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On Minor Left Prime Factorization Problem for Multivariate Polynomial Matrices

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Journal of Systems Science & Complexity 2024年第3期37卷 1295-1307页

作者： lu Dong WANG Dingkang xiao Fanghui School of Mathematics Southwest Jiaotong University KLMM Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences MOE-LCSM School of Mathematics and Statistics Hunan Normal University

A new necessary and sufficient condition for the existence of minor left prime factorizations of multivariate polynomial matrices without full row rank is presented. The key idea is to establish a relationship between a matrix and any of its full row rank submatrices. Based on the new result,the authors propose an algorithm for factorizing matrices and have implemented it on the computer algebra system Maple. Two examples are given to illustrate the effectiveness of the algorithm, and experimental data shows that the algorithm is efficient.

关键词： Free modules Gröbner bases minor left prime (MLP) multivariate polynomial matrices polynomial matrix factorizations

3D trajectory inversion of an adjacent well using scattered P-wave

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Petroleum Science 2023年第2期20卷 857-865页

作者： lu Cheng xiao-Hua Che Wen-xiao Qiao Teng Zhao State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China Key Laboratory of Earth Prospecting and Information Technology Beijing102249China

In oil and gas exploitation,cluster well technology can significantly reduce costs and improve efficiency.An effective adjacent well detection method can greatly reduce the risk of collision between adjacent wells.This study proposes a method to invert the 3D trajectory of an adjacent well using a scattered P-wave obtained by borehole azimuthal acoustic reflection imaging.After obtaining the scattered P-wave from the raw data of the target well using the wave field separation technology,the waveform data in an imaging profile can be obtained by the downhole acoustic directional reception technology.Migration imaging technology is then used to obtain the image of the formation in the imaging profile.Subsequently,by analyzing the images of the formation in the imaging profile of the different azimuths,the well spacing and azimuth of the target well can be determined.Finally,the 3D trajectory of the target well can be obtained by solving the inversion equation.This method was validated by processing the field data from a deviated well in a deep formation.The comparison of the inversion and actual trajectories of the target well demonstrated that the maximum deviation of the inversion trajectory is 0.9 m in the north-south direction,0.78 m in the east-west direction,1.45 m in the well spacing,and 2.48°in the azimuth.The field data inversion result demonstrated that the method can effectively use the azimuth reflection acoustic data to invert the 3D trajectory of an adjacent well,which indicates that the borehole azimuthal acoustic reflection imaging technology has great potential within the context of adjacent well detection.

关键词： Acoustic imaging Acoustic reflection logging Directional reception Adjacent well

Partners in Epoxide Copolymerization Catalysis:Approach to High Activity and Selectivity

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Chinese Journal of Polymer Science 2022年第11期40卷 1331-1348页

作者： xiao-Bing lu Bai-Hao Ren State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

The ring-opening alternating copolymerization processes of epoxides with small-molecule monomers,such as carbon dioxide(CO_(2)),carbonyl sulfide(COS)and cyclic anhydrides,are powerful strategies for preparing polymeric materials with degradable carbonate/ester/thiocarbonate main-chain backbone units.The catalysts selected for copolymerization processes play crucial roles in determining their reaction rates and productivities,as well as the selectivity,regio-and stereochemistry,compositions,and the molecular weights of their resultant copolymers.These processes often generate undesirable byproducts such as polyether or ether linkages dispersed randomly within the copolymer's chain,and/or more thermodynamically stable cyclic products.In this account,we outline our efforts of over a dozen years on developing highly active well-defined metal catalysts based on inter-and intra-molecular synergistic strategies to selectively produce completely alternating copolymers from epoxides and various small-molecule monomers.Much attention was paid to the enantioselective resolution copolymerization processes of racemic epoxides via regioselective ring-openings,and the asymmetric copolymerization processes of meso-epoxides with CO_(2),COS,or cyclic anhydrides via dissymmetrical ring-openings using multichiral catalytic systems,and affording isotactic copolymers with main-chain chirality.In addition,this account provides a thorough mechanistic understanding of the high reactivities,excellent selectivity,and unprecedented stereochemical controls of these copolymerization systems,mediated by interand intramolecular synergistic catalysis.

关键词： Epoxide Ring-opening copolymerization Synergistic catalysis CO_(2) Stereochemistry control

Humidity sensor based on BiOBr synthesized under ambient condition

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Journal of Semiconductors 2022年第12期43卷 95-100页

作者： Chaofan Cao Guixian xiao Yao lu Second Affiliated Hospital Shenyang Medical CollegeShenyang 110035China State Key Laboratory of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China

Flexible humidity sensors are effective portable devices for human respiratory monitoring.However,the current pre-paration of sensitive materials need harsh terms and the small production output limits their practicability.Here,we report a syn-thesis method of single-crystal BiOBr nanosheets under room temperature and atmospheric pressure based on a sonochemic-al strategy.A flexible humidity sensor enabled by BiOBr nanosheets deliver efficient sensing performance,a high humidity sensit-ivity(Ig/I0=550%)with relative humidity from 40%to 100%,an excellent selectivity,and a detection response/recovery time of 11 and 6 s,respectively.The flexible humidity sensor shows a potential application value as a wearable monitoring device for res-piratory disease prevention and health monitoring.

关键词： human breathing BiOBr nanosheets sonochemical strategy flexible humidity sensor

Conformal Vector Fields on Finsler Warped Product Manifolds

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Acta Mathematica Sinica,English Series 2023年第8期39卷 1624-1634页

作者： xiao Ling ZHANG Ya lu FENG College of Mathematics and Systems Science Xinjiang UniversityUrumqi 830046P.R.China

In this paper,we study the conformal vector fields on Finsler warped product manifolds.We obtain a system of equivalent equations that the conformal vector fields on Finsler warped product manifolds satisfy and completely characterize conformal vector fields on such manifolds.Further,by solving the equation,we give the classification.And we also give some examples.

关键词： Finsler warped product manifold conformal vector field homothetic vector field Killing vector field

Precipitation Microphysical Characteristics of Typhoon Ewiniar(2018) before and after Its Final Landfall over Southern China

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Advances in Atmospheric Sciences 2023年第6期40卷 1005-1020页

作者： lu FENG Hui xiao Xiantong LIU Sheng HU Huiqi LI Liusi xiao xiao HAO Guangzhou Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510641China Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction China Meteorological AdministrationGuangzhou 510641China Guangzhou Meteorological Observatory China Meteorological AdministrationGuangzhou 511430China

In this paper, the evolution of the microphysical characteristics in different regions(eyewall, inner core, and outer rainbands) and different quadrants [downshear left(DL), downshear right(DR), upshear left(UL), and upshear right(UR)]during the final landfall of Typhoon Ewiniar(2018) is analyzed using two-dimensional video disdrometer and S-band polarimetric radar data collected in Guangdong, China. Due to the different types of underlying surfaces, the periods before landfall(mainly dominated by underlying sea surface) and after landfall(mainly dominated by underlying land surface) are also analyzed. Both before landfall and after landfall, the downshear quadrants had the dominate typhoon precipitation. The outer rainbands had more graupel than the inner core, resulting in a larger radar reflectivity, differential reflectivity, specific differential phase shift, and mass-weighted mean diameter below the melting layer. Compared with other regions, the eyewall region had the smallest mean logarithmic normalized intercept parameter before landfall and the smallest mean mass-weighted mean diameter and the largest mean logarithmic normalized intercept parameter after landfall. The hydrometeor size sorting was obvious in the eyewall and inner core(especially in the eyewall) after landfall. A high concentration of large raindrops fell in the DL quadrant, and more small raindrops fell in the UR quadrant. Although the icephase process and warm rain process were both important in the formation of tropical cyclone precipitation, the warm rain process(ice-phase process) contributed more liquid water before landfall(after landfall). This investigation provides a reference for improving the microphysical parameterization scheme in numerical models.

关键词： tropical cyclone precipitation microphysics raindrop size distribution southern China

Experimental distillation of tripartite quantum steering with an optimal local filtering operation

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Photonics Research 2024年第3期12卷 552-562页

作者： QIAN-XI ZHANG xiao-XU FANG HE lu School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Shenzhen Research Institute of Shandong University Shenzhen 518057China

Multipartite Einstein-Podolsky-Rosen(EPR)steering admits multipartite entanglement in the presence of uncharacterized verifiers,enabling practical applications in semi-device-independent protocols.Such applications generally require stronger steerability,while the unavoidable noise weakens steerability and consequently degrades the performance of quantum information processing.Here,we propose the local filtering operation that can maximally distill genuine tripartite EPR steering from N copies of three-qubit generalized Greenberger-Horne-Zeilinger states,in the context of two semi-device-independent scenarios.The optimal filtering operation is determined by the maximization of assemblage fidelity.Analytical and numerical results indicate the advantage of the proposed filtering operation when N is finite and the steerability of initial assemblages is weak.Experimentally,a proof-of-principle demonstration of two-copy distillation is realized with the optical system.The advantage of the optimal local filtering operation is confirmed by the distilled assemblage in terms of higher assemblage fidelity with perfectly genuine tripartite steerable assemblages,as well as the greater violation of the inequality to witness genuine tripartite steerable assemblages.Our results benefit the distillation of multipartite EPR steering in practice,where the number of copies of initial assemblages is generally finite.

关键词： filtering distillation optimal

Gut microbiota:closely tied to the regulation of circadian clock in the development of type 2 diabetes mellitus

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Chinese Medical Journal 2020年第7期133卷 817-825页

作者： lu Ding Xin-Hua xiao Department of Endocrinology Key Laboratory of EndocrinologyMinistry of HealthPeking Union Medical College HospitalDiabetes Research Center of Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

Type 2 diabetes mellitus(T2DM),a worldwide epidemic disease,has caused tremendous economic and social burden,but the pathogenesis remains uncertain.Nowadays,the impact of unrhythmic circadian clock caused by irregular sleep and unhealthy diet on T2DM has be increasingly studied.However,the contribution of the endogenous circadian clock system to the development of T2DM has not yet been satisfactorily explored.It is now becoming clear that the gut microbiota and the circadian clock interact with each other to regulate the host metabolism.Considering all these above,we reviewed the literature related to the gut microbiota,circadian clock,and T2DM to elucidate the idea that the gut microbiota is closely tied to the regulation of the circadian clock in the development of T2DM,which provides potential for gut microbiota-directed therapies to ameliorate the effects of circadian disruptions linked to the occurrence and development of T2DM.

关键词： Gut microbiota Circadian clock Type 2 diabetes mellitus Metabolites

从“音乐肖像”到“寻谣计划”:陆晔、小河谈公共艺术实践如何连接公众、激活社区

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公共艺术 2021年第3期 62-67页

作者：陆晔小河复旦大学信息与传播研究中心复旦大学新闻学院不详

小河是著名民谣歌手和音乐制作人,美好药店乐队主唱,河乐队成员,"音乐肖像""回响行动""寻谣计划"发起人。2010年,小河发起了音乐项目"音乐肖像",2018年发起"寻谣计划",前者邀请专业音乐人为普通人写歌,后者对国内日渐消失的老童谣进行... 详细信息

小河是著名民谣歌手和音乐制作人,美好药店乐队主唱,河乐队成员,"音乐肖像""回响行动""寻谣计划"发起人。2010年,小河发起了音乐项目"音乐肖像",2018年发起"寻谣计划",前者邀请专业音乐人为普通人写歌,后者对国内日渐消失的老童谣进行发掘和改编,通过音乐将人们联系在一起。"寻谣计划"持续至今,小河及其团队的寻谣足迹遍布北京、上海、长沙、杭州、邯郸、晋城、洛阳、三门峡、西安、延安、银川等地,走过社区、公园和乡村,将老人、孩子和年轻人聚在一起,将被时间遗忘的优美旋律唱给更多的人听。

关键词：陆晔公共艺术童谣肖像三门峡发起人