Valve morphology of three species of Neidiomorpha (Bacillariophyceae) from Zoigê Wetland, China, including description of Neidiomorpha sichuaniana nov. sp.

Phytotaxa ◽  
2014 ◽  
Vol 166 (2) ◽  
pp. 123 ◽  
Author(s):  
QI LIU ◽  
J. P. KOCIOLEK ◽  
QUANXI WANG ◽  
CHENGXIN FU

A new diatom species, Neidiomorpha sichuaniana sp. nov., is described from Zoigê Wetland, China. The morphology of N. sichuaniana is documented by light and scanning electron microscope and discussed in detail, including a comparison with the two other species in the genus Neidiomorpha also found in Zoigê. Neidiomorpha sichuaniana has a smaller central area and smaller central constriction than N. binodiformis and less apiculate ends than N. binodis. We comment on the systematic position of Neidiomorpha based on the morphology of these three species.

Zootaxa ◽  
2021 ◽  
Vol 4981 (2) ◽  
pp. 275-300
Author(s):  
BORIS SIRENKO

The genus chiton Loricella is revised. It comprises nine species. Two of these species, L. neoguinensis n. sp. and L. solomonensis n. sp., are described as new. Based on the analysis of morphological features studied using a scanning electron microscope, a revised diagnosis of the genus is provided. The characters diagnostic for this that distinguish it from the related genus Squamophora are as follows: a tubular hollow inside the dorsal scales, bristles on the dorsal side of the girdle, a wide ventral mouth region, a narrow mantle fold covered with simple longitudinally ribbed scales, smooth ventral scales, pits arranged in longitudinal rows in the central area of the tegmentum, and a bicuspid head of the major lateral teeth of the radula. 


Author(s):  
David S. McKay

Introduction. Samples of rock, mineral, and glass fragments returned by Apollo 11 and 12 contain a variety of microcraters which were formed by the impacts of small projectiles. The craters are especially prominent in some of the small glass spherules and related forms.Crater types. It is possible to classify these microcraters on the basis of morphology as seen by the scanning electron microscope. Type I microcraters (Figure 1) show the following characteristics:A. A glassy central area is present which has been melted by the impact. This glass is primarily material from the target but may also contain melted projectile material. The central area is normally very smooth and may or may not have a smooth raised lip.


2018 ◽  
Vol 52 (1) ◽  
pp. 7-11
Author(s):  
S. I. Genkal ◽  
M. I. Yarushina

A new planktonic pennate diatom species, Stauroneis guslyakovii Genkal et Yarushina, sp. nov., was described from the Yamal and Tazovsky peninsulas using a scanning electron microscope. The new species is morphologically similar to S. gracilior and S. francisci-josefi, but differs from them in number of striae and areolae in 10 μm, length and width of valve.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Author(s):  
S. Saito ◽  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.


Author(s):  
Emil Bernstein

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.


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