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1.
Wireless sensor networks (WSNs) play an important role in forest fire risk monitoring. Various applications are in operation. However, the use of mobile sensors in forest risk monitoring remains largely unexplored. Our research contributes to fill this gap by designing a model which abstracts mobility constraints within different types of contexts for the inference of mobile sensor behaviour. This behaviour is focused on achieving a suitable spatial coverage of the WSN when monitoring forest fire risk. The proposed mobility constraint model makes use of a Bayesian network approach and consists of three components: (1) a context typology describing different contexts in which a WSN monitors a dynamic phenomenon; (2) a context graph encoding probabilistic dependencies among variables of interest; and (3) contextual rules encoding expert knowledge and application requirements needed for the inference of sensor behaviour. As an illustration, the model is used to simulate the behaviour of a mobile WSN to obtain a suitable spatial coverage in low and high fire risk scenarios. It is shown that the implemented Bayesian network within the mobility constraint model can successfully infer behaviour such as sleeping sensors, moving sensors, or deploying more sensors to enhance spatial coverage. Furthermore, the mobility constraint model contributes towards mobile sensing in which the mobile sensor behaviour is driven by constraints on the state of the phenomenon and the sensing system.  相似文献   
2.
The motives for constructing Spatial Data Infrastructures (SDIs) are often based on their anticipated benefits for society, economy, and environment. According to those widely articulated but rarely proven benefits, SDI coordinators have been defining more specific objectives to be achieved by their SDIs. However, there is a limited number of assessment approaches that are able to demonstrate whether SDIs indeed realize the intended goals. In this article we develop, apply and evaluate an assessment view for evaluating the extent to which SDIs realize their goals. The assessment view has been developed stepwise using the Multi-view SDI assessment framework as a guideline. The application of the proposed view in the Dutch SDI demonstrates its potential. In addition, the evaluation of the proposed view by the potential users confirms to a certain extent its usability. The results also show that the ease of determining assessment indicators depends on the precision with which the SDI goals are formulated.  相似文献   
3.
We study the degradation of photovoltaic cells with poly(3-hexyl thiophene) (P3HT) and (6,6)-phenyl C61-butyric acid methyl ester (PCBM) blends under long-term continuous illumination as well as in shelf-life conditions, both in inert N2 atmosphere. Degradation of the illuminated solar cells mainly occurs by a rapid decrease of the fill factor (FF) after 300 h, while short-circuit current and open-circuit voltage follow a linear decay after the initial burn-in. The sudden drop of the FF is correlated with an increase of the series resistance and proves irreversible upon annealing. Electrical measurements indicate that it stems from reduced charge extraction due to the photodegradation of the organic-electrode interfaces. Furthermore, as the external quantum efficiency (EQE) spectrum is evenly lowered over the entire wavelength range, we could exclude major changes in the blend morphology or significant changes to optical properties of the active layer. Introducing a thin C60 layer leads to complete suppression of the FF decay over 1000 h, further proving that interface degradation dominates. Interestingly, similar improved lifetime over 1000 h was achieved by separate substitution of MoO3 for PEDOT:PSS.  相似文献   
4.
Early detection of infection is very important for efficient management of Mycosphaerella graminicola leaf blotch. To monitor and quantify the occurrence of this fungus during the growing season, a diagnostic method based on real-time PCR was developed. Standard and real-time PCR assays were developed using SYBR Green chemistry to quantify M. graminicola in vitro or in wheat samples. Microsatellite dinucleotide specific-primers were designed based on microsatellite repeats of sequences present in the genome of M. graminicola. Specificity was checked by analyzing DNA of 55 M. graminicola isolates obtained from different geographical origins. The method appears to be highly specific for detecting M. graminicola; no fluorescent signals were observed from 14 other closely related taxa. Primer (CT) 7 G amplified a specific amplicon of 570 bp from all M. graminicola isolates. The primers did not amplify DNA extracted from 14 other fungal species. The approximate melting temperature (Tm) of the (CT) 7 G primer was 84.2 °C. The detection limit of the real-time PCR assay with the primer sets (CT) 7 G is 10 fg/25 μL, as compared to 10 pg/25 μL using conventional PCR technology. From symptomless leaves, a PCR fragment could be generated two days after inoculation. Both conventional and real-time PCR could successfully detect the fungus from artificially inoculated wheat leaves. However, real-time PCR appeared much more sensitive than conventional PCR. The developed quantitative real-time PCR method proved to be rapid, sensitive, specific, cost-effective and reliable for the identification and quantification of M. graminicola in wheat.  相似文献   
5.
Estimating mycotoxin contents of Fusarium-damaged winter wheat kernels   总被引:1,自引:0,他引:1  
Winter wheat (Triticum aestivum L., cultivars Ritmo and Dekan) grain was sampled in Northern Germany between 2001 and 2006. Kernels damaged by fungi of the genus Fusarium were separated from sound grain by visual assessment. Samples containing 0%, 20%, 40%, 60%, 80% and 100% of Fusarium-damaged kernels were compiled and analyzed for the Fusarium type B trichothecenes deoxynivalenol (DON, 2001-2006), nivalenol (NIV, 2006), 3-acetyl-deoxynivalenol (3AcDON, 2006) and 15-acetyl-deoxynivalenol (15AcDON, 2006). The relationship between mycotoxin contents and the percentage of Fusarium-damaged kernels was calculated for each lot of grain. Apart from one exception, relationships between the percentage of Fusarium-damaged kernels and NIV, 3AcDON or 15AcDON were non-significant. In contrast, close relationships between the percentage of Fusarium-damaged kernels and the DON content were observed (r(2)=0.93-0.99). The y-axis intercepts were not significantly different from zero, but the DON content of the damaged kernels varied by a factor of 11.59 between years and by a factor of 1.87 between cultivars. Fusarium-damaged kernels contained between 0.21 and 2.39 microg DON kernel(-1). The overall average DON content of a Fusarium-damaged wheat kernel was 1.29 +/- 0.11 microg. The DON content of diseased kernels was affected by environment and wheat genotype but not by genotype x environment interaction. On average, Fusarium-damaged kernels contained 9.7-fold more DON than 15AcDON, 19.5-fold more DON than NIV, and 26.9-fold more DON than 3AcDON. 3AcDON and 15AcDON contents per wheat kernel were not significantly different between cultivars. On average, 4.27% of Fusarium-damaged kernels were sufficient to reach the 1.25 mg DON kg(-1) grain limit for unprocessed cereals in the EU. Given the low percentages of Fusarium-damaged kernels that are equivalent to current legal DON limits, grading accuracies >96% would be needed when using automatic grading systems for separating sound from damaged kernels.  相似文献   
6.
The purpose of this pilot study was: 1) to describe factors associated with a perceived harmful outcome following medication errors made by nurses and 2) to refine the Medication Error Risk Profile (MERP) (Wolf, 1992). Ninety-four registered nurses and licensed practical nurses completed the MERP. Multiple stepwise regression analyses were used to explain the variance in the dependent variable of perceived patient harm with: 1) phases of preparation and administration; 2) categories of person responsible for the error; 3) interventions needed following the error and symptoms related to the error. The exploratory regression analysis suggests a model in which the dispensing phase of administration, the physician and pharmacist categories of persons responsible for the error, and the interventions of patient transfer to another unit and additional medications given following the error explain 53% of the variance in perceived harmful outcome for patients consequent to medication errors. A moderately strong correlation (r = .46, P < .001) existed between perceived patient harm as measured on the four-point scale and total intervention score following medication errors.  相似文献   
7.
The goals of this investigation were to identify and evaluate the use of polymorphic microsatellite marker (PMM) analysis for molecular typing of seventeen plant pathogenic fungi. Primers for di-, tri-, and tetranucleotide loci were designed directly from the recently published genomic sequence of Mycospherlla graminicola and Fusarium graminearum. A total of 20 new microsatellite primers as easy-to-score markers were developed. Microsatellite primer PCR (MP-PCR) yielded highly reproducible and complex genomic fingerprints, with several bands ranging in size from 200 to 3000 bp. Of the 20 primers tested, only (TAGG)4, (TCC)5 and (CA)7T produced a high number of polymorphic bands from either F. graminearum or F. culmorum. (ATG)5 led to successful amplifications in M. graminicola isolates collected from Germany. Percentage of polymorphic bands among Fusarium species ranged from 9 to 100%. Cluster analysis of banding patterns of the isolates corresponded well to the established species delineations based on morphology and other methods of phylogenetic analysis. The current research demonstrates that the newly designed microsatellite primers are reliable, sensitive and technically simple tools for assaying genetic variability in plant pathogenic fungi.  相似文献   
8.
The objective of this study was to document trends in public participation within environmental impact assessment (EIA) in Kenya, using a Consultation and Public Participation Index (CPPI) developed for the analysis of EIA Study Reports submitted to the Environment Authority between 2002 and 2010. Results indicated that public participation remained relatively low, with the highest score of 1.65 in 2010, out of a possible score of 5. Scores for individual dimensions within the index fluctuated during the study period, with participation methods and type of participants scoring the highest, following increased emphasis by the Environment Authority on the conducting and reporting of public participation. This was followed by venue, notification and language used, in that order, which were often not reported, and, when reported, choices per dimension were limited. This is the first time this index has been used, yet it serves as a good starting point to evaluate public participation within EIA.  相似文献   
9.
This paper focuses on a geoportal from a “what lies beneath” perspective. It analyses processes of budgeting, planning, monitoring, performance measurement, and reporting of the national initiative titled Digital Information of the Dutch Subsurface (known by its Dutch acronym, DINO). The study is used as a means to empirically refine a conceptual model that illuminates how external agents influence or control the coordination of geo-information in the public sector. DINO is developed and maintained in a formal principal-agent relationship with clear objectives and accountability. DINO is managed by the Netherlands Institute of Applied Geoscience (the agent) through a performance-based management contract with the sponsoring Geo-Information Commission (the principals). The DINO program is characterized by the pooling of financial resources from five ministries, the internal tracking of activity progression, the routine reporting to the user community, and the regular monitoring and evaluation of DINO by the Geo-Information Commission. The case study reveals that ‘soft’ rather than ‘hard’ controls are used and that ‘mutual shaping’ takes place, with the agent influencing how it is ‘controlled’ by the principal. However, the management contract still relies on a power disparity and reinforces previous research findings that external parties can influence network/coordination conditions. In-depth case studies such as this work can increase understanding of evaluation in the context of politico-administrative processes and improve researchers’ ability to critically compare geoportal initiatives.  相似文献   
10.
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