scholarly journals A NEW GOOSEBERRY PLANT-LOUSE

1901 ◽  
Vol 33 (8) ◽  
pp. 227-228 ◽  
Author(s):  
W. P. Cockerell ◽  
T. D. A. Cockerell
Keyword(s):  
Winged Form ◽  
Black Spots ◽  
Half Length

Myzus Neomexicanus, n. sp.—Winged form. General colour of head and thorax black; prothorax sage-green with a transverse black shield, narrowest in the middle; sides of thorax green; antennæ black; wings clear, stigma and nervures very dark brown; abdomen sage-green, four quadrate black marks on each side anterior to honey-tubes, the last sometimes a mere speck; honey-tubes blackish, darkest basally; segment bearing honey-tubes with a few black spots, this and the following two segments with transverse black bands; legs black, tibiæ brown. Ocelliferous tubercle prominent; frontal tubercles low and broad, these and first antennal joint very slightly gibbous. Honey-tubes not swollen, 300 μ long and 40 broad, 200 μ short of tip of abdomen, cingulate. Body about 2100 μ long, antennæ about 1030, half length of body. Tibia of anterior leg 700, of hind leg 880 μ. Antennal joints (counting the so-called 7th joint as 6b) measuring: (1) 70, (2) 60, (3) 270, (4) 190, (5) 184, (6a) 100, (6b) 270.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

A new approach to the hydraulic fracture geometric dimensions determination

2017 ◽  
Vol 12 (1) ◽  
pp. 126-134
Author(s):  
A.M. Ilyasov
Keyword(s):  
Exact Solution ◽  
Hydraulic Fracture ◽  
Pressure Gauge ◽  
Hyperbolic Type ◽  
Fluid Injection ◽  
Fracturing Fluid ◽  
New Approach ◽  
Gauge Data ◽  
Bottomhole Pressure ◽  
Half Length

Based on the generalized Perkins-Kern-Nordgren model (PKN) for the development of a hyperbolic type vertical hydraulic fracture, an exact solution is obtained for the hydraulic fracture self-oscillations after terminating the fracturing fluid injection. These oscillations are excited by a rarefaction wave that occurs after the injection is stopped. The obtained solution was used to estimate the height, width and half-length of the hydraulic fracture at the time of stopping the hydraulic fracturing fluid injection based on the bottomhole pressure gauge data.

The North American Allies of Hylobius piceus (De Geer) (Coleoptera: Curculionidae)

1957 ◽  
Vol 89 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Stephen L. Wood
Keyword(s):  
North American ◽  
Distinct Species ◽  
Morphological Characters ◽  
North American Species ◽  
Winged Form ◽  
The North ◽  
The Status ◽  
Field Workers ◽  
Dimorphic Species ◽  
Biological Differences

While investigating the biology of the North American species of Hypomolyx, field workers in Manitoba found a vestigial, or short-winged, and a long-winged form under apparently identical conditions in about equal numbers. Although biological differences were nor then apparent, there was doubt as to whether they were dealing with one dimorphic species or with two distinct species, A search for morphological characters brought to light numerous differences between the two forms, supporting the view that two species were present. These differences, a description the previously unrecognized species, and notes concerning the status of the genera Hylobius and Hypomolyx are reported below.

Sign in / Sign up

Export Citation Format

Share Document