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In the subwavelength regime, several nanophotonic configurations have been proposed to overcome the conventional light trapping or light absorption enhancement limit in solar cells also known as the Yablonovitch limit. It has been recently suggested that establishing such limit should rely on computational inverse electromagnetic design instead of the traditional approach combining intuition and a priori known physical effect. In the present work, by applying an inverse full wave vector electromagnetic computational approach, a 1D nanostructured optical cavity with a new resonance configuration is designed that provides an ultrabroadband (≈450 nm) light absorption enhancement when applied to a 107 nm thick active layer organic solar cell based on a low‐bandgap (1.32 eV) nonfullerene acceptor. It is demonstrated computationally and experimentally that the absorption enhancement provided by such a cavity surpasses the conventional limit resulting from an ergodic optical geometry by a 7% average over a 450 nm band and by more than 20% in the NIR. In such a cavity configuration the solar cells exhibit a maximum power conversion efficiency above 14%, corresponding to the highest ever measured for devices based on the specific nonfullerene acceptor used.  相似文献   
33.
Nest box supplementation is widely used to increase nest‐site availability for cavity nesting animals but the analysis of its effects on individuals breeding in natural cavities is often neglected. This study offers a novel restoration technique to revert abandonment of natural breeding sites by a secondary cavity avian bird, the European roller (Coracias garrulus), and other ecologically similar species. We found that, after a program of nest box supplementation with ensuing monitoring, rollers gradually abandon nesting in natural and seminatural cavities in favor of nest boxes because the latter are of higher quality. We examine whether reducing the entrance size of natural and seminatural cavities improves their suitability for rollers. A 6‐year program reduced the diameter of the entrance of sandstone cavities and cavities in bridges. This led to a high occupancy (59%) of manipulated nest‐sites. Manipulated sites were most frequently occupied by rollers and little owls (Athene noctua) (31 and 18% of sites, respectively). Manipulation did not affect clutch size or fledgling success. We suggest that nest‐site diversity and nesting in natural cavities should be preserved to reduce nest box dependence. Our study illustrates the value of nest boxes when used alongside restoration of natural breeding sites and provides insights for the management of natural cavities.  相似文献   
34.
Taenia crassiceps cysticerci is used as an experimental model to cysticercosis studies; however there are subcutaneous cases of cysticercosis caused by these cysticerci. It remains unclear in the literature the energetic and fatty acid metabolism in cestodes. Its metabolic study may provide knowledge of pathways that may serve as potential anti-helminthic drugs sites of action. In this work we studied the citric acid cycle organic acids and the fatty acid oxidation in cysticerci removed from mice with 21 and 42 days of infection in two different evolutive stages: growing and final. The organic acids were extracted using perchloric acid and analyzed by HPLC methodology. We found significant statistically differences in oxalate, malate, lactate, and beta-hydroxybutirate concentrations between cysticerci. These results indicate the aerobic metabolism in vivo in spite of the low oxygen concentration of its habitat, and also indicate the presence of fatty acid oxidation as an alternative energetic source.  相似文献   
35.
谢明念 《现代生物医学进展》2007,7(12):1886-1887,1873
目的:针对电流治疗骨折等疾病时存在的问题,提出相应的改进方法。方法:分析以往使用电流对骨折等疾病进行治疗时存在的电化学副作用、创口易于感染、重复施术不便等问题,提出相应的诸如使用溶液导电、隔离电解物、使电极与创口闭合生长等改进方法;并提出将电流治疗与药物治疗相结合的骨科疾病电流疗法改良方案。结果:将电流与药物相结合治疗骨折等疾病是很有可行性的治疗方法,本法不仅克服了已往疗法存在的一些问题,还为骨伤药物直接进入病患部位提供了有效的平台,使骨折、骨不连等疾病能够快速愈合。今后应加强研究骨折愈合各阶段所需的直接注射药物及其配比。完善电流—药物复合电极使用方法,以便与本法尽快进入临床实践。结论:将电流与药物相结合治疗骨折等疾病是很有可行性的治疗方法。  相似文献   
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Understanding the ephemerality of trees used as roosts by wildlife, and the number of roost trees needed to sustain their populations, is important for forest management and wildlife conservation. Several studies indicate that roosts are limiting to bats, but few studies have monitored longevity of roost trees used by bats over several years. From 2004–2007 in Cypress Hills Interprovincial Park, Saskatchewan, Canada, several big brown bats (Eptesicus fuscus) from a maternity group roosted in cavities in trembling aspen (Populus tremuloides) trees approximately 7 km southeast away from their original known roosting area (RA1). Using a long-term data set of the roost trees used by bats in this area from 2000–2007, we evaluated whether the movement of bats to the new roosting area (RA4) corresponded with annual and cumulative losses of roost trees. We also determined whether longevity of the roosts from the time we discovered bats first using them differed between the 2 roosting areas based on Kaplan-Meier estimates. Bats began using RA4 in addition to RA1 in 2004, when the cumulative loss of roost trees in RA1 over 3 consecutive years reached 18%. Most bats exclusively roosted in RA4 in 2007, when the cumulative loss of roost trees over 6 consecutive years had reached 46% in RA1. Annual survival for roost trees, from when we first discovered bats using them, was generally lower in RA1 than in RA4. Our results suggest that the movement of bats to the new roosting area corresponded with high losses of roost trees in RA1. This provides additional evidence that to maintain high densities of suitable roost trees for bats in northern temperature forests over several decades, management plans need to recruit live and dead trees in multiple age classes and stages of decay that will be suitable for the formation of new cavities. © 2019 The Wildlife Society.  相似文献   
38.
Aluminum tolerance was assessed in the moderately Al-tolerant wheat (Triticum aestivum L.) cultivar Chinese Spring and a set of ditelosomic lines derived from Chinese Spring. Three ditelosomic lines lacking chromosome arms 4DL, 5AS and 7AS, respectively, exhibited decreased Al tolerance relative to the euploid parent Chinese Spring based on reduced root growth in Al-containing solutions. The physiological basis of the reduced Al tolerance was investigated. Measurements by inductively coupled argon plasma mass spectroscopy of root apical Al accumulation demonstrated that two of these three lines had a decreased ability to exclude Al from the root apex, the site of Al phytotoxicity. As Al-induced malate exudation has been suggested to be an important physiological mechanism of Al tolerance in wheat, this parameter was quantified and malate exudation was shown to be smaller in all three deletion lines compared with Chinese Spring. These results suggest that the decreased Al tolerance in at least two of the three ditelosomic lines is due to the loss of different genes independently influencing a single Al-tolerance mechanism, rather than to the loss of genes encoding alternative Al-tolerance mechanisms. Received: 3 July 2000 / Accepted: 9 August 2000  相似文献   
39.
鳜鱼口咽腔味蕾和行为反应特性及其对捕食习性的适应   总被引:9,自引:0,他引:9  
梁旭方 《动物学报》1996,42(1):22-27
用扫描电镜观察和行为学实验研究鳜鱼口咽腔味蕾形态和分布及吞食行为反应特性,结果表明,鳜鱼口咽腔味蕾丰富,几乎都是I型和Ⅱ型味蕾,着生于表皮乳突上,主要分布于上颌骨齿周围及内侧,下颌齿周围及外侧,舌前中区,下鳃骨细齿内侧等部位,其它区域分布较少,鳜鱼口咽腔味蕾对食物味道和软硬均非常敏感,鳜鱼仅吞食同时具有一定味道和软硬度的食物,本文探讨了鳜鱼口咽腔味蕾的结构功能关系及其对捕食习性的适应意义。  相似文献   
40.
The oral dentition and type and number of taste buds (TB) on the lips and in the oropharyngeal cavity were compared by means of SEM in 11 species of cardinal fishes (Apogonidae) belonging to five genera. The occurrence of a dense cover of skin papillae on the lips of some species (e.g., Apogon frenatus), as well as differences in structure of vomer, tongue, and palatinum, expose additional morphological characters important for clarification of the taxonomy of this group of fishes. Differences are also revealed in the type of dentition, such as on the vomer and epi-hypopharyngeal bones. Strong and dense dentition of the anterior part of the oral cavity and a high number of TB on this site in species feeding on larger prey (e.g., Cheilodipterus spp) is compared to the relatively feeble jaw armor and richness of TB on the more pharyngeal site in species feeding on smaller prey (e.g., Apogon angustatus, A. frenatus). In addition to the three types of TB (Types I-III) previously described from various teleost fish, a fourth type (Type IV), comprising very small buds, was found in some cardinal fish (Apogon angustatus, A. frenatus). The various TB are distributed from the lips to the pharyngeal bones, on the breathing valves, tongue, palatinum, and pharyngeal bones; their number and type on the various sites differ in the different species. In all species studied the Types I and II TB, elevated above the surrounding epithelium, dominated the lips and anterior part of mouth, while Types III and IV, which end apically at the level with the epithelium, dominated the more posterior pharyngeal region. The highest number of TB, around 24,600, were found in Fowleria variegata, a typical nocturnal species, and the lowest in the diurnal and crepuscular Apogon cyanosoma (1,660) and Cheilodipterus quinquestriatus (2,400). Differences are also revealed in the type of dentition, such as on the vomer and epi-hypopharyngeal bones. The number of TB increased with growth of the fishes. The differences in the total number of TB and their distribution in the oropharyngeal cavity in the various species indicates possible different mechanisms of foraging and food-recognition.  相似文献   
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