查询词典 ecological systems

The persistence, existence, stability and global attractivity of periodic solutions of Lotka-Volterra systems are an important direction of mathematical ecology research. It has been an important topic to give a definite criterion of the properties of a complicated ecological system. Many ecologist and mathematician have paid much attention in this field.

生态系统的持久性、周期解的存在性及稳定性、全局吸引性等问题是数学生态学理论中的一个重要研究内容，对上述问题给出明确的判定准则是数学生态学的一个重要课题，历来受到生态学家与数学家的广泛重视。

The actuality of combination of farming and graziery incarnates the differences of two production systems, agriculture and stock raising, in aspects of input and output, absorbing labour force and intensity acting on environment, which is result of confliction and balance of human and environment. Of course this balance did not consider the environmental cost and ecological risk, and land degradation is the problem of this selection.

科尔沁沙地农牧交错的现状体现着农、牧业两种生产系统的投入产出差异、对劳动力消纳能力以及对土地作用强度的多相矛盾，是人地矛盾协调与平衡的结果，是&人尽其责，地尽其用&追求最大效应的选择结果，当然这种选择是没有考虑环境成本与生态风险，而土地退化就是这种选择对生态环境影响的重要表现形式。

Odum,revises energy theory of value,by incorporating aspects of ecological hierarchy and energy quality,to valuate the contribution of natural environment to human economic systems.

引言自然生态系统、人类经济系统及社会系统各组分及其作用，均涉及能量的流动、转化与贮存，能量可用于表达和了解生命与环境、人与自然的关系。

On the ecosystem health, definitions from utilization and ecosystem views are introduced, the contents and difficulties in assessing it are discussed. On the biodiversity enhancement, the relationship between forest structural complexity and forest biodiversity are discussed, the significance of old growth structure are highlighted, and measures of changing forest structure to promote forest biodiversity are put forward. On the landscape planning in forest management, some patterns, theoretical foundations and models are introduced, especially three conceptual models, i.e., key habitat\|corridors model, nature landscape model, and supportive features model. On the alternative silvicultural systems, reasons for developing alternative silvicultural system by mimic of nature disturbance are discussed, and some advanced techniques and their ecological basis are noted. Finally, on the ecosystem service, its contents and importance of assessment are illustrated.

关于森林生态系统健康，讨论了不同角度对生态系统健康的定义和不同层次上的生态系统健康的内容及评价生态系统健康的困难所在；②关于森林生物多样性，探讨了森林结构复杂性与生物多样性的关系，老龄林结构对森林生态系统的意义和作用，以及如何通过经营调整结构促进生物多样性；③关于森林经营的景观规划，描述了进行景观规划的途径、理论和模型，并对三种概念模型进行了介绍；④关于森林经营的替代技术体系，介绍了模拟自然干扰设计替代技术体系的原理，分析了替代经营技术体系产生的原因和有关最新技术研究进展；⑤关于森林生态系统服务，讨论了生态系统服务的基本内容和评价在森林生态系统管理中的重要意义。

The thesis may be divided into two sections:Firstly, author locked on Ancient Mongolian, the great aggregation of grassland culture, as the research object, generalize and hackle transversally the culture of materials, spirits, systems level in order to excavate and settle the positive and rational elements of The Ecological Culture, preserve and develop the excellent culture of Mongolian.

首先，本文以北方草原文化的集大成者的古代蒙古族作为研究对象，分别从物质文化、精神文化及制度文化等层面中，进行横向的归纳和梳理，挖掘其中蕴涵的积极合理的生态因素，致力于民族生态学的研究，以期对古代蒙古族优秀的传统文化加以保存和发展。

The result showed that:(1) the unrenewable industrial assistance emergy were mainly in the region of farming eco-economic system, and the chemical fertilizers greater impacted on agriculture output;(2) the intensity of emergy use was higher than the national average on agriculture, which indicated that there were a higher levels of investment in science and technology in the region;(3) the net output rate of emergy in the planting economic ecosystem was higher than the level of the national average and developed regions of guangdong province, which showed that the system had higher economic vitality, and the better function of agricultural system, more efficient operation, higher returns of emergy;(4) the rate of environmental loading was a lower level, which indicated that agricultural production had less pressure on the entire regional ecosystems, and caused less damage to the ecological environment, and agriculture, environmental resources for further development and utilization;(5) the sustainable development index in yanqi basin indicated that farming systems in the region belonged to sustainable development areas.

结果表明：(1)焉耆盆地绿洲2006种植业生态经济系统的能值投入以不可更新的工业辅助能为主。在不可更新工业辅助能中，化肥对农业的产出影响较大；(2)该区域的能值利用强度高于全国平均水平，说明农业的科技投入水平较高；(3)系统的净能值产出率高于全国平均水平和发达地区水平，表明系统具有较高的经济活力，农业系统整体功能较好，运转效率较高，能值回报率较高；(4)农业生产对整个区域生态系统的压力较轻，引起的生态环境破坏较小，农业环境资源还有进一步开发利用的潜力；(5)焉耆盆地种植业系统具有可持续发展的潜力。

Constant exchanges of substances,energy,and information can be found within the sub-systems of human settlements and between the outside environments,which are connected with centralization and diffusions of the ecological flows so as to exert the functions of human settlements.

人居环境各子系统之间或它们与系统外部环境之间，不断地进行物质、能量和信息的交换，并且通过生态流的集聚与扩散形式联接起来，以此实现人居环境各种功能的正常发挥。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。