25 research outputs found
Methyl Esterification of Arachidonic Acid in Microbial Oil
作者简介:董宏祯(1988 —),男,硕士研究生,研究方向为天然产物化学。E-mail:[email protected]
通信作者:许建中(1954 —),男,高级工程师,本科,研究方向为生物化工。E-mai l:[email protected][中文文摘]以微生物油脂为原料,对其中花生四烯酸的甲酯化方法进行筛选和优化。在确定合适的花生四烯酸甲酯化方法基础上,考察酯化温度、酯化时间、催化剂体积分数及搅拌转速对花生四烯酸酯化效果的影响。结果表明:酯化温度80℃、酯化时间8h、浓硫酸体积分数2.0%、转速400r/min时,花生四烯酸甲酯质量分数达到37.75%,产率达到91.54%。甲酯化后的花生四烯酸沸点较低,适用于分子蒸馏。[英文文摘]In order to maximize arachidonic acid methyl ester production,the methyl esterification of microbial oil was optimized with respect to temperature,reaction time,catalyst(concentrated sulfuric acid) dosage and agitation speed using one-factor-a-at-a-time combined with orthogonal array design method.The highest yield of 91.54% was achieved after 8 h of reaction at 80 ℃ and an agitation speed of 400 r/min under the catalysis of 2.0% concentrated sulfuric acid.The obtained product contained 37.75% arachidonic acid methyl ester and its boiling point was lower than before the reaction, facilitating molecular distillation.厦门海洋研究开发院共建项目; 福建省海洋与渔业厅科技重点项目([2009]2-10);厦门市科技计划项目(3502Z20112005);福建省2010年第二批产业技术开发项目(5012060403
Effects of Acid Extraction Parameters on Properties of Pectin from Pomelo Peel
作者简介:林晓锋(1986 —),男,硕士研究生,研究方向为化学工程。E-mail:[email protected]
通信作者:许建中(1953 —),男,高级工程师,研究方向为生物化工。E-mail:[email protected][中文文摘]选用福建特产琯溪蜜柚果皮为原料,考察酸提工艺条件对果胶的酯化度、黏均分子质量和半乳糖醛酸含量的影响,设计正交试验L9(34)考察各因素的影响。结果表明:在试验范围内,酸提工艺条件对果胶的酯化度基本无影响,对半乳糖醛酸的含量有明显的影响,对果胶的分子质量影响最显著。9个不同试验条件下,酸提果胶的酯化度63.5%~63.8%,半乳糖醛酸含量74.2%~88.5%,果胶的黏均分子质量101~202ku。[英文文摘]The effects of process parameters such as temperature,solid/liquid ratio,extraction time and pH for pectin extraction from Guanxi honey pomelo peel with dilute hydrochloric acid on degree of esterification(DE),viscosity-average molecular mass and galacturonic acid content of pectin were investigated using an L9(34) orthogonal array design.The results showed that the process parameters had little effect on pectin DH,remarkable effect on galacturonic acid content,and the largest effect on viscosity-average molecular mass
and galacturonic acid content of pectin were investigated using an L9(34) orthogonal array design. The results showed that the process parameters had little effect on pectin DH, remarkable effect on galacturonic acid content, and the largest effect on viscosityaverage molecular mass. The 9 orthogonal array runs resulted in a DH of 63.5%-63.8%, a galacturonic acid content of 74.2%-88.5% and a viscosity-average molecular weight of 101-202 ku.福建省科技计划重点项目(2010Y0035
Separation and Purification of Naringin by Solid Phase Extraction Using Strong Anion Exchange Cartridge
作者简介:宁方刚(1986 —),男,硕士研究生,研究方向为天然产物化学。E-mail:[email protected]
* 通信作者:许建中(1954 —),男,高级工程师,本科,研究方向为生物化工。E-mail:[email protected][中文文摘]目的:建立固相萃取分离纯化柚皮苷的方法。方法:以强阴离子交换(strong anion exchange,SAX)填料为吸附材料,利用柚皮苷与填料的功能基团之间的静电作用将柚皮苷吸附在填料上,考察洗脱液离子强度、洗脱液体积,洗脱流速对洗脱效果的影响。结果:选用5mL碳酸氢钠溶液(0.1mol/L,pH9.0)为洗脱液,以0.5mL/min的流速进行洗脱,回收率达到91%以上。结论:本方法简单、高效,选择性好,可为柚皮苷样品的纯化提供理论依据。 [英文文摘]Purpose: A solid-phase extraction procedure for the separation and purification of naringin(NG) was developed using strong anion exchange(SAX) cartridge.Method: Naringin was adsorbed onto the cartridge by electrostatic interaction between naringin and functional groups.Several variables affecting the elution performance of SAX,such as ionic strength of elution,elution volume and elution rate,were studied.Results: The application of 5 mL of sodium bicarbonate solution(0.1 mol/L,pH = 9.0) to elute SAX cartridge at a flow rate of 0.5 mL/min resulted in a recovery rate of 91%.Conclusions: The established method is simple and efficient.福建省科技计划重点项目(2010Y0035
支撑应力对骨小梁分布的影响及股骨头坏死因素的研究
目的通过犬股骨颈骨折螺钉内固定模型的力学检测及组织学观察,从微观角度认识骨小梁重建对股骨头坏死的影响。方法选取18只成年田园犬制作成股骨颈骨折螺钉内固定模型,于造模后12周确认所有股骨颈骨折已愈合随机分为取钉组、取钉植骨组及不取钉组,于造模后20周分离所有犬的股骨并进行股骨颈力学测试及组织学观察。结果取钉组、取钉植骨组及不取钉组断裂点载荷、最大载荷差异有统计学意义(P0.05),不取钉组与取钉植骨组断裂点载荷大于取钉组;不取钉组最大载荷大于取钉植骨组与取钉组,取钉植骨组最大载荷大于取钉组。取钉组、取钉植骨组及不取钉组骨小梁宽度与新鲜骨面积差异有统计学意义(P<0.05);不取钉组骨小梁宽度、新鲜骨面积大于取钉植骨组,且取钉植骨组大于取钉组。结论支撑应力的改变将导致骨小梁重新分布,骨小梁再分布是影响股骨头坏死塌陷的重要因素。福建省卫生系统中青年骨干人才培养项目(2014-ZQNJC-34
DOCUMENT IMAGE BINARISATION BASED ON BACKGROUND ESTIMATION AND EDGE DETECTION
为提高文档图像在对比度低、光照不均、大块噪声等复杂图像背景下二值化效果,提出一种背景估计与边缘检测相结合的图像二值化方法.该方法先利用Sauvola算法有效地估计图像的背景,并在此基础上,结合改进的Canny算法获取边缘变化信息,利用基于局部阈值的策略进行二值化.实验结果表明,该算法取得了较好的二值化效果,在开放的DIBC0 2011数据集上测试,其性能与Otsu、Niblack、Sauvola经典方法相比有大幅提高,其F值比ICDAR2011二值化竞赛中第一名的算法略有提高.To enhance the binarisation effect of image documents in complex image background of low contrast,uneven illumination and bulk noise, etc.,we present an image binarisation method combining the background estimation and edge detection. Firstly, Sauvola' s algorithm is used in the method to estimate image background effectively. On this basis, the improved Canny edge detection algorithm is combined to get edge variation information. At last the local threshold-based policy is employed for binarisation. Experimental results demonstrate that the algorithm achieves better binarisation effect,test is carried out on open Document Image Binarisation Contest (DIBCO) 2011 dataset, the performance of the proposed method has promising improvement than classic methods of Otsu,s, Niblack, s and Sauvola's, its F value is slightly higher than that of the No. 1 algorithm in ICDAR2011 binarisation contest
Determination of Glucosamine Compounds by HPLC-nano-quantity Analyte Detector
通信作者:[email protected][中文文摘]核粒子计数检测器是基于水凝聚激光计数专利技术(WCPC),对低紫外吸收的化合物有较强的优势.建立了高效液相色谱-核粒子计数检测器(HPLC-NQAD)检测D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的方法.采用AsahipakNH2(250mm×4.6mm,5μm)色谱柱,V(乙腈)∶V(0.5%三乙胺水溶液)=75∶25为流动相,流速为0.8mL/min,进样量为10μL,10min内完成检测.在NQAD蒸发管温度55℃、气体压力200kPa条件下,D-氨基葡萄糖盐酸盐与N-乙酰-D-氨基葡萄糖之间的分离度2.32,前者的检出限为16ng,定量限为50ng,后者的检出限为8ng,定量限为24ng.D-氨基葡萄糖盐酸盐在10.03~2 005.20μg/mL范围内线性回归相关系数为0.999 5,N-乙酰-D-氨基葡萄糖在10.18~2 036.80μg/mL范围内线性回归相关系数为0.999 9.检测D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的精密度实验的相对标准偏差(RSD)分别为1.53%和1.38%,平均回收率分别为100.18%和101.02%.该方法用于D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的检测,可靠、快速、简便.[英文文摘].Nano-quantity analyte detector(NQAD),which was based on water condensation particle counter(WCPC) technology,was advantageous for detection of low UV-absorbing compounds.An effective HPLC method with NQAD used for the detection of D-glucosamine hydrochloride(GAH) and N-acetyl-D-glucosamine(GN) was developed.The separation was performed on a 250 mm×4.6 mm NH2 column with a diameter of 5 μm(Asahipak).Isocratic elution was conducted using acetonitrile/(0.5% triethylamine)(75∶25,by vol.) with a flow rate of 0.8mL/min,and the injection volume of 10μL.This HPLC process was completed within 10 min.The resolution of GAH and GN was 2.32when the evaporation temperature of NQAD was 55℃and the pressure was 200kPa.The detection limit was 16ng for GAH and 8ng for GN,and the quantitation limit was 50ng for GAH and 24ng for GN.GAH showed a good linearity in the range of 10.03~2005.20μg/mL (r=0.999 5,)and the linearity range for GN was 10.18~2036.80μg/mL(r=0.9999,).The relative standard deviation of precision for GAH and GN were 1.53% and 1.38%,respectively.
The average recovery rates of GAH and GN were 100.18% and 101.02%,respectively.These results indicated that the HPLCNQAD
method was a reliable,quick and simple method for the detection of GAH and GN.海洋公益性专项(201005022
Enrichment of Arachidonic Acid from Microbial Oil by Molecular Distillation
通信作者:[email protected][中文文摘]对分子蒸馏富集微生物油脂中花生四烯酸进行了研究.实验过程中微生物油脂预先进行皂化和甲酯化反应,制得混脂肪酸甲酯,作为分子蒸馏原料.考察了多种分离工艺参数对花生四烯酸纯度和产率的影响.结果表明,操作压力1.0Pa,蒸馏温度80℃,刮膜器转速150r/min,冷凝温度10℃,进料速度1.5mL/min条件下,产品的纯度和产率分别达到67.48%和85.86%.[英文文摘]The enrichment of arachidonic acid from microbial oil by molecular distillation was studied.The molecular distillation feed was prepared by saponification of microbial oil,followed by the methyl esterification.The effects of operation pressure,distillation temperature,agitated speed,cool temperature and feed flow rate on the refining of arachidonic acid were investigated.The results showed that the mass fraction and the yield of arachidonic acid could reach 67.48% and 85.86%,respectively,under the operation pressure of 1.0 Pa,distillation temperature of 80℃,agitated speed of 150r/min,cool temperature of 10℃ and feed flow rate of 1.5 mL/min.福建省发改委2010年第二批产业技术开发项目(5012060403);福建海洋与渔业厅科技重点项目([2009]2-10);厦门市科技计划项目(3502Z20112005);厦门海洋研究开发院共建项目;基本科研业务费专项资金项目(海三科2011037
基于Visual Basic的无级变速器脉动发生机构的运动仿真
利用Visual Basic面向对象以及包含协助开发环境的事件驱动为机制的可视化程序设计的特点,进行无级变速器脉动发生机构的运动仿真。从运动仿真中对脉动式无级变速器的机构性能进行研究。已探讨出了一种四边形的高效率脉动发生机构
功能化离子液体萃取分离甘氨酸
以结构和功能可设计的离子液体为萃取剂,通过液–液萃取分离甘氨酸,考察了不同结构的咪唑和季铵离子液体萃取分离甘氨酸的效果,研究了pH值、萃取温度、萃取时间、甘氨酸初始浓度和二环己基-18-冠醚-6(DCH18C6)浓度等工艺参数对甘氨酸分配系数和萃取率的影响,考察了胆碱双三氟甲磺酰亚胺盐(N1112(OH)NTf2)的循环利用性,通过FT-IR和量子化学计算探究了N1112(OH)NTf2和DCH18C6萃取甘氨酸的机理。结果表明,N1112(OH)NTf2的萃取率高于其它离子液体,加入DCH18C6可提高萃取率,N1112(OH)NTf2–DCH18C6复配体系中,甘氨酸萃取率可达85.4%。在最优条件下,分配系数和萃取率分别为10.9和94.4%。离子液体循环利用5次,甘氨酸萃取率仍保持90%。N1112(OH)NTf