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Theoretical dispersion curves for borehole real-valued wave modes in vertically transverse isotropic formations

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Petroleum Science 2022年第6期19卷 2649-2662页

作者： Fu-qiang zeng Chao Li Hubei Subsurface Multi-scale Imaging Key Laboratory Institute of Geophysics and GeomaticsChina University of GeosciencesWuhan430074HubeiChina State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing100190China Beijing Engineering and Technology Research Center for Deep Drilling Exploration and Measurement Beijing100190China

The dispersion curves of real-valued modes in a fluid-filled borehole are widely used in acoustic well *** accurate dispersion curves are the precondition of theoretical analysis and inversion ***,these curves can be obtained by solving the conventional dispersion equation for isotropic formations and most vertically transverse isotropy(VTI)***,if the real-valued solutions exist when the radial wavenumbers for the formation quasi-P and quasi-S equals to each other,the existed methods based on the conventional dispersion equation could lead to incorrect results for some VTI *** studies have focused on the influence of these real-valued solutions on dispersion curve *** remove these real-valued solutions,we have proposed a modified dispersion equation and its corresponding solving *** solving the dispersion equation,the Scholte wave velocity of VTI formation at high frequency is used as the initial *** two synthetic examples including fast and slow VTI formations validate that these real-valued solutions do not contribute to the wavefield,and the new dispersion curve extraction method is suitable for all kinds of VTI ***,the method can provide reliable dispersion curves for both theoretical analysis and anisotropic parameters inversion in VTI formations.

关键词： Dispersion equation Scholte wave velocity Acoustic properties Transverse isotropy Thomsen anisotropic parameters inversion

Experimental study on the oxidation kinetics of coal in typical coal mining areas of the Southern Junggar coalfield,Xinjiang,China

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International Journal of Coal Science & Technology 2022年第6期9卷 138-150页

作者： qiang zeng Li Shen School of Ecology and Environment Sciences Xinjiang UniversityUrumqi 830017China Institute for Arid Ecology and Environment Xinjiang UniversityUrumqi 830017China Key Laboratory of Oasis Ecology of Ministry of Education Urumqi 830017China

Coal spontaneous combustion(CSC)is a disaster associated with coal mining that leads to loss of coal resources and envi-ronmental and human health *** investigate kinetic characteristics for oxidation of coal,three coal samples were collected from different coal mining areas in the Southern Junggar ***,the collected coal samples were ground into different particle sizes and tested using microscopic and macroscopic methods,including thermal gravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffraction,and temperature-programmed *** results obtained are as follows:the sharpest absorption peak(002)indicates that graphitization is ***,the results show that the SKS coal sample is prone to spontaneous combustion;the greater the aromatic hydrocarbon content is,the more difficult it is for CSC to occur,while the opposite is true for oxygen-containing functional *** SKS data confirmed this conclusion;the rate for generation of CO and CO_(2)controlled the possibility of SKS oxidation at 110℃and provided an indication of the *** the dehydration stage,the WD sample had the lowest activation energy,indicating that it was most susceptible to spontaneous *** the combustion stage,the lowest activation energy was found for the SKS sample with particle sizes<0.075 mm,indicating that particle size was one of the factors affecting spontane-ous *** activation energy for dehydration was significantly lower than that for combustion,which showed that the coal oxygen reaction was more likely to occur in the dehydration *** on DSC curves,the SKS sample had the largest exothermicity,indicating that it would ignite more readily.

关键词： Southern Junggar coalfield Oxidation Kinetics Coal spontaneous combustion

Influence of freezing rate on cryo-damage of cementitious material

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 17-21页

作者： Ke-fei LI qiang zeng Civil Engineering Department Tsinghua University Beijing 100084 China

We report an experimental investigation on the impact of the freezing rate on the cryo-deformation and cryo-damage of cementitious ***,dried and air-entrained mortar specimens are subjected to laboratory freeze-thaw cycles under three freezing rates without moisture exchange with the *** addition to basic mechanical properties and pore distribution,the measurement is also effectuated for freezing expansion,residual deformation of the specimens in each *** the results it is observed that a high freezing rate does augment the freezing expansion of material while the cryo-damage is more important for a low freezing ***,both the freezing rate and freezing duration should be taken into account for the cyro-damage extent of cementitious materials.

关键词： Freezing rate Deformation Crystallization pressure Damage

Common Sentiment and Price Contagion

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Journal of Systems Science & Complexity 2019年第5期32卷 1426-1437页

作者： zeng Qingduo LIU Shancun ZHANG qiang School of Economics and Management Beijing University of Chemical TechnologyBeijing 100029China School of Economics and Management Beihang UniversityBeijing 100191China School of Economics and Management Beijing University of Chemical TechnologyBeijing 100029China.

This paper investigates the informational role of prices in segmented markets which are shocked by a kind of common sentiment resulting from financial contagion. This common sentiment bridges the connection between prices learned by rational traders and thus can weaken the uncertainty from noise shock. The authors find that there exist comovement effect and crowding-out effect in information acquisition among different markets. These two effects capture financial contagion when markets experience large downward or upward tendency, which offers an explanation for market crisis to some extent.

关键词： Contagion crisis rational expectation equilibrium sentiment

Comprehensive bibliometric analysis of pharmacotherapy for bipolar disorders:Present trends and future directions

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World Journal of Psychiatry 2025年第1期15卷 153-167页

作者： Bo-Fan Chen Li Liu Fang-Zhen Lin Hai-Min zeng Hai-qiang Huang Chun-Fang Zhang Cong-Cong Liu Xiang Chen Jie Peng Yun-Fa Wang Zhi-Lin Wang Bin Chen De-Le Liu Yun Liu Zheng-Zheng Li Xin-Xing zeng The Second Affiliated Hospital Jiangxi Medical CollegeNanchang UniversityNanchang 330006Jiangxi ProvinceChina The Second Clinical Medical College Jiangxi Medical CollegeNanchang UniversityNanchang 330006Jiangxi ProvinceChina Department of Rehabilitation Medicine The Second Affiliated HospitalJiangxi Medical CollegeNanchang UniversityNanchang 330006Jiangxi ProvinceChina Jiangxi Provincial People’s Hospital The First Affiliated Hospital of Nanchang Medical CollegeNanchang 330006Jiangxi ProvinceChina Department of Psychiatry Jiangxi Mental HospitalHospital of Nanchang UniversityNanchang UniversityNanchang 330029Jiangxi ProvinceChina

BACKGROUND Bipolar disorder(BD)is a severe mental illness characterized by significant mood *** drug treatment modalities are crucial for managing *** To analyze the current status and future trends of global research on BD drug treatment over the last *** The Web of Science Core Collection database spanning from 2015 to 2024 was utilized to retrieve literature related to BD drug treatment.A total of 2624 articles were *** visualization and analysis were conducted using CiteSpace,VOSviewer,Pajek,Scimago Graphica,and R-studio bibliometrix to identify RESULTS The United States,China,and the United Kingdom have made the most significant contributions to research on BD drug treatment and formed notable research collaboration *** University of Pittsburgh,Massachusetts General Hospital,and the University of Michigan have been identified as the major research institutions in this *** Journal of Affective Disorders is the most influential journal.A keyword analysis revealed research hotspots related to clinical symptoms,drug efficacy,and genetic mechanisms.A citation analysis identified the management guidelines published by Yatham et al in 2018 as the most cited *** This study provides a detailed overview of the field of BD drug treatment,highlighting key contributors,research hotspots,and future *** study findings can be employed as a reference for future research and policymaking,which may enable further development and optimization of BD pharmacotherapy.

关键词： Bipolar disorder Drug treatment Bibliometric analysis Visualization Mental disorder

Effect of Fe2O3 on the size and components of spinel crystals in the CaO–SiO2–MgO–Al2O3–Cr2O3 system

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1113-1119页

作者： Qi-qiang Mou Jian-li Li qiang zeng Hang-yu Zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China

size of spinel crystals in the CaO–SiO2–MgO –Al2O3–Cr2O3 system was investigated using lab experiments carried out in a carbon tube furnace. Scanning electron microscopy with energy-dispersive X-ray spectroscopy（SEM–EDS） and X-ray diffraction（XRD） were used to analyze the microstructure, components, and the mineral phases of synthetic slags. FactS age 7.1 was used to calculate the crystallization process of the molten slag. The results showed that the addition of Fe2O3 promoted the precipitation of spinel crystals and inhibited the formation of dicalcium silicate. The size of spinel crystals increased from 2.74 to 8.10 μm and the contents of chromium and iron in the spinel varied as the Fe2O3 addition was increased from 0 to 20 wt%. Fe2O3 thermodynamically provided the spinel-forming components to enhance the formation of FeCr2O4, MgFe2O4, and Fe3O4. The addition of Fe2O3 increased the fraction of liquid phase in a certain temperature range and promoted diffusion by decreasing the slag’s viscosity. Therefore, Fe2O3 is beneficial to the growth of spinel crystals in stainless steel slag.

关键词： ferric oxide stainless steel slag spinel crystal size chromic oxide

Fermions tunneling from the Horowitz-Strominger Dilaton black hole

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Science China(Physics,Mechanics & Astronomy) 2009年第6期52卷 813-817页

作者： LI qiang zeng XiaoXiong Department of Physics and Engineering Technology Sichuan University of Arts and ScienceDazhou 635000China

Based on the work of Kerner and Mann, fermions tunneling from the Horowitz-Strominger Dilaton black hole on the membrane is studied. Owing to the coupling among electromagnetic field, matter field and gravity field, the Dirac equation of charged particles is introduced, and according to that, the expected emission temperature is obtained. After the self-gravitational interaction is considered, it is found that the tunneling rate of fermions also satisfies the underlying Unitary theory as the case of scalar particles.

关键词： Hawking radiation fermions tunneling Horowitz-Strominger Dilaton black hole

Tree-based differential evolution algorithm for QoS multicast routing

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 76-81页

作者： KONG Sun CHEN zeng-qiang Department of Automation Nankai University Tianjin 300071 China

Differential evolution （DE） algorithm has attracted more and more attention due to its fast optimization performance and good stability. When DE algorithm is applied into multi-constrained multicast routing optimization problem, a common solution to such problem is to merge the paths into a tree after finding paths from the source node to each destination node. This method maybe obtains the better result, but it can consume a lot of computational time. To solve the problem, a tree-based DE algorithm is introduced in this paper. The central operations of the algorithm are realized with tree structure. This method saves the time of finding paths and integrating them to construct a multicast tree. The experiments show that the proposed algorithm can achieve higher success rate than several common algorithms with much smaller running time for different networks.

关键词： quality of service (QoS) multicast routing DE tree structure

Radical and(photo)electron transfer induced mechanisms for lignin photo-and electro-catalytic depolymerization

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Green Energy & Environment 2023年第2期8卷 383-405页

作者： Kejia Wu Minglong Cao qiang zeng Xuehui Li School of Chemistry and Chemical Engineering State Key Laboratory of Pulp&Paper EngineeringSouth China University of TechnologyGuangzhou510640China

As one of the three major components of woody biomass,lignin is a kind of natural organic polymer and the only abundant natural renewable resource with aromatic *** catalysis induced depolymerization is an important and effective approach for lignin *** particular,photocatalysis and electrocatalysis show great potential in accurately activating C-O/C-C bonds,which is a critical point of selective cleavage of *** this contribution,we focus on radical and(photo)electron transfer induced reaction mechanisms of the photo(electro)catalytic depolymerization of ***,the general situation of Carbon-centered radicals and active oxygen species mediated lignin conversion has been *** the mechanisms for(photo)electron transfer mediated lignin depolymerization have been *** the end of this review,the challenges and opportunities of photo(electro)catalysis in the applications of lignin valorization have been forecasted.

关键词： Lignin Photocatalysis Electrocatalysis Depolymerization Reaction mechanism