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51.
At first, it may seem as if the sustainable transition would force us to make a cynical trade-off between (a) the immediate needs of the global poor and (b) the future needs of the global rich. Crucial objectives, such as climate stability, are commonly held to be unattainable if the rest of the world would come to enjoy present Western living standards.Challenging this pessimistic analysis, this essay explores the possibility of opening up advanced technological paths to environmental sustainability by means of a “global Fordian compromise”. Built around trade reform, such a compromise would resemble its historic namesake by not seeking individual moral reform, as emphasized in environmental citizenship theory, but rather by drawing on the momentum of existing socio-economic dynamics.  相似文献   
52.
Levels of tri- to decabrominated diphenyl ethers (BDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and 1,2-bis(pentabromophenyl)ethane (DeBDethane) were determined in air, sedimentary dust and human plasma from five households in Sweden. The levels of the individual BDEs in the plasma samples were in the same order of magnitude as in other studies of the general population in Scandinavia, and varied between non-detectable (<0.41 ng g(-1) l.w.) to 17 ng g(-1) (l.w.). BDE#28 and #47 were present in all air samples, with mean values of 0.015 and 0.12 ng m(-3), respectively, except for one sample where the BDE#47 concentration was below the limit of detection (<0.17 ng m(-3)). BDE#209 was found in one of the five air samples at a concentration of 0.26 ng m(-3). DeBDethane was also detected in one sample, in which the BDE#209 level was below LOD (<0.021 ng m(-3)), at a level of 0.023 ng m(-3). All the target compounds were found in the sedimentary dust samples at levels from 0.51 to 1600 ng g(-1), the highest concentration representing BDE#209. The most abundant components in plasma, air and dust were BDE#47, #99 and #209. In the plasma samples BDE#207 and #206 were also present at similar concentrations as BDE#47. In the sedimentary dust samples, DeBDethane was also among the most abundant BFRs. A positive relationship was found for the sumBDE concentrations in dust and plasma, although the relationship was strongly dependent on one of the five observations. BFR levels in dust and air were not dependent on the house characteristics such as living area, floor material or number of electronic devices.  相似文献   
53.

Adsorption and mobility of linuron (3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea) and diuron (3-(3,4-dichlorophenyl)-1, 1-dimethylurea) were studied in clayey soils from the Gharb area (Morocco). Soils A and B were planted with sun flower (Helianthus annuus) while soil C was planted with sugar cane (Saccharum offcinarum). Adsorption was studied for linuron in soils A and B, while mobility was studied only in soil B. Adsorption data were found to fit the Freundlich equation with correlation coefficients r2 > 0.9. Freundlich coefficients (Kf, nf) were in agreement with L and S isotherm types for soils A and B, respectively. Values of Koc (195 and 102) indicate moderate adsorption. Desorption isotherms for linuron showed hysteresis for both soils. The pesticide would be more bound to soil A (H = 8.44) than to soil B (H = 4.01). The effect of alternating wet and dry conditions was tested for soils A and B. Results showed that retention would increase in soil subject to an additional wet and dry cycle. In the case of diuron isotherm was of type L in soil C. Desorption was noticeable at high concentrations and tended to decrease when concentrations diminished. Mobility of linuron was tested in polyvinyle chloride (PVC) columns, which received different treatments before their percolation. The pesticide was more mobile in a previously saturated column. In columns subject to a drying step after saturation with water, linuron mobility was greatly reduced.  相似文献   
54.
Extensive ringing data from a coastal site (Falsterbo Bird Observatory) in southwesternmost Sweden were used to investigate the occurrence of reverse autumn migration among 20 passerine bird species of widely different migration categories. The data demonstrate that reverse migration is a widespread and regular phenomenon among nocturnal as well as diurnal migrants and among irruptive migrants, temperate zone migrants, and long-distance migrants destined for tropical winter quarters. The reoriented movements were directed approximately opposite to the normal migration direction, i.e. between NNW and ENE from the coast and towards inland. Median distances of reverse movements varied between 9 and 65 km. Some individuals of irruptive and partial migrants settled to winter in the reverse direction. Bird species with relatively small fat reserves at capture were more likely to perform reverse migratory movements than species with larger fat deposits. In two species birds performing forward migration were significantly heavier within 10 days after capture than individuals performing reverse movements. The reoriented movements probably are of adaptive significance for birds confronted with the sea and pre-disposed to refuelling during migration. A bimodal orientation mechanism will bring the birds from an area with high competition for food and high predation risk to more suitable resting and feeding grounds before resuming migration in the forward direction and crossing the barrier. Received: 11 July 1995/Accepted after revision: 19 November 1995  相似文献   
55.
Several roadside soil samples were collected at two field sites in Sweden. They were analysed for total elemental content (using both ICP-MS and XRF) and stable lead isotopes. Extraction with deicing salt solution and sequential extraction were performed in order to elucidate the potential mobility due to the use of deicing agents. The total concentrations of elements, especially lead, have decreased and lead is presently almost at background concentrations (15-51 ppm for surface samples). However, the isotopic signature indicates that old gasoline lead still is left at the site constructed prior to 1975. The field site constructed in 1992 showed, however, no 206Pb/207Pb ratio below 1.14. Only minor amounts were leached using deicing salt solutions; for lead only 0.29%, on average, was extracted indicating that the mobile fraction already was released. Sequential extraction indicated that lead mainly was associated with reducible (34.4%) and oxidisable (35.4%) fractions. Exchangable and acid soluble fractions contained 20.3% while 10.0% was found in the residual fraction. The salt extraction released, however, very low concentrations indicating that most in fraction 1 is acid soluble (e.g. carbonates). Tungsten was also found at high concentrations indicating a possible impact from studded tires. For tungsten the following composition was obtained: residual (48.0%) > oxidisable (47.6%) > reducible (3.3%) > exchangeable/acid soluble (1.1%). From the isotopic studies it was also suggested that the order for incorporating anthropogenic lead into soils is exchangeable/carbonates > (hydr)oxides > organic matter > residual. The multivariate technique principal component analysis (PCA) seems promising for evaluating large sequential extraction datasets.  相似文献   
56.
The molecular weight changes in abiotically and biotically degraded LDPE and LDPE modified with starch and/or prooxidant were compared with the formation of degradation products. The samples were thermooxidized for 6 days at 100°C to initiate degradation and then either inoculated with Arthobacter paraffineus or kept sterile. After 3.5 years homologous series of mono- and dicarboxylic acids and ketoacids were identified by GC-MS in abiotic samples, while complete disappearance of these acids was observed in biotic environments. The molecular weights of the biotically aged samples were slightly higher than the molecular weights of the corresponding abiotically aged samples, which is exemplified by the increase in from 5200 g/mol for a sterile sample with the highest amount of prooxidant to 6000 g/mol for the corresponding biodegraded sample. The higher molecular weight in the biotic environment is explained by the assimilation of carboxylic acids and low molecular weight polyethylene chains by microorganisms. Assimilation of the low molecular weight products is further confirmed by the absence of carboxylic acids in the biotic samples. Fewer carbonyls and more double bonds were seen by FTIR in the biodegraded samples, which is in agreement with the biodegradation mechanism of polyethylene.  相似文献   
57.
An air sampling method for the determination of isocyanates, aminoisocyanates and amines formed during the thermal degradation of polyurethane (PUR) is presented. The method is based on the collection of air samples using impinger flasks containing di-n-butylamine (DBA) in toluene with a glass fibre filter in series. Isocyanates are derivatized with DBA to urea derivatives, and amines are derivatized in a subsequent work-up procedure with ethyl chloroformate (ET) to carbamate esters. Amine, aminoisocyanate and isocyanate derivatives were characterized using liquid chromatography-time of flight mass spectrometry (LC-TOFMS) and liquid chromatography-chemiluminescent nitrogen detection (LC-CLND). Quantification was performed by LC-MS, monitoring molecular ions [MH]+ in the electrospray mode. The instrumental detection limits for amines, aminoisocyanates and isocyanates were in the ranges 30-40, 2-3 and 3-70 fmol, respectively. Thermal degradation products of PUR were observed in high concentrations during welding in district heating pipes and PUR-coated metal sheets. Eleven isocyanates, three amines and five aminoisocyanates were identified. The concentrations of isocyanates, aminoisocyanates and amines in samples collected in the smoke close to the welding spot were in the ranges 150-650, 4-290 and 1-70 ppb, respectively. In samples collected in the breathing zone, isocyanates and aminoisocyanates were observed in the ranges 9-120 and 4-19 ppb, respectively. The compounds were present in both gas and particle phases. Volatile compounds dominated in the gas phase, whereas less volatile compounds dominated in the particle phase. The method presented makes it possible to sample and determine amines and aminoisocyanates, in addition to isocyanates. The need to monitor these compounds is clearly illustrated by the high concentrations found during the thermal degradation of PUR.  相似文献   
58.
A method for determination of technical grade isocyanates used in the production of polyurethane (PUR) is presented. The isocyanates in technical grade products were characterised as di-n-butylamine (DBA) derivatives using LC-MS and LC-chemiluminescent nitrogen detection (CLND) and the total isocyanate content was compared to a titration assay. For collection of isocyanates in air, an impinger-filter sampling technique with DBA as derivatisation reagent was used. Characterised DBA and nonadeuterium labelled DBA derivatives of isocyanates in technical products were used as calibration standards and internal standards, respectively, in the analysis of air samples. Three workplaces were studied where PUR products were produced either by spraying or by moulding. In both technical products and in air samples, a number of monomeric, oligomeric and prepolymeric isocyanates of e.g. methylenebisphenyl diisocyanate (MDI) and hexamethylene diisocyanate (HDI) were characterised. Several of these have not previously been described in workplace atmospheres. In the technical isocyanate products, between 69 and 102% of the NCO content determined by titration was accounted for by LC-CLND. Quantifications of a wide range of isocyanates in air samples were performed with correlation coefficients in the range 0.988-0.999 (n= 8) and the instrumental detection limits were 0.7-25 pg. At the two workplaces where MDI- and HDI isocyanurate-based products were sprayed, the isocyanate composition in the air reflected the composition in the technical product. At the workplace where a MDI-based product was used in a moulding process, only the monomeric isocyanates were found in the air. The advantage of using characterised technical grade isocyanates as analytical standards was clearly demonstrated and the possibility of using index compounds when monitoring isocyanate exposure is discussed.  相似文献   
59.
Major inorganic ions, pH, total N and P were analyzed in eight arctic snow samples collected in March, April and May 1984 during an expedition in the North Pole region (N83018′ W73006′ - N89.9600). The concentrations of the ions in different samples were close to each other and the values obtained seem to be representative for mean concentrations in the snow. In the sample taken from the North Pole the pH value was 5.00 while the H+-, SO2?4- and NO?3-concentrations were 0.24, 6.2 and 4.3 μmol/l, respectively. The concentrations are exceedingly low and agree very well with earlier results from arctic snow samples.  相似文献   
60.
An air sampling method for simultaneous determination of organic acid anhydrides and isocyanates is presented. Air samples are collected in impinger flasks filled with 0.01 M di-n-butylamine (DBA) in a mixture of toluene-acetonitrile (7:3, v/v) with a 13 millimetre glass fibre filter in series. The amount of anhydrides and isocyanates are determined as their amide and urea derivatives using LC-MS. Four anhydrides, maleic anhydride (MA), phthalic anhydride (PA), tetrahydrophthalic anhydride (TA) and cis-hexahydrophthalic anhydride (HA) and 11 isocyanates could be separated in 9 minutes using gradient elution. Anhydride-DBA derivatives in standard solutions were quantified using LC with chemiluminescent nitrogen detection (CLND). Anhydride-DBA derivatives were found to be stable for at least two months when stored in acetonitrile or toluene in the freezer. The yield of DBA derivatives of anhydrides in the 0.01 M DBA in toluene-acetonitrile (7:3, v/v) was in the range of 70->95%. Using MS and negative electrospray ionisation (ES-) linear calibrations curves were obtained for the anhydrides with correlation coefficients ranging from 0.9970-0.9997. The instrumental detection limit for the anhydrides ranged from 10-30 fmol, based on a signal to noise root mean square (RMS) ratio of 3. Monitoring positive and negative ions simultaneously, both isocyanates and anhydrides could be determined as their DBA derivatives in the same chromatographic run. When air samples were collected during thermal degradation of different coated metal sheets both anhydrides and isocyanates were present in the same samples and all the studied anhydrides were found.  相似文献   
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