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High Temperature Iron Ethylene Polymerization Catalysts Bearing N,N,N'-2-(1-(2,4-Dibenzhydryl-6-fluorophenylimino)ethyl)-6-(1-(arylphenylimino)ethyl)pyridines

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Chinese Journal of Polymer Science 2024年第2期42卷 188-201,I0007页

作者： Chantsalnyam Bariashir Qiu-Yue Zhang Bayasgalan Ulambayar gregory A.Solan Tong-Ling Liang Wen-Hua Sun Institute of Chemistry and Chemical Technology Mongolian Academy of SciencesUlaanbaatar13330Mongolia Key Laboratory of Engineering Plastics and Beijing National Laboratory for molecular Science Institute of ChemistryChinese Academy of SciencesBeijing100190China Department of Chemistry University of LeicesterUniversity RoadLeicesterLE17RHUK State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

The N,N,N'-ferrous chloride complexes,[2-{CmeN(2,4-(CHPh)_(2)-6-FC_(6)H_(2))}-6-(CmeNAr)C_(5)H_(3)N]FeCl_(2)(Ar=2,6-me_(2)C_(6)H_(3) Fe1,2,6-Et_(2)C_(6)H_(3)Fe2,2,6-^(i)Pr_(2)C_(6)H_(3) Fe3,2,4,6-me_(3)C_(6)H_(2) Fe4 and 2,6-Et_(2)-4-meC_(6)H_(2) Fe5),each possessing one N-2,4-dibenzhydryl-6-fluorophenyl group,were readily synthesized from their respective unsymmetrical bis(imino)pyridines,*** identification of Fe2 highlighted the variation in the steric properties provided by the dissimilar N-aryl *** pre-treatment with either mAO or mmAO,complexes Fe1-Fe5 all displayed,at an operating temperature of 80℃,high activities for ethylene polymerization with levels falling in the order:Fe4> Fe1> Fe5> Fe2> ***,Fe4/mAO displayed the highest activity of 1.94×10^(7) g_(PE)·mol_(Fe)^(-1)·h^(-1) of the study with only a modest loss in performance at 90℃.Generally,the resulting polyethylenes were highly linear(T_(m) range:122-132℃),narrowly disperse and of low molecular weight(m_(w) range:6.73-46.04kg·mol^(-1)),with the most sterically hindered Fe3 forming the highest molecular weight polymer of the ***-group analysis by ^(1)H-and ^(13)CNmR spectroscopy revealed saturated alkyl(n-propyl and i-propyl) and unsaturated vinyl chain ends indicative of the role of both β-H elimination and chain transfer to aluminum as termination *** comparison with previou sly reported iron precatalysts with similar tridentate ligand skeletons,it is evident that the introduction of a large benzhydryl group in combination with a fluorine as the ortho-substituents of one N-aryl group has the effect of enhancing thermal stability of the iron polymerization catalyst whilst maintaining appreciable polymer molecular weight.

关键词： Iron catalyst Ethylene polymerization Linear polyethylene Fluoride effect Thermal stability

Integrins and their potential roles in mammalian pregnancy

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Journal of Animal Science and Biotechnology 2024年第1期15卷 1-19页

作者： gregory A.Johnson Robert C.Burghardt Fuller W.Bazer Heewon Seo Joe W.Cain Department of Veterinary Integrative Biosciences School of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843‑4459USA Department of Animal Science College of Agriculture and Life SciencesTexas A&M UniversityCollege StationTX 77843‑2471USA

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECm) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the sc

关键词： Humans Implantation Integrins Pigs Pregnancy Rodents Sheep

晶粒长大对高纯Al{111}/{111}近奇异晶界的影响

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金属学报 2024年第1期60卷 80-94页

作者：冯小铮王卫国 gregory S.Rohrer 陈松洪丽华林燕王宗谱周邦新福建理工大学晶界工程研究所福州350118 福建理工大学材料科学与工程学院福州350118 Department of materials Science and Engineering Carnegie Mellon UniversityPittsburghPA 15213-3890USA 上海大学材料研究所上海200072

{111}/{111}近奇异晶界较比一般晶界更耐蚀,如何提高此类晶界比例以显著提高Al及其合金晶界腐蚀抗力是一个新课题。本工作选用99.99%(质量分数)高纯Al为研究对象,考察晶粒长大对{111}/{111}近奇异晶界的影响。样品经室温多向锻造和370... 详细信息

{111}/{111}近奇异晶界较比一般晶界更耐蚀,如何提高此类晶界比例以显著提高Al及其合金晶界腐蚀抗力是一个新课题。本工作选用99.99%(质量分数)高纯Al为研究对象,考察晶粒长大对{111}/{111}近奇异晶界的影响。样品经室温多向锻造和370℃再结晶退火后,再经500℃保温不同时间,采用基于EBSD和五参数分析的晶界界面匹配表征方法对样品进行测试和分析。结果表明,随着晶粒长大,{111}/{111}近奇异晶界的比例显著增加。当平均晶粒尺寸由38μm长大至77μm时,{111}/{111}近奇异晶界的比例由3.91%增加至6.56%。离线原位EBSD和晶界迹线分析表明,晶粒长大过程中,{111}/{111}近奇异晶界主要通过具有/θ(θ为取向差转角)取向差关系的两两晶粒吞并周边晶粒并相遇后形成;具有/θ取向差关系的相邻晶粒,其晶界通过再取向调整至{111}/{111}位置,亦可形成此类近奇异晶界。{111}/{111}近奇异晶界存在旋错结构,其原子排列有序度显著高于一般晶界,这是此类晶界比一般晶界更耐蚀的原因。

关键词：高纯Al 晶粒长大近奇异晶界晶界界面匹配

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有向图上的一些猜想和开放问题

数学进展 2024年第1期53卷 1-12页

作者：艾江东 gregory GUTIN 史永堂 Ander YEO 南开大学数学科学学院核心数学与组合数学教育部重点实验室天津300371 伦敦大学皇家霍洛威学院计算机科学系英国萨里郡TW200EX 南开大学组合数学中心核心数学与组合数学教育部重点实验室天津300371 南丹麦大学数学与计算机科学系丹麦欧登塞M区DK-5230 约翰内斯堡大学数学与应用数学系南非约翰内斯堡2006

讨论了有向图上的几个猜想和开放问题.一些尚未解决的问题是新的.

关键词：有向图出度圈路分划最大有向割集拟核 Seymour二次邻域猜想无圈2-染色

Efficient visual learning by bumble bees in virtual-reality conditions:Size does not matter

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Insect Science 2023年第6期30卷 1734-1748页

作者： gregory Lafon marco paoli Benjamin HPaffhausen Gabriela de Brito Sanchez mathieu Lihoreau Aurore Avarguès-Weber martin Giurfa Centre de Recherches sur la Cognition Animale Centre de Biologie Intégrative(CBI)University of ToulouseCNRSUPSToulouseFrance French Academy of Sciences for University Professors Institut Universitaire de France(IUF)ParisFrance

Recent developments allowed establishing virtual-reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigate the visual learning in the buff-tailed bumble bee Bombus terrestris. Based on responses to appetitive and aversive reinforcements used for conditioning, we show that bumble bees had the proper appetitive motivation to engage in the VR experiments and that they learned efficiently elemental color discriminations. In doing so, they reduced the latency to make a choice, increased the proportion of direct paths toward the virtual stimuli and walked faster toward them. Performance in a short-term retention test showed that bumble bees chose and fixated longer on the correct stimulus in the absence of reinforcement. Body size and weight, although variable across individuals, did not affect cognitive performances and had a mild impact on motor performances. Overall, we show that bumble bees are suitable experimental subjects for experiments on visual learning under VR conditions, which opens important perspectives for invasive studies on the neural and molecular bases of such learning given the robustness of these insects and the accessibility of their brain.

关键词： Bombus terrestris bumble bees interindividual size/weight differences reinforcement responses visual learning virtual reality

室温和深冷轧制对纯Al再结晶{111}/{111}近奇异晶界的影响

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金属学报 2024年

作者：李振想王卫国 gregory S Rohrer 洪丽华陈松林燕周邦新福建理工大学材料科学与工程学院福建理工大学晶界工程研究所上海大学材料研究所 Department of material Science and Engineering Carnegie Mellon University

{111}/{111}近奇异晶界比一般晶界更耐蚀，研究此类晶界的形成条件、影响因素和生成机制，设法调控此类晶界并提高其比例是改善相关铝合金晶界腐蚀性能的根本途径。为了解铝合金生成{111}/{111}近奇异晶界的本征行为，本工作选择高纯Al ... 详细信息

{111}/{111}近奇异晶界比一般晶界更耐蚀，研究此类晶界的形成条件、影响因素和生成机制，设法调控此类晶界并提高其比例是改善相关铝合金晶界腐蚀性能的根本途径。为了解铝合金生成{111}/{111}近奇异晶界的本征行为，本工作选择高纯Al (99.99%)为实验材料，首先经室温反复多向锻造和370℃再结晶退火获得晶粒尺寸均匀、平均晶粒尺寸约为20μm且晶粒取向随机分布的组织均匀化初始样品；再将初始样品分别在室温(25℃)和-196℃深冷进行厚度减缩量为80%的轧制变形，及370℃、30 min再结晶退火处理。采用EBSD和基于五参数分析的晶界界面匹配定量表征方法对两样品进行测试和分析。结果表明，经-196℃深冷轧制并再结晶的样品，其{111}/{111}近奇异晶界比例达到6.0%，相比室温轧制并再结晶的样品提升了120%。XRD、EBSD及硬度结果表明，经室温和-196℃深冷轧制的样品中均形成了较强的{011}形变织构；较比室温轧制，经-196℃深冷轧制的样品内残余压应力更大，晶粒碎化更严重、储能更高。在后续370℃退火过程中，经室温和-196℃深冷轧制的样品，其再结晶机制均以{011}取向生长为主；较比于室温轧制，经-196℃深冷轧制的样品可提供更大的晶界迁移驱动力，其样品再结晶组织的平均晶粒尺寸更大且{011}再结晶织构更强。统计结果表明，{011}取向晶粒与其他取向的晶粒毗连所形成的晶界中存在较高比例的{111}/{111}近奇异晶界；同时，为{011}取向晶粒与其相邻的且具有{011}漫散取向的晶粒间也形成较多的{111}/{111}近奇异晶界，这是导致经-196℃深冷轧制及再结晶的样品中{111}/{111}近奇异晶界比例较高的主要原因。

关键词：高纯Al 深冷轧制近奇异晶界晶界界面匹配择尤取向

Introducing RiverProfileApp,a web application for near-global,exploratory,longitudinal river profile analysis

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International Journal of Digital Earth 2022年第1期15卷 679-689页

作者： gregory A.Ruetenik Czech Academy of Sciences Institute of GeophysicsPragueCzech Republic

River profile analysis has been used extensively in the earth sciences. Commonly,exploration of river profiles requires downloading and processing Digital Elevation models (DEms) for specific areas,which limits the scope of exploratory analysis. Presented here is a web application designed to analyze river profiles at 90m resolution at a near-global scale. The app allows users to quickly query downstream or upstream from selected points anywhere within ±60 degrees latitude,in order to interactively analyze corresponding river profiles. River profile analysis can be performed in both distance and χ space,where χ is a metric that is proportional to the presumed steady-state shape of the river profile. River locations are based on the HydroSHEDS 90m drainage direction grid,as well as custom computed D8 drainage direction and void-filled SRTm DEms. RiverProfileApp is open source,and although currently it is designed as an exploratory tool,more functions can be easily added via community contributions and/or from existing toolsets. It is available from ***.

关键词： River profile analysis geomorphology big data science communication

Lactate as a regulator of iron homeostasis

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Life metabolism 2023年第5期2卷 8-11页

作者： gregory J.Anderson David m.Frazer Iron metabolism Laboratory QIMR Berghofer Medical Research InstituteBrisbaneQueensland 4006Australia molecular Nutrition Laboratory QIMR Berghofer Medical Research InstituteBrisbaneQueensland 4006Australia

The key metabolic intermediate lactate can increase expression of the liver-derived peptide hepcidin,the central regulator of body iron homeostasis.A new paper by Liu et *** that lactate achieves this by binding to and activating soluble adenylyl cyclase,thereby increasing cellular cyclic adenosine monophosphate(cAmP)and enhancing signaling through the bone morphogenetic protein(BmP)pathway to modulate hepcidin expression.

关键词： expression thereby homeostasis

Repeatability and Variability of the 3-min All-Out Test at the Subject Level

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Journal of Science in Sport and Exercise 2023年第1期5卷 77-86页

作者： Vijay Sarthy m.Sreedhara gregory m.mocko Randolph E.Hutchison Department of mechanical Engineering Clemson University243 Fluor Daniel EIBClemsonSC 29634-0921USA Department of Health Sciences Furman UniversityGreenvilleSC 29613USA

Purpose The constant work-rate to exhaustion tests must be repeated several times at each work-rate to estimate subject-level trial-to-trial variance(intra-individual variability,IIV)of critical power(CP)and work capacity(W').Alternatively,these parameters and their variance can be estimated by repeating the 3-min all-out test(3mT)fewer *** purpose of this study was to propose a method to determine subject-level repeatability of the 3mT and demonstrate the need to repeat the test multiple times to estimate *** Seven cyclists performed a ramp test and four 3mTs on a *** parameters CP,W',peak power(Pp),and total work(TW)were compared across trials using repeated measures ANOVA,Bland-Altman analysis,Intraclass Cor-relation Coefficients(ICC),Typical Error(TE)of measurement,and Coefficient of Variation(CV).Results For the group,average CP and W'were 284±58 W and 10.214±3.143 *** reliability statistics,CP(ICC=0.97,TE=8 W,CV=2.94%)and W'(ICC=0.88,TE=1.11 kJ,CV=10.87%),indicated strong ***-level repeatability was determined by comparing time-to-peak power(TPp),absolute difference in Pp(δPp),and TW(δTW)for pairs of *** average IIVs estimated by the 95%confidence intervals were±15 W for CP and±1.68 kJ for W'.Conclusions Thresholds are proposed for TPp(7 s),δPp(10%),andδTW(3%)to determine subject-level repeatability of the 3mT before computing the IIV of CP and W'.It is suggested that the 3mT is repeated at least three times to estimate the IIV,which aids in personalized measurement of training improvements and performance optimization。

关键词： Critical power W' 3-min all-out test Repeatability Intra-individual variability