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1.
Journal of Material Cycles and Waste Management - The relationship between local structure and visible-light-activated photocatalytic ability of glass–ceramics prepared from Municipal Solid...  相似文献   
2.
Sub-Saharan African countries are being strongly urged to enhance their rice production, because their rice consumption and importation rates have been rapidly increasing in recent years. Areas planted to rice in Africa are classified agro-ecologically into rainfed upland, rainfed lowland, and irrigated. Rainfed lowland includes extensive areas of unexploited land that has great potential for the promotion of rice growing. For the unexploited rainfed lowlands of Ghana, we have been studying the development of low-cost rice-farming systems that require no large-scale irrigation or land reclamation. For such systems, it is important to select suitable areas where water for rice farming can be obtained naturally; floodwaters offer promise for this purpose. Delineation and mapping of floodwater prone areas suitable for rice production is important for successful utilization of this land resource. Here, we propose a method of assessing flood probability from submergence frequency, as estimated from satellite imagery and geospatial data. ALOS/PALSAR images acquired in May, June, August, and September 2010 were used to classify land and water, and then a submerged-area map was produced. From the results, we were able to accurately detect non-submerged areas and submerged areas with water depths of at least 3?cm. The number of times classified into submerged area was defined as submergence frequency, and it was approximated by distance from reservoirs representing White Volta River, ponds, and swamps. In addition, flood extent derived from reservoirs was simulated using digital elevation model (DEM). Finally, a flood probability assessment map was produced by integration of the estimated submergence frequency and flood extent simulation. The results of a comparison of soil moisture data measured at 69 points in the field and the NDVIs computed by ALOS/AVNIR showed that areas with high potential for flooding retained high levels of soil moisture and were more likely to show less deterioration of vegetation in the dry season. The validation of these results confirmed the adequacy of the flood probability assessment method.  相似文献   
3.
为了研究森林衰退的原因,于2000,2001和2002年的8月,分别选择出现森林衰退的日本奥日光白根山落叶树森林和未出现森林衰退的长野县大芝高原红松森林设立监测点,对光化学氧化剂臭氧(O3)和过氧化物的浓度进行监测,同时利用人工气候室对森林植物山毛榉和白桦进行了50′10-9O3、100′10-9O3和50′10-9O3+2′10-9~3′10-9过氧化物(过氧化氢(H2O2)及甲基过氧化氢(MHP))的暴露实验.野外监测结果表明,监测期间奥日光和长野的O3平均浓度相同,奥日光的H2O2及MHP平均浓度均高于长野;大气中的H2O2和MHP总是与O3共存,并且其浓度随O3浓度的增加而增加.暴露实验结果表明,暴露于50′10-9O3+2′10-9~3′10-9过氧化物的山毛榉和白桦出现了不同于O3暴露的叶片伤害症状;与100′10-9O3相比,50′10-9O3+2′10-9~3′10-9过氧化物导致植物出现了严重的叶片伤害和显著的光合速率下降.研究结果表明,除O3外,大气中的过氧化物也是导致森林衰退的原因之一.  相似文献   
4.
ABSTRACT

Easy-to-use commercial kit-based enzyme-linked immunosorbent assays (ELISAs) have been used to detect neonicotinoid dinotefuran, clothianidin and imidacloprid in Chinese chives, which are considered a troublesome matrix for chromatographic techniques. Based on their high water solubility, water was used as an extractant. Matrix interference could be avoided substantially just diluting sample extracts. Average recoveries of insecticides from spiked samples were 85–113%, with relative standard deviation of <15%. The concentrations of insecticides detected from the spiked samples with the proposed ELISA methods correlated well with those by the reference high-performance liquid chromatography (HPLC) method. The residues analyzed by the ELISA methods were consistently 1.24 times that found by the HPLC method, attributable to loss of analyte during sample clean-up for HPLC analyses. It was revealed that the ELISA methods can be applied easily to pesticide residue analysis in troublesome matrix such as Chinese chives.  相似文献   
5.
Observations of air pollutants were conducted in remote Japanese islands (Oki Island and Okinawa Island) in early spring to clarify the extent of trans-boundary air pollution from the Asian continent. A three-dimensional Eulerian model calculation, which included parameters on emission, transport and transformation of sulfur oxides, nitrogen oxides and ammonia, was performed to compile sulfate isosurface concentrations over the observational sites. Concentrations of non-sea-salt sulfate (nss-SO42−) of greater than 10 μg m−3 were observed at Oki after the northeastward passage of low-pressure systems in the Sea of Japan. At these times, the weather showed a typical winter pattern and air pollutants over China were transported southeastward to Japan with the northwesterly wind. The model calculation reproduced the observed variations of nss-SO42− concentration well, except for one case in which the model calculation could not reproduce the extremely low nss-SO42− concentration observed on 8 March. In Hedo (Okinawa Island), we observed long-lasting (3 days) medium concentrations of nss-SO42− (approximately 5 μg m−3). Although the model reproduced these observed medium concentrations well, in general the observed results were reproduced better for Oki than for Hedo. Under the synoptic weather conditions of early spring, high concentrations of nss-sulfate were sometimes transported to these remote Japanese islands from areas of continental Asia with a strong outflow of air pollutants.  相似文献   
6.
Polycarbonate (PC) pellets were subjected to dilute aqueous ammonia solution under hydrothermal conditions in a semi-batch reactor at temperatures ranging from 433 to 463 K and at a pressure of 10 MPa. The PC pellets were almost completely converted to bisphenol A (BPA). During an initial certain period, referred to as an induction time, neither BPA nor total organic carbon in solution were detected, and the BPA yield increased with time. The monomer yield was well represented by a surface reaction model, two-thirds-order reaction with respect to the mass of unreacted PC. The overall rate constant of the reaction in 0.6 mol/kg aqueous ammonia solution at 433 K was about 15 times greater than that in 0.6 mol/kg NaOH solution. The rate constant at 433 K was proportional to the ammonia or NaOH concentration. There was a correlation between the induction time and temperature, as well as the ammonia or NaOH concentration. By carrying out the reaction in aqueous mixtures of (NH4)2SO4 and NaOH at various concentrations of NaOH, ammonia was confirmed not to function as an alkaline reagent, but as a nucleophile reagent.  相似文献   
7.
DFT calculations in gas and aqueous solution phases have been performed to study the mechanism of carbamate formation by the absorption of CO2 in 2-amino-2-methyl-1-propanol (AMP). The results reveal the importance of considering the effect of water as solvent for the reaction to proceed. Furthermore water molecules play an important role as a basic reactant leading to stable intermediates formation. These results point at a single-step, third order reaction as the most probable mechanism for the formation of carbamate by the absorption process.  相似文献   
8.
9.
Chronic effects of Cd on reproduction of Polypedilum nubifer (Chironomidae) were investigated by Cd-exposure from the egg stage using a flow-through aquarium. No significant effect of Cd on reproduction was observed in the midge larvae which had been exposed to 10 or 20 microg Cd litre(-1). Emergence of the Cd-exposed larvae peaked several days before that of the control, although growth was impaired in 1st and/or 2nd instars. The percentage emergence success decreased to about 46% of the control at 40 microg Cd litre(-1). However, other reproductive processes (adult sex ratio, oviposition success and egg hatchability) were not impaired. The emergence success decreased to less than 3% of the control at 80 microg Cd litre(-1). The emergence success of midge larvae which had been fed Cd-contaminated food with 220 or 1800 microg Cd g(-1) decreased to nearly 60% of the control. However, other reproductive processes were not impaired. Emergence success of larvae exposed to food containing 22 microg Cd g(-1) was unaffected.  相似文献   
10.
Chronic effects of chlornitrofen (CNP) on the reproduction of Brachionus urceolaris (Rotatoria) were investigated by exposure of individuals to CNP from the egg stage, which had been attached to the adult. The survivors of 12 neonates, which had been exposed to CNP100, 70 or 40 microg liter(-1) decreased to 50% at the age of c. 2, 4 and 6 days, respectively, compared to c. 6.5 days for those exposed to 0, 10 and 20 microg liter(-1) CNP. Release of offspring (mostly two individuals per day) started at two days old. At the peak, four days old, a control female produced 8.1+/-0.9 offspring per day compared with 4.5+/-1.3 (mean+/-SD, n=12) at 40 microg liter(-1). The cumulative numbers of offspring produced by a female were 25.8+/-1.2, 24.2+/-2.9, 22.3+/-3.6 and 13.6+/-3.1 (mean+/-SD, n=12) at control, 10, 20 and 40 microg liter(-1) CNP exposure, respectively. The 50% reproductive impairment concentration was calculated to be 37 microg liter(-1). Growth of neonates was barely detectable at 70 microg liter(-1), and the rapid increase in the effect of CNP from 40 to 70 microg liter(-1) was attributed to an increase in tolerance with growth of the neonates. The effects of CNP on reproduction were also tested by CNP exposure through food (CNP-accumulated Chlorella). The 50% reproductive impairment concentration of CNP in the alga was calculated to be c.60 microg g(-1) (wet weight) by the same method used to assess the dissolved CNP, although the effect of CNP which may have been released from the alga to the water could not be estimated precisely.  相似文献   
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