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Three‑dimensional numerical simulation of dynamic strength and failure mode of a rock mass with cross joints

International Journal of Coal Science & Technology 2024年第2期11卷 35-52页

作者： Tingting Liu Wenxu Huang Chang xiang Qian dong Xinping Li Chao Zhang Hubei Key Laboratory of Blasting Engineering Jianghan UniversityWuhan 430056China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Hainan Institute Wuhan University of TechnologySanya 572025China

To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence ratioη,a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling *** validity of the model was verified by comparing and analyzing it in conjunction with laboratory test ***-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and *** study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact *** results show that the peak stress of the specimens decreases first and then increases with the increase of the cross ***α<60°,regardless of the value ofη,the dynamic stress of the specimens is controlled by the main ***α≥60°,the peak stress borne by the specimens decreases with increasingη.Whenα<60°,the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint,and the final failure surface of the specimens is composed of the main joint and wing ***α≥60°orη≥0.67,the secondary joint guides the expansion of the wing cracks,and multiple failure surfaces composed of main and secondary joints,wing cracks,and co-planar cracks are *** lateral confinement significantly increases the dynamic peak stress able to be borne by the *** triaxial conditions,the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.

关键词： Cross joints Joint distribution form Dynamic failure characteristics FEM–DEM BHPB

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Flower development and sexual dimorphism in Vernicia montana

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Horticultural Plant Journal 2024年第2期10卷 586-600页

作者： Wenying Li Jingzhen Chen xiang dong Meilan Liu Guibin Wang Lin Zhang Key Laboratory of Cultivation and Protection for Non-wood Forest Trees Ministry of EducationCentral South University of Forestry and TechnologyChangshaHunan 410004China State Key Laboratory of Utilization of Woody Oil Resource Hunan Academy of ForestryChangshaHunan 410004China College of Forestry Nanjing Forestry UniversityNanjingJiangsu 210037China

The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers:(Ⅰ) differentiation of male or female primordia to produce staminate flowers(SFs) or transient hermaphrodite flowers(HFs),and(Ⅱ) complete abortion of stamens in transient HFs to generate pistillate flowers(PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptomebased analysis revealed that the differentially expressed genes(DEGs) between PFs and SFs in phase Ⅰ involved in abscisic acid(ABA), auxin(AUX), cytokinin(CK), ethylene(ET), and gibberellin(GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid(JA) and salicylic acid(SA) pathways displayed opposite expression patterns. Moreover,differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MSbased analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase Ⅱ indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.

关键词： Mu oil tree Flower development Sexual dimorphism Sex bias Ethylene

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Angiosperm-wide analysis of fruit and ovary evolution aided by a new nuclear phylogeny supports association of the same ovary type with both dry and fleshy fruits

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Journal of Integrative Plant Biology 2024年第2期66卷 228-251页

作者： Yezi xiang Taikui Zhang Yiyong Zhao Hongjin dong Hongyi Chen Yi Hu Chien-Hsun Huang Jun xiang Hong Ma State Key Laboratory of Genetic Engineering Ministry of Education Key Laboratory of Biodiversity and Ecological EngineeringInstitute of Plant BiologyCenter of Evolutionary BiologySchool of Life SciencesFudan UniversityShanghai 200438China Department of Biology Howard Hughes Medical InstituteDuke UniversityDurhamNC 27708USA Department of Biology the Eberly College of Scienceand the Huck Institutes of the Life Sciencesthe Pennsylvania State UniversityUniversity ParkPA 16802USA Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization College of Biology and Agricultural ResourcesHuanggang Normal UniversityHuanggang 438000China

Fruit functions in seed protection and dispersal and belongs to many dry and fleshy types,yet their evolutionary pattern remains unclear in part due to uncertainties in the phylogenetic relationships among several orders and *** we used nuclear genes of 502 angiosperm species representing 231 families to reconstruct a well supported phylogeny,with resolved relationships for orders and families with previously uncertain *** this phylogeny as a framework,molecular dating supports a Triassic origin of the crown angiosperms,followed by the emergence of most orders in the Jurassic and Cretaceous and their rise to ecological dominance during the Cretaceous Terrestrial *** robust phylogeny allowed an examination of the evolutionary pattern of fruit and ovary types,revealing a trend of parallel carpel fusions during early diversifications in eudicots,monocots,and ***,taxa in the same order or family with the same ovary type can develop either dry or fleshy fruits with strong correlations between specific types of dry and fleshy fruits;such associations of ovary,dry and fleshy fruits define several ovaryfruit"modules"each found in multiple *** of the frequent modules has an ovary containing multiple ovules,capsules and berries,and another with an ovary having one or two ovules,achenes(or other single-seeded dry fruits)and *** new perspective of relationships among fruit types highlights the closeness of specific dry and fleshy fruit types,such as capsule and berry,that develop from the same ovary type and belong to the same module relative to dry and fleshy fruits of other modules(such as achenes and drupes).Further analyses of gene families containing known genes for ovary and fruit development identified phylogenetic nodes with multiple gene duplications,supporting a possible role of whole-genome duplications,in combination with climate changes and animal behaviors,in angiosperm fruit and ovary diversificat

关键词： angiosperm fruit evolution MADS-box molecular clock nuclear phylogeny ovary and fruit developmental genes

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Precise Planar-Twisted Molecular Engineering to Construct Semiconducting Polymers with Balanced Absorption and Quantum Yield for Efficient Phototheranostics

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Research 2024年第2期2023卷 227-238页

作者： xiang Su Zhirong Bao Wei Xie Deliang Wang Ting Han dong Wang Ben Zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China Department of Radiation and Medical Oncology Hubei Key Laboratory of Tumor Biological BehaviorsHubei Cancer Clinical Study CenterZhongnan Hospital of Wuhan UniversityWuhan 430071China Department of Materials Chemistry Huzhou UniversityHuzhou 313000China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdong 518172China

Semiconducting polymers(SPs)have shown great feasibility as candidates for near-infrared-II(NIR-Ⅱ)fluorescence imaging-navigated photothermal therapy due to their strong light-harvesting ability and flexible ***,the fluorescence signal of traditional SPs tends to quench in their aggregate states owing to the strongπ-πstacking,which can lead to the radiative decay pathway shutting *** address this issue,aggregation-induced emission effect has been used as a rational tactic to boost the aggregate-state fluorescence of NIR-Ⅱ*** this contribution,we developed a precise molecular engineering tactic based on the block copolymerizations that integrate planar and twisted segments into one conjugated polymer backbone,providing great flexibility in tuning the photophysical properties and photothermal conversion capacity of *** monomers featured with twisted and planar architectures,respectively,were tactfully incorporated via a ternary copolymerization approach to produce a series of new *** optimal copolymer(SP2)synchronously shows desirable absorption ability and good NIR-Ⅱquantum yield on the premise of maintaining typical aggregation-induced emission characteristics,resulting in balanced NIR-Ⅱfluorescence brightness and photothermal ***-dispersible nanoparticles fabricated from the optimal SP2 show efficient photothermal therapeutic effects both in vitro and in *** in vivo investigation reveals the distinguished NIR-Ⅱfluorescence imaging performance of SP2 nanoparticles and their photothermal ablation toward tumor with prominent tumor accumulation ability and excellent biocompatibility.

关键词： property. conducting twisted

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Modeling Method of Multi-Energy Systems Based on LSTM Algorithm

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1701-1709页

作者： Di Qiu Fei Chen dong Liu min Cao Siyang Liu Shanghai Jiao Tong University Shanghai 200240China Yunnan Power Grid Co. Ltd

The development of the Energy Internet has improved the efficiency of energy utilization and promoted sustainable development of power and energy *** multi-energy system modeling considering the dynamic process of transmission line is one of the key research points of Energy Internet operation *** the energy circuit theory,the lumped parameter model of natural gas pipelines is built and the dynamic characteristic parameters under the control instruction are *** with dynamic characteristic parameters,the long short-term memory(LSTM)neural network is designed to fit the natural gas pipeline dynamic process into discrete linear time-varying(LTV)*** with the equations,an energy hub method is used to build a control model of industrial parks with multi-energy distribution *** the rolling optimal control strategy given in this paper,the model is solved by the Matlab-Yalmip solver and rolling control instructions of each energy conversion unit are ***,the case study demonstrates that the LSTM neural network-based modeling method presented in this paper can accurately fit the dynamic process of a natural gas pipeline *** rolling control model of the multi-energy system can improve the efficiency of energy utilization,exhibit the transmission line status constraints during the optimization control process and improve reliability of the multi-energy system operation.

关键词： Energy hub LSTM multi-energy supply system pipeline system modeling

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Construction of daily precipitation series and the observational characteristics of extreme precipitation in Tianjin,China during 1888-2022

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Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： Peng SI Qing-xiang LI Xiao-Yang CHEN min WANG Chuan-Jun LUO Tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for Tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the Tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in Tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

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The Non-inclusion Diagnosability of Hypercubes Under the PMC Model

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Journal of the Operations Research Society of China 2024年第2期12卷 478-484页

作者： Mei-Jie Ma min Xu Tong-Tong Ding xiang-Jun Li Qiang Zhu School of Mathematics and Statistics Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353ShandongChina School of Mathematical Sciences Beijing Normal UniversityLaboratory of Mathematics and Complex SystemsMinistry of EducationBeijing 100875China School of Information and Mathematics Yangtze UniversityJingzhou 434023HubeiChina School of Mathematics and Statistics XiDian UniversityXi'an 710071ShaanXiChina

Diagnosability of a multiprocessor system is an important measure of the reliability of interconnection ***-level diagnosis is a primary strategy to identify the faulty processors in a multiprocessor *** on a sound assumption proposed by Zhu et ***,we proposed a new diagnosability named non-inclusion diagnosability and showed that the non-inclusion diagnosability tN(Q_(n))of the hypercube under the PMC model is *** is,assume that if two vertex sets Fi and F2 are both consistent with a syndrome and F_(1)C F_(2),then F2 is not the faulty set which we are looking for;the faulty set F is 1-step diagnosable if|F|≤2n-2 in Qn under the PMC model.

关键词： Interconnection network Diagnosability Hypercube PMC model

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Picotesla fiberized diamond-based AC magnetometer

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Photonics Research 2024年第6期12卷 1250-1261页

作者： SHAO-CHUN ZHANG YONG LIU LONG-KUN SHAN XUE-dong GAO JIA-QI GENG CUI YU YANG dong xiang-dong CHEN GUANG-CAN GUO FANG-WEN SUN CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China National Key Laboratory of ASIC Hebei Semiconductor Research InstituteShijiazhuang 050051China Electric Power Quantum Sensing Joint Laboratory of Anhui Province State Grid Anhui Electric Power Research InstituteHefei 230601China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Portable quantum sensors are crucial for developing practical quantum sensing and metrology *** nitrogen-vacancy(NV)centers in diamonds have emerged as one of the most promising candidates for compact quantum ***,due to the difficulty of coherently controlling the ensemble spin and noise suppression in a large volume,it often faces problems such as reduced sensitivity and narrowed bandwidth in integrated lensless ***,we propose a fluorescence signal treatment method for NV spin ensemble manipulation by the exponential fitting of spin polarization processes,instead of integrating the photon *** enables spin state readout with a high signal-to-noise ratio and applies to the pulse sensing protocols for large-volume NV *** on this,we further developed a fiberized diamond-based AC *** an XY8-N dynamical decoupling pulse sequence,we demonstrated a T_(2)-limited sensitivity of 8pT/√Hz and T_(1)-limited frequency resolution of 90 Hz over a wide frequency band from 100 kHz to 3 *** integrated diamond sensor leverages quantum coherence to achieve enhanced sensitivity in detecting AC magnetic fields,making it suitable for implementation in a compact and portable endoscopic sensor.

关键词： magnetometer quantum ensemble

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Intelligent representation method of image flatness for cold rolled strip

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1177-1195页

作者： Yang-huan Xu dong-cheng Wang Hong-min Liu Bo-wei Duan National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710018ShaanxiChina State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina

Real flatness images are the bases for flatness detection based on machine vision of cold rolled *** characteristics of a real flatness image are analyzed,and a lightweight strip location detection(SLD)model with deep semantic segmentation networks is *** interference areas in the real flatness image can be eliminated by the SLD model,and valid information can be *** this basis,the concept of image flatness is proposed for the first *** image flatness representation(IFAR)model is established on the basis of an autoencoder with a new *** optimal structure of the bottleneck layer is 16×16×4,and the IFAR model exhibits a good representation ***,interpretability analysis of the representation factors is carried out,and the difference and physical meaning of the representation factors for image flatness with different categories are *** flatness with new defect morphologies(bilateral quarter waves and large middle waves)that are not present in the original dataset are generated by modifying the representation factors of the no wave ***,the SLD and IFAR models are used to detect and represent all the real flatness images on the test *** average processing time for a single image is 11.42 ms,which is suitable for industrial *** research results provide effective methods and ideas for intelligent flatness detection technology based on machine vision.

关键词： Cold rolled strip Image flatness Location detection Representation learning Bottleneck layer

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Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current

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Nano-Micro Letters 2024年第3期16卷 212-226页

作者： min Zhang Aihui Cao Yucui xiang Chaogang Ban Guang Han Junjie Ding Li‑Yong Gan Xiaoyuan Zhou College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing 401331People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou 350002People’s Republic of China College of Materials Science and Engineering Chongqing UniversityChongqing 400044People’s Republic of China Institute of New Energy Storage Materials and Equipment Chongqing 401135People’s Republic of China State Key Laboratory of Coal mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044People’s Republic of China

Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance ***,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible *** a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to ***,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 *** work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2).

关键词： Electrochemical CO_(2)reduction Coupled Ag/Sn-SnO_(2)nanosheets Electronic structure Porous solid electrolyte Pure

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