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ESMO2023:恩扎卢胺联合雄激素剥夺治疗对比安慰剂联合雄激素剥夺治疗在中国转移性激素敏感性前列腺癌患者中的疗效和安全性(中国ARCHES)
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作者 李永红 《现代泌尿外科杂志》 2024年第1期81-82,共2页
2019年发表的全球ARCHES试验(NCT02677896)结果显示,与安慰剂(placebo,PBO)+雄激素剥夺治疗(androgen deprivation therapy,ADT)相比,恩扎卢胺+ADT延长了转移性激素敏感性前列腺癌(metastatic hormone-sensitive prostate cancer,mHSPC... 2019年发表的全球ARCHES试验(NCT02677896)结果显示,与安慰剂(placebo,PBO)+雄激素剥夺治疗(androgen deprivation therapy,ADT)相比,恩扎卢胺+ADT延长了转移性激素敏感性前列腺癌(metastatic hormone-sensitive prostate cancer,mHSPC)患者的总生存期和放射影像学无进展生存期(radiographic progression-free survival,rPFS)^([1])。然而,该试验无中国患者入组。欧洲肿瘤内科学会(European Society for Medical Oncology,ESMO)2023年会议报道了中国ARCHES研究(NCT04076059)的初步结果,这是一项评估恩扎卢胺+ADTvs.PBO+ADT在中国m HSPC患者中的疗效和安全性的多中心、随机、双盲、PBO对照的Ⅲ期试验^([2])。 展开更多
关键词 转移性激素敏感性前列腺癌 恩扎卢胺 雄激素剥夺治疗 安慰剂 中国患者 archeS
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Mechanical properties and influence mechanism of confined concrete arches in high-stress tunnels 被引量:5
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作者 Bei Jiang Zhongxin Xin +4 位作者 Xiufeng Zhang Yusong Deng Mingzi Wang Shidong Li Wentao Ren 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第7期829-841,共13页
Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,whic... Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,which makes it difficult to meet the requirements of ground control under complex conditions. As a new support form with high strength and rigidity, the confined concrete arch plays an important role in controlling the rock deformation under complex conditions. The section shape of the tunnel has an important impact on the mechanical properties and design of the support system. However, studies on the mechanical properties and influence mechanism of the new confined concrete arch are rarely reported. To this end, the mechanical properties of traditional U-shaped steel and new confined concrete arches are compared and comparative tests on arches of circular and straight-leg semicircular shapes in deep tunnels are conducted. A large mechanical testing system for underground engineering support structure is developed. The mechanical properties and influence mechanism of confined concrete arches with different section shapes under different loading modes and cross-section parameters are systematically studied. Test results show that the bearing capacity of the confined concrete arch is 2.10 times that of the U-shaped steel arch, and the bearing capacity of the circular confined concrete arch is 2.27 times that of the straight-leg semicircular arch. Among the various influencing factors and their engineering parameters,the lateral stress coefficient has the greatest impact on the bearing capacity of the confined concrete arch,followed by the steel pipe wall thickness, steel strength, and core concrete strength. Subsequently, the economic index of bearing capacity and cost is established, and the optimization design method for the confined concrete arch is proposed. Finally, this design method is applied to a high-stress tunnel under complex conditions, and the deformation of the surrounding rock is effectively controlled. 展开更多
关键词 High-stress tunnel Confined concrete arch Section shape Mechanical properties Design method
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Elastic responses of underground circular arches considering dynamic soil-structure interaction:A theoretical analysis 被引量:10
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作者 Hai-Long Chen Feng-Nian Jin Hua-Lin Fan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第1期110-122,共13页
Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibra... Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches. 展开更多
关键词 Underground protective arches - Dynamic soilstructure interaction Dynamic responses Analytical solution
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Measurement of vibration frequencies of ties in masonry arches by means of a robotic total station
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作者 Marco Gatti 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2022年第2期489-500,共12页
Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dim... Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dimensional positions of a reflector situated at 1/2 or 1/4 of the length of the tie during vertical oscillation induced by an impulsive load.The recording slips,vibration amplitudes(and their accuracy),hourly diagram and experimental spectra of vibrations,and the corresponding frequencies were calculated.The results were verified by comparing them with the vibration frequencies and indirectly the tension and fixed support constraint calculated from accelerometric measurements.The study provides interesting information on the accuracies of the reflector′s three-dimensional coordinates,but highlighted certain limits in the application of robotized total stations for measuring vibration frequencies of ties in masonry arches. 展开更多
关键词 RTS FREQUENCY vibrations TIES archeS
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Origin of Erosion and Hydraulic Problems of the San Roque Underground Arched Culvert Channel and Its Relationship with the Maximum Flow Rate and the Maximum Permissible Velocity
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作者 Martín Mundo-Molina Daniel Hernández-Cruz 《Journal of Water Resource and Protection》 2020年第12期1123-1139,共17页
This work presents the hydrologic estimations of the hydraulic underground arched culvert channel (UACC) in Sabinal Basin, Chiapas, México and the hydrological problems associated with it, such as the erosion phe... This work presents the hydrologic estimations of the hydraulic underground arched culvert channel (UACC) in Sabinal Basin, Chiapas, México and the hydrological problems associated with it, such as the erosion phenomenon and abrasion cavity formation in it. On the other hand, the maximum flows that the UACC could transport were analyzed, concluding that it no longer has the hydraulic capacity to transport the flow rate associated to return periods equal to or greater than five years and that maximum permissible velocity UACC’s bottom is 3 m/s. 展开更多
关键词 Collapse Underground arched Culvert Channel Maximum Flow Rate Maximum Permissible Water Velocity Open Channel Bottom Erosion
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The Arche of All Nature——The Relationship of Humanity to Nature
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作者 贺欣欣 《海外英语》 2017年第7期176-177,共2页
Natural philosophy of ancient Greece is the original form of western philosophy as well as the forerunner of modern natural sci-ence.The most interested question that natural philosophy concerned is the Arche of the u... Natural philosophy of ancient Greece is the original form of western philosophy as well as the forerunner of modern natural sci-ence.The most interested question that natural philosophy concerned is the Arche of the universe and the origin of all nature,and it is al-so to think over the philosophy questions when people are in face of the nature.This paper is conducted to explore how the nature origi-nate and in what way exist and to reflect on the relationship between humanity and nature with the increasing of environmental pollutionand ecological deterioration. 展开更多
关键词 natural philosophy arche EXISTENCE
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Study on Structure of Arched Longitudinal Beams of Deep-Water Wharf 被引量:3
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作者 翟秋 鲁子爱 张淑华 《China Ocean Engineering》 SCIE EI 2008年第4期705-711,共7页
High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate l... High-pile and beam-slab quays have been widely used after several years development. They are mature enough to be one of the most important structural types of wharves in China coastal areas. In order to accommodate large tonnage vessels, wharves should be eorrstructed in deep water gradually. However, conventional high-pile and beam-slab structares are hard to meet the requirements of large deep-water wharf. According to arch' s stress characteristics, a new type of wharf with catenary arched longitudinal beams is presented in this paper. The new wharf structure can make full use of arch's overhead crossing and reinforced concrete compression resistance, improve the interval between transverse bents greatly, and decrease underwater construction quantity. Thus, the construction cost cab be reduced. Take the third phase project of the Yangshan Deep-water Port for example, comparative analysis on catenary arched longitudinal beams and conventional longitudinal beams has been made. The result shows that with the same wharf length and width, the same loads and same longitudinal beam moment, catenary arch structure can improve the interval between bents up to 28 m, decrease the nmnber of piles and underwater construction quantity. 展开更多
关键词 WHARF structural type cateriary arch internal force COST
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Nonlinear dynamic behaviors of viscoelastic shallow arches
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作者 易壮鹏 王连华 赵跃宇 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第6期771-777,共7页
The nonlinear dynamic behaviors of nonlinear viscoelastic shallow arches sub- jected to external excitation are investigated. Based on the d'Alembert principle and the Euler-Bernoulli assumption, the governing equati... The nonlinear dynamic behaviors of nonlinear viscoelastic shallow arches sub- jected to external excitation are investigated. Based on the d'Alembert principle and the Euler-Bernoulli assumption, the governing equation of a shallow arch is obtained, where the Leaderman constitutive relation is applied. The Galerkin method and numerical in- tegration are used to study the nonlinear dynamic properties of the viscoelastic shallow arches. Moreover, the effects of the rise, the material parameter and excitation on the nonlinear dynamic behaviors of the shallow arch viscoelastic shallow arches may appear to have a are investigated. The results show that chaotic motion for certain conditions. 展开更多
关键词 viscoelastic shallow arch Leaderman constitutive relation Galerkin method bifurcation CHAOS
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The New Arched Bridge over Dnipro in Kyiv
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作者 Michael Korniiev 《Journal of Civil Engineering and Architecture》 2020年第3期133-143,共11页
The Podilskyi Arch bridge is crossing the Dnipro River in center of Kiev and is part of a 7.4 km long link which connects the center of Kiev with the “sleeping district” on the left bank of the river. The bridge has... The Podilskyi Arch bridge is crossing the Dnipro River in center of Kiev and is part of a 7.4 km long link which connects the center of Kiev with the “sleeping district” on the left bank of the river. The bridge has a main span of 344 m intended for six lanes of vehicles in the top level and two metro lines in the bottom level plus large diameter water pipes. The bridge is of steel, except of the reinforced concrete bases of the lower parts of the arches. The draft design works began in 1991 and in 2005 parallel design and construction work started. Due to the financial crisis in Ukraine, the work was interrupted for several years but construction recommenced in 2018 and the bridge is now planned to be completed in 2020 and the first stage of the transition in 2022. 展开更多
关键词 Ukraine Podilskyi BRIDGE CROSSING Dnipro RIVER composite steel and CONCRETE ROAD overpasses ARCH BRIDGE loads and
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Application of a Machine Learning Algorithm for the Structural Optimization of Circular Arches with Different Cross-Sections
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作者 Jonathan Melchiorre Amedeo Manuello Bertetto Giuseppe Carlo Marano 《Journal of Applied Mathematics and Physics》 2021年第5期1159-1170,共12页
<div style="text-align:justify;"> Arches are employed for bridges. This particular type of structures, characterized by a very old use tradition, is nowadays, widely exploited because of its strength, ... <div style="text-align:justify;"> Arches are employed for bridges. This particular type of structures, characterized by a very old use tradition, is nowadays, widely exploited because of its strength, resilience, cost-effectiveness and charm. In recent years, a more conscious design approach that focuses on a more proper use of the building materials combined with the increasing of the computational capability of the modern computers, has led the research in the civil engineering field to the study of optimization algorithms applications aimed at the definition of the best design parameters. In this paper, a differential formulation and a MATLAB code for the calculation of the internal stresses in the arch structure are proposed. Then, the application of a machine learning algorithm, the genetic algorithm, for the calculation of the geometrical parameters, that allows to minimize the quantity of material that constitute the arch structures, is implemented. In this phase, the method used to calculate the stresses has been considered as a constraint function to reduce the range of the solutions to the only ones able to bear the design loads with the smallest volume. In particular, some case studies with different cross-sections are reported to prove the validity of the method and to compare the obtained results in terms of optimization effectiveness. </div> 展开更多
关键词 Structural Optimization Genetic Algorithm Boundary Value Problem ARCH Volume Minimization
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In-Plane Elastic Stability of Arches under a Radial Concentrated Load
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作者 Yongjun Xu Xiaoming Gui +1 位作者 Bin Zhao Ruiqi Zhou 《Engineering(科研)》 2014年第9期572-583,共12页
This paper is concerned with the in-plane elastic stability of arches subjected to a radial concentrated load. The equilibrium equation for pin-ended circular arches is established by using energy method, and it is pr... This paper is concerned with the in-plane elastic stability of arches subjected to a radial concentrated load. The equilibrium equation for pin-ended circular arches is established by using energy method, and it is proved that the axial force is nearly a constant along the circumference of the circular arches. Based on force method, the equation for the primary eigen function is derived and solved, and the approximate analytical solution of critical instability load is obtained. Numerical examples are given and discussed. 展开更多
关键词 IN-PLANE ELASTIC Stability BUCKLING Critical Load Circular ARCH Force Method
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Design and Construction Strategy of Arched Continuous Rigid-frame Bridge
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作者 Yueqi Gao 《Journal of World Architecture》 2021年第1期5-7,共3页
With the current rapid development of urbanization in China,people's living standards have been greatly improved.In the context of such a development background,the requirements for road traffic are getting more s... With the current rapid development of urbanization in China,people's living standards have been greatly improved.In the context of such a development background,the requirements for road traffic are getting more stringent,especially for bridge projects.The arched continuous rigid-frame bridge was developed under this social background.The advantage of the bridge lies in the design of a bridge model that integrates various functions such as transportation,landscape,and sightseeing.Based on the above,this paper first refers to the case to analyze the design and construction strategy of the arched continuous rigid-frame bridge,in hope of providing a valuable reference for relevant personnel. 展开更多
关键词 ARCH Continuous steel structure Bridge design CONSTRUCTION
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ARCHEOLOGICAL DISCOVERIES IN DULAN——A Link to the "Highland Silk Road"
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作者 Huo Wei(文/图) 《China's Tibet》 2021年第5期54-57,共4页
2018 Xue Wei Tomb#1(XWT1 for short)has recently been listed among the top ten new archeological discoveries from across China in 2020.This giant tomb is seated in a Tubo-period graveyard along the northern riverbanks ... 2018 Xue Wei Tomb#1(XWT1 for short)has recently been listed among the top ten new archeological discoveries from across China in 2020.This giant tomb is seated in a Tubo-period graveyard along the northern riverbanks of Chahanwusu in Reshui Township of Dulan,Qinghai Province,and is a close neighbor to another giant graveyard named the Nine-Tier Ghostly Tower. 展开更多
关键词 ARCH LISTED DISCO
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股票市盈率波动有偏性对投资者股票交易量的影响研究--基于沪深300指数
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作者 江海潮 范晨宇 《衡阳师范学院学报》 2024年第2期54-60,共7页
有着独特波动规律的股票市盈率,会对投资者的股票交易产生影响。从市盈率波动有偏性的角度出发,以沪深300指数的市盈率数据为研究样本,构建回归模型,实证检验市盈率波动有偏性对股票交易量的影响,结果表明:沪深300指数市盈率波动相对于... 有着独特波动规律的股票市盈率,会对投资者的股票交易产生影响。从市盈率波动有偏性的角度出发,以沪深300指数的市盈率数据为研究样本,构建回归模型,实证检验市盈率波动有偏性对股票交易量的影响,结果表明:沪深300指数市盈率波动相对于正常波动水平存在明显右偏性;沪深300指数市盈率波动的持续时间较长且具有非对称性;沪深300指数市盈率波动右偏性对股票成交量具有显著的反向影响,并且这种影响受到经济增长、出口量、利率、汇率、居民消费价格指数和货币供应量的非对称约束。要稳定股市交易量,就需要综合考虑上述因素的影响,并根据市场变动灵活调整政策措施。 展开更多
关键词 市盈率 交易量 波动有偏性 ARCH模型
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Roof collapse mechanism of weak surrounding rock for deep-buried tunnels under high geostress conditions
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作者 ZHANG Qi GUO Xiaokang +2 位作者 YAN Zhiguo LEI Zhongdai SHEN Yixin 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2408-2426,共19页
High geostress,a typical attribute of tunnels located at significant depths,is crucial in causing stress-induced failure and influencing the stability of the tunnel crown.This study developed an analytical method for ... High geostress,a typical attribute of tunnels located at significant depths,is crucial in causing stress-induced failure and influencing the stability of the tunnel crown.This study developed an analytical method for the failure mechanism that occurs in deep-buried tunnel roofs,taking into account the influence of geostress.The limit analysis theory was utilized for deriving analytical solutions about the geometry of the collapsing surface and the limit supporting pressure.The collapsing surface obtained by the analytical solution was validated by the findings of the physical model test,which shows a high level of agreement with the actual one.An extensive investigation was done to explore the effects of the lateral pressure coefficients,the tunnel buried depth,the geological conditions of the surrounding rock,the long-short axis ratio,and the size of the tunnel profile.The findings indicate that an increase in the lateral pressure coefficient from 0.5 to 1.5 results in a reduction in the height of the collapsing zone by 2.08 m and the width of the collapsing zone by 1.15 m,while simultaneously increases the limit supporting pressure by 18.9%.The proposed upper bound method accurately determines the limit supporting pressure and the geometry of the collapsing surface,which aligns well with the results acquired through numerical modelling and on-site monitoring in actual engineering applications.The proposed analytical method can serve as a reference for similar crown failure issues of deep-buried tunnels. 展开更多
关键词 Geostress Deep-buried tunnels Collapse mechanism Pressure arch Limit analysis HoekBrown criterion
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Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model
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作者 Er-feng Zhao Xin Li Chong-shi Gu 《Water Science and Engineering》 EI CAS CSCD 2024年第2期177-186,共10页
Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in China.Safety control is essential to long-term operation of these dams.This study employed the flexibility coefficient and ... Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in China.Safety control is essential to long-term operation of these dams.This study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams.A comprehensive analysis was conducted,focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in China.Subsequently,the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored,including periodicity,convergence,and time-effect characteristics.These findings revealed the governing mechanism of main factors.Furthermore,a heterogeneous spatial panel vector model was developed,considering both common factors and specific factors affecting the safety and performance of arch dams.This model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions,introducing a specific effect quantity to characterize local deformation differences.Ultimately,the proposed model was applied to the Xiaowan arch dam,accurately quantifying the spatiotemporal heterogeneity of dam performance.Additionally,the spatiotemporal distri-bution characteristics of environmental load effects on different parts of the dam were reasonably interpreted.Validation of the model prediction enhances its credibility,leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan dam.The findings not only enhance the predictive ability and timely control of ultrahigh arch dams'performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures. 展开更多
关键词 Ultrahigh arch dam Structural performance Deformation behavior Diagnosis criterion Panel data model
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Numerical Simulation Analysis of Welded Joints in Arch Ribs of Large Span Steel Pipe Arch Bridges
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作者 Deer He Nianchun Deng Xiuning Peng 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第3期19-30,共12页
In order to study the residual stress distribution law of welded joints of arch ribs of large-span steel pipe concrete arch bridges,numerical simulation of temperature,stress and strain fields based on ABAQUS for weld... In order to study the residual stress distribution law of welded joints of arch ribs of large-span steel pipe concrete arch bridges,numerical simulation of temperature,stress and strain fields based on ABAQUS for welded joints of arch-ribbed steel tubes using 7-,8-and 9-layer welds is carried out and its accuracy is demonstrated.The steel pipe welding temperature changes,residual stress distribution,different processes residual stress changes in the law,the prediction of post-weld residual stress distribution and deformation are studied in this paper.The results show that the temperature field values and test results are more consistent with the accuracy of numerical simulation of welding,the welding process is mainly in the form of heat transfer;Residual high stresses are predominantly distributed in the Fusion zone(FZ)and Heat-affected zone(HAZ),with residual stress levels tending to decrease from the center of the weld along the axial path,the maximum stress appears in the FZ and HAZ junction;The number of welding layers has an effect on the residual stress distribution,the number of welding layers increases,the residual stress tends to decrease,while the FZ and HAZ high stress area range shrinks;Increasing the number of plies will increase the amount of residual distortion. 展开更多
关键词 steel pipe and concrete arch bridge arch rib multi-pass welding residual stress numerical simulation
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基于政策利率时间序列分析的硅谷银行破产启示
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作者 黄岩渠 彭向宇 《广西财经学院学报》 2024年第1期107-119,共13页
加息超调背景下的硅谷银行破产事件引起广泛关注,研究选取美国纳斯达克100指数、标准普尔500指数、硅谷银行股价数据进行时间序列的ARCH效应分析,发现美联储低利率刺激以及2022年6月起始的加息超调使两种指数与硅谷银行股价时间序列产... 加息超调背景下的硅谷银行破产事件引起广泛关注,研究选取美国纳斯达克100指数、标准普尔500指数、硅谷银行股价数据进行时间序列的ARCH效应分析,发现美联储低利率刺激以及2022年6月起始的加息超调使两种指数与硅谷银行股价时间序列产生了波动聚集反应,并存在异常值。采用多元时间序列VAR模型进行格兰杰因果检验以及脉冲响应分析,发现政策利率调整对硅谷银行股价造成了冲击。基于研究结果,提出顺周期效应具备客观性及前瞻性,央行相机抉择要精准;银行业需要重视市场存在的异动和相关指标检测;面对风险新形态需采用前沿管理技术;避免业务模式单一化和集中化等风险管理建议。 展开更多
关键词 加息周期 风险积聚 利率变化风险 ARCH效应 VAR模型
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基于SARIMA-ARCH的电量预测模型
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作者 许然 杨黎娜 钟强 《电脑与电信》 2024年第5期88-91,共4页
电量预测是供电单位购电的重要依据,是电力经济稳定运行的根本基础。提出采用SARIMA-ARCH融合模型对某地区售电量进行预测。首先,采用季节时间序列分析方法(SARIMA)对月度电量时间序列进行建模,通过ACF和PACF图筛选确定出最佳模型阶数,... 电量预测是供电单位购电的重要依据,是电力经济稳定运行的根本基础。提出采用SARIMA-ARCH融合模型对某地区售电量进行预测。首先,采用季节时间序列分析方法(SARIMA)对月度电量时间序列进行建模,通过ACF和PACF图筛选确定出最佳模型阶数,得到季节性时间序列模型(SARIMA)基础预测模型;提取模型残差的波动性,建立自回归条件异方差(ARCH)模型;最后,将SARIMA-ARCH模型与常规SRIAM和ARIMA的预测值进行对比分析。结果表明,SARIMAARCH混合模型的预测精度较高。 展开更多
关键词 SARIMA 时间序列分析 ARCH效应 售电量
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Nonlinear Bending Analysis of Functionally Graded CNT-Reinforced Shallow Arches Placed on Elastic Foundations
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作者 Yuanyuan Zhang Bo Zhang +3 位作者 Huoming Shen Yuxing Wang Xin Zhang Juan Liu 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2020年第2期164-186,共23页
This research explores the nonlinear bending behaviors of functionally graded carbon nanotube-reinforced(FG-CNTR)shallow arches with unmovable simply supported ends and clarnped-clamped ends;these arches are subjected... This research explores the nonlinear bending behaviors of functionally graded carbon nanotube-reinforced(FG-CNTR)shallow arches with unmovable simply supported ends and clarnped-clamped ends;these arches are subjected to a uniform radial pressure and rest on a nonlinear elastic foundation.The temperature-dependent material properties of the arches are considered.Within the framework of Reddy shear deformation theory possessing von Karman nonlinearity,the motion equations and boundary conditions for the FG-CNTR arches are determined by the Euler-Lagrange variational principle.Then,a two-step perturbation technique is adopted to determine the load-deflection relationship analytically.To verify the validity of the developed model and related perturbation solutions,a numerical investigation is conducted for shallow arches with five distribution patterns of carbon nanotube(CNT)reinforcements uniaxially aligned in the axial direction.Finally,the influences of various factors,including the elastic foundation,layout type,and volume fraction of CNTs and geometric factors,on the nonlinear behaviors of FG-CNTR shallow arches are examined.The obtained results show that the load deflection curves exhibit less snap-through instability as the CNT volume fraction increases.The transverse shear stress versus the thickness of FG-CNTR shallow arches is markedly affected by the layout type and content of reinforcements. 展开更多
关键词 Nonlinear bending.Carbon nanotube-reinforced composites Shallow arches Two-step perturbation technique
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