重金属污染对土壤动物的影响

随着工业污染的加剧和农用化学物质的增加,土壤中的重金属污染日益严重,其中一部分重金属残留物被土壤动物吸收和富集后,通过食物链对动物和人类健康造成了很大的威胁。该文在讨论重金属富集特性的基础上,从个体、种群及群落水平上综合分析了重金属污染对土壤动物的毒害作用,并论述了土壤动物对重金属污染的解毒策略,最后从重金属污染的毒性测定方法、复合污染机制、分子机理研究和土壤动物的生态恢复作用等几个方面,阐述了当前研究主要动态和今后的发展趋势,旨在为今后的研究提供参考依据。     

Aeration strategy for controlling grain storage based on simulation and on real data acquisition

In this work a new control strategy for grain aeration systems was proposed. This strategy was implemented in a software package called AERO and relates four conditions which depend on real time data acquisition and on the process simulation. The main advantage of AERO controller is that it can be used in different geographic regions, during different seasons and with different aeration systems, automatically adjusting its set points. The objectives of AERO controller are to equalize the temperatures inside the bin, to cool the grain mass whenever is possible and to maintain the moisture content under safe conditions. The results showed that the proposed strategy is efficient to achieve these objectives. Moreover, significant energy saving has been achieved with the AERO controller.     

基于SWOT分析的灌区专管机构发展策略研究

从灌区专管机构的角度探讨灌区管理体制改革的相关问题,提出采用SWOT分析法研究灌区专管机构改革与发展策略的制定方法。以五岸灌区专管机构为例,分析了灌区的外部环境和内部条件,并对内部条件的优势、劣势以及外部环境的机会、威胁进行分析,建立了SWOT矩阵,以此研究提出了灌区相应的发展策略。     

浅谈英语语音教学在大学英语教学中的重要性

当前,随着我国对外开放和社会发展对复合型外语人才的强烈需求,能自由、准确地在竞争激烈的商务、求学等领域运用英语与来自世界各地的人进行沟通与交流越来越显得更重要,尤其是英语专业的学生。但是我们在教学中也遗憾地发现我们的学生英语水平是在不断的提高,但是使用英语进行交流的能力还是很差。本文首先对中国的语音学习现状以及发音方面存在的问题进行分析。并在此基础上提出解决问题的办法。     

SUV车自动变速器换挡规律的研究

根据发动机和液力变矩器的工作特性图,找出两者匹配时的工作点。在此基础上以相邻两挡加速度相等为换挡点,推导出了发动机和液力变矩器共同工作时换挡规律的理论模型。并根据此理论模型进行仿真,得出了自动变速器的换挡规律图。得出的结果对进一步研究换挡延迟等特性有重要的参考价值。     

制约非英语专业学生英语口语交际能力的因素及思考

分析制约非英语专业学生口语交际能力的因素并尝试性地提出解决策略,通过提高教师的教学方法和规范口语测试两方面来提高非英语专业学生的口语交际能力。     

影响大学生英语阅读理解的障碍分析及相应对策

英语阅读水平的高低是衡量学生英语水平的一个重要方面。但目前影响大学生阅读水平的提高有很多障碍。作者主要从学生对阅读的认识,单词识别和图式的积累方面进行分析,从而提出相应的对策,为英语阅读教学提供参考。     

应用元认知理论，改进英语写作教学方法

元认知是指人们了解、控制和监测自己认知活动的能力。元认知理论强调主体知识、任务知识和策略知识。在阐述元认知理论的基础上,探讨外语教学中,如何有效利用元认知来调动学生的积极性,促进大学英语写作,提高学生的写作水平。     

Breeding for organic agriculture: the example of winter wheat in Austria

Breeding for organic agriculture (BFOA) is a strategy for a commercial breeding company based on the exploitation of the frequently observed high correlation for many traits between conventional, low input (LI) and organic agriculture (ORG). Indirect selection under LI can be useful to roughly divide the germplasm into the genotypes better adapted to high input and those better adapted to LI or ORG conditions. BFOA is an evolving process, in which two methods are currently applied: early generations are either selected following the pedigree system under LI, or grown as bulk populations on ORG fields. In the latter case the system switches to LI after individual ear selection under ORG conditions. In both methods, the first replicated yield trial is grown parallel under ORG and LI. Subsequently, the genotypes are grouped into conventional or ORG advanced trial series. The BFOA strategy allows that the larger genetic variability of both the organic and conventional gene pool can be exploited in the selection for ORG. Hitherto, seven winter wheat varieties were released in Austria after exclusive organic VCU testing.     

河北省农产品品牌塑造策略探析

随着经济全球化进程的加快。农产品市场竞争已由产品品质竞争上升为品牌的竞争。塑造一批农产品强势品牌成为河北省实施农产品品牌战略中一项亟待解决的工作。针对河北省农产品品牌化发展现状,找出并分析了河北省农产品品牌化经营中存在的问题,并提出了河北省农产品品牌塑造与提升的策略。