敌敌畏臭氧氧化影响因素的研究

文章开展了敌敌畏臭氧氧化影响因素实验的研究.研究发现,敌敌畏溶液的初始浓度、溶液初始pH、不同光照强度对其均有影响.     

电催化氧化苯酚废水中间产物分析与降解途径探讨

采用电催化氧化法降解苯酚废水,利用高效液相色谱仪分析其降解的中间产物.通过对比标准物质和苯酚废水电催化氧化过程中产生中间产物各组分在高效液相色谱图中的保留时间以及直接在降解废水中加入标准物质前后各物质组分的色谱峰面积变化情况来实现物质组分的定性、定量分析,从而确定苯酚电催化氧化的中间产物.根据中间产物的产生情况及含量变化,探讨了苯酚电催化氧化的降解途径.     

不同操作条件对连续生成微酸性电生功能水的影响

利用复极连续式电生功能水生成系统,研究了不同操作条件(电压、盐酸溶液供给量、原水pH值和盐酸溶液质量分数)对电生功能水中有效氯浓度、pH值及电导率的影响。实验结果表明,微酸性电生功能水中的有效氯浓度随电压(3～5 V)的增大而增大(P<0.01),但pH值和电导率的变化不显著(P>0.05);随着盐酸溶液供给量增加,微酸性电生功能水中的有效氯浓度和电导率也随之增加,而pH值随之降低(P<0.01);随着原水的pH值升高,微酸性电生功能水的pH值升高而电导率减小(P<0.01),有效氯浓度变化不显著(P>0.05);微酸性电生功能水随盐酸溶液质量分数的增加,有效氯浓度和电导率随之增加,而pH值随之降低(P<0.01)。     

铁屑微电解——共沉淀法处理电解锰废水

采用铁屑微电解-共沉淀法对电解锰废水进行处理,考察了铁屑用量、pH值、反应时间对电解锰废水中Cr6+、Mn2+去除率的影响。实验结果表明:当铁屑用量为15%,pH为4.0,反应时间为2h时,Cr6+、Mn2+去除率最高,处理后废水中的Cr6+和Mn2+去除率均可达99%以上。     

高铁酸钾氧化-絮凝处理苯酚废水过程中pH值的变化

以提高苯酚去除率为目的,通过改变反应条件,研究高铁酸钾氧化-絮凝降解模拟苯酚废水时快速搅拌1min、氧化反应完成、絮凝反应完成时pH值的变化,根据pH值变化做机理分析。结果表明:快速反应1 min后与最终滤液的pH值在最适温度度下最高;絮凝反应后最终滤液的pH值会随高铁酸钾投加量先增大后减小,随原水pH值由极酸到极碱的变化,最终滤液的pH值固定在7.22~12.05碱性范围内。此研究表明,在较好的氧化条件下产酸较多,使pH值呈现降低趋势,在较好的絮凝条件下会产生Fe(OH)3使得最终滤液的pH值呈现增加趋势,但最终滤液的pH值会固定在弱碱性范围内。     

农业有机废水的三维电解试验及参数优化

研究以13.275 mg/L亚甲基蓝溶液为试验对象模拟农业有机废水，分别以电解时间（5、10、15、20、25、30和35 min）、pH值（2、4、6、8、10和12）和电流密度（2、4、6、8、10和12 mA/cm2）为工艺条件进行单因素试验；以电解时间、pH值和电流密度为因素设计3因素3水平L9（33）正交试验，处理效果以废水中的COD去除率和脱色率为参考标准，得到以Fe2O3-GAC为三维电极的电解试验处理有机废水的最佳参数组合。试验结果表明，三维电解处理该废水的最佳工艺参数为电解时间30 min、电流密度8 mA/cm2和pH值为6，在最佳参数下，废水COD去除率可达59.7%，脱色率达到88.5%，实现较好的处理效果。      

花生壳活性炭吸附染料废水中结晶紫的研究

利用磷酸处理微波照射制备花生壳活性炭,以一定浓度的结晶紫溶液为模拟染料废水,研究了吸附剂粒径、溶液pH值、结晶紫的初始浓度、吸附剂用量、吸附时间、吸附温度对结晶紫吸附性能的影响。结果表明花生壳活性炭是具有高去除率的廉价吸附剂,最大去除率达96%。结晶紫染料在花生壳活性炭上的吸附过程符合二级动力学模型和Freundlich等温吸附方程。     

三维电极法处理低浓度氨氮废水的研究

养殖场污水处理系统厌氧/好氧阶段的出水,氨氮浓度较低、较难生物降解。针对此类废水中的特征污染物氨氮,研究通过单因素实验和响应面设计实验得到三维电极最优电解条件,即pH值5.0,电解质浓度0.20 mol/L,电压9.86 V,极板间距6.47 cm。在最优条件下处理氨氮浓度为140.00 mg/L的原水,出水氨氮浓度降至34.50 mg/L,低于《鄱阳湖生态经济区水污染物排放标准》(DB36/852-2015)中高效集约发展区氨氮限值。运用X射线衍射仪检测到,在烧结温度为200℃时,活性炭表面附着了α-MnO2、β-MnO2和Mn3O4。结合电化学反应特性,分析所构建的三维电极体系的反应机理。     

电解含溴饮用水过程中溴酸盐的形成

分别采用BDD电极和钌铱钛电极作为阳极,钛板作为阴极,进行了模拟含溴饮用水的电化学氧化研究。通过对溴离子、活性溴、溴酸盐的浓度监测以及循环伏安扫描、RNO褪色实验等手段,对两种电极电解时溴酸盐的形成机理进行了探讨,并对电流密度、pH值和溴离子初始浓度c0(Br-)等反应条件对溴酸盐形成的影响规律进行了分析。结果表明,与钌铱钛电极相比,BDD电极电解时更易形成溴酸盐,其拥有的更强的·OH等活性物质生成能力是出现这种现象的主要原因。电流密度越大或溴离子初始浓度越高,都会使溴酸盐更易形成;中性pH条件下,溴酸盐的形成浓度要高于强酸强碱条件下。     

电化学法预处理沼液的研究

文章采用石墨为电极,研究了电化学法对沼液预处理效果,考察了极电压、反应时间、极板间距、初始pH值及不同电化学反应条件对沼液中COD和TP的去除率影响,确定了电化学法处理沼液的最佳试验条件,结果表明,极电压15 V,反应时间3.0 h,极板间距20 mm,初始pH值为5.0,在改变电化学反应条件的情况下都可以提高出水COD和TP的去除率。     

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。