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291.
Xiao Wang 《Psychology & health》2013,28(7):800-817
Objective : Because interpersonal discussion about condom use can encourage subsequent condom use, this project aims to examine the psychological antecedents of intentions to discuss or request the use of condoms with a sexual partner. Method : The data were collected from 849 heterosexual college students in the USA through an online survey. The survey contained several measures related to attitude functions (i.e. motivations), efficacy, norms and intentions to discuss condom use with a sexual partner. Results : Participants’ attitude functions weakly predicted intentions to discuss condom use. Communication efficacy was a more important predictor of intentions for females (vs. males) and for those in other relationships or not in a relationship (vs. long-term monogamous relationships). Anticipated negative emotions were a stronger predictor of intentions for those in long-term monogamous relationships (vs. other relationships or not in a relationship). Implications : Future research needs to consider more detailed attitude functions and anticipated emotions. Furthermore, background variables (e.g. gender and relationship status) can be moderators in addition to being distal predictors. 相似文献
292.
Jian-Ying Zhan Kim Cornish Jie Shao Chun-Hong Xie Yan-Xia Wang 《Child neuropsychology》2013,19(1):82-95
Attention is a complex domain that has reawakened research interest in recent years. There are relatively few studies that have examined age-related changes across different attention subcomponents, such as selection, maintenance, and control, using large samples covering a wide age range. The present study assessed performance in 466 participants in order to identify the ages at which mature performance was reached across differing attention subcomponents. Furthermore, we investigated whether the nature of the attentional demands or task difficulty predicted the age at which stable levels of performance were reached. The results supported the former rather than the latter alternative. 相似文献
293.
Y. Wang S.L. Shang H. Zhang L.-Q. Chen Z.-K. Liu 《Philosophical Magazine Letters》2013,93(12):851-859
To understand the Invar anomalies, such as negative thermal expansion and spontaneous magnetization, we have applied our recently developed thermodynamic framework for a system with itinerant-electron magnetism to the ordered Fe3Pt. The framework has coherently predicted the finite temperature intermixing between the fully ferromagnetic (FM) configuration and the spin-flipping configurations (SFCs). We have also discovered a tri-critical point at which a high-temperature second-order phase transition, between the fully ordered FM phase and the paramagnetic phase which is disordered due to SFCs, becomes first order at low temperatures. 相似文献
294.
The electrostatic potential and associated space charge across a 24°, [001] tilt boundary of SrTiO3 ceramic have been determined using electron holography. The results reveal a positive charged interface with a negative space charge on either side. The form of the double Schottky barrier and the local charge-density distribution at the interface are derived from the results. 相似文献
295.
Experimental results relating to the plateau behaviour in the cyclic stress-strain (CSS) curve of copper single crystals located on different sides of the stereographic triangle are summarized. Unlike the situation for single-sliporiented crystals, the crystallographic orientation has a strong effect on the plateau behaviour in the CSS curves of double- and multiple-slip-oriented crystals. The existence or non-existence of a plateau in the CSS curves, as well as the corresponding plateau stress amplitude, depend not only on the modes and intensities of dislocation interactions among slip systems operating in the crystals but also on the slip deformation characteristics associated with crystal orientations. The plateau region in CSS curve disappears only when multiple slip plays a determining role during cyclic deformation. 相似文献
296.
Tae Wook Heo Yi Wang Saswata Bhattacharya Xin Sun Shenyang Hu Long-Qing Chen 《Philosophical Magazine Letters》2013,93(2):110-121
We propose a phase-field model for modeling microstructure evolution during deformation twinning. The order parameters are proportional to the shear strains defined in terms of twin plane orientations and twinning directions. Using a face-centered cubic Al as an example, the deformation energy as a function of shear strain is obtained using first-principle calculations. The gradient energy coefficients are fitted to the twin boundary energies along the twinning planes and to the dislocation core energies along the directions that are perpendicular to the twinning planes. The elastic strain energy of a twinned structure is included using the Khachaturyan's elastic theory. We simulated the twinning process and microstructure evolution under a number of fixed deformations and predicted the twinning plane orientations and microstructures. 相似文献
297.
In this letter, the dislocation patterns on the common primary slip plane in a fatigued \[1-34]-\[182-7] copper bicrystal with a Sigma=19b grain boundary (GB) have been investigated using the electron channelling contrast technique in a scanning electron microscope. The results show that the two-phase dislocation structure, such as veins and persistent slip band (PSB) walls, embedded within veins, can be clearly seen on the common primary slip plane. In particular, the interactions of PSBs with the GB are clearly revealed. It is found that there are three kinds of interaction mode between the GB and the dislocations during cyclic deformation, and those are discussed. It is suggested that the dislocations carried by PSBs cannot transfer through the GB continuously even though the bicrystal has a common primary slip plane and its surface slip bands are continuous across the GB. 相似文献
298.
The microstructure and crystallization behaviour of melt-spun Al88Ni9Ce2Fe1 amorphous alloy and nanophase composites have been studied by means of X-ray diffraction, transmission electron microscopy and scanning and isothermal calorimetry. The diffraction patterns from Al88Ni9Ce2Fe1 amorphous alloys are diffuse, indicating a basically amorphous structure but contain two rings presumed to be associated with quenched-in nuclei. In the cases of Al88Ni9Ce2Fe1 nanophase composites, nanoscale precipitated particles are homogeneously dispersed in an amorphous matrix, and the crystallite diameter and volume fraction are sensitive to quenching conditions. During thermal crystallization, a two-step phase transformation occurs in the amorphous alloy and nanocomposites, which is characterized by a diffusion-controlled precipitation of nanoscale Al particles and the growth of a Al3(Ni, Fe) nanophase prior to a Al11Ce3 nanophase. This study gives insight into structure-control for obtaining nanophases dispersed in an amorphous matrix by rapid quenching. 相似文献
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