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Interface engineering has emerged as a great strategy for the fabrication of high efficiency and stable perovskite solar cells (PSCs).

Slow growth, branch dieback and scarce acorn yield are visible symptoms of decay in abandoned Quercus pyrenaica coppices. A hypothetical root-to-shoot (R:S) imbalance provoked by historical coppicing is investigated as the underlying driver of stand degradation. After stem genotyping, 12 stems belonging to two clones covering 81 and 16 m2 were harvested and excavated to measure above- and below-ground biomass and nonstructural carbohydrate (NSC) pools. To study root system functionality, root connections and root longevity were assessed by radiocarbon analysis. Seasonality of NSC was monitored on five additional clones. NSC pools, R:S biomass ratio and fine roots-to-foliage ratio were higher in the large clone, whose centennial root system, estimated to be 550 years old, maintained large amounts of sapwood (51.8%) for NSC storage. 248 root connections were observed within the large clone, whereas the small clone showed comparatively simpler root structure (26 connections). NSC concentrations were higher in spring (before bud burst) and autumn (before leaf fall), and lower in summer (after complete leaf expansion); they were always higher in roots than in stems or twigs. The persistence of massive and highly inter-connected root systems after coppicing may lead to increasing R:S biomass ratios and root NSC pools over time. We highlight the need of surveying belowground organs to understand aboveground dynamics of Q. pyrenaica, and suggest that enhanced belowground NSC storage and consumption reflect a trade-off between clonal vegetative resilience and aboveground performance.

AbstractClimate change has likely altered high‐latitude forests globally, but direct evidence remains rare. Here we show that throughout a ≈1000‐km transect in Scots pine (Pinus sylvestris L.) forests in Sweden, mature trees in ≈2015 had longer needles with shorter lifetimes than did trees in ≈1915. These century‐scale shifts in needle traits were detected by sampling needles at 74 sites from 2012 to 2017 along the same transect where needle traits had been assessed at 57 sites in 1914–1915. Climate warming of ≈1 °C all along the transect in the past century has driven this temporal shift in foliage traits known to be physiologically critical to growth and carbon cycling processes. These century‐scale changes in Scandinavian Scots pine forests represent a fingerprint of climate change on a fundamental biological element, the leaf, with repercussions for productivity and sensitivity to future climate, which are likely to be mirrored by similar changes for evergreen conifers across the boreal biome.

Micro-grids are known as a means of localization of renewable energy production and consumption. However, due to the intermittent nature of renewable energy sources, one of the main challenges in Micro-grid energy control and management is to handle any deviation from the prior forecasted power generation/consumption. Our proposed distributed multi-agent algorithm tries to handle power imbalance situations in a PV-based grid connected Micro-grid through optimizing a combination of storage usage, load curtailment, and main grid power purchase. In this model, the users’ consumption preferences are considered as an important factor in the decision making. We first devise a community of consumers with various energy usage preferences and then investigate the performance of our proposed algorithm over multiple scenarios having different users’ reactions to the energy conservation requests. The results obtained show the convergence and feasibility of the proposed algorithm. Moreover, the cost of imbalance handling is considerably reduced, preserving the level of satisfaction in the community, as the inconvenience effect of load curtailment is compensated by paying back to the consumers.

Geographic isolation and growing climate aridity played major roles in the evolution of Australian legumes. It is likely that these two factors also impacted on the evolution of their root-nodule bacteria. To investigate this issue, we applied a multilocus sequence analysis (MLSA) approach to examine Bradyrhizobium isolates originating from temperate areas of Western Australia (WA) and the tropical-monsoon area of the Northern Territory (NT). The isolates were mostly collected from the nodules of legumes belonging to tribes, genera and species endemic or native to Australia. Phylogenetic analyses of sequences for the housekeeping atpD, dnaK, glnII, gyrB, recA and 16S rRNA genes and nodulation nodA gene revealed that most isolates belonged to groups that are distinct from non-Australian Bradyrhizobium isolates, which is in line with earlier studies based on 16S rRNA gene sequence analyses. Phylogenetic analysis of the nodA data allowed identification of five major Clades among the WA and NT isolates. All WA isolates grouped in a subgroup I.1 of Clade I with strains originating from temperate eastern Australia. In contrast, the NT isolates formed part of Clades I (subgroup I.2), III (subgroup III.3), IV, V and X. Of these nodA clades, Clade I, Clade IV, Clade X presumably have an Australian origin. Overall, these data demonstrate that the impact of geographic isolation of the Australian landmass is manifested by the presence of numerous unique clusters in housekeeping and nodulation gene trees. In addition, the intrinsic climate characteristics of temperate WA and tropical-monsoon NT were responsible for the formation of distinct legume communities selecting for unrelated Bradyrhizobium groups.

Abstract The question addressed here is whether coals contain a substantial fraction of relatively small molecules clathrated within the macromolecular network and requiring long time or extra thermal energy for release. The debate primarily hinges on the interpretation of 1 H n.m.r. data, but some other relevant findings reported in the literature are recapitulated. Cases are made out by the original authors for two different interpretations of the n.m.r. data (it should be emphasized that there is no dispute about the actual data, only about its interpretation). It appears that there are two (or possibly three) populations of protons in coals, which exhibit appreciably different free induction decay times and hence have quite different levels of rotational mobility. This is a fact of considerable interest in its own right, but the possession of high mobility does not necessarily mean that the mobile protons must be in relatively small molecules which are free to tumble in cages within the macromolecular network. Taking into account evidence from extractability and other experiments, it is possible to draw the conclusion that the content of relatively small molecules held within coal is larger than has been supposed and is essentially equal to the content of substances containing highly mobile protons, though a substantial proportion of these substances can probably be extracted only under various special conditions. However, it should be stated that there is disagreement between the authors on the admissibility of evidence from solvent extraction experiments. There is certainly evidence that the very high extractability of lignites with ethylenediamine is due to chemical reaction, and it is argued that this may be true also of higher-rank coals.

The identification of recombination centers in perovskite solar cells is highly challenging.

The paper presents recent advances in Poland in the field of high temperature fuel cells. The achievements in the materials development, manufacturing of advanced cells, new fabrication techniques, modified electrodes and electrolytes and applications are presented. The work of the Polish teams active in the field of solid oxide fuel cells (SOFC) and molten carbonate fuel cell (MCFC) is presented and discussed. The review is oriented towards presenting key achievements in the technology at the scale from microstructure up to a complete power system based on electrochemical fuel oxidation. National efforts are covering wide range of aspects both in the fundamental research and the applied research. The review present the areas of (i) novel materials for SOFC including ZrO2-based electrolytes, CeO2-based electrolytes, Bi2O3 based electrolytes and proton conducting electrolytes, (ii) cathode materials including thermal shock resistant composite cathode material and silver-containing composites, (iii) anode materials, (iv) metallic interconnects for SOFC, (v) novel fabrication techniques, (vi) pilot scale SOFC, including electrolyte supported SOFC (ES-SOFC) and anode supported SOFC (AS-SOFC), (vii) metallic supported SOFC (MS-SOFC), (viii) direct carbon SOFC (DC-SOFC), (ix) selected application of SOFC, (x) advances in MCFC and their applications, (xi) advances in numerical methods for simulation and optimization of electrochemical systems.