Cuticular wax formation on the surface of plant leaves is associated with drought-stress tolerance.The identification of wax biosynthesis-related genes will contribute to the genetic improvement of drought resistance ...Cuticular wax formation on the surface of plant leaves is associated with drought-stress tolerance.The identification of wax biosynthesis-related genes will contribute to the genetic improvement of drought resistance in plants.In this study,we characterize a novel Dianthus spiculifolius mutant with increased cuticular wax.The mutant exhibited stronger drought resistance as indicated by less leaf wilting and death,higher leaf relative water content and water retention capacity,and slower water loss and chlorophyll extraction than did the wild type during drought treatment.In the mutant leaves,2730 upregulated and 2151 downregulated differentially expressed genes(DEGs)were identified by transcriptome sequencing.A wax biosynthesis pathway of the identified DEGs was significantly enriched.Finally,three key genes(DsCER1,DsMAH1,and DsWSD1)involved in wax biosynthesis were identified and verified by qPCR.These results suggest that differential expression of DEGs involved in wax biosynthesis may be associated with the increase in cuticular wax in the mutant.Taken together,our results help elucidate wax formation patterns in D.spiculifolius.Furthermore,the DEGs involved in wax biosynthesis identified here may be valuable genetic resources for improving plant stress tolerance through increased accumulation of cuticular wax.展开更多
The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the ba...The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the balance between electrode activity and stability more difficult.Here,we develop an efficient and durable electrode for water oxidation reaction(WOR),which yields a high current density of 1000 mA cm−2 at an overpotential of only 284 mV in 1M KOH at 25°C and shows robust stability even in 6M KOH strong alkali with an elevated temperature up to 80°C.This electrode is fabricated from a cheap nickel foam(NF)substrate through a simple one-step solution etching method,resulting in the growth of ultrafine phosphorus doped nickel-iron(oxy)hydroxide[P-(Ni,Fe)O_(x)H_(y)]nanoparticles embedded into abundant micropores on the surface,featured as a self-stabilized catalyst–substrate fusion electrode.Such self-stabilizing effect fastens highly active P-(Ni,Fe)O_(x)H_(y)species on conductive NF substrates with significant contribution to catalyst fixation and charge transfer,realizing a win–win tactics for WOR activity and durability at high current densities in harsh environments.This work affords a cost-effective WOR electrode that can well work at large current densities,suggestive of the rational design of catalyst electrodes toward industrial-scale water electrolysis.展开更多
Kaolin as a raw material for mesoporous support was firstly modified by calcination,acid treatment,and then was used to prepare nickel catalysts.The amount of alumina which was activated in kaolin during thermal treat...Kaolin as a raw material for mesoporous support was firstly modified by calcination,acid treatment,and then was used to prepare nickel catalysts.The amount of alumina which was activated in kaolin during thermal treatment and then leached out in the acid was different.XRD pattern of the kaolin calcined at 600°C or 900°C exhibited only the diffraction peaks for amorphous silica and quartz while that calcined at 1100°C showed obvious peaks forγ-Al2 O3.Therefore,the nickel-based catalysts exhibited different physic-chemical properties.Atmospheric syngas methanation over the catalysts clarified an activity order of CA-1100 N CA-900 N CA-1400 N CA-600 N KA≈0 at temperatures of 350–650°C and a space velocity of 120 L·g-1·h-1.Metallic nickel with small diameter which has medium interaction with the modified kaolin and is well dispersed on the support would have reasonably good activity and carbon-resistance for syngas methanation.展开更多
The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under di...The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under different temperature.Specific speaking,express ZmGST in Escherichia coli,then purify the recombinant protein and make the thermal stability analysis.Therefore,the experiments were carried out to provide a theoretical basis for the further elaboration to the population degradation mechanisms of Z.marina.In conclusion,the thermostability and the response of ZmGST gene to temperature changes can determine its temperature tolerance range,and affect its resilience in turn.展开更多
Lignocellulose is the most abundant renewable resource on earth.However,owing to the tightly entangled structural characteristics,it is challenging to convert lignocellulose into bio-based products in the biorefinery ...Lignocellulose is the most abundant renewable resource on earth.However,owing to the tightly entangled structural characteristics,it is challenging to convert lignocellulose into bio-based products in the biorefinery process without pretreatment.Pretreatment can destroy the natural resistance structure of lignocellulosic biomass,which is conducive to its downstream enzymatic saccharification and fermentation process.Physical,chemical,and physicochemical pretreatments have been widely conducted for lignocellulosic biomass;several updated approaches and peculiar chemicals have also been proposed for these pretreatment methods in the recent years.Hence,this study comprehensively reviews the novel technologies and chemicals that were applied in the various pretreatments.In addition,the mechanisms,advantages,and disadvantages of the updated pretreatments are discussed to provide a reference for developing new pretreatment methods.展开更多
A general approach is reported for ultra-fast phosphating synthesis of a series of ultra-small(<5 nm)noble metal phosphides(MPX/CNT,M=Pd,Pt,Ru)which are successfully produced in just 75 s for the first time.The cat...A general approach is reported for ultra-fast phosphating synthesis of a series of ultra-small(<5 nm)noble metal phosphides(MPX/CNT,M=Pd,Pt,Ru)which are successfully produced in just 75 s for the first time.The catalytic performance of the catalysts can be optimized by controlling the nanomaterials as the metastable crystalline phases.By altering the phosphorus source under the same conditions,the hexagonal structured Pd_(7)P_(3)(NaH_(2)PO_(2).H_(2)O as P source)and monoclinic structured Pd_(6)P(Na_(4)P_(2)O_(7) as P source)can be prepared successfully.Both of them exhibit excellent polyol oxidation performance in alkaline media.Monoclinic Pd_(6)P/CNT and hexagonal Pd_(7)P_(3)/CNT have large ECSA which are confirmed as 82.1 m2 g^(-1)and 86.2 m2 g^(-1),respectively.Hexagonal Pd_(7)P_(3)/CNT has the highest mass activity of 6.14 A mgPd^(-1)(3.21 A mgPd^(-1)for Pd_(6)P/CNT)for GOR,which far exceeded Pt/C(2.81 A mgPt^(-1)).Meanwhile,the mass activity of monoclinic Pt_(5)P_(2)/CNT for EGOR achieved 12.4 A mg_(Pt)^(-1),which far exceeded Pt/C(6.8 A mg_(Pt)^(-1)).The stability test proved that the activity decay of these catalysts was negligible after the 12-hour durability test.Meanwhile,they have excellent CO anti-poisoning abilities.展开更多
The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS de...The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS deformation fields based on SAR images and applied offset tracking methods to obtain offset measurements based on optical satellite images.The maximum displacement of about 6 m is detected in the direction away from the satellite on the south-west side and also towards the satellite on the north-east side.The 3D deformation field is then resolved by the combination of these measurements with a least-square solve method,and comparisons with 3 components of GPS stations show good consistency.Despite complex features demonstrated in the 3D deformation field,there are still clear spatial correlations between surface deformation and faults distribution.It reveals that more than ten faults were ruptured during the earthquake,including some faults were previously understudies for their tectonic activities.The maximum horizontal deformation of about 10 m occurs along the Kekerengu fault with the vertical deformation up to 2 m.The 3D deformation shows that the mainshock is a multisegments faulting with a rupture process of strike-slip,compression,transpressional rupture and strike-slip in space along the NE direction.展开更多
Pb-based group-IV chalcogenides including Pb Te and Pb Se have been extensively studied as high performance thermoelectric materials during the past few decades.However,the toxicity of Pb inhibits their applications i...Pb-based group-IV chalcogenides including Pb Te and Pb Se have been extensively studied as high performance thermoelectric materials during the past few decades.However,the toxicity of Pb inhibits their applications in vast fields due to the serious harm to the environment.Recently the Pb-free group-IV chalcogenides have become an extensive research subject as promising thermoelectric materials because of their unique thermal and electronic transport properties as well as the enviromentally friendly advantage.This paper briefly summarizes the recent research advances in Sn-,Ge-,and Sichalcogenides thermoelectrics,showing the unexceptionally high thermoelectric performance in Sn Se single crystal,and the significant improvement in thermoelectric performance for those polycrystalline materials by successfully modulating the electronic and thermal transport through using some well-developed strategies including band engineering,nanostructuring and defect engineering.In addition,some important issues for future device applications,including N-type doping and mechanical and chemical stabilities of the new thermoelectrics,are also discussed.展开更多
The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have ...The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have not been studied in great detail.Previous studies identified,using integrated multipleomics analysis,revealed that APETALA2(AP2)is an important candidate gene that modulates type formation of P.lactiflora flowers.To further reveal the expression mechanism of AP2 in P.lactiflora petals,we examined the profile of AP2 expression in the inner and outer petals of‘ZiFengyu’at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis.Based on our data,the AP2 levels in the outer petals were obviously increased,relative to the inner petals.In addition,the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1,thereby promoting bloom stage S2,while declining stage S4.Using chromosome walking,the 2000 bp of the 5′-end upstream promoter region was achieved.This region harbored a CpG island(−665∼−872 bp),with multiple essential transcription factor binding sites(TFBS)such as NF-kappa B,GATA-1,Sp1,and C/EBP.Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the AP2 promoter,thereinto,the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals.Correlation analysis revealed a negative association between the level of methylation(CpG-3,CpG-6),and AP2 mRNA expression.CpG-3 was located on the Sp1 transcription factor binding site.Thus,we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter,thereby regulating AP2 expression.Herein,we examined the role of AP2 in the determination of flower patterns in P.lactiflora.Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in P.lactiflora.展开更多
Herbaceous peony(Paeonia lactiflora Pall.)is an important ornamental plant worldwide.In its natural state,P.lactiflora often manifests traits like rapidly elongating internodal growth,loose plant types,and soft inflor...Herbaceous peony(Paeonia lactiflora Pall.)is an important ornamental plant worldwide.In its natural state,P.lactiflora often manifests traits like rapidly elongating internodal growth,loose plant types,and soft inflorescence stems.However,very little has been known about the measures for controlling these traits.This study investigated the effect of applying paclobutrazol(PBZ)on the plant growth and flower quality in P.lactiflora.The results indicated that PBZ application reduced the plant height(8.05%),plant crown width(14.72%),and leaf area(10.90%),but increased the leaf thickness(18.18%)and stem diameter(over 11%)in P.lactiflora.Meanwhile,PBZ application was also found to increase the chlorophyll(Chl)a(29.63%),Chl b(33.33%),Chl a+b(30.56%),SPAD(27.32%),relative water content(0.47%),soluble sugar(5.09%)and activities of three antioxidant enzymes(superoxide dismutase 169.66%,peroxidase 3.59%,catalase 319.30%),but decreased the relative electrical conductivity(18.52%).Additionally,the application of PBZ was found to affect the flowering quality of P.lactiflora,increasing the flower diameter and fresh weight only in the flower-bud stage.This initiates the bloom stage,where there was a decrease in the total content of the aromatic compounds except for the flower-bud stage,and faded the flower color by reducing the content of anthocyanin.These results demonstrated that the application of PBZ can regulate the P.lactiflora plant types with no significant decrease in its ornamental values.This might provide a theoretical basis for further applying PBZ in P.lactiflora for use in urban landscape spaces.展开更多
[ Objective ] This study aimed to obtain the recombinant Pichia yeast strain which can efficiently degrade guar gum. The properties of the recombinant enzyme were studied preliminarily. [ Method ] A positive clone tha...[ Objective ] This study aimed to obtain the recombinant Pichia yeast strain which can efficiently degrade guar gum. The properties of the recombinant enzyme were studied preliminarily. [ Method ] A positive clone that could hydrolyze guar gum was obtained through the construction and functional screening of a soil genome library. Sequence analysis indicated that the 1485-bp clone encodes a 494-amino acid protein with a relative molecular mass of 53 949 kD, containing a cellulose-binding domain. The recombinant plasmid pHBM731 was generated by inserting the optimized target gene into a Pichia pastoris expression vector pHBMg05 that was transformed into three Pichia pastoris strains, GS115, KM71 and SMD1168. The biochemical properties of the enzyme were assessed. [ Result] The cloned galactonumnan （GM）-degrading enzyme was expressed and secreted by Pichia pastoris GSll5. High cell density fermentation was induced in recombi- nant Pichia pastoris at 25 and 28 ~C ; a higher enzyme activity was observed at an induction temperature of 28 ~C. The optimal temperature for the recombinant en- zyme is 60 ~C, and the optimal pH is 6.6. The enzyme activity was 38.61 U under optimal conditions. Over 50% of the enzyme activity was maintained under the optimal conditions after 9 h. Under the optimal conditions, the effect of metal ions on enzyme activity was analyzed. Ca2 ＋ , Fe2 ＋ and Li ~ slightly enhanced enzyme activity, while Mn2＋ and Co2＋ had little effect. Enzyme activity was modestly suppressed by Mg2~ , K~ and Na＋ , but considerably suppressed by Ag2~ and Zn2~ , with Cu2 ＋ showing the strongest inhibitory effects. [ Conclusion] A novel GM-degrading enzyme expressed by soil yeast was cloned, which can potentially be used in industrial applications to obtain eommereially useful guar gum-degradation products.展开更多
By means of the microstructure observation and creep properties measurement, an investigation has been made into the influence of the salt quenching temperatures on the microstructure and creep property of FGH95 super...By means of the microstructure observation and creep properties measurement, an investigation has been made into the influence of the salt quenching temperatures on the microstructure and creep property of FGH95 superalloy. The results shown that, after full heat treatment, a high volume of g￠ phase and some granular carbide dispersedly precipitate in the matrix. Thereinto, as the molten salt temperature decreases from 650℃to520℃, the size of fine g￠ phase in the alloy decrease gradually and the amount of carbides increase in the alloy. And the alloy quenched in molten salt at520℃possesses better creep resistance due to the fact that there are more granular carbides precipitating in the alloy to enhance the grain strength. During creep, the deformation features of the alloy are that the configurations of stacking fault and slipping dislocations are activated in the alloy.展开更多
With the growing demand for environmental protection and physical health,food safety is now receiving more and more attention all over the world.However,pesticides are indispensable in agricultural production.Therefor...With the growing demand for environmental protection and physical health,food safety is now receiving more and more attention all over the world.However,pesticides are indispensable in agricultural production.Therefore,how to efficiently degrade pesticides and remove their residues in foods has always been a hot research topic in recent decades.This paper not only summarizes the types,degradation mechanism and artificial degradation of organophosphorus pesticides,but also highlights the latest advances in chemical degradation,photocatalytic degradation and biodegradation.展开更多
Given the threat of Vespa mandarinia invasion to ecological balance,according to the data and information provided,the dynamic reproduction model of Vespa mandarinia is established by using natural domain inter&...Given the threat of Vespa mandarinia invasion to ecological balance,according to the data and information provided,the dynamic reproduction model of Vespa mandarinia is established by using natural domain interpolation,and the variation law of total bumblebee with time,latitude,and longitude is obtained.At the same time,we established the classification prediction model by using a neural network and established the mapping relationship between time and space to evaluation grade.We meshed the area provided by the title,assigned values to the location of Vespa mandarinia(VM),and established a VM diffusion model with natural neighborhood interpolation.Its propagation process is simulated by cellular automata.It is determined that VM spreads in a circular shape centered at(122.93174°W,48.93457°N)and(122.57376°W,49.07848°N)in the Washington area,with the farthest distance being 1184.4 km and 985 km respectively.We set up a classification prediction model for better classification.According to the image upload time and location,SVM and neural network are used for classification prediction,and the classification accuracy is 74.26%and 97.60%,respectively,and the neural network has higher classification accuracy.So we choose the neural network.展开更多
[Objectives] To prepare Ibuprofen-β-CD for thermosensitive in situ gel administration to achieve a slow drug release. [Methods]By saturation solution process,the best inclusion technology was screened out with orthog...[Objectives] To prepare Ibuprofen-β-CD for thermosensitive in situ gel administration to achieve a slow drug release. [Methods]By saturation solution process,the best inclusion technology was screened out with orthogonal design. [Results]The prescription of in situ gel contained ibuprofen-β-CD complex,poloxamer P407,P188,and HPMCK4M( w/v 10%,18%,3%,and 0. 5%). The gelation temperature of ibuprofen gel was 34. 6 ± 0. 3℃. The viscosity of ibuprofen gel increased significantly above 35℃ and showed semi-solid attribute. [Conclusions] The release of ibuprofen from in situ gel was slow and stable in 96 h,demonstrated a proximate zero order release between 24 h and 96 h.展开更多
基金This work was supported by grants from the Natural Science Foundation of Heilongjiang Province of China,no.C2016024the China Postdoctoral Science Foundation,no.2016M601409+1 种基金the Heilongjiang Postdoctoral Fund to Pursue Scientific Research in Heilongjiang Province of China,no.LBH-Z16024the Young Talent Project of Northeast Agricultural University of China,no.16QC06.
文摘Cuticular wax formation on the surface of plant leaves is associated with drought-stress tolerance.The identification of wax biosynthesis-related genes will contribute to the genetic improvement of drought resistance in plants.In this study,we characterize a novel Dianthus spiculifolius mutant with increased cuticular wax.The mutant exhibited stronger drought resistance as indicated by less leaf wilting and death,higher leaf relative water content and water retention capacity,and slower water loss and chlorophyll extraction than did the wild type during drought treatment.In the mutant leaves,2730 upregulated and 2151 downregulated differentially expressed genes(DEGs)were identified by transcriptome sequencing.A wax biosynthesis pathway of the identified DEGs was significantly enriched.Finally,three key genes(DsCER1,DsMAH1,and DsWSD1)involved in wax biosynthesis were identified and verified by qPCR.These results suggest that differential expression of DEGs involved in wax biosynthesis may be associated with the increase in cuticular wax in the mutant.Taken together,our results help elucidate wax formation patterns in D.spiculifolius.Furthermore,the DEGs involved in wax biosynthesis identified here may be valuable genetic resources for improving plant stress tolerance through increased accumulation of cuticular wax.
基金National Natural Science Foundation of China,Grant/Award Numbers:11974303,12074332Qinglan Project of Jiangsu Province,Grant/Award Number:137050317the Interdisciplinary Research Project of Chemistry Discipline,Grant/Award Number:yzuxk202014 and High‐End Talent Program of Yangzhou University,Grant/Award Number:137080051。
文摘The key challenge of industrial water electrolysis is to design catalytic electrodes that can stabilize high current density with low power consumption(i.e.,overpotential),while industrial harsh conditions make the balance between electrode activity and stability more difficult.Here,we develop an efficient and durable electrode for water oxidation reaction(WOR),which yields a high current density of 1000 mA cm−2 at an overpotential of only 284 mV in 1M KOH at 25°C and shows robust stability even in 6M KOH strong alkali with an elevated temperature up to 80°C.This electrode is fabricated from a cheap nickel foam(NF)substrate through a simple one-step solution etching method,resulting in the growth of ultrafine phosphorus doped nickel-iron(oxy)hydroxide[P-(Ni,Fe)O_(x)H_(y)]nanoparticles embedded into abundant micropores on the surface,featured as a self-stabilized catalyst–substrate fusion electrode.Such self-stabilizing effect fastens highly active P-(Ni,Fe)O_(x)H_(y)species on conductive NF substrates with significant contribution to catalyst fixation and charge transfer,realizing a win–win tactics for WOR activity and durability at high current densities in harsh environments.This work affords a cost-effective WOR electrode that can well work at large current densities,suggestive of the rational design of catalyst electrodes toward industrial-scale water electrolysis.
基金Supported by the National Natural Science Foundation of China(21161140329)the National High Technology Research and Development Program of China(2015AA050502).
文摘Kaolin as a raw material for mesoporous support was firstly modified by calcination,acid treatment,and then was used to prepare nickel catalysts.The amount of alumina which was activated in kaolin during thermal treatment and then leached out in the acid was different.XRD pattern of the kaolin calcined at 600°C or 900°C exhibited only the diffraction peaks for amorphous silica and quartz while that calcined at 1100°C showed obvious peaks forγ-Al2 O3.Therefore,the nickel-based catalysts exhibited different physic-chemical properties.Atmospheric syngas methanation over the catalysts clarified an activity order of CA-1100 N CA-900 N CA-1400 N CA-600 N KA≈0 at temperatures of 350–650°C and a space velocity of 120 L·g-1·h-1.Metallic nickel with small diameter which has medium interaction with the modified kaolin and is well dispersed on the support would have reasonably good activity and carbon-resistance for syngas methanation.
基金The Open Fund of Key Laboratory of Marine Spil Oil Identification and Damage Assessment Technology,State Oceanic Administration under contract No.201704the Shandong Provincial Natural Science Foundation of China under contract No.ZR2018MD020
文摘The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under different temperature.Specific speaking,express ZmGST in Escherichia coli,then purify the recombinant protein and make the thermal stability analysis.Therefore,the experiments were carried out to provide a theoretical basis for the further elaboration to the population degradation mechanisms of Z.marina.In conclusion,the thermostability and the response of ZmGST gene to temperature changes can determine its temperature tolerance range,and affect its resilience in turn.
基金This work was sponsored by the Natural Science Foundation of Jiangsu Province(BK20180772)National Natural Science Foundation of China(31800501)Qing Lan Project.
文摘Lignocellulose is the most abundant renewable resource on earth.However,owing to the tightly entangled structural characteristics,it is challenging to convert lignocellulose into bio-based products in the biorefinery process without pretreatment.Pretreatment can destroy the natural resistance structure of lignocellulosic biomass,which is conducive to its downstream enzymatic saccharification and fermentation process.Physical,chemical,and physicochemical pretreatments have been widely conducted for lignocellulosic biomass;several updated approaches and peculiar chemicals have also been proposed for these pretreatment methods in the recent years.Hence,this study comprehensively reviews the novel technologies and chemicals that were applied in the various pretreatments.In addition,the mechanisms,advantages,and disadvantages of the updated pretreatments are discussed to provide a reference for developing new pretreatment methods.
基金supported by the National Natural Science Foundation of China(51772162,22001143,and 52072197)the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(2019KJC004)+4 种基金the Outstanding Youth Foundation of Shandong Province,China(ZR2019JQ14)the Taishan Scholar Young Talent Program(tsqn201909114,tsqn201909123)the Natural Science Foundation of Shandong Province(ZR2020YQ34)the Major Basic Research Program of Natural Science Foundation of Shandong Province under Grant(ZR2020ZD09)the Major Scientific and Technological Innovation Project(2019JZZY020405)。
文摘A general approach is reported for ultra-fast phosphating synthesis of a series of ultra-small(<5 nm)noble metal phosphides(MPX/CNT,M=Pd,Pt,Ru)which are successfully produced in just 75 s for the first time.The catalytic performance of the catalysts can be optimized by controlling the nanomaterials as the metastable crystalline phases.By altering the phosphorus source under the same conditions,the hexagonal structured Pd_(7)P_(3)(NaH_(2)PO_(2).H_(2)O as P source)and monoclinic structured Pd_(6)P(Na_(4)P_(2)O_(7) as P source)can be prepared successfully.Both of them exhibit excellent polyol oxidation performance in alkaline media.Monoclinic Pd_(6)P/CNT and hexagonal Pd_(7)P_(3)/CNT have large ECSA which are confirmed as 82.1 m2 g^(-1)and 86.2 m2 g^(-1),respectively.Hexagonal Pd_(7)P_(3)/CNT has the highest mass activity of 6.14 A mgPd^(-1)(3.21 A mgPd^(-1)for Pd_(6)P/CNT)for GOR,which far exceeded Pt/C(2.81 A mgPt^(-1)).Meanwhile,the mass activity of monoclinic Pt_(5)P_(2)/CNT for EGOR achieved 12.4 A mg_(Pt)^(-1),which far exceeded Pt/C(6.8 A mg_(Pt)^(-1)).The stability test proved that the activity decay of these catalysts was negligible after the 12-hour durability test.Meanwhile,they have excellent CO anti-poisoning abilities.
基金co-supported by the National Key Research and Development Program of China(Grant No.2019YFC1509204)the National Nonprofit Fundamental Research Grant of China,Institute of Geology,China Earthquake Administration(Grant No.IGCEA2005 and No.IGCEA2014)the National Science Foundation of China(Grant No.41631073)
文摘The 2016 MW7.8 Kaikoura earthquake struck the northern part of south Island,New Zealand,within the active and complex Australia-Pacific plate boundary system.Firstly,we used the InSAR method to obtain coseismic LOS deformation fields based on SAR images and applied offset tracking methods to obtain offset measurements based on optical satellite images.The maximum displacement of about 6 m is detected in the direction away from the satellite on the south-west side and also towards the satellite on the north-east side.The 3D deformation field is then resolved by the combination of these measurements with a least-square solve method,and comparisons with 3 components of GPS stations show good consistency.Despite complex features demonstrated in the 3D deformation field,there are still clear spatial correlations between surface deformation and faults distribution.It reveals that more than ten faults were ruptured during the earthquake,including some faults were previously understudies for their tectonic activities.The maximum horizontal deformation of about 10 m occurs along the Kekerengu fault with the vertical deformation up to 2 m.The 3D deformation shows that the mainshock is a multisegments faulting with a rupture process of strike-slip,compression,transpressional rupture and strike-slip in space along the NE direction.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51472052 and U1601213)
文摘Pb-based group-IV chalcogenides including Pb Te and Pb Se have been extensively studied as high performance thermoelectric materials during the past few decades.However,the toxicity of Pb inhibits their applications in vast fields due to the serious harm to the environment.Recently the Pb-free group-IV chalcogenides have become an extensive research subject as promising thermoelectric materials because of their unique thermal and electronic transport properties as well as the enviromentally friendly advantage.This paper briefly summarizes the recent research advances in Sn-,Ge-,and Sichalcogenides thermoelectrics,showing the unexceptionally high thermoelectric performance in Sn Se single crystal,and the significant improvement in thermoelectric performance for those polycrystalline materials by successfully modulating the electronic and thermal transport through using some well-developed strategies including band engineering,nanostructuring and defect engineering.In addition,some important issues for future device applications,including N-type doping and mechanical and chemical stabilities of the new thermoelectrics,are also discussed.
基金the National Natural Science Funds(32102411)the Natural Science Foundation of Jiangsu Province of China(BK20200924)+3 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions of China(20KJB210005)Jiangsu Association for Science and Technology Young Scientific and Technological Talents Project-Supported by Yanqing Wu,the Agricultural Science&Technology Independent Innovation Fund of Jiangsu Province(CX[20]3021)the Graduate Innovation Program of Jiangsu Province(XKYCX19_119)the Excellent Doctoral Dissertation Fund of Yangzhou University。
文摘The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have not been studied in great detail.Previous studies identified,using integrated multipleomics analysis,revealed that APETALA2(AP2)is an important candidate gene that modulates type formation of P.lactiflora flowers.To further reveal the expression mechanism of AP2 in P.lactiflora petals,we examined the profile of AP2 expression in the inner and outer petals of‘ZiFengyu’at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis.Based on our data,the AP2 levels in the outer petals were obviously increased,relative to the inner petals.In addition,the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1,thereby promoting bloom stage S2,while declining stage S4.Using chromosome walking,the 2000 bp of the 5′-end upstream promoter region was achieved.This region harbored a CpG island(−665∼−872 bp),with multiple essential transcription factor binding sites(TFBS)such as NF-kappa B,GATA-1,Sp1,and C/EBP.Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the AP2 promoter,thereinto,the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals.Correlation analysis revealed a negative association between the level of methylation(CpG-3,CpG-6),and AP2 mRNA expression.CpG-3 was located on the Sp1 transcription factor binding site.Thus,we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter,thereby regulating AP2 expression.Herein,we examined the role of AP2 in the determination of flower patterns in P.lactiflora.Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in P.lactiflora.
基金the National Natural Science Funds(32102411)the Natural Science Foundation of Jiangsu Province of China(BK20200924)+3 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions of China(20KJB210005)the Agricultural Science&Technology Independent Innovation Fund of Jiangsu Province(CX[20]3021)the Graduate Innovation Program of Jiangsu Province(XKYCX19_119)the Excellent Doctoral Dissertation Fund of Yangzhou University.
文摘Herbaceous peony(Paeonia lactiflora Pall.)is an important ornamental plant worldwide.In its natural state,P.lactiflora often manifests traits like rapidly elongating internodal growth,loose plant types,and soft inflorescence stems.However,very little has been known about the measures for controlling these traits.This study investigated the effect of applying paclobutrazol(PBZ)on the plant growth and flower quality in P.lactiflora.The results indicated that PBZ application reduced the plant height(8.05%),plant crown width(14.72%),and leaf area(10.90%),but increased the leaf thickness(18.18%)and stem diameter(over 11%)in P.lactiflora.Meanwhile,PBZ application was also found to increase the chlorophyll(Chl)a(29.63%),Chl b(33.33%),Chl a+b(30.56%),SPAD(27.32%),relative water content(0.47%),soluble sugar(5.09%)and activities of three antioxidant enzymes(superoxide dismutase 169.66%,peroxidase 3.59%,catalase 319.30%),but decreased the relative electrical conductivity(18.52%).Additionally,the application of PBZ was found to affect the flowering quality of P.lactiflora,increasing the flower diameter and fresh weight only in the flower-bud stage.This initiates the bloom stage,where there was a decrease in the total content of the aromatic compounds except for the flower-bud stage,and faded the flower color by reducing the content of anthocyanin.These results demonstrated that the application of PBZ can regulate the P.lactiflora plant types with no significant decrease in its ornamental values.This might provide a theoretical basis for further applying PBZ in P.lactiflora for use in urban landscape spaces.
基金Supported by Yantai Municipal Science and Technology Development Plan(2013ZH097)Scientific and Technological Innovation Fund for Students in Binzhou Medical University(BY2013DKCX122)
文摘[ Objective ] This study aimed to obtain the recombinant Pichia yeast strain which can efficiently degrade guar gum. The properties of the recombinant enzyme were studied preliminarily. [ Method ] A positive clone that could hydrolyze guar gum was obtained through the construction and functional screening of a soil genome library. Sequence analysis indicated that the 1485-bp clone encodes a 494-amino acid protein with a relative molecular mass of 53 949 kD, containing a cellulose-binding domain. The recombinant plasmid pHBM731 was generated by inserting the optimized target gene into a Pichia pastoris expression vector pHBMg05 that was transformed into three Pichia pastoris strains, GS115, KM71 and SMD1168. The biochemical properties of the enzyme were assessed. [ Result] The cloned galactonumnan （GM）-degrading enzyme was expressed and secreted by Pichia pastoris GSll5. High cell density fermentation was induced in recombi- nant Pichia pastoris at 25 and 28 ~C ; a higher enzyme activity was observed at an induction temperature of 28 ~C. The optimal temperature for the recombinant en- zyme is 60 ~C, and the optimal pH is 6.6. The enzyme activity was 38.61 U under optimal conditions. Over 50% of the enzyme activity was maintained under the optimal conditions after 9 h. Under the optimal conditions, the effect of metal ions on enzyme activity was analyzed. Ca2 ＋ , Fe2 ＋ and Li ~ slightly enhanced enzyme activity, while Mn2＋ and Co2＋ had little effect. Enzyme activity was modestly suppressed by Mg2~ , K~ and Na＋ , but considerably suppressed by Ag2~ and Zn2~ , with Cu2 ＋ showing the strongest inhibitory effects. [ Conclusion] A novel GM-degrading enzyme expressed by soil yeast was cloned, which can potentially be used in industrial applications to obtain eommereially useful guar gum-degradation products.
文摘By means of the microstructure observation and creep properties measurement, an investigation has been made into the influence of the salt quenching temperatures on the microstructure and creep property of FGH95 superalloy. The results shown that, after full heat treatment, a high volume of g￠ phase and some granular carbide dispersedly precipitate in the matrix. Thereinto, as the molten salt temperature decreases from 650℃to520℃, the size of fine g￠ phase in the alloy decrease gradually and the amount of carbides increase in the alloy. And the alloy quenched in molten salt at520℃possesses better creep resistance due to the fact that there are more granular carbides precipitating in the alloy to enhance the grain strength. During creep, the deformation features of the alloy are that the configurations of stacking fault and slipping dislocations are activated in the alloy.
基金Supported by the Science and Technology Innovation Program of Hunan Province (2019NK4170)High Quality Course for Graduate Students (Xiang Jiao Tong No.[2019]370)
文摘With the growing demand for environmental protection and physical health,food safety is now receiving more and more attention all over the world.However,pesticides are indispensable in agricultural production.Therefore,how to efficiently degrade pesticides and remove their residues in foods has always been a hot research topic in recent decades.This paper not only summarizes the types,degradation mechanism and artificial degradation of organophosphorus pesticides,but also highlights the latest advances in chemical degradation,photocatalytic degradation and biodegradation.
文摘Given the threat of Vespa mandarinia invasion to ecological balance,according to the data and information provided,the dynamic reproduction model of Vespa mandarinia is established by using natural domain interpolation,and the variation law of total bumblebee with time,latitude,and longitude is obtained.At the same time,we established the classification prediction model by using a neural network and established the mapping relationship between time and space to evaluation grade.We meshed the area provided by the title,assigned values to the location of Vespa mandarinia(VM),and established a VM diffusion model with natural neighborhood interpolation.Its propagation process is simulated by cellular automata.It is determined that VM spreads in a circular shape centered at(122.93174°W,48.93457°N)and(122.57376°W,49.07848°N)in the Washington area,with the farthest distance being 1184.4 km and 985 km respectively.We set up a classification prediction model for better classification.According to the image upload time and location,SVM and neural network are used for classification prediction,and the classification accuracy is 74.26%and 97.60%,respectively,and the neural network has higher classification accuracy.So we choose the neural network.
基金Supported by Shandong Science and Technology Development Project in 2014(2014GSF118168)National Natural Science Foundation in 2016(81673360)
文摘[Objectives] To prepare Ibuprofen-β-CD for thermosensitive in situ gel administration to achieve a slow drug release. [Methods]By saturation solution process,the best inclusion technology was screened out with orthogonal design. [Results]The prescription of in situ gel contained ibuprofen-β-CD complex,poloxamer P407,P188,and HPMCK4M( w/v 10%,18%,3%,and 0. 5%). The gelation temperature of ibuprofen gel was 34. 6 ± 0. 3℃. The viscosity of ibuprofen gel increased significantly above 35℃ and showed semi-solid attribute. [Conclusions] The release of ibuprofen from in situ gel was slow and stable in 96 h,demonstrated a proximate zero order release between 24 h and 96 h.
