Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agricult...Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.展开更多
功率变换器采用脉宽调制时产生的高共模电压CMV(common-mode voltage)会使电机轴电压过高,进而导致高频高幅值轴电流破坏电机绝缘、增加电磁干扰等。为减小中点钳位型NPC(neutral point clamped)三电平变换器的共模电压,提出了基于代数...功率变换器采用脉宽调制时产生的高共模电压CMV(common-mode voltage)会使电机轴电压过高,进而导致高频高幅值轴电流破坏电机绝缘、增加电磁干扰等。为减小中点钳位型NPC(neutral point clamped)三电平变换器的共模电压,提出了基于代数调制框架的共模电压抑制策略:首先,将占空比的确定问题转化为非齐次线性方程组的求解问题;然后,合理地选择调制自由度以实现中点电压NPV(neutral point voltage)平衡控制的目标;其次,根据占空比约束,选择偏置量获取最终占空比;最后,使中间相开关采用反相载波得到新的开关状态组合,实现降低共模电压的目的。所提调制策略无需额外的控制器,实现简单,在保证中点钳位型三电平变换器的中点电压具有良好平衡特性的前提下,可将共模电压降低至直流侧电压的1/6范围内。实验结果验证了所提调制策略的有效性和可行性。展开更多
A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence ...A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.展开更多
文摘Synthetic fertilizers are widely used to address the urgent challenge of ensuring food supplies for a growing world population in the context of climate change. However, their industrial production and use in agriculture have a negative impact on the environment and consequently on human health. While chemical fertilizers may not have to be abandoned in agricultural production systems, limiting their use could help to make agriculture sustainable and resilient to climate change. In Senegal, the level of mineral fertilizers used in market gardening has become alarming in the Niayes area. As a result, microbial biotechnologies have been promoted for biofertilizer production of common bean (Phaseolus vulgaris L.) cultivation. Rhizobial inoculums have thus been used to reduce the rate of chemical nitrogen fertilizers being applied in cropping systems. Several investigations in the laboratory, on experimental stations and in the field have shown a possibility of a significant reduction in the use of nitrogen fertilizers in common bean production. Conventional mineral fertilization use can be reduced from over 120 kg N/ha to 20 kg N/ha. This contributes both to a very significant reduction in the application rate with the same level of yield and to an improvement in the standard of living. In addition, the environmental impact of using chemical fertilizers can be mitigated. This study is a contribution to the promotion of biofertilizers adoption in agricultural systems.
文摘功率变换器采用脉宽调制时产生的高共模电压CMV(common-mode voltage)会使电机轴电压过高,进而导致高频高幅值轴电流破坏电机绝缘、增加电磁干扰等。为减小中点钳位型NPC(neutral point clamped)三电平变换器的共模电压,提出了基于代数调制框架的共模电压抑制策略:首先,将占空比的确定问题转化为非齐次线性方程组的求解问题;然后,合理地选择调制自由度以实现中点电压NPV(neutral point voltage)平衡控制的目标;其次,根据占空比约束,选择偏置量获取最终占空比;最后,使中间相开关采用反相载波得到新的开关状态组合,实现降低共模电压的目的。所提调制策略无需额外的控制器,实现简单,在保证中点钳位型三电平变换器的中点电压具有良好平衡特性的前提下,可将共模电压降低至直流侧电压的1/6范围内。实验结果验证了所提调制策略的有效性和可行性。
文摘A 1.5-hour recording of six (Gulf of Mexico) captive common bottlenose dolphins (Tursiops truncatus) at Sea Life Park, Hawaii shows that: 1) they have a song of a sequence of tonal (often slurred) notes. The evidence for their song comes from: a) their emitting songs that were complex (both tonally and rhythmically), b) their likely improvising (as inferred from their most complex songs not being repeated), c) songs based on a theme (used repeatedly), d) a bout of singing (at times) including social creativity, e) songs with a distinct beginning, middle and end section, and f) one song consisting of in part, a theme, 2) their songs are not sung in key (as determined from analysing the beginning tonal value of a note with spectral-frequency analysis), and 3) are sung in bouts, and 4) mostly with tonal-striated vocalizations (in the literature termed squawks and bray calls). Their apparent creativity (likely improvisations) and social creativity are of importance to how they evolved cognitively, to the study of song culture (between populations and delphinid species), understanding their (intra and inter-species) associations, and kinds of relationships, determining individual personalities, and perhaps will provide supporting evidence for their ability to reason. As inferred, they sing without being intentionally manipulative from: 1) their use of Gquic psychology [1] (as explained in this article), and 2) as inferred from their likely having an ability to reason [1] [2] (as deduced from their behavioural ecology (their unique exceptional evolutionary freedom), including their comparatively peaceful composure between conspecifics, in line with the proof of The Peaceful Composure Theorem), suggesting (per The Peaceful Composure Theorem) they have an egalitarian-like society. Their interspecies (displaced) aggression towards smaller odontocete species is shown to be a function of jealousies that emerge from their stronger social bonds than other species, from their compassionate nature, and females and males not pairing up in long-term associations. Species with greater cultural freedom are shown to have a more complex song providing further evidence for species culture not crucial to survival. The conclusive evidence for specie culture from my recent publications is of relevance to the scientific community’s acceptance of two new theories of evolution, and Gquic psychology. The loud burst-pulse sounds, chasing, charging and raking behaviours described in the literature could be a play behaviour, ought not be labelled as aggressive behaviours, as inferred from dog mock-fight play behaviour. In regard to future comparative behavioural ecology studies, aggressive animal behaviour should only be defined as an act of displacement (that is shown to commonly occur in the Indo-Pacific bottlenose dolphin species (Tursiops aduncus)), or as acts of biting, and hitting.
