轴类零件形位误差的数据处理

在万能工具显微镜上用光学分度头对典型轴类零件形位误差如圆度、轴线同轴度等的测量误差进行了探讨 ,并介绍了最小二乘法以及豪斯荷尔德分解法在进行数据处理时的应用及精度分析。     

基于PSO的高线性四次分谐波下变频混频器设计

在介绍分谐波混频器的原理基础上,提出一种以粒子群算法作为全局搜索算法,以性能参数作为评估的混频器电路优化方法,利用ADS软件设计出一种本振为23 GHz,射频为92～94 GHz下的变频器电路,应用CST软件优化脊波导微带过渡结构,实现了W波段的信号到混频器射频端的引导。优化算法可以快速得到优化结果,仿真结果表明该下变频器的变频差损小于15dB,1dB压缩点较高,具有良好的线性度。     

气淬钢渣烧结基础性能的试验研究

研究了气淬钢渣和几种烧结用铁矿粉的烧结基础性能,结果表明：气淬钢渣具有适宜的同化性能、较好的流动性能和较高的粘结相强度;气淬钢渣含铁品位较低、熔剂含量较高,可以作为烧结熔剂.     

Genome-Wide Comparative Analysis of the R2R3-MYB Gene Family in Five Solanaceae Species and Identification of Members Regulating Carotenoid Biosynthesis in Wolfberry

The R2R3-MYB is a large gene family involved in various plant functions, including carotenoid biosynthesis. However, this gene family lacks a comprehensive analysis in wolfberry (Lycium barbarum L.) and other Solanaceae species. The recent sequencing of the wolfberry genome provides an opportunity for investigating the organization and evolutionary characteristics of R2R3-MYB genes in wolfberry and other Solanaceae species. A total of 610 R2R3-MYB genes were identified in five Solanaceae species, including 137 in wolfberry. The LbaR2R3-MYB genes were grouped into 31 subgroups based on phylogenetic analysis, conserved gene structures, and motif composition. Five groups only of Solanaceae R2R3-MYB genes were functionally divergent during evolution. Dispersed and whole duplication events are critical for expanding the R2R3-MYB gene family. There were 287 orthologous gene pairs between wolfberry and the other four selected Solanaceae species. RNA-seq analysis identified the expression level of LbaR2R3-MYB differential gene expression (DEGs) and carotenoid biosynthesis genes (CBGs) in fruit development stages. The highly expressed LbaR2R3-MYB genes are co-expressed with CBGs during fruit development. A quantitative Real-Time (qRT)-PCR verified seven selected candidate genes. Thus, Lba11g0183 and Lba02g01219 are candidate genes regulating carotenoid biosynthesis in wolfberry. This study elucidates the evolution and function of R2R3-MYB genes in wolfberry and the four Solanaceae species.     

Comparison of absorption efficiency of three hydrogen sulfide absorbents and optimization of absorption conditions of potassium iodate system

Hydrogen sulfide is corrosive and toxic, and the use of absorbents to absorb hydrogen sulfide gas is an important desulfurization treatment. The absorption efficiency of different absorbent is different. The absorption efficiency of three different hydrogen sulfide absorbent, namely ferric chloride system, potassium iodate system and alkaline potassium ferricyanide system, was firstly compared. Based on this, the absorption parameters of potassium iodate system were optimized, and the effects of concentration, temperature, pH, gas flow rate and time on the hydrogen sulfide gas absorption efficiency were discussed. The optimum absorption conditions were obtained by orthogonal test: temperature 55℃, pH 6.01, H₂S flow rate 0.3 L·min^-1, absorption time 1 min, the third-order absorption efficiency of 8%(mass) potassium iodate is 51.56%. The results of this study provide a theoretical reference for the absorption of hydrogen sulfide and support for the study of indirect electrolysis process.     

微生物发酵法综合利用啤酒生产废弃物研究新成果

采用一种或多种微生物发酵,将啤酒废弃物转化成高附加值的新型产品,用于生产营养饲料、调味品、酶制剂、新型食品和燃料等,具有环保、节能、安全、投入少、效益高等特点,有非常广阔的应用前景.     

共混改性聚酯纤维染色性能

为改善聚酯纤维的染色性能,在共混纺丝中加入改性添加剂.探讨了在不同工艺条件下,分散染料改性聚酯纤维的染色性能.试验结果表明,改性聚酯纤维在染料浓度为1.5%owf,染色温度98℃,染色时间60min,pH值为4.5的条件下,即可达到普通聚酯纤维在高温高压下染色效果.     

酶法制备低甲氧基果胶的工艺优化研究

以酸橙皮渣为原料,在酸法提取果胶的基础上,向果胶提取液中加入外源性果胶酯酶,制备低甲氧基果胶.通过单因素试验和Box-Behnken设计以及响应面分析确定酶法制备低甲氧基果胶的最佳工艺参数为加入经1 000倍稀释的果胶酯酶5.39 mL、反应50 min、42.71 ℃、pH 4.61,在此条件下果胶酯化度由67.83%降低至42.55%.     

白酒中己酸乙酯测定的不确定度评估

参照国家标准GB/T10781-89,采用气相色谱法测定白酒中己酸乙酯含量。通过对己酸乙酯的测定进行测量不确定度的评估实验,介绍了一种内标定量法的测量不确定度评估方法,表达出了合成标准不确定度和扩展不确定度,为白酒质量控制提供有效、可靠、可溯源的测量数据。