为实现空空导弹快速越肩发射,研究了一种利用导弹在大攻角、超大攻角过失速过程中出现的静不稳定段,以实现导弹快速重新定向的越肩发射技术。采用计算流体力学/刚体动力学(computational fluid dynamics/rigid body dynamics,CFD/RBD)...为实现空空导弹快速越肩发射,研究了一种利用导弹在大攻角、超大攻角过失速过程中出现的静不稳定段,以实现导弹快速重新定向的越肩发射技术。采用计算流体力学/刚体动力学(computational fluid dynamics/rigid body dynamics,CFD/RBD)耦合的数值模拟方法,结合运动嵌套网格,针对一种放宽静稳定度设计的无翼布局空空导弹,对导弹过失速重新定向过程的轨迹、姿态及气动特性进行了数值模拟,研究了预置舵偏角、弹射角速度、喷流直接力控制对导弹重新定向过程的影响规律。给出了一种预置舵偏角与喷流直接力控制相结合的发射策略,可实现导弹1.5 s内完成重新定向机动,对新一代空空导弹实现快速后向攻击具有参考价值。展开更多
Enhancement release has been proven effective in natural resources recovery of Chinese shrimp Fenneropenaeus chinensis in the last several decades in China, however, to assess the effectiveness of enhancement release,...Enhancement release has been proven effective in natural resources recovery of Chinese shrimp Fenneropenaeus chinensis in the last several decades in China, however, to assess the effectiveness of enhancement release, we still need to develop a high-efficient and easy-operational method to replace those physical-tagging release method with labor intensive, size-and number-limited. In the present study, single(with maternal known) parentage identification using eight simple sequence repeat(SSR) markers genotype fingerprint was used to trace Chinese shrimp released in Bohai Bay in 2013. A total of 884 shrimp spawners were collected from two hatcheries in Tianjin City respectively after enhancement release of shrimp larvae in May 2013. A total of 844 shrimp samples were recaptured around the release location approximately 4 months after the shrimp larvae were released into the natural sea. Genotype data of 8 SSR loci of the 1,726 samples were used for maternal-offspring parentage identification using CEervus 3.0 software. The allele number in each locus ranged from 8 to 68 with an average value of 33.25, which produced the cumulative exclusion probability with one parent known of all these sight loci up to 99%. Among the 844 recaptured shrimp samples, 448(♂:♀=212:232, gender information was lost for 4 samples) were successfully traced to their 337 maternal parents using a logarithm of odds(LOD) > 3.0 threshold. Among these 337 maternal parents, 253 had a single offspring, 62 had two offspring, 18 had three offspring, 3 had four offspring, and 1 had five offspring. For the first time, a large number of released shrimp were identified from recapture samples, and this study showed that it is possible to trace all released Chinese shrimp without using any type of physical tag in enhancement release activities. This not only means more precise recapture ratio assessment than ever expected, but also this method demonstrates an effective method for large-scale hatchery release as well as for organisms used in hatchery enhancement which are not suitable for physical tagging.展开更多
The proteasome is a large, polymeric protease complex responsible for the degradation of intracellular pro- teins and generation of peptides that bind to class I major histocompatibility complex （MHC） molecules. Thi...The proteasome is a large, polymeric protease complex responsible for the degradation of intracellular pro- teins and generation of peptides that bind to class I major histocompatibility complex （MHC） molecules. This study identified a new member of proteasomal subunits in turbots （Scophthalrnus rnaxirnus）. The full- length cDNA sequence of turbot proteasomal subunit was obtained. Sequence analysis indicated that its primary structure is highly similar to that of LMP7 from other vertebrates. The relationship between the turbot LMP7 expression and immune responses to pathogen infection was reported. Quantitative reverse transcriptase polymerase chain reaction showed that LMPTwas expressed differently in various tissues, with higher expression in the spleen, liver, muscle, and skin. The LMP7 expression was the highest at 96 h after challenge with lymphocyctis disease virus （LCDV） and at 12 h after challenge with Vibrio anguillarurn in the turbot liver, kidney, and spleen. Furthermore, the LMP7 expression distinctly increased in turbot kidney cells at 24 h after challenge with V. anguillarurn and at 96 h after challenge with LCDV. These results indicate that the turbot LMP7 protein participates in immune responses and may play a significant role in the immune process.展开更多
The ovary is an excellent system for studying stem cell renewal and differentiation, which is under the control of ovarian somatic cells. In order to understand oogenesis in Fugu rubripes （Temminck et. Schlegel） as ...The ovary is an excellent system for studying stem cell renewal and differentiation, which is under the control of ovarian somatic cells. In order to understand oogenesis in Fugu rubripes （Temminck et. Schlegel） as a marine fish model of aquaculture importance, we established cell lines called TSOC 1 and TSOC2 from a juvenile ovary of this organism. TSOC1 is composed of spindle epithelial-like cells, while the other is cobblestone-like ceils. Therefore, TSOC1 and TSOC2 appear to consist of ovarian somatic cells. Growth requirement condition was investigated including temperature, concentration of FBS and pH. Significant fluorescent signals were observed after TSOC1 and TSOC2 cells were transfected with pEGFP-N3 vector, indicating its potential utility for genetic manipulation such as gene function studies. It is shown that these cell lines are effective for infection by the turbot reddish body iridovirus and flounder lymphosystis disease virus as evidenced by the appearance of cytopathic effect and virus propagation in the virus-infected cells, and most convincingly, the observation of viral particles by electron microscopy, demonstrating that TSOC1 and TSOC2 are suitable to study interactions between virus and host cells. It is believed that TSOC1 and TSOC2 will be useful tools to study sex-related events and interactions between primordial germ cells and oogonia cells during oogenesis. Therefore, establishment of ovary cell lines from Fugu rubripes seems to be significant for those research areas.展开更多
Using brown .used alumina and top grade bauxite as main starting materials, ultrafine alumina, silica fume, and pure calcium aluminate cement as bonding system, the effcts of brown filsed alumina and top grade bauxite...Using brown .used alumina and top grade bauxite as main starting materials, ultrafine alumina, silica fume, and pure calcium aluminate cement as bonding system, the effcts of brown filsed alumina and top grade bauxite additions on the properties and microstructure of zero-cement Al2O3-SiO2 castables after dried at 110 ℃C and fired at 1 250℃ for 3 h were studied. The micro- structure was analyzed and discussed. The results show that the hot modulus of rupture of zero-cement Al2O3 - SiO2 castables at 1 250℃ is up to 22. 1 MPa when the bauxite addition is optimum at 12.5 wt%. The mullite formation mechanism in this castables is dissolutionprecipitation mechanism and the hot modulus of rupture of the castables is closely related to in-situ mullite formation. Compared with brown fused alumina, the top grade bauxite is more helpful to in-situ mullite formation and improvement of hot modulus of rupture of the castables.展开更多
基金supported by the National Key Research and Development Program of China(No.2017YFB1300102)the National Natural Science Foundation of China(No.U1613227)。
基金This work was supported by National Basic Research Program of China(973 Program)(2015CB453303)and International Science and Technology Cooperation Program of China(2013DFA31410)
文摘Enhancement release has been proven effective in natural resources recovery of Chinese shrimp Fenneropenaeus chinensis in the last several decades in China, however, to assess the effectiveness of enhancement release, we still need to develop a high-efficient and easy-operational method to replace those physical-tagging release method with labor intensive, size-and number-limited. In the present study, single(with maternal known) parentage identification using eight simple sequence repeat(SSR) markers genotype fingerprint was used to trace Chinese shrimp released in Bohai Bay in 2013. A total of 884 shrimp spawners were collected from two hatcheries in Tianjin City respectively after enhancement release of shrimp larvae in May 2013. A total of 844 shrimp samples were recaptured around the release location approximately 4 months after the shrimp larvae were released into the natural sea. Genotype data of 8 SSR loci of the 1,726 samples were used for maternal-offspring parentage identification using CEervus 3.0 software. The allele number in each locus ranged from 8 to 68 with an average value of 33.25, which produced the cumulative exclusion probability with one parent known of all these sight loci up to 99%. Among the 844 recaptured shrimp samples, 448(♂:♀=212:232, gender information was lost for 4 samples) were successfully traced to their 337 maternal parents using a logarithm of odds(LOD) > 3.0 threshold. Among these 337 maternal parents, 253 had a single offspring, 62 had two offspring, 18 had three offspring, 3 had four offspring, and 1 had five offspring. For the first time, a large number of released shrimp were identified from recapture samples, and this study showed that it is possible to trace all released Chinese shrimp without using any type of physical tag in enhancement release activities. This not only means more precise recapture ratio assessment than ever expected, but also this method demonstrates an effective method for large-scale hatchery release as well as for organisms used in hatchery enhancement which are not suitable for physical tagging.
基金The finance special program of Tianjin and the transformation project of Tianjin Agricultural Achievements
文摘The proteasome is a large, polymeric protease complex responsible for the degradation of intracellular pro- teins and generation of peptides that bind to class I major histocompatibility complex （MHC） molecules. This study identified a new member of proteasomal subunits in turbots （Scophthalrnus rnaxirnus）. The full- length cDNA sequence of turbot proteasomal subunit was obtained. Sequence analysis indicated that its primary structure is highly similar to that of LMP7 from other vertebrates. The relationship between the turbot LMP7 expression and immune responses to pathogen infection was reported. Quantitative reverse transcriptase polymerase chain reaction showed that LMPTwas expressed differently in various tissues, with higher expression in the spleen, liver, muscle, and skin. The LMP7 expression was the highest at 96 h after challenge with lymphocyctis disease virus （LCDV） and at 12 h after challenge with Vibrio anguillarurn in the turbot liver, kidney, and spleen. Furthermore, the LMP7 expression distinctly increased in turbot kidney cells at 24 h after challenge with V. anguillarurn and at 96 h after challenge with LCDV. These results indicate that the turbot LMP7 protein participates in immune responses and may play a significant role in the immune process.
基金The finance special program of Tianjinthe transformation project of Tianjin Agricultural Achievements
文摘The ovary is an excellent system for studying stem cell renewal and differentiation, which is under the control of ovarian somatic cells. In order to understand oogenesis in Fugu rubripes （Temminck et. Schlegel） as a marine fish model of aquaculture importance, we established cell lines called TSOC 1 and TSOC2 from a juvenile ovary of this organism. TSOC1 is composed of spindle epithelial-like cells, while the other is cobblestone-like ceils. Therefore, TSOC1 and TSOC2 appear to consist of ovarian somatic cells. Growth requirement condition was investigated including temperature, concentration of FBS and pH. Significant fluorescent signals were observed after TSOC1 and TSOC2 cells were transfected with pEGFP-N3 vector, indicating its potential utility for genetic manipulation such as gene function studies. It is shown that these cell lines are effective for infection by the turbot reddish body iridovirus and flounder lymphosystis disease virus as evidenced by the appearance of cytopathic effect and virus propagation in the virus-infected cells, and most convincingly, the observation of viral particles by electron microscopy, demonstrating that TSOC1 and TSOC2 are suitable to study interactions between virus and host cells. It is believed that TSOC1 and TSOC2 will be useful tools to study sex-related events and interactions between primordial germ cells and oogonia cells during oogenesis. Therefore, establishment of ovary cell lines from Fugu rubripes seems to be significant for those research areas.
文摘Using brown .used alumina and top grade bauxite as main starting materials, ultrafine alumina, silica fume, and pure calcium aluminate cement as bonding system, the effcts of brown filsed alumina and top grade bauxite additions on the properties and microstructure of zero-cement Al2O3-SiO2 castables after dried at 110 ℃C and fired at 1 250℃ for 3 h were studied. The micro- structure was analyzed and discussed. The results show that the hot modulus of rupture of zero-cement Al2O3 - SiO2 castables at 1 250℃ is up to 22. 1 MPa when the bauxite addition is optimum at 12.5 wt%. The mullite formation mechanism in this castables is dissolutionprecipitation mechanism and the hot modulus of rupture of the castables is closely related to in-situ mullite formation. Compared with brown fused alumina, the top grade bauxite is more helpful to in-situ mullite formation and improvement of hot modulus of rupture of the castables.
