Light Intensity and Photoperiod Affect Growth and Nutritional Quality of Brassica Microgreens

We explored the effects of different light intensities and photoperiods on the growth, nutritional quality and antioxidant properties of two Brassicaceae microgreens (cabbage Brassica oleracea L. and Chinese kale Brassica alboglabra Bailey). There were two experiments: (1) four photosynthetic photon flux densities (PPFD) of 30, 50, 70 or 90 μmoL·m⁻²·s⁻¹ with red:blue:green = 1:1:1 light-emitting diodes (LEDs); (2) five photoperiods of 12, 14, 16, 18 or 20 h·d⁻¹. With the increase of light intensity, the hypocotyl length of cabbage and Chinese kale microgreens shortened. PPFD of 90 μmol·m⁻²·s⁻¹ was beneficial to improve the nutritional quality of cabbage microgreens, which had higher contents of chlorophyll, carotenoids, soluble sugar, soluble protein and vitamin C, as well as increased antioxidant capacity. The optimal PPFD for Chinese kale microgreens was 70 μmol·m⁻²·s⁻¹. Increasing light intensity could increase the antioxidant capacity of cabbage and Chinese kale microgreens, while not significantly affecting glucosinolate (GS) content. The dry and fresh weight of cabbage and Chinese kale microgreens were maximized with a 14-h·d⁻¹ photoperiod. The chlorophyll, carotenoid and soluble protein content in cabbage and Chinese kale microgreens were highest for a 16-h·d⁻¹ photoperiod. The lowest total GS content was found in cabbage microgreens under a 12-h·d⁻¹ photoperiod and in Chinese kale microgreens under 16-h·d⁻¹ photoperiod. In conclusion, the photoperiod of 14~16 h·d⁻¹, and 90 μmol·m⁻²·s⁻¹ and 70 μmol·m⁻²·s⁻¹ PPFD for cabbage and Chinese kale microgreens, respectively, were optimal for cultivation.     

Suspension quality and power consumption of the complex multiphase flow field in a draft-tube stirred reactor

Experiment and simulation were used to study the flow fields of a liquid-solid-solid three-phase system in a draft-tube stirred reactor with a six-flat-bladed t...     

Cs4SrI6:Eu晶体的生长和闪烁性能研究

采用垂直布里奇曼法成功生长了一种Cs4SrI6:3;Eu闪烁晶体.毛坯晶体尺寸最大为φ25×70 mm3,是目前最大的Cs4SrI6:Eu单晶.XRD结果表明,晶体具有K4-CdCl6晶体结构,属于R-3C空间群,通过紫外-可见荧光光谱和X射线激发发射光谱,研究了晶体的荧光性能.研究了在137Cs662 keV辐射下Cs4SrI6:Eu单晶的闪烁性能和衰减时间,表明该晶体具有较高的光输出和优良的能量分辨率,衰减时间约为1.86μs.通过分析Eu2+在晶体中不同部位的浓度,计算出Cs4SrI6:Eu晶体中Eu2+的分凝系数约为1.136,结果表明Cs4SrI6:Eu晶体在辐射探测中具有潜在的应用前景.     

Modelling and dynamic analysis of spline-connected multi-span rotor system

Meccanica - Self-excited oscillation induced by the internal frictions of spline joints is a major cause of rotor system instability. In this study, the dynamic equations of spline-connected...     

用同步辐射X-荧光定量测定电泳分离后蛋白条带内的微量元素

建立了同步辐射X荧-光(SRXRF)定量测定生物样品等电聚焦(IEF)分离后蛋白条带内的微量元素Fe、Cu和Zn的方法。用薄层聚丙烯酰胺凝胶分离人血红蛋白后,用SRXRF测定了各亚型条带内的金属含量,用加一定量金属的含蛋白聚丙烯酰胺凝胶做SRXRF定量测定蛋白条带内微量元素Fe、Cu和Zn的定量标准,校准曲线线性回归系数r在0~8μg/g范围内均大于0.99;检出限分别为2.43、1.12和0.96μg/g;测定蛋白条带内Fe和Zn的回收率分别为90.4%和115.7%。该联用技术可用于生物样品中微量元素的化学形态分析,同时给出蛋白质的微量元素组成和等电点等信息。     

抗坏血酸和尿酸在胶束体系中的电化学行为及选择性测定的应用

以玻碳电极为工作电极,在PBS中用循环伏安法研究了抗坏血酸(AA)和尿酸(UA)在胶束体系中的电化学行为。在溴化十六烷基吡啶(CPB)胶束体系中,AA和UA的氧化峰电流增加,峰电位负移;在十二烷基苯磺酸钠(SDBS)胶束体系中,AA和UA的氧化峰电流减小,峰电位正移。在CPB中,AA和UA的氧化峰电位相差约270 mV,以此建立了AA和UA的同时测定方法。用微分脉冲伏安法测定AA和UA的氧化峰电流分别在1.0×10-6~1.0×10-2mol/L和5.0×10-7~1.0×10-3mol/L的范围内与各自的浓度范围呈良好的线性关系。在200倍AA共存时UA的检出限为5.0×10-6mol/L。此方法可应用于人体尿样中UA的测定,结果令人满意。     

量子点标记链霉亲和素及其生物活性检测

选用无机盐为前驱体,在水相中合成CdTe量子点,并用此量子点标记链霉亲和素,通过SephadexG-100层析分离纯化量子点标记的链霉亲和素,采用磁颗粒标记的链霉亲和素与量子点标记的链霉亲和素竞争结合辣根过氧化酶标记的生物素,即酶联免疫竞争抑制分析法检测链霉亲和素标记量子点后的生物活性,计算约70.3%的链霉亲和素标记到量子点上,且具有生物活性。每毫克量子点大约可偶联0.14 mg的链霉亲和素。采用荧光光谱研究量子点标记前后的荧光变化,标记后量子点的最大发射波长蓝移了8 nm,而发射光谱的半峰宽基本不变,说明量子点与链霉亲和素结合后粒子没有团聚,分散性好。     

meso-四(4-甲氧基-3磺酸基苯)卟啉与环糊精超分子体系的研究

采用极谱法、紫外可见光谱法及荧光光谱法研究了水溶性卟啉T(4-Mop)PS4与α-CD、-βCD、γ-CD、Hp-β-CD及SBE--βCD 5种环糊精的相互作用,结果表明T(4-Mop)PS4分别与这5种环糊精形成了T(4-Mop)PS4-CD s超分子体系。此外,本研究还采用极谱法、紫外可见光谱法及荧光光谱法测定了T(4-Mop)PS4-CD s超分子体系的包结常数和包结比,比较了T(4-Mop)PS4与5种环糊精的包结能力,并由此推测了包结机理,为T(4-Mop)PS4卟啉、环糊精的进一步应用提供了理论信息。     

漂移管工作温度对离子迁移率谱的影响

离子迁移率、反应物离子的种类和产量与漂移管工作温度有很大的关系。本研究在不同温度下进行了离子迁移率实验,结果表明,离子迁移率随温度的升高而增大,而提高工作温度可以减少水分子对产物离子的影响,有利于改善系统检测的分辨率;选择合适漂移管工作温度,能有效地增加反应物离子的产量,从而提高系统检测的灵敏度和选择性。     

A Novel 3D Na(I) Coordination Polymer Constructed by 3,5-Bis(4'-Carboxy-Phenyl)-1,2,4-Triazole: Synthesis,Crystal Structure,and Photocatalytic Property

Crystallography Reports - A novel 3D metal coordination polymer, {[Na4(µ2-H2O)(DMF)2(BCT)2]?DMF}n (I) (DMF = N,N-dimethylformamide, H2BCT =...