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Investigation of oil and water migrations in lacustrine oil shales using 20 MHz 2D NMR relaxometry techniques 被引量:1
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作者 Bo Liu Xiao-Wen Jiang +1 位作者 Long-Hui Bai Rong-Sheng Lu 《Petroleum Science》 SCIE CAS CSCD 2022年第3期1007-1018,共12页
The behavior of oil and water in tight rocks can change the distribution of oil or water in pores,which affects the production of crude oil.Nuclear Magnetic Resonance(NMR)method is an effective and nondestructive tool... The behavior of oil and water in tight rocks can change the distribution of oil or water in pores,which affects the production of crude oil.Nuclear Magnetic Resonance(NMR)method is an effective and nondestructive tool for evaluating rocks with comparison and analysis both quantitatively and qualitatively.In our study,20 MHz NMR Relaxometry is used as a key technique to study the changes of water and oil behaviors in Chinese lacustrine Qingshankou shales under different saturated states(imbibition and evaporation without pressure).The results show that variation in different proton populations(water,oil and organic)can be distinguished using 2D T_(1)-T_(2)maps.The comparison among T_(1)-T_(2)maps with different saturated states shows that different signal regions changed during oil and water migrations,which the 1D NMR Relaxometry may be not easy to approach.Combined with the pyrolysis analysis,T2 shift and differences of signal regions in T_(1)-T_(2)maps can reflect properties such as wettability and composition(organic matter,clay and magnetic minerals)to some extent.This study provides better insight into oil and water behaviors in lacustrine oil shales with further understanding of 20 MHz NMR 2D T_(1)-T_(2)maps both in qualitative and quantitative analysis. 展开更多
关键词 NMR Relaxometry Lacustrine oil shales Oil and water migrations T_(1)-T_(2)map
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Fuel load and flight ranges of blackcaps Sylvia atricapilla in northern Iberia during autumn and spring migrations
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作者 Juan ARIZAGA Emilio BARBA 《Current Zoology》 SCIE CAS CSCD 北大核心 2009年第6期401-410,共10页
Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory, birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or bet... Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory, birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or between seasons (autumn and spring migrations) is crucial to our understanding of bird migration strategies. Our aim here was to analyse whether migratory blackcaps Sylvia atrieapilla passing through northern Iberia differ in their mean fuel loads, rate of fuel accumulation and ' potential' flight ranges between migration seasons. Blackcaps were mist netted for 4 h-periods beginning at dawn from 16 September to 15 November 2003 - 2005, and from 1 March to 30 April 2004 - 2006 in a European Atlantic hedgerow at Loza, northern Iberia. Both fuel load and fuel deposition rate (this latter assessed with difference in body mass of within-season recaptured individuals) were higher in autumn than in spring. Possible hypotheses explaining these results could be seasonal-associated variations in food availability (likely lower during spring than during autumn), the fact that a fraction of the migrants captured in spring could breed close to the study area and different selective pressures for breeding and wintering 展开更多
关键词 Blackcap Srlvia atricapilla Fuel load lberia Migration STOPOVER
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New observations-with older ones reviewed-on mass migrations in millipedes based on a recent outbreak on Hachijojima(Izu Islands) of the polydesmid diplopod(Chamberlinius hualienensis,Wang 1956):Nothing appears to make much sense
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作者 Victor Benno MEYER-ROCHOW 《Zoological Research》 CAS CSCD 2015年第3期119-132,共14页
Mass aggregations and migrations of millipedes despite numerous attempts to find causes for their occurrences are still an enigma. They have been reported from both southern and northern hemisphere countries, from hig... Mass aggregations and migrations of millipedes despite numerous attempts to find causes for their occurrences are still an enigma. They have been reported from both southern and northern hemisphere countries, from highlands and lowlands of both tropical and temperate regions and they can involve species belonging to the orders Julida and Spirobolida, Polydesmida and Glomerida. According to the main suggestions put forward in the past, mass occurrences in Diplopoda occur:(1) because of a lack of food and a population increase beyond sustainable levels;(2) for the purpose of reproduction and in order to locate suitable oviposition sites;(3) to find overwintering or aestivation sites;(4) because of habitat disruption and changes in the local environment;(5) as a consequence of weather conditions the year(or winter and spring) before. A recent outbreak(November 2014) of a mass migration of the polydesmid Chamberlinius hualienensis Wang 1956 on the Japanese Izu Island of Hachijojima 300 km to the south of Tokyo gave this author an opportunity to review the existing literature on millipede mass migrations and to carry out additional observations on the phenomenon in the field as well as the laboratory. Hitherto unreported heavy infestations with phoretic deutonymphs of the mite Histiostoma sp. as well as dense populations of internal rhabditid nematodes(Oscheius cf. necromena and an unidentified species of the genus Fictor), suggest that infestations of this kind could be necromenic and either have been a contributing factor for the mass migration or been a consequence of so manyindividuals occurring together at close proximity. It is concluded that mass migrations and aggregations in millipedes do not have one common cause, but represent phenomena that often are seasonally recurring events and appear identical in their outcome, but which have evolved as responses to different causes in different millipede taxa and therefore need to be examined on a case-to-case basis. 展开更多
关键词 Myriapoda Spawning migration Aggregation behaviour Diplopod commensals and parasites
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Evaluation of a Cloud Management System for Live Migrations
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作者 Md Israfil Biswas Philip Morrow Sally McClean 《Journal of Computer and Communications》 2019年第11期121-137,共17页
IT infrastructures have been widely deployed in datacentres by cloud service providers for Infrastructure as a Service (IaaS) with Virtual Machines (VMs). With the rapid development of cloud-based tools and techniques... IT infrastructures have been widely deployed in datacentres by cloud service providers for Infrastructure as a Service (IaaS) with Virtual Machines (VMs). With the rapid development of cloud-based tools and techniques, IaaS is changing the current cloud infrastructure to meet the customer demand. In this paper, an efficient management model is presented and evaluated using our unique Trans-Atlantic high-speed optical fibre network connecting three datacentres located in Coleraine (Northern Ireland), Dublin (Ireland) and Halifax (Canada). Our work highlights the design and implementation of a management system that can dynamically create VMs upon request, process live migration and other services over the high-speed inter-networking Datacentres (DCs). The goal is to provide an efficient and intelligent on-demand management system for virtualization that can make decisions about the migration of VMs and get better utilisation of the network. 展开更多
关键词 CLOUD COMPUTING VIRTUAL Machine LIVE MIGRATION Network Management
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Evaluation of Program Code Caching for Mobile Agent Migrations
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作者 Masayuki Higashino Kenichi Takahashi Takao Kawamura Kazunori Sugahara 《Computer Technology and Application》 2013年第7期356-363,共8页
Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side prog... Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system. 展开更多
关键词 Mobile agent agent migration cache.
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The Impact of Hula Project (1993-2018) on Nutrient Migrations
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作者 Moshe Gophen 《Open Journal of Ecology》 2024年第3期215-227,共13页
During the 1950s the Hula wetlands and old lake were drained and the land converted utilization to agriculture and ecotourism. As a result of the drainage, the Peat Soil was exposed to atmospheric oxygen. The geochemi... During the 1950s the Hula wetlands and old lake were drained and the land converted utilization to agriculture and ecotourism. As a result of the drainage, the Peat Soil was exposed to atmospheric oxygen. The geochemical environment was modified from reductive to oxidative and the Nitrogen in it was converted from Ammonium to Nitrate. Intensive migration of Nitrate from the Hula Valley induced a national concern of water quality deterioration in the lake which was dissipated when Nitrogen deficiency was developed in Lake Kinneret. Forty years after drainage the ecosystem structure was renovated (Hula Project, HP) aimed at agricultural management and nutrient migration reduction. The paper examines through evaluation of the ecological data record (1993-2018) the impact of hydrological changes, attributed to the HP implementation on nutrient dynamics within surface waters in the Hula Valley. It is suggested that soil moisture elevation by irrigation in summer reduced Phosphorus and enhanced Nitrate concentrations. 展开更多
关键词 Nitrogen PHOSPHORUS Migration RUNOFF Peat Land HEADWATERS
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Two distinct electrophiles enabled sequential dual migrations of alkynyl tetracoordinate borons
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作者 Hejun An Wei Zhu +4 位作者 Mengwei Tan Meihui Cai Yi Huang Xingxing Ma Qiuling Song 《Science China Chemistry》 2025年第11期5713-5720,共8页
Herein,we report a distinctive and marvelous dual-migration of alkynyl tetracoordinate borons activated by both hydrochloric acid(HCl)and N-chlorosuccinimide(NCS),which is significantly different from conventional mig... Herein,we report a distinctive and marvelous dual-migration of alkynyl tetracoordinate borons activated by both hydrochloric acid(HCl)and N-chlorosuccinimide(NCS),which is significantly different from conventional migration modes under basic conditions.In this protocol,HCl,as the first electrophile,activates the C≡C bond,triggering the first 1,2-aryl migration.Subsequently,NCS promotes a secondary metallate shift,enabling the construction of polysubstituted alkenes.Notably,this process can work well under mild conditions,exhibits high efficiency,and provides valuable products.This transformation reveals that Zweifel olefination is not just limited to traditional basic conditions,it can proceed smoothly under acidic conditions as well,which greatly expands the scope of this well-known olefination reaction. 展开更多
关键词 distinct electrophile tetracoordinate borons dual migrations multi-substituted olefins
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Visible-light-induced selective alkylsulfonylation of unactivated alkenes via remote heteroaryl migrations 被引量:1
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作者 Xin Yuan Jie Liu +7 位作者 Hao Lv Long-Zhou Qin Xiu Duan Jian Wang Meng-Yu Wu Beining Chen Jiang-Kai Qiu Kai Guo 《Green Synthesis and Catalysis》 2024年第2期126-130,共5页
Photocatalyzed alkylsulfonylation of unactivated alkenes using DABCO.(SO_(2))_(2) and thianthrenium salts via a distal heteroaryl migration process has been developed,which provides a new means of synthesizing a varie... Photocatalyzed alkylsulfonylation of unactivated alkenes using DABCO.(SO_(2))_(2) and thianthrenium salts via a distal heteroaryl migration process has been developed,which provides a new means of synthesizing a variety of valuable alkylsulfonyl-substituted compounds.These alkylsulfonyl radicals couple with unactivated alkenes to undergo efficient intermolecular reactions,followed by distal heteroaryl migration.This mild catalytic method is tolerant of functional groups and affords medicinally relevant alkylsulfonylated heterocycles. 展开更多
关键词 Visible-light-induced Remote heteroaryl migrations Alkylsulfonylation Radical reaction Unactivated alkenes
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Gas‑Phase Construction of Compact Capping Layers for High‑Performance Halide Perovskite X‑Ray Detectors
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作者 Bin Zhang Chuanyun Hao +17 位作者 Shoufeng Zhang Bin Xue Xiangfan Xie Shengqiao Zeng Bin Yang Fang Xu Hui Li Xin’an Zhang Zhang Qu Kai‑Hang Ye Guangda Niu Wallace CHChoy Kezhou Fan Kam Sing Wong Lei Yan Xingzhu Wang Shuang Xiao Cangtao Zhou 《Nano-Micro Letters》 2026年第3期388-405,共18页
Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract in... Halide perovskites have emerged as promising materials for X-ray detection with exceptional properties and reasonable costs.Among them,heterostructures between 3D perovskites and low-dimensional perovskites attract intensive studies of their advantages due to low-level ion migration and decent stability.However,there is still a lack of methods to precisely construct heterostructures and a fundamental understanding of their structure-dependent optoelectronic properties.Herein,a gas-phase method was developed to grow 2D perovskites directly on 3D perovskites with nanoscale accuracy.In addition,the larger steric hindrance of organic layers of 2D perovskites was proved to enable slower ion migration,which resulted in reduced trap states and better stability.Based on MAPbBr_(3)single crystals with the(PA)_(2)PbBr_(4)capping layer,the X-ray detector achieved a sensitivity of 22,245μC Gy_(air)^(−1)cm^(−2),a response speed of 240μs,and a dark current drift of 1.17.10^(–4)nA cm^(−1)s^(−1)V^(−1),which were among the highest reported for state-of-the-art perovskite-based X-ray detectors.This study presents a precise synthesis method to construct perovskite-based heterostructures.It also brings an in-depth understanding of the relationship between lattice structures and properties,which are beneficial for advancing high-performance and cost-effective X-ray detectors. 展开更多
关键词 Halide perovskite Ion migration Interface HETEROSTRUCTURE X-ray detection
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DLG3 Promotes Breast Cancer Cell Proliferation and Migration by Mediating STAT3 Activation
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作者 Khalid Idris GIDADO Rabiu LAWAN +4 位作者 PENG Xixia ZHANG Ziyang WAN Xiaochun LU Zhen ZHANG Guizhong 《集成技术》 2026年第1期41-55,共15页
Breast cancer(BRCA)is characterized by high heterogeneity,with aggressive subtypes frequently showing poor prognosis and resistance to conventional therapies,making the discovery of new therapeutic targets and strateg... Breast cancer(BRCA)is characterized by high heterogeneity,with aggressive subtypes frequently showing poor prognosis and resistance to conventional therapies,making the discovery of new therapeutic targets and strategies imperative.Although elevated expression of discs large homolog 3(DLG3)has been reported in BRCA,its functional role in disease progression remains unclear.We performed bioinformatic analyses of clinical datasets to evaluate the prognostic significance of DLG3 expression in BRCA patients.In vitro gain-and loss-of-function experiments were conducted to assess the impact of DLG3 on BRCA cell proliferation,migration,and colony formation.Transcriptomic profiling,coupled with pharmacological inhibition,was employed to identify and validate downstream signaling pathways.Additionally,we extended our validation to an in vivo model to assess the role of DLG3 in tumor progression.We found that elevated DLG3 levels correlated with poor prognosis in breast cancer patients.Functionally,DLG3 overexpression significantly promoted cell proliferation and migration in estrogen receptor-positive MCF7 and triple-negative MDA-MB-231 breast cancer cells,whereas its knockdown suppressed these effects.Transcriptomic analyses revealed that DLG3 activates signal transducer and activator of transcription 3(STAT3)signaling,a finding further corroborated by Western blot.Critically,treatment with the STAT3 inhibitor Stattic attenuated DLG3-driven proliferation and migration,supporting a DLG3-STAT3 oncogenic axis.Furthermore,in vivo studies validated the role of DLG3 in promoting tumor growth and its correlation with elevated STAT3 signaling,consistent with our in vitro findings.Our findings establish DLG3 as a novel driver of breast cancer progression that directly activates STAT3 signaling.DLG3 thus represents both a potential prognostic biomarker and a promising therapeutic target for aggressive breast cancer subtypes,including triple-negative breast cancer. 展开更多
关键词 breast cancer DLG3 STAT3 PROLIFERATION MIGRATION
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Multifunctional Dipoles Enabling Enhanced Ionic and Electronic Transport for High‑Energy Batteries
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作者 Shihai Cao Yuntong Sun +4 位作者 Yinghao Li Ao Wang Wenyao Zhang Zhendong Hao Jong‑Min Lee 《Nano-Micro Letters》 2026年第3期685-724,共40页
Achieving high-energy density remains a key objective for advanced energy storage systems.However,challenges,such as poor cathode conductivity,anode dendrite formation,polysulfide shuttling,and electrolyte degradation... Achieving high-energy density remains a key objective for advanced energy storage systems.However,challenges,such as poor cathode conductivity,anode dendrite formation,polysulfide shuttling,and electrolyte degradation,continue to limit performance and stability.Molecular and ionic dipole interactions have emerged as an effective strategy to address these issues by regulating ionic transport,modulating solvation structures,optimizing interfacial chemistry,and enhancing charge transfer kinetics.These interactions also stabilize electrode interfaces,suppress side reactions,and mitigate anode corrosion,collectively improving the durability of high-energy batteries.A deeper understanding of these mechanisms is essential to guide the design of next-generation battery materials.Herein,this review summarizes the development,classification,and advantages of dipole interactions in high-energy batteries.The roles of dipoles,including facilitating ion transport,controlling solvation dynamics,stabilizing the electric double layer,optimizing solid electrolyte interphase and cathode–electrolyte interface layers,and inhibiting parasitic reactions—are comprehensively discussed.Finally,perspectives on future research directions are proposed to advance dipole-enabled strategies for high-performance energy storage.This review aims to provide insights into the rational design of dipole-interactive systems and promote the progress of electrochemical energy storage technologies. 展开更多
关键词 High-energy batteries Electrochemical processes Ionic transport Electronic migration DIPOLES
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Retraction:MicroRNA-133b Inhibits Proliferation,Cellular Migration,and Invasion via Targeting LASP1 in Hepatocarcinoma Cells
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作者 Oncology Research Editorial Office 《Oncology Research》 2026年第1期621-621,共1页
The published article titled“MicroRNA-133b Inhibits Proliferation,Cellular Migration,and Invasion via Targeting LASP1 in Hepatocarcinoma Cells”has been retracted from Oncology Research,Vol.25,No.8,2017,pp.1269–1282.
关键词 lasp cellular migration PROLIFERATION INVASION hepatocarcinoma cells targeting lasp microrna b
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Oxime ester as bifunctional reagent for the alkylamination of alkynes via C-centered radical addition and N-centered radical migration
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作者 Keyuan Zhang Min Wang +3 位作者 Qi Jiang Bowu Dong Xin-Hua Duan Le Liu 《Science China Chemistry》 2026年第2期858-862,共5页
The radical addition/functional group migration strategy has emerged as a powerful tool for the difunctionalization of unsaturated hydrocarbons,yet the heteroatom-mediated functional group migration remains largely un... The radical addition/functional group migration strategy has emerged as a powerful tool for the difunctionalization of unsaturated hydrocarbons,yet the heteroatom-mediated functional group migration remains largely unexplored.Herein,we report an unprecedented radical difunctionalization of alkynes employing oxime esters as bifunctional reagents through a novel C-centered radical addition/N-centered radical translocation sequence.This innovative transformation paradigm enables efficient alkylamination of alkynes under mild photocatalytic redox conditions.Mechanistic investigations reveal a cascade sequence initiated by single-electron transfer from oxime derivatives,proceeding through radical addition,6-exo-trig cyclization,and subsequent imino group migration. 展开更多
关键词 bifunctional reagent alkylamination N-centered radical migration PHOTOREDOX tetrasubstituted alkenes
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Cell type-dependent role of transforming growth factor-βsignaling on postnatal neural stem cell proliferation and migration
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作者 Kierra Ware Joshua Peter +1 位作者 Lucas McClain Yu Luo 《Neural Regeneration Research》 2026年第3期1151-1161,共11页
Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postn... Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo. 展开更多
关键词 adult neurogenesis DOUBLECORTIN HIPPOCAMPUS MIGRATION neural stem cells PROLIFERATION transforming growth factor-β
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Chemical synthesis of the highly functionalized O-antigen repeating unit from Pseudomonas aeruginosa serotype O3 for glycoconjugate vaccine development
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作者 Guochao Lv Guangzong Tian +7 位作者 Guodong Chen Shengyong Zhu Jialong Bao Chunjun Qin Xiaopeng Zou Jing Hu Peter H.Seeberger Jian Yin 《Chinese Chemical Letters》 2026年第2期379-385,共7页
Pseudomonas aeruginosa is an opportunistic pathogen responsible for severe nosocomial infections.This multidrug-resistant bacterium can cause pneumonia and cystic fibrosis,both of which are associated with high morbid... Pseudomonas aeruginosa is an opportunistic pathogen responsible for severe nosocomial infections.This multidrug-resistant bacterium can cause pneumonia and cystic fibrosis,both of which are associated with high morbidity and mortality rates.The lipopolysaccharide of P.aeruginosa serves as an attractive target for the development of effective glycoconjugate vaccines.In this article,we report the first chemical synthesis of the highly challenging tetrasaccharide repeating unit of the P.aeruginosa serotype O3 O-antigen using a two-directional[1+(2+1)]glycosylation strategy.The synthesis is particularly challenging due to the poor nucleophilicity of the axial C4 hydroxyl group of l-galactose and the steric hindrance imposed by the 3S-hydroxybutyryl(Hb)chain.Furthermore,the presence of an acetyl group at the ortho position relative to the glycosylation site on l-galactose can lead to undesirable acetyl migration.Additionally,it is noteworthy that the selective removal of a 2-naphthylmethyl ether(Nap)during the late stages of synthesis,particularly in the presence of multiple benzyl groups,can be somewhat challenging to predict.Through the careful selection of synthetic strategies,building blocks,and optimized reaction conditions,we achieved the stereoselective glycosylations,selective oxidation of primary alcohols,remarkable enhancement of acceptor activity,and efficient introduction of the 3S-Hb group.The synthetic methodology presented in this work serves as a valuable reference for the preparation of structurally related oligosaccharides.By incorporating an aminopropyl linker,the target tetrasaccharide facilitates glycan microarray preparation and in vivo immunological assessments,thereby accelerating progress toward a synthetic glycoconjugate vaccine for P.aeruginosa. 展开更多
关键词 Chemical synthesis Pseudomonas aeruginosa Lipopolysaccharide Steric hindrance Poor nucleophilicity Acetyl migration Glycoconjugate vaccines
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Polygonal Fault Systems in the Zhongjiannan Basin of South China Sea:Geometry,Evolution and Implications
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作者 HU Shouxiang ZHAO Fang 《Journal of Ocean University of China》 2026年第1期184-196,共13页
Polygonal fault systems(PFS),characterized by multi-directional fault patterns within layered sequences,are well-documented features in global continental margin basins.While the geometry and formation mechanisms of P... Polygonal fault systems(PFS),characterized by multi-directional fault patterns within layered sequences,are well-documented features in global continental margin basins.While the geometry and formation mechanisms of PFS have been extensively studied in the northern South China Sea,the PFS in the Zhongjiannan Basin(western South China Sea)remain relatively unexplored,with a lack of quantitative analysis regarding their propagation.This study addresses this gap by using high-resolution three-dimensional(3D)seismic data and conducting a quantitative fault analysis to thoroughly examine the planform,cross-sectional geometry,and evolution of PFS in the northern Zhongjiannan Basin.The absence of a dominant strike direction among these polygonal faults suggests that their evolution is not controlled by anisotropic stress.Our interpretation of seismic data,constrained by the spatial relationship among PFS,gullies,and pockmarks,indicates that PFS mainly developed within the Miocene strata,with their initiation occurring during the late Miocene.Furthermore,the PFS act as key conduits connecting gullies to pockmarks in this area.The formation and development of PFS may be primarily driven by thermally triggered processes within siliceous sediments.The necessary heat source is probably associated with the abundant submarine magmatism observed in the Zhongjiannan Basin.To reconstruct the regional geological history,a four-stage evolutionary model,incorporating the formation of PFS,is presented.This research significantly improves our understanding of the regional geological evolution of the Zhongjiannan Basin,providing critical insights into the initiation and development of PFS in the western South China Sea. 展开更多
关键词 South China Sea Zhongjiannan Basin polygonal faults layer-bound faults fluid migration GULLIES POCKMARK
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Redundant source-wavelet amplitude influence in wave-equation migration/demigration flow and its removal
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作者 QianCheng Liu JiaLe Kang Jie Li 《Earth and Planetary Physics》 2026年第1期75-81,共7页
In wave-equation migration and demigration,the cross-correlation imaging/forwarding step implicitly injects an additional copy of the source wavelet,so that the amplitude spectrum of the wavelet is applied redundantly... In wave-equation migration and demigration,the cross-correlation imaging/forwarding step implicitly injects an additional copy of the source wavelet,so that the amplitude spectrum of the wavelet is applied redundantly(effectively imposing a wavelet-spectrum weighting,often akin to an amplitude-squared bias).This redundancy degrades structural fidelity and amplitude balance yet is frequently overlooked.We(i)formalize the mechanism by which cross-correlation duplicates the source-wavelet amplitude effect in both migration and demigration,and(ii)introduce a source-equalized operator that removes the redundancy by deconvolving(or dividing by)the wavelet amplitude spectrum in the imaging condition and its demigration counterpart,while leaving phase/kinematics intact.Using a band-limited Ricker wavelet on a two-layer model and on Marmousi,we show that,if unmanaged,the redundant wavelet spectrum broadens main lobes,introduces ringing,and suppresses vertical resolution in migrated images,and inflates spectrum mismatches between demigrated and observed data even when peak times agree.With our correction,images recover observed-data-consistent bandwidth and sharpened interfaces,and demigrated data also exhibit improved spectrum conformity and reduced amplitude misfit.The results clarify when source amplitudes matter,why cross-correlation makes them redundantly matter,and how a lightweight spectral correction restores physically meaningful amplitude behavior in wave-equation migration/demigration. 展开更多
关键词 wave-equation migration DEMIGRATION cross-correlation imaging condition source wavelet amplitude spectrum spectral deconvolution
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Impact of roadside water on sloped subgrade stability along the Qingzang Railway with two-phase closed thermosyphon and crushed rock revetment
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作者 LI Yasheng WEN Zhi +1 位作者 ZHANG Mingli MA Wei 《Journal of Mountain Science》 2026年第1期254-269,共16页
In permafrost regions of the QinghaiXizang Plateau,embankments of the Qinghai-Xizang Highway and Qinghai-Xizang Railway experiencing roadside water accumulation exhibit more pronounced engineering deteriorations.A wid... In permafrost regions of the QinghaiXizang Plateau,embankments of the Qinghai-Xizang Highway and Qinghai-Xizang Railway experiencing roadside water accumulation exhibit more pronounced engineering deteriorations.A widely accepted view is that the accumulated water adjacent to the embankment possesses substantial thermal energy,which accelerates the degradation-even disappearance-of the underlying permafrost.Moreover,the presence of roadside water keeps the embankment soil in a persistently high-moisture state,thereby making the frozen-soil embankment more susceptible to deformation under traffic loading.However,in the permafrost regions of the QinghaiXizang Plateau,deteriorations of embankments affected by roadside water are more commonly manifested as undulating pavement surfaces,and extensive crack networks appear on the embankment crest even where thermosyphons are installed.These manifestations are not fully consistent with the deterioration mechanisms proposed by existing viewpoints.We propose the hypothesis that temperature gradients,formed due to the freezing and thawing processes between the roadside wateraffected soil and the roadbed soil,lead to moisture migration under the influence of temperature gradients,resulting in frost heave and thaw settlement in the roadbed soil.To validate this hypothesis,we conducted the following investigations sequentially.Initially,we selected a roadbed with a thermosyphon(TPCT)system,which has a significant cooling effect,as the study object.By analyzing the temperature monitoring data of the roadbed section,the temperature variance was calculated to identify the time nodes where the temperature gradient of the roadbed soil was maximum and minimum.Subsequently,corresponding roadbed temperature distribution maps were drawn,illustrating the changes in the temperature and position of the lowtemperature core near the TPCT over time.Furthermore,using small-scale indoor model experiments,we qualitatively concluded that moisture in the soil migrates toward the TPCT due to the temperature gradient.Thereafter,combining borehole water content data and precipitation data from the sloped terrain construction site,the formation mechanisms and timing characteristics of roadside water accumulation were analyzed.Ultimately,by integrating the ground temperature data,air temperature data,roadside water formation mechanisms,and the operating characteristics of the TPCT,it was concluded that roadside water,while in a thawed state during TPCT operation,acts as a supplementary source for moisture migration in the roadbed soil.This migration leads to cracking in the TPCT roadbed.Therefore,this study reveals a novel damage mechanism:asynchronous freeze-thaw processes induce temperature gradients,which drive the migration of roadside water into the roadbed and are responsible for the cracking damage. 展开更多
关键词 Roadside water Low-temperature core Two-phase closed thermosyphon Temperature gradient Water migration Field test
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Effect of particle size on migration and retention of bacteria in sand and its biomineralization
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作者 Hanjiang Lai Shuiquan Deng +5 位作者 Mingjuan Cui Shaohui Zheng Junjie Zheng Runming Liu Jianwei Zhang Yu Song 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1496-1503,共8页
Bacterial cells are widely accepted as nucleation sites for calcium carbonate precipitation in biomineralization based on the Microbially Induced Carbonate Precipitation(MICP)process.For MICP-based insitu biotreatment... Bacterial cells are widely accepted as nucleation sites for calcium carbonate precipitation in biomineralization based on the Microbially Induced Carbonate Precipitation(MICP)process.For MICP-based insitu biotreatment,the firstproblem to be solved is how to introduce and retain the bacterial cells in the soil,which involves the migration and retention of bacterial cells during the biogrouting process.Soil particle size,a key factor in determining pore throat size,can have a significanteffect on the migration and retention of bacterial cells in the soil and therefore on biomineralization.To investigate the effect of particle size on the migration and retention of bacterial cells in sand and its biomineralization,two sets of tests were carried out in this study,including percolation tests and sand column treatment tests.Soil urease activity(definedas urease activity per unit mass of soil)and calcium carbonate content of the biomineralized sand were measured to comprehensively assess the migration and retention of bacterial cells in the sand.The results indicate that sands with a particle size smaller than 0.25 mmwould inhibit the migration of bacteria in the sand,resulting in a nonuniform distribution of precipitated calcium carbonate and a low strength enhancement of biomineralization.On the other hand,sands with a particle size larger than 1.18 mm are unfavorable for retaining bacterial cells in the sand,resulting in low calcium conversion efficiency.Meanwhile,particle size would also affect the formation of effective calcium carbonate through interparticle contact number and interparticle pore size,and thus biomineralization. 展开更多
关键词 Microbially induced carbonate precipitation(MICP) Soil particle size Bacterial cell MIGRATION RETENTION BIOMINERALIZATION
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