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261.
262.
A method is proposed for determining the heat capacity of posistors. The temperature dependence of the heat capacity is considered.  相似文献   
263.
To evaluate the use of multi-frequency, polarimetric Synthetic Aperture Radar (SAR) data for quantifying the above ground biomass (AGB) of open forests and woodlands, NASA JPL AIRSAR (POLSAR) data were acquired over a 37 × 60 km area west of Injune, central Queensland, Australia. From field measurements recorded within 32 50 × 50 m plots, AGB was estimated by applying species-specific allometric equations to stand measurements. AGB was then scaled-up to the larger area using relationships established with Light Detection and Ranging (LiDAR) data acquired over 150 (10 columns, 15 rows) 500 × 150 m cells (or Primary Sampling Units, PSUs) spaced 4 × 4 km apart in the north- and east-west directions. Large-scale (1 : 4000) stereo aerial photographs were also acquired for each PSU to assess species composition. Based on the LiDAR extrapolations, the median AGB for the PSU grid was 82 Mg ha− 1 (maximum 164 Mg ha− 1), with the higher levels associated with forests containing a high proportion of Angophora and Callitris species. Empirical relationships between AGB and SAR backscatter confirmed that C-, L- and P-band saturated at different levels and revealed a greater strength in the relationship at higher incidence angles and a larger dynamic range and consistency of relationships at HV polarizations. A higher level of saturation (above ∼50 Mg ha− 1) was observed at C-band HV compared to that reported for closed forests which was attributable to a link between foliage projected cover (FPC) and AGB. The study concludes that L-band HV backscatter data acquired at incidence angles approaching or exceeding 45° are best suited for estimating the AGB up to the saturation level of ∼80-85 Mg ha− 1. For regional mapping of biomass below the level of saturation, the use of the Japanese Space Exploration Agency (JAXA) Advanced Land Observing Satellite (ALOS) Phase Arrayed L-band SAR (PALSAR) is advocated.  相似文献   
264.
Bimetallic nanoparticles have been widely studied for wastewater treatment, but the study of nanoFeCu for sewage treatment is minimal. In the previous work, ammonia was removed by nanoFeCu via an oxidation reaction, and nitrogen gas was released. However, the performance and reusability of nanoFeCu in treating industrial wastewater have not been reported elsewhere. This study revealed the performance of nanoFeCu for sewage treatment on both laboratory-scale and pilot-scale for the first time. A varied mass of embedded nanoFeCu (eFeCu4) was exposed to sewage water, and the quality of the effluent was measured in terms of ammonia, biological oxygen demand (BOD), and chemical oxygen demand (COD) removal. Fe2+ and Cu2+ concentrations were measured to determine the stability of eFeCu4 in nine reuse cycles. Results showed that the laboratory-scale experiment removed 20%–30% ammonia from sewage. A similar removal rate was reported in all nine cycles of reuse, which confirmed the usability and reliability of eFeCu4. In the pilot-scale study, ammonia was removed from ~22.3 to ~4.8 mg/L, while BOD and COD were reduced from ~204 to ~56 mg/L and ~71 to ~39.7 mg/L, respectively. The treated effluent quality complies with the effluent discharge standard of Malaysia, and it is also comparable with the effluent quality at sewage treatment plants in Malaysia and overseas. In conclusion, nanoFeCu could be an alternative method for sewage treatment due to its stability and pollutant removal performance. A sustainability and cost-effectiveness study should be conducted to determine the feasibility of a full-scale application.  相似文献   
265.
Clean Technologies and Environmental Policy - The production of dairy products is related to water and energy costs and generation of large amounts of emissions of pollutants. Full sustainability...  相似文献   
266.
Environmental or abiotic stresses are a common threat that remains a constant and common challenge to all plants. These threats whether singular or in combination can have devastating effects on plants. As a semiaquatic plant, rice succumbs to the same threats. Here we systematically look into the involvement of salicylic acid (SA) in the regulation of abiotic stress in rice. Studies have shown that the level of endogenous salicylic acid (SA) is high in rice compared to any other plant species. The reason behind this elevated level and the contribution of this molecule towards abiotic stress management and other underlying mechanisms remains poorly understood in rice. In this review we will address various abiotic stresses that affect the biochemistry and physiology of rice and the role played by SA in its regulation. Further, this review will elucidate the potential mechanisms that control SA-mediated stress tolerance in rice, leading to future prospects and direction for investigation.  相似文献   
267.
While response time and accuracy indicate overall performance, their value in uncovering cognitive processes, underlying learning, is limited. A promising online measure, designed to track decision-making, is computer mouse tracking, where mouse attraction towards different locations may reflect the consideration of alternative response options. Using a speedy arithmetic multiple-choice game in an online adaptive learning environment, we examined whether mouse movements could reflect arithmetic difficulties when error rates are low. Results showed that mouse movements towards alternative responses in correctly answered questions mapped onto the frequency of errors made in this online learning system. This mapping was stronger for the younger children, as well as for easy arithmetic problems. On an individual level, users showed more mouse movement towards their previously made response errors than towards other alternative options. This opens the possibility of adapting feedback and instruction on an individual basis through mouse tracking.  相似文献   
268.
Bayesian networks for system reliability reassessment   总被引:2,自引:0,他引:2  
This paper proposes a methodology to apply Bayesian networks to structural system reliability reassessment, with the incorporation of two important features of large structures: (1) multiple failure sequences, and (2) correlations between component-level limit states. The proposed method is validated by analytical comparison with the traditional reliability analysis methods for series and parallel systems. The Bayesian network approach is combined with the branch-and-bound method to improve its efficiency and to facilitate its application to large structures. A framed structure with multiple potential locations of plastic hinges and multiple failure sequences is analyzed to illustrate the proposed method.  相似文献   
269.
The importance of lymphatic vessels in a myriad of human diseases is rapidly gaining recognition; lymphatic vessel dysfunction is a feature of disorders including congenital lymphatic anomalies, primary lymphoedema and obesity, while improved lymphatic vessel function increases the efficacy of immunotherapy for cancer and neurological disease and promotes cardiac repair following myocardial infarction. Understanding how the growth and function of lymphatic vessels is precisely regulated therefore stands to inform the development of novel therapeutics applicable to a wide range of human diseases. Lymphatic vascular development is initiated during embryogenesis following establishment of the major blood vessels and the onset of blood flow. Lymphatic endothelial progenitor cells arise from a combination of venous and non-venous sources to generate the initial lymphatic vascular structures in the vertebrate embryo, which are then further ramified and remodelled to elaborate an extensive lymphatic vascular network. Signalling mediated via vascular endothelial growth factor (VEGF) family members and vascular endothelial growth factor receptor (VEGFR) tyrosine kinases is crucial for development of both the blood and lymphatic vascular networks, though distinct components are utilised to different degrees in each vascular compartment. Although much is known about the regulation of VEGFA/VEGFR2 signalling in the blood vasculature, less is understood regarding the mechanisms by which VEGFC/VEGFD/VEGFR3 signalling is regulated during lymphatic vascular development. This review will focus on recent advances in our understanding of the cellular and molecular mechanisms regulating VEGFA-, VEGFC- and VEGFD-mediated signalling via VEGFRs which are important for driving the construction of lymphatic vessels during development and disease.  相似文献   
270.
Pavlovian learning tasks have been widely used as tools to understand basic cognitive and emotional processes in humans. The present studies investigated one particular task, Pavlovian-to-instrumental transfer (PIT), with human participants in an effort to examine potential cognitive and emotional effects of Pavlovian cues upon instrumentally trained performance. In two experiments, subjects first learned two separate instrumental response-outcome relationships (i.e., R1-O1 and R2-O2) and then were exposed to various stimulus-outcome relationships (i.e., S1-O1, S2-O2, S3-O3, and S4-) before the effects of the Pavlovian stimuli on instrumental responding were assessed during a non-reinforced test. In Experiment 1, instrumental responding was established using a positive-reinforcement procedure, whereas in Experiment 2, a quasi-avoidance learning task was used. In both cases, the Pavlovian stimuli exerted selective control over instrumental responding, whereby S1 and S2 selectively elevated the instrumental response with which it shared an outcome. In addition, in Experiment 2, S3 exerted a nonselective transfer of control effect, whereby both responses were elevated over baseline levels. These data identify two ways, one specific and one general, in which Pavlovian processes can exert control over instrumental responding in human learning paradigms, suggesting that this method may serve as a useful tool in the study of basic cognitive and emotional processes in human learning. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
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