野生酸枣果硒多糖纯化与光谱分析

采用热水浸提、乙醇沉淀法获得酸枣果硒多糖粗品.苯酚-硫酸法测其多糖含量为(92.6±4.72) mg/g,原子荧光光度法测其硒含量为( 17.8±2.05)μg/kg.DEAE-25纤维素和Sephadex G-75凝胶层析柱进一步分离纯化得白色絮状多糖.薄层层析和高效阴离子交换色谱法分析其单糖组成.结果表明:该多糖是由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、木糖等单糖组成,其摩尔比为3.21∶8.36∶5.61∶0.96∶1.82.红外光谱分析表明具有明显的多糖特征吸收峰,核磁共振波谱表明该多糖结构主要为β-糖苷键连接的吡喃型葡聚糖.     

无花果多糖分离纯化工艺及抗氧化性能研究

本研究旨在更好地利用无花果副产物,提高其经济价值,并探究无花果多糖抗氧化性能。采用微波辅助提取无花果多糖,并对提取工艺进行优化。最佳条件下为：提取温度为70 °C,料液比为1:40,微波功率为800 W,提取时间为50 min。在此条件下,无花果多糖提取率为12.32%。以残渣模拟无花果生产后的废料,采用碱液浸提并分析碱提滤渣多糖热稳定性。结果表明,多糖在260 ℃以下具有良好的热稳定性;采用离子交换柱和凝胶柱对其进行分离纯化得到分子量为28.188 kDa的多糖组分PFCA2;单糖组成结果表明,PFCA2主要由鼠李糖、葡萄糖、阿拉伯糖、半乳糖、葡萄糖醛酸、半乳糖醛酸组成;体外抗氧化实验表明,PFCA2具有良好的DPPH自由基和羟基自由基清除活性,其IC50值分别为0.5041 mg/mL和3.2802 mg/mL。该研究表明,无花果滤渣多糖具有良好的抗氧化能力,是天然的抗氧化剂,本研究为无花果工业副产物精深加工提供理论依据。     

不同土壤含水率对太行红豆杉幼苗生长及品质的影响

【目的】探寻不同土壤含水率对盆栽太行红豆杉生长和相关品质的影响。【方法】以5a生太行红豆杉为试验材料,研究不同土壤含水率处理对太行红豆杉幼苗期的生长量、可溶性蛋白、丙二醛、叶绿素及黄酮、多糖量的影响。不同土壤含水率处理设为田间最大持水率的90%~100%(W1)、80%~90%(W2)、70%~80%(W3)、60%~70%(W4)、50%~60%(W5)。【结果】在W2处理下植株苗高、地径、冠幅以及叶面积指数和叶绿素a、叶绿素b和总叶绿素量均达到最大,比W1处理分别提高了11.4%、26.7%、11.7%、15.6%、14.4%、8.9%和13.0%,且该处理丙二醛量最低,比W1处理降低了14.1%;W4处理多糖和可溶性蛋白量最大,比W1处理分别提高了107.5%和42.0%;70%~80%处理黄酮量达到最高比W1处理提高了93.6%。【结论】W2处理有利于太行红豆杉的生理生长,W3处理有利于太行红豆杉中黄酮量的积累,W4处理有利于太行红豆杉多糖量的积累。     

淡腌青鱼中木糖葡萄球菌碳源代谢能力研究

为探究淡腌青鱼的腐败与其微生物代谢能力的关系,利用Biolog GENⅢ微孔板对淡腌青鱼货架期终点的特定腐败菌(木糖葡萄球菌)在5、15、25、33℃4种温度下的碳源利用情况进行研究,采用修正的Gompertz模型对代谢曲线进行拟合,并以平均颜色变化率(AWCD)为指标研究其代谢速率,分析木糖葡萄球菌利用碳源能力的动力学特征。结果表明:木糖葡萄球菌能利用糖、氨基酸和羧酸类等碳源;相同温度下木糖葡萄球菌对碳源的代谢能力由大到小依次为糖、羧酸、氨基酸,其中单糖(葡萄糖、甘露糖)、双糖(蔗糖、海藻糖)、多糖及其糖类衍生物(N-乙酰-β-D-甘露糖胺、β-甲酰-D-葡糖)、氨基酸(谷氨酸、丝氨酸)和羧酸(L-乳酸)的代谢较强。木糖葡萄球菌在25℃下的延滞期最短,进入指数期最快。通过对木糖葡萄球菌在不同温度下各种碳源代谢能力的分析,为优化产品配方有效抑制微生物的活动、延长产品货架期提供理论依据。     

黑加仑多糖的提取及纯化工艺研究

本研究以市售黑加仑果实为原料,首先采用热水浸提法对黑加仑多糖进行提取研究,最佳浸提工艺参数为:料液比1:30、浸提温度80℃、浸提时间2h、浸提次数2次、醇沉黑加仑多糖乙醇浓度80%效果最好;Sevag法去除蛋白质的最佳条件为:Sevag试剂成分三氯甲烷与正丁醇比为5:1、Sevag试剂与多糖样液比为3:1、去蛋白次数为4次,蛋白质脱除率可高达86.4%。去除蛋白质后的黑加仑多糖经DEAE-纤维素层析法纯化,采用不同浓度的NaCl溶液分段洗脱,可收集两种主要的黑加仑多糖组分P1和P3。     

不同溶剂下葡萄糖制取5-羟甲基糠醛的动力学研究

为了研究溶剂效应对单糖转化制取5-羟甲基糠醛(HMF)的影响,考察了葡萄糖在3种不同溶剂(水、二甲亚砜(DMSO)、水-DMSO)下较宽温度范围内(100~200℃)无催化条件下的降解行为,实验结果显示,在175℃水-DMSO混合溶剂下,HMF的产率可达到20.7%,远高于水溶剂下的11.86%和DMSO溶剂下的10.0%。采用涉及5-羟甲基糠醛(HMF)、乙酰丙酸(LA)和腐殖质(humin)生成的反应模型分析了葡萄糖降解动力学,该模型较好地吻合了实验结果。动力学分析表明,DMSO的存在改变了葡萄糖的异构化途径并生成了果糖和半乳糖,同时抑制了HMF进一步发生再水合反应生成LA和发生聚合反应生成humin。此外,针对humin的结构表征进一步揭示了水和DMSO对humin生成的不同作用机制。     

栀子多糖和山楂黄酮浸提工艺

采用超声波辅助浸提方法分别对栀子多糖和山楂黄酮进行浸提。通过单因素试验和正交试验,分别取得栀子多糖浸提最佳工艺条件:浸提温度50℃,浸提时间60 min,料水比1∶15;山楂黄酮浸提最佳工艺条件:乙醇溶液体积分数80%,浸提温度60℃,浸提时间45 min,料液比1∶25。所得山楂黄酮浸提液经40℃,0.1 MPa的减压蒸馏,除去乙醇。     

超声波法提取发菜多糖工艺研究

研究超声波法提取发菜多糖的工艺。通过单因素试验研究料液比、提取温度、提取时间和超声波功率对提取工艺的影响,采用正交试验L9(34)优化超声波提取工艺。确定最佳提取条件为:以水为提取溶剂,料液比1∶50,超声波功率100 W,温度60℃,超声时间20 min,连续提取2次。此条件下发菜粗多糖的提取率为7.369%,证明超声波方法可以快速、大量提取发菜多糖。     

栀子多糖和山楂黄酮浸提工艺

采用超声波辅助浸提方法分别对栀子多糖和山楂黄酮进行浸提。通过单因素试验和正交试验,分别取得栀子多糖浸提最佳工艺条件:浸提温度50 ℃,浸提时间60 min,料水比1∶15;山楂黄酮浸提最佳工艺条件:乙醇溶液体积分数80%,浸提温度60 ℃,浸提时间45 min,料液比1∶25。所得山楂黄酮浸提液经40 ℃,0.1 MPa的减压蒸馏,除去乙醇。      

龙眼多糖超声波-酶解辅助提取工艺优化

采用Box-Benhnken中心组合试验设计优化龙眼果肉多糖的超声波-酶解辅助提取工艺,建立了包括纤维素酶添加量、超声波功率、酶解温度、pH值和时间的五因素回归模型。经回归模型分析并结合验证试验,确定多糖的最佳提取工艺条件为：以龙眼干果肉（含水率8.47%）为原料,选取纤维素酶（酶活大于等于200 U/mg）添加量2000 U/g、超声波功率250 W、酶解温度55℃、pH值 5.0、时间60 min,在该条件下多糖提取率达38.71%,比传统热水法、酶法、超声波法和微波法分别高9.85%、6.41%、4.35%和3.99%,且差异达到显著水平（     

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。