645 resultados para 944


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本文从现代供应链管理概念及要求出发 ,指出协调与合作在供应链管理中的重要作用 ,应用分布式人工智能理论及分析方法 ,提出了基于多 agent的供应链管理结构 ,定义了各功能agent的作用和职能 ,研究了基于多 agent的供应链管理协作内容、特点及解决方法 ,介绍了基于CORBA的分布式系统开发方法 ,提出了基于 CORBA规范及 KQML协议的支持供应链管理协作研究及开发的软件结构 .

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本文从企业生产管理信息系统的现状出发,详细分析了现有信息系统在生产计划管理、生产过程跟踪和系统软件结构方面存在的问题。在此基础上,进一步分析了未来企业对制造信息系统的需求及表现形式,并从信息技术角度研究了构件技术在未来企业制造管理信息系统中的作用,建立了构件技术特征与制造信息系统技术特征之间的映射关系,提出了为实现构件化信息系统所要解决的一些技术问题。

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在介绍CIM/CIMS在我国取得的重大进展的基础上,探讨了CIMS推广应用过程中存在的问题,分析了原因并介绍了解决问题的几点经验.

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A practical and efficient disposal method for hydrodechlormation of polychlorinated biphenyls (PCBs) in transformer oil is reported. Transformer oil containing PCBs was treated by nanometric sodium hydride (nano-NaH) and transition metal catalysts. High destruction and removal efficiency (89.8%) can be attained by nano-NaH alone under mild conditions. The process exhibits apparent characteristics of a first order reaction. The reductive ability of nano-NaH was enhanced by the addition of transition metal catalysts. In the presence of TiCl4, 99.9% PCBs was hydrodechlorinated. The complex reducing reagents, Ni(OAc)(2) + i-PrONa, show extra hydrodechlorinating activity for di-chlorinated biphenyls. (c) 2004 Elsevier Ltd. All rights reserved.

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Bain, William, Between Anarchy and Society: Trusteeship and the Obligations of Power (Oxford: Oxford University Press, 2003), pp.viii+216 RAE2008

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BACKGROUND:Zambia was the first African country to change national antimalarial treatment policy to artemisinin-based combination therapy - artemether-lumefantrine. An evaluation during the early implementation phase revealed low readiness of health facilities and health workers to deliver artemether-lumefantrine, and worryingly suboptimal treatment practices. Improvements in the case-management of uncomplicated malaria two years after the initial evaluation and three years after the change of policy in Zambia are reported.METHODS:Data collected during the health facility surveys undertaken in 2004 and 2006 at all outpatient departments of government and mission facilities in four Zambian districts were analysed. The surveys were cross-sectional, using a range of quality of care assessment methods. The main outcome measures were changes in health facility and health worker readiness to deliver artemether-lumefantrine, and changes in case-management practices for children below five years of age presenting with uncomplicated malaria as defined by national guidelines.RESULTS:In 2004, 94 health facilities, 103 health workers and 944 consultations for children with uncomplicated malaria were evaluated. In 2006, 104 facilities, 135 health workers and 1125 consultations were evaluated using the same criteria of selection. Health facility and health worker readiness improved from 2004 to 2006: availability of artemether-lumefantrine from 51% (48/94) to 60% (62/104), presence of artemether-lumefantrine dosage wall charts from 20% (19/94) to 75% (78/104), possession of guidelines from 58% (60/103) to 92% (124/135), and provision of in-service training from 25% (26/103) to 41% (55/135). The proportions of children with uncomplicated malaria treated with artemether-lumefantrine also increased from 2004 to 2006: from 1% (6/527) to 27% (149/552) in children weighing 5 to 9 kg, and from 11% (42/394) to 42% (231/547) in children weighing 10 kg or more. In both weight groups and both years, 22% (441/2020) of children with uncomplicated malaria were not prescribed any antimalarial drug.CONCLUSION:Although significant improvements in malaria case-management have occurred over two years in Zambia, the quality of treatment provided at the point of care is not yet optimal. Strengthening weak health systems and improving the delivery of effective interventions should remain high priority in all countries implementing new treatment policies for malaria.

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The atom pencil we describe here is a versatile tool that writes arbitrary structures by atomic deposition in a serial lithographic process. This device consists of a transversely laser-cooled and collimated cesium atomic beam that passes through a 4-pole atom-flux concentrator and impinges on to micron- and sub-micron-sized apertures. The aperture translates above a fixed substrate and enables the writing of sharp features with sizes down to 280 nm. We have investigated the writing and clogging properties of an atom pencil tip fabricated from silicon oxide pyramids perforated at the tip apex with a sub-micron aperture.

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This paper reports a new strategy, recursive directional ligation by plasmid reconstruction (PRe-RDL), to rapidly clone highly repetitive polypeptides of any sequence and specified length over a large range of molecular weights. In a single cycle of PRe-RDL, two halves of a parent plasmid, each containing a copy of an oligomer, are ligated together, thereby dimerizing the oligomer and reconstituting a functional plasmid. This process is carried out recursively to assemble an oligomeric gene with the desired number of repeats. PRe-RDL has several unique features that stem from the use of type IIs restriction endonucleases: first, PRe-RDL is a seamless cloning method that leaves no extraneous nucleotides at the ligation junction. Because it uses type IIs endonucleases to ligate the two halves of the plasmid, PRe-RDL also addresses the major limitation of RDL in that it abolishes any restriction on the gene sequence that can be oligomerized. The reconstitution of a functional plasmid only upon successful ligation in PRe-RDL also addresses two other limitations of RDL: the significant background from self-ligation of the vector observed in RDL, and the decreased efficiency of ligation due to nonproductive circularization of the insert. PRe-RDL can also be used to assemble genes that encode different sequences in a predetermined order to encode block copolymers or append leader and trailer peptide sequences to the oligomerized gene.

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BACKGROUND: Interleukin (IL)-15 is a chemotactic factor to T cells. It induces proliferation and promotes survival of activated T cells. IL-15 receptor blockade in mouse cardiac and islet allotransplant models has led to long-term engraftment and a regulatory T-cell environment. This study investigated the efficacy of IL-15 receptor blockade using Mut-IL-15/Fc in an outbred non-human primate model of renal allotransplantation. METHODS: Male cynomolgus macaque donor-recipient pairs were selected based on ABO typing, major histocompatibility complex class I typing, and carboxy-fluorescein diacetate succinimidyl ester-based mixed lymphocyte responses. Once animals were assigned to one of six treatment groups, they underwent renal transplantation and bilateral native nephrectomy. Serum creatinine level was monitored twice weekly and as indicated, and protocol biopsies were performed. Rejection was defined as a increase in serum creatinine to 1.5 mg/dL or higher and was confirmed histologically. Complete blood counts and flow cytometric analyses were performed periodically posttransplant; pharmacokinetic parameters of Mut-IL-15/Fc were assessed. RESULTS: Compared with control animals, Mut-IL-15/Fc-treated animals did not demonstrate increased graft survival despite adequate serum levels of Mut-IL-15/Fc. Flow cytometric analysis of white blood cell subgroups demonstrated a decrease in CD8 T-cell and natural killer cell numbers, although this did not reach statistical significance. Interestingly, two animals receiving Mut-IL-15/Fc developed infectious complications, but no infection was seen in control animals. Renal pathology varied widely. CONCLUSIONS: Peritransplant IL-15 receptor blockade does not prolong allograft survival in non-human primate renal transplantation; however, it reduces the number of CD8 T cells and natural killer cells in the peripheral blood.

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Olfactory receptors (ORs) govern a prime sensory function. Extant birds have distinct olfactory abilities, but the molecular mechanisms underlining diversification and specialization remain mostly unknown. We explored OR diversity in 48 phylogenetic and ecologically diverse birds and 2 reptiles (alligator and green sea turtle). OR subgenomes showed species- and lineage-specific variation related with ecological requirements. Overall 1,953 OR genes were identified in reptiles and 16,503 in birds. The two reptiles had larger OR gene repertoires (989 and 964 genes, respectively) than birds (182-688 genes). Overall, birds had more pseudogenes (7,855) than intact genes (1,944). The alligator had significantly more functional genes than sea turtle, likely because of distinct foraging habits. We found rapid species-specific expansion and positive selection in OR14 (detects hydrophobic compounds) in birds and in OR51 and OR52 (detect hydrophilic compounds) in sea turtle, suggestive of terrestrial and aquatic adaptations, respectively. Ecological partitioning among birds of prey, water birds, land birds, and vocal learners showed that diverse ecological factors determined olfactory ability and influenced corresponding olfactory-receptor subgenome. OR5/8/9 was expanded in predatory birds and alligator, suggesting adaptive specialization for carnivory. OR families 2/13, 51, and 52 were correlated with aquatic adaptations (water birds), OR families 6 and 10 were more pronounced in vocal-learning birds, whereas most specialized land birds had an expanded OR family 14. Olfactory bulb ratio (OBR) and OR gene repertoire were correlated. Birds that forage for prey (carnivores/piscivores) had relatively complex OBR and OR gene repertoires compared with modern birds, including passerines, perhaps due to highly developed cognitive capacities facilitating foraging innovations.

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Con el presente proyecto de investigación se pretenden proponer algunas estrategias didácticas en la perspectiva de potenciar el pensamiento variacional en estudiantes de octavo y Noveno grados, de Educación Básica, a través de situaciones problemas. El estudio se realiza en tres Instituciones Educativas de carácter Público, del municipio de Sincelejo, Colombia. Se emplea un diseño cualitativo que se aproxima a la investigación-acción. Este estudio es realizado por el grupo de investigación “Pensamiento Matemático” (PEMA), con el auspicio de la Universidad de Sucre de Sincelejo, Colombia.

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Las clases de matemáticas no debieran tener como objetivo fundamental el aprendizaje de contenidos (definiciones, teoremas, axiomas…) que posteriormente serán aplicados a la resolución de un gran listado de ejercicios y problemas propuestos por el profesor y que justificará el aprendizaje de dichos contenidos, sino que, por el contrario, debieran partir con un problema concreto y familiar para el alumno. Una vez planteado éste y discutido por todos, estudiantes y profesor, traerá como consecuencia la obligación de resolverlo y por tanto la necesidad del aprendizaje de las técnicas que son necesarias para ello y recurrir al uso de tecnología disponible. Es muy importante destacar que durante todo el proceso el alumno hace conjeturas que irá verificando en cada paso. Se dará cuenta que algunas de las conjeturas que hizo son correctas y que otras no lo son, es decir, cometerá errores y aciertos, en función de los cuales irá cimentando su aprendizaje. Pero, por sobre todo, debe aprender que “va al colegio a equivocarse”, pero que no debe quedarse en el error, que en la discusión con sus compañeros y el profesorado encontrará la(s) solucione(s), que es probable que más de una sirva, pero que también unas son mejores que otras, que en algunos casos hay una solución óptima, en definitiva irá “aprendiendo a aprender”. Se ilustra lo anterior planteando resolver un clásico problema de construcción de cajas utilizando como herramienta de aprendizaje el software DERIVE 5.

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Nitrogen is now used in wave soldering machines to help lower the amount of dross that can be formed on the solder bath surface. The paper provides details on the use of computational fluid dynamics in helping understand the flow profiles of nitrogen in a wave soldering machine and to predict the concentration of nitrogen and oxygen around the solder bath.