胡柚皮总黄酮超临界CO2萃取工艺

为研究超临界CO2萃取胡柚皮总黄酮的工艺,在夹带剂试验和单因素试验的基础上,采用四因素三水平正交试验设计,以萃取压力、萃取温度、动态萃取时间、CO2流量为考察因素,优选了超临界CO2萃取胡柚皮总黄酮的最佳工艺.结果表明:该试验无需使用夹带剂,各因素对得率的影响大小依次为:CO2流量、萃取时间、萃取压力、萃取温度.最佳萃取工艺条件为:萃取压力35 MPa,萃取温度45℃,静态萃取40 min后动态萃取60 min,CO2流量3 L/min,此条件下胡柚皮总黄酮的得率可达1.01 mg/g.     

超临界流体萃取技术对沙棘籽及果渣脱脂的工艺研究

本文采用CO2超临界流体萃取技术对沙棘籽及果渣进行脱脂,通过正交试验确定萃取的最佳工艺条件:萃取压力25MPa、萃取温度为40℃、萃取120min和CO2流量为15L/min,在此工艺下能够脱除脂肪17.82%,萃取率可达到94.18%,并着重探讨了各萃取条件对沙棘籽及果渣脱脂效果的影响。     

柠檬酸法鱼鳞脱钙的工艺研究

用柠檬酸对罗非鱼鱼鳞进行脱钙研究,考察了柠檬酸浓度、料液比、温度和脱钙时间等因素对脱钙率的影响,在单因素试验的基础上,利用正交试验对工艺条件进行优化,得到了用柠檬酸脱除罗非鱼鱼鳞中羟基磷酸钙等无机盐的最佳工艺条件:脱钙温度为室温、柠檬酸浓度8%、料液比1∶17和脱钙时间3.5h,该条件下鱼鳞的脱钙率达到96.13%。     

3种吸附剂不同压力下脱除沼气中CO_2对比实验

研究了不同压力下常用几种吸附剂脱除沼气中CO2的效果,以提高混合气体中CH4的浓度,并得出最佳吸附压力,从而为工业生产提供沼气净化的吸附剂。本实验选取工业上常用的ZGA-高强度活性氧化铝、5A分子筛和13X-APG空分专用分子筛3种吸附剂,在不同压力下测定分离后混合气体中的CH4的浓度。实验结果表明:在0.1~0.8MPa压力范围下,5A分子筛吸附后的尾气中CO2和N2的浓度相对ZGA氧化铝和13X-APG分子筛低,且CH4浓度高,说明5A分子筛对混合气中CO2的脱除效果要比ZGA氧化铝和13X-APG分子筛明显;并且在0.7MPa的压力下,尾气中的CH4浓度达到了90.26%。因此,5A分子筛较适合应用于工业化脱除沼气中的CO2。     

物理法提取茶多酚技术的研究

采用对产品无溶剂和重金属残留,对环境无污染的物理场(采用超临界CO2萃取、微波和分子蒸馏技术相结合的复合提取方法)提取咖啡碱、茶多酚、儿茶素等。研究了茶叶含水率在30%~50%时对超临界CO2脱除咖啡碱的影响,研究表明,咖啡碱的脱除率从4.4%上升到52%,表没食子儿茶素没食子酸酯(EGCG)的含量明显提高。     

固相萃取法测定海水中14种有机磷农药

通过对固相萃取法中萃取剂的选择、用量和样品溶液pH值等条件进行优化处理,建立海水中常见有机磷农药的分析方法。研究结果表明,pH值对萃取结果无影响,当萃取剂选择二氯甲烷、且萃取剂用量为20mL时,萃取结果最优。     

反胶束法前萃取葵花蛋白的工艺研究

本文采用由琥珀酸二(2-乙基己基)酯璜酸钠(AOT)—异辛烷—氯化钾缓冲溶液组成的反胶束体系从葵花粕中前萃取蛋白质,考查了AOT浓度、缓冲溶液pH值、葵花粕粉加入量和温度对葵花蛋白萃取率的影响,并在单因素试验基础上,通过响应面分析法确定反胶束法前萃取葵花蛋白的最佳工艺条件:缓冲溶液pH值为9.3、AOT浓度为1.98g/50mL异辛烷、葵花粕粉加入量为0.75g和温度为37℃。在此最佳工艺条件下,葵花蛋白萃取率可以达到82.61%,与模型的预测值(84.49%)基本相符。     

反胶束法前萃取玉米胚芽蛋白的工艺条件优化

本文利用反胶束法萃取玉米胚芽蛋白,考察了AOT浓度、缓冲溶液的pH值、提取温度和脱脂玉米胚芽粉加入量对玉米胚芽蛋白前萃率的影响,并且在单因素试验的基础上,通过响应面分析法确定反胶束法前萃取玉米胚芽蛋白的最佳工艺条件:脱脂玉米胚芽粉加入量0.75g、AOT浓度2.19g/50mL异辛烷、缓冲溶液pH值7.17和温度38℃,此时脱脂玉米胚芽蛋白前萃率可以达到58.36%,与模型的预测值(59.77%)基本相符。     

响应面法优化沙棘中熊果酸提取工艺

利用响应面分析法对沙棘中熊果酸的提取工艺进行优化。以提取果汁和沙棘籽后的沙棘果皮渣为原料,在单因素实验的基础上,选取对熊果酸浸出率影响较大的因素,利用统计软件SAS中响应面分析法Box-Behnken中心组合设计,以浸出率为参考指标,得出熊果酸最佳提取工艺参数为：萃取压力为22.5MPa,萃取温度为40.4℃、CO2流量为23.3L.h-1。在此条件下熊果酸浸出率为：374mg/100g。     

反胶束法后萃取玉米胚芽蛋白的工艺条件优化

本文利用反胶束法萃取玉米胚芽蛋白,考察了KCl溶液浓度、pH值和萃取时间对玉米胚芽蛋白后萃率的影响,并且在单因素试验的基础上,通过响应面分析法确定反胶束法后萃取玉米胚芽蛋白的最佳工艺条件为:萃取液KCl溶液浓度1.14mol/L、pH值10.14和萃取时间53min,此时脱脂玉米胚芽蛋白后萃取率可以达到64.57%。     

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.     

车用发动机润滑油失效规律与更换周期研究

研究在正常使用条件下１０Ｗ／３０－ＱＣ级润滑油用于某型车用发动机时所表现的失效规律,确认期服从两参数Ｗｅｉｂｕｌｌ分布,并给出分布的尺度参数η和形状参数ｍ之最佳线性无偏估计（ＢＬＵＥ）同时,还为定量分析,计算车用发动机润滑油的使用可靠性和合理确定其更换周期提供了一套可供借鉴的方法,并给出了具体的计算实例。     

农村剩余劳动力就业问题的探讨

论述了我国农村剩余劳动力就业的意义，并针对我国农村剩余劳动力的现状，提出多渠道促进农村剩余劳动力就业的途径和办法。     

乡（镇）农业技术推广体系存在的问题及对策

乡（镇）农技推广体系是农业发展的关键。介绍朝阳市农业技术推广体系的现状,针对目前体制及运行机制、服务手段等方面存在的问题,提出适合朝阳市乡（镇）农技推广体系改革与发展的对策,以期对全省农技推广体系改革和发展起到一些借鉴作用。     

草莓的采收与贮藏

草莓果味酸甜爽口,营养价值高,为人们所喜爱的应市鲜果之一。由于草莓易受损伤和微生物侵染,因此其采收、贮藏过程极为重要。介绍草莓采收过程中的注意事项以及11种贮藏保鲜技术的实施步骤和操作方法,推介9种加工方式,为草莓产业化提供技术支持。     

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。     

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。     

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.