Nervonic acid(NA)is a very-long-chain monounsaturated fatty acid with pharmaceutical and nutraceutical functions that plays an important role in treating several neurological disorders.One major source of NA is plant ...Nervonic acid(NA)is a very-long-chain monounsaturated fatty acid with pharmaceutical and nutraceutical functions that plays an important role in treating several neurological disorders.One major source of NA is plant seed oil.Here we report fatty acid profiles of seeds and germplasm diversity of six plant species,including three woody plants with high amounts of NA-enriched seed oil,Malania oleifera,Macaranga adenantha,and M.indica.M.oleifera had the largest seed(average 7.40 g single seed),highest oil content(58.71%),and highest NA level(42.22%).The germplasm diversity of M.oleifera is associated with its habitat but not elevation.Seeds of M.adenantha contained higher NA levels(28.41%)than M.indica(21.77%),but M.indica contained a significantly higher oil content(29.22%)and seed yield.M.adenantha germplasm varied among populations,with one population having seeds with high oil content(22.63%)and NA level(37.78%).Although M.indica grow naturally at a range of elevations,no significant differences were detected between M.indica populations.These results suggest that M.indica and M.oleifera have greater potential as a source of NA,which will contribute to constructing a germplasm resource nursery and establishing a selection and breeding program to improve the development of NA-enriched plants.展开更多
Incorporation of heteroatoms into the framewo rk of zeolites has become a significant strategy to improve their performance in catalysis and adsorption,because the obtained heteroatom zeolites exhibit quite different ...Incorporation of heteroatoms into the framewo rk of zeolites has become a significant strategy to improve their performance in catalysis and adsorption,because the obtained heteroatom zeolites exhibit quite different properties from the conventional aluminosilicate zeolites in aspects of surface acidity,pore structures,particle size and so on.In this review,the progress on the heteroatom zeolites including their synthesis and application is highlighted.First,the recent advance on the design and synthesis of different heteroatom zeolites is summarized.Special emphasis is placed on the introduction and comparison of three typical methods,including the direct synthesis,post synthesis and improved direct synthesis,for the traditional heteroatom zeolites(such as TS-1,Sn-MFI,Sn-β) and newly-reported heteroatom zeolites(such as W-MFI,Mo-MFI).According to their intrinsic characteristics,the application of heteroatom zeolites in diverse fields,such as production of fine chemicals,air pollution control and biomass conversion is then discussed.Finally,the challenges and perspective on the future development of heteroatom zeolites in low-cost preparation and practical application are proposed.展开更多
A fully distributed microgrid system model is presented in this paper.In the user side,two types of load and plug-in electric vehicles are considered to schedule energy for more benefits.The charging and discharging s...A fully distributed microgrid system model is presented in this paper.In the user side,two types of load and plug-in electric vehicles are considered to schedule energy for more benefits.The charging and discharging states of the electric vehicles are represented by the zero-one variables with more flexibility.To solve the nonconvex optimization problem of the users,a novel neurodynamic algorithm which combines the neural network algorithm with the differential evolution algorithm is designed and its convergence speed is faster.A distributed algorithm with a new approach to deal with the inequality constraints is used to solve the convex optimization problem of the generators which can protect their privacy.Simulation results and comparative experiments show that the model and algorithms are effective.展开更多
In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl...In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate.At 70℃,up to 97%conversion of ethylene carbonate and 91%yield of dimethyl ca rbonate were obtained with 1 mol%[DBUH][Im](relative to ethylene carbonate)as catalyst in 2 h.Even at room temperature,the conversion of ethylene carbonate can reach 94%and the yield of dimethyl carbonate can approach 81%for 6 h.Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect,wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formatio n.Although the reusability of the ionic liquid need to be further improved,high efficiency and comme rcial availability of[DBUH][Im]render it a promising catalyst for the preparation of dimethyl carbonate.展开更多
Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole mo...Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with 4.45 ns in water. This can be ascribed between C343 and hydrogen donating increasing solvent polarity from 3.09 ns in toluene to to the intermolecular hydrogen bonding interactions solvents展开更多
Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding di...Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding diagnosis of the jamming signals are essential to normal opera-tions and the innovations in anti-jamming equipment.This paper demonstrates a comprehensive survey on jamming monitoring algorithms and applications.The methods in dealing with jamming signals are summarized primarily.Subsequently,the jamming detection,identification,and direc-tion finding techniques are addressed separately.Based on the established studies,we also provide some potential trends of the demonstrated jamming monitoring issues.展开更多
The influence of in-situ precipitation on corrosion behaviors of wire arc directed energy deposited (WADED) Al-Mg-(Sc-Zr) was studied. WADED Al-Mg showed a homogeneous microstructure with coarse equiaxed grains. WADED...The influence of in-situ precipitation on corrosion behaviors of wire arc directed energy deposited (WADED) Al-Mg-(Sc-Zr) was studied. WADED Al-Mg showed a homogeneous microstructure with coarse equiaxed grains. WADED Al-Mg-Sc-Zr exhibited fine equiaxed grains along the molten pool boundary (MPB) and inter-layer zone (ITZ) while coarse equiaxed grains were inside the molten pool. The in-situ precipitation resulted in the primary Al_(3)(Sc, Zr) aggregated along MPB and ITZ while minor-sized secondary Al_(3)(Sc, Zr) existed inside the molten pool. WADED Al-Mg-Sc-Zr showed improved electrochemical behavior than Al-Mg. WADED Al-Mg presented random pittings that occurred near dispersed β-Al_(3)Mg_(2). WADED Al-Mg-Sc-Zr exhibited pittings along MPB and ITZ, where Al_(3)(Sc, Zr) aggregated and induced galvanic corrosion. Corrosion anisotropy was obvious in Al-Mg-Sc-Zr since more MPBs and ITZs make the XOZ plane susceptive to localized corrosion.展开更多
A film hole arrangement guideline along the temperature difference is proposed.The performance of different film holes arrangement and the impact of parameters are investigated though cascade wind tunnel test and nume...A film hole arrangement guideline along the temperature difference is proposed.The performance of different film holes arrangement and the impact of parameters are investigated though cascade wind tunnel test and numerical simulations.Finally,the optimized flow field structure and the mechanism of its effects are explored.Under the same operating conditions,Hole pattern#2(arrangement along the 50 K temperature difference line)can reduce coolant consumption by half while achieves the same cooling effect as original film hole arrangement.Additionally,Hole pattern#2 reduces the temperature difference between the suction and pressure sides of the vane,effectively protecting the structural strength.At mass flow ratio is 6.23%,Hole pattern#2 achieves both good cooling effectiveness and relatively saves coolant consumption,offering the highest costeffectiveness.The modulation in the position of film holes results in different local pressures affecting the flow inside the cooling chamber.The coupling of internal and external flows leads to different vortex structures near the outlet of the film holes,thereby influencing the film effectiveness.Hole pattern#2 does not exhibit significant high-cooling regions,but it shows a more uniform distribution of overall cooling effectiveness.Therefore,optimizing the arrangement of film holes and spacing them along the temperature difference is considered a crucial technical means to enhance the efficiency of gas turbines.展开更多
文摘为提升废弃混凝土资源化利用效率,系统探究了硅灰与熟石灰单掺及复合改性对再生混凝土力学性能的影响。采用三重搅拌技术(triple mixing,TM),通过抗压试验和劈裂抗拉试验,研究再生混凝土的基本力学性能,并借助扫描电子显微镜(scanning electron microscope,SEM)解析其微观结构特征。结果表明:单掺硅灰或熟石灰对再生混凝土的抗压强度与劈裂抗拉强度提升有限,复合硅灰与熟石灰对其提升效果显著。微观分析显示,复合体系中的微观结构致密程度显著提高,骨料与浆体的粘接强度增强。研究成果可为再生粗骨料的应用提供参考。
基金supported by the Applied Basic Research Key Project of Yunnan,China(Grant No.202101AS07001)Reserve Talents for Yunnan Young and Middle-aged Academic and Technical Leaders,China(Grant No.202105AC160083)National Natural Science Foundation of China(Grant No.31671732).
文摘Nervonic acid(NA)is a very-long-chain monounsaturated fatty acid with pharmaceutical and nutraceutical functions that plays an important role in treating several neurological disorders.One major source of NA is plant seed oil.Here we report fatty acid profiles of seeds and germplasm diversity of six plant species,including three woody plants with high amounts of NA-enriched seed oil,Malania oleifera,Macaranga adenantha,and M.indica.M.oleifera had the largest seed(average 7.40 g single seed),highest oil content(58.71%),and highest NA level(42.22%).The germplasm diversity of M.oleifera is associated with its habitat but not elevation.Seeds of M.adenantha contained higher NA levels(28.41%)than M.indica(21.77%),but M.indica contained a significantly higher oil content(29.22%)and seed yield.M.adenantha germplasm varied among populations,with one population having seeds with high oil content(22.63%)and NA level(37.78%).Although M.indica grow naturally at a range of elevations,no significant differences were detected between M.indica populations.These results suggest that M.indica and M.oleifera have greater potential as a source of NA,which will contribute to constructing a germplasm resource nursery and establishing a selection and breeding program to improve the development of NA-enriched plants.
基金supported by the National Natural Science Foundation of China(Nos.21875044,21673048)Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.17JC1400100)+2 种基金the support by the state key laboratory of Transducer Technology of China(No.SKT1904)Program of Shanghai Academic Research Leader(No.19XD1420300)Research Supporting Project(No.RSP-2019/155)by King Saud University。
文摘Incorporation of heteroatoms into the framewo rk of zeolites has become a significant strategy to improve their performance in catalysis and adsorption,because the obtained heteroatom zeolites exhibit quite different properties from the conventional aluminosilicate zeolites in aspects of surface acidity,pore structures,particle size and so on.In this review,the progress on the heteroatom zeolites including their synthesis and application is highlighted.First,the recent advance on the design and synthesis of different heteroatom zeolites is summarized.Special emphasis is placed on the introduction and comparison of three typical methods,including the direct synthesis,post synthesis and improved direct synthesis,for the traditional heteroatom zeolites(such as TS-1,Sn-MFI,Sn-β) and newly-reported heteroatom zeolites(such as W-MFI,Mo-MFI).According to their intrinsic characteristics,the application of heteroatom zeolites in diverse fields,such as production of fine chemicals,air pollution control and biomass conversion is then discussed.Finally,the challenges and perspective on the future development of heteroatom zeolites in low-cost preparation and practical application are proposed.
基金the Natural Science Foundation of China(61773320)the Central Universities(XDJK2020TY003)the Natural Science Foundation Project of Chongqing Science and Technology Commission(cstc2018jcyjAX0583)。
文摘A fully distributed microgrid system model is presented in this paper.In the user side,two types of load and plug-in electric vehicles are considered to schedule energy for more benefits.The charging and discharging states of the electric vehicles are represented by the zero-one variables with more flexibility.To solve the nonconvex optimization problem of the users,a novel neurodynamic algorithm which combines the neural network algorithm with the differential evolution algorithm is designed and its convergence speed is faster.A distributed algorithm with a new approach to deal with the inequality constraints is used to solve the convex optimization problem of the generators which can protect their privacy.Simulation results and comparative experiments show that the model and algorithms are effective.
基金the Ministry of Science and Technology of China(National Key Research and Development Program,No.2016YFA0602900)the National Natural Science Foundation of China(No.21672119)for financial support。
文摘In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate.At 70℃,up to 97%conversion of ethylene carbonate and 91%yield of dimethyl ca rbonate were obtained with 1 mol%[DBUH][Im](relative to ethylene carbonate)as catalyst in 2 h.Even at room temperature,the conversion of ethylene carbonate can reach 94%and the yield of dimethyl carbonate can approach 81%for 6 h.Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect,wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formatio n.Although the reusability of the ionic liquid need to be further improved,high efficiency and comme rcial availability of[DBUH][Im]render it a promising catalyst for the preparation of dimethyl carbonate.
文摘Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with 4.45 ns in water. This can be ascribed between C343 and hydrogen donating increasing solvent polarity from 3.09 ns in toluene to to the intermolecular hydrogen bonding interactions solvents
基金supported by the National Key Research and De-velopment Program of China(2020YFB0505601)。
文摘Complicated electromagnetic environments of the space situational awareness facilities(i.e.,satellite navigation systems,radar)would significantly impact normal operations.Effective monitoring and the corresponding diagnosis of the jamming signals are essential to normal opera-tions and the innovations in anti-jamming equipment.This paper demonstrates a comprehensive survey on jamming monitoring algorithms and applications.The methods in dealing with jamming signals are summarized primarily.Subsequently,the jamming detection,identification,and direc-tion finding techniques are addressed separately.Based on the established studies,we also provide some potential trends of the demonstrated jamming monitoring issues.
基金supported by the National Natu-ral Science Foundation of China(grant Nos.52105315,U20B2031,52075022,52075024,and 52175283)the Natural Science Founda-tion of Beijing Municipality(grant Nos.L248031 and3222013)+1 种基金the State Key Lab of Advanced Welding and Joining,Harbin Institute of Technology(No.AWJ-24M05)the Fundamental Research Funds for the Central Universities(Nos.JKF-20240264 andYWF-22-L-607).
文摘The influence of in-situ precipitation on corrosion behaviors of wire arc directed energy deposited (WADED) Al-Mg-(Sc-Zr) was studied. WADED Al-Mg showed a homogeneous microstructure with coarse equiaxed grains. WADED Al-Mg-Sc-Zr exhibited fine equiaxed grains along the molten pool boundary (MPB) and inter-layer zone (ITZ) while coarse equiaxed grains were inside the molten pool. The in-situ precipitation resulted in the primary Al_(3)(Sc, Zr) aggregated along MPB and ITZ while minor-sized secondary Al_(3)(Sc, Zr) existed inside the molten pool. WADED Al-Mg-Sc-Zr showed improved electrochemical behavior than Al-Mg. WADED Al-Mg presented random pittings that occurred near dispersed β-Al_(3)Mg_(2). WADED Al-Mg-Sc-Zr exhibited pittings along MPB and ITZ, where Al_(3)(Sc, Zr) aggregated and induced galvanic corrosion. Corrosion anisotropy was obvious in Al-Mg-Sc-Zr since more MPBs and ITZs make the XOZ plane susceptive to localized corrosion.
基金co-supported by the Basic Research for National Science and Technology Major Project of China(No. J2019-I-0012)the National Natural Science Foundation of China (No. 12102478)the Natural Science Basic Research Program Youth Project of Shaanxi Province,China (No.2021JQ-356)
文摘A film hole arrangement guideline along the temperature difference is proposed.The performance of different film holes arrangement and the impact of parameters are investigated though cascade wind tunnel test and numerical simulations.Finally,the optimized flow field structure and the mechanism of its effects are explored.Under the same operating conditions,Hole pattern#2(arrangement along the 50 K temperature difference line)can reduce coolant consumption by half while achieves the same cooling effect as original film hole arrangement.Additionally,Hole pattern#2 reduces the temperature difference between the suction and pressure sides of the vane,effectively protecting the structural strength.At mass flow ratio is 6.23%,Hole pattern#2 achieves both good cooling effectiveness and relatively saves coolant consumption,offering the highest costeffectiveness.The modulation in the position of film holes results in different local pressures affecting the flow inside the cooling chamber.The coupling of internal and external flows leads to different vortex structures near the outlet of the film holes,thereby influencing the film effectiveness.Hole pattern#2 does not exhibit significant high-cooling regions,but it shows a more uniform distribution of overall cooling effectiveness.Therefore,optimizing the arrangement of film holes and spacing them along the temperature difference is considered a crucial technical means to enhance the efficiency of gas turbines.
