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Homoclinic Solutions for a Class of Second Order Discrete Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2012年第3期28卷 609-622页

作者： xian Hua TANG xiao Yan LIN School of Mathematical Sciences and Computing Technology Central South University Department of Mathematics Huaihua College

Consider the second order discrete Hamiltonian systems

关键词： Homoclinic solution discrete Hamiltonian system critical point

Cloning and characterization of CaGID1s and CaGAI in Capsicum annuum L.

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Journal of Integrative Agriculture 2016年第4期15卷 775-784页

作者： CAO Ya-cong ZHANG zheng-hai WANG Li-hao SUI xiao-lei ZHANG zhen-xian ZHANG Bao-xi Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops China Agricultural University Key Laboratory of Horticultural Crop Biology and Germplasm Innovation Ministry of AgricultureInstitute of Vegetables and Flowers Chinese Academy of Agricultural Sciences

Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.

关键词： Capsicum annuum L. fruit GID1 DELLA

Wake-promoting effects of vagus nerve stimulation after traumatic brain injury: upregulation of orexin-A and orexin receptor type 1 expression in the prefrontal cortex

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Neural Regeneration Research 2018年第2期13卷 244-251页

作者： xiao-yang Dong zhen Feng Department of Rehabilitation Medicine the First Affiliated Hospital of Nanchang University

Orexins, produced in the lateral hypothalamus, are important neuropeptides that participate in the sleep/wake cycle, and their expres- sion coincides with the projection area of the vagus nerve in the brain. Vagus nerve stimulation has been shown to decrease the amounts of daytime sleep and rapid eye movement in epilepsy patients with traumatic brain injury. In the present study, we investigated whether vagus nerve stimulation promotes wakefulness and affects orexin expression. A rat model of traumatic brain injury was established using the free fall drop method. In the stimulated group, rats with traumatic brain injury received vagus nerve stimulation （frequency, 30 Hz, current, 1.0 mA; pulse width, 0.5 ms; total stimulation time, 15 minutes）. In the antagonist group, rats with traumatic brain injury were intracerebroventricularly injected with the orexin receptor type 1 （OXIR） antagonist SB334867 and received vagus nerve stimulation. Changes in consciousness were observed after stimulation in each group. Enzyme-linked immunosorbent assay, western blot assay and immunohistochemistry were used to assess the levels of orexin-A and OX1R expression in the prefrontal cortex. In the stimulated group, consciousness was substantially improved, orexin-A protein expression gradually increased within 24 hours after injury and OX1R expres- sion reached a peak at 12 hours, compared with rats subjected to traumatic brain injury only. In the antagonist group, the wake-promoting effect of vagus nerve stimulation was diminished, and orexin-A and OX1R expression were decreased, compared with that of the stim- ulated group. Taken together, our findings suggest that vagus nerve stimulation promotes the recovery of consciousness in comatose rats after traumatic brain injury. The upregulation of orexin-A and OXIR expression in the prefrontal cortex might be involved in the wake-promoting effects of vagus nerve stimulation.

关键词： nerve regeneration brain injury orexin-A orexin receptor type 1 vagus nerve stimulation traumatic brain injury wake-promoting coma wakefulness prefrontal cortex neurotransmitter neural regeneration

Effects of Trajectory Wind Direction on Ion Concentration of PM_(10)

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Biomedical and Environmental Sciences 2006年第4期19卷 262-267页

作者： xiao-zhen LIU STEVE SMITH Department of Environmental Engineering College of Environment and Chemical Engineering Nanchang Institute of Aeronautic Technology 173 Shanghai Road Nanchang 330034 Jiangxi China Division of Life Sciences Kings College London Franklin-Wilkins Building 150 Stamford Street London SE1 9NN UK

Objective To study the characterization apportionment of main ion concentrations of PM10 under the influence of trajectory wind direction in London. Methods PM10 samples from 1 May 1995 to 30 October 1995 of Oxford Street of Central London were collected, the metals and anions of which were measured using atomic absorption spectrometry （AAS） and ion chromatography （IC）. Composite trajectories representative of the air mass arriving in London at the same period were calculated based on basic routine back trajectories from the British Atmospheric Data Centre （BADC）. Results Concentration apportionments of main ions were similar when the trajectory was plotted back at 6 h, 12 h, and 24 h, some were obviously different. Mg, Ba, Pb, and Cu had similar peak apportionments at the area 180°-320°, but Zn and Ni at the area of 90°-270°, NO3^- and SO4^2- at the area of 100°-220°. Cl^- concentration peak apportionment was at the area of 220°-300°, which showed that Cl^- mainly came from the North Sea. Conclusion Trajectory wind direction has important effect on ion concentration apportionment of PM10 in London. The ions have similar concentration peak apportionments or their correlation coefficients are statistically significant.

关键词： Ion concentration PM10 Trajectory wind direction

Commissioning and operation of the cryostat for 3W1 SC wiggler

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Nuclear Science and Techniques 2023年第6期34卷 43-54页

作者： Miao-Fu Xu xiang-zhen Zhang Rui Ye Jin-Can Wang xiao-Juan Bian Yao Gao Min-xian Li Fu-San Chen xiao-Chen Yang Rui Ge Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Key Laboratory of Particle Acceleration Physics and Technology Chinese Academy of SciencesBeijing100049China Center for Superconducting RF and Cryogenics Institute of High Energy PhysicsBeijing100049China University of Chinese Academy of Sciences Beijing100049China

A 3W1 superconducting wiggler(SCW)with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November,*** goal of zero liquid helium consumption was achieved,and the cryogenic system exhibited a 12%residual cooling capacity(approximately 0.69 W@4.2 K).The 3W1-SCW was set to operate at 2.49 T and has been operating for more than seven *** instances of magnet quenching occurred during the normal *** evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank is higher than the parameter value(the setpoint of the pressure value is 1.2 bara).The cryogenic system can be recovered within 4 h if sufficient liquid helium is available to inject into the cryostat.

关键词： Cryostat Commissioning SC wiggler Synchrotron radiation

Template-free Synthesis of a Novel 3D Cage-like Nanostructured α-Fe_2O_3

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Chemical Research in Chinese Universities 2009年第6期25卷 963-965页

作者： YU Ran-bo LI zhen-min WANG Dan XING Chao-jian LAI xiao-yong XING xian-ran Department of Physical Chemistry University of Science and Technology Beijing Beijing 100083 P. R. China State Key Laboratory of Multi-phase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 P. R. China Key Laboratory of Ecologic ＆ Recycle Metallurgy Ministry of Education University of Science and Technology Beijing Beijing 100083 P. R. China

Synthesis of inorganic nanostructures with specific size and well defined morphologies has attracted considerable attention due to their superior electrical, optical, magnetic, and chemical properties. Up to now, various kinds of metal oxide, sulfide, and hydrate with controlled hierarchical and complex morphologies have been successfully synthesized.

关键词： Template-free α-Fe2O3 Nanostructure

Analysis of the vortices in the inner flow of reversible pump turbine with the new omega vortex identification method

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Journal of Hydrodynamics 2018年第3期30卷 463-469页

作者： Yu-ning Zhang Kai-hua Liu Jin-wei Li Hai-zhen xian xiao-ze Du Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China Key Laboratory of Condition Monitoring and Control for Power Plant Equipment(Ministry of Education) North China Electric Power UniversityBeijing 102206China Beijing South-to-North Water Diversion Tuancheng Lake Management Office Beijing 100195China China Institute of Water Resources and Hydropower Research Beijing 100048China

Reversible pump turbines are widely employed in the pumped hydro energy storage power plants. The frequent shifts among various operational modes for the reversible pump turbines pose various instability problems, e.g., the strong pressure fluctuation, the shaft swing, and the impeller damage. The instability is related to the vortices generated in the channels of the reversible pump turbines in the generating mode. In the present paper, a new omega vortex identification method is applied to the vortex analysis of the reversible pump turbines. The main advantage of the adopted algorithm is that it is physically independent of the selected values for the vortex identification in different working modes. Both weak and strong vortices can be identified by setting the same omega value in the whole passage of the reversible pump turbine. Five typical modes（turbine mode, runaway mode, turbine brake mode, zero-flow-rate mode and reverse pump mode） at several typical guide vane openings are selected for the analysis and comparisons. The differences between various modes and different guide vane openings are compared both qualitatively in terms of the vortex distributions and quantitatively in terms of the areas of the vortices in the reversible pump turbines. Our findings indicate that the new omega method could be successfully applied to the vortex identification in the reversible pump turbines.

关键词： Reversible pump turbine vorticity vortex identification omega method

Enhanced formaldehyde sensitivity of two-dimensional mesoporous SnO_(2) by nitrogen-doped graphene quantum dots

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Rare Metals 2021年第6期40卷 1561-1570页

作者： zhen-Lu Chen Ding Wang xian-Ying Wang Jun-He Yang School of Materials Science and Engineering University of Shanghai for Science&TechnologyShanghai 200093China

Formaldehyde(HCHO) is widely known as an indoor air pollutant,and the monitoring of the gas has significant ***,most HCHO sensing materials do not have low detection limits and operate at high ***,two-dimensional(2D) mesoporous ultrathin SnO_(2) modified with nitrogen-doped graphene quantum dots(N-GQDs) was *** N-GQDs/SnO_(2) nanocomposite demonstrated high efficiency for HCHO *** the addition of 1.00 wt%N-GQDs,the response(Ra/Rg) of SnO_(2) gas sensor increased from 120 to 361 at 60℃ for the detection of 10×10^(-6) *** addition,the corresponding detection limit was as low as 10×10^(-9).Moreover,the sensor exhibited excellent selectivity and stability for the detection of *** enhanced sensing performance was attributed to both the large specific surface area of SnO_(2) and electron regulation of ***,this study presents a novel HCHO sensor,and it expands the research and application potential of GQDs nanocomposites.

关键词： Nitrogen-doped graphene quantum dots Formaldehyde sensor Two-dimensional SnO_(2) Nanocomposites

AN EFFECTIVE CONTINUOUS ALGORITHM FOR APPROXIMATE SOLUTIONS OF LARGE SCALE MAX-CUT PROBLEMS

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Journal of Computational Mathematics 2006年第6期24卷 749-760页

作者： Cheng-xian Xu xiao-liang Feng-min Xu Department of Mathematics Xi 'an Jiaotong University Xi ' an 710049 China

An effective continuous algorithm is proposed to find approximate solutions of NP-hard max-cut problems. The algorithm relaxes the max-cut problem into a continuous nonlinear programming problem by replacing n discrete constraints in the original problem with one single continuous constraint. A feasible direction method is designed to solve the resulting nonlinear programming problem. The method employs only the gradient evaluations of the objective function, and no any matrix calculations and no line searches are required. This greatly reduces the calculation cost of the method, and is suitable for the solution of large size max-cut problems. The convergence properties of the proposed method to KKT points of the nonlinear programming are analyzed. If the solution obtained by the proposed method is a global solution of the nonlinear programming problem, the solution will provide an upper bound on the max-cut value. Then an approximate solution to the max-cut problem is generated from the solution of the nonlinear programming and provides a lower bound on the max-cut value. Numerical experiments and comparisons on some max-cut test problems （small and large size） show that the proposed algorithm is efficient to get the exact solutions for all small test problems andwell satisfied solutions for most of the large size test problems with less calculation costs.

关键词： Max-cut problems Algorithm Feasible direction method Laplacian matrix,Eigenvectors.