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Biological sources, paleoenvironment, and organic matter enrichment in source rocks of the Ordovician Majiagou Formation, Ordos Basin, China:Evidence from biomarkers,microfossils, and inorganic geochemical analyses

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Journal of Palaeogeography 2024年第1期13卷 92-115页

作者： jing-jing cao Wen-Zhe Gang Shang-Ru Yang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Bejing)Beijing 102249China College of Geosciences China University of Petroleum(Bejing)Beijing 102249China Oil and Gas Technology Research Institute PetroChina Changqing Oifield CompanyXi'an 710018Shaanxi ProvinceChina

Carbonate deposits in the Ordovivian Majiagou Formation are significant source rocks for natural gas generation in the Ordos Basin, northwestern China. Previous studies mainly focused on the organic matter enrichment mechanism of shales rather than carbonate rocks. The biological sources and paleoenvironment of carbonate source rocks, and the main controlling factors of organic matter enrichment in the carbonate source rocks were studied in this paper in combination with evidence from biomarkers, microfossils and inorganic geochemistry analysis. The results show that four types of microfacies were identified in the Majiagou Formation, respectively as: mud flat microfacies, mud-dolomite flat microfacies, dolomite flat microfacies, and open marine microfacies. The biological sources of organic matter are chiefly planktonic algae, followed by bacteria. The mud flat and mud-dolomite flat contain a high abundance of terrigenous detrital inputs, as indicated by the high content of Al_(2)O_(3), TiO_(2), Th, and Zr. The low Sr/Cu and high Rb/Sr values reveal warm and humid paleoclimate conditions in the mud flat and mud-dolomite flat, whereas the dolomite flat and open marine were likely formed in hot and arid paleoclimate conditions. The mud flat and mud-dolomite flat deposits were characterized by high paleoproductivity of the Majiagou Formation. Low Sr/Ba values were found in the mud flat samples, indicating fresh to brackish water condition, whereas samples of other facies have a relatively high degree of salinity. Based on U_(auth), Mo_(auth), Cr_(auth), Co_(auth), δCe, and δEu values, the mud flat microfacies was formed in a suboxic and anoxic environment, whereas the mud-dolomite flat, dolomite flat and open marine microfacies were within dysoxic to oxic conditions. A model of organic matter enrichment in the Majiagou Formation is thus established. The level of terrigenous detrital inputs is the principal factor of organic matter enrichment in the Majiagou Formation,

关键词： Biological source Microfacies Trace elements Organic matter Majiagou Formation Ordos Basin

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The nonlocal transport and switch effect in light-and electric-controlled silicene–superconductor hybrid structure

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Chinese Physics B 2018年第12期27卷 121-126页

作者： Fenghua Qi Jun cao jie cao Lifa Zhang Center for Quantum Transport and Thermal Energy Science School of Physics and TechnologyNanjing Normal UniversityNanjing 210023China School of Electronic Engineering Nanjing Xiaozhuang UniversityNanjing 211171China College of Science Hohai UniversityNanjing 210098China

We theoretically investigate the influence of off-resonant circularly polarized light field and perpendicular electric field on the quantum transport in a monolayer silicene-based normal/superconducting/normal *** to the tunable band structure of silicene,a pure crossed Andreev reflection process can be realized under the optical and electrical ***,a switch effect among the exclusive crossed Andreev reflection,the exclusive elastic cotunneling and the exclusive Andreev reflection,where the former two are the nonlocal transports and the third one is the local transport,can be obtained in our system by the modulation of the electric and light *** addition,the influence of the relevant parameters on the nonlocal and local transports is calculated and analyzed as well.

关键词： switch effect silicene crossed Andreev reflection

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Multiple Positive Solutions for a Nonlinear Elliptic Equation Involving Hardy–Sobolev–Maz'ya Term

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Acta Mathematica Sinica,English Series 2015年第6期31卷 893-912页

作者： Shuang jie PENG jing YANG School of Mathematics and Statistics Central China Normal University

In this paper, we study the existence and nonexistence of multiple positive solutions for the following problem involving Hardy-Sobolev-Maz＇ya term：-Δu-λ u/｜y｜2 = （｜u｜pt-1u）/｜y｜t ＋ μf（x）, x∈ Ω,where Ω is a bounded domain in RN（N ≥ 2）, 0 ∈ Ω, x = （y, z） ∈ Rk ×RN-k and pt = （N＋2-2t）/（N-2）（0 ≤ t ≤ 2）. For f（x） ∈ C1（Ω）／{0}, we show that there exists a constant μ＊〉0 such that the problem possesses at least two positive solutions if μ ∈ （0, μ＊） and at least one positive solution if μ = μ＊. Furthermore, there are no positive solutions if μ ∈ （μ＊,＋∞）.

关键词： Hardy-Sobolev-Maz'ya inequality Mountain Pass Lemma positive solutions subsolutionand supersolution

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A Non-axisymmetric Spherical α~2-Dynamo

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Chinese Journal of Astronomy and Astrophysics 2006年第2期6卷 227-236页

作者： jie Jiang jing-Xiu Wang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Using the Chebyshev-tau method, the generation of oscillatory nonaxisymmetric stellar magnetic fields by the α^2-dynamo is studied in spherical geometry. Following the boundary conditions given by Schubert ＆ Zhang, the spherical α^2-dynamo consists of a fully convective spherical shell with inner radius ri and outer radius ro. A comparison of the critical dynamo numbers of axisymmetric and φ-dependent modes for different thicknesses of the convective shell and different α- profiles leads to the following qualitative results：（i） when the angular factor of α- profile is sin^n θ cosθ （n= 1, 2, 4） the solutions of the α^2dynamo are oscillatory and non-axisymmetric, （ii） the thinner the convective shell, the more easily is the nonaxisymmetric mode excited and the higher is the latitudinal wave number, （iii） the thickness of the outer convective shell has an effect on the symmetries of the magnetic fields.

关键词： stars: magnetic fields - methods: numerical

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The Inhibitory Degree Between Skeletonema costatum and Dinoflagllate Prorocentrum donghaiense at Different Concentrations of Phosphate and Nitrate/Phosphate Ratios

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Journal of Ocean University of China 2012年第2期11卷 153-158页

作者： cao jing WANG Jiangtao Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 266100P.R.China

Interactions between Skeletonema costatum (S. costatum) and Prorocentrum donghaiense (P. donghaiiense) were inves-tigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1μmolL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6μmolL-1/2 d). At low concen-tration of PO4-P (0.1μmolL-1/2 d), or high concentration of PO4-P (0.6μmolL-1/2 d) with high N/P ratio (160), the interactions be-tween S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6μmolL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The de-gree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with con-centration 0.1μmolL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 μmolL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6μmolL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1μmolL-1/2 d and 0.6μmolL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the competition was more sig

关键词： Skeletonema costatum Prorocentrum donghaiense inhibitory effect phosphate species competition N/P ratio

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Wandering Subspaces and Quasi-wandering Subspaces in the Hardy-Sobolev Spaces

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1684-1692页

作者： jie Sheng XIAO Guang Fu cao Nanhu College Jiaxing University Department of Mathematics South China Apicultural University

In this paper, we prove that for -1/2≤β≤0, suppose M is an invariant subspaces of the Hardy Sobolev spaces Hβ^2（D） for Tz^β, then M zM is a generating wandering subspace of M, that is, M = [M zM]Tz^β. Moreover, any non-trivial invariant subspace M of Hβ^2（D） is also generated by the quasi-wandering subspace PMTz^βM^⊥, that is, M = [PMTz^βM^⊥]Tz^β.

关键词： Hardy-Sobolev space invariant subspace wandering subspace quasi-wandering sub- space Beurling type theorem

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Security Issues and Defensive Approaches in Deep Learning Frameworks

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Tsinghua Science and Technology 2021年第6期26卷 894-905页

作者： Hongsong Chen Yongpeng Zhang Yongrui cao jing Xie Department of Computer Science University of Science and Technology Beijing(USTB)Beijing 100083China Beijing Key Laboratory of Knowledge Engineering for Materials Science Beijing 100083China Department of Computer Science and Technology University of Science and Technology Beijing(USTB)Beijing 100083China Defense Electronics Institute China Industrial Control System Cyber Emergency Response TeamBeijing 100040China

Deep learning frameworks promote the development of artificial intelligence and demonstrate considerable potential in numerous ***,the security issues of deep learning frameworks are among the main risks preventing the wide application of *** on deep learning frameworks by malicious internal or external attackers would exert substantial effects on society and *** start with a description of the framework of deep learning algorithms and a detailed analysis of attacks and vulnerabilities in *** propose a highly comprehensive classification approach for security issues and defensive approaches in deep learning frameworks and connect different attacks to corresponding defensive ***,we analyze a case of the physical-world use of deep learning security *** addition,we discuss future directions and open issues in deep learning *** hope that our research will inspire future developments and draw attention from academic and industrial domains to the security of deep learning frameworks.

关键词： adversarial examples deep learning frameworks defensive approaches security issues

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Analysis of MIMO antenna array based on 3D Von Mises Fisher distribution

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The Journal of China Universities of Posts and Telecommunications 2015年第2期22卷 15-23页

作者： Zhou jie cao Zhigang Hisakazu Kikuchi Jiangsu Key Laboratory of Meteorological Observation and Information Processing Department of Electrical and Electronic Engineering

A three-dimensional （3D） Von Mises Fisher （VMF） distribution model was derived in multiple-input and multiple-output （MIMO） antenna communication environment. The azimuth of arrival and elevation of arrival are distributed for VMF distribution instead of the uniform or other traditional distributions. In particular the MIMO uniform Y-shaped array （UYA） and the uniform circular array （UCA） antenna topology are considered at mobile station and base station. The developed spatial fading correlation of the VMF model is determined by parameters of the concentration parameter, antenna spacing, mean azimuth of arrival, mean elevation of arrival. Using the channel model, the effects of the concentration parameter and the mean elevation angle on the capacity of MIMO antenna systems was analyzed. It is shown that the mean elevation of arrival must be taken into account in 3D MIMO communication environment.

关键词： MIMO antenna array VMF distribution spatial fading correlation channel capacity

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Solutions for the Prescribing Mean Curvature Equation

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 497-510页

作者： Dao-min cao Shuang-jie Peng Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China School of Mathematics and Statistics Central China Normal University Wuhan 430079 China

By variational methods, for a kind of Yamabe problem whose scalar curvature vanishes in the unit ball BN and on the boundary S^N-1 the mean curvature is prescribed, we construct multi-peak solutions whose maxima are located on the boundary as the parameter tends to 0^＋ under certain assumptions. We also obtain the asymptotic behaviors of the solutions.

关键词： Mean curvature critical point concentrating solutions

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Tribocorrosion behavior of antibacterial Ti-Cu sintered alloys in simulated biological environments

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Rare Metals 2022年第6期41卷 1921-1932页

作者： Jia-Qi Zhang Shuang cao Ying Liu Mian-Mian Bao jing Ren Sheng-Yi Li Er-Lin Zhang Jian-jie Wang Departments of Immunology College of Basic MedicineJiamusi UniversityJiamusi 154007China Key Laboratory for Anisotropy and Texture of Materials School of Materials Science and EngineeringEducation Ministry of ChinaNortheastern UniversityShenyang 110819China Research Center for Metallic Wires Northeastern UniversityShenyang 110819China

Ti-Cu alloys have strong antibacterial proper-ties,high strength and excellent corrosion resistance,which might be used in orthopedic and dental *** this paper,the tribocorrosion behaviors of Ti-Cu alloy with different Cu contents were investigated in four simulated biological environments compared with *** results showed that Ti-Cu sintered alloy exhibited higher corro-sion resistance,lower coefficient friction and wear loss than cp-Ti in all tested solutions due to the formation of fine and homogeneously distributed Ti_(2)Cu phase,espe-cially in solution with lower F ion and *** Cu content and extrusion process improved the corrosion resistance and the wear resistance because of high Ti_(2)Cu phase fraction and fine grain ***,aggressive solution,such as the solution with lower F ion and pH,accelerated wear in comparison with other solutions for cp-Ti and Ti-Cu sintered *** electron microscope(SEM)surface morphology demonstrated that the wear mecha-nism of cp-Ti during tribocorrosion process was mainly abrasive wear and adhesive wear while that of Ti-Cu alloy was abrasive *** summary,Ti-Cu sintered alloys showed much better tribocorrosion property than cp-Ti,which shows great potential application in condition for wear and corrosion resistance.

关键词： Ti-Cu alloys Tribocorrosion Corrosion Wear In vitro Antibacterial metal alloy

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