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91.
Microstructural transformations of heat affected zones in duplex steel welded joints 总被引:2,自引:0,他引:2
The influence of the welding thermal conditions exemplified by heat input and heat treatment after welding on the structure of the heat affected zone (HAZ) UNS S31803 has been analysed. The post weld treatment was used to create the precisely defined thermal conditions for the decomposition of primary phases in the HAZ, by a multi-layer welding thermal cycle stimulation. Detailed analyses of the microstructure and chemical composition of the phases in the different post welded conditions were performed by scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS) and transmission electron microscopy (TEM). Three types of secondary precipitates have been observed: secondary austenite (γ2), carbides: M23C6 and M7C3. The dependence of the secondary austenite volume fraction and morphology in the HAZ on thermal cycle have been interpreted. The eutectoid decomposition of the primary phases in the analysed thermal conditions was confirmed. 相似文献
92.
While concerns about the psychological effects of war are not new, only recently has systematic attention been paid to such problems among past and present military personnel. There is increasing recognition that mental health has serious implications for operational performance, retention, and compensation. Although little controlled research exists with this population, preliminary evidence suggests that psychological treatments for posttraumatic stress disorder may be beneficial, albeit less so than for civilian populations. This article reviews evidence for each of several psychological treatment stages: stabilization and engagement, psychoeducation, symptom management, prolonged exposure, cognitive restructuring, and relapse prevention, with particular reference to the clinical issues raised by military personnel. Possible explanations for reduced treatment effects in this population compared with civilians are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
93.
New accurate two-noded shear-flexible curved beam elements 总被引:2,自引:0,他引:2
There are two purposes of this work. One is to present two accurate two-noded finite elements which are derived from the
potential energy principle and the Hellinger–Reissner functional principle respectively. The second is to show the successful
application of the internal displacement parameters in developing a high-order related displacement-rotation interpolation
field. Because the derived interpolation field is capable of accurately modeling deformation modes in extreme thin curved
beams and nearly straight beams, both shear locking and membrane shocking are avoided. Several standard numerical tests display
superior behaviors of the present elements.
Received: 5 February 2002 / Accepted: 16 September 2002 相似文献
94.
M. Nishida T. Hanabusa Y. Ikeuchi N. Minakawa 《Materialwissenschaft und Werkstofftechnik》2003,34(1):49-55
Stress measurement methods using neutron and X‐ray diffraction were examined by comparing the surface stresses with internal stresses in the continuous tungsten‐fiber reinforced copper‐matrix composite. Surface stresses were measured by X‐ray stress measurement with the sin2ψ method. Furthermore, the sin2ψ method and the most common triaxal measurement method using Hooke's equation were employed for internal stress measurement by neutron diffraction. On the other hand, microstress distributions developed by the difference in the thermal expansion coefficients between these two phases were calculated by FEM. The weighted average strains and stresses were compared with the experimental results. The FEM results agreed with the experimental results qualitatively and confirmed the importance of the triaxial stress analysis in the neutron stress measurement. 相似文献
95.
Stress Concentration Factors for a Circular Hole in Curved Beams Under Bending Loads 总被引:1,自引:0,他引:1
Abstract: As a contribution to the field of stress concentration studies, the case of circular hole in curved bar elements under bending is hereby studied. Trend values of stress concentration factors (SCF) are presented based on selected variables of the problem for two critical hole locations. The results will help to identify an SCF law for practical use by applying the statistical method of regression analysis. Two approximations obtained by means of computational methods are compared with those obtained by photoelastic experimental method. 相似文献
96.
为了解决水文巡测设备中数据传输的可靠性,电力载波通讯中的单频阻波器技术被应用到巡测设备上。此法简单易行,稳定可靠。 相似文献
97.
The current study examined psychological and physical health outcomes of the written disclosure paradigm and the hypothesis that the principles of therapeutic exposure account for the beneficial effects of the paradigm. Participants were randomly assigned to either a written disclosure condition or a control condition. Reactivity to the writing sessions was examined using both subjective and physiological measures. Measures of psychological and physical health were completed before and 1 month after the sessions. Participants assigned to the disclosure condition reported fewer psychological and physical symptoms at follow-up compared with control participants, though reductions were clinically significant for only 1 outcome measure. Physiological activation to the 1st disclosure session was associated with reduced psychological symptoms at follow-up for disclosure participants. Subjective reports of emotional responding corresponded with physiological reactivity. Implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
In contrast to D. C. Zuroff, M. Mongrain, and D. A. Santor (2004), the current authors find the promissory note of dependency-sociotropy (DEP-SOC) and self-criticism-autonomy (SC-AUT) as a model of risk for depression to be in default. The authors propose reorganizing what has been cast as unitary effort into 3 distinct endeavors: a psychoanalytic clinical theory, development of a refined empirical model of risk for clinical depression, and research examining the effects of DEP-SOC and SC-AUT on interpersonal relationships in nonclinical samples. The authors identify some issues that need to be accommodated regardless of whether the assessment of Zuroff et al. (2004) or their own is accepted. DEP-SOC and SC-AUT are best construed as correlated, continuous dimensions. Future work also needs to accommodate depression as chronic recurrent condition, advances in developmental psychopathology, and more stringent criteria for positing a risk factor for clinical disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
100.
M. Peacock 《Journal of Computer Assisted Learning》1988,4(3):162-172
Abstract Selections of English Language and Literature CSE (now GCSE) course work essays are graded by a total of 411 teachers in two forms: handwritten and wordprocessed. Mistakes in the original handwritten versions are not edited out. It is found that the wordprocessed English Language essays are, on average, marked up a grade. However, it is found that relatively high quality English Literature work is not affected. Results suggest:
— that the less directly pupil work is specifically related to an external referent (such as a work of literature), the more likely it is that computer-assisted methods of presentation will significantly enhance its apparent quality relative to handwritten work.
— that relatively lower quality work will tend to be enhanced more than relatively higher quality work.
The implications of the results for examination boards are also considered. 相似文献
— that the less directly pupil work is specifically related to an external referent (such as a work of literature), the more likely it is that computer-assisted methods of presentation will significantly enhance its apparent quality relative to handwritten work.
— that relatively lower quality work will tend to be enhanced more than relatively higher quality work.
The implications of the results for examination boards are also considered. 相似文献