Liyao Lyu, Zhen Zhang, Minxin Chen, Jingrun Chen,
In recent years, a significant amount of attention has been paid to solve partial differential equations (PDEs) by deep learning. For example, deep Galerkin method (DGM) uses the PDE residual in the least-squares sense as the loss function and a deep neural network (DNN) to approximate the PDE solution. In this work, we propose a deep mixed residual method (MIM) to solve PDEs with high-order derivatives. Notable examples include Poisson equation, Monge-Ampére equation, biharmonic equation, and Korteweg- ...
Tópico(s): Nuclear Engineering Thermal-Hydraulics
2022 - Elsevier BV | Journal of Computational Physics
Jialu Xu, Qingle Ma, Yue Zhang, Ziying Fei, Yifei Sun, Qin Fan, Бо Лю, Jinyu Bai, Yue Yu, Jianhong Chu, Jingrun Chen, Chao Wang,
Abstract Microbe-based cancer immunotherapy has recently emerged as a hot topic for cancer treatment. However, serious limitations remain including infection associated side-effect and unsatisfactory outcomes in clinic trials. Here, we fabricate different sizes of nano-formulations derived from yeast cell wall (YCW NPs) by differential centrifugation. The induction of anticancer immunity of our formulations appears to inversely correlate with their size due to the ability to accumulate in tumor-draining ...
Tópico(s): Immunotherapy and Immune Responses
2022 - Nature Portfolio | Nature Communications
Jingrun Chen, Cheng Wang, Changjian Xie,
The numerical approximation for the Landau-Lifshitz equation, which models the dynamics of the magnetization in a ferromagnetic material, is taken into consideration. This highly nonlinear equation, with a non-convex constraint, has several equivalent forms, and involves solving an auxiliary problem in the infinite domain. All these features have posed interesting challenges in developing numerical methods. In this paper, we first present a fully discrete semi-implicit method for solving the Landau- ...
Tópico(s): Advanced Numerical Methods in Computational Mathematics
2021 - Elsevier BV | Applied Numerical Mathematics
Liyao Lyu, Keke Wu, Rui Du Rui Du, Jingrun Chen,
In theory, boundary and initial conditions are important for the wellposedness of partial differential equations (PDEs). Numerically, these conditions can be enforced exactly in classical numerical methods, such as finite difference method and finite element method. Recent years have witnessed growing interests in solving PDEs by deep neural networks (DNNs), especially in the high-dimensional case. However, in the generic situation, a careful literature review shows that boundary conditions cannot ...
Tópico(s): Advanced Numerical Methods in Computational Mathematics
2021 - | CSIAM Transactions on Applied Mathematics
Panchi Li, Changjian Xie, Rui Du, Jingrun Chen, Xiaoping Wang,
In this paper, we present two improved Gauss-Seidel projection methods with unconditional stability. The first method updates the gyromagnetic term and the damping term simultaneously and follows by a projection step. The second method introduces two sets of approximate solutions, where we update the gyromagnetic term and the damping term simultaneously for one set of approximate solutions and apply the projection step to the other set of approximate solutions in an alternating manner. Compared ...
Tópico(s): Model Reduction and Neural Networks
2019 - Elsevier BV | Journal of Computational Physics
Changjian Xie, Carlos J. Garcı́a-Cervera, Cheng Wang, Zhennan Zhou, Jingrun Chen,
Micromagnetics simulations require accurate approximation of the magnetization dynamics described by the Landau-Lifshitz-Gilbert equation, which is nonlinear, nonlocal, and has a non-convex constraint, posing interesting challenges in developing numerical methods. In this paper, we propose two second-order semi-implicit projection methods based on the second-order backward differentiation formula and the second-order interpolation formula using the information at previous two temporal steps. Unconditional ...
Tópico(s): Advanced Numerical Methods in Computational Mathematics
2019 - Elsevier BV | Journal of Computational Physics
Dongxiao Cui, Chaoqun Yan, Junqiu Miao, Xiaoyan Zhang, Jingrun Chen, Liqian Sun, Liqiang Meng, Taigang Liang, Qingshan Li,
Selenium nanoparticles (Se NPs) attract a lot of attention as potential cancer therapeutic agents. However, the antitumor activities of pure Se NPs are poor, and some modifiers are needed to enhance the activities. In the present study, we prepared Ferulic Acid (FA)-modified selenium nanoparticles in a facile synthetic approach. The obtained FA-Se NPs were characterized using transmission electron microscope (TEM), dynamic light scattering (DLS), ultraviolet-visible spectrophotometer (UV-VIS), Fourier ...
Tópico(s): Cholinesterase and Neurodegenerative Diseases
2018 - Elsevier BV | Materials Science and Engineering C
Wenna Zhang, Jingrun Chen, Shutao Xu, Yueying Chu, Yingxu Wei, Yuchun Zhi, Jindou Huang, Anmin Zheng, Xinqiang Wu, Xiangju Meng, Feng‐Shou Xiao, Feng Deng, Zhongmin Liu,
Methanol to olefins (MTO) reaction over H-RUB-50 zeolite, an eight-membered ring (8-MR) and cavity-type zeolite, presents higher selectivity for ethene. The host–guest interaction was dissected and used to explain the cavity-controlled reaction route and product selectivity. By the aid of the in situ 13C MAS NMR spectroscopy, GC-MS, 12C/13C-methanol switch experiments, and theoretical calculations, the methylbenzenium cations, methylcyclopentenyl cations (triMB+, tetraMB+, and triMCP+), and their deprotonated ...
Tópico(s): Mesoporous Materials and Catalysis
2018 - American Chemical Society | ACS Catalysis
Mozhi Zhang, Shutao Xu, Yingxu Wei, Jinzhe Li, Jingrun Chen, Jinbang Wang, Wenna Zhang, Shushu Gao, Xiujie Li, Congxin Wang, Zhongmin Liu,
The different behaviors of retained organic species and their reaction routes in three 10-membered ring zeolites are presented.
Tópico(s): Catalytic Processes in Materials Science
2016 - Royal Society of Chemistry | RSC Advances
Jinbang Wang, Jinzhe Li, Shutao Xu, Yuchun Zhi, Yingxu Wei, Yanli He, Jingrun Chen, Mozhi Zhang, Quanyi Wang, Wenna Zhang, Xinqiang Wu, Xinwen Guo, Zhongmin Liu,
Tópico(s): Catalysis and Oxidation Reactions
2015 - Elsevier BV | CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION)
Jinbang Wang, Yingxu Wei, Jinzhe Li, Shutao Xu, Wenna Zhang, Yanli He, Jingrun Chen, Mozhi Zhang, Anmin Zheng, Feng Deng, Xinwen Guo, Zhongmin Liu,
An induction period and MCP + formed in the methanol conversion have been observed successfully for the first time, indicating that the hydrocarbon pool (HCP) mechanism cannot be ruled out over H-ZSM-22.
Tópico(s): Catalysis for Biomass Conversion
2015 - Royal Society of Chemistry | Catalysis Science & Technology
Jingrun Chen, Jinzhe Li, Cuiyu Yuan, Shutao Xu, Yingxu Wei, Quanyi Wang, You Zhou, Jinbang Wang, Mozhi Zhang, Yanli He, Shuliang Xu, Zhongmin Liu,
The mechanism of the methanol to olefin (MTO) reaction over AlPO-18 (without Brønsted acid sites) and two SAPO-18 (with different Brønsted acid site densities) catalysts has been investigated. The Brønsted acid site density of AlPO-18 and SAPO-18 catalysts was determined by 1H MAS NMR spectroscopy. Methanol conversion over the catalysts showed that the catalytic activity of the catalysts was strongly influenced by their Brønsted acid site density. Using 13C magic angle spinning (MAS) NMR, we directly ...
Tópico(s): Catalysis and Hydrodesulfurization Studies
2014 - Royal Society of Chemistry | Catalysis Science & Technology
Jinzhe Li, Yingxu Wei, Jingrun Chen, Shutao Xu, Peng Tian, Xiaofeng Yang, Bing Li, Jinbang Wang, Zhongmin Liu,
Organic reaction intermediates confined in zeolite cavities are very important for product formation during methanol-to-olefins (MTO) conversion; however, direct evidence is still required to understand the particular function of these intermediates. Herein, for the first time, by careful selection of SAPO molecular sieves with different cavity size but identical 8MR pore openings, the reactivity and role of these intermediates played in olefin generation are verified by isotopic tracing method and ...
Tópico(s): Catalysis and Oxidation Reactions
2014 - American Chemical Society | ACS Catalysis
Jason Lin, Oleksandr V. Mikhnenko, Jingrun Chen, Zarifi Masri, Arvydas Ruseckas, Alexander Mikhailovsky, Reilly P. Raab, Jianhua Liu, Paul W. M. Blom, Maria Antonietta Loi, Carlos J. Garcı́a-Cervera, Ifor D. W. Samuel, Thuc‐Quyen Nguyen,
Six techniques are used to measure the exciton diffusion length as a function of systematic chemical modifications.
Tópico(s): Organic Light-Emitting Diodes Research
2014 - Royal Society of Chemistry | Materials Horizons
Quanyi Wang, Shutao Xu, Jingrun Chen, Yingxu Wei, Jinzhe Li, Dong Fan, Zhengxi Yu, Qi Yue, Yanli He, Shuliang Xu, Cuiyu Yuan, You Zhou, Jinbang Wang, Mozhi Zhang, Bao‐Lian Su, Zhongmin Liu,
Different templates usage for mesoporous ZSM-5 synthesis and their catalytic properties were systematically investigated.
Tópico(s): Mesoporous Materials and Catalysis
2014 - Royal Society of Chemistry | RSC Advances
Michele Guide, Jason Lin, Christopher M. Proctor, Jingrun Chen, Carlos J. Garcı́a-Cervera, Thuc‐Quyen Nguyen,
The effects of copper metalation of tetrabenzoporphyrin on the properties and performance of organic solar cells are studied. Tetrabenzoporphyrin (BP) and copper tetrabenzoporphyrin (CuBP) are both solution processed from soluble precursor materials and thermally converted in the thin film. Despite high field-effect hole mobility above 1 cm2 V−1 s−1, the power conversion efficiency (PCE) of solar cell devices with CuBP is severely diminished compared to those with BP. Conducting atomic force microscopy ( ...
Tópico(s): Perovskite Materials and Applications
2014 - Royal Society of Chemistry | Journal of Materials Chemistry A
Guoju Yang, Yingxu Wei, Shutao Xu, Jingrun Chen, Jinzhe Li, Zhongmin Liu, Jihong Yu, Ruren Xu,
In this work, we systematically investigated the size effect of silicoaluminophosphate molecular sieve catalysts SAPO-34 on the catalytic performance of methanol-to-olefin (MTO) reactions. Four highly crystalline SAPO-34 molecular sieves with different crystallite sizes were synthesized under hydrothermal conditions carried out in conventional or microwave ovens with the same starting gel composition using TEAOH as the structure-directing agent. The as-prepared SAPO-34s have similar composition, ...
Tópico(s): Chemical Synthesis and Characterization
2013 - American Chemical Society | The Journal of Physical Chemistry C
Shutao Xu, Anmin Zheng, Yingxu Wei, Jingrun Chen, Jinzhe Li, Yueying Chu, Mozhi Zhang, Quanyi Wang, You Zhou, Jinbang Wang, Feng Deng, Zhongmin Liu,
Carbenium ions in zeolites: Two important carbenium ions have been observed for the first time under working conditions of the methanol-to-olefins (MTO) reaction over chabazite zeolites using 13C NMR spectroscopy. Their crucial roles in the MTO reaction cycles have been demonstrated by combining experiments and theoretical calculations. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized ...
Tópico(s): Chemical Synthesis and Characterization
2013 - Wiley | Angewandte Chemie International Edition
Jingrun Chen, Jinzhe Li, Yingxu Wei, Cuiyu Yuan, Bing Li, Shutao Xu, You Zhou, Jinbang Wang, Mozhi Zhang, Zhongmin Liu,
Three kinds of 8-membered ring silicoaluminophosphate (SAPO) molecular sieves with different cage structures, SAPO-34, SAPO-18 and SAPO-35, were employed in methanol-to-olefin (MTO) reaction. The main products over SAPO-34 and SAPO-18 were propene and butenes, whereas ethene and propene especially ethene were predominantly generated over SAPO-35. Coke species formation greatly depended on reaction temperature and varied systematically with cage size. The differences in production distribution and ...
Tópico(s): Catalysis and Oxidation Reactions
2013 - Elsevier BV | Catalysis Communications
Shutao Xu, Anmin Zheng, Yingxu Wei, Jingrun Chen, Jinzhe Li, Yueying Chu, Mozhi Zhang, Quanyi Wang, You Zhou, Jinbang Wang, Feng Deng, Zhongmin Liu,
Carbeniumionen in Zeolithen: Mit 13C-NMR-Spektroskopie wurden erstmals zwei wichtige Carbeniumionen unter Bedingungen der Methanol-zu-Olefin(MTO)-Reaktion über Chabazit-Zeolithen beobachtet. Die entscheidenden Rollen dieser Ionen im MTO-Zyklus wurden mithilfe kombinierter experimenteller und theoretischer Studien aufgezeigt. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online ...
Tópico(s): Metal-Organic Frameworks: Synthesis and Applications
2013 - Wiley | Angewandte Chemie
Bing Li, Peng Tian, Jinzhe Li, Jingrun Chen, Yangyang Yuan, Xiong Su, Dong Fan, Yingxu Wei, Qi Yue, Zhongmin Liu,
SAPO-35 molecular sieve samples with different Si contents were hydrothermally synthesized using hexamethyleneimine as the template and characterized by XRD, XRF, SEM, MAS NMR, XPS and N 2 physisorption. Three SAPO-35 samples were tested as methanol-to-olefins catalysts. After the reaction, the evolution of coke species was investigated over SAPO-35 and SAPO-34 catalysts with similar Si concentrations. A correlation between the cage size of the molecular sieves and the coke species was obtained. ...
Tópico(s): Catalysis and Oxidation Reactions
2013 - Elsevier BV | CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION)
Yingxu Wei, Cuiyu Yuan, Jinzhe Li, Shutao Xu, You Zhou, Jingrun Chen, Quanyi Wang, Lei Xu, Qi Yue, Qing Zhang, Zhongmin Liu,
Abstract The methanol‐to‐olefins (MTO) process is becoming the most important non‐petrochemical route for the production of light olefins from coal or natural gas. Maximizing the generation of the target products, ethene and propene, and minimizing the production of byproducts and coke, are major considerations in the efficient utilization of the carbon resource of methanol. In the present work, the heterogeneous catalytic conversion of methanol was evaluated by performing simultaneous measurements ...
Tópico(s): Catalytic Processes in Materials Science
2012 - Wiley | ChemSusChem
Yingxu Wei, Jinzhe Li, Cuiyu Yuan, Shutao Xu, You Zhou, Jingrun Chen, Quanyi Wang, Qing Zhang, Zhongmin Liu,
Formation of adamantane hydrocarbons and their confinement in SAPO-34 caused the long induction period and the quick catalyst deactivation in methanol conversion. Via ship-in-a-bottle synthesis, adamantane and methyladamantanes could be produced from methanol conversion in the cage of 8-ring SAPO catalysts under very mild reaction conditions.
Tópico(s): Catalytic Processes in Materials Science
2012 - Royal Society of Chemistry | Chemical Communications
Abstract We propose a multigrid method to solve the molecular mechanics model (molecular dynamics at zero temperature). The Cauchy-Born elasticity model is employed as the coarse grid operator and the elastically deformed state as the initial guess of the molecular mechanics model. The efficiency of the algorithm is demonstrated by three examples with homogeneous deformation, namely, one dimensional chain under tensile deformation and aluminum under tension and shear deformations. The method exhibits ...
Tópico(s): Elasticity and Material Modeling
2011 - Cambridge University Press | Communications in Computational Physics
Jinzhe Li, Yingxu Wei, Jingrun Chen, Peng Tian, Xiong Su, Shutao Xu, Qi Yue, Quanyi Wang, You Zhou, Yanli He, Zhongmin Liu,
The heptamethylbenzenium cation (heptaMB(+)) has been speculated to be one of the most important active intermediates involved in the "hydrocarbon pool" mechanism of methanol-to-olefin (MTO) conversion. By the use of DNL-6, a newly synthesized SAPO-type molecular sieve with large cavities, heptaMB(+) has for the first time been directly observed during methanol conversion under real working conditions. (13)C-labeling experiments suggested that olefin formation mediated by heptaMB(+) mainly follows the ...
Tópico(s): Mesoporous Materials and Catalysis
2011 - American Chemical Society | Journal of the American Chemical Society
Jinzhe Li, Yingxu Wei, Shutao Xu, Peng Tian, Jingrun Chen, Zhongmin Liu,
Methanol conversion over sapo molecular sieve dnl-6 was investigated from the view point of the reaction mechanism. the organic materials confined in the cavities of dnl-6 were mostly polymethylbenezenes. by combination of in situ nmr study with ex situ gc-ms measurements, the structure of heptamethylbenzenium ion (heptamb(+)) formed during mto reaction was definitely confirmed. further evidences from the mass spectra and c-13 solid-state nmr spectra in the isotopic switch experiments showed that ...
Tópico(s): Mesoporous Materials and Catalysis
2013 - Elsevier BV | Catalysis Today
We study the accuracy of the divide-and-conquer method for electronic structure calculations. The analysis is conducted for a prototypical subdomain problem in the method. We prove that the pointwise difference between electron densities of the global system and the subsystem decays exponentially as a function of the distance away from the boundary of the subsystem, under the gap assumption of both the global system and the subsystem. We show that the gap assumption is crucial for the accuracy of ...
Tópico(s): Advanced Chemical Physics Studies
2015 - American Mathematical Society | Mathematics of Computation
Jingrun Chen, Shi Jin, Liyao Lyu,
Objective functions in large-scale machine-learning and artificial intelligence applications often live in high dimensions with strong non-convexity and massive local minima. First-order methods, such as the stochastic gradient method and Adam, are often used to find global minima. Recently, the consensus-based optimization (CBO) method has been introduced as one of the gradient-free optimization methods and its convergence is proven with dimension-dependent parameters, which may suffer from the ...
Tópico(s): Advanced Optimization Algorithms Research
2022 - Cambridge University Press | Communications in Computational Physics
Zhiwen Wang, Minxin Chen, Jingrun Chen,
Machine learning has been successfully applied to various fields of scientific computing in recent years. In this work, we propose a sparse radial basis function neural network method to solve elliptic partial differential equations (PDEs) with multiscale coefficients. Inspired by the deep mixed residual method, we rewrite the second-order problem into a first-order system and employ multiple radial basis function neural networks (RBFNNs) to approximate unknown functions in the system. To aviod the ...
Tópico(s): Composite Material Mechanics
2023 - Elsevier BV | Journal of Computational Physics
Jingrun Chen, Panchi Li, Rui Du Rui Du, Liyao Lyu, Panchi Li, Liyao Lyu,
Tópico(s): Probabilistic and Robust Engineering Design
2021 - Cambridge University Press | Numerical Mathematics Theory Methods and Applications