High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm...High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.展开更多
Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron s...Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.展开更多
Clean utilization of coal depends on the quality of raw coal,which depends on the coal-forming parent materials(petrology and chemical composition of coal),the multiple media of the coal-forming environment,and some e...Clean utilization of coal depends on the quality of raw coal,which depends on the coal-forming parent materials(petrology and chemical composition of coal),the multiple media of the coal-forming environment,and some epigenetic conditions,such as thermal evolution(coalification),magmatic hydrothermal fluid,groundwater.Based on the research results of predecessors and prediction studies of coal resources since the founding of China,the present status of research on coal petrology,coal quality,coal metamorphism,and coal geochemistry in China is discussed in detail,with emphasis on research progress and the general situation of highly efficient and clean utilization of coal in the technical fields of coking,pyrolysis,combustion,gasification,and liquefaction,and the development prospects of coal petrology and coal quality in China are prospected.展开更多
Background: In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproducti...Background: In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproduction in birds is less well established. This experiment was conducted to elucidate the role of leptin on the onset of reproduction in bird, as a first step, to detect the changes of peripheral leptin and leptin receptor mRNA expression in hypothalamus between mature and immature hens at the same age. 120 ISA brown pullets at D60 were allocated randomly into two groups, long light(LL) group being raised under artificial light regimes with incrementally increased light phase(from 8 L:16D to 14 L:12D) and short light(SL) group raised on consistent light(8 L:16D) for 12 wk. Results: The results showed that pullets in LL group reached sexual maturation 15 d earlier than those in SL group. Serum E2 showed a significant increase with age, but no difference was observed between two groups. Serum leptin concentration decreased significantly from D112 to D136 in LL, and was markedly higher in LL group than that in SL at D112, while there was no significant difference between two groups at D136. Leptin receptor and GnRH-I mRNA expression in hypothalamus were significantly increased with age, yet there was no significant difference between SL and LL chickens at the same age. The expression of FSH-β and LH-β mRNA in pituitary was increased with age but did not show significant difference between LL and SL group. GnRH-I mRNA expression was very rich in pineal gland, and decreased from D112 to D136 in LL but not in SL group, and there was no difference between two groups at the same age. Conclusions: These results indicate that the earlier sexual maturation in hens induced by long-light regime is not accompanied with an increase in serum leptin or leptin receptor gene expression in hypothalamus, or genes expression in HPG axis.展开更多
In China,the connection between coal utilization and environmental pollution has been increasingly evident due to the rapid growth in energy consumption.Clean coal technology(CCT)is one of the effective methods to add...In China,the connection between coal utilization and environmental pollution has been increasingly evident due to the rapid growth in energy consumption.Clean coal technology(CCT)is one of the effective methods to address coal-associated pollution.However,CCT needs the practical and theoretical support of clean coal geology(CCG).In this paper,a new definition of CCG is proposed,based on the definitions of coal,coal geology,and CCT,combined with the development of national CCG.CCG is the discipline comprehensively researching the genesis,nature,distribution,cleaning potential,clean utilization and environmental effects of resources(coal,coal bed methane,and other coal-associated resources)that can be cleaned by CCT.The research content of CCG is discussed from different aspects,such as cleaning potential evaluation,geological guarantee for coal mining,ash yields and sulfur contents,trace elements,pollution caused by coal,and mine reclamation.The progress of CCG in China is also briefly divided into four stages and delineated.Finally,scientific problems in CCG are summarized and an outlook for CCG is given.展开更多
In this paper,we reported a first-principles investigation on the structural and electronic properties of O adsorption on the γ-TiAl(111) surface,to illustrate the oxidation process.It has been found that:(1) rather ...In this paper,we reported a first-principles investigation on the structural and electronic properties of O adsorption on the γ-TiAl(111) surface,to illustrate the oxidation process.It has been found that:(1) rather than stopping with one full monolayer of coverage,oxygen adsorption continues till two monolayer coverage,rendering an oxide-like structure;(2) full structural relaxation makes the surface oxide layer denser and more stable,which hinders the subsequent O adsorption(oxidation) process.In addition,the transformation from metal to oxide surface was identified by analyzing the local density of states through the oxidation steps,which was in good agreement with experimental results.展开更多
Seven coal samples were collected from Changguang area,a typical bark coal field in Zhejiang Province,China.The organic geochemical characteristics and depositional environment of bark coal were studied by Rock–Eval ...Seven coal samples were collected from Changguang area,a typical bark coal field in Zhejiang Province,China.The organic geochemical characteristics and depositional environment of bark coal were studied by Rock–Eval pyrolysis,gas chromatography(GC),and gas chromatography–mass spectrometry(GC–MS)analysis.The results show that all samples are type II kerogen.The values of total organic carbon(TOC),potential yield(S1+S2),and hydrogen index of these samples ranged from 65.80 wt%–87.00 wt%,170.43–232.89 mg HC/g,and 234–295 mg HC/g TOC,respectively.In aromatic hydrocarbons compounds of bark coal samples,the phenanthrene series occupy the largest proportion(43.48%–53.74%),followed by the dibenzothiophens(7.33%–16.53%).The distributions of naphthalenes,diphenyls,and chrysene of the samples indicate the source inputs are mainly derived from terrestrial higher plants.Furthermore,the ratios of naphthalene and phenanthrene series compounds reveal the samples are in the mature stage.Some biomarkers(Pr/Ph and C35/C31–35 homohopane),aromatic hydrocarbons(fluorene,dibenzofuran and dibenzothiophene),and high inertinite contents(14.7%–41.8%)suggest that bark coal was formed under relatively oxic conditions and was influenced by marine or brackish lakes environment.展开更多
In wireless sensor networks, the traditional multi-relay incremental cooperative relaying (MIR) scheme could improve the system throughput over the fading channel enormously by exploiting multiple relay nodes to retra...In wireless sensor networks, the traditional multi-relay incremental cooperative relaying (MIR) scheme could improve the system throughput over the fading channel enormously by exploiting multiple relay nodes to retransmit the copy of the source packet to the destination in turn, but increase the energy consumption and transmission delay. In order to mitigating the energy consumption and transmission delay, this paper proposes a new cooperative relaying scheme termed as incremental-selective relaying with best-relay selection (ISR), which selects the best relay node from the candidate relays to retransmit the packet to the destination only when the direct transmission between the source and the destination is not successful. Expressions of normalized throughput, normalized delay and energy efficiency for the ISR and MIR systems are derived respectively and their performances are compared through simulations. The results show that normalized throughput, normalized delay and energy efficiency for the ISR system all outperform the corresponding performances of the MIR system. Especially, there are different the optimal number of relays which can maximize the energy efficiency of system.展开更多
In wireless relaying networks, the traditional incremental cooperative relaying scheme (IR) could improve the system throughput enormously over fading channels by exploiting relay nodes to retransmit the source data p...In wireless relaying networks, the traditional incremental cooperative relaying scheme (IR) could improve the system throughput enormously over fading channels by exploiting relay nodes to retransmit the source data packet to the destination. In order to enhance the system throughput over time-varying fading channels, this paper proposes an adaptive incremental cooperative re-laying scheme (AIR) based on adaptive modulation and coding, which implements adaptive rate transmission for the source and relay nodes according to channel state information. We derive expressions for the AIR system throughput, and then give a gradient-based search algorithm to find the optimized adaptive solution for the AIR system by maximizing throughput subject to the constraint of packet error rate at the data link layer. The results indicate that throughput of AIR system outperforms that of traditional IR system greatly for any SNR value.展开更多
The effects of modified inorganic water-based matrix content on the properties of friction material was studied in the present paper, the regular pattern of the influence of friction material’s friction coefficient a...The effects of modified inorganic water-based matrix content on the properties of friction material was studied in the present paper, the regular pattern of the influence of friction material’s friction coefficient and wear rate on matrix content have been got. It provides technical support for the study of cold forming friction material, and provides the basis for the development and production of the green pollution-free friction material.展开更多
Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-...Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-situ and real-time response to mechanical stimulus.Trap-controlled ML materials realize reproducible,quantitative mechano-optical conversion resulting from the released carriers for the trap-mediated charge storage and release.Herein,modulating traps matters the controllable ML behavior for their promising applications.In this work,a deep trap distributed ranging from 0.9 to 1,3 eV is realized consecutively for the introduction of Sm^(3+)ions into LaGaO_(3) matrix,which contributes to the red emission at 600 nm under mechanical stimuli.Moreover,tunable ML emission modulated from 600to 545 nm is successfully achieved for the codopant of Tb^(3+)ions.It is unambiguously indicated that the released carriers from the trap sharing rather than an additional constructed trap contribute to the modulated ML color.Accordingly,multi-mode anti-counterfeiting and encryption are achieved with the as-explored Sm^(3+),Tb^(3+)co-activated ML phosphor.展开更多
The US President Obama launched the Materials Genome Initiative on June 24,2011,aimed at speeding up the pace of discovering,developing,manufacturing,and deploying advanced materials by at least twice as fast as is po...The US President Obama launched the Materials Genome Initiative on June 24,2011,aimed at speeding up the pace of discovering,developing,manufacturing,and deploying advanced materials by at least twice as fast as is possible at present,at a fraction of the cost with the help of existing advanced computer technology.According to the authors’understanding to the event,this article will first give a brief discussion on the origin of material genome,its scientific implication,research significance,and the far-reaching influence of materials genome study to the developments of materials science and human society.Then,the subsequent contents will introduce the research progresses of the related works carried out by the authors’research group over the last decade,on the first-principles studies of crystalline materials genome.The highlights are focused on the method implementations for configuration optimization of lattice structure,first-principles calculations of various physical parameters on elastic,electronic,dielectric,and thermodynamic properties,and simulations of phase transition and particle transport in solids.The technical details for extending these methods to low-dimensional crystalline materials are also discussed.The article concludes with an outlook on the prospect of materials genome research.展开更多
The microstructural evolution of rapidly solidified(RS) ZK60 powders extruded at 250 C was investigated.It was shown that formation of new ultrafine grains took place through continuous dynamic recrystallization(CDRX)...The microstructural evolution of rapidly solidified(RS) ZK60 powders extruded at 250 C was investigated.It was shown that formation of new ultrafine grains took place through continuous dynamic recrystallization(CDRX),accompanied by the perfect bonding of powders via severe plastic deformation.At a low strain level,a well-defined structure made up of equiaxed and elongated subgrains was developed.Simultaneously,the operation of basal and non-basal dislocation slip led to the formation of low-angle dislocation cells(LADC) within the elongated subgrains.With increasing strain,the number and average misorientation of LADC increased,resulting in fragmentation of original elongation subgrains into a finally homogeneous fine-grained structure.Almost full-recrystallized structure with an average grain size of 0.4 μm was finally evolved after large cumulative strain.The results suggested that structural change was connected with thermal strain,where dislocation activities dominated this process.展开更多
Trichoderma harzianum is a plant-beneficial fungus that secretes small cysteine-rich proteins that induce plant defense responses;however, the molecular mechanism involved in this induction is largely unknown.Here, we...Trichoderma harzianum is a plant-beneficial fungus that secretes small cysteine-rich proteins that induce plant defense responses;however, the molecular mechanism involved in this induction is largely unknown.Here, we report that the class Ⅱ hydrophobin Th Hyd1 acts as an elicitor of induced systemic resistance(ISR) in plants. Immunogold labeling and immunofluorescence revealed Th Hyd1 localized on maize(Zea mays) root cell plasma membranes. To identify host plant protein interactors of Hyd1, we screened a maize B73 root c DNA library. Th Hyd1 interacted directly with ubiquilin1-like(UBL). Furthermore, the N-terminal fragment of UBL was primarily responsible for binding with Hyd1 and the eight-cysteine amino acid of Hyd1 participated in the protein-protein interactions. Hyd1 from T. harzianum(Thhyd1) and ubl from maize were co-expressed in Arabidopsis thaliana, they synergistically promoted plant resistance against Botrytis cinerea. RNA-sequencing analysis of global gene expression in maize leaves 24 h after spraying with Curvularia lunata spore suspension showed that Thhyd1-induced systemic resistance was primarily associated with brassinosteroid signaling, likely mediated through BAK1. Jasmonate/ethylene(JA/ET)signaling was also involved to some extent in this response. Our results suggest that the Hyd1-UBL axis might play a key role in inducing systemic resistance as a result of Trichoderma-plant interactions.展开更多
This study reports a strain of Trichoderma harzianum CCTCC-SBW0162 with potential to enhance biocontrol activity against gray mold pathogen, Botrytis cinerea, and with a pivotal role in tomato(Solanum esculentum) plan...This study reports a strain of Trichoderma harzianum CCTCC-SBW0162 with potential to enhance biocontrol activity against gray mold pathogen, Botrytis cinerea, and with a pivotal role in tomato(Solanum esculentum) plant growth enhancement. A total of 254 Trichoderma isolates were screened by in vitro antagonistic assay. Of these, 10 were selected for greenhouse experiments based on their greater inhibition of B. cinerea.The in vitro antagonistic assay and greenhouse experiments indicated that T. harzianum CCTCC-SBW0162 gave the highest inhibition rate(90.6%) and disease reduction(80.7%). Also, to study the possible mechanism associated with antifungal activity of CCTCC-SBW0162 against B. cinerea, molecular docking was used to assess the interactions between CCTCC-SBW0162-derived metabolites, and pathogencity and virulence related proteins of B. cinerea. The molecular docking results indicated that the combination of harzianopyridone,harzianolide and anthraquinone C derived from CCTCCSBW0162 could synergistically improve antifungal activity against B. cinerea through the inhibition/modification of pathogenicity and virulence related proteins.However, this computerized modeling work emphasized the need for further study in the laboratory to confirm the effect T. harzianum-derived metabolites against the proteins of B. cinerea and their interactions.展开更多
Red emitting phosphors play a significant role in accelerating the improvement of illumination quality for white light emitting diodes(WLEDs).In this work,by using solid-state reaction method,an efficient novel Ba_(2)...Red emitting phosphors play a significant role in accelerating the improvement of illumination quality for white light emitting diodes(WLEDs).In this work,by using solid-state reaction method,an efficient novel Ba_(2)LuNbO_(6):Eu^(3+)phosphor with double-perovskite structure was successfully prepared.Here,a series of Ba_(2)LuNbO_(6):Eu^(3+)red phosphors can be efficiently pumped by the near-ultraviolet(UV)light and then present high-brightness at orange emission(598 nm,~5D_(0)→~7 F_(1))and red emission(610 nm,~5D_(0)→~7 F_(2)).The ratio values of 610 to 598 nm in Ba_(2)LuNbO_(6):Eu^(3+)phosphors exceed 1 when the content of Eu^(3+)is larger than 0.4 mol,because the occupation of Eu^(3+)ions is changed from Lu^(3+)ions with symmetric sites to Ba^(2+)ions with asymmetric sites.Besides,the optimized concentration of Eu^(3+)at the~5D_(0)→~7 F_(2)transitions is obtained when x=1,indicating that there is non-concentration quenching in Ba_(2)LuNbO_(6):Eu^(3+)phosphors.Moreover,the CIE chromaticity coordinates of Ba_(2)LuNbO_(6):Eu^(3+)was calculated to be(0.587,0.361),the color purity was calculated to be 72.26%and internal quenching efficiency(IQE)was measured to be 67%.Finally,the thermal stability of Ba_(2)LuNbO_(6):Eu^(3+)phosphors was also studied.Our work demonstrates that the novel double-perovskite red-emitting Ba_(2)LuNbO_(6):Eu^(3+)phosphors are prospective red emitting elements for WLEDs applications.展开更多
基金supported by Natural Science Basic Research Program in Shaanxi Province of China(No.2023-JCYB-574)National Natural Science Foundation of China(No.62204203).
文摘High qualityβ-Ga_(2)O_(3)single crystal nanobelts with length of 2−3 mm and width from tens of microns to 132μm were synthesized by carbothermal reduction method.Based on the grown nanobelt with the length of 600μm,the dual-Schottky-junctions coupling device(DSCD)was fabricated.Due to the electrically floating Ga_(2)O_(3)nanobelt region coupling with the double Schottky-junctions,the current I_(S2)increases firstly and rapidly reaches into saturation as increase the voltage V_(S2).The saturation current is about 10 pA,which is two orders of magnitude lower than that of a single Schottky-junction.In the case of solar-blind ultraviolet(UV)light irradiation,the photogenerated electrons further aggravate the coupling physical mechanism in device.I_(S2)increases as the intensity of UV light increases.Under the UV light of 1820μW/cm^(2),I_(S2)quickly enters the saturation state.At V_(S2)=10 V,photo-to-dark current ratio(PDCR)of the device reaches more than 104,the external quantum efficiency(EQE)is 1.6×10^(3)%,and the detectivity(D*)is 7.5×10^(12)Jones.In addition,the device has a very short rise and decay times of 25−54 ms under different positive and negative bias.DSCD shows unique electrical and optical control characteristics,which will open a new way for the application of nanobelt-based devices.
基金supported by the National Natural Science Foundation of China (Grant No. 62204203)the Shaanxi Natural Science Basic Research Program (Grant No. 2022JQ-701)。
文摘Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.
基金This research was supported by the National Natural Science Foundation of China(41572146,41872175)National Basic Research Program of China(2014CB238905,2012CB214901)+2 种基金the National Coal Resource Potential Evaluation Project(1212011121043)the National Special,Scarce Coal Resource Survey Project(121201002020)the National Natural Science Foundation of China(No.41872175).
文摘Clean utilization of coal depends on the quality of raw coal,which depends on the coal-forming parent materials(petrology and chemical composition of coal),the multiple media of the coal-forming environment,and some epigenetic conditions,such as thermal evolution(coalification),magmatic hydrothermal fluid,groundwater.Based on the research results of predecessors and prediction studies of coal resources since the founding of China,the present status of research on coal petrology,coal quality,coal metamorphism,and coal geochemistry in China is discussed in detail,with emphasis on research progress and the general situation of highly efficient and clean utilization of coal in the technical fields of coking,pyrolysis,combustion,gasification,and liquefaction,and the development prospects of coal petrology and coal quality in China are prospected.
基金supported by a grant from National Natural Science Foundation of China(Project No.30800809)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Background: In mammals, leptin is an attractive candidate for mediating the metabolic signal and the reproductive function via the specific receptor in hypothalamus. However, till now, the role of leptin on reproduction in birds is less well established. This experiment was conducted to elucidate the role of leptin on the onset of reproduction in bird, as a first step, to detect the changes of peripheral leptin and leptin receptor mRNA expression in hypothalamus between mature and immature hens at the same age. 120 ISA brown pullets at D60 were allocated randomly into two groups, long light(LL) group being raised under artificial light regimes with incrementally increased light phase(from 8 L:16D to 14 L:12D) and short light(SL) group raised on consistent light(8 L:16D) for 12 wk. Results: The results showed that pullets in LL group reached sexual maturation 15 d earlier than those in SL group. Serum E2 showed a significant increase with age, but no difference was observed between two groups. Serum leptin concentration decreased significantly from D112 to D136 in LL, and was markedly higher in LL group than that in SL at D112, while there was no significant difference between two groups at D136. Leptin receptor and GnRH-I mRNA expression in hypothalamus were significantly increased with age, yet there was no significant difference between SL and LL chickens at the same age. The expression of FSH-β and LH-β mRNA in pituitary was increased with age but did not show significant difference between LL and SL group. GnRH-I mRNA expression was very rich in pineal gland, and decreased from D112 to D136 in LL but not in SL group, and there was no difference between two groups at the same age. Conclusions: These results indicate that the earlier sexual maturation in hens induced by long-light regime is not accompanied with an increase in serum leptin or leptin receptor gene expression in hypothalamus, or genes expression in HPG axis.
基金This paper was jointly supported by the National Key Basic Research Program of China(2014CB238905)the National Natural Science foundation of China(41572146)+2 种基金the National Coal Resource Potential Evaluation Project(1212011121043)the Survey Project of Special and Scarce Coal Resources(1212011085511)the Public Welfare Project of the Ministry of Land and Resources(201211003)。
文摘In China,the connection between coal utilization and environmental pollution has been increasingly evident due to the rapid growth in energy consumption.Clean coal technology(CCT)is one of the effective methods to address coal-associated pollution.However,CCT needs the practical and theoretical support of clean coal geology(CCG).In this paper,a new definition of CCG is proposed,based on the definitions of coal,coal geology,and CCT,combined with the development of national CCG.CCG is the discipline comprehensively researching the genesis,nature,distribution,cleaning potential,clean utilization and environmental effects of resources(coal,coal bed methane,and other coal-associated resources)that can be cleaned by CCT.The research content of CCG is discussed from different aspects,such as cleaning potential evaluation,geological guarantee for coal mining,ash yields and sulfur contents,trace elements,pollution caused by coal,and mine reclamation.The progress of CCG in China is also briefly divided into four stages and delineated.Finally,scientific problems in CCG are summarized and an outlook for CCG is given.
基金supported by the National Basic Research Program of China under grant No.2006CB605103
文摘In this paper,we reported a first-principles investigation on the structural and electronic properties of O adsorption on the γ-TiAl(111) surface,to illustrate the oxidation process.It has been found that:(1) rather than stopping with one full monolayer of coverage,oxygen adsorption continues till two monolayer coverage,rendering an oxide-like structure;(2) full structural relaxation makes the surface oxide layer denser and more stable,which hinders the subsequent O adsorption(oxidation) process.In addition,the transformation from metal to oxide surface was identified by analyzing the local density of states through the oxidation steps,which was in good agreement with experimental results.
基金This research was supported by the National Natural Science Foundation of China for financial support(Research Project No.41472132)the Yueqi Youth Scholar Project,China University of Mining&Technology(Beijing).
文摘Seven coal samples were collected from Changguang area,a typical bark coal field in Zhejiang Province,China.The organic geochemical characteristics and depositional environment of bark coal were studied by Rock–Eval pyrolysis,gas chromatography(GC),and gas chromatography–mass spectrometry(GC–MS)analysis.The results show that all samples are type II kerogen.The values of total organic carbon(TOC),potential yield(S1+S2),and hydrogen index of these samples ranged from 65.80 wt%–87.00 wt%,170.43–232.89 mg HC/g,and 234–295 mg HC/g TOC,respectively.In aromatic hydrocarbons compounds of bark coal samples,the phenanthrene series occupy the largest proportion(43.48%–53.74%),followed by the dibenzothiophens(7.33%–16.53%).The distributions of naphthalenes,diphenyls,and chrysene of the samples indicate the source inputs are mainly derived from terrestrial higher plants.Furthermore,the ratios of naphthalene and phenanthrene series compounds reveal the samples are in the mature stage.Some biomarkers(Pr/Ph and C35/C31–35 homohopane),aromatic hydrocarbons(fluorene,dibenzofuran and dibenzothiophene),and high inertinite contents(14.7%–41.8%)suggest that bark coal was formed under relatively oxic conditions and was influenced by marine or brackish lakes environment.
文摘In wireless sensor networks, the traditional multi-relay incremental cooperative relaying (MIR) scheme could improve the system throughput over the fading channel enormously by exploiting multiple relay nodes to retransmit the copy of the source packet to the destination in turn, but increase the energy consumption and transmission delay. In order to mitigating the energy consumption and transmission delay, this paper proposes a new cooperative relaying scheme termed as incremental-selective relaying with best-relay selection (ISR), which selects the best relay node from the candidate relays to retransmit the packet to the destination only when the direct transmission between the source and the destination is not successful. Expressions of normalized throughput, normalized delay and energy efficiency for the ISR and MIR systems are derived respectively and their performances are compared through simulations. The results show that normalized throughput, normalized delay and energy efficiency for the ISR system all outperform the corresponding performances of the MIR system. Especially, there are different the optimal number of relays which can maximize the energy efficiency of system.
文摘In wireless relaying networks, the traditional incremental cooperative relaying scheme (IR) could improve the system throughput enormously over fading channels by exploiting relay nodes to retransmit the source data packet to the destination. In order to enhance the system throughput over time-varying fading channels, this paper proposes an adaptive incremental cooperative re-laying scheme (AIR) based on adaptive modulation and coding, which implements adaptive rate transmission for the source and relay nodes according to channel state information. We derive expressions for the AIR system throughput, and then give a gradient-based search algorithm to find the optimized adaptive solution for the AIR system by maximizing throughput subject to the constraint of packet error rate at the data link layer. The results indicate that throughput of AIR system outperforms that of traditional IR system greatly for any SNR value.
文摘The effects of modified inorganic water-based matrix content on the properties of friction material was studied in the present paper, the regular pattern of the influence of friction material’s friction coefficient and wear rate on matrix content have been got. It provides technical support for the study of cold forming friction material, and provides the basis for the development and production of the green pollution-free friction material.
基金Project supported by the Yunnan Provincial Natural Science Foundation (202101AT070126)the Research Start-up Fund of Chengdu University of Technology (10912-KYQD2020-08476)+1 种基金Fund of Hubei Key Laboratory of Plasma Chemistry,Advanced Materials (KF202103)Sichuan Natural Science Foundation (2022YFH0108,2022JDJQ0030)。
文摘Mechano-luminescence(ML) has been found diverse applications such as stress sensing,3-D signature,energy harvesting,and anti-counterfeiting,due to the unique properties of the corresponding ML phosphors performing in-situ and real-time response to mechanical stimulus.Trap-controlled ML materials realize reproducible,quantitative mechano-optical conversion resulting from the released carriers for the trap-mediated charge storage and release.Herein,modulating traps matters the controllable ML behavior for their promising applications.In this work,a deep trap distributed ranging from 0.9 to 1,3 eV is realized consecutively for the introduction of Sm^(3+)ions into LaGaO_(3) matrix,which contributes to the red emission at 600 nm under mechanical stimuli.Moreover,tunable ML emission modulated from 600to 545 nm is successfully achieved for the codopant of Tb^(3+)ions.It is unambiguously indicated that the released carriers from the trap sharing rather than an additional constructed trap contribute to the modulated ML color.Accordingly,multi-mode anti-counterfeiting and encryption are achieved with the as-explored Sm^(3+),Tb^(3+)co-activated ML phosphor.
基金supported by the National Basic Research Program of China(2006CB605103,2011CB606403)the National Natural Science Foundation of China(50072035,50472085,51071149)
文摘The US President Obama launched the Materials Genome Initiative on June 24,2011,aimed at speeding up the pace of discovering,developing,manufacturing,and deploying advanced materials by at least twice as fast as is possible at present,at a fraction of the cost with the help of existing advanced computer technology.According to the authors’understanding to the event,this article will first give a brief discussion on the origin of material genome,its scientific implication,research significance,and the far-reaching influence of materials genome study to the developments of materials science and human society.Then,the subsequent contents will introduce the research progresses of the related works carried out by the authors’research group over the last decade,on the first-principles studies of crystalline materials genome.The highlights are focused on the method implementations for configuration optimization of lattice structure,first-principles calculations of various physical parameters on elastic,electronic,dielectric,and thermodynamic properties,and simulations of phase transition and particle transport in solids.The technical details for extending these methods to low-dimensional crystalline materials are also discussed.The article concludes with an outlook on the prospect of materials genome research.
基金supported by the Doctoral Fundation of Jiangsu University (No.1281220014)the Graduate Independent Innovation Foundation of Shandong University (No.yzc09054)
文摘The microstructural evolution of rapidly solidified(RS) ZK60 powders extruded at 250 C was investigated.It was shown that formation of new ultrafine grains took place through continuous dynamic recrystallization(CDRX),accompanied by the perfect bonding of powders via severe plastic deformation.At a low strain level,a well-defined structure made up of equiaxed and elongated subgrains was developed.Simultaneously,the operation of basal and non-basal dislocation slip led to the formation of low-angle dislocation cells(LADC) within the elongated subgrains.With increasing strain,the number and average misorientation of LADC increased,resulting in fragmentation of original elongation subgrains into a finally homogeneous fine-grained structure.Almost full-recrystallized structure with an average grain size of 0.4 μm was finally evolved after large cumulative strain.The results suggested that structural change was connected with thermal strain,where dislocation activities dominated this process.
基金supported by the grant from National Key Projects of I Intergovernmental Cooperation in Scientific and Technological Innovation(2017YFE 0104900)the National Natural Science Foundation of China(31872015,31672072)+2 种基金National Key Research and Development Program of China(2017YFD0200901)Agriculture Research System of Shanghai(Grant No.201710)China Agriculture Research System Project(CARS-02)。
文摘Trichoderma harzianum is a plant-beneficial fungus that secretes small cysteine-rich proteins that induce plant defense responses;however, the molecular mechanism involved in this induction is largely unknown.Here, we report that the class Ⅱ hydrophobin Th Hyd1 acts as an elicitor of induced systemic resistance(ISR) in plants. Immunogold labeling and immunofluorescence revealed Th Hyd1 localized on maize(Zea mays) root cell plasma membranes. To identify host plant protein interactors of Hyd1, we screened a maize B73 root c DNA library. Th Hyd1 interacted directly with ubiquilin1-like(UBL). Furthermore, the N-terminal fragment of UBL was primarily responsible for binding with Hyd1 and the eight-cysteine amino acid of Hyd1 participated in the protein-protein interactions. Hyd1 from T. harzianum(Thhyd1) and ubl from maize were co-expressed in Arabidopsis thaliana, they synergistically promoted plant resistance against Botrytis cinerea. RNA-sequencing analysis of global gene expression in maize leaves 24 h after spraying with Curvularia lunata spore suspension showed that Thhyd1-induced systemic resistance was primarily associated with brassinosteroid signaling, likely mediated through BAK1. Jasmonate/ethylene(JA/ET)signaling was also involved to some extent in this response. Our results suggest that the Hyd1-UBL axis might play a key role in inducing systemic resistance as a result of Trichoderma-plant interactions.
基金supported by the National Key Research and Development Program of China (2017YFD0200400, 2017YFD0201108, SQ2017ZY06102)the National Natural Science Foundation of China (20090073110048)+1 种基金the National Modern Agriculture Industry Technique Systems (CARS-02)Special Project of Basic Work Project for Science and Technology (2014FY120900)
文摘This study reports a strain of Trichoderma harzianum CCTCC-SBW0162 with potential to enhance biocontrol activity against gray mold pathogen, Botrytis cinerea, and with a pivotal role in tomato(Solanum esculentum) plant growth enhancement. A total of 254 Trichoderma isolates were screened by in vitro antagonistic assay. Of these, 10 were selected for greenhouse experiments based on their greater inhibition of B. cinerea.The in vitro antagonistic assay and greenhouse experiments indicated that T. harzianum CCTCC-SBW0162 gave the highest inhibition rate(90.6%) and disease reduction(80.7%). Also, to study the possible mechanism associated with antifungal activity of CCTCC-SBW0162 against B. cinerea, molecular docking was used to assess the interactions between CCTCC-SBW0162-derived metabolites, and pathogencity and virulence related proteins of B. cinerea. The molecular docking results indicated that the combination of harzianopyridone,harzianolide and anthraquinone C derived from CCTCCSBW0162 could synergistically improve antifungal activity against B. cinerea through the inhibition/modification of pathogenicity and virulence related proteins.However, this computerized modeling work emphasized the need for further study in the laboratory to confirm the effect T. harzianum-derived metabolites against the proteins of B. cinerea and their interactions.
基金Project supported by the Excellent Youth Project of Yunnan Province Applied Basic Research Project(2019FI001)the National Natural Science Foundation of China(61775187,61965012,12064022)the Key Project of Yunnan Provincial Natural Science Foundation(202101AT070126)。
文摘Red emitting phosphors play a significant role in accelerating the improvement of illumination quality for white light emitting diodes(WLEDs).In this work,by using solid-state reaction method,an efficient novel Ba_(2)LuNbO_(6):Eu^(3+)phosphor with double-perovskite structure was successfully prepared.Here,a series of Ba_(2)LuNbO_(6):Eu^(3+)red phosphors can be efficiently pumped by the near-ultraviolet(UV)light and then present high-brightness at orange emission(598 nm,~5D_(0)→~7 F_(1))and red emission(610 nm,~5D_(0)→~7 F_(2)).The ratio values of 610 to 598 nm in Ba_(2)LuNbO_(6):Eu^(3+)phosphors exceed 1 when the content of Eu^(3+)is larger than 0.4 mol,because the occupation of Eu^(3+)ions is changed from Lu^(3+)ions with symmetric sites to Ba^(2+)ions with asymmetric sites.Besides,the optimized concentration of Eu^(3+)at the~5D_(0)→~7 F_(2)transitions is obtained when x=1,indicating that there is non-concentration quenching in Ba_(2)LuNbO_(6):Eu^(3+)phosphors.Moreover,the CIE chromaticity coordinates of Ba_(2)LuNbO_(6):Eu^(3+)was calculated to be(0.587,0.361),the color purity was calculated to be 72.26%and internal quenching efficiency(IQE)was measured to be 67%.Finally,the thermal stability of Ba_(2)LuNbO_(6):Eu^(3+)phosphors was also studied.Our work demonstrates that the novel double-perovskite red-emitting Ba_(2)LuNbO_(6):Eu^(3+)phosphors are prospective red emitting elements for WLEDs applications.
