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371.
Landfill and sea-dumping appear to be on their way out as acceptable methods for the disposal of untreated industrial wastes in Taiwan. Recently, there has been interest in the application of fluidized bed technology to waste incineration for efficient energy utilization and environmental protection. A pilot fluidized bed combustion system was used to investigate the incineration performance and parametric test for the waste from an industrial park. According to the experimental results, the appropriate operating conditions, including temperatures of 800-840 degrees C, aeration rates of U(0)/Um(f)-2.0 or so, and on-bed feeding, were recommended to treat such waste. The emissions of SO(x), NO(x) and CO in flue gas meet the ROC-EPA regulation. 相似文献
372.
Saturated water solutions of calcium chloride, calcium bromide and their 1:1 mixture are commonly used as "high density brines" for pressure control in oil wells. To compare the effect of these chemicals of technical grade with the effect of the chemicals of analytical grade the Lemna test was used. The multiplication rate, fresh weight, dry to fresh weight ratio, area covered by plants and chlorophyll content were measured as toxicity parameters. The concentrations of tested chemicals were 0.025, 0.05. 0.075 and 0.1 mol dm(-3). Generally, the chemicals of both technical and analytical grade in concentrations of 0.025 mol dm(-3) stimulated the Lemna minor growth, while tested chemicals in concentrations of 0.05 mol dm(-3) did not affect the growth significantly. The exceptions were results obtained by measuring fresh weight. Most of tested chemicals in concentrations of 0.075 mol dm(-3) and all chemicals in concentrations of 0.1 mol dm(-3) reduced the growth. No major differences between effects of tested chemicals of technical and analytical grade on plant growth were observed, except that tested chemicals of analytical grade in concentrations of 0.1 mol dm(-3) increased dry to fresh weight ratio much stronger than chemicals of technical grade. All tested chemicals in all concentrations increased chlorophyll content. After treatment with chemicals of analytical grade much higher increase of chlorophyll a concentration in comparison to increase of chlorophyll b was noticed, while chemicals of technical grade caused more prominent increase of chlorophyll b. 相似文献
373.
A study was conducted to investigate the suitability of phosphate recovery from greenhouse wastewaters by using precipitation/crystallization process. More than 90% of the phosphate could be removed from the greenhouse wastewater. Various calcium phosphate salts were obtained in the process; hydroxyapatite [Ca5(PO4)3OH] could be the main product from the precipitates. Phosphate removal was affected by the presence of magnesium ion in wastewaters. An increase of magnesium concentrations in wastewaters decreased phosphate removal rates. The chemical contents of precipitates in terms of calcium, magnesium and phosphate were affected by calcium to magnesium molar ratio. Higher calcium contents were obtained at wastewaters with high calcium to magnesium molar ratio. An addition of magnesium did not affect the potassium contents in the precipitates. K-struvite, MgKPO4 x 6H2O, was not the major product in the precipitate, even with addition of a large quantity of magnesium. 相似文献
374.
375.
Paolo Lo Bue Stefano Colazza Lisa D. Forster Jocelyn G. Millar Robert F. Luck 《Chemoecology》2004,14(3-4):151-156
Summary. Metaphycus sp. nr.
flavus (Encyrtidae: Hymenoptera)
is a parasitoid species collected from the Mediterranean
region which lays its eggs in the immature stages of several
economically important soft scale insects (Hemiptera:
Coccidae), including brown soft scale, Coccus hesperidum
L. (= host insect). Preliminary tests suggested that the parasitoid
is most successful in producing offspring when it
oviposits in the younger stages of brown soft scale. In
Y-olfactometer bioassays measuring wasp choices and residence
times, naïve parasitoids were significantly more
attracted to yucca leaves infested with 26, 27, or 28 d-old
scale than to uninfested leaves, whereas leaves with older
(29-30 d-old) scale were no more attractive than uninfested
leaves. Parasitoids also spent significantly more time in the
arm with yucca leaves infested with 26 d-old scale than in
the arm with uninfested leaves. These results are consistent
with observations of the parasitoids reproductive success on
scale of different ages, whereby older scale are more likely
to encapsulate the developing eggs of M.
sp. nr. flavusfemales than are younger scale. Further bioassays determined
that yucca leaves that had been infested with 26 d-old
scale but from which the scale had been removed were as
attractive as infested leaves. In contrast, infested yucca
leaves from which scale had been removed and the leaves
subsequently washed with distilled water were less attractive
than infested leaves. Furthermore, the wash water
containing scale residues was attractive to female wasps. In
total, these results suggest that Metaphycussp. nr. flavus
females utilize volatile, water soluble compounds produced
by brown soft scale as cues to locate suitable hosts. 相似文献
376.
Carl?SmithEmail author Martin?Reichard Pavel?Jurajda 《Behavioral ecology and sociobiology》2003,53(4):206-213
We investigated male assessment of sperm competition in the bitterling, Rhodeus sericeus, a freshwater fish that spawns on the gills of living unionid mussels. Field experiments showed males increased their inspection rate of mussels into which a testis solution containing sperm had been experimentally released. Males avoided leading females to mussels that contained high numbers of embryos, but did not alter their leading behavior in response to the presence of sperm. In laboratory experiments males also increased their inspection rate of mussels into which a testis solution had been released and also failed to alter their leading behavior in response to the presence of sperm in mussels. However, males avoided leading females to mussels in close proximity to other males, and thereby may avoid sperm competition. In a second field study, territorial males were shown to ejaculate into mussels at a low rate in the absence of competitors, increase the frequency of ejaculations in competition with a rival, then decrease relative ejaculate expenditure as the number of competing males increased. Observed data were shown to be significantly correlated with predicted estimates of ejaculate expenditure for a model of sperm competition intensity. We discuss our results in the context of adaptive responses of males to sperm competition. 相似文献
377.
Angela Dibenedetto Rosa Lo Noce Carlo Pastore Michele Aresta Carlo Fragale 《Environmental Chemistry Letters》2006,3(4):145-148
A new biotechnological synthetic approach to 4-hydroxybenzoic acid is reported. Thauera aromatica cells produce the phenylphosphate carboxylase enzyme that selectively carboxylates phenylphosphate in the para position, without any formation of the ortho isomer. Here we show that the enzyme also works in supercritical carbon dioxide, opening a new technological solution to the recovery of the products that is a key problem when aqueous media are used. The enzyme shows an activity comparable with that shown under CO2 pressure in aqueous media and does not require the presence of NaHCO3. 相似文献
378.
V.?BoudonEmail author J.-P.?Champion T.?Gabard G.?Pierre M.?Lo?te C.?Wenger 《Environmental Chemistry Letters》2003,1(1):86-91
Highly symmetrical molecules such as CH4, CF4 or SF6 are known to be atmospheric pollutants and greenhouse gases. High-resolution spectroscopy in the infrared is particularly
suitable for the monitoring of gas concentration and radiative transfers in the earth's atmosphere. This technique requires
extensive theoretical studies for the modeling of the spectra of such molecules (positions, intensities and shapes of absorption
lines). Here, we have developed powerful tools for the analysis and the simulation of absorption spectra of highly symmetrical
molecules. These tools have been implemented in the spherical top data system (STDS) and highly-spherical top data system
(HTDS) software available at http://www.u-bourgogne.fr/LPUB/shTDS.html. They include a compilation of modeled data obtained
during the last 20 years. An overview of our latest results in this domain will be presented.
Electronic Publication 相似文献
379.
Summary. HPLC analysis of secondary metabolites represents an efficient tool for the studying of plant chemical diversity under different
aspects: chemotaxonomy, metabolomics, adaptative responses to ecological factors, etc. Statistical analyses of HPLC databases,
e.g. correlation analysis between HPLC peaks, can reliably provide information on the similarity/dissimilarity degrees between
the chemical compounds. The similarities, corresponding to positive correlations, can be interpreted in terms of analogies
between chemical structures, synchronic metabolisms or co-evolution of two compounds under certain environment conditions,
etc. . In terms of metabolism, positive correlations can translate precursor-product relationships between compounds; negative
correlations can be indicative of competitive processes between two compounds for a common precursor(s), enzyme(s) or substrate(s).
Furthermore, the correlation analysis under a metabolic aspect can help to understand the biochemical origins of an observed
polymorphism in a plant species. With the aim of showing this, we present a new approach based on a simplex mixture design,
Scheffé matrix, which provides a correlation network making it possible to graphically visualise and to numerically model
the metabolic trends between HPLC peaks. The principle of the approach consisted in mixing individual HPLC profiles representative
of different phenotypes, then from a complete mixture set, a series of average profiles were calculated to provide a new database
with a small variability. Several iterations of the mixture design provided a smoothed final database from which the relationships
between the secondary metabolites were graphically and numerically analysed. These relationships were scale-dependent, namely
either deterministic or systematic: the first consisted of a monotonic global trend covering the whole variation field of
each metabolites’ pair; the second consisted of repetitive monotonic variations which gradually attenuated or intensified
along a global trend. This new metabolomic approach was illustrated from 404 individual plants of Astragalus caprinus (Leguminoseae), belonging to four chemical phenotypes (chemotypes) on the basis of flavonoids analysed in their leaves. After
smoothing, the relationships between flavonoids were numerically fitted using linear or polynomial models; therefore the co-response
coefficients were easily interpreted in terms of metabolic affinities or competitions between flavonoids which would be responsible
of the observed chemical polymorphism (the four chemotypes). The statistical validation of the approach was carried out by
comparing Pearson correlations to Spearman correlations calculated from the smoothed and the crude HPLC database, respectively.
Moreover, the signs of the smoothed relationships were finely supported by analogies and differences between the chemical
structures of flavonoids, leading to fluent interpretation in relation to the pathway architecture. 相似文献
380.
The little-known cladoceran population of the Aegean Sea was studied. One hundred and seventy-six planktonic samples were collected during 8 cruises in the Aegean Sea (4 in the northern part, 4 in the southern part). From these samples, the following 4 species of Cladocera were determined: Evadne spinifera Muller, Evadne tergestina Claus, Penilia avirostris Dana, Podon intermedius Lilljeborg. All species were found both in the north and in the south Aegean Sea, with the exception of P. avirostris, which was found only in the northern Aegean Sea. Its absence from the southern part is attributed to the higher salinities and the pelagic character of the area. With regard to abundance, E. spinifera is by far the commonest in this area; P. avirostris and E. tergestina could be characterised as frequent forms; P. intermedius is scarce. P. avirostris, E. spinifera and E. tergestina are thermophilic; their occurrence is more or less restricted to the warm season; P. intermedius is psychrophilic and appears only in winter. 相似文献