Scanning transmission optical sectioning

We shall use Eqs. (73) and (75) to study image formation in two types of optical instruments, the transmission electron microscope (TEM) and its scanning transmission counterpart, the STEM. This is the subject of the next section. 

At low temperatures, partial co-crystallisation was indicated by transmission electron microscopy and differential scanning calorimetry [156, 157]. Both electron microscopy of stained sections and optical microscopy showed that the segregated low molar mass material was present as small domains between the stacks of dominant lamellae within the spherulites/ax-ialites [115, 157, 158],... 

Measurements. The morphology of the blends was studied by optical microscopy (Leitz Dialux Pol), transmission electron microscopy (Jeol 100 U), and scanning electron microscopy (Cambridge MK II). Ultramicrotome sections were made with an LKB Ultratome III. Samples for scanning electron microscopy were obtained by fracturing sheets at low temperature. The fracture surfaces were etched with a 30% potassium hydroxide solution to hydrolyse the polycarbonate phase. Stress-relaxation and tensile stress-strain experiments were performed with an Instron testing machine equipped with a thermostatic chamber. Relaxation measurements were carried out in flexion (E > 108 dyn/cm2) or in traction (E < 108 dyn/cm2). Prior to each experiment, the samples were annealed to obtain volumetric equilibrium. 

Fibers of the control and selected chemically modified cottons were examined techniques of optical microscopy described previously.Ultra thin cross sections of the fibers were subjected to layer expansion by polymerization of methyl methacrylate and to solubility tests in 0.5 M cupriethylenediamine (cuene) and were examined by the techniques of transmission electron microscopy as previously reported.Scanning electron micrographs of fibers of selected samples before and after subjection to various solvents were also obtained. 

A series of new ( )-4,4 -bis(diphenylammo)stilbene derivatives have been synthesized to investigate nonlinear absorptivities with attention paid to the peripheral substituent effect and multibranched modification effect by the open aperture femtosecond Z-scan technique and the nanosecond nonlinear optical transmission (NET), respectively [36]. Two-photon fluorescence for ( )-4,4 -bis(di-phenylamino)stilbene in THE was detected. It was found that substituent group attached to the periphery of BDPAS has no obvious contribution to TPA enhancement and that the dramatic increase in effective TPA cross sections of multibranched samples in nanosecond regime strongly suggested their larger excited-state absorption. 

Since ceramic films and coatings are most often used fot ptotective overcoats ot optical applications, it is usually impottant to be able to deposit films with a minimum of porosity and voids. If the voids and potes ate latge, they can easily be seen with scanning electron microscopy (SEM). Transmission electron microscopy (TEM) is commonly used to evaluate voids and potes on a smallet scale. This is illustrated in Figure 3.1, which shows TEM plan and cross-sectional views for a... 

Optical, scanning and transmission electron micrographs of a commercial cellulose acetate asymmetric membrane are shown in Fig. 5.26. Each view provides a different perspective on the membrane structure while, together, they give the complete structural model. Specimen preparation for OM and TEM cross sections was by microtomy of embedded membrane strips using a method developed to limit structural collapse (Section 4.3.4). An optical micrograph (Fig. 5.26A)... 

Figure 6.5 Spectral features as a function of the apodisation function in mid-IR microspectroscopy of tissues (colon tissue cryo-section, same sample position as in Figure 6.4). Transmission type spectra were acquired using Bruker s IRScope II microscope and an IFS28/B spectrometer. Further measurement parameters aperture diameter 900 pm, Cassegrain objective (36 x, NA 0.5), 128 scans, optical substrate CaF2 pm of 1 mm thickness. Spectral resolution 6 cm zero-filling factor (ZFF) 4. Transmission spectra were processed with a first derivative Savitzky-Golay filter with nine smoothing points.

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