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Structure-Preserving Recurrent Neural Networks for a Class of Birkhoffian Systems

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Journal of Systems Science & Complexity 2024年第2期37卷 441-462页

作者： XIAO shanshan chen Mengyi zhang Ruili TANG Yifa LSEC ICMSECAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China

In this paper,the authors propose a neural network architecture designed specifically for a class of Birkhoffian systems—The Newtonian *** proposed model utilizes recurrent neural networks(RNNs)and is based on a mathematical framework that ensures the preservation of the Birkhoffian *** authors demonstrate the effectiveness of the proposed model on a variety of problems for which preserving the Birkhoffian structure is important,including the linear damped oscillator,the Van der Pol equation,and a high-dimensional *** with the unstructured baseline models,the Newtonian neural network(NNN)is more data efficient,and exhibits superior generalization ability.

关键词： Birkhoffian system k(z,t)-symplectic neural networks recurrent neural network

Effects of arbuscular mycorrhizal fungi on carbon assimilation and ecological stoichiometry of maize under combined abiotic stresses

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JOURNAL OF PLANT ECOLOGY 2024年第2期17卷 74-88页

作者： Ran, Qiong zhang, Songlin Arif, Muhammad Yin, Xueting chen, shanshan Ren, Guangqian Chongqing Univ Technol Sch Management Chongqing 400054 Peoples R China Chinese Acad Sci Chongqing Inst Green & Intelligent Technol Key Lab Reservoir Aquat Environm Chongqing 400714 Peoples R China Southwest Univ Sch Life Sci Key Lab Ecoenvironm Three Gorges Reservoir Reg Minist EducState Cultivat Base Ecoagr Southwest M Chongqing 400715 Peoples R China Jiangsu Univ Inst Environm & Ecol Acad Environm Hlth & Ecol Secur Sch Environm & Safety Engn Zhenjiang 212013 Peoples R China

Arbuscular mycorrhizal fungi (AMF) enhance plant tolerance to abiotic stresses like salinity and improve crop yield. However, their effects are variable, and the underlying cause of such variation remains largely unknown. This study aimed to assess how drought modified the effect of AMF on plant resistance to high calcium-saline stress. A pot experiment was performed to examine how AMF inoculation affects the growth, photosynthetic activity, nutrient uptake and carbon (C), nitrogen (N) and phosphorus (P) stoichiometric ratio (C:N:P) of maize under high calcium stress and contrasting water conditions. The results showed that high calcium stress significantly reduced mycorrhizal colonization, biomass accumulation, C assimilation rate and C:N stoichiometric ratio in plant tissues. Besides, the adverse effects of calcium stress on photosynthesis were exacerbated under drought. AMF inoculation profoundly alleviated such reductions under drought and saline stress. However, it barely affected maize performance when subjected to calcium stress under well-watered conditions. Moreover, watering changed AMF impact on nutrient allocation in plant tissues. Under well-watered conditions, AMF stimulated P accumulation in roots and plant growth, but did not induce leaf P accumulation proportional to C and N, resulting in increased leaf C:P and N:P ratios under high calcium stress. In contrast, AMF decreased N content and the N:P ratio in leaves under drought. Overall, AMF inoculation improved maize resistance to calcium-salt stress through enhanced photosynthesis and modulation of nutrient stoichiometry, particularly under water deficit conditions. These results highlighted the regulatory role of AMF in carbon assimilation and nutrient homeostasis under compound stresses, and provide significant guidance on the improvement of crop yield in saline and arid regions.

关键词： arbuscular mycorrhizal fungi compound abiotic stresses C:N:P stoichiometry induced systemic resistance calcium-salt stress PLANT-GROWTH ROOT COLONIZATION WATER RELATIONS NUTRIENT-UPTAKE DROUGHT SOIL TOLERANCE SALINITY SALT AVAILABILITY

Improved simulation of winter wheat yield in North China Plain by using PRYM-Wheat integrated dry matter distribution coefficient

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Journal of Integrative Agriculture 2024年第4期23卷 1381-1392页

作者： Xuan Li Shaowen Wang Yifan chen Danwen zhang shanshan Yang Jingwen Wang Jiahua zhang Yun Bai Sha zhang Research Center for Remote Sensing and Digital Earth College of Computer Science and TechnologyQingdao UniversityQingdao266071China Center for Geospatial Information Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China School of Geographical Sciences Hebei Normal UniversityShijiazhuang 050024China

The accurate simulation of regional-scale winter wheat yield is important for national food security and the balance of grain supply and demand in ***,most remote sensing process models use the“biomass×harvest index(HI)”method to simulate regional-scale winter wheat ***,spatiotemporal differences in HI contribute to inaccuracies in yield simulation at the regional ***-series dry matter partition coefficients(Fr)can dynamically reflect the dry matter partition of winter *** this study,Fr equations were fitted for each organ of winter wheat using site-scale *** equations were then coupled into a process-based and remote sensingdriven crop yield model for wheat(PRYM-Wheat)to improve the regional simulation of winter wheat yield over the North China Plain(NCP).The improved PRYM-Wheat model integrated with the fitted Fr equations(PRYM-Wheat-Fr)was validated using data obtained from provincial yearbooks.A 3-year(2000-2002)averaged validation showed that PRYM-Wheat-Fr had a higher coefficient of determination(R^(2)=0.55)and lower root mean square error(RMSE=0.94 t ha^(-1))than PRYM-Wheat with a stable HI(abbreviated as PRYM-Wheat-HI),which had R^(2) and RMSE values of 0.30 and 1.62 t ha^(-1),*** PRYM-Wheat-Fr model also performed better than PRYM-Wheat-HI for simulating yield in verification years(2013-2015).In conclusion,the PRYM-Wheat-Fr model exhibited a better accuracy than the original PRYM-Wheat model,making it a useful tool for the simulation of regional winter wheat yield.

关键词： dry matter partition remote sensing model winter wheat yield North China Plain

Efficient Spin-Flip between Charge-Transfer States for High-Performance Electroluminescence, without an Intermediate Locally Excited State

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Research 2024年第1期2023卷 339-349页

作者： Donghai zhang shanshan Jiang Xiaodong Tao Fulin Lin Lingyi Meng Xu-Lin chen Can-Zhong Lu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian 361021China University of Chinese Academy of Sciences Beijing 100049China

Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains ***,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5%to 96.3%),and approximate energy levels of the lowest excited singlet states(S_(1)),but significantly different spin-flipping RISC rates(0.03×10^(6) s^(−1) vs.2.26×10^(6) s^(−1))and exciton lifetime(297.1 to 332.8μs vs.6.0μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(^(3)CT–^(1)CT)transition.

关键词： transition lifetime desired

Reaction Kinetics and Secondary Organic Aerosol Composition Analysis of 2-Cyclohexen-1-one with NO_(3) Radicals

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Chemical Research in Chinese Universities 2024年第4期40卷 730-736页

作者： HU Lin TONG Shengrui XU Yanyong zhang Hailiang YU shanshan chen Meifang GE Maofa Structural Chemistry of Unstable and Stable Species Chinese Academy of Sciences Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190P.R.China College of Ecology and Environment Xinjiang UniversityUrumqi830017P.R.China University of Chinese Academy of Sciences Beijing100049P.R.China

Unsaturated ketones are typical oxygenated volatile organic compounds(OVOCs)with high reactivity,and are important precursors in air *** sources of OVOCs are complex and include direct emissions and secondary oxidation formation of VOCs in the atmosphere.2-Cyclohexen-1-one is a widespread substance,and is derived from the industrial catalytic oxidation of *** this paper,we investigated the rate constants of the chemical reactions of 2-cyclohexen-1-one with NO_(3) radicals,which is(7.25±0.29)×10^(-15) cm^(3)·molecule^(-1)·s^(-1) at 298 K and under 1 atm(1 atm=101325Pa).It supplemented the kinetics of NO_(3) radicals database,and revealed its effects in the nighttime *** addition,the reaction products of 2-cyclohexen-1-one with NO_(3) radicals were detected by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS),which revealed a series of nitrate esters in the composition of the secondary organic aerosol(SOA),which may reduce atmospheric ***,the possible pathways for the generation of the products were developed.

关键词： Kinetics Unsaturated ketone Nitrate radical Secondary organic aerosol

Exploring device physics of perovskite solar cell via machine learning with limited samples

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Journal of Energy Chemistry 2024年第7期94卷 441-448页

作者： shanshan Zhao Jie Wang Zhongli Guo Hongqiang Luo Lihua Lu Yuanyuan Tian Zhuoying Jiang Jing zhang Mengyu chen Lin Li cheng Li School of Electronic Science and Engineering Xiamen UniversityXiamen 361005FujianChina Future Display Institute of Xiamen Xiamen 361005FujianChina

Perovskite solar cells(PsCs)have developed tremendously over the past ***,the key factors influencing the power conversion efficiency(PCE)of PSCs remain incompletely understood,due to the complexity and coupling of these structural and compositional *** this research,we demon-strate an effective approach to optimize PSCs performance via machine learning(ML).To address chal-lenges posed by limited samples,we propose a feature mask(FM)method,which augments training samples through feature transformation rather than synthetic *** this approach,squeeze-and-excitation residual network(SEResNet)model achieves an accuracy with a root-mean-square-error(RMSE)of 0.833%and a Pearson's correlation coefficient(r)of ***,we employ the permu-tation importance(PI)algorithm to investigate key features for ***,we predict PCE through high-throughput screenings,in which we study the relationship between PCE and chemical *** that,we conduct experiments to validate the consistency between predicted results by ML and experimental *** this work,ML demonstrates the capability to predict device performance,extract key parameters from complex systems,and accelerate the transition from laboratory findings to commercialapplications.

关键词： Perovskite solar cell Machine learning Device physics Performance prediction Limited samples

Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of CD19-specific CAR T-cells via TGF-βsignaling

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Frontiers of Medicine 2024年第1期18卷 128-146页

作者： Yuanyuan Hao Panpan chen shanshan Guo Mengyuan Li Xueli Jin Minghuan zhang Wenhai Deng Ping Li Wen Lei Aibin Liang Wenbin Qian Department of Hematology The Second Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou310009China Department of Hematology Henan Provincial People’s HospitalZhengzhou University People’s HospitalZhengzhou450003China Key Laboratory of Laboratory Medicine Ministry of EducationSchool of Laboratory Medicine and Life SciencesWenzhou Medical UniversityWenzhou325000China Department of Hematology Tongji Hospital of Tongji UniversityShanghai200065China

Tumor-derived exosomes (TEXs) enriched in immune suppressive molecules predominantly drive T-cell dysfunction and impair antitumor immunity. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising treatment for refractory and relapsed hematological malignancies, but whether lymphoma TEXs have the same impact on CAR T-cell remains unclear. Here, we demonstrated that B-cell lymphoma-derived exosomes induce the initial activation of CD19-CAR T-cells upon stimulation with exosomal CD19. However, lymphoma TEXs might subsequently induce CAR T-cell apoptosis and impair the tumor cytotoxicity of the cells because of the upregulated expression of the inhibitory receptors PD-1, TIM3, and LAG3 upon prolonged exposure. Similar results were observed in the CAR T-cells exposed to plasma exosomes from patients with lymphoma. More importantly, single-cell RNA sequencing revealed that CAR T-cells typically showed differentiated phenotypes and regulatory T-cell (Treg) phenotype conversion. By blocking transforming growth factor β (TGF-β)-Smad3 signaling with TGF-β inhibitor LY2109761, the negative effects of TEXs on Treg conversion, terminal differentiation, and immune checkpoint expression were rescued. Collectively, although TEXs lead to the initial activation of CAR T-cells, the effect of TEXs suppressed CAR T-cells, which can be rescued by LY2109761. A treatment regimen combining CAR T-cell therapy and TGF-β inhibitors might be a novel therapeutic strategy for refractory and relapsed B-cell lymphoma.

关键词： tumor-derived exosome chimeric antigen receptor T-cell lymphoma TGF-β

Sucrose-associated SnRK1a1-mediated phosphorylation of Opaque2 modulates endosperm filling in maize

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Molecular Plant 2024年第5期17卷 788-806页

作者： Tao Yang Yunqin Huang Longyu Liao shanshan Wang Haoyu zhang Jingying Pan Yongcai Huang Xiaoling Li Di chen Tao Liu Xiaoduo Lu Yongrui Wu State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China Sichuan Agricultural UniversityChengdu 611130SichuanChina National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesShanghai lnstitute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China Institute of Molecular Breeding for Maize Qilu Normal UniversityJinanChina

During maize endosperm filling,sucrose not only serves as a source of carbon skeletons for storage-reserve synthesis but also acts as a stimulus to promote this ***,the molecular mechanisms underlying sucrose and endosperm filling are poorly *** this study,we found that sucrose promotes the expression of endosperm-filling hub gene Opaque2(O2),coordinating with storage-reserve *** showed that the protein kinase SnRK1a1 can attenuate O2-mediated transactivation,but sucrose can release this *** assays revealed that SnRK1a1 phosphorylates O2 at serine 41(S41),negatively affecting its protein stability and transactivation *** observed that mutation of SnRK1a1 results in larger seeds with increased kernel weight and storage reserves,while overexpression of SnRK1a1 causes the opposite *** of the native O2(O2-OE),phospho-dead(O2-SA),and phospho-mimetic(O2-SD)variants all increased 100-kernel *** O2-SA seeds exhibit smaller kernel size,they have higher accumulation of starch and proteins,resulting in larger vitreous endosperm and increased test weight.O2-SD seeds display larger kernel size but unchanged levels of storage reserves and test weight.O2-OE seeds show elevated kernel dimensions and nutrient storage,like a mixture of O2-SA and O2-SD ***,our study discovers a novel regulatory mechanism of maize endosperm *** of S41 as a SnRK1-mediated phosphorylation site in O2 offers a potential engineering target for enhancing storage-reserve accumulation and yield in maize.

关键词： maize Opaque2 SnRK1 endosperm phosphorylation sucrose

Filterless narrowband photodetectors enabled by controllable band modulation through ion migration: The case of halide perovskites

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InfoMat 2024年第1期6卷 123-138页

作者： Yu Li shanshan Yu Junjie Yang Kai zhang Mingyu Hu Weitao Qiu Fumin Guo Wei Qian Sean Reinecke Tao chen Makhsud I.Saidaminov Jian Wang Shihe Yang Guangdong Provincial Key Lab of Nano-Micro Materials Research School of Chemical Biology and BiotechnologyShenzhen Graduate SchoolPeking UniversityShenzhenGuangdongthe People's Republic of China Shenzhen Bay Laboratory Institute of Biomedical EngineeringShenzhenGuangdongthe People's Republic of China School of Advanced Materials Shenzhen Graduate SchoolPeking UniversityShenzhenGuangdongthe People's Republic of China Department of Chemistry The University of Hong KongHong Kong SARthe People's Republic of China Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy ConversionDepartment of Materials Science and EngineeringSchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefeiAnhuithe People's Republic of China College of Materials and Energy South China Agricultural UniversityGuangzhouGuangdongthe People's Republic of China Department of Chemistry University of VictoriaVictoriaBritish ColumbiaCanada

Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral *** the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.

关键词： band structure ion migration narrowband detection perovskite spatial distribution of charge carriers