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Nonlinear constitutive models of rock structural plane and their applications

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 790-806页

作者： wenlin feng Shuangjian Niu Chunsheng Qiao Dujian Zou School of Civil and Environmental Engineering Harbin Institute of TechnologyShenzhenChina Shenzhen Municipal Engineering Corporation Shenzhen518000China School of Civil Engineering Beijing Jiaotong UniversityBeijing100044China

Structural planes play an important role in controlling the stability of rock engineering,and the influence of structural planes should be considered in the design and construction process of rock *** this paper,mechanical properties,constitutive theory,and numerical application of structural plane are studied by a combination method of laboratory tests,theoretical derivation,and program *** test results reveal the change laws of various mechanical parameters under different roughness and normal *** the pre-peak stage,a non-stationary model of shear stiffness is established,and threedimensional empirical prediction models for initial shear stiffness and residual stage roughness are *** nonlinear constitutive models are established based on elasto-plastic mechanics,and the algorithms of the models are developed based on the return mapping *** to a large number of statistical analysis results,empirical prediction models are proposed for model parameters expressed by structural plane characteristic ***,the discrete element method(DEM)is chosen to embed the constitutive models for practical *** running programs of the constitutive models have been compiled into the discrete element model *** comparison results between the proposed model and the Mohr-Coulomb slip model show that the proposed model can better describe nonlinear changes at different stages,and the predicted shear strength,peak strain and shear stiffness are closer to the test *** research results of the paper are conducive to the accurate evaluation of structural plane in rock engineering.

关键词： Structural plane Engineering stability Roughness Normal stress Elasto-plastic constitutive model Discrete element method

Electrocatalytic oxygen evolution activities of metal chalcogenides and phosphides:Fundamentals,origins,and future strategies

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Journal of Energy Chemistry 2023年第6期81卷 167-191,I0006页

作者： Xiaolin Hu Ronghua Wang wenlin feng Chaohe Xu Zidong Wei School of Science Chongqing University of TechnologyChongqing 400054China College of Aerospace Engineering Chongqing UniversityChongqing 400044China School of Chemistry and Engineering Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The development of inexpensive and efficient electrocatalysts is key to commercializing energy-related electrocatalytic techniques such as water electrolyzers and metal-air *** particular,novel oxygen evolution reaction(OER)pre-catalysts,such as transition metal chalcogenides(TMCs)and phosphides(TMPs),have evolved in recent years from traditional stable OER electrocatalysts,which show superior OER electrocatalytic performance compared with transition metal oxides(TMOs)or(oxy)hydroxides(TMOHs).In this feature article,we summarize recent advances in the development of TMCand TMP-based OER electrocatalysts,as well as approaches to improve the OER performance in terms of morphology,structure,composition,surface engineering,lattice-strained and in-situ transformation in the electrolysis *** particular,the electrochemical stability of TMCs and TMPs in alkaline electrolytes and the evolution of morphology,structure and composition under OER conditions are *** the last section,we discuss the challenges that need to be addressed in this specific area of research and the implications for further research.

关键词： Oxygen evolution reaction Electrocatalysis Pre-catalysts Modulated strategies Structure-activity relationships Transition metal base compounds

Fiber-optic dual Fabry-Pérot interferometric carbon monoxide sensor with polyaniline/Co3O4/graphene oxide sensing membrane

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Chinese Chemical Letters 2020年第8期31卷 2145-2149页

作者： Jin Peng Jie Liao Xiaozhan Yang wenlin feng Department of Physics and Energy Chongqing University of TechnologyChongqing 400054China Chongqing Key Laboratory of Green Energy Materials Technology and Systems Chongqing 400054China

An optical fiber dual Fabry-Perot interferometric carbon monoxide gas sensor based on PANI/Co3 O4/GO(PCG)sensing membrane coated on the end face of the optical fiber is proposed and *** end face of photonic crystal fiber(PCF)without cut-off wavelength is fused with a single-mode fiber(SMF),and the other end face of the PCF is coated with PCG sensing *** collapsed layer formed during the air hole fusion of PCF is used as the first reflector,the interface between PCF and sensing membrane is used as the second reflector,and the interface between the sensing membrane and the air is used as the third reflector,thus the dual Fabry-Pe rot structure sensor is *** results show that the sensor has excellent sensitivity and selectivity to carbon *** the increasing concentration of carbon monoxide gas in the range of 0-60 ppm,the intensity of interference spectrum *** sensitivity of the sensor is 0.3473 dB m/ppm,and its linearity is *** response time and recovery time are 68 s and 106 s,*** sensor has the advantages of the compact size,low cost,high sensitivity,strong selectivity and simple *** is suitable for the sensing detection of low concentration carbon monoxide gas.

关键词： Carbon monoxide Dual Fabry-Perot interferometer Gas sensor PANI/Co3O4/GO Sensing membrane

Ab initio MO study of reaction mechanism for carbonyl migration of Co complex

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Chinese Science Bulletin 2000年第13期45卷 1176-1178页

作者： LEI Ming feng wenlin XU Zhenfeng Department of Applied Chemistry Beijing University of Chemical TechnologyBeijing 100029China Department of Chemistry Beijing Normal UniversityBeijing 100875China

Ab initio method under the effective core potential (ECP) approximation is employed to study the reaction mechanism of carbonyl migration of the cycle of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)3 at Hartree-Fock (HF) level. The structures of the reactant, transition state and product for the reaction are determined. The energy of each stationary point is corrected at MP2/LAN2DZ//LANL2DZ+ZPE (zero-point energy) level. The calculated activation barrier is 28.89 kJ/mol.

关键词： carbonyl cobalt hydroformylation ab initio method effective core potential.

A Theoretical Study on Nonadiabatic Trapping Models of the Reaction NH+H←→N+H_2

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Chinese Chemical Letters 1999年第3期10卷 207-208页

作者： Shu Xia YIN Yan WANG wenlin feng(Department of Chemistry,Beijing Normal University,Beijing 100873) Beijing Normal Univ Dept Chem Beijing 100875 Peoples R China

The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbrmation obtained by ah initio calculations at QCISD/631 IG** ie\el. Using the unitied statistical theory fornonadiabatic trapping models. the thermal rateconstants over the temperature range of 2000-3000K are computed which are in excellent agreementwith the experiment results.

关键词： Intrinsic reaction coordinate (IRC) unified statistical theory (UST) nonadiabatic trapping model thermal rate constant

Discussion of the Relationship between Fairness and Efficiency——Based on Rawls'“A Theory of Justice”

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Review of Educational Theory 2021年第4期4卷 114-118页

作者： wenlin feng Sichuan Institute of Education Sciences ChengduSichuan610225China

Since China’s reform and opening up,from the Third Plenary Session of the 14th Central Committee of the Communist Party of China that put forward"efficiency first and fairness"to the 18th National Congress of the Communist Party of China,"first distribution and redistribution must deal with the relationship between fairness and efficiency,and redistribution pays more attention to fairness"Distribution policy,in 2021,the tenth meeting of the Central Finance and Economics Committee clearly stated that it is necessary to promote common prosperity in *** relationship between fairness and efficiency has always been the basic principle and standard for the country to formulate policies,and it is also the core issue discussed by *** utilitarianism and Rawls'two principles of justice provide us with different perspectives to explore the relationship between fairness and *** article focuses on Rawls's critique of utilitarianism and the specific content of the two justice principles,and makes a simple discussion on the relationship between fairness and efficiency and its enlightenment on the formulation of distribution policies in our country.

关键词： Fairness Efficiency Utilitarianism Two principles of justice

IRC analysis of methanol carbonylation reaction catalyzed by rhodium complex

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Science China Chemistry 2004年第1期47卷 41-49页

作者： HAO Maorong, feng wenlin, Jl Yongqiang & LEI MingFaculty of Science, Beijing University of Chemical Engineering, Beijing 100029, China Faculty of Chemical Engineering, Ningxia University, Yinchuan 750021, China 1. Faculty of Science Beijing University of Chemical Engineering 00029 Beijing China 2. Faculty of Chemical Engineering Ningxia University 750021 Yinchuan China

In the reaction cycle for methanol carbonylation catalyzed by Rh complex, the structure geometries of the reactant, intermediates, transition states and product of each elemental reaction have been studied by using the energy gradient method at HF/LANL2DZ level, and the changes of their potential profiles have also been calculated. Through IRC analyses of the transition states for each elemental reaction, it is confirmed that the various structure geometries obtained are stationary points on the cycle reaction pathway of methanol carbonylation catalyzed by Rh complex, and the changes are given in energies and structure geometries of the reactant molecules along the reaction pathway of lowest energy. It has been proposed that the geometrical conversions of intermediates play an important role during the cycle reaction. Through analyses of structure geometries, it has been suggested that, in addition to cis- and transstructure exchange linkage of catalysis reactive species, the two pathways, cis- and frans-catalyzed cycle reactions, can also be linked through geometrical conversion of intermediates, of which the activation energy is 49.79 kJ/mol. Moreover, the reductive elimination elemental reaction may be neither c/s-cycle nor trans- one, showing that the cycle reaction can be achieved through various pathways. However different the pathway, the oxidative addition elemental reaction of CH3I is the rate-controlling step.

关键词： rhodium complex catalyst, methanol carbonylation, ab initio method, homogeneous catalysis.

基于薄芯-三芯细锥-薄芯光纤结构的应变传感器

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光学学报 2020年第18期40卷 25-31页

作者：徐施施冯文林重庆理工大学理学院物理与能源系重庆400054 绿色能源材料技术与系统重庆市重点实验室重庆400054

提出一种新的弱耦合三芯锥形光纤结构的应变传感器,该结构两端由薄芯光纤、中间由熔融拉锥三芯光纤构成,形成薄芯-三芯细锥-薄芯的三明治结构。实验研究了三芯长度和锥腰直径长度对传感器的应变与温度特性影响。结果表明:在0~1600με... 详细信息

提出一种新的弱耦合三芯锥形光纤结构的应变传感器,该结构两端由薄芯光纤、中间由熔融拉锥三芯光纤构成,形成薄芯-三芯细锥-薄芯的三明治结构。实验研究了三芯长度和锥腰直径长度对传感器的应变与温度特性影响。结果表明:在0~1600με应变范围内,传感器的干涉光谱随应变增大发生蓝移,当三芯光纤长度为7.4 cm,锥腰直径长度为41.20μm时,其最大应变灵敏度为-3.47 pm/με,线性拟合度为0.9876;同时对温度传感特性进行探究,在25~60℃温度范围内,传感器温度灵敏度为34.52 pm/℃,线性拟合度0.9979。交叉敏感度为9.95με/℃。该应变传感器具有成本低廉、结构简单、测量范围较大的优点,在工业生产、建筑监测等领域有潜在的应用价值。

关键词：光纤光学光纤传感三芯光纤细锥应变测量

基于无芯-多模-无芯光纤结构的硫化氢气体传感性质研究

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光学学报 2019年第10期39卷 126-131页

作者：刘敏冯德玖冯文林重庆理工大学理学院重庆400054 绿色能源材料技术与系统重庆市重点实验室重庆400054

提出一种基于无芯-多模-无芯光纤(NMN)结构的硫化氢(H2S)气体传感器。该传感器将两个无芯光纤(NCF)熔接在多模光纤(MMF)的两端,构建NMN的结构。光从单模光纤(SMF)进入NCF中激发出不同高阶模式,进入MMF中时,激发出的高阶模与基模分别在MM... 详细信息

提出一种基于无芯-多模-无芯光纤(NMN)结构的硫化氢(H2S)气体传感器。该传感器将两个无芯光纤(NCF)熔接在多模光纤(MMF)的两端,构建NMN的结构。光从单模光纤(SMF)进入NCF中激发出不同高阶模式,进入MMF中时,激发出的高阶模与基模分别在MMF的包层和纤芯中传输从而产生相位差,形成模式干涉。同时,对不同长度NCF和MMF的传输特性进行了优化。采用浸渍提拉法在NCF的外表面形成二氧化钛薄膜,利用薄膜对H2S气体的吸附,实现对H2S的快速响应。随着H2S浓度的增加,干涉谱出现红移,在H2S气体体积分数为0~3×10^-5的范围内,得到了7.36 pm/10^-6的灵敏度和良好的线性度。此外,二氧化钛对H2S具有良好的选择性,响应和恢复时间分别约为50 s和65 s。该传感器具有结构简单、灵敏度高、制造方便等优点,在低浓度H2S气体的安全监测领域有潜在的应用价值。

关键词：光纤光学光纤传感模式干涉二氧化钛硫化氢