检索结果-南通市图书馆

Dual polarization strategy to enhance CH_(4) uptake in covalent organic frameworks for coal-bed methane purification

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 545-548页

作者： Junhua Wang Xin Lian Xichuan Cao Qiao Zhao Baiyan Li Xian-He Bu School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China School of Chemical engineering and Technology China University of Mining and TechnologyXuzhou 221116China School of Materials Science and engineering National Institute for Advanced MaterialsTKL of Metal and Molecule-Based Material ChemistryNankai UniversityTianjin 300350China

The purification of low-grade coal-bed methane is extremely important,but challenging,due to the very similar physical properties of CH_(4)and ***,we proposed a dual polarization strategy by employing triazine and polyfluoride sites to construct polar pores in COF materials,achieving the efficient separa-tion of CH_(4)from *** expected,the dual polarized F-CTF-1 and F-CTF-2 exhibit higher CH_(4)adsorption capacity and CH_(4)/N_(2)selectivity than CTF-1 and CTF-2,***,the CH4 uptake capacity and CH_(4)/N_(2)selectivity of F-CTF-2 is 1.76 and 1.42 times than that of *** work not only developed promising COF materials for CH4/N_(2)separation,but also provided important guidance for the separation of other adsorbates with similar properties.

关键词： Dual polarization strategy Covalent organic frameworks(COFs) Coal-bed methane purification Chemical/thermal stability Cycling stability

Enhancing XRF sensor-based sorting of porphyritic copper ore using particle swarm optimization-support vector machine(PSO-SVM)algorithm

在线全文

学校读者我要写书评

暂无评论

International Journal of mining Science and Technology 2024年第4期34卷 545-556页

作者： Zhengyu Liu Jue Kou Zengxin Yan Peilong Wang Chang Liu Chunbao Sun Anlin Shao Bern Klein School of Civil and Resources engineering University of Science and TechnologyBeijing 100083China institute of Minerals Research University of Science and TechnologyBeijing 100083China State Key Laboratory of Mineral Processing Beijing 102628China Ansteel Group mining Co.Ltd. Anshan 114000China Norman B.Keevil institute of mining engineering University of British ColumbiaVancouverBC V6T 1Z4Canada

X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hindering widespread technology *** classification models are crucial to determine if actual grade exceeds the sorting threshold using localized XRF *** studies mainly used linear regression(LR)algorithms including simple linear regression(SLR),multivariable linear regression(MLR),and multivariable linear regression with interaction(MLRI)but often fell short attaining satisfactory *** study employed the particle swarm optimization support vector machine(PSO-SVM)algorithm for sorting porphyritic copper ore ***-scale results showed PSO-SVM out-performed LR and raw data(RD)models and the significant interaction effects among input features was *** poor input data quality,PSO-SVM demonstrated exceptional ***-scale sorting achieved 93.0%accuracy,0.24%grade increase,84.94%recovery rate,57.02%discard rate,and a remarkable 39.62 yuan/t net smelter return(NSR)increase compared to no *** improvements were achieved by the PSO-SVM model with optimized input combinations and highest data quality(T=10,T is XRF testing times).The unsuitability of LR methods for XRF sensor-based sorting of investigated sample is *** element selection and mineral association analysis elucidate element importance and influence mechanisms.

关键词： XRF sensor-based sorting PSO-SVM algorithm Copper ore pebble Receiver operating curve(ROC) Net smelter return(NSR)

Actively tuning anisotropic light-matter interaction in biaxial hyperbolic materialα-MoO_(3) using phase change material VO_(2) and graphene

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 631-638页

作者：周昆胡杨吴必园仲晓星吴小虎 School of Safety engineering China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Gas and Fire Control for Coal Mines China University of Mining and TechnologyXuzhou 221116China Shandong institute of Advanced Technology Jinan 250100China School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China

Anisotropic hyperbolic phonon polaritons(PhPs)in natural biaxial hyperbolic materialα-MoO_(3) has opened up new avenues for mid-infrared nanophotonics,while active tunability ofα-MoO_(3) PhPs is still an urgent problem necessarily to be *** this study,we present a theoretical demonstration of actively tuningα-MoO_(3) PhPs using phase change material VO_(2) and *** is observed thatα-MoO_(3) PhPs are greatly dependent on the propagation plane angle of *** insulator-to-metal phase transition of VO_(2) has a significant effect on the hybridization PhPs of theα-MoO_(3)/VO_(2) structure and allows to obtain actively tunableα-MoO_(3) PhPs,which is especially obvious when the propagation plane angle of PhPs is ***,when graphene surface plasmon sources are placed at the top or bottom ofα-MoO_(3) inα-MoO_(3)/VO_(2)structure,tunable coupled hyperbolic plasmon-phonon polaritons inside its Reststrahlen bands(RB s)and surface plasmonphonon polaritons outside its RBs can be *** addition,the above-mentionedα-MoO_(3)-based structures also lead to actively tunable anisotropic spontaneous emission(SE)*** study may be beneficial for realization of active tunability of both PhPs and SE ofα-MoO_(3),and facilitate a deeper understanding of the mechanisms of anisotropic light-matter interaction inα-MoO_(3) using functional materials.

关键词： light-matter interaction hyperbolic material phase change material graphene

Testing method of rock structural plane using digital drilling

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2563-2578页

作者： Qi Wang Yuncai Wang Bei Jiang Hongke Gao Fenglin Ma Dahu Zhai Songlin Cai State Key Laboratory for Tunnel engineering China University of Mining and Technology(Beijing)Beijing100083China

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and ***,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground ***,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground *** paper presents the digital drilling technology as a new testing method of rock mass structural *** rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling *** analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive ***,an identification model for the characteristic parameters of rock mass structural planes during drilling is *** test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45°and 0.82 mm,*** identification model while drilling is verified to be correct due to the high identification *** on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is *** research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

关键词： Structural planes in the rock mass Digital drilling Drilling parameters Equivalent compressive strength Testing method

Slope stability of reclaimed coal mines through a new water filling index

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2024年第3期16卷 828-839页

作者： Antonios Mikroutsikos Alexandros I.Theocharis Nikolaos C.Koukouzas Ioannis E.Zevgolis Chemical Process&Energy Resources institute Centre for Research&Technology HellasAthensGreece School of mining and Metallurgical engineering National Technical University of AthensAthensGreece

A common reclamation practice for closed coal surface mines is filling them with water to form pit *** creation and sustainability of these lakes are significantly affected by the stability of the corresponding *** present study provides a general framework for analyzing the water filling’s effect on slope stability based on a new water filling index,which can indirectly consider the factors affecting the process and efficiently quantify the filling speed’s *** assumptions of the proposed approach are thoroughly discussed,and the range of the water filling index is ***,the safety factor is calculated using the finite element method with the shear strength reduction technique during the filling process for various conditions(soil properties,slope geometry,hydraulic conditions,and water filling speed).Results are presented as normalized stability charts for practical *** the water filling,the stability gradually decreases until the reservoir reaches a critical level of 10%e40%of the total height;it then increases to even more stable conditions than the initial ***,the present analysis allows for the preliminary stability evaluation of a coal mine during the formation of a pit lake and the appropriate quantification of the water filling’s effect.

关键词： Post-coal era Open-pit flooding Stability charts Critical level

Knowledge and data jointly driven aeroengine gas path performance assessment method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 533-557页

作者： Zhe WANG Xuyun FU Rui ZHANG Zhengfeng BAI Xiangzhao XIA Wei JIANG Department of Mechanical engineering Harbin Institute of TechnologyWeihai 264209China Weihai Key Laboratory of Intelligent Operation and Maintenance Harbin Institute of TechnologyWeihai 264209China Control system Design Laboratory AECC ShenYang Engine Research InstituteShenyang 110015China

Aeroengines,as the sole power source for aircraft,play a vital role in ensuring flight *** gas path,which represents the fundamental pathway for airflow within an aeroengine,directly impacts the aeroengine's performance,fuel efficiency,and ***,timely and accurate evaluation of gas path performance is of paramount *** paper proposes a knowledge and data jointly driven aeroengine gas path performance assessment method,combining Fingerprint and gas path parameter deviation ***,Fingerprint is used to correct gas path parameter deviation values,eliminating parameter shifts caused by non-component performance ***,coarse errors are removed using the Romanovsky criterion for short-term data divided by an equal-length overlapping sliding ***,an Ensemble Empirical Mode Decomposition and Non-Local Means(EEMD-NLM)filtering method is designed to“clean”data noise,completing the preprocessing for gas path parameter deviation ***,based on the characteristics of gas path parameter deviation values,a Dynamic Temporary Blended Network(DTBN)model is built to extract its temporal features,cascaded with Multi-Layer Perceptron(MLP),and combined with Fingerprint to construct a Dynamic Temporary Blended AutoEncoder(DTB-AutoEncoder).Eventually,by training this improved autoencoder,the aeroengine gas path multi-component performance assessment model is formed,which can sufficiently decouple the nonlinear mapping relationship between aeroengine gas path multi-component performance degradation and gas path parameter deviation values,thereby achieving the performance assessment of engine gas path *** practical application cases,the effectiveness of this model in assessing the aeroengine gas path multi-component performance is verified.

关键词： Performance assessment Aeroengine Fingerprint Gas path parameter deviation values Jointly drive

Influence of Film Thickness on Nanofabrication of Graphene Oxide

在线全文

学校读者我要写书评

暂无评论

Nanomanufacturing and Metrology 2024年第2期7卷 13-25页

作者： Chuan Tang Lei Chen Linmao Qian Tribology Research institute The State Key Laboratory of Rail Vehicle SystemSchool of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Nanofabrication of two-dimensional materials through mechanical machining is normally influenced by not only process parameters such as load and velocity but also intrinsic properties such as strength and ***,we examined the effects of graphene oxide(GO)film thickness on nanofabrication on the plane surfaces and at the step edges using scanning probe microscope *** material removal of GO initiates at the load above a critical value,which strongly depends on film thickness and *** the increase in film thickness,the critical load decreases monotonically on the plane surfaces but increases gradually at the step ***,the critical load for the GO monolayer at the step edges is at least 25 times lower than that on the plane surfaces,and the gap decreases to around 3 times when GO thickness increases to four ***,mechanical nanofabrication initiating from the GO step edge allows producing various nanopatterns under extremely low loads around 1 ***,the GO nanostructures are deoxidized by annealing at 800°C in high-purity argon to restore their highly functionalized conjugated structures,which are supported by X-ray diffraction and Raman *** work provides a novel approach to fabricating graphene-like nanostructures by deoxidizing GO after nanofabrication,which holds significant potential for applications in graphene-based devices.

关键词： Graphene oxide Nanofabrication Film thickness step edge Nanopattern Deoxidized treatment

Reward Function Design Method for Long Episode Pursuit Tasks Under Polar Coordinate in Multi-Agent Reinforcement Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2024年第4期29卷 646-655页

作者： DONG Yubo CUI Tao ZHOU Yufan SONG Xun ZHU Yue DONG Peng School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China Beijing institute of Electronic system engineering Beijing100854China

Multi-agent reinforcement learning has recently been applied to solve pursuit ***,it suffers from a large number of time steps per training episode,thus always struggling to converge effectively,resulting in low rewards and an inability for agents to learn *** paper proposes a deep reinforcement learning(DRL)training method that employs an ensemble segmented multi-reward function design approach to address the convergence problem mentioned *** ensemble reward function combines the advantages of two reward functions,which enhances the training effect of agents in long ***,we eliminate the non-monotonic behavior in reward function introduced by the trigonometric functions in the traditional 2D polar coordinates observation *** results demonstrate that this method outperforms the traditional single reward function mechanism in the pursuit scenario by enhancing agents’policy scores of the *** ideas offer a solution to the convergence challenges faced by DRL models in long episode pursuit problems,leading to an improved model training performance.

关键词： multi-agent reinforcement learning deep reinforcement learning(DRL) long episode reward function

Entropy consistency-based adaptive sampling method for determining the scale effect in the joint roughness coefficient

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年

作者： Jibo Qin Jun Ye Xiaoming Sun Shigui Du State Key Laboratory for Tunnel engineering， China University of mining and Technology-Beijing School of Mechanics and Civil engineering， China University of mining and Technology-Beijing institute of Rock Mechanics， Ningbo University

The joint roughness coefficient （JRC） is one of the key parameters for evaluating the shear strength of rock joints. Because of the scale effect in the JRC， reliable JRC values are of great importance for most rock engineering projects. During the collection process of JRC samples， the redundancy or insufficiency of representative rock joint surface topography （RJST） information in serial length JRC samples is the essential reason that affects the reliability of the scale effect results. Therefore， this paper proposes an adaptive sampling method， in which we use the entropy consistency measure Q（a） to evaluate the consistency of the joint morphology information contained in adjacent JRC samples. Then the sampling interval is automatically adjusted according to the threshold Q(at) of the entropy consistency measure to ensure that the degree of change of RJST information between JRC samples is the same， and ultimately makes the representative RJST information in the collected JRC samples more balanced. The application results of actual cases show that the proposed method can obtain the scale effect in the JRC efficiently and reliably.

关键词：