Application of biosolids to soil affects Cu and Zn accumulation and antioxidant activity of lettuce (Lactuca sativa L.)

The application of biosolids to agricultural fields is becoming increasingly common. The effect of biosolids on the behavior of metals in different plants has been reported to be variable and ambiguous. A greenhouse experiment was conducted on a soil spiked with four rates of copper (Cu) (0, 50, 100, and 150 mg kg^?1) and zinc (Zn) (0, 150, 300, and 450 mg kg^?1) in lettuce culture. When Cu and Zn were spiked to anaerobically-digested biosolids, their availability in lettuce increased. Root and shoot fresh weight decreased due to a decrease in photosynthetic rate. superoxide dismutase (SOD) and peroxidases (POD) activity increased after the application of Cu and Zn. The bioavailability of Zn in lettuce was greater than that of Cu because of a higher transfer factor in plants and due to a higher endogenous Zn concentration.These results will allow for better fertilization management when biosolids are applied to tomato culture.     

Opposite effects of two organic wastes on the physical quality of an agricultural soil

Soil application of organic wastes (OWs) can be beneficial for soil quality, depending on the quality of the wastes as well as on the amended soil. We performed a field experiment comparing the effects of two different OWs, an industrial sewage sludge (ISS) and a municipal solid waste compost (MSWC), on the physical, chemical and biological quality of an agricultural soil cultivated with maize in central Iran. The two OWs were mixed into the topsoil of the plots at rates of 15 and 45 t ha^?1 (dry matter). The analysis of soil samples taken 31, 74, 132 and 241 days after OW application showed both OW increased organic matter, microbial respiration, and urease activity and decreased bulk density. In contrast, they had opposite effects on water retention and saturated hydraulic conductivity. While the MSWC increased water retention at high saturation and saturated hydraulic conductivity, the ISS decreased them. The negative effects of the ISS on physical soil quality, which may have been due to pore-clogging and hydrophobicity effects, were related to a smaller yield increase in the ISS than in the MSWC treatments, demonstrating the importance that physical OW properties can have for the quality of amended soil.     

The effect of winery solid waste compost application on maize growth,biomass yield,and nutrient content under greenhouse conditions

A greenhouse study was conducted to assess the fertilizer value and determine the optimum application rate of five winery solid waste (WSW) composts containing varied filter material (FM) mixed proportions with grape marc and pruning canes using maize. The composts comprised of 4, 10, 20, 30, and 40% FM (w/w) designated C4FM, C10FM, C20FM, C30FM, and C40FM, respectively. Application rates of 5, 10, 20, 40, and 80 t ha^?1 were used; while unamended control and inorganic NPK fertilizer treatments were included as references. The results showed that application of composts with 20% FM or more at 80 t ha^?1 significantly increased the dry matter yield more than NPK fertilizer but full potential was not reached due to inadequate nitrogen supply. Maize shoot K content from compost treatments exceeded the critical nutrient level while the shoot Zn content from compost treatments with 20% FM or less also exceeded the critical level. The results revealed that these composts could serve as potential good sources of K and Zn for maize production, particularly, in sandy soils where these nutrients are often reported to be deficient. Quantitative estimate of the optimum rate of the composts for dry matter production ranged from 75 to 307 t ha^?1.     

餐厨垃圾乳酸菌发酵生产生物饲料的研究

为了实现餐厨垃圾的资源化高效利用,以餐厨垃圾为原料,采用乳酸菌进行固态发酵,结合正交试验、单因素试验优化了餐厨垃圾乳酸菌发酵生产生物饲料的工艺条件。结果表明:最佳发酵工艺为餐厨垃圾添加10%麦麸和4%豆粕搅拌均匀,加入125%的水,121℃灭菌20 min,冷却后,接种2.0%乳酸菌,32℃厌氧培养48 h。在此发酵条件下发酵产物中粗蛋白含量比原料提高了5.36%,粗脂肪、粗纤维、粗灰分均有下降,并且乳酸菌含量达到了24.8×10~8CFU/g;卫生指标均符合国家饲料卫生标准(GB13078—2001)。     

烤烟烟叶淀粉晶体结构的光谱分析

利用固体核磁共振波谱仪(CP/MAS 13C NMR)、粉末X–射线衍射仪(XRD)和扫描电子显微镜(SEC)研究了烤烟烟叶淀粉晶体的结构特性。结果表明:烤烟烟叶淀粉晶体CP/MAS 13C NMR波谱显示在C1区域,在化学位移99.3和100.2处有2个明显的结晶峰,同时,XRD波谱2θ在17o处有较强的衍射峰,在5.6o、15o、20o、22o和24o附近有较弱的衍射峰,均表现出典型的B–型晶体特征。根据CP/MAS 13C NMR波谱计算出的烟叶淀粉晶体的相对结晶度和双螺旋含量分别为36.1%和21.3%,其结晶度比采用XRD波谱计算值略高。     

生物酶法制备生物柴油研究综述

就生物酶法制备生物柴油的研究现状进行了扼要概括,探讨了固定化脂肪酶法、液体酶法和全细胞催化法制备生物柴油的最新工艺进展。     

纳米有机蒙脱土在实木地板上的应用试验

采用纳米有机蒙脱土,以水溶性酚醛树脂为复合介质,在真空加压条件下对软银叶树(Heritiera borneensis)和红山樟(Dryobanops aromatica)2种实木地板坯料进行纳米复合处理.结果表明,纳米材料用于实木地板提高其性能可行,2种地板处理增重率约为7％,阻湿率提高37％以上,吸水率改善幅度达26.2％以上,阻燃效果也得到了提高,氧指数提高了15％,耐磨性得到改善,固化定型后的抗流失性较好,20℃水时的抗流失性在0.6％以下,80℃水时的抗流失性在2％以下,纳米复合处理对地板的环保性能基本无影响.     

热带假丝酵母固体发酵代谢物提取方法的比较分析

本试验比较了几种提取微生物固体发酵代谢物的方法,旨在筛选出一种尽可能多保留了代谢物的方法.试验采用热带假丝酵母固体发酵棉粕源底物,以液相色谱串联质谱( LC-MS)为分析平台,分别采用50％冷甲醇溶液(甲醇法)、酸性甲醇-乙腈溶液(酸性甲醇-乙腈法)和50％乙腈溶液(乙腈法)提取发酵代谢物.结果表明:采用酸性甲醇-乙腈法、乙腈法和甲醇法分别提取出1 831、1 522和1 262种代谢物,提取效率表现为酸性甲醇-乙腈法＞甲醇法＞乙腈法.本试验中3种方法相比,酸性甲醇-乙腈法提取的代谢物种类最多,提取效率最佳,是微生物固体发酵代谢物提取的有效方法.     

基于Prolog语言的小型动物分类专家系统的研究与应用

论文在分析Prolog语言的特点和基本结构,专家系统的定义、组成及工作原理的基础上,运用Prolog语言设 计了一个小型的动物分类专家系统.该专家系统采用问答方式,推断出用户想象中的动物.     

Determination of Tetracyclines and Their Epimers in Agricultural Soil Fertilized with Swine Manure by Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry

A rapid,sensitive and specific ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS) method was developed for the analysis of tetracycline antibiotics,including tetracycline (...