热锻过程中工模具温度场的有限元迭代解法

热锻过程中温度对成形过程的影响是显著的，了解热锻过程中工模具内温度场的分布对控制锻件的成形是有益的，工模具的热传导问题，由于热性能参数随温度变化和／或存在辐射换热，所以是一个非线笥瞬态问题，本文提出求解此问题的有限迭代解法，用此算法分析了热锻过程中的对模阶段的工模具温度变化，并给出了它们的温度场分布。     

吡咯烷生物碱新手性合成子的合成

报道了从（Ｓ）－苹果酸出发，立体选择性地合成五个新吡咯烷生物碱手性合成子．观察到Ｃ＿４－位上保护的羟基对Ｃ＿５－位手性中心的形成具有良好的不对称诱导作用．     

指数函数e^x的高阶有理分式近似

构造了指数函数ｅｘ的任意高阶有理分式近似类，给出了它Ａ－可接受的准则及其误差项的精确表达式，为构造常微数值方法提供了新的有效途径．．     

阻抗圆图法测量双极型晶体管EM_2模型参数r′_b,r′_e及τ_F

在双极型晶体管EM_2模型参数中引入的基极电阻r'_b是重要的也是较难测量的参数之一。本文报导了用阻抗圆图法测量晶体管在小讯号正向运用时的基极电阻r'_b,发射极电阻r'_e以及r'_b和r'_e随工作点的变化。并用圆图法求得正向渡越时间τ_F。     

球形汞膜电极恒电流溶出分析法理论及其验证

推导出球形汞膜电极上的恒电流溶出分析法的理论方程式。实验结果与理论基本一致,从而建立了球形汞膜电极的恒电流溶出分析法的基础理论。     

美国Diamond V Mills公司饲料添加剂菌体生长动力学

在不同温度、不同pH值,不同培养基组成以及通风的条件下,研究了美国DiamondV Mills公司饲料添加剂菌体生长动力学,求出了各种条件下的动力学参数,找出了菌体生长的最适温度(29℃)和最适pH值(pH5.3),为实现最优控制奠定了基础。     

CDM项目的经济性分析——太阳能发电在中国商业楼宇中的导入

运用数学模型，对在中国的商业楼字中以清洁发展机制（CDM）的方式导入太阳能发电进行了分析．该模型可以在满足电力供求平衡的前提下确定最佳的导入容量．运用该模型对投资费用和电价进行了参数分析．分析结果表明，在一定的条件下，即使没有CDM的参与，在中国的商业楼字中导入太阳能发电也是可行的．但是，通过CDM项目，可以极大地减小太阳能发电的导入壁垒，CO2的减排收益也可弥补太阳能发电的投资费用，使项目双方都获得相应的利益．     

Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma

Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using (NH₄)₂SO₄, KNO₃ and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L (NH₄)₂SO₄, 0.49 g/L KNO₃ and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively.     

Linking leach chemistry and microbiology of low-grade copper ore bioleaching at different temperatures

The effects of temperature on chalcocite/pyrite oxidation and the microbial population in the bioleaching columns of a low-grade chalcocite ore were investigated in this study. Raffinate from the industrial bioleaching heap was used as an irrigation solution for columns operated at 20, 30, 45, and 60℃. The dissolution of copper and iron were investigated during the bioleaching processes, and the microbial community was revealed by using a high-throughput sequencing method. The genera of Ferroplasma, Acidithiobacillus, Leptospirillum, Acidiplasma, and Sulfobacillus dominated the microbial community, and the column at a higher temperature favored the growth of moderate thermophiles. Even though microbial abundance and activity were highest at 30℃, the column at a higher temperature achieved a much higher Cu leaching efficiency and recovery, which suggested that the promotion of chemical oxidation by elevated temperature dominated the dissolution of Cu. The highest pyrite oxidation percentage was detected at 45℃. Higher temperature resulted in precipitation of jarosite in columns, especially at 60℃. The results gave implications to the optimization of heap bioleaching of secondary copper sulfide in both enhanced chalcocite leaching and acid/iron balance, from the perspective of leaching temperature and affected microbial community and activity.