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101.
Achieving High Open‐Circuit Voltages up to 1.57 V in Hole‐Transport‐Material‐Free MAPbBr3 Solar Cells with Carbon Electrodes 下载免费PDF全文
Yongqi Liang Yajuan Wang Cheng Mu Sen Wang Xinnan Wang Dongsheng Xu Licheng Sun 《Liver Transplantation》2018,8(4)
An open‐circuit voltage (Voc) of 1.57 V under simulated AM1.5 sunlight in planar MAPbBr3 solar cells with carbon (graphite) electrodes is obtained. The hole‐transport‐material‐free MAPbBr3 solar cells with the normal architecture (FTO/TiO2/MAPbBr3/carbon) show little hysteresis during current–voltage sweep under simulated AM1.5 sunlight. A solar‐to‐electricity power conversion efficiency of 8.70% is achieved with the champion device. Accordingly, it is proposed that the carbon electrodes are effective to extract photogenerated holes in MAPbBr3 solar cells, and the industry‐applicable carbon electrodes will not limit the performance of bromide‐based perovskite solar cells. Based on the analysis of the band alignment, it is found that the voltage (energy) loss across the interface between MAPbBr3 and carbon is very small compared to the offset between the valence band maximum of MAPbBr3 and the work function of graphite. This finding implies either Fermi level pinning or highly doped region inside MAPbBr3 layer exists. The band‐edge electroluminescence spectra of MAPbBr3 from the solar cells further support no back‐transfer pathways of electrons across the MAPbBr3/TiO2 interface. 相似文献
102.
103.
It is generally assumed in dendroecological studies that annual tree-ring growth is adequately determined by a linear function of local or regional precipitation and temperature with a set of coefficients that are temporally invariant. However, various researchers have maintained that tree-ring records are the result of multivariate, often nonlinear biological and physical processes. To describe critical processes linking climate variables with tree-ring formation, the process-based tree-ring Vaganov–Shashkin model (VS-model) was successfully used. However, the VS-model is a complex tool requiring a considerable number of model parameters that should be re-estimated for each forest stand. Here we present a new visual approach of process-based tree-ring model parameterization (the so-called VS-oscilloscope) which allows the simulation of tree-ring growth and can be easily used by researchers and students. The VS-oscilloscope was tested on tree-ring data for two species (Larix gmeliniiand Picea obovata) growing in the permafrost zone of Central Siberia. The parameterization of the VS-model provided highly significant positive correlations (p < 0.0001) between simulated growth curves and original tree-ring chronologies for the period 1950–2009. The model outputs have shown differences in seasonal tree-ring growth between species that were well supported by the field observations. To better understand seasonal tree-ring growth and to verify the VS-model findings, a multi-year natural field study is needed, including seasonal observation of the thermo-hydrological regime of the soil, duration and rate of tracheid development, as well as measurements of their anatomical features. 相似文献
104.
Fitness-related patterns of genetic variation in rhesus macaques 总被引:2,自引:0,他引:2
Blomquist GE 《Genetica》2009,135(2):209-219
105.
106.
《Geobios》2016,49(5):349-354
87Sr/86Sr values from otoliths of the worldwide-distributed fish Hygophum hygomii are used for the purpose of isotope chemostratigraphy. In order to evaluate the potential of H. hygomii otoliths for strontium (Sr) isotopic studies, we first compare the 87Sr/86Sr ratio of current representatives of the species with that of modern sea water. Then, three fossil otoliths of H. hygomii collected in middle Miocene sediments of the Aquitaine Basin (Lafaurie locality, SW France) and the Carpathian Foredeep of the Central Paratethys (Brno-Kralovo Pole locality, SE Czech Republic) are analysed. The age inferred from the 87Sr/86Sr ratio at Lafaurie places the two analysed otoliths within the time interval of 15.5–15.1 Ma. This time interval matches the published early Langhian age obtained from the 87Sr/86Sr ratio of bivalves measured at the same locality. At the Brno-Kralovo Pole, the 87Sr/86Sr ratio of the analysed otolith returns a wider timespan of 14.78–13.10 Ma, falling into an interval of poor time resolution of the 87Sr/86Sr chemostratigraphy. Comparisons with published biostratigraphic and paleoclimatic data suggest that the analysed fossil otoliths of H. hygomii were mineralized during the late part of the Langhian, at ∼14.2 Ma. This work represents a first attempt to use otoliths for 87Sr/86Sr chemostratigraphy, and indicates that such a use may represent a powerful tool for testing stratigraphic correlations in the future. 相似文献
107.
Berlind A 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2001,128(3):377-390
Monoamine agonists and antagonists were applied to the lobster cardiac ganglion in an attempt to clarify the different actions of 5-hydroxytryptamine (5HT) and dopamine (DA) on this rhythmic pattern generator. Experiments were designed to determine whether the similar responses to 5HT and DA applied to the anterior region of the ganglion could be separated by pharmacological approaches, and whether the different responses to 5HT applied to the anterior and posterior regions of the ganglion could be attributed to mediation by different receptors. A small number of the 5HT agonists which were tested mimic the effects of 5HT, in that they increase the frequency of bursting and decrease burst duration when applied to the whole ganglion, but decrease burst frequency and increase burst duration when applied only to the posterior half. Other 5HT agonists decrease frequency and prolong bursts when applied to the whole ganglion. Of the DA agonists tested, none acts as DA itself does. Rather, they mimic the effects of 5HT applied to the posterior ganglion, by slowing bursting and prolonging bursts. The actions of agonists do not correspond in any clear way to the receptor specificities as defined in vertebrates. Most antagonists tested do not show similar specificities to their effects in vertebrates. In particular, most of the DA antagonists tested are more effective in blocking exogenous 5HT than DA. One monoamine agonist directly alters the properties of endogenous burst-organizing potentials (driver potentials) in the motorneurons of the ganglion. 相似文献
108.
S. Amador-Vargas 《Insectes Sociaux》2008,55(3):241-245
Acacia ants (Pseudomyrmex spinicola) usually prune all of the vegetation growing in the vicinity of their host plant (Acacia collinsii). This lack of branches in contact with the host tree makes the main stem of the acacia the only point of access for ants
invading the resident colony. The present study assessed whether the intrusion site affects the probability of the intruder
being detected. It also investigated whether ants that remain inactive on the main trunk base (a) are involved in defensive
duties and (b) are morphologically different from other colony members (e.g. foraging ants). In the field, intruder ants were
placed on the trunk and leaves of acacias inhabited by P. spinicola; colony members on the trunk base and the leaves were marked and monitored; and head length, head width, and thorax length
of ants that were either foraging on the leaves or immobile on the trunk were measured. P. spinicola ants found intruder ants entering their host acacia via the trunk more rapidly than those entering by means of the leaves.
Ants on the base of the trunk do not exchange tasks with foragers: between 5 and 47% of the 1063 ants originally marked on
the trunk were re-observed there, whereas only two of the 804 ants marked on the leaves were seen on the trunk. However, ants
on the trunk were similar to foragers in morphology, suggesting that defensive ants may be part of a behavioral caste.
Received 30 November 2007; revised 29 February 2008; accepted 17 March 2008. 相似文献
109.
药物杂质的分析和控制是用药安全有效的基础。从杂质谱分析、杂质检测、杂质限度的制定等方面综述了近年来国内外化学药
物杂质研究进展,旨在为化学药物杂质的研究提供有效思路和方法。 相似文献
110.
Insect societies vary greatly in social organization, yet the relative roles of ecological and genetic factors in driving this variation remain poorly understood. Identifying how social structure varies along environmental gradients can provide insights into the ecological conditions favouring alternative social organizations. Here, we investigate how queen number variation is distributed along elevation gradients within a socially polymorphic ant, the Alpine silver ant Formica selysi. We sampled low‐ and high‐elevation populations in multiple Alpine valleys. We show that populations belonging to different drainage basins are genetically differentiated. In contrast, there is little genetic divergence between low‐ and high‐elevation populations within the same drainage basin. Thus, elevation gradients in each of the drainage basins represent independent contrasts. Whatever the elevation, all well‐sampled populations are socially polymorphic, containing both monogynous (= one queen) and polygynous (= multiple queen) colonies. However, the proportion of monogynous colonies per population increases at higher elevation, while the effective number of queens in polygynous colonies decreases, and this pattern is replicated in each drainage basin. The increased prevalence of colonies with a single queen at high elevation is correlated with summer and winter average temperature, but not with precipitation. The colder, unpredictable and patchy environment encountered at higher elevations may favour larger queens with the ability to disperse and establish incipient monogynous colonies independently, while the stable and continuous habitat in the lowlands may favour large, fast‐growing polygynous colonies. By highlighting differences in the environmental conditions favouring monogynous or polygynous colonies, this study sheds light on the ecological factors influencing the distribution and maintenance of social polymorphism. 相似文献