Severe plastic deformation (SPD) and nanostructured materials by machining

Large plastic strains between 1 and 15 can be imposed in chips formed by plane-strain (2-D) machining of metals and alloys. This approach has been used to examine microstructure changes induced by large strain deformation in model systems—copper and its alloys, precipitation-hardenable aluminum alloys, high-strength materials such as titanium, Inconel 718 and 52100 steel, and an amorphous alloy. It is shown that materials with average grain sizes in the range of 60 nm–1 μm can be created by varying the parameters of machining, which in turn affects the deformation processes. Furthermore, a switch-over from an elongated subgrain microstructure to an equi-axed nanocrystalline microstructure, with a preponderance of large-angle grain boundaries, has been demonstrated at the higher levels of strain in several of these materials. This switch-over can be readily controlled by varying the deformation conditions. Dynamic recrystallization has been demonstrated in select material systems under particular conditions of strain and temperature. This study may be seen as providing an important bridge between furthering the understanding of microstructural refinement by large strain deformation and the practical utilization of nanostructured materials in structural and mechanical applications. Conventional plane-strain machining has been shown to be a viable SPD method for examining the underlying processes of very large strain deformation.     

热轧铸造高速钢工作辊表面氧化膜研究

研究了热轧铸造高速钢工作辊的辊面氧化膜形态、主要失效特征,分析了氧化膜失效对辊面粗糙度和磨损状态的影响.通过实物轧辊试样的连续变温氧化试验、恒温持续氧化试验和湿热氧化试验,研究了高速钢材质的氧化生长过程.采用SEM、XRD分析了氧化膜生长机制、分布形态、结合状态等的变化规律,进而提出了改进工作辊冷却效果的措施,为有效控制高速钢工作辊氧化膜状态和带钢断面质量奠定了基础.     

The A-B therapy-type distinction, accurate empathy, nonpossessive warmth, and therapist genuineness in psychotherapy.

Assessed the therapist-offered conditions present among 4 A- and 2 B-type therapists paired variously with 29 neurotic and 20 schizophrenic patients. Results suggest that therapist-offered conditions relate to depth of patient self-exploration but not to rated improvement. Furthermore, A-type therapists were more empathetic with schizophrenic than with neurotic patients, but B-type therapists showed no significant increases of beneficial therapist qualities as a function of the patient's diagnosis. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct determination of epitaxial interface structure in Gd2O3 passivation of GaAs

Obtaining accurate structural information on epitaxial films and interfaces is nowhere more critical than in semiconductor passivation layers, where details of the atomic structure and bonding determine the nature of the interface electronic states. Various non-destructive methods have been used to investigate the structure of films and interfaces, but their interpretation is model-dependent, leading occasionally to wrong conclusions. We have developed a new X-ray method for the direct determination of epitaxial structures, coherent Bragg rod analysis (COBRA). The usefulness of our technique is demonstrated by mapping, with atomic precision, the structure of the interfacial region of a Gd2O3 film grown epitaxially on a (100) GaAs substrate. Our findings reveal interesting behaviour not previously suggested by existing structural methods, in particular a lock-in of the in-plane Gd atomic positions to those of the Ga/As atoms of the substrate. Moreover, we find that the bulk stacking of the Gd2O3 atomic layers is abandoned in favour of a new structure that is directly correlated with the stacking sequence of the substrate. These results have important implications for Gd2O3 as an effective passivation layer for GaAs (ref. 7). Our work shows that the COBRA technique, taking advantage of the brilliance of insertion device synchrotron X-ray sources, is widely applicable to epitaxial films and interfaces.     

Ruthenate and Cuprate High-Tc Superconductivity

The onset of superconductivity is 49 K in Cu-doped (but cuprate-plane-free) Sr₂YRuO₆, almost the same as the 45 K onsets in GdSr₂Cu₂RuO₈ and in R_{2 – z} Ce _z Sr₂Cu₂RuO₁₀ (for R = Gd or Eu), implying that the superconductivity in all four compounds originates in the SrO layers, not in the cuprate-planes. Muon studies show that the superconducting condensate in YBa₂Cu₃O₇ is either s-wave or extended s-wave, not d-wave, confirming earlier work.     

Sr2YRu1?uCuuO6: Evidence for SrO-Layer Superconductivity

Sr₂YRuO₆ doped on its Ru site by Cu superconducts at the below 45 K, although its Ru and Cu are magnetically ordered at 23 K and 86 K, respectively. The SrO layers superconduct. Ba₂GdRuO₆, when doped with Cu, does not superconduct, because L = 0 Gd is not crystal-field split, and so induces Cooper pair-breaking.     

Influence of client characteristics on initial counselor perceptions.

Analyzed the reactions of 30 professionally employed counselors to a role-played, videotaped intake interview with a potential client by a counselor who was not in view. The Ss assessed the probability that they would elect to counsel the person. They also rated both themselves and the client on A. Barak and M. LaCrosse's (1975) Counselor Rating Form (CRF). Results indicate that the trustworthiness dimension seemed to incorporate those characteristics that most influence initial counselor perceptions. It is suggested that the CRF can be used to obtain counselor as well as client perceptions and that the use of relativistic measures of attributes, that is, the use of scores that reflect the differences between one's own attributes and those of the other, may be a valuable methodological addition to research that uses the CRF. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

2004年世界电子业——快乐日子又来了!

2003年:半导体业重返好时光 　　iSuppli公司预计,2003年世界半导体市场销售将增长13.9%,与2002年的增长1.6%不可同日而语.……     

Sexual bias in the WAIS.

The WAIS protocols of 50 male and 50 female college students were analyzed for differential subtest performance. Although no significant differences were found for education, age, or Verbal, Performance, or Full Scale IQ, males were found to be highly superior on the Information, Arithmetic, Block Design, and Picture Arrangement subtests. Females were markedly superior on the Digit Symbol subtest. Wechsler's M-F score was calculated for each group and was found to differentiate the sexes better than any single subtest. The results suggest the presence of sexual bias in the WAIS even when age, education, IQ, and experience are held fairly constant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electromagnetism and quantum theory

Devices dependent upon such results of quantization as plasmas, semiconduction, or individual energy-level transitions now occupy a diverse and important position within the broad scope of electrical engineering. Their further development requires a thorough understanding of quantum theory on the part of device research and development engineers. To meet this need, many departments of electrical engineering may soon find it necessary to offer their own courses in quantum theory, just as they did in electromagnetic field theory after World War II.