奎河灌溉水体中微生物分布及与有机污染物的相关性研究

以奎河水体中微生物群落为研究对象,分析了其数量分布以及与有机污染物的相关性。结果表明：奎河徐州过境段水体中的微生物数量从上游地区（1号采样点）、中游地区（2号采样点）到下游地区（3号采样点）呈现先下降后升高的趋势;水体中的微生物数量与有机污染物含量关系密切,细菌总数、大肠菌群数与总氮显著正相关,且相关系数R分别为0.817、0.836;细菌总数、大肠菌群数、蛔虫卵数与COD显著正相关且R分别为0.821、0.838、0.949,大肠菌群数与悬浮固体（SS）显著正相关且R为0.737;细菌总数、大肠菌群数、蛔虫卵数与总磷、色度相关性不显著。     

绿茶加工过程中有害微生物污染试验研究

绿茶作为外销茶的主体,其卫生安全问题已成为我国茶叶出口的主要问题之一,绿茶加工过程中微生物的变化直接影响茶叶的总体品质。通过试验,测定了绿茶加工过程中各个主要环节细菌总数、霉菌总数、大肠菌群、大肠杆菌、沙门氏菌和金黄色葡萄球菌的污染情况,分析其产生的原因,从改进机械设备工作原理和操作方法的角度出发,探索了控制绿茶加工过程中污染问题的控制措施。     

土壤低含量铅时冬小麦幼苗根际微生物群落的变化

采用土壤盆栽试验法研究了土壤低含量铅(Pb)(质量比小于300 mg/kg干土)对冬小麦幼苗根际微生物的影响特征.与对照相比,幼苗生长3周和7周时,低含量Pb对细菌数量的平均抑制率分别为16.25％和8.62％(p＜0.01);幼苗生长3周、7周和12周时,低含量Pb对真菌数量的平均抑制率分别为34.08％、39.89％和17.49％(p＜0.01);7周和12周时,与对照相比,低含量Pb极显著(p＜0.01)抑制放线菌数量增殖.幼苗生长3周时,真菌数量与Pb含量极显著(p＜0.01)相关;7周时,真菌、放线菌和微生物总数与Pb含量显著(p＜0.05)相关.低含量Pb处理下,根际真菌/细菌比值较对照显著降低,微生物代谢功能多样性变化显著.研究结果表明:土壤低含量Pb对冬小麦幼苗根际土壤微生物数量及微生物群落结构特征影响显著.     

宁夏枸杞园土壤线虫和微生物群落多样性研究

为了揭示宁夏枸杞园土壤质量变化趋势,以宁夏枸杞之乡——中宁县为研究区,选取不同树龄宁夏枸杞园土壤,分析不同季节、土层和树龄条件下土壤线虫和微生物群落特征变化规律。结果表明,随树龄的增加,枸杞园0~20 cm土壤线虫总数先增加后减少,6 a树龄时达最大值。不同树龄表层土壤均为食细菌线虫所占比例最大(夏季和秋季平均分别为57.23%和61.19%),植物寄生线虫次之;亚表层植物寄生线虫比例显著提高。夏季表层土壤总磷脂脂肪酸(PLFA)和细菌PLFA浓度随树龄呈减小-增大-减小的趋势,9 a树龄各菌群PLFA浓度普遍最大。随树龄的增加,夏季0~20 cm土壤线虫多样性和丰富度指数先增大后减小,但土壤微生物多样性指数、均匀度指数都逐渐减小,线虫和微生物群落优势度指数都逐渐增大;20~40 cm土壤线虫和微生物数量、多样性指数和优势度指数变化趋势一致。土壤EC与微生物总PLFA浓度、细菌PLFA浓度达显著负相关;土壤有机质、全氮、速效磷含量与土壤各线虫数量和微生物浓度相关性普遍达显著或极显著水平。土壤线虫总数、食细菌线虫数量与细菌、真菌和放线菌PLFA浓度均显著或极显著相关。总之,季节、土层和树龄对土壤线虫和微生物群落均有不同程度的影响,但树龄对其影响相对最小;季节、土层和树龄对土壤微生物群落的影响比对土壤线虫群落更显著。在相同季节和土层条件下,土壤微环境质量随着树龄的增加呈现出先改善后退化的趋势。     

铅对小白菜根际微生物群落与其生理功能的影响

通过不同铅浓度下小白菜根际土壤微生物数量、硝化和反硝化速率及呼吸速率等特征的研究,揭示铅污染对植物根际微生态系统生态安全性的影响。结果表明,随着铅浓度的增加,细菌、真菌和放线菌数量均呈现先升后降的变化趋势,峰值所对应的铅浓度分别为300、300和600 mg/kg,3种微生物的耐铅能力为真菌放线菌细菌。土壤硝化和反硝化细菌数、硝化和反硝化速率及呼吸速率也随着铅浓度的增加先升后降,各指标峰值所对应的铅浓度均为300 mg/kg;硝化速率与硝化细菌数、反硝化速率与反硝化细菌数及土壤呼吸速率与微生物总数决定系数分别为0.684 7、0.851 1和0.684 3,均显著正相关。研究发现,当土壤铅浓度达到或超过1 200 mg/kg时,小白菜根际微生态系统出现显著的微生物群落结构和功能退化。     

玉米秸秆还田对土壤微生物群落数量的影响

为探讨玉米秸秆还田对土壤微生物群落数量的影响,设置不同季节与不同剂量秸秆还田试验,寻求最佳季节与用量。研究结果表明:随季节变化推移,土壤中细菌、真菌、自生固氮菌、纤维素分解菌的群落数量在秋季达到最大,放线菌数量在夏季达到最大,硝化细菌数量随季节变化不明显;当秸秆施入量为800kg/667m2时,除硝化细菌数量变化不显著外,其余各微生物群落数量均达到最大,且与各处理相比差异极显著。     

再生水灌溉对植物根际土壤特性和微生物数量的影响

采用盆栽试验方法,以自来水灌溉为对照,分析研究了不同水质灌溉下对不同园林植物根际土壤特性的影响.结果表明:在土壤理化性状方面,再生水灌溉情况下,几种园林植物的土壤pH与对照相比无显著差异;土壤全盐量、水溶性钠和氯离子含量均高于自来水灌溉,多种植物土壤中含量与自来水灌溉相比达到了显著差异或极显著差异;在土壤养分方面,与对照相比,碱解氮、有效磷、速效钾含量差异不显著;在土壤微生物方面,再生水灌溉不同程度的促进了土壤微生物数量的增加,其中,细菌增加显著,放线菌和真菌数量与对照相比虽有所升高,但并未达到显著水平.     

超高压处理对树莓汁杀菌效果的影响

以新鲜树莓汁为主要原料,研究了超高压处理对新鲜树莓汁菌落总数变化以及霉菌、酵母菌、大肠杆菌、沙门氏菌存活量的影响。结果表明:压力越高,杀菌效果越好; 保压时间的延长有助于微生物的杀灭,在室温（25℃）,压力为200MPa、保压时间为5min时,大肠杆菌被完全杀灭;在压力为300MPa、保压时间为15min时,沙门氏菌被完全杀灭;在压力为400MPa、保压时间为15min时,酵母菌和霉菌也可被完全杀灭;在压力为600MPa、保压时间为25min时,虽不能完全杀灭所有微生物,但菌落总数可降至10cfu/mL以内,达到国家食品相关标准要求。     

不同灰分生物质炭对红壤理化特性与微生物特性的影响

为探讨不同灰分含量的生物质炭对酸性红壤特性和微生物特性的协同影响,采用盆栽试验,添加1%～10%土壤质量的高灰分稻壳炭(RHC)和低灰分油茶壳炭(COSC),以无添加为对照,50 d后测定土壤含水率、p H值和土壤碱解氮、速效磷、速效钾含量,以及土壤微生物群落数量、微生物量碳含量和微生物活性。结果表明,添加1%～10%的RHC和COSC,土壤含水率由15. 54%增加至17. 47%～28. 28%,p H值由5. 40提高至7. 05～7. 75,其中,10%RHC处理土壤的含水率显著(p 0. 05)提高81. 98%,p H值显著提高43. 52%。酸性红壤的营养元素随RHC添加量的增加而提高,10%RHC处理土壤的碱解氮、速效磷、速效钾含量分别显著增加84. 83%、70. 47%和595. 57%,COSC添加对土壤碱解氮含量有负相关影响,使其降低14. 65%～29. 27%。微生物群落数量随RHC、COSC添加量的增加呈现先增大、后减小的趋势,5%RHC处理对细菌、真菌、放线菌数量影响显著,分别增长了1 040. 05%、715. 00%和713. 59%; 5%COSC处理对土壤真菌数量影响显著,增长了1 265. 00%。土壤微生物生物量碳含量和微生物活性均随RHC和COSC添加量的增加呈先升高、后降低的趋势,5%COSC处理对微生物生物量碳含量影响显著,较对照组增长了11倍,5%RHC处理对微生物活性影响显著,较对照组增加了60. 50%。因此,适量添加高灰分稻壳炭改良红壤,可协同改良土壤理化特性、增加微生物群落数量和微生物活性。本研究结果可为高灰分生物质炭改良酸性土壤提供科学依据。     

长期污水灌溉对小麦根际土壤微生物区系的影响

研究长期污水灌溉对小麦根际土壤微生物区系的影响.采用大田采样和室内培养分析,结果表明,与对照相比,长期污灌区根际土壤中细菌、放线茵、固氮茵、硝化细茵、氨化细茵和纤维分解茵浓度降低,真菌、反硝化细菌浓度增加.综合考虑各种微生物对作物的不同影响,长期污水灌溉不利于植物生长.     

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。