减少锡须

组建iNEMI锡须用户研究小组的目的就是为了把锡须引起的故障风险减至最小程度。本文回顾了该小组的推荐意见，它反映了现在可以获得的有关锡须形成和控制的最新资料．包括常用的无铅处理涂层的信息及其帮助减少锡须的效果。[编者按]     

Preschool children's conceptions of transgressions: Effects of varying moral and conventional domain-related attributes.

57 38–76 mo old Ss enrolled in preschool and/or day care centers were assigned to either 6 story-stimulus conditions or to a word-evaluation condition. Ss in the 6 story-stimulus conditions either heard stories describing familiar moral or conventional transgressions or stories varying in the consistency of prohibitions regarding actions and responses to events. Some events were unspecified. Ss were asked to justify the events' wrongness and make a series of judgments on criteria previously found to be associated with the domains. Ss' judgments and justifications were reassessed 1 wk later. Results show that Ss differentiated between familiar moral and social-conventional transgressions and that they treated stories having attributes associated with each domain like prototypical moral or conventional transgressions. The presence or absence of information regarding event-unspecified consequences of actions differentiated criterion judgments. Responses to the word-evaluation condition (in which Ss' judgments were assessed in the absence of stories) revealed no response biases to the questions. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In the Eye of the Beholder: Subjective and Observer Ratings of Middle-Class African American Mother-Adolescent Interactions.

Middle-class African American mothers and adolescents (n=81) participated in a dyadic interaction task in early adolescence (M=13.06 years, SD=1.27) and then again 2 years later (M=15.01 years, SD=1.27). Following the task, mothers and adolescents rated their own and their partner's support and involvement in the task; observers rated videotaped interactions for the same dimensions. African American mothers perceived adolescents' behavior in the interactions more positively than did observers, and both mothers and observers viewed mothers' behavior as more positive than adolescents' behavior. With observers' ratings controlled, early adolescents' more negative perceptions of their mothers' interactions led to less trust and communication with mothers 2 years later, but subjective understanding did not influence later ratings of conflict intensity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure and Properties of Aluminum Alloys Modified with Silicon Carbide by Laser Surface Treatment

We study the structure and properties of AA6082 and AA7075 aluminum alloys modified with particles of SiC with the help of a laser. It is shown that the wear resistance of alloys laser reinforced with SiC in the case of friction against an abrasive wheel is 30–75 times higher than for nonmodified alloys. On the basis of the data of electrochemical investigations, it is shown that, for AA7075 alloy, the influence of its structural heterogeneity on the variation of corrosion potentials decreases as the corrosion activity of the medium increases. We measured the values of corrosion currents of the surfaces of alloys in various corrosive solutions. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 3, pp. 34–40, May–June, 2005.     

Phase relations in the Pr-Fe-Sb and Pr-Co-Sb systems

The phase relations in the Pr-Fe-Sb and Pr-Co-Sb systems have been studied, and the 600°C sections of their phase diagrams have been constructed. In the Pr-Fe-Sb system, the three earlier known ternary compounds PrFe₄Sb₁₂, PrFeSb₂, and Pr₆Fe₁₃Sb have been obtained, and two new antimonides have been identified: PrFeSb₃ (sp. gr. Pbcm, CeNiSb₃ structure, a = 1.251(8) nm, b = 0.606(4) nm, c = 1.848(9) nm) and Pr₅Fe₂Sb (sp. gr. I4/mcm, Mo₅B₂Si structure, a = 0.7541(2) nm, c = 1.4161(2) nm). In the Pr-Co-Sb system, the existence of the compound PrCo_1?x Sb₂ has been confirmed, and two new antimonides have been identified: PrCoSb₃ (sp. gr. Pbcm, CeNiSb₃ structure, a = 1.2673(4) nm, b = 0.6127(2) nm, c = 1.8129(7) nm) and Pr₅CoSb₂ (sp. gr. Pnma, Y₅Ni_xSb_3?x -related structure, a = 1.2476(2) nm, b = 0.9088(1) nm, c = 0.8104(1) nm).     

Development of Glass Frit Free Metallization Systems for AIN

Currently only glass bonding thick film conductor systems are commercially available for metallizing AlN-ceramic. The glass phase formed between metallization and ceramic impairs the high thermal conductivity of AlN. A new glass frit free metallization system has been developed utilizing the bonding mechanism of active brazing to provide the adhesion of metallization onto the ceramic. Aspects of paste preparation range from the derivation of the metallic powder to the selection of an appropriate printing vehicle which must decompose completely during the firing process under an inert atmosphere. The adhesion strength of the new paste system with the alternative bonding mechanism has been evaluated and contrasted with that of standard thick film pastes.     

Nucleoli in human pseudostratified columnar epithelium cells. (Microscopic classification of nucleoli)

The human pseudostratified epithelium was investigated to provide more information on the incidence of main nucleolar types in its epithelial cells. The compact nucleoli or nucleoli with nucleolonemas investigated by light microscopy were usually present in epithelial cells with highly basophilic cytoplasm. The absence of these nucleoli and the presence of ring-shaped nucleoli and/or micronucleoli (reflecting the decrease or inhibition of the RNA synthesis) were observed in epithelial cells which were characterized by the diminished or disappeared basophilic properties of the cytoplasm. These observations indicating the gradual inhibition of the nucleolar (ribosomal) RNA suggest that similar maturation processes may occur in investigated human pseudostratified columnar epithelium which are known for cell lines of the mesenchymal origin.     

Characterization of QT interval adaptation to RR interval changes and its use as a risk-stratifier of arrhythmic mortality in amiodarone-treated survivors of acute myocardial infarction

A new method is proposed to evaluate the dynamics of QT interval adaptation in response to heart rate (HR) changes. The method considers weighted averages of RR intervals (RR) preceding each cardiac beat to express RR interval history accounting for the influence on repolarization duration. A global optimization algorithm is used to determine the weight distribution leading to the lowest regression residual when curve fitting the [QT, RR1 data using a patient-specific regression model. From the optimum weight distribution, a memory lag L90 is estimated, expressing the delay in the QT adaptation to HR changes. On average, RR intervals of the past 150 beats (approximately 2.5 min) are required to model the QT response accurately. From a clinical point of view, the interval of the initial tens of seconds to one minute seems to be most important in the majority of cases. A measure of the optimum regression residual (r(opt)) has been calculated, discriminating between post-myocardial infarction patients at high and low risk of arrhythmic death while on treatment with amiodarone. A similar discrimination has been achieved with a variable expressing the character of QT lag behind the RR interval dynamics.     

Distribution of polylactosamines and vinculin in macrophages and foreign body giant cells colonizing the cellophane implant surface

The membrane poly-N-acetyllactosamines participate in the control of the adhesivity of macrophages and/or monocytes. They have been visualized by FITC labelled tomato lectin in macrophages and multinucleate foreign body giant cells colonizing a cellophane implant in this study. The maximal positivity was found in the periphery of poorly spread macrophages. The multinucleate cells exhibited positivity also in the dorsal surface. The cytoskeletal protein vinculin represents a part of adhesive plaques and participates in anchoring actin fibres to the integrin receptor. The immunohistochemical detection of this protein in the same model indicated poor accumulation of vinculin in the ventral membrane of mononuclear macrophages and multinucleate cells. The increased incidence of this protein was observed in the area of mutual contact between some macrophages.     

Influence of vermiculite on the formation of porous cordierites

Porous cordierites were prepared from mixtures of talc, kaolinite and vermiculite with alumina or aluminum hydroxide by sintering in an argon atmosphere at 1300 °C for 1 h (porous cordierites of Group I) and 2 h (porous cordierites of Group II). Group I and Group II were different in pore size distribution, quantitative content of mineral phases and cordierite structure parameters. The crystalline phases identified in porous cordierites prepared without vermiculite were cordierite (69–88 vol.%), protoenstatite (25–13 vol.%) and corundum (3–10 vol.%). Vermiculite increased the content of cordierite (84–90 vol.%) and Mg–Al spinel (4–15 vol.%) at the expense of protoenstatite. The calculated unit cell parameters of cordierites were between those of orthogonal and hexagonal cordierites (Group I) and corresponded to disordered orthorhombic rather than hexagonal cordierites (Group II). Group I cordierites had pore size maxima at about ~ 35 µm or ~ 20 µm, while Group II had maxima at about 35 µm, 25 µm and 18 µm. Porous cordierites prepared from alumina admixture had slightly lower pore volumes than those prepared from gibbsite. Cordierites prepared from mixtures rich in vermiculite and gibbsite showed the highest porosity (63% and 57%).