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Darboux Transformation for Tzitzeica Equation

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Communications in Theoretical Physics 2006年第4期45卷 577-580页

作者： ZHU Jun-yi geng Xian-Guo Department of Mathematics Zhengzhou University. Zhengzhou 450052 China

We present a Darboux transformation for Tzitzeica equation associated with 3 × 3 matrix spectral *** explicit solution of Tzitzeica equation is obtained,

关键词： Darboux transformation nonlinear evolution equation soliton solutions

A New Integrable Symplectic Map of Neumann Type

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Communications in Theoretical Physics 2007年第4期47卷 577-581页

作者： ZHU Jun-yi geng Xian-Guo Department of Mathematics Zhengzhou University Zhengzhou 450052 China

By resorting to the nonlinearization approach, a Neumann constraint associated with a discrete 3 × 3 matrix eigenvalue problem is considered. A new symplectic map of the Neumann type is obtained through nonlinearization of the discrete eigenvalue problem and its adjoint one. The generating function of integrals of motion is presented, by which the symplectic reap＇is further proved to be completely integrable in the Liouville sense.

关键词： Neumann constraint symplectic map Liouville integrablility

Gel electrolytes containing several kinds of particles used in quasi-solid-state dye-sensitized solar cells

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Rare Metals 2006年第Z1期25卷 201-206页

作者： geng yi SUN Xiaodan CAI Qiang SHI Yantao LI Hengde Laboratory of Advanced Materials Department of Materials Science&EngineeringTsinghua UniversityBeijing 100084China

Composite gel electrolytes containing several kinds of particles used as the quasi-solid-state electrolytes in dye-sensitized solar cells(DSSCs)were *** particles(MCM-41)with unique structures composed of ordered nanochannels were served as a new kind of gelator for quasi-solid-state ***-41,hydrophobic fumed silica Aerosil R972 and TiO_(2)nanopatricles P25 were dispersed into gel electrolytes *** solar energy-to-electricity conversion efficiency of these cells is 4.65%,6.85%and 5.05%respectively under 30 mW·cm^(-2)*** preparation methods and the particles sizes exert an influence on the performance of corresponding solar *** to unique pore structures and high specific BET surface area,mesoporous silica MCM-41 was expected to have the potential to afford conducting nanochannels for redox couple diffusion.

关键词： dye-sensitized solar cells nanocomposite gel electrolyte mesoporous nanoparticle

Locking Function of a Key Residue in Kinesin＇s Gating Mechanism

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Chinese Physics Letters 2014年第4期31卷 201-205页

作者： geng yi-Zhao ZHANG Hui JI Qing YAN Shi-Wei College of Nuclear Science and Technology Beijing Normal University Beijing 100875 School of Science Hebei University of Technology Tianjin 300401 Institute of Biophysics Hebei University of Technology Tianjin 300401

In kinesin＇s mechanochemical cycle, ATP＇s binding to the nucleotide-free leading head is exquisitely gated so that futile hydrolysis is effectively avoided, Experiments show that, when both kinesin heads bind to a microtubule~ ATP cannot bind to kinesin＇s leading head when the neck linker （NL） of this head has a backward orientation. How NL＇s backward orientation is maintained needs understanding on a structural basis. By using steered molecular dynamics and rrmtation simulations, we investigate the backward-pointing conformation of the leading head＇s NL under different inter-head tensions. We find that the NL cannot keep in a strict backward orientation solely by the inter-head tension. LYS325 （amino acid sequence in 2KIN） has an assistant locking function which locks the NL and β0 to the β-domain. This locking function has an enhanced positive cooperation with the inter-head tension. When the inter-head tension is weakened, this locking function can be broken, resulting in a loose backward orientation of the NL. The difference between the strict and loose backward orientation of the NL might be a crucial factor in the gating mechanism. These results are consistent with relevant experiments and proposals.

关键词： Mechanism Locking nucleotide-free

Structural effects and competition mechanisms targeting the interactions between p53 and MDM2 for cancer therapy

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Frontiers of physics 2017年第3期12卷 107-116页

作者： Shu-Xia Liu yi-Zhao geng Shi-Wei Yan College of Nuclear Science and Technology Beijing Normal University Beijing 100875 China School of Science Hebei University of Technology Tianjin 300401China Beijing Radiation Center Beijing 100875 China

Approximately half of all human cancers show normal TP53 gene expression but aberrant overexpres- sion of MDM2 and/or MDMX. This fact suggests a promising cancer therapeutic strategy in targeting the interactions between p53 and MDM2/MDMX. To help realize the goal of developing effective in- hibitors to disrupt the p53-MDM2/MDMX interaction, we systematically investigated the structural and interaction characteristics of p53 with inhibitors of its interactions with MDM2 and MDMX from an atomistic perspective using stochastic molecular dynamics simulations. We found that some spe- cific a helices in the structures of MDM2 and MDMX play key roles in their binding to inhibitors, and that the hydrogen bond formed by the Trp23 residue of p53 with its counterpart in MDM2 or MDMX determines the dynamic competition processes of the disruption of the MDM2-p53 interaction and replacement of p53 from the MDM2-p53 complex in vivo. The results reported in this paper are expected to provide basic information for designing functional inhibitors and realizing new strategies of cancer gene therapy.

关键词： p53 MDMX MDM2 molecular dynamics simulation inhibitors cancer therapy

On the properties of the Rational Function Spectrum describing waves near islands and reefs in South China Sea

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Journal of Hydrodynamics 2021年第5期33卷 879-888页

作者： yi-geng Wang Zhi Zong Li Zhou Xiao-long Liu Xue-kang Gu School of Naval Architecture Dalian University of TechnologyDalian 116024China China Ship Scientific Research Center Wuxi 214082China

On-site measurements show that water waves near islands and reefs in South China Sea exhibit different properties of wave energy distributions with regard to wave frequencies,among which the most prominent factor is the interplay of swells arising from the West Pacific Ocean and the local wind *** also show that the breaking waves continuously appear,containing more energy in high frequency components,and the nonlinear characteristics of the waves are important in adjusting the energy *** properties may explain the large discrepancies between the well-accepted wave spectra(for example the P-M spectrum,Neumann spectrum,ITTC spectrum etc.)and the measured wave spectra near islands and reefs in South China ***,a new Rational Function Spectrum is proposed in this paper to describe waves near islands and reefs which turns out to show satisfactory *** well captures wave power distributions in the form of single and double peaks,at low-and high-frequency regions,as well as nonlinear scale power *** on the investigation of the measured data near an island in South China Sea,the relation between the parameters used in the Rational Function Spectrum and the statistical parameters of water waves(significant wave height and wave period)is *** is noted that the wave properties at low-and high-frequencies are controlled by the local wind velocities at the wave growth stage,but remain constant at the wave decay *** parameter peak frequency is only dependent on the wave period corresponding to the maximum wave *** parameter spectral peak is determined from the wave height and the wave *** relations help to clarify the physical meanings of the parameters used in the Rational Function Spectrum,and thus provide an alternative spectral form to describe random waves near islands and reefs.

关键词： Rational Function Spectrum double peak near islands and reefs swell nonlinear

Numerical and experimental study on the falling film flow characteristics with the effect of co-current gas flow in hydrogen liquefaction process

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Petroleum Science 2024年第2期21卷 1369-1384页

作者： Chong-Zheng Sun Yu-Xing Li Hui Han Xiao-yi geng Xiao Lu College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590ShandongChina College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety China University of PetroleumQingdao 266580ShandongChina

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process(LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2spiral wound heat *** results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

关键词： Hydrogen liquefaction Spiral wound heat exchanger Flow pattern transition Falling film flow

Identification of proteins of human colorectal carcinoma cell line SW480 by two-dimensional electrophoresis and MALDI-TOF mass spectrometry

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World Journal of Gastroenterology 2005年第30期11卷 4679-4684页

作者： ying-Tao Zhang yi-Ping geng Le Zhou Bao-Chang Lai Lv-Sheng Si yi-Li Wang The-Key Laboratory of Biomedical Information Engineering of Education Ministry Institute of Cancer Research School of Life Science and Technology Xi'an Jiaotong University Xi'an 710061 Shaanxi Province China Department of Gastroenterology First Hospital Xi'an Jiaotong University Xi'an 710061 Shaanxi Province China

AIM： To conduct bhe proteomic analysis of human colorectal carcinoma cell line, SW480 by using two-dimensional electrophoresis （2-DE） and matrix-assisted laser desorption /ionization-time of flight mass spectrometry （MALDITOFMS）. METHODS： The total proteins of human colorectal carcinoma cell line, SW480 were separated with 2-DE by using immobilized pH gradient strips and visualized by staining with silver nitrate. The gel images were acquired by scanner and 2-DE analysis software, Image Master 2D Elite. Nineteen distinct protein spots were excised from gel randomly and digested in gel by TPCK-trypsin. Mass analysis of the byptic digest peptides mixture was performed by using MALDI-TOF MS. Peptide mass fingerprints （PMFs） obtained by the MALDI-TOF analysis were used to search NCBI, SWISS-PROT and MSDB databases by using Mascot software. RESULTS： PMF maps of all spots were obtained by MALDI-TOF MS and thirteen proteins were preliminarily identified. CONCLUSION： The methods of analysis and identification of protein spots of tumor cells in 2-DE gel with silver staining by MALDI-TOF MS derived PMF have been established. Protein expression profile of SW480 has been obtained. It is demonstrated that a combination of proteomics and cell culture is a useful approach to comprehend the process of colon carcinogenesis.

关键词： Colorectal carcinoma SW480 cell line Twodimensional electrophoresis MALDI-TOF MS Peptide mass fingerprinting

Syntheses, Crystal Structures and Antibacterial Activities of Two New Methyl 12-Alkylamino-13,14-dinitrodeisopropyl-dehydroabietates

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Chinese Journal of Structural Chemistry 2019年第2期38卷 257-262,167页

作者： CHEN Hao geng yi WANG Shi-Fa GU Wen Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals College of Chemical Engineering Nanjing Forestry University

The title compounds(5 a and 5 b) were synthesized from dehydroabietic acid and characterized by MS, IR, NMR and elemental analysis. The crystal structure of compound 5 a was determined by single-crystal X-ray diffraction. The compound is of monoclinic system, space group P21 with a = 8.0860(16), b = 14.011(3), c = 9.799(2) ?, β = 106.31(3)?, Z = 2, V = 1065.5(4) ?3, Mr = 431.48, Dc = 1.345 Mg/m3, S = 1.002, μ = 0.099 mm-1, F(000) = 460, the final R = 0.0617 and wR = 0.1532 for 1397 observed reflections(I > 2σ(I)). The preliminary antibacterial assay showed that compound 5 a exhibited considerable inhibitory activity against Bacillus subtilis, Staphylococcus aureus and Methicillin-resistant S. aureus(MRSA) with MIC values of 2～8 μg/mL.

关键词： dehydroabietic acid synthesis crystal structure antibacterial activity