Numerical studies of the annular waveguide laser electromagnetic field with allmetallic materials

基于麦克斯韦方程组,导出金属环状波导内电磁场的数学模型,在此基础上分析了环状波导内电磁场的模式特征,并以TE模式为例详细分析了其分布特性,近、远场特性。The mathematical model of electromagnetic field in the annular waveguide with all-metallic materials is presented based on Maxwell equations.Mode properties of electromagnetic field in the annular waveguide is analyzed based on this model,and the properties of the electromagnetic field distribution,near-and far-field of TE modes are analyzed in detail.福建省自然科学基金资助(项目编号:A0210007

超前消费效用最大的一个必要条件

传统的消费效用分析,是根据市场价格信息,在现有收入水平前提下,讨论如何选择商品,以达到效用最大。随着社会改革,人们消费观念的变化,贷款超前消费已成时尚。文章对这种贷款超前消费进行讨论,得出达到效用最大的必要条件

Comparison of Two Axisymmetrical Finite Element Models for Pulsed Eddy Current Simulation

脉冲涡流检测技术是近年来发展迅速的一种新型涡流检测技术。由于其激励信号频谱宽广,不同频率分量的涡流能够渗透到不同深度,使其检测信号包含更丰富的深度方向的缺陷信息,在航空维修等工业领域有着重要的意义。对脉冲涡流检测的仿真可以指导脉冲涡流检测技术的研究。本文利用二维轴对称模型,介绍了脉冲涡流有限元仿真的两种方法—傅里叶变换法和时间步进法,并详细比较了这两种方法的优缺点。Pulsed eddy current testing(PECT) is one of the new techniques of eddy current testing.Thanks to the large amount of frequency components,the response signal contains rich information about defect and material properties along the depth direction.Therefore the PECT plays a significant role in the maintenance of aircrafts,nuclear power plants and so on.This paper introduces the two main methods used in the finite element modeling of PECT.Comparison of the methods is given.航空科学基金项目资助(批准号:2009ZD68004

壁面微通道冷却对旋流燃烧室性能影响实验

为了探索微通道高效换热技术在低污染燃烧室壁面冷却中的应用,实验研究了壁面微通道冷却对模型旋流燃烧室性能的影响。结果表明:微通道结构对燃烧室热壁面具有显著的冷却效果,在雷诺数小于350时,雷诺数增加对壁面冷却有明显提升作用,在雷诺数大于350后,雷诺数的增大对冷却效果提高的促进作用减小;雷诺数增大对相同进气工况下CH*化学发光信号表征的火焰时均结构几乎不产生影响,但在个别工况下会使火焰产生黄色火星,甚至间歇地产生黄色火焰,带来不完全的燃烧;雷诺数增大会增强微通道对流换热程度,加大壁面传热速率,加剧火焰和微通道换热间的相互作用,使火焰表面发生较大的热量损失,最终造成CO排放量增加,NOx排放量降低,并使整体燃烧效率下降。国家自然科学基金(51406171);;福建省自然科学基金(2016J06011);;中央高校基本科研业务费(20720180058);;航空科学基金(20152868006

Studies on the Interactions between Bioactive Peroxovanadium Complexes Bearing Organic Ligands and Histidine

在合成和表征了 4种具有较强生物活性双过氧钒配合物K3 [VO(O2 ) 2 (ox) ]·2H2 O ,Na[VO(O2 ) 2 (bipy) ]·5H2 O ,K[VO(O2 ) 2 (phen) ]·3H2 O和K2 [VO(O2 ) 2 (pic) ]·2H2 O [分别缩写为pV(ox) ,pV(bipy) ,pV(phen)和pV(pic) ,其中ox为草酸根 ,bipy为 2 ,2′ 联吡啶 ,phen为邻菲咯啉 ,pic为 2 羧酸吡啶负离子 ]的基础上 ,利用多种NMR技术和电喷雾质谱 (ESI MS)研究了这 4种含有机配体双过氧钒配合物与组氨酸 (His)在溶液中的相互作用以及反应物浓度、时间、pH等对相互作用体系的影响 .51VNMR跟踪监测的结果表明 :双过氧钒配合物pV(ox)和pV(pic)与His在中性水溶液中存在强配位相互作用 ,而pV(bipy)和pV(phen)与His在中性水溶液中无明显作用 .我们还利用谱学方法确定了pV(ox)和His相互作用后所生成产物是pV(ox)分别与His咪唑基上的 3 N和 1 N配位的一对异构体. 　In order to explore the structure2activity relationship and molecular mechanism of the specific recognition between peroxovanadium (pV) complexes bearing organic ligands and the target enzymes of tyrosine phosphatase , several NMR techniques and ESI2MS were used to study the interactions of four pV complexes {pV(ox) , pV ( bipy) , pV (phen) and pV (pic) , where pV = [VO (O2 ) 2L ] n - , in which L = oxalic acid dianion (ox) , bipyridine (bipy) , 1 ,102phenanthroline (phen) , and pyridine222carboxylic acid (pic) } towards histidine. Strong coordination interactions between imidazole of histidine and vanadium of pV(ox) or pV(pic) were observed in neutral solution , while there are not obvious interactions between histidine and pV(bipy) or pV(phen) . All 13C and 1H NMR signals of 1∶1 stoichiometric mixture of pV(ox) and histidine were assigned. Spectroscopic studies demonstrated that new complexes in the mixture of pV(ox) and histidine are a pair of isomers in which the vanadium in pV(ox) binding to the 32N and 12N of the imidazole ring. Moreover , the results of effective factors on the interaction system indicated that the new isomers were stable under the condition of physiological pH and the structure2activity relationship of these pV complexes may be relevant to their specific recognition towards histidine residues in tyrosine phosphatase.国家自然科学基金 (Nos.2 0 172 0 42 ,2 9832 0 2 0 )资助项

Non-cyanide copper plating on steel substrate in alkaline citrate bath

以柠檬酸盐为配位剂,结合胺化合物为辅助配位剂,研究了钢铁基体上无氰镀铜工艺。探索了搅拌方式、温度、PH、铜离子质量浓度和添加剂质量浓度对镀层质量的影响以及该工艺抗fE2+、fE3+、zn2+、Sn4+等杂质的能力。试验结果表明,电流效率在90%左右,并随电流密度、温度和PH的提高而增大;镀液深镀能力达100%。通过极化曲线,解释了配位剂和添加剂的作用。The process of alkaline non-cyanide copper electroplating on steel substrate was studied using citrate as complexing agent and amine compound as assistant complexing agent.The effects of agitation mode, temperature, pH, copper ions concentration and additive content on deposit quality were discussed.The ability of bath to resist impurities such as Fe2+, Fe3+, Zn2+ and Sn4+ was revealed.The test results showed that the current efficiency is about 90% and is increased with increasing current density, temperature and pH.The throwing power of the bath is 100%.The action mechanisms of the complexing agents and additive were explained based on polarization curves.广东省教育部产学研结合专项资金项目(2006D90404019);福建省科技计划重点项目(2008H0086);国家自然科学基金项目(20873114

Mapping QTLs for Rice Grain Shape with QTL×Environment Interactions and Epistatic Effects Analysis

利用广陆矮4号x佳辐占水稻重组自交系构建了SSr标记的遗传图谱.联合2007年和2008年获得的两组稻米粒长(gl)、粒宽(gW)、长宽比(l/W)数据应用混合线性模型方法进行QTl定位,并作加性效应、加性x加性上位互作效应以及加性QTl、上位性QTl与环境的互作效应分析.结果显示;(1)在加性效应分析中两个群体共检测到4个控制粒长的QTl,4个控制粒宽的QTl,5个控制长宽比的QTl,贡献率分别为13.81%、15.36%和16.29%.(2)在上位互作效应分析中两个群体共检测到2对控制粒长的互作QTl,1对控制粒宽的互作QTl,3对控制长宽比的互作QTl,贡献率分别为5.77%、2.59%和7.42%.(3)环境互作检测中,发现共有13个加性QTl和4对QTl的加性x加性上位性与环境产生了互作效应.结果表明,上位性效应和加性效应都影响稻米粒形遗传,QE互作效应也对粒形有着显著的影响.In this study,a recombinant inbred line (RIL) population derived from the indica-indica rice cross ‘Guangluai 4’בJiafuzhan’ was used in mapping of Quantitative trait loci (QTLs).Based on mixed linear model QTLmapper1.6,mapping was carried out for grain shape such as grain length (GL),grain width (GW) and length-width ratio (L/W) in rice in 2007 and 2008.QTLs were determined at the one-locus and two-locus levels,and QTL-by-environment (QE) interactions were analyzed.Four,four and five QTLs were detected to have significant additive effects for GL,GW and L/W,and the contribution rate were 13.81%,15.36% and 16.29%,respectively.Two,one and three pairs of epistatic QTLs with significant additive-by-additive (AA) interaction effects (epistatic effects) were identified for the three traits,and the contribution rate were 5.77%,2.59% and 7.42%,respectively.Significant QE interactions were found for thirteen QTLs with additive effects and four pairs of epistatic QTLs.The results indicated that the epistatic and additive effects played an important role on the inheritance of grain shape,and the environmental factor had significant effects on the three traits.国家863计划项目(2007AA10Z179);福建省科技计划重点项目(2008N0122);厦门大学科技创新项目(XDKJCX20063004

基于光纤环形镜的掺磷光纤拉曼激光器

报道了一种由宽带光纤环形镜(FLM)作为腔反射元件的法布里-珀罗腔掺磷光纤拉曼激光器(RFL),并与使用窄带光纤布拉格光栅(FBG)作为高反镜的腔结构进行了对比研究。研究结果表明,使用宽带FLM替代FBG仍可实现掺磷RFL的窄带激光输出,并且可有效避免拉曼激光从高反镜端的泄漏。在相同的输出镜反射率情况下,使用FLM作为高反镜比使用FBG作为高反镜具有更低的振荡阈值和更高的光-光转换效率。当抽运功率为9.45W时,拉曼激光(1.24μm)输出功率为4.31W,激光器斜效率和光-光转换效率分别为57.9%和45.6%

亚硫酸氢钠在马铃薯切片过程中防褐变作用机理的研究

多酚氧化酶(PPO)是蔬果酶促褐变的关键酶,抑制该酶活性是防止蔬果褐变的有效措施.在实验中发现NaHSO3对马铃薯PPO具有显著的抑制作用及在马铃薯切片护色中具有防褐变功能.实验结果表明:马铃薯PPO催化L-多巴形成的褐变物质在475 nm波长处有特征性的吸收峰,并且该吸收峰随着NaHSO3浓度的增加明显降低.NaHSO3的抑制作用表现为不可逆效应,既可以延长酶促反应的迟滞时间,也降低了稳态的酶活力.当NaHSO3浓度增至0.12 mmol/L时,酶促反应的迟滞时间从0延长至56 s,稳态的酶活力下降了35.5%.在马铃薯切片保鲜实验中,对照组在第3天褐变指数达到2,第6天已经完全褐变,而50 mmol/L NaHSO3处理的实验组在第6天褐变指数仅为0.6,有效遏制了马铃薯切片的酶促褐变,实验显示,NaHSO3通过抑制马铃薯PPO活力实现防褐变的效应