微波改性废酵母茵吸附废水中铜（Ⅱ）离子热力学动力学研究

通过大量的实验研究了应用低成本吸附剂废酵母菌在微波改性后去除废水中重金属铜（Ⅱ）离子,并通过改变反应过程中的pH值、反应时间、初始浓度、废酵母菌投加量、反应温度等因素来影响吸附效果。研究结果表明：在PH值为7．0、反应时间为90min、温度为55℃、Cu2＋初始浓度为40mg／L、微波改性废酵母菌投加量为4g／L时,微波改性酵母茵的最大吸附容量为41．84mg／g。吸附过程符合Langmuir吸附等温模式。吸附过程的热力学常数△G0、△H0和△S0,分别为-6．12kJ／mol、9．2kJ／mol和48．19kJ／mol。说明废酵母菌对Cu2＋的吸附是自发的吸热反应。微波改性废酵母菌对Cu2＋的吸附动力学模型能够较好地符合准二级动力学方程。     

不同乳化剂对姜黄素乳液理化稳定性的影响

姜黄素具有许多生物活性功能,但较差的溶解度和稳定性限制了其在食品和医药领域的应用。为筛选出具有良好稳定性的姜黄素乳液,本研究以亚麻籽油为姜黄素的油相载体,经高压均质法制备出姜黄素乳液中研究卵磷脂、吐温-80、阿拉伯胶和乳清分离蛋白4种食品级乳化剂对姜黄素乳液的理化特性和贮藏稳定性的影响,从包埋率、浊度、粒径、电位等方面进行稳定性评价。结果表明,吐温-80稳定的姜黄素乳液中姜黄素包埋率较高(76.98%),浊度和平均粒径最小,分别为848.0 NTR、214.23±1.52 nm;同时在贮藏期内姜黄素乳液的平均粒径变化最小,增长不到1%,贮藏稳定性表现良好。同时,4℃低温条件下姜黄素保留率最高,达到88.02%。结果表明,选用吐温-80作为乳化剂,姜黄素乳液具有最好的溶解性和稳定性,这为今后姜黄素在食品工业中的广泛应用提供了新思路。     

Effects of different loading rates and types of biochar on passivations of Cu and Zn via swine manure composting

Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China. Safe disposal of the contained toxic pollution with animal manure by co-composting with biochar is one of the alternative methods. Biochars from different sources (wheat straw, peanut shells and rice husks) amended with different loading rates were investigated for passivations of copper and zinc (Cu and Zn) in swine manure composting. Results showed that the passivation effects of the three types of biochar on Cu and Zn were enhanced with increasing biochar dose. Contents of Cu and Zn measured by diethylenetriaminepentaacetic acid (DTPA) and Community Bureau of Reference (CBR) showed that wheat straw biochar with the loading rates of 10%-13% (w/w) was superior to the other two types of biochar in this study. Compared with the control, sample from wheat straw biochar was more favorable for the bacterial growth of Proteobacteria, Firmicutes and Actinobacteria. In addition, pot experiment showed that organic fertilizer amended with wheat straw biochar could significantly improve the growth of Chinese pakchoi and enzyme activities (superoxide dismutase, peroxidase, polyphenol oxidase and catalase) as compared with the control. Cu and Zn contents of Chinese pakchoi in the organic fertilizer group containing wheat straw biochar reduced by 73.2% and 45.2%, 65.8% and 33.6%, respectively, compared with the group without loading biochar. There was no significant difference in the contents of vitamin C and reducing sugar between the groups of organic fertilizer amended with/without wheat straw biochar, however, there was significant difference compared with the heavy metal addition group. The application of organic fertilizer formed by adding biochar can effectively reduce the adverse effects of heavy metals on crops.     

基于正交试验的花生种养结合栽培方式研究

种养结合是农业循环经济发展的重要措施之一。通过正交试验设计,分析了不同种植密度、复合肥用量、腐熟干粪用量对花生生长发育及产量的影响。分析结果表明:1)三因素中高钾复合肥用量对花生的生长发育及产量影响最大。2)13-10-20高钾复合肥用量为300kg/hm2的处理组合普遍表现出植株较高、分枝数较多、单株结果数多等特点。3)产量分析结果显示:最优处理组合为种植密度120 000穴/hm2、高钾复合肥300kg/hm2、腐熟干粪30kg/hm2,同时影响产量大小的因素顺序为:高钾复合肥腐熟干粪种植密度。     

Comparison of different strategies for cotton insect pest management in Africa

Anticipating the direction for change in the current cotton insect pest management system in francophone African countries, different pest management strategies were investigated to reduce cotton protection costs and to improve overall pest control decision-making at the farmer level. Four strategies aimed at timing and limiting insecticide applications, were designed to fit the semiliterate level of farmers and pest profiles. Strategy 1 focused on using control thresholds early in the season, Strategy 2 on reducing the dosage in mixtures, while Strategies 3 and 4 were associated with the use of single active ingredients instead of mixtures. These strategies were assessed at the main research station Bouaké, Côte d'Ivoire, and were shown to be effective when compared with the current protection programme. The number of treatments and the amount of insecticides applied was reduced while achieving equal or better pest control and yields. The strategies proved to be safer to some beneficial arthropods. Their cost-effectiveness needs to be assessed in more detail at farm level to select the most financially attractive strategy.     

面条改良乳化剂在挂面中的应用研究

面条改良乳化剂是一种以单甘脂、卵磷酯或色拉油为有效成分的复配型的水包油型乳液。利用粉质仪和拉伸仪测定,研究了面条改良乳化剂在挂面中的使用效果及合适的添加量。并结合实际的应用效果表明,使用面筋质较好、含量较高的面粉添加面条改良乳化剂制作挂面时,对挂面的改良效果明显;而对软质面粉还可增添少量的廉价的无机盐类添加剂或蛋白质类进行复配,可制取优质挂面。     

种毒接种剂量与鸡胚尿囊液量的相关性研究

对分成3组而同机孵化的180个9日龄罗曼蛋鸡鸡胚分别尿囊腔接种NDVLasota种毒液0.1mL／个,0.15mL／个和0.20mL／个。结果：尿囊液的收集量与种毒接种量呈显著负相关,而血凝价受接种剂量的影响不显著。     

北方寒带地区水泥混凝土路面配合比设计

本文结合寒带地区的气候特点,减少施工过程的断板率,提高路面抗冻耐久性,保证路面良好的使用状态是水泥砼路面配合比设计中的重点。     

低剂量外源稀土积累对黄褐土中微生物主要生理类群的生态效应

采用田间小区试验和室内低剂量模拟叠加试验相结合的方法,研究低剂量外源混合稀土在黄褐土中积累对土壤微生物主要生理类群的生态效应。结果表明,外源低剂量稀土的持续积累会对土壤氨化细菌、硝化细菌、纤维素分解菌和自生固氮菌产生刺激、抑制、再刺激的交替作用。4种土壤微生物生理类群对混合稀土抑制敏感性依大小排序为:纤维素分解菌>氨化细菌>硝化细菌>自生固氮菌。对田间小区低浓度稀土积累下土壤微生物学数据进行模拟计算,稀土积累对纤维素分解菌、氨化细菌、硝化细菌和自生固氮菌的E C50(半抑制浓度)值分别为7.7～10.9、42.3～74.3、12.1～78.4和30.4～91.2m g·kg-1。稀土积累对参与有机碳转化的细菌类群比对参与氮素转化的细菌类群产生更强的抑制作用,纤维素分解菌可作为稀土积累生态效应的指示菌。由于土壤细菌对土壤生物活性的重要贡献,外源稀土在黄褐土中积累对细菌的安全临界值可以初步确定为10～30m g·kg-1。     

杀虫剂防治水稻褐飞虱的有效利用率分析

通过综合分析杀虫剂对水稻褐飞虱的毒力测定结果、褐飞虱田间防治指标、杀虫剂田间推荐剂量及杀虫剂经稻田叶面喷施后在田间的分布等文献资料,发现杀虫剂防治褐飞虱的田间推荐剂量的有效利用率不足0.1%。理论上,通过室内毒力测定可获得杀虫剂杀死褐飞虱种群90%个体的致死剂量 (LD₉₀,单位:μg/头),用稻田中褐飞虱的发生量乘以LD₉₀值即为杀死90%田间虫量的杀虫剂有效用量;而实际上杀虫剂的田间推荐剂量却是其有效用量的千倍以上。分析出现这种现象的原因可能有:1) 在褐飞虱为害的水稻孕穗期和扬花期,采用手动喷雾器进行叶面喷雾时,杀虫剂在水稻上的沉积率为34.25%～46.10%,但其中82%以上分布在水稻冠层以上部位,分布在水稻基部茎秆部位的不足2%,只占杀虫剂使用量的0.5%左右;2) 褐飞虱获取致死剂量的杀虫剂后死亡,但杀虫剂和褐飞虱在田间的分布极不均匀,当最低剂量的杀虫剂和最多虫量的褐飞虱出现在同一株水稻上时,该剂量必须能够控制褐飞虱的为害,那么对于有更多杀虫剂和更少褐飞虱的植株而言,就必然造成杀虫剂的浪费,从而降低其有效利用率;3) 约有50%以上的杀虫剂洒落在稻田水中,经田水稀释后的质量浓度远远低于杀死褐飞虱种群10%个体的致死浓度 (LC₁₀值,单位:mg/L),不能有效杀死褐飞虱。作者认为,通过人工智能,将杀虫剂直接喷洒在褐飞虱发生为害的部位,并根据虫量进行变量施药,必将大幅提高杀虫剂防治水稻褐飞虱的有效利用率。