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两类食植系统的对比分析 被引量:3
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作者 姜福全 范思乡 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2007年第4期4-9,共6页
研究了带有Beddington-DeAngelis功能反应的食植系统和具有密度制约项的食植系统的全局动力学行为.以此为基础,考察了密度制约效应对系统动力学的影响,并从多角度对两个系统进行了对比.研究表明这两个系统具有极为相似的动力学行为.
关键词 食植系统 Beddington-DeAngelis功能反应 密度制约 极限环
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一个有相互干扰的食植系统的研究 被引量:2
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作者 应益荣 党新益 《生物数学学报》 CSCD 北大核心 1996年第1期54-57,共4页
本文运用常微分方程定性理论讨论了一个放牧有相互干扰的食植系统,获得了该系统极限环存在唯一性及全局渐近稳定性的充分条件.
关键词 食植系统 极限环 数学生态学
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一类离散食植系统的定性分析
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作者 姜福全 《长春大学学报》 2007年第10期13-15,共3页
首先对一类连续的食植系统进行离散化处理,而后对得到的离散系统进行定性分析,获得了系统正平衡点存在的充要要件。并对边界平衡点及正平衡点的无穷远点的稳定性做出了判断。
关键词 离散模型 食植系统 平衡点
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一类食植系统的无穷远点性态浅析
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作者 姜福全 《伊犁师范学院学报(自然科学版)》 2007年第4期5-7,共3页
对一类食植系统的无穷远点进行了详尽的定性分析,得到了无穷远奇点存在的充分条件,指明了其性态,并指出了此系统在无穷远处轨线的走向.
关键词 线性近似 食植系统 无穷远奇点
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一个相互干扰的食植系统的定性分析 被引量:1
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作者 沃松林 邹云 《应用数学学报》 CSCD 北大核心 2003年第4期708-714,共7页
本文运用微分方程定性理论讨论了一个相互干扰的食植系统(2),获得了该系统在J(r_2+η1/Kδ^(1/2)) <1时,极限环存在唯一以及在J(r_2+η1/Kδ^(1/2)≥1时;正平衡点全局渐近稳定。
关键词 食植系统 定性分析 微分方程 极限环 存在性 唯一性 正平衡点 全局渐近稳定性
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一个放牧有相互干扰的食—植系统极限环的存在性与唯一性
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作者 丰建文 《郧阳师范高等专科学校学报》 1997年第2期1-6,共6页
本文对一个放牧有相互干扰的食—植系统(E)极限环的存在性与唯一性进行了重新讨论,首先通过对奇点性态的分析得到了系统(E)极限环的存在性,接着通过一系列变换将其化为广义Li(?)bard方程,最后分析方程的性质得到了极限环唯一性的猜测.
关键词 系统 极限环 存在性 唯一性
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Gelling Behavior of Plant Proteins and Polysaccharides in Food Systems
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作者 Florence O. Uruakpa 《Journal of Food Science and Engineering》 2012年第5期247-256,共10页
Biological macromolecules, such as proteins and polysaccharides, are widely used in food systems because their interactions impart a desirable texture to food products. Plant proteins interact with food components via... Biological macromolecules, such as proteins and polysaccharides, are widely used in food systems because their interactions impart a desirable texture to food products. Plant proteins interact with food components via protein-protein and protein-polysaccharide associations, and the formation of a matrix, which can entrap other food components such as water, lipids and flavors. These networks provide structural integrity to food products and can serve as important functional ingredients in processed foods. Intermolecular interactions of typical polysaccharides result either in simple associations or in the form of a double or triple helix. The linear double helical segments may then interact to form a super junction and a three-dimensional gel network. The formation of these structural networks takes place during processing and involves the transformation from a liquid or viscous sol into a solid material with elastic properties. Interests in the behavior of mixed gels center on the prospects of enhanced flexibility in their mechanical and structural properties compared to those of pure gels. Findings on molecular interactions between plant proteins (e.g., soy, canola and pea proteins) and polysaccharides (e.g., guar gum, carrageenan, and pectin) allow for the modification of physical and textural characteristics of mixed biopolymers to meet desired functional property. 展开更多
关键词 Molecular interactions plant proteins and polysaccharides gelling macromolecules.
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Integrating Crops-Tree Systems with Outgrower Schemes and Food Security
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作者 Arlete Maria da Silva Alves Syaka Sadio 《Journal of Agricultural Science and Technology(B)》 2013年第9期661-674,共14页
Outgrower Schemes have been implemented in different parts of the world to provide wood to forest and other companies and as income alternatives for farmers in rural areas. They have been considered by some researcher... Outgrower Schemes have been implemented in different parts of the world to provide wood to forest and other companies and as income alternatives for farmers in rural areas. They have been considered by some researchers and practitioners as important advances in the area of planted forest and promoted by governments and forest companies in partnership with rural farmers and communities. Considering the importance of subsistence crops and forest products to smallholders and consumers and the economic viability of agroforestry, attention is given in this paper to Outgrower Schemes that combine tree planting with agroforestry, to contribute to food security and environment preservation in developing countries. The issue of Outgrower Schemes through integrated crops-tree systems was raised in a previous study of Outgrower Schemes in Brazil, commissioned by the FAO1. This paper examines, based on the research done for that study, the views and perspectives of the companies' personnel, the tree growers that participate in the programs studied, and other stakeholders' related institutions involved in such schemes with regard to the promotion of Outgrower Schemes through integrated crops-tree systems, linking them with agroforestry, which is a way those Outgrower Schemes can contribute to food security and environment preservation goals. 展开更多
关键词 Agriculture agroforestry systems food security FORESTS Outgrower Schemes.
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First Estimations of Plant Acridone Alkaloid Implemented in Mushroom Mycelium Growth
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作者 Olga Tsivileva Inna Uchaeva +3 位作者 Alexei Pankratov Tatyana Kudryavtseva Yurii Markovich Valentina 《Journal of Agricultural Science and Technology(B)》 2013年第12期873-879,共7页
Acridone derivatives are widespread in nature and known to be capable of having a variety of biological activities, but there is not any information on the acridone series compounds in relation to higher fungi, includ... Acridone derivatives are widespread in nature and known to be capable of having a variety of biological activities, but there is not any information on the acridone series compounds in relation to higher fungi, including edible mushrooms available in literature at all. Research into the character of the mode of action of these substances on various living systems is necessary to elucidate the possible unfavorable biological consequences and improve measures on their ecological safety. In this work, the effect of acridone-N-acetic acid on mushroom mycelial growth was tested and the culture of basidiomycete Lentinula edocles (shiitake) has been used. The influence of acridone additive upon the fungal mycelium growth on liquid (submerged) and agar media was examined within the wide concentration range of acridone carboxy-derivative. The results obtained testify to the relative ecological safety of these substances for mushroom organism, and to the mycelial growth promoting capability of acridone-N-acetic acid at favorable concentrations, both under the solid-phase and liquid-phase culture conditions. In fact, the very first step toward the investigation into the systems "macromycete-acridone series compound" has been made. 展开更多
关键词 MUSHROOMS Lentinula edodes acridone-N-acetic acid solid-phase fungal culture submerged fungal culture.
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No correlation between the diversity and productivity of assemblages: evidence from the phytophage and predator assemblages in various cotton agroecosystems
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作者 GAO Feng MEN XingYuan GE Feng 《Science China(Life Sciences)》 SCIE CAS 2014年第9期936-943,共8页
Biodiversity research has shown that primary productivity increases with plant species number,especially in many experimental grassland systems.Here,we assessed the correlation between productivity and diversity of ph... Biodiversity research has shown that primary productivity increases with plant species number,especially in many experimental grassland systems.Here,we assessed the correlation between productivity and diversity of phytophages and natural enemy assemblages associated with planting date and intercropping in four cotton agroecosystems.Twenty-one pairs of data were used to determine Pearson correlations between species richness,total number of individuals,diversity indices and productivity for each assemblage every five days from 5 June to 15 September 2012.At the same trophic level,the productivity exhibited a significant positive correlation with species richness of the phytophage or predator assemblage.A significant correlation was found between productivity and total number of individuals in most cotton fields.However,no significant correlations were observed between productivity and diversity indices(including indices of energy flow diversity and numerical diversity)in most cotton fields for either the phytophage or the predator assemblages.Species richness of phytophage assemblage and total individual numbers were significantly correlated with primary productivity.Also,species richness of natural enemy assemblage and total number of individuals correlated with phytophage assemblage productivity.A negative but not significant correlation occurred between the indices of numerical diversity and energy flow diversity and lower trophic-level productivity in the cotton-phytophage and phytophage-predator assemblages for most intercropped cotton agroecosystems.Our results clearly showed that there were no correlations between diversity indices and productivity within the same or lower trophic levels within the phytophage and predator assemblages in cotton agroecosystems,and inter-cropped cotton fields had a stronger ability to support the natural enemy assemblage and potentially to reduce phytophages. 展开更多
关键词 CORRELATION PRODUCTIVITY DIVERSITY cotton agroecosystem insect assemblage
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