Additive Composition of Supervised Self-Organizing Maps

The learning of complex relationships can be decomposed into several neural networks. The modular organization is determined by prior knowledge of the problem that permits to split the processing into tasks of small dimensionality. The sub-tasks can be implemented with neural networks, although the learning examples cannot be used anymore to supervise directly each of the networks. This article addresses the problem of learning in a modular context, developing in particular additive compositions. A simple rule allows defining efficient training, and combining, for example, several Supervised-SOM networks. This technique is important because it introduces interesting generalizations in many modular compositions, permitting data fusion or sequential combinations of neural networks. This revised version was published online in August 2006 with corrections to the Cover Date.     

Discrepancy of clinical, radiographic and histopathologic findings in two children with chronic pulmonary graft-versus-host disease after HLA-identical sibling stem cell transplantation

We report two children who presented with cough and shortness of breath 7-8 months after a matched sibling stem cell transplant (SCT) for chronic myelogenous leukemia and myelodysplastic syndrome, respectively. Pulmonary function tests (PFTs) revealed severe airways obstruction (AO). However, radiographic investigations showed no serious abnormalities in the early phase and open lung biopsy revealed only mild lymphocytic bronchiolitis and bronchiolitis obliterans consistent with pulmonary graft-versus-host disease (GVHD). Despite administration of bronchodilators and various immunosuppressive agents obstructive lung disease progressed to pulmonary failure in patient 1, whereas stabilization of the clinical course was observed in patient 2. Serial PFTs were the best predictor of the clinical course in contrast to radiographic and histologic findings. It is concluded that PFTs should be performed repeatedly in pediatric patients after allogeneic SCT with the aim of diagnosing GVHD-associated AO in the subclinical phase. Progressive post-transplant AO necessitates prompt initiation of intensive immunosuppressive therapy in order to stop the underlying immunopathologic process even in the absence of severe radiographic and histologic findings.     

Silica filled elastomers: polymer chain and filler characterization in the undeformed state by a SANS-SAXS approach

The reinforcing phenomenon by blending soft elastomeric materials with rigid colloidal filler particles is, despite of its technological relevance, still poorly understood on the microscopic level although several macroscopic approaches have dealt with some of the mechanisms successfully. In order to contribute to bridge this gap, a study of a composite made up of a commercially silica-based hard phase and of a PI polymer matrix has been performed. The undeformed ‘reference’ state for such studies has been investigated by means of the small angle scattering technique on partially labeled samples. The single chain behaviour was isolated from neutron scattering although the condition of composition matching was not met, whereas the precipitated fractal filler structure was characterized by synchrotron X-ray scattering. The effective 3-component system has been successfully described through a combined approach of neutron and X-ray data and relationships dealing with 4-component structures have been presented. This work deals for the first time directly with the soft matrix in a reinforced 2-phase composite and is the basis for the treatment of anisotropic data in terms of both filler and chain dependence on uniaxial strain.     

In vivo resistance to strains of Trypanosoma rhodesiense, Mozambique, 1985

We report the existence of high resistance to Melarsoprol and low resistance to Suramin in 11 Trypanosoma rhodesiense species. They were isolated from humans in the Tete province, Mozambique, and kept in mice at the Maputo National Health Institute. The preliminary results obtained with Suramin administered intracranially, are also reported.     

Study of partial oxidation of Cu clusters by HRTEM

Cu clusters of diameters less than 10 nm were selected as models to study oxidation as a function of size, chemical composition, and structure. The investigations were performed with high-resolution electron microscopy. It was shown that beginning with multiply twinned particles as stable structures for particles with diameters less than 5 nm and of cuboctahedra for larger particles, in the transitional state between pure metal and oxide both states can coexist within the same particle; this latter can be proved by HRTEM. It was also demonstrated that this is due to incorporating distortions as step dislocations within grain boundaries which can be shown in electron micrographs of high resolution better than 0.18 nm after image processing. The creation of sub-oxides with less reactivity than the pure metal clusters could also be demonstrated leading to morphologies which are different from those of the pure metal. This revised version was published online in July 2006 with corrections to the Cover Date.     

Amorphization reaction during mechanical alloying: influence of the milling conditions

Amorphous Ni-Zr powders have been prepared by mechanical alloying of elemental crystalline powders. The glass-forming range has been determined in detail at different milling intensities. Depending on the milling conditions, at least partial crystallization of the formerly amorphous material can occur from 66 to 75 at% Ni, due to a temperature rise during milling at high intensity. In comparison with isothermal annealing experiments at various temperatures on completely amorphous powder, a relation between milling temperature and milling time is shown. This confirms the similarity of the amorphization process during mechanical alloying with the solid-state interdiffusion reaction in alternating crystalline multilayers.     

Rotor‐Stator and Disc Systems for Emulsification Processes

Emulsions now find a wide range of applications in industry and daily life. In the pharmaceutical industry lipophilic active ingredients as well as many nutritional products such as vitamins are often formulated in the dispersed phase of oil‐in‐water emulsions. Emulsions can be produced with different mechanical emulsification techniques. In the following review, the process of rotor‐stator systems and disc systems are compared to other popular mechanical emulsification systems. On the basis of experimental results from the authors' laboratory, a discontinuous gear‐rim dispersing system, discontinuous disc system, and a continuous high pressure system are compared with regard to their attainable mean droplet diameter and drop size distribution in an oil‐in‐water emulsion. It can be shown that dissolver discs with a very simple geometry attain very small mean droplet diameters and a very narrow droplet size distribution, comparable to the emulsions obtained with established rotor‐stator systems such as gear‐rim dispersers.     

从技术层面看国内燃气灶具的发展

改革开放以来,天然气作为清洁能源,已进入千家万户.消费者对不同类型的燃具需求不一,质量的要求也不断提高,主要体现在热效率、结碳、堵塞、泄漏、压力控制等几个方面,而所有这些特点都与灶具所采用的燃烧技术有着千丝万缕的联系.