In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line select...In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.展开更多
Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the lev...Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.展开更多
[Objective]This experiment aimed to establish fast and slow feathering lines from purified and rejuvenated core breeding flock. [Method] Individual and family selection were used for continuous selection from zero to ...[Objective]This experiment aimed to establish fast and slow feathering lines from purified and rejuvenated core breeding flock. [Method] Individual and family selection were used for continuous selection from zero to the second generation. [Result]The results showed that in the fast feathering line,the average weight gain was improved by 108. 34 g per generation in roosters at the age of 20 weeks while a 54. 5 g increase was got per generation in hens. Hen housed egg production was increased from 150 to 170 at the age of 66 weeks,and the healthy rate of chicken flock was raised by 0. 7 percent. In the slow feathering line,the average weight gain was increased by 156. 6g per generation in roosters while a 38. 9 g increase was got per generation in hens,and the hen housed egg production was increased from 158 to 179 at the age of 66 weeks. [Conclusion] This research had a great significance in increasing native chicken＇s production performance and developing its market competitiveness.展开更多
Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withide...Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withideal agronomic characters were identified. Weincorporated the WC gene into restorer linesby crossing these japonica WC lines with ob-tained indica lines. Some WC restorer lineswith indica-japonica medium type were ob-tained and their application value in intersub-specific hybrid rice breeding were evaluated. 1. Effect of crossing methods on selectionefficiencies of WC restorer lines展开更多
To filter the ancient king highway view library area tunnel project as the main research object, on the basis of the project feasibility study plan, the preliminary design stage route scheme selection, fully consideri...To filter the ancient king highway view library area tunnel project as the main research object, on the basis of the project feasibility study plan, the preliminary design stage route scheme selection, fully considering the topographical, geological and ecological environment along the features, such as engineering structure in order to achieve reliable, crane operation safety, respecting nature, the principle to select in harmony with the surrounding environment. This paper optimizes the route location and arranges the scheme, balances the main factors that affect the project investment, construction risk and operation risk, such as the horizontal and vertical design index of the route, geological conditions and project scale, comprehensively compares the various route schemes of Guanwen reservoir area, and puts forward the reasonable and optimal scheme.展开更多
The design speed of the new Zhengzhou-Wanzhou railway line is 350km/h. The Chongqing section of the project is located in the Three Gorges Reservoir area, which is characterized by steep topography and complex geology...The design speed of the new Zhengzhou-Wanzhou railway line is 350km/h. The Chongqing section of the project is located in the Three Gorges Reservoir area, which is characterized by steep topography and complex geology. It is difficult to implement the project, high cost, high risk of construction and operation, many sensitive points in the environment, and difficult to abandon slag. Railway line selection should be combined with topography, adverse geology, engineering conditions, engineering cost and so on to make a comprehensive comparison. Based on the practical experience in the investigation and design process of Zhengzhou-Wanzhou high-speed Railway, this paper reviews and summarizes the route selection research work of the small Three Gorges tunnel passing through the Qiyao Mountain anticline karst and fault poor geological development area, which can be used as a reference for subsequent projects.展开更多
The Huilai section of new Shantou railway is across the way of Longjiang town, Huilai County, and in the form of roadbed through the south of the Lintongxuantomb. According to the Jieyang city peoples government on th...The Huilai section of new Shantou railway is across the way of Longjiang town, Huilai County, and in the form of roadbed through the south of the Lintongxuantomb. According to the Jieyang city peoples government on the request to support coordination shanyou railway line design adjustment letter of the opinion requirements, the new shanyou railway Hui to adjust the longitudinal line change, then through comparative analysis and the location of the cemetery, thick Pilin reservoir, combined with engineering investment, engineering feasibility and local government opinions, finally recommended after change around the cemetery and across the reservoir scheme.展开更多
In the city of La Plata （Argentina） and the surroundings, there are tomato landraces, widely known as ＂tomate platense＂ and particularly prized because of their flavor. The objective was to evaluate seven promisso...In the city of La Plata （Argentina） and the surroundings, there are tomato landraces, widely known as ＂tomate platense＂ and particularly prized because of their flavor. The objective was to evaluate seven promissory lines of ＂tomate platense＂ （TL） derived from local varieties and a commercial hybrid （CH） considering yield, fruit characters and their possible associations. Nine plants per treatment were arranged in a randomized complete block design （r = 4）. The following parameters were determined： diameter （cm）, height （cm）, diameter/height （D/H） ratio, weight per fruit （g）, number of locules, the average number of fruits per plant, the average weight of fruits per plant （kg/ptant）, the yield （ton/ha） and the survival percentage. ANOVA, Tukey＇s test and Pearson correlation coefficient were applied. The TL showed greater （P ≤ 0.01） diameter, D/H ratio and number of locules than CH. In all materials, both diameter and height were associated （P ≤ 0.05） with the weight per fruit. Six of TL had greater （P ≤ 0.01） weight per fruit than HC. Respect to number of fruits per plant, weight of fruits per plant and yield, there were no significant differences among the materials. The survival for CH was lower （P ≤0.05） than that for TL. Although fruits with a smaller size and less flattened have been selected, the lines show enough similarity in these characters that identified their common origin. With the fruits smaller and more uniform, and having no joined fruits, these lines may be of interest to be cultivated under low-input system conditions and practical for low-income producers.展开更多
[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in ...[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in Yongzhou,Hunan Province,exploring growth indices and analyzing seedling height and ground diameter.[Result] As per the selection rate at 20％,PB17,PB9 and PB12 were selected from the 17 species.Specifically,the seedling height averaged 36.52 cm of the selected three seedlings,which was higher by 16.1％ compared with average of 17 species （31.45％）.As for ground diameter,the selected species averaged 2.6 mm,which was higher （13.0％） compared with the average level （2.3 mm）.[Conclusion]Both of seedling height and ground diameter reached extremely significant differences,which indicated that half-sib families of Phoebe bournei have rich variations,with selection and breeding potential.展开更多
When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is...When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is much slower. This paper analyses the DC component of fault branch, and has found it is much bigger than that of the normal branches in transient state. All the simulation results obtained from three compensation types, different fault time and different wave cycles show that the DC component of fault branch is much higher than that of those normal branches. These results verify the effectiveness of taking the DC component as the method of fault line selection in the arc suppression coil grounding system.展开更多
Due to the complicated unfavorable geology in LumTakong Reservoir section of Bangkok-Nakhon Ratchasima high-speed railway in Thailand, the influencing factors of route scheme comparison are complicated, and the scheme...Due to the complicated unfavorable geology in LumTakong Reservoir section of Bangkok-Nakhon Ratchasima high-speed railway in Thailand, the influencing factors of route scheme comparison are complicated, and the scheme selection is difficult. By means of geological condition analysis and engineering economic and technical comparison, this paper discusses in detail the types, scale, distribution characteristics, genetic mechanism and so on of bad geological bodies, and evaluates the stability of bad geological bodies and their influence on the proposed high-speed railway. Through comprehensive analysis of various geological and engineering economic and technical conditions, the scheme of avoiding bad geological areas in situ is finally determined as a reasonable route scheme.展开更多
Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can b...Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can be achieved by employing short-and long-term storage plants buffering and complementing renewable energy sources. A representative grid consists of a natural-gas-fired plant serving as frequency leader, long-term storage plant, wind-power farm with associated short-term storage plantfor energy buffering, and photovoltaic farm with associated short-term storage plant interconnected by a long transmission line to two load circuits. Transient analysis is performed with Mathemafica solving the differential equation system for frequency variation. Powerflow through the AC transmission line is limited by its impedance. The long transmission line must be segmented to achieve stability and voltage control over an 800 km distance. The renewable plants must be operated together with the storage plants in order tominimize frequency variations by smoothing the power output of renewable plants, achieving step-wise control of the transmission-line power. Although to date only AC Iransmission lines in Germany exist, it is anticipated that within the next 10 years these will beaugmented by DC high-voltage lines.展开更多
文摘In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.
基金supported by grants from the National High Technology Research and Development Program (2012AA10A405-6)National Natural Science Foundation of China (31372524)Special Fund for Independent Innovation of Shandong Province (2013CX80202)
文摘Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.
基金Supported by the Ministry of Science and Technology Development Project(10050306003)
文摘[Objective]This experiment aimed to establish fast and slow feathering lines from purified and rejuvenated core breeding flock. [Method] Individual and family selection were used for continuous selection from zero to the second generation. [Result]The results showed that in the fast feathering line,the average weight gain was improved by 108. 34 g per generation in roosters at the age of 20 weeks while a 54. 5 g increase was got per generation in hens. Hen housed egg production was increased from 150 to 170 at the age of 66 weeks,and the healthy rate of chicken flock was raised by 0. 7 percent. In the slow feathering line,the average weight gain was increased by 156. 6g per generation in roosters while a 38. 9 g increase was got per generation in hens,and the hen housed egg production was increased from 158 to 179 at the age of 66 weeks. [Conclusion] This research had a great significance in increasing native chicken＇s production performance and developing its market competitiveness.
文摘Since the middle of 1980’s, wide compatibility(WC) rice lines have been screened by ricebreeders in China and applied in hybrid ricebreeding program. Several WC lines such asPecos, T984, Lunhui 422, and 02428 withideal agronomic characters were identified. Weincorporated the WC gene into restorer linesby crossing these japonica WC lines with ob-tained indica lines. Some WC restorer lineswith indica-japonica medium type were ob-tained and their application value in intersub-specific hybrid rice breeding were evaluated. 1. Effect of crossing methods on selectionefficiencies of WC restorer lines
文摘To filter the ancient king highway view library area tunnel project as the main research object, on the basis of the project feasibility study plan, the preliminary design stage route scheme selection, fully considering the topographical, geological and ecological environment along the features, such as engineering structure in order to achieve reliable, crane operation safety, respecting nature, the principle to select in harmony with the surrounding environment. This paper optimizes the route location and arranges the scheme, balances the main factors that affect the project investment, construction risk and operation risk, such as the horizontal and vertical design index of the route, geological conditions and project scale, comprehensively compares the various route schemes of Guanwen reservoir area, and puts forward the reasonable and optimal scheme.
文摘The design speed of the new Zhengzhou-Wanzhou railway line is 350km/h. The Chongqing section of the project is located in the Three Gorges Reservoir area, which is characterized by steep topography and complex geology. It is difficult to implement the project, high cost, high risk of construction and operation, many sensitive points in the environment, and difficult to abandon slag. Railway line selection should be combined with topography, adverse geology, engineering conditions, engineering cost and so on to make a comprehensive comparison. Based on the practical experience in the investigation and design process of Zhengzhou-Wanzhou high-speed Railway, this paper reviews and summarizes the route selection research work of the small Three Gorges tunnel passing through the Qiyao Mountain anticline karst and fault poor geological development area, which can be used as a reference for subsequent projects.
文摘The Huilai section of new Shantou railway is across the way of Longjiang town, Huilai County, and in the form of roadbed through the south of the Lintongxuantomb. According to the Jieyang city peoples government on the request to support coordination shanyou railway line design adjustment letter of the opinion requirements, the new shanyou railway Hui to adjust the longitudinal line change, then through comparative analysis and the location of the cemetery, thick Pilin reservoir, combined with engineering investment, engineering feasibility and local government opinions, finally recommended after change around the cemetery and across the reservoir scheme.
文摘In the city of La Plata （Argentina） and the surroundings, there are tomato landraces, widely known as ＂tomate platense＂ and particularly prized because of their flavor. The objective was to evaluate seven promissory lines of ＂tomate platense＂ （TL） derived from local varieties and a commercial hybrid （CH） considering yield, fruit characters and their possible associations. Nine plants per treatment were arranged in a randomized complete block design （r = 4）. The following parameters were determined： diameter （cm）, height （cm）, diameter/height （D/H） ratio, weight per fruit （g）, number of locules, the average number of fruits per plant, the average weight of fruits per plant （kg/ptant）, the yield （ton/ha） and the survival percentage. ANOVA, Tukey＇s test and Pearson correlation coefficient were applied. The TL showed greater （P ≤ 0.01） diameter, D/H ratio and number of locules than CH. In all materials, both diameter and height were associated （P ≤ 0.05） with the weight per fruit. Six of TL had greater （P ≤ 0.01） weight per fruit than HC. Respect to number of fruits per plant, weight of fruits per plant and yield, there were no significant differences among the materials. The survival for CH was lower （P ≤0.05） than that for TL. Although fruits with a smaller size and less flattened have been selected, the lines show enough similarity in these characters that identified their common origin. With the fruits smaller and more uniform, and having no joined fruits, these lines may be of interest to be cultivated under low-input system conditions and practical for low-income producers.
基金Supported by Hunan Forestry Scientific Research(2010-07)~~
文摘[Objective] The aim was to explore growth performance of Phoebe bournei in seedling stage.[Method] Based on 17 superior plus trees of Phoebe bournei,a seedling cultivation test was conducted in Jindong Forest Farm in Yongzhou,Hunan Province,exploring growth indices and analyzing seedling height and ground diameter.[Result] As per the selection rate at 20％,PB17,PB9 and PB12 were selected from the 17 species.Specifically,the seedling height averaged 36.52 cm of the selected three seedlings,which was higher by 16.1％ compared with average of 17 species （31.45％）.As for ground diameter,the selected species averaged 2.6 mm,which was higher （13.0％） compared with the average level （2.3 mm）.[Conclusion]Both of seedling height and ground diameter reached extremely significant differences,which indicated that half-sib families of Phoebe bournei have rich variations,with selection and breeding potential.
文摘When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is much slower. This paper analyses the DC component of fault branch, and has found it is much bigger than that of the normal branches in transient state. All the simulation results obtained from three compensation types, different fault time and different wave cycles show that the DC component of fault branch is much higher than that of those normal branches. These results verify the effectiveness of taking the DC component as the method of fault line selection in the arc suppression coil grounding system.
文摘Due to the complicated unfavorable geology in LumTakong Reservoir section of Bangkok-Nakhon Ratchasima high-speed railway in Thailand, the influencing factors of route scheme comparison are complicated, and the scheme selection is difficult. By means of geological condition analysis and engineering economic and technical comparison, this paper discusses in detail the types, scale, distribution characteristics, genetic mechanism and so on of bad geological bodies, and evaluates the stability of bad geological bodies and their influence on the proposed high-speed railway. Through comprehensive analysis of various geological and engineering economic and technical conditions, the scheme of avoiding bad geological areas in situ is finally determined as a reasonable route scheme.
文摘Power systems in Germany mainly containing intermittently operating renewable sources require load/frequency control which is performed up to now at the AC transmissioh and distribution levels. Frequency control can be achieved by employing short-and long-term storage plants buffering and complementing renewable energy sources. A representative grid consists of a natural-gas-fired plant serving as frequency leader, long-term storage plant, wind-power farm with associated short-term storage plantfor energy buffering, and photovoltaic farm with associated short-term storage plant interconnected by a long transmission line to two load circuits. Transient analysis is performed with Mathemafica solving the differential equation system for frequency variation. Powerflow through the AC transmission line is limited by its impedance. The long transmission line must be segmented to achieve stability and voltage control over an 800 km distance. The renewable plants must be operated together with the storage plants in order tominimize frequency variations by smoothing the power output of renewable plants, achieving step-wise control of the transmission-line power. Although to date only AC Iransmission lines in Germany exist, it is anticipated that within the next 10 years these will beaugmented by DC high-voltage lines.
