硒化坛紫菜多糖的制备、结构表征和活性研究

本文合成坛紫菜硒多糖并测定其含硒量,研究坛紫菜硒多糖的结构表征及抗氧化活性。将坛紫菜多糖与无机硒反应得到硒多糖,采用红外光谱鉴定硒多糖的结构,通过其清除超氧阴离子自由基、羟自由基和还原能力3方面来研究硒多糖的抗氧化活性。硒多糖中含硒量为4.5mg/g;硒多糖的特殊结构为硒氧双键;坛紫菜硒多糖具有清除超氧阴离子自由基和羟自由基的活性并具有一定的还原能力。结果表明:人工合成的硒多糖的含硒量高于自然硒多糖中的含量,并具有一定的抗氧化活性。     

富硒有机肥对大蒜中硒元素及其形态的影响

建立了高分辨-连续光源石墨炉原子吸收光谱法（HR-CS GFAAS）测定富硒大蒜中不同形态硒含量的方法，研究富硒有机肥对大蒜中硒元素及其形态的影响。通过单因素试验优化得出硒元素最佳测定条件，即最佳基体改进剂为Pd（NO3）2（1 g/L）和Mg（NO3）2（0.5 g/L）混合溶液，且最佳添加体积为5 μL。参照标准DBS 42/002—2014制备出富硒大蒜总硒和无机硒测定试样，再使用HR-CS GFAAS法测定总硒含量为8.933～9.476 μg/g，无机硒含量为5.784～6.021 μg/g，计算出有机硒含量为3.124～3.491 μg/g，所占百分比为34.16%～36.84%，这说明富硒有机肥能有效提高大蒜中总硒和有机硒的含量。该方法的精密度为3.0%～5.2%，总硒和无机硒的加标回收率分别为96.3%和93.7%，这表明参照DBS 42/002—2014分析富硒大蒜中硒元素含量及其形态，结果准确可靠，添加的标样（无机硒）几乎全部在待测无机硒试样中。该方法快速、准确且稳定，具有较高的实用价值，为分析食品中微量元素含量及其形态提供科学依据。      

南瓜籽多糖乙醇分级沉淀与超声波改性研究

采用热水浸提、Saveg脱蛋白制备南瓜籽多糖,蒸馏水复溶后采用0~30%、30%~60%、60%~80%乙醇分级沉淀法得到3种多糖PSP-30、PSP-60和PSP-80。通过测定多糖、蛋白含量、单糖组成及利用红外和紫外光谱检测表明:PSP-30、PSP-60和PSP-80均为结合一定量蛋白的多糖,不含糖醛酸;PSP-30、PSP-60由鼠李糖、阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖6种单糖组成,PSP-80由鼠李糖、阿拉伯糖、木糖、葡萄糖、半乳糖5种单糖组成。3种多糖对DPPH自由基均有较高清除作用,其中PSP-60效果最好,当质量浓度2.5 mg/m L时,清除率为61.90%。多糖PSP-60经不同频率超声波处理后,单糖组成的物质的量比和抗氧化活性均有所改变,证实超声波可以造成多糖中单糖的转化和生物活性的改变。     

18L罐中使用添加米糠汁和硒的培养基时灰树花的发酵试验

为高值化利用米糠,用灰树花发酵添加米糠汁的培养基生产灰树花多糖或多糖复合硒功能性产品。在摇瓶试验的基础上,使用18L罐进行放大试验,并研究发酵罐中的代谢过程。使用添加米糠汁和硒的培养基,装样量为15L、发酵温度28±1℃、通气量0.8v/v/min、搅拌速度150r/min和罐表压0.05MPa的条件下,发酵培养5d,测定不同时间的菌丝量、多糖量和菌丝中硒的量,绘制代谢曲线。在发酵时间为2d左右时,总多糖含量达到最大值,为631mg/100mL。同时得到了灰树花在添加米糠汁的培养基上富集硒和生产多糖放大试验的代谢过程,为进一步放大提供理论依据。     

超声-微波辅助提取木棉花多糖工艺

以木棉花多糖提取率为考察指标,通过单因素与响应面分析相结合方法,探讨超声-微波辅助提取木棉花中多糖的影响因素及最佳工艺。结果表明:影响超声-微波辅助提取木棉花中多糖提取率的因素顺序为微波功率＞提取时间＞料液比;最佳提取工艺条件为料液比1∶40 g/mL,提取时间16 min,微波功率202 W,木棉花多糖提取率为0.953%±0.015%。此外,与传统水浴浸提法相比,超声-微波辅助提取法提高木棉花多糖的提取率,缩短提取时间,具有广泛的应用前景。      

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。     

植物硒多糖制备及结构鉴定研究进展

硒多糖是无机硒与多糖有机结合的产物,具备硒和多糖的生理活性,拓展了多糖的免疫调节、抗氧化、抗肿瘤、抗衰老等生物活性,其制备具有研究价值。综述化学合成为主的植物硒多糖制备及结构鉴定方法,为植物硒多糖制备与开发提供研究思路。     

中国北方大豆主产区主栽品种检测与分析

采用国家标准(见正文)规定的方法对东北地区20种主栽大豆品种中3种营养成分——蛋白质、钙和维生素A的含量进行测定。结果表明:所测样品中蛋白质含量平均值在42%以上。其中,黑农35、黑农54、公02127-243个品种的蛋白质含量都在45%以上;2002-339-2号含钙量最高,达到66mg/100g;吉育68号维生素A含量最高,含量达到26μg/100g。     

丁香活性物质提取工艺优化与抗氧化活性研究

对丁香抗氧化活性物质提取工艺及其抗氧化活性进行了研究.结果表明,最佳提取工艺条件为:60%乙醇、提取温度60℃、料液比1∶20和提取时间40 min;在此工艺条件下抗氧化活性物质提取率为(10 480.4±40.3)μmol/g,获得的相应丁香粗提物具有较强的抗氧化活性,总还原力弱于相同质量浓度的阳性对照BHT和VC(P<0.01或P<0.001),FRAP法抗氧化能力和DPPH自由基清除能力弱于相同质量浓度的VC,强于相同质量浓度的BHT(P<0.05、P<0.01或P<0.001);通过生物活性追踪发现丁香抗氧化活性物质主要存在于其弱极性的乙酸乙酯部分,该部分100 μg/mL质量浓度样液的总还原力达0.634±0.040,FRAP法抗氧化能力达0.433±0.005,DPPH自由基清除率达(85.294±0.499)%;相关关系表明丁香抗氧化活性的主要物质基础为总多酚和总黄酮.     

不同多糖条件下大豆蛋白-绿原酸凝胶特性研究

为研究添加果胶、黄原胶和κ-卡拉胶3种多糖的种类和质量浓度(0.002、0.004、0.006 g/mL)对大豆蛋白(SPI)-绿原酸(CA)水凝胶的凝胶特性和分子间作用力的影响,通过测定SPI-CA/多糖三元凝胶的红外光谱,分子间作用力、流变学、水分分布和微观结构等指标,最终探明不同多糖与SPI-CA相互作用机制以及不同多糖对SPI-CA凝胶性质改善的差异性和相似性。结果表明,添加黄原胶和κ-卡拉胶后,蛋白中β-折叠相对含量从24.59%升高至24.87%～26.65%,无规则卷曲含量显著降低(P<0.05),这有利于凝胶网络结构的形成。3种多糖的添加均显著增强了凝胶中氢键的作用以及凝胶中固定水的结合能力,相较于果胶和黄原胶,添加κ-卡拉胶后凝胶中的氢键的作用更强,T₂₁的弛豫时间更短,凝胶结构也更加致密。凝胶的储能模量G′、损耗模量G″、硬度和咀嚼性均与κ-卡拉胶的浓度呈正相关。适量的果胶和黄原胶的加入能够形成稳定的凝胶,但是过度填充果胶和黄原胶会降低凝胶的热稳定性,破坏凝胶网络结构。     

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。