The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new...The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.展开更多
Through the analysis on the leaf color and photosynthetic characteristics of new strains and main cultivars of Rehmannia glutinosa,it is expected to provide theoretical basis for breeding of new varieties. Chlorophyll...Through the analysis on the leaf color and photosynthetic characteristics of new strains and main cultivars of Rehmannia glutinosa,it is expected to provide theoretical basis for breeding of new varieties. Chlorophyll,anthocyanin,and net photosynthetic rate（Pn）,stomatal conductance（Cond）,transpiration rate（Tr）,and intercellular CO2concentration（Ci） in 8 varieties of Rehmannia glutinosa were measured by spectrophotometer and LI-6400 XT Portable Photosynthesis System. The results showed that the chlorophyll content of Huaidijin 8（2. 84 mg/g）,Huaidi 81（2. 71 mg/g）,Huaidi 85-5（2. 69 mg/g）,Jinjiu（2. 66 mg/g） and Huaidi 83（2. 63 mg/g） was higher; the anthocyanin content of Jinjiu（0. 169） and Huaidijin 8（0. 165） was higher,while the anthocyanin content Huaidi 83（0. 060） was the lowest; Pn of Huaidi81[2. 41 μmol/（m2·s） ],Huaidi 83[2. 37 μmol/（m2·s） ]and Huaidijin 8[2. 25 μmol/（m2·s） ]was higher,and the anthocyanin content was positively correlated with Pn,while the anthocyanin content was negatively correlated with Pn; Huaidijin 8 and Huaidi 83 showed dominant advantages in single plant fresh weight,indicator component,and resistance over the main cultivars. This indicates that the new variety Huaidijin 8 and Huaidi 83 have excellent comprehensive traits and can be properly popularized.展开更多
FK01 is a new strain of oil-sunflower with cytoplasmic male sterile line HA as female parent and cytoplasmicmale sterile restorer line 19540 as male parent. 19540 is a mutant irradiated by carbon ion which seed oil co...FK01 is a new strain of oil-sunflower with cytoplasmic male sterile line HA as female parent and cytoplasmicmale sterile restorer line 19540 as male parent. 19540 is a mutant irradiated by carbon ion which seed oil contentincreases.FK01 joined 2014 Gansu province regional test of oil-sunflower and planted in six sites: Jingyuan agriculturaltechnique spreading center, Minqin agricultural technique spreading center, Jingtai agricultural technique spreadingcenter, Jiuquan agricultural sciences research institute, Tianshui agricultural sciences research institute, andHuanxian seed control station.展开更多
Study on crack propagation process of brittle rock is of most significance for cracking-arrest design and cracking-network optimization in rock engineering.Phase-field model(PFM)has advantages of simplicity and high c...Study on crack propagation process of brittle rock is of most significance for cracking-arrest design and cracking-network optimization in rock engineering.Phase-field model(PFM)has advantages of simplicity and high convergence over the common numerical methods(e.g.finite element method,discrete element method,and particle manifold method)in dealing with three-dimensional and multicrack problems.However,current PFMs are mainly used to simulate mode-I(tensile)crack propagation but difficult to effectively simulate mode-II(shear)crack propagation.In this paper,a new mixed-mode PFM is established to simulate both mode-I and mode-II crack propagation of brittle rock by distinguishing the volumetric elastic strain energy and deviatoric elastic strain energy in the total elastic strain energy and considering the effect of compressive stress on mode-II crack propagation.Numerical solution method of the new mixed-mode PFM is proposed based on the staggered solution method with self-programmed subroutines UMAT and HETVAL of ABAQUS software.Three examples calculated using different PFMs as well as test results are presented for comparison.The results show that compared with the conventional PFM(which only simulates the tensile wing crack but not mode-II crack propagation)and the modified mixed-mode PFM(which has difficulty in simulating the shear anti-wing crack),the new mixed-mode PFM can successfully simulate the whole trajectories of mixed-mode crack propagation(including the tensile wing crack,shear secondary crack,and shear anti-wing crack)and mode-II crack propagation,which are close to the test results.It can be further extended to simulate multicrack propagation of anisotropic rock under multi-field coupling loads.展开更多
New strain induced melt activation（new SIMA） method was employed to prepare high-quality semisolid billet of AZ61 magnesium alloy.Optical microscopy and tensile test were used to study the microstructure and mechani...New strain induced melt activation（new SIMA） method was employed to prepare high-quality semisolid billet of AZ61 magnesium alloy.Optical microscopy and tensile test were used to study the microstructure and mechanical properties of the thixo-extruded component.The results showed that the optimal process parameters for achieving the complete filling status involved the applied pressure of 784 MPa,the pressure holding time of 90 s and the die temperature of 450 ℃.Compared to semisolid isothermal treatment,high mechanical properties such as the tensile strength of 300.5 MPa and elongation of 22% and fine microstructure were obtained in the thixo-extruded parts.With increasing the isothermal temperature and holding time,the tensile strength and elongation were increased firstly and then decreased.When the press pass was increased from 1 to 4,the tensile strength and elongation of the thixo-extruded parts were greatly enhanced and microstructure was refined obviously.展开更多
基金National Tilapia Industry Technical System(nycytx-48-3)National Tilapia Seed Program(nyhyzx07-044-01)
文摘The NEW GIFT Nile tilapia （Oreochromis niloticus niloticus L.） is a nationally certificated new strain selected over 14 years and 9 generations from the base strain of GIFT Nile tilapia, introduced in 1994. This new variety has been extended in most of areas of China. The management of genetically improved strains, including the genetic markers for identification is needed urgently. RAPD analysis was conducted and their conversion to SCAR markers was developed. From NEW GIFT Nile tilapia, two strain-specific RAPD bands, S304624 bp and S36568 bp were identified. The strain-specific RAPD bands were gel-purified, cloned, and sequenced. Locus-specific primers were then designed to amplify the strain-specific bands. PCR amplification was conducted to test the variations in allele frequencies of two converted SCAR markers among the NEW GIFT Nile tilapia and its base strains, as well as 7 additional farmed strains worldwide. The frequency of SCAR marker Ⅰ （553 bp） was 85.7% in NEW GIFT Nile tilapia, but 16.7% in the base strain. The frequency of SCAR marker Ⅱ （558 bp） was 91.4% in NEW GIFT Nile tilapia, but 0% 70% in the 7 other strains. In order to confirm the utility of these two markers, an examination was conducted for a wild population from Egypt, resulted the frequency of SCAR Ⅰ and Ⅱ was 10% and 70%, respectively, much lower than that of New GIFT strain. The increase in allele frequency of these two SCAR markers suggests that these markers might be genetically linked to the quantitative trait loci （QTL） underlining the performance traits by long term selection, and indicate the bright potential of SCAR marker technology for tracking generations during selection progress and for distinguishing among genetically improved strain and other strains.
基金Supported by the Public Health Project of State Administration of Traditional Chinese Medicine of the People’s Republic of China[Cai She(2011)76]National Level Project Cultivation Fund of Henan Normal University in 2014(2014PL15)
文摘Through the analysis on the leaf color and photosynthetic characteristics of new strains and main cultivars of Rehmannia glutinosa,it is expected to provide theoretical basis for breeding of new varieties. Chlorophyll,anthocyanin,and net photosynthetic rate（Pn）,stomatal conductance（Cond）,transpiration rate（Tr）,and intercellular CO2concentration（Ci） in 8 varieties of Rehmannia glutinosa were measured by spectrophotometer and LI-6400 XT Portable Photosynthesis System. The results showed that the chlorophyll content of Huaidijin 8（2. 84 mg/g）,Huaidi 81（2. 71 mg/g）,Huaidi 85-5（2. 69 mg/g）,Jinjiu（2. 66 mg/g） and Huaidi 83（2. 63 mg/g） was higher; the anthocyanin content of Jinjiu（0. 169） and Huaidijin 8（0. 165） was higher,while the anthocyanin content Huaidi 83（0. 060） was the lowest; Pn of Huaidi81[2. 41 μmol/（m2·s） ],Huaidi 83[2. 37 μmol/（m2·s） ]and Huaidijin 8[2. 25 μmol/（m2·s） ]was higher,and the anthocyanin content was positively correlated with Pn,while the anthocyanin content was negatively correlated with Pn; Huaidijin 8 and Huaidi 83 showed dominant advantages in single plant fresh weight,indicator component,and resistance over the main cultivars. This indicates that the new variety Huaidijin 8 and Huaidi 83 have excellent comprehensive traits and can be properly popularized.
文摘FK01 is a new strain of oil-sunflower with cytoplasmic male sterile line HA as female parent and cytoplasmicmale sterile restorer line 19540 as male parent. 19540 is a mutant irradiated by carbon ion which seed oil contentincreases.FK01 joined 2014 Gansu province regional test of oil-sunflower and planted in six sites: Jingyuan agriculturaltechnique spreading center, Minqin agricultural technique spreading center, Jingtai agricultural technique spreadingcenter, Jiuquan agricultural sciences research institute, Tianshui agricultural sciences research institute, andHuanxian seed control station.
基金supports by National Natural Science Foundation of China(Grant Nos.51874351 and 52078495)Excellent Postdoctoral Innovative Talents Project of Hunan Province,China(Grant No.2020RC2001).
文摘Study on crack propagation process of brittle rock is of most significance for cracking-arrest design and cracking-network optimization in rock engineering.Phase-field model(PFM)has advantages of simplicity and high convergence over the common numerical methods(e.g.finite element method,discrete element method,and particle manifold method)in dealing with three-dimensional and multicrack problems.However,current PFMs are mainly used to simulate mode-I(tensile)crack propagation but difficult to effectively simulate mode-II(shear)crack propagation.In this paper,a new mixed-mode PFM is established to simulate both mode-I and mode-II crack propagation of brittle rock by distinguishing the volumetric elastic strain energy and deviatoric elastic strain energy in the total elastic strain energy and considering the effect of compressive stress on mode-II crack propagation.Numerical solution method of the new mixed-mode PFM is proposed based on the staggered solution method with self-programmed subroutines UMAT and HETVAL of ABAQUS software.Three examples calculated using different PFMs as well as test results are presented for comparison.The results show that compared with the conventional PFM(which only simulates the tensile wing crack but not mode-II crack propagation)and the modified mixed-mode PFM(which has difficulty in simulating the shear anti-wing crack),the new mixed-mode PFM can successfully simulate the whole trajectories of mixed-mode crack propagation(including the tensile wing crack,shear secondary crack,and shear anti-wing crack)and mode-II crack propagation,which are close to the test results.It can be further extended to simulate multicrack propagation of anisotropic rock under multi-field coupling loads.
基金Project(51075099) supported by the National Natural Science Foundation of ChinaProject(E201038) supported by the Natural Science Foundation of Heilongjiang Province,China+3 种基金Project(20090460884) supported by the China Postdoctoral Science FoundationProjects (HIT.NSRIF.2013007 and 2012038) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (2011RFQXG010) supported by the Harbin City Young Scientists Foundation under the GrantProject(LBH-T1102) supported by the Specially Postdoctoral Science Foundation of Heilongjiang Province,China
文摘New strain induced melt activation（new SIMA） method was employed to prepare high-quality semisolid billet of AZ61 magnesium alloy.Optical microscopy and tensile test were used to study the microstructure and mechanical properties of the thixo-extruded component.The results showed that the optimal process parameters for achieving the complete filling status involved the applied pressure of 784 MPa,the pressure holding time of 90 s and the die temperature of 450 ℃.Compared to semisolid isothermal treatment,high mechanical properties such as the tensile strength of 300.5 MPa and elongation of 22% and fine microstructure were obtained in the thixo-extruded parts.With increasing the isothermal temperature and holding time,the tensile strength and elongation were increased firstly and then decreased.When the press pass was increased from 1 to 4,the tensile strength and elongation of the thixo-extruded parts were greatly enhanced and microstructure was refined obviously.
