检索结果-南通市图书馆

Process optimization and mechanism study of ionic liquid-based mixed amine biphasic solvents for CO_(2) capture in biogas upgrading procedure

引用

Frontiers of Environmental Science & Engineering 2024年第8期18卷 43-57页

作者： Fanzhi meng Siyu Han li lin Jinglin li Kailun Chen Jianguo Jiang School of Environment Tsinghua UniversityBeijing 100084China

This study focused on enhancing the efficiency of methane upgrading and reducing energy consumption in the biogas upgrading process through the use of biphasic *** aqueous-based biphasic solvent,comprising methyl monoethanolamine(MMEA),N-methyldiethanolamine(MDEA),and 1-butyl-3-methylimidazolium tetrafluoroborate(ItFB),was meticulously *** biogas upgrading effect,regeneration efficiency,regeneration energy consumption,economic viability,selectivity,and phase separation characteristics of this absorbent were systematically *** parameters,including different inlet flow rates,stirring rate,methane inlet concentrations,reaction temperatures,and amine mixing ratios,were adjusted to investigate their impact.A comprehensive evaluation was conducted on the biogas upgrading effect and substance migration trends of the biphasic *** process parameters were determined,demonstrating the favorable impact of the biphasic solvent on biogas *** upgraded gas achieved a methane purity exceeding 96%,and the regeneration energy consumption decreased by 44.27% compared to 30 wt.%MEA,resulting in a more than 50% improvement in economic *** interaction between the ionic liquid and carbamate facilitated the phase separation process,with carbon enrichment after separation exceeding 95%.This enhancement significantly contributed to the improvement of regeneration energy *** study thus concludes that biphasic solvents,exemplified by the described aqueous-based solution,offer a promising avenue for effective biogas upgrading with notable advancements in economic and energy efficiency.

关键词： Biphasic solvents Biogas upgrading Energy consumption Process parameters Ionic liquid

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

Multiscale causes of the 2022 Yangtze mega-flash drought under climate change

引用

Science China Earth Sciences 2024年第8期67卷 2649-2660页

作者： Xing yuan Yumiao WANG Shiyu ZHOU Hua li Chenyuan li School of Hydrology and Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of Water Resources Nanjing University of Information Science and TechnologyNanjing 210044China

The 2022 Yangtze mega-flash drought is characterized by strong intensity and rapid development both in time and space,accompanied by a persistent anticyclonic circulation ***,the causes of the extreme event remain elusive given the multiscale nature of *** we presented a brief overview for the oceanic and terrestrial causes of the megaflash drought during the summer of 2022,and estimated the risk in a changing *** the soil moisture percentile as the drought index,it was found that the drought expanded to the entire Yangtze River basin within two months,with 80%of basin under severe drought conditions at the end of *** the intensity and onset speed of the 2022 mega-flash drought were ranked as the first during the past 62 years,with return periods of 86 and 259 years,*** results of composite analysis showed that the spring La Ni?a can facilitate the abrupt change from a wet/normal condition in May–June to drought in July–August over the Yangtze River basin,which was beneficial for the increase of flash drought intensity and onset speed *** analysis through the linear regression also indicated that the unprecedented intensity was associated with the negative phase of the Pacific Decadal *** by a coupling strength index for soil moisture and vapor pressure deficit,it was found that there was a strong land-atmosphere coupling over the Yangtze River basin during July–August *** attribution by using CMIP6 climate models suggested that land-atmosphere coupling increased the risks of flash drought intensity and onset speed like 2022 by 61%±6%and 64%±7%under natural climate forcings,and the synergy of coupling and anthropogenic climate change would increase the risks by 75%±22%and 85%±12%.Our findings emphasized the role of landatmosphere coupling combined with anthropogenic climate change in intensifying flash droughts.

关键词： Flash drought Yangtze River basin Land-atmosphere coupling Climate change Attribution

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

Breaking the geometry-performance tradeoff in compressor deviation modeling:Nested principal component analysis

引用

Chinese Journal of Aeronautics 2024年第9期37卷 131-149页

作者： Mingzhi li Xianjun YU Dejun meng Guangfeng AN Baojie liU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China AECC Shenyang Engine Research Institute Shenyang 110015China

Uncertainties in the aerodynamic performance of compressors,introduced by manufac-turing variations,have received more and more attentions in recent *** deviation model plays a crucial role in evaluating this uncertainty and facilitating robust ***,current deviation models with a few variables cannot simultaneously achieve a precise geometric approxi-mation of deviation and provide an accurate assessment of performance *** paper introduces a novel deviation modeling method named Nested Principal Component Analysis(NPCA)to break this *** this method,both geometry-based and performance-based modes are utilized to describe manufacturing *** considering aerodynamic sensitivity,surface deformations that significantly impact aerodynamic performance can be extracted for deviation *** demonstrate the superiority of this newly proposed method,ninety-eight newly man-ufactured compressor rotor blades were measured using a coordinate measurement machine,and both NPCA and Principal Component Analysis(PCA)were employed to model the real manufac-turing *** results indicate that,in comparison to the PCA method,the NPCA method achieves an equivalent level of accuracy in geometric reconstruction and evaluation of mean ***,the same level of accuracy can be obtained with eight NPCA modes and fifty PCA modes when assessing the scatter in aerodynamic ***,the working mecha-nism of the NPCA method for accurate uncertainty quantification was further investigated.

关键词： Manufacturing variation Uncertainty quantification Dimension reduction Aerodynamics Flow mechanism

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

Effect of Fluoride on the Ion-association of Calcium Phosphate and Crystallization of Hydroxyapatite

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 831-838页

作者：宋昊月 CAI meng 袁萍邹朝勇 School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

Using a titration setup to accurately control the reaction conditions and in situ monitor the reaction,we showed that fluoride exhibited negligible effects on the ion association process of calcium and phosphate and the formation of ACP nanospheres in a buffer solution with constant ionic ***,the stability of ACP increased with increasing fluoride concentration,which was ascribed to the inhibitory effect of fluoride on the aggregation of ACP nanospheres and the nucleation of nanocrystals on the surface of ACP ***,fluoride could inhibit the lateral growth of HAP nanosheets and promote the formation of rod-like *** results further improve our understanding of the crystallization pathway of HAP crystals and the regulatory effects of fluoride.

关键词： crystallization amorphous calcium phosphate hydroxyapatite fluoride

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

CONSERVATIVE CONFORMING AND NONCONFORMING VEMS FOR FOURTH ORDER NONliNEAR SCHRODINGER EQUATIONS WITH TRAPPED TERM

引用

Journal of Computational Mathematics 2024年第2期42卷 454-499页

作者： meng li Jikun Zhao Zhongchi Wang Shaochun Chen School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China School of Computer Science and Engineering Beihang universityBeijing 100083China

This paper aims to construct and analyze the conforming and nonconforming virtual element methods for a class of fourth order nonlinear Schrodinger equations with trapped *** mainly consider three types of virtual elements,including H^(2) conforming virtual element,C^(0) nonconforming virtual element and Morley-type nonconforming virtual *** fully discrete schemes are constructed by virtue of virtual element methods in space and modified Crank-Nicolson method in *** prove the mass and energy conservation,the boundedness and the unique solvability of the fully discrete *** introducing a new type of the Ritz projection,the optimal and unconditional error estimates for the fully discrete schemes are presented and ***,two numerical examples are investigated to confirm our theoretical analysis.

关键词： H^(2)conforming virtual element C^(0)nonconforming virtual element Morleytype nonconforming virtual element Nonlinear Schrodinger equation Conservation Convergence

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

Decoupled deep hough voting for point cloud registration

引用

Frontiers of Computer Science 2024年第2期18卷 147-155页

作者： Mingzhi yuan Kexue FU Zhihao li Manning WANG Digital Medical Research Center School of Basic Medical SciencesFudan UniversityShanghai 200032China Shanghai Key Laboratory of Medical Image Computing and Computer Assisted Intervention Shanghai 200032China

Estimating rigid transformation using noisy correspondences is critical to feature-based point cloud ***,a series of studies have attempted to combine traditional robust model fitting with deep *** them,DHVR proposed a hough voting-based method,achieving new state-of-the-art ***,we find voting on rotation and translation simultaneously hinders achieving better ***,we proposed a new hough voting-based method,which decouples rotation and translation ***,we first utilize hough voting and a neural network to estimate *** based on good initialization on rotation,we can easily obtain accurate rigid *** experiments on 3DMatch and 3DLoMatch datasets show that our method achieves comparable performances over the state-of-the-art *** further demonstrate the generalization of our method by experimenting on KITTI dataset.

关键词： point cloud registration robust model fitting deep learning hough voting

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

Effect of particle composition and consolidation degree on the wave-induced liquefaction of soil beds

引用

Acta Oceanologica Sinica 2024年第2期43卷 11-22页

作者： Zhiyuan Chen Yupeng Ren Guohui Xu meng li Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province Qinhuangdao 066000China Key Laboratory of Marine Environment and Ecology(Ocean University of China) Ministry of EducationQingdao 266100China Key Laboratory of Submarine Geoscience and Prospecting Techniques(Ocean University of China) Ministry of EducationQingdao 266100China

The wave-induced liquefaction of seabed is responsible for causing damage to marine *** composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave *** present study conducted wave flume experiments on silt and silty fine sand beds with varying particle ***,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic *** experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand ***,the duration and development depth of liquefaction are greater in the silt *** dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation *** permeability coefficient and compression modulus of silt are lower than those of silty fine ***,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external *** research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure ***,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction *** study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.

关键词： wave flume liquefaction pore water pressure consolidation permeability experiment discrete element simulation

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

Experimental investigation on the gravity driven discharge of cohesive particles from a silo with two outlets

引用

Particuology 2024年第6期89卷 11-21页

作者： li Dai Zhulin yuan Fengxian Fan Conghui Gu School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China

An experimental study on the gravity driven discharge of cohesive particles from a silo with two outlets was *** discharge behaviors under the conditions that a single outlet was open and two outlets were open were investigated by varying the moisture content of the particles and the filling height of the particles in the *** results show that the discharge rate of the cohesive particles increases gradually at the beginning,then almost keeps constant,and finally drops *** discharge rate in case of two openings is around 1.1–1.6 times that in case of a single *** filling height leads to lower discharge rate in case of a single opening but results in higher discharge rate in case of two ***,the avalanche dynamics in case of a single opening was examined,and the mixing behavior of the cohesive particles was *** is observed that the discharge flow is promoted by the avalanche phenomenon in the silo,generating a general trend that the normalized mass of discharge increases with the filling height at higher moisture *** case of a single opening,the transition from mass flow to funnel flow favors the particle mixing,resulting in an increasing mixing index as the moisture content *** general,a better performance of mixing can be achieved in case of a single opening compared with in case of two *** study provides vital information for fundamental understanding of the gravity driven discharge of cohesive particles from the silo with multiple outlets.

关键词： Cohesive particles Moisture content Discharge rate Avalanche Mixing

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

Finite-Time Stabilization for Constrained Discrete-time Systems by Using Model Predictive Control

引用

IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1656-1666页

作者： Bing Zhu Xiaozhuoer yuan li Dai Zhiwen Qiang IEEE the Seventh Research Division Beihang UniversityBeijing 100191China the School of Automation Beijing Institute of TechnologyBeijing 100081China

In this paper, a model predictive control(MPC)framework is proposed for finite-time stabilization of linear and nonlinear discrete-time systems subject to state and control constraints. The proposed MPC framework guarantees the finite-time convergence property by assigning the control horizon equal to the dimension of the overall system, and only penalizing the terminal cost in the optimization, where the stage costs are not penalized explicitly. A terminal inequality constraint is added to guarantee the feasibility and stability of the closed-loop *** feasibility can be improved via augmentation. The finite-time convergence of the proposed MPC is proved theoretically,and is supported by simulation examples.

关键词： Constraints deadbeat control finite-time stabilization model predictive control(MPC)

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

Time-varying parameters estimation with adaptive neural network EKF for missile-dual control system

引用

Journal of Systems Engineering and Electronics 2024年第2期35卷 451-462页

作者： yuan Yuqi ZHOU Di li Junlong LOU Chaofei School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Electronic System Engineering Beijing 100854China

In this paper, a filtering method is presented to estimate time-varying parameters of a missile dual control system with tail fins and reaction jets as control variables. In this method, the long-short-term memory(LSTM) neural network is nested into the extended Kalman filter(EKF) to modify the Kalman gain such that the filtering performance is improved in the presence of large model uncertainties. To avoid the unstable network output caused by the abrupt changes of system states,an adaptive correction factor is introduced to correct the network output online. In the process of training the network, a multi-gradient descent learning mode is proposed to better fit the internal state of the system, and a rolling training is used to implement an online prediction logic. Based on the Lyapunov second method, we discuss the stability of the system, the result shows that when the training error of neural network is sufficiently small, the system is asymptotically stable. With its application to the estimation of time-varying parameters of a missile dual control system, the LSTM-EKF shows better filtering performance than the EKF and adaptive EKF(AEKF) when there exist large uncertainties in the system model.

关键词： long-short-term memory(LSTM)neural network extended Kalman filter(EKF) rolling training time-varying parameters estimation missile dual control system

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：