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Calibration Curve Establishment and Fractionation Temperature Selection of Polyethylene for Preparative Temperature Rising Elution Fractionation

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Chinese Journal of Polymer Science 2015年第7期33卷 1000-1008页

作者： Yan-hu Xue Shu-qin Bo 姬相玲 State key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences

A series of copolymers of ethylene with 1-hexene synthesized using a metallocene catalyst are selected and mixed. The blend is fractionated via preparative temperature rising elution fractionation（P-TREF）. All fractions are characterized via high-temperature gel permeation chromatography（GPC）, 13 C nuclear magnetic resonance spectroscopy（13C-NMR）, and differential scanning calorimetry（DSC）. The changes in the DSC melting peak temperatures of the fractions from P-TREF as a function of elution temperature are almost linear, thereby providing a reference through which the elution temperature of TREF experiments could be selected. Moreover, the standard calibration curve（ethylene/1-hexene） of P-TREF is established, which relates to the degree of short-chain branching of the fractions. The standard calibration curve of P-TREF is beneficial to study on the complicated branching structure of polyethylene. A convenient method for selecting the fractionation temperature for TREF experiments is elaborated. The polyethylene sample is fractionated via successive self-nucleation and annealing（SSA） thermal fractionation. A multiple-melting endotherm is obtained through the final DSC heating scan for the sample after SSA thermal fractionation. A series of fractionation temperatures are then selected through the relationship between the DSC melting peak temperature and TREF elution temperature.

关键词： TREF Calibration curve Fractionation temperature SSA Polyethylene

A multi-source image fusion algorithm based on gradient regularized convolution sparse representation

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Journal of Systems Engineering and Electronics 2020年第3期31卷 447-459页

作者： WANG Jian qin Chunxia ZHANG Xiufei YANG ke REN Ping School of Electronics and Information Engineering Northwestern Polytechnical UniversityXi’an 710072China No.365 Institute Northwestern Polytechnical UniversityXi’an 710065China

Image fusion based on the sparse representation(SR)has become the primary research direction of the transform domain ***,the SR-based image fusion algorithm has the characteristics of high computational complexity and neglecting the local features of an image,resulting in limited image detail retention and a high registration misalignment *** order to overcome these shortcomings and the noise existing in the image of the fusion process,this paper proposes a new signal decomposition model,namely the multi-source image fusion algorithm of the gradient regularization convolution SR(CSR).The main innovation of this work is using the sparse optimization function to perform two-scale decomposition of the source image to obtain high-frequency components and low-frequency *** sparse coefficient is obtained by the gradient regularization CSR model,and the sparse coefficient is taken as the maximum value to get the optimal high frequency component of the fused *** best low frequency component is obtained by using the fusion strategy of the extreme or the average *** final fused image is obtained by adding two optimal *** results demonstrate that this method greatly improves the ability to maintain image details and reduces image registration sensitivity.

关键词： gradient regularization convolution sparse representation(CSR) image fusion

Hierarchical Optimization Method for Federated Learning with Feature Alignment and Decision Fusion

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Computers, Materials & Continua 2024年第10期81卷 1391-1407页

作者： ke Li Xiaofeng Wang hu Wang College of Computer Science and Engineering North Minzu UniversityYinchuan750021China The key Laboratory of Images&Graphics Intelligent Processing of State Ethnic Affairs Commission North Minzu UniversityYinchuan750021China

In the realm of data privacy protection,federated learning aims to collaboratively train a global ***,heterogeneous data between clients presents challenges,often resulting in slow convergence and inadequate accuracy of the global *** shared feature representations alongside customized classifiers for individual clients emerges as a promising personalized ***,previous research has frequently neglected the integration of global knowledge into local representation learning and the synergy between global and local classifiers,thereby limiting model *** tackle these issues,this study proposes a hierarchical optimization method for federated learning with feature alignment and the fusion of classification decisions(FedFCD).FedFCD regularizes the relationship between global and local feature representations to achieve alignment and incorporates decision information from the global classifier,facilitating the late fusion of decision outputs from both global and local ***,FedFCD employs a hierarchical optimization strategy to flexibly optimize model *** experiments on the Fashion-MNIST,CIFAR-10 and CIFAR-100 datasets,we demonstrate the effectiveness and superiority of *** instance,on the CIFAR-100 dataset,FedFCD exhibited a significant improvement in average test accuracy by 6.83%compared to four outstanding personalized federated learning ***,extended experiments confirm the robustness of FedFCD across various hyperparameter values.

关键词： Federated learning data heterogeneity feature alignment decision fusion hierarchical optimization

Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

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Current Medical Science 2023年第6期43卷 1221-1228页

作者： Zun-xiang ke Ge-zheng CHEN ke hu Shan ZHANG Peng ZHOU Dian-xi CHEN Yi-qing LI qin LI Chao YANG Department of Emergency Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Department of Vascular Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Objective This study aimed to investigate the safety and efficacy of endovascular aortic repair(EVAR)for the treatment of an abdominal aortic aneurysm(AAA)with a hostile neck anatomy(HNA).Methods From January 1,2015 to December 31,2019,a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this *** on the morphological characteristics of the proximal neck anatomy,the patients were divided into the HNA group and the friendly neck anatomy(FNA)*** patients were followed up for up to 4 *** The average follow-up time was 1056.1±535.5 *** I endoleak occurred in 4 patients in the HNA group,and 2 patients in the FNA *** death nor intraoperative switch to open repair occurred in either *** time of the operation was significantly longer in the HNA group(FNA ***,99.2±51.1 min vs.117.5±63.8 min,P=0.011).There were no significant differences in short-term clinical success rate(P=0.228)or midterm clinical success rate(P=0.889)between the two *** overall mortality rate was 10.4%,and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period(P=0.889).Conclusion EVAR was feasible and safe in patients with an AAA with a proximal *** early and midterm results were promising;however,further studies are needed to verify the long-term effectiveness of EVAR.

关键词： abdominal aortic aneurysm hostile aneurysm neck endovascular aortic repair endoleak prognosis

Gapless vortex bound states in superconducting topological semimetals

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National Science Review 2023年第2期10卷 139-145页

作者： Yi Zhang Shengshan qin Kun Jiang Jiangping hu Department of Physics Shanghai University Kavli Institute of Theoretical Sciences University of Chinese Academy of Sciences Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Collaborative Innovation Center of Quantum Matter

We find that the vortex bound states in superconducting topological semimetals are gapless owing to topological massless excitations in their normal *** demonstrate this univers al result in a variety of semimetals,including Dirac and Weyl semimetals,three-fold degenerate spin-1 fermions,spin-3/2Rarita-Schwinger-Weyl fermion semimetals and other exotic fermion *** formation of these gapless bound states is closely related to their Andreev specular refle ction and propagating Andreev modes in π-phase superconductor-normal metal-superconductor *** further demonstrate that these gapless states are topologically protected and can be derived from a topological pumping process.

关键词： superconductivity superconducting vortices topological semimetals Andreev reflection

Investigation of the structural, electronic and mechanical properties of CaO–SiO_(2) compound particles in steel based on density functional theory

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International Journal of Minerals,Metallurgy and Materials 2023年第4期30卷 744-755页

作者： Chao Gu Ziyu Lyu qin hu Yanping Bao State key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China

CaO–SiO_(2)compounds compromise one of the most common series of oxide particles in liquid steels, which could significantly affect the service performance of the steels as crack initiation sites. However, the structural, electronic, and mechanical properties of the compounds in CaO–SiO_(2)system are still not fully clarified due to the difficulties in the experiments. In this study, a thorough investigation of these properties of CaO–SiO_(2)compound particles in steels was conducted based on first-principles density functional theory. Corresponding phases were determined by thermodynamic calculation, including gamma dicalcium silicate(γ-C2S), alpha-prime(L) dicalcium silicate(αL′-C2S), alpha-prime(H) dicalcium silicate(αH′-C2S), alpha dicalcium silicate(α-C2S), rankinite(C3S2), hatrurite(C3S), wollastonite(CS), and pseudowollastonite(Ps-CS). The results showed that the calculated crystal structures of the eight phases agree well with the experimental results. All the eight phases are stable according to the calculated formation energies, and γ-C2S is the most stable. O atom contributes the most to the reactivity of these phases. The Young’s modulus of the eight phases is in the range of 100.63–132.04 GPa. Poisson’s ratio is in the range of0.249–0.281. This study provided further understanding concerning the CaO–SiO_(2)compound particles in steels and fulfilled the corresponding property database, paving the way for inclusion engineering and design in terms of fracture-resistant steels.

关键词： CaO–SiO_(2) density functional theory structural property electronic property mechanical property

Uncertain multicast under dynamic behaviors

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Frontiers of Computer Science 2020年第1期14卷 130-145页

作者： Yudong qin Deke GUO Zhiyao hu Bangbang REN Science and Technology on Information System Engineering Laboratory National University of Defense TechnologyChangsha 410073China

Multicast transfer can efficiently save the bandwidth consumption and reduce the load on the source node than a series of independent unicast ***,many applications employ the content replica strategy to improve the robustness and efficiency;hence each file and its replicas are usually distributed among multiple *** such scenarios,the traditional deterministic multicast develops into the Uncertain multicast,which has more flexibility in the source *** this paper,we focus on building and maintaining a minimal cost forest(MCF)for any uncertain multicast,whose group members(source nodes and destination nodes)may join or leave after constructing a *** formulate this dynamic minimal cost forest(DMCF)problem as a mixed integer programming *** then design three dedicated methods to approximate the optimal *** them,our a-MCF aims to efficiently construct an MCF for any given uncertain multicast,without dynamic behaviors of multicast group *** d-MCF method motivates to slightly update the existing MCF via local modifications once appearing a dynamic *** can achieve the balance between the minimal cost and the minimal modifications to the existing *** last r-MCF is a supplement method to the d-MCF method,since many rounds of local modifications maymake the resultant forest far away from the optimal ***,our r-MCF method monitors the accumulated degradation and triggers the rearrangement process to reconstruct an new MCF when *** comprehensive evaluation results demonstrate that our methods can well tackle the proposed DMCF problem.

关键词： uncertain multicast dynamic behaviors routing forest approximation algorithm Steiner tree

Simplifying the detection of optical distortions by machine learning

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Journal of Innovative Optical Health Sciences 2020年第3期3卷 61-69页

作者： Shuwen hu Lejia hu Biwei Zhang Wei Gong ke Si State key Laboratory of Modern Optical Instrumentation Department of Neurobiology of the First Affiliated Hospital Zhejiang University School of Medicine Hangzhou 310027 P.R.China College of Optical Science and Engineering Zhejiang University Hangzhou 310027 P.R.China Center for Neuroscience Department of Neurobiology NHC and CAMS key Laboratory of Medical Neurobiology Zhejiang University School of Medicine Hangzhou 310058 P.R.China

Adaptive optics has been widely used in biological science to recover high-resolution optical image deep into the tissue,where optical distortion detection with high speed and accuracy is strongly ***,we introduce convolutional neural networks,one of the most popular machine learning models,into Shack-Hartmann wavefront sensor(SHWS)to simplify optical distortion detection *** image segmentation or centroid positioning algorithm,the trained network could estimate up to 36th Zernike mode coefficients directly from a full SHWS image within 1.227ms on a personal computer,and achieves prediction accuracy up to 97.4%.The simulation results show that the average root mean squared error in phase residuals of our method is 75.64%lower than that with the modal-based SHWS *** the high detection accuracy and simplified detection processes,this work has the potential to be applied in wavefront sensor-based adaptive optics for in vivo deep tissue imaging.

关键词： Machine learning adaptive optics wavefront sensor

Nonlinear energy harvesting based on a modified snap-through mechanism

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Applied Mathematics and Mechanics(English Edition) 2019年第1期40卷 167-180页

作者： Zeqi LU ke LI hu DING Liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai key Laboratory of Mechanics in Energy Engineering Shanghai University Department of Mechanics College of Sciences Shanghai University

A modified snap-through mechanism is used in an electromagnetic energy harvester to improve its effectiveness. It mainly comprises three springs that are configured so that the potential energy of the system has two stable equilibrium points. In particular, the small vibration behavior of the harvester around one of the equilibriums is of interest. A multi-scale method(MSM) is used to analyze the frequency response curve. Two snap-through mechanisms are considered. One has both horizontal and vertical springs. The other has only horizontal springs. The frequency response curves of these two classes are compared under the same excitation and electric loading conditions. The latter exhibits more bending of the frequency response curve than the former one. The results are also validated by some numerical work. The averaged power subject to the Gaussian white noise is calculated numerically, and the results demonstrate that bi-stable energy harvesting with only horizontal springs can outperform the mechanism with both horizontal and vertical springs for the same distance between two equilibriums.

关键词： energy harvesting nonlinear stiffness snap-through random excitation