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Variable Selection for Generalized Varying Coefficient Partially Linear Models with Diverging Number of Parameters

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Acta Mathematicae Applicatae Sinica 2012年第2期28卷 237-246页

作者： zheng-yan Lin Yu-ze Yuan Department of Mathematics Zhejiang University Hangzhou 310027 China

Semiparametric models with diverging number of predictors arise in many contemporary scientific areas. Variable selection for these models consists of two components： model selection for non-parametric components and selection of significant variables for the parametric portion. In this paper, we consider a variable selection procedure by combining basis function approximation with SCAD penalty. The proposed procedure simultaneously selects significant variables in the parametric components and the nonparametric components. With appropriate selection of tuning parameters, we establish the consistency and sparseness of this procedure.

关键词： generalized linear model varying coefficient high dimensionality SCAD basis function.

ENSO Frequency Asymmetry and the Pacific Decadal Oscillation in Observations and 19 CMIP5 Models

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Advances in Atmospheric Sciences 2018年第5期35卷 495-506页

作者： Renping LIN Fei zheng Xiao DONG International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of Sciences Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology

Using observational data and the pre-industrial simulations of 19 models from the Coupled Model Intercomparison Project Phase 5（CMIP5）, the El Ni o（EN） and La Ni a（LN） events in positive and negative Pacific Decadal Oscillation（PDO） phases are examined. In the observational data, with EN（LN） events the positive（negative） SST anomaly in the equatorial eastern Pacific is much stronger in positive（negative） PDO phases than in negative（positive） phases. Meanwhile,the models cannot reasonably reproduce this difference. Besides, the modulation of ENSO frequency asymmetry by the PDO is explored. Results show that, in the observational data, EN is 300% more（58% less） frequent than LN in positive（negative）PDO phases, which is significant at the 99% confidence level using the Monte Carlo test. Most of the CMIP5 models exhibit results that are consistent with the observational data.

关键词： ENSO frequency asymmetry Pacific Decadal Oscillation decadal variation Monte Carlo method CM1P5

Toxic effects of three perfluorinated or polyfluorinated compounds(PFCs)on two strains of freshwater algae:Implications for ecological risk assessments

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Journal of Environmental Sciences 2023年第9期131卷 48-58页

作者： Liangliang Zhang Xiaowei zheng Xianglin Liu Jue Li Yanyao Li Zeming Wang Nan zheng Xiangrong Wang zhengqiu Fan Department of Environmental Science and Engineering Fudan UniversityShanghai 200433China Laboratory of Industrial Water and Ecotechnology Department of Green Chemistry and TechnologyGhent UniversityKortrijk 8500Belgium jinan Environmental Research Academy Jinan 250102China

Perfluorinated or polyfluorinated compounds(PFCs)continue entering to the environmental as individuals or mixtures,but their toxicological information remains largely ***,we investigated the toxic effects and ecological risks of Perfluorooctane sulfonic acid(PFOS)and its substitutes on prokaryotes(Chlorella vulgaris)and eukaryotes(Microcystis aeruginosa).Based on the calculated EC50 values,the results showed that PFOS was significantly more toxic to both algae than its alternatives including Perfluorobutane sulfonic acid(PFBS)and 6:2 Fluoromodulated sulfonates(6:2 FTS),and the PFOS-PFBS mixture was more toxic to both algae than the other two PFC *** action mode of binary PFC mixtures on Chlorella vulgaris was mainly shown as antagonistic and on Microcystis aeruginosa as synergistic,by using Combination index(CI)model coupled with Monte Carlo *** mean risk quotient(RQ)value of three individual PFCs and their mixtures were all below the threshold of 10^(−1),but the risk of those binary mixtures were higher than that of PFCs individually because of their synergistic *** findings contribute to enhance the understanding of the toxicological information and ecological risks of emerging PFCs and provide a scientific basis for their pollution control.

关键词： Toxicity Combination index model Monte Carlo simulation Action mode Algae

Accelerating degradation rate of pure iron by zinc ion implantation

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Regenerative Biomaterials 2016年第4期3卷 205-215页

作者： Tao Huang Yufeng zheng Yong Han State Key Laboratory for Turbulence and Complex System and Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Mechanical Behavior of Materials Xian Jiaotong UniversityXian 710049China

Pure iron has been considered as a promising candidate for biodegradable implant ***,a faster degradation rate of pure iron is needed to meet the clinical *** this work,metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure *** showed that the implantation depth of zinc ions was about 60 *** degradation rate of pure iron was found to be accelerated after zinc ion *** cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested *** terms of hemocompatibility,the hemolysis of zinc ion implanted pure iron was lower than 2%.However,zinc ions might induce more adhered and activated platelets on the surface of pure ***,zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications.

关键词： biodegradable metals iron zinc ion implantation biocompatibility

PhIO-mediated Synthesis of Ketones from Aikynes and Alkenes

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Chemical Research in Chinese Universities 2019年第1期35卷 26-32页

作者： WEI Ying zheng Xiangping XIE Xinmiao Center for Molecular Systems and Organic Devices(CMSOD) Key Laboratory for Organic Electronics and Information Displays &Jiangsu Key Laboratory for BiosensorsInstitute of Advaneed Materials(LAM) Jiangsu National Synergetie Innovation Center for Advaneed Materials(SICAM) Nanjing University of Posts & TelecommunicationsNanjing 210023P.R.China

A facile and efficient method for the preparation of methyl ketones was developed in the reaction of alkynes and alkenes with PhIO-BF3·*** reaction features mild conditions,short time and metal-free *** possible mech... 详细信息

关键词： Alkyne Alkene Ketone Hydration reaction

Design and Implementation of Network Communication Interface Based on μCLinux

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维普期刊数据库

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Semiconductor Photonics and Technology 2008年第4期14卷 279-283页

作者： LV Jie WANG jin-hai zheng Yu College of Information and Communication Engineering Tianjin Polytechnic University Tianjin 300160 CHN

In order to meet the requirements of real-time and high efficient data transmission in data acquisition and industrial control fields,a scheme of network communication interface is presented. The design of hardware circuit and the realization of software program are mainly introduced. The result of the experiment shows that this embedded system has high reliability and stability. It can realize high-speed data transmission,and also can satisfy the requirements of network communication in the industrial control fields.

关键词： μCLinux LPC2292 DM9000 socket

Design of proton beam collimation system for HIAF-BRing

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Radiation Detection Technology and Methods 2022年第4期6卷 519-529页

作者： wen-Heng zheng Jian-Cheng Yang Peng Li Da-Yu Yin Guo-Dong Shen Jie Li Li-Ping Yao Fu-Dong Shi Wei-Ping Chai Li-Jun Mao Wu-yuan Li Geng Wang Bo Yang Cheng Luo wen-wen Ge Zhong-Shan Li Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Science Beijing 100049China

Background The Booster Ring is further designed to store and accelerate protons up to 2×1012 particles per pulse in the High-Intensity heavy-ion Accelerator Facility project,which was originally designed to accelerate high-intensity heavy ion *** and Methods To minimize the uncontrolled proton beam halo loss around the ring in operation,a two-stage collimation system is proposed to provide a well-shielded dump for localizing the proton beam halo *** and conclusion In this paper,the simulation is carried out to evaluate the collimation system which shows a 92.93%collimation efﬁ***,several factors that affect the collimation efﬁciency are taken into consideration,including the physical aperture,the offset and rotation errors of the collimators,the closed orbit distortion,as well as the Betatron tunes.

关键词： Proton beam Two-stage collimation system ORBIT Collimation efﬁciency

Regional Clustering and Synchronization of Provincial Business Fluctuations in China

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Chinese Geographical Science 2018年第4期28卷 571-583页

作者： SONG Tao zheng Tingguo XIA Kai Institute of Economics Xiamen University Department of Statistics School of Economics Xiamen University Wang Yanan Institute for Studies in Economics Xiamen University

In this article, we propose a novel, multilevel, dynamic factor model, to determine endogenously clustered regions for the investigation of regional clustering and synchronization of provincial business fluctuations in China. The parameter identification and model estimation was conducted using the Markov Chain Monte Carlo method. We then conducted an empirical study of the provincial business fluctuations in China(31 Chinese provinces are considered except Hong Kong, Macao, and Taiwan due to the data unavailability), which were sampled from January 2000 to December 2015. Our results indicated that these provinces could be clustered into four regions: leading, coincident, lagging, and overshooting. In comparison with traditional geographical divisions, this novel clustering into four regions enabled the regional business cycle synchronization to be more accurately captured. Within the four regional clusters it was possible to identify substantial heterogeneities among regional business cycle fluctuations, especially during the periods of the 2008 financial crisis and the ‘four-trillion economic stimulus plan'.

关键词： regional division business cycle synchronization multilevel dynamic factor model variance decomposition

Factors associated with gastrointestinal stromal tumor rupture and pathological risk:A single-center retrospective study

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World Journal of Radiology 2023年第12期15卷 350-358页

作者： Jia-zheng Liu Zhong-wen Jia Ling-Ling Sun Department of Radiology The Fourth Affiliated Hospital of China Medical UniversityShenyang 110033Liaoning ProvinceChina

BACKGROUND Gastrointestinal stromal tumor(GIST)is a rare gastrointestinal mesenchymal tumor with potential *** the tumor ruptures,regardless of tumor size and mitotic number,it can be identified into a high-risk *** is of great significance for the diagnosis,treatment,and prognosis of GIST if non-invasive examination can be performed before surgery to accurately assess the risk of *** To identify the factors associated with GIST rupture and pathological *** A cohort of 50 patients with GISTs,as confirmed by postoperative pathology,was selected from our *** and computed tomography data of the patients were *** regression analysis was used to evaluate factors associated with GIST rupture and pathological risk *** Pathological risk grade,tumor diameter,tumor morphology,internal necrosis,gas-liquid interface,and Ki-67 index exhibited significant associations with GIST rupture(P<0.05).Gender,tumor diameter,tumor rupture,and Ki-67 index were found to be correlated with pathological risk grade of GIST(P<0.05).Multifactorial logistic regression analysis revealed that male gender and tumor diameter≥10 cm were independent predictors of a high pathological risk grade of GIST[odds ratio(OR)=11.12,95%confidence interval(95%CI):1.81-68.52,P=0.01;OR=22.96,95%CI:2.19-240.93,P=0.01].Tumor diameter≥10 cm,irregular shape,internal necrosis,gas-liquid interface,and Ki-67 index≥10 were identified as independent predictors of a high risk of GIST rupture(OR=9.67,95%CI:2.15-43.56,P=0.01;OR=35.44,95%CI:4.01-313.38,P<0.01;OR=18.75,95%CI:3.40-103.34,P<0.01;OR=27.00,95%CI:3.10-235.02,P<0.01;OR=4.43,95%CI:1.10-17.92,P=0.04).CONCLUSION Tumor diameter,tumor morphology,internal necrosis,gas-liquid,and Ki-67 index are associated with GIST rupture,while gender and tumor diameter are linked to the pathological risk of *** findings contribute to our understanding of GIST and may inform non-invasive examination stra

关键词： Gastrointestinal stromal tumors Imaging findings Tumor rupture Pathological risk grades