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1.
K-J. Lehtinen 《Marine environmental research》1984,12(4):273-283
The harpacticoid copepod, Nitocra spinipes Boeck, was used as an experimental animal in a series of tests where the toxicity of different fractions (solid and soluble) of TiO2 industrial waste water was investigated. The tests were performed in brackish water (7). Water temperature was used as a variable in the fractionation of the waste water. Temperature was found to influence the acute toxicity of the waste water. LC50 values for N. spinipes were 0·087 (± 4°C), 0·105 (+ 7°C)) and 0·12% (+ 21°C) of undiluted waste water. At room temperature the animal's fecundity was affected at two intervals, one in dilutions between 0·0003% and 0·001% and the other between 0·03% and 0·3%. An acute toxicity test with the dried solid metal fraction resuspended into clean brackish water had an acute LC50 value of 7·6% of undiluted waste water. The results show that different fractions of the waste water have different harmful biological effects under different temperature conditions. 相似文献
2.
Petroleum hydrocarbons in the sediments of the Bothnian Bay, Baltic proper, Öresund, Kattegatt and Skagerrak were analysed in a survey of oil pollution along the Swedish coast in 1974 and 1975. Sixty-one of these sediment stations were revisited in 1982 and analysed with the methods used in the first survey. The mean content of petroleum hydrocarbons (paraffin-naphthene fraction) in the sediment surface showed a statistically significant increase from 199 to 252 μg g?1 dry wt. The main increase had taken place in the coastal areas. Within 0–20 km distance of urbanized areas (>20 000 inhabitants) petroleum hydrocarbons had increased from 371 to 447 μg g?1. Sediment levels increased from 76 to 117 μg g?1, 20–50 km from urbanized areas. The increase in these areas was equivalent to 0.119 g m?2 yr?1. 相似文献
3.
The lavas of the Nyiragongo volcano in Eastern Zaire contain partially fused granite xenoliths. The relictic feldspars found in these xenoliths were studied by microprobe analysis and by X-ray diffraction methods. Some xenoliths represent originally two-feldspar granites, in others only alkali feldspars or those of an anorthoclase composition were detected. All feldspars are homogeneous without perthitic textures detectable under the microscope. In thebc-diagram of Stewart and Wright all feldspars plot on the analbite-high sanidine join. These feldspars have been perfectly disordered through heating in the melilite-nephelinite magma of the volcano. 相似文献
4.
Martti Lehtinen 《Contributions to Mineralogy and Petrology》1974,47(3):223-230
Unit-cell parameters, c */b* ratios, Δbc values (Stewart and Ribbe, 1969), Or contents and the positions of two of the characteristic infared absorption bands are presented for 16 K-rich and for 5 Na-rich alkali feldspar samples. A more specific interpretation is given for the characteristic absorption bands. It is shown that the position of one of the infrared absorption bands depends on the degree of Al/Si order whereas the other depends both on the degree of Al/Si order and to a lesser degree on chemical composition. It is recommended that a combination of X-ray and infrared data is useful in studying certain mineralogical and petrogenetic problems associated with the alkali feldspars. 相似文献
5.
Kurt Johansson Rune B. Larsen Markku J. Lehtinen Lars Persson Mika Raeisaenen Stig A. Schack Pedersen Paer Weihed Nils-Gunnar Wik 《《幕》》2008,31(1):133-139
The Nordic countries, including Greenland, have a long tradition in mining. The industrial minerals sector is expanding in most Nordic countries and extensive development has taken place during the last few years. The main commodities mined are carbonate rocks, quartz, feldspar, apatite, olivine and talc.
A number of diferent types of dimension stones are quarried in all countries. Rock aggregates are increasingly important, replacing sand and gravel aggregate as construction materials in some countries due to the need to protect ground water supplies. 相似文献
A number of diferent types of dimension stones are quarried in all countries. Rock aggregates are increasingly important, replacing sand and gravel aggregate as construction materials in some countries due to the need to protect ground water supplies. 相似文献
6.
N. J. Lehtinen S. Pohjolainen K. Huttunen-Heikinmaa R. Vainio E. Valtonen A. E. Hillaris 《Solar physics》2008,247(1):151-169
A high-speed, halo-type coronal mass ejection (CME), associated with a GOES M4.6 soft X-ray flare in NOAA AR 0180 at S12W29
and an EIT wave and dimming, occurred on 9 November 2002. A complex radio event was observed during the same period. It included
narrow-band fluctuations and frequency-drifting features in the metric wavelength range, type III burst groups at metric – hectometric
wavelengths, and an interplanetary type II radio burst, which was visible in the dynamic radio spectrum below 14 MHz. To study
the association of the recorded solar energetic particle (SEP) populations with the propagating CME and flaring, we perform
a multi-wavelength analysis using radio spectral and imaging observations combined with white-light, EUV, hard X-ray, and
magnetogram data. Velocity dispersion analysis of the particle distributions (SOHO and Wind
in situ observations) provides estimates for the release times of electrons and protons. Our analysis indicates that proton acceleration
was delayed compared to the electrons. The dynamics of the interplanetary type II burst identify the burst source as a bow
shock created by the fast CME. The type III burst groups, with start times close to the estimated electron-release times,
trace electron beams travelling along open field lines into the interplanetary space. The type III bursts seem to encounter
a steep density gradient as they overtake the type II shock front, resulting in an abrupt change in the frequency drift rate
of the type III burst emission. Our study presents evidence in support of a scenario in which electrons are accelerated low
in the corona behind the CME shock front, while protons are accelerated later, possibly at the CME bow shock high in the corona. 相似文献
7.
J. Magdalenić B. Vršnak S. Pohjolainen M. Temmer H. Aurass N. J. Lehtinen 《Solar physics》2008,253(1-2):305-317
We present a multiwavelength study of the large-scale coronal disturbances associated with the CME?–?flare event recorded on 24 December 1996. The kinematics of the shock wave signature, the type II radio burst, is analyzed and compared with the flare evolution and the CME kinematics. We employ radio dynamic spectra, position of the Nançay Radioheliograph sources, and LASCO-C1 observations, providing detailed study of this limb event. The obtained velocity of the shock wave is significantly higher than the contemporaneous CME velocity (1000 and 235 km?s?1, respectively). Moreover, since the main acceleration phase of the CME took place 10?–?20 min after the shock wave was launched, we conclude that the shock wave on 24 December 1996 was probably not driven by the CME. However, the shock wave was closely associated with the flare impulsive phase, indicating that it was ignited by the energy release in the flare. 相似文献
8.
Th. G. Sahama Martti Lehtinen Pentti Rehtijärvi 《Contributions to Mineralogy and Petrology》1973,39(2):171-174
Single crystals of boehmite, up to 0.1 mm in size, were found in open cavities inside a corundum crystal from the Ratnapura area gem gravels in Ceylon. The unit cell parameters are (X-ray powder pattern): a
0=3.695 Å b
0=12.212 Å, c
0=2.867 Å. The crystallographic orientation is based on X-ray single-crystal precession photographs. The crystals show the faces (it010), (001), (101), and (221). Systematic extinctions agree with the space group Amam. Optical orientation: a, b, c. Refractive indices are given. The mineral is optically positive with a large optic axial angle. 相似文献
9.
Theoretical and experimental studies of ultra-high-frequency (UHF) and microwave radiometry to sense remotely the thickness and other characteristics of low-salinity (less than one per mille) sea ice are described. The experimental studies used a 600-MHz and a multichannel, multibeam, 4.7-GHz radiometer carried by a helicopter to measure the brightness temperature of different types of sea ice in the Gulf of Bothnia in 1975 and 1976.The developed theory and experiments show that the brightness temperature of low-salinity sea ice oscillates as a function of ice thickness at UHF frequencies. Due to higher attenuation, the oscillations quickly die away at 4.7 GHz and the brightness temperature reaches an almost constant value when the thickness exceeds a few decimetres. By using a three-channel UHF radiometer with suitably selected center frequencies, the oscillations can be reduced and the effective brightness temperature will grow more linearly with the ice thickness.Experiments show that ice ridges appear as thick ice at 600 MHz and as thinner ice at 4.7 GHz, thus allowing them to be detected by radio techniques. 相似文献
10.
Matson CW Franson JC Hollmén T Kilpi M Hario M Flint PL Bickham JW 《Marine pollution bulletin》2004,49(11-12):1066-1071
Common eiders nesting in the Baltic Sea are exposed to generally high levels of contaminants including potentially genotoxic polycyclic aromatic hydrocarbons and organochlorines. Blood samples were collected from eiders at eight sites in the Baltic Sea and two sites in the Beaufort Sea. DNA content variation was estimated using the flow cytometric method, and subsequently utilized as a biomarker of genetic damage. We observed no significant differences in genetic damage among populations within either the Baltic or Beaufort Seas. However, eider populations from the Baltic Sea had significantly elevated estimates of genetic damage compared to populations from the Beaufort Sea. 相似文献