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STABILITY AND LOCAL BIFURCATION IN A SIMPLY-SUPPORTED BEAM CARRYING A MOVING MASS

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Acta Mechanica Solida Sinica 2007年第2期20卷 123-129页

作者： Liu pan Ni qiao Wang Lin Yuan Liang Department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China

The stability and local bifurcation of a simply-supported flexible beam （Bernoulli- Euler type） carrying a moving mass and subjected to harmonic axial excitation are investigated. In the theoretical analysis, the partial differential equation of motion with the fifth-order nonlinear term is solved using the method of multiple scales （a perturbation technique）. The stability and local bifurcation of the beam are analyzed for 1/2 sub harmonic resonance. The results show that some of the parameters, especially the velocity of moving mass and external excitation, affect the local bifurcation significantly. Therefore, these parameters play important roles in the system stability.

关键词： stability local bifurcation simply-supported beam moving mass

Molecular path for ligand search

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Chinese Chemical Letters 2011年第9期22卷 1130-1134页

作者： Tao Lu Yuan Yuan qiao pan Wen Shen College of Chemistry Nankai University Tianjin 300071 China

A ligand is a small molecule bind to several residues of a receptor. We adapt the concept of molecular path for effective ligand search with its contacting residues. Additionally, we allow wild type definitions on atoms and bonds of molecular paths for fuzzy algorithms on structural match. We choose hydrogen bond interactions to characterize the binding mode of a ligand by several proper molecular paths and use them to query the deposited ligands in PDBe that interact with their residues in the same way. Expression of molecular path and format of database entries are described with examples. Our molecular path provides a new approach to explore the ligand-receptor interactions and to provide structural framework reference on new ligand design.

关键词： Ligand Residue Path Database

Precise and accurate Ga isotope ratio measurements of geological samples by multi-collector inductively coupled plasma mass spectrometry

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Acta Geochimica 2024年第6期43卷 1054-1064页

作者： Yuxu Zhang pan qiao Chuanwei Zhu Haifeng Fan Hanjie Wen State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of Sciences99 West Lincheng RoadGuiyang 550081Guizhou ProvinceChina School of Earth Sciences and Resources Chang’an University126 Yanta RoadXi’an 710054Shaanxi ProvinceChina College of Resources and Environment University of Chinese Academy of SciencesBeijing 101408China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Gallium isotope is a potential geochemical tool for understanding planetary processes,environmental pollution,and ore deposit *** reported Ga isotope compositions(δ^(71)Ga NIST994 values)of some international geological standards,such as BCR-2 and BHVO-2 basalts,exhibit inconsistencies between diff erent *** mass spectrometry analysis,we found thatδ^(71)Ga NIST994 values of geological standards with or without the correction of the interference of^(138)Ba^(2+)(mass/charge ratio=69)on 69 Ga show signifi cant isotope off sets,and thus effi cient separation of Ba and correcting the interference of^(138)Ba^(2+)are both crucial to obtain accurateδ^(71)Ga *** comparingδ^(71)Ga NIST994 values(relative to NIST SRM 994 Ga)of the same geostandards from diff erent laboratories,we suggest that the isotopic heterogeneity from NIST SRM 994 Ga is one of the key reasons for the inconsistencies inδ^(71)Ga NIST994 values of BCR-2 and *** facilitate inter-laboratory comparisons,we measured the Ga isotopic compositions of 11 geological reference materials(including Pb-Zn ore,bauxite,igneous rocks,and loess)and two Ga solution standards(NIST SRM 3119a and Alfa Aesar).Theδ^(71)Ga NIST994 andδ^(71)Ga IPGP values of these reference materials vary from 1.12‰to 2.63‰and−0.13‰to 1.38‰,respectively,and can be used to evaluate the precision and accuracy of Ga isotope data from diff erent laboratories.

关键词： Ga isotopes MC-ICP-MS Reference materials Chemical purification Ba interference

Performance of Flexible Warp Knitting Metal Mesh with Notch

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Journal of Donghua University(English Edition) 2014年第5期31卷 582-588页

作者： SHAO Guang-wei JIANG Jin-hua pan qiao-ling LIU Yuan-yuan CHEN Nan-liang College of Textiles Donghua University Shanghai 201620 China Engineering Research Center of Technical Textiles Ministry of Education Donghua University Shanghai 201620 China Research Institute of Donghua University Shanghai 201620 China

Three different kinds of notch involving single edge notch （ SEN）, double edge notch （ DEN ） and central notch （ CEN ） were preset in flexible warp knitting metal mesh, and the tensile properties of notch samples were tested. Three kinds of notch samples＇ sensitivity were investigated through different notch lengths. Then failure process and tensile properties were contrasted and analyzed between intact and notch samples. Experiment and analysis results showed that positive Poisson＇s ratio effect gave rise to obvious waist binding and special inverted triangle loading area. All samples were sensitive to three kinds of notches. And notch sensitivity was closely related to notch form and notch length. The notch procession obviously deteriorated the mechanical properties of flexible warp knitting metal mesh. Sample with different notch lengths and breakage locations determined different tensile strengths that sample could bear. The fitting function of waist binding track satisfied the parabolic equation.

关键词： warp knitting metal mesh notch sensitivity tensilestrength preset notch stainless steel wire

Sky location of massive black hole binaries in the foreground of Galactic white dwarf binaries

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 97-108页

作者： pan Guo Hong-Bo Jin Cong-Feng qiao Yue-Liang Wu The International Centre for Theoretical Physics Asia-Pacific University of Chinese Academy of Sciences The School of Physical Sciences University of Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University National Astronomical Observatories Chinese Academy of Sciences Institute of Theoretical Physics Chinese Academy of Sciences

For space-based gravitational wave （GW） detection,the main noise source for massive black hole binaries （MBHBs） is attributed to approximately 10～7double white dwarf binaries in the *** a GW source,the amplitude of the detector response,recorded by a space-based gravitational wave detector,exhibits a modulation effect with a year period when observing the source from various orbital *** the adverse conditions mentioned above,where there is a strong foreground noise and annual modulation in the signals,we employed the wavelet transform and the strong-amplitude relevant orbital position search methods,which allows the weak MBHB sources to achieve higher locating *** detail,for two MBHB sources of lower intensity,the precision of luminosity distance,represented by the ratio ?DL/DLat the 95%confidence level,is enhanced by factors of ～*** angular resolutions,denoted by??s,are enhanced by a factor of ～*** improvements increase the number of detectable GW sources,facilitate multi-messenger follow-up observations and provide constraints on the cosmological constant.

关键词： space-based gravitational wave detection gravitational waves massive black hole binaries

Modulating the alloying mode in the doping-induced synthesis of Au-Pd nanowires

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Nano Research 2024年第4期17卷 3334-3343页

作者： Hui Jin Xiaoliang Wei Lecheng Zhao Jialong Yu qiao pan Shumin Li Qian Wang Zhaotong Yuan Dan Yang Donghui Zhao Hongyu Chen Yawen Wang Institute of Advanced Synthesis School of Chemistry and Molecular EngineeringJiangsu National Synergistic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 211816China School of Science Westlake UniversityHangzhou 310064China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310064China

Heterogeneous doping is one effective strategy for synthesizing metal alloy ***,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and ***-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping *** effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were ***,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical *** kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy *** addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.

关键词： gold nanowires Au-Pd alloy oleylamine post-synthetic modification

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用于高速IPv6网络流量抽样测量的算法

西安电子科技大学学报 2007年第3期34卷 377-381页

作者：潘乔裴昌幸西安电子科技大学计算机网络与信息安全教育部重点实验室陕西西安710071

为了解决高速IPv6网络流量测量,提出了一种基于数据包首部内容分析的流量抽样测量算法.算法将IPv6数据包首部内容进行关键字段的掩码匹配,通过Hash映射,利用判断Hash值是否属于抽样域来决定数据包的采集与否.其特点是利用信息熵理论,分... 详细信息

为了解决高速IPv6网络流量测量,提出了一种基于数据包首部内容分析的流量抽样测量算法.算法将IPv6数据包首部内容进行关键字段的掩码匹配,通过Hash映射,利用判断Hash值是否属于抽样域来决定数据包的采集与否.其特点是利用信息熵理论,分析IPv6数据包首部,选择出熵值较大的字段,将其作为抽样算法掩码匹配的关键字段,这样就避免了对数据包首部内容的全抽样,在保证抽样样本随机性的前提下,有效地减少了运算量.实验结果表明,总体流量和抽样样本的数据包大小分布函数曲线十分吻合,验证了该算法的正确性.

关键词： IPv6 抽样测量分布式测量信息熵

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一种新的可变采样率的网络流量抽样测量方法

西安电子科技大学学报 2008年第6期35卷 968-972页

作者：潘乔裴昌幸西安电子科技大学综合业务网理论及关键技术国家重点实验室陕西西安710071 东华大学计算机科学与技术学院上海210051

随机报文抽样方法是目前常用的流量抽样测量方法,但是它倾向于采集长流,影响了异常检测的正确性.提出了一种新的基于IP流可变采样率的网络流量抽样测量方法,将到达的数据报文按照流标识分类,并以每一个报文在所属流中的位置和流的大小... 详细信息

随机报文抽样方法是目前常用的流量抽样测量方法,但是它倾向于采集长流,影响了异常检测的正确性.提出了一种新的基于IP流可变采样率的网络流量抽样测量方法,将到达的数据报文按照流标识分类,并以每一个报文在所属流中的位置和流的大小为参数设置可变采样率进行抽样测量.实验表明,该方法提高了短流中报文的采样率,减少了随机报文抽样方法对异常检测的影响,检测结果能正确地反映原始数据的异常情况.

关键词：抽样测量可变采样率抽样 IP流端口扫描 Internet

Stiffness-tunable biomaterials provide a good extracellular matrix environment for axon growth and regeneration

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Neural Regeneration Research 2025年第5期20卷 1364-1376页

作者： Ronglin Han Lanxin Luo Caiyan Wei Yaru qiao Jiming Xie Xianchao pan Juan Xing Department of Pathophysiology School of Basic Medical SciencesSouthwest Medical UniversityLuzhouSichuan ProvinceChina Department of Medicinal Chemistry School of PharmacySouthwest Medical UniversityLuzhouSichuan ProvinceChina

Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.

关键词： alginate axon growth biomaterials extracellular matrix neural repair neurons neuroregeneration polyacrylamide polydimethylsiloxane stiffness