由稻壳炭合成介孔二氧化硅

以稻壳发电残渣稻壳炭的碱提取液为硅源,十六烷基三甲基溴化铵(CTAB)为模板剂,在碱性条件下通过溶胶-凝胶方法合成多孔二氧化硅前驱体。获得的前驱体采用萃取的方式脱除模板剂,合成产品采用低温氮气吸脱附、XRD、TEM、白度仪等手段进行了表征,确证得到的产品为高比表面、有序介孔二氧化硅。讨论了前处理和脱模方式对合成产物结构和性质的影响。     

高效液相色谱测定三苯基乙酸锡在水稻中的残留

[目的]建立三苯基乙酸锡在水稻植株和土壤中残留量的高效液相色谱检测方法。[方法]样品用乙腈提取后,二氯甲烷萃取,经酸性氧化铝柱净化,以乙腈-0.5%磷酸水(体积比30∶70)为流动相,用紫外检测器测定。[结果]水稻植株和土壤样品中三苯基乙酸锡的添加平均回收率分别为86.4%～102.9%、88.8%～105.2%,相对标准偏差分别为5.1%～10.2%、2.4%～8.3%,最小检出量为1.0×10-10 g,最低检测质量分数为2.0×10-3 mg/kg。[结论]方法操作简便,符合农药残留分析的要求,为其他作物中三苯基乙酸锡残留量的测定提供参考。     

辐照法制备秸秆絮凝剂的研究

通过辐照法制得秸秆改性阳离子絮凝剂,并探讨了该絮凝剂对高岭土悬浊液的絮凝作用,着重考察了单体(丙烯酰胺)与处理后秸秆的配比、LiCl/DMAc溶液浓度、辐照剂量对秸秆改性阳离子絮凝剂接枝率的影响。实验结果表明,水稻秸秆改性阳离子絮凝剂最佳的合成条件为:单体与处理后秸秆的质量比为3∶2,LiCl/DMAc溶液质量浓度为10 g/mL,辐照剂量为9 kGy。制得的秸秆改性阳离子絮凝剂的接枝率为50%,对高岭土悬浊液的去除率达到63%。     

单季晚稻机插田化学除草技术

[目的]随着小苗机插稻田面积的扩大,机插田草害发生也日益严重,为有效控制机插田杂草的危害,2008—2009年在浙江省桐庐县单季晚稻机插田进行不同施药时期和施药剂量对主要杂草防效试验。[结果]5%丁草胺GR 750 g a.i./hm2+10%苄嘧磺隆WP 30 g a.i./hm2和20%乙.苄WP 90 g a.i./hm2在插后3 d施药,插后50 d对总草鲜质量防效极显著高于插后7 d的防效。53%苄嘧.苯噻酰WP 318、477、636 g a.i./hm2于插后5 d施药,药后30、50 d,对异型莎草、阔叶草、总杂草的防效有差异;而50%苄.丁.异丙隆WP 450、600 g a.i./hm2的防效差异均不显著;药后50 d对总草株防效均达93%以上、鲜质量防效99%以上,且增产8.2%~14.4%。上述处理除20%乙.苄WP 90 g a.i./hm2在药后15 d内对机插稻有一定影响外,其余均较安全。[结论]在小苗机插后3~5 d,使用5%丁草胺GR 750 g a.i./hm2+10%苄嘧磺隆WP 30 g a.i./hm2或53%苄嘧.苯噻酰WP 318~636 g a.i./hm2,或...     

Rice hull biocomposites,part 2: Effect of the resin composition on the properties of the composite

A free radical thermoset resin consisting of a copolymer of conjugated linseed oil (CLO) or conjugated soybean oil (CSO), n‐butyl methacrylate (BMA), divinylbenzene (DVB), and maleic anhydride (MA) has been reinforced with rice hulls. Composites containing 70 wt % of the filler were compression molded, the conjugated oil content in the resin was kept constant at 50 wt %, and the relative amounts of BMA, DVB, and MA were varied to afford composites with different resin compositions. Tensile tests, DMA, thermogravimetric analysis, and Soxhlet extraction of the different composites prepared have been used to establish the relationship between resin composition and the properties of the composites. Overall, the mechanical properties tend to improve when MA is introduced into the resin. Scanning electron microscopy of selected samples showed a better filler–resin interaction for MA‐containing composites and samples prepared from CLO exhibit better properties than those prepared from CSO. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of organo‐modified layered silicates on flammability performance of high‐density polyethylene/rice husk flour nanocomposite

This research was carried out to investigate on the effect of organomodified montmorillonite (OMMT) on the flame retarding characteristics and clay dispersion of composites based on high‐density polyethylene and rice husk flour. To meet this objective, the blend nanocomposites were prepared through the melt mixing of high‐density polyethylene and rice husk flour at 50% weight ratios, with various amounts of OMMT (0, 2, 4, and 6 per hundred compounds) in Hakee internal mixer; then, the samples were made by injection molding. Results indicated that the burning rate, total smoke production, and heat release rate of samples decreased with increasing the OMMT content. Also, the char residue and time to ignition increased with increasing the nanoclay loading. X‐ray diffraction patterns revealed that the nanocomposites formed were intercalated. Also, morphological findings showed that samples containing 2 per hundred compounds of OMMT had higher order of intercalation and better dispersion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

日本大米食味理化学测定

大米食味的理化学测定，是对大米食味的科学分析和判定。本文从日本现有研究成果中，总结简述了日本有关大米食味理化学测定的测定指标和测定方法，并介绍了它们与感观性检查的相关性。     

稻米中的脂类

综述了近年来国内外对稻米脂类及与稻米脂类有关的酶研究的新进展，以求对稻米脂类及稻米脂类与稻米品质的关系有较全面的认识。     

V_2O_5-沸石-活性炭-凹土脱硝催化剂的研制及脱硝性能

稻壳炭化后添加碱液和铝源分别合成了A型、A+X型和X型沸石-活性炭复合材料,加入凹凸棒石黏土成型,采用浸渍法负载V2O5制备V2O5-沸石-活性炭-凹土复合脱硝催化剂。采用XRD、SEM、N2吸附和EDX对样品进行表征,考察载体类型、V2O5含量和反应温度对催化剂低温脱硝活性的影响。结果表明,二元载体和V2O5协同催化脱硝,其脱硝率高于纯凹土制备的脱硝催化剂。催化剂脱硝活性随V2O5含量的增加而降低。反应温度越高,催化剂脱硝活性越高,最佳的反应温度为250℃,温度大于280℃后活性炭被氧化。     

Cadmium in agricultural soils,vegetables and rice and potential health risk in vicinity of Dabaoshan Mine in Shaoguan,China

Soil cadmium （Cd） contamination resulted from mining and smelting is a major environmental concern,and health risk associated with Cd exposure to multi-media through muti-pathway is increasing.Cd concentrations in soils,vegetables and paddy rice were investigated,and potential non-carcinogenic and carcinogenic health risks exposure to Cd were estimated at six villages around the Dabaoshan Mine,South China.A total of 87 soil samples were found to exceed the China＇s maximum permission level （MPL） for Cd,while the highest value of 4.42 mg/kg was found near irrigation ditch associated with Hengshi River in Xinyi （XY） Village.Cd contents in vegetables and rice exceeded the maximum permissible concentration by more than five times in every village.Cadmium accumulation in plants is in the order of celery 〉 lactuca sativa L 〉 Chinese cabbage 〉 Romaine lettuce 〉 asparagus lettuce 〉 mustard 〉 cabbage mustard 〉 cabbage.The mean hazard quotient （HQ） of all villages is in the range of [5.29,25.75],and the mean values of cancer risk for investigated areas are more than 10 times greater than the USEPA （2009） threshold limit value of 10-4.Moreover,human non-carcinogenic and carcinogenic risks are mainly attributable to paddy rice intake,followed by vegetables intake,soil ingestion,inhalation,and dermal contact.The results indicate that Cd has a huge potential risk on human health for the local residents.