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Computer Model of Phase Transformation From Hot-Deformed Austenite in Niobium Microalloyed Steels

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Journal of Iron and Steel Research International 2007年第2期14卷 66-69页

作者： XU Yun-bo YU yong-mei liu xiang-hua WANG Guo-dong State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

Based on thermodynamics and kinetics, a new mathematical model was developed to calculate the CCT diagrams and the transformation kinetics in low carbon niobium steels, in which the effect of deformation on the degree of supercooling was taken into account. The undercooling caused by deformation is the major reason for the increase of the starting transition temperature during continuous cooling. The critical cooling rate of bainite formation is within 2--5 ℃s for the studied niobium steels and deformation is suitable for the occurrence of pearlite. The ferrite volume fraction increases with the increase of the austenite boundary area, and decreases with the increase of the cooling rate. The calculated CCT diagrams and the volume fraction of each phase are in good agreement with the measurements.

关键词： low carbon niobium steel thermodynamics supercooling degree continuous cooling transformation computer model

Thermodynamic Calculation of Carbide Precipitate in Niobium Microalloyed Steels

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Journal of Iron and Steel Research International 2006年第6期13卷 53-56页

作者： XU Yun-bo YU yong-mei liu xiang-hua WANG Guo-dong State Key Lab of Rolling and Automation Northeastern University Shenyang 110004 Liaoning China

On the basis of regular solution sublattice model, thermodynamic equilibrium of austenite/carbide in Fe-Nb-C ternary system was investigated. The equilibrium volume fraction, chemical driving force of carbide precipitates and molar fraction of niobium and carbon in solution at different temperatures were evaluated respectively. The volume fraction of precipitates increases, molar fraction of niobium dissolved in austenite decreases and molar fraction of carbon increases with decreasing the niobium content. The driving force increases with the decrease of temperature, and then comes to be stable at relatively low temperatures. The predicted ratio of carbon in precipitates is in good agreement with the measured one.

关键词： microalloyed steel thermodynamic calculation phase equilibrium carbide prediction model

Extraction of reflected waves from acoustic logging data using variation mode decomposition and curvelet transform

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Petroleum Science 2024年第5期21卷 3142-3156页

作者： Fan-Tong Kong yong-xiang liu Xi-Hao Gu Li Zhen Cheng-Ming Luo Sheng-Qing Li Ocean College Jiangsu University of Science and TechnologyZhenjiang212100jiangsuChina School of Geosciences China University of Petroleum(East China)Qingdao266580Shandong.China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu610059SichuanChina

Remote reflection waves, essential for acquiring high-resolution images of geological structures beyond boreholes, often suffer contamination from strong direct mode waves propagating along the ***, the extraction of weak reflected waves becomes pivotal for optimizing migration image quality. This paper introduces a novel approach to extracting reflected waves by sequentially operating in the spatial frequency and curvelet domains. Using variation mode decomposition(VMD), single-channel spatial domain signals within the common offset gather are iteratively decomposed into high-wavenumber and low-wavenumber intrinsic mode functions(IMFs). The low-wavenumber IMF is then subtracted from the overall waveform to attenuate direct mode waves. Subsequently, the curvelet transform is employed to segregate upgoing and downgoing reflected waves within the filtered curvelet domain. As a result, direct mode waves are substantially suppressed, while the integrity of reflected waves is fully preserved. The efficacy of this approach is validated through processing synthetic and field data, underscoring its potential as a robust extraction technique.

关键词： Borehole acoustic reflection imaging Variation mode decomposition Curvelet transform Weak signal extraction

Cytological Behavior of Hybridization Barriers Between Oryza sativa and Oryza officinalis

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Agricultural Sciences in China 2011年第10期10卷 1489-1500页

作者： FU Xue-lin LU yong-gen liu xiang-dong LI Jin-quan ZHAO Xing-juan Key Laboratory of Plant Molecular Breeding Guangdong Province/College of Agriculture South China Agricultural University Guangzhou510642 P.R. China

Oryza officinalis is one of the important wild species in the tertiary gene pool of Oryza sativa. It has a number of elite genes for rice breeding in resistance or tolerance. However, breeding barriers are so serious that the gene transfer is much difficult by sexual cross method between O. sativa and O. officinalis. Characteristics of the breeding barriers were systemically studied in this paper. When both the diploid （AA, 2n=2x=24） and autotetraploid （AAAA, 2n=4x=48） cultivated rice were crossed as maternal parents with O. officinalis （CC, 2n=2x=24）, none F1 hybrid seeds were obtained. The young hybrid ovaries aborted at 13-16 d after pollinations （DAP）. By rescuing hybrid embryos, in vitro F1 plantlets were obtained in 2x×2x combinations with the crossabilities lower than 0.5%. Lower rates of double-fertilization and abnormal development of hybrid embryo and endosperm were mainly observed in both combinations of 2x×2x and 4x×2x. Free endosperm nuclei in hybrid degenerated early at 1 DAP in a large scale. Almost no normal endosperm cells formed at 3 DAP. Development of a lot of embryos ceased at globularor pear-shaped stage as well as some degenerated gradually. The hybrid plantlets were both male and female sterility. Due to the abnormal development, a diversity of abnormal embryo sacs formed in hybrids, and hybrid pollen grains were typically abortive. It showed that conflicts of genome A and C in hybrid induced abnormal meioses of meiocytes.

关键词： breeding barriers interspecific hybridization crossability hybrid sterility Oryza sativa Oryza officinalis

Detection of Distorted Segregation in Genotype of Pollen Calli Derived from Hybrid F_1 of Cultivated Rice (Oryza sativa L.) Using SSR Markers

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Agricultural Sciences in China 2006年第6期5卷 412-416页

作者： YAO Yan LU yong-gen liu xiang-dong FENG Jiu-huan ZHANG Gui-quan Guangdong Provincial Key Laboratory of Plant Molecular Breeding South China Agricultural University Guangzhou 510642 P.R.China

S-a, S-b and S-c are three loci for F1 pollen sterility in cultivated rice （Oryza sativa L.）. Taichung 65 （T65） is all Sj/Sj at these three loci, while its F1 pollen sterile near-isogenic lines, TISL2 （S-b）, TISL4 （S-a） and TISL5 （S-c） is Sj/Sj according to their respective sterility locus. Using SSR molecular marker to detect the segregation of the allele Si and Sj in pollen calli population induced from different hybrid F1, which have different pollen sterility locus, showed that the segregation of allele Si and Sj was distorted. The distorted direction of pollen calli population in vitro was not the same as F2 population in vivo. The quantities of pollen callus carrying Sj were much more than that of carrying Siat S-a and S-c locus, the ratio of Si and Sj were 1：4.81 and 1：1.96 respectively. But the opposite tendency was observed at S-b locus, the ratio of Si and Sj being 1：0.35. At the same time, all these results were undisturbed by either culture medium or culture period.

关键词： rice (Oryza sativa L.) pollen sterility pollen callus distorted segregation SSR marker

Progress on Transferring Elite Genes from Non-AA Genome Wild Rice into Oryza sativa through Interspecific Hybridization

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Rice science 2008年第2期15卷 79-87页

作者： Fu Xue-lin LU yong-gen liu xiang-dong LI Jin-quan Guangdong Provincial Key Laboratory of Plant Molecular Breeding South China Agricultural University Guangzhou 510642 China

The progress of research on transferring elite genes from non-AA genome wild rice into Oryza sativa through interspecific hybridization are in three respects, that is, breeding monosomic alien addition lines （MAALs）, constructing introgression lines （ILs） and analyzing the heredity of the characters and mapping the related genes. There are serious reproductive barriers, mainly incrossability and hybrid sterility, in the interspecific hybridization of O. sativa with non-AA genome wild rice. These are the ＇bottleneck＇ for transferring elite genes from wild rice to O. sativa. Combining traditional crossing method with biotechnique is a reliable way to overcome the reproductive barriers and to improve the utilizing efficiency of non-AA genome wild rice.

关键词： Oryza sativa non-AA genome wild rice interspecific hybridization monosomic alien addition line introgression line reproductive barrier gene mapping

Comparative Embryological Studies on Infertility of Interspecific Hybridizations Between Oryza sativa with Different Ploidy Levels and O. officinalis

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Rice science 2009年第1期16卷 58-64页

作者： FU Xue-lin LU yong-gen liu xiang-dong LI Jin-quan ZHAO Xing-juan Guangdong Provincial Key Laboratory of Plant Molecular Breeding South China Agricultural University Guangzhou 510642 China

As maternal parents, diploid （L202-2x） and autotetraploid （L202-4x） of Oryza sativa cv. L2O2 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. There were no mature hybrid seeds obtained because all the hybridized spikelets died 30 days after pollination. The main reasons for no seed set were abnormal fertilization and development of the embryos and endosperms in the interspecific hybrids. There were doublefertilization, egg cell single-fertilization and non-fertilization in these crosses. Although 59.45% and 54.87% of hybrid embryos produced in the crosses of L202-2x/O. officinalis and L202-4x/O. officinalis, respectively, hybrid embryos ceased to develop or degenerated and plenty of free endosperm nuclei were in disaggregating state without developing cellular endosperms three days after pollination. Besides, some embryological differences in these two crosses were found, that is, the rate of double-fertilization and total rate of doubleand single-fertilization in L202-2x/O. officinalis were higher than those in L202-4x/O. officinalis. The embryo and endosperm of hybrids developed more slowly, and embryos and free endosperm nuclei were more severely degenerated in L202-4x/O. officinalis than in L202-2x/O. officinalis. Five days after pollination, a few of embryos in L202-2x/O. officinalis developed into pear-shaped ones, however, embryos in L202-4x/O. officinalis were all degenerated. Therefore, it is more difficult to obtain interspecific hybrids by wide crosses between autotetraploid of O. sativa and O. officinalis.

关键词： Oryza sativa Oryza officinalis diploid rice autotetraploid rice wild rice interspecific hybridization embryo development infertility

Changes in intestinal microflora in rats with acute respiratory distress syndrome

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World Journal of Gastroenterology 2014年第19期20卷 5849-5858页

作者： Yan Li xiang-yong liu Ming-Ming Ma Zhi-Jiang Qi Xiao-Qiang Zhang Zhi Li Guo-Hong Cao Jun Li Wei-Wei Zhu Xiao-Zhi Wang Department of Respiratory Medicine and Intensive Care Unit Affiliated Hospital of Binzhou Medical University Department of Intensive Care Unit Zhangqiu People’s Hospital Department of Cell Biology Binzhou Medical University Department of Intensive Care Unit Dezhou People’s Hospital

AIM: To implement high-throughput 16S rDNA sequencing to study microbial diversity in the fecal matter of rats with acute lung injury/acute respiratory distress syndrome (ALI/ARDS).

关键词： Lipopolysaccharide Acute lung injury Acute respiratory distress syndrome Intestinal microflora High-throughput sequencing

Abnormal Structure of Embryo Sac in Autotetraploid Rice

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Rice science 2006年第4期13卷 257-264页

作者： Guo Hai-bin FENG Jiu-huan Lu yong-gen liu xiang-dong Guangdong Provincial Key Laboratory of Plant Molecular Breeding South China Agricultural University Guangzhou 510642 China

The structures of mature embryo sacs in 13 genetic stock lines of autotetraploid rice （Oryza sativa L.）, including indica, japonica and javanica, were studied by using the whole-mount stain-clearing laser scanning confocal microscopy （WCLSM）. Among the 13 autotetraploid rice, the majority of ovaries possess normal polygonum-type embryo sacs, while a few ovaries were characterized by abnormal embryo sacs. The abnormalities of embryo sacs could be classified into six categories, i. e. no female germ unit, abnormal polar nuclei, embryo sac degeneration, no egg apparatus, small embryo sac and ＇double set＇ of embryo sacs. The frequency of abnormal embryo sac in japonica （26.6%） was higher than that in indica （19.34%）. In addition, the major abnormalities in each autotetraploid line varied, suggesting that the abnormalities may be related to the genotypes of the varieties.

关键词： autotetraploid rice structure anatomy embryo sac seed setting rate