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矿山机电设备故障检修技术的应用与研究

世界有色金属 2024年第14期 54-56页

作者：齐英争中核沽源铀业有限责任公司河北张家口076550

矿山机电设备故障检修技术的应用对于保障矿山生产效率、提高设备可靠性和安全性具有重要意义。本文详细论述了故障诊断技术重要性,介绍了矿山机电设备故障检修技术。通过矿山机电设备故障检修技术应用与研究,可以提高矿山机电设备故障... 详细信息

矿山机电设备故障检修技术的应用对于保障矿山生产效率、提高设备可靠性和安全性具有重要意义。本文详细论述了故障诊断技术重要性,介绍了矿山机电设备故障检修技术。通过矿山机电设备故障检修技术应用与研究,可以提高矿山机电设备故障检修工作的效率和准确性,确保矿山生产的安全和顺利进行。矿山工作人员应不断学习和掌握相关的维修知识和技术,提高故障检修能力,为矿山的可持续发展贡献力量。

关键词：矿山机电设备故障检测故障维修

Joint Effects of Multipollutant Mixtures on Mortality in Chengdu,China

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Biomedical and Environmental Sciences 2024年第1期37卷 112-116页

作者： ZHANG ying TIAN qi qi HU Wen Dong ZHANG Shao Bo WANG Shi Gong zheng Can Jun Plateau Atmosphere and Environment Key Laboratory of Sichuan Province School of Atmospheric SciencesChengdu University of Information TechnologyChengdu 610225SichuanChina Yunnan R&D Institute of Natural Disaster on Chengdu University of Information Technology Kunming 650034YunnanChina Chengdu Plain Urban Meteorology and Environment Sichuan Provincial Field Scientific Observation and Research Station Chengdu 610225SichuanChina Chinese Center for Disease Control and Prevention National Institute for Communicable Disease Control and PreventionBeijing 102206China

Significant epidemiological research has revealed that exposure to air pollution is substantially associated with numerous detrimental health consequences^([1-3]).The negative health effects of individual air pollutants(e.g.,fine particulate matter:PM_(2.5);nitrogen dioxide:NO_(2);carbon monoxide,CO;or ozone:O_(3))have been widely explored^([4]).However,humans are constantly exposed to multipollutant mixtures in real life,and biological responses to inhaled pollutants are likely to depend on the interplay of pollutant ***,it is critical and imperative to explore the joint effects of multipollutant mixtures on human beings.

关键词： mixtures monoxide consequences

Particle Distribution Informed by Chain Rigidity in Diblock Copolymer Melts: The Effect of Entropy

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Chinese Journal of Polymer Science 2024年第3期42卷 388-399,I0009页

作者： Yuguo Chen Shuanhu qi ying Jiang School of Chemistry Beihang UniversityBeijing 100191China

We study the effect of chain rigidity on tailoring the nanoparticle locations for neutral and selective particles embedded in the lamellar morphology formed by semiflexible diblock copolymer chains using self-consistent field calculations. The nanoparticles are modeled through a cavity function, and the semiflexible chains are represented by the continuous Kratsky-Porod chain model. In general situation, the nanoparticles prefer to stay at the interface in order to reduce the interface areas and thus the system free energy. However, the particle distribution at the domain center is subtle, and the underlying physics is intrinsically different depending on the polymer flexibility. In the case of flexible chains, the entropy just contributes a constant shift to the free energy when the nanoparticles move around the domain center indicating that the local metastable state if appears at the domain center is wholly attributed to the local minimum in the enthalpy. If the polymers are rigid, the variation of the particle distribution at the domain center has a close relation with the polymer rigidity and nanoparticle size. In the case of strongly rigid polymers with small nanoparticles, a nearly uniform particle distribution at the domain center is observed, while in other cases, a local enhancement of particle distribution there is found. In contrast to the case of flexible chains, further analysis reveals the crucial role of entropy in controlling the shape of particle distributions at the phase domain. Specifically, the local metastable state appears in the domain center is determined by the large entropy there which arises from the weak coupling of bond orientations that allows the polymer chains to be relatively relaxed. When the particle becomes selective, its distribution in the phase domain exhibits a shift almost uniformly rather than changes its profile, and the underlying physics still holds. In all, our study establishes a strong coupling between the chain rigi

关键词： Semiflexible diblock copolymer Nanoparticle distribution Self-consistent field theory Entropic effect

A Fibonacci View on the Galois NFSR Used in Trivium

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Journal of Systems Science & Complexity 2024年第3期37卷 1326-1350页

作者： WANG Hongyu zheng Qunxiong qi Wenfeng PLA Strategic Support Force Information Engineering University Zhengzhou 450001China

Trivium is an international standard of lightweight stream ciphers(ISO/IEC 29192-3:2012).In this paper,the Trivium-like NFSRs,a class of Galois NFSRs generalized from the Galois NFSR of Trivium,are studied from the perspective of Fibonacci *** is shown that an n-stage Trivium-like NFSR cannot be equivalent to an n-stage Fibonacci NFSR,which is proved by showing the existence of“collision initial states”.As an intermediate conclusion,a necessary and sufficient condition for a kind of linear degeneracy of a Trivium-like NFSR is obtained from the persepective of interleaved ***,the smallest stage number of a Fibonacci NFSR that can generate all the output sequences of an n-stage Trivium-like NFSR is shown to be greater than n-7 and this value is no less than 371=287+min{93,84,111}specifically for the 288-stage Galois NFSR used in *** results contradict the existence of a equivalent Fibonacci model of Trivium NFSR of small stage,which implies that Trivium algorithm possesses a fair degree of immunity against“structure attack”.

关键词： Fibonacci NFSR galois NFSR interleaved sequence linear degeneracy trivium

Sustainable ammonia synthesis:An in-depth review of non-thermal plasma technologies

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Journal of Energy Chemistry 2024年第9期96卷 1-38页

作者： Vahid Shahed Gharahshiran ying zheng Department of Chemical and Biochemical Engineering Thompson Engineering BuildingWestern UniversityLondonON N6A 5B9Canada

Ammonia serves both as a widely used fertilizer and environmentally friendly energy source due to its high energy density,rich hydrogen content,and emissions-free ***,it offers convenient transportation and storage as a hydrogen *** dominant method used for large-scale ammonia production is the Haber-Bosch process,which requires high temperatures and pressures and is ***,non-thermal plasma offers an eco-friendly alternative for ammonia synthesis,gaining significant *** enables ammonia production at lower temperatures and pressures using plasma *** review provides insights into the catalyst and reactor developments,which are pivotal for promoting ammonia efficiency and addressing existing *** first,the reaction kinetics and mechanisms are introduced to gain a comprehensive understanding of the reaction pathways involved in plasma-assisted ammonia ***,the enhancement of ammonia synthesis efficiency is discussed by developing and optimizing plasma reactors and effective *** effect of other feeding sources,such as water and methane,instead of hydrogen is also ***,the challenges and possible solutions are outlined to facilitate energy-saving and enhance ammonia efficiency in the future.

关键词： Nitrogen fixation Ammonia synthesis NH_(3) Non-thermal plasma Ni Ru catalyst

An Example of Embedded Singular Continuous Spectrum for Discrete Schrödinger Operators

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1837-1849页

作者： zheng qi FU Xiong LI Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

We present an example of a potential such that the corresponding discrete Schrödinger operator has singular continuous spectrum embedded in the absolutely continuous spectrum.

关键词： Sparse potentials singular continuous spectrum Prüfer variables

Microscale spherical TiO_(2)powder prepared by hydrolysis of TiCl_(4)solution:Synthesis and kinetics

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Particuology 2024年第1期84卷 60-71页

作者： Peiyi Yan ying Zhang Shili zheng School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Panzhihua617000China

Hydrolysis of TiCl_(4)solution is capable of preparing microscale TiO_(2)*** research studied the synthesis of microscale spherical TiO_(2)powders and the hydrolysis *** effects of the flow field generated by different agitators and baffles in the crystallizer,the initial free acid concentration,the initial equivalent TiO_(2)concentration,and the temperature on the hydrolysis progress and powder morphology were systematically *** results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders,and the axial flow can improve the sphericity of the *** increased free HCl and equivalent TiO_(2)concentrations in the pregnant solution inhibit the forward hydrolysis reaction,prolong the time to reach equilibrium,and reduce the *** appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and *** with sizes ranging from around 5 um-40μm can be tuned under controlled flow field,solution compositions,and temperature *** addition,the Cheng and Wunderlich modified Avrami equation was used for the crystallization kinetic *** effects of the free HCl concentration,equivalent TiO_(2)concentration,and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction *** the free HCl and equivalent TiO_(2)concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei,thus increasing the final powder size,while increasing the temperature will lead to the opposite results.

关键词： TiCl_(4) Hydrolysis Microscale TiO_(2) Spherical Kinetics

Greedy Lattice Paths with General Weights

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2213-2222页

作者： Yin Shan CHANG An qi zheng College of Mathematics Sichuan UniversityChengdu 610065P.R.China

Let{X_(v):v∈Z^(d)}be *** *** S(π)=Σ_(v∈π)X_(v)be the weight of a self-avoiding lattice pathπ.Let M_(n)=max{S(π):πhas length n and starts from the origin}.We are interested in the asymptotics of Mn as n→∞.This model is closely related to the first passage percolation when the weights{X_(v):v∈Z^(d)}are non-positive and it is closely related to the last passage percolation when the weights{X_(v):v∈Z^(d)}are *** general weights,this model could be viewed as an interpolation between first passage models and last passage ***,this model is also closely related to a variant of the position of right-most particles of branching random *** the two assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)<+∞and that E[(X_(0)^(−))^(4)]<+∞,we prove that M_(n)/n converges to the same constant M almost surely as n tends to infinity.

关键词： Last passage percolation first passage percolation greedy lattice path

Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS

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Satellite Navigation 2024年第1期5卷 52-73页

作者： Yunhan qi zheng Yao Mingquan Lu Department of Electronic Engineering Tsinghua UniversityBeijing100084China Beijing National Research Center for Information Science and Technology Beijing100084China

With the evolution of Global Navigation Satellite System(GNSS),new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques,which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal(WMS).Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency of signals,their multi-component structures and wide root mean square bandwidths introduced by high-frequency subcarriers also provide the possibility to improve the GNSS ranging ***,this paper proposes a Dual-assisted Multi-component Tracking(DMT)technique,which can not only fully use high-frequency subcarriers in WMSs,but also effectively track carrier,subcarrier,and code by jointly utilizing all components in *** this paper,the tracking and ranging performances of DMT are comprehensively analyzed theoretically and by simulation and real *** results show that compared with existing WMS tracking methods,DMT can achieve tracking results with lower tracking jitters and ranging results with higher precision,providing a highly advantageous solution for new generation GNSS signal processing.

关键词： Wideband multiplexed signal Dual-assisted Multi-component High precision tracking