检索结果-南通市图书馆

Multivariable identification of membrane fouling based on compacted cascade neural network

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第1期53卷 37-45页

作者： kun ren Zheng Jiao Xiaolong Wu Honggui Han Faculty of Information Technology Beijing University of TechnologyBeijing 100124China Engineering Research Center of Digital Community Ministry of EducationBeijing 100124China Beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing 100124China

The membrane fouling phenomenon,reflected with various fouling characterization in the membrane bioreactor(MBR)process,is so complicated to distinguish.This paper proposes a multivariable identification model(MIM)based on a compacted cascade neural network to identify membrane fouling accurately.Firstly,a multivariable model is proposed to calculate multiple indicators of membrane fouling using a cascade neural network,which could avoid the interference of the overlap inputs.Secondly,an unsupervised pretraining algorithm was developed with periodic information of membrane fouling to obtain the compact structure of MIM.Thirdly,a hierarchical learning algorithm was proposed to update the parameters of MIM for improving the identification accuracy online.Finally,the proposed model was tested in real plants to evaluate its efficiency and effectiveness.Experimental results have verified the benefits of the proposed method.

关键词： Membrane fouling Permeability Cascade neural networks Model Prediction

Intensified shape selectivity and alkylation reaction for the two-step conversion of methanol aromatization to p-xylene

在线全文

学校读者我要写书评

暂无评论

中国化学工程学报:英文版 2023年第7期59卷 240-250页

作者： Tingjun Fu Ran Wang kun ren Liangliang Zhang Zhong Li State Key Laboratory of Clean and Efficient Coal Utilization College of Chemical Engineering and TechnologyTaiyuan University of TechnologyTaiyuan 030024China

Two-step conversion of methanol to aromatics via light hydrocarbons can significantly improve the conversion stability compared with direct aromatization of methanol,but it remains a challenge to achieve a high p-xylene(PX)selectivity.Herein,silica coating was firstly used to passivate external acid sites of ZSM-5 catalyst for the aromatization of light hydrocarbons by the chemical liquid deposition method.With the increase of SiO_(2) deposition,the density of the external acid sites of the catalyst was decreased from 0.1 to 0.03 mmol·g^(-1),which inhibited the surface secondary reactions and increased the PX/X from 34.6% to 60.0%.In view of the fact that the aromatization process in the second step was partly inhibited as methanol was consumed in advance in the upper methanol-to-light hydrocarbons catalyst layer,part of methanol was directly introduced into the lower aromatization catalyst layer to promote the alkylation process during the aromatization,which decreased the toluene selectivity from 34.5% to 14.3% but increased the xylene selectivity from 40.0%to 55.3%.It was also found that an appropriate external acid density was needed for aromatization catalyst to strengthen the alkylation process and improve the selectivity of xylene under the conditions of methanol introduction.

关键词： Methanol to aromatics Two-step conversion Para-xylene Zeolite Silica Catalysis

Polarization-sensitive and active controllable electromagnetically induced transparency in U-shaped terahertz metamaterials

在线全文

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2021年第2期14卷 221-228页

作者： kun ren Ying ZHANG Xiaobin ren Yumeng HE Qun HAN College of Precision Instrument and Opto-electronics Engineering Tianjin UniversityKey Laboratory of Opto-electronics Information TechnologyMinistry of EducationTianjin 300072China School of Science Tianjin University of Science and TechnologyTianjin 300222China

Electromagnetically induced transparency(EIT)phenomenon is observed in simple metamaterial which consists of concentric double U-shaped resonators(USRs).The numerical and theoretical analysis reveals that EIT arises from the bright-bright mode coupling.The transmission spectra at different polarization angle of incident light shows that EIT transparency window is polarization sensitive.More interestingly,Fano resonance appears in the transmission spectrum at certain polarization angles.The sharp and asymmetric Fano lineshape is high valuable for sensing.The performance of sensor is investigated and the sensitivity is high up to 327 GHz/RIU.Furthermore,active control of EIT window is realized by incorporating photosensitive silicon.The proposed USR structure is simple and compact,which may find significant applications in tunable integrated devices such as biosensor,filters,and THz modulators.

关键词： electromagnetically induced transparency(EIT) metamaterial polarization-sensitive active optical devices sensor

Skin Organoid Research Progress and Potential Applications

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

International Journal of Dermatology and Venereology 2022年第2期5卷 101-106页

作者： Hong-Yang Li kun ren Cheng Wang Wen-Bo Bu Pharmacal Research Laboratory Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIsHospital for Skin Diseases(Institute of Dermatology)Chinese Academy of Medical Science and Peking Union Medical CollegeNanjingJiangsu 210042China Jiangsu Center for Pharmacodynamics Research and Evaluation China Pharmaceutical UniversityNanjingJiangsu 210009China Department of Dermatology Zhongda Hospital Southeast UniversityNanjingJiangsu 210009China Department of Surgery Hospital for Skin Diseases(Institute of Dermatology)Chinese Academy of Medical Science and Peking Union Medical CollegeNanjingJiangsu 210042China.

Skin diseases were characterized by various types and high incidence,which seriously affect people’s health.At present,skin pathogenesis research and the therapeutic drug development for skin diseases are limited by the lack of reasonable research models that recapitulate the development of skin diseases.Organoids are three-dimensionally cultured cell populations derived from skin stem cells,which exhibits the ability of multicell assembly and the similar histological characteristics with the living tissues and organs.This article reviews the establishment of normal skin organoids and skin tumor organoids,and summarizes the application of skin organoids in the evaluation of drug sensitivity,pathological mechanism research,and individualized treatment.In addition,the advantages and limitations of organoids in skin disease research are also discussed,which provides a basis for revealing the pathogenesis of skin diseases and developing preventive and therapeutic drugs for skin diseases.

关键词： skin disease organoid three-dimensional culture personalized treatment drug screening

OSCILLATORY SHEAR-ACCELERATED EXFOLIATION OF GRAPHITE IN POLYPROPYLENE MELT DURING INJECTION MOLDING

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第1期31卷 98-109页

作者： Nan Li Wei Cheng kun ren Feng Luo 王柯傅强 College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan University

In this study, good dispersion status of graphite in a nonpolar, intractable polymer, i.e. polypropylene （PP）, was realized in melt processing by using a specific dynamic packing injection molding （DPIM） technique. The exfoliation extent of graphite increased remarkably from the skin zone to the core zone of the molded part, as confirmed by combination of WAXD, SEM and TEM analyses, indicating an accelerated exfoliation occurred during the DPIM processing. This phenomenon is due to decreased melt flow channel and increased melt viscosity as the solidification takes place from the wall into the center, which leads to greatly increased shear force. The good dispersion of graphite results in obvious reinforcements of both tensile strength and impact strength by adding moderate amount of graphite. The present study proposes a promising route for realizing the large-scale fabrication of structural parts of polymer/exfoliated-graphite nanocomposites with excellent mechanical properties.

关键词： Polymer-matrix composites Mechanical properties Injection moulding.

Corner Transition Toolpath Generation Based on Velocity-Blending Algorithm for Glass Edge Grinding

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2019年第5期32卷 50-58页

作者： kun ren Yujia Pan Danyan Jiang Jun Pan Wenhua Chen Xuxiao Hu College of Mechanical Engineering and Automation Zhejiang Sci-Tech University

Sharp corners usually are used on glass contours to meet the highly increasing demand for personalized products,but they result in a broken wheel center toolpath in edge grinding.To ensure that the whole wheel center toolpath is of G1 continuity and that the grinding depth is controllable at the corners,a transition toolpath generation method based on a velocity-blending algorithm is proposed.Taking the grinding depth into consideration,the sharp-corner grinding process is planned,and a velocity-blending algorithm is introduced.With the constraints,such as traverse displacement and grinding depth,the sharp-corner transition toolpath is generated with a three-phase motion arrangement and with confirmations of the acceleration/deceleration positions.A piece of glass with three sharp corners is ground on a three-axis numerical-control glass grinding equipment.The experimental results demonstrate that the proposed algorithm can protect the sharp corners from breakage efficiently and achieve satisfactory shape accuracy.This research proposed a toolpath generation method based on a velocity-blending algorithm for the manufacturing of personalized glass products,which generates the transition toolpath as needed around a sharp corner in real time.

关键词： Glass edge grinding Toolpath planning Velocity blending Grinding depth control

Accurate and precise determination of lead isotope composition in selected geochemical reference materials

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2017年第3期36卷 421-425页

作者： Guangliang Wu Jian-Ming Zhu Decan Tan Guilin Han Lixing Zhang kun ren State Key Laboratory of Geological Processes and Mineral Resources Institute of Earth Sciences China University of Geosciences Beijing 100083 China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry CAS Guiyang 550081 China University of Chinese Academy of Sciences Beijing 100049China

Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated ^(205)Tl/^(203)Tl=2.38865(NIST SRM 997)for mass discrimination correction.The long-term external precision(2SD)for NISTSRM 981 of Pb,BCR-2,and BHVO-2 are 0.31‰(n=105),0.42‰(n=11),and 0.25‰(n=5)for ^(208)Pb/ ^(206)Pb and 0.16‰,0.53‰,and 0.07‰for ^(206)Pb/ ^(207)Pb,both respectively,and their Pb isotopic ratios are in excellent agreement with the recommended values.Using this method,we report for the first time Pb isotopic compositions in shale SGR-1b(USGS);coal CLB-1(USGS);stream sediments GSD-17,-21,and-23(IGGE);soils GSS-12,-13,-14,-15,and-16(IGGE);plants GSV-1,-2,and-3(IGGE);and human hair GSH-1(IGGE).

关键词：铅同位素组成地球化学参考物质铅同位素比值测定 USGS 水系沉积物运输途径

From octahedral structure motif to sub-nanosecond phase transitions in phase change materials for data storage

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2018年第8期61卷 132-146页

作者： Zhitang SONG Sannian SONG Min ZHU Liangcai WU kun ren Wenxiong SONG Songling FENG State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Micro-system and Information Technology Chinese Academy of Sciences

Phase change random access memory(PCRAM) has been successfully applied in the computer storage architecture, as storage class memory, to bridge the performance gap between DRAM and Flashbased solid-state drive due to its good scalability, 3 D-integration ability, fast operation speed and compatible with CMOS technology. Focusing on phase change materials and PCRAM for decades, we have successfully developed 128 Mb embedded PCRAM chips, which can meet the requirements of most embedded systems.3 D Xpoint(3 D PCRAM), invented by Intel and Micron, has been regarded as a new breakthrough in the last 25 years since the application of NAND in 1989, which represents state-of-the-art memory technology.This technology has some remarkable features, such as the confined device structure with 20 nm size, the metal crossbar electrodes to reduce the resistance variations in PCRAM arrays, and the ovonic threshold switching selector that can provide a high drive current and a low leakage current. A good understanding of phase change mechanism is of great help to design new phase change materials with fast operation speed,low power consumption and long-lifetime. In this paper, we firstly review the development of PCRAM and different understandings on phase change mechanisms in recent years, and then propose a new view on the mechanism, which is based on the octahedral structure motifs and vacancies. Octahedral structure motifs are generally found in both amorphous and crystalline phase change materials. They are considered to be the basic units during phase transition, which are severely defective in the amorphous phase. These configurations turn into more ordered ones after minor local rearrangements, the growth of which results in the crystallization of rocksalt(RS) phase with a large amount of vacancies in the cation sites. Further driven by thermodynamic driving force, these vacancies move and layer along certain directions; consequently, the metastable RS structure transforms into the stable hexagonal(HEX) structure. Based on

关键词： phase change memory phase change materials octahedral structure motif fast crystallization speed phase change mechanism

空间·机制·效能:政务新媒体赋能地方政府形象塑造探析——以山东省为例

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

山东行政学院学报 2024年第4期 24-32页

作者：任堃赵晨昕复旦大学国际关系与公共事务学院上海200433 政治和法律教研部济南250014

政务新媒体具有社交媒体与政务服务二元属性。政务新媒体深度耦合于政府组织体系、政务服务及行政实践之中,并有效赋能政府治理理念与策略革新,已成为中国式现代化视阈下地方政府探索社会治理创新的重要工具。基于4R危机管理理论,运用... 详细信息

政务新媒体具有社交媒体与政务服务二元属性。政务新媒体深度耦合于政府组织体系、政务服务及行政实践之中,并有效赋能政府治理理念与策略革新,已成为中国式现代化视阈下地方政府探索社会治理创新的重要工具。基于4R危机管理理论,运用政府形象系统组成要素构建分析框架,可从空间、机制和效能三个维度探究政务新媒体赋能地方政府形象塑造的作用机理。泛媒介时代地方政府应以形象规划、形象调整、形象治理为道路遵循,深入理解和掌握新媒体的传播规律,激发政务新媒体赋能政府形象塑造内在活力,深入挖掘其价值,以推动国家治理体系与治理能力现代化。

关键词：政务新媒体地方政府政府形象多维塑造治理创新