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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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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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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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Effects of comprehensive nursing with cognitive behavioral therapy in orthodontic osteodilated arch treatment
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作者 Xin Yang Zeng-Xiang Wang +3 位作者 Yu-Xing Tian Chao Peng Hui-Ning Yang Ying Wu 《World Journal of Clinical Cases》 SCIE 2024年第22期5051-5058,共8页
BACKGROUND This work explored the effects of cognitive behavior therapy(CBT)-based comprehensive nursing intervention(CNI)mode in arch expansion to treat patients with orthodontic osteodilated arch(OOA).AIM To explore... BACKGROUND This work explored the effects of cognitive behavior therapy(CBT)-based comprehensive nursing intervention(CNI)mode in arch expansion to treat patients with orthodontic osteodilated arch(OOA).AIM To explore the application effect of CBT-based CNI model in orthodontic expansion arch treatment.METHODS Using convenient sampling method,81 patients with OOA were selected and rolled into a control group(Ctrl group,40 cases)and an observation group(Obs group,41 cases).During the treatment,patients in the Ctrl group received routine nursing intervention mode,and the those in the Obs group received CBT mode on the basis of this.Before and after intervention,the incidence of oral mucositis,the mastery rate of correct arch expansion method,self-rating anxiety scale score,soft scale index,and plaque index were compared for patients in different groups.In addition,satisfaction and complications were comparatively analyzed.RESULTS Incidence of oral mucositis in the Obs group was lower(14.6%vs 38.5%),and the mastery rate of correct arch expansion method was obviously higher(90.2%vs 55.0%)was obviously higher(all P<0.05).Meanwhile,the soft scale index and plaque index in the Obs group were much lower(P<0.05).The compliance(90.24%)and satisfaction(95.12%)in the Obs group were greatly higher(P<0.05).CONCLUSION The CBT-based CNI mode greatly improved the mastery rate of correct arch expansion method during arch expansion in treating patients with OOA and enhanced the therapeutic effect of arch expansion and the oral health of patients,improving the patient compliance. 展开更多
关键词 Orthodontic osteodilated arch Cognitive behavior therapy Comprehensive nursing intervention mode Nursing effect Pain management Oral care
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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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Mechanical properties and influence mechanism of confined concrete arches in high-stress tunnels 被引量:9
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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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Deformation critical threshold estimation of Xiaowan ultrahigh arch dam with time-varying grey model 被引量:1
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作者 Er-feng Zhao Bo Li +1 位作者 Hao Chen Bing-bing Nie 《Water Science and Engineering》 EI CAS CSCD 2023年第3期302-312,共11页
The structural behavior of the Xiaowan ultrahigh arch dam is primarily influenced by external loads and time-varying characteristics of dam concrete and foundation rock mass during long-term operation. According to ov... The structural behavior of the Xiaowan ultrahigh arch dam is primarily influenced by external loads and time-varying characteristics of dam concrete and foundation rock mass during long-term operation. According to overload testing with a geological model and the measured time series of installed perpendicular lines, the space and time evolution characteristics of the arch dam structure were analyzed, and its mechanical performance was evaluated. Subsequently, the deformation centroid of the deflective curve was suggested to indicate the magnitude and unique distribution rules for a typical dam section using the measured deformation values at multi-monitoring points. The ellipse equations of the critical ellipsoid for the centroid were derived from the historical measured time series. Hydrostatic and seasonal components were extracted from the measured deformation values with a traditional statistical model, and residuals were adopted as a grey component. A time-varying grey model was developed to accurately predict the evolution of the deformation behavior of the ultrahigh arch dam during future operation. In the developed model, constant coefficients were modified so as to be time-dependent functions, and the prediction accuracy was significantly improved through introduction of a forgetting factor. Finally, the critical threshold was estimated, and predicted ellipsoids were derived for the Xiaowan arch dam. The findings of this study can provide technical support for safety evaluation of the actual operation of ultrahigh arch dams and help to provide early warning of abnormal changes. 展开更多
关键词 arch dam Deformation behavior EVOLUTION Critical threshold Grey model
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基于ARCH类模型的农产品价格波动特征研究 被引量:1
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作者 王溯 胡长情 陈健(指导) 《中国林业经济》 2023年第2期80-84,共5页
基于2011年1月至2022年8月的月度价格指数,运用自回归条件异方差ARCH类模型对猪肉、牛肉、棉花、大豆、稻谷、羊肉六种农产品进行价格波动特征分析研究。结果表明:具有较为显著的ARCH效应是牛肉、大豆、猪肉、棉花这四种农产品;其中农... 基于2011年1月至2022年8月的月度价格指数,运用自回归条件异方差ARCH类模型对猪肉、牛肉、棉花、大豆、稻谷、羊肉六种农产品进行价格波动特征分析研究。结果表明:具有较为显著的ARCH效应是牛肉、大豆、猪肉、棉花这四种农产品;其中农产品价格具有波动集聚性特征的是牛肉、大豆、猪肉、棉花;牛肉、大豆、猪肉、棉花价格不具备高风险和高报酬的特征;农产品价格均具有非对称性是棉花、大豆、猪肉。基于研究分析结果,本文提出相关政策建议,为农产品市场价格调控提供参考。 展开更多
关键词 农产品 价格波动特征 arch类模型
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Structural Damage Identification System Suitable for Old Arch Bridge in Rural Regions: Random Forest Approach 被引量:1
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作者 Yu Zhang Zhihua Xiong +2 位作者 Zhuoxi Liang Jiachen She Chicheng Ma 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期447-469,共23页
A huge number of old arch bridges located in rural regions are at the peak of maintenance.The health monitoring technology of the long-span bridge is hardly applicable to the small-span bridge,owing to the absence of ... A huge number of old arch bridges located in rural regions are at the peak of maintenance.The health monitoring technology of the long-span bridge is hardly applicable to the small-span bridge,owing to the absence of technical resources and sufficient funds in rural regions.There is an urgent need for an economical,fast,and accurate damage identification solution.The authors proposed a damage identification system of an old arch bridge implemented with amachine learning algorithm,which took the vehicle-induced response as the excitation.A damage index was defined based on wavelet packet theory,and a machine learning sample database collecting the denoised response was constructed.Through comparing three machine learning algorithms:Back-Propagation Neural Network(BPNN),Support Vector Machine(SVM),and Random Forest(R.F.),the R.F.damage identification model were found to have a better recognition ability.Finally,the Particle Swarm Optimization(PSO)algorithm was used to optimize the number of subtrees and split features of the R.F.model.The PSO optimized R.F.model was capable of the identification of different damage levels of old arch bridges with sensitive damage index.The proposed framework is practical and promising for the old bridge’s structural damage identification in rural regions. 展开更多
关键词 Old arch bridge damage identification machine learning random forest particle swarm optimization
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Improved super-elastic Ti–Ni alloy wire intrusion arch for skeletal class Ⅱ malocclusion combined with deep overbite:A case report 被引量:1
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作者 Ching-Yu Yang Chih-Chieh Lin +2 位作者 I-Jia Wang Yuan-Hou Chen Jian-Hong Yu 《World Journal of Clinical Cases》 SCIE 2023年第17期4142-4151,共10页
BACKGROUND Treatment for deep overbite cases can be difficult. This case report presents some techniques with improved super-elastic Ti–Ni alloy wire(ISW) for deep overbite correction.CASE SUMMARY A 21-year-old woman... BACKGROUND Treatment for deep overbite cases can be difficult. This case report presents some techniques with improved super-elastic Ti–Ni alloy wire(ISW) for deep overbite correction.CASE SUMMARY A 21-year-old woman had a chief complaint of flaring maxillary teeth. Orthodontic evaluation revealed a skeletal class Ⅱ malocclusion and a convex profile appearance. A deep overbite with palatal impingement and large overjet were also noted. Bilateral maxillary first premolars were extracted, and spaces were closed using a closed-coil spring and elastic chain. The deep overbite was corrected by applying the ISW curve and ISW intrusion arch. Intermaxillary elastics was used to adjust the intermaxillary relationship. Active treatment took approximately 3 years, and the appearance and dentition alignment noticeably improved.CONCLUSION The use of the ISW technique in a case of skeletal class Ⅱ malocclusion with deep overbite achieved a desirable result, and the patient was satisfied with the treatment outcome. 展开更多
关键词 Dentistry ORTHODONTICS Skeletal class II Intrusion arch Case report
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基于ARCH族模型的石油价格波动性分析
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作者 晁玉 王传会 《国际会计前沿》 2023年第2期235-244,共10页
随着中国成为世界第二大经济实体,能源在经济发展方面的重要地位也与日俱增,石油价格的波动牵动着全球经济的“神经”,会对经济发展产生极大的影响,因此降低石油价格波动所产生风险非常必要。本文以1987~2021年WTI原油价格为原始数据,利... 随着中国成为世界第二大经济实体,能源在经济发展方面的重要地位也与日俱增,石油价格的波动牵动着全球经济的“神经”,会对经济发展产生极大的影响,因此降低石油价格波动所产生风险非常必要。本文以1987~2021年WTI原油价格为原始数据,利用ARCH族模型对油价波动进行实证分析,研究表明石油价格波动具有肥尾分布和波动率聚类的特征且具有均值回归的倾向,当面对“黑天鹅事件”时能够以较快的速度减小危机带来的冲击,从而得出石油价格波动在突发情形下具有较大弹性的一般结论,并基于此提出完善市场机制作为主要政策实施方向和发展石油期货期权等衍生产品的政策建议,从而减小经济发展的不确定性风险。 展开更多
关键词 arch模型 油价波动 不确定性风险 异方差 能源安全
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Dynamic soil arching in piled embankment under train load of high-speed railways
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作者 Niu Tingting Yang Yule +2 位作者 Ma Qianli Zou Jiuqun Lin Bin 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期719-730,共12页
Piled embankments have many advantages that have been applied in high-speed railway construction engineering.However,the load transfer mechanism of piled embankments,such as soil arching and tension membranes,is still... Piled embankments have many advantages that have been applied in high-speed railway construction engineering.However,the load transfer mechanism of piled embankments,such as soil arching and tension membranes,is still unclear,especially under dynamic loads.To investigate the soil arching and tension membrane under dynamic train loads on high-speed railways,a large-scale piled embankment model test with X-shaped piles as vertical reinforcement was performed,in which twenty-eight earth pressure cells were installed in the piled embankment and an M-shaped wave was adopted to simulate the high-speed railway train load.The results show that dynamic soil arching only occurs when two bogies of a carriage pass by and disappears at other times.The dynamic soil arching and membrane effect are the most significant under the concrete base.The arching height,stress concentration ratio and pile-soil load sharing ratio have a minimal value at 25 Hz.The dynamic soil arching degrades severely at 25 Hz,whose height at 25 Hz is only 0.35 times that at 5 Hz.The arching height fluctuates over a narrow range with increasing loading amplitude.The stress concentration ratio and the pile-soil load sharing ratio increase monotonically as the loading amplitude increases. 展开更多
关键词 dynamic soil arching membrane effect piled embankment train load model test
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基于马尔科夫转换ARCH模型的房地产市场波动研究——以房地产市场景气指数为例 被引量:1
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作者 顾稚平 《现代商业》 2023年第2期49-52,共4页
近年来,我国房价波动较大,房地产投机现象时有发生。因此,研究房地产市场的运行规律,对于预测房价、防范房地产泡沫具有重要意义。本文研究了中国住房市场的波动状态。使用ARCH和GARCH模型来寻找房地产市场景气指数随时间变化的证据。... 近年来,我国房价波动较大,房地产投机现象时有发生。因此,研究房地产市场的运行规律,对于预测房价、防范房地产泡沫具有重要意义。本文研究了中国住房市场的波动状态。使用ARCH和GARCH模型来寻找房地产市场景气指数随时间变化的证据。然后利用马尔科夫转移模型(MS模型)连续分析2000年~2021年中国住房市场波动状态的动态。结果表明,中国住房市场存在低波动性、中波动性和高波动性三种状态。实证分析发现,2002年之前,房地产市场一直处于低波动状态,2002年以后,房地产市场在中波动状态和高波动状态来回转换,针对每一个波动拐点,也可以找到当年政府发布的与房地产市场相关的政策,这在一定程度也说明政府行为对房地产市场常起导向作用。本文以房地产市场景气指数为数据,运用EViews和MATLAB进行实践操作,对研究问题进行求解,目的是了解中国房地产市场的波动情况,判断房地产市场的稳定性,为相关房地产企业经营决策和政府部门的规范管理提供参考。 展开更多
关键词 国房景气指数 波动性 arch族模型 马尔科夫转移模型
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Comparison of seismic fragility analysis methods for arch dams
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作者 Jin Aiyun Qiu Yixiang Wang Jinting 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第1期173-189,共17页
This study focuses on the seismic fragility analysis of arch dams.The multiple stripe analysis(MSA),cloud analysis(CLA),and incremental dynamic analysis(IDA)methods are compared.A comprehensive dam-reservoir-foundatio... This study focuses on the seismic fragility analysis of arch dams.The multiple stripe analysis(MSA),cloud analysis(CLA),and incremental dynamic analysis(IDA)methods are compared.A comprehensive dam-reservoir-foundation rock system,which considers the opening of contraction joints,the nonlinearity of dam concrete and foundation rock,the radiation damping effect of semi-unbounded foundation,and the compressibility of reservoir water,is used as a numerical example.225,80,and 15 earthquake records are selected for MSA,CLA,and IDA,respectively.The results show that MSA provides satisfactory fragility analysis,while both CLA and IDA have assumptions that may lead to deviations.Therefore,MSA is the most reliable method among the three methods and is recommended for the fragility analysis of arch dams.It is also shown that the choice of demand level affects the reliability of fragility curves and the effect of the material uncertainty on the fragility of the dam is not significant. 展开更多
关键词 arch dam seismic fragility analysis cloud analysis incremental dynamic analysis multiple stripe analysis
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Predictive value of the trans-perineal three-dimensional ultrasound measurement of the pubic arch angle for vaginal delivery
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作者 Zhu-Wei Liang Wan-Li Gao 《World Journal of Clinical Cases》 SCIE 2023年第20期4874-4882,共9页
BACKGROUND Numerous variables are linked to the success of vaginal delivery,including the subpubic arch angle(SPAA)during labor,the importance of which has not yet been fully elucidated.AIM To examine the SPAA distrib... BACKGROUND Numerous variables are linked to the success of vaginal delivery,including the subpubic arch angle(SPAA)during labor,the importance of which has not yet been fully elucidated.AIM To examine the SPAA distributional characteristics and to ascertain SPAA’s ability to predict the type and duration of labor.METHODS We determined the SPAA and analyzed the corresponding data.We also evaluated the relationship between the SPAA and the mode of delivery and the duration of labor by regression.The present study comprised a total of 301 pregnant women who had given birth at Beijing Tiantan Hospital of the Capital Medical University between January and December of 2021.RESULTS Our analysis of 301 pregnant women revealed that the SPAA measured using three-dimensional trans-perineal ultrasound had a minimum angle of 81°and a maximum angle of 122.2°.The angle in the normal vaginal delivery group was greater than that in the labor cesarean group(P=0.000).The SPAA was a highly significant positive predictor of normal vaginal delivery(P=0.000)with an area under the curve of 0.782(P=0.000;95%CI:0.717-0.848).We found the length of the second stage of labor to be positively influenced by the SPAA using linear regression analysis(P=0.045).CONCLUSION The SPAA was a highly significant positive predictor of normal vaginal delivery.The length of the second stage of labor and normal vaginal birth were predicted by SPAA. 展开更多
关键词 Three-dimensional ultrasound Subpubic arch angle Trans-perineal Vaginal delivery
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基于GARCH族模型人民币离岸价格收益率波动预测分析
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作者 耿春燕 《统计学与应用》 2023年第6期1667-1674,共8页
我国是个外贸依存度很高的国家,汇率的较大波动会对我国经济造成重大影响,准确预测汇率波动性能够为降低中国企业的外贸、投资的汇率风险规避提供一定的参考价值。因此,本文选取了2022年1月3日~2023年7月15日香港美元人民币市场的每日... 我国是个外贸依存度很高的国家,汇率的较大波动会对我国经济造成重大影响,准确预测汇率波动性能够为降低中国企业的外贸、投资的汇率风险规避提供一定的参考价值。因此,本文选取了2022年1月3日~2023年7月15日香港美元人民币市场的每日收盘价格,用2022年1月3日至2022年6月30日的样本内数据建模,并用模型进行2023年7月3日至2023年7月21日的样本外预测以评价模型的预测能力。研究结果显示,IGARCH模型是数据拟合模型最优的,反映了人民币离岸价格收益波动率受冲击影响持久。 展开更多
关键词 收益率波动 arch效应 Garch族模型 预测能力
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Persistent left superior vena cava in right hemiarch replacement under deep hypothermic circulatory arrest:A case report
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作者 Ze-Yu Mi Gang He +1 位作者 Hong-Li Gao Chao Li 《World Journal of Clinical Cases》 SCIE 2023年第32期7858-7864,共7页
BACKGROUND Persistent left superior vena cava(PLSVC),a relatively rare thoracic vascular malformation,can inconvenience perfusionists and operators when encountered during deep hypothermic circulatory arrest(DHCA).CAS... BACKGROUND Persistent left superior vena cava(PLSVC),a relatively rare thoracic vascular malformation,can inconvenience perfusionists and operators when encountered during deep hypothermic circulatory arrest(DHCA).CASE SUMMARY Herein,we describe the case of a patient with concurrent giant aortic arch aneurysm,aortic stenosis,and PLSVC.To treat these conditions,we performed right hemiarch and aortic valve replacements under DHCA.Notably,we applied“bilateral superior vena cava retrograde cerebral perfusion(RCP)”for cerebral protection,which significantly optimized the surgical procedure and reduced the risk of postoperative complications.The patient was discharged 14 d after surgery with no complications.CONCLUSION Surgical intervention for PLSVC under DHCA can be performed using the bilateral superior vena cava RCP approach. 展开更多
关键词 Persistent left superior vena cava Aortic arch aneurysm Hemiarch replacement Deep hypothermic circulatory arrest Retrograde cerebral perfusion Case report
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一类双函数系数ARCH-M模型的经验似然估计
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作者 姜茜 赵培信 《重庆工商大学学报(自然科学版)》 2023年第2期106-112,共7页
针对一类双函数系数自回归条件异方差-均值(ARCH-M)模型的估计问题,提出一种基于经验似然的估计方法;在该估计方法中,所提出的模型允许金融时间序列的风险效应和收益效应同时为某一变量的函数结构,可以有效地刻画金融时间序列的风险和... 针对一类双函数系数自回归条件异方差-均值(ARCH-M)模型的估计问题,提出一种基于经验似然的估计方法;在该估计方法中,所提出的模型允许金融时间序列的风险效应和收益效应同时为某一变量的函数结构,可以有效地刻画金融时间序列的风险和平均收益之间的关系,具有较广的适应性;同时,与经典矩估计法和极大似然估计法相比,基于经验似然的估计方法具有独特的优势,可以充分考虑金融序列的异方差性,并且所构造的置信区间不涉及任何渐近方差的估计,因此具有较好的稳健性和有效性;在一些正则条件下,对所构造的经验对数似然比统计量及函数系数估计量的渐近分布进行了理论分析;结果表明:关于风险效应函数系数和收益效应函数系数的经验对数似然比统计量均渐近收敛于中心卡方分布,同时函数系数估计量渐近收敛于正态分布;进而对风险效应函数系数和收益效应函数系数分别构造了相应函数系数的逐点置信区间。 展开更多
关键词 函数系数模型 arch-M模型 经验似然 置信区间
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大跨度混凝土钢筋框架梁挠度超限研究 被引量:3
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作者 张玉明 尚彦宾 +1 位作者 边广生 陈国斌 《建筑技术》 2024年第3期322-324,共3页
根据大量的工程实践,大跨度钢筋混凝土框架梁由于设计不合理引起大跨度梁超限的工程案例很少,大多数是施工原因导致挠度超限。以某工程挠度超限的大跨度钢筋混凝土梁为例,根据设计资料和现场检测资料,从设计和施工两方面,利用数值计算... 根据大量的工程实践,大跨度钢筋混凝土框架梁由于设计不合理引起大跨度梁超限的工程案例很少,大多数是施工原因导致挠度超限。以某工程挠度超限的大跨度钢筋混凝土梁为例,根据设计资料和现场检测资料,从设计和施工两方面,利用数值计算和有限元模拟,验证分析大跨度钢筋混凝土框架梁挠度超限的原因。验证分析表明,梁板混凝土实际浇筑厚度超限与梁模板起拱高度不足可能引起梁挠度增加。当梁下立杆稳定承载力不足时,梁也易随立杆屈曲变形产生较大挠度。 展开更多
关键词 梁挠度 模板起拱高度 稳定承载力 立杆屈曲
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沥青混凝土心墙堆石坝心墙拱效应研究 被引量:1
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作者 李勇 李炎隆 +1 位作者 温立峰 李维妹 《水利水运工程学报》 CSCD 北大核心 2024年第1期119-128,共10页
心墙拱效应是影响土石坝安全稳定运行的重要因素,心墙力学特性复杂且受众多因素的影响,复杂地形地质条件对心墙拱效应具有重要影响。首先对比了直心墙、斜心墙、下直上斜式心墙拱效应的差异,在此基础上选取岸坡坡度、河谷宽度、覆盖层... 心墙拱效应是影响土石坝安全稳定运行的重要因素,心墙力学特性复杂且受众多因素的影响,复杂地形地质条件对心墙拱效应具有重要影响。首先对比了直心墙、斜心墙、下直上斜式心墙拱效应的差异,在此基础上选取岸坡坡度、河谷宽度、覆盖层厚度以表征坝体所处的地形地质条件。基于数值计算定量研究复杂地质条件对沥青混凝土心墙拱效应的影响规律。结果表明:心墙应力拱效应主要集中在心墙中部3/4坝高附近及靠近岸坡处;斜心墙应力拱效应相对较小,可以很好地改善心墙的整体受力状况;岸坡变陡,斜心墙整体的拱效应强度增加,应力传递的核心区域由心墙中部拓宽至心墙两岸坡;随着河谷宽度的增加,应力传递的重心逐渐由底部转移到心墙两岸及心墙中上部;斜心墙整体的应力拱效应并非随着河谷宽度的增加单调变化,当坝轴线长度与坝高比值增加到3~4时,河谷产生的河谷效应对斜心墙变形及拱效应的影响大幅下降;随着覆盖层厚度的增加,斜心墙底部的拱效应明显增强,底部的拱效应系数分布逐渐集中化、区域化,容易产生局部破坏。 展开更多
关键词 沥青混凝土心墙 地形 地质 拱效应 土石坝
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