Shrinkage of shrub forest and recovery of mire ecosystem by river restoration in northern Japan

Because anthropogenic stressors have caused mire degradations in the subarctic northern Japan such as the drying and the invasion of alder-dominant shrub forest, the Japanese governments recently started a new project to restore a meandering former river channel in the catchment in order to diminish shrub forest and to recover mire ecosystem. In this study, the author developed the integrated catchment-based eco-hydrology model to include the mass transport and vegetation succession processes in the mire (NICE-VEG). NICE-VEG simulated the water/heat budget, the mass transport, and vegetation succession processes iteratively including the competition between two vegetation types (alder-dominant shrub forest and reed–sedge vegetation) in order to evaluate the relationship between drying and alder invasion in the mire and to clarify a method for mire recovery. NICE-VEG reproduced well the alder invasion in the mire so far by various anthropogenic stressors, which indicate that it is important to add newly the growth reduction factor for water table depth in the model. Simulation results indicated that restoring meanders to the river channel could be effective for decreasing discharge and sediment loading of the river, and increasing groundwater level at the downstream of restoration area around the mire. Simulation also forecasted the mire recovery more or less by restoring meanders to the river channel in the future. These results suggest that the policy of river restoration could be effective as one of mire conservation plans for the recovery of mire vegetation. It is powerful to apply the process-based model to assess the linkage of hydrological change and vegetation succession.     

挖坑机钻轴部分减振装置设计

介绍了一种挖坑机主轴部分的减振装置,其外形小,结构简单,能从主轴处直接降低振动,可有效地减少振动的向上传递,降低主轴部分振动对工作人员及其他机械部件的影响.     

落实哈尔滨兆麟公园在城市防灾体系中的作用

通过分析哈尔滨市面临的防灾减灾问题,提出有必要健全城市公园绿地的防灾避险配套设施。在确保公园日常生态、景观、游憩、文化功能发挥的前提下,确定合理的灾时避险人口容量,完善场地竖向、植物种植及园林建筑设计。本文从哈尔滨兆麟公园设计方案入手,解决好公园的平灾转换功能,是落实公园在城市防灾体系中作用的重要举措。     

硫酸盐作为共存电子受体对微生物Fe(Ⅲ)还原过程的影响

Fe(Ⅲ)和SO42-都是水稻土中主要的电子受体,对厌氧过程中的电子传递起着重要作用。本研究采用土壤浸提液厌氧培养和纯培养的试验方法,探讨了SO42-作为电子竞争受体对不同水稻土微生物群落和铁还原细菌的Fe(Ⅲ)还原过程的影响。土壤浸提液培养试验结果表明,添加SO42-后Fe(Ⅲ)还原受到显著的抑制,Fe(Ⅲ)反应速率随着浓度的增加而降低。随着培养时间延长,Fe(Ⅲ)还原反应依然可以进行,Fe(Ⅱ)最终累积量达到与CK2相同的水平。在利用铁还原菌的纯培养试验中,添加SO42-对供试的四株铁还原菌的Fe(Ⅲ)还原过程并未产生抑制效应,表明铁还原菌本身并不受SO42-的影响。     

1株抗铜细菌的分离、鉴定及其还原特性的研究

从湖北省某重金属矿区的土壤中分离、筛选到1株能够还原Cu2 的菌株TT1.该菌株可以单抗3mmol/L的Cu2 .经对该菌株进行形态特征以及16SrDNA序列比对分析,确认该菌株属于地衣芽孢杆菌(Bacillus licheniformis).TT1与Bacillus licheni formis的同源性最高,达到98%.在含有0.2mmol/L Cu2 的培养条件下,菌株TT1的生长不受影响.Cu2 还原的最适温度为30℃,在该温度下,24h时间内TT1可以还原71%的Cu2 ;Cu2 最适还原的pH为6.因此,TT1菌株有望用于含Cu2 废水的处理.     

城市燃气管网的风险识别

鉴于风险识别的方法大多以定性为主而缺乏客观评价的状况,提出了一种基于故障树分析和粗集理论的风险识别方法。利用故障树分析可以全面系统地找出影响燃气管道安全的各种因素,借助粗集理论中的属性约简算法对这些因素进行属性约简,最终识别出影响城市燃气管网的风险因素,可以为风险分析评价提供必要的依据。     

中洛线添加减阻剂运行现场试验

介绍了HG减阻剂的使用特点和作用机理,简述了中洛线添加减阻剂运行现场试验的情况,讨论了分散时间对减阻剂的减阻增输效果的影响。结果表明,添加不同量的减阻剂均可获得较好的减阻增输效果,并能提高管道运行的安全性。     

欧洲地区选择性虾拖网渔具的研究进展

虾拖网渔业是世界上兼捕、抛弃问题最为严重的渔业.为了缓解虾拖网渔业的这一突出问题,世界各国、各组织的研究人员在世界各主要虾拖网渔业中开展了多样而有效的选择性研究.北大西洋北方长额虾Pandalus borealis拖网渔业、东北大西洋和地中海海螯虾Nephrops norvegicus拖网渔业是欧洲开展选择性研究最早、最全面的渔业,作者从上述2种虾拖网渔业及其兼捕、抛弃特点出发,通过对渔业中有关的尺寸选择性和种类选择性研究,特别是兼捕减少装置(BRD)的设计开发进行归纳和总结,结合渔业中有关兼捕减少技术措施的介绍,探讨了这2种渔业中选择性研究的特点及其对其他渔业选择性研究的借鉴意义,为我国今后开展虾拖网渔业选择性研究和渔业立法提供一定的参考依据.     

高原夏菜贮运保鲜关键技术研究

高原夏菜产业已成为甘肃省的战略主导产业。围绕高原夏菜采后处理、贮运保鲜过程中存在的问题,开展预冷技术、气体变化规律,以及控制技术、保鲜剂研制等方面的研究,为高原夏菜产业的发展提供科技支撑。     

Outflow reduction and salt and nitrogen dynamics at controlled drainage in the YinNan Irrigation District, China

The YinNan Irrigation District in NingXia, China diverts each year about 1.6 × 10⁹ m³ water from the Yellow River for irrigation use. More than half of that water is discharged back to the downstream channel or some low-lying depressions as a result of agricultural drainage. Several studies have indicated that the District is excessively drained, partially caused by the over-dimensioning of the existing drainage system, and proposed to improve the situation by controlled drainage practice. We subsequently carried out a field experiment of controlled drainage in the rice growing area of the District in 2004–2005. Field observations showed that reduction of the drainage depth of field ditches from 1 to 0.4 m resulted in a drainage flow reduction of 50–60%. Drainage water salinity increased only slightly but was still below the salt tolerance level of rice. Measurements of nitrogen concentrations showed no clear trend of changes as the result of irregular fertilization practice in the experimental site.