检索结果-南通市图书馆

Probing the interaction between asphaltene-wax and its effects on the crystallization behavior of waxes in heavy oil via molecular dynamics simulation

引用

Petroleum Science 2024年第4期21卷 2839-2848页

作者： Yong Hu Xi Lu Hai-Bo Wang Ji-Chao fang Yi-Ning Wu Jian fang Sun SINOPEC Petroleum Exploration and Production Research Institute Shandong Key Laboratory of Oilfield Chemistry School of Petroleum Engineering China University of Petroleum (East China)

High content of asphaltenes and waxes leads to the high pour point and the poor flowability of heavy oil,which is adverse to its efficient development and its transportation in *** the interaction mechanism between asphaltene-wax is crucial to solve these problems,but it is still *** this paper,molecular dynamics simulation was used to investigate the interaction between asphaltenewax and its effects on the crystallization behavior of waxes in heavy *** show that molecules in pure wax are arranged in a paralleled *** wax molecules in heavy oil,which are close to the surface of asphaltene aggregates,are bent and arranged *** the mass fraction of asphaltenes in asphaltene-wax system(ωasp) is 0-25 wt%,the attraction among wax molecules decreases and the bend degree of wax molecules increases with the increase of ω*** ωaspincreases from 0 to 25 wt%,and the attraction between asphaltene-wax is stronger than that among *** causes that the wax precipitation point changes from 353 to 333 *** the ωaspincreases to 50 wt%,wax molecules are more dispersed owing to the steric hindrance of asphaltene aggregates,and the interaction among wax molecules transforms from attraction to *** causes that the ordered crystal structure of waxes can't be formed at normal ***,the asphaltene,with the higher molecular weight or the more hetero atoms,has more obvious inhibition to the formation of wax ***,resins also have an obvious inhibition on the wax crystal due to the formation of asphalteneresin aggregates with a larger *** results reveal the interaction mechanism between asphaltene-wax,and provide useful guidelines for the development of heavy oil.

关键词： Heavy oil Interaction mechanism Asphaltenes Waxes Molecular dynamics

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Sufficient Conditions for Amalgamated 3-Manifolds to be ∂-Irreducible

引用

Chinese Annals of Mathematics,Series B 2024年第2期45卷 161-172页

作者： Bing fang Fengchun LEI Liang LIANG School of Mathematical Sciences Dalian University of TechnologyDalian 116024LiaoningChina School of Mathematics Liaoning Normal UniversityDalian 116029LiaoningChina

In this paper,the authors give some sufficient conditions for an amalgamated 3-manifold along a compact connected surface F with boundary to be ∂-irreducible in terms of distances between some kinds of vertex subsets ... 详细信息

关键词： ∂-Irreducibility Irreducibility Amalgamated 3-manifold Curve complex Arc complex

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermo-hydro-mechanical (THM) coupled simulation of the land subsidence due to aquifer thermal energy storage (ATES) system in soft soils

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1952-1966页

作者： Yang Wang Fengshou Zhang fang Liu Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai200092China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai200092China Shanghai Engineering and Technology Research Center of Shallow Geothermal Energy Shanghai200072China

Aquifer thermal energy storage(ATES)system has received attention for heating or cooling ***,it is well known that land subsidence becomes a major environmental concern for ATES ***,the effect of temperature on land subsidence has received practically no attention in the *** paper presents a thermo-hydro-mechanical(THM)coupled numerical study on an ATES system in Shanghai,*** water wells were installed for seasonal heating and cooling of an agriculture *** target aquifer at a depth of 74e104.5 m consisted of alternating layers of sand and silty sand and was covered with *** level,temperature,and land subsidence data from 2015 to 2017 were collected using field monitoring *** by data,we constructed a field scale three-dimensional(3D)model using TOUGH(Transport of Unsaturated Groundwater and Heat)and FLAC3D(Fast Lagrangian Analysis of Continua)equipped with a thermo-elastoplastic constitutive *** effectiveness of the numerical model was validated by field *** model was used to reproduce groundwater flow,heat transfer,and mechanical responses in porous media over three years and capture the thermo-and pressure-induced land *** results show that the maximum thermoinduced land subsidence accounts for about 60%of the total *** thermo-induced subsidence is slightly greater in winter than that in summer,and more pronounced near the cold well area than the hot well *** study provides some valuable guidelines for controlling land subsidence caused by ATES systems installed in soft soils.

关键词： Aquifer thermal energy storage(ATES) Land subsidence TOUGH-FLAC3D Thermo-elastoplastic constitutive model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Probability-Enhanced Anchor-Free Detector for Remote-Sensing Object Detection

引用

Computers, Materials & Continua 2024年第6期79卷 4925-4943页

作者： Chengcheng Fan Zhiruo fang Innovation Academy for Microsatellites of CAS Shanghai201210China Shanghai Engineering Center for Microsatellites Shanghai201210China College of Artificial Intelligence Nanjing Agricultural UniversityNanjing210095China

Anchor-free object-detection methods achieve a significant advancement in field of computer vision,particularly in the realm of real-time ***,in remote sensing object detection,anchor-free methods often lack of capability in separating the foreground and *** paper proposes an anchor-free method named probability-enhanced anchor-free detector(ProEnDet)for remote sensing object ***,a weighted bidirectional feature pyramid is used for feature ***,we introduce probability enhancement to strengthen the classification of the object’s foreground and *** detector uses the logarithm likelihood as the final score to improve the classification of the foreground and background of the *** is verified using the DIOR and NWPU-VHR-10 *** experiment achieved mean average precisions of 61.4 and 69.0 on the DIOR dataset and NWPU-VHR-10 dataset,*** achieves a speed of 32.4 FPS on the DIOR dataset,which satisfies the real-time requirements for remote-sensing object detection.

关键词： Object detection anchor-free detector probabilistic fully convolutional neural network remote sensing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Performance of iron-air battery with iron nanoparticle-encapsulated C-N composite electrode

引用

Frontiers in Energy 2024年第1期18卷 42-53页

作者： Can fang Xiangmei TANG Jiaoyan WANG Qingfeng YI School of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtan 411201China Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion Xiangtan 411201China

Highly efficient and stable iron electrodes are of great significant to the development of iron-air battery(IAB).In this paper,iron nanoparticle-encapsulated C–N composite(NanoFe@CN)was synthesized by pyrolysis using polyaniline as the C–N *** performance of the NanoFe@CN in different electrolytes(alkaline,neutral,and quasi-neutral)was investigated via cyclic voltammetry(CV).The IAB was assembled with NanoFe@CN as the anode and IrO_(2)+Pt/C as the *** effects of different discharging/charging current densities and electrolytes on the battery performance were also *** K_(2)SO_(4)electrolyte can effectively suppress the passivation of iron electrode,and the battery showed a good cycling stability during 180 charging/discharging *** to the pure nano-iron(NanoFe)battery,the NanoFe@CN battery has a more stable cycling stability either in KOH or NH_(4)Cl+KCl electrolyte.

关键词： energy storage and conversion metallic composites nanocomposites iron-air battery iron anode

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Capturability-based Fuzzy Footstep Planner for a Biped Robot with Centroidal Compliance

引用

Journal of Bionic Engineering 2024年第1期21卷 84-100页

作者： Zihan Xu Qin fang Yong Ren Chengju Liu Robot and Artificial Intelligence Lab(RAIL) College of Electronic and Information EngineeringTongji UniversityShanghai 201804China Applied Technology College Soochow UniversitySuzhou 215000China

Compliance motion and footstep adjustment are active balance control strategies from learning human subconscious *** force estimation without direct end-actuator force measurement and the optimal footsteps based on complex analytical calculation are still challenging tasks for elementary and kid-size position-controlled *** this paper,an online compliant controller with Gravity Projection Observer(GPO),which can express the external force condition of perturbations by the estimated Projection of Gravity(PoG)with estimation covariance,is proposed for the realization of disturbance absorption,with which the robustness of the humanoid contact with environments can be *** fuzzy footstep planner based on capturability analysis is proposed,and the Model Predictive Control(MPC)is applied to generate the desired *** fuzzification rules are well-designed and give the corresponding control output responding to complex and changeable external *** validate the presented methods,a series of experiments on a real humanoid robot are *** results verify the effectiveness of the proposed balance control framework.

关键词： Biped walking Centroidal compliance Gravity projection observer Fuzzy footstep planner

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Kinetic model of vibration screening for granular materials based on biological neural network

引用

Particuology 2024年第5期88卷 98-106页

作者： Zhan Zhao Yan Zhang fang Qin Mingzhi Jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening *** this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration *** material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen *** dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was *** screening parameters were randomly selected,and the corresponding relationships were established as a ***,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,*** training results indicated that ANFIS models had good stability and *** flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Discontinuous phase diagram of amorphous carbons

引用

National Science Review 2024年第4期11卷 164-171页

作者： YinBo Zhu ZhouYu fang ZhongTing Zhang HengAn Wu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

The short-range order and medium-range order of amorphous carbons demonstrated in experiments allow us to rethink whether there exist intrinsic properties hidden by atomic disordering. Here we presented six representative phases of amorphous carbons（0.1–3.4 g/cm3）, namely, disordered graphene network（DGN）, high-density amorphous carbon（HDAC）, amorphous diaphite（a-DG）, amorphous diamond（a-D）, paracrystalline diamond（p-D）, and nano-polycrystalline diamond（NPD）, respectively, classified by their topological features and microstructural characterizations that are comparable with experiments. To achieve a comprehensive physical landscape for amorphous carbons, a phase diagram was plotted in the sp3/sp2versus density plane, in which the counterintuitive discontinuity originates from the inherent difference in topological microstructures, further guiding us to discover a variety of phase transitions among different amorphous carbons. Intriguingly, the power law, log（sp3/sp2） ∝ ρn, hints at intrinsic topology and hidden order in amorphous carbons, providing an insightful perspective to reacquaint atomic disorder in non-crystalline carbons.

关键词： amorphous carbons disordered carbons phase diagram microstructural topology phase transition

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

高龄冠状动脉性心脏病患者经皮冠状动脉介入治疗的临床特点及预后

引用

上海医学 2011年第2期34卷 125-128页

作者：施鸿毓陈晖仇兴标宋洁方唯一上海交通大学附属胸科医院心血管内科 200030

目的观察≥75岁高龄冠状动脉性心脏病患者经皮冠状动脉介入治疗(PCI)的临床特点及其预后。方法回顾性分析2005年6月—2007年6月间所有于上海交通大学附属胸科医院行PCI的老年患者,分为高龄组(年龄≥75岁,115例)和老年组(年龄≥60岁且0... 详细信息

目的观察≥75岁高龄冠状动脉性心脏病患者经皮冠状动脉介入治疗(PCI)的临床特点及其预后。方法回顾性分析2005年6月—2007年6月间所有于上海交通大学附属胸科医院行PCI的老年患者,分为高龄组(年龄≥75岁,115例)和老年组(年龄≥60岁且0.05),脑卒中、陈旧性心肌梗死、心力衰竭的构成比显著增加(P值均<0.05)。高龄组在住院期间及远期的主要不良心脏事件、死亡和心源性死亡的发生率均显著高于老年组(P值均<0.05)。多因素分析提示,左心室射血分数(LVEF)≤0.40、多支血管病变及急性冠状动脉综合征是影响预后的独立因素,而年龄≥75岁不是独立危险因素。结论尽管高龄冠状动脉性心脏病患者的一般情况较差,远期临床预后较差,然而年龄≥75岁并不是影响预后的独立因素,LVEF低和急性冠状动脉综合征才是导致临床预后较差的主要原因。

关键词：高龄冠状动脉性心脏病经皮冠状动脉介入治疗

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nonlinear metamaterial enabled aeroelastic vibration reduction of a supersonic cantilever wing plate

引用

Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1749-1772页

作者： Peng SHENG Xin fang Dianlong YU Jihong WEN Laboratory of Science and Technology on Integrated Logistics Support College of Intelligence Science and TechnologyNational University of Defense TechnologyChangsha 410073China

The violent vibration of supersonic wings threatens aircraft *** paper proposes the strongly nonlinear acoustic metamaterial(NAM)method to mitigate aeroelastic vibration in supersonic wing *** employ the cantilever plate to simulate the practical behavior of a *** aeroelastic vibration model of the NAM cantilever plate is established based on the mode superposition method and a modified third-order piston *** aerodynamic properties are systematically studied using both the timedomain integration and frequency-domain harmonic balance *** presenting the flutter and post-flutter behaviors of the NAM wing,we emphasize more on the preflutter broadband vibration that is prevalent in *** results show that the NAM method can reduce the low-frequency and broadband pre-flutter steady vibration by 50%-90%,while the post-flutter vibration is reduced by over 95%,and the critical flutter velocity is also slightly *** clarified,the significant reduction arises from the bandgap,chaotic band,and nonlinear resonances of the NAM *** reduction effect is robust across a broad range of parameters,with optimal performance achieved with only 10%attached *** work offers a novel approach for reducing aeroelastic vibration in aircraft,and it expands the study of nonlinear acoustic/elastic metamaterials.

关键词： nonlinear acoustic metamaterial(NAM) hypersonic aeroelastic vibration vibration reduction fluid-structure interaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：