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Study of primordial deuterium abundance in Big Bang nucleosynthesis

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Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： zhi-Lin Shen Jian-jun He Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRImaT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi Meng zhi-Ming ma Academy of mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Fast charge transfer kinetics in Sv-ZnIn_(2)S_(4)/Sb_(2)S_(3)S-scheme heterojunction photocatalyst for enhanced photocatalytic hydrogen evolution

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Rare Metals 2024年第2期43卷 533-542页

作者： Wei Li Jia-jun Li zhi-Fei Liu Hong-Yu ma Peng-Fei Fang Rui Xiong Jian-Hong Wei Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education School of Physics and TechnologyWuhan UniversityWuhan430072China

Constructing a S-scheme heterojunction with tight interface contact and fast charge transfer is beneficial to improving the photocatalytic hydrogen evolution ***,a unique one-dimensional(1D)/two-dimensional(2D)S-scheme heterojunction containing 1D Sb_(2)S_(3) nanorods and 2D ZnIn_(2)S_(4) with affluent sulfur vacancies(denoted as Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3)) was *** introduced sulfur vacancy can promote the effective adsorption of H+for the following interfacial hydrogen-evolution ***,the larger contact area and stronger electron interaction between Sb_(2)S_(3) and ZnIn_(2)S_(4) effectively inhibits the recombination of photo-generated electron–hole pairs and abridges the migration distance of *** a result,the optimal Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) sample achieves H_(2) evolution activity of 2741.3 mol·h^(−1)·g^(−1),which is 8.6 times that of pristine ZnIn_(2)S_(4) and 3.0 times that of the Sv-ZnIn_(2)S_(4) *** on the experimental result,the photo-reactivity S-scheme mechanism of hydrogen evolution from water splitting with Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) is *** work provides an effective method for developing S-scheme heterojunction composites of transition metal sulfide with high hydrogen evolution performance.

关键词： ZnIn_(2)S_(4) nanosheets S-scheme heterojunction Sulfur vacancy Charge transfer and separation Photocatalytic H_(2)evolution

Equivalence between the internal observability and equation

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Applied mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： LIU Wen-jun TU zhi-yu School of mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-Gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-Gibson-Thompson equation internal observability exponential stability

CRITICAL EXAMINATION OF WETLANDS ECOSYSTEM SERVICE IN SHANGHAI, CHINA

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湿地科学 2005年第4期3卷 279-285页

作者： Zhao Bin Yang Feng-Hui Gao Yu ma zhi-jun Li Bo Chen Jia-Kuan Key Laboratory for Biodiversity Science and Ecological Engineering Ministry of Chinese Education Institute of Biodiversity Science Fudan University Shanghai 200433 China

Wetlands provide many important services to human society, but are at the same time ecologically sensitive and adaptive systems, and are under heavy pressure. As a wetland city, Shanghai city has various types of natural wetlands (chiefly, includes coastal, riverine, lacustrine, and reservoir and pond wetlands), which account for 23.5% of total areas. Meanwhile, Shanghai is a metropolitan city, being confronted with the pressure of port expansion and urban and industrial sprawl, just like the other megalopolises in the world. Based on our earlier study on estimating the ecological service values of wetlands in Shanghai, this paper analyzed the ecological functions of the wetland city, such as nutrient cycling, water regulation and supply, food supply, disturbance control, water treatment, habitats and refugia, aesthetic, education and culture, tidal flats and potential land resources. Unfortunately, the wetland function was being degraded and the ecosystem service was discounted accordingly because of over-reclamation, over-fishing, water pollution, and rapid urbanization in the city. It’s therefore recommended that, to improve the environment of Shanghai ciry, and make the ecosystems sustainable function appropriately, the effective wetland management strategies should be taken.

关键词：生态系统生态功能湿地上海

The Multi-parameter Test of Gravitational Wave Dispersion with Principal Component Analysis

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Research in Astronomy and Astrophysics 2024年第5期24卷 140-150页

作者： zhi-Chu ma Rui Niu Wen Zhao CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

In this work, we consider a conventional test of gravitational wave(GW) propagation which is based on the phenomenological parameterized dispersion relation to describe potential departures from General Relativity(GR)along the propagation of GWs. But different from tests conventionally performed previously, we vary multiple deformation coefficients simultaneously and employ the principal component analysis(PCA) method to remedy the strong degeneracy among deformation coefficients and obtain informative posteriors. The dominant PCA components can be better measured and constrained, and thus are expected to be more sensitive to potential departures from the waveform model. Using this method we analyze ten selected events and get the result that the combined posteriors of the dominant PCA parameters are consistent with GR within 99.7% credible intervals. The standard deviation of the first dominant PCA parameter is three times smaller than that of the original dispersion parameter of the leading order. However, the multi-parameter test with PCA is more sensitive to not only potential deviations from GR but also systematic errors of waveform models. The difference in results obtained by using different waveform templates hints that the demands of waveform accuracy are higher to perform the multiparameter test with PCA. Whereas, it cannot be strictly proven that the deviation is indeed and only induced by systematic errors. It requires more thorough research in the future to exclude other possible reasons in parameter estimation and data processing.

关键词： gravitational waves-gravitation-black hole physics

Full waveform inversion based on hybrid gradient

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Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang Xie zhi-Liang Qin Jian-Hua Wang Peng Song Heng-Guang Shen Sheng-Qi Yu Ben-jun ma Xue-Qin Liu Qingdao Innovation and Development Base Harbin Engineering UniversityQingdao266000ShandongChina Qingdao Innovation and Development Center Harbin Engineering UniversityQingdao266000ShandongChina CNOOC Research Institute Co. Ltd.Beijing100028China College of marine Geoscience Ocean University of ChinaQingdao266100ShandongChina Weihai Sunfull Geophysical Exploration Equipment Co. Ltd.Weihai264209ShandongChina

The low-wavenumber components in the gradient of full waveform inversion(FWI)play a vital role in the stability of the ***,when FWI is implemented in some high frequencies and current models are not far away from the real velocity model,an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion *** solve this problem,this paper firstly derives a formula of scattering angle weighted gradient in FWI,then proposes a hybrid *** hybrid gradient combines the conventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived *** weighted hybrid mode,we can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion,and use more high-wavenumber components in the high-frequency inversion to improve the convergence *** results of synthetic data experiment demonstrate that compared to the conventional FWI,the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion *** also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the *** the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI)has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle weighted Low-wavenumber component

Greedy is Good:Constrained Non-submodular Function maximization via Weak Submodularity

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Journal of the Operations Research Society of China 2024年第3期12卷 627-648页

作者： ma-jun Shi Wei Wang School of Statistics Xi’an University of Finance and EconomicsXi’an710100ShaanxiChina School of mathematics and Statistics Xi’an Jiaotong UniversityXi’an710049ShaanxiChina

The widely used greedy algorithm has been recently shown to achieve near-optimal theoretical guarantees for the problems of constrained monotone non-submodular function maximization,with competitive performances in *** this paper,we investigate the problems of maximizing monotone non-submodular set functions under three classes of independent system constraints,including p-matroid intersection constraints,p-extendible system constraints and p-system *** prove that the greedy algorithm yields an approximation ratio ofγ/p+γfor the former two problems,andξγ/p+ξγfor the last problem,which further has been improved toγ/p+γ,whereγ,ξdenote the submodularity ratio and the diminishing returns ratio of set function *** addition,we also show that the greedy guarantees have a further refinement of for all the problems mentioned above,whereαis the generalized curvatureξ/p+αγof set ***,we show that our greedy algorithm does yield competitive practical performances using a variety of experiments on synthetic data.

关键词： Non-submodular function p-matroid intersection p-extendible system p-system Greedy algorithm

Unlocking T cell exhaustion:Insights and implications for CAR-T cell therapy

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Acta Pharmaceutica Sinica B 2024年第8期14卷 3416-3431页

作者： Dian Xiong Haijun Yu zhi-jun Sun State Key Laboratory of Oral&maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei Key Laboratory of StomatologySchool&Hospital of StomatologyFrontier Science Center for Immunology and MetabolismTaikang Center for Life and Medical ScienceWuhan UniversityWuhan 430079China Department of Radiation and Medical Oncology Hubei Province Cancer Clinical Study CenterHubei Key Laboratory of Tumor Biological BehaviorsZhongnan Hospital of Wuhan UniversityWuhan 430071China

Chimeric antigen receptor T(CAR-T)cell therapy as a form of adoptive cell therapy(ACT)has shown significant promise in cancer treatment,demonstrated by the FDA-approved CAR-T cell therapies targeting CD19 or B cell maturation antigen(BCma)for hematological malignancies,albeit with moderate outcomes in solid ***,despite these advancements,the efficacy of CAR-T therapy is often compromised by T cell exhaustion,a phenomenon that impedes the persistence and effector function of CAR-T cells,leading to a relapse rate of up to 75%in patients treated with CD19 or CD22 CAR-T cells for hematological *** to overcome CAR-T exhaustion employ state-of-the-art genomic engineering tools and single-cell sequencing *** this review,we provide a comprehensive understanding of the latest mechanistic insights into T cell exhaustion and their implications for the current efforts to optimize CAR-T cell *** insights,combined with lessons learned from benchmarking CAR-T based products in recent clinical trials,aim to address the challenges posed by T cell exhaustion,potentially setting the stage for the development of tailored next-generation approaches to cancer treatment.

关键词： Cancer immunotherapy CAR-T therapy T cell exhaustion Tumor immune microenvironment Spatial immune contexture Single-cell technologies CAR-T engineering Combination therapy