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考虑车轮跳轨的有砟轨道路-桥过渡段动力响应影响规律分析

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中南大学学报(自然科学版) 2025年第1期56卷 397-408页

作者：林士财龚凯向俊董楠褚卫松苏玮中铁第一勘察设计院集团有限公司陕西西安710043 华东交通大学轨道交通基础设施性能监测与保障国家重点实验室江西南昌330013 中南大学土木工程学院湖南长沙410075 中国铁路西安局集团有限公司陕西西安710043 中国铁路设计集团有限公司天津300308

为明确提速线路路-桥过渡段提速必要条件,基于列车车轮跳轨全过程计算方法,分析考虑车轮跳轨的路-桥过渡段轨道动力响应特性,研究列车速度和过渡段折角对车轮跳轨特征和轨道动力响应的影响。研究结果表明:当轮轨密贴时,轮轨力、钢轨竖... 详细信息

为明确提速线路路-桥过渡段提速必要条件,基于列车车轮跳轨全过程计算方法,分析考虑车轮跳轨的路-桥过渡段轨道动力响应特性,研究列车速度和过渡段折角对车轮跳轨特征和轨道动力响应的影响。研究结果表明:当轮轨密贴时,轮轨力、钢轨竖向位移等动力学指标随过渡段折角和列车速度的增大呈逐渐增大的趋势,且过渡段折角对这些动力学指标的影响明显比列车速度对其的影响大,如列车速度由160 km/h增至300 km/h,轮轨竖向力由105 kN增至140 kN,增幅33.3%;过渡段折角由0.05%增至0.25%,轮轨竖向力由84 kN增至143 kN,增幅70.2%。考虑轮轨分离时,跳轨持续时间和车轮跳轨高度车轮跳轨高度随列车速度或过渡段折角的增大而增大,且过渡段折角对车轮跳轨特征影响明显,如当列车速度由280 km/h增至320 km/h时,车轮跳轨高度和跳轨持续时间跳轨高度由4 ms、4.12 mm分别增至6 ms、4.52 mm,增幅分别为50%、9.7%;过渡段折角由0.18%增至0.22%,跳轨持续时间和车轮跳轨高度由3.7 ms、2.89 mm分别增至7.9 ms、6.04 mm,增幅分别为113.5%、109.0%;轨道动力响应随列车速度或过渡段折角的增大而增大,且建议考虑车轮跳轨发生后冲击阶段的轮轨相互作用。250 km/h提速300 km/h有砟轨道线路,路-桥过渡段折角建议不应大于0.20%。

关键词：铁道工程有砟轨道跳轨高度持续时间过渡段折角

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Tetraolefin stereospecific photodimerization and photopolymerization in coordination polymers

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Science China Chemistry 2022年第10期65卷 1867-1872页

作者： Wei-Jie gong Zhan-Yong Yang Yu-Xuan Hong dong Liu Zheng Niu Pierre Braunstein jian-Ping Lang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials School of Chemistry and Chemical EngineeringHuaiyin Normal UniversityHuaian 223300China Universitéde Strasbourg-CNRS Institut de Chimie(UMR 7177 CNRS)4 rue Blaise Pascal-CS 90032Strasbourg 67081France

In the context of the highly desirable design and preparation of smart materials with adjustable properties based on photoreactive compounds,we report two unique photoreactive coordination polymers(CPs),{[Zn(4-Iba)_(2)(4-tkpvb)]·H_()2O}_(n)(1,4-HIba=4-iodobenzoic acid,4-tkpvb=1,2,4,5-tetrakis(4-pyridylvinyl)benzene)and[Cd(1,4-bdc)(4-tkpvb)]_(n)(2,1,4-H_(2)bdc=1,4-benzenedicarboxylic acid).Depending on the metal ions and auxiliary carboxylate ligands used,the 4-tkpvb ligands in 1 and 2 adopt different mutual arrangements,which facilitate the photodimerization and photopolymerization reactions in single crystal to single crystal(SCSC)*** UV light irradiation which results in the dimerization of the 4-tkpvb ligands,the one-dimensional(1D)zigzag chainsof 1 are transformed into a two-dimensional(2D)network of{[Zn(4-Iba)_(2)(bpbtpvcb)_(0.5)]·H_(2)O}_(n)(1a,bpbtpvcb=1,3-bis(4-pyridyl)-2,4-bis(2,4,5-tri(2-(4-pyridyl)vinyl)phenylcyclobutane).Similarly,in the crystals of 2,all 4-tkpvb ligands experience a photopolymerization reaction to form an unprecedented 1D linear organic polymer,poly-1,3-bis(4-pyridyl)-2,5-bis(2-(4-pyridyl)-vinyl)phenyl)cyclobutane(poly-bpbpvpcb).Furthermore,the 2D network of 2 is converted into a three-dimensional(3D)framework of[Cd_(n)(1,4-bdc)_(n)(poly-bpbpvpcb)](2a).This work not only offers a new protocol to selectively synthesize new supramolecular cyclic compounds,but also expands the application of photopolymerization to the synthesis of macromolecules.

关键词： coordination polymers single-crystal to single-crystal transformation photodimerization photopolymerization cycloaddition

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Architecture design for reliable and reconfigurable FPGA-based GNC computer for deep space exploration

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Science China(Technological Sciences) 2016年第2期59卷 289-300页

作者： YANG MengFei LIU Bo gong jian LIU HongJin HU HongKai dong YangYang SHI Lei ZHAO YunFu MIAO ZhiFu China Academy of Space Technology Beijing 100094 China Beijing Institute of Control Engineering Beijing 100190 China

SRAM(static random access memory)-based FPGA(field programmable gate array), owing to its large capacity, high performance, and dynamical reconfiguration, has become an attractive platform for So PC(system on programmable chip) development. However, as the configuration memory and logic memory of the SRAM-based FPGA are highly susceptible to SEUs(single-event upsets) in deep space, it is a challenge to design and implement a highly reliable FPGA-based system for spacecraft, and no practical architecture has been proposed. In this paper, a new architecture for a reliable and reconfigurable FPGAbased computer in a highly critical GNC(guidance navigation and control) system is proposed. To mitigate the effect of an SEU on the system, multi-layer reconfiguration and multi-layer TMR(triple module redundancy) techniques are proposed, with a reliable reconfigurable real-time operating system(Space OS) managing the system level fault tolerance of the computer in the architecture. The proposed architecture for the reconfigurable FPGA-based computer has been implemented with COTS(commercial off the shelf) FPGA and has firstly been applied to the GNC system of a circumlunar return and reentry flight vehicle. The in-orbit results show that the proposed architecture is capable of meeting the requirements of high reliability and high availability, and can provide the expressive varying functionality and runtime flexibility for an FPGA-based GNC computer in deep space.

关键词： fault tolerance system on programmable chip (SoPC) field programmable gate array (FPGA) multi-layer triple mod-ule redundancy intelligence reconfiguration

Analysis of PM2.5 and O3 Pollution Causes in Hangzhou Based on High-resolution Enhanced Observation During the Asian Games

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Huanjing Kexue/Environmental Science 2025年第3期46卷 1302-1313页

作者： Yan, Ren-Chang Lai, Yong Zhang, Tian Jin, Jia-Jia Lin, Xu Wang, Yun-Yun Shuai, Qi-Fan Fei, Luo-Lan Shen, jian-dong Ye, Xuhong Zhu, Shu-Hui Hangzhou Ecological Environment Monitoring Center of Zhejiang Hangzhou310007 China Shanghai Academy of Environmental Sciences Shanghai200003 China

Based on the high-resolution enhanced observation data of PM2.5 organic molecular tracers,aldehydes and ketone OVOC components,long-chain alkane IVOC components,and key species of atmospheric oxidation during September 1 to October 27,2023,the causes of PM2.5 and O3 pollution in Hangzhou were analyzed. Seven pollution processes were selected with the average daily concentration of PM2.5 exceeding 35 µg·m-3 or the maximum 8-hour concentration of O3 exceeding 160 µg·m-3. Then,these pollution processes were divided into four types:north-northeast transmission type(T1),east-southeast transmission type(T2),north-northwest transmission type(T3),and statically stable type(T4)by airflow trajectory. The research results indicated that the T2 pollution process exhibited strong PM2.5 and O3 composite pollution characteristics and the photochemical oxidation reaction of active VOC components,such as long-chain alkanes and terpenes in the atmospheric environment was the major pollution cause of this type. In the process of T1 and T3 pollution,the overall reactivity of VOCs was low,resulting in relatively weak O3 generation. However,the causes of PM2.5 in these two types of pollution processes were different. T1 pollution was affected by low temperature and high humidity meteorological conditions and the enhanced liquid-phase oxidation process led to a significant increase in nitrate concentration. T3 pollution was significantly affected by emissions from coal combustion,biomass combustion,and other sources,with a relatively high proportion of primary components in PM2.5. The T4 pollution process was significantly affected by local primary anthropogenic emissions,thus the control of local catering source and mobile source emissions must be strengthened. © 2025 Science Press. All rights reserved.

关键词： Coal combustion

Phase Selection and Microstructure Evolution Dependance on Composition for Zr-Fe Eutectic Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第10期37卷 1689-1702页

作者： dong-dong Zuo jian Chang Hai-Peng Wang School of Physical Science and Technology Northwestern Polytechnical UniversityXi’an710072China

The knowledge of the phase selection and microstructure evolution of Zr-Fe eutectic alloys is still poorly *** presumed eutectic alloy with a nominal composition of Zr76.0Fe24.0 was discovered to contain a significant proportion ofα-Zr ***,phase selection and microstructure evolution dependance on composition for Zr-Fe eutectic alloys was experimentally determined by using differential scanning calorimetry(DSC)and meticulous electron *** alloys,spanning the composition range of 73.5-74.7%Zr,were examined to investigate microstructure evolution and non-isothermal crystallization *** indicate that in alloys ranging from Zr_(73.5)Fe_(26.5) to Zr_(73.9)Fe_(26.1),the primary FeZr_(2) phase demonstrates preferential growth,followed by eutectic microstructure formation during liquid alloy *** volume fraction of FeZr_(2) dendrites decreases as the Zr content ***,in alloys ranging from Zr_(74.0)Fe_(26.0) to Zr_(74.7)Fe_(25.3),primaryβ-Zr dendrites preferentially grow,followed by a eutectic reaction in the remaining liquid *** content ofα-Zr dendrites reduces with decreasing Zr *** mentioned above,a critical composition range for phase selection is defined as Zr_(x)Fe100.0−x(73.9

关键词： Phase selection Thermal analysis Microstructure evolution Crystallization kinetic

太湖县花凉亭水库流域地下水水化学特征及水质评价

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环境科学 2025年第2期46卷 809-820页

作者：刘海黄健敏宋阳赵国红王旭东魏伟安徽省公益性地质调查管理中心合肥230091 四川农业大学建筑与城乡规划学院成都611830

以太湖县花凉亭水库流域为研究对象,采集了42组井水样品和20组泉水样品测定了主要水化学指标,综合运用数理统计、Piper图、Gibbs图、离子比值和因子分析等方法研究了研究区井水和泉水的特征及控制因素,基于熵权质量指数(EWQI)评价了井... 详细信息

以太湖县花凉亭水库流域为研究对象,采集了42组井水样品和20组泉水样品测定了主要水化学指标,综合运用数理统计、Piper图、Gibbs图、离子比值和因子分析等方法研究了研究区井水和泉水的特征及控制因素,基于熵权质量指数(EWQI)评价了井水和泉水的水质,根据健康风险评价模型(HHRA)对井水和泉水的NO_(3)^(-)的潜在风险进行了评估.结果表明,研究区井水和泉水整体呈弱碱性,优势阳离子和阴离子分别为Na^(2+)、Ca^(2+)和HCO_(3)^(-),水化学类型主要为HCO_(3)-Na·Ca型;井水和泉水形成主要受岩石风化作用和阳离子交替吸附作用控制,井水和泉水中Ca^(2+)、Mg^(2+)和HCO_(3)^(-)的主要来源为碳酸岩盐溶解,农业活动、生活污水排放等导致Na^(+)、Cl^(-)和NO_(3)^(-)的富集;研究区井水和泉水水质整体较好,为良好至优良等级,健康风险评价表现为男人、女人和儿童均具有较低的非致癌风险,但儿童的健康风险明显高于成人.研究成果可为花凉亭水库流域地下水资源可持续开发利用和保护提供参考.

关键词：水化学特征水岩作用熵权质量指数健康风险花凉亭水库

The effect of wind on the dispersal of a tropical small river plume

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Frontiers of Earth Science 2018年第1期12卷 170-190页

作者： Junpeng ZHAO Wenping gong jian SHEN School of Marine Sciences Sun Yat-Sen University Guangzhou 510275 China Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering Sun Yat-Sen University Guangzhou 510275 China Virginia Institute of Marine Science The College of William and Mary Gloucester Point VA 23062 USA

Wanquan River is a small river located in Hainan, a tropical island in China. As the third largest river in Hainan, the river plume plays an important role in the regional terrigenous mass transport, coastal circulation, and the coral reef＇s ecosystem. Studies have shown that wind forcings significantly influence river plume dynamics. In this study, wind effects on the dispersal of the river plume and freshwater transport were examined numerically using a calibrated, unstructured, finite volume numerical model （FVCOM）. Both wind direction and magnitude were determined to influence plume dispersal. Northeasterly （downwelling-favorable） winds drove fresh- water down-shelf while southeasterly （onshore） winds drove water up-shelf （in the sense of Kelvin wave propagation） , and were confined near the coast. Southwesterly （upwelling-favorable） and northwesterly （off： shore） winds transport more freshwater offshore. The transport flux is decomposed into an advection, a vertical shear, and an oscillatory component. The advection flux dominates the freshwater transport in the coastal area and the vertical shear flux is dominant in the offshore area. For the upwelling-favorable wind, the freshwater transport becomes more controlled by the advection transport with an increase in wind stress, due to enhanced vertical mixing. The relative importance of wind forcing and buoyancy force was investigated. It was found that, when the Wedderburn number is larger than one, the plume was dominated by wind forcing, although the importance of wind varies in different parts of the plume. The water column stratification decreased as a whole under the prevailing southwesterly wind, with the exception of the up-shelf and offshore areas.

关键词： small river plume wind effect freshwater transport

低渗—特低渗气藏储集层物性与电性下限变化规律

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新疆石油地质 2025年第1期46卷 29-38页

作者：胡向阳吴健杨冬张恒谭伟袁伟中海石油(中国)有限公司湛江分公司研究院广东湛江524057 中海石油(中国)有限公司海南分公司研究院海口570311

南海西部东方A区气藏和文昌X/Y区气藏均为低渗—特低渗气藏,储集层微观孔隙结构复杂,对物性和电性下限变化规律认识不清。通过开展不同压差条件下的岩心单相驱替实验,结合高温高压条件下岩心毛细管压力-岩电联测实验,开展研究区低渗—... 详细信息

南海西部东方A区气藏和文昌X/Y区气藏均为低渗—特低渗气藏,储集层微观孔隙结构复杂,对物性和电性下限变化规律认识不清。通过开展不同压差条件下的岩心单相驱替实验,结合高温高压条件下岩心毛细管压力-岩电联测实验,开展研究区低渗—特低渗储集层下限研究,分别获取储集层孔隙度、渗透率、含气饱和度和电阻率下限。在此基础上,开展储集层下限变化规律研究,结果表明,东方A区气藏储集层物性与气体流量呈正相关关系,而文昌X/Y区特低渗岩心气体流量极低,且增大实验压差提高气体流量不明显。在束缚水条件下,随着生产压差增大,2个区块孔隙度和渗透率下限逐渐降低。随着储集层物性变好,含水饱和度上限均变低。东方A区气藏电阻率下限随物性变好而逐渐增大,文昌X/Y区气藏特低渗气层电阻率下限随物性变好而逐渐降低,其原因主要是受储集层微观孔隙结构和地层流体赋存状态影响。

关键词：特低渗储集层物性下限电性下限生产压差渗透率毛细管压力岩电实验

Quantum key distribution protocol of mesh network structure based on n+1 EPR pairs

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Journal of Systems Engineering and Electronics 2010年第2期21卷 334-338页

作者： jian dong jianfu Teng School of Electronic Information Engineering Tianjin University Tianjin 300072 P. R. China

Quantum key distribution （QKD） is used in quantum cryptographic systems to exchange secret key between parties who need to communicate secretly. According to the structure of European Secoqc QKD network, a QKD protocol is proposed. Entanglement swapping between Einstein-Podolsky-Rosen （EPR） pairs can be used to exchange message bits in two remote places. Based on this idea, n ＋ 1 EPR pairs are used as logical quan- tum channel （for n nodes per routing）, while measurements of Bell operator are transmitted by classical channel. Random space quantum channel selection is exploited in our protocol to improve the probability of revealing Eve. Compared with traditional EPR protocol, the proposed protocol exhibits many features, which are minutely described.

关键词： quantum cryptography quantum key distribution (QKD) EPR pair quantum entanglement entanglement swapping.