buyer s cost model and his decision problem
Micromechanical properties and domain structures of PZN PT piezoelectric single crystals
... directions and their stress intensity contours from ANSYS® simulation xii Fig 3.1 Schematic diagram showing various crystallographic orientations of the PZN-PT single crystals samples used in this study ... the scope of this thesis 13 Chapter 1.5 Thesis Outline This Ph.D thesis consists of two parts Chapters to form the first part of this thesis, concerning the micromechanical characterization and ... observe domain structures and domain switching mechanisms of the crystals using Scanning Electron Acoustic Microscopy (SEAM) and Piezoresponse Force Microscopy (PFM) techniques, and • to investigate...
Ngày tải lên: 10/09/2015, 15:48
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 1
... phase in this case is metastable stabilized by the residual stress in the crystal, which partly transforms to the stable rhombohedral phase when the residual stress in the surface layer is relieved ... process may induce new phases [65] In addition, the domain structures of these single crystals and ground powders have been found to be sensitive to their prior processing history - this means that ... response to the applied stress σjk with denoting the stress tensor elements and dijk is the piezoelectric coefficients For the converse effect, εjk denotes as the strain tensor and Ei denotes...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 2
... domains located near the surface of the sample This effect was explained by the compressive residual stress parallel to the sample surface generated by grinding In BaTiO3 this residual stress was ... surface of observation and is placed in intense compression in the plane of the surface such that the lattice dimension across the specimen thickness is further elongated due to the Poisson s ... (002)R peak and the effects of surface layer on x-ray diffraction study of PZN-PT single crystals are presented and discussed in this chapter 5.2 5.2.1 Polished surface vs fractured surface at...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 3
... highly distorted R phase owing to the soft elastic constants of R The distorted R phases are microscopic in size, of a wide range of lattice parameters and are stressed in intense compression in ... also investigated Figure 5.12 shows the XRD profiles when a dc E-field of increasing strength was applied to the as-polished sample This figure shows that the lower 2θ peak is no longer present after ... the persistence of the lower 2θ peak after poling to 1.5 kV/mm at room condition Sample thickness is 1mm 76 (b) High-resolution synchrotron RSMs revealed that this surface layer consisted of...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 4
... directions are randomly distributed As the size of domains is very small, they are not visible in the optical microscope In this case, since the surface layer is composed of randomly oriented submicroscopic ... direction of polishing, suggesting that the surface phase is always present regardless of the direction and/ or mode of polishing This behavior can be explained in the following way If the polishing 66 ... patterns of (001)-cut PZN-4.5%PT crystal plate as a result of none crystallographic polishing direction 68 direction changes in a non-coordinated manner, the directions of induced surface stresses and...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 5
... Figure 6.3 shows the diagram of transformations of various phases between a crystal group and its subgroups Solid and dashed lines indicate the transformations of first and second order, respectively ... effect is enhanced as the twin thickness decreases Note also that the streaking effect is not as obvious for microdomains, as illustrated in Figures 6.2(d)-(e) When T micro- and nanotwin domains coexist, ... thickness decreases 6.2.3 Crystal group theory of phase transformation Landau theory of phase transformation has been the most widely used method in analyzing structural relations in crystals Figure...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 6
... represented by circles of half-intensity contours Since the R phase of PZN-PT is elastically soft, individual variant diffractions broaden as a result of residual stresses arising from the crystal ... two possible assignments for the new diffractions The first is that it may be a new M phase, which is likely a MC phase in this case The MC phase has pc–type mirror planes and the various diffractions, ... result of residual stresses arising from the crystal growth process and accompanied phase transformations during cooling of the crystal to room conditions The resultant RSM pattern is given in (b)-(d)...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 7
... volume and shape changes and associated transformation stresses The % of volume increase accompanying the T-R phase transformation for PZN-PT single crystals has been estimated from the crystal ... the lateral constraint from the neighbouring R phases remains In other words, most of the residual stresses remain and so does the metastable T phase Figure 8.7(b) shows the case of slant {110}R//{110}T ... twinning serves to relax the residual stresses in the perovskite structure Note that micro- and/ or nanotwin domains exist in both the R and T phases although only those in the T phase (distinguished...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 8
... PZN-(68)%PT single crystals at room condition Our HR-XRD RSM results indicate that the T phase is likely to be a metastable phase stabilized by the transformation-cum-cooling stress in the crystal This ... above-experiment was repeated with several other unpoled PZN-8%PT single crystal samples Similar results were obtained It is also interesting to note that a string of current signals was detected over ... twin diffractions in as-grown PZN-6%PT single crystal may be due to the higher residual stress and/ or the presence of a much higher portion of T nanotwin domains in this crystal sample, or a combination...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 9
... the crystal into powders of sufficiently smaller particle sizes, the residual stress is removed and the Tσ phase may no longer be present This may explain why the extended MPB region is missing ... crystal directions This, with the slight tilting of the R diffraction out of the ω = 0° plane indicates that both crystals existed in a strained state as the result of poling induced stresses This ... thermodynamically stable phases of comparable Gibb s free energies More interestingly, the present work has shown that due to the presence of residual stresses in the crystal, the MPB, in effect, has been...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 10
... unpoled samples of broad R phase The strained state of the poled crystals is the result of poling induced stresses in the crystals 177 (f) In the event of PP-ZFH in PZN-(4.5-7)%PT, the TR-T occurs ... current density data of [001]-poled crystals Determined by means of HR- XRD results 176 9.5 Summary of main observations (a) A revised phase diagram for the PZN-PT system has been constructed Two ... PZN-4.5%PT showed clear signs of hysteresis on cooling to room temperature Above this temperature, the area of the dielectric hysteresis increases with increasing heating temperature The heating and...
Ngày tải lên: 14/09/2015, 08:40
High resolution x ray diffraction study of phase and domain structures and thermally induced phase transformations in PZN (4 5 9)%PT 11
... PMN-PT single crystals, especially near their MPBs (j) This present work does not support the existence of M phases in PZN-PT single crystals considering the transformations from M to C, R to MC, and ... the transformation stresses in the crystal 180 (g) A revised phase diagram for the PZN-PT system has been constructed Two new evident features of this revised phase diagram are: (a) the expanded ... cooling-cum-transformation stresses in the crystal This is manifested by the disappearing of the (100)T diffractions on the fracture surface, a result attributed to the stress relaxation effect in the surface...
Ngày tải lên: 14/09/2015, 08:40
A comparative study of discourse structures and some major linguistic features of international declarations and international conventions on human rights part 2
... the study 1.5 Organization of the study Chapter II: literature review 2.1 Discourse and discourse structure 2.1.1 Discourse 2.1.2 Discourse Analysis 2.1.3 Discourse structure 2.1.3.1 What is discourse ... discourse structure? 2.1.3.2 Two views of discourse structure: as product and as process5 2.1.4 Thematization 2.2 Some major linguistic features 2.2.1 Modality 2.2.2 Active and Passive voices 2.2.3 ... similarities and differences between international Declarations and Conventions in terms of discourse structures and major linguistic features 5.1 32 a, Type of discourse 32 b, Register (or Functional style)...
Ngày tải lên: 07/11/2012, 14:17
A comparative study of discourse structures and some major linguistic features of international declarations and international conventions on human rights part 3
... commands, orders, requests, suggestions expressed by verbs as order, command, request, allow, - Commissives are those kinds of speech acts that speakers use to commit themselves to some future action ... - Expressive are those kinds of speech acts that state what the speaker feels They express psychological states and can be statement of pleasure, pain, likes, dislikes, joy or sorrow Some typical ... conclusions on typical similarities and differences between Declarations and Conventions on Human Rights in terms of discourse structure and some linguistic features, and necessary comments should...
Ngày tải lên: 07/11/2012, 14:17
A comparative study of discourse structures and some major linguistic features of international declarations and international conventions on human rights part 4
... him or her, and, to this end, shall take all appropriate legislative and administrative measures States Parties shall ensure that the institutions, services and facilities responsible for the ... of illness and rehabilitation of health States Parties shall strive to ensure that no child is deprived of his or her right of access to such health care services States Parties shall pursue full ... conditions and within their means, shall take appropriate measures to assist parents and others responsible for the child to implement this right and shall in case of need provide material assistance and...
Ngày tải lên: 07/11/2012, 14:17
Time-Domain Analysis and z Transform
... also be expressed as the sum of its transient response and steady-state response But there is again a misconception that the natural response of a system is the same as the transient response, ... given in (2.8) is devoid of any signal concepts, soon concepts such as frequency response and time-domain response are used in the analysis of discrete-time systems and signal processing Our derivation ... following sections we will use both of these definitions to model discrete-time systems Then, in the remainder of this chapter, we will discuss several ways of analyzing the discrete-time systems in...
Ngày tải lên: 29/09/2013, 21:20
reported speech English 9 ( structures and ẻcises )
... name s Mary and she is years old.She has dark short hair.She is ( ) ………………………………………shorts – the blue shorts and a long sleeved blouse.She is wearing a ( ) …………………………………of shoes – the brown shoes She ... grades D Competition may discourage students from pursuing subjects such as drama and art Magdalena Smith think that there should be A more emphasis on grades B less emphasis on grades C less emphasis ... less emphasis on music, dramatics and sports D less emphasis on an arbitrary standard of success Part 3: Read the passage below and choose the correct answer among A, B, C or D ( 10 points) TRAFFIC...
Ngày tải lên: 10/10/2013, 18:11