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Low-cycle fatigue behaviour of Mg-9Gd-4Y-2Zn-0.5Zr alloys with different structures

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Journal of Magnesium and Alloys 2023年第9期11卷 3382-3393页

作者： jinsheng ji jie Zheng Leichen jia yong Zhang Yunfei jia Yusha Shi Heng Zhang yong Xue School of Materials Science and Engineering North University of ChinaTaiyuan 030051China Key Laboratory of Pressure Systemsand Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China

The strain-controlled cyclic deformation behaviour of Mg-9Gd-4Y-2Zn-0.5Zr with different structures was investigated. Alloys were prepared by solution, extrusion and pre-ageing extrusion, and the microstructures before and after the fatigue tests were *** results indicated that the bimodal structure owned the better performance in fatigue test, which was attributed to the higher yield strength. For the equiaxed structure, cyclic hardening induced stress concentration until the failure. Stable cyclic deformation and persistent cyclic softening played an important role at the low and high strain amplitudes, respectively. This was attributed to the formation of fine grains relieving the stress concentration during cyclic loading. In addition, residual twins were observed in equiaxed structure to induce crack, and the bimodal structure effectively restrain it.

关键词： Strain-controlled fatigue Bimodal structure Fractography Mg-Gd-Y-Zn-Zr alloy

Changes in brain activation patterns according to cross-training effect in serial reaction time task An functional MRI study

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Neural Regeneration Research 2013年第7期8卷 639-646页

作者： yong Hyun Kwon Jung Won Kwon ji Won Park Department of Physical Therapy Yeungnam College of Science & Technology Department of Physical Therapy College of Health Science Catholic University of Daegu

Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral limb. We used functional MRI to investigate whether motor performance of the untrained limb could be improved using a serial reaction time task according to motor sequential learning of the trained limb, and whether these skill acquisitions led to changes in brain activation patterns. We recruited 20 right-handed healthy subjects, who were randomly allocated into training and control groups. The training group was trained in performance of a serial reaction time task using their non-dominant left hand, 40 minutes per day, for 10 days, over a period of 2 weeks. The control group did not receive training. Measurements of response time and percentile of response accuracy were performed twice during pre- and post-training, while brain functional MRI was scanned during performance of the serial reaction time task using the untrained right hand. In the training group, prominent changes in response time and percentile of response accuracy were observed in both the untrained right hand and the trained left hand between pre- and post-training. The control group showed no significant changes in the untrained hand between pre- and post-training. In the training group, the activated volume of the cortical areas related to motor function （i.e., primary motor cortex, premotor area, posterior parietal cortex） showed a gradual decrease, and enhanced cerebellar activation of the vermis and the newly activated ipsilateral dentate nucleus were observed during performance of the serial reaction time task using the untrained right hand, accompanied by the cross-motor learning effect. However, no significant changes were observed in the control group. Our findings indicate that motor skills learned over the 2-week training using the trained limb were transferred to the opposi

关键词： neural regeneration neuroimaging cross-training effects motor skill learning cortical activation cerebellar activation serial reaction time task functional MRI response time response accuracy primary motor cortex dentate nucleus vermis grants-supported paper photographs-containingpaper neuroregeneration

The Frattini Subalgebra of Restricted Lie Superalgebras

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1343-1356页

作者： Liang Yun CHEN Dao ji MENG yong Zheng ZhaNG Department of Mathematics Harbin Institute of Technology Harbin 150001 P. R. China Department of Mathematics Northeast Normal University Changchun 130024 P. R. China Department of Mathematics Nankai University Tianjin 300071 P. R. China

In the present paper, we study the Frattini subalgebra of a restricted Lie superalgebra （L, [p]）. We show first that if L = A1 ＋ A2 ＋… ＋An, then Фp（L） = Фp（A1）＋Фp（A2）＋…＋Фp（An）, where each Ai is a p-ideal of L. We then obtain two results： F（L） = Ф（L） = J（L） = L if and only if L is nilpotent; Fp（L） and F（L） are nilpotent ideals of L if L is solvable. In addition, necessary and sufficient conditions are found for Фp-free restricted Lie superalgebras. Finally, we discuss the relationships of E-p-restricted Lie superalgebras and E-restricted Lie superalgebras.

关键词： restricted Lie superalgebras E-p-restricted Lie superalgebras Frattini p-subalgebra Фp- free p-elementary

Effect of solanine on the membrane potential of mitochondria in HepG_2 cells and [Ca^(2+)]i in the cells

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World Journal of Gastroenterology 2006年第21期12卷 3359-3367页

作者： Shi-yong Gao Qiu-Juan Wang Yu-Bin ji Physiology Section Department of Pharmacy China Pharmaceutical University Nanjing 210009 Jiangsu Province China Postdoctoral Research Station The Institute of Materia Medica Harbin University of Commerce Harbin 150076 Heilongjiang Province China

AIM： To observe the effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca^2＋]i in the cells, and to uncover the mechanism by which solanine induces ***： HepG2 cells were double stained with AO/EB, and morphological changes of the cells were observed using laser confocal scanning microscopy （LCSM）. HepG2 cells were stained with TMRE, and change in the membrane potential of mitochondria in the cells were observed using LCSM. HepG2 cells were double stained with Fluo-3/AM, and change of [Ca^2＋]i in the cells were observed using LCSM. HepG2 cells were double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca^2＋]i in the cells were observed using ***： Cells in treated groups showed typical signs of apoptosis. Staining with TMRE showed that solanine could lower membrane potential; staining with Fluo-3/AM showed that solanine could increase the concentration of Ca^2＋ in tumor cells; and those of double staining with TMRE and Fluo-3/AM showed that solanine could increase the concentration of Ca^2＋ in the cells at the same time as it lowered the membrane potential of ***： Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca^2＋ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca^2＋ in the cell, turning on the mechanism for apoptosis.

关键词： Solanine Hepatocarcinomatic cell Ca^2+ in the cell Membrane potential Laser confocal scanning microscopy

Transcriptome datasets supply basic gene information for RNAi pest management and gene functional studies in Nephotettix cincticeps(Uhler)

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Journal of Integrative Agriculture 2016年第4期15卷 840-847页

作者： CHEN Tai-yu HOU ji-xiang LIN yong-jun National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University College of Plant Science & Technology Huazhong Agricultural University

RNA interference （RNAi） technology has the potential to be used in pest management in crop production. Here, the transcriptome of Nephotettix cincticeps （Uhler） was deeply sequenced to investigate the systematic RNAi mechanism and candidate genes for dsRNA feeding. In our datasets, a total of 81 225 transcripts were obtained with the length from 150 bp to about 4.2 kb. Almost all the genes related to the RNAi core pathway were proved to be present in N. cincticeps transcriptome. Two transcripts that respectively encode a systemic interference defective （SID） were identified in our da- tabase, indicating that the systematic RNAi pathway can function effectively in N. cincticeps. Our datasets not only supply basic gene information for the studies of gene expression and functions in N. cincticeps, such as the control genes for gene expression analysis, but also provide candidate genes for RNAi pest management, such as the genes that encode P450 monooxygenase, V-ATPase and chitin synthase.

关键词： Nephotettix cincticeps transcriptome RNA interference house-keeping genes

Formation and thermal stability of amorphous Ni-Mo-P alloys

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 147-151页

作者： ZhaNG Yi MA Jun FANG yong-kui DUAN ji-guo School of Municipal and Environmental Engineering Harbin Institute of TechnologyHarbin 150090 China College of Chemistry and Chemical Engineering Daqing Petroleum Institute Daqing 163318 China College of Chemistry and Chemical Engineering Daqing Petroleum Institute Daqing 163318 China School of Municipal and Environmental Engineering Harbin Institute of TechnologyHarbin 150090 China School of Municipal and Environmental Engineering Harbin Institute of TechnologyHarbin 150090 China

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.

关键词： chemical deposition Ni-Mo-P alloy amorphous phase crystallization

PROPAGATION OF LOVE WAVES IN PRESTRESSED PIEZOELECTRIC LAYERED STRUCTURES LOADED WITH VISCOUS LIQUID

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Acta Mechanica Solida Sinica 2008年第6期21卷 542-548页

作者： jianke Du Kai Xian ji Wang Yook-Kong yong Department of Mechanics and Engineering Science School of Engineering Ningbo University Ningbo 315211 China Department of Civil and Environmental Engineering Rutgers University Piscataway NJ 08854 USA

We investigate analytically the effect of initial stress in piezoelectric layered structures loaded with viscous liquid on the dispersive and attenuated characteristics of Love waves, which involves a thin piezoelectric layer bonded perfectly to an unbounded elastic substrate. The effects of initial stress in the piezoelectric layer and the viscous coefficient of the liquid on the phase velocity of Love waves are analyzed. Numerical results are presented and discussed. The analytical method and the results can be useful for the design of chemical and biosensing liquid sensors.

关键词： Love waves piezoelectric viscous liquid initial stress

Strain rate response of a Zr-based composite fabricated by Bridgman solidification

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 214-219页

作者： Jun-wei Qiao yong Zhang ji-heng Li Guo-liang Chen State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

Zr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0 bulk metallic glass matrix composites,containingβ-Zr dendrites,were fabricated by Bridgman solidification at the withdrawal velocity of 1.0 mm/s through a temperature gradient of～45 K/*** to the increasing compressive strain rates,the monotonic increasing and decreasing were obtained for the maximum strength and the fracture strain,*** results show that high strain rate may induce the insufficient time for the interaction between shear bands and the crystalline phase,and early fracture occurs as a *** fractographs are consistent with the mechanical properties,and the failure mode of the present Zr-based composites is in agreement with the frame of the ellipse criterion.

关键词： bulk metallic glass composites Bridgman solidification mechanical properties

Equilibrium Crystallization Temperature of Syndiotactic Polystyrene γ Form

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Chinese Journal of Polymer Science 2018年第6期36卷 749-755页

作者： hai Wang Chun-ji Wu Dong-Mei Cui yong-Feng Men State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences

The crystallization behavior of syndiotactic polystyrene（s PS） γ form undergoing annealing at various temperatures was investigated using the thermodynamic phase diagram based on Strobl＇s crystallization theory. On the basis of the differential scanning calorimetric results, it was observed that γ form melt-recrystallization occurred at a higher temperature with the increasing lamellar thickness, which resulted from the pre-annealing at the elevating temperature after acetone induced crystallization. Further temperature dependent small-angle X-ray scattering（SAXS） measurement revealed the evolution of the γ form lamellae upon heating until phase transition, involving three different regimes： lamellae stable region（25-90 °C）, melt-recrystallization region（90-185 °C） and pre-phase transition region（185-195 °C）. As a result, recrystallization line, equilibrium recrystallization line and melting line were developed for the s PS γ form crystallization process. Since the melt of γ form involved a γ-to-α/β form phase transition, the melting line was also denoted as the phase transition line in this special case. Therefore, the equilibrium crystallization temperature and melting（phase transition） temperatures were determined at around 390 and 220 °C on the basis of the thermodynamic phase diagram of the s PS γ form.

关键词： Syndiotactic polystyrene γ form Crystallization behavior Equilibrium crystallization temperature Equilibrium melting temperature