Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from ex...Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from expressed sequence tags （EST） provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1 148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis （PCA） and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.展开更多
It is extremely difficult to introduce high-density nano twins during the solidification process of TiAl alloy.In this study,high-density nanotwins are inducted in the as-cast Ti48Al2Cr alloyed by adding Re element.Ph...It is extremely difficult to introduce high-density nano twins during the solidification process of TiAl alloy.In this study,high-density nanotwins are inducted in the as-cast Ti48Al2Cr alloyed by adding Re element.Phase transformation,morphology characteristics of nano twins,compressive and tensile proper-ties,and the related mechanisms have been studied.Results show that B2 phase enriched with Re tends to precipitate along theα_(2)/γinterface within lamellar colony.The stacking fault energy(SFE)ofγphase decreases from 43 mJ/m^(2) to 16 mJ/m^(2) as Re content increases from 0 at.%to 0.6 at.%,decreasing the crit-ical shear stress for twin formation.Compared to the mismatch value ofα_(2)/γinterface(0.004),which of B2/α_(2) and B2/γinterfaces increase to 0.247 and 0.149,respectively.Driven by high interfacial stress,high-density dislocations are generated at the B2/α_(2) interface,providing the dislocation slip channel for the formation of stacking faults(SFs)and nanotwins at the B2/γinterface.Therefore,the mechanism of inducting high-density nanotwins is to reduce the stacking fault energy ofγphase by Re and form highly mismatched B2/α_(2) interface.Compressive strength and the strain increase from 1723 MPa to 2398 MPa and 29%to 39%as Re content increases from 0 at.%to 0.6 at.%,respectively.Tensile strength increases from 356 MPa to 452 MPa without sacrificing plasticity.The improvement in strength and plasticity are attributed to the nano-twinning strengthening and interfacial thermal mismatch strengthening.Forming nanotwins during solidification process serve as the nucleation sites for newly formed twins during de-formation process,increasing the deformation tolerance of TiAl alloy.展开更多
The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the ...The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic （As） geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium （Cr）, zinc （Zn）, copper （Cu）, lead （Pb）, nickel （Ni）, cadmium （Cd） and As using inductively coupled plasma mass spectrometry （ICP-MS）. Results showed that soil properties （salinity, total organic carbon and grain-size distribution） and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal （except Ni） and As mobility decreased in the following order： wetland 〉 dryland 〉 paddy field 〉 forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal fiat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.展开更多
The development of expressed sequence tag-derived simple sequence repeats(EST-SSRs) provided a useful tool for investigating plant genetic diversity.In the present study,22 polymorphic EST-SSRs from grain soybean were...The development of expressed sequence tag-derived simple sequence repeats(EST-SSRs) provided a useful tool for investigating plant genetic diversity.In the present study,22 polymorphic EST-SSRs from grain soybean were identified and used to assess the genetic diversity in 48 vegetable soybean accessions.Among the 22 EST-SSR loci,tri-nucleotides were the most abundant repeats,accounting for 50.00% of the total motifs.GAA was the most common motif among tri-nucleotide repeats,with a frequency of 18.18%.Polymorphic analysis identified a total of 71 alleles,with an average of 3.23 per locus.The polymorphism information content(PIC) values ranged from 0.144 to 0.630,with a mean of 0.386.Observed heterozygosity(H o) values varied from 0.0196 to 1.0000,with an average of 0.6092,while the expected heterozygosity(H e) values ranged from 0.1502 to 0.6840,with a mean value of 0.4616.Principal coordinate analysis and phylogenetic tree analysis indicated that the accessions could be assigned to different groups based to a large extent on their geographic distribution,and most accessions from China were clustered into the same groups.These results suggest that Chinese vegetable soybean accessions have a narrow genetic base.The results of this study indicate that EST-SSRs from grain soybean have high transferability to vegetable soybean,and that these new markers would be helpful in taxonomy,molecular breeding,and comparative mapping studies of vegetable soybean in the future.展开更多
A Co-free as-cast AlCrAlCrFe_(2)Ni_(2)medium entropy alloy(MEA)with multi-phases was remelted by fiber laser in this study.The effect of laser remelting on the microstructure,phase distribution and mechanical properti...A Co-free as-cast AlCrAlCrFe_(2)Ni_(2)medium entropy alloy(MEA)with multi-phases was remelted by fiber laser in this study.The effect of laser remelting on the microstructure,phase distribution and mechanical properties was investigated by characterizing the as-cast and the remelted AlCrAlCrFe_(2)Ni_(2)alloy.The laser remelting process resulted in a significant decrease of grain size from about 780μm to 58.89μm(longitudinal section)and 15.87μm(transverse section)and an increase of hardness from 4.72±0.293 GPa to 6.40±0.147 GPa(longitudinal section)and 7.55±0.360 GPa(transverse section).It was also found that the long side plate-like microstructure composed of FCC phase,ordered B2 phase and disordered BCC phase in the as-cast alloy was transformed into nano-size weave-like microstructure consisting of alternating ordered B2 and disordered BCC phases.The mechanical properties were evaluated by the derived stressstrain relationship obtained from nano-indentation tests data.The results showed that the yield stress increased from 661.9 MPa to 1347.6 MPa(longitudinal section)and 1647.2 MPa(transverse section)after remelting.The individual contribution of four potential strengthening mechanisms to the yield strength of the remelted alloy was quantitatively evaluated,including grain boundary strengthening,dislocation strengthening,solid solution strengthening and precipitation strengthening.The calculation results indicated that dislocation and precipitation are dominant strengthening mechanisms in the laser remelted MEA.展开更多
Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogeno...Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put （10 mmol L＂） and its biosynthetic inhibitor D-arginine （D-Arg） （0.5 mmol L-1） were added to nutrient solution when vegetable soybean （Glycine max L. cv. Huning 95-1） seedlings were exposed to 100 mmol L^-11 sodium chloride （NaCl）. The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine （Spd） and spermine （Spm） were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase （ADC）, S-adenosylmethionine decarboxylase （SAMDC）, diamine oxidase （DAO）, and polyamine oxidase （PAO） were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species （ROS） production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.展开更多
Additively manufactured(AM)metallic materials commonly possess substantial tensile surface residual stress,which is detrimental to the load-bearing service behavior.Recently,we demonstrated that deep cryogenic treatme...Additively manufactured(AM)metallic materials commonly possess substantial tensile surface residual stress,which is detrimental to the load-bearing service behavior.Recently,we demonstrated that deep cryogenic treatment(DCT)is an effective method for improving the tensile properties of CoCrFeMnNi high-entropy alloy(HEA)samples fabricated by laser melting deposition(LMD),by introducing high compressive residual stress and deformation microstructures without destroying the AM shape.However,carrying out the DCT in a single-step mode does not improve the residual stress gradients inherent from the LMD process,which are undesirable as the mechanical properties will not be homogeneous within the sample.In this work,we show that carrying out the DCT in a cyclic mode with repeated cryogenic cooling and reheating can significantly homogenize the residual stress in LMD-fabricated Co Cr Fe Mn Ni HEA,and improve tensile strength and ductility,compared with single-step DCT of the same cryogenic soaking duration.Under cyclic DCT,the thermal stress is re-elevated to a high value at each cryogenic cooling step,leading to the formation of denser and more intersecting reinforcing crystalline defects and hcp phase transformation,compared to single-step DCT of the same total cryogenic soaking duration in which the thermal stress relaxes towards a low value over time.The enhancement of defect formation in the cyclic mode of DCT also leads to more uniform residual stress distribution in the sample after the DCT.The results here provide important insights on optimizing DCT processes for post-fabrication improvement of mechanical properties of AM metallic net shapes.展开更多
A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with h...A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.展开更多
In this study, the effects of oxygen flow rate and annealing temperature on Gd_2 O_3 structures and optical properties were systematically analyzed. Gd_2 O_3 films were deposited on both quartz and ZnS substrates by m...In this study, the effects of oxygen flow rate and annealing temperature on Gd_2 O_3 structures and optical properties were systematically analyzed. Gd_2 O_3 films were deposited on both quartz and ZnS substrates by magnetron sputtering and then annealed under vacuum at 700, 800 and 900℃, Restructure and phase transformation from cubic to monoclinic occur at different temperatures depending on the oxygen flow rate. The optical band gap, which is more sensitive to the annealing temperature than oxygen flow rate changes from 5.32 to 5.65 eV. The refractive index is approximately 1.75 at 550 nm and is adjustable by the oxygen flow rate. The transmittance of the ZnS substrate with Gd_2 O_3 film exceeds 80% and reaches82% at the 7.5-9.5 μm range. When ZnS is coated on both sides, the transmittance is increased to approximately 90%. Our results indicate that Gd_2 O_3 films are promising new candidates for anti-reflective coatings in the infrared region.展开更多
The development of expressed sequence tags(ESTs) from pea has provided a useful source for mining novel simple sequence repeat(SSR) markers.In the present research,in order to find EST-derived SSR markers,18 552 pea E...The development of expressed sequence tags(ESTs) from pea has provided a useful source for mining novel simple sequence repeat(SSR) markers.In the present research,in order to find EST-derived SSR markers,18 552 pea ESTs from the National Center for Biotechnology Information(NCBI) database were downloaded and assembled into 10 086 unigenes.A total of 586 microsatellites in 530 unigenes were identified,indicating that merely 5.25% of sequences contained SSRs.The most abundant SSRs within pea were tri-nucleotide repeat motifs,and among all the tri-nucleotide repeats,the motif GAA was the most abundant type.In total,49 SSRs were used for primer design.EST-SSR loci were subsequently screened on 10 widely adapted varieties in China.Of these,nine loci showed polymorphic profiles that revealed two to three alleles per locus.The polymorphism information content value ranged from 0.18 to 0.58 with an average of 0.41.Furthermore,transferable analysis revealed that some of these loci showed transferability to faba bean.Because of their polymorphism and transferability,these nine novel EST-SSRs will be valuable tools for marker-assisted breeding and comparative mapping of pea in the future.展开更多
Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning...Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning temperature and partitioning time)which affect the properties dramatically.As a result,it remains a challenge to get the best parameters in a low-cost way for Q&P process.Here,the orthogonal experimental design combined with a local optimization was adopted to optimize the quenching and partitioning parameters of 65Si2MnWA steel.By using this method,the combination between strength and ductility was optimized;meanwhile,the number of experiments was reduced significantly.When treated by quenching at 180℃followed by partitioning at 330℃for 20 min,the steel reached the best combination between strength and ductility.In detail,the product of ultimate tensile strength and reduction in area was 1.36 times(from 64.9 to 88.8 GPa%)that treated by quenching and tempering.In addition,owing to the grain refinement,the strength and ductility increase simultaneously.Specifically,the reduction in area increased by 27.4%(from 35.8%to 45.6%)coupled with a little improvement in ultimate tensile strength(7.4%).展开更多
Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentant...Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera （G. Don） Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi （Sweet） Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding ＆ Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.展开更多
It is reported that alkali-metal borohydrides （MBH4, M = Li, Na and K） are efficient catalysts for ring opening polymerization （ROP） of α-amino acid N-carboxyanhydrides （NCAs）. Polypeptides are prepared in quan...It is reported that alkali-metal borohydrides （MBH4, M = Li, Na and K） are efficient catalysts for ring opening polymerization （ROP） of α-amino acid N-carboxyanhydrides （NCAs）. Polypeptides are prepared in quantitative yields with relatively narrow molecular weight distributions （MWDs = 1.1-1.5） which depend on the reaction temperature. End groups of the produced polypeptide are studied in detail by MALDI-ToF MS, IH-NMR, 13C-NMR, IH-1H COSY and IH-13C HMQC analyses. The results indicate that α-hydroxy-ω-aminotelechelic polypeptides are formed which are suitable for post- polymerization functionalization.展开更多
High Nb-TiAl (Ti-44Al-8Nb-0.2W-0.2B-0.5Y,at.%) ingot was fabricated by vacuum arc remelting (VAR).The as-cast ingot was hot-isostatic pressed (HIP) and homogenizing annealing processed.The influence of heat treatment ...High Nb-TiAl (Ti-44Al-8Nb-0.2W-0.2B-0.5Y,at.%) ingot was fabricated by vacuum arc remelting (VAR).The as-cast ingot was hot-isostatic pressed (HIP) and homogenizing annealing processed.The influence of heat treatment temperature and thermomechanical processing on the microstructure and tensile property of the alloy was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM) and tensile tests.It was found that the high Nb-TiAl alloy after HIP and annealing was mainly composed of coarse α2/γ lamellae,β/B2 phase and γ phase and the solidification path of this alloy was:L→L+β→β→α+β→α→α+β+γ→α2+β+γ.The water quenching results showed that the alloy was in α single phase region at 1,340 °C.After heating at 1,340 °C for 30 min followed by furnace cooling,the alloy showed a full lamellar microstructure and its ultimate tensile strength was about 538 MPa,with an elongation of 0.3% at room temperature.Free-crack forged pancakes with fine-grained fully lamellar structure (FFLS) were obtained with an initial deformation temperature of 1,340 °C and the ultimate tensile strength of forged alloy was about 820 MPa,with an elongation of 0.9% at room temperature,which was much higher than that of alloy after HIP and annealing because of microstructural refinement.展开更多
Changes of surface shape, aggregate state, and microstructure of Apocynum fiber before and after irradia-tion were studied by XRD, IR, SEM, ESR, and solid state 13C CP/ MAS NMR. The results show that the surface shape...Changes of surface shape, aggregate state, and microstructure of Apocynum fiber before and after irradia-tion were studied by XRD, IR, SEM, ESR, and solid state 13C CP/ MAS NMR. The results show that the surface shape and microstructure were not spoiled under 50 kGy gamma irradiation, while the crystallization of Apocynum fiber changed under 280 kGy . It also shows that different free radicals appear after irradiation and their concentration increases with the increase of irradiation dose.展开更多
Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two ge...Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato （Pst） DC3000 and Xanthomonas oryzae pv. oryzae （Xoo） PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-l-carboxylic acid （PCA） of Pst DC3000 accumulated to 13.4 IJg L-1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL-1 PCA, while Xoo PXO99A was sensitive to 50 IJg mL ~ PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.展开更多
Transition metal cation ordering is essential for controlling the electrochemical performance of cubic spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO),which is conventionally adjusted by optimizing the high temperature sintering...Transition metal cation ordering is essential for controlling the electrochemical performance of cubic spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO),which is conventionally adjusted by optimizing the high temperature sintering and annealing procedures.In this present work,multiple characterization techniques,including 6,7Li NMR,XRD and HRTEM,have been combined to trace the phase transformation and morphology evolution during synthesis.It has been illustrated that simultaneous formation of LiMn_(2)O_(4)(LMO)and LiNiO_(2)(LNO)binary oxides and their conversion into highly reactive LixNi^(3+)_(y)Mn_(3.5+)_(z)O ternary intermediate is a thermal dynamically difficult but crucial step in the synthesis of LNMO ternary oxide.A new strategy of modifying the intermediates formation pathway from binary mode to ternary mode using thermal regulating agent has been adopted.LNMO synthesized with thermal regulating agent exhibits supreme rate capability,long-cycling performance(even at elevated temperature)and excellent capacity efficiency.At a high rate of 100 C,the assembled battery delivers a discharge capacity of 99 mAh g^(-1).This study provides a way to control the formation pathway of complex oxides using thermal regulating agent.展开更多
Two rare earth complexes of Ts-β-AlaH with the formula of [Ln2（H2O）4（Ts-β-AlaH）6]n·4nH2O （where Ln = Nd（1）, Gd（2）; Ts-β-AlaH = N-p-tolylsulfonyl-β-Alanine） have been synthesized and characterized by...Two rare earth complexes of Ts-β-AlaH with the formula of [Ln2（H2O）4（Ts-β-AlaH）6]n·4nH2O （where Ln = Nd（1）, Gd（2）; Ts-β-AlaH = N-p-tolylsulfonyl-β-Alanine） have been synthesized and characterized by elemental analysis, IR and X-ray diffraction. The results show that the two complexes are isostructural. They crystallize in a monoclinic system with P21/n space group. Crystal data for 1： a = 0.95149（19） nm, b = 1.9012（4） nm, c = 2.2863（5） nm, β= 100.37（3）°, Z= 4, De= 1.509 mg/cm^3, F（000） = 1880, R1= 0.0560, wR2= 0.1564 [I 〉 2σ（/）]; for 2： a = 0.9495（2） nm, b = 1.9037（4） nm, c = 2.2987（5） nm, β= 99.87（3）°, Z = 4, Dc= 1.541 mg/cm^3, F（000） = 1916, R1= 0.0515, wR2= 0.1566 [I〉2σ（I）]. The two complexes are one-dimensional chains and the coordination number of the Nd^3＋ or Gd^3＋ ion is nine.展开更多
A dinuclear copper（Ⅱ） complex[Cu2（TATP）2（L-Leu）2（CIO4）2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the tricl...A dinuclear copper（Ⅱ） complex[Cu2（TATP）2（L-Leu）2（CIO4）2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the triclinic space group P1, with two independent molecules in a unit cell. Two Cu（Ⅱ） ions in each complex [Cu2（TATP）2（L-Leu）2（CIO4）2] molecule were found to be in different coordination geometries, i.e., Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP, the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate, and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms, and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4. The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.展开更多
The wear mechanism of metallic card clothing,used in textile industry,was analyzed.A fast wear test for metallic card clothing racks was developed,which was used as collecting the wear metal particles.The failure type...The wear mechanism of metallic card clothing,used in textile industry,was analyzed.A fast wear test for metallic card clothing racks was developed,which was used as collecting the wear metal particles.The failure type of card clothing was analyzed by the mean of scanning electron microscopy(SEM)and ferro-spectrum technology.The results show that the main wear mechanism of metallic card clothing is low load and high repetition interval fatigue wear caused by friction force between fiber and metal wire teeth.The appropriate quenching microstructure,which improves the wear resistance of the metallic card clothing rack is also discussed.展开更多
基金supported by the Zhejiang Provincial Science and Technology Program, China (2007C32013)the Natural Science Foundation of Zhejiang Province, China (Y3090660)
文摘Faba bean （Vicia faba L.）, one of the most important legumes in the world, evolved different types of cultivars due to its partial cross-pollination. The development of simple sequence repeat （SSR） markers from expressed sequence tags （EST） provided a useful tool for investigation of its genetic diversity. The purpose of the present study was to investigate the genetic diversity of faba bean from China and Europe using EST-SSR markers. 5 031 faba bean ESTs from the NCBI database were downloaded and assembled into 1 148 unigenes. A total of 107 microsatellites in 96 unigenes were identified, indicating that merely 8.36% of sequences contained SSRs. The most abundant SSR within faba bean was tri-nucleotide repeat motif, and among all the tri-nucleotide repeats, the motif AAG/CTT was the most abundant type. Based on these results, 11 EST-SSR markers were used to assess the genetic diversity of 29 faba bean cultivars from China and Europe with two to three alleles per locus. The polymorphism information content value ranged from 0.0644 to 0.4278 with an average of 0.2919. Principal coordinate analysis （PCA） and phylogenetic clustering based on these 11 EST-SSR markers distinguished these cultivars into different groups. The results indicated that faba bean in China had a narrow genetic basis, and the additional sources of genetic cultivars/accessions should be introduced to enhance the genetic variability. The results of this study proved that the EST-SSR marker is very effective in evaluation of faba bean germplasm.
基金supported by the National Natural Science Foundation of China(No.U21A2042)the National Nature Fund Youth Fund Project of China(No.52101038)Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001).
文摘It is extremely difficult to introduce high-density nano twins during the solidification process of TiAl alloy.In this study,high-density nanotwins are inducted in the as-cast Ti48Al2Cr alloyed by adding Re element.Phase transformation,morphology characteristics of nano twins,compressive and tensile proper-ties,and the related mechanisms have been studied.Results show that B2 phase enriched with Re tends to precipitate along theα_(2)/γinterface within lamellar colony.The stacking fault energy(SFE)ofγphase decreases from 43 mJ/m^(2) to 16 mJ/m^(2) as Re content increases from 0 at.%to 0.6 at.%,decreasing the crit-ical shear stress for twin formation.Compared to the mismatch value ofα_(2)/γinterface(0.004),which of B2/α_(2) and B2/γinterfaces increase to 0.247 and 0.149,respectively.Driven by high interfacial stress,high-density dislocations are generated at the B2/α_(2) interface,providing the dislocation slip channel for the formation of stacking faults(SFs)and nanotwins at the B2/γinterface.Therefore,the mechanism of inducting high-density nanotwins is to reduce the stacking fault energy ofγphase by Re and form highly mismatched B2/α_(2) interface.Compressive strength and the strain increase from 1723 MPa to 2398 MPa and 29%to 39%as Re content increases from 0 at.%to 0.6 at.%,respectively.Tensile strength increases from 356 MPa to 452 MPa without sacrificing plasticity.The improvement in strength and plasticity are attributed to the nano-twinning strengthening and interfacial thermal mismatch strengthening.Forming nanotwins during solidification process serve as the nucleation sites for newly formed twins during de-formation process,increasing the deformation tolerance of TiAl alloy.
基金supported by the National Natural Science Foundation of China (Nos. 41271466 and 40871216)
文摘The reclamation of tidal fiats has been one of the important approaches to replenish the arable lands in the coastal areas; pollution status of reclaimed soils has received wide attention recently, especially for the study of heavy metals due to the relative high pollutant concentrations in wetlands. To understand the impact of land use change on heavy metal and arsenic （As） geochemistry by the reclamation of wetlands for agriculture, surface soils and soil profiles were collected from the agricultural land reclaimed in the 1990s and the intertidal flat wetland at Dongtan on Chongming Island in the Yangtze River Estuary, China. The soil samples were analyzed for total concentrations and chemical speciation of chromium （Cr）, zinc （Zn）, copper （Cu）, lead （Pb）, nickel （Ni）, cadmium （Cd） and As using inductively coupled plasma mass spectrometry （ICP-MS）. Results showed that soil properties （salinity, total organic carbon and grain-size distribution） and the concentrations of heavy metals and As in the soils differed under the different land use types. The conversion of wetland to forest had caused obvious losses of all the measured heavy metals. In paddy field and dryland with frequent cultivation, the concentrations of Cr, Zn, Cu, Ni and As were higher when compared to forest land which was disturbed rarely by human activities. Speciation analysis showed that Cr, Zn, Cu, Ni and As were predominated by the immobile residual fraction, while Pb and Cd showed relatively higher mobility. In general, metal （except Ni） and As mobility decreased in the following order： wetland 〉 dryland 〉 paddy field 〉 forest land, which suggested that the reclaimed soils had lower metal and As mobility than the intertidal fiat wetland. The results of this study contribute to a better understanding of the effects of land use on heavy metals and As in the reclaimed soils of the study area and other similar coastal areas.
基金Project supported by the National Natural Science Foundation of China(Nos.31101538,31000942,and 31000676)the Grand Science and Technology Special Project of Zhejiang Province(Nos.2010 C02006,2012C12903-4-1,and 2012C12903-6-3)+2 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LY12C15004)the Public Welfare Project of Zhejiang Province(No.2011C22011)the Shaoxing Important Science and Technology Projects (No.2012A22008),China
文摘The development of expressed sequence tag-derived simple sequence repeats(EST-SSRs) provided a useful tool for investigating plant genetic diversity.In the present study,22 polymorphic EST-SSRs from grain soybean were identified and used to assess the genetic diversity in 48 vegetable soybean accessions.Among the 22 EST-SSR loci,tri-nucleotides were the most abundant repeats,accounting for 50.00% of the total motifs.GAA was the most common motif among tri-nucleotide repeats,with a frequency of 18.18%.Polymorphic analysis identified a total of 71 alleles,with an average of 3.23 per locus.The polymorphism information content(PIC) values ranged from 0.144 to 0.630,with a mean of 0.386.Observed heterozygosity(H o) values varied from 0.0196 to 1.0000,with an average of 0.6092,while the expected heterozygosity(H e) values ranged from 0.1502 to 0.6840,with a mean value of 0.4616.Principal coordinate analysis and phylogenetic tree analysis indicated that the accessions could be assigned to different groups based to a large extent on their geographic distribution,and most accessions from China were clustered into the same groups.These results suggest that Chinese vegetable soybean accessions have a narrow genetic base.The results of this study indicate that EST-SSRs from grain soybean have high transferability to vegetable soybean,and that these new markers would be helpful in taxonomy,molecular breeding,and comparative mapping studies of vegetable soybean in the future.
文摘A Co-free as-cast AlCrAlCrFe_(2)Ni_(2)medium entropy alloy(MEA)with multi-phases was remelted by fiber laser in this study.The effect of laser remelting on the microstructure,phase distribution and mechanical properties was investigated by characterizing the as-cast and the remelted AlCrAlCrFe_(2)Ni_(2)alloy.The laser remelting process resulted in a significant decrease of grain size from about 780μm to 58.89μm(longitudinal section)and 15.87μm(transverse section)and an increase of hardness from 4.72±0.293 GPa to 6.40±0.147 GPa(longitudinal section)and 7.55±0.360 GPa(transverse section).It was also found that the long side plate-like microstructure composed of FCC phase,ordered B2 phase and disordered BCC phase in the as-cast alloy was transformed into nano-size weave-like microstructure consisting of alternating ordered B2 and disordered BCC phases.The mechanical properties were evaluated by the derived stressstrain relationship obtained from nano-indentation tests data.The results showed that the yield stress increased from 661.9 MPa to 1347.6 MPa(longitudinal section)and 1647.2 MPa(transverse section)after remelting.The individual contribution of four potential strengthening mechanisms to the yield strength of the remelted alloy was quantitatively evaluated,including grain boundary strengthening,dislocation strengthening,solid solution strengthening and precipitation strengthening.The calculation results indicated that dislocation and precipitation are dominant strengthening mechanisms in the laser remelted MEA.
基金supported by the National Natural Science Foundation of China(31101538,31000942 and 31000676)the Grand Science and Technology Special Project of Zhejiang Province,China(2010C02006)the Public Welfare Project of Zhejiang Province,China(2011R23A52D04)
文摘Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put （10 mmol L＂） and its biosynthetic inhibitor D-arginine （D-Arg） （0.5 mmol L-1） were added to nutrient solution when vegetable soybean （Glycine max L. cv. Huning 95-1） seedlings were exposed to 100 mmol L^-11 sodium chloride （NaCl）. The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine （Spd） and spermine （Spm） were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase （ADC）, S-adenosylmethionine decarboxylase （SAMDC）, diamine oxidase （DAO）, and polyamine oxidase （PAO） were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species （ROS） production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.
基金the National Natural Science Foundation of China(Nos.52171154,and 51871076)the National Key Research and Development Programs of China(Nos.2018YFB1105200 and 2019YFA0209904)+1 种基金the Guangdong Province Basic and Applied Research Key Projects(Nos.2020190718102)the National Key R&D Programme,Ministry of Science and Technology of China(No.2019YFA0209)。
文摘Additively manufactured(AM)metallic materials commonly possess substantial tensile surface residual stress,which is detrimental to the load-bearing service behavior.Recently,we demonstrated that deep cryogenic treatment(DCT)is an effective method for improving the tensile properties of CoCrFeMnNi high-entropy alloy(HEA)samples fabricated by laser melting deposition(LMD),by introducing high compressive residual stress and deformation microstructures without destroying the AM shape.However,carrying out the DCT in a single-step mode does not improve the residual stress gradients inherent from the LMD process,which are undesirable as the mechanical properties will not be homogeneous within the sample.In this work,we show that carrying out the DCT in a cyclic mode with repeated cryogenic cooling and reheating can significantly homogenize the residual stress in LMD-fabricated Co Cr Fe Mn Ni HEA,and improve tensile strength and ductility,compared with single-step DCT of the same cryogenic soaking duration.Under cyclic DCT,the thermal stress is re-elevated to a high value at each cryogenic cooling step,leading to the formation of denser and more intersecting reinforcing crystalline defects and hcp phase transformation,compared to single-step DCT of the same total cryogenic soaking duration in which the thermal stress relaxes towards a low value over time.The enhancement of defect formation in the cyclic mode of DCT also leads to more uniform residual stress distribution in the sample after the DCT.The results here provide important insights on optimizing DCT processes for post-fabrication improvement of mechanical properties of AM metallic net shapes.
基金supported by the Talent Foundation of Anhui Science and Technology University (No. ZRC2014401)
文摘A highly effective phase transfer of a quaternary ammonium gemini surfactant with ester groups（（diethylhexanedioate） diyl-a,v-bis（dimethyl dodecyl ammonium bromide） referred to as 12-10-12）was synthesized with high yield and characterized by infrared spectroscopy, elemental analysis and1 HNMR. Then, 12-10-12 was used as a phase transfer catalyst to study the catalytic effect on the reaction of anhydrous sodium acetate and 4-methylbenzyl chloride. The possible catalytic mechanism and the influence of surfactant concentration, temperature and type are also discussed. The experimental results showed that the catalysis efficiency was more active than the traditional, single-chained surfactant,tetrabutyl ammonium bromide. It also revealed that the reaction was first-order with respect to the concentration of 4-methylbenzyl chloride. The concentration of 4-methylbenzyl chloride grew linearly with the concentration of 12-10-12 and as the reaction temperature increased. The optimum reaction time was 7 h.
基金supported by the National Science Fund for Distinguished Young Scholars(51625201)National Key Research and Development Program of China(2016YFE0201600)+3 种基金National Natural Science Foundation of China(51372053)Innovative Research Group of National Natural Science Foundation of China(11421091)International Science&Technology Cooperation Program of China(2015DFR50300)the Major State Basic Search Program(2014CB46505)
文摘In this study, the effects of oxygen flow rate and annealing temperature on Gd_2 O_3 structures and optical properties were systematically analyzed. Gd_2 O_3 films were deposited on both quartz and ZnS substrates by magnetron sputtering and then annealed under vacuum at 700, 800 and 900℃, Restructure and phase transformation from cubic to monoclinic occur at different temperatures depending on the oxygen flow rate. The optical band gap, which is more sensitive to the annealing temperature than oxygen flow rate changes from 5.32 to 5.65 eV. The refractive index is approximately 1.75 at 550 nm and is adjustable by the oxygen flow rate. The transmittance of the ZnS substrate with Gd_2 O_3 film exceeds 80% and reaches82% at the 7.5-9.5 μm range. When ZnS is coated on both sides, the transmittance is increased to approximately 90%. Our results indicate that Gd_2 O_3 films are promising new candidates for anti-reflective coatings in the infrared region.
基金supported by the Zhejiang Provincial Science and Technol-ogy Program (No. 2007C32013)the Zhejiang Provincial Natural Science Foundation (No. Y3090660) of China
文摘The development of expressed sequence tags(ESTs) from pea has provided a useful source for mining novel simple sequence repeat(SSR) markers.In the present research,in order to find EST-derived SSR markers,18 552 pea ESTs from the National Center for Biotechnology Information(NCBI) database were downloaded and assembled into 10 086 unigenes.A total of 586 microsatellites in 530 unigenes were identified,indicating that merely 5.25% of sequences contained SSRs.The most abundant SSRs within pea were tri-nucleotide repeat motifs,and among all the tri-nucleotide repeats,the motif GAA was the most abundant type.In total,49 SSRs were used for primer design.EST-SSR loci were subsequently screened on 10 widely adapted varieties in China.Of these,nine loci showed polymorphic profiles that revealed two to three alleles per locus.The polymorphism information content value ranged from 0.18 to 0.58 with an average of 0.41.Furthermore,transferable analysis revealed that some of these loci showed transferability to faba bean.Because of their polymorphism and transferability,these nine novel EST-SSRs will be valuable tools for marker-assisted breeding and comparative mapping of pea in the future.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51401099).The authors would like to acknowledge Yi Zhou,Rui-yang Li,Zhi-xuan Chen and Lian-bo Luo for useful advice and discussion.
文摘Quenching and partitioning(Q&P)which provides a balance between toughness and strength is a promising heat treatment in iron and steel industry.However,there are three parameters(quenching temperature,partitioning temperature and partitioning time)which affect the properties dramatically.As a result,it remains a challenge to get the best parameters in a low-cost way for Q&P process.Here,the orthogonal experimental design combined with a local optimization was adopted to optimize the quenching and partitioning parameters of 65Si2MnWA steel.By using this method,the combination between strength and ductility was optimized;meanwhile,the number of experiments was reduced significantly.When treated by quenching at 180℃followed by partitioning at 330℃for 20 min,the steel reached the best combination between strength and ductility.In detail,the product of ultimate tensile strength and reduction in area was 1.36 times(from 64.9 to 88.8 GPa%)that treated by quenching and tempering.In addition,owing to the grain refinement,the strength and ductility increase simultaneously.Specifically,the reduction in area increased by 27.4%(from 35.8%to 45.6%)coupled with a little improvement in ultimate tensile strength(7.4%).
基金supported by the National Natural Science Foundation of China (Grant No.30370106)
文摘Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera （G. Don） Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi （Sweet） Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding ＆ Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.
基金financially supported by the National Natural Science Foundation of China(No.21174122)Special Funds for Major Basic Research Projects(No.G2011CB606001)Zhejiang Provincial Natural Science Foundation of China(No.Y4110115)
文摘It is reported that alkali-metal borohydrides （MBH4, M = Li, Na and K） are efficient catalysts for ring opening polymerization （ROP） of α-amino acid N-carboxyanhydrides （NCAs）. Polypeptides are prepared in quantitative yields with relatively narrow molecular weight distributions （MWDs = 1.1-1.5） which depend on the reaction temperature. End groups of the produced polypeptide are studied in detail by MALDI-ToF MS, IH-NMR, 13C-NMR, IH-1H COSY and IH-13C HMQC analyses. The results indicate that α-hydroxy-ω-aminotelechelic polypeptides are formed which are suitable for post- polymerization functionalization.
基金the National Natural Science Foundation of China(Project Nos.:51971074,51471056)the State Key Laboratory for Advanced Metal and Materials Foundation(Project No.:2013-ZD06)the National Basic Research Program of China(Project No.:2011CB605502)。
文摘High Nb-TiAl (Ti-44Al-8Nb-0.2W-0.2B-0.5Y,at.%) ingot was fabricated by vacuum arc remelting (VAR).The as-cast ingot was hot-isostatic pressed (HIP) and homogenizing annealing processed.The influence of heat treatment temperature and thermomechanical processing on the microstructure and tensile property of the alloy was investigated by X-ray diffractometry (XRD),scanning electron microscopy (SEM) and tensile tests.It was found that the high Nb-TiAl alloy after HIP and annealing was mainly composed of coarse α2/γ lamellae,β/B2 phase and γ phase and the solidification path of this alloy was:L→L+β→β→α+β→α→α+β+γ→α2+β+γ.The water quenching results showed that the alloy was in α single phase region at 1,340 °C.After heating at 1,340 °C for 30 min followed by furnace cooling,the alloy showed a full lamellar microstructure and its ultimate tensile strength was about 538 MPa,with an elongation of 0.3% at room temperature.Free-crack forged pancakes with fine-grained fully lamellar structure (FFLS) were obtained with an initial deformation temperature of 1,340 °C and the ultimate tensile strength of forged alloy was about 820 MPa,with an elongation of 0.9% at room temperature,which was much higher than that of alloy after HIP and annealing because of microstructural refinement.
基金Supported by National National Science Foundation (20464002)
文摘Changes of surface shape, aggregate state, and microstructure of Apocynum fiber before and after irradia-tion were studied by XRD, IR, SEM, ESR, and solid state 13C CP/ MAS NMR. The results show that the surface shape and microstructure were not spoiled under 50 kGy gamma irradiation, while the crystallization of Apocynum fiber changed under 280 kGy . It also shows that different free radicals appear after irradiation and their concentration increases with the increase of irradiation dose.
基金supported by the grants from the Genetically Modified Organisms Breeding Major Projects, China (2014ZX0800905B)the Fundamental Research Funds for the Central Universities, Chinathe Program for New Century 151 Talents of Zhejiang Province, China
文摘Phenazines are secondary metabolites with broad spectrum antibiotic activity and thus show high potential in biological control of pathogens. In this study, we identified phenazine biosynthesis （phz） genes in two genome-completed plant pathogenic bacteria Pseudomonas syringae pv. tomato （Pst） DC3000 and Xanthomonas oryzae pv. oryzae （Xoo） PXO99A. Unlike the phz genes in typical phenazine-producing pseudomonads, phz homologs in Pst DC3000 and Xoo PXO99A consisted of phzC/D/E/F/G and phzC/E1/E2/F/G, respectively, and the both were not organized into an operon. Detection experiments demonstrated that phenazine-l-carboxylic acid （PCA） of Pst DC3000 accumulated to 13.4 IJg L-1, while that of Xoo PXO99A was almost undetectable. Moreover, Pst DC3000 was resistant to 1 mg mL-1 PCA, while Xoo PXO99A was sensitive to 50 IJg mL ~ PCA. Furthermore, mutation of phzF blocked the PCA production and significantly reduced the pathogenicity of Pst DC3000 in tomato, while the complementary strains restored these phenotypes. These results revealed that Pst DC3000 produces low level of and is resistant to phenazines and thus is unable to be biologically controlled by phenazines. Additionally, phz-mediated PCA production is required for full pathogenicity of Pst DC3000. To our knowledge, this is the first report of PCA production and its function in pathogenicity of a plant pathogenic P. syringae strain.
基金financially supported by the National Natural Science Foundation of China(Grant No.21673065 and 21875057)the Key-Area Research and Development Program of Guangdong Province(No.1934212200002)the Innovation and Entrepreneurship Team Project of Zhuhai(No.ZH01110405170016PWC)。
文摘Transition metal cation ordering is essential for controlling the electrochemical performance of cubic spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO),which is conventionally adjusted by optimizing the high temperature sintering and annealing procedures.In this present work,multiple characterization techniques,including 6,7Li NMR,XRD and HRTEM,have been combined to trace the phase transformation and morphology evolution during synthesis.It has been illustrated that simultaneous formation of LiMn_(2)O_(4)(LMO)and LiNiO_(2)(LNO)binary oxides and their conversion into highly reactive LixNi^(3+)_(y)Mn_(3.5+)_(z)O ternary intermediate is a thermal dynamically difficult but crucial step in the synthesis of LNMO ternary oxide.A new strategy of modifying the intermediates formation pathway from binary mode to ternary mode using thermal regulating agent has been adopted.LNMO synthesized with thermal regulating agent exhibits supreme rate capability,long-cycling performance(even at elevated temperature)and excellent capacity efficiency.At a high rate of 100 C,the assembled battery delivers a discharge capacity of 99 mAh g^(-1).This study provides a way to control the formation pathway of complex oxides using thermal regulating agent.
基金[This work was supported by the National Natural Science Foundation of China (No. 20471026) and the Natural Science Foundation of Henan province of China (No. 0311021200).]
文摘Two rare earth complexes of Ts-β-AlaH with the formula of [Ln2（H2O）4（Ts-β-AlaH）6]n·4nH2O （where Ln = Nd（1）, Gd（2）; Ts-β-AlaH = N-p-tolylsulfonyl-β-Alanine） have been synthesized and characterized by elemental analysis, IR and X-ray diffraction. The results show that the two complexes are isostructural. They crystallize in a monoclinic system with P21/n space group. Crystal data for 1： a = 0.95149（19） nm, b = 1.9012（4） nm, c = 2.2863（5） nm, β= 100.37（3）°, Z= 4, De= 1.509 mg/cm^3, F（000） = 1880, R1= 0.0560, wR2= 0.1564 [I 〉 2σ（/）]; for 2： a = 0.9495（2） nm, b = 1.9037（4） nm, c = 2.2987（5） nm, β= 99.87（3）°, Z = 4, Dc= 1.541 mg/cm^3, F（000） = 1916, R1= 0.0515, wR2= 0.1566 [I〉2σ（I）]. The two complexes are one-dimensional chains and the coordination number of the Nd^3＋ or Gd^3＋ ion is nine.
基金the Natural Science Foundation of Guangdong Province,China(No. 04105986)
文摘A dinuclear copper（Ⅱ） complex[Cu2（TATP）2（L-Leu）2（CIO4）2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the triclinic space group P1, with two independent molecules in a unit cell. Two Cu（Ⅱ） ions in each complex [Cu2（TATP）2（L-Leu）2（CIO4）2] molecule were found to be in different coordination geometries, i.e., Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP, the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate, and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms, and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4. The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.
文摘The wear mechanism of metallic card clothing,used in textile industry,was analyzed.A fast wear test for metallic card clothing racks was developed,which was used as collecting the wear metal particles.The failure type of card clothing was analyzed by the mean of scanning electron microscopy(SEM)and ferro-spectrum technology.The results show that the main wear mechanism of metallic card clothing is low load and high repetition interval fatigue wear caused by friction force between fiber and metal wire teeth.The appropriate quenching microstructure,which improves the wear resistance of the metallic card clothing rack is also discussed.
