Adenosine cyclic phosphate with ultrasonic-assisted pectinase extraction alleviated allergic reactions in RBL-2H3 through inhibiting the influx of intracellular Ca^(2+)

Jujube contains abundant cyclic adenosine monophosphate(cAMP)and the ultrasonic-assisted pectinase extraction(UAPE)conditions for obtaining the maximum cAMP yield from jujube were optimized.Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield.The results showed that the optimal cAMP yield(783.0μg/g)was derived at ratio of liquid to solid 5 mL/g,ratio of pectinase to raw material 1.5%,time 60 min and temperature 40℃.Moreover,the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E(IgE)and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia(RBL-2 H3)cells using dinitrophenylated(DNP)-bovine serum albumin(BSA)-IgE.The results showed that cAMP interfered with sensitized cells,effectively inhibited the occurrence of basophil degranulation in dose dependence,and significantly reduced the activity ofβ-hexosamindase(β-hex),at the optimal concentration of 50μg/mL.The level of anti-inflammatory factor interleukin-10(IL-10)was promoted and the content of pro-inflammatory factor tumor necrosis factor-α(TNF-α)was suppressed by cAMP.In addition,influx of intracellular Ca^(2+) was repressed effectively.Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca^(2+),with the prevention of allergy symptoms.

Antioxidant and hepatoprotective effects of Ajuga nipponensis extract by ultrasonic-assisted extraction

Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.

Optimization of Ultrasonic-Assisted Extraction Process of Polysaccharides from American Ginseng and Evaluation of Its Immunostimulating Activity

Ultrasonic-assisted extraction （UAE） of American ginseng polysaccharides （AGP） was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography （GC） analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides.

Pressurized Synchronous Extraction of Volatile Oils, Total Flavonoids and Tannic Acid from Artemisia argyi

[Objectives] This study aimed to optimize the conditions for pressurized synchronous extraction of volatile oils, total flavonoids and tannic acid from Artemisia argyi .[Methods] Single factor experiments and orthogonal experiments were conducted.[Results] Pressurization had a significant effect on the extraction rate of chemical constituents of A. argyi . The optimal conditions for pressurized synchronous extraction of volatile oils, total flavonoids and tannic acid from A. argyi were as follows: solvent concentration of 70%, solid to liquid ratio of 1∶ 30 (g/mL), extraction pressure of 0.9 MPa, extraction time of 40 min and extraction temperature of 90 ℃. Under the optimal extraction conditions, the yields of volatile oils, total flavonoids and tannic acid were 0.852%, 4.66% and 6.79%, respectively.[Conclusions] Compared with other extraction methods, the pressurized assistant solvent extraction method can achieve the synchronous extraction of volatile oils, total flavonoids and tannic acid from A. argyi . The process is stable, short in extraction time, high in solvent utilization rate and ideal in extraction effect of the three components from A. argyi .

Isolation and purification of carbazole contained in anthracene slag by extraction combined with medium pressure liquid chromatography

Ultrasonic-assisted extraction(UAE)combined with medium pressure liquid chromatography(MPLC)was designed for carbazole separation from anthracene slag(AS).The effects of liquid/solid ratio,temperature,and extraction times on carbazole separation were investigated.When using CC14 and ethyl acetate as extraction solvents and combining with MPLC,carbazole recovery and purity are 75.1%and 95.4%,respectively.The mechanism for carbazole separation were presumed by examining intermolecular interactions such as N-H…π,π-π,and C-Cl…πinteractions.These results demonstrate that UAE/MPLC has a considerable potential as a green and promising strategy for separating and purifying carbazole and other chemicals from AS.

Optimization of Extraction Process of Quercetin from Flos Sophorae Immaturus Using Orthogonal Design

[Objectives]This study aimed to optimize the ultrasonic-assisted extraction process of quercetin from Flos Sophorae Immaturus.[Methods]The natural product quercetin in Flos Sophorae Immaturus was extracted by ultrasonic-assisted method,and the content of quercetin in the extract was determined by ultraviolet spectrophotometry.The effect of ethanol concentration,solid/liquid ratio,temperature,time and ultrasonic power on the yield of quercetin in Flos Sophorae Immaturus was investigated by using single-factor experiments.Based on the results of single-factor experiments,an orthogonal experiment was designed to optimize the extraction process.The experimental data obtained were subjected to range analysis,analysis of variance and SSR test using SPSS 20.0 software to obtain the optimal extraction process.The results concluded were verified.[Results]The optimal ultrasonic-assisted extraction process for quercetin in Flos Sophorae Immaturus was as follows:temperature of 85℃,time of 30 min,solid/liquid ratio of 1∶20 g/mL,ethanol concentration of 50%.Under the optimal extraction conditions,the yield of quercetin in Flos Sophorae Immaturus was the highest.[Conclusions]This study provides a theoretical basis for the application of quercetin in Flos Sophorae Immaturus.

Extraction Hydrolysates from Larimichthys Polyactis Swim Bladder Using Enzymatic Hydrolysis

As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak antigenicity.To enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal experiments.With 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 h.As for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis processes.With ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),respectively.The Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical forms.The Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 nm.The results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient temperature.However,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.

PARTIALLY BLIND EXTRACTION OF CONTINUOUS CHAOTIC SIGNALS FROM A LINEAR MIXTURE

In this paper, we address the problem of blind extraction and separation of a continuous chaotic signal from a linear mixture consisting of some chaotic signal and/or random signals. The problem of blind extraction is firstly formulated as a problem of the synchronization-based parameter estimation. Then an efficient least square based parameter estimation method is introduced to determine the desired extracting vector. The proposed blind signal extraction scheme is applicable to blind separation of chaotic signals by formulating the separation problem as the extraction of each chaotic source. Numerical simulation shows that the proposed approach can blindly extract and separate the desired chaotic signals and it is also robust to measurement noise.

基于主动式阻尼的混合式步进电机转速振荡抑制控制

混合式步进电机因其特殊的机械结构导致自身阻尼极小,在实际运行过程中会发生振荡过大,甚至失步的问题。为提高混合式步进电机的控制品质,提出一种基于主动式阻尼的步进电机转速振荡抑制方法。首先,将电机模型转化至同步旋转dq坐标系,将电流i_d控制恒为额定电流,利用位置误差和速度误差调节电流i_q生成瞬时转矩,抑制电机运行时存在的振荡现象。其次,为实现电机闭环反馈控制,提出一种将同步频率提取滤波器(SFF)与三阶锁相环(PLL~3rd)相结合的无传感器控制方法。SFF可以滤除反电动势信号中的高次谐波,PLL~3rd能消除转速变化过程中的稳态误差。实验证明,该方法有效抑制了步进电机运行过程中的振荡现象,提升了电机的运行品质。

复杂工况下的永磁同步电机典型绕组故障在线诊断

绕组故障作为永磁同步电机常见的故障之一,严重影响电机正常运行。但由于电机运行工况复杂,故障特征波动严重,基于故障特征的诊断精度较低。为提高复杂工况下绕组故障的诊断精度,该文提出一种复杂工况下基于控制器信号的在线诊断方法。首先,对典型绕组故障进行故障机理分析,并通过基于自适应随机窗的快速傅里叶变换(FFT),提取控制器信号的相应故障特征;其次,通过研究单一工况和复杂工况下的各故障特征分布,揭示部分故障特征会在低转速工况下失效;再次,定义了复杂工况下故障特征性能指标,用于筛选故障特征;最后,在人工神经网络的基础上,提出了深度优化人工神经网络,引入批量归一化(BN)算法,并对深度网络结构残差化,提高网络泛化能力和诊断准确性。实验结果表明,通过计算故障特征性能指标,能够在诊断前对故障特征进行有效筛选,且深度优化人工神经网络的诊断准确性高、泛化能力强,在复杂工况下能够实现电机典型绕组故障的精确在线诊断。

脉搏与呼吸信号检测系统设计

设计了脉搏和呼吸同步检测系统,用于探究不同情形下生理信号的变化情况。系统通过STM32控制脉搏和呼吸采集电路获取相应信号,测算后实时显示心率、呼吸频率等参数,将数据传输至上位机,并保存到数据库。实验测试结果表明,该系统可监测不同情形下的脉搏和呼吸波形,波形状态良好;与医用脉搏血氧仪相比,测算出的心率、血氧饱和度误差在3%以内,呼吸频率与实际数值相比误差在5%以内,验证了系统信号采集的准确性。该系统体积小、成本低、穿戴舒适,可应用于与脉搏和呼吸信号相关的实验研究。

金银花多酚和多糖同步提取工艺优化及其抗氧化活性研究

以金银花为原料,以硫酸铵浓度、乙醇含量、料液比、超声时间、提取温度、超声功率六个因素进行同步提取单因素实验。在单因素实验基础上,以多酚和多糖提取量为双指标,利用响应面法优化超声辅助乙醇-硫酸铵双水相萃取法同步提取金银花中多酚和多糖的工艺。并对提取的金银花多酚和多糖进行体外抗氧化研究。提取最优工艺条件为硫酸铵浓度0.2 mg/mL,超声时间30 min,超声温度59℃,料液比1∶70(g/mL),以此条件下测得多酚提取量为25.6 mg/g,多糖提取量为152.11 mg/g。体外抗氧化结果表明,金银花多酚和多糖对DPPH·、ABTS^(+)·具有显著清除能力,对Fe^(3+)有较强还原能力。利用超声辅助双水相萃取法实现了金银花多糖和多酚同步提取。多糖和多酚抗氧化活性均显著,其中金银花多酚抗氧化能力在一定范围内强于VC。

基于同步电荷提取和翻转的可扩展异质能量俘获电路

为了提供更加稳定可靠的能量,针对异质能的混合能量俘获问题,提出了一种基于同步电荷提取和翻转的可扩展异质能量俘获(Extensible Synchronous Charge Extraction and Inversion for Heterogeneous Energy Harvesting,EH-SCEI)电路。所提出的EH-SCEI电路,利用无源的峰值检测电路和RC微分电路在压电电压峰值时实现异质能源同步提取,并提出将部分电荷提取到储能端而另一部分电荷进行翻转以提高俘能效率的方法。仿真和实验结果均表明,所提出的电路可以对多个具有任意相位差的压电换能器进行能量采集并可根据实际的应用场景进行扩展;与现有电路相比,在输入输出范围、负载相关性、俘获效率等性能上,均有较大改善。

角度补偿同步平均的二级行星齿轮箱行星轮故障特征提取方法

加窗同步平均克服了行星齿轮传动引起的振动传递路径时变性问题,可有效应用于单级行星齿轮箱齿轮故障特征提取。但二级行星齿轮箱存在两级行星结构共用传动轴引起的振动耦合问题,该方法不易有效提取第一级行星轮的故障特征,为此本文提出一种角度补偿同步平均的二级行星齿轮箱行星轮故障特征的提取方法。通过等角度重采样消除转速波动的影响;采用角度补偿同步平均分离重采样振动中存在的第二级太阳轮的干扰,并通过差运算将其从重采样振动中消除;提取残余振动的包络信号;通过加窗同步平均构建第一级行星轮的合成包络信号,并采用包络同步平均提取第一级行星轮的故障特征。通过二级行星齿轮箱实验台实测信号分析验证,所提方法能够有效地提取第一级行星轮的故障特征。

Determination of Total Flavonoids in Acanthopanax senticosus(Rupr. et Maxim.) Harms by Enzymolysis and Its Technological Optimization

In order to optimize the ultrasonic extraction technique for the total flavonoid of leaf yellows plus, the contents of 21 leaf yellows plus total flavonoid from four regions in Heilongjiang Province were comparatively analyzed. The ultrasonic extraction technology was optimized by Box-Behnken response surface method, and the total flavonoid content of 21 kinds of Acanthopanax senticosus(Rupr. et Maxim.) Harms from different producing areas were analyzed by cluster analysis. The optimal process conditions were determined as ultrasonic time 30 min, solid-liquid ratio 1 : 12 and ultrasonic power 250 W, and the average yield of the total flavonoid was 1.453 mg·g^ (-1). By optimizing the ultrasonic-assisted extraction method, the total flavonoid content from different producing areas was compared in the experiment, which provided certain data support for the optimization of the extraction process in the future and laid a certain theoretical foundation for the quality analysis of Chinese medicinal materials.

改进小波变换下的永磁同步电机机械故障识别

针对永磁同步电机部件参数具有延续性关联性特征,机械故障特征难以提取,导致识别精准度较低的问题,研究改进小波变换下的永磁同步电机机械故障识别技术。建立永磁同步电机内定子、转子的同步状态参数数学模型,通过三相方程按照正弦分布变化规律,得到在电机正常同步状态下各项参数的周期性数据,以该值作故障状态特征提取的初始参照。以永磁同步电机内高、低频作为特征提取尺度,基于改进小波包变换完成电机机械故障特征信号重构提取;基于Kalman滤波残差估计算法计算重构信号的故障残差值,与初始状态对比,完成故障识别。经过实验证明,所提方法识别精准度高,可以识别出短路故障下的三相定子电流和电机输出转矩,具有一定的实用价值。

机械弹性储能用永磁同步电机多源谐波提取及统一抑制

针对柔性涡簧振动和电力电子装置等引起机械弹性储能(MEES)系统机械侧谐波难以准确建模、多源谐波无法整体表征及统一抑制的问题,该文提出MEES用永磁同步电机多源谐波提取及统一抑制方法。首先,建立MEES系统数学模型,利用电机转速谐波对多源谐波进行整体表征;然后,提出融合奇异值差分的矩阵束算法,利用其对含噪实测转速数据进行处理以获取包含不同频率成分的多源谐波信息;最后,设计定子电流矢量定向下基于反推控制的多源谐波统一抑制算法,完成对不同频率成分谐波的同时抑制。仿真和实验结果表明,利用融合奇异值差分的矩阵束算法能快速、准确地识别转速信号中的多源谐波成分,统一抑制算法有效降低了多源谐波导致的电磁转矩脉动,改善了系统运行性能。

基于错位叠加法的同步液压马达冲击故障成分的降噪提取

同步液压马达经常工作于高负载条件下,对其进行在线故障监测可有效避免严重安全事故和经济损失。为提高故障监测的准确性,提出了一种基于改进的错位叠加法的同步液压马达故障成分自适应降噪以及提取方法,并以同步液压马达的齿轮磨损状态的声信号为对象进行了研究。实验表明,该方法对同步液压马达齿轮磨损状态的冲击故障成分具有良好的降噪和提取效果。

低透气性煤层多孔同步分段水力压裂增透技术研究

为了提高煤层透气性的增透效率,研究了煤层多孔同步分段水力压裂增透技术,介绍了多孔同步分段水力压裂技术的基本原理,通过实验室测试了高压封孔胶囊的耐压强度及多孔同步分段水力压裂系统的自动控制工艺,结果表明:高压封孔胶囊的最小破坏强度为35 MPa,多孔同步分段水力压裂可通过自动控制系统实时监测每个钻孔的压力数据,实现压裂过程的自动控制。同时在三元煤矿进行了现场工业试验,工业试验表明,3#煤层的起裂压力为23.3~25.4 MPa,当压裂距离为10 m时,压裂孔的裂纹扩展时间为26~38 min,裂纹沟通时间为28~40 min,可有效提高压裂效率。经过多孔同步分段水力压裂增透的煤层,相对于未压裂煤层,在30 d的统计时间内,压裂后的平均瓦斯浓度是未压裂的1.12倍,平均混合流量是未压裂的2.17倍,平均瓦斯纯量是未压裂的2.44倍,能够有效的增加煤层透气性,提高瓦斯抽采效果。

基于CEEMDAN-HT的永磁同步电机匝间短路振动信号故障特征提取研究

由于长时间处于高负荷运行状态,永磁同步电机(permanent magnet synchronous motor, PMSM)定子绕组线圈匝与匝之间的绝缘性能容易降低,导致出现匝间短路,此时电机的振动强度会发生改变。针对此现象,提出将自适应噪声完备经验模态分解(complete ensemble empirical mode decomposition with adaptive noise, CEEMDAN)与希尔伯特变换(Hilbert transform, HT)结合,构成一种CEEMDAN-HT非线性信号分析方法,并将其应用于提取振动信号故障特征。首先,利用CEEMDAN算法分解振动信号,得到一系列本征模态函数(intrinsic mode function, IMF),并将主元分析中的方差贡献率用于识别包含故障特征信息的IMF。其次,使用HT对方差贡献率较高的IMF进行分析,并以三维联合时频图呈现时间、瞬时频率与幅值,得到了主要故障特征。最后,使用ANSYS有限元软件建立了电机短路故障模型,并搭建了短路故障试验平台,通过对比有限元仿真结果与试验结果,对提出的方法进行了有效性和准确性验证。