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九里香醇提物中抗肿瘤活性成分的研究

中国药学杂志 2017年第18期52卷 1585-1588页

作者：平耀东张艳华李勇北京大学肿瘤医院暨北京市肿瘤防治研究所药剂科恶性肿瘤发病机制及转化研究教育部重点实验室北京100142 山西大学环境科学研究所太原030006

目的研究中药九里香醇提物中抗肿瘤活性的贡献成分。方法采用MTT和SRB法测定九里香醇提物(1~100μmol·L^(-1))对U937,HL-60,K562.Bel7402.Hela 5种人肿瘤细胞的生长抑制活性。运用常规色谱方法对活性成分进行追踪分离,采用现代谱学技... 详细信息

目的研究中药九里香醇提物中抗肿瘤活性的贡献成分。方法采用MTT和SRB法测定九里香醇提物(1~100μmol·L^(-1))对U937,HL-60,K562.Bel7402.Hela 5种人肿瘤细胞的生长抑制活性。运用常规色谱方法对活性成分进行追踪分离,采用现代谱学技术鉴定化合物的结构,并对分离得到的化合物进行体外活性测定。结果在给药48 h后,部分醇提物随着给药浓度的增加,肿瘤细胞的存活率明显下降,在醇提物的A8和A9部分共归属并鉴定出九里香抗肿瘤有效部位的活性化合物4个,分别为异落叶松脂醇(Ⅰ),二甲氧基异落叶松脂醇(Ⅱ),3-甲氧基异落叶松脂醇(Ⅲ)和5'-甲氧基异落叶松脂醇(Ⅳ)。结论化合物Ⅰ和Ⅱ可能为九里香醇提物中抗肿瘤作用的活性成分,化合物Ⅰ~Ⅳ为首次从该植物中分离得到。

关键词：九里香醇提物抗肿瘤异落叶松脂醇二甲氧基异落叶松脂醇

Concentration breaking on two optimization problems

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Science China Mathematics 2024年第7期67卷 1555-1570页

作者： yong Huang Qinfeng li Qiuqi li School of Mathematics Hunan UniversityChangsha410082China

In the present paper, we study the boundary concentration-breaking phenomena on two thermal insulation problems considered on lipschitz domains, based on Serrin's overdetermined result, the perturbation argument, and a comparison of Laplacian eigenvalues with different boundary conditions. Since neither of the functionals in the two problems is C^(1), another key ingredient is to obtain the global H?lder regularity of minimizers of both problems on lipschitz domains. Also, the exact dependence on the domain of breaking thresholds is given in the first problem, and the breaking values are obtained in the second problem on ball domains, which are related to 2. in dimension 2.

关键词： spectral inequalities symmetry breaking Laplacian eigenvalue

Seismic responses of an intensively constructed metro station-passageway-shaft structure system

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Frontiers of Structural and Civil Engineering 2024年第5期18卷 760-775页

作者： Ruohan li yong YUAN Hong CHEN Xinxing li Emilio BILOTTA Department of Geotechnical Engineering Tongji UniversityShanghai 200092China Department of Civil Architectural and Environmental EngineeringUniversity of Naples Federico IINaples 80125Italy State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China Shanghai Tunnel Engineering&Rail Transit Design and Research Institute Shanghai 200235China

Intensive construction methods offer benefits for metro station development,yet they present challenges for seismic design due to the spatially asymmetric configuration of passageway-shaft *** this study,a detailed numerical model of a station-passageway-shaft structure system built using intensive construction methods was developed and the deformation and damage modes under seismic loadings were *** results indicate that inconsistent deformation between the shaft and the station generates interaction through the connecting passageway,leading to damage near the opening of the station structure and both ends of the connecting passageway Damage is more severe under longitudinal *** with the opening plan that spans four segments,the opening plan that spans five segments exacerbates the overall degree of damage to the structure *** transverse excitation,the presence of interior structures intensifies the damage to the station and connecting passageway,while with such internal structure in place the impact is relatively minor under longitudinal *** with steel segments near the station opening can appreciably attenuate the *** contrast,introducing flexible joints at both ends of the connecting passageway intensifies the ***,reinforcement using steel segments emerges as an optimal seismic mitigation strategy.

关键词： earthquake intensive construction metro station numerical simulation

Design method of multivariable PI controller for turboprop engine based on equivalent transfer function

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Chinese Journal of Aeronautics 2024年第9期37卷 237-260页

作者： Shancheng li yong WANG Haibo ZHANG Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Traditional centralized Proportional Integral(PI)controller design methods based on Equivalent Transfer Functions(ETFs)have poor decoupling effect in turboprop *** this paper,a centralized PI design method based on dynamic imaginary matrix and equivalent transfer function is ***,a method for solving equivalent transfer functions based on the dynamic imaginary matrix is proposed,which adopts dynamic imaginary matrix to describe the dynamic characteristics of the system,and obtains the equivalent transfer function based on the dynamic imaginary matrix ***,for the equivalent transfer function,a central-ized PI control gain is designed using the Taylor expansion ***,this paper further proves that the centralized PI design method proposed in this paper has integral ***-ering the impact of altitude and Mach number on turboprop engines,a linear feedforward control method based on the transfer function matrix is further proposed based on the centralized PI con-troller,and the stability of the entire comprehensive control method is ***,to ensure the safe and effective operation of the turboprop engine,a temperature and torque limiting protection controller is designed for the turboprop *** results show that the centralized PI con-troller design method and linear feedforward control method proposed can effectively improve the control quality of turboprop engine control systems.

关键词： Multivariable control sys-tems Equivalent transfer function Disturbance compensation control Control parameter design Turboprop engine control

Modeling analysis of cobalt-based Fischer-Tropsch catalyst particles

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Chinese Journal of Chemical Engineering 2024年第6期70卷 82-92页

作者： Huashuai Wu Gang Wang yong Yang yongwang {2. College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China National Energy Research&Development Center for Coal to liquid Fuels Synfuels China CompanyLimitedBeijing 101400China

The influences of particle size,shape,and catalyst distribution on the reactivity and hydrocarbon product selectivity of a cobalt-based catalyst for Fischer-Tropsch synthesis were investigated in the present work.A self-consistent kinetic model for Fischer-Tropsch reaction proposed here was found to correlate experimental data well and hence was used to describe the consumption rates of reactants and formation rates of hydrocarbon *** perturbed-chain statistical associating fluid theory equation of state was used to describe vapor-liquid equilibrium behavior associated with Fischer-Tropsch *** interaction between intraparticle diffusion and Fischer-Tropsch reaction was investigated in *** showed that in order to avoid the adverse influence of intraparticle diffusional limitations on catalyst reactivity and product selectivity,the use of small particles is *** eggshell spherical particles are shown to keep the original catalyst reactivity and enhance the selectivity of heavy hydrocarbon *** suitable layer thickness for a spherical particle with a diameter of 2.mm is nearly 0.15 *** the same outer diameter of 2.mm,the catalyst reactivity and heavy product selectivity of hollow cylindrical particles with a layer thickness of 0.2. mm are found to be larger than eggshell spherical *** the viewpoint of catalytic performance,hollow cylindrical particles are a better choice for industrial applications.

关键词： Fischer-Tropsch synthesis Kinetic modeling Vapor-liquid equilibria Numerical simulation Intraparticle diffusion Particle shapes

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1210-1220页

作者： Xiao-yong Gao Hong Wei li-feng Zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

The KAM theorem on the modulus of continuity about parameters

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Science China Mathematics 2024年第3期67卷 577-592页

作者： Zhicheng Tong Jiayin Du yong li School of Mathematics Jilin UniversityChangchun 130012China Institute of Mathematics Jilin UniversityChangchun 130012China School of Mathematics and Statistics Center for Mathematics and Interdisciplinary SciencesNortheast Normal UniversityChangchun 130024China

In this paper,we study the Hamiltonian systems H(y,x,ξ,ε)=〈ω(ξ),y〉+εP(y,x,ξ,ε),where ω and P are continuous about ξ.We prove that persistent invariant tori possess the same frequency as the unperturbed tori,under a certain transversality condition and a weak convexity condition for the frequency mapping ω.As a direct application,we prove a Kolmogorov-Arnold-Moser(KAM) theorem when the perturbation P holds arbitrary Holder continuity with respect to the parameter ξ.The infinite-dimensional case is also *** our knowledge,this is the first approach to the systems with the only continuity in the parameter beyond H?lder's type.

关键词： Hamiltonian systems invariant tori frequency-preserving weak regularity

Metarelation2.ec:A Metapath-Free Scalable Representation Learning Model for Heterogeneous Networks

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Tsinghua Science and Technology 2024年第2期29卷 553-575页

作者： Lei Chen Yuan li yong Lei Xingye Deng School of Information and Electrical Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Computer Science and Engineering Hunan University of Science and TechnologyXiangtan 411201China

Metapaths with specific complex semantics are critical to learning diverse semantic and structural information of heterogeneous networks(HNs)for most of the existing representation learning ***,any metapaths consisting of multiple,simple metarelations must be driven by domain *** sensitive,expensive,and limited metapaths severely reduce the flexibility and scalability of the existing models.A metapath-free,scalable representation learning model,called Metarelation2.ec,is proposed for HNs with biased joint learning of all metarelations in a bid to address this ***,a metarelation-aware,biased walk strategy is first designed to obtain better training samples by using autogenerating cooperation probabilities for all metarelations rather than using expert-given ***,grouped nodes by the type,a common and shallow skip-gram model is used to separately learn structural proximity for each node ***,grouped links by the type,a novel and shallow model is used to separately learn the semantic proximity for each link ***,supervised by the cooperation probabilities of all meta-words,the biased training samples are thrown into the shallow models to jointly learn the structural and semantic information in the HNs,ensuring the accuracy and scalability of the *** experimental results on three tasks and four open datasets demonstrate the advantages of our proposed model.

关键词： metarelation random walk heterogeneous network metapath representation learning

Construction technology for deep tunnels crossing superhigh-temperature fault zones with high water surges

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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1267-1280页

作者： yong ZHAO Tingyu ZHU li YU Ming LU Sichuan–Xizang Railway Co. Ltd.Linzhi 860000China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610036China

The harsh environment in tunnels with high geothermal temperatures and humidity can adversely impact machinery,personnel,and *** main causes of specific problems are the unknown mechanisms of local geothermal formation,inappropriate temperature control measures,and insufficient systematic *** this study,three work sections relating to a high geothermal tunnel are:the tunnel face,middle-of-tunnel section,and outside-oftunnel section.A cooling strategy is proposed to offer technical support in achieving comprehensive cooling,overall as well as for each of the ***,a comprehensive geological survey explores the mechanism and exact location of the heat ***,grouting and centralized drainage measures are used to control the heat release of hot *** ventilation,ice chillers and other applicable measures are used to control the ambient ***,a monitoring and early warning system is established to prevent *** cooling strategy has been applied in the field with good results.

关键词： high geothermal tunnels cooling strategy comprehensive cooling measures safety and security