密集烘烤关键温度点不同湿度控制烤烟主要化学成分的动态变化

针对密集烘烤存在的干物质降解不充分和香气物质不足的问题,以‘K326’品种为材料,在湖南省浏阳市开展了密集烘烤关键温度点不同湿度控制烟叶化学成分动态变化研究。结果表明：（1）在密集烘烤过程中,42℃前淀粉含量迅速下降、总糖和还原糖含量及糖碱比迅速升高;42~47℃,淀粉含量缓慢下降、总糖和还原糖含量缓慢升高;在47℃后,淀粉、总糖、还原糖含量及糖碱比基本保持稳定,变化很小。（2）烟叶烟碱、总氮含量随烘烤进程略呈下降趋势,但变化较小;氮碱比变化不大。（3）在烟叶变黄期和定色期适当增加湿球温度,可使化学成分更加协调。     

基于LS-SVM逆系统的焦炉集气管压力系统内模控制

焦炉集气管压力是炼焦生产过程中重要的工艺参数,其值是否稳定,直接影响到煤气质量、焦炉寿命、焦炭质量和生产环境。针对焦炉集气管压力系统是一个强干扰、非线性和多变量耦合的复杂系统,采用LS-SVM辨识出焦炉集气管压力系统的逆系统模型,并将其串联在原系统之前,运用逆系统的方法将集气管压力系统解耦成2个相互独立的单输入单输出伪线性子系统。同时,对解耦后的系统采用非线性内模控制策略以保证系统的鲁棒性和稳定性。仿真和应用结果表明该控制策略的解耦控制效果较好,提高了系统的快速调节能力和跟踪精度,而且增强了系统的鲁棒性,可以保证焦炉集气管压力稳定在现场工艺要求的范围内。     

发酵菜粕流化干燥技术的研究

为改善发酵菜粕干燥工艺,利用流化床设备对其进行干燥研究。对干燥过程中定时采样的数据进行计算统计,得出干燥过程中发酵菜粕的干燥特性曲线,分析发酵菜粕在干燥过程中物料水分变化的特性。结果表明,120℃恒定干燥条件下,发酵菜粕的恒定干燥速率为82.62 kg/(m2 ·h),恒速干燥阶段蒸发的水分占总蒸发量的44.54%。该研究获得了发酵菜粕的干燥曲线和干燥速率曲线,为发酵饲料的流化床干燥工艺的优化提供参考和依据。     

不同钝化材料对农田土壤中砷的钝化效果研究

笔者探究不同添加比例钝化材料对贵州喀斯特岩溶地区农田土壤中有效态As钝化特征,旨在为砷污染土壤修复提供参考.试验通过向砷污染土壤中分别添加生石灰等12种不同比例钝化剂,分析不同钝化剂对土壤pH、有效As和钝化率的影响.6种无机钝化材料中铁矿粉、钢渣和煤渣均能有效降低农田土壤中As有效态含量,以施用煤渣效果最佳,使土壤p...     

Influence of microwave radiation on phosphorus-removal process of oolitic high-phosphorus iron ore fines

Influence of microwave radiation on newly proposed phosphorus removal process(gaseous reduction and slag/metal separation) is studied. Microwave radiation on the ore fines is carried out using MW-HS multi-function high temperature microwave reactor. The treated ore fines are subjected to examinations of SEM, EDS and TG. TG tests are conducted using thermal analyzer(LINSEIS STA PT 1600). Results show that microwave pretreatment can obviously change the microstructure of the ore fine. After microwave pretreatment, arc cracks develop along the boundaries between phosphorite phase and hematite phase and loose zones in the areas where multi-minerals coexist. Microwave pretreatment has an intesification effect in the late stage of the gaseous reduction of the ore fines. Results of gaseous reduction and melt separation tests indicate microwave pretreatment could greatly improve the metal recovery rate in processing the ore fines using the proposed phosphorus removal method while phosphorus content in the metal sample is slightly increased. Under the condtion that the reduction temperture is 1 273 K, reduction atmosphere full CO and reduction time 2 hours, metallization rate of the sample pretreated using microwave power of 450 W could reach 90%. And in the melting separation process, its metal recovery rate reaches 83% with a phosphorus content of 0.48%(mass percent) in the metal sample.     

氢还原竖炉的模拟分析

利用一组物料、热量守衡式及其他有关约束关系,建立了氢还原竖炉模拟模型,可定量考察消耗量、生成量和氮气、CO兑入成分、DRI金属化率、入炉煤气温度等的关系。模拟结果表明：兑入CO可使入炉煤气量从纯氢还原的1650 N·m³左右下降到1200 N·m³左右;当CO和H₂的体积之比V（CO）/V（H₂）约为0.6时,氮气兑入量约为0,竖炉能量利用最佳;当V（CO）/V（H₂）体积比为0.3时,最佳氮气兑入成分约为11%;纯氢还原最佳氮气兑入成分约为25%;兑入氮气可以减少入炉氢气的量,但不能减少入炉气体的总量。对氢还原竖炉模拟结果可为其工艺设计、操作和节能等提供参考信息。     

An Experimental Research on Coal base Reducing Poor Siderite to Sponge Iron

A series of experiments were carried out in the department laboratory and showed that using fixed bed jar method the coal base reduction of poor siderite can produce reduction ore.by ball milling and magnetic separation the sponge iron(TFe>80%,SiO 2<6%) was obtained.Thereby the scientific basis for developing and utilizing the low grade siderite were provided.     

A calculation method for coalbed permeability by using drainage data

In order to more accurately calculate the changes in the permeability of coalbed during production process, a calculation method for coalbed permeability based on production data is established by combining with material balance equations and production equations, and it gives the fact that the output data can be a good reflection of the inner permeability of coalbed. The average pressure of coalbed in production process can be calculated through material balance equation. Dimensionless water production index is introduced into the production equation in the stage only with water production. In the next stage with both gas and water, gas and water production ratio is introduced to eliminate the influence of flush-flow radius, skin factor as well as other uncertain factors on the calculation of CBM permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. There is a trend that the permeability declines firstly and then increases after wells in Qinshui CBM field are calculated. The results show that reservoir permeability increase after drainage stage, but the growth rate decrease gradually. The regression result of the permeability ratio and surface cumulative fluid production agrees with the theoretical mathematic relationship.     

氧气高炉工艺研究进展及新炉型设计

从氧气高炉的数学模型、实验室实验以及工业试验角度系统分析了氧气高炉工艺的发展现状及趋势,同时讨论了氧气高炉炉型的设计依据。论述了氧气高炉的静态工艺模型研究需要计算合适的直接还原度和热空区温度,同时应考虑氧气高炉工况下生产率的变化、热损失的变化、风口煤粉的喷吹上限以及N₂的循环积累等问题。指出了多维动力学模型和多目标优化模型中尚需解决的问题,以及氧气高炉数学模型的主要发展方向。结合文献研究中的氧气高炉特点,从炉身高度设计、炉腹角和炉身角设计以及风口设计3方面综述了氧气高炉炉型设计的变化规律。     

Energy transmission process of combustion flame radiation in the tuyeres and raceways of blast furnaces

We developed a process model of flame beam transmission using pulverized coal powder and coke combustion in a raceway. We employed a Monte Carlo computation method equation based on charge couple devrce(CCD) target heat flow distribution for radiation heat transfer. We explored the factors impacting radiation transmission. Based on these, a three dimensional reconstruction was analyzed at varying coke particle concentrations. This model provided an effective method to produce on line monitoring of raceway working states.     

装箱密度对片烟醇化质量的影响

为进一步提升贮存片烟醇化质量,为片烟醇化科学管理提供技术支撑,运用化学成分可用性综合评价方法,开展不同等级(B₃F、C₃F)装箱密度(100、150、200 kg/0.593 m³)对片烟醇化质量的影响研究。结果表明：无论是上部还是中部等级片烟,装箱密度为100 kg/0.593 m³时,片烟水分含量波动最大;不同等级装箱密度的片烟主要化学成分可用性均表现为150 kg/0.593 m³处理更好;感官质量随醇化时间呈抛物线变化趋势,适宜醇化期内片烟样品的感官质量评吸总分表现为150 kg/0.593 m³>100 kg/0.593 m³>200 kg/0.593 m³。综上,片烟在150 kg/0.593 m³的装箱密度时综合质量相对最优。     

夏玉米施氮量对后茬冬小麦土壤氮素供应与利用的影响

在冬小麦施氮144 kg/hm2的基础上,研究了夏玉米4个施氮量(0,90,180,270和360 kg/hm2)对后茬冬小麦生长期间土壤硝态氮含量变化、无机氮供应以及小麦氮素吸收与利用的影响。结果表明:与玉米不施氮(简称不施氮)相比,玉米施氮(简称施氮)0~200 cm土壤硝态氮含量在冬小麦生长期间显著增加,自冬小麦拔节起,0~40,0~130和0~200 cm 3层深的土壤硝态氮含量均随着玉米施氮量(简称施氮量)的增加而明显递增;与冬小麦播种时相比,不施氮0~130 cm土壤无机氮减少156 kg/hm2,施氮90 kg/hm2该层土壤无机氮富积41 kg/hm2,且富积量随着施氮量继续增加而递增;随着施氮量增加,冬小麦收获时的植株吸氮量和子粒氮素积累量均增加;当施氮量低于180 kg/hm2时,植物氮素积累量在不同施氮量之间无显著差异;当施氮量低于270 kg/hm2时,不同施氮量的子粒氮素积累量差异不明显。在本试验条件下,冬小麦子粒氮肥利用率随着施氮量增加而递增,但差异不显著。     

密集烤房热湿循环利用系统的设计与应用

为合理利用密集烘烤过程中产生的余热余湿,设计密集烤房热湿循环利用系统并进行研究应用。结果表明,该系统节能效果明显,节煤幅度达27.86%~28.78%,烘烤成本降低0.59~0.61元/kg,烤后橘黄烟叶、中上等烟比例提高,均价提高 1.6~1.8元/kg;烤后烟叶油分增加、色度增强、挂灰杂色和含青程度减轻;提高总糖、还原糖含量和钾氯比,降低总氮、氯离子含量,主要化学成分趋于协调;提高香气质量、减轻杂气,明显改善感官评吸质量。     

Medium and Long Term Decomposition Process of Litter in Abies Fabri Forest

Litter is an important part of forest ecosystem and its decomposition process is the key link of nutrient cycling in forest ecosystem.Accurate determination of litter decomposition dynamics is very important to study the pattern and process of forest ecosystem.This paper selected The Gongga Mountain Alpine Ecosystem Observation and Experiment Station at an altitude of 3000 m to observe and determine litter decomposition process of the Abies fabri forest over a long period of time.The results showed that:①The decomposition rate of litter was broadleaf>needles>dead branches,and the time required to decompose half of broadleaf,needles and dead branches was 6.8 years,10.5 years and 14.5 years respectively;the time of decompose 95%of them was 29.3 years,45.6 years and 63.1 years,respectively;②Regardless of broadleaf,needles or dead branches,the organic carbon content of them decreased with time,while the decomposition rate of organic carbon increased with time;By using the exponential decay model the decomposition coefficient of litter organic carbon calculated was broadleaf>needle>dead branches;③The organic carbon released by the annual decomposition of broadleaf,needles and dead branches in Abies fabri forest was 52.18,4.32 and 0.67 kg/hm^2,respectively.The total amount of organic carbon released by various litter was 61.13 kg/hm^2 per year,accounting for 6.58%of the total organic carbon of litter.     

Method to Predict the Coke Rate Based on BP Neural Network

Coke rate is a very important technique index in the processing of metallurgical, and it is also an important goal that should be reached and controlled in practice.The blast furnace is a countercurrent heat and mass exchange reactor involving the solid, liquid and gaseous phases. Using computer encoded mathematical and statistical methods can not get the precise result. An improved 9-9-1 BP(Back propagation) neural network was trained and used in the prediction of the coke rate. The result indicates that the BP nets can predict coke rate accurately and the error between prediction and real coke rate less than 2%. And the use of a hybrid model in actual on-line intelligence control was also discussed.     

Pressure Sweep Adsorption Processes for the Concentration of Methane from Coal-bed Gas Extracted

The coal-bed gas was usually extracted from mine in order to avoid coal gas outburst.The Methane(CH4),a main component in coal-bed gas,is a kind of excellent gas fuel and raw material for chemical industry.China is very rich in the resource of coal bed gas,however,most of the coal bed gas extracted from mine is wasted because of the too low concentration of methane. Pressure sweep adsorption(PSA) technique is noticeable among the methods for the concentration of methane from coal-bed gas.However,there are a few studies about this field.Studies on the pressure sweep adsorption(PSA) process for the separation of CH4/N2 using actived carbon as adsorbent are summarized.The thermodynamic relationships and kinetic processes and the influence of the operate parameters on the concentration of methane are investigated.These results have a direct application in coal-bed gas.Some suggestions for the problems need to be solved in PSA process for the separation of methane are also proposed.     

白点鲑的耗氧率及窒息点研究

2009年在中国水产科学研究院黑龙江水产研究所渤海冷水鱼实验站,对两种不同体重规格的白点鲑的耗氧率、耗氧量及窒息点进行了测定,结果表明,白点鲑的耗氧率和窒息点随体重的增加而减小;耗氧量随体重的增加而增加。温度在13.08℃,平均体重2.06g的白点鲑平均耗氧率为6.14mg／g?h,平均耗氧量为13.58mg／尾?h;平均体重85.95g的白点鲑平均耗氧率为0.46mg／g?h,平均耗氧量为39.69mg／尾?h。平均体重2.06g的白点鲑,窒息点为1.28mg／L,平均体重85.95g的白点鲑窒息点为0.96mg／L。同等规格白点鲑的昼夜耗氧率差异不显著,但其夜间平均耗氧率要高于白天。通过研究结果综合分析认为在9：00、12：00、18：00投喂,每天投喂3次,而且傍晚的投喂量占一天总量的3／5,从而有效提高饲料的利用率,也符合白点鲑的活动规律,有利于鱼体生长。     

稻田肥料减施对小麦秸秆腐解规律的影响

以稻田肥料等量减施为背景,研究小麦秸秆在腐解过程中秸秆残余率、氮、磷、钾以及纤维素类碳水化合物的累积释放率和平均释放速率。全氮采用H₂SO₄-H₂O₂消煮-蒸馏法,全磷采用钼锑抗比色法,全钾采用火焰光度计法测定,纤维素、半纤维素、木质素采用分光度计比色法进行测定。计算秸秆的残余率、物质累积释放率、物质平均释放率,并采用修正后的Olson指数衰减模型对秸秆的腐解动态进行拟合。结果表明,施肥会促进小麦秸秆在稻田中的腐解、秸秆残余率的降低,采用修正后的Olson指数衰减模型对秸秆腐解进程的模拟显示,CK和F₅₀处理下秸秆腐解50%的理论预测时间比CK₀处理分别缩短22天和12天,CK和F₅₀处理下秸秆腐解95%的理论预测时间比CK₀处理分别缩短95天和59天,施用肥料可促进秸秆中氮、磷、钾及纤维素类碳水化合物的累积释放率和平均释放速率,其中,肥料减施对钾素累积释放率影响最小,秸秆中氮磷钾养分前期的平均释放速率相对较快,纤维素、半纤维素和木质素的秸秆释放周期较长。稻麦轮作系统中,施用肥料可促进小麦秸秆的氮、磷、钾及纤维素类碳水化合物的累积释放率和平均释放速率。研究结果可为小麦秸秆肥料化利用提供理论支持。     

The influence of initial internal structure of coal sample on gas flow characteristic

Three kinds of coal samples with different components are chosen as study objects.Density calculation and SEM are adopted to study their internal structures,and a self made triaxial gas seepage instrument is used to study their internal gas flow characteristics.The results show that internal structures of coal samples made of different particle size coal powders under identical external conditions are various,and nonlinearity is presented on the influence caused by fabric.Gas flow characteristic is complex in complete stress strain process,generally it firstly increases and then decreases,initial gas flow velocity is lower than the one after the failure of coal sample,and obvious hysteretic nature of gas flow characteristic is showed.The influence of gas flow characteristic caused by initial internal structure of coal sample is nonlinear and the stress sensitivity is high on the influence of gas flow characteristic caused by initial internal structure.The more complex the initial internal structure of the coal sample is,the lower the axial tress sensitivity is,and the higher the confining pressure sensitivity is.     

Establishment and analysis of dynamic mathematical model for coal gasifier

Based on the analysis of flowing combustion, gasification reaction, and lumped parameter, a three region model is established to predict the temperature and gas components of Texaco coal gasifier. Using mass balance and energy balance equations to each zone, the model takes account of gas solid two phase flow, coal pyrolysis, radiation heat transfer, and heterogeneous and homogeneous kinetic chemical reactions. Based on the model, a program is developed for dynamic and static simulation. After parameterization and simulation analysis, some important trends and conclusions are attained. Because the model can accurately predict the temperature and gas components in jet region, it has widespread engineering application value.