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Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu Qiang fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Strip method to construct a two-dimensional quasilattice witheight-fold symmetry

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Chinese Physics B 2024年第9期33卷 462-465页

作者： Weishen Huang Xiujun fu School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

Based on the substitution rule and symmetry, we propose a method to generate an octagonal quasilattice consisting ofsquare and rhombus tiles. Local configurations and Ammann lines are used to guide the growth of the tiles in a quasiperiodicorder. The structure obtained is a perfect eight-fold symmetric quasilattice, which is confirmed by the radial distributionfunction and the diffraction pattern.

关键词： quasicrystals eight-fold symmetry Ammann–Beenker tiling

基于Pro/E和MasterCAM的注射模CAD/CAM应用研究

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新技术新工艺 2010年第11期 22-23页

作者：付士军朱院院宝鸡文理学院陕西宝鸡721016

简要介绍了注射模的CAD/CAM设计思路,通过实例用Pro/E软件对塑件进行了注射模具设计,得到了模具成型零部件,并重点阐述了其设计流程,然后运用MasterCAM软件对该塑件的型芯进行了加工刀路设计,模拟其加工过程,生成了NC代码。将2者结合使... 详细信息

简要介绍了注射模的CAD/CAM设计思路,通过实例用Pro/E软件对塑件进行了注射模具设计,得到了模具成型零部件,并重点阐述了其设计流程,然后运用MasterCAM软件对该塑件的型芯进行了加工刀路设计,模拟其加工过程,生成了NC代码。将2者结合使用,可显著提高模具设计及数控加工的质量和效率。

关键词：注射模数控加工 Pro/E MasterCAM

A fuzzy Trust Management Mechanism with Dynamic Behavior Monitoring for Wireless Sensor Networks

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China Communications 2024年第5期21卷 177-189页

作者： fu Shiming Zhang Ping Shi Xuehong School of Artificial Intelligence Chongqing University of EducationChongqing 400065China School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information *** wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various *** encryption and authentication mechanisms cannot prevent attacks launched by internal malicious *** trust-based security mechanism is usually adopted to solve this problem in ***,the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor ***,how to efficiently collect behavioral evidences are rarely *** address these issues,in this paper,we present a trust management mechanism based on fuzzy logic and a cloud ***,a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate ***,the cloud model is introduced to estimate the trust values for sensor ***,a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety *** results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring.

关键词： behavior monitoring cloud fuzzy trust wireless sensor networks

A high-order target phase approach for the station-keeping of periodic orbits

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Astrodynamics 2024年第1期8卷 61-75页

作者： Xiaoyu fu Nicola Baresi Roberto Armellin Surrey Space Centre University of SurreyGuildfordGU27XHUK Te PūnahaĀtea-Auckland Space Institute University of AucklandAuckland1010New Zealand

A novel high-order target phase approach(TPhA)for the station-keeping of periodic orbits is proposed in this *** key elements of the TPhA method,the phase-angle Poincare map and high-order maneuver map,are constructed using differential algebra(DA)techniques to determine station-keeping epochs and calculate correction maneuvers.A stochastic optimization framework tailored for the TPhA-based station-keeping process is leveraged to search for fuel-optimal and error-robust TPhA ***-satellite orbits(QSOs)around Phobos are investigated to demonstrate the efficacy of TPhA in mutli-fidelity dynamical *** Carlo simulations demonstrated that the baseline QSO of JAXA’s Martian Moons eXploration(MMX)mission could be maintained with a monthly maneuver budget of approximately 1 m/s.

关键词： target phase approach(TPhA) station-keeping Poincarémap differential algebra(DA) quasi-satellite orbit(QSO)

Low-Complexity Reconstruction of Covariance Matrix in Hybrid Uniform Circular Array

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China Communications 2024年第3期21卷 66-74页

作者： fu Zihao Liu Yinsheng Duan Hongtao Information School Communication University of ChinaBeijing 100024China Beijing Institute of Electronic System Engineering Beijing 100854China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China Beijing Radio Monitoring Station of State Radio Monitoring Center(SRMC) Beijing 100037China

Spatial covariance matrix(SCM) is essential in many multi-antenna systems such as massive multiple-input multiple-output(MIMO). For multi-antenna systems operating at millimeter-wave bands, hybrid analog-digital structure has been widely adopted to reduce the cost of radio frequency *** this situation, signals received at the antennas are unavailable to the digital receiver, and as a consequence, traditional sample average approach cannot be used for SCM reconstruction in hybrid multi-antenna systems. To address this issue, beam sweeping algorithm(BSA) which can reconstruct the SCM effectively for a hybrid uniform linear array, has been proposed in our previous works. However, direct extension of BSA to a hybrid uniform circular array(UCA)will result in a huge computational burden. To this end, a low-complexity approach is proposed in this paper. By exploiting the symmetry features of SCM for the UCA, the number of unknowns can be reduced significantly and thus the complexity of reconstruction can be saved accordingly. furthermore, an insightful analysis is also presented in this paper, showing that the reduction of the number of unknowns can also improve the accuracy of the reconstructed SCM. Simulation results are also shown to demonstrate the proposed approach.

关键词： hybrid array millimeter-wave spatial covariance matrix uniform circular array

Oligodendrocytes in central nervous system diseases:the effect of cytokine regulation

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Neural Regeneration Research 2024年第10期19卷 2132-2143页

作者： Chengfu Zhang Mengsheng Qiu Hui fu Center for Cognition and Brain Disorders The Affiliated Hospital of Hangzhou Normal UniversityHangzhouZhejiang ProvinceChina Department of Psychiatry National Clinical Research Center for Mental Disordersand National Center for Mental DisordersThe Second Xiangya Hospital of Central South UniversityChangshaHunan ProvinceChina Institute of Life Sciences Key Laboratory of Organ Development and Regeneration of Zhejiang ProvinceCollege of Life and Environment SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Aging and Cancer Biology of Zhejiang Province School of Basic Medical SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina

Cytokines including tumor necrosis factor, interleukins, interferons, and chemokines are abundantly produced in various diseases. As pleiotropic factors, cytokines are involved in nearly every aspect of cellular functions such as migration, survival, proliferation, and differentiation. Oligodendrocytes are the myelin-forming cells in the central nervous system and play critical roles in the conduction of action potentials, supply of metabolic components for axons, and other functions. Emerging evidence suggests that both oligodendrocytes and oligodendrocyte precursor cells are vulnerable to cytokines released under pathological conditions. This review mainly summarizes the effects of cytokines on oligodendrocyte lineage cells in central nervous system diseases. A comprehensive understanding of the effects of cytokines on oligodendrocyte lineage cells contributes to our understanding of central nervous system diseases and offers insights into treatment strategies.

关键词： astrocyte central nervous system disease CXC chemokine cytokine interferonγ interleukin microglia oligodendrocyte oligodendrocyte precursor cell tumor necrosis factorα

Trace formula of the integro-differential operator on a quantum graph

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 311-318页

作者： WEI Li-xiao YANG Chuan-fu School of Mathematics and Statistics Nanjing University of Science and TechnologyNanjing 210094China.

In this paper we study the eigenvalue problem for integro-differential operators on a lasso *** trace formula of the operator is established by applying the residual technique in complex analysis.

关键词： integro-differential operators eigenvalue trace formula

Nanotechnology approaches towards biodeterioration-resistant wood:A review

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Journal of Bioresources and Bioproducts 2024年第1期9卷 3-26页

作者： Ayyoob Arpanaei Qiliang fu Tripti Singh Scion Private Bag 3020Rotorua 3046New Zealand Co-Innovation Center of Efficient Processing and Utilization of Forest Resources College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China

Wood can be a suitable alternative to energy-intensive materials in various ***-ertheless,its susceptibility to weathering and decay has significantly hindered the broad adop-tion of the most commercially significant wood *** current solutions do tackle certain challenges,they often come with disadvantages like high costs,environmental risks,and/or ***-based methods can be employed to mitigate these weaknesses and create durable,sustainable wood *** this review,we delve into cutting-edge advance-ments in the development of biodeterioration-resistant wood through innovative nanotechnol-ogy *** methods usually involve the application of nanomaterials,either pos-sessing biocidal properties or serving as carriers for *** systematically describe these approaches and compare them to conventional wood modification ***,this re-view provides a brief overview of the prevalent biodeteriorating organisms and their mechanisms of action,which notably impact the development and choice of a suitable strategy for wood mod-ification/*** the requirements of biodeteriorating organisms for growth and wood degradation,it is expected that the new nanotechnology-based approaches to enhance wood dura-bility may provide innovative broad-spectrum biocidal *** systems can simulta-neously induce alterations in the physicochemical properties of wood,thereby constraining the availability of the growth *** alterations can efficiently inhibit the biodeterio-ration process by decreasing water absorption,restricting access to the wood components,and reducing void spaces within the wood ***,this review highlights the new oppor-tunities,challenges,and perspectives of nanotechnology methods for biodeterioration-resistant wood,through which some techno-economic,environmental and safety aspects associated with these methods are addressed.

关键词： Wood durability Decay Wood modification Biodeterioration mechanisms Biocides Wood nanotechnology