汾河流域湿地植物对农业污染的净化效果研究

以山西省人工湿地系统中常用的3种挺水植物美人蕉、香蒲和茭白为研究对象,研究单一植物对农村生活污水、农田回水、村田混合水的生长适应性及其污水净化效果,旨在探明3种湿地植物的耐污能力及其在人工湿地系统处理农村污水中的应用价值。30 d静态试验的结果表明,在农田回水和村田混合水条件下,3种供试植物的生长特征和氮净化能力均无明显不同,茭白的磷净化能力最强。在农村生活污水条件下,美人蕉和香蒲均长势良好,茭白则全部死亡;对植物生物量研究发现,美人蕉的生物量显著大于香蒲,分别为112.5、80.04 g/株;挺水植物对农村生活污水净化能力为:美人蕉香蒲茭白,分别为57.09%、46.38%、19.11%。综合考虑植物的氮净化能力、生长特征和实际应用效果,美人蕉和茭白可以作为汾河流域利用人工湿地系统处理农村生活污水的优选挺水植物。     

乌梁素海夏季不同介质间氮元素迁移规律的研究

TN是乌梁素海水体富营养化的指示性污染因子之一,富集于水体、沉积物和水生植物中,不同季节TN在这3个介质间迁移转换,在一定程度上起到调控水体富营养化程度的作用。为了揭示从夏季初至夏季末湖水水质变化情况,以及氮素在水体、挺水植物芦苇和沉积物各介质间的迁移转换规律,2013年5月和8月分别在乌梁素海湖区采集了水、挺水植物芦苇和沉积物试样,测定其TN含量。分析结果显示:8月份不仅芦苇生物量比5月份高出2.9倍,而且芦苇试样氮含量平均值也高出4.2倍,与此同时,水体中的TN平均浓度从5月份的3.511mg/g降低至8月份的2.019mg/g,沉积物中的TN平均浓度也从5月份的2.02mg/g降低至8月份的1.42mg/g。表明在夏季芦苇生长期中,水体和沉积物中的部分营养元素氮显著地向芦苇迁移并转换,至5月和8月采样期,芦苇从水体和沉积物中移出的氮总量分别为5 221.08t和61 053.56t。     

冀南稻麦轮作区化肥施用与氮磷流失状况分析

于2004年调查了冀南稻麦轮作区化肥施用状况和作物产量,并分析了稻田土壤速效氮和速效磷(Olsen-P)、田面水样及受田面影响的附近田外水样全氮、磷。结果表明:冀南地区施肥以化肥为主,有机肥施用比例较小,传统施肥对氮、磷地表流失明显,尤其是化肥用量大且配施有机肥的氮、磷流失最严重。田面水与田外水中氮、磷含量均达到极显著水平,氮、磷化肥不合理施用对附近水体存在较大污染风险。而试验区Ⅰ和Ⅱ,氮、磷流失较低。减少化肥施用量,合理施肥可降低施用化肥的环境风险。     

三种漂浮植物对水体净化效果比较研究

研究三种漂浮植物对水体的净化效果,对生长有凤眼莲、浮萍及槐叶萍的静止水体进行长期监测,结果表明:漂浮植物对改善水体透明度意义不大;植物在生长过程中,一旦盖度达到100%,对水质无明显改善水质作用,其中水体DO含量降低,水体TN、TP、IMn等主要水质指标较对照水体有所上升;因此,静态富营养化水体在生态修复过程中,使用漂浮植物作为净化物种时,应根据物种要严格控制其盖度,可选择地通过人工打捞的方式,从水体中取走植株固定的氮磷等元素,达到脱氮、除磷,控制水体富营养化的目的。     

南四湖水体氮磷及叶绿素空间分布特征

研究分析了南四湖水体氮、磷、叶绿素a含量及空间分布特征。结果表明,南四湖水质主要参数在各湖区的分布存在明显的非均一性。南阳湖水体TN、DTN、NH4+-N、TP、DTP、PO43--P浓度均显著高于其他3湖区的,但独山湖、昭阳湖和微山湖水体不同形态氮、磷浓度间无显著差异;水体中DTN、NH4+-N与TN以及DTP、PO43--P与TP浓度呈显著相关;南四湖水体中叶绿素浓度的分布呈现出较大的差异,南阳湖水体叶绿素浓度最高、微山湖的最低,叶绿素a浓度与TN/TP比值、pH值间呈显著的对数负相关,与不同形态氮、磷及COD浓度间呈显著的对数正相关。     

不同挺水植物对水体净化效果及生长特性研究

通过室内模拟自然水体的方法,选择了千屈菜和黄花鸢尾2种常见的挺水植物,对比研究了不同配置下TN、NO3--N、TP、PO34--P的去除效果和植物在受污染水体中的生长状况。结果表明,千屈菜对水体中TN、TP和PO34--P去除效果最好,去除率依次为40.8%、52.7%、35.1%,而黄花鸢尾对NO3--N的去除效果最好,去除率为32.5%;千屈菜植株高度增量最大;千屈菜-黄花鸢尾组合2种植物的叶片长度增长率最大,在2种配置中黄花鸢尾叶片宽度增长率均高于千屈菜。     

平菇高产栽培营养液

据试验,平菇在出菇期间喷施营养液1～2种,高产优质效果明显。可用营养液有: (1)淘米水 即当天烧饭淘洗的水,0.5公斤米洗5公斤水。 (2)2％草木灰浸出液 此液含钾盐和钙、磷、镁、硫、硅等元素,可提高平菇酶系生理活性,促进菇体健壮。 (3)豆浆汁 干黄豆50克磨浆煮沸化水25公斤,既具氮、碳素,又富含硫素,能增     

挺水植物修复技术在处理受污染开放水体中的实验研究

对水体生态治理和修复技术的原理进行了概述,并对开放水体受污染生态技术处理方法进行了分析和探讨,提出应用挺水植物修复技术来处理受污染开放水体的方法,并对该方法进行了试验研究,实验结果表明该方法处理效果较好,从而提出了适合受污染开放水体治理方法。     

海洋的瘟神——赤潮

所谓赤潮 ,就是浮游生物在短期内迅速繁殖并聚集蔓延 ,导致海水变色 ,同时散发出怪异恶臭味的海洋现象。赤潮生物的大量繁殖 ,是由于城市工业向海洋大量排放富含营养物质 (如氮、磷等有机元素 )的污水。同时农田大量使用化肥 ,排出的污水中含有大量的有机物和无机物 ,造成海水中贮存了大量的氮、磷等营养成分 ,我们称之为“富营养化”。富营养化水体促进了海藻及微小浮游生物的繁殖 ,在阳光和水温适宜的季节中 ,藻类繁殖特别迅速 ,可达 10 0万个 /升以上。大量繁殖的赤潮生物密密麻麻地覆盖在水面上 ,遮蔽了阳光 ,使水的透明度降低 ,水体溶…     

农业面源污染对水生态环境的影响分析与防控

农业面源污染所产生的氮、磷等污染物严重影响水生态环境的自然平衡,对地表水和地下水形成了污染。文章介绍了农业面源污染对地表水和地下水的影响——过度排放的氮、磷以及无机盐等不仅会造成水体的富营养化,而且会改变土壤的理化性质,造成土壤板结。为此,笔者提出了相应的防控举措,以期为水生态环境的持续健康发展助力。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。