长江中下游湿地开发模式探讨

长江中下游是我国重要的湿地之一,也是我国湖泊湿地比较集中的区域,具有比较成熟的单独的养殖或种植、综合利用模式、生态旅游模式等,综合利用模式主要包括林农复合模式和水面立体生态模式。笔者最后关于开发模式提出了几点建议。     

密集烘烤不同装烟方式对下部烟叶质量的影响

[目的]研究不同装烟方式对下部叶质量的影响。[方法]试验设置散叶插扦、散叶打捆、散叶筐篮、常规挂杆4种装烟方式,研究各装烟方式对下部烤后烟叶外观质量和经济性状的影响。[结果]挂杆烘烤烤后烟叶橘黄烟比例、中等烟比例、烟叶均价均好于散叶插扦、散叶打捆、散叶筐篮装烟方式。在下部叶烘烤时采用常规挂杆烘烤,中上部叶烘烤时再使用散叶插扦、散叶打捆、散叶筐篮等装烟方式进行散叶烘烤。[结论]研究可为提高下部烟叶烘烤质量提供参考。     

环境温度对长毛兔的影响

本文以大量实测的数据来阐明环境温度对长毛兔的生理和生产的影响。在生理方面说明了环境温度对长毛兔体温调节的影响和一系列连锁反应。包括外周血液循环、呼吸、气体代谢、水分代谢、采食量和消化机能等的反应。在生产方面说明了环境温度影响长毛兔的成长性能、性机能、泌乳机能、产毛量和质量等的变化。此外,本文还说明了气象因素的综合作用和影响,以及环境温度的控制要点。     

下辽河平原典型地域耕地系统弹性时空分异特征

科学准确地刻画耕地系统弹性时空分异格局是制定耕地保护差别化管理制度的基本前提。为此,该研究以下辽河平原典型地域沈阳市为研究区,基于社会生态系统弹性思维的抵抗力-适应力-转型力视角,重构耕地系统弹性的科学内涵,探讨2009—2018年研究区耕地系统弹性时空分异特征及影响因素。结果表明:1)耕地系统弹性是由耕地系统的抵抗力、适应力和转型力共同作用的结果,分别发挥维持现状、治理弹性和优化弹性的作用;2)2013年为研究区耕地生产力发生突变的时间节点,突变后期研究区整体和各区县的耕地系统弹性均显著减弱,耕地系统适应力减弱是耕地系统弹性减弱的主要因素,其次为转型力和抵抗力;3)突变前后研究区耕地系统弹性整体均呈现出中部高,西北部低的空间分布格局,高高型集聚的耕地向西部和北部迁移,低低型集聚的耕地集中于南部;4)耕地系统弹性变化同时受人类活动和自然禀赋综合影响,农业建设活动和自然条件分别是研究区中南部和西北部的耕地系统弹性空间分异的主要原因。研究表明阐明耕地系统抵抗力、适应力和转型力之间的作用关系可为刻画耕地系统弹性的时空分异格局提供有效途径,据此构建差别化的耕地保护制度体系,为实现下辽河平原农业...     

北太平洋2种鱿鱼类角质颚生长特性及其种类判别

根据2018年9—11月中国鱿钓船在北太平洋海域（41°05''N~43°45''N,154°05''E~159°43''E）采集的柔鱼（Ommastrephes bartramii）和北方拟黵乌贼（Gonatopsis borealis）样本,对样本的胴长（mantle length,ML）、体质量（body mass,BM）以及角质颚的12个形态学参数进行了测定,研究角质颚的生长特性。结果显示,两个种类在胴长和体质量上均存在极显著差异。主成分分析认为,上脊突长（UCL）最适合用来表征柔鱼角质颚的生长,UCL和下侧壁长（LLWL）最适合用来表征北方拟黵乌贼角质颚的生长。赤池信息量准则（akaike’s information criterion,AIC）认为：柔鱼的上头盖长（UHL）、下头盖长（LHL）、LLWL、下翼长（LWL）与胴长呈幂函数关系,UCL、上侧壁长（ULWL）、上翼长（UWL）、下脊突长（LCL）与胴长呈对数函数关系;北方拟黵乌贼的UHL、下喙长（LRL）和LLWL与胴长呈幂函数关系,UCL和LCL与胴长呈指数函数关系,上喙长（URL）、ULWL和LHL与胴长呈对数函数关系。逐步判别分析显示,上、下角质颚的判别正确率分别为92.70%和84.50%,并建立判别方程。研究认为,角质颚外部形态可较好地应用于2种头足类的判别。     

长江中下游地区化肥消费与供需特征及调控策略

根据国家统计数据、农业部农户调查数据以及化肥生产数据,分析了长江中下游地区7省(市)化肥消费特征与市场供需平衡情况.结果表明,该区化肥消费以氮肥和复合肥为主,而钾肥和复合肥增长最快,2004年有82.8%化肥施用于小麦、水稻、玉米、棉花、蔬菜、果树等作物;氮肥(除果树外)施用过量,磷钾肥相对不足;种植结构中粮食播种面积的下降,经济作物播种面积上升将会促进磷肥、钾肥需求量的增加;2005年该区化肥自给率为90.6%,氯肥、磷肥均出现盈余,但钾肥缺口很大.因此,未来长江中下游地区化肥消费将继续增长,上海、浙江、湖北等地将成为磷复肥、钾肥消费增长区,该区农业主管部门应推广合理施肥技术,相关企业应根据不同作物化肥消费特征合理安排化肥生产,保证区域化肥供应,促进当地农业生产的可持续发展.     

Geochemical conditions in groundwater systems: Implications for the attenuation of agricultural nitrate

Nitrate resulting from nitrogen fertilisers used in Agriculture is a widespread contaminant of shallow groundwater and causes adverse effects on human, animal and ecosystem health. In order to evaluate the full extent of groundwater nitrate contamination, and how it might evolve in time, it is essential to understand controls on aquifer assimilative capacity. This level of understanding will also help to better target policies and incentives aimed at controlling the amount of nitrate entering downstream water systems.The potential for nitrate attenuation in groundwater was assessed by examining the concentration and distribution pattern of electron donors such as dissolved organic carbon (DOC), ferrous iron, and redox indicators such as dissolved oxygen (DO) and Eh in 57 monitoring bores on the lower Burdekin coastal floodplain, one of Queensland's and Australia's premier irrigation districts. Nitrate concentrations ranged from 0.1 to 14.4 mg/L NO₃-N but were mostly undetectable in bores close to the coast. Groundwater age dates suggest that while there are nitrate ‘hot spots’ in certain areas, some or most of the nitrate is being consumed on its way to the ocean. Low nitrate concentrations were coupled with high ferrous concentrations. The low DO concentrations (<2 mg/L) and high ferrous concentrations found in 55% of the bores indicate that redox conditions are suitable for nitrate attenuation by either denitrification or dissimilatory nitrate reduction to ammonium. The reducing environment may be associated with the high DOC concentrations (up to 82 mg C/L) found in these groundwaters. Furthermore, high levels of ferrous iron found in the Ayr area combined with the wide spread geographical distribution of DOC indicate that these areas have a high potential for sustaining geochemical processes that reduces nitrate levels. The distribution of geochemical indicators also suggests that the shallower depths (<15 m) of the groundwater systems have more potential for nitrate reduction than the deeper depths. The map identifying areas within the lower Burdekin with most potential for denitrification is a valuable first step in helping to understand and manage the fate of nitrate entering the groundwater.     

塔里木河下游垦区耕地面积变化及驱动力的多层次分析

通过引入土地利用/覆盖变化驱动力研究中常用的逐步回归方法和人文社会科学中最近兴起的多层次分析方法,研究了塔里木河下游垦区农二师五个团场耕地面积的影响因素,得到了团场层各变量和区域层变量对各团场耕地面积的影响程度,影响因素主要为,团场层:引水量、粮食产量、粮食种植面积、劳动力均种植业总产值;区域层:年蒸发总量、日照时数和最高、最低温。     

柴西南跃进地区下干柴沟组高分辨率层序地层学研究

结合研究区的露头剖面、钻井岩心、测井资料等,对跃进地区下干柴沟组进行了高分辨率层序地层学研究．识别出由V级层序界面控制的短期基准面旋回层序,按结构类型的不同划分为向上“变深”的非对称型、向上“变浅”的非对称型和对称型。阐述了研究区各类短期基准面旋回层序的砂体发育情况。对下干柴沟组中期、长期旋回层序进行了划分,识别出7个中期基准面旋回,3个长期基准面旋回,并预测了岩性油气藏发育的有利相带。     

Middle upper beak fracture in a Red-crowned crane that completely recovered with external skeletal fixation

An adult Red-crowned crane in captivity that had a displaced compound fracture of the middle upper beak caused by an accident was treated by using Type I-a external skeletal fixator (ESF). The ESF that was equipped with a unilateral epoxy putty fixator and with five half-pins was fixed on the premaxilla bone. The crane with the ESF on the beak was able to feed smoothly by itself. The ESF was removed 49 days after the first surgery. Beak malocclusion, which was observed in the latter half period of fixing, spontaneously improved within one month after removal of the ESF. This is the first successful case of repair of an upper beak fracture in a Red-crowned crane.