Flower‐shaped ultra‐wideband fractal antenna

A flower‐shaped ultra‐wideband fractal antenna is presented. It comprises a fourth iterative flower‐shaped radiator, asymmetrical stub‐loaded feeding line, and coplanar quarter elliptical ground planes. A wide operating band of 12.12 GHz (4.58‐16.7 GHz) for S ₁₁ ≤ ? 10 dB is achieved along with an overall antenna footprint of 15.7 × 11.4 mm². In addition, other desirable characteristics, that is, omnidirectional radiation patterns, peak gain upto 5 dB, and fidelity factor more than 75% are achieved. A good agreement exists between the simulation and measured results. The obtained results illustrate that this antenna has wide operating range and compact dimensions than available structures.     

GC-MS用于花果香气成分研究进展

香气是衡量花果品质的重要感官指标,决定着花果制品的风味和加工特性。不同的花果具有特殊的香气成分,通常由挥发性有机化合物(volatile organic compounds,VOCs)组成,VOCs是一类分子量较小的次生代谢产物。VOCs可由气相色谱-质谱(gas chromatography-mass spectrometer,GC-MS)联用技术进行检测与分析。目前,国内外学者对不同种类花果的香气成分研究有很多报道,但对其香气成分的检测方法及成分对比未进行归纳总结。该文综述目前国内外花果香气成分的检测方法、香气成分的主要组成和功能特性,以期对花果香气成分研究的未来发展趋势进行预测,为花果香气成分的研究提供参考。     

不同大小沙田柚品质差异及其分子机理探究

本文研究不同大小沙田柚果实之间品质的差异,并探讨品质差异产生的机制。将沙田柚依据果实大小进行分类,测量可溶性固形物含量、种子数目、果皮厚度和果形指数,同时对不同大小的沙田柚进行转录组测序。结果表明,大小适中的沙田柚,即950~1000 g的沙田柚可溶性固形物含量高,沙田柚果皮厚度和种子数目随着沙田柚重量的增加而增大,果形指数不受沙田柚果实大小的影响。转录组测序后,比对KEGG数据库,显著富集了20条通路,其中10条涉及到风味品质相关的物质代谢,2条与植物激素相关。沙田柚果实大小和可溶性固形物含量、果皮厚度、种子数目相关,和果形指数无关,植物激素信号转导和风味物质代谢相关基因的差异表达可能是产生品质差异的原因。     

体外模拟消化过程中核桃花提取物抗氧化活性的变化

为研究体外模拟消化过程中核桃花提取物抗氧化活性的变化，对核桃花提取物依次进行模拟口腔消化、胃消化和小肠消化，分别采用福林酚法和亚硝酸钠-硝酸铝法测定核桃花提取物在不同消化阶段的总酚和总黄酮含量，以DPPH自由基、ABTS自由基清除能力和铁还原能力为指标，考察核桃花提取物抗氧化活性的变化情况。结果表明：在口腔消化、胃消化和小肠消化过程中，核桃花提取物的总酚、总黄酮含量以及抗氧化活性均呈下降趋势。其中总酚含量从消化前的3.30 mg/mL降至消化后的0.62 mg/mL，降低了81.21%；总黄酮含量从2.88 mg/mL降至0.02 mg/mL，降低了99.31%；核桃花提取物清除DPPH自由基的IC50值从211.02 μg/mL上升到424.45 μg/mL，清除ABTS自由基的IC50值从220.63 μg/mL上升至421.82 μg/mL，铁还原能力从106.13 μg/mL下降为40.47 μg/mL。在模拟胃消化和小肠消化阶段，酸碱环境和消化酶的作用破坏了核桃花提取物中的抗氧化成分，使其抗氧化活性发生了显著下降。     

Extraction optimization and adsorption isotherm kinetics of polyphenols from blossoms of Citrus aurantium L. var. amara Engl

ABSTRACT

Crude extracts were extracted from blossoms of Citrus aurantium L. var. amara Engl. with 50% ethanol (CAVAP-E), 50% methanol (CAVAP-M), and hot water (CAVAP-W). CAVAP-W had the highest polyphenol yield of 3.7%. The optimum values of liquid/solid ratio, ultrasonic time, and ultrasonic power were 34.06 mL/g, 1 h, and 81.04 W, respectively. The adsorption characteristics of polyphenols were investigated using different macroporous resins. AB-8 and HP-20 resins offered higher adsorption and desorption capacities. Langmuir equation was more suitable to predict the adsorption of polyphenols. The pseudo second-order model was satisfactory to describe the kinetic data of polyphenols onto AB-8 and HP-20.     

不同加工方法下丹参花茶的质量评价

目的:研究丹参非传统药用部位花的制茶工艺,以及不同加工条件下丹参花茶的主要化学成分分析和感官评价。方法:于盛花期采摘紫花丹参花蕾和开放初花,采用正交试验设计不同制茶工艺,采用紫外分光光度计测量制得花茶中叶绿素、类胡萝卜素、可溶性糖、总多酚、氨基酸以及总黄酮含量,进一步采用HPLC法检测丹参花茶中迷迭香酸、丹酚酸B、丹参素的含量,并进行了相应的方法学考察。结果:丹参花茶中含有较高的总多酚,具体成分以迷迭香酸为主,含有少量的游离氨基酸、黄酮、多糖以及微量的叶绿素和类胡萝卜素。结论:采摘丹参花蕾利用微波杀青、微波干燥,可以保留较多活性成分,同时具有较好的外观和口感。     

Designing a closed-loop supply chain network for citrus fruits crates considering environmental and economic issues

Most cities, notably major and agricultural ones, are faced with environmental and waste problems. Distribution and collection of agricultural crops can be challenging duties as world demand and production are substantially increased. Accordingly, resource depletion, environmental concern, and the importance of the circular economy have convinced this research group to focus on a Closed-Loop Supply Chain (CLSC) network design. In this study, a new mixed linear mathematical model for a CLSC was developed which minimizes the CLSC’s total costs and which tackles and controls air pollution. Contrary to previous works about supply chain network design, we firstly consider citrus fruits’ crates in our model. To solve the model, two leading algorithms, Genetic Algorithm and Simulated Annealing, are employed and a third recently successful method, Keshtel Algorithm, is utilized. Further, two hybridization algorithms stemmed from mentioned ones are applied. Finally, the results are assessed by different criteria and compared, and then the two best algorithms are chosen in this case. Consequently, in order to achieve the most effective result, a real case study of crates was conducted. The results obviously presented applicability and efficiency of the proposed model. Thus, the most suitable network for CLSC of citrus fruits’ crates was designed in which the costs and emissions were reduced.     

两种发酵方式柑橘果醋品质特性的比较

以柑橘为原料，在单因素试验的基础上通过正交试验对柑橘果醋一次发酵法发酵条件进行优化，并对一次发酵法与二次发酵法制备的柑橘果醋的品质特性进行比较。结果表明，柑橘果醋一次发酵法最优发酵条件为酒精度6.0%vol、柑橘果汁含量为50%、发酵温度34 ℃，在此优化条件下，柑橘果醋中总酸含量为6.0%，酒精转化率为96.31%，分别比优化前提高了0.27%、5.24%。一次发酵法和二次发酵法制备的柑橘果醋中最高总酸含量无显著差异（P＞0.05），但一次发酵法的启动时间比二次发酵法延迟48 h，整个发酵时间延迟了24 h。以柑橘果汁为参比，一次发酵法与二次发酵法制备的柑橘果醋相比，黄色度（b*值）、透光率、嗅觉成分、味觉中的鲜味和丰富度更相近于柑橘果汁。     

中国菊花主题花展及其对行业发展的作用

中国的菊花主题花展(菊花展览)是最重要的赏菊形式,对我国3种主要类型的菊花展览,即综合性菊花展览(中国菊花展览会、国际博览会菊花专项展和各级城市菊花展)、菊花专类园和菊花花田花海的发展现状进行了研究,并分析了菊花展览在促进菊花产业发展、弘扬菊花文化、服务生态文明及美丽乡村建设、加强菊花非物质文化遗产保护中的重要作用,为推动我国菊花展览水平的提高提供借鉴。