沸石的有机改性及其对苯酚的吸附机制研究

采用十六烷基三甲基溴化铵(CTMAB)对人造沸石进行了改性,并研究了其对苯酚吸附性能.结果表明:将人造沸石用于处理含酚废水,必须先活化;活化沸石对CTMAB的吸附等温线类似于Langmuir型吸附;改性条件为:20℃,质量浓度为5 g/L的CTMAB溶液,间歇振荡24 h.改性沸石对水中苯酚的吸附规律较好的符合Henry吸附等温式,吸附作用机制为苯酚在沸石表面的有机相和溶液中的分配及双分子层正电性表面与苯酚之间的静电吸附作用.温度升高,吸附量减少.     

土壤水分对包膜尿素氮素溶出特性影响的研究

研究土壤水分对自行研制的包膜尿素(BG、BF)氮素溶出特性的影响.采用室内恒温土壤培养方式,探讨土壤水分为田间持水量的10％、40％、80％和100％条件下包膜尿素氮素溶出特性.结果表明:土壤水分为田间持水量的40％以下时,BG和BF在各培养时期内的氮素溶出率都比较低,在培养第42天氮素溶出率仅为66.3％和68.4％,土壤水分在田间持水量的80％以上时,溶出率均达到了80％以上;土壤水分在田间持水量40％、80％和100％条件下,氮素溶出50％所需要的天数,BG型包膜尿素比BF型延长了4.6d 、0.2d和0.9d;氮素溶出特性可以用一级反应动力学方程N1=N0[1-exp(-kt)]描述,k为氮素溶出速率常数,包膜尿素BG的k值小于BF.土壤水分对包膜尿素氮素溶出率影响较大,随着土壤含水量的增加,氮素溶出率增大;硅藻土作为包膜材料对养分的缓释效果要好于沸石粉.     

一种快速提取小麦基因组DNA的改良CTAB方法

旨在寻求一种微量、快速提取小麦DNA的方法。以小麦幼叶为材料,用改良CTAB法、改良SDS法、沸水浴法提取小麦叶片总DNA,通过琼脂糖凝胶电泳法、紫外吸收法和PCR检测DNA完整性和纯度。改良CTAB法提取小麦基因组DNA质量和纯度高、无降解,每人每天可以轻松提取200个DNA样品,对转基因植株的PCR检测显示扩增目标条带清晰一致,无假阳性,试验结果理想。改良SDS法所提DNA纯度和浓度虽略不如改良CTAB法,但仍然符合实验要求。沸水浴法提取量少且杂质多,PCR无有效扩增,结果不理想。改良CTAB法提供了一种简便、快速微量小麦DNA提取方法,适用于PCR和其他分子生物学研究。     

Influence of Characteristic of Zeolite on Loading Nano-TiO2 for Photocatalytic Degradation of Oxytetracyline in Aqueous Solution

The composite photocatalysts were made by using solid dispersion method with nano-TiO2 loaded on hydrophobic or hydrophilic zeolite and zeolite with different pore diameters. The removal and mineralization efficiency of oxytetracycline (OTC) in aqueous solution were investigated under the irradiation of 32 W UV lamps by composite photocatalysts loaded with different ratios of nano-TiO2. The results showed that UV/10%TZ2 (hydrophilic zeolite) achieved a better removal efficiency of OTC than UV/40%TZ1 (hydrophobic zeolite) while UV/15%T5A (hydrophilic zeolite with a pore diameter of 0.5 nm) achieved a better removal efficiency of OTC than UV/10%T13X (hydrophilic zeolite with a pore diameter of 1 nm). That is to certify that the hydrophilic zeolite and zeolite with small pore diameters loaded with nano-TiO2 could achieve better removal effects for OTC in aqueous solution. The OTC that adsorbed on the inside surface of 13X cannot be degraded due to the out range of hydroxyl radicals attack.     

Synthesis and Properties of Fumaropimaric Acid Modified RTV Silicone Rubber北大核心CSCD

Fumaropimaric acid modified aminopropyltriethoxysilane(FA) was prepared by derivative reaction with rosin as raw material and the structure of the product was confirmed by FT-IR, 1H NMR and 13C NMR. Fumaropimaric acid modified room temperature vulcanized(RTV)silicone rubber was prepared by the dealcoholization condensation reaction of crosslinking agent(FA) and hydroxyl end-blocked dimethylsiloxane(PDMS). And the effects of hydrogenated phenanthrene ring of rosin on the morphology, mechanical and thermal properties of fumaropimaric acid modified RTV silicone rubber were studied, it was found that fumaropimaric acid modified RTV silicone rubber had better the mechanical and thermal properties compared to the unmodified silicone rubber. The tensile strength and elongation at break were 1.22 MPa and 315%; and The 10% mass loss temperature increased to 472 ℃ (SRFA-1), the greatest rate of mass loss temperature increased to 569 ℃, and the residual rate was 3.88%, respectively. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

马铃薯红外干燥特性研究

以马铃薯为原料,研究其红外干燥特性及数学模型。通过试验收集了不同切片厚度和干燥温度下马铃薯水分比(MR)随干燥时间(t)的变化数据,得到了马铃薯的干燥曲线,并计算了干燥过程中的有效水分扩散系数(Deff)和干燥活化能(Ea)。结果表明,干燥温度(T)与切片厚度(L)对马铃薯红外干燥特性有较大影响,干燥温度越高,切片厚度越薄,马铃薯的干燥速率(DR)越快,干燥时间越短;同时,通过拟合计算发现,在10种干燥模型中Modified Henderson and Pabis的预测值与实测值比较吻合,能够更好地反映干燥过程。在试验条件下,Deff在0.238 4×10-10~12.557 3×10-10m~2·s-1之间,且随着干燥温度和切片厚度的增加而增大。1、3、5、7 mm厚的马铃薯片红外干燥活化能分别为34.386 0、31.041 8、28.783 2、30.060 1 k J/mol。     

Soil quality indicators in Vertisols under sugarcane

Maintaining or improving soil quality is crucial for agricultural productivity. This study was undertaken on the north coast of Cuba with the objective to select soil quality indicators to characterise Vertisols. For the selection of soil quality indicators, we have conducted four field experiments where organic fertilisers (sugarcane filter cake, compost) and natural minerals (dolomite, zeolite) were applied. Sugarcane (Saccharum officinarum L.) was used in all experiments. Soil properties were determined such as the amount of water-stable aggregates, permeability, plastic limit, pH in water, pH in KCl, organic matter, P₂O₅ and K₂O. The sugarcane yield components such as cane yield (t ha^?1) and sucrose yield (t ha^?1) were evaluated. Principal components analysis and simple regression analysis were also performed. Both organic matter and water-stable aggregates were closely related to cane yield, with r values of 0.87–0.97. The properties with best responses to treatments over time were permeability, water-stable aggregates, degree of soil aggregation and organic matter; therefore, they can be considered as soil quality indicators for the studied Vertisols.     

吸附法除磷研究进展

磷是造成水体富营养化的重要因子,也是废水处理领域较难解决的问题之一,环境矿物质对磷具有优越的吸附性能,而且储量丰富、成本低廉,在废水处理领域有广阔的应用前景。就环境矿物质对磷吸附研究的现状和发展进行了分析和介绍。     

用Penman-Monteith方法与Penman修正算法计算参照作物腾发量的比较

利用阿克苏地区1975-2004年的逐日气象资料,分别采用Penman—Monteith公式与Penman修正公式计算了新疆农一师灌区的参照作物腾发量及其辐射项和空气动力项的逐日均值和旬日均值,比较了2种计算方法的绝对偏差和相对偏差,并对引起偏差的原因进行了分析。     

氯化钠改性沸石对氨氮的吸附作用

采用30℃和90℃的NaCl溶液改性浙江缙云产天然沸石,通过静态吸附实验考察天然沸石及改性沸石对溶液中氨氮的吸附能力及机制,结果表明,NaCl改性可以提高沸石对氨氮的吸附能力。天然沸石及NaCl改性沸石对氨氮的吸附动力学过程符合“初期快速吸附,后期缓慢稳定”的特点。假二级动力学模型适合描述天然沸石及NaCl改性沸石对氨氮的吸附过程,颗粒内扩散模型仅适合于描述吸附反应初期天然沸石及NaCl改性沸石对氨氮的吸附过程。天然沸石和NaCl改性沸石对溶液中氨氮的吸附过程满足Langmuir和Freundlich等温吸附模型。90℃ NaCl改性沸石、30℃ NaCl改性沸石及天然沸石的氨氮饱和吸附量分别为19.5 mg/g、17.8 mg/g和17.2 mg/g。离子交换作用决定了溶液中氨氮向天然沸石及NaCl改性沸石的全部转移量。