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Heterocatalytic ethylene methoxycarbonylation via a pseudo-hydride pathway over Pt/MoS

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Science China Chemistry 2024年

作者： bo-hang zhao Bin Zhang Institute of Molecular Plus Department of Chemistry School of Science Tianjin University

Ethylene (C2H4) methoxycarbonylation (EMC) with CO and methanol (CH3OH) to methyl propanoate (MP) is industrially important due to its 100%atom efficiency [1].However, the heavy reliance on homogeneous Pd-based catalysts and strong acid media over commercial EMC processes still causes economic and environmental concerns[2]. At present, supported single-atom catalysts (SACs) can serve as bridges for accessing homogeneous catalysts in traditional heterogeneous catalytic processes. SACs have been extensively studied because they may provide new opportunities for exploring heterogeneous catalysts for the EMC process [3]. However, the mechanism of the heterocatalytic EMC process on SACs is still unclear. Therefore,developing efficient SACs and unveiling their working mechanism are highly important for identifying the heterocatalytic EMC field.

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Nitrite-catalyzed economic and sustainable bromocyclization of tryptamines/tryptophols to access hexahydropyrrolo[2,3-b]indoles/tetrahydrofuroindolines in batch and flow

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Chinese Chemical Letters 2024年第7期35卷 247-252页

作者： Xiao Xiao Biao Chen Jia-Wei Li Jun-bo Zheng Xu Wang hang zhao Fen-Er Chen Institute of Pharmaceutical Science and Technology Collaborative Innovation Center of Yangtze River Delta Region Green PharmaceuticalsZhejiang University of TechnologyHangzhou 310014China College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022China Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs Shanghai 200433China

A highly efficient and concise bromocyclization has been successfully achieved,in which tryptamine/tryptophol derivates can be transformed to valuable HPI/TFI scaffolds with economic and green ***,a controllable cascade transformation of bromocyclization and aromatic bromination has also been smoothly achieved to form dibrominated HPIs and *** could be successfully scaled up under both the batch process and a continuous flow *** most remarkable peculiarity of our process over all previous methods is that the generated water is the major ***,successful application of this new protocol has been demonstrated by the pharmaceutical and natural products syntheses.

关键词： Tryptamines and tryptophols Nitrite Economic and sustainable bromocyclization HPI and TFI structures Bath and flow

Noteworthy phenomena in pediatric inherited cardiomyopathy

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World Journal of Pediatrics 2024年第6期20卷 635-637页

作者： Jin-hang Jiang Jie Tian bo Pan Department of Pediatric Cardiology National Clinical Key Cardiovascular SpecialtyNational Clinical Research Center for Child Health and DisordersMinistry of Education Key Laboratory of Child Development and DisordersChildren's Hospital of Chongqing Medical University136 Zhongshan Er RoadYuzhong DistirctChongqing 400014China Key Laboratory of Children's Important Organ Development and Diseases Chongqing Municipal Health CommissionChongqingChina

Pediatric cardiomyopathy has an early onset and poor ***,it was referred to as idiopathic cardiomyopathy due to unknown ***,recent advances in molecular genetics and molecular biology have demonstrated that most pediatric cardiomyopathy cases are related to genetic factors,mainly involving single gene and single nucleotide mutations[1,2].Although the pathogenicity of some gene mutations in patients has not been fully elucidated,genetic factors are still considered the main cause of pediatric cardiomyopathy.

关键词： cardiomyopathy pediatric etiology

A Multi-Token Sector Antenna Neighbor Discovery Protocol for Directional Ad Hoc Networks

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China Communications 2024年第7期21卷 149-168页

作者： Zhang hang Li bo Yan Zhongjiang Yang Mao Li Xinru School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710072China The 54th Research Institute of CETC Shijiazhuang 050081China

In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc *** central concept of our work involves maintaining multiple tokens across the *** prevent mutual interference among multi-token holders,we introduce the time and space non-interference ***,we propose a master-slave strategy between *** the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each *** on this foundation,we provide a comprehensive procedure for the M-SAND *** also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation ***,simulation results demonstrate the time efficiency of the M-SAND *** compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.

关键词： multi-token neighbor discovery SAND protocol sector antenna ad hoc network

Perenniality:From model plants to applications in agriculture

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Molecular Plant 2024年第1期17卷 141-157页

作者： bo zhao Jia-Wei Wang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences(CEMPS)Institute of Plant Physiology and Ecology(SIPPE)Chinese Academy of Sciences(CAS)Shanghai 200032China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Plant Carbon Capture CASShanghai 200032China New Cornerstone Science Laboratory Shanghai 200032China

To compensate for their sessile nature,plants have evolved sophisticated mechanisms enabling them to adapt to ever-changing *** such prominent feature is the evolution of diverse life history strategies,particularly such that annuals reproduce once followed by seasonal death,while perennials live longer by cycling growth *** intrinsic phenology is primarily genetic and can be altered by environmental *** evolutionary transitions between annual and perennial life history strategies are common,perennials account for most species in nature because they survive well under year-round *** proportion,however,is reversed in ***,perennial crops promise to likewise protect and enhance the resilience of agricultural ecosystems in response to climate *** significant endeavors that have been made to generate perennial crops,progress is slow because of barriers in studying perennials,and many developed species await further *** findings in model species have illustrated that simply rewiring existing genetic networks can lead to lifestyle *** implies that engineering plant life history strategy can be achieved by manipulating only a few key *** this review,we summarize our current understanding of genetic basis of perenniality and discuss major questions and challenges that remain to be addressed.

关键词： perenniality developmental plasticity flowering time poplar Arabis alpina perennial crops life history strategy

Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang YING Xinning ZHOU hang SU Jun ZHU bo Zhang Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack

Pr-Tb synergistic strengthening on coercivity of Nd-Ce-Fe-B magnets grain boundary diffused with Pr-Tb-Al-Ga alloys

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Journal of Rare Earths 2024年第9期42卷 1704-1709页

作者： Ruifang Song hang zhao Haibo Feng Institute of Functional Materials Central Iron & Steel Research Institute

Sintered Nd-Ce-Fe-B magnets were grain boundary diffused（GBDed） with PrxTb80-xAl10Ga10（at%）(x=0,20,40,60,80) *** effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was *** Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb80Al10Ga10diffused *** element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity *** with low melting point diffuses deeply along liquid grain boundary phase during GBD *** can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb ***,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization *** method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth（HRE）elements.

关键词： Grain boundary diffusion Rare earths Microstructure Synergistic strengthening

Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China

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Plant Diversity 2024年第2期46卷 158-168页

作者： Rong Ma Qi Xu Yongqian Gao Deli Peng hang Sun bo Song State Key Laboratory of Plant Diversity and Specialty Crops/Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China College of Life Sciences Shaanxi Normal UniversityXi'an 710119China Yunnan Forestry Technological College Kunming 650224China School of Life Science/Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment Yunnan Normal UniversityKunming 650500YunnanChina

Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous *** was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.

关键词： Floral traits Fruit type Growth form Pollination system Reproductive phenology

How plants sense and respond to osmotic stress

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Journal of Integrative Plant Biology 2024年第3期66卷 394-423页

作者： bo Yu Dai-Yin Chao Yang zhao Shanghai Center for Plant Stress Biology CAS Center for Excellence in Molecular Plant SciencesThe Chinese Academy of SciencesShanghai 200032China Key Laboratory of Plant Carbon Capture The Chinese Academy of SciencesShanghai 200032China National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyThe Chinese Academy of SciencesShanghai 200032China University of Chinese Academy of Sciences Beijing 100049China

Drought is one of the most serious abiotic stresses to land *** sense and respond to drought stress to survive under water *** have studied how plants sense drought stress,or osmotic stress caused by drought,ever since Charles Darwin,and gradually obtained clues about osmotic stress sensing and signaling in *** stress is a physical stimulus that triggers many physiological changes at the cellular level,including changes in turgor,cell wall stiffness and integrity,membrane tension,and cell fluid volume,and plants may sense some of these stimuli and trigger downstream *** this review,we emphasized water potential and movements in organisms,compared putative signal inputs in cell wall-containing and cell wall-free organisms,prospected how plants sense changes in turgor,membrane tension,and cell fluid volume under osmotic stress according to advances in plants,animals,yeasts,and bacteria,summarized multilevel biochemical and physiological signal outputs,such as plasma membrane nanodomain formation,membrane water permeability,root hydrotropism,root halotropism,Casparian strip and suberin lamellae,and finally proposed a hypothesis that osmotic stress responses are likely to be a cocktail of signaling mediated by multiple *** also discussed the core scientific questions,provided perspective about the future directions in this field,and highlighted the importance of robust and smart root systems and efficient source-sink allocations for generating future high-yield stress-resistant crops and plants.

关键词： cell volume drought membrane tension osmotic stress turgor