电热式浸提,浓缩多用设备的研制

本文介绍一种浸提、浓缩多用设备，具有电热管加热，回流提取，真空浓缩，溶剂回收等项功能。该设备加热方便，自动控温，操作容易，便于清洗，适用于科研、院校等单位的多品种，小批量浸提、浓缩实验研究，还可用于药厂、医院、食品厂、饮料厂、化工厂等生产单位的需要     

甲鱼养殖废水作为温室番茄栽培灌溉用水的效果研究

针对甲鱼养殖废水排放所造成的环境负荷、资源浪费和温室栽培灌溉的大量用水需求，采用塑料温室栽培试验方法，研究了将甲鱼养殖废水作为温室樱桃番茄栽培灌溉用水的可行性和效果。试验中养殖废水与自来水混合的比例设为：0、50％和100％，栽培试验在无基肥和添加基肥两种情况下进行。结果显示．无基肥添加时，用100％养殖废水灌溉番茄时对其茎粗生长和产量的促进作用明显，番茄茎粗比用纯自来水灌溉的增大约8．6％，产量增加24％左右。50％的养殖废水灌溉效果介于纯甲鱼废水和纯自来水之间；添加基肥时，用50％养殖废水灌溉的番茄茎粗比纯自来水灌溉的增大6％左右，50％和100％养殖废水灌溉情况下的番茄收获量在6月底基本相同，比用纯自来水灌溉的增加约3．8％。养殖甲鱼废水中的养分能部分供给作物生长需要，对有、无基肥添加情况下的樱桃番茄生长都显示出一定的促进作用，但养殖废水的稀释程度对作物生长效果要根据栽培基质的养分管理不同而定。     

6种城市绿地空气PM2.5浓度变化规律的研究

为合理安排树木的种植和配置结构,发挥绿色植物在改善城市生态环境方面的重要功能,研究6种城市绿地空气PM2.5浓度的日变化规律、月变化规律,分析不同类型绿地空气PM2.5浓度差异以及不同天气条件下PM2.5浓度.结果表明:PM2.5浓度日变化和月变化规律明显,不同季节有显著差异;6种城市绿地空气PM2.5浓度在同一季节内没有显著差异,从均值来看,春、秋、冬季有乔木的绿地内空气PM2.5浓度较低,夏季草坪内空气PM2.5浓度较低;阴天颗粒物的浓度比晴天高45%,雨后阴天颗粒物的浓度比雨后晴天高426%,降水对PM2.5的清除作用在雨后晴天发挥的较好.     

晋西黄土区坡面糙率的研究

坡面糙率是研究地表径流最为重要的参数之一,对坡面水文过程和土壤侵蚀过程模拟具有重要意义.该文采用野外实地冲刷水槽法,在测定不同地类地表糙率的基础上,研究了地表鲜草量、枯枝落叶量和地表硬度对地表糙率的影响,并探讨了地表糙率与地表径流泥沙含量的关系. 研究结果表明,不同地类地表糙率差异显著;地表糙率与鲜草量成线性关系;枯枝落叶对地表糙率的影响存在极值;地表糙率随土壤硬度的增加而减小,且成幂函数关系;地表径流的泥沙含量随地表糙率的增加而减小,二者成对数关系.      

基于RBF网络的冯家山水库出库含沙量预测研究

蓄洪排沙是冯家山水库的排沙方式,然而在实际调度运行过程中,对入库洪量和出库排沙泄量的调配缺乏共性关联,排沙泄量未能从定性定量上予以科学界定。针对此问题,文章对冯家山水库蓄洪排沙过程进行了研究,采用RBF网络建立了该水库出库含沙量预测模型,模型根据沙峰、洪峰入库时间与开闸排沙时间的不同分别选择网络结构。采用冯家山水库历史排沙资料对模型进行检验的结果表明,模型训练及检验结果确定性系数均较大。可见,采用RBF网络建立的出库含沙量预测模型是可行的。     

低磷日粮添加植酸酶对肥育期肉鸭营养学效应的影响

:1 6 0只 3周龄樱桃谷肉鸭随机分为 4组 ,研究了低磷日粮添加植酸酶和磷酸氢钙对肉鸭生长性能、血浆磷浓度及胫骨特性的影响。Ⅰ组为低磷组 (0 .1 8%AP) ,Ⅱ组为添加磷酸氢钙组 (0 .35 %AP) ,Ⅲ ,Ⅳ组为添加植酸酶组 (0 .1 8%AP 75 0 μ/kg ,0 .1 8%AP 1 5 0 0 μ/kg)。结果表明 :(1 )当肉鸭在生长前期 (1～ 3周龄 )采食了含充足磷的日粮后 ,在生长后期 (4～ 6周龄 )饲喂低磷日粮无需另外添加无机磷 ,只要用植酸酶 (75 0 μ/kg)强化一下就能满足其正常生长发育所需的磷。 (2 )添加植酸酶能提高血浆磷浓度、胫骨干物质和矿物质含量 ,改善骨骼状况。     

泥沙矿物成分对混凝土材料磨蚀的影响

中国多沙河流居多,水流中泥沙是由不同矿物成分（石英,长石,白云石等）组成,含沙高速水流中泥沙矿物成分对泄洪建筑物混凝土材料磨蚀有何影响令人关注。该研究在自主研发的小型循环式水洞中,对不同含沙量的泥沙矿物成分进行试验研究,以揭示泥沙矿物成分对混凝土材料磨蚀破坏影响的机理。首先在循环式水洞内配制不同矿物成分（石英、长石、白云石、云母、辉石）、不同含沙量（S=2.5,12.0,20.0 kg/m³）的挟沙水流,利用压力数据采集系统（YE6263）实时采集空化区和磨蚀区压力;其次,试验采用强度相同的混凝土试件,在相同粒径、不同含沙量、不同矿物成分工况下,进行历时4 h的磨蚀试验,通过试件每小时的质量损失来表征磨蚀量。试验结果表明：在中值粒径为 0.150 mm,喉部流速为 38.6 m/s的条件下,随着矿物含沙量（2.5～20.0 kg/m³）的增加,空化区压力降低,磨蚀区压力升高,压力降、升幅度随矿物成分而异,空化磨蚀现象严重,试件累积磨蚀量与矿物含沙量呈线性相关。含沙量相同时,空化区测点压力随矿物摩氏（Mohs）硬度（2.5～7.0）的增大而降低,磨蚀区测点压力则随矿物硬度的增大而升高;混凝土试件配合比、龄期不变时,混凝土试件的磨蚀程度随矿物含沙量的增加而加剧,其磨蚀量增加一倍多,与矿物成分有关;当矿物硬度增加时,磨蚀程度也随之加剧,磨蚀量成倍增长。由此得出,泥沙矿物成分随其含沙量的增加和硬度的增大,对水流空化和混凝土磨蚀具有促进作用。该研究可为农业水利工程中泄洪建筑物（溢洪道、泄洪洞、消力池等）及渠系建筑物的设计和维护提供参考。     

ZINC-COATED UREA IMPROVES PRODUCTIVITY AND QUALITY OF BASMATI RICE (ORYZA SATIVA L.) UNDER ZINC STRESS CONDITION

A field study conducted for two years (2006 and 2007) at the Research Farm of the Indian Agricultural Research Institute, New Delhi, India showed that zinc (Zn) fertilization increased yield attributes, grain and straw yield, enhanced Zn concentrations and its uptake and improved kernel quality before and after cooking in basmati rice ‘Pusa Sugandh 5’. A 2% Zn-coating with zinc sulfate (ZnSO₄·7H₂O) was found to be the best but a 2% Zn-coating with zinc oxide (ZnO) was very close to it in terms of grain and straw yield and Zn concentrations in basmati rice grain and straw under Zn stress conditions. Partial factor productivity (PFP) of applied Zn varied from 984–3,387 kg grain kg Zn^?1, agronomic efficiency (AE) varied from 212–311 kg grain kg^?1 Zn (applied) and physiological efficiency (PE) of Zn varied from 6,384–17,077 kg grain kg^?1 Zn (absorbed). Thus, adequate Zn fertilization of basmati rice can lead to higher grain yield and Zn-denser grains with improved cooking quality in basmati rices under Zn stress soil conditions.     

IMPACT OF SALT STRESS ON MICRONUTRIENTS IN CORDYLINE FRUTICOSA VAR. ‘RED EDGE'

This trial was carried out to study the influence of the nutrient solution on the microelements concentration and distribution in C. fruticosa var. ‘Red Edge' plants. Four treatments were tested: T₁ [control, 1.5 dS m^?1, 14.3 mmol L^?1 sodium chloride (NaCl)], T₂ (2.5 dS m^?1, 22.2 mmol L^?1 NaCl), T₃ (3.5 dS m^?1, 32.7 mmol L^?1 NaCl) and T₄ (4.5 dS m^?1, 38.2 mmol L^?1 NaCl). In roots and stems, iron (Fe) concentrations were lower in the no saline treatment. Stems accumulated more Fe with treatments T₃ and T₄. Copper concentration and extraction were not affected by salinity. The highest manganese (Mn) concentration in roots was observed in T₂, while in petioles was higher in T₃ and T₄. Manganese extraction reached higher levels in the saline treatments in roots and stems, while in petioles it was lower in T₁, T₂ and T₃. In roots, zinc (Zn) concentration was lower with the extreme treatments. Micronutrients concentration in leaves was unaffected by salinity, because an exclusion mechanism that consists on accumulation in roots and stems was developed.     

INFLUENCE OF CORN (ZEA MAYS L.) CULTIVAR DEVELOPMENT ON RESIDUE PRODUCTION

The amount and composition of crop residues added to soil in agroecosystems can influence decomposition processes and soil organic matter levels. This study aimed to evaluate residues (quantity and quality) of different corn cultivars commonly used in Brazilian cropping systems. The experiment was conducted for two seasons (2005/2006 and 2006/2007) in Rolândia, Paraná State, Brazil. Ten corn cultivars that represent five degrees of breeding development (i.e., landrace, commercial variety, double cross, triple cross, and single cross hybrids) were evaluated. At harvest, carbon (C) and nitrogen (N) of non-yield residue and grain were determined. Except for grain C, other measures (grain N concentration, residue C and N concentration, and C:N ratio) varied among cultivars. In general, the hybrids had higher residue C and lower residue N concentrations than the landraces and commercial varieties. Findings suggest that breeding selection may have altered residue production and composition, which may influence soil C dynamics.