检索结果-南通市图书馆

The gold-telluride connection:Evidence for multiple fluid pulses in the Jinqingding telluride-rich gold deposit of Jiaodong Peninsula,Eastern China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第3期15卷 146-165页

作者： Wenyan cai mingchun Song m.Santosh Jian Li School of Resources and Environmental Engineering Shandong University of TechnologyZibo 255049China Hebei Key Laboratory of Strategic Critical mineral Resources Hebei GEO UniversityShijiazhuang 050031China School of Earth Sciences and Resources China University of Geosciences Beijing29 Xueyuan RoadBeijing 100083China Department of Earth Science University of AdelaideAdelaide SA 5005Australia

The mechanism of gold migration,enrichment,and precipitation in forming world-class gold deposits has been a topic of wide interest,particularly where these deposits are abundant in *** Jiaodong Peninsula in eastern China hosts some of the world-class gold deposits among which the Jinqingding deposit is one of the best examples with substantial telluride mineralization and thus provides opportunity to investigate the genetic connection between tellurium and gold *** orebody in this deposit is hosted in the NE-NNE-trending Jiangjunshi-Quhezhuang fault with the Jurassic Kunyushan granitic pluton as wall *** deposit involved three mineralization stages as inferred from assemblages and crosscutting relationships between *** stages are:(I)pre-ore gold-poor quartz-pyrite veins,(II)main ore auriferous quartz-pyrite-Te/Bi-minerals±sphalerite±chalcopyrite±barite±marcasite veins,and(III)post-ore quartz-calcite *** present here the textural,isotopic,and geochemical variations of different stages/generations of pyrite based on scanning electron microscopy-energy dispersive spectroscopy(SEm-EDS),electron probe microanalysis(EPmA),and laser ablation inductively coupled plasma mass spectrometry(LA-ICP-mS).Pyrite in the Jinqingding deposit displays distinct ***1a shows a porous and dissolution-reprecipitation texture in the core,whereas Py1b exhibits a smooth and flat *** analysis reveals contrasting elemental compositions,with Py1a characterized by low Au(avg.0.14 ppm),As(avg.15.57 ppm),Ag(avg.17.71 ppm),and Te(avg.19.22 ppm)contents,but elevated Co(avg.1068.10 ppm)and Ni(224.12 ppm)concentrations,and variable sulfur isotopic composition(δ^(34)SV-CDT=9.54‰-12.12‰).Conversely,Py1b displays increased concentrations of these elements and a more concentratedδ^(34)SV-CDT value(11.99‰-12.23‰),possibly associated with weak coupled dissolution-reprecipitation(CDR)*** Stage II,pyrite can be further categorized

关键词： Episodic fluid pulses Sulfur reservoir Gold-Te precipitation Jinqingding deposit Jiaodong Peninsula

Shor's algorithm does not factor large integers in the presence of noise

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 305-320页

作者： Jin-Yi cai College of Letters and Science University of Wisconsin

We consider Shor's quantum factoring algorithm in the setting of noisy quantum gates. Under a generic model of random noise for(controlled) rotation gates, we prove that the algorithm does not factor integers of the form pq when the noise exceeds a vanishingly small level in terms of n—the number of bits of the integer to be factored, where p and q are from a well-defined set of primes of positive density. We further prove that with probability 1-o(1) over random prime pairs(p, q), Shor's factoring algorithm does not factor numbers of the form pq, with the same level of random noise present.

关键词： random noise Shor’s algorithm rotation gates quantum computing prime factorization

Whittle’s Index Based Sensor Scheduling for multiprocess Systems Under DoS Attacks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 329-350页

作者： cai Zai DING Kemi Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China.

In this paper,the authors consider how to design defensive countermeasures against DoS attacks for remote state estimation of multiprocess *** each system,a sensor will measure its state and transmits the data packets through an unreliable channel which is vulnerable to be jammed by an *** limited communication bandwidth,only a subset of sensors are allowed for data transmission,and how to select the optimal one to maximize the accuracy of remote state estimation is the focus of the proposed *** authors first formulate this problem as a markov decision process and investigate the existence of optimal ***,the authors demonstrate the piecewise monotonicity structure of optimal *** the difficulty of obtaining an optimal policy of large-scale problems,the authors develop a suboptimal heuristic policy based on the aforementioned policy structure and Whittle’s ***,a closed form of the indices is derived in order to reduce implementation complexity of proposed scheduling policy and numerical examples are provided to illustrate the proposed developed results.

关键词： DoS attacks Kalman filter remote state estimation Whittle’s index.

Polarized imaging dynamic light scattering for simultaneous measurement of nanoparticle size and morphology

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 213-223页

作者： Bingyao Wang Tianyi cai Xiaoshu cai Wu Zhou Zeqi Liu Schoolof Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai200093China Shanghai Key Laboratory of multiphase Flow and Heat Transfer in Power Engineering Shanghai200093China Jiaxing meaParTech Instrument Technology Co. LtdZhejiang314000China

The performance of nanoparticles is often affected by particle size and ***,electron microscopy or atomic force microscopy is typically utilized to determine the size and morphology of ***,there are issues such as difficult sample preparation,long processing times,and challenges in quantitative ***,it is of great significance to develop a fast,accu-rate,and statistical method to measure the size and morphology of *** this study,a new method,called polarized imaging dynamic light scattering(PIDLS),is *** nanoparticles are irradiated with a vertical linearly polarized laser beam,and a polarization camera collected the dynamic light scattering images of particles at four different polarization directions(0°,45°,90°,and 135°)at a scattering angle of 90°.The average particle size and distribution are obtained using the imaging dy-namic light scattering method at 0°polarization direction,and the morphology of the particles is ob-tained based on the depolarization patterns of the scattered *** optical sphericityΦis defined based on the degree of linear polarization(DoLP).It is also implemented for the quantitative evaluation of the sphericity of the nanoparticles,including spherical,octahedral,nanoplate,nanorod,and linear *** with the Poincarésphere parameterψ,the morphology of the nanoparticles can be roughly *** addition,PIDLS enables the measurement of particle size and morphology distributions simultaneously for evaluating the uniformity of *** effectiveness of PIDLS is verified by the measurement of five kinds of industrial titanium dioxide as well.

关键词： Imaging dynamic light scattering Polarized light scattering Non-spherical nanoparticles morphology Online measurement

An ultra-porous g-C_(3)N_(4) micro-tube coupled with mXene(Ti_(3)C_(2)TX)nanosheets for efficient degradation of organics under natural sunlight

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 Environmental Sciences 2024年第3期137卷 258-270页

作者： Zongyang Ya Qiyou Wang Jingjin cai Peng Wang Xinyu Jiang Zhiyin cai Shanglin Xiang Tingwei Wang Dongyu cai College of materials Science&Engineering Nanjing Tech University30 South PuZhu RoadNanjing 211816China Key Laboratory of Flexible Electronics(KLOFE)&Institute of Advanced materials(IAm) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech University30 South PuZhu RoadNanjing 211816China

It remains as a challenge for realizing efficient photo-responsive catalysts towards largescale degradation of organic pollutants under natural *** work reports a new pore engineering strategy for creating ultra-porous g-C_(3)N_(4) micro-tubes with an unprecedentedly high specific surface area of 152.96 m^(2)/*** is mainly associated with releasing internal vapor pressure in the autoclave where the hydrothermal treatment of the urea/melamine mixture is *** by microscopic observation,porosity measurement and spectroscopic characterization,it is found that releasing the pressure at halfway of hydrothermal process is vital for forming exfoliated rod-like precursors and the de-aggregation of these rods presents substantial benefits on the production of mesopores on g-C_(3)N_(4) microtubes during the calcination of *** offers a large number of reactive sites required by photocatalytic *** these micro-tubes with Ti_(3)C_(2)T_(X) nanosheets via electrostatic interaction yields a 1D/2D heterojunction with a close interfacial *** addition of metallically conductive Ti_(3)C_(2)T_(X) nanosheets accelerates the separation between electrons and holes,and also enhances the light *** these merits of structural design lead to forming a group of highly efficient catalysts demonstrating an excellent photocatalytic degradation rate of k=0.0560 min^(-1)for RhB dyes under 100 mW/cm~2 visible light radiation that micks sunlight *** laboratory valuation is further supported by an outdoor test that shows a fast degradation rate of 0.0744 min^(-1)under natural sunlight.

关键词： Carbon nitride mXene Heterojunction Photocatalysis

mathematical framework of nonlinear elastic waves propagating in pre-stressed media

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第10期45卷 1705-1716页

作者： Jiangcheng cai mingxi DENG College of Aerospace Engineering Chongqing UniversityChongqing 400044China

Acoustic nonlinearity holds potential as a method for assessing material *** to the acoustoelastic effect,where the velocity of elastic waves is influenced by third-order elastic constants,the propagation of nonlinear acoustic waves in pre-stressed materials would be influenced by higher-order elastic *** this,there has been a notable absence of research exploring this ***,this paper aims to establish a theoretical framework for governing the propagation of nonlinear acoustic waves in pre-stressed *** delves into the impact of pre-stress on higher-order material parameters,and specifically examines the propagation of one-dimensional acoustic waves within the contexts of the uniaxial stress and the biaxial *** paper establishes a theoretical foundation for exploring the application of nonlinear ultrasonic techniques to measure pre-stress in materials.

关键词： acoustoelastic effect nonlinear elastic wave pre-stress medium higher-order elastic constant

microbial carbon pump shapes chemical signatures of refractory dissolved organic carbon in ocean water column

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第7期67卷 2408-2410页

作者： Ruanhong cai Nianzhi JIAO Fujian Key Laboratory of marine Carbon Sequestration Xiamen UniversityXiamen 361102China Department of Ocean Science The Hong Kong Universityof Science and TechnologyHong Kong SAR 999077China Carbon Neutral Innovation Research Center Xiamen UniversityXiamen 361102China

The global ocean sequesters a great amount of dissolved organic carbon(DOC),which is mainly originated from indigenous microbial activities(such as photosynthesis and chemoautotrophy)in the water column,as well as various exogenous sources such as riverine input,sediment mobilization,aerosol dissolution,hydrothermal vent effusion,and others(cai and Jiao,2023).

关键词： ocean originated aerosol

Review of dynamics and active control of large-scale space membrane antenna

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2024年第1期8卷 1-26页

作者： Xiang Liu Guoping cai Department of Engineering mechanics MOE Key Laboratory of HydrodynamicsChongqing Research InstituteShanghai Jiao Tong UniversityShanghai200240China

Large-scale space membrane antennas have significant potential in satellite communication,space-based early warning,and Earth *** of their large size and high flexibility,the dynamic analysis and control of membrane antenna are *** maintain the working performance of the antenna,the pointing and surface accuracies must be strictly ***,the accurate dynamic modeling and effective active control of large-scale space membrane antennas have great theoretical significance and practical value,and have attracted considerable interest in recent *** paper reviews the dynamics and active control of large-scale space membrane ***,the development and status of large-scale space membrane antennas are ***,the key problems in the dynamics and active control of large membrane antennas,including the dynamics of wrinkled membranes,large-amplitude nonlinear vibration,nonlinear model reduction,rigid-flexible-thermal coupling dynamic modeling,on-orbit modal parameter identification,active vibration control,and wave-based vibration control,are discussed in ***,the research outlook and future trends are presented.

关键词： large-scale space membrane antenna dynamicmodeling active control

SOLVING SYSTEmS OF PHASELESS EQUATIONS VIA RIEmANNIAN OPTImIZATION WITH OPTImAL SAmPLING COmPLEXITY

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 Computational mathematics 2024年第3期42卷 755-783页

作者： Jianfeng cai Ke Wei Department of mathematics Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SARChina School of Data Science Fudan UniversityShanghaiChina

A Riemannian gradient descent algorithm and a truncated variant are presented to solve systems of phaseless equations|Ax|^(2)=*** algorithms are developed by exploiting the inherent low rank structure of the problem based on the embedded manifold of rank-1 positive semidefinite *** recovery guarantee has been established for the truncated variant,showing that the algorithm is able to achieve successful recovery when the number of equations is proportional to the number of *** key ingredients in the analysis are the restricted well conditioned property and the restricted weak correlation property of the associated truncated linear *** evaluations show that our algorithms are competitive with other state-of-the-art first order nonconvex approaches with provable guarantees.

关键词： Phaseless equations Riemannian gradient descent manifold of rank-1 and positive semidefinite matrices Optimal sampling complexity