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| 1 | Rapid changes of microsatellite flanking sequence in the allopolyploidization of new synthesized hexaploid wheat显示文摘It was suggested that the rapid changes of DNA sequence and gene expression oc- curred at the early stages of allopolyploid formation. In this study, we revealed the microsatellite (SSR) differences between newly formed allopolyploids and their donor parents by using 21 primer sets specific for D genome of wheat. It was indicated that rapid changes had occurred in the “shock” process of the allopolyploid formation between tetraploid wheat and Aegilops tauschii. The changes of SSR flanking sequence resulted in appearance of novel bands or disappearance of parental bands. The disappearance of the parental bands showed much higher frequencies in comparison with that of appearance of novel bands. Disappearance of the parental bands was not random. The frequency of disappearance in tetraploid wheat was much higher than in Ae. tauschii, i. e. the disappearance frequency in AABB genome was much higher than in D genome. Changes of SSR flanking sequence occurred at the early stage of F1 hybrid or just after chro- mosome doubling. From the above results, it can be inferred that SSR flanking sequence region was very active and was amenable to change in the process of polyploidization. This suggested that SSR flanking sequence probably had special biological function at the early stage of ploy- ploidization. The rapid and directional changes at the early stage of polyploidization might con- tribute to the rapid evolution of the newly formed allopolyploid and allow the divergent genomes to act in harmony. | ZHANG Lianquan LIU Dengcai YAN Zehong LAN Xiujin ZHENG Youliang ZHOU Yonghong | 2004 | Science China(Life Sciences)2004，47，6： | 25 |
| 2 | Identification and PID Control for a Class of Delay Fractional-order Systems显示文摘In this paper,a new model identification method is developed for a class of delay fractional-order system based on the process step response.Four characteristic functions are defined to characterize the features of the normalized fractionalorder model.Based on the time scaling technology,two identification schemes are proposed for parameters' estimation.The scheme one utilizes three exact points on the step response of the process to calculate model parameters directly.The other scheme employs optimal searching method to adjust the fractional order for the best model identification.The proposed two identification schemes are both applicable to any stable complex process,such as higher-order,under-damped/over-damped,and minimum-phase/nonminimum-phase processes.Furthermore,an optimal PID tuning method is proposed for the delay fractionalorder systems.The requirements on the stability margins and the negative feedback are cast as real part constraints(RPC)and imaginary part constraints(IPC).The constraints are implemented by trigonometric inequalities on the phase variable,and the optimal PID controller is obtained by the minimization of the integral of time absolute error(ITAE) index.Identification and control of a Titanium billet heating process is given for the illustration. | Zhuoyun Nie Qingguo Wang Ruijuan Liu Yonghong Lan | 2016 | IEEE/CAA Journal of Automatica Sinica2016，3，4： | 6 |
| 3 | Effect of trace tungsten on the microstructure of TiAl alloys containing Nb and B显示文摘New TiAl alloys, containing 45 at.% Al, 7 at.% Nb, x at.% W, and 0.15 at.% B (x = 0, 0.2, 0.4, and 0.7) were prepared by arc melting and drop casting consequently. Using optical microscopy, scanning electron microscopy (SEM), and electron superprobe technologies, the effects of tungsten on the microstructural evolution of the TiAl alloys, including the colony size and lamellar spacing, were analyzed. It was found that cellular structures and dendrites were formed in the as-cast TiAl alloys, and heavy metals, such as niobium and tungsten, tend to segregate strongly at the interface of the cellu- lar structures and dendrites. Trace tungsten can effectively impede the grain growth and narrow the interlamellar spacing. 0.4 at.% tungsten is more effective in refining the microstructure of the TiAl alloys. | LIU Bin LIU Yong HUANG Lan HUANG Jinsong ZHANG Yonghong HUANG Boyun | 2007 | Rare Metals2007，26，4： | 2 |
| 4 | Reduced Sp1 expression inhibits the proliferation and migration of HepG2 cells显示文摘Specificity protein 1(Sp1)is a ubiquitously expressed transcription factor involved in the regulation of a large number of genes including housekeeping genes as well as actively regulated genes.Increasing evidences have indicated that Sp1 is closely correlated with the occurrence and progression of many tumors.The plasmid expression vector of short hairpin RNA(shRNA)targeting Sp1 was constructed and transfected into HepG2 cells by Lipo2000 transfection reagent.Immunocytochemistry,Western blot and quantitative real-time PCR were applied to determine Sp1 expression,and MTT and Transwell assay were used to analyze the cell proliferation and migration,respectively.The expressions of Sp1 protein and mRNA decreased significantly in HepG2 cell after transfection with Sp1 shRNA,and reduced Sp1 expression inhibited proliferation and migration of HepG2 cells. | Lan Yonghong Rao Langyu Cui Zhigang Niu Haiyan Qi Yaling Yang Zhi | 2021 | 解剖学杂志2021，44，S01： | 0 |
| 5 | Microbial degradation and its influence on components of coalbed gases in Enhong syncline, China显示文摘Coalbed gases (CBG) in Enhong syncline are characterized by high concentration of C2+ (C2-5 ), with the highest content of ethane over 30%. However, the concentrations of C2+ are not evenly distributed in the syncline. Based on the analysis of δ13C1 , δ13C2 , δ13C3 , δ13CO2 , δDCH4 of CBG and their origin diagrams in the normal and abnormal areas, this research shows that gases in both areas are thermogenic gases and the reason for the uneven distribution of C2+ is that the microbial degradation action on gases is stronger in the normal area than in the abnormal area. The secondary biologic gases in the normal area are mainly characterized by that the carbon isotopes become obviously lighter in methane and become heavier in ethane, whereas the molecular and isotopic compositions of CO2 change little. These features indicate that the secondary biologic gases are mainly generated by the microbial degradation of C2+ , not generated by the reduction of CO2 . The degradation process is selective to make the residual ethane being enriched in 13C and the generated methane rich in 12C. | Lan Fengjuan Qin Yong Li Ming Tang Yonghong Guo Chen Zhang Fei | 2013 | International Journal of Mining Science and Technology2013，23，2： | 0 |
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