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Optimizing mechanical properties of HIPS fabricated with low-cost desktop 3D printers:investigating the impact of process parameters

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Advances in manufacturing 2024年第2期12卷 379-395页

作者： Jin-Ting Xu Guang-Wei Zhang man-man chen School of Automotive Engineering Dalian University of TechnologyDalian116024People’s Republic of China

Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread ***,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D *** this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were *** experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed *** prediction models of the process parameters were regressed to produce the optimal combination of process *** experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile *** an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer *** addition,they all increased with an increase of infill *** was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were *** results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.

关键词： Desktop three-dimensional(3D)printers Fused deposition modeling(FDM) High-impact polystyrene(HIPS) Process parameters

A Wiener-Hopf factorization related potential measure for spectrally negative Lévy process

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Frontiers of Mathematics in China 2021年第2期16卷 325-343页

作者： man chen Xianyuan WU Xiaowen ZHOU School of Mathematical Sciences Capital Normal UniversityBeijing 100048China Department of Mathematics and Statistics Concordia UniversityMontrealQC H3G 1M8Canada

For spectrally negative Lévy process (SNLP), we find an expression, in terms of scale functions, for a potential measure involving the maximum and the last time of reaching the maximum up to a draw-down time. As applications, we obtain a potential measure for the reflected SNLP and recover a joint Laplace transform for the Wiener-Hopf factorization for SNLP.

关键词： Spectrally negative Lévy process(SNLP) potential measure draw-down time excursion theory scale function Wiener-Hopf factorization

Construction and evaluation of in-house methylation-sensitive SNaPshot system and three classification prediction models for identifying the tissue origin of body fluid

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2023年第9期24卷 839-852页

作者： Yating FANG man chen Bofeng ZHU Guangzhou Key Laboratory of Forensic Multi-Omics for Precision Identification School of Forensic MedicineSouthern Medical UniversityGuangzhou510515China School of Basic Medical Sciences Anhui Medical UniversityHefei230031China Microbiome Medicine Center Department of Laboratory MedicineZhujiang HospitalSouthern Medical UniversityGuangzhou510515China

The identification of tissue origin of body fluid can provide clues and evidence for criminal case *** establish an efficient method for identifying body fluid in forensic cases,eight novel body fluid-specific DNA methylation markers were selected in this study,and a multiplex single base extension reaction(SNaPshot)system for these markers was constructed for the identification of five common body fluids(venous blood,saliva,menstrual blood,vaginal fluid,and semen).The results indicated that the in-house system showed good species specificity,sensitivity,and ability to identify mixed biological *** the same time,an artificial body fluid prediction model and two machine learning prediction models based on the support vector machine(SVM)and random forest(RF)algorithms were constructed using previous research data,and these models were validated using the detection data obtained in this study(n=95).The accuracy of the prediction model based on experience was 95.79%;the prediction accuracy of the SVM prediction model was 100.00%for four kinds of body fluids except saliva(96.84%);and the prediction accuracy of the RF prediction model was 100.00%for all five kinds of body *** conclusion,the in-house SNaPshot system and RF prediction model could achieve accurate tissue origin identification of body fluids.

关键词： DNA methylation Body fluid Forensic identification Single base extension reaction(SNaPshot) Machine learning

Multiple-Stimuli Responsive and Tunable Luminescent Suprarnolecular Assembly by Oligo（p-phenylvinylene） and Surfactant

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Chinese Journal of Chemistry 2018年第6期36卷 526-530页

作者： Xu-man chen Yong chen Yu Liu College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Nankai University Tianjin 300071 China

Achieving multicolor photoluminescence under multiple stimuli response based on a single fluorescent compound remains a great challenge. Herein, we report a novel multicolor fluorescent supramolecular assembly, which was constructed from surfactant sodium dodecyl sulfate （SLS） and fluorescent compound 1 bearing a rigid symmetrical acceptor-donor-acceptor structure. The luminescence property of 1/SLS assembly showed the multiple stimuli response towards temperature, cyclodextrin complexation and UV light irradiation, exhibiting the tunable emission wavelengths from 490 nm to 590 nm and the multicolor photoluminescence including cyan, green, yellow and orange. Furthermore, this assembly could be used in light writing owing to the fast fluorescence change within 15 s. These results could provide a convenient and useful method for fabricating smart tunable photoluminescent materials.

关键词： tunable photoluminescence supramolecular assembly multiple stimuli response oligo(p-phenylvinylene) surfactant

Superior de/hydrogenation performances of MgH2 catalyzed by 3D flower-like TiO2@C nanostructures

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Journal of Energy Chemistry 2020年第7期29卷 191-198,I0006页

作者： Meng Zhang Xuezhang Xiao Bosang Luo Meijia Liu man chen Lixin chen State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027ZhejiangChina Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province Hangzhou 310013ZhejiangChina Guangdong Provincial Key Laboratory of Advance Energy Storage Materials South China University of TechnologyGuangzhou 510640GuangdongChina

Magnesium hydride has been seen as a potential material for solid state hydrogen storage,but the kinetics and thermodynamics obstacles have hindered its development and ***-dimensional flower-like TiO2@C and TiO2 were synthesized as the catalyst for MgH2 system and great catalytic activities are acquired in the hydrogen sorption *** also show that the flower-like TiO2@C is superior to flower-like TiO2 in improving the hydrogen storage properties of *** hydrogen desorption onset and peak temperatures of flower-like TiO2 doped MgH2 is reduced to 199.2℃and 245.4℃,while the primitive MgH2 starts to release hydrogen at 294.6℃and the rapid dehydrogenation temperature is even as high as 362.6℃.The onset and peak temperatures of flower-like TiO2@C doped MgH2 are further reduced to 180.3℃and 233.0℃.The flower-like TiO2@C doped MgH2 composite can release6.0 wt%hydrogen at 250℃within 7 min,and 4.86 wt%hydrogen at 225℃within 60 min,while flowerlike TiO2 doped MgH2 can release 6.0 wt%hydrogen at 250℃within 8 min,and 3.89 wt%hydrogen at225℃within 60 *** absorption kinetics is also improved ***,compared with primitive MgH2 and the flower-like TiO2 doped MgH2,the activation energy of flower-like TiO2@C doped MgH2 is significantly decreased to 67.10 kJ/*** the improvement of hydrogen sorption properties can be ascribed to the flower-like structure and the two-phase coexistence of TiO2 and amorphous *** phase composition and unique structure are proved to be the critical factor to improve the hydrogen sorption properties of MgH2,which can be considered as the new prospect for improving the kinetics of light-metal hydrogen storage materials.

关键词： Hydrogen storage Magnesium hydride TiO2 Flower-like structure Catalytic effects

The evolution of cooperation in public good game with deposit

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Chinese Physics B 2019年第8期28卷 22-30页

作者： Xian-Jia Wang Wen-man chen Economics and management School Wuhan UniversityWuhan 430070China Institute of System and Engineer Wuhan UniversityWuhan 430070China

The emergence of cooperation still remains a fundamental conundrum in the social and behavior *** introduce a new mechanism,deposit mechanism,into theoretical model to explore how this mechanism promotes cooperation in a well-mixed ***,we extend the common binary-strategy combination of cooperation and defection in public good game by adding a third strategy,namely,deposit *** players with deposit cooperation strategy pay a deposit in advance to obtain the benefits of public good at a lower contributions compared with the players with cooperation strategy,when the provision of public good is ***,we explore the evolution of cooperation in the public good game with deposit by means of the replicator *** computations and stimulations show that the deposit mechanism can promote cooperation in a well-mixed population,and the numbers of equilibrium point are determined by variables of public good *** the one hand,when the coexistence of cooperators and defectors is the stable equilibrium point in the evolutionary system,increasing the threshold of public good and adopting the weak altruism way for share benefits can enhance the level of cooperation in the *** the other hand,if the coexistence of deposit cooperators and defectors is the stable equilibrium point,it is effective to promote the deposit cooperation by lowering the values of discount and deposit,and raising the threshold of public good.

关键词： evolutionary game theory cooperation deposit weak altruism discount rate

On Ramanujan Sums over a Dedekind Domain with Finite Norm Property

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Acta Mathematica Sinica,English Series 2023年第1期39卷 149-160页

作者： Zhi Yong ZHENG man chen Zi Wei HONG School of Mathematics Renmin University of ChinaBeijing 100872P.R.China School of Mathematical Sciences Beihang UniversityBeijing 100191P.R.China

In this paper,we consider Ramanujan’s sums over arbitrary Dedekind domain with finite norm *** define the Ramanujan’s sumsη(a,A)andη(B,A),where a is an arbitrary element in a Dedekind domain,B is an ideal and A is a non-zero *** particular,we discuss the Kluyver formula and Hèolder formula forη(a,A)andη(B,A).We also prove the reciprocity formula enjoyed byη(B,A)and the orthogonality relations forη(a,A)in the last two parts.

关键词： Dedekind domains Ramanujan Sums primitive additive character reciprocity formula orthogonality property

Synthesis and Crystal Structure of a Novel manganese Coordination Polymer Constructed by 3,5-Dimethylbenzoic Acid with 4,4'-Bipyridine

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1213-1216页

作者： ZHANG Chun-Hua chen man-Sheng KUANG Dai-Zhi Department of Chemistry and Materials Science Hengyang Normal University Hengyang 421008 China

A novel manganese coordination polymer [Mn（L）2（bipy）]n （HL = 3,5-dimethylbenzoic acid, 4,4＇-bipy = 4,4＇-bipyridine） has been synthesized by a hydrothermal method. The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 2.0996（8）, b = 1,1835（5）, c = 0.9958（4） nm, β = 110.161（5）°, V = 2,3229（16） nm^3, Z = 4, C28H26MnN2O4, Mr = 509.45, Dc= 1.457 g/cm^3,μ = 0.607 mm^-1, F（000） = 1060, Rim = 0.0566, R = 0.0334 and wR = 0.1078. In the crystal the manganese atom is six-coordinated by two nitrogen atoms from 4,4＇-bipy and four oxygen atoms from 3,5-dimethylbenzolate molecules, completing an octahedral geometry. The 4,4＇-bipy molecules bridge the infinite chain [Mn（L）2（bipy）]n to form a two-dimensional layer.

关键词： manganese coordination polymer hydrothermal synthesis crystal structure

Cyclodextrin/polyethylenimine-based supramolecular nanoparticles for loading and sustained release of ATP

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Chinese Chemical Letters 2018年第6期29卷 989-991页

作者： Lu Liang Yong chen Xu-man chen Yi Zhang Yu Liu College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai University Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Nankai University

A supramolecular nanoparticle that realized the loading and sustained release of ATP was successfully constructed from sulfato-b-cyclodextrin（SCD） and polyethylenimine（PEI）. The assembly and disassembly behaviors of supramolecular nanoparticle were investigated by means of Tyndall effect,UV–vis spectroscopy, dynamic light scattering（DLS）, zeta potential and transmission electron microscopy（TEM）. Significantly, the resulting nanoparticle was disrupted with the increasing of p H and recovered to the spherical nanoparticle as the p H decreased to initial value. Owing to the positive zeta potential, the supramolecular nanoparticle showed the good loading and sustained release abilities towards ATP.

关键词： Sulfato-b-cyclodextrin Polyethylenimine ATP pH-responsive Sustained release