The determination of the derivatives in Brown's lunar theory

The fundamental matrix solutionT for the variational equations of a Hamiltonian system is symplectic. We use this fact to completeT when it is only partially known. We discuss three cases. The last one gives an easy proof for the method invented by Brown in his lunar theory.Paper presented at the 1981 Oberwolfach Conference on Mathematical Methods in Celestial Mechanics.Dedicated to Victor Szebehely.     

Integrated fluxes for emission lines in the ultraviolet spectra of several planetary nebulae

The IUE satellite observatory has been used to obtain absolutely-calibrated emission line fluxes for diagnostic lines of multiply-ionized C, N, O, Si, Ne, and Ar which occur in the ultraviolet spectral region of planetary nebulae. These data, when combined with data from the blue, visual, and near infrared, will provide improved estimates of ionic concentrations, plasma temperatures and densities, and elemental abundances.     

内蒙古伊盟盐海子YaO2孔氧碳同位素记录的第四纪末次冰期及全新世气候特征

从内蒙古伊盟盐海YaO2孔氧碳同位素资料中可以看到:东亚季风气候在22 000aBP时由第四纪末次冰期气候开始转入末次间冰期气候。东亚季风带第四纪末次冰期时的气候环境是湿冷的淡化期。而末次间冰期的气候环境是热干的成盐期。其次,末次冰期以来,气候由湿冷转变为热干,5400aBP时气候达到热干的大暖期的最热点。之后又逐级降至现代暖趋冷的气候特征。东亚季风气候带的末次间冰期开始界线在22 000aBP左右。δ18O资料告诉我们内蒙古高原第四纪末次冰期曾有过冰川或冰盖地貌景现,在22000aBP以后才消融进入第四纪末次间冰期。     

Annual stability in the use of coves near inlets as settlement areas for winter flounder (Pseudopleuronectes americanus)

Coves near an ocean inlet in Little Egg Harbor in southern New Jersey may be important settlement areas for winter flounder (Pseudopleuronectes americanus), based on the high abundance of small postlarval individuals. During 1994–1996 we sampled in two coves and adjacent areas of this same estuary to determine if this pattern was annually consistent. Collections in spring and early summer indicated that small, recently-settled winter flounder (10–45 mm TL) were abundant in the coves from May to mid-June in every year with maximum mean densities ranging from 1.5–2.5 ind m⁻² and that these same size individuals were never collected at these densities in other habitats in the same estuary. Densities in the coves declined soon after settlement, usually by late June to early July in each year. In order to determine factors that may influence these high settlement rates we examined aspects of habitat quality by determining habitat-specific growth rates in cages for recently-settled individuals (17.5–38.3 mm TL) both inside and outside the coves during 1995. These rates (3.7–9.1 wt d⁻¹) overlapped those of other estuarine habitats (3.1–10.5 wt d⁻¹) suggesting that habitat quality, based on growth, does not differentiate the coves from other potential settlement habitats. Mark/recapture experiments for recently settled individuals (range 13–70 mm TL) in 1994 and 1996 had low recapture rates (1% in both years) suggesting that dispersal from the cove occurred soon after settlement. This pattern confirms that these coves are used as settlement areas but they are probably not used as nurseries because winter flounder, at least in this system, do not settle and stay and, as a result, use other habitats as primary nursery areas.     

Spatial variation in delaware bay (U.S.A.) marsh creek fish assemblages

Delaware Bay is one of the largest estuaries on the U.S. eastern seaboard and is flanked by some of the most extensive salt marshes found in the northeastern U.S. While physicochemical and biotic gradients are known to occur along the long axis of the bay, no studies to date have investigated how the fish assemblage found in salt marsh creeks vary along this axis. The marshes of the lower portion of the bay, with higher salinity, are dominated bySpartina spp., while the marshes of the upper portion, with lower salinity, are currently composed primarily of common reed,Phragmites australis, S. alterniflora, or combinations of both. Extensive daytime sampling (n=815 tows) during May–November 1996 was conducted with otter trawls (4.9 m, 6 mm mesh) in six intertidal and subtidal marsh creek systems (upper and lower portions of each creek) where creek channel depths ranged from 1.4–2.8 m at high tide. The fish taxa of the marsh creeks was composed of 40 species that were dominated by demersal and pelagic forms including sciaenids (5 species), percichthyids (2), and clupeids (7), many of which are transients that spawn outside the bay but the early life history stages are abundant within the bay. The most abundant species wereMorone americana (24.3% of the total catch),Cynoscion regalis (15.4%),Micropogonias undulatus (15.3%),Anchoa mitchilli (12.0%), andTrinectes maculatus (10.8%). Non-metric Multi-Dimensional Scaling ordination of catch per unit effort (CPUE) data indicated two fish assemblages that were largely independent of the two major vegetation types, but generally corresponded with spatial variation in salinity. This relationship was more complex because some of the species for which we could discriminate different age classes by size had different patterns of distribution along the salinity gradient.     

Low abundance of the dinoflagellates,Pfiesteria piscicida, P. shumwayae, andCryptoperidiniopsis spp., in South Carolina tidal creeks and open estuaries

The toxicPfiesteria complex are a group of dinoflagellates that have received considerable attention in recent years as causative factors in fish kill or lesion events in North Carolina estuaries and in the Pocomoke River of Chesapeake Bay. In response to the potentialPfiesteria threat, the South Carolina Task Group on Harmful Algae was formed in late 1997 and implemented programs to monitor harmful algal blooms and respond to fish kills or lesion events with particular emphasis on the Bushy Park (Cooper River, Charleston) region, a site of annually recurrent menhaden lesion events.Pfiesteria piscicida, Pfiesteria shumwayae, andCryptoperidiniopsis spp. were documented in South Carolina estuaries. Routine monitoring and fish kill or lesion event sampling consistently indicated low abundances compared to estimates from similar programs in North Carolina and Maryland that sampled areas with a history ofPfiesteria toxic activity. The finding thatPfiesteria-like organism (PLO) abundances were always low in samples collected during menhaden lesion events in Bushy Park suggested other causes for lesion progression, althoughPfiesteria spp. could not be ruled out as a factor in lesion initiation. Based on the previously demonstrated positive relationship between PLO abundance, chlorophylla, and inorganic nutrient concentrations (in laboratory experiments and North Carolina field observations), we hypothesized that the relatively low abundance ofPfiesteria spp. and other PLO (e.g.,Cryptoperidiniopsis) in South Carolina estuaries is related to the relatively low supply of phytoplankton prey, as supported by interstate comparisons in chlorophylla concentrations. Nitrate concentrations were generally much lower in South Carolina estuaries. Estuarine eutrophication may be an important consideration in explaining interstate differences in susceptibility toPfiesteria-related toxic events.     

White K-mica evolution from phengite to muscovite in shales and shale matrix melange,Diablo Range,California

 Eleven samples from high-pressure/low-temperature (HP/LT) shales and shale-matrix melange from four areas in the Diablo Range were studied using electron microprobe (EMP), transmission electron microscopy (TEM), and analytical electron microscopy (AEM) to provide information about white K-mica evolution and about the controls on illite “crystallinity” (IC) in these areas. The data indicate that: (1) compositional gradients from phengitic to muscovitic compositions occur along the long axis, perpendicular to c*, of white K-mica crystals; (2) compositional gradients parallel to c* were not observed, and thus coherent scattering domains along c* are homogeneous; (3) white K-mica crystals with compositions close to muscovite generally contain fewer planar defects and have larger defect-free distances than those with more phengitic compositions; (4) muscovitic white K-mica is less common than phengitic white K-mica. In the literature, grain growth has often been described to occur by the process of Ostwald ripening. Ostwald ripening is defined as an isochemical process and involves the reduction of surface free energy due to simultaneous dissolution and growth by transferring material from smaller particles to larger ones. However, in the present case: (1) coherent scattering domain boundaries often are created by intragranular faults such as dislocations, intergrown smectite layers (and other polysomatic defects), or incoherent layer rotations, which interrupt the 1.0 nm periodicity; (2) recrystallization from phengite to muscovite involves chemical changes. This implies that crystal growth can not be described by the term Ostwald ripening. Therefore, grain growth of white K-mica from the Diablo Range is described as a function of several processes that result in (1) reduction of surface free energy; (2) reduction of strain energy; (3) minimization of the Gibbs free energy due to change in composition. During growth of muscovitic white K-mica, planar defects become less abundant, and the defect-free distance (=coherent scattering domain size parallel to c*) increases. Strain energy decreases. Log-normal frequency distributions of coherent white K-mica scattering domains were found for three samples. The mode of these data coincides with the number of unit cells parallel to c* as calculated from the Scherrer equation. Thus, IC values from shales and shale matrix melange from the Diablo Range are the result of a physical mixture of numerous small phengitic coherent scattering domains and smaller numbers of slightly larger muscovitic coherent scattering domains. This implies that IC from the Diablo Range does not directly reflect maximum temperatures achieved by these rocks. It follows that IC data from terranes with a metamorphic evolution similar to that of the Diablo Range must be interpreted with caution. Received: 23 August 1995 / Accepted: 30 November 1995     

Effects of dithiocarbamate and 8-hydroxyquinoline additions on algal uptake of ambient copper and nickel in South San Francisco Bay water

The addition of synthetic organic ligands such as diethyldithiocarbamate (DDC) and 8-hydroxyquinoline (Ox) to the dissolved fraction (<0.2 μm) of South San Francisco Bay water facilitated the transport of ambient Cu and Ni into phytoplankton cells. The uptake mechanism is diffusion of the lipophilic organic Cu(DDC)₂ ⁰ and Cu(Ox)₂ ⁰ complexes (and corresponding Ni complexes) across the plasma membrane. Short-term uptake experiments were carried out using a coastal diatom,Thalassiosira weissflogii, and resulted in rapid uptake rates and high cellular concentrations of the metal relative to the bay water control. Steady-state conditions between the solution and cellular Cu concentrations occurred within 10 min for a 4 μM addition of DDC and after 3 h for a 100 μM addition of Ox. Steady-state cellular Cu concentrations were over 10 times and 6 times greater, for DDC and Ox treatments, than in the bay water controls. Steady-state cellular Ni concentrations were attained within 10 min for both ligand additions and were more than 6 times and 2 times greater than in the absence of the added ligands. Using this bioassay, we were also able to gain insight into the character of the background organic Cu complexes in South Bay. Our results suggest that the natural organic Cu complexes are relatively hydrophilic in character and do not appear to be directly assimilated across the plasmalemma.     

Extreme ultraviolet spectra of solar active regions and their analysis

Extreme ultraviolet spectra of several active regions are presented and analyzed. Spectral intensities of 3 active regions observed with the NRL Skylab XUV spectroheliograph (170–630 Å) are derived. From this data density sensitive line ratios of Mg viii, Si x, S xii, Fe ix, Fe x, Fe xi, Fe xii, Fe xiii, Fe xiv, and Fe xv are examined and typically yield, to within a factor of 2, electron pressures of 1 dyne cm^–2 (n _e T = 6 × 10¹⁵ cm^–3 K). The differential emission measure of the brightest 35 × 35 portion of an active region is obtained between 1.4 × 10⁴ K and 5 × 10⁶ K from HCO OSO-VI XUV (280–1370 Å) spectra published by Dupree et al. (1973). Stigmatic EUV spectra (1170–1710 Å) obtained by the NRL High Resolution Telescope and Spectrograph (HRTS) are also presented. Doppler velocities as a function of position along the slit are derived in an active region plage and sunspot. The velocities are based on an absolute wavelength scale derived from neutral chromospheric lines and are accurate to ±2 km s^–1. Downflows at 10⁵ K are found throughout the plage with typical velocities of 10 km s^–1. In the sunspot, downflows are typically 5 to 20 km s^–1 over the umbra and zero over the penumbra. In addition localized 90 and 150 km s^–1 downflows are found in the umbra in the same 1 × 1 resolution elements which contain the lower velocity downflows. Spectral intensities and velocities in a typical plage 1 resolution element are derived. The velocities are greatest ( 10 km s^–1) at 10⁵ K with lower velocities at higher and lower temperatures. The differential emission measure between 1.3 × 10⁴ K and 2 × 10⁶ K is derived and is found to be comparable to that derived from the OSO-VI data. An electron pressure of 1.4 dynes cm^–2 (n _e T = 1.0 × 10¹⁶ cm^–3 K) is determined from pressure sensitive line ratios of Si iii, O iv, and N iv. From the data presented it is shown that convection plays a major role in determining the structure and dynamics of the active region transition zone and corona.