By using complete-diallel cross design(Griffing method I), the influence of the combination of different high-yield genotypes of maize on the drought tolerance of their offspring, the general combining ability, the ...By using complete-diallel cross design(Griffing method I), the influence of the combination of different high-yield genotypes of maize on the drought tolerance of their offspring, the general combining ability, the specific combining ability and the back cross effect of drought tolerance between parents and the main genetic parameters for drought tolerance were analyzed. The result indicated that there were significant differences in general combining ability effects(GCA) of maize; there were highly significant differences in special combining ability effects(SCA); there was no significant difference in reciprocal effects(R). There were apparent differences in drought tolerance among six parents; to be specific, Zheng 58 had the highest drought tolerance, while PH4CV had the lowest. Improving drought-tolerant parents with Zheng 58, Ji 853 and Xinzi 8717 had gain superiority effects on the increase of drought tolerance in offspring. The influence of the genetic additive effect on the drought tolerance of offsprings varied with different parents and combinations. Therefore, the expression of drought tolerance inheritance genes was determined only by the additive and non-additive genetic effects but had little relationship with reciprocal effects. The selection of drought tolerance of maize should be conducted at higher generations.展开更多
The general combining ability(GCA), special combining ability(SCA) and genetic parameter of ten characters of 22 maize inbred lines including plant height and ear height were analyzed using 10×12 through inco...The general combining ability(GCA), special combining ability(SCA) and genetic parameter of ten characters of 22 maize inbred lines including plant height and ear height were analyzed using 10×12 through incomplete diallel cross(NC Ⅱ).The results showed that:(1) Among the 22 maize inbred lines, the yield GCAs of11 HN 097, 11 HN 099, 11 HN 105 and 11 HN 110 were high, which were elite inbred lines to collocate hybridized combinations with strong heterosis. The yield of11 HN110 × 11 HN097, 11 HN110 × 11 HN105, 11 HN112 × 11 HN 097 and 11 HN 106 × 11 HN 104 were in the first four place. The yielding abilities, adaptabilities and yielding stabilities of the four combinations can be further identified by experiment. The heredities of the ten characters were mainly controlled by additive gene effect whereas the influence of non-addictive gene effect was small. The narrow heritabilities of plant height, ear height, ear rows, ear length, kernels per row,100-grain weight and seed-producing percentage were more than 50%. The variances were mainly caused by heredity and early-generation selection should be conducted. The narrow heritabilities of ear diameter, bare tip length and yield was low, which should not be selected in early-generation.展开更多
The combining ability and correlation of eight ear characteristics in 99 maize hybrids generated by crossing nine female parents with 11 male parents were analyzed by incomplete diallel cross (NC II ) design. The re...The combining ability and correlation of eight ear characteristics in 99 maize hybrids generated by crossing nine female parents with 11 male parents were analyzed by incomplete diallel cross (NC II ) design. The results showed that the line F6 had the highest general combining ability (GCA) for yield, followed by F7, M3, M4 and M8. All of the five lines have great potential in maize breeding. The cross combination M3xF10 had the highest specific combining ability (SCA) for yield, showing strong heterosis. Heritability analysis of ear characteristics showed that GCA variance was higher than SCA variance in ear diameter, number of rows per ear and seed rate, and they were mainly controlled by the additive gene effect, indicating that that the selections for these traits are effective at early generations. The other three traits had lower SCA, for which the selections should be carried out at late generations. The correlation analysis revealed that ear length, number of grains per row, ear diameter, number of rows per ear, 100-seed weight and seed rate had extremely significant positive correlations with grain yield per plant. Among them, number of grains per row had the most significant effect on yield per plant. Barren tip length had a significant negative correlation with grain yield per plant. Therefore, we concluded that the combinations with more grains per row and shorter barren tip should be selected to achieve high yield of maize.展开更多
The leaf angle in waxy corn is a significant trait for breeding corn with compact plant type, which is beneficial to improve yield. According to the Griffing method II, the GCA (general combining ability) and SCA (...The leaf angle in waxy corn is a significant trait for breeding corn with compact plant type, which is beneficial to improve yield. According to the Griffing method II, the GCA (general combining ability) and SCA (specific combining ability) of leaf angle trait in the 7 waxy corn inbred lines and 21 combinations were esti-mated, and the genetic characteristics of leaf angle in corn were also analyzed. The results showed that among the 7 inbred lines, the GCA values ranked as N22 〉N8 〉 N28 〉 N7 〉 N23 〉 N27 〉 N4. The GCA of N27 showed great negative ef-fect, and the genetic variance of its SCA was lower. It suggested that the N27 can be used as an ideal parent for breeding excel ent combinations with smal leaf angle and compact plant type. The inheritance of leaf angle trait in waxy corn is in ac-cordance with the model of "additive - dominant - epistatic". The efficiency of leaf angle trait is control ed by recessive genes. The broad heritability of leaf angle trait in waxy corn is relative low (68.5%), but its narrow heritability is relatively high (72.62%). In the breeding practices, the early-generation selection is more suitable for the leaf angel trait.展开更多
Five cytoplasmic male sterile (CMS) lines were used as parents in an incomplete diallet cross and six restorer lines of rice design (Nc II design). Thirty hybrid combinations with the same growth period were selec...Five cytoplasmic male sterile (CMS) lines were used as parents in an incomplete diallet cross and six restorer lines of rice design (Nc II design). Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level (P〈0.01), indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation.展开更多
The development of heterogeneous catalytic processes is crucial for the synthesis of chiral compounds for both academic and industrial applications.However,thus far,such achievements have remained elusive.Herein,we re...The development of heterogeneous catalytic processes is crucial for the synthesis of chiral compounds for both academic and industrial applications.However,thus far,such achievements have remained elusive.Herein,we report the heterogeneous asymmetric hydrogenation of 2-methylquinoline over solid chiral catalysts,which were prepared by the one-pot polymerization of(1R,2R)-N-(4-vinyl-benzenesulfonyl)-1,2-diphenylethane-1,2-diamine(VDPEN)and divinylbenzene(DVB)in the presence or absence of activated carbon(C)or carbon nanotubes(CNTs),followed by Ru coordination and anion exchange.The solid chiral catalysts were fully characterized by N2 sorption analysis,elemental analysis,TEM,FT-IR spectroscopy,and 13C CP-MAS NMR.All the solid chiral catalysts could efficiently catalyze the asymmetric hydrogenation of 2-methylquinoline to afford 2-methyl-1,2,3,4-tetrahydroquinoline with 90%ee.Studies have shown that polymer/C and polymer/CNTs composites are more active than pure polymers.The polymer/CNTs composite exhibited the highest activity among all the solid chiral catalysts under identical conditions,owing to the unique morphology of CNTs.The recycling stabilities of the solid chiral catalysts were greatly improved when ionic liquids(ILs)were employed as solvents;this is mainly attributed to the decreased leaching amount of anions owing to the confinement effect of ILs on ionic compounds.展开更多
The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diamete...The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB (λex = 550 nm and λem = 400 nm) depending on concentration of ZnSB and size of AuNP also suggested intermolecular (electric) interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.展开更多
A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste ele...A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.展开更多
A cost-effective,facile solution-based hot-injection synthetic route has been developed to synthesize NiSb nanoparticles in oleylamine(OAm)using commercially available inexpensive precursor with reducing toxicity at a...A cost-effective,facile solution-based hot-injection synthetic route has been developed to synthesize NiSb nanoparticles in oleylamine(OAm)using commercially available inexpensive precursor with reducing toxicity at a relatively low temperature of 160℃.Especially,an organic reductant of borane-tert-butylamine complex is intentionally involved in the reaction system to promote a fast reduction of metallic Ni and Sb for the formation of the NiSb nanoparticles.Structural characterizations reveal that the NiSb nanoparticles are hexagonal phase with space group P63/mmc and they are composed of small granules with size about 10 nm that tend to form agglomerates with porous-like geometries.This is the first report on the generation of transition metal antimonide via solution-based strategy,and the asfabricated nanoparticles possess actively electrocatalytic hydrogen evolution reaction(HER)property in acidic electrolytes when the long-chain ligand of OAm adhered on the surface of the nanoparticles is exchanged by ligand-removal and exchange procedure.It is found that the NiSb nanoparticles as a new kind of non-noble-metal HER electrocatalysts only require overpotentials of 437 and 531 mV to achieve high current densities of 10 and 50 mA/cm^2 respectively,as well as exhibit low charge transfer resistance and excellent HER stability.展开更多
Carbon nanotube(CNT)/polymer nanocomposites have vast application in industry because of their light mass and high strength. In this work, a cylindrical tube which is made up of functionally graded(FG) PmP V/CNT nanoc...Carbon nanotube(CNT)/polymer nanocomposites have vast application in industry because of their light mass and high strength. In this work, a cylindrical tube which is made up of functionally graded(FG) PmP V/CNT nanocomposite, is optimally designed for the purpose of torque transmission. The main confining parameters of a rotating shaft in torque transmission process are mass of the shaft, critical speed of rotation and critical buckling torque. It is required to solve a multi-objective optimization problem(MOP) to consider these three targets simultaneously in the process of design. The three-objective optimization problem for this case is defined and solved using a hybrid method of FEM and modified non-dominated sorting genetic algorithm(NSGA-II), by coupling two softwares, MATLAB and ABAQUS. Optimization process provides a set of non-dominated optimal design vectors. Then, two methods, nearest to ideal point(NIP) and technique for ordering preferences by similarity to ideal solution(TOPSIS), are employed to choose trade-off optimum design vectors. Optimum parameters that are obtained from this work are compared with the results of previous studies for similar cylindrical tubes made from composite or a hybrid of aluminum and composite that more than 20% improvement is observed in all of the objective functions.展开更多
Ever since the pioneering work of Bardeen, Cooper and Schrieffer in the 1950 s, exploring novel pairing mechanisms for fermion superfluids has become one of the central tasks in modern physics. Here, we investigate a ...Ever since the pioneering work of Bardeen, Cooper and Schrieffer in the 1950 s, exploring novel pairing mechanisms for fermion superfluids has become one of the central tasks in modern physics. Here, we investigate a new type of fermion superfluid with hybridized s-and p-wave pairings in an ultracold spin-1/2 Fermi gas. Its occurrence is facilitated by the co-existence of comparable s-and p-wave interactions, which is realizable in a two-component 40 K Fermi gas with close-by s-and p-wave Feshbach resonances. The hybridized superfluid state is stable over a considerable parameter region on the phase diagram, and can lead to intriguing patterns of spin densities and pairing fields in momentum space. In particular, it can induce a phase-locked p-wave pairing in the fermion species that has no p-wave interactions. The hybridized nature of this novel superfluid can also be confirmed by measuring the s-and p-wave contacts, which can be extracted from the high-momentum tail of the momentum distribution of each spin component. These results enrich our knowledge of pairing superfluidity in Fermi systems, and open the avenue for achieving novel fermion superfluids with multiple partial-wave scatterings in cold atomic gases.展开更多
In this paper,the nanometer-sized(200 nm)quaternary rare-earth complex Eu(BA)(TTA)2phen was successfully prepared by using the method of optimizing chemical precipitation.The characterizations of these nanoparticles w...In this paper,the nanometer-sized(200 nm)quaternary rare-earth complex Eu(BA)(TTA)2phen was successfully prepared by using the method of optimizing chemical precipitation.The characterizations of these nanoparticles were performed by using elemental analysis,thermogravimetric analysis,infrared spectroscopy,fluorescence spectroscopy,transmission electron microscopy and luminescence quantum-yield.The results indicate that they are better than common ternary complexes at light-emitting performance,luminescence properties,thermal stability,uniformity and particle size;they can also be further mixed with a suitable polymer to form functional rare earth polymers.Compared to the common solid materials,the quaternary complex has better and unique characteristics such as nanoparticle size effect and surface effect.A foundation had been laid for the further expansion of its application in the field of light-emitting and magnetic materials.展开更多
Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, ...Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, and fluorescence spectra were also measured to identify the complexes. Elemental analysis showed that the compositions of these complexes were Tb(p-BrBA)3- H20, Tb(p-CIBA)3- 2H20, Tb(p-FBA)3- H20, Tb(o-FBA)3·2H20, Tb(o-CIBA)3· H20, and Tb(o-BrBA)3. H20, respectively. The monodispersed Ag@SiO2 core-shell nanoparticles with silica thicknesses of 10, 15, and 25 nm were success- fully prepared and characterized by transmission-electron microscopy. Fluorescence intensities of the complexes were detected before and after Ag@SiO2core-shell nanoparticles were added; the enhancement times were related to the silica-shell thick- ness. The fluorescence enhancement times were largest when the thickness of the silica shell was 25 nm. The mechanism may be attributed to the localized surface-plasmon resonance. Furthermore, the enhancement effect of terbium fluoro-benzoate complexes was the strongest in these complexes. This result may be attributed to the hydrogen bond between the hydroxyl on the surface of the silica shell and the fluorine atom.展开更多
We review some recent progresses on the study of ultracold Fermi gases with synthetic spin-orbit coupling.In particular,we focus on the pairing superfluidity in these systems at zero temperature.Recent studies have sh...We review some recent progresses on the study of ultracold Fermi gases with synthetic spin-orbit coupling.In particular,we focus on the pairing superfluidity in these systems at zero temperature.Recent studies have shown that different forms of spin-orbit coupling in various spatial dimensions can lead to a wealth of novel pairing superfluidity.A common theme of these variations is the emergence of new pairing mechanisms which are direct results of spin-orbit-coupling-modified single-particle dispersion spectra.As different configurations can give rise to single-particle dispersion spectra with drastic differences in symmetry,spin dependence and low-energy density of states,spin-orbit coupling is potentially a powerful tool of quantum control,which,when combined with other available control schemes in ultracold atomic gases,will enable us to engineer novel states of matter.展开更多
Magnetite nanoparticles with different sizes and different assemblies were synthesized via hydrothermal method.Micromagnetic simulation shows the magnetite nanocubes with different sizes have different energy states,w...Magnetite nanoparticles with different sizes and different assemblies were synthesized via hydrothermal method.Micromagnetic simulation shows the magnetite nanocubes with different sizes have different energy states,which determines the assembly mode.Magnetite nanocubes with the side length of 30-60 nm tended to be dispersed while both nanochains and dispersed nanoparticles were found to grow for the nanocubes with the side length less than 30 nm,which can be explained in the fact that the above two assembly modes have very close energies.The assembly mode of nanocubes with the size bigger than 60 nm is generally nanorings consisting of connected inter-grown nanocubes and the nanocubes are no longer single domain.The simulations are consistent with the experimental results.展开更多
基金Supported by National Special Fund for Construction of Technical System for Maize Industry of China(CARS-02-68)Science and Technology Supporting Program of Xinjiang Uygur Autonomous Region(201191220)+1 种基金Agriculture Science and Technology Achievement Transformation Fund of Xinjiang Uygur Autonomous Region(2011GB2G400001)Science and Technology Supporting Program of Xinjiang Uygur Autonomous Region(201231104)~~
文摘By using complete-diallel cross design(Griffing method I), the influence of the combination of different high-yield genotypes of maize on the drought tolerance of their offspring, the general combining ability, the specific combining ability and the back cross effect of drought tolerance between parents and the main genetic parameters for drought tolerance were analyzed. The result indicated that there were significant differences in general combining ability effects(GCA) of maize; there were highly significant differences in special combining ability effects(SCA); there was no significant difference in reciprocal effects(R). There were apparent differences in drought tolerance among six parents; to be specific, Zheng 58 had the highest drought tolerance, while PH4CV had the lowest. Improving drought-tolerant parents with Zheng 58, Ji 853 and Xinzi 8717 had gain superiority effects on the increase of drought tolerance in offspring. The influence of the genetic additive effect on the drought tolerance of offsprings varied with different parents and combinations. Therefore, the expression of drought tolerance inheritance genes was determined only by the additive and non-additive genetic effects but had little relationship with reciprocal effects. The selection of drought tolerance of maize should be conducted at higher generations.
基金Supported by"Study on New Method and Technology of Maize Breeding"of the 12th Five-Year Plan in Chongqing(cstc 2012 gg C 80003)"Study on Maize DH Breeding Technology and New Variety Breeding"of the 12th Five-Year Plan of National Science and Technology Plan Project in Rural Areas(2012 AA 101203-2)+2 种基金"Basic Work of Special Agricultural Science and Technology"(cstc 2013 yykfc 80002)"National Maize Industry Technology System"(CARS-02-74)Fundamental Research Project"Genetic differences DH maize lines~~
文摘The general combining ability(GCA), special combining ability(SCA) and genetic parameter of ten characters of 22 maize inbred lines including plant height and ear height were analyzed using 10×12 through incomplete diallel cross(NC Ⅱ).The results showed that:(1) Among the 22 maize inbred lines, the yield GCAs of11 HN 097, 11 HN 099, 11 HN 105 and 11 HN 110 were high, which were elite inbred lines to collocate hybridized combinations with strong heterosis. The yield of11 HN110 × 11 HN097, 11 HN110 × 11 HN105, 11 HN112 × 11 HN 097 and 11 HN 106 × 11 HN 104 were in the first four place. The yielding abilities, adaptabilities and yielding stabilities of the four combinations can be further identified by experiment. The heredities of the ten characters were mainly controlled by additive gene effect whereas the influence of non-addictive gene effect was small. The narrow heritabilities of plant height, ear height, ear rows, ear length, kernels per row,100-grain weight and seed-producing percentage were more than 50%. The variances were mainly caused by heredity and early-generation selection should be conducted. The narrow heritabilities of ear diameter, bare tip length and yield was low, which should not be selected in early-generation.
文摘The combining ability and correlation of eight ear characteristics in 99 maize hybrids generated by crossing nine female parents with 11 male parents were analyzed by incomplete diallel cross (NC II ) design. The results showed that the line F6 had the highest general combining ability (GCA) for yield, followed by F7, M3, M4 and M8. All of the five lines have great potential in maize breeding. The cross combination M3xF10 had the highest specific combining ability (SCA) for yield, showing strong heterosis. Heritability analysis of ear characteristics showed that GCA variance was higher than SCA variance in ear diameter, number of rows per ear and seed rate, and they were mainly controlled by the additive gene effect, indicating that that the selections for these traits are effective at early generations. The other three traits had lower SCA, for which the selections should be carried out at late generations. The correlation analysis revealed that ear length, number of grains per row, ear diameter, number of rows per ear, 100-seed weight and seed rate had extremely significant positive correlations with grain yield per plant. Among them, number of grains per row had the most significant effect on yield per plant. Barren tip length had a significant negative correlation with grain yield per plant. Therefore, we concluded that the combinations with more grains per row and shorter barren tip should be selected to achieve high yield of maize.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest of China(201303008)Special Funds for Modern Agricultural Science and Technology Innovation,Promotion and Information Construction in Guangdong Province(YCN[2014]492)+1 种基金Science and Technology Plan Project of Guangdong Province(2012B020301006)Key Breeding Project for Special Maize of Department of Agriculture of Guangdong Province(B3071328)~~
文摘The leaf angle in waxy corn is a significant trait for breeding corn with compact plant type, which is beneficial to improve yield. According to the Griffing method II, the GCA (general combining ability) and SCA (specific combining ability) of leaf angle trait in the 7 waxy corn inbred lines and 21 combinations were esti-mated, and the genetic characteristics of leaf angle in corn were also analyzed. The results showed that among the 7 inbred lines, the GCA values ranked as N22 〉N8 〉 N28 〉 N7 〉 N23 〉 N27 〉 N4. The GCA of N27 showed great negative ef-fect, and the genetic variance of its SCA was lower. It suggested that the N27 can be used as an ideal parent for breeding excel ent combinations with smal leaf angle and compact plant type. The inheritance of leaf angle trait in waxy corn is in ac-cordance with the model of "additive - dominant - epistatic". The efficiency of leaf angle trait is control ed by recessive genes. The broad heritability of leaf angle trait in waxy corn is relative low (68.5%), but its narrow heritability is relatively high (72.62%). In the breeding practices, the early-generation selection is more suitable for the leaf angel trait.
基金Supported by Youth Fund Project of Sichuan Academy of Agricultural Sciences(2009QNJJ015)~~
文摘Five cytoplasmic male sterile (CMS) lines were used as parents in an incomplete diallet cross and six restorer lines of rice design (Nc II design). Thirty hybrid combinations with the same growth period were selected as experimental ma- terials to investigate the heterosis, combined ability and heredity of Cd content in brown rice of indica hybrid rice. According to the results, Cd content in brown rice showed a significantly negative heterosis; the general combining ability and specific combination ability of Cd content in CMS and restorer lines both reached extremely significant level (P〈0.01), indicating that both genetic improvement of parents and e- valuation of combinations are important to the breeding of hybrid combinations with low accumulation of Cd; the broad-sense heritabitity and narrow-sense heritability of Cd content were both relatively high with slight differences, which respectively reached 97.73% and 80.10%, indicating that Cd content in brown rice mainly de- pends on the additive action of genes; in addition, parent improvement showed bet- ter effect on the selection of early generation.
基金supported by the National Natural Science Foundation of China (21733009, 21621063)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020200)~~
文摘The development of heterogeneous catalytic processes is crucial for the synthesis of chiral compounds for both academic and industrial applications.However,thus far,such achievements have remained elusive.Herein,we report the heterogeneous asymmetric hydrogenation of 2-methylquinoline over solid chiral catalysts,which were prepared by the one-pot polymerization of(1R,2R)-N-(4-vinyl-benzenesulfonyl)-1,2-diphenylethane-1,2-diamine(VDPEN)and divinylbenzene(DVB)in the presence or absence of activated carbon(C)or carbon nanotubes(CNTs),followed by Ru coordination and anion exchange.The solid chiral catalysts were fully characterized by N2 sorption analysis,elemental analysis,TEM,FT-IR spectroscopy,and 13C CP-MAS NMR.All the solid chiral catalysts could efficiently catalyze the asymmetric hydrogenation of 2-methylquinoline to afford 2-methyl-1,2,3,4-tetrahydroquinoline with 90%ee.Studies have shown that polymer/C and polymer/CNTs composites are more active than pure polymers.The polymer/CNTs composite exhibited the highest activity among all the solid chiral catalysts under identical conditions,owing to the unique morphology of CNTs.The recycling stabilities of the solid chiral catalysts were greatly improved when ionic liquids(ILs)were employed as solvents;this is mainly attributed to the decreased leaching amount of anions owing to the confinement effect of ILs on ionic compounds.
文摘The authors have prepared suprameolecular systems of chiral Schiffbase ZnAZSB (Zn(II) complexes with azo-groups) or without ZnSB (azo-groups) and colloidal AuNP (gold nanoparticles) of 10, 40 and 80 nm diameters. They exhibited gradual shifts of surface plasmon bands as well as fluorescence bands. The authors observed and discussed induced CD bands on gold nanoparticles from chiral ZnAZSB or ZnSB. Absence of cis-trans photoisomerization of ZnAZSB with AuNP also supported direct contact near the surface of AuNP. Quenching and splitting of fluorescence bands of ZnSB (λex = 550 nm and λem = 400 nm) depending on concentration of ZnSB and size of AuNP also suggested intermolecular (electric) interaction on the surface of AuNE Decrease of the intensity of the CD band around 380 nm resulted from reciprocal induced CD effect due to parallel arrangement of electric transition moments of ZnAZSB or ZnSB and surface of AuNP.
文摘A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.
基金supported by the National Natural Science Foundation of China(No.21571166 and No.51271173)
文摘A cost-effective,facile solution-based hot-injection synthetic route has been developed to synthesize NiSb nanoparticles in oleylamine(OAm)using commercially available inexpensive precursor with reducing toxicity at a relatively low temperature of 160℃.Especially,an organic reductant of borane-tert-butylamine complex is intentionally involved in the reaction system to promote a fast reduction of metallic Ni and Sb for the formation of the NiSb nanoparticles.Structural characterizations reveal that the NiSb nanoparticles are hexagonal phase with space group P63/mmc and they are composed of small granules with size about 10 nm that tend to form agglomerates with porous-like geometries.This is the first report on the generation of transition metal antimonide via solution-based strategy,and the asfabricated nanoparticles possess actively electrocatalytic hydrogen evolution reaction(HER)property in acidic electrolytes when the long-chain ligand of OAm adhered on the surface of the nanoparticles is exchanged by ligand-removal and exchange procedure.It is found that the NiSb nanoparticles as a new kind of non-noble-metal HER electrocatalysts only require overpotentials of 437 and 531 mV to achieve high current densities of 10 and 50 mA/cm^2 respectively,as well as exhibit low charge transfer resistance and excellent HER stability.
文摘Carbon nanotube(CNT)/polymer nanocomposites have vast application in industry because of their light mass and high strength. In this work, a cylindrical tube which is made up of functionally graded(FG) PmP V/CNT nanocomposite, is optimally designed for the purpose of torque transmission. The main confining parameters of a rotating shaft in torque transmission process are mass of the shaft, critical speed of rotation and critical buckling torque. It is required to solve a multi-objective optimization problem(MOP) to consider these three targets simultaneously in the process of design. The three-objective optimization problem for this case is defined and solved using a hybrid method of FEM and modified non-dominated sorting genetic algorithm(NSGA-II), by coupling two softwares, MATLAB and ABAQUS. Optimization process provides a set of non-dominated optimal design vectors. Then, two methods, nearest to ideal point(NIP) and technique for ordering preferences by similarity to ideal solution(TOPSIS), are employed to choose trade-off optimum design vectors. Optimum parameters that are obtained from this work are compared with the results of previous studies for similar cylindrical tubes made from composite or a hybrid of aluminum and composite that more than 20% improvement is observed in all of the objective functions.
基金supported by the National Natural Science Foundation of China(Grant Nos.11374177,11374283,11421092,11522545,and11534014)the Programs of Chinese Academy of Sciences,and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences(Grant No.XDB01030200)
文摘Ever since the pioneering work of Bardeen, Cooper and Schrieffer in the 1950 s, exploring novel pairing mechanisms for fermion superfluids has become one of the central tasks in modern physics. Here, we investigate a new type of fermion superfluid with hybridized s-and p-wave pairings in an ultracold spin-1/2 Fermi gas. Its occurrence is facilitated by the co-existence of comparable s-and p-wave interactions, which is realizable in a two-component 40 K Fermi gas with close-by s-and p-wave Feshbach resonances. The hybridized superfluid state is stable over a considerable parameter region on the phase diagram, and can lead to intriguing patterns of spin densities and pairing fields in momentum space. In particular, it can induce a phase-locked p-wave pairing in the fermion species that has no p-wave interactions. The hybridized nature of this novel superfluid can also be confirmed by measuring the s-and p-wave contacts, which can be extracted from the high-momentum tail of the momentum distribution of each spin component. These results enrich our knowledge of pairing superfluidity in Fermi systems, and open the avenue for achieving novel fermion superfluids with multiple partial-wave scatterings in cold atomic gases.
基金supported by the Open Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm201332)the "Chunlei" Project in Shandong University of Science and Technology(06540040701)
文摘In this paper,the nanometer-sized(200 nm)quaternary rare-earth complex Eu(BA)(TTA)2phen was successfully prepared by using the method of optimizing chemical precipitation.The characterizations of these nanoparticles were performed by using elemental analysis,thermogravimetric analysis,infrared spectroscopy,fluorescence spectroscopy,transmission electron microscopy and luminescence quantum-yield.The results indicate that they are better than common ternary complexes at light-emitting performance,luminescence properties,thermal stability,uniformity and particle size;they can also be further mixed with a suitable polymer to form functional rare earth polymers.Compared to the common solid materials,the quaternary complex has better and unique characteristics such as nanoparticle size effect and surface effect.A foundation had been laid for the further expansion of its application in the field of light-emitting and magnetic materials.
基金supported by the National Natural Science Foundation of China(21161013)the Natural Science Foundation of Inner Mongolia(2011MS0202)the Opening Foundation for Significant Fundamental Research of Inner Mongolia(2010KF03)
文摘Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, and fluorescence spectra were also measured to identify the complexes. Elemental analysis showed that the compositions of these complexes were Tb(p-BrBA)3- H20, Tb(p-CIBA)3- 2H20, Tb(p-FBA)3- H20, Tb(o-FBA)3·2H20, Tb(o-CIBA)3· H20, and Tb(o-BrBA)3. H20, respectively. The monodispersed Ag@SiO2 core-shell nanoparticles with silica thicknesses of 10, 15, and 25 nm were success- fully prepared and characterized by transmission-electron microscopy. Fluorescence intensities of the complexes were detected before and after Ag@SiO2core-shell nanoparticles were added; the enhancement times were related to the silica-shell thick- ness. The fluorescence enhancement times were largest when the thickness of the silica shell was 25 nm. The mechanism may be attributed to the localized surface-plasmon resonance. Furthermore, the enhancement effect of terbium fluoro-benzoate complexes was the strongest in these complexes. This result may be attributed to the hydrogen bond between the hydroxyl on the surface of the silica shell and the fluorine atom.
基金supported by National Fundamental Research Program of China(Grant Nos.2011CB921200 and 2011CBA00200)National Key Basic Research Program(Grant No.2013CB922000)+4 种基金National Natural Science Foundation(Grant No.60921091)National Science Foundation of China(Grant Nos.10904172,11104158,11374177,11105134,1127409and 11374283)the Fundamental Research Funds for the Central Universities(Grant No.WK2470000006)the Research Funds of Renmin University of China(Grant No.10XNL016)the programs of Chinese Academy of Sciences
文摘We review some recent progresses on the study of ultracold Fermi gases with synthetic spin-orbit coupling.In particular,we focus on the pairing superfluidity in these systems at zero temperature.Recent studies have shown that different forms of spin-orbit coupling in various spatial dimensions can lead to a wealth of novel pairing superfluidity.A common theme of these variations is the emergence of new pairing mechanisms which are direct results of spin-orbit-coupling-modified single-particle dispersion spectra.As different configurations can give rise to single-particle dispersion spectra with drastic differences in symmetry,spin dependence and low-energy density of states,spin-orbit coupling is potentially a powerful tool of quantum control,which,when combined with other available control schemes in ultracold atomic gases,will enable us to engineer novel states of matter.
基金supported by the National Natural Science Foundation of China (Grant No. 50971011)Beijing Natural Science Foundation (Grant No. 1102025)Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20091102110038)
文摘Magnetite nanoparticles with different sizes and different assemblies were synthesized via hydrothermal method.Micromagnetic simulation shows the magnetite nanocubes with different sizes have different energy states,which determines the assembly mode.Magnetite nanocubes with the side length of 30-60 nm tended to be dispersed while both nanochains and dispersed nanoparticles were found to grow for the nanocubes with the side length less than 30 nm,which can be explained in the fact that the above two assembly modes have very close energies.The assembly mode of nanocubes with the size bigger than 60 nm is generally nanorings consisting of connected inter-grown nanocubes and the nanocubes are no longer single domain.The simulations are consistent with the experimental results.