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Raman spectroscopic imaging is a label-free spectral technology to investigate the distribution of transdermal targets in skin. However, it is difficult to analyze low content of analytes in skin by direct imaging analysis. Combining Raman mapping technology with multiple linear regression algorithms, concentration contribution factor of targets in ex vivo human skin tissue at every point has been calculated. The distribution profiles are visualized as heat maps demonstrating the targets levels in different skin layers. This method has been successfully employed to investigate the vibrational imaging of distribution of hyaluronic acid and lidocaine in skin. Moreover, three dimensional (3D) images of the penetration profiles of hyaluronic acid with different molecular weight have been obtained. The results from 3D images were in good agreement with these from two-dimensional images, indicating that this method was a reliable way for monitoring the distribution of targets in skin.

Singlet oxygen (1 O2 ) is widely regarded as the main cytotoxic substance that induces the biological damage for photodynamic therapy (PDT). In this study, the previously developed near-infrared (NIR) optical imaging system was optimized for fast imaging of 1 O2 luminescence. The optical imaging system enables direct imaging of 1 O2 luminescence in blood vessels within 2 s during vascular-targeted PDT (V-PDT), which makes this system extremely practical for in vivo studies. The dependence of RB concentration on 1 O2 luminescence image was investigated for V-PDT, and the data imply that 1270 nm signal is attributed to 1 O2 luminescence. The imaging system operates with a field of view of 9.60 × 7.68 mm2 and a spatial resolution of 30 μm, which holds the potential to elucidate the correlation between cumulative 1 O2 luminescence and vasoconstriction for V-PDT.

Integrated differential phase-contrast scanning transmission electron microscopy (iDPC-STEM) is capable of directly probing guest molecules in zeolites, owing to its sufficient and interpretable image contrast for both heavy and light elements under low-dose conditions. This unique ability is demonstrated by imaging volatile organic compounds adsorbed in zeolite Silicalite-1; iDPC-STEM was then used to investigate molybdenum supported on various zeolites including Silicalite-1, ZSM-5, and mordenite. Isolated single-Mo clusters were observed in the micropores of ZSM-5, demonstrating the crucial role of framework Al in driving Mo atomically dispersed into the micropores. Importantly, the specific one-to-one Mo-Al interaction makes it possible to locate Al atoms, that is, catalytic active sites, in the ZSM-5 framework from the images, according to the positions of Mo atoms in the micropores.

With the emergence of nanotechnology and nanoscience in the past two decades a thorough characterization at the nanoscale became more and more important. The characterization of nanoparticles is the main issue for the understanding of their properties. Besides averaging methods like scattering techniques the direct imaging of nanoparticles by microscopy methods is the major characterization method. Especially electron microscopy proved to be a valuable tool to obtain morphological and analytical information. The aim of this article is to point out the prospects as well as the pitfalls of this technique with special emphasis on the electron microscopical imaging of polymeric nanoparticles. We will present two alternative methods to cryo-TEM preparation: embedding the sample into an ultrathin film of trehalose as already used for the preparation for biological samples and the preparation of an ultrathin, free standing ionic liquid film as embedding matrix for nanoparticular structures.

Newly synthesized proteins constitute an important subset of the proteome involved in every cellular process, yet existing chemical tools used to study them have major shortcomings. Herein we report a suite of cell-permeable puromycin analogues capable of being metabolically incorporated into newly synthesized proteins in different mammalian cells, including neuronal cells. Subsequent labeling with suitable bioorthogonal reporters, in both fixed and live cells, enabled direct imaging and enrichment of these proteins. By taking advantage of the mutually orthogonal reactivity of these analogues, we showed multiplexed labeling of different protein populations, as well as quantitative measurements of protein dynamics by fluorescence correlation spectroscopy, could be achieved in live-cell environments.

A total of 28 young nearby stars (ages ≤60 Myr) have been observed in the Ks-band with the adaptive optics imager Naos-Conica of the Very Large Telescope at the Paranal Observatory in Chile. Among the targets are ten visual binaries and one triple system at distances between 10 and 130 pc, all previously known. During a first observing epoch a total of 20 faint stellar or sub-stellar companion-candidates were detected around seven of the targets. These fields, as well as most of the stellar binaries, were re-observed with the same instrument during a second epoch, about one year later. We present the astrometric observations of all binaries. Their analysis revealed that all stellar binaries are co-moving. In two cases (HD 119022 AB and FG Aqr B/C) indications for significant orbital motions were found. However, all sub-stellar companion candidates turned out to be non-moving background objects except PZ Tel which is part of this project but whose results were published elsewhere. Detection limits were determined for all targets, and limiting masses were derived adopting three different age values; they turn out to be less than 10 Jupiter masses in most cases, well below the brown dwarf mass range. The fraction of stellar multiplicity and of the sub-stellar companion occurrence in the star forming regions in Chamaeleon are compared to the statistics of our search, and possible reasons for the observed differences are discussed. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Spin-coated polymer blends possess a rich variety of accessible non-equilibrium morphologies, formed through a process of phase separation and self-assembly, the complexities of which remain incompletely understood. The technique of stroboscopic microscopy has now been developed to allow direct observations of microscopic and mesoscopic morphological development during spin-coating and has afforded unequivocal information regarding morphological development. The technique so far has three modes of operation providing information on topographical, compositional, and crystal development. In this review, we look at the technique's development, its applications and comment on the future potential for this technique. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 17–25

We have studied the orientational order in films of vertically aligned single walled carbon nanotubes, by means of resonant Raman spectroscopy, resonant X-ray absorption, and direct imaging. These methods investigate the hierarchical morphology at different length scales. Here, we discuss the systematic comparison of orientational order as function of wavelength in films with different inherent morphologies and provide thus a basis to quantitatively evaluate and compare the different experimental approaches.

Background Migrating motor complex phase III (MMC phase III) of intestine is an important physiological mechanism traditionally recognized by myoelectric recordings or pressure tracings. Direct imaging is difficult and sonographic visualization in human has not been reported. Methods We have demonstrated this unique phenomenon in three patients who underwent abdominal sonographic examinations. Characteristic images were recorded by videotape and both spatial and temporal features were analyzed. Key Results Occurrences of multiple equally spaced, rhythmic intestinal contractions were observed. Parameters including wave frequency, propagation velocity, and duration of the events agreed with those of the well-known phase III. The presence of distinct cyclic patterns observed in two and abolition by meal in the other patient further support our conclusion. Conclusions & Inferences We conclude that the migrating waves observed in our study represent the human MMC phase III. This unique finding in human subjects merits further investigation.

MRI of hyperpolarized (129)Xe dissolved in pulmonary tissues, and blood has the potential to offer a new tool for regional evaluation of pulmonary gas exchange and perfusion; however, the extremely short T2* and low magnetization density make it difficult to acquire the image. In this study, an ultrashort echo-time sequence was introduced, and its feasibility to quantitatively assess emphysema-like pulmonary tissue destruction by a combination of dissolved- and gas-phase (129)Xe lung MRI was investigated. The ultrashort echo-time has made it possible to acquire dissolved (129)Xe images with reasonably high spatial resolution of 0.625 × 0.625 mm(2) and to obtain T2* of 0.67 ± 0.30 ms in a spontaneously breathing mouse at 9.4 T. The regional dynamic alveolar gas uptake as well as subsequent transport by pulmonary blood flow was also visualized. The ratio of (129)Xe magnetization that diffused into the septa relative to the gas-phase magnetization F was regionally evaluated. The mean F value of elastase-treated mice was 2.28 ± 0.46%, which was significantly reduced from that of control mice 3.41 ± 0.48% (P = 0.0052). This reflects the reduced uptake efficiency due to alveolar tissue destruction and is correlated with the histologically derived alveolar surface-to-volume ratio.

Low back pain (LBP) syndromes represent a heterogeneous category of pathology, such as the failed back surgery syndrome (FBSS). LBP treatment includes conservative and interventional procedures, with high costs and low efficacy in most cases. Epiduroscopy has been revalued only recently for the treatment of LBP. The procedure was first performed using a percutaneous approach, which is still used with efficacy for LBP and/or radiculopathy. The classic epiduroscopy procedure, however, has a great limitation, because it uses only liquids to visualize the dura space, and it can not overcome fibrotic obstructions of the channel. Because of these limitations, we introduced a new epiduroscopy technique, which allows a direct visualization of the dura during the lysis, and reduces the risks related to the procedure. We performed a literature review of the percutaneous approach and compared it to our experience with Resaflex and Resascope for epidurolysis, in order to assess the therapeutic benefits of the two methods, and their role in the study of dura morphological components in FBSS. Percutaneous adhesiolysis and our endoscopic method showed similar efficacy level, however, the Resascope resulted in less complications and a better lysis. Since our endoscopic method proved to be safe and repeatable for the treatment of FBSS and the study of normal and pathological morphologies of the dura with direct imaging, we suggest using it as first choice in patients suffering from FBSS.

Convenient route to cyclic polymers: Ultrahigh molecular weight cyclic brush polymers were synthesized through ring-expansion metathesis polymerization of various macromonomers. Atomic force microscopy was used to visualize toroidal shapes and large opening pores, along with linear chains, which may result from high sensitivity of brush polymers to mechanical degradation.

Accurate echocardiographic evaluation of the pulmonary valve is technically difficult because of its close proximity to the left lung, which often limits decision making. Pulmonary valvotomy is the intervention of choice for symptomatic pulmonary valve stenosis, but fluoroscopy lacks appropriate real time anatomic detail. In this report, we present a case where direct imaging of the pulmonary valve with live/real time three-dimensional transesophageal echocardiography (3DTEE) aided in accurate evaluation and was then used to help guide and monitor successful valvuloplasty of a stenotic pulmonary valve bioprosthesis. We demonstrate that even in cases where two-dimensional (2D) evaluation of the pulmonary valve is difficult, the use of live/real time 3DTEE allows for accurate evaluation of bioprosthetic pulmonary valve structure and function, and enhances the precision and monitoring of percutaneous valvuloplasty.

Carotid plaque calcification normally appears as a signal void with clinical MR sequences. Here, we describe the use of an adiabatic inversion recovery prepared two-dimensional ultrashort echo time sequence to image and characterize carotid plaque calcification using a clinical 3-T scanner. T1, T, and free water content were measured for seven carotid samples, and the results were compared with micro-CT imaging. Conventional gradient echo and fast spin echo images were also acquired for comparison. Correlations between T1, T, free water concentration, and mineral density were performed. There was a close correspondence between inversion recovery prepared two-dimensional ultrashort echo time morphologic and micro-CT appearances. Carotid plaque calcification varied significantly from sample to sample, with T1s ranging from 94 ± 19 to 328 ± 21 msec, Ts ranging from 0.31 ± 0.12 to 2.15 ± 0.25 msec, and free water concentration ranging from 5.7 ± 2.3% to 16.8 ± 3.4%. There was a significant positive correlation between T1 (R = 0.709; P < 0.074), T (R = 0.816; P < 0.025), and free water concentration, a negative correlation between T1 (R = 0.773; P < 0.042), T (R = 0.948; P < 0.001) and CT measured mineral density, and a negative correlation between free water concentration (R = 0.936; P < 0.002) and mineral density. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc.

The tailoring of organic systems is crucial to further extend the efficiency of charge transfer mechanisms and represents a cornerstone for molecular device technologies. However, this demands control of electrical properties and understanding of the physics behind organic interfaces. Here, a quantitative spatial overview of work function characteristics for phthalocyanine architectures on Au substrates is provided via kelvin probe microscopy. While macroscopic investigations are very informative, the current approach offers a nanoscale spatial rendering of electrical characteristics which is not possible to attain via conventional techniques. Interface dipole is observed due to the formation of charge accumulation layers in thin F16 CuPc, F16 CoPc, and MnPc films, displaying work functions of 5.7, 6.1, and 5.0 eV, respectively. The imaging and quantification of interface locations with significant surface potential and work function response (

The application and quantification of well-controlled tissue strains is required for investigations into mechanisms of tissue adaptation within the musculoskeletal system. Although many commercial and custom extensometry systems exist for large biological samples, integrated loading/strain measurement for small samples is not as readily available. Advanced imaging modules such as laser scanning microscopy provide in situ, minimally invasive tools to probe cellular and molecular processes with high spatiotemporal resolution. Currently, a need exists to devise loading/strain measurement systems that can be integrated with such advanced imaging modules. We describe the development and validation of a fluorescence-based, optical extensometry system directly integrated within a confocal microscopy platform. This system allows in situ measurement of surface strain and is compatible with the direct imaging of cellular processes within small bone samples. This optical extensometry system can accurately and reproducibly measure physiologically relevant surface strains (200 to 3000 microstrain) in beams machined from various well-characterized materials, including bovine femoral cortex, and in intact murine tibia. This simple system provides a powerful tool to further our investigation of the relationships between mechanical loading, fluid and solute transport, and mechanosensation within the musculoskeletal system.

Direct imaging of a histological slice is challenging. The vast difference in dimension between planar size and the thickness of histology slices would require an RF coil to produce a uniform RF magnetic (B1) field in a 2D plane with minimal thickness. In this work a novel RF coil designed specifically for imaging a histology slice was developed and tested. The experimental data demonstrate that the coil is highly sensitive and capable of producing a uniform B1 field distribution in a planar region of histological slides, allowing for the acquisition of high-resolution T2 images and T2 maps from a 60-microm-thick histological sample. The image intensity and T2 distributions were directly compared with histological staining of the relative iron concentration of the same slice. This work demonstrates the feasibility of using a microimaging histological coil to image thin slices of pathologically diseased tissue to obtain a precise one-to-one comparison between stained tissue and MR images.

A solid-liquid-vapor interface dominated by a three-phase contact line usually serves as an active area for interfacial reactions and provides a vital clue to surface behavior. Recently, direct imaging of the triphase interface of superwetting interfaces on the microscale/nanoscale has attracted broad scientific attention for both theoretical research and practical applications, and has gradually become an efficient and intuitive approach to explore the wetting behaviors of various multiphase interfaces. Here, recent progress on characterizing the solid-liquid-vapor triphase interface on the microscale/nanoscale with diverse types of imaging apparatus is summarized. Moreover, the accurate, visible, and quantitative information that can be obtained shows the real interfacial morphology of the wetting behaviors of multiphase interfaces. On the basis of fundamental research, technical innovations in imaging and complicated multiphase interfaces of the superwetting surface are also briefly presented.

Direct electron and X-ray detectors have extraordinary imaging and analytical spectroscopy properties, which makes them most attractive for established experimental settings and the development of new experimental techniques in electron and X-ray science. This article describes the advantages of a pnCCD direct detector and compares it in brief to a conventional electron imaging camera.

Arguably, the biggest current mystery in water relations research is how embolized xylem vessels refill despite negative pressures in the surrounding transpiration stream (Nardini, Lo Gullo & Salleo 2011). In this issue, Wheeler et al. (2013) set out to investigate the phenomenon in two known refillers, Acer rubrum and Fraxinus americana (Zwieniecki & Holbrook 1998; Zwieniecki et al. 2000). Instead, they made the sobering discovery that the ‘refilling’ in these species was an experimental artefact. And the artefact was seen in other species too. They report what amounts to a series of control experiments that should have been done decades ago. The results demand attention from anyone interested in xylem function and plant water relations. Xylem studies are complicated by the remarkable fact that the liquid sap is transported under negative pressure. Negative gas pressures are impossible, but negative liquid pressures can exist as long as intermolecular forces hold. The strong bonding between water molecules combined with exclusion of large gas bubbles or other destabilizing surfaces allows liquid sap to be pulled up to the leaves by pressures far below vapour pressure. By analogy with a solid that can be placed under tension, negative sap pressures can also be referred to as (positive) tensions. The xylem water column is consequently metastable, and any gas bubble over a critical size nucleates ‘cavitation’: the phase change to vapour. The resulting vapour void can grow to occupy the entire conduit, and this gas ‘embolism’ blocks transport. The phenomena of cavitation and its reversal have grown over the years from a minor footnote to a significant chapter in plant physiology. The metastability of xylem sap creates experimental difficulties. Any observation of xylem conduit functioning, whether by direct imaging or measurement of a bulk property like hydraulic conductivity, is only accurate if the observation itself does not nucleate cavitation and embolism. The need to validate observations with the appropriate control experiment is probably the single most limiting factor to progress in the field. It can be hard to know when a control is even necessary. There have been many interesting setbacks over the years when observations have subsequently been shown by belated controls to be experimental artefacts (Tyree 1997; Cochard et al. 2000). The artefact exposed by Wheeler et al. has to do with how plant organs are excised prior to standard measurements of xylem hydraulic conductivity (see Fig. 1).As any florist knows, the excision must be made under water. If a stem is cut in air, negative pressure pulls the sap away from the surface and aspirates air into the open conduits, reducing future water uptake. But what Wheeler et al. show very convincingly, is that in 3 out of 4 species, significant blockage can be created even if the cut is made under water (see Fig. 1a,b schematics). Only if the negative pressures are relaxed before making the final underwater cut is the additional embolism avoided (Fig. 1c,d). The potential for the ‘excision artefact’ was shown to increase with more negative sap pressures, but to decrease with the amount of embolism present before cutting. The mechanism of the excision artefact is unknown. The likely explanation is that gas gets drawn into the conduits during the cut by the sap negative pressure, blocking the openings to the conduits (Fig. 1a,b). The gas could either be aspirated from existing pockets in the tissue exposed by the cutting edge, or from cavitation nucleated as the blade slices open the conduit. Greater negative pressure would pull more gas and create more blockage.The blockage may be localized close to the exposed surface (e.g. Fig. 1b) because sap pressures should moderate quickly as water and gas are taken up. Interestingly, the only species showing no sign of the artefact was paper birch (Betula papyrifera), which has scalariform perforation plates. The narrow gaps in these perforation plates may be sufficient to trap gas near the cut surface, preventing measurable blockage. Of historical interest is that the excision artefact was predicted long ago by Dixon and Joly (Dixon 1914, quoted at the beginning of the Wheeler et al. Discussion). Precautionary protocols designed to avoid the artefact were detailed in the Materials and Methods of M.H. Zimmermann’s pioneering 1978 article on hydraulic architecture (Zimmermann 1978). Early practitioners of these methods continued these practices (Sperry, Donnelly & Tyree 1988), but the precautions were gradually dropped from the Materials and Methods sections. Why? Because no one . . . neither Dixon, nor Zimmermann, nor anyone else . . . had ever bothered to demonstrate whether the excision artefact actually existed. If you do not know whether it matters, it is human nature to forget over time about taking precautions. Wheeler et al. show that the excision artefact does indeed matter. In some species, like red maple (A. rubrum), it matters a lot: cutting negatively pressurized xylem under water can decrease the hydraulic conductivity by 2–3-fold below what is arguably the correct value. From now on, researchers know that they really do have to take the precaution of relaxing xylem pressure before the final excision of a segment for assaying xylem conduit functioning. The consequences of the excision artefact are significant. As emphasized by Wheeler et al., it casts doubt on numerous Correspondence: J. Sperry. e-mail: j.sperry@utah.edu Plant, Cell and Environment (2013) doi: 10.1111/pce.12148 bs_bs_banner

Water molecules associated with collagen have short transverse (T2) relaxation times. Projection-reconstruction techniques are able to achieve an echo time (TE) much shorter than conventional techniques, allowing imaging of tissues with T2 < 5 ms. Using these techniques, a conventional 1.5-T MRI human imaging system can directly image collagen-associated water from knee menisci and tendons in normal volunteers and patients. Long-T2 suppression improves the contrast between these structures and the surrounding tissue with long-T2 relaxation times. Spectroscopic imaging provides improved lipid/water registration and information about chemical composition and relaxation times. Direct imaging of tendons and menisci may provide more information about these structures and provide a new way to assess both injury and repair.

We investigated imaging of chemiluminescent signals from 1,2-dioxetanes with cooled CCD cameras. Non-radioactive detection methods for biomolecules utilizing these chemiluminescent substrates for alkaline phosphatase have been developed. Applications which have been successfully adapted to this technology include Southern and Northern blotting, immunoblotting, ELISA methods and DNA sequencing. Dephosphorylation of the dioxetane CSPD by alkaline phosphatase generates an unstable anion that decomposes resulting in light production. The wavelength of the emitted light is approximately 460 nm. We have utilized Photometrics Star and MXC 200L cooled CCD cameras for direct imaging of chemiluminescent signals. Benefits of utilizing a CCD detector include rapid data digitization and more accurate quantitation of chemiluminescent signals compared to film-based densitometry owing to the significantly greater dynamic range. Chemiluminescent images from dot blots of biotinylated DNA, Southern blots and DNA sequencing gel blots were obtained. In a chemiluminescent microtitre plate assay, serial dilutions of alkaline phosphatase spanning four orders of magnitude can be detected. Our results indicate that the digitization of chemiluminescent signal data with cooled CCD cameras is an excellent alternative to 32P detection methods utilizing storage phosphor screen imaging systems.

A field-ion microscope (FIM) was used in the investigation of hydrogen oxidation at temperatures between 300 K and 430 K and pressures of p(O2) = 5 · 10−4 mbar, p(H2) = 3 · 10−4 to 7 · 10−4 mbar. The H2O molecules produced act as an imaging gas and display the catalytically active surface area. The structure-sensitive H2O formation was studied under steady-state conditions or in the oscillatory regime or in form of chemical waves. The displacement of Pt lattice atoms is spectacular in the Pt(100) plane, where the transformation from (1 × 1) Pt(100) to hex Pt(100) can be directly imaged.

In this paper we present a novel laser transfer method for imaging color filter arrays directly onto e-paper displays. This method provides perfect means to deal with registration and other process issues associated with imaging color filters directly on plastic and will enable the next-generation of color, plastic-based, e-paper displays. Experimental results are presented.

We have now developed a CF fabrication system, which have some small variable masks and expose by the UV pulse laser. The system can handle maximum 8th generation substrates. The feature is that the masks consist of 2 movable apertures and the sizes of apertures are relatively small (about 120 * 150 mm for one imaging head).

Using a scanning force microscope, direct imaging of the metal/polymer interface was achieved for the first time by removing the evaporated metal film from the deposited polymer and imaging the side that was exposed to the polymer. This technique allows direct sight of the metal/polymer interface and provides information about the possible effects related to metal deposition on polymers. For comparison, two different metals, gold and aluminium, with fairly different physical properties were evaporated on a spin-coated poly-3-octylthiophene polymer. While the gold film exhibits fine granulates forming a semi-homogeneous film, the aluminium film shows large elongated protrusions forming a network structure.

SUMMARY A long chain amphiphilic molecule—the phospholipid 1,2-dihexadecyl sn glycerophosphoethanolamine—has been crystallized epitaxially so that the interlamellar molecular periodicity is parallel to the substrate and hence normal to the electron beam in the electron microscope. This has permitted the direct resolution of the 55·6 A lamellae in unstained crystals at room temperature. The lattice images have shown the presence of line dislocations and lenticular cracks in the crystals. Of significance to their biological properties is that the lattice is undulating with a periodicity of 0·1–0·5 μm. This would also account for the difficulties encountered by X-ray and electron diffraction techniques when examining these crystals.

The structure of γ-brasses is often described as a simple array (e.g. b.c.c., CsCl, or f.c.c.) of complex clusters of atoms. It is the purpose of this study to use high resolution imaging techniques for obtaining information on the γ-brass structures and their defects, and to find out how the cluster description is related to the observations. Two alloys of this type are investigated: Al8Mn5 and Al4Cu9. The former has a rhombohedrally deformed b.c.c. structure whereas the latter has a less deformed but still rhombohedral CsCl-type of structure composed of clusters with slightly different composition. High resolution observations of these alloys reveal that the configuration of clusters may be directly imaged and compared with the structure model. It is also possible to make a distinction between the images of the two types of clusters in Al4Cu9. Defects such as antiphase boundaries and orientation variants in the cluster array can be interpreted in a straightforward manner. The rhombohedral distortion of the Al8Mn5 structure gives rise to a particular domain structure; this can be analysed in terms of the strains induced by the deformation and high resolution images enable a direct analysis of the domain configurations. In the case of Al4Cu9 it may be shown by observations of the antiphase boundary behaviour that in the process of structure formation, the CsCl ordering precedes the rhombohedral distortion. Die Struktur von γ-Messing wird oft als einfache Anordnung (z. B. k.r.z., CsCl oder k.f.z.) von komplexen Clustern von Atomen beschrieben. Es ist der Zweck dieser Untersuchung, hochauflosende Techniken zur Gewinnung von Informationen uber die γ-Messingstrukturen und ihre Defekte zu erhalten und herauszufinden, wie die Clusterbeschreibung mit den Beobachtungen verknupft ist. Zwei Legierungen dieser Art werden untersucht: Al8Mn5 und Al4Cu9. Die erstere besitzt eine rhombisch deformierte k.r.z.-Struktur, wahrend die letztere eine weniger deformierte, jedoch noch rhombische CsCl-Struktur hat, die aus Clustern mit leicht unterschiedlicher Zusammensetzung besteht. Beobachtungen dieser Legierungen bei hoher Auflosung zeigen, das die Anordnung der Cluster direkt abgebildet und mit dem Strukturmodell verglichen werden kann. Es ist ebenfalls moglich, zwischen den Diagrammen der beiden Clusterarten in Al4Cu9 zu unterscheiden. Defekte, wie Antiphasengrenzen und Orientierungsvarianten in den Clusteranordnungen, lassen sich zwanglos interpretieren. Die rhombische Verzerrung der Al8Mn5-Struktur gibt Anlas zu einer speziellen Domanenstruktur, die mit den Spannungen korreliert werden kann, die durch die Deformation induziert werden, und die Hochauflosungsdiagramme ermoglichen eine direkte Analyse der Domanenkonfigurationen. Im Falle des Al4Cu9 kann durch das Verhalten der Antiphasengrenze gezeigt werden, das wahrend des Prozesses der Strukturbildung die CsCl-Anordnung die rhombische Verzerrung annimmt.

The use of vector correlations to elucidate the photodissociation dynamics of CH3I, OCS, and glyoxal is discussed. The correlations occur between the vectors Ě, the electric vector of the photolysis light, μ, the transition dipole moment of the parent, v, the relative recoil velocity of the fragments, and J, the angular momentum of one of the fragments. The Ě – μ – v correlation is illustrated by a direct imaging technique in the photodissociation of CH3I; it shows that dissociation takes place by a parallel transition and is rapid compared to parent rotation. The “triple vector correlation”, Ě – μ – (v – J), is used to show that the dissociation of OCS proceeds on two surfaces, one of A″ and one of A′ symmetry in the Cs point group. The v – J correlation in the dissociation of glyoxal illustrates two points, that dissociation of this molecule takes place in a plane and that vector correlations can exist even for dissociations which are slow compared to parent rotation.

Direct imaging of ordered structures at the atomic level has been proved to be very effective in the case of Ni3V and the 9R polytype of Ni3(Ti, V) and this technique was used to determine the stacking sequence of the 21R polytype of Ni3(Ti, V) to be [(2,1) (2,2)]3. Imaging of projected two-dimensional lattices can be obtained at a somewhat lower resolution in which units of 2H, 4H, and the three layer subperiod of 9R can be clearly identified. This technique does not require the stringent conditions of atomic imaging and is used to determine the ordered structure of the 16H polytype of Ni3(Ti, V) being (2,1)2(2,2) (1,2)2. The intergrowth of different polytypes can also be easily observed by this method. Die direkte Abbildung von geordneten Strukturen im atomaren Bereich hat sich fur den Fall von Ni3V und den 9R-Polytypen von Ni3(Ti, V) als sehr effektiv erwiesen und diese Technik wurde benutzt, um die Stapelsequenz der 21R-Polytype von Ni3(Ti, V) zu [(2,1) (2,2)]3 zu bestimmen. Eine Abbildung von projizierten zweidimensionalen Gittern last sich mit einer etwas niedrigeren Auflosung erhalten, mit der Einheiten von 2H, 4H und die Dreischicht-Subperiode von 9R klar identifiziert werden konnen. Diese Technik erfordert nicht die strengen Bedingungen der atomaren Abbildung und wird benutzt, rim die geordnete Struktur der 16H-Polytype von Ni3(Ti, V) zu (2.1)2 (2,2) (1,2)2 zu bestimmen. Ineinanderwachsen von verschiedenen Polytypen last sich mit dieser Methode ebenfalls leicht beobachten.