检索结果-南通市图书馆

New progresses of fine-grained sediment gravity-flow deposits and their importance for unconventional shale oil and gas plays

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Petroleum science 2025年第1期22卷 1-15页

作者： Tian Yang Ying-Lin Liu State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology) Institute of Sedimentary Geology Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of natural Resources Chengdu University of Technology

Fine-grained sediments are widely distributed and constitute the most abundant component in sedimentary systems, thus the research on their genesis and distribution is of great significance. In recent years, fine-grained sediment gravity-flows(FGSGF) have been recognized as an important transportation and depositional mechanism for accumulating thick successions of fine-grained sediments. Through a comprehensive review and synthesis of global research on FGSGF deposition, the characteristics,depositional mechanisms, and distribution patterns of fine-grained sediment gravity-flow deposits(FGSGFD) are discussed, and future research prospects are clarified. In addition to the traditionally recognized low-density turbidity current and muddy debris flow, wave-enhanced gravity flow, lowdensity muddy hyperpycnal flow, and hypopycnal plumes can all form widely distributed FGSGFD. At the same time, the evolution of FGSGF during transportation can result in transitional and hybrid gravityflow deposits. The combination of multiple triggering mechanisms promotes the widespread development of FGSGFD, without temporal and spatial limitations. Different types and concentrations of clay minerals, organic matters, and organo-clay complexes are the keys to controlling the flow transformation of FGSGF from low-concentration turbidity currents to high-concentration muddy debris flows. Further study is needed on the interaction mechanism of FGSGF caused by different initiations, the evolution of FGSGF with the effect of organic-inorganic synergy, and the controlling factors of the distribution patterns of FGSGFD. The study of FGSGFD can shed some new light on the formation of widely developed thin-bedded siltstones within shales. At the same time, these insights may broaden the exploration scope of shale oil and gas, which have important geological significances for unconventional shale oil and gas.

关键词： Fine-grained sediment gravity-flow Depositional mechanism Transportation and evolution Distribution pattern Shale oil and gas

Decentralized fault diagnos.s of discrete-event systems with unreliable sensors using linear temporal logic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2025年第1期68卷 322-341页

作者： Weijie DONG Shaoyuan LI Xiang YIN Key Laboratory of System Control and Information Processing Ministry of EducationDepartment of Automation Shanghai Jiao Tong University

In this paper,we investigate a decentralized diagnos.s problem of a discrete-evnt system(DES) subject to unreliable sensors,where the sensor observations of local diagnos.rs may be non-deterministic as a result of possible *** studies on decentralized robust diagnos.s can only deal with different types of sensor failures separately,e.g.,all sensors suffer from the same type of sensor failures such as intermittent sensor failures or permanent sensor ***,since sensors of different local diagnos.rs may face different external environments and have different internal characteristics,sensors corresponding to different local diagnos.rs may also have their own fault *** this paper,we propose a flexible framework of decentralized diagnos.s for DES subject to unreliable sensors such that sensors of different local diagnos.rs are permitted to have different types of sensor *** this end,we extend the existing decentralized diagnos.s framework to the case where there exist common sensors broadcasting their observations to all local *** apply linear temporal logic(LTL) to constrain infinite behaviors of private sensors of local diagnos.rs and common ***,a new notion of φ-codiagnos.bility is proposed as the necessary and sufficient condition for the existence of a decentralized diagnos.r that works correctly under sensors,satisfying LTL-based sensor ***,we provide an effective approach to verify the φ-codiagnos.bility.

关键词： discrete event systems decentralized diagnos.s codiagnos.bility automata

Recent advances,strategies,and future perspectives of peptide-based drugs in clinical applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of natural Medicines 2025年第1期23卷 31-42页

作者： Qimeng Yang Zhipeng Hu Hongyu Jiang Jialing Wang Han Han Wei Shi Hai Qian Centre of Drug Discovery State Key Laboratory of Natural Medicines China Pharmaceutical University Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease China Pharmaceutical University

Peptide-based therapies have attracted considerable interest in the treatment of cancer, diabetes, bacterial infections, and neurodegenerative diseases due to their promising therapeutic properties and enhanced safety profiles. This review provides a comprehensive overview of the major trends in peptide drug discovery and development, emphasizing preclinical strategies aimed at improving peptide stability, specificity, and pharmacokinetic properties. It assesses the current applications and challenges of peptide-based drugs in these diseases, illustrating the pharmaceutical areas where peptide-based drugs demonstrate significant potential. Furthermore, this review analyzes the obstacles that must be overcome in the future,aiming to provide valuable insights and references for the continued advancement of peptidebased drugs.

关键词： Antimicrobial peptides Diabetes Neurodegenerative diseases Oncology Peptide-based drugs

Modular assembly of Co4-thiacalix[4]arene units and Keggin-type SiW12O40 for visible-light photothermal conversion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tungsten 2025年第1期7卷 112-119页

作者： Jia-Hui Li Qing Zhao Dong-Ao Mao Kun Zhou Bao-Kuan Chen Yan-Feng Bi School of Petrochemical Engineering Liaoning Petrochemical University

The construction of metal-organic coordination clusters（MCCs） using modular secondary building units is an important method for preparing functional *** this study,two new MCCs modularly assembled from Keggin-type {SiW12O40}H4TC4A=p-tert-Butylthiacalix[4]arene(SiW12) units and thiacalixarene-supported Co4-thiacalix[4]arene(Co4-TC4A polynuclear second-building units（PSBUs,H4TC4A=p-tert-Butylthiacalix[4]arene） are *** two MCCs,abbreviated as Co4-SiW12and Co8-SiW12,were structurally characterized by single-crystal X-ray *** Co4-SiW12is a supramolecular structure involving cation-anion interactions between Co4-TC4A PSBUs and ***8-SiW12features "barbell-like" shapes with two Co4-TC4A coordinatively linked to a Keggin-type SiW12unit on opposite via W-O_t-Co *** coordination of Co4-TC4A to SiW12in Co8-SiW12resulted in significantly improved photothermal conversion performances compared with Co4-SiW12and pure SiW12or ***-gap determination and photophysical analysis combined with density functional theory calculations indicated the binding mode between Co4-TC4A PSBUs and SiW12,which considerably influences the way of electron transport and the conversion ability of visible light to heat.

关键词： Modular construction Photothermal conversion Polyoxometalate Thiacalixarene

Structural engineering of high-entropy alloys for advanced electrocatalytic reactions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tungsten 2025年第1期7卷 1-31页

作者： Qiao Xie Ying-Jie Yu Hai-Jun Zhang Ya-Ping Deng Wen Lei The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Department of Chemical Engineering Waterloo Institute for Sustainable Energy Waterloo Institute for Nanotechnology University of Waterloo

High-entropy alloys(HEAs) have emerged as promising candidates to replace traditional precious metal catalysts,owing to their unique chemical and physical *** review commences by revisiting the fundamental concepts of HEAs,including their synthesis methods and structural control strategies in *** underscores the critical role of meticulously manipulating both macroscopic and microscopic structures of the HEAs to optimize their catalytic performance.A deep understanding of the structure-activity relationship in HEAs across various configurations is pivotal in developing more effective *** review methodically encapsulates the research progress of structural control strategies for HEAs in achieving efficient energy conversion,with the aim of gaining a better understanding of the relationship between structure and *** review concludes by summarizing the current achievements and challenges,and suggestions for potential future directions of HEAs in the fields of energy conversion and environmental purification.

关键词： Electrocatalytic Energy conversion High-entropy alloys Structural modulation

Robust free-base and metalated corrole radicals with reduction-induced emission

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2025年第2期36卷 426-431页

作者： Pengfei Li Chulin Qu Fan Wu Hu Gao Chengyan Zhao Yue Zhao Zhen Shen State Key Laboratory of Coordination Chemistry Collaborative Innovation Center of Advanced MicrostructuresSchool of Chemistry and Chemical EngineeringNanjing University School of Chemistry and Materials science Nanjing Normal University College of Materials science and Engineering Nanjing Forestry University

Preparing free-base porphyrinoid radicals that can function as coordination ligands is a challenging task. Here we report the synthesis of a stable, free-base benzocorrole(BC) radical containing only two inner NH protons via a retro-Diels-Alder conversion. The radical character of BC was fully supported by crystallographic analysis, spectroscopic evidence, and theoretical calculations. This neutral radical ligand allowed easy insertion of Zn(Ⅱ), Ga(Ⅲ), and Pd(Ⅱ) ions to produce radical complexes. All these radicals exhibited luminescence-on responses under weak reducing atmosphere, corresponding to the conversion to their aromatic anions. The red fluorescence was observed for BC and its Zn(Ⅱ) and Ga(Ⅲ) complexes,and the near-infrared phosphorescence(>900 nm) was detected for Pd(Ⅱ) complex at room ***, Ga(Ⅲ) corrole exhibited a variation in fluorescence in response to axial coordination. Our findings provide a promising radical platform for coordination and developing novel functional materials with switchable spin and emission.

关键词： Luminescence Macrocyclic ligands Porphyrinoids Radicals Redox chemistry

Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： Fan YANG Zhaoyang MA Xingming GUO Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai Institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

关键词： flexural wave bandgap graded design local resonance metamaterial O421+.5

Resilient satellite-based PNT system design and key technologies

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china Earth sciences 2025年第3期68卷 669-682页

作者： Yuanxi YANG Zheng YAO Yue MAO Tianhe XU Dixing WANG Key Laboratory of Smart Earth Xi'an Research Institute of Surveying and Mapping Department of Electronic Engineering Tsinghua University School of Space science and Technology Shandong University

Satellite-based positioning navigation and timing(PNT) system is the most fundamental and convenient application system in PNT fields now and in the future, thus the satellite-based PNT service system should be more and more robust, reliable and easy to be applied. Aiming at the weak service performance of the existing BeiDou constellation in the Antarctic and Arctic regions and the possible discontinuous problems in the autonomous orbit determination using BeiDou terminals on board of low earth orbit(LEO) satellites, we propose a scheme to optimize the BeiDou constellation configuration. A relatively optimized deep space PNT service constellation is designed in order to overcome the weak service capability of the BeiDou navigation constellation in deep space. We find that more satellites in the same orbital plane have better positioning geometry than increasing the number of constellation orbital planes. Furthermore, the idea of resilient satellite-based PNT service mode combining deep, high, medium, and low earth orbit navigation constellations is proposed, in order to improve the service capability of multi navigation constellations. To strengthen the satellite PNT service ability, the resilient strategies of on-board phased array antenna, on-board atomic clocks and satellite signal generator are proposed, in which the adaptively possible adjustment of signal power, signal frequency, signal modulation waveform and information format are discussed. Some examples to demonstrate the resilient satellite-based PNT application modes are given.

关键词： BeiDou navigation constellation Resilient navigation constellation Resilient PNT service Resilient signal modulation Adaptive signal power

Steady-state and transient investigation of a small pressurized water reactor ACPR50S for different ATFs based on Bamboo-C code

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2025年第1期36卷 192-206页

作者： Kun Zhuang Ying-Zhen Wang Li-Na Deng Yong-Zhan Wang Wen Shang Si-Peng Wang Department of Nuclear science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Small modular reactors have received widespread attention owing to their inherent safety,low investment,and *** pressurized water reactors(SPWRs)have become important candidates for SMRs owing to their high technological *** the Fukushima accident,research on accident-tolerant fuels(ATFs),which are more resistant to serious accidents than conventional fuels,has gradually *** study analyzes the neutronics and thermal hydraulics of an SPWR(ACPR50S)for different ATFs,BeO+UO_(2)−SiC,BeO+UO_(2)−FeCrAl,U_(3)Si_(2)−SiC,and U_(3)Si_(2)−FeCrAl,based on a PWR fuel management code,the Bamboo-C deterministic *** the steady state,the burnup calculations,reactivity coefficients,power and temperature distributions,and control rod reactivity worth were *** transients of the control rod ejection accident for the two control rods with the maximum and minimum reactivity worth were *** results showed that 5%B-10 enrichment in the wet annular burnable absorbers assembly can effectively reduce the initial reactivity and end-of-life reactivity *** BeO+UO2−SiC core exhibited superior neutronic characteristics in terms of burnup and negative temperature reactivity compared with the other three cases owing to the strong moderation ability of BeO+UO_(2)and low neutron absorption of ***,the U_(3)Si_(2)core had a marginally better power-flattening effect than BeO+UO_(2),and the differential worth of each control rod group was similar between different *** the transient of a control rod ejection,the changes in the fuel temperature,coolant temperature,and coolant density were *** maximum difference was less than 10℃ for the fuel temperature and 2℃ for the coolant temperature.

关键词： ACPR50S Small pressurized water reactor ATF Steady Transient

维普期刊数据库