焦炉煤气还原硫酸钠制硫化钠的研究

在固定床反应器内600～700℃的温度范围研究了焦炉煤气还原硫酸钠制硫化钠的反应速率和影响因素，在固定床内随着温度的提高，反应速率增大，并能达到较高的转化率．温度低于680℃，表现为催化反应，Fe2O3是活性较高的催化剂；在700℃以上表现为非催化反应。焦炉煤气中氢气的浓度和硫酸钠的颗粒直径对反应有一定的影响．在反应器内只要控制合适条件，往硫酸钠中加入脂肪酸的钠盐可以避免烧结，并能获得更高的反应速率。     

Comparative Potency Method for Cancer Risk Assessment: Application to Diesel Particulate Emissions1

An estimation of the human lung cancer “unit risk” from diesel engine particulate emissions has been made using a comparative potency approach. This approach involves evaluating the tumorigenic and mutagenic potencies of the particulates from four diesel and one gasoline engine in relation to other combustion and pyrolysis products (coke oven, roofing tar, and cigarette smoke) that cause lung cancer in humans. The unit cancer risk is predicated on the linear nonthreshold extrapolation model and is the individual lifetime excess lung cancer risk from continuous exposure to 1 μg carcinogen per m³ inhaled air. The human lung cancer unit risks obtained from the epidemiologic data for coke oven workers, roofing tar applicators, and cigarette smokers were, respectively, 9.3 × 10^?4, 3.6 × 10^?4, and 2.2 × 10^?6 per μg particulate organics per m³ air. The comparative potencies of these three materials and the diesel and gasoline engine exhaust particulates (as organic extracts) were evaluated by in vivo tumorigenicity bioassays involving skin initiation and skin carcinogenicity in SENCAR mice and by the in vitro bioassays that proved suitable for this analysis: Ames Salmonella microsome bioassay, L5178Y mouse lymphoma cell mutagenesis bioassay, and sister chromatid exchange bioassay in Chinese hamster ovary cells. The relative potencies of the coke oven, roofing tar, and cigarette smoke emissions, as determined by the mouse skin initiation assay, were within a factor of 2 of those determined using the epidemiologic data. The relative potencies, from the in vitro bioassays as compared to the human data, were similar for coke oven and roofing tar, but for the cigarette smoke condensate the in vitro tests predicted a higher relative potency. The mouse skin initiation bioassay was used to determine the unit lung cancer risk for the most potent of the diesel emissions. Based on comparisons with coke oven, roofing tar, and cigarette smoke, the unit cancer risk averaged 4.4 × 10^?4. The unit lung cancer risks for the other, less potent motor-vehicle emissions were determined from their comparative potencies relative to the most potent diesel using three in vitro bioassays. There was a high correlation between the in vitro and in vivo bioassays in their responses to the engine exhaust particulate extracts. The unit lung cancer risk per μg particulates per m³ for the automotive diesel and gasoline exhaust particulates ranged from 0.20 × 10^?4 to 0.60 × 10^?4; that for the heavy-duty diesel engine was 0.02 × 10^?4. These unit risks provide the basis for a future assessment of human lung cancer risks when combined with human population exposure to automotive emissions.     

禅宗与庭园——对日本枯山水的研究

禅宗的基本义理在于“心”和“顿悟”:“心”为禅宗哲学的义理的基托,其实就是强调主观性体验,而“顿悟”就是主观性体验发生突变的主要手段。在对日本枯山水的分析中,着重研究了枯山水中存在的两种基本的意境美:凝固美和枯淡美。凝固美就是研究在日本的枯山水中所展现的沧桑之美,枯淡美就是研究在日本的枯山水中所展现的悲怆之美。在论述枯山水两种意境美时,把禅宗的义理作为论点贯穿于整个文章论证之中。     

热风干燥枸杞的试验研究

本文介绍了在自制试验台上,对我区产的枸杞进行热风烘干的试验研究,得出了其干燥特性典线,据此提出了烘干枸杞时热风的温度,风速及湿度合理选择的建议。     

基于ANSYS的中药浸膏微波真空干燥罐体的结构优化

针对中药浸膏微波真空干燥设备工作时出现的封板反复变形及旋转轴与封板连接处气体泄漏的问题,文章基于 ANSYS的手段和理论分析,设计了旋转轴支撑方式的封板以及旋转密封与平面密封相结合的密封方式,优化了中药浸 膏微波真空干燥罐体的结构。改进后的设备结构受力均匀,最大应力发生在封板近中央处,封板的变形及设备漏气的问 题得到了有效的控制。优化设计提高了设备的安全性及可靠性。     

玉米干燥过程中的应力裂纹研究进展

综述了玉米干燥应力裂纹产生的机理、干燥过程中引起裂纹产生和扩展的因素以及预测应力纹理论模型的研究进展,对今后在该领域的研究方向提出了建议。     

红外辐射与热风振动流化稻谷干燥实验研究

在双循环的红外辐射与热风联合振动流化床上,顺应稻谷结构特性,采用逐渐升温,且外循环升温内循环降温的方法对水稻进行干燥处理,每小时脱水率为3.8%,爆腰增加率为1.25%,优化了稻谷的传热传质与生理过程,具有重要的理论与工程意义。     

物料干燥特性的研究

本文通过对四种中药材的干燥性能试验，探讨了影响物料干燥过程的主要因素，给出了干燥过程的数学模型，为设计物料干燥装置和提高热能利用率提供了依据．     

新型喷雾干燥烟气脱硫性能实验研究

提出了一种新型喷雾干燥烟气脱硫工艺，实验研究了影响该工艺性能的主要运行因素，并进行了机理分析，研究结果为该工艺的推广设计提供参考依据。     

铁基无硫无铬型CO高温变换催化剂的研制——Ⅱ干燥方式对催化剂性能影响的研究

本文对以铁和硝酸为主要原料制备大型合成氨厂铁基无硫无铬型CO高温变换催化剂的干燥方式进行了研究，探讨了喷雾干燥机的进口温度，固液比等对物料含水量的影响，并对普通箱式干燥和喷雾干燥方式对催化剂性能的影响进行了研究。