It is self-evident that vocabulary work is the most essential and necessary task in foreign language accepition. English language teachers should develop students’ vocabulary learning skills.
To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malon...To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malonaldelyde (MDA) were determined. The root oxidizing ability and yield characters of rice were examined. Results showed that appropriate amount of Se enhanced the activity of glutathione peroxidase and the oxidizing ability of rice roots significantly, reduced the concentration of MDA, increased 1000-grain weight of rice, F = 26.96**, decreased empty and blighted grain rate, increased the rice yield, F = 11.53**, and enhanced the rice resistance under ferrous stress.展开更多
With continuing advances in technology, computer-assisted instruction provides opportunities for individualized, interactive instruction. The philosophy of constructivism has encouraged instructional designers to crea...With continuing advances in technology, computer-assisted instruction provides opportunities for individualized, interactive instruction. The philosophy of constructivism has encouraged instructional designers to create less behavioral, more democratic programs that promote learner control. In the area of ESL (English as a second language), computers are seen to be a highly motivating, instructional tool.展开更多
Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of l...Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in rice seedling,as well as the effect of se on oxidizing ability of roots under ferrous stress.Results showed that appropriate amount of se significantly increased GSH-Px activity in rice leaves,F=5.5 *,enhanced the amount of GSH and oxidizing ability of roots and reduced the concentration of MDA,F=4.9 *.Compared with Se0+Fe treatment,Se treatments increased the dry matter weight of rice seedling from 10.06% to 10.43%,F=4.09 *.展开更多
The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Base...The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Based on an exponent model, the testing coefficients of straw bale were estimated using Levenberg-Marquardt Method. The results of test showed that the relation between failure density and loading ability and compressing energy was linear in the phase of high density. The loading ability of straw bale could meet the building bill.展开更多
Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hy...Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.展开更多
Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and cor...Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and corrosion resistance, was used as binder for fabricating Fe40Al/TiC composites b y pressureless melt infiltration. The wetting ability of liquid Fe40Al in porous TiC pre-form was studied by in-situ monitoring the melting and infiltration p rocess. The infiltration ability was investigated by observing the distance of l iquid Fe40Al intrusion in porous TiC pre-forms at different infiltration temper atures and times by using optical microscope. Porous TiC per-forms with density of 60%～88%TD (theoretical density), prepared under pre-defined sintering temp e rature cycles, were used for fabricating Fe40Al/TiC composites in the range of 1 2%～40% metal content by volume. Almost full dense Fe40Al/TiC composites were su c cessfully fabricated by this technique. Liquid Fe40Al exhibited excellent infilt ration ability, the distance of complete intrusion of liquid Fe40Al in the TiC s intered pre-form with density of 88%TD was over 7 mm after 5 min at the inf iltration temperature of 1 450 ℃. Microstructural observation by SEM and TEM also showed that liquid Fe40Al filled the very narrow gaps among TiC particles, the interfaces of TiC particles and F e40Al plastic ligaments being metallurgical bonded. TEM revealed that high densi ty of dislocations formed in Fe40Al ligaments during solidification, which favor the mechanical properties. Ti decomposed from TiC particles and dissolved into Fe40Al during infiltration. According to the compositional analysis of TEM-EDS, the concentration of Ti in Fe40Al ranges at 1at%～4at% depending on composite f a bricating conditions and the distance from the measuring point to the closest Ti C particles. XRD analysis indicated that the composites were composed of two pha ses, the original TiC and Fe 0.4Al 0.6 intermetallic. No new phase formed during infiltration, but the lattice parameter of Fe 0.4Al 0.6 was expended due to the Ti in the solid solution.展开更多
Background As the most widely cultivated fiber crop,cotton production depends on hybridization to unlock the yield potential of current varieties.A deep understanding of genetic dissection is crucial for the cultivati...Background As the most widely cultivated fiber crop,cotton production depends on hybridization to unlock the yield potential of current varieties.A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits,such as high yield and fine fiber quality.In this study,the general combining ability(GCA)and specific combining ability(SCA)of yield and fiber quality of nine cotton parents(six lines and three testers)and eighteen F1 crosses produced using a line×tester mating design were analyzed.Results The results revealed significant effects of genotypes,parents,crosses,and interactions between parents and crosses for most of the studied traits.Moreover,the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes.The F1 hybrids of(Giza 90×Aust)×Giza 86,Uzbekistan 1×Giza 97,and Giza 96×Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics.Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield,while lint percentage showed the highest negative direct effect on seed cotton yield.Principal component analysis identified specific parents and hybrids associated with higher cotton yield,fiber quality,and other agronomic traits.Conclusion This study provides insights into identifying potential single-and three-way cross hybrids with superior cotton yield and fiber quality characteristics,laying a foundation for future research on improving fiber quality in cotton.展开更多
Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability,the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desir...Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability,the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desirable parents.The present study was carried out with six parents crossed in full diallel fashion and generated 30 F1 hybrids.These hybrids were evaluated in two replications in Randomized Block Design at Department of Cotton,TNAU for combining ability and gene action.Diallel analysis was carried out according to Griffing’s method-I(parents + F_(1) + reciprocals) and model-I and Hayman’s graphical approach by using INDOSTAT software.Results Analysis of variance for combining ability indicated that mean square values of GCA,SCA and reciprocals were highly significant for all the traits except for the uniformity index.RG763 and K12 showed highly positively significant GCA effects for most of the yield traits while PA838 and K12 for fibre quality traits,so they were found as best general combiners.PAIG379 × K12 and PDB29 × K12 for yield traits,and PDB29 × PA838,RG763 × PA838,and CNA1007 × RG763 cross combinations for fibre quality traits could be recommended for future breeding programms.Conclusion The results of both Griffing’s and Hayman’s approaches showed that non-additive gene action predominates as SCA variance was bigger than GCA variance,so heterosis breeding is thought to be a more fruitful option for enhancing GCA of many traits.展开更多
Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence...Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence of these compounds limits their usage as food and feed.To obtain a glandless cotton variety with high-frequency somatic embryo production ability,27 glandless varieties展开更多
A wheat breeding model for high yield in the middle and south of Hebei Province was developed. Wheat variety Ji 84-5418 has been bred on this model. The analysis results of high-yield and stability indicated that Ji 8...A wheat breeding model for high yield in the middle and south of Hebei Province was developed. Wheat variety Ji 84-5418 has been bred on this model. The analysis results of high-yield and stability indicated that Ji 84-5418 was not only an aggregate of varied excellent characters,but a recombined biotype which could early differentiate spike and develop coordi-nately,and had better self-regulation ability and potential high productivity. Its yield is stable at 6000-8250 kg/ha.展开更多
The character of Sn-Bi plating chips,such as the effect of whisker preventing, solder ability,temperature cycle(T/C) test and thermal humidity bias(THB) test result was introduced.The research result shows that the Sn...The character of Sn-Bi plating chips,such as the effect of whisker preventing, solder ability,temperature cycle(T/C) test and thermal humidity bias(THB) test result was introduced.The research result shows that the Sn-Bi plating chips have good effect of prevent whisker from growing,these chips can pass the T/C test and THB test.展开更多
Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were cert...Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were certified by Sichuan Province Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 had been used widely with accumulated areas of 1 200 000 hm2. By using Yihui1577 as breeding material, an excellent restore line Yihui 3003 and some other restore lines, such as Yihui 1979, Yihui 315 with good rice quality and good combination ability had been bred. Analysis of combination ability and stability about restore line Yihui 1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made in complete dual crossing method with 4 CMS lines and 6 restorer lines. It showed that the general combination ability effect value of Yihui1577 was 0.226, while Minghui63 was -0.113. So the general combination ability ofYihui1577 was prior to that of Minghui 63. Stability analysis showed that the F value of Gangyou1577 was 1.81378, while Sanyou 63 was 1.40327, both didn＇t reach significant level. So Gangyou1577 had the same stability as Sanyou 63. The same conclusion had got in the stability analysis of the breeds of Ⅱ you 1577, Yixiang 1577, Nyou 1577 and so on.展开更多
The male sterile line is very important in the hybrid breeding program of rapeseed. This study was conducted to evaluate the combining ability of many characters of male sterile lines in Brassica napus L. Ten recessiv...The male sterile line is very important in the hybrid breeding program of rapeseed. This study was conducted to evaluate the combining ability of many characters of male sterile lines in Brassica napus L. Ten recessive genetic male sterile （RGMS） lines were used as parents to produce 45 single cross hybrids by using a half diallel cross method. These 45 crosses and their 10 parents were evaluated at Guiyang during 2007-2008. The results showed that both general combining ability （GCA） and specific combiing ability （SCA） effects were important for all characters, but additive gene effects were more predominant than non-additive gene effects. Qianyou 8AB and You 2894AB gave respective highly significant GCA effects of 230.94 and 127.65 kg-hm-2 for seed yield. Lines You 2894AB, QH303-4AB, You 157AB and You 2341AB gave highly significant GCA effects for oil content of 0.99, 1.62, 1.20 and 1.53%, respectively. The crosses among lines Qianyou 3AxQianyou 8B, Qianyou 8AxYou 2894B, You 2894AxQianyou 6B, Qianyou 8AxQH303-4B and Qianyou 8Ax Qianyou 6B gave high SCA effects of 616.29, 398.71,356.48, 394.24 and 303.79 kg hm-2 for seed yield, respectively. All these crosses also gave high seed yield indicating that these crosses could be used in the breeding program.展开更多
The types of teachers’ written feedback and their effects have been the focuses of researches on feedback in EFL writing. This paper aims at providing some references and suggestions on the effective feedback types i...The types of teachers’ written feedback and their effects have been the focuses of researches on feedback in EFL writing. This paper aims at providing some references and suggestions on the effective feedback types in EFL writing in China through reviewing the recent ten-year researches on teachers’ written feedback in EFL writing in China from the perspectives of feedback source, content, types and comments, and exploring the future development of the researches from research design, feedback types, and research perspectives and so on.Literature research shows that the answers remain controversial on which kind of feedback source, feedback content, feedback type, and feedback comments are the best to students in EFL writing. However, the supplementary roles of peer feedback and electronic feedback are well recognized; form-focused feedback combined with content-focused feedback is popular with the students; the demand for the degree of feedback directness and feedback comments varies with the level of students. Compared to the past, recent domestic researches on teachers’ feedback are more various in research methods, more diversified in research perspectives and extended more in research content. Future domestic research on teachers’ feedback needs to make efforts on designing the experiment, expanding the feedback content, combining different feedback types and broadening research perspectives in order to further verify the effectiveness of teachers’ written feedback.展开更多
The paper viewed the current problem that state-owned enterprises in northeast industry base hadn＇t technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction f...The paper viewed the current problem that state-owned enterprises in northeast industry base hadn＇t technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.展开更多
Background Studies on genetic variation and combining ability are essential tools to employ the suitable breeding programme,particularly for hybrid production,to exploit the heterosis in cross-pollinated crops like co...Background Studies on genetic variation and combining ability are essential tools to employ the suitable breeding programme,particularly for hybrid production,to exploit the heterosis in cross-pollinated crops like cotton.Thus,combining ability studies in desi cotton(Gossypium arboreum L.)was carried out using 13 diverse parents through diallel mating design,evaluating 78 F,hybrids along with their parents,without reciprocals using Griffing's and Hayman's approaches.Results Genotypes H 509,AC 3265,AKH 496,and PBN 565 exhibited superior per se performance,indicating their potential use as parents in future breeding programs to develop superior hybrids.The general combining ability(GCA)effect of the genotypes revealed that AC 3097 and AKA 13-SP1 were good general combiners for most traits in this study.Genotypes PBS 1127-SP1,AKH 496,H 509,N11-54-31-32,and AKA 13-SP1 exhibited strong combining ability,contributing to a significant specific combining ability(SCA)effect in seven selected crosses(AC 3265×PBS1127-SP1,AKH 496×H 509,AKH 496×AC 3097,PBS 1127-SP1×N11-54-31-32,AC 3216×AKA 13-SP1,H 503×N11-54-31-32,and H 509×AKA 13-SP1)for yield improvement.These crosses showed positive heterosis in a positive direction.Conclusion From the present study,five genotypes(AC 3097,AKA 13-SP1,N11-54-31-32,AC 3265,and H 509)were identified as good general combiners for producing hybrids,and seven combinations showed a promising hybrid for future breeding programs.展开更多
The bulk Fe<sup>60 CoxZr<sup>10 Mo5W2B<sup>23-x （x=1, 3, 5, 7, 9） amorphous rods with diameters of 1.5 mm were successfully prepared by copper mold casting method with the low purity raw materials....The bulk Fe<sup>60 CoxZr<sup>10 Mo5W2B<sup>23-x （x=1, 3, 5, 7, 9） amorphous rods with diameters of 1.5 mm were successfully prepared by copper mold casting method with the low purity raw materials. The amorphous and crystalline states, and thermal parameters, such as the glass transition temperature （Tg）, the initial crystallization temperature （Tx）, the supercooled liquid region （ΔTx=Tx-Tg）, the reduced glass transition temperature T<sup>rg （Tg/Tm, Tm: the onset temperature of melting of the alloy, and Tg/Tl, Tl: the finished temperature of melting of the alloy） were investigated by X-ray diffractometry （XRD） and differential scanning calorimetry （DSC） analysis. Glass forming ability of Fe<sup>60 CoxZr<sup>10 Mo5W2B<sup>23-x （x=1,3,5,7,9） bulk metallic glasses has been studied. According to the results, the alloy （x=7） with the highest T<sup>rg （Tg/Tl=0.607, Tg/Tl=0.590） value, has the strongest glass forming ability among these alloys because its composition is near eutectic composition. The wide supercooled liquid region over 72 K indicates the high thermal stability for this alloy system. This bulk metallic glass exhibits quite high strength （Hv 1020）. The success of production of the Fe-based bulk metallic glass with industrial materials is of great significance for the future progress of basic research and practical application.展开更多
This article has presented some stereotypical views held by Western people about Chinese teachers,and then clarified these misperceptions caused by Western people's different understanding of the meanings of "...This article has presented some stereotypical views held by Western people about Chinese teachers,and then clarified these misperceptions caused by Western people's different understanding of the meanings of "teacher authority","double parental identities",and"strictness"compared to their Chinese counterparts.Then a case study of three Chinese student teachers studying in one Australian university is conducted to analyze their feelings and experiences of teaching in Australia.Finally,the study suggests that Chinese teacher must retain the essence of Chinese good teachers while adopting the advantages of Western teaching culture to improve his / her own teaching practice,and if so,these self changes could be significant to recreate themselves as new Chinese teachers.展开更多
A thermodynamic study has been carried out on M-Si-B (M=Fe, Ni) ternary systems. A regular solution approximation based on the sublattice model was adopted to describe the Gibbs energy for the individual phases in the...A thermodynamic study has been carried out on M-Si-B (M=Fe, Ni) ternary systems. A regular solution approximation based on the sublattice model was adopted to describe the Gibbs energy for the individual phases in the binary and ternary systems. Thermodynamic parameters for each phase were evaluated by using the experimental data. These parameters enabled us to obtain reproducible calculations of the isothermal and vertical section diagrams. The amorphous-forming ability of M-Si-B ternary alloys has been evaluated by introducing thermodynamic quantities obtained from the phase diagram calculations into Davies-Uhlmann kinetic formulations. For the computation, the time-temperature- transformation (TTT) diagram, which gives the time necessary for the formation of the detectable amount of crystal during transformation, was obtained at a finite temperature. The critical cooling rate for amorphization could be defined as the minimum cooling speed that does not intersect the TTT curve and, hence, these critical cooling rates enable us to evaluate the glass-forming ability of M-Si-B ternary alloys. The driving force for the crystallization of the crystalline phase was derived, on the basis of the thermodynamic functions of each phase formulated by the present study. The calculated results showed good agreement with the experimental data on the compositional range of amorphization in these alloy systems.展开更多
文摘It is self-evident that vocabulary work is the most essential and necessary task in foreign language accepition. English language teachers should develop students’ vocabulary learning skills.
文摘To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malonaldelyde (MDA) were determined. The root oxidizing ability and yield characters of rice were examined. Results showed that appropriate amount of Se enhanced the activity of glutathione peroxidase and the oxidizing ability of rice roots significantly, reduced the concentration of MDA, increased 1000-grain weight of rice, F = 26.96**, decreased empty and blighted grain rate, increased the rice yield, F = 11.53**, and enhanced the rice resistance under ferrous stress.
文摘With continuing advances in technology, computer-assisted instruction provides opportunities for individualized, interactive instruction. The philosophy of constructivism has encouraged instructional designers to create less behavioral, more democratic programs that promote learner control. In the area of ESL (English as a second language), computers are seen to be a highly motivating, instructional tool.
文摘Water culture experiment was conducted to study the effects of selenium(Se) on glutathione peroxidase(GSH-Px) activity,reduced glutathione(GSH) concentration and the accumulation of malonaldehyde(MDA),the product of lipid peroxidation in rice seedling,as well as the effect of se on oxidizing ability of roots under ferrous stress.Results showed that appropriate amount of se significantly increased GSH-Px activity in rice leaves,F=5.5 *,enhanced the amount of GSH and oxidizing ability of roots and reduced the concentration of MDA,F=4.9 *.Compared with Se0+Fe treatment,Se treatments increased the dry matter weight of rice seedling from 10.06% to 10.43%,F=4.09 *.
基金Supported by the Returnee Foundation of Ministry of Education and Project (1054hz023)Supported by the Key Research Foundation of Ministry of Science in Heilongjiang Province
文摘The loading ability of straw bale was tested by Electronical Testing Machine. The linear regression equations were proposed between failure density and loading ability, and failure density and compressing energy. Based on an exponent model, the testing coefficients of straw bale were estimated using Levenberg-Marquardt Method. The results of test showed that the relation between failure density and loading ability and compressing energy was linear in the phase of high density. The loading ability of straw bale could meet the building bill.
基金Higher Education Commission of Pakistan for funding the experiments
文摘Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential.This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids.Fifty cotton genotypes and 40 F1(hybrids)were tested under field conditions following the treatments,viz.,high temperature stress and control at peak flowering stage in August and October under April and June sowing,respectively.Results The mean squares revealed significant differences among genotypes,treatments,genotype×treatment for relative cell injury,chlorophyll contents,canopy temperature,boll retention and seed cotton yield per plant.The genetic diversity among 50 genotypes was analyzed through cluster analysis and heat susceptibility index(HSI).The heat tolerant genotypes including FH-Noor,NIAB-545,FH-466,FH-Lalazar,FH-458,NIAB-878,IR-NIBGE-8,Weal-AGShahkar,and heat sensitive,i.e.,CIM-602,Silky-3,FH-326,SLH-12 and FH-442 were hybridized in line×tester fashion to produce F1 populations.The breeding materials’populations(40 F1)revealed higher specific combining ability variances along with dominance variances,decided the non-additive type gene action for all the traits.The best general combining ability effects for most of the traits were displayed by the lines,i.e.,FH-Lalazar,NIAB-878 along with testers FH-326 and Silky-3.Specific combining ability effects and better-parent heterosis were showed by the crosses,viz.,FH-Lalazar×Silky-3,FH-Lalazar×FH-326,NIAB-878×Silky-3,and NIAB-878×FH-326 for seed cotton yield and yield contributing traits under high temperature stress.Conclusion Heterosis breeding should be carried out in the presence of non-additive type gene action for all the studied traits.The best combiner parents with better-parent heterosis may be used in crossing program to develop high yielding cultivars,and hybrids for high temperature stress tolerance.
文摘Pressureless melt infiltration is an economic route f or preparation of high-density ceramic/melt composites. In this study, the Fe40 Al iron aluminide intermetallic, a low cost material of excellent oxidation and corrosion resistance, was used as binder for fabricating Fe40Al/TiC composites b y pressureless melt infiltration. The wetting ability of liquid Fe40Al in porous TiC pre-form was studied by in-situ monitoring the melting and infiltration p rocess. The infiltration ability was investigated by observing the distance of l iquid Fe40Al intrusion in porous TiC pre-forms at different infiltration temper atures and times by using optical microscope. Porous TiC per-forms with density of 60%～88%TD (theoretical density), prepared under pre-defined sintering temp e rature cycles, were used for fabricating Fe40Al/TiC composites in the range of 1 2%～40% metal content by volume. Almost full dense Fe40Al/TiC composites were su c cessfully fabricated by this technique. Liquid Fe40Al exhibited excellent infilt ration ability, the distance of complete intrusion of liquid Fe40Al in the TiC s intered pre-form with density of 88%TD was over 7 mm after 5 min at the inf iltration temperature of 1 450 ℃. Microstructural observation by SEM and TEM also showed that liquid Fe40Al filled the very narrow gaps among TiC particles, the interfaces of TiC particles and F e40Al plastic ligaments being metallurgical bonded. TEM revealed that high densi ty of dislocations formed in Fe40Al ligaments during solidification, which favor the mechanical properties. Ti decomposed from TiC particles and dissolved into Fe40Al during infiltration. According to the compositional analysis of TEM-EDS, the concentration of Ti in Fe40Al ranges at 1at%～4at% depending on composite f a bricating conditions and the distance from the measuring point to the closest Ti C particles. XRD analysis indicated that the composites were composed of two pha ses, the original TiC and Fe 0.4Al 0.6 intermetallic. No new phase formed during infiltration, but the lattice parameter of Fe 0.4Al 0.6 was expended due to the Ti in the solid solution.
文摘Background As the most widely cultivated fiber crop,cotton production depends on hybridization to unlock the yield potential of current varieties.A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits,such as high yield and fine fiber quality.In this study,the general combining ability(GCA)and specific combining ability(SCA)of yield and fiber quality of nine cotton parents(six lines and three testers)and eighteen F1 crosses produced using a line×tester mating design were analyzed.Results The results revealed significant effects of genotypes,parents,crosses,and interactions between parents and crosses for most of the studied traits.Moreover,the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes.The F1 hybrids of(Giza 90×Aust)×Giza 86,Uzbekistan 1×Giza 97,and Giza 96×Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics.Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield,while lint percentage showed the highest negative direct effect on seed cotton yield.Principal component analysis identified specific parents and hybrids associated with higher cotton yield,fiber quality,and other agronomic traits.Conclusion This study provides insights into identifying potential single-and three-way cross hybrids with superior cotton yield and fiber quality characteristics,laying a foundation for future research on improving fiber quality in cotton.
文摘Background For the purpose of utilising hybrid vigour to produce possible hybrids with a suitable level of stability,the knowledge of gene activity and combining ability is a crucial prerequisite before choosing desirable parents.The present study was carried out with six parents crossed in full diallel fashion and generated 30 F1 hybrids.These hybrids were evaluated in two replications in Randomized Block Design at Department of Cotton,TNAU for combining ability and gene action.Diallel analysis was carried out according to Griffing’s method-I(parents + F_(1) + reciprocals) and model-I and Hayman’s graphical approach by using INDOSTAT software.Results Analysis of variance for combining ability indicated that mean square values of GCA,SCA and reciprocals were highly significant for all the traits except for the uniformity index.RG763 and K12 showed highly positively significant GCA effects for most of the yield traits while PA838 and K12 for fibre quality traits,so they were found as best general combiners.PAIG379 × K12 and PDB29 × K12 for yield traits,and PDB29 × PA838,RG763 × PA838,and CNA1007 × RG763 cross combinations for fibre quality traits could be recommended for future breeding programms.Conclusion The results of both Griffing’s and Hayman’s approaches showed that non-additive gene action predominates as SCA variance was bigger than GCA variance,so heterosis breeding is thought to be a more fruitful option for enhancing GCA of many traits.
文摘Most of model cotton varieties used in tissue culture have glands on both the reproductive and vegetative parts of the plant.These glands contain compounds that are toxic to human and non-ruminant animals.The presence of these compounds limits their usage as food and feed.To obtain a glandless cotton variety with high-frequency somatic embryo production ability,27 glandless varieties
文摘A wheat breeding model for high yield in the middle and south of Hebei Province was developed. Wheat variety Ji 84-5418 has been bred on this model. The analysis results of high-yield and stability indicated that Ji 84-5418 was not only an aggregate of varied excellent characters,but a recombined biotype which could early differentiate spike and develop coordi-nately,and had better self-regulation ability and potential high productivity. Its yield is stable at 6000-8250 kg/ha.
文摘The character of Sn-Bi plating chips,such as the effect of whisker preventing, solder ability,temperature cycle(T/C) test and thermal humidity bias(THB) test result was introduced.The research result shows that the Sn-Bi plating chips have good effect of prevent whisker from growing,these chips can pass the T/C test and THB test.
基金Supported by the State 863 Program in China(2002AA2070002)Sichuan Province 15 Rice Breeding Key Project
文摘Yihui1577 was bred after over 10 generations by crossing RI6 and Yunnan purple rice. Many new hybrid rice varieties had been bred with Yihui 1577, of which Gangyou 1577, Ⅱ you1577, Nyou 1577 and Yixiang1577 were certified by Sichuan Province Crop Variety Release Committee, Gangyou1577 and Yixiang1577 were certified by National Crop Variety Release Committee. The series varieties bred with Yihui1577 had been used widely with accumulated areas of 1 200 000 hm2. By using Yihui1577 as breeding material, an excellent restore line Yihui 3003 and some other restore lines, such as Yihui 1979, Yihui 315 with good rice quality and good combination ability had been bred. Analysis of combination ability and stability about restore line Yihui 1577 was made by using agricultural experimentation and statistical approach. The combination ability analysis was made in complete dual crossing method with 4 CMS lines and 6 restorer lines. It showed that the general combination ability effect value of Yihui1577 was 0.226, while Minghui63 was -0.113. So the general combination ability ofYihui1577 was prior to that of Minghui 63. Stability analysis showed that the F value of Gangyou1577 was 1.81378, while Sanyou 63 was 1.40327, both didn＇t reach significant level. So Gangyou1577 had the same stability as Sanyou 63. The same conclusion had got in the stability analysis of the breeds of Ⅱ you 1577, Yixiang 1577, Nyou 1577 and so on.
基金Supportd by the 11th Five-year Plan of Rapeseed Program in Guizhou Province [N2 No. (2005) 3006-02-03]
文摘The male sterile line is very important in the hybrid breeding program of rapeseed. This study was conducted to evaluate the combining ability of many characters of male sterile lines in Brassica napus L. Ten recessive genetic male sterile （RGMS） lines were used as parents to produce 45 single cross hybrids by using a half diallel cross method. These 45 crosses and their 10 parents were evaluated at Guiyang during 2007-2008. The results showed that both general combining ability （GCA） and specific combiing ability （SCA） effects were important for all characters, but additive gene effects were more predominant than non-additive gene effects. Qianyou 8AB and You 2894AB gave respective highly significant GCA effects of 230.94 and 127.65 kg-hm-2 for seed yield. Lines You 2894AB, QH303-4AB, You 157AB and You 2341AB gave highly significant GCA effects for oil content of 0.99, 1.62, 1.20 and 1.53%, respectively. The crosses among lines Qianyou 3AxQianyou 8B, Qianyou 8AxYou 2894B, You 2894AxQianyou 6B, Qianyou 8AxQH303-4B and Qianyou 8Ax Qianyou 6B gave high SCA effects of 616.29, 398.71,356.48, 394.24 and 303.79 kg hm-2 for seed yield, respectively. All these crosses also gave high seed yield indicating that these crosses could be used in the breeding program.
文摘The types of teachers’ written feedback and their effects have been the focuses of researches on feedback in EFL writing. This paper aims at providing some references and suggestions on the effective feedback types in EFL writing in China through reviewing the recent ten-year researches on teachers’ written feedback in EFL writing in China from the perspectives of feedback source, content, types and comments, and exploring the future development of the researches from research design, feedback types, and research perspectives and so on.Literature research shows that the answers remain controversial on which kind of feedback source, feedback content, feedback type, and feedback comments are the best to students in EFL writing. However, the supplementary roles of peer feedback and electronic feedback are well recognized; form-focused feedback combined with content-focused feedback is popular with the students; the demand for the degree of feedback directness and feedback comments varies with the level of students. Compared to the past, recent domestic researches on teachers’ feedback are more various in research methods, more diversified in research perspectives and extended more in research content. Future domestic research on teachers’ feedback needs to make efforts on designing the experiment, expanding the feedback content, combining different feedback types and broadening research perspectives in order to further verify the effectiveness of teachers’ written feedback.
文摘The paper viewed the current problem that state-owned enterprises in northeast industry base hadn＇t technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.
基金supported by ICAR-Central Institute for Cotton Research,Regional Station,Coimbatore,India。
文摘Background Studies on genetic variation and combining ability are essential tools to employ the suitable breeding programme,particularly for hybrid production,to exploit the heterosis in cross-pollinated crops like cotton.Thus,combining ability studies in desi cotton(Gossypium arboreum L.)was carried out using 13 diverse parents through diallel mating design,evaluating 78 F,hybrids along with their parents,without reciprocals using Griffing's and Hayman's approaches.Results Genotypes H 509,AC 3265,AKH 496,and PBN 565 exhibited superior per se performance,indicating their potential use as parents in future breeding programs to develop superior hybrids.The general combining ability(GCA)effect of the genotypes revealed that AC 3097 and AKA 13-SP1 were good general combiners for most traits in this study.Genotypes PBS 1127-SP1,AKH 496,H 509,N11-54-31-32,and AKA 13-SP1 exhibited strong combining ability,contributing to a significant specific combining ability(SCA)effect in seven selected crosses(AC 3265×PBS1127-SP1,AKH 496×H 509,AKH 496×AC 3097,PBS 1127-SP1×N11-54-31-32,AC 3216×AKA 13-SP1,H 503×N11-54-31-32,and H 509×AKA 13-SP1)for yield improvement.These crosses showed positive heterosis in a positive direction.Conclusion From the present study,five genotypes(AC 3097,AKA 13-SP1,N11-54-31-32,AC 3265,and H 509)were identified as good general combiners for producing hybrids,and seven combinations showed a promising hybrid for future breeding programs.
文摘The bulk Fe<sup>60 CoxZr<sup>10 Mo5W2B<sup>23-x （x=1, 3, 5, 7, 9） amorphous rods with diameters of 1.5 mm were successfully prepared by copper mold casting method with the low purity raw materials. The amorphous and crystalline states, and thermal parameters, such as the glass transition temperature （Tg）, the initial crystallization temperature （Tx）, the supercooled liquid region （ΔTx=Tx-Tg）, the reduced glass transition temperature T<sup>rg （Tg/Tm, Tm: the onset temperature of melting of the alloy, and Tg/Tl, Tl: the finished temperature of melting of the alloy） were investigated by X-ray diffractometry （XRD） and differential scanning calorimetry （DSC） analysis. Glass forming ability of Fe<sup>60 CoxZr<sup>10 Mo5W2B<sup>23-x （x=1,3,5,7,9） bulk metallic glasses has been studied. According to the results, the alloy （x=7） with the highest T<sup>rg （Tg/Tl=0.607, Tg/Tl=0.590） value, has the strongest glass forming ability among these alloys because its composition is near eutectic composition. The wide supercooled liquid region over 72 K indicates the high thermal stability for this alloy system. This bulk metallic glass exhibits quite high strength （Hv 1020）. The success of production of the Fe-based bulk metallic glass with industrial materials is of great significance for the future progress of basic research and practical application.
文摘This article has presented some stereotypical views held by Western people about Chinese teachers,and then clarified these misperceptions caused by Western people's different understanding of the meanings of "teacher authority","double parental identities",and"strictness"compared to their Chinese counterparts.Then a case study of three Chinese student teachers studying in one Australian university is conducted to analyze their feelings and experiences of teaching in Australia.Finally,the study suggests that Chinese teacher must retain the essence of Chinese good teachers while adopting the advantages of Western teaching culture to improve his / her own teaching practice,and if so,these self changes could be significant to recreate themselves as new Chinese teachers.
文摘A thermodynamic study has been carried out on M-Si-B (M=Fe, Ni) ternary systems. A regular solution approximation based on the sublattice model was adopted to describe the Gibbs energy for the individual phases in the binary and ternary systems. Thermodynamic parameters for each phase were evaluated by using the experimental data. These parameters enabled us to obtain reproducible calculations of the isothermal and vertical section diagrams. The amorphous-forming ability of M-Si-B ternary alloys has been evaluated by introducing thermodynamic quantities obtained from the phase diagram calculations into Davies-Uhlmann kinetic formulations. For the computation, the time-temperature- transformation (TTT) diagram, which gives the time necessary for the formation of the detectable amount of crystal during transformation, was obtained at a finite temperature. The critical cooling rate for amorphization could be defined as the minimum cooling speed that does not intersect the TTT curve and, hence, these critical cooling rates enable us to evaluate the glass-forming ability of M-Si-B ternary alloys. The driving force for the crystallization of the crystalline phase was derived, on the basis of the thermodynamic functions of each phase formulated by the present study. The calculated results showed good agreement with the experimental data on the compositional range of amorphization in these alloy systems.
