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31.
Applicants' pretest expectations about the forthcoming selection procedure may serve as a key factor in applicants' decision‐making. The current study examined the validity of the theory of planned behavior (TPB) as an explanatory mechanism of the relationship between pretest selection expectations (warmth/respect, chance to demonstrate potential, difficulty of faking, unbiased assessment, feedback) and job pursuit behavior. Data were collected at two points in time, using a sample of applicants for the military. Selection expectations, job pursuit attitude, subjective norm, and controllability were significantly related to job pursuit intention. Job pursuit attitude mediated the relationship between selection expectations and job pursuit intention. Subjective norm and time lag were the only significant predictors of job pursuit behavior. Practical implications, strengths and limitations, as well as directions for further research are discussed. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
32.
Aluminium (Al) speciation is a characteristic that can be used as a tool for describing the soil acidification process. The question that was answered is how tree species (beech vs spruce) and type of soil horizon affect Al speciation. Our hypotesis is that spruce and beech forest vegetation are able to modify the chemical characteristics of organic horizon, hence the content of Al species. Moreover, these characteristics are seasonally dependent. To answer these questions, a detailed chromatographic speciation of Al in forest soils under contrasting tree species was performed. The Jizera Mountains area (Czech Republic) was chosen as a representative mountainous soil ecosystem. A basic forestry survey was performed on the investigated area. Soil and precipitation samples (throughfall, stemflow) were collected under both beech and spruce stands at monthly intervals from April to November during the years 2008–2011. Total aluminium content and Al speciation, pH, and dissolved organic carbon were determined in aqueous soil extracts and in precipitation samples. We found that the most important factors affecting the chemistry of soils, hence content of the Al species, are soil horizons and vegetation cover. pH strongly affects the amount of Al species under both forests. Fermentation (F) and humified (H) organic horizons contain a higher content of water extractable Al and Al3+ compared to organo-mineral (A) and mineral horizons (B). With increasing soil profile depth, the amount of water extractable Al, Al3+ and moisture decreases. The prevailing water-extractable species of Al in all studied soils and profiles under both spruce and beech forests were organically bound monovalent Al species. Distinct seasonal variations in organic and mineral soil horizons were found under both spruce and beech forests. Maximum concentrations of water-extractable Al and Al3+ were determined in the summer, and the lowest in spring.  相似文献   
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34.
We performed detrended correspondence analysis (DCA) ordination to compare seven successional seres running in stone quarries, coal mining spoil heaps, sand and gravel pits, and extracted peatlands in the Czech Republic in central Europe. In total, we obtained 1,187 vegetation samples containing 705 species. These represent various successional stages aged from 1 to 100 years. The successional seres studied were more similar in their species composition in the initial stages, in which synathropic species prevailed, than in later successional stages. This vegetation differentiation was determined especially by local moisture conditions. In most cases, succession led to a woodland, which usually established after approximately 20 years. In very dry or wet places, by contrast, where woody species were limited, often highly valuable, open vegetation developed. Except in the peatlands, the total number of species and the number of target species increased during succession. Participation of invasive aliens was mostly unimportant. Spontaneous vegetation succession generally appears to be an ecologically suitable and cheap way of ecosystem restoration of heavily disturbed sites. It should, therefore, be preferred over technical reclamation.  相似文献   
35.
Environmental Geochemistry and Health - Identifying a suitable geochemical background level (GBL) and an appropriate normalizer is imperative for ensuring soil quality, health, and security. The...  相似文献   
36.
The synthesis of microcellular porous polymers based on 2-hydroxyethyl methacrylate (HEMA) by free radical polymerisation of a continuous phase of high internal phase emulsion (HIPE) is reported. N,N’-methylene bisacrylamide (MBAA) and glutaraldehyde are used as crosslinking agents. GA is added to the monomer phase either during the emulsion preparation or post polymerisation crosslinking of HEMA is performed. The crosslinker influences the morphological structure of porous poly(HEMA) materials. In the case of using MBAA as the crosslinker, homogeneous polyHIPE structure is obtained, with average cavities diameter approximately 8 μm and interconnecting pore diameter approximately 3 μm. In the case of using GA in situ crosslinking a polyHIPE is obtained exhibiting cavities of diameter approximately 12 μm and interconnecting pores of approximately 3 μm. Post polymerisation crosslinking with GA influence the structural features resulting in a different morphology. Samples are characterised using FTIR spectroscopy, scanning electron microscopy, nitrogen adsorption and swelling behaviour measurements. Polymers are prepared in the form of monoliths and membranes.  相似文献   
37.
Bioavailable water concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed at several freshwater sites in and around the city of Amsterdam. Carp (Cyprinus carpio) were caged for 4 weeks at 10 sites, together with semipermeable membrane devices (SPMDs). In addition, sediment samples were taken at each site. SPMDs and sediments were analysed for PAHs, PCBs and OCPs. Carp muscle tissues were analysed for PCBs and OCP, while PAH metabolites were assessed in fish bile. Contaminant concentrations in the water phase were estimated using three different methods: 1. Using fish tissue concentrations and literature bioconcentration factors (BCFs), 2. Using SPMD levels and a kinetic SPMD uptake model, and 3. Using sediment levels and literature sorption coefficients (Kocs). Since PAH accumulation in fish is not considered an accurate indicator of PAH exposure, calculated aqueous PAH concentrations from SPMD data were compared with semiquantitatively determined biliary PAH metabolite levels. Contaminant concentrations in the water phase estimated with fish data (Cwfish) and SPMD data (Cwspmd) were more in line for compounds with lower Kow than for compounds with higher Kow values. This indicates that the assumption of fish–water sorption equilibrium was not valid. At most sites, sediment-based water levels (Cwsed) were comparable with the Cwspmd, although large differences were observed at certain sites. A significant correlation was observed between biliary PAH metabolite levels in fish and aqueous PAH concentrations estimated with SPMD data, suggesting that both methods may be accurate indicators of PAH exposure in aquatic ecosystems.  相似文献   
38.
Vegetation development of sites restored by two different methods, spontaneous revegetation and forestry reclamation, was compared in four sand pit mining complexes located in the southern part of the Czech Republic, central Europe. The space-for-time substitution method was applied to collect vegetation records in 13 differently aged and sufficiently large sites with known history. The restoration method, age (time since site abandonment/reclamation), groundwater table, slope, and aspect in all sampled plots were recorded in addition to the visual estimation of percentage cover of all present vascular plant species. Multivariate methods and GLM were used for the data elaboration. Restoration method was the major factor influencing species pattern. Both spontaneously revegetated and forestry reclaimed sites developed towards forest on a comparable timescale. Although the sites did not significantly differ in species richness (160 species in spontaneously revegetated vs. 111 in forestry reclaimed sites), spontaneously revegetated sites tended to be more diverse with more species of conservation potential (10 Red List species in spontaneous sites vs. 4 Red List species in forestry reclaimed sites). These results support the use of spontaneous revegetation as an effective and low-cost method of sand pit restoration and may contribute to implementation of this method in practice.  相似文献   
39.
Dredging and dumping of dredged sediments in estuarine and coastal waters may lead to increased turbidity and enhanced sediment deposition at dump sites. This mainly affects primary production by phytoplankton, performance of visual predators (e.g. fish, birds), and growth and survival of benthic organisms. This paper combines a compilation of literature information and results of additional experimental studies on the effect of enhanced concentrations of suspended matter (SPM) on growth of bivalve molluscs, and on survival of macro- and meiozoobenthos after dumping of dredged sediments. Furthermore, it focuses on non-toxic dredged sediments only. Release of nutrients from dredged sediments did, so far, hardly influence estuarine phytoplankton production. Increased turbidity may affect dab as well as prey location by sandwich terns. Enhanced SPM-concentrations are unfavourable for young herring and smelt. Growth of filter-feeding bivalves may be impaired, especially at SPM-concentrations >250 mg/l. Estuarine nematodes can survive burial by 10 cm of dumped dredged sediment provided that its physical characteristics are similar to those of the original sediment. Sessile benthos organisms such as mussels and oysters can cope with sediment deposition of only 1–2 cm. Other macrozoobenthos can survive sediment deposition of 20–30 cm. Recovery of benthos at a dump site will occur if the interval between successive dumpings is sufficiently long. Options for management of dumping of dredged sediments are described, relating to different locations of dump sites in estuarine and coastal waters, to different seasons, and to the actual use (area and frequency) of dump sites.  相似文献   
40.
The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznań (Poland). The determined aluminium content amounted from <0.0001 to 752.7 μg L(-1). The aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling.  相似文献   
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