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Source wavefield reconstruction based on an implicit staggered-grid finite-difference operator for seismic imaging

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Petroleum Science 2022年第5期19卷 2095-2106页

作者： Zhi-ming ren xue Dai Qian-Zong Bao Chang'an University College of Geological Engineering and GeomaticsXi'anShaanxi710064China National Engineering Research Center of Offshore Oil and Gas Exploration Beijing100028China

Reverse time migration and full waveform inversion involve the crosscorrelation of two wavefields,propagated in the forward-and reverse-time directions,*** a result,the forward-propagated wavefield needs to be stored,and then accessed to compute the correlation with the backward-propagated ***-value methods reconstruct the source wavefield using saved boundary wavefields and can significantly reduce the storage ***,the existing boundary-value methods are based on the explicit finite-difference(FD)approximations of the spatial *** FD methods exhibit greater accuracy and thus allow for a smaller operator *** develop two(an accuracy-preserving and a memory-efficient)wavefield reconstruction schemes based on an implicit staggered-grid FD(SFD)*** former uses boundary wavefields at M layers of grid points and the spatial derivatives of wavefields at one layer of grid points to reconstruct the source wavefield for a(2M+2)th-order implicit SFD *** latter applies boundary wavefields at N layers of grid points,a linear combination of wavefields at M–N layers of grid points,and the spatial derivatives of wavefields at one layer of grid points to reconstruct the source wavefield(0≤N

关键词： Finite difference Reverse time migration Source wavefield reconstruction Implicit Staggered grid

Normalized Solution for p-Kirchhoff Equation with a L2-supercritical Growth

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 414-429页

作者： Zhi-min ren Yong-yi LAN School of Sciences Jimei UniversityXiamen 361005China

In this paper,we investigate the following p-Kirchhoff equation{∫R^(N)|u|^(2)dx=ρ,(a+b)∫RN(|Δu}^(p)+|u|^(p))dx)(-Δpu+|u|^(p-2u)=|u|^(s-2)u+μu,x∈R^(N),where a>0,b≥0,p>0 are constants,constants,p*=N-P/Np is the ... 详细信息

关键词： p-Kirchhoff equation normalized solution mountain-pass lemma

Partitioning Complete Graphs by Heterochromatic Trees

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Acta Mathematicae Applicatae Sinica 2012年第4期28卷 625-630页

作者： Ze-min JIN xue-liang LI Department of Mathematics Zhejiang Normal University Center for Combinatorics and LPMC Nankai University

A heterochromatie tree is an edge-colored tree in which any two edges have different colors. The heterochromatic tree partition number of an r-edge-colored graph G, denoted by tr （G）, is the minimum positive integer p such that whenever the edges of the graph G are colored with r colors, the vertices of G can be covered by at most p vertex-disjoint heterochromatic trees. In this paper we determine the heterochromatic tree partition number of r-edge-colored complete graphs. We also find at most tr（Kn） vertex-disjoint heterochromatic trees to cover all the vertices in polynomial time for a given r-edge-coloring of Kn.

关键词： edge-colored graph heterochromatic tree partition

Catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations

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Science China Chemistry 2023年第12期66卷 3331-3346页

作者： ren-Fei Cao Zhi-min Chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai 200240China

Chiral organosulfur compounds are not only widely distributed in bioactive natural products and pharmaceuticals,but also play a significant role in chiral ligands/*** the history of synthetic organic chemistry,chemists have been absorbed in the construction of centrally chiral organosulfur ***,there are relatively few reports on installing sulfur functional groups into axially chiral *** is one of the fundamental phenomena in nature,which ubiquitously exists in natural *** more than a century of development,atropisomers have been designed and extensively applied to pharmaceuticals,functional materials and chiral ligands/*** to the importance of chiral sulfurcontaining atropisomers,there is an increasing demand for enantioselective synthesis of ***,a diversity of approaches by C-S bond formations have been established for the construction of enantioenriched sulfur-containing atropisomers,however,there is no comprehensive review to summarize this great *** this mini-review,we summarize recent progress in catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations,which includes sulfur nucleophilic reactions,sulfur electrophilic reactions and sulfur radical ***,the reaction mechanisms are also *** hope that this mini-review will enable more researchers to further explore this field.

关键词： atropisomers asymmetric catalysis C-S bond formations chiral organosulfur compounds

Phosphate enrichment mechanism in CaO–SiO_2–FeO–Fe_2O_3–P_2O_5 steelmaking slags with lower binary basicity

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International Journal of minerals,Metallurgy and Materials 2016年第5期23卷 520-533页

作者： Jin-yan Li Mei Zhang min Guo xue-min Yang State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083China Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

The addition of silica to steelmaking slags to decrease the binary basicity can promote phosphate enrichment in quenched slag samples. In this study, we experimentally investigated phosphate enrichment behavior in CaO-SiO2-FeO-Fe203-P205 slags with a P205 content of 5.00% and the binary basicity B ranging from 1.0 to 2.0, where the （%Fe/O）/（%CaO） mass percentage ratio was maintained at 0.955. The experimental results are explained by the defined enrichment degree c, of solid solution 2CaO·SiO2-3CaO·P205 （C2S-C3P）, where R_C2S-C3P is a component of the developed ion and molecule coexistence theory （IMCT）-Ni model for calculating the mass action concentrations Ni of structural units in the slags on the basis of the IMCT. The asymmetrically inverse V-shaped relation be- tween phosphate enrichment and binary basicity B was observed to be correlated in the slags under applied two-stage cooling conditions. The maximum content of PROs in the C2S-C3P solid solution reached approximately 30.0% when the binary basicity B was controlled at 1.3.

关键词： phosphates enrichment mechanisms steelmaking slags basicity

A novel and facile synthesis of 2-oxo-1,2-dihydropyridine-fused 1,3-diazaheterocycles via heterocyclic ketene aminals and Konevenagel adducts formed by phthalic anhydride and ethyl cyanacetate

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Chinese Chemical Letters 2014年第12期25卷 1515-1519页

作者： min-ming Zou Feng-Juan Zhu xue Tian Li-Ping ren Xu-Sheng Shao Zhong Li Shanghai Key Laboratory of Chemical Biology School of PharmacyEast China University of Science and Technology

An efficient synthetic pathway to 2-oxo-1,2-dihydropyridine-fused 1,3-diaza heterocycles from heterocyclic ketene aminals,phathalic anhydride and ethyl cyanacetate was *** protocol involved aza-ene reaction/imine-enam... 详细信息

关键词： Heterocyclic ketene aminals 2-Oxo-1 2-dihydropyridine 1 3-Diazaheterocycle Synthesis

A compact scheme for two-dimensional nonlinear time fractional wave equations

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第5期12卷 143-161页

作者： Guanghui Zhang min ren College of Mathematics and Statistics Suzhou University SuzhouAnhui 234000P.R.China

Based on the equivalent integro-differential form of the considered problem, a numerical approach to solving the two-dimensional nonlinear time fractional wave equations(NTFWEs) is considered in this paper. To this end, an alternating direction implicit(ADI) numerical scheme is derived. The scheme is established by combining the secondorder convolution quadrature formula and Crank–Nicolson technique in time and afourth-order difference approach in space. The convergence and unconditional stability of the proposed compact ADI scheme are strictly discussed after a concise solvabilityanalysis. A numerical example is shown to demonstrate the theoretical analysis.

关键词： Two-dimensional nonlinear time fractional wave equations ADI scheme convergence

Shining more light on G protein signalling modules:a novel optogenetic tool for Gq activation

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Science China(Life Sciences) 2022年第12期65卷 2567-2568页

作者： Jing ren Tian xue Liping Wang Division of Neurobiology MRC Laboratory of Molecular BiologyCambridge CB20QHUnited Kingdom School of Life Sciences Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

The use of optogenetic and chemogenetic approaches to control cellular activities with high temporal,spatial and cell-type specific resolution has profoundly transformed the field of *** addition to enabling the manipulation of neuronal excitability,there is a great need for targeting intracellular signalling proteins and secondary messengers precisely。

关键词： transformed precisely profound

Optimization of sowing date and seeding rate for high winter wheat yield based on pre-winter plant development and soil water usage in the Loess Plateau,China

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Journal of Integrative Agriculture 2019年第1期18卷 33-42页

作者： ren Ai-xia SUN min WANG Pei-ru xue Ling-zhu LEI Miao-miao xue Jian-fu GAO Zhi-qiang YANG Zhen-ping College of Agriculture Shanxi Agricultural University

Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing *** sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–*** variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity *** consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain ***2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or *** productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three *** highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall *** number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was *** results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth *** selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved

关键词： accumulated temperature dry-land sowing date seeding rate soil water winter wheat yield components