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Results on Local Times of a Class of Multiparameter Gaussian Processes

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Acta Mathematicae Applicatae Sinica 2006年第1期22卷 81-90页

作者： zong-mao cheng Xiu-yun Wang Zheng-yan Lin Department of Mathematics Zhejiang University Hangzhou 310028 China Hangzhou Dianzi University Hangzhou 310018 China

In this paper, we introduce a class of Gaussian processes Y={Y（t）：t∈R^N},the so called hifractional Brownian motion with the indcxes H=（H1,…,HN）and α. We consider the （N, d, H, α） Gaussian random field x（t） = （x1 （t）,..., xd（t））,where X1 （t）,…, Xd（t） are independent copies of Y（t）, At first we show the existence and join continuity of the local times of X = {X（t）, t ∈ R＋^N}, then we consider the HSlder conditions for the local times.

关键词： Bi-fractional Brownian motiom local time Gaussian random field

A multithreaded parallel upwind sweep algorithm for the S_(N) transport equations discretized with discontinuous finite elements

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Nuclear Science and Techniques 2023年第12期34卷 229-241页

作者： Zhi‑Wei zong mao‑Song cheng Ying‑Chi Yu Zhi‑Min Dai Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The complex structure and strong heterogeneity of advanced nuclear reactor systems pose challenges for high-fidelity neutron-shielding calculations. Unstructured meshes exhibit strong geometric adaptability and can overcome the deficiencies of conventionally structured meshes in complex geometry modeling. A multithreaded parallel upwind sweep algorithm for S_(N) transport was proposed to achieve a more accurate geometric description and improve the computational efficiency. The spatial variables were discretized using the standard discontinuous Galerkin finite-element method. The angular flux transmission between neighboring meshes was handled using an upwind scheme. In addition, a combination of a mesh transport sweep and angular iterations was realized using a multithreaded parallel technique. The algorithm was implemented in the 2D/3D S_(N) transport code ThorSNIPE, and numerical evaluations were conducted using three typical benchmark problems:IAEA, Kobayashi-3i, and VENUS-3. These numerical results indicate that the multithreaded parallel upwind sweep algorithm can achieve high computational efficiency. ThorSNIPE, with a multithreaded parallel upwind sweep algorithm, has good reliability, stability, and high efficiency, making it suitable for complex shielding calculations.

关键词： Shielding calculation Discrete ordinates method Discontinuous Galerkin finite element method Unstructured meshes

Coevolution of global brachiopod palaeobiogeography and tectonopalaeogeography during the Carboniferous

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Journal of Palaeogeography 2021年第3期10卷 284-301页

作者： Ning Li cheng-Wen Wang Pu zong Yong-Qin mao College of Earth Sciences Jilin UniversityChangchun 130061Jilin ProvinceChina International Center of Future Science Dinosaur Evolution Research CenterJilin UniversityChangchun 130061Jilin ProvinceChina Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Guizhou Mountain Resources Research Institution Guiyang 550001Guizhou ProvinceChina

The global brachiopod palaeobiogeography of the Mississippian is divided into three realms, six regions, and eight provinces, while that of the Pennsylvanian is divided into three realms, six regions, and nine provinces. On this basis,we examined coevolutionary relationships between brachiopod palaeobiogeography and tectonopalaeogeography using a comparative approach spanning the Carboniferous. The appearance of the Boreal Realm in the Mississippian was closely related to movements of the northern plates into middle–high latitudes. From the Mississippian to the Pennsylvanian, the palaeobiogeography of Australia transitioned from the Tethys Realm to the Gondwana Realm,which is related to the southward movement of eastern Gondwana from middle to high southern latitudes. The transition of the Yukon–Pechora area from the Tethys Realm to the Boreal Realm was associated with the northward movement of Laurussia, whose northern margin entered middle–high northern latitudes then. The formation of the six palaeobiogeographic regions of Mississippian and Pennsylvanian brachiopods was directly related to "continental barriers", which resulted in the geographical isolation of each region. The barriers resulted from the configurations of Siberia, Gondwana, and Laurussia, which supported the Boreal, Tethys, and Gondwana realms, respectively. During the late Late Devonian–Early Mississippian, the Rheic seaway closed and North America(from Laurussia) joined with South America and Africa(from Gondwana), such that the function of "continental barriers" was strengthened and the differentiation of eastern and western regions of the Tethys Realm became more distinct. In the Barents Ocean tectonic domain during the Pennsylvanian, the brachiopods on the northern margin of the Barents Ocean formed the Verkhoyansk–Taymyr Province, while those on the southern margin formed the Yukon–Pechora Province. The Mongolia–Okhotsk Province was formed by brachiopods of the Mongolia–Okhotsk Ocean tectoni

关键词： Carboniferous Brachiopod Palaeobiogeography Tectonopalaeogeography Coevolution

Regulation on polymerization degree and surface feature in graphitic carbon nitride towards efficient photocatalytic H2 evolution under visible-light irradiation

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Journal of Materials Science & Technology 2022年第3期98卷 160-168页

作者： cheng cheng Chung-Li Dong Jinwen Shi Liuhao mao Yu-cheng Huang Xing Kang Shichao zong Shaohua Shen International Research Center for Renewable Energy(IRCRE) State Key Laboratory of Multiphase Flow in Power Engineering(MFPE)Xi'an Jiaotong University(XJTU)28 West Xianning RoadXi’an 710049China Department of Physics Tamkang University151 Yingzhuan RoadTamsui 25137TaiwanChina

A kind of graphitic carbon nitride(TSC-550) with high polymerization degree and improved surface property was prepared by a new precursor of thiosemicarbazide. The sulfur motif and high nitrogen content in thiosemicarbazide promoted the polymerization of thiosemicarbazide to form graphitic carbon nitride framework with high degree of polymerization, which significantly influenced the electronic structure and surface chemical properties. TSC-550 possessed a narrow bandgap of 2.19 eV that facilitated the utilization of visible light, and possessed a less positive charge, acidic surface that resulted in enhanced hydrogen adsorption ability in water solution, which promoted the H;evolution kinetics. In addition, the extended π-conjugated electronic system promoted the separation and migration of photogenerated charge carries in plane of TSC-550 framework, as well as the increasing interlayer C–N interactions in TSC-550 created conductive paths across the layers to tunnel interlayers for rapid electron transportation. As a result, TSC-550 nanosheets showed excellent photocatalytic H;production activity,the AQY achieved 36.4% at 425 nm.

关键词： Degree of polymerization Graphitic carbon nitride Photocatalysis Solar energy Hydrogen

Experimental study of dual nano-network, high-temperature resistant aerogel material as an integration of thermal management functions

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Journal of Energy Chemistry 2025年第1期 157-170页

作者： Yueyue Xiao Tianke mao Zun Zhao Yuelei Pan Heping Zhang Xudong cheng State Key Laboratory of Fire Science University of Science and Technology of China

Thermal management system is highly desirable to guarantee the performance and thermal safety of lithium-ion batteries,but it reduces the energy density of battery modules and even is unable to provide highly effective ***,a thermal management function integrated material is presented based on high-temperature resistant aerogel and phase change material and is applied at both charge–discharge process and thermal runaway *** this sandwich structure Paraffin@SiC nanowire/Aerogel sheet （denoted as PA@SAS） system,SiC nanowires endow the middle aerogel sheet （SAS） a dual nano-network *** enhanced mechanical properties of SAS were studied by compressive tests and dynamic mechanical ***,the thermal conductivity of SAS at 600°C is only 0.042 W/（m K）.The surface phase change material layers facilitate temperature uniformity of batteries （surface temperature difference less than 1.82°C） through latent ***,a large-format battery module with four 58 Ah LiNi0.5Co0.2Mn0.3O2LIBs was ***@SAS successfully prevents thermal runaway propagation,yielding a temperature gap of 602°C through the 2 mm-thick cross ***@SAS also exhibits excellent performance in other safety issues such as temperature rise rate,flame heat flux,*** lightweight property and effective insulation performance achieves significant safety enhancement with mass and volume energy density reduction of only 0.79%and 5.4%,*** originality of the present research stems from the micro and macro structure design of the proposed thermal management material and the combination of intrinsic advantages of every *** work provides a reliable design of achieving the integration of thermal management functions into an aerogel composite and improves the thermal safety of lithium-ion batteries.

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Two New Eremophilenolides from Cacalia ainsliaeflora

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Chinese Chemical Letters 2003年第5期14卷 479-482页

作者： Man Jun mao cheng Shan YUAN Chuan zong ZOU Zhong Jian JIA Department of Chemistry National Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000

Two new eremophilenolides (3b-angeloyloxy-8b, 10b-dihydroxy-6b-ethoxyeremophile- nolide (1) and 3b, 6b-diangeloyloxy-8a-methoxy-10a-hydroxyeremophilenolide (2) were isolated from the roots of Cacalia ainsliaeflora. T... 详细信息

关键词： Cacalia ainsliaeflora Compositae eremophiane sesquiterpene.

Stacking fault,dislocation dissociation,and twinning in Pt_(3) Hf compounds:a DFT study

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Rare Metals 2021年第4期40卷 1020-1030页

作者： Shun-Meng Zhang Kai Xiong cheng-Chen Jin zong-Bo Li Jun-Jie He Yong mao National Center for International Research on Photoelectric and Energy Materials School of Materials and EnergyMaterials Genome InstituteYunnan UniversityKunming 650091China

The Pt3Hf compound plays a decisive role in strengthening Pt-Hf alloy *** the stacking fault,dislocation dissociation,and twinning mechanisms in Pt3Hf is the first step in understanding its plastic *** this work,the generalized stacking fault energies(GSFE),including the complex stacking fault(CSF),the superlattice intrinsic stacking fault(SISF),and the antiphase boundary(APB) energies,are calculated using firstprinciples *** dislocation dissociation,deformation twinning,and yield behavior of Pt3Hf are discussed based on GSFE after their incorporation into the Peierls-Nabarro *** found that the unstable stacking fault energy(γus) of(111)APB is lower than that of SISF and(010) APB,implying that the energy barrier and critical stress required for(111)APB generation are lower than those required for(010)APB *** result indicates that the a superdislocation will dissociate into two collinear a/2 superpartial *** a/2 dislocation could further dissociate into a a/6 Shockley dislocation and a a/3 superShockley dislocation connected by a SISF,which results in an APB→SISF *** study also discovered that Pt3 Hf exhibits normal yield behavior,although the cross-slip of a a/2 dislocation is not forbidden,and the anomalous yield criterion is ***,it is observed that the energy barrier and critical stress for APB formation increases with increasing pressure and decreases as the temperature is *** the temperature rises above 1400 K,the a/2 dislocation slipping may change from the {111} planes to the {100} planes.

关键词： Platinum alloys Stacking fault energy Dislocation dissociation Twinning First-principles

Application of material-mesh algebraic collapsing acceleration technique in method of characteristics——based neutron transport code

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Nuclear Science and Techniques 2021年第8期32卷 95-109页

作者： Ming Dai mao-Song cheng Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China

The algebraic collapsing acceleration(ACA)technique maximizes the use of geometric flexibility of the method of characteristics(MOC).The spatial grids for loworder ACA are the same as the high-order transport,which makes the numerical solution of ACA equations costly,especially for large-size *** speed-up the MOC transport iterations effectively for general geometry,a coarse-mesh ACA method that involves selectively merging fine-mesh cells with identical materials,called material-mesh ACA(MMACA),is *** energy group batching(EGB)strategy in the tracing process is proposed to increase the parallel efficiency for microscopic crosssection *** and macroscopic crosssection benchmark problems are used to validate and analyse the accuracy and efficiency of the MMACA *** maximum errors in the multiplication factor and pin power distributions are from the VERA-4 B-2 D case with silver-indium-cadmium(AIC)control rods inserted and are 104 pcm and 1.97%,*** with the single-thread ACA solution,the maximum speed-up ratio reached 25 on 12 CPU cores for microscopic cross-section VERA-4-2 D *** the C5 G7-2 D and LRA-2 D benchmarks,the MMACA method can reduce the computation time by approximately one *** present work proposes the MMACA method and demonstrates its ability to effectively accelerate MOC transport iterations.

关键词： Algebraic collapsing acceleration Material-mesh ACA Method of characteristics OpenMP Arbitrary geometry

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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