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New Identities for Weak KAM Theory(For Haim Brezis,in continuing admiration)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 379-392页

作者： Lawrence Craig evans Department of Mathematics University of CaliforniaBerkeleyUSA.

This paper records for the Hamiltonian H =1/2|p|~2+ W(x) some old and new identities relevant for the PDE/variational approach to weak KAM theory.

关键词： Weak KAM theory, Effective Hamiltonian, Hamiltonian dynamics

Social Computing Unhinged

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Journal of Social Computing 2020年第1期1卷 1-13页

作者： James evans University of Chicago ChicagoIL 60637and Santa Fe InstituteSanta FeNM 87501USA.

Social computing is ubiquitous and intensifying in the 21st *** used to reference computational augmentation of social interaction through collaborative filtering,social media,wikis,and crowdsourcing,here I propose to expand the concept to cover the complete dynamic interface between social interaction and computation,including computationally enhanced sociality and social science,socially enhanced computing and computer science,and their increasingly complex combination for mutual *** recommends that we reimagine Computational Social Science as Social Computing,not merely using computational tools to make sense of the contemporary explosion of social data,but also recognizing societies as emergent computers of more or less collective intelligence,innovation and *** further proposes we imagine a socially inspired computer science that takes these insights into account as we build machines not merely to substitute for human cognition,but radically complement *** leads to a vision of social computing as an extreme form of human computer interaction,whereby machines and persons recursively combine to augment one another in generating collective intelligence,enhanced knowledge,and other social goods unattainable without each *** the example of science and technology,I illustrate how progress in each of these areas unleash advances in the others and the beneficial relationship between the technology and science of social computing,which reveals limits of sociality and computation,and stimulates our imagination about how they can reach past those limits together.

关键词： social computing complex systems computer supported cooperative work computational social science artificial intelligence human computer interaction human-centered computing

Review： Sugar beets as a substitute for grain for lactating dairy cattle

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Journal of Animal Science and Biotechnology 2017年第3期8卷 539-548页

作者： Essi evans Ulrike Messerschmidt Technical Advisory Services Inc 64 Scugog St Bowmanville ON L1C3J Canada KWS SAAT SE Grimsehlstr. 31 P.O. Box 1463D-37555 Einbeck Germany

Dairy cows are customarily given grains and highly digestible byproduct ingredients as additions to forage to support milk production. In many parts of the world growing seasons are short, and the grain crops that can be grown may not provide adequate yields. Sugar beets, on the other hand are relatively hardy, and dry matter yields surpass the yields of most grain crops. There are however, perceptions that beets may not be suitable as a feed ingredient due to the fact that the storage form of carbohydrate is sugar rather than starch. With little analytical support, sugar has been rejected in many feeding programs with the view that sugar reduces rumen pH, fiber digestion and microbial yield. This review explores available facts revolving around these concerns. Information regarding the feeding of sugar beets is provided and the use of sugar beets as a partial replacement for grain is proposed.

关键词： Dairy cattle Feed beets Fodder beets Methane Sugar Sugar beets

A CLASS OF ASYNCHRONOUS MATRIX MULTI-SPLITTING MULTI-PARAMETER RELAXATION ITERATIONS

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Journal of Computational Mathematics 1998年第3期16卷 221-238页

作者： Bai, ZZ Wang, DR evans, DJ Chinese Acad Sci ICMSEC Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Dept Comp Studies Loughborough LE11 3TU Leics England

A class of asynchronous matrix multi-splitting multi-parameter relaxation methods, including the asynchronous matrix multisplitting SAOR, SSOR and SGS methods as well. as the known asynchronous matrix multisplitting AOR, SOR and GS methods, etc., is proposed for solving the large sparse systems of linear equations by making use of the principle of sufficiently using the delayed information. These new methods can greatly execute the parallel computational efficiency of the MIMD-systems, and are shown to be convergent when the coefficient matrices are H-matrices. Moreover, necessary and sufficient conditions ensuring the convergence of these methods are concluded for the case that the coefficient matrices are L-matrices.

关键词： system of linear equations asynchronous iteration matrix multisplitting relaxation convergence

ON THE CONVERGENCE OF ASYNCHRONOUS NESTEDMATRIX MULTISPLITTING METHODS FOR LINEARSYSTEMS

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Journal of Computational Mathematics 1999年第6期17卷 575-588页

作者： Bai, ZZ Wang, DR evans, DJ Acad Sinica State Key Lab Sci Engn Comp Inst Computat Math & Sci Engn Comp Beijing 100080 Peoples R China Shanghai Univ Dept Math Shanghai 201800 Peoples R China Loughborough Univ Technol Parallel Algorithms Res Ctr Loughborough LE11 3TU Leics England

A class of asynchronous nested matrix multisplitting methods for solving large-scale systems of linear equations are proposed, and their convergence characterizations are studied in detail when the coefficient matrice... 详细信息

关键词： solution of linear systems asynchronous parallel iteration matrix multisplitting relaxation method convergence

Palladium-catalyzed S_(N)2 glycosylation of phenols

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Science China Chemistry 2024年第4期67卷 1037-1038页

作者： Yu Zhu P.Andrew evans Department of Chemistry Queen’s University90 Bader LaneKingstonK7L 3N6Canada Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China

Glycosides are essential structural motifs present in an array of important medicines,materials,and natural products[1].Nevertheless,the chemo-and stereoselective construction of the glycosidic linkage is a long-standing challenge because relatively minor variations in the glycosyl donor or acceptor’s structure can impact stereoselectivity,thus influencing the product's functional properties.

关键词： properties Palladium catalyzed

Immobilization of Penicillin G Acylase on Calcined Layered Double Hydroxides

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Chemical Research in Chinese Universities 2003年第3期19卷 324-329页

作者： evans D.G. Key Laboratory of Science & Technology of Controllable Chemical Reactions

A hydrotalcite-like Mg 2+ /Al 3+ layered double hydroxide(LDH) material was prepared by means of a modified coprecipitation method involving a rapid mixing step followed by a separate aging process. LDH calcined at 500 ℃, denoted as CLDH, was characterized by XRD, IR and BET surface area measurements. CLDH has a poor crystalline MgO-like structure with a high surface area and porosity. CLDH was used as a support for the immobilization of penicillin G acylase(PGA). The effect of varying the immobilization conditions, such as pH, contact time and the ratio of enzyme to support, on the activity of the immobilized enzyme in the hydrolysis of penicillin G has been studied. It was found that the activity of the immobilized enzyme decreased slightly with decreasing pH and reached a maximum after a contact time of 24 h. The activity of the immobilized enzyme increased with increasing the ratio of enzyme to support. It was found that the adsorption of PGA inhibited the expected reaction of CLDH with an aqueous medium to regenerate a LDH phase. Its original activity(36%) after 15 cycles of reuse of the immobilized enzyme was retained, but no further loss in the activity was observed.

关键词： Immobilized enzyme Penicillin G acylase Layered double hydroxide Calcination

Study on the supramolecular structure of sorbic acid inter-calated Zn-Al layered double hydroxides and its thermal decomposition

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Chinese Science Bulletin 2005年第22期50卷 2575-2581页

作者： David G. evans Ministry of Education Key Laboratory of Science and Technology of Controllable Chemical Reactions Beijing University of Chemical Tech- nology Beijing 100029 China

A novel organic-inorganic composite, sorbic acid intercalated zinc aluminum layered double hydroxides (SA-ZnAl-LDHs) has been successfully assembled by a sim- ple direct coprecipitation method. A holistic approach in- cluding normal XRD, FT-IR, and UV-Vis measurements and simultaneous TG/DTA/MS and in situ HT-XRD techniques was employed to explore the supramolecular intercalation structure and the thermal decomposition properties of as-synthesized SA-ZnAl-LDHs material.

关键词：氢氧化铝超分子结构热量分解插入结构 HT-XRD 有机化合物

Modeling endodermal organ development and diseases using human pluripotent stem cell-derived organoids

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Journal of Molecular Cell Biology 2020年第8期12卷 580-592页

作者： Fong Cheng Pan Todd evans Shuibing Chen Department of Surgery Weill Cornell Medical CollegeNew YorkNY 10065USA

Recent advances in development of protocols for directed differentiation from human pluripotent stem cells(hPSCs)to defined lineages,in combination with 3D organoid technology,have facilitated the generation of various endoderm-derived organoids for in vitro modeling of human gastrointestinal development and associated *** this review,we discuss current state-ofthe-art strategies for generating hPSC-derived endodermal organoids including stomach,liver,pancreatic,small intestine,and colonic *** also review the advantages of using this system to model various human diseases and evaluate the shortcomings of this ***,we emphasize how other technologies,such as genome editing and bioengineering,can be incorporated into the 3D hPSC-organoid models to generate even more robust and powerful platforms for understanding human organ development and disease modeling.

关键词： human pluripotent stem cells endoderm gastrointestinal development disease modeling