乙烷-氧-水氧化裂解制乙烯反应的研究

研究了不同反应体系组成的乙烷造反然的反应性能,考究了乙烷－氧－水反应体系氧化裂解制乙烯的反应条件。结果表明,在不同反应体系中,以Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解制乙烯反应性能最佳,８００℃的乙烷转化率为８５．１％,乙烯选择性为６８．１％,乙烯收率可达５８％,Ｃ２Ｈ６－Ｏ２－Ｈ２Ｏ氧化裂解帛乙烯体系最佳工艺参数;反应温度为８５０℃,原料气组成为５０．５％,Ｃ２Ｈ６＋２５．２％Ｏ２＋２４．３％Ｈ２Ｏ停留     

KNbO_3粉体的低温合成研究

以尿素为燃烧剂,采用低温燃烧法在较低的温度下合成了纯相的KNbO3粉体。采用XRD、SEM和TG-DSC研究了KN晶相的形成过程。结果表明,采用该法可在550℃下合成纯相的KN粉体,当煅烧温度升高至700℃时,立方相的KN粉体转变成了正交相的KN粉体。本研究还就工艺参数对粉体物相的影响进行了讨论。     

低温处理中间相沥青炭微球的充放电性能研究

研究了在500-1000℃下停留不同时间低温炭化处理的中间相沥青炭微球（MCMBs)的充放电性能，并与其XRD结构相关联。研究表明：在500-1000℃停留4h炭化处理的中间相炭微球中，700℃炭化处理的MCMBs充放电性能最好，充放电容量最高，不可逆容量损失最小；在700℃炭化温度下停留时间的延长有利于MCMBs循环性能的提高。     

GRAIN DRYING OPTIMISATION AT LOW TEMPERATURES

ABSTRACT

The optimisation of grain drying systems was studied through the dynamic programming technique focusing on the minimisation of the energy consumption, lakingin account the conservation of the product quality and avoiding excessive humidity gradients in the bed at the end stages of drying. An algorithm was developed, where the input data were the initial conditions of the product and the climate data of the region. The operational conditions considered were: fan on or off, and different degrees of air heating (1 to 5 °C). The result obtained was an optimised management strategy for the operation of the dryer, specified for each stage of the process, in two situations: calculated from the mean climate dam of ten years, and corrected day by day with up to date climate data.     

THIN-LAYER DRYING CHARACTERISTICS OF ROUGH RICE AT LOW AND HIGH TEMPERATURES

Abstract

Thin-layer drying characteristics of rough rice were determined at temperature ranging from 11.8 to 51 °C and for relative humidities ranging from 37.1% to 91.3%, with initial moisture contents in the range of 24.7 to 41.6% dry basis. An oven, a self contain air conditioning unit, recently developed in Japan, was used for this experiments. With this apparatus, very smooth drying curves were obtained. The data of sample weight, and dry and wet bulb temperatures of the drying air were recorded continuously throughout the drying period for each test. The drying process was terminated when the moisture content change in 24 h was less than 0.2 % d.b. (weight change was less than 0.05 g). The final points were recorded as the dynamic equilibrium moisture contents.

The drying data were than fitted to the Page model. The model gave a very good fit for the moisture content with an average standard error of 0.294 % d.b? Both the drying parameters, K and N, are function of drying air temperature and relative humidity. The effect of variable initial moisture content was also described effectively by the empirical Page model. The drying time employed had a large effect on the K and N values. The results presented here, over typically 5 day drying, will be useful in the long term moisture transfer process occurring during ventilated storage.     

THIN-LAYER DRYING CHARACTERISTICS OF ROUGH RICE AT LOW AND HIGH TEMPERATURES

Thin-layer drying characteristics of rough rice were determined at temperature ranging from 11.8 to 51 °C and for relative humidities ranging from 37.1% to 91.3%, with initial moisture contents in the range of 24.7 to 41.6% dry basis. An oven, a self contain air conditioning unit, recently developed in Japan, was used for this experiments. With this apparatus, very smooth drying curves were obtained. The data of sample weight, and dry and wet bulb temperatures of the drying air were recorded continuously throughout the drying period for each test. The drying process was terminated when the moisture content change in 24 h was less than 0.2 % d.b. (weight change was less than 0.05 g). The final points were recorded as the dynamic equilibrium moisture contents.

The drying data were than fitted to the Page model. The model gave a very good fit for the moisture content with an average standard error of 0.294 % d.b¨ Both the drying parameters, K and N, are function of drying air temperature and relative humidity. The effect of variable initial moisture content was also described effectively by the empirical Page model. The drying time employed had a large effect on the K and N values. The results presented here, over typically 5 day drying, will be useful in the long term moisture transfer process occurring during ventilated storage.     

低温烧结SrTiO3陶瓷晶界层电容器材料的掺杂分析

借助于晶格常数的精确测定、透射电子显微镜及其电子衍射和X射线能谱分析,结合材料性能,对还原气氛中低温一次烧结的srTiO_2陶瓷晶界层电容器材料的掺杂状况进行了分析。结果表明Li~+不能进入srTiO_2晶格的填隙位置形成施主。在Nb_2O_5和Li_2O同时存在的情况下,也没有产生施主-受主相互补偿进入晶格的现象,而是Nb_2O_5进入晶格起施主作用使晶粒半导化,Ll_2O偏析在晶界上,与聚集在晶界上的SZO_2一起形成活性液相,促进烧结的进行,并形成复杂的锂硅酸盐化合物产生绝缘性的晶界,从而形成晶界层电容器的显微结构,这是能够在低温下一次烧成SrTiO_2陶瓷晶界层电容器材料的根本原因。     

催化裂解和蒸汽裂解制烯烃工艺技术经济分析

根据近年来乙烯裂解发展趋势,以炼厂液化气和LNG凝析液等轻烃资源为主要原料,通过实例对比分析催化裂解和蒸汽裂解制烯烃的技术以及经济性,并提出石油石化公司应根据区域丙烯和丁二烯市场需求以及企业自身的发展定位,因地制宜地选取合理的烯烃裂解工艺。     

停工状态下转化炉上发夹管腐蚀开裂原因分析

通过对一段转化炉上发夹管受力分析、裂纹特征、断面金相、电镜扫描、微区能谱、材质等分析,找出了上发夹管开裂的原因是应力腐蚀断裂,提出防护措施.     

低温烧结SrTiO_3陶瓷晶界层电容器材料的研究

研究了施主杂质Nb_2O_5,碱金属氧化物添加物Li_2O和烧成温度对低温一次烧成SrTiO_3陶瓷晶界层电容器介电性能和显微结构的影响。结果表明。Li_2O的加入量对液相烧结的进行和晶粒的生长有很大影响。具有一定特性的液相还能作为氧在晶界上迁移的通道,而有利于氧的挥发,促进晶粒的半导化,Nb_2O_5含量为0.1mol％左右时就能具有良好的效果。在液相特性不能满足晶粒生长要求的情况下,Nb_2O_5含量显著影响着晶粒的半导化程度。添加过多的Nb_2O_5会阻碍晶粒的生长。烧结温度对晶粒生长和材料的介电常数也有明显的影响,适当提高烧结温度能提高材料的介电常数。     

轻油中痕量溶解氧的测定研究

运用碱性靛蓝胭脂比色法测定了合成氨原料轻油中痕量溶解氧含量。本法操作简便,测定结果准确,测定解氧为０￣１４２μｇ／Ｌ,在０￣２２μｇ／Ｌ范围内,色阶变化尤为明显。     

硫酸钠掺量对混凝土早期收缩开裂的影响

研究了分别掺加占胶结料质量分数1％,2％的硫酸钠对混凝土早期收缩开裂的影响。用非接触式混凝土收缩测量仪及板式混凝土开裂架进行实验。用电子显微镜对硫酸钠混凝土试件早期亚微观结构进行较为直观的研究分析。结果表明：硫酸钠对混凝土早期收缩开裂在不同孔径中的作用不尽相同。硫酸钠对混凝土早期收缩的影响与水胶比及硫酸钠的掺量有一定的关系。硫酸钠掺量相同情况下,水胶比较小混凝土早期收缩值较大;在相同水胶比情况下,硫酸钠掺量较大混凝土早期收缩值较小。硫酸钠对混凝土早期开裂的影响与养护方式相关,空气中养护与密封条件下养护这2种养护制度相比,在空气中养护混凝土表面出现裂纹的时间较早,裂纹较宽且较多。在这2种养护制度下,水分蒸发速度的不同决定了硫酸钠结晶初始深度的不同,是硫酸钠对混凝土早期开裂的主要影响机理。     

氧化沟中试装置低温条件下脱氮除磷效果分析

以实际污水处理厂沉砂池出水为研究对象,检测分析了低温运行条件下微孔曝气氧化沟中试装置脱氮除磷效果随温度的变化情况。结果表明,水温低于11℃时,试验装置的脱氮除磷效果明显变差,并分析了硝化和反硝化效率不高的原因,提出了相应的运行调整措施与建议,其结论对同类型污水处理厂的运行管理有参考价值。     

复合铁酶促活性和普通活性污泥系统低温启动对比研究

对比研究了＜15℃的低温条件下复合铁酶促活性污泥和普通活性污泥系统的启动过程.结果表明,向2个平行试验装置投加等量的接种污泥,两系统在以下工况条件经32 d均成功启动:HRT为20 h,污泥龄30d,进水体积流量与回流污泥体积流量比200％,DO的质量浓度2.0～4.0 mg·L-1;培养过程中,复合铁酶促活性污泥系统比普通活性污泥系统污泥含量更高,系统启动速度快;对COD、NH3-N、PO43--P的平均去除率较普通活性污泥系统分别提高6.10.11个百分点;脱氢酶活性、NH3-N硝化速率、吸磷速率分别提高了5.20 μg·mg-1·h、3.15 mg·L-1.h-1、2.0mg·L-1·h-1,表明复合铁活性污泥系统在低温条件下较普通活性污泥系统具有更高的微生物活性.     

工艺条件对低温烧结90氧化铝陶瓷显微结构及性能的影响

本文使用CaO-MgO-BaO-SiO2-ZrO2作为90氧化铝陶瓷的烧结助剂,在1420℃烧结得到了密度达3.77g/cm3的90氧化铝陶瓷。探讨了氧化铝粉末的活性、原料细度、成型工艺、烧结温度和保温时间等工艺条件对氧化铝陶瓷的烧结密度及其显微结构的影响。结果表明:活性高细度小的氧化铝粉末可显著降低氧化铝陶瓷的烧结温度,提高烧结体的密度;等静压成型与模压成型试样的烧结密度相近,但前者的强度则比后者提高了60~80%;其它工艺条件对氧化铝陶瓷的结构及性能的影响不显著。     

DETERMINATION OF ATMOSPHERIC NITRO-POLYCYCLIC AROMATIC HYDROCARBONS AND THEIR PRECURSORS AT A HEAVY TRAFFIC ROADSIDE AND AT A RESIDENTIAL AREA IN OSAKA,JAPAN

Concentrations of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) and polycyclic aromatic hydrocarbons (PAHs) in airborne particles collected at two sites, a residential area and a roadside with high traffic density in Osaka, Japan, in summer and winter were quantified. Five nitro-PAHs, 1-nitropyrene (1-NP), 2-nitropyrene (2-NP), 2-nitrofluoranthene (2-NF), 3-nitrofluoranthene (3-NF), and 2-nitrotriphenylene (2-NTP) and five PAHs, pyrene (Py), fluoranthene (Fl), triphenylene (Tp), benzo[k]fluoranthene (B(k)F), and benzo[a]pyrene (B(a)P) were determined by high-performance liquid chromatography with chemiluminescence and fluorescence detection. At both sites, the mean concentration of 1-NP was higher in winter than in summer. On the contrary, the mean concentrations of 2-NF and 2-NP were higher in summer than in winter. Observed 2-NF/2-NP ratio in the range from 0.40 to 16 suggests that 2-NF and 2-NP were dominantly formed via OH radical initiated reaction in the atmosphere. Nitro-PAH and PAH concentrations were generally higher at a roadside area than at a residential area due to extremely higher concentration of particles at a roadside area. 1-NP/B(k)F ratio was higher at a roadside area than at a residential area, while 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were higher at a residential area than at a roadside area. The diurnal changes of 2-NF/B(k)F, 2-NP/B(k)F, and 2-NTP/B(k)F ratios were slightly different from those of 1-NP/B(k)F and 3-NF/B(k)F ratios. Thus, the differences in the patterns of nitro-PAHs/B(k)F ratios may be due to the disparity in formation pathways of each nitro-PAH.     

煤裂解和气化过程中焦油裂解的实验研究

在热解和气化过程中产生的焦油 ,影响系统的正常运行 ,分析了煤热解和气化过程中温度、停留时间、压力、气氛、粒径以及床料等对焦油热裂解和催化裂解产生的影响 .同时 ,对比了不同催化剂的催化能力 .采用石灰石为催化剂 ,在 1 MW热态实验台上进行了实验 ,研究焦油和煤气成分在循环煤气作气化剂时不同钙硫比工况下的变化情况 .结果表明 ,石灰石的加入降低了焦油产率 ,提高了煤气产率 ,改善了煤气质量 .     

DESORPTION ISOTHERMS OF APPLES AT SEVERAL TEMPERATURES

ABSTRACT

The desorption isotherms of apples of the Granny Smith variety, treated with 0.5% citric acid aqueous solution, were determined using the gravimetric static method. Experiments at three temperature levels: 20^°C, 40^°C and 60^°C and ten water activity levels from 0.112 to 0.856 were carried out. Along with five well known models - modified Chung-Pfost, modified Halsey, modified Oswin, modified Henderson and GAB (Guggenheim-Anderson-de Boer), a new fraction-linear model has been applied to fit the data and to calculate the isosteric heat of desorption determination.     

乙苯脱氢氧化制苯乙烯工艺中氢氧化反应器的开发

通过对乙苯脱氢氧化新工艺的过程分析，对氢氧化反应器的开发研究可进行必要的简化。对影响氧化反应结果的工艺及工程因素进行了实验考察，为氢氧化反应器的开发提供了依据和必要的数据。     

常压渣油催化裂化装置技术改造

采用新工艺、新设备对盐城市石油液化气厂５０ｋｔ／ａ常压渣油催化裂化装置进行技术改造,使装置处理能力提高到９０ｋｔ／ａ,取得了显著的经济和社会效益。