A subadult individual of Styracosaurus albertensis (Ornithischia: Ceratopsidae) with comments on ontogeny and intraspecific variation in Styracosaurus and Centrosaurus.

Styracosaurus albertensis is an iconic centrosaurine horned dinosaur from the Campanian of Alberta, Canada, known for its large spike-like parietal processes. Although described over 100 years ago, subsequent discoveries were rare the last few decades, during which time several new skulls, skeletons, and bonebeds were found. Here we described an immature individual, the smallest known for the species, represented by a complete skull and fragmentary skeleton. Although ~80% maximum size, it possesses a suite of characters associated with immaturity, and is regarded as a subadult. The ornamentation is characterized by a small, recurved, but fused nasal horncore; low, rounded postorbital horncores; and short, triangular, and flat parietal processes. Using this specimen, and additional skulls and bonebed material, the cranial ontogeny of Styracosaurus is described, and compared to Centrosaurus. Styracosaurus shows a similar early ontogeny of the nasal horncore, starting thin, recurved, and unfused, but retains the recurved morphology into large adult size, and never develops the procurved morphology common in Centrosaurus. The postorbital horncores of Styracosaurus are lower and more rounded than those of Centrosaurus throughout ontogeny, and show greater resorption later in ontogeney. The length and thickness of the parietal processes increase drastically through ontogeny, but their position and orientation are static across the size series. Several diagnostic Styracosaurus albertensis specimens now preserve medially orientated P3 spikes, causing issues for the diagnosis of S. ovatus. Variability in parietal ornamentation, either expression of P1 and P2 parietal processes, or other cranial ornamentations, does not appear to correlate with stratigraphy.

Odontidium andinum spec. nov. (Bacillariophyta) from Mendoza, Argentina

The genus Odontidium is characterized by the presence of robust internal transapical ribs, a wide sternum and a complex cingulum composed by several open bands with ligulae, differentiated in copulae and pleurae. Only two species of Odontidium have been recorded from Argentina. In samples collected in the upper basin of the Diamante River, Mendoza Province the dominant specimens were of this genus but differed from those species already known. Examination of the valve morphology of these specimens, and comparison with other species of the genus, showed it is a new species Odontidium andinum. O. andinum has valves broadly lanceolate to linear with rounded to subcapitate ends. It is similar to O. hyemale, O. mesodon and O. rostratum. Although smaller specimens of all these species are similar when using the light microscope, with a complete size series it is possible to see marked differences in the valves’ outline. These differences correspond with others found in the fine structure of the valves and girdles. These specimens also match those previously named as Diatoma hyemalis (Roth) Heiberg sensu lato, collected in the Chilean Andes and with others recently found in a high altitude river in Argentinean Patagonia, showing the Andean distribution of the species.

Correlated Color Temperature Tunable White Electroluminescence from Cadmium-Free ZnS Quantum Dots

We propose correlated color temperature tunable white light-emitting from different sizes cadmiumfree quantum dots (QDs) without organic ligand-modulation. A size series of free-standing ZnS QDs were prepared by coprecipitation method. Experimental results show that the broad electroluminescences (EL) spectra from all samples cover almost the entire visible region and the electroluminescence peak is significantly redshifted from 489 to 580 nm with ZnS QDs sizes increasing from 1.1 to 4 nm. Moreover, the chromaticity coordinates calculated from EL spectra are (0.27, 0.36), (0.36, 0.42) and (0.42, 0.46) for QDs with average sizes 1.1, 2 and 4 nm drived at 15 V respectively, correspondingly, white EL spectra with a continuously tunable color changes from bluish white (CCT 12400 K) to yellowish white (CCT 3700 K). The differences between the photoluminescence (PL) and EL spectra were observed. Furthermore, the comparison between EL and PL spectra and active defect-levels of ZnS QDs with various sizes are discussed to understand the mechanism of the tunable spectra. The results offer that a convenience method to obtain tunable EL spectra in white color from ZnS QDs defects by controlling the size of the QDs.

The revival of a so-called rotten fish: the ontogeny of the Devonian acanthodian Triazeugacanthus

Since its original description as a chordate, the Late Devonian Scaumenella mesacanthi has been interpreted alternately as a prochordate, a larval ostracoderm and an immature acanthodian. For the past 30 years, these minute specimens were generally considered as decayed acanthodians, most of them belonging to Triazeugacanthus affinis. Among the abundant material of ‘ Scaumenella ’, we identified a size series of 188 specimens of Triazeugacanthus based on otolith characteristics. Despite taphonomic alteration, we describe proportional growth and progressive appearance of skeletal elements through size increase. Three ontogenetic stages are identified based on squamation extent, ossification completion and allometric growth. We demonstrate that what has been interpreted previously as various degrees of decomposition corresponds to ontogenetic changes.

Analysis of Raw Silk Fineness Series and the Fine Limit Point

In this thesis, the fineness and the size are measured, in order to analyze and compare them. The fineness is measured with the cross-sectional area and the size is measured with traditional gravimetric method. The section shape of raw silk is assumed be approximately elliptical, and the diameters of different grade raw silk are measured in mutual perpendicular directions with Fiber fineness instrument, which connects microscope with computer, and the shapes and diameters of raw silk can be directly watched and measured on the computer screen. Meanwhile the weights of the corresponding segments of the raw silk are weighed. The raw silk fineness series and size series are analyzed through statistic parameters such as the expectation, variance, auto-correlation coefficient, correlation coefficient. And the difference between different grades of raw silk is analyzed. The result of this study is useful for improvement of raw silk reeling process and inspection of raw silk quality.

Analysis on Casing Size and Steel Grade and Application in High-Temperature High-Pressure Gas Wells

Analysis on casing size and steel grade and application in high-temperature high-pressure gas wells are important in natural gas production engineering. This paper presents the standard casing size series, casing steel grade standard and code, types of casing steel grade, main problems in high-temperature high-pressure gas wells, using casing material suitable as solving means for high-temperature high-pressure gas well and application. For application, the study above is good and easy for on-the-spot application.

Oil and Gas Well Hole Structure and Application in Superdeep Well with Analysis of Material Properties

The designing level of oil and gas well hole structure and application in superdeep well with analysis of material properties play a key role in the expected production target to superdeep oil and gas wells. This paper introduces the hole structure of standard casing size series, main problems in superdeep wells with analysis of material properties, and solving means such as: using liner as production casing, cementing under small clearances of borehole-casing annulus and intermediate casing-production casing annulus, reaming and close clearance hole structure, analysis of material properties and so on. By application, the study above has a good practicality.