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用静电模壁润滑—温压复合工艺增高粉末冶金零件生坯与烧结件性能

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粉末冶金技术 2006年第3期24卷 227-232页

作者： P.Lemieux y.thomas P.E.Mongeon S.Pelletier S.St-Laurent 郭瑞金韩凤麟（译） Industrial Materials Institute National Research Council 75 de MortagneBouchervilleQuebecCanada J4B 6Y4 Quebec Metal Powders Limited 1655 Marie VictorinSorel-TracyQuebec J3R 4R4 不详

对于生产静态与动态力学性能高的粉末冶金零件,在合理价格下,使零件材料达到高密度,有一定效益。采用温压—模壁润滑复合工艺是增高粉末冶金零件材料密度的一条很受人关注的途径。在试验室条件下进行的一些研究证实了这条工艺路线的潜... 详细信息

对于生产静态与动态力学性能高的粉末冶金零件,在合理价格下,使零件材料达到高密度,有一定效益。采用温压—模壁润滑复合工艺是增高粉末冶金零件材料密度的一条很受人关注的途径。在试验室条件下进行的一些研究证实了这条工艺路线的潜力。在工业生产条件下,对于这种复合工艺的实际效益需要进一步探索。为确定这种复合工艺使材料达到较高密度,从而达到较高的力学性能方面能达到何种程度,在工业生产用机械式压机上进行了试验研究。这篇论文对这种复合工艺和常规的冷压与温压工艺,以及冷压—模壁润滑复合工艺的效益进行了比较与评估。

关键词：温压静电模壁润滑粉末冶金零件

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高密度零件用润滑剂的使用性能

粉末冶金工业 2014年第4期24卷 11-19页

作者： S.St-Laurent V.Paris y.thomas 韩凤麟魁北克金属粉末公司魁北克J3R4R4加拿大加拿大国家研究院魁北克J4B6Y4加拿大

随着粉末冶金零件应用领域的不断扩大,对高密度零件的需求量逐步增多,这些零件都需要较先进的混合粉与高使用性能的润滑剂。润滑剂的含量必须尽量低,以使零件达到较高的密度。所以,高密度零件用润滑剂必须在比传统润滑剂的浓度低得多的... 详细信息

随着粉末冶金零件应用领域的不断扩大,对高密度零件的需求量逐步增多,这些零件都需要较先进的混合粉与高使用性能的润滑剂。润滑剂的含量必须尽量低,以使零件达到较高的密度。所以,高密度零件用润滑剂必须在比传统润滑剂的浓度低得多的条件下,能提供和传统润滑剂同样的润滑性能。本文介绍了为使铁基粉末冶金零件的密度达到7.30 g/cm3以上,专门设计的新润滑剂的压制与脱出性能。在实际生产条件下,对这些润滑剂进行了系统评定,讨论了用这些润滑剂制备的混合粉的物理与烧结性能。最后,将试验结果和粉末冶金产业中一般使用的润滑剂进行了比较。

关键词：高密度润滑剂钢粉

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压制温度对粉末材料零件中润滑剂分布的影响

重庆钢研 2000年第25期 56-64页

作者： M.Gagu y.thomas

温压是一种可制取高压坯强度、高压坯密度的粉末冶金工艺，压制温度的提高降低了金属颗粒应力流动，提高了金属颗粒的延性，使得粉末的压制性提高，颗粒间的冶金结合及机械结合加强。尽管有许多温压方面的论文发表，但很少涉及到压制温... 详细信息

温压是一种可制取高压坯强度、高压坯密度的粉末冶金工艺，压制温度的提高降低了金属颗粒应力流动，提高了金属颗粒的延性，使得粉末的压制性提高，颗粒间的冶金结合及机械结合加强。尽管有许多温压方面的论文发表，但很少涉及到压制温度对润滑剂作用的影响，在多数情况下，润滑剂的选择仅仅只考虑到了金属／润滑剂系统压制性能和脱模性能的提高。本文研究了水雾化铁粉混合物在25℃-150℃之间温压时润滑剂的特性。采用了诸如SEM、WDS和SIMS等技术手段，对含有不同润滑剂（LiSt和EBS）混合粉的压坯的显微结构、零件中润滑剂的发布情况等进行了分析观察，其结果与零件压制过程中铁粉及润滑剂的特性有关。

关键词：粉末冶金润滑剂致密化压制温度

Exponentially Convergent Multiscale Finite Element Method

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Communications on Applied Mathematics and Computation 2024年第2期6卷 862-878页

作者： yifan Chen thomas y.Hou yixuan Wang Applied and Computational Mathematics CaltechPasadena 91106USA

We provide a concise review of the exponentially convergent multiscale finite element method(ExpMsFEM)for efficient model reduction of PDEs in heterogeneous media without scale separation and in high-frequency wave *** ExpMsFEM is built on the non-overlapped domain decomposition in the classical MsFEM while enriching the approximation space systematically to achieve a nearly exponential convergence rate regarding the number of basis *** most generalizations of the MsFEM in the literature,the ExpMsFEM does not rely on any partition of unity *** general,it is necessary to use function representations dependent on the right-hand side to break the algebraic Kolmogorov n-width barrier to achieve exponential ***,there are online and offline parts in the function representation provided by the *** online part depends on the right-hand side locally and can be computed in parallel *** offline part contains basis functions that are used in the Galerkin method to assemble the stiffness matrix;they are all independent of the right-hand side,so the stiffness matrix can be used repeatedly in multi-query scenarios.

关键词： Multiscale method Exponential convergence Helmholtz's equation Domain decomposition Nonlinear model reduction

人胰岛素基因的合成——Ⅷ.表达型质粒的构建和在大肠杆菌内生产含有胰岛素原的融合蛋白

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生物工程学报 1985年第2期 14-33页

作者：郭礼和 Piotr P.Stepien 曹仲欣 Roland Brousseau Saran Narang David y.thomas 吴瑞中国科学院上海细胞生物学研究所 Division of Biological Sciences National Research Council of Canada Section of Biochemistry Molecular and Cell Biology Cornell University Ithaca Ny 14853 U.S.A.

我们已构建两组质粒,适合于在大肠杆菌内克隆基因和直接大量合成融合蛋白。这些质粒含有***的lac启动基因和部分编码β-半乳糖苷酶的序列,编码的蛋白长度约590或450个氨基酸残基(原基因编码1023个氨基酸残基)。被缩短的β-半乳糖苷酶基... 详细信息

我们已构建两组质粒,适合于在大肠杆菌内克隆基因和直接大量合成融合蛋白。这些质粒含有***的lac启动基因和部分编码β-半乳糖苷酶的序列,编码的蛋白长度约590或450个氨基酸残基(原基因编码1023个氨基酸残基)。被缩短的β-半乳糖苷酶基因的末端跟随一个多种限制性酶的接头序列;这个序列可被八种限制性酶中的任一种切断,然后插入任何蛋白基因。每组质粒有三种,可以满足所有三种不同的翻译读框。我们克隆了人工合成的人胰岛素原基因到这些质粒上去,在大肠杆菌内可以生产大量β-半乳糖苷酶残基——人胰岛素原融合蛋白。

关键词： BCA gene 大肠杆菌大肠埃希氏菌埃希氏杆菌属融合蛋白蛋白质质粒基因载体

Insights into carbon dioxide sequestration into coal seams through coupled gas flow-adsorption-deformation modelling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 26-40页

作者： Hywel thomas Min Chen Geoenvironmental Research Centre Cardiff School of EngineeringCardiff UniversityQueen’s BuildingsThe ParadeNewport RoadCardiffCF243AAUK Key Laboratory of Marine Geology Tongji UniversityShanghai200092China

Injecting carbon dioxide(CO_(2))into coal seams may unlock substantial carbon sequestration *** the coal acts like a carbon filter,it can preferentially absorb significant amounts of CO_(2).To explore this further,desorption of the adsorbed gas due to pressure drop is investigated in this paper,to achieve an improved understanding of the long-term fate of injected CO_(2) during post-injection *** paper presents a dual porosity model coupling gas flow,adsorption and geomechanics for studying coupled processes and effectiveness of CO_(2) sequestration in coals.A new adsorption?desorption model derived based on thermodynamics is incorporated,particularly,the desorption hysteresis is *** reliability of the proposed adsorption-desorption isotherm is examined via validation *** is indicated that occurrence of desorption hysteresis is attributed to the adsorption-induced pore *** injection ceases,the injected gas continues to propagate further from the injection well,while the pressure in the vicinity of the injection well experiences a significant *** the adsorbed gas near the well also decreases,this decrease is less compared to that in pressure because of desorption *** unceasing spread of CO_(2) and drops of pressure and adsorbed gas depend on the degree of desorption hysteresis and heterogeneity of coals,which should be considered when designing CO_(2) sequestration into coal seams.

关键词： CO_(2)geological storage Coal seam Adsorption Desorption hysteresis

CLASSIFICATIONS OF DUPIN HyPERSURFACES IN LIE SPHERE GEOMETRy

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Acta Mathematica Scientia 2024年第1期44卷 1-36页

作者： thomas E.CECIL Department of Mathematics and Computer Science College of the Holy CrossWorcesterMA01610USA

This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere *** emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in *** with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of S^(n)(or R^(n)),are described in *** paper also contains several important constructions of Dupin hypersurfaces with certain special properties.

关键词： Dupin hypersurfaces isoparametric hypersurfaces Lie sphere geometry Lie sphere transformations Lie curvatures

Proximity-dependent protein (de)stabilization: screening the human ORFeome for protein degraders and stabilizers

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Signal Transduction and Targeted Therapy 2024年第8期9卷 3161-3162页

作者： thomas Hermanns Kay Hofmann Institute for Genetics University of CologneCologneGermany

In a recent study published in Nature,Poirson et *** an unbiased screen for proteins that can either bring about-or prevent-the destruction of proteinaceous model substrates in a proximity-dependent *** of such protein degraders and stabilizers will be instrumental in the development of new drug classes that specifically regulate the abundance of their target proteins.

关键词： al. stabilization stabilizers

How to enhance agricultural plastic waste management in China?Insights from public participation

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Journal of Integrative Agriculture 2024年第6期23卷 2127-2143页

作者： Aibo Hao thomas Dogot Changbin yin State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Economics and Rural Development Laboratory TERRA Teaching and Research CentreGembloux Agro-Bio TechUniversity of LiègeGembloux B-5030Belgium Research Center for Agricultural Green Development in China Beijing 100081China

Agricultural plastics play a pivotal role in agricultural ***,due to expensive costs,agricultural plastic waste management(APWM)encounters a vast funding *** one of the crucial stakeholders,the public deserves to make appropriate efforts for ***,identifying whether the public is willing to pay for APWM and clarifying the decisions’driving pathways to explore initiatives for promoting their payment intentions are essential to address the dilemma confronting *** this end,by applying the extended theory of planned behavior(TPB),the study conducted an empirical analysis based on 1,288 residents from four provinces(autonomous regions)of northern *** illustrate that:1)respondents hold generally positive and relatively strong payment willingness towards APWM;2)respondents’attitude(AT),subjective norm(SN),and perceived behavioral control(PBC)are positively correlated with their payment intentions(INT);3)environmental cognition(EC)and environmental emotion(EE)positively moderate the relationships between AT and INT,and between SN and INT,posing significant indirect impacts on *** study’s implications extend to informing government policies,suggesting that multi-entity cooperation,specifically public payment for APWM,can enhance agricultural non-point waste management.

关键词： agricultural plastic waste extended theory of planned behavior public payment environmental cognition environmental emotion