Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 o...Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 of a Mine hybrid rice production system. In the restorer line, Ce64, the developing microsporocytes have dense cytoplasm and a distinct set of circumferential microtubules around the nucleus. Successive cytokinesis results in the formation of tetrads. The microtubules within the cells of tetrads and microspores radiate from the surface of the nucleus towards the outer edge of the cytoplasm. Subsequent pollen development is normal. During the course of microspore formation tubulin speckles can be found in the cytoplasm. The general pattern of development and microtubule organization in the maintainer lined Zhen Shan 97B, is similar to Ce64, except that a few more tubulin speckles appear during microspore formation. In the case of the mate sterile line, Zhen Shan 97A, a number of abnormalities can be discerned during early microsporogenesis. These include vacuoles forming within the developing microsporocyte and faintly stained microtubules with no defined distribution pattern. Prominent tubulin speckles are common within the cytoplasm. For those microsporocytes that undergo meiosis, no defined organizational patterns of microtubules can be found within the tetrad. All microspores abort soon after. Abnormalities and defects in microtubule organization observed in Zhen Shan 97A showed that complex interactions between the cytoplasm and the nucleus began at very early stage of microsporocyte development.展开更多
Cave-in failure is apt to occur in joints of trusses made of square hollow sections. In order to turn the failure mode into a strength failure mode of joint members, the idea is proposed that the chord of the truss is...Cave-in failure is apt to occur in joints of trusses made of square hollow sections. In order to turn the failure mode into a strength failure mode of joint members, the idea is proposed that the chord of the truss is grouted to increase the cave-in beating capacity of a hollow tube chord. An experiment of eight specimens of N- joints made of grout-filled square steel tubes is performed. Based on the experimental study, the geometrical parameters of specimens are analyzed, and the effects of the confinement index ε, the spacing between the two web members g and the ratio of side length of the vertical web member to that of the chord β on the behavior of specimens are investigated through simulation analysis by simulation analyses, the mechanical properties and the failure an ANSYS program. Based on the test results and modes of this kind of joints are analyzed and the formulae to predict the ultimate bearing capacities corresponding to different failure modes are developed. The ultimate bearing capacity of compressive N-joints is calculated in accordance with the cave-in failure mode of a chord member; the ultimate bearing capacity of tension N-joints is calculated in accordance with the punchingshear failure mode; the ultimate bearing capacity of a chord member is calculated in accordance with the shear failure mode in normal sections.展开更多
To improve the wall surface hydrophilicity of a tube type indirect evaporative cooler,a new method adopting porous ceramics is proposed.This method realizes the combination of porous ceramics and the evaporative cooli...To improve the wall surface hydrophilicity of a tube type indirect evaporative cooler,a new method adopting porous ceramics is proposed.This method realizes the combination of porous ceramics and the evaporative cooling technique.The design calculation of the porous ceramics tube type dew point indirect evaporative cooler are carried out from such aspects as the volumes and status parameters of the primary and secondary air,the cooler structure,the heat transfer of the solid porous ceramic tubes and the resistance of the cooler.The calculation results show that the design is reasonable.Finally,based on the design calculation,the porous ceramics tube type dew point indirect evaporative cooler is successfully manufactured.展开更多
In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae w...In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae were investigated in this study. After the processes of screening pregnant sows, programmed therapy for sows, SEW, three-point breeding and management in the barrier isolation system and programmed therapy for piglets, the newly-bred piglets were monitored as long as four months by serum antibody detection of Mycoplasma hyopneumoniae and fluorescent quantitative PCR of nose swabs. The results showed that when the newlybred five batches of piglets were older than 35 d, they were all negative by serum antibody detection and nose swab antigen detection. Therefore, the combination therapy, SEW and three-point production and management system can effectively purify Mycoplasma hyopneumoniae, providing theoretical basis and clinical experience for the control and purification of domestic mycoplasmal pneumonia.展开更多
The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change o...The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change of band gaps in MWNTs depend on the intershell interaction.The VHS makes the probability of optical transitions enhanced,but the intershell interaction suppresses such radiative transitions.The excitation in the experiment involves a two-photon absorption process and the emission light has the effect of the optical frequency up-conversion.展开更多
Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and ligh...Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and lightweight properties,several display techniques have been demonstrated.There are mainly four types of electronic display device:cathode ray tube(CRT),liquid-crystal display(LCD),organic light-emitting diode(OLED),and micro-LED.Due to the different working principles and device structures,each type of display device has its special characteristic properties.The performance of devices could be adjusted through the material selection or device design.With careful device structure regulation,not only the efficiency but also the stability would be improved.Herein,a brief review of innovative strategies towards the structure design is presented.展开更多
文摘Histological changes that occur during microsporogenesis are documented in a gene-cytoplasmic male sterile rice ( Oryza saliva L.) line, Zhen Shan 97A, its maintainer line, Zhen Shan 97B, and the restorer line, Ce64 of a Mine hybrid rice production system. In the restorer line, Ce64, the developing microsporocytes have dense cytoplasm and a distinct set of circumferential microtubules around the nucleus. Successive cytokinesis results in the formation of tetrads. The microtubules within the cells of tetrads and microspores radiate from the surface of the nucleus towards the outer edge of the cytoplasm. Subsequent pollen development is normal. During the course of microspore formation tubulin speckles can be found in the cytoplasm. The general pattern of development and microtubule organization in the maintainer lined Zhen Shan 97B, is similar to Ce64, except that a few more tubulin speckles appear during microspore formation. In the case of the mate sterile line, Zhen Shan 97A, a number of abnormalities can be discerned during early microsporogenesis. These include vacuoles forming within the developing microsporocyte and faintly stained microtubules with no defined distribution pattern. Prominent tubulin speckles are common within the cytoplasm. For those microsporocytes that undergo meiosis, no defined organizational patterns of microtubules can be found within the tetrad. All microspores abort soon after. Abnormalities and defects in microtubule organization observed in Zhen Shan 97A showed that complex interactions between the cytoplasm and the nucleus began at very early stage of microsporocyte development.
基金The National Natural Science Foundation of China(No50178026)Program for New Century Excellent Talents in University+1 种基金the Key Technologies R & D Program of Heilongjiang Province(NoGC04A609)the Key Technologies R & D Program of Harbin City(No2004AA9CS187)
文摘Cave-in failure is apt to occur in joints of trusses made of square hollow sections. In order to turn the failure mode into a strength failure mode of joint members, the idea is proposed that the chord of the truss is grouted to increase the cave-in beating capacity of a hollow tube chord. An experiment of eight specimens of N- joints made of grout-filled square steel tubes is performed. Based on the experimental study, the geometrical parameters of specimens are analyzed, and the effects of the confinement index ε, the spacing between the two web members g and the ratio of side length of the vertical web member to that of the chord β on the behavior of specimens are investigated through simulation analysis by simulation analyses, the mechanical properties and the failure an ANSYS program. Based on the test results and modes of this kind of joints are analyzed and the formulae to predict the ultimate bearing capacities corresponding to different failure modes are developed. The ultimate bearing capacity of compressive N-joints is calculated in accordance with the cave-in failure mode of a chord member; the ultimate bearing capacity of tension N-joints is calculated in accordance with the punchingshear failure mode; the ultimate bearing capacity of a chord member is calculated in accordance with the shear failure mode in normal sections.
基金The National Natural Science Foundation of China(No.50846056)
文摘To improve the wall surface hydrophilicity of a tube type indirect evaporative cooler,a new method adopting porous ceramics is proposed.This method realizes the combination of porous ceramics and the evaporative cooling technique.The design calculation of the porous ceramics tube type dew point indirect evaporative cooler are carried out from such aspects as the volumes and status parameters of the primary and secondary air,the cooler structure,the heat transfer of the solid porous ceramic tubes and the resistance of the cooler.The calculation results show that the design is reasonable.Finally,based on the design calculation,the porous ceramics tube type dew point indirect evaporative cooler is successfully manufactured.
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund[CX(12)1001-05]~~
文摘In order to explore a breeding method for mycoplasmal pneumonia-negative swine population, the purifying effects of combination therapy, SEW and three-point breeding and management system on Mycoplasma hyopneumoniae were investigated in this study. After the processes of screening pregnant sows, programmed therapy for sows, SEW, three-point breeding and management in the barrier isolation system and programmed therapy for piglets, the newly-bred piglets were monitored as long as four months by serum antibody detection of Mycoplasma hyopneumoniae and fluorescent quantitative PCR of nose swabs. The results showed that when the newlybred five batches of piglets were older than 35 d, they were all negative by serum antibody detection and nose swab antigen detection. Therefore, the combination therapy, SEW and three-point production and management system can effectively purify Mycoplasma hyopneumoniae, providing theoretical basis and clinical experience for the control and purification of domestic mycoplasmal pneumonia.
文摘The absorption spectrum and photoluminescence spectrum of multiwalled carbon nanotubes(MWNTs) and the peaks related with Van Hove singularities(VHS) were obtained experimentally.Both the VHS formation and the change of band gaps in MWNTs depend on the intershell interaction.The VHS makes the probability of optical transitions enhanced,but the intershell interaction suppresses such radiative transitions.The excitation in the experiment involves a two-photon absorption process and the emission light has the effect of the optical frequency up-conversion.
基金Projects(71572028,71872027)supported by the National Natural Science Foundation of China。
文摘Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and lightweight properties,several display techniques have been demonstrated.There are mainly four types of electronic display device:cathode ray tube(CRT),liquid-crystal display(LCD),organic light-emitting diode(OLED),and micro-LED.Due to the different working principles and device structures,each type of display device has its special characteristic properties.The performance of devices could be adjusted through the material selection or device design.With careful device structure regulation,not only the efficiency but also the stability would be improved.Herein,a brief review of innovative strategies towards the structure design is presented.
