猪粪水热预处理和厌氧消化条件下的典型抗生素降解性能

畜禽养殖过程中排泄的粪污中残存大量抗生素给环境带来潜在风险。为进一步了解水热预处理和厌氧消化对畜禽粪污中典型抗生素降解变化特征,同时明晰抗生素与产甲烷性能的相关性,以猪粪为研究对象,考察了不同温度（70、90、120、150、170℃）水热预处理对3种抗生素（磺胺嘧啶、土霉素和恩诺沙星）的消减作用,研究了3种抗生素在中温厌氧消化过程中的降解规律及其对产甲烷性能的影响。结果表明,磺胺嘧啶和恩诺沙星在70℃水热处理条件下100%去除,而土霉素在90℃水热处理条件下100%去除;3种抗生素的去除率随着厌氧消化时间的延长而逐渐增加,恩诺沙星在厌氧消化5d基本达到100%的去除;土霉素在厌氧消化15d基本达到100%去除,而磺胺嘧啶在厌氧消化30d去除率达52.9%;厌氧消化过程中磺胺嘧啶的去除率随着起始浓度的增加而降低,低浓度组（SDZ-1、SDZ-2和SDZ-3）在前12d均能够完全降解,高浓度组SDZ-4和SDZ-5在厌氧消化36d后的去除率分别为65%和71%。此外,猪粪中磺胺嘧啶为5~150mg/kg范围内,未见对猪粪厌氧消化产甲烷性能产生负面影响作用,厌氧消化累积沼气和甲烷产量与磺胺嘧啶浓度呈负线性相关（R2=0.9546和R2=0.8654）。因此,水热预处理和厌氧消化对猪粪中磺胺嘧啶、土霉素和恩诺沙星具有明显的消减作用,可为后续水热预处理耦合厌氧消化处理含抗生素粪污的研究提供数据支撑。     

不同含固率和接种比对尾菜厌氧消化的影响

文章通过尾菜中温批式厌氧消化实验,研究不同含固率(4%,8%)和接种比(RI/S=0.8,1.0,1.2)对尾菜厌氧消化产气特性的影响。结果表明,累计甲烷产量随含固率的提高而增加,随接种比的提高而降低,在含固率为8%,接种比为0.8时,累计甲烷产量最大,达到253.81 mL·g^-1VS。含固率一定时,接种比越高,越有利于缩短厌氧消化周期,但会降低累计甲烷产量;接种比一定时,含固率越高,产甲烷延滞期越长,累计甲烷产量越高。厌氧消化第9天各处理组均开始出现不同程度的丙酸积累现象,含固率为8%,接种比为0.8时,丙酸浓度最高可达1981.522 mg·L^-1。含固率越低,接种比越高,越有利于丙酸降解。厌氧消化第33天时,各处理组丙酸全部被转化利用。     

能源草厌氧发酵产气性能与动力学分析

选取象草和杂交狼尾草等5种能源草为发酵原料,采用中温批式厌氧消化工艺,研究能源草发酵前后理化特性变化和发酵产气性能,并对累积产气动力学分析。研究结果表明:不同能源草的发酵产气性能与原料特性之间有较大的关系,其产气率与木质素成负线性相关。杂交狼尾草由于刈割时生长时间较长,使得木质素质量分数(24.88%)较高,其产气性能较差,实际产甲烷率仅为理论产甲烷率的26.95%,而华南象草刈割时木质素质量分数(15.82%)较低,其产气性能较好,VS累积产气率为379.58 m L/g,VS产甲烷率为228.55 m L/g,生物燃气中甲烷体积分数为60.21%。对累积产气曲线拟合,发现采用修正Gompertz方程能较好模拟能源草发酵累积产气率的变化过程。该研究可对能源草的能源化开发利用提供参考。     

湿贮存对玉米秸秆厌氧消化性能的影响

文章以华北地区和东北地区的玉米秸秆为原料,经前期原料特性分析及沼气发酵潜力的对比研究,分别进行实验室规模和工业规模湿贮存试验,研究湿贮存对原料产气潜力的影响并通过修正Gompertz模型进行动力学分析。研究结果表明,湿贮存可明显提高玉米秸秆厌氧发酵日均产甲烷峰值和甲烷含量。两个地区的玉米秸秆的沼气累积净产量分别为395 m L·g-1VS和396 m L·g-1VS,经过湿贮存60天的玉米秸秆品质较佳,沼气累积净产量分别提高7.5%和14.7%;在青贮壕内湿贮存365天的玉米秸秆品质明显降低,沼气累积净产量降低了23%。采用修正Gompertz方程能够较好模拟湿贮存前后玉米秸秆厌氧消化性能。因此玉米秸秆的高效湿贮存是其沼气工程高效稳定运行的前提。     

多元混合物料协同厌氧消化产甲烷性能研究

为研究农牧废弃物多元混合物料协同厌氧消化对产甲烷性能的影响,文章以牛粪、蔬菜废弃物和玉米秸秆为发酵原料,分别设定了单一原料、两种及3种混合原料发酵组,在中温(37℃±1℃)和固体质量分数为12%条件下进行厌氧消化实验。结果表明:混合厌氧消化的协同作用贡献率为25.84%~39.83%,显著提高了产甲烷能力。三物料混合厌氧消化产甲烷性能明显优于两种混合物料,当牛粪、蔬菜废弃物和玉米秸秆VS混合比例为1∶0.4∶0.6时,累计甲烷产量达到最大值20713 m L,比其他单一物料和混合物料厌氧消化甲烷产量提高了11.86%~23.65%。修正的Gompertz方程能较好反映物料厌氧消化产甲烷过程,拟合结果的R2在0.9872~0.9986之间。该研究结果可为农牧废弃物多元混合物料厌氧消化产沼气工程提供参考。     

预处理和菌种驯化对剩余污泥连续厌氧消化的影响

为了提高剩余污泥厌氧消化的转化效率,文章探讨碱/超声联合预处理和菌种驯化对污泥厌氧连续消化的影响。实验结果表明:碱/超声联合预处理可以提高污泥的可生化性,污泥的SCOD增加了9742.9 mg·L~(-1),在后续的厌氧消化中甲烷产量提高20%;与原始菌种相比,驯化菌种可提高产甲烷量6%;污泥连续厌氧消化的最适有机负荷可达到2.3 kg VS·m~(-3)d~(-1),水力停留时间缩短为20 d。     

绿化废弃物与污水污泥混合比对污水污泥厌氧消化性能的影响

文章以污水处理厂污水污泥和干湿绿化废弃物(Gd,Gw)为研究对象,采用中温(35℃)共厌氧消化的方法,研究了干湿绿化废弃物与污水污泥(S)VS混合比分别为1∶2,1∶3时,与单纯污水污泥厌氧消化相比,在产甲烷量和溶解性有机物转化率上的差异,明确添加绿化废弃物对污水污泥厌氧消化性能的影响。研究结果表明,在相同VS条件下,绿化废弃物与污水污泥混合体系的甲烷产量与有机物转化率均明显高于单纯污水污泥体系;不同混合比对绿化废弃物和污水污泥共厌氧消化的甲烷产量有明显影响,且相同VS混合比的湿绿化废弃物较干绿化废弃物产甲烷量高;湿绿化废弃物与污水污泥VS混合比为1∶2时,混合体系单位VS累积产甲烷量最高,达291.58m L·g-1VS,较污泥单独厌氧消化提高了14.29%,较相同VS混合比干绿化废弃物提高了6.27%;最优产气工况Gw∶S为1∶2时,SCOD和溶解性碳水化合物、溶解性蛋白质和VS的转化率较污泥单独厌氧消化分别提高了2.28%,10.22%,16.89%和14.70%。由于添加绿化废弃物后,混合体系相比单独污水污泥系统,提高了有机物转化效率,是其产甲烷量较高的根本原因。     

不同生物预处理方式对污泥厌氧消化过程性能的影响

利用微生物处理技术对经聚丙烯酰胺脱水后的污泥进行不同方式微生物预处理,研究进料总固体(TS)质量分数为3%、发酵温度为35℃时厌氧消化过程中累积产气量与产甲烷含量、p H值、氨氮和化学需氧量(TCOD)等参数的变化趋势,探索真菌宛氏拟青霉不同预处理方式对脱水污泥厌氧消化过程特性的影响。试验结果表明:微生物预处理脱水污泥厌氧消化技术具有较好的可行性。直接添加宛氏拟青霉和添加宛氏拟青霉预处理2 d的污泥进行厌氧消化反应能够有效提高产气量和产甲烷量,加快水解速率,促进污泥中有机物的有效降解,使产甲烷过程顺利进行。直接添加宛氏拟青霉处理的产甲烷效果最优,其净累积产气量和产甲烷量较纯污泥分别提高85.79%和42.76%,且1 kg污泥可产甲烷12.69 L,较纯污泥提高42.74%。     

番茄茎叶与牲畜粪便协同厌氧消化性能研究

为确定番茄茎叶与牲畜粪便混合物料的协同作用对厌氧消化产甲烷的影响,文章研究了中温(37℃±1℃)和固体质量分数为12%时,牛粪或猪粪与番茄茎叶按挥发性固体比例(1∶0,3∶1,2∶1,1∶1,1∶2,1∶3,0∶1)混合厌氧消化产甲烷性能。结果表明:添加高比例的牲畜粪便对甲烷产量具有明显的协同促进作用。当牲畜粪便与番茄茎叶混合比例为3∶1时,甲烷产率和累计甲烷产量达到最大值,猪粪混合组分别为294.41 mL·g~(-1) VS和16087mL,较牛粪混合时分别提高了23.84%和10.79%。牛粪或猪粪与番茄茎叶混合厌氧消化协同作用值分别为-9.97%~25.48%和-7.05%~20.34%,混合比例为1∶3时产生了拮抗作用,甲烷产量分别降低了9.97%和7.05%。修正的Gompertz方程能较好反映物料混合厌氧消化产甲烷过程,拟合结果的R2在0.9855~0.9989之间。     

餐厨垃圾与牛粪联合厌氧消化效率研究北大核心

试验对餐厨垃圾（FW）与牛粪（CM）联合厌氧消化效率进行了研究.在初始总固体（TS）负荷为6.7％和中温（35℃）条件下,考察不同的餐厨垃圾与牛粪TS配比（0：1,1：1,2：1,3：1,4：1,1：0）对联合厌氧消化过程的影响.结果表明：FW与CM联合厌氧消化单位VS沼气产量与甲烷含量均明显提高.FW：CM为2时（T3）,沼气产量和甲烷含量均最高,分别为574.15 mL·g-1VS和69.78％.整个厌氧消化过程T1 ～ T5的pH值稳定在6.0 ～8.0之间,未出现挥发性有机酸（VFAs）抑制现象,VFM浓度随着FW的比例增加而升高,FW单独发酵时,VFAs大量累积,第7d时达到35600 mg·L-1.产甲烷菌群利用丙酸转化为甲烷的效率较低,VFAs中丙酸浓度下降的幅度明显低于乙酸、丁酸.厌氧消化过程中T1～T5也未出现氨抑制现象,氨氮浓度整体呈现先迅速升高,后缓慢下降,再缓慢升高的变化规律.在常温沼气工程应用中,初始总固体（TS）为6.7％时,建议FW与CM的TS比为2：1.     

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。