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A Simplified Method for the Stress Analysis of Underground Transfer Structures Crossing Multiple Subway Tunnels
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作者 Shen Yan Dajiang Geng +2 位作者 Ning Dai Mingjian Long Zhicheng Bai 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2893-2915,共23页
According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer str... According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment. 展开更多
关键词 crossing tunnels transfer structure force mechanism simplify analysis layered soil mass
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A Study of the Teaching Effects of Case Analysis in Cross-Cultural Communication Class-Taking Individualism-Collectivism Cultural Dimension Class as an Example
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作者 ZHOU Qingyan 《Sino-US English Teaching》 2024年第8期372-376,共5页
This study introduces the individualism-collectivism dimension of the cultural dimension of cross-cultural communication initiated by Geert Hofstede.Different cultures must develop a way of correlating that strikes a ... This study introduces the individualism-collectivism dimension of the cultural dimension of cross-cultural communication initiated by Geert Hofstede.Different cultures must develop a way of correlating that strikes a balance between caring for themselves and showing concern for others.Individualist culture encourages uniqueness and independence while collectivist culture emphasizes conformity and mutual assistance.This article introduces how to use case analysis method to effectively carry out classroom teaching in this cultural dimension. 展开更多
关键词 cultural dimension case analysis cross cultural communication teaching effects
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Generalized response displacement methods for seismic analysis of underground structures with complex cross section
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作者 Xu Zigang Ding Linling +2 位作者 Du Xiuli Xu Chengshun Zhuang Haiyang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第4期979-993,共15页
The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing ... The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of RDM.Springs and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular structures.It is necessary to propose simplified seismic analysis methods for structures with complex cross sections.This paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the structure.In GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the structure.In GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in GRDM2.The time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified methods.Results show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and GRDM3.Among the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and accuracy.Therefore,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections. 展开更多
关键词 underground structures seismic analysis response displacement method equivalent seismic load complex cross section
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Design & Test of an Advanced Web Security Analysis Tool (AWSAT)
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作者 Meenakshi S. P. Manikandaswamy Vijay Madisetti 《Journal of Software Engineering and Applications》 2024年第5期448-461,共14页
Considering the escalating frequency and sophistication of cyber threats targeting web applications, this paper proposes the development of an automated web security analysis tool to address the accessibility gap for ... Considering the escalating frequency and sophistication of cyber threats targeting web applications, this paper proposes the development of an automated web security analysis tool to address the accessibility gap for non-security professionals. This paper presents the design and implementation of an automated web security analysis tool, AWSAT, aimed at enabling individuals with limited security expertise to effectively assess and mitigate vulnerabilities in web applications. Leveraging advanced scanning techniques, the tool identifies common threats such as Cross-Site Scripting (XSS), SQL Injection, and Cross-Site Request Forgery (CSRF), providing detailed reports with actionable insights. By integrating sample payloads and reference study links, the tool facilitates informed decision-making in enhancing the security posture of web applications. Through its user-friendly interface and robust functionality, the tool aims to democratize web security practices, empowering a wider audience to proactively safeguard against cyber threats. 展开更多
关键词 Web Security Automated analysis Vulnerability Assessment Web Scanning cross-Site Scripting SQL Injection cross-Site Request Forgery
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A Cross-Reference Method for Nonlinear Time Series Analysis in Semi-Blind Case
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作者 杨绿溪 何振亚 《Journal of Southeast University(English Edition)》 EI CAS 1999年第1期3-8,共6页
In this paper, we propose a cross reference method for nonlinear time series analyzing in semi blind case, that is, the dynamic equations modeling the time series are known but the corresponding parameters are not. ... In this paper, we propose a cross reference method for nonlinear time series analyzing in semi blind case, that is, the dynamic equations modeling the time series are known but the corresponding parameters are not. The tasks of noise reduction and parameter estimation which were fulfilled separately before are combined iteratively. With the positive interaction between the two processing modules, the method is somewhat superior. Some prior work can be viewed as special cases of this general framework. The simulations for noise reduction and parameter estimation of contaminated chaotic time series show improved performance of our method compared with previous work. 展开更多
关键词 nonlinear time series analysis noise reduction parameter estimation cross reference
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Neo-translation,Appreciation and Analysis of Tennyson's Crossing the Bar
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作者 李绍青 《海外英语》 2011年第9X期223-224,共2页
As a world-widely popular poem,Tennyson's Crossing the Bar attracts more and more people to cherish it.And this paper aims at translating it in a new way,and analyzing it in a fully scientific way.
关键词 TENNYSON crossING the BAR new TRANSLATION APPRECIATION analysis
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Geometry Design and Tooth Contact Analysis of Crossed Beveloid Gears for Marine Transmissions 被引量:11
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作者 ZHU Caichao SONG Chaosheng +1 位作者 LIM Teik Chin VIJAYAKAR Sandeep 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第2期328-337,共10页
Beveloid gears,also known as conical gears,gain more and more importance in industry practice due to their abilities for power transmission between parallel,intersected and crossed axis.However,this type of gearing wi... Beveloid gears,also known as conical gears,gain more and more importance in industry practice due to their abilities for power transmission between parallel,intersected and crossed axis.However,this type of gearing with crossed axes has no common plane of action which results in a point contact and low tooth durability.Therefore,a geometry design approach assuming line contact is developed to analyze the tooth engagement process of crossed beveloid gears with small shaft angle for marine transmission applications.The loaded gear tooth contact behavior is simulated by applying a quasi-static analysis to study the effects of gearing parameters on mesh characteristics.Using the proposed method,a series of sensitivity analyses to examine the effects of critical gearing parameters such as shaft angle,cone angle,helix angle and profile-shift coefficient on the theoretical gear mesh is performed.The parametric analysis of pitch cone design shows that the dominant design parameters represented by the angle between the first principle directions(FPD) and normal angular factor are more sensitive to the shaft and cone angles than they are to the helix angle.The theoretical contact path is highly sensitive to the profile-shift coefficient,which is determined from the theoretical tooth contact analysis.The FPD angle is found to change the distribution of contact pattern,contact pressure and root stress as well as the translational transmission error and the variation of the mesh stiffness significantly.The contact pattern is clearly different between the drive and coast sides due to different designed FPD angles.Finally,a practical experimental setup for marine transmission is performed and tooth bearing test is conducted to demonstrate the proposed design procedure.The experimental result compared well with the simulation.Results of this study yield a better understanding of the geometry design and loaded gear mesh characteristics for crossed beveloid gears used in marine transmission. 展开更多
关键词 beveloid gears loaded tooth contact analysis crossed axes marine transmission
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Multi-factor analysis of initial poor graft function after orthotopic liver transplantation 被引量:12
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作者 Chen, Hao Peng, Cheng-Hong +5 位作者 Shen, Bai-Yong Deng, Xia-Xing Shen, Chuan Xie, Jun-Jie Dong, Wei Li, Hong-Wei 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2007年第2期141-146,共6页
BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study s... BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors. 展开更多
关键词 orthotopic liver transplantation poor liver function multi-factor analysis
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Variation Analysis of Seed and Seedling Traits of Cross Combination Progenies in Populus 被引量:3
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作者 Li Shan-wen Zhang Zhiyi +3 位作者 He Cheng-zhong An Xin-min Yu Zhi-shui Li Bai-lian 《Forestry Studies in China》 CAS 2005年第3期61-69,共9页
Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds... Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds per infructescence, thousand-seed weight, germination rate of seeds among these cross combinations were tested. The results indicated that the cross combinational effects were significant for these traits, and demonstrated that the length of infructescence, thousand-seed weight were positively affected by female parent. In addition, seedling height, diameter above ground, diameter at breast height (DBH) of 17 cross combination progenies were investigated. The analysis of mean and standard deviation of these three traits showed that seedling height, diameter above ground, DBH had extensive variation among combinations and individuals within combination. Variance analysis and estimate of heritability indicated that the three traits had wide variation and were controlled by heredity. It was feasible to select superior cross combinations and seedlings. Further more, the result of multiple comparison showed that P.deltoides ‘Lux'× P.deltoides ‘D324', P.ussuriensis cl. ‘U4'× P deltoides ‘T66', P.ussuriensis cl. ‘U4'× P. deltoides ‘T26', P.deltoides ‘Lux'× P.ussuriensis cl. ‘U3', (P.tomentosa×P.bolleana)×(P.alba×P.glandulosa), (P.alba×P.tomentosa)×(P.alba×P.glandulosa), and (P.alba×P.glandulosa‘No.2')× P. tomentosa ‘Lumao 50' were superior cross combinations with higher growth rate. Finally, 123 elite seedlings were selected for further test. 展开更多
关键词 POPLAR cross combination HYBRID variation analysis
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Detection of Mechanical Deformation in Old Aged Power Transformer Using Cross Correlation Co-Efficient Analysis Method 被引量:2
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作者 Asif Islam Shahidul Islam Khan Aminul Hoque 《Energy and Power Engineering》 2011年第4期585-591,共7页
Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an... Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an effective low-voltage, off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the Transformer, due to large electromechanical forces occurring from the fault currents or due to Transformer transportation and relocation. In this method, the frequency response of a transformer is taken both at manufacturing industry and concern site. Then both the response is compared to predict the fault taken place in active part. But in old aged transformers, the primary reference response is unavailable. So Cross Correlation Co-Efficient (CCF) measurement technique can be a vital process for fault detection in these transformers. In this paper, theoretical background of SFRA technique has been elaborated and through several case studies, the effectiveness of CCF parameter for fault detection has been represented. 展开更多
关键词 Core Damage RADIAL DEFORMATION AXIAL DEFORMATION SWEEP Frequency Response analysis cross Correlation Co-efficient Power Transformer
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A Hybrid Neural Network Model for Marine Dissolved Oxygen Concentrations Time-Series Forecasting Based on Multi-Factor Analysis and a Multi-Model Ensemble 被引量:2
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作者 Hui Liu Rui Yang +1 位作者 Zhu Duan Haiping Wu 《Engineering》 SCIE EI 2021年第12期1751-1765,共15页
Dissolved oxygen(DO)is an important indicator of aquaculture,and its accurate forecasting can effectively improve the quality of aquatic products.In this paper,a new DO hybrid forecasting model is proposed that includ... Dissolved oxygen(DO)is an important indicator of aquaculture,and its accurate forecasting can effectively improve the quality of aquatic products.In this paper,a new DO hybrid forecasting model is proposed that includes three stages:multi-factor analysis,adaptive decomposition,and an optimizationbased ensemble.First,considering the complex factors affecting DO,the grey relational(GR)degree method is used to screen out the environmental factors most closely related to DO.The consideration of multiple factors makes model fusion more effective.Second,the series of DO,water temperature,salinity,and oxygen saturation are decomposed adaptively into sub-series by means of the empirical wavelet transform(EWT)method.Then,five benchmark models are utilized to forecast the sub-series of EWT decomposition.The ensemble weights of these five sub-forecasting models are calculated by particle swarm optimization and gravitational search algorithm(PSOGSA).Finally,a multi-factor ensemble model for DO is obtained by weighted allocation.The performance of the proposed model is verified by timeseries data collected by the pacific islands ocean observing system(PacIOOS)from the WQB04 station at Hilo.The evaluation indicators involved in the experiment include the Nash–Sutcliffe efficiency(NSE),Kling–Gupta efficiency(KGE),mean absolute percent error(MAPE),standard deviation of error(SDE),and coefficient of determination(R^(2)).Example analysis demonstrates that:①The proposed model can obtain excellent DO forecasting results;②the proposed model is superior to other comparison models;and③the forecasting model can be used to analyze the trend of DO and enable managers to make better management decisions. 展开更多
关键词 Dissolved oxygen concentrations forecasting Time-series multi-step forecasting multi-factor analysis Empirical wavelet transform decomposition Multi-model optimization ensemble
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Multi-factor sensitivity analysis of shallow unsaturated clay slope stability 被引量:1
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作者 ZhuoyingTan MeifengCai 《Journal of University of Science and Technology Beijing》 CSCD 2005年第3期193-202,共10页
An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was... An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified. 展开更多
关键词 unsaturated clay slope stability multi-factor sensitivity analysis
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Detrended cross-correlation analysis of electroencephalogram 被引量:5
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作者 Wang Jun Zhao Da-Qing 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期577-580,共4页
In the paper we use detrended cross-correlation analysis (DCCA) to study the electroencephalograms of healthy young subjects and healthy old subjects. It is found that the cross-correlation between different leads o... In the paper we use detrended cross-correlation analysis (DCCA) to study the electroencephalograms of healthy young subjects and healthy old subjects. It is found that the cross-correlation between different leads of a healthy young subject is larger than that of a healthy old subject. It was shown that the cross-correlation relationship decreases with the aging process and the phenomenon can help to diagnose whether the subject's brain function is healthy or not. 展开更多
关键词 detrended cross-correlation analysis ELECTROENCEPHALOGRAM brain function aging process
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Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus 被引量:1
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作者 Yang Liu Yi Liu +5 位作者 Ying-Nan Zhang Ai-Peng Li Jing Zhang Qing-Feng Liang Ying Jie Zhi-Qiang Pan 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第9期1419-1429,共11页
AIM:To compare the effectiveness and safety between modified cross-linking(MC)and standard cross-linking(SC)in mild or moderate progressive keratoconus.METHODS:Eligible studies were retrieved from four electroni... AIM:To compare the effectiveness and safety between modified cross-linking(MC)and standard cross-linking(SC)in mild or moderate progressive keratoconus.METHODS:Eligible studies were retrieved from four electronic databases,including CENTRAL,Clinical Trials gov,Pup Med and OVID MEDLINE.We set post-surgical maximum K value(Kmax)as the primary outcome.In addition,uncorrected and corrected distant visual acuity(UDVA and UDVA),spherical equivalent(SE),endothelial cell density(ECD),central cornea thickness(CCT)and depth of demarcation line(DDL)were Meta-analyzed as secondary outcomes.Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity.RESULTS:Twenty-four comparative studies either on accelerated cross-linking(AC)compared with SC or on transepithelial cross-linking(TC)compared with SC were included and pooled for analysis.The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration[AC vs SC 0.49(95%CI:0.04-0.94,I2=75%,P=0.03);TC vs SC 1.15(95%CI:0.54-1.75,I2=50%,P=0.0002)].SE decreased significantly for SC when compared to AC[0.62(95%CI:0.38-0.86,I2=22%,P〈0.00001)].DDL of SC was more significantly deeper than that of TC[-133.49(95%CI:-145.94 to-121.04,I2=33%,P〈0.00001)].Other outcomes demonstrated comparable results between MC and SC.CONCLUSION:SC is more favorable at halting the progression of keratoconus,but visual acuity improvement showed comparable results between MCs and SC. 展开更多
关键词 progressive keratoconus cross-linking standardcross-linking accelerated cross-linking trans-epithelial cross-linking META-analysis
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Analysis of Dynamic Cross Response between Spindles in a Dual Spindle Type Multi-Functional Turning Machine
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作者 Y. H. Choi S. T. Kim +1 位作者 T. Y. Seo K. H. Kim 《Journal of Power and Energy Engineering》 2013年第7期20-24,共5页
In order to meet increasing demand for higher productivity and flexibility, recently many kinds of multi-functional machine tools, which are capable of multiple machining functions or different kinds of machining proc... In order to meet increasing demand for higher productivity and flexibility, recently many kinds of multi-functional machine tools, which are capable of multiple machining functions or different kinds of machining processes on one machine, have been developed and widely used in manufacturing industries. In this study, a multi-functional turning lathe, which has two spindles and two turrets so that multiple turning operations and various machining processes could be performed simultaneously, has been developed. Furthermore, the equations of correlation between whole responses and cross responses of the two spindles have been derived to examine to what extent the two spindles affect each other’s vibrations. 展开更多
关键词 Multi-Functional LATHE Multi-Spindles Frequency RESPONSE cross RESPONSE FEM Structural analysis
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Rate of Patient Delay among Students with Pulmonary Tuberculosis in China: A Meta-Analysis
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作者 Jiaxin Du Dongxia Cai Yongfa Chen 《Journal of Biosciences and Medicines》 2023年第4期278-295,共18页
Objective: To systematically review the rate of patient delay of pulmonary tuberculosis (PTB) patients among students in China. Methods: Databases including Web of Science Core Collection, PubMed, The Cochrane Library... Objective: To systematically review the rate of patient delay of pulmonary tuberculosis (PTB) patients among students in China. Methods: Databases including Web of Science Core Collection, PubMed, The Cochrane Library, CBM, CNKI, VIP, and WANFANG DATA were electronically searched to collect cross-sectional studies on the incidence of delayed consultation in students with PTB in China from January 1, 2000, to November 15, 2022. Two researchers independently screened studies, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed by Stata 16.0 software. Results: In total, 60 cross-sectional studies with 260,707 cases involving 136,701 delayed consultation PTB patients were included. The results of meta-analysis showed that the rate of patient delay was 46.4% (95% CI 44.3% to 48.4%) among students with PTB in China. Results of subgroup analyses showed that: 1) The rates were 46.8% and 50.4% for male and female students, respectively. 2) The rates for the East, Central and West parts of China were 42.3%, 45.6% and 50.5%, respectively. 3) The rates were increased first and then decreased during 2007 to 2020. 4) The rates of students from primary school, junior high school, senior high school and university were 50.3%, 49.8%, 40.7% and 44.9%, respectively. 5) The rates for the Han and the other nationalities were 50.3% and 53.9%, respectively. 6) The rates for local and non-local students were 47.2% and 50.5%, respectively. 7) The rates of patients detected by consultation due to symptoms, recommendation due to symptoms, referral, tracking and healthy physical examination were 50.5%, 51.6%, 46.6%, 55.6% and 16.2%, respectively. 8) The rates of patients with initial PTB and retreatment PTB were 53.1% and 59.6%, respectively. 9) The rates of patients with positive etiology, negative etiology and without etiological results were 55.9%, 47.0% and 51.6%, respectively. 10) The rates of severe and non-severe patients were 59.4% and 52.9%, respectively. Conclusion: The patient delay rate for Chinese students with PTB is generally at a high level. There are substantial differences in the patient delay rate for students with PTB among different genders, regions, study stages, nationalities, household registration types, detection methods, and treatment classifications. 展开更多
关键词 China STUDENT Pulmonary Tuberculosis Patient Delay META-analysis cross-Sectional Study
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Physical analysis on improving the recovery accuracy of the Earth's gravity field by a combination of satellite observations in along-track and cross-track directions 被引量:4
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作者 郑伟 许厚泽 +1 位作者 钟敏 员美娟 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期633-640,共8页
The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this... The physical investigations on the accuracy improvement to the measurement of the Earth's gravity field recovery are carried out based on the next-generation Pendulum-A/B out-of-plane twin-satellite formation in this paper. Firstly, the Earth's gravity field complete up to degree and order 100 is, respectively, recovered by the collinear and pendulum satellite formations using the orbital parameters of the satellite and the matching accuracies of key payloads from the twin GRACE satellites. The research results show that the accuracy of the Earth's gravity field model from the Pendulum-A/B satellite formation is about two times higher than from the collinear satellite formation, and the further improvement of the determination accuracy of the Earth's gravity field model is feasible by the next-generation Pendulum-A/B out-of-plane twin-satellite formation. Secondly, the Earth's gravity field from Pendulum-A/B complete up to degree and order 100 is accurately recovered based on the orbital parameters of the satellite (e.g., an orbital altitude of 400 km, an intersatellite range of 100 km, an orbital inclination of 89° and an orbital eccentricity of 0.001), the matching accuracies of space- borne instruments (e.g. 10-6 m in the intersatellite range, 10-3 m in the orbital position, 10-6 m/s in orbital velocity, and 10-11 m/s2 in non-conservative force), an observation time of 30 days and a sampling interval of 10 s. The measurement accuracy of the Earth's gravity field from the next-generation Pendulum-A/B out-of-plane twin-satellite formation is full of promise for being improved by about l0 times compared with that from the current GRACE satellite formation. Finally, the physical requirements for the next-generation Pendulum-A/B out-of-plane twin-satellite formation are analyzed, and it is proposed that the satellite orbital altitude be preferably designed to be close to 400±50 km and the matching precision of key sensors from the Pendulum-A/B mission be about one order of magnitude higher than from the GRACE program. 展开更多
关键词 twin pendulum-MB satellites collinear and pendulum satellite formations along-cross-track ob-servations physical analysis satellite gravity recovery
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Modeling and analysis of piezoelectric beam with periodically variable cross-sections for vibration energy harvesting 被引量:7
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作者 M.HAJHOSSEINI M.RAFEEYAN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第8期1053-1066,共14页
A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigate... A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule (GDQR) method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight. 展开更多
关键词 vibration energy harvesting piezoelectric cantilever beam periodically variable cross-section vibration band gap forced vibration analysis generalized differential quadrature rule (GDQR)
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Correlation between X-ray cross-complementing group 1 polymorphisms and the onset risk of glioma A meta-analysis 被引量:1
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作者 Xinquan Gu Hongyan Sun +4 位作者 Liping Chang Ran Sun Hongfeng Yang Xuewen Zhang Xianling Cong 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第26期2468-2477,共10页
OBJECTIVE: To evaluate the association of X-ray cross-complementing group 1 (XRCC1) Arg399GIn, Arg194Trp and Arg280His polymorphisms with the risk of glioma. DATA SOURCES: A systematic literature search of papers ... OBJECTIVE: To evaluate the association of X-ray cross-complementing group 1 (XRCC1) Arg399GIn, Arg194Trp and Arg280His polymorphisms with the risk of glioma. DATA SOURCES: A systematic literature search of papers published from January 2000 to August 2012 in PubMed, Embase, China National Knowledge Infrastructure database, and Wanfang da- tabase was performed. The key words used were "glioma", "polymorphism", and "XRCC1 or X-ray repair cross-complementing group 1". References cited in the retrieved articles were screened manually to identify additional eligible studies. STUDY SELECTION: Studies were identified according to the following inclusion criteria: case-control design was based on unrelated individuals; and genotype frequency was available to estimate an odds ratio (OR) and 95% confidence interval (CI). Meta-analysis was performed for the selected studies after strict screening. Dominant and recessive genetic models were used and the relationship between homozygous mutant genotype frequencies and mutant gene frequency and glioma incidence was investigated. We chose the fixed or random effect model according to the heterogeneity to calculate OR and 95%CI, and sensitivity analyses were conducted. Publication bias was examined using the inverted funnel plot and the Egger's test using Stata 12.0 software. MAIN OUTCOME MEASURES: Association of XRCC1 Arg399GIn, Arg194Trp, and Arg280His polymorphisms with the risk of glioma, and subgroup analyses were performed according to differ- ent ethnicities of the subjects.RESULTS: Twelve articles were included in the meta-analysis. Eleven of the articles were concerned with the Arg399GIn polymorphism and glioma onset risk. Significantly increased glioma risks were found only in the dominant model (Gin/Gin + GIn/Arg versus Arg/Arg: OR = 1.26, 95%CI= 1.03-1.54, P = 0.02). In the subgroup analysis by ethnicity, significantly increased risk was found in Asian subjects in the recessive (OR = 1.46, 95%CI= 1.04-2.45, P = 0.03) and dominant models (OR = 1.40, 95%CI= 1.10-1.78, P = 0.007), and homozygote contrast (OR = 1.69, 95%CI= 1.17-2.45, P = 0.005), but not in Caucasian sub- jects. For association of the Arg194Trp (eight studies) and Arg280His (four studies) polymorphisms with glioma risk, the meta-analysis did not reveal a significant effect in the allele contrast, the recessive genetic model, the dominant genetic model, or homozygote contrast. CONCLUSION: The XRCC1 Arg399GIn polymorphism may be a biomarker of glioma susceptibility, espe- cially in Asian populations. The Arg194Trp and Arg280His polymorphisms were not associated with overall glioma risk. 展开更多
关键词 neural regeneration META-analysis GLIOMA X-ray cross-complementing group 1 gene polymorphism meta-analysis susceptibility onset risk gene mutation grants-supported paper neuroregeneration
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Cross-correlation analysis of crude oil and new energy markets: A new perspective based on carbon emission market 被引量:1
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作者 FENG You-shuai LING Mei-jun 《Ecological Economy》 2019年第1期2-18,共17页
Taking the return series of the EU carbon allowance price, WTI crude oil price, the European renewable energy index and Shenzhen carbon emission price, Daqing crude oil price, the China securities new energy index as ... Taking the return series of the EU carbon allowance price, WTI crude oil price, the European renewable energy index and Shenzhen carbon emission price, Daqing crude oil price, the China securities new energy index as sample data, the multifractal detrend cross-correlation analysis method(MF-DCCA)is used to research the dynamic cross-correlation relationships among the carbon emission market, crude oil market and the new energy market in Europe and China and the source of the multifractality. The empirical analysis shows that the cross-correlations among the carbon emission market, crude oil market and new energy market in Europe and China have all significant multifractal characteristics. Moreover, the multifractal strength of cross-correlation between the carbon emission market and crude oil market is less than that between the carbon emission market and new energy market in Europe. The Chinese market is the opposite. In addition, the multifractal strength of cross-correlation between the crude oil market and new energy market in Europe is more than that between the crude oil market and new energy market in China. It is also found that the long-range correlation of the sequences themselves and the fat-tailed distribution in fluctuations are the common causes of the multifractality, and the fat-tailed in fluctuations distribution contributes more to the multifractals of the series. 展开更多
关键词 carbon emission market crude oil market new energy market cross-CORRELATION multifractal statistical analysis
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