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Stannous sulfate is commonly used as an additive in the positive lead pastes of lead-acid batteries, but its real function and mechanism are still vague and need further study. The present work investigates the intrinsic effects of tin additives on the positive electrode performance under well-controlled experimental conditions. The tin additives are added in three ways: the SnSO4 dissolved in 4.5 M H2SO4 electrolyte, the metal Sn melted in metal Pb substrate, and the SnSO4 mixed in homemade industrial lead pastes. A series of evolutions are clearly revealed in structure, composition, and redox activity of the positive active materials with the content of Sn. Both the SnSO4 in the electrolyte and in the positive lead pastes have a significant inhibiting effect on the transformation between PbSO4 and PbO2, leading to a decrease in the charge/discharge capacities with increasing content of SnSO4. A similar but weaker inhibiting effect was also found for the Sn melted in the Pb-Sn alloys. The SnSO4 has a significant enhancement effect on the grain size of PbSO4/PbO2, which increases the resistance of the solid-phase transformation deep inside the grains during the charge/discharge. All these results do not support the use of SnSO4 in the positive pastes of lead-acid batteries. [ABSTRACT FROM AUTHOR]

Annual wild soybean is the ancestor of cultivated soybean. The 100-seed weight gradually increases in the long-term domestication process. Clarifying the genetic basis of this change is of great significance to the evolutionary research and variety improvement of soybean. In order to analyze the genetic basis of 100-seed weight during soybean domestication, a wild soybean chromosome segment substitution line population (SojaCSSLP5) composed of 177 whole-genome resequencing lines were used in this study. 13 QTLs/segments of 100-seed weight were detected by phenotypic evaluation in three different environments. All of 13 wild chromosome segments had the additive effect of reducing 100-seed weight, ranging from -0.49 g to -1.19 g, which was consistent with the smaller 100-seed weight of wild soybeans. These detected domesticated segments from 11 chromosomes explained 76.70% of the phenotypic variation, and the phenotypic contribution rate of a single segment ranged from 2.45% to 15.14%. The contribution rate of segments Gm03_LDB_15 and Gm12_LDB_46 exceeded 10%, which were major influence on the evolution of 100-seed weight of wild soybeans. Combined the transcriptome data and genome data of parental cultivated soybean Nannong 1138-2 and wild soybean N24852, a total of 13 candidate genes were predicted in these segments, and were involved in the pathways of plant seed size, including ubiquitin protein kinase regulatory pathway, G protein signal pathway, mitogen-activated protein kinase pathway, plant hormone pathway, transcription regulator pathway, and IKU (HAIKU) pathway. Compared with previous QTLs mapping results with cultivated soybeans, 4 of the 13 QTLs/segments were newly detected in this study, indicating that 9 wild chromosome segments might be passed to cultivated soybeans during domestication, and the corresponding cultivated segments of these 4 wild segments may be unique evolutionary segments of cultivated soybean. [ABSTRACT FROM AUTHOR]