碱性过硫酸钾氧化-钼酸铵分光光度法测定水中的总磷及其不确定度的评定

经过消解前加入氢氧化钠和改用聚四氟乙烯消化管等方面的改进,碱性过硫酸钾氧化-钼酸铵分光度法的实际操作更简便,更适用于各类水样的监测。它具有较低的捡出限（O．004mg／L）,较高的精密度（RSD=1．1％）和较好的准确度（测定标样溶液相对误差1．6％,加标回收率为97．2％-102．1％）。测定IERM测量审核样的结果也较好（取得了合格证书）。不确定度的评定依照相关标准的原则进行,并使用残差来量化曲线不碹定度分量,减少了工作量。经评定,改进方法的扩展不确定度为3．2％。     

Combined alkaline and ultrasonic pretreatment of sludge before aerobic digestion

Alkaline and ultrasonic sludge disintegration can both be used as pretreatments of waste activated sludge (WAS) for improving the subsequent anaerobic or aerobic digestion. The pretreatment has been carried out using different combination of these two methods in this study. The effect was evaluated based on the quantity of soluble chemical oxygen demand (SCOD) in the pretreated sludge as well as the degradation of organic matter in the following aerobic digestion. For WAS samples with combined pretreatment, the released COD was in high level than those with ultrasonic or alkaline treatment. When combined with the same ultrasonic treatment, NaOH treatment resulted in more solubilization of WAS than Ca(OH)2. For combined NaOH and ultrasonic treatments with different sequences, the released COD were in the order: simultaneous treatment > ultrasonic treatment following NaOH treatment > NaOH treatment following ultrasonic treatment. For simultaneous treatment, low NaOH dosage (100 g/kg dry solid), short duration (30 min) of NaOH treatment, and low ultrasonic specific energy (7 500 kJ/kg dry solid) were beneficial for sludge disintegration. Using combined NaOH and ultrasonic pretreatment with the optimium parameters, the degradation efficiency of organic matter was increased from 38.0% to 50.7%, which is much higher than with ultrasonic (42.5%) or with NaOH pretreatment (43.5%) in the subsequent aerobic digestion at the same retention time.     

氯化三丁基锡对牡蛎2种免疫相关酶活性及血细胞吞噬作用的影响

将牡蛎(Crassostrea gigas)暴露于不同浓度的氯化三丁基锡(TBTCI),96 h后取样,测定牡蛎组织碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)的活性和血细胞的吞噬作用.结果表明,随着TBTCI浓度的增加AKP活性呈现先降低后升高的趋势,而SOD的活性呈逐渐降低的趋势,TBTCI对血细胞的吞噬作用具有...     

维护中华传统膳食对发展低碳经济有举足轻重的作用

中华传统膳食符合低碳经济原则;过食动物性食物危害健康;坚持低碳饮食也是保护环境;健康饮食有利于减少碳排放。人类的食物大体上分作两大类,一类是动物性食物,主要是畜禽肉类、鱼虾类和蛋类,俗称荤食,另一类是必须重视人类食物的碳排放     

嗜碱菌A4—10碱性纤维素酶产生及性质的初步研究

从４８份土壤和天然碱湖榈分离出能产生胞外碱性纤维素酶的嗜碱细菌１３５株,其中７株菌产酶活力大于３Ｕ／ｍＬ,菌株Ａ４－１０经条件试验后酶活力达２１Ｕ／ｍＬ,该菌产生碱性纤维素酶最适培养温度为３４℃,最适碳源为ＣＭＣ－Ｎａ,最适氮源为复合蛋白胨和酵母粉,该酶的最适反应温度５５℃,最适反应ｐＨ９．０。     

该为农村环境"买单"了

近年来,由于经常下乡的关系,越来越多问题开始不断地困扰着记者：印象中绿树掩映、清水环绕的村庄哪里去了?什么时候洁净的山村变得如此的污水四溢、垃圾遍地?在作为食物主产地的农村,如此恶化的环境,将给人们生活带来什么影响?这么多年了,为什么我们还在重蹈先污染后治理的覆辙?我们还要等到啥时才动手治理已然严重的农村环境污染,难道真要忍无可忍了才肯付出?     

春季话养生

春季从立春开始,经过雨水、惊蛰、春分、清明、谷雨,共6个节气,止于立夏前一天,现在正值4月春暖花开的时节,一派万象更新,草长莺飞,阳气生发,生机盎然的气象。     

能杀死体内癌细胞的食物

1茄子:霜打茄子是好药中药许多方剂及民间验方中,时常使用秋后老茄子、霜打茄子。越来越多证据表明,茄子具有抗癌功能。曾有试验将从茄子中提取的一种无毒物质,用于治疗胃癌、子宫颈癌等收到良效。另外,茄子中含有龙葵碱、葫芦素、水苏碱、胆碱、紫苏甙、茄色甙等多种生物碱物质,其中龙葵碱、葫芦素被证实具抗癌能力,茄花、茄蒂、茄根、茄汁皆为良药,古代就有用     

生态文明视域下贯彻大食物观的法治保障

大食物观是生态文明思想的延续,其在宏观层面反映了对人与自然和谐共生的价值追求,在中观层面契合了绿水青山就是金山银山的绿色发展理念,在微观层面依赖于山水林田湖草沙生命共同体。贯彻大食物观与生态文明建设密不可分,当前作为大食物观外部支撑的农业生态现状不容乐观,农业生态法治保护面临困境。对此,应以严密法治观搭建起四梁八柱,改善农业生态,保障大食物观的贯彻落实。