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This study presents the application of different chemometric approaches on the dataset obtained during the monitoring of offset printing wastewater quality in Pozarevac, Serbia. Collecting of wastewaters was performed during a working week, five working days, in five offset printing facilities. Twenty five physico-chemical parameters were analyzed in wastewaters using the standard analytical and instrumental methods. The obtained dataset were subjected to cluster analysis and principal component analysis. Cluster analysis showed four groups of similarity between the printing facilities reflecting the different physico-chemical characteristics and pollution levels of studied wastewaters. Principal component analysis identified two principal components responsible for the data structure explaining 86 % of total variance of offset printing wastewaters. The obtained principal components indicate the parameters that are the most responsible for variation of offset printing wastewaters. This study clearly demonstrates the usefulness of chemometric methods in analysis of printing wastewater quality, identification of the main sources and understanding of spatial variations in wastewater quality. Also, it could be useful for the selection of an appropriate wastewater treatment plant.  相似文献   
2.
Some 15% of solar flares having a soft X-ray flux above GOES class C5 are reported to lack coherent radio emission in the 100 – 4000 MHz range (type I – V and decimetric emissions). A detailed study of 29 such events reveals that 22 (76%) of them occurred at a radial distance of more than 800″ from the disk center, indicating that radio waves from the limb may be completely absorbed in some flares. The remaining seven events have statistically significant trends to be weak in GOES class and to have a softer non-thermal X-ray spectrum. All of the non-limb flares that were radio-quiet above 100 MHz were accompanied by metric type III emission below 100 MHz. Out of 201 hard X-ray flares, there was no flare except near the limb (R>800″) without coherent radio emission in the entire meter and decimeter range. We suggest that flares above GOES class C5 generally emit coherent radio waves when observed radially above the source.  相似文献   
3.
Miljacka is a karst spring situated in Dalmatia, Croatia. The interpretation of the Miljacka Spring catchment area boundary has repeatedly changed in the past, and the main conclusions of previous studies were that the spring, which is located in the Krka River canyon, receives all of its water from another karst river, Zrmanja. Here, we review a new hypothesis that the Miljacka Spring receives some of its water from the Krka River. It was not possible to verify the hypothesis by solely studying the geological composition, structural–tectonic relations and tracer test results. Therefore, a hydrochemical study was performed to confirm the hypothesis. By studying the geological composition, it was found that part of the catchment area of the Krka River is built of evaporites (gypsum and anhydrite), which are different in their mineral composition than carbonates, the usual rock mass of the Dinaric karst. The hydrochemical model was made using the NETPATH-WIN and PHREEQC software packages. The mixing model results confirmed the hypothesis that the Miljacka Spring waters come from both the Zrmanja (including smaller proportion of precipitation infiltrated directly in the karst aquifer) and Krka rivers. This case study shows the great importance of the application of hydrochemical investigations in karst hydrogeology, where research is often difficult due to the complexity of the groundwater system.  相似文献   
4.
Natural Resources Research - The Bokanjac–Poli?nik system, as a complex set of mutually interrelated Dinaric karst catchments and sub-catchments, is a highly vulnerable and limited...  相似文献   
5.
In the last decades, the development of transport infrastructure has been necessary because of the population increase and expansion of urban centres. Infrastructure development leads to modification and changes in areas characterized by high human population density. The lack of adequate transport infrastructure inhibits local economic and social performance. In the period of economic stability (from 1970 to 1990), important roads that increased the connectedness of the Kolubara District (Western Serbia) with other parts of the country and the surrounding countries were built, but there is still a need for the construction of new roads. In order to examine the attitude of the local population in regard to transport infrastructure, a survey was conducted using a questionnaire consisting of closed questions. This topic is one that has not previously been examined. The data obtained were analyzed statistically and showed that local people have a positive attitude towards the existing infrastructure and towards the construction of new roads. There are statistically significant differences between the attitudes of the local population in different municipalities. The results from this research offer an opportunity to develop guidelines which can influence traffic development in these and similar areas.  相似文献   
6.
Theoretical and Applied Climatology - Due to intense highway congestion in Europe, increased percentage of highway accidents, as well as mortality rate, safety is an imperative in highway planning...  相似文献   
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