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Astronomical influence of the development of Paleogene thin coal seam groups in offshore Lacustrine basins:A case study of the ZhuⅠDepression's Enping Formation located in the northern South China Sea

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Acta Oceanologica Sinica 2024年第4期43卷 136-150页

作者： Yan Liu shengbing Huang Dongdong Wang nan Li Yuting Yin Ying chen Zengxue Li College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China CNOOC Research Institute Co. Ltd.Beijing 100028China School of Geography Earth and Environmental SciencesUniversity of BirminghamBirmingham B152TTUK

The development of the Paleogene coal seams in China's offshore basin areas generally had the characteristics of coal measures with large thicknesses,large numbers of coal seams,thin single coal seams,poor stability,scattered vertical distribution,and a wide distribution *** study selected the Enping Formation of the ZhuⅠDepression in the northern section of the South China Sea as an example to determine the macro-control factors of the development of the Paleogene coal seam *** analysis was carried out on the influencing effects and patterns of the astronomical cycles related to the development of the thin coal seam groups in the region.A floating astronomical time scale of the Enping Formation was established,and the sedimentary time limit of the Enping Formation was determined to be approximately 6.15 Ma±.In addition,the cyclostratigraphy analysis results of the natural gamma-ray data of Well XJ in the Enping Formation of the Xijiang Sag revealed that the development of the thin coal seams had probably been affected by short eccentricity and precession *** formation process of coal seams was determined to have been affected by high seasonal contrast,precipitation,and *** the periods with high values of short eccentricity,the seasonal contrasts tended to be *** those periods,fluctuations in the precession controls resulted in periodic volume changes in precipitation and insolation of the region,resulting in the development of thin coal *** was also found that the periods with low precession were the most conducive to coal seam *** that basis,combined with such factors as sedimentary environmental conditions conducive to the development of thin coal seam groups,this study established a theoretical model of the comprehensive influences of short eccentricity and precession on the development and distribution of Paleogene thin coal seam groups in offshore lacustrine *** patterns of the Paleogene astrono

关键词： Paleogene Pearl(Zhujiang)River Mouth Basin coal seam development astronomical cycles

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Toward understanding the microstructure characteristics,phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

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International Journal of Extreme Manufacturing 2024年第1期6卷 277-294页

作者： Bo Yao nan Kang Xiangyu Li Dou Li Mohamed EL Mansori Jing chen Haiou Yang Hua Tan Xin Lin State Key Laboratory of Solidiffcation Processing Northwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Arts et Metiers Institute of Technology MSMPHESAM UniversitéF-51006 Chˆalons-en-ChampagneFrance Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843United States of America

Nd-Fe-B permanent magnets play a crucial role in energy conversion and electronic *** essential magnetic properties of Nd-Fe-B magnets,particularly coercivity and remanent magnetization,are significantly infuenced by the phase characteristics and *** this work,Nd-Fe-B magnets were manufactured using vacuum induction melting(VIM),laser directed energy deposition(LDED)and laser powder bed fusion(LPBF)*** evolution and phase selection of Nd-Fe-B magnets were then clarified in *** results indicated that the solidification velocity(V)and cooling rate(R)are key factors in the phase *** terms of the VIM-casting Nd-Fe-B magnet,a large volume fraction of theα-Fe soft magnetic phase(39.7 vol.%)and Nd2Fe17Bxmetastable phase(34.7 vol.%)areformed due to the low R(2.3×10-1?C s-1),whereas only a minor fraction of the Nd2Fe14B hard magnetic phase(5.15 vol.%)is *** the LDED-processed Nd-Fe-B deposit,although the Nd2Fe14B hard magnetic phase also had a low value(3.4 vol.%)as the values of V(10-2m s-1)and R(1.45×106?C s-1)in the LPBF process resulted in the substantial formation of the Nd2Fe14B hard magnetic phase(55.8 vol.%)directly from the liquid,while theα-Fe soft magnetic phase and Nd2Fe17Bxmetastable phase precipitation are suppressed in the LPBF-processed Nd-Fe-B ***,crystallographic texture analysis reveals that the LPBF-processedNd-Fe-B magnets exhibit isotropic magnetic ***,the LPBF-processed Nd-Fe-B deposit,exhibiting a coercivity of 656 k A m-1,remanence of 0.79 T and maximum energy product of 71.5 k J m-3,achieved an acceptable magnetic perfor

关键词： laser additive manufacturing(LAM) Nd-Fe-B permanent magnets numerical simulation microstructure magnetic properties

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Application of CFD and FEA Coupling to Predict Structural Dynamic Responses of A Trimaran in Uni-and Bi-Directional Waves

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China Ocean Engineering 2024年第1期38卷 81-92页

作者： LIAO Xi-yu XIA Jin-song chen Zhan-yang TANG Qin ZHAO nan ZHAO Wei-dong GUI Hong-bin Marine Design&Research Institute of China Shanghai 200011China Ship Structure Division China Ship Scientific Research CenterWuxi 214082China College of Ocean Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China School of Foreign Studies Jiangnan UniversityWuxi 214122China

To predict the wave loads of a flexible trimaran in different wave fields,a one-way interaction numerical simulation method is proposed by integrating the fluid solver(Star-CCM+)and structural solver(Abaqus).Differing from the existing coupled CFD-FEA method for monohull ships in head waves,the presented method equates the mass and stiffness of the whole ship to the hull shell so that any transverse and longitudinal section stress of the hull in oblique waves can be ***,verification study and sensitivity analysis are carried out by comparing the trimaran motions using different mesh sizes and time step *** on the wave elevation of uni-and bi-directional waves is also carried *** a comprehensive analysis on the structural responses of the trimaran in different uni-directional regular wave and bi-directional cross sea conditions is carried out,***,the differences in structural response characteristics of trimaran in different wave fields are *** results show that the present method can reduce the computational burden of the two-way fluid-structure interaction simulations.

关键词： CFD-FEA fluid-structure coupling structural responses trimaran bi-directional cross sea

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Linearized waveform inversion for vertical transversely isotropic elastic media:Methodology and multi-parameter crosstalk analysis

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Petroleum Science 2024年第1期21卷 252-271页

作者： Ke chen Lu Liu Li-nan Xu Fei Hu Yuan Yang Jia-Hui Zuo Le-Le Zhang Yang Zhao National Key Laboratory of Petroleum Resources and Engineering Unconventional Petroleum Research InstituteChina University of Petroleum(Beijing)Beijing102249China Aramco Beijing Research Center Aramco AsiaBeijing100102China University of Lausanne LausanneCH-1015Switzerland Bureau of Geophysical Prospecting China National Petroleum CorporationZhuozhou 072750HebeiChina

Seismic migration and inversion are closely related techniques to portray subsurface images and identify hydrocarbon *** migration aims at obtaining structural images of subsurface geologic *** specifically,seismic migration estimates the reflectivity function(stacked average reflectivity or pre-stack angle-dependent reflectivity)from seismic reflection *** the other hand,seismic inversion quantitatively estimates the intrinsic rock properties of subsurface *** seismic inversion methods are applicable to detect hydrocarbon reservoirs that may exhibit lateral variations in the inverted *** there exist many differences,pre-stack seismic migration is similar with the first iteration of the general linearized seismic ***,seismic migration and inversion techniques assume an acoustic or isotropic elastic *** reservoirs such as shale and tight sand formation have notable anisotropic *** present a linearized waveform inversion(LWI)scheme for weakly anisotropic elastic media with vertical transversely isotropic(VTI)*** is based on two-way anisotropic elastic wave equation and simultaneously inverts for the localized perturbations(ΔVp_(0)/Vp_(0)/Vs_(0)/Vs_(0)/,Δ∈,Δδ)from the long-wavelength reference *** proposed VTI-elastic LWI is an iterative method that requires a forward and an adjoint operator acting on vectors in each *** derive the forward Born approximation operator by perturbation theory and adjoint operator via adjoint-state *** inversion has improved the quality of the images and reduces the multi-parameter crosstalk comparing with the adjoint-based *** have observed that the multi-parameter crosstalk problem is more prominent in the inversion images for Thomsen anisotropy ***,the Thomsen parameter is the most difficult to *** also analyze the multi-parameter crosstalk using scattering radiation patte

关键词： Elastic Anisotropy Least-squares imaging Waveform inversion Computational geophysics

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Chronological Study of Coal-seam Water and its Implication on Gas Production in the South Qinshui Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 207-219页

作者： chen Biying FANG Lujia LANG Yunchao XU sheng LIU Congqiang ZHANG Luyuan HOU Xiaolin Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China Institute of Earth Environments Chinese Academy of SciencesXi’an 710061China

The knowledge of the residence time of formation water is fundamental to understanding the subsurface flow and hydrological *** better identify the origin and evolution of coal seam water and its impact on gas storage and production,this study collected coalbed methane co-produced water in the southeast Qinshui Basin and detected chemical and isotopic compositions,especially 36Cl and 129I *** calculated tracer ages of 129I(5.2–50.6 Ma)and 36Cl(0.13–0.76 Ma)are significantly younger than the age of coal-bearing formation(Pennsylvanian-Cisuralian),indicating freshwater recharge after coal *** model that utilises 129I/I and 36Cl/Cl ratios to constrain the timing of recharge and the proportion of recharge water reveals that over 60%of pre-anthropogenic meteoric water entered coal seams since 10 Ma and mixed with residue initial deposition water,corresponding to the basin inversion in *** spatial distribution of major ion concentrations reveals the primary recharge pathway for meteoric water from coal outcrops at the eastern margin to the basin *** study demonstrates the occurrence of higher gas production rates from wells that accept water recharge in recent times and suggests the possible potential of the non-stagnant zones for high gas production.

关键词： CBM co-produced water iodine-129 chlorine-36 water chemistry Qinshui Basin

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A Dynamic Covalent Bonding-based nanoplatform for Intracellular Co-Delivery of Protein Drugs and Chemotherapeutics with Enhanced Anti-Cancer Effect

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Chinese Journal of Polymer Science 2024年第5期42卷 559-569,I0005页

作者： Sai-nan Liu Jia-Hui Meng Li-Yun Cui Hua chen Lin-Qi Shi Ru-Jiang Ma Key Laboratory of Functional Polymer Materials of Ministry of Education Institute of Polymer ChemistryTianjin Key Laboratory of Functional Polymer MaterialsState Key Laboratory of Medicinal Chemical BiologyFrontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin300192China

Efficient intracellular delivery of protein drugs is critical for protein *** combination of protein drugs with chemotherapeutics represents a promising strategy in enhancing anti-cancer ***,co-delivery systems for efficient delivery of these two kinds of drugs are still lacking because of their different ***,we show a well-designed delivery system based on dynamic covalent bond for efficient intracellular co-delivery of ribonuclease A(RNase A)and doxorubicin(DOX).Two polymers,PEG-b-P(Asp-co-AspDA)and PAE-b-P(Asp-co-AspPBA),and two 2-acetylphenylboronic acid(2-APBA)-functionalized drugs,2-APBA-RNase A and 2-APBA-DOX,self-assemble into mixed-shell nanoparticles(RNase A/DOX@MNPs)via dynamic phenylboronic acid(PBA)-catechol bond between PBA and dopamine(DA)*** PBA-catechol bond endows the nanoparticles with high stability and excellent stimulus-responsive drug release *** the slight acidic environment at tumor tissue,RNase A/DOX@MNPs are positively charged,promoting their *** cellular uptake into endosome,further protonation of PAE chains leads to the rupture of endosomes because of the proton sponge effect and the cleavage of PBA-catechol bond promotes the release of two *** cytoplasm,the high level of GSH removed the modification of 2-APBA on *** restored RNase A and DOX show a synergistic and enhanced antic-cancer *** system may be a promising platform for intracellular co-delivery of protein drugs and chemotherapeutics.

关键词： Drug co-delivery Combination therapy Dynamic covalent bond

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Ground-layer Adaptive Optics for the 2.5 m Wide-field and High-resolution Solar Telescope

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Research in Astronomy and Astrophysics 2024年第3期24卷 224-236页

作者： Ying Yang Lan-Qiang Zhang nan-Fei Yan Jin-sheng Yang Zhen Li Teng-Fei Song Xue-Jun Rao Chang-Hui Rao Key Laboratory on Adaptive Optics Chinese Academy of SciencesChengdu 610209China Institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China School of Electronic Electrical and Communication Engineering of the University of Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern A&A Ministry of EducationNanjing 210023China Yunnan Observatories Chinese Academy of SciencesKunming 650216.China

The 2.5 m wide-field and high-resolution solar telescope(WeHoST)is currently under developing for solar *** aims to achieve high-resolution observations over a super-wide field of view(FOV)of5′×5′,and a desired resolution of 0.3″.To meet the scientific requirements of WeHoST,the ground-layer adaptive optics(GLAO)with a specially designed wave front sensing system is as the primary *** introduce the GLAO configuration,particularly the wave front sensing *** analytic method,we simulate the performance of both classical AO and GLAO systems,optimize the wave front sensing system,and evaluate GLAO performance in terms of PSF uniformity and correction improvement across whole *** results indicate that,the classical AO will achieve diffraction-limited resolution;the suggested GLAO configuration will uniformly improve the seeing across the full 5′×5′FOV,reducing the FWHM across the axis FOV to less than0.3″(λ≥705 nm,r0≥11 cm),which is more than two times *** specially designed wave front sensor schedule offers new potential for WeHoST’s GLAO,particularly the multi-FOV GLAO and the flexibility to select the detected *** capabilities will significantly enhance the scientific output of the telescope.

关键词： instrumentation adaptive optics-instrumentation detectors-instrumentation high angular resolution-methods numerical-telescopes-Sun activity

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How Effective are Decentralized Anti-poverty Programs?

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China & World Economy 2024年第4期32卷 85-113页

作者： Shuai chen Mingda cheng Jie-sheng Tan-Soo China Academy for Rural Development and School of Public Affairs Zhejiang UniversityChina Jiangxi Caitong Supply Chain Financial Group Co. Ltd.Jiangxi Financial Holding Group Co.Ltd.China Lee Kuan Yew School of Public Policy National University of SingaporeSingapore

This study examines the effectiveness of China's National Poor Counties(NPC)program,a decentralized anti-poverty initiative,by analyzing five rounds of individual-level panel data from 1988 to *** impact of two waves of the NPC program(1994 and 2001)is evaluated utilizing a panel fixed-effects regression *** results indicate substantial positive effects,with residents in NPC counties experiencing a 47 percent income increase,3.1 percent higher employment rates,and a 5.7 percent rise in household expenditure from 1988 to 2008,in comparison with non-NPC ***,the program benefited vulnerable populations,dispelling concerns about"elite capture."The study also reveals that evolving policy focus has played a pivotal role in sustaining the effects of the program over *** 1994 round prioritized low-skilled employment,and the 2001 wave emphasized productivity enhancement through skills *** findings highlight the continued efficacy of decentralized anti-povertyefforts.

关键词： decentralization elite capture National Poor Counties program poverty

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A homing rescue gene drive with multiplexed gRNAs reaches high frequency in cage populations but generates functional resistance

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Journal of Genetics and Genomics 2024年第8期51卷 836-843页

作者： Shibo Hou Jingheng chen Ruobing Feng Xuejiao Xu nan Liang Jackson Champer Center for Bioinformatics Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing 100871China

CRISPR homing gene drives have considerable potential for managing populations of medically and agriculturally significant *** operate by Cas9 cleavage followed by homology-directed repair,copying the drive allele to the wild-type chromosome and thus increasing in frequency and spreading throughout a ***,resistance alleles formed by end-joining repair pose a significant *** address this,we create a homing drive targeting the essential hairy gene in Drosophila *** resistance alleles are recessive lethal,while drive carriers have a recoded“rescue”version of *** drive inheritance rate is moderate,and multigenerational cage studies show drive spread to 96%–97%of the ***,the drive does not reach 100%due to the formation of functional resistance alleles despite using four *** alleles have a large deletion but likely utilize an alternate start ***,revised designs targeting more essential regions of a gene may be necessary to avoid such functional *** of the rescue element’s native 3'UTR with a homolog from another species increases drive inheritance by 13%–24%.This was possibly because of reduced homology between the rescue element and surrounding genomic DNA,which could also be an important design consideration for rescue gene drives.

关键词： Genedrive Homing drive Rescueelement Population modification Multiplexed gRNAs Resistance alleles Cage study

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Palladium-catalyzed stereoselective decarboxylative[4+2]cyclization of 2-methylidenetrimethylene carbonates with pyrrolidone-derived enones:Straightforward access to chiral tetrahydropyran-fused spiro-pyrrolidine-2,3-diones

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Chinese Chemical Letters 2024年第6期35卷 279-282页

作者： Ke Zhang sheng Zuo Pengyuan You Tong Ru Fen-Er chen Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of EducationCollege of PharmacyYanbian UniversityYanji 133002China College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China Engineering Center of Catalysis and Synthesis for Chiral Molecules Fudan UniversityShanghai 200433China Shanghai Engineering Center of Industrial Catalysis for Chiral Drugs Shanghai 200433China

A novel asymmetric[4+2]cycloaddition of 2-methylidenetrimethylene carbonate with pyrrolidonederived enones has been achieved to produce the functionalized tetrahydropyran-fused spirocyclic scaffolds via *** array of enantioenriched spiro-pyrrolidine-2,3-diones bearing adjacent quaternary and tertiary stereocenters are obtained in high yields with excellent enantioselectivities(up to 96% yield and 99% ee).The further transformation of the product has been accomplished for the construction of medical interesting β^(2,2)-amino acids and β-*** mechanistic research was well conducted.

关键词： Pyrrolidine-2,3-diones 2-Methylidenetrimethylene carbonate Asymmetric annulation Spiroheterocycles Allylic 1,3-strain

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