不同预处理方法对玉米芯成分的影响

对辽宁康平和湖北襄樊产的两种玉米芯进行了原始成分分析，并分别用1％氢氧化钠、10％氨水、热水、氢氧化钠—过氧化氢溶液、1％硫酸进行处理，然后再进行成分测定，比较了不同的处理方法对玉米芯中纤维素、戊聚糖、木质素含量的影响。     

改性玉米芯的制备及其对Pb~(2+)吸附性能研究

在N,N-二甲基甲酰胺中,以次磷酸钠为催化剂,采用柠檬酸对氢氧化钠处理过的玉米芯进行化学改性,制备得到生物吸附剂,并研究其对Pb~(2+)的吸附性能。通过探讨投加量、吸附时间、Pb~(2+)溶液的不同吸附温度、pH等因素研究改性玉米芯对废水Pb~(2+)吸附性能的影响。结果表明,改性的玉米芯投加质量为0.5 g、pH为7、Pb~(2+)初始质量浓度为100 mg/L时,吸附性能较好,吸附平衡时间t为120 min,最大吸附率为88.10%、最大吸附量为35.24 mg/g。可以用准二级动力学方程和Langmuir方程描述改性玉米芯的吸附过程。     

玉米芯脱盐及脱蛋白的预处理工艺

玉米芯等生物质资源的开发与利用是可持续发展的重要课题。本文对酸法脱除玉米芯中盐及可溶性蛋白的预处理工艺进行了研究。在80℃和100℃下,分别以水和稀硫酸按固液比1g∶10m L的条件对玉米芯进行萃取处理,优化工艺条件;还研究了玉米芯中金属离子去除率的分析方法。结果表明:萃取液中金属离子含量能够表示玉米芯的除盐率;在水中100℃下玉米芯中可溶性蛋白去除率最大,稀硫酸不利于玉米芯中可溶性蛋白的去除;较高的温度和酸度有利于玉米芯中金属离子的去除;同时去除可溶性蛋白与金属离子的合适工艺为:玉米芯与水在100℃下反应0.5h,然后加硫酸至0.1%反应1h。按此工艺,玉米芯中可溶性蛋白和金属离子的去除率分别为97.1%和94.3%。预处理后的玉米芯表面较原料玉米芯表面光滑且多孔。     

碳酸钠在环己基过氧化物分解过程中的应用研究

用碳酸钠部分代替氢氧化钠对环己烷氧化液进行了处理,考察了碳酸钠浓度、温度等因素对氧化液中过氧化物分解的影响,结果表明,采用10%碳酸钠和4%氢氧化钠于80℃下两段处理氧化液各30 m in,过氧化物转化率98%,氢氧化钠消耗比单独用氢氧化钠时降低60%。     

改性玉米芯吸附柱处理含Cr6+废水的试验研究

以废弃玉米芯为原料,以磷酸为活化剂制备改性玉米芯,对比研究了玉米芯和活化玉米芯吸附柱对含Cr6+废水的处理效果。结果发现,相同试验条件下,活化改性后的玉米芯吸附柱对Cr6+的处理效果明显优于未改性的玉米芯吸附柱。试验考查了吸附柱有效吸附高度、Cr6+含量、进水流速、废水pH对含铬废水处理效果的影响。在pH=1、吸附柱有效吸附高度≥1.5 m、进水体积流量为≤2.5 L/min时,初始质量浓度为100 mg/L的含Cr6+模拟废水,Cr6+去除率均在99%以上。对所研究的某机械加工废水处理时,进水体积流量≤2.5 L/min、有效吸附高度为2 m时,废水COD去除率在75%左右,Cr6+、总Cr、Zn2+的去除率分别在86%、88%、98%以上。     

草酸预浸连续汽爆玉米芯制备木糖的模拟与中试研究

以草酸预浸玉米芯,对预浸料进行连续汽爆处理,考察了汽爆条件对木糖产量的影响,研究了水洗后汽爆物料的酶解状况. 结果表明,1.0 MPa汽爆压力、8 min维压时间、草酸/干玉米芯比45 g/kg为草酸连续汽爆制备木糖的最优条件. 采用SPSS statistics软件构建汽爆参数模型,方程相关系数均大于0.9,可用于描述实验条件与木糖产量的关系. 中试结果表明,3.81 kg干玉米芯可得415.50 g木糖,即约9.17 t玉米芯可产1 t木糖,达到工业生产要求. 酶解结果表明,草酸预浸汽爆玉米芯葡萄糖产量较中性汽爆玉米芯和未处理玉米芯分别提高32.30%和214.87%.     

改性玉米芯吸附废水中苯酚的性能研究

用不同表面活性剂对玉米芯改性,初步研究了改性玉米芯吸附废水中苯酚的影响因素.结果表明:用十二烷基苯磺酸钠改性玉米芯,活化3 h,其比表面积达1 372.5 m2/g,在酸性条件下对苯酚的去除率＞90%.该试验结果可为玉米芯的废物再利用和废水的处理问题提供参考.     

玉米芯处理含铬废水的研究

利用玉米芯对含Cr^6＋废水处理进行了研究.结果表明,玉米芯对Cr^6＋有较好的吸附效果,活化玉米芯对Cr^6＋的吸附比普通玉米芯效果更好.溶液的pH值在1左右,吸附时间为2 h左右,活化玉米芯对Cr^6＋的吸附率可达到83%以上.     

玉米芯改性纤维素絮凝剂的制备及性能研究

为了降低污水处理成本并提高污水处理效果,以玉米芯和2,3-环氧丙基三甲基氯化铵(EPTMAC)为原料,利用专利技术通过对玉米芯中的纤维素进行改性,合成玉米芯改性纤维素絮凝剂,并对污水进行了处理。从处理的效果来看,当水体的pH值为8,絮凝剂投放量为35.5mg/100mL污水时,该絮凝剂对污水的COD去除率可达68%,絮凝效果理想。     

氢氧化钠的乙醇溶液对聚酯纤维的碱处理

用乙醇为溶剂的氢氧化钠溶液对聚酯纤维进行碱处理,所获得的减量率比在相同浓度、时间和温度条件下用氢氧化钠水溶液处理的要高。处理后纤维的性能不依赖于处理液中溶剂的成分,因此,采用乙醇作溶剂可大大缩短处理时间,得到与水相碱处理同样的效果。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

卫生陶瓷烧成用窑炉发展之我见

归纳了当今卫生陶瓷工业的发展现状和水平 ,对窑炉产业提出了的新要求 ,分析了某一新型窑炉的特点 ,对发展我国陶瓷窑炉产业提出了建议     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.