检索结果-南通市图书馆

Entropy Production along Dominant Pathway of Nonequilibrium Phase Transition in Mesoscopic Chemical System

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2013年第5期26卷 549-552,I0003页

作者： han-shuang chen Gang He Feng Huang Chuan-sheng Shen School of Physics and Materials Science Anhui University Hefei 230039 China . __ Department of Mathematics and Physics Anhui University of Architecture Hefei 230601 China Department of Physics Anqing Teachers College Anqing 246011 China

We consider a bistable mesoscopic chemical reaction system and calculate entropy produc- tion along the dominant pathway during nonequilibrium phase transition. Using probability generating function method and eikonal approximation, we first convert the chemical master equation into the classical Hamilton-Jacobi equation, and then find the dominant pathways between two steady states in the phase space by calculating zero-energy trajectories. We find that entropy productions are related to the actions of the forward and backward dominant pathways. At the coexistence point where the stabilities of the two steady states are equiv alent, both the system entropy change and the medium entropy change are zero; whereas at non-coexistence point both of them are nonzero.

关键词： Entropy production Mesoscopic chemical reaction Nonequilibrium phasetransition

Ferroelectric perovskite PbTiO_(3)for advanced photocatalysis

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

Rare Metals 2024年第9期43卷 4038-4055页

作者： shuang Zhao Shi-Shi Shen Lu han Bo-Chao Tian Na Li Wei chen Xi-Bao Li School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051China School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China Department of Chemistry National University of SingaporeSingapore 117543Singapore

The ferroelectric semiconductor material PbTiO_(3)exhibits remarkable spontaneous polarization and photoelectric properties,positioning it as a promising polar *** internal electric field of ferroelectrics can separate photocarriers and enhance the catalytic performance of ***,when combined with other semiconductors,PbTiO_(3)contributes to the construction of a depolarization field,extending the catalytic applications of PbTiO_(3)***_(3)exhibits optical absorption,semiconductor,and piezoelectric *** piezoelectric polarization field enhances charge separation,modulates band structure,surface charge conduction,and heterojunction interface charge conduction,thereby amplifying photocatalytic *** paper begins by examining the structure,properties,and preparation methods of PbTiO_(3).Subsequently,it delves into the optimization of PbTiO_(3)'s structure and performance,exploring applications in photocatalysis as a ferroelectric *** is placed on the detailed discussion of surface modification,heterostructure formation,and ferroelectric polarization of PbTiO_(3)*** aspects are thoroughly explored for their role in regulating activity and optimizing the performance of photocatalysis and photopiezoelectric *** conclusion,the paper addresses the current research status of PbTiO_(3)ferroelectric materials and highlights the challenges that lie *** intention is to provide valuable references for the ongoing research in PbTiO_(3)ferroelectric materials.

关键词： PbTiO_(3) Ferroelectric polarization Photocatalysis Piezoelectric catalysis Polarization

Anti-saturation fault-tolerant adaptive torsional vibration control with fixed-time prescribed performance for rolling mill main drive system

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 660-669页

作者： shuang Liu chen Du Cong Zhang Zhen-hua Bai Key Lab of Industrial Computer Control Engineering of Hebei Province Yanshan UniversityQinhuangdao 066004HebeiChina National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004HebeiChina

An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input saturation,actuator faults,sensor measurement errors,and parameter ***,we gave a continuously differentiable saturation function to approximate the control input saturation characteristic of the RMMDS,translating the saturation characteristic into the matched uncertainty and unknown time-varying gain in the ***,an RMMDS mathematical model with unmatched uncertainty and unknown time-varying gain was developed,taking into account the presence of control input saturation,actuator faults,sensor measurement errors,and parameter *** on the established mathematical model,an error transformation model of the roll speed tracking was constructed by the equivalent error transformation *** to the error transformation model,a barrier Lyapunov function and a novel adaptive controller were studied to ensure that the roll speed tracking error always evolves inside a fixed-time asymmetric ***,numerical simulations were performed in Matlab/Simulink to verify the effectiveness and superiority of the proposed control method in suppressing the RMMDS torsional vibration.

关键词： Fixed-time prescribed performance Control input saturation Actuator fault Unknown time-varying gain Adaptive control Asymmetric constraint

Geochemistry and origins of hydrogen-containing natural gases in deep Songliao Basin,China:Insights from continental scientific drilling

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

Petroleum Science 2024年第2期21卷 741-751页

作者： shuang-Biao han Chao-han Xiang Xin Du Lin-Feng Xie Jie Huang cheng-Shan Wang College of Geoscience and Surveying Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing100083China

The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen *** gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been *** on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different *** gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(N_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary *** increasing depth,the origins of N_(2)and CO_(2)change gradually from a mixture of organic and inorganic to *** origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and *** shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic ***,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived *** discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas.

关键词： Gas compositions Stable isotopes Gas origins Hydrogen gas Songliao Basin

Pd-catalyzed intermolecular Si–O formation via Si–C activation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2661-2669页

作者： shuang Liu Yu-Shu chen Yichen Wu Peng Wang State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistryand Material Technology of Ministry of EducationHangzhou Normal UniversityHangzhou 311121China

The development of efficient Si–O bond formation reaction with 100% atom-economy, excellent functional group tolerance, and broad scope under mild conditions is highly desired due to the prevalence of silanol, silyl ether, and their derivatives in synthetic chemistry and materials science. Here, we have realized the Pd-catalyzed Si–O formation reaction via a Si–C activation approach with 100% atom-economy by employing silacyclobutanes(SCBs) and various hydroxy-containing substrates, including water,alcohols, phenols, and silanols. This protocol features a broad substrate scope, remarkable functional compatibility and mild conditions, providing a series of silanols, silyl ethers in high efficiency. Notably, this protocol could also be used for selective protection of hydroxy functionalities, and for the access of a class of novel polymers containing Si–O main chain. Preliminary mechanistic studies unveiled that this reaction underwent a Pd-catalyzed concerted ring-opening mechanism.

关键词： Si–O formation Si–C activation palladium silacyclobutane silanol silyl ether

List of 85 typical catastrophic landslides from March 2004 to February 2024

在线全文

学校读者我要写书评

暂无评论

China Geology 2024年第2期7卷 369-370页

作者： Rui-chen chen Yong-shuang Zhang School of Engineering and Technology China University of GeosciencesBeijing 100083China Institute of Geosafety China University of GeosciencesBeijing 100083China

Landslides are one of the most dangerous natural hazards that cause significant property damage and loss of *** often destroy farmland,villages,houses,factories,schools,roads and other facilities,injuring humans and ***,entire towns are devastated by *** to their pervasiveness,varied triggering factors,and sudden occurrence,landslides are currently one of the most challenging natural disasters to prevent and mitigate.

关键词： stated farmland catastrophic

Trajectory Time Series Compression Algorithm Based on Unsupervised Segmentation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2024年第3期12卷 360-378页

作者： shuang SUN Yan chen Zaiji PIAO School of Maritime Economics and Management Dalian Maritime UniversityDalian 116026China School of Software Dalian University of Foreign LanguagesDalian 116044China

Aiming at the problem of ignoring the importance of starting point features of trajecory segmentation in existing trajectory compression algorithms,a study was conducted on the preprocessing process of trajectory time ***,an algorithm improvement was proposed based on the segmentation algorithm GRASP-UTS(Greedy Randomized Adaptive Search Procedure for Unsupervised Trajectory Segmentation).On the basis of considering trajectory coverage,this algorithm designs an adaptive parameter adjustment to segment long-term trajectory data reasonably and the identification of an optimal starting point for *** the compression efficiency of typical offline and online algorithms,such as the Douglas-Peucker algorithm,the Sliding Window algorithm and its enhancements,was compared before and after *** experimental findings highlight that the Adaptive Parameters GRASP-UTS segmentation approach leads to higher fitting precision in trajectory time series compression and improved algorithm efficiency ***,the compression performance of the Improved Sliding Window algorithm post-segmentation showcases its suitability for trajectories of varying scales,providing reasonable compression accuracy.

关键词： trajectory time series unsupervised segmentation trajectory compression greedy ran-domized adaptive search

Pathological and Physiological High-frequency Oscillations on Electroencephalography in Patients with Epilepsy

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2024年第5期40卷 609-620页

作者： Hongyi Ye Cong chen Shennan A.Weiss shuang Wang Department of Neurology Epilepsy CenterSecond Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou310009China Department of Neurology State University of New York DownstateBrooklynNY11203USA Department of Physiology and Pharmacology State University of New York DownstateBrooklynNY11203USA Department of Neurology New York City Health+Hospitals/Kings CountyBrooklynNY11203USA

High-frequency oscillations(HFOs)encompass ripples(80 Hz–200 Hz)and fast ripples(200 Hz–600 Hz),serving as a promising biomarker for localizing the epileptogenic zone in *** fast ripples are always pathological,while ripples may be physiological or *** physiological from pathological ripples is important not only for designating epileptogenic brain regions,but also for investigations that study ripples in the context of memory encoding,consolidation,and recall in patients with *** studies have sought to identify distinguishing features between pathological and physiological ripples over the past two *** and pathological ripples differ with respect to their spatial location,cellular mechanisms,morphology,and coupling with background electroencephalographic *** studies have demonstrated that differentiating between pathological and physiological ripples can improve surgical outcome *** this review,we summarize the characteristics,differences,and applications of pathological and physiological HFOs and discuss strategies for their clinical translation.

关键词： Ripples Epilepsy Memory Sleep Surgical outcome

Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction

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

Nuclear Science and Techniques 2024年第3期35卷 40-52页

作者： Ding-han Zhu Xiong Zhang Xiao-Qiang Li Peng Li Yan-Bin Wang shuang Zhang State Key Laboratory of NBC Protection for Civilian Beijing 102205China

In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such *** pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric *** quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering *** proposed method is an improvement over the traditional analytical method that only computes direct-transmission *** traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo *** improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain ***,its computation time is 48,000 times faster than that of the Monte Carlo *** results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects.

关键词： High-altitude nuclear detonation Atmospheric transmission Pulsed X-rays Scattering correction Analytical method Monte Carlo method