant hormones on plant height,root length,fresh weight,morphological characteristics,four phenolics and 20 volatile compounds.[Results]The results showed that the exogenous plant hormone of 3 mg/L GA_(3)significantly increased plant height by 79.9%over the control;the exogenous plant hormone of 3 mg/L IAA significantly increased root length by 52.6%over the control;and the exogenous plant hormone of 1 mg/L GA_(3)significantly increased fresh weight of single plant by 458.2%over the control.In the treatment group of 1 mg/L NAA,chlorogenic acid content was significantly increased by 52.6%compared with the control;in the treatment group of 1 mg/L IAA,chlorogenic acid,rutin,isodendrin and quercetin content were significantly increased by 109.1%,100.6%,173.8%,and 198.7%compared with the control,respectively;in the treatment of 3 mg/L GA_(3),chlorogenic acid,rutin,isoquercitin,and quercitin content were significantly increased by 65.3%,104.9%,139.0%and 191.2%over the control.In addition,the content of volatile compounds was significantly higher in all H.cordata treated with exogenous plant hormones of 2 mg/L NAA,1 mg/L IAA,and 3 mg/L GA_(3);however,the content of volatile compounds was lower in all of the treatments with 2 mg/L GA_(3).[Conclusions]Different exogenous plant hormones have certain effects on the growth morphology and secondary metabolic content of H.cordata,which provides theoretical basis and technical support for the development and utilization of medicinal plants.展开更多
[Objectives]To study the effects of fungi Fusarium sp.to rhizosphere soil and physiological characteristics of Camellia oleifera Abel.[Methods]We investigated the effects of Fusarium sp.to rhizosphere soil nutrient el...[Objectives]To study the effects of fungi Fusarium sp.to rhizosphere soil and physiological characteristics of Camellia oleifera Abel.[Methods]We investigated the effects of Fusarium sp.to rhizosphere soil nutrient element content and metabolites of C.oleifera.C.oleifera was inoculated with the suspension of Fusarium sp.in pot experiments and ammonium-N,available phosphorus,available potassi-um,organic matter,enzymes and pH of rhizosphere soil,MDA content,activity of SOD,POD of C.oleifera leaves were analyzed.[Results]Fusarium sp.stress significantly inhibited soil enzyme activities and significantly reduced available phosphorus content,especially for phospha-tase and sucrase.Antioxidant enzyme activities in C.oleifera tissues showed that Fusarium sp.stress significantly increased MDA and SOD enzyme activities and decreased POD enzyme activity.Especially,SOD enzyme activity was elevated by 53.86%compared with the CK group.In addition,analysis of the content of major metabolites in C.oleifera leaves showed that Fusarium sp.stress significantly reduced the content of total flavonoids,quercetin,isoquercitrin and isoquercitrin in C.oleifera leaves by 7.80%,50.00%and 75.90%,respectively.[Conclusions]Our results are an important step which showed strong resistance of C.oleifera and can give a novel insight for researches on the effects in the rhizosphere soil enzyme,soil nutrient elements and metabolites of C.oleifera under the Fusarium sp.too.展开更多
The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hi...The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hinders the understanding of the interaction mechanism between surfactant groups and oxygen-containing functional groups at the surface of low-rank coal.In this study,we investigate the flotation of low-rank coal in the presence of a composite collector by using a combined theoretical and experimental approach.The maximum flotation mass recovery achieved was 82.89%using a 3:1 mixture of dodecane and castor oil acid.Fourier-transform infrared and X-ray photoelectron spectroscopic analyses showed that castor oil acid was effectively adsorbed onto the surface of low-rank coal,enhancing the hydrophobicity of the coal.In addition,the diffusion coefficient of water molecules in the water-composite collector-coal system was greater than that in the dodecane system.Moreover,due to the presence of castor oil acid in the flotation process,the adsorption distance of dodecane and low-rank coal became shorter.Molecular dynamics simulations revealed that the diffusion and interaction of surfactant molecules at the interface of low-rank coal particles and water was enhanced because the adsorption of the dodecane-castor oil acid mixture is primarily controlled by hydrogen bonds and electrostatic attraction.Based on these results,a better surfactant for flotation of low-rank coal is also proposed.展开更多
The traditional multi-access edge computing (MEC) capacity isoverwhelmed by the increasing demand for vehicles, leading to acute degradationin task offloading performance. There is a tremendous number ofresource-rich ...The traditional multi-access edge computing (MEC) capacity isoverwhelmed by the increasing demand for vehicles, leading to acute degradationin task offloading performance. There is a tremendous number ofresource-rich and idle mobile connected vehicles (CVs) in the traffic network,and vehicles are created as opportunistic ad-hoc edge clouds to alleviatethe resource limitation of MEC by providing opportunistic computing services.On this basis, a novel scalable system framework is proposed in thispaper for computation task offloading in opportunistic CV-assisted MEC.In this framework, opportunistic ad-hoc edge cloud and fixed edge cloudcooperate to form a novel hybrid cloud. Meanwhile, offloading decision andresource allocation of the user CVs must be ascertained. Furthermore, thejoint offloading decision and resource allocation problem is described asa Mixed Integer Nonlinear Programming (MINLP) problem, which optimizesthe task response latency of user CVs under various constraints. Theoriginal problem is decomposed into two subproblems. First, the Lagrangedual method is used to acquire the best resource allocation with the fixedoffloading decision. Then, the satisfaction-driven method based on trial anderror (TE) learning is adopted to optimize the offloading decision. Finally, acomprehensive series of experiments are conducted to demonstrate that oursuggested scheme is more effective than other comparison schemes.展开更多
In order to separate methyl acetate and methanol azeotrope, the ionic liquid(IL) 1,3-dimethylimidazolium dimethylphosphate([DMIM]DMP) was used as the solvent. The Aspen Plus software was used to design and optimize th...In order to separate methyl acetate and methanol azeotrope, the ionic liquid(IL) 1,3-dimethylimidazolium dimethylphosphate([DMIM]DMP) was used as the solvent. The Aspen Plus software was used to design and optimize the extractive distillation process. Under the optimized conditions, the mass fractions of methyl acetate and methanol were both above 99.5%. Compared with the dimethyl sulfoxide(DMSO) process, the [DMIM]DMP process has the advantages of saving energy and lower equipment investment cost. The result shows that using [DMIM]DMP as the solvent to separate a methyl acetate and methanol azeotrope has better prospect in industrial application.展开更多
The curvature of the γ-ray spectrum in blazars may reflect the intrinsic distribution of emitting electrons, which will further give some information on the possible acceleration and cooling processes in the emitting...The curvature of the γ-ray spectrum in blazars may reflect the intrinsic distribution of emitting electrons, which will further give some information on the possible acceleration and cooling processes in the emitting region. The γ-ray spectra of Fermi blazars are normally fitted either by a single power-law(PL) or a log-normal(call Logarithmic Parabola, LP) form. The possible reason for this difference is not clear. We statistically explore this issue based on the different observational properties of 1419 Fermi blazars in the 3 LAC Clean Sample. We find that the γ-ray flux(100 Me V–100 Ge V) and variability index follow bimodal distributions for PL and LP blazars, where the γ-ray flux and variability index show a positive correlation. However, the distributions of γ-ray luminosity and redshift follow a unimodal distribution. Our results suggest that the bimodal distribution of γ-ray fluxes for LP and PL blazars may not be intrinsic and all blazars may have an intrinsically curved γ-ray spectrum, and the PL spectrum is just caused by the fitting effect due to less photons.展开更多
Survey was conducted to investigate the occurrence laws of bacterial canker disease of kiwifruits in Liupanshui area,Guizhou Province,and the pathogens and hazard symptoms of the canker disease were introduced. The re...Survey was conducted to investigate the occurrence laws of bacterial canker disease of kiwifruits in Liupanshui area,Guizhou Province,and the pathogens and hazard symptoms of the canker disease were introduced. The results showed that the factors influencing the occurrence of bacterial canker disease of kiwifruit were identified as inter-species resistance,agronomic traits,meteorological and ecological conditions,cultivation and management techniques and fertilization levels. Techniques for the comprehensive control of kiwi canker disease were stated,and control suggestions were proposed.展开更多
It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X...It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands.A geometric interpretation and standard shock or stochastic acceleration models of blazar emission have difficulty reproducing these observed behaviors.The present paper introduces a linear acceleration by integrating the reconnection electric field into the particle transport model for the observed behaviors of Mrk 421.We note that strong evidence for evolution in characteristic of multi-wavelength spectral energy distribution including shifting the peak frequency,accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands provides an important electrostatic acceleration diagnostic in a blazar jet.Assuming suitable model parameters,we apply the results of the simulation to the 13-day flaring event in March 2010 of Mrk 421,concentrating on the evolution of multiwavelength spectral energy distribution characteristic by shifting the peak frequency.It is clear that the ratio of the electric field and magnetic field strength plays an important role in temporal evolution of the peak frequency of synchrotron spectral energy distribution component.We suggest it is reasonable that the electrostatic acceleration is responsible for the evolution of multi-wavelength spectral energy distribution characteristic by shifting the peak frequency.Based on the model results,we assert that the peak frequency of the synchrotron spectral energy distribution component may signify a temporary characteristic of blazars,rather than a permanent one.展开更多
(A)[B]2O4ferrite samples with the composition Co1-xCrxFe2O4(0.0 ≤ x ≤ 1.0) are prepared using a hydrothermal method, and subjected to calcining in a tube furnace with an argon-flow at 1673 K for 2 h. X-ray diffracti...(A)[B]2O4ferrite samples with the composition Co1-xCrxFe2O4(0.0 ≤ x ≤ 1.0) are prepared using a hydrothermal method, and subjected to calcining in a tube furnace with an argon-flow at 1673 K for 2 h. X-ray diffraction patterns indicate that each of all the samples has a single phase cubic spinel structure with a space group of Fdˉ3m. Magnetic measurements show that the saturation magnetization decreases with as the Cr content x increases. The cation distribution of the samples is estimated by fitting the dependence of the magnetic moments on x at 10 K, using the quantum mechanical model previously proposed by our group. The calculated sum of the content values of the Cr3+and Cr2+cations occupying the(A) sites increases as the value of x increases. In the fitting process, the magnetic moment directions of the Cr3+and Cr2+cations are assumed to be antiparallel to those of the Fe and Co cations, respectively, which is in accordance with Hund's rules.展开更多
Ag-doped manganite powder samples, La0.7Sr0.1AgxMnO3-δ(x = 0.00, 0.025, 0.05, 0.075, and 0.10) were synthesized using the sol–gel method. X-ray diffraction patterns indicated that the samples had two phases with the...Ag-doped manganite powder samples, La0.7Sr0.1AgxMnO3-δ(x = 0.00, 0.025, 0.05, 0.075, and 0.10) were synthesized using the sol–gel method. X-ray diffraction patterns indicated that the samples had two phases with the R3c perovskite being the dominant phase and Mn3O4 being the second phase. X-ray energy dispersive spectra indicated that the ratio of Ag to La was very close to that of the nominal composition in the samples. The specific saturation magnetizations at 300 K increased from 32.0 A·m2/kg when x = 0.00 to 46.8 A·m2/kg when x = 0.10. The Curie temperature, T C, of the samples increased from 310 K when x = 0.00 to 328 K when x = 0.10. Because the atomic concentration ratios of La, Sr, and Mn in the five samples were all the same and only the Ag concentration changed, the variations of the specific saturation magnetizations at 300 K and the Curie temperatures suggested that the Ag cations have been doped into the A sites of the perovskite phase in the samples.展开更多
We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junc tion with local variation of Fermi velocity, where the properties of charge, valley, and spin transpor...We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junc tion with local variation of Fermi velocity, where the properties of charge, valley, and spin transport through the junction ar investigated. By matching the wavefunctions at the normal-ferromagnetic interfaces, it is demonstrated that the variation of Fermi velocity in a small range can largely enhance the total conductance while keeping the current nearly fully valley and spin-polarized. Further, the variation of Fermi velocity in ferromagnetic silicene has significant influence on the valley and spin polarization, especially in the low-energy regime. It may drastically reduce the high polarizations, which can b realized by adjusting the local application of a gate voltage and exchange field on the junction.展开更多
Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized...Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes’ cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.展开更多
Polycrystalline Bi_4Ti_3O_(12) thin films with various fractions of a-axis, c-axis and random orientations have been grown on Pt(111)/Ti/Si O_2/Si substrates by laser-ablation under different kinetic growth conditions...Polycrystalline Bi_4Ti_3O_(12) thin films with various fractions of a-axis, c-axis and random orientations have been grown on Pt(111)/Ti/Si O_2/Si substrates by laser-ablation under different kinetic growth conditions. The relationship between the structure and ferroelectric property of the films was investigated, so as to explore the possibility of enhancing ferroelectric polarization by controlling the preferred orientation. The structural characterization indicated that the large growth rate and high oxygen background pressure were both favorable for the growth of non-c-axis oriented grains in the Bi_4Ti_3O_(12) thin films. The films with high fractions of a-axis and random orientations, i e, f(a-sxis) = 28.3% and f(random) = 69.6%, could be obtained at the deposition temperature of 973 K, oxygen partial pressure of 15 Pa and laser fluence of 4.6 J/cm^2, respectively. It was also noted that the variation of ferroelectric polarization was in accordance with the evolution non-c-axis orientation. A large value of remanent polarization(2 Pr = 35.5 μC/cm^2) was obtained for the Bi_4Ti_3O_(12) thin films with significant non-c-axis orientation, even higher than that of rare-earth-doped Bi_4Ti_3O_(12) films.展开更多
The transport property of electrons tunneling through arrays of magnetic and electric barriers is studied in silicene.In the tunneling transmission spectrum, the spin-valley-dependent filtered states can be achieved i...The transport property of electrons tunneling through arrays of magnetic and electric barriers is studied in silicene.In the tunneling transmission spectrum, the spin-valley-dependent filtered states can be achieved in an incident energy range which can be controlled by the electric gate voltage. For the parallel magnetization configuration, the transmission is asymmetric with respect to the incident angle θ, and electrons with a very large negative incident angle can always transmit in propagating modes for one of the spin-valley filtered states under a certain electromagnetic condition. But for the antiparallel configuration, the transmission is symmetric about θ and there is no such transmission channel. The difference of the transmission between the two configurations leads to a giant tunneling magnetoresistance(TMR) effect.The TMR can reach to 100% in a certain Fermi energy interval around the electrostatic potential. This energy interval can be adjusted significantly by the magnetic field and/or electric gate voltage. The results obtained may be useful for future valleytronic and spintronic applications, as well as magnetoresistance device based on silicene.展开更多
The pressure swing distillation(PSD)process for separation of ethyl acetate and ethanol mixture in subplateau region was simulated.The pressure of low-pressure column was set at 0.086 MPa,which is in accordance with t...The pressure swing distillation(PSD)process for separation of ethyl acetate and ethanol mixture in subplateau region was simulated.The pressure of low-pressure column was set at 0.086 MPa,which is in accordance with the atmospheric pressure in the Yunnan-Guizhou region,while the pressure of high-pressure column was determined as 0.304 MPa.Various design parameters,including the plate number,the reflux ratio,and the feeding positions,were optimized,while taking into consideration the total annual cost(TAC).Furthermore,based on the general PSD,the partially heatintegrated pressure swing distillation(PHIPSD)process and the fully heat-integrated pressure swing distillation(FHIPSD)process were also studied.The processes with heat integration showed lower capital cost and lower energy cost,and TACs of the PHIPSD and FHIPSD decreased to 377.21×103$/a and 371.66×103$/a,respectively.Compared with the non-heat integrated process,TACs of the PHIPSD and FHIPSD could be reduced by 27.82%and 28.89%,respectively.The results showed that the FHIPSD process could effectively separate the ethyl acetate-ethanol mixture,and it was more economical and reasonable.This work can provide some technical references for the separation of such azeotropes in the sub-plateau region.展开更多
In the fourth Fermi Large Area Telescope source catalog(4 FGL),5064γ-ray sources are reported,including 3207 active galactic nuclei(AGNs),239 pulsars,1336 unassociated sources,92 sources with weak association with bl...In the fourth Fermi Large Area Telescope source catalog(4 FGL),5064γ-ray sources are reported,including 3207 active galactic nuclei(AGNs),239 pulsars,1336 unassociated sources,92 sources with weak association with blazars at low Galactic latitudes and 190 other sources.We employ two different supervised machine learning classifiers,combined with the direct observation parameters given by the 4 FGL fits table,to search for sources potentially classified as AGNs and pulsars in the 1336 unassociated sources.In order to reduce the error caused by the large difference in the sizes of samples,we divide the classification process into two separate steps in order to identify the AGNs and the pulsars.First,we select the identified AGNs from all of the samples,and then select the identified pulsars from the remaining cases.Using the 4 FGL sources associated or identified as AGNs,pulsars and other sources with the features selected through the K-S test and the random forest(RF)feature importance measurement,we trained,optimized and tested our classifier models.Then,the models are applied to classify the 1336 unassociated sources.According to the calculation results of the two classifiers,we report the sensitivity,specificity,accuracy in each step and the class of unassociated sources given by each classifier.The accuracy obtained in the first step is approximately 9595%;in the second step,the obtained overall accuracy is approximately 80%.Combining the results of the two classifiers,we predict that there are 583 AGN-type candidates,115 pulsar-type candidates,154 other types ofγ-ray candidates and 484 of uncertain types.展开更多
With the rise of open-source software,the social development paradigm occupies an indispensable position in the current software development process.This paper puts forward a variant of the PageRank algorithm to build...With the rise of open-source software,the social development paradigm occupies an indispensable position in the current software development process.This paper puts forward a variant of the PageRank algorithm to build the importance assessment model,which provides quantifiable importance assessment metrics for new Java projects based on Java open-source projects or components.The critical point of the model is to use crawlers to obtain relevant information about Java open-source projects in the GitHub open-source community to build a domain knowledge graph.According to the three dimensions of the Java open-source project’s project influence,project activity and project popularity,the project is measured.A modified PageRank algorithm is proposed to construct the importance evaluation model.Thereby providing quantifiable importance evaluation indicators for new Java projects based on or components of Java open-source projects.This article evaluates the importance of 4512 Java open-source projects obtained on GitHub and has a good effect.展开更多
Located in Zhutang, Lancang County, Laomian language, which still enjoys its vitality recently, is surrounded by variousdominant languages. But as the development of the links between ethnic groups, especially with th...Located in Zhutang, Lancang County, Laomian language, which still enjoys its vitality recently, is surrounded by variousdominant languages. But as the development of the links between ethnic groups, especially with the Han group, the Laomian lan-guage has undergone many variations, among which typically includes an increase of words. This paper is based on the research onLaomian village regarding the Chinese loanwords in Laomian language under the language contact.展开更多
基金Supported by Science and Technology Plan Project of Guizhou Province,China(QianKeKe Basics20201Y179)Key Field Project of Guizhou Provincial Department of Education(QJHKY2021044)+3 种基金Project of Guizhou Provincial Characteristic Key Laboratory(QJHKY2021002)Science and Technology Support Plan Project of Guizhou Province(QKHZCGeneral2021243)Science and Technology Plan Project of Liupanshui(52020-2021-PT-01)National Natural Science Foundation of China(41761010).
文摘[Objectives]To improve the yield and secondary metabolite content of medicinal plants and to further develop and utilize the medicinal and other functions of medicinal plants.[Methods]We used the sterile tissue culture method with Houttuynia cordata Thunb.as the research object.Different concentrations of 1-naphthalene acetic acid(NAA),auxin(indole-3-acetic acid,IAA)and gibberellin acid(GA_(3))were added to the group culture medium of H.cordata to investigate the effects of exogenous plant hormones on plant height,root length,fresh weight,morphological characteristics,four phenolics and 20 volatile compounds.[Results]The results showed that the exogenous plant hormone of 3 mg/L GA_(3)significantly increased plant height by 79.9%over the control;the exogenous plant hormone of 3 mg/L IAA significantly increased root length by 52.6%over the control;and the exogenous plant hormone of 1 mg/L GA_(3)significantly increased fresh weight of single plant by 458.2%over the control.In the treatment group of 1 mg/L NAA,chlorogenic acid content was significantly increased by 52.6%compared with the control;in the treatment group of 1 mg/L IAA,chlorogenic acid,rutin,isodendrin and quercetin content were significantly increased by 109.1%,100.6%,173.8%,and 198.7%compared with the control,respectively;in the treatment of 3 mg/L GA_(3),chlorogenic acid,rutin,isoquercitin,and quercitin content were significantly increased by 65.3%,104.9%,139.0%and 191.2%over the control.In addition,the content of volatile compounds was significantly higher in all H.cordata treated with exogenous plant hormones of 2 mg/L NAA,1 mg/L IAA,and 3 mg/L GA_(3);however,the content of volatile compounds was lower in all of the treatments with 2 mg/L GA_(3).[Conclusions]Different exogenous plant hormones have certain effects on the growth morphology and secondary metabolic content of H.cordata,which provides theoretical basis and technical support for the development and utilization of medicinal plants.
基金Supported by Key Field Project of Education Department of Guizhou Province(QJHKYZ[2021]044)Forestry Research Project of Guizhou Province(QLKH[2021]11)+1 种基金Project of Guizhou Provincial Characteristic Key Laboratory(QJHKY[2021]002)National Natural Science Foundation of China(41761010).
文摘[Objectives]To study the effects of fungi Fusarium sp.to rhizosphere soil and physiological characteristics of Camellia oleifera Abel.[Methods]We investigated the effects of Fusarium sp.to rhizosphere soil nutrient element content and metabolites of C.oleifera.C.oleifera was inoculated with the suspension of Fusarium sp.in pot experiments and ammonium-N,available phosphorus,available potassi-um,organic matter,enzymes and pH of rhizosphere soil,MDA content,activity of SOD,POD of C.oleifera leaves were analyzed.[Results]Fusarium sp.stress significantly inhibited soil enzyme activities and significantly reduced available phosphorus content,especially for phospha-tase and sucrase.Antioxidant enzyme activities in C.oleifera tissues showed that Fusarium sp.stress significantly increased MDA and SOD enzyme activities and decreased POD enzyme activity.Especially,SOD enzyme activity was elevated by 53.86%compared with the CK group.In addition,analysis of the content of major metabolites in C.oleifera leaves showed that Fusarium sp.stress significantly reduced the content of total flavonoids,quercetin,isoquercitrin and isoquercitrin in C.oleifera leaves by 7.80%,50.00%and 75.90%,respectively.[Conclusions]Our results are an important step which showed strong resistance of C.oleifera and can give a novel insight for researches on the effects in the rhizosphere soil enzyme,soil nutrient elements and metabolites of C.oleifera under the Fusarium sp.too.
基金the Foundation of Guizhou Province(No.Qiankehe-ZK[2021]Yiban 255)the National Natural Science Foundation of China(No.52264032)the Foundation of Liupanshui Normal University(No.LPSSYLPY202122).
文摘The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal.However,in previous studies,the selection of surfactants was primarily based on flotation procedures,which hinders the understanding of the interaction mechanism between surfactant groups and oxygen-containing functional groups at the surface of low-rank coal.In this study,we investigate the flotation of low-rank coal in the presence of a composite collector by using a combined theoretical and experimental approach.The maximum flotation mass recovery achieved was 82.89%using a 3:1 mixture of dodecane and castor oil acid.Fourier-transform infrared and X-ray photoelectron spectroscopic analyses showed that castor oil acid was effectively adsorbed onto the surface of low-rank coal,enhancing the hydrophobicity of the coal.In addition,the diffusion coefficient of water molecules in the water-composite collector-coal system was greater than that in the dodecane system.Moreover,due to the presence of castor oil acid in the flotation process,the adsorption distance of dodecane and low-rank coal became shorter.Molecular dynamics simulations revealed that the diffusion and interaction of surfactant molecules at the interface of low-rank coal particles and water was enhanced because the adsorption of the dodecane-castor oil acid mixture is primarily controlled by hydrogen bonds and electrostatic attraction.Based on these results,a better surfactant for flotation of low-rank coal is also proposed.
基金supported by the National Natural Science Foundation of China (61871400)Natural Science Foundation of Jiangsu Province (BK20211227)Scientific Research Project of Liupanshui Normal University (LPSSYYBZK202207).
文摘The traditional multi-access edge computing (MEC) capacity isoverwhelmed by the increasing demand for vehicles, leading to acute degradationin task offloading performance. There is a tremendous number ofresource-rich and idle mobile connected vehicles (CVs) in the traffic network,and vehicles are created as opportunistic ad-hoc edge clouds to alleviatethe resource limitation of MEC by providing opportunistic computing services.On this basis, a novel scalable system framework is proposed in thispaper for computation task offloading in opportunistic CV-assisted MEC.In this framework, opportunistic ad-hoc edge cloud and fixed edge cloudcooperate to form a novel hybrid cloud. Meanwhile, offloading decision andresource allocation of the user CVs must be ascertained. Furthermore, thejoint offloading decision and resource allocation problem is described asa Mixed Integer Nonlinear Programming (MINLP) problem, which optimizesthe task response latency of user CVs under various constraints. Theoriginal problem is decomposed into two subproblems. First, the Lagrangedual method is used to acquire the best resource allocation with the fixedoffloading decision. Then, the satisfaction-driven method based on trial anderror (TE) learning is adopted to optimize the offloading decision. Finally, acomprehensive series of experiments are conducted to demonstrate that oursuggested scheme is more effective than other comparison schemes.
基金financially supported by the Guizhou Province Science and Technology United Fund (Qiankehe J zi LKLS[2013]28, LKLS[2013]27)the Guizhou Province Education Department (GZSJG10977201604)+3 种基金the Excellent Engineers Education Training Plan (LPSSY zyjypyjh201702)the Guizhou Province Education Department (Qianjiaohe KY zi [2017]258)Guizhou Solid Waste Recycling Laboratory of Coal Utilization ([2011]278)the Guizhou Ordinary College Innovation Team of Coal Solid Waste Recycling Technology ([2014]46)
文摘In order to separate methyl acetate and methanol azeotrope, the ionic liquid(IL) 1,3-dimethylimidazolium dimethylphosphate([DMIM]DMP) was used as the solvent. The Aspen Plus software was used to design and optimize the extractive distillation process. Under the optimized conditions, the mass fractions of methyl acetate and methanol were both above 99.5%. Compared with the dimethyl sulfoxide(DMSO) process, the [DMIM]DMP process has the advantages of saving energy and lower equipment investment cost. The result shows that using [DMIM]DMP as the solvent to separate a methyl acetate and methanol azeotrope has better prospect in industrial application.
基金Supported by the National Natural Science Foundation of China （50874107） the Guizhou Science and Technology Fund （Qiankehe J zi [2012]2306）+1 种基金 the Guizhou High-level Talent Special Assistant Fund （TZJF-2011-04） the Guizhou Research Laboratory Platform of Clean and Efficient Use of Coal Resources （Qianke Platform [2011] 4003）
基金supported by the National Natural Science Foundation of China(Grant Nos.11763005,11622324,11573009,11763002,U1431111 and U1431126)supported by the Research Foundation for Advanced Talents of Liupanshui Normal University(LPSSYKYJJ201506)+3 种基金the Open Fund of Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processingthe Physical Electronic Key Discipline of Guizhou Province(ZDXK201535)the Natural Science Foundation of the Department of Education of Guizhou Province(QJHKYZ[2015]455)the Research Foundation of Liupanshui Normal University(LPSSYDXS1514 and LPSSY201401)
文摘The curvature of the γ-ray spectrum in blazars may reflect the intrinsic distribution of emitting electrons, which will further give some information on the possible acceleration and cooling processes in the emitting region. The γ-ray spectra of Fermi blazars are normally fitted either by a single power-law(PL) or a log-normal(call Logarithmic Parabola, LP) form. The possible reason for this difference is not clear. We statistically explore this issue based on the different observational properties of 1419 Fermi blazars in the 3 LAC Clean Sample. We find that the γ-ray flux(100 Me V–100 Ge V) and variability index follow bimodal distributions for PL and LP blazars, where the γ-ray flux and variability index show a positive correlation. However, the distributions of γ-ray luminosity and redshift follow a unimodal distribution. Our results suggest that the bimodal distribution of γ-ray fluxes for LP and PL blazars may not be intrinsic and all blazars may have an intrinsically curved γ-ray spectrum, and the PL spectrum is just caused by the fitting effect due to less photons.
基金Supported by the Fund Project for the Growth of Young Scientific Talents of the Department of Education of Guizhou Province(Qianjiaoguhe KY[2016]No.269)the Open-end Fund for the Key Laboratory of Green Pesticide and Agricultural Bioengineering of the Ministry of Education,Guizhou University(2016GDGP0101)the Projects for Undergraduates of Liupanshui Teachers Normal University(LPSSYDXS1613)
文摘Survey was conducted to investigate the occurrence laws of bacterial canker disease of kiwifruits in Liupanshui area,Guizhou Province,and the pathogens and hazard symptoms of the canker disease were introduced. The results showed that the factors influencing the occurrence of bacterial canker disease of kiwifruit were identified as inter-species resistance,agronomic traits,meteorological and ecological conditions,cultivation and management techniques and fertilization levels. Techniques for the comprehensive control of kiwi canker disease were stated,and control suggestions were proposed.
基金the National Natural Science Foundation of China(Grant Nos.11673060,11763005,11873043 and 11991051)the Specialized Research Fund for Shandong Provincial Key Laboratory(Grant No.KLWH201804)the Research Foundation for Scientific Elitists of the Department of Education of Guizhou Province(Grant No.QJHKYZ[2018]068)。
文摘It is surprising to find an instance of migration in the peak positions of synchrotron spectral energy distribution components during the activity epochs of Markarian 421(Mrk 421),accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands.A geometric interpretation and standard shock or stochastic acceleration models of blazar emission have difficulty reproducing these observed behaviors.The present paper introduces a linear acceleration by integrating the reconnection electric field into the particle transport model for the observed behaviors of Mrk 421.We note that strong evidence for evolution in characteristic of multi-wavelength spectral energy distribution including shifting the peak frequency,accompanying an orphan flare at the X-ray and GeV-TeVγ-ray bands provides an important electrostatic acceleration diagnostic in a blazar jet.Assuming suitable model parameters,we apply the results of the simulation to the 13-day flaring event in March 2010 of Mrk 421,concentrating on the evolution of multiwavelength spectral energy distribution characteristic by shifting the peak frequency.It is clear that the ratio of the electric field and magnetic field strength plays an important role in temporal evolution of the peak frequency of synchrotron spectral energy distribution component.We suggest it is reasonable that the electrostatic acceleration is responsible for the evolution of multi-wavelength spectral energy distribution characteristic by shifting the peak frequency.Based on the model results,we assert that the peak frequency of the synchrotron spectral energy distribution component may signify a temporary characteristic of blazars,rather than a permanent one.
基金Project supported by the National Natural Science Foundation of China(Grant No.NSF-11174069)the Natural Science Foundation of Hebei Province,China(Grant No.E2011205083)+1 种基金the Key Item Science Foundation of the Education Department of Hebei Province,China(Grant No.ZD2010129)the Young Scholar Science Foundation of the Education Department of Hebei Province,China(Grant No.QN20131008)
文摘(A)[B]2O4ferrite samples with the composition Co1-xCrxFe2O4(0.0 ≤ x ≤ 1.0) are prepared using a hydrothermal method, and subjected to calcining in a tube furnace with an argon-flow at 1673 K for 2 h. X-ray diffraction patterns indicate that each of all the samples has a single phase cubic spinel structure with a space group of Fdˉ3m. Magnetic measurements show that the saturation magnetization decreases with as the Cr content x increases. The cation distribution of the samples is estimated by fitting the dependence of the magnetic moments on x at 10 K, using the quantum mechanical model previously proposed by our group. The calculated sum of the content values of the Cr3+and Cr2+cations occupying the(A) sites increases as the value of x increases. In the fitting process, the magnetic moment directions of the Cr3+and Cr2+cations are assumed to be antiparallel to those of the Fe and Co cations, respectively, which is in accordance with Hund's rules.
基金supported by the National Natural Science Foundation of China(Grant No.NSF-11174069)the Natural Science Foundation of Hebei Province,China(Grant No.E2011205083)+2 种基金the Key Item Science Foundation of Hebei Province,China(Grant No.10965125D)the Key Item Science Foundation of the Education Department of Hebei Province,China(Grant No.ZD2010129)the Young Scholar Science Foundation of the Education Department of Hebei Province,China(Grant No.QN20131008)
文摘Ag-doped manganite powder samples, La0.7Sr0.1AgxMnO3-δ(x = 0.00, 0.025, 0.05, 0.075, and 0.10) were synthesized using the sol–gel method. X-ray diffraction patterns indicated that the samples had two phases with the R3c perovskite being the dominant phase and Mn3O4 being the second phase. X-ray energy dispersive spectra indicated that the ratio of Ag to La was very close to that of the nominal composition in the samples. The specific saturation magnetizations at 300 K increased from 32.0 A·m2/kg when x = 0.00 to 46.8 A·m2/kg when x = 0.10. The Curie temperature, T C, of the samples increased from 310 K when x = 0.00 to 328 K when x = 0.10. Because the atomic concentration ratios of La, Sr, and Mn in the five samples were all the same and only the Ag concentration changed, the variations of the specific saturation magnetizations at 300 K and the Curie temperatures suggested that the Ag cations have been doped into the A sites of the perovskite phase in the samples.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274108)
文摘We address velocity-modulation control of electron wave propagation in a normal/ferromagnetic/normal silicene junc tion with local variation of Fermi velocity, where the properties of charge, valley, and spin transport through the junction ar investigated. By matching the wavefunctions at the normal-ferromagnetic interfaces, it is demonstrated that the variation of Fermi velocity in a small range can largely enhance the total conductance while keeping the current nearly fully valley and spin-polarized. Further, the variation of Fermi velocity in ferromagnetic silicene has significant influence on the valley and spin polarization, especially in the low-energy regime. It may drastically reduce the high polarizations, which can b realized by adjusting the local application of a gate voltage and exchange field on the junction.
基金Supported by the Guizhou Provincial Science and Technology Foundation(No.LKLS[2013]20)the Scientific and Technological Innovation Platform of Liupanshui(52020-2018-02-01 and 52020-2017-02-02)+1 种基金Youth Talent Growth Project of Educational Department of Guizhou Province(No.KY [2017]271)2011 Collaborative Innovation Center of Guizhou Province(Qian Jiao he xietongchuangxin zi [2016]02)
文摘Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H2O)]·H2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu2(2,4-D)4(Hnta)2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes’ cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.
基金Funded by the International Science and Technology Cooperation Project of Hubei Province(2016AHB008)the Natural Science Foundation of Hubei Province(2015CFB724,2016CFA006)+1 种基金the National Natural Science Foundation of China(51272195,51521001)the National Key Research and Development Program of China(2017YFB0310400)
文摘Polycrystalline Bi_4Ti_3O_(12) thin films with various fractions of a-axis, c-axis and random orientations have been grown on Pt(111)/Ti/Si O_2/Si substrates by laser-ablation under different kinetic growth conditions. The relationship between the structure and ferroelectric property of the films was investigated, so as to explore the possibility of enhancing ferroelectric polarization by controlling the preferred orientation. The structural characterization indicated that the large growth rate and high oxygen background pressure were both favorable for the growth of non-c-axis oriented grains in the Bi_4Ti_3O_(12) thin films. The films with high fractions of a-axis and random orientations, i e, f(a-sxis) = 28.3% and f(random) = 69.6%, could be obtained at the deposition temperature of 973 K, oxygen partial pressure of 15 Pa and laser fluence of 4.6 J/cm^2, respectively. It was also noted that the variation of ferroelectric polarization was in accordance with the evolution non-c-axis orientation. A large value of remanent polarization(2 Pr = 35.5 μC/cm^2) was obtained for the Bi_4Ti_3O_(12) thin films with significant non-c-axis orientation, even higher than that of rare-earth-doped Bi_4Ti_3O_(12) films.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11547249,51501102,and 11647157)the Science Foundation for Excellent Youth Doctors of Three Gorges University,China(Grant No.KJ2014B076)
文摘The transport property of electrons tunneling through arrays of magnetic and electric barriers is studied in silicene.In the tunneling transmission spectrum, the spin-valley-dependent filtered states can be achieved in an incident energy range which can be controlled by the electric gate voltage. For the parallel magnetization configuration, the transmission is asymmetric with respect to the incident angle θ, and electrons with a very large negative incident angle can always transmit in propagating modes for one of the spin-valley filtered states under a certain electromagnetic condition. But for the antiparallel configuration, the transmission is symmetric about θ and there is no such transmission channel. The difference of the transmission between the two configurations leads to a giant tunneling magnetoresistance(TMR) effect.The TMR can reach to 100% in a certain Fermi energy interval around the electrostatic potential. This energy interval can be adjusted significantly by the magnetic field and/or electric gate voltage. The results obtained may be useful for future valleytronic and spintronic applications, as well as magnetoresistance device based on silicene.
基金This work is financially supported by the Guizhou Province United Fund(Qiankehe J zi LKLS[2013]27)the Guizhou Province Education Department(Qianjiaohe KY zi[2019]137),the Guizhou Province United Fund(Qiankehe LH zi[2015]7608)+2 种基金the Guizhou Solid Waste Recycling Laboratory of Coal Utilization([2011]278)the Guizhou Provincial Education Department’s Scientific and Technological Innovation Team([2017]054)the Academician Workstation of Liupanshui Normal University(Qiankehepingtairencai[2019]5604).
文摘The pressure swing distillation(PSD)process for separation of ethyl acetate and ethanol mixture in subplateau region was simulated.The pressure of low-pressure column was set at 0.086 MPa,which is in accordance with the atmospheric pressure in the Yunnan-Guizhou region,while the pressure of high-pressure column was determined as 0.304 MPa.Various design parameters,including the plate number,the reflux ratio,and the feeding positions,were optimized,while taking into consideration the total annual cost(TAC).Furthermore,based on the general PSD,the partially heatintegrated pressure swing distillation(PHIPSD)process and the fully heat-integrated pressure swing distillation(FHIPSD)process were also studied.The processes with heat integration showed lower capital cost and lower energy cost,and TACs of the PHIPSD and FHIPSD decreased to 377.21×103$/a and 371.66×103$/a,respectively.Compared with the non-heat integrated process,TACs of the PHIPSD and FHIPSD could be reduced by 27.82%and 28.89%,respectively.The results showed that the FHIPSD process could effectively separate the ethyl acetate-ethanol mixture,and it was more economical and reasonable.This work can provide some technical references for the separation of such azeotropes in the sub-plateau region.
基金the National Natural Science Foundation of China(Grant Nos.11763005 and 11873043)the Science and Technology Foundation of Guizhou Province(QKHJC[2019]1290)the Research Foundation for Scientific Elitists of the Department of Education of Guizhou Province(QJHKYZ[2018]068)。
文摘In the fourth Fermi Large Area Telescope source catalog(4 FGL),5064γ-ray sources are reported,including 3207 active galactic nuclei(AGNs),239 pulsars,1336 unassociated sources,92 sources with weak association with blazars at low Galactic latitudes and 190 other sources.We employ two different supervised machine learning classifiers,combined with the direct observation parameters given by the 4 FGL fits table,to search for sources potentially classified as AGNs and pulsars in the 1336 unassociated sources.In order to reduce the error caused by the large difference in the sizes of samples,we divide the classification process into two separate steps in order to identify the AGNs and the pulsars.First,we select the identified AGNs from all of the samples,and then select the identified pulsars from the remaining cases.Using the 4 FGL sources associated or identified as AGNs,pulsars and other sources with the features selected through the K-S test and the random forest(RF)feature importance measurement,we trained,optimized and tested our classifier models.Then,the models are applied to classify the 1336 unassociated sources.According to the calculation results of the two classifiers,we report the sensitivity,specificity,accuracy in each step and the class of unassociated sources given by each classifier.The accuracy obtained in the first step is approximately 9595%;in the second step,the obtained overall accuracy is approximately 80%.Combining the results of the two classifiers,we predict that there are 583 AGN-type candidates,115 pulsar-type candidates,154 other types ofγ-ray candidates and 484 of uncertain types.
基金This work has been supported by the National Science Foundation of China Grant No.61762092“Dynamic multi-objective requirement optimization based on transfer learning,”and the Open Foundation of the Key Laboratory in Software Engineering of Yunnan Province,Grant No.2017SE204+1 种基金“Research on extracting software feature models using transfer learning,”and the National Science Foundation of China Grant No.61762089“The key research of high order tensor decomposition in a distributed environment”.
文摘With the rise of open-source software,the social development paradigm occupies an indispensable position in the current software development process.This paper puts forward a variant of the PageRank algorithm to build the importance assessment model,which provides quantifiable importance assessment metrics for new Java projects based on Java open-source projects or components.The critical point of the model is to use crawlers to obtain relevant information about Java open-source projects in the GitHub open-source community to build a domain knowledge graph.According to the three dimensions of the Java open-source project’s project influence,project activity and project popularity,the project is measured.A modified PageRank algorithm is proposed to construct the importance evaluation model.Thereby providing quantifiable importance evaluation indicators for new Java projects based on or components of Java open-source projects.This article evaluates the importance of 4512 Java open-source projects obtained on GitHub and has a good effect.
文摘Located in Zhutang, Lancang County, Laomian language, which still enjoys its vitality recently, is surrounded by variousdominant languages. But as the development of the links between ethnic groups, especially with the Han group, the Laomian lan-guage has undergone many variations, among which typically includes an increase of words. This paper is based on the research onLaomian village regarding the Chinese loanwords in Laomian language under the language contact.
