基于酶传感器的农药浓度便携式实时测量装置

设计了一种应用酶传感器的便携式农药浓度测量装置,由丝网印刷酶电极、信号调理电路和单片机C8051F040组成.酶传感电极修饰方法使涂层电荷转移电阻减小而加速电荷转移.装置检测出酶抑制率与农药(西维因)浓度的对数在农药(西维因)质量浓度为5 ng/mL～2 μg/mL时呈线性关系,最低检出限为1.7 ng/mL,检出时间小于161 s,系统尺寸小,可采用电池供电,为数量级μg/L的农药质量浓度现场检测(如农药喷雾现场)提供了一种便携式快速测量装置.     

超声提取—HPLC法分析蔬菜中的多种农残

建立了一种超声提取—高效液相色谱(HPLC)同时检测吡虫啉、多菌灵、嘧霉胺的方法。样品经超声辅助提取后,再进行净化、检测,节省了检测时间。以甲醇+水为流动相,采用梯度洗脱,结果表明,3种农药完全分离,线性范围均为0.05~1μg/mL,平均加标回收率为85%~103%,检出限均≤0.002 5μg/mL,定量限≤0.01μg/mL。该方法耗时短、准确度高,适用于批量农药多残留检测。     

农田环境中农药残留比例型荧光传感系统研究

为监测农业环境中有机磷农药的残留,从种养源头管控农产品安全,基于锆离子和1,2,4,5-四（4-羧苯基）苯（H-4-TCPB）合成了蓝色荧光金属-有机框架材料（MOFs）Zr-TCPB,并与红色荧光量子点QDs组装成双荧光QDs@MOFs复合物,基于Zr-TCPB对有机磷农药特异性荧光淬灭效应,构建比例型荧光化学传感器系统,实现了有机磷农药的快速、灵敏、可视化检测。甲基对硫磷与对硫磷的检测限（LOD）分别为1.9μg/L和4.9μg/L,线性检测范围为0.005~2mg/L。研究表明,该荧光分析法能有效用于农业环境水样中甲基对硫磷及对硫磷的现场快速测定,甲基对硫磷回收率为93.23%~116.46%,平均相对标准偏差（RSD）为5.29%,对硫磷回收率为92.52%~107.83%,平均RSD为5.74%。该方法在环境样品农药残留快速监测方面具有巨大的应用价值。     

基于电化学和虚拟仪器的土壤重金属检测系统研究

采用超声波辅助提取法对土壤样本进行快速前处理,以铋膜修饰丝网印刷电极作为传感器,结合差分脉冲阳极溶出伏安法对土壤浸提液中的铅和镉进行精确测量。检测仪器以Lab View平台软件为工作核心,结合MSP430单片机、恒电位电路、I/V转换电路、电磁阀和蠕动泵等硬件设备实现了对土壤浸提液的自动进样、电化学分析以及排液清洗等铅和镉的操作。针对实际土壤样本测量时可能产生的误差,分别采用了概率统计算法以及多次标准添加法加以消除。系统检测限分别达到2.6μg/L和1.8μg/L。对不同地区采集到的多个土壤样本进行分析,结果表明该系统具有检测精度高、重现性好、速度快、功耗低等优点,适合对农田土壤重金属进行快速检测和评估。     

HPLC法快速测定婴幼儿配方奶粉中维生素B2

建立了快速测定婴幼儿配方奶粉中维生素B2的高效液相色谱测定法。方法采用ZorbaxXDB-C18(5μm,4.6mm×250mmi.d)反相色谱柱,以0.05mol/L乙酸钠水溶液:甲醇(60:40,V/V,调pH值4.5)为流动相,流速为1.0mL/min,进样量10μL。方法定量限0.5mg/kg,加标回收率86.7%～91.9%,线性范围0.00～1.00μg/mL,相对标准偏差为2.12%。该法具有样品预处理简单,灵敏度高,分析时间短等优点,适用于婴幼儿配方奶粉中维生素B2的快速测定。     

食用酱油中对羟基苯甲酸酯的高效液相色谱法测定

运用高效液相色谱(HPLC)法在不改变流动相和检测波长的情况下,测定食用酱油中4种对羟基苯甲酸酯的含量;检测条件:流动相为0.02mol/L磷酸二氢钠(pH值4.0)∶乙腈=50∶50,检测波长为255nm,检测浓度范围为0.05～250μg/mL,最小检测浓度为0.025μg/mL。样品回收率为95.8%～104.3%。     

多层纸基微流控芯片的设计及其对农药的可视化检测

为了满足对农药残留快速、简便、低成本和现场检测的要求,基于适配体的荧光法检测原理,从提高混合效果的角度,设计了一种高效混合的阵列式多层纸基微流控芯片。通过对半圆环式交错结构、截圆式交错结构和圆环式堆叠结构的流动混合仿真,得出"d_2-1700μm型"截圆式交错结构的混合通道的混合效果最佳,I_e值为0.924 41。利用显色剂对仿真优化的结果进行试验,对20次试验的结果进行图像处理算得混合强度值的平均值为0.713。分别对啶虫脒和丙溴磷两种农药进行可视化检测试验,测得对啶虫脒的检测范围是50～600μg/kg;对丙溴磷的检测范围是60～480μg/kg。     

离子液体/纳米Fe 3O 4修饰的丝网印刷电极重金属检测

设计了一种N-辛基吡啶六氟硝磷酸盐离子液体粘合纳米四氧化三铁修饰丝网印刷电极,结合方波阳极溶出伏安法实现了重金属镉、铅离子的同步检测。并用循环伏安法、交流阻抗法、方波溶出伏安法进一步研究修饰电极的电化学性能,表明采用离子液体/纳米四氧化三铁复合膜可有效提高丝网印刷电极的电子传递能力和有效面积,修饰电极对镉离子和铅离子显示出了良好的检测灵敏性。在最优检测条件下,修饰电极对镉离子和铅离子峰电流在浓度分别为0.2~35.0 μg/L和0.2～20.0 μg/L范围内呈现良好的线性关系,检测下限分别为0.06、0.1 μg/L（ S/N =3）。将该电极用于检测土壤和水样本中的重金属镉和铅,表现出较好的选择性和检测精度。     

便携式蔬菜叶片重金属镉含量无损检测仪设计与试验

针对蔬菜叶片重金属镉检测传统方法存在的检测仪器体积大、检测成本高和具有破坏性等问题,提出一种基于可见光-近红外波段光谱蔬菜叶片重金属镉检测方法,并设计了一款无需预处理、检测速度快、体积小且便于携带的重金属镉检测仪,能够适用于移动式的现场检测.配置4个重金属镉胁迫梯度(0、1、3、5 mg/L)营养液,培育各镉胁迫的生菜...     

椰糠基质有效氮近红外检测仪设计与试验

为了实现椰糠基质有效氮含量的快速实时检测,基于漫反射光谱设计了椰糠基质有效氮近红外检测仪。该检测仪的硬件系统主要由前处理装置、气力输送装置、重力式沉降样品室、近红外光谱检测装置、样品回收装置和空气压缩机等组成。制备了不同有效氮含量的椰糠基质样本135个,采用研制的检测仪获取了样本原始光谱数据,并建立了椰糠基质有效氮含量的最优偏最小二乘回归预测模型,其校正集相关系数和验证集相关系数分别为0.973和0.965,校正集均方根误差和验证集均方根误差分别为14.025 mg/(100 g)和15.757 mg/(100 g),残差预测偏差为3.72。基于MFC开发工具,采用C/C++语言开发了检测仪硬件控制及实时检测分析软件界面,将建立的最优有效氮光谱预测模型移植到软件程序中,实现了椰糠基质有效氮近红外检测仪功能硬件控制及有效氮检测的一键式操作。试验验证结果表明,所研制仪器预测值与国标测量值相关系数为0.883,测试集均方根误差为18.605 mg/(100 g)。该检测仪实现了椰糠基质有效氮含量的快速实时检测,并且预测性能较好,可以满足快速评价椰糠基质养分的实际需求。     

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。