胶束电动色谱法测定辣椒中的辣椒碱

目的:建立分离辣椒碱和二氢辣椒碱,测定辣椒中辣椒碱的毛细管电泳新方法。方法:采用胶束电动毛细管色谱法,缓冲溶液体系由15mmol/L的硼砂、30 mmol/L的十二烷基硫酸钠组成,缓冲溶液的pH值为9.70,运行操作电压为20kV。结果:辣椒碱检测浓度在1～400mg/L范围内线性关系良好(r=0.9996),平均回收率为97%～103%(RSD<5%)。结论:该方法简单、快速、分析准确度高,能有效地分离辣椒碱和二氢辣椒碱,并测定辣椒中的辣椒碱。     

辣椒碱类物质的荧光检测方法研究

建立了对辣椒碱和二氢辣椒碱及总量进行快速测定的荧光分析方法。在Ex均为282nm,Em分别为313nm和352nm,光电管负高压为400V下,辣椒碱及二氢辣椒碱含量在2.0~12.0μg/mL范围内其标准曲线方程为:I1=6.8883C1-4.1840,I2=4.802C2+6.345,R2分别为0.9997和0.9976,线性关系良好。对样品进行总碱含量测定,精密度RSD为1.82%,回收率为103.5%,检测结果与HPLC-UV接近,能满足一般定量检测的需要且操作简便。     

辣椒栽培技术

<正>辣椒,又叫番椒、海椒、辣子、辣角、秦椒等,是一种茄科辣椒属植物。辣椒属为一年或多年生草本植物。果实通常呈圆锥形或长圆形,未成熟时呈绿色,成熟后变成鲜红色、黄色或紫色,以红色最为常见。辣椒的果实因果皮含有辣椒素而有辣味。能增进食欲。辣椒营养丰富,且具有较高的药用价值。辣椒中含有丰富的维生素C、β―胡萝卜素、叶酸、镁及钾;经常进食辣椒可以有效延缓动脉粥样硬化的发展及血液中脂蛋白的氧化。少量食用,能健脾     

日光温室辣椒长季节高产栽培技术

现阶段,日光温室的出现扩展了作物的可生长时间,可以通过调节环境因素的方式种植反季节蔬菜,提供数量和种类更多的蔬菜。为了满足市场对辣椒的广泛需求,相关人员需要从选种、育苗、定植、整地、施肥等多个方面应用高产栽培技术,把握辣椒生长发育的关键时期,提高辣椒的产量和质量,为辣椒种植户提供帮助和参考,进而促进农业发展。     

高效液相色谱法测定个人护理产品中的4种热感剂

建立了化妆品中4种热感剂的高效液相色谱分析方法。采用甲醇超声提取样品,用ZORBAX Eclipse XDB-Phenyl色谱柱分离,乙腈和1%甲酸为流动相梯度洗脱,高效液相色谱(配二极管阵列检测器)进行测定,可同时对姜酮、香兰基丁醚、辣椒素、合成辣椒素4种物质进行定性和定量分析。在优化的实验条件下,4种热感剂在0.2~100mg/L范围内线性关系良好,空白样品在5.0、10.0、100mg/kg 3个加标水平下,回收率为86%~107%,相对标准偏差为1.0%~8.8%。方法的定量下限(S/N=10)香兰基丁醚、姜酮为2.0mg/kg,辣椒素、合成辣椒素为5.0mg/kg。该方法简单、灵敏、准确,可满足化妆品中4种热感剂的检测要求。     

辣椒嫁接栽培技术的实践探究

辣椒属于土传病害危害严重的一类作物,嫁接是辣椒育苗较为常用的方式,辣椒类蔬菜应用嫁接技术可以有效预防土传病害,提高土壤水肥利用率、增强耐低温能力,提高辣椒产量。对辣椒嫁接的方法加以论述,为提高辣椒产量、生产无公害蔬菜提供有效的解决措施。     

固液萃取-高效液相色谱法测定正天丸中钩藤碱和异钩藤碱的含量

目的:采用固液萃取-高效液相色谱法,建立正天丸中钩藤碱和异钩藤碱的含量测定方法,为正天丸质量控制提供依据。方法:采用高效液相色谱法,色谱柱Agilent Eclipse Plus-C18(4.6mm×250mm,5μm),以甲醇-0.1%三乙胺溶液(冰醋酸调pH值7.5)(60:40)为流动相,检测波长为246nm,流速1ml·min-1。结果:钩藤碱和异钩藤碱进样量均在0.133—0.665μg之间与峰面积呈线性相关,R均为1.000;钩藤碱和异钩藤碱的平均加样回收率分别为100.4%、102.1%,RSD分别为1.8%、1.5%,供试品溶液室温条件下36小时内稳定,测定10批正天丸中钩藤碱和异钩藤碱含量之和范围为0.0612-0.2037mg/g。结论:该方法快速、准确,操作简单,专属性强,可为正天丸的质量控制提供参考依据。     

乌头碱、中乌头碱、次乌头碱及水解产物的电喷雾质谱裂解机制研究

目的:研究乌头碱、中乌头碱和次乌头碱及其水解产物的质谱裂解机制。方法:采用直接进样(FAB)-电喷雾(ESI)-质谱(MS)的方法,在正离子模式下对3种双酯碱和其水解产物进行了多级质谱检测。结果:均产生了[M+H]~+准分子离子,裂解过程中以失掉水,甲醇,一氧化碳中性分子为主。结论:该数据有利于进一步研究乌头属生物碱的化学成分和质量标准的建立。     

大棚温室辣椒栽培新技术及病虫害防治

大棚蔬菜种植是近些年来进行农业结构调整的新模式,大棚蔬菜种植模式可以提供反季节蔬菜,对人们的生活质量提高有着极大的改善。其中辣椒作为蔬菜中最常见的种植作物之一,也是中国民众日常生活中必不可少的蔬菜品种。随着辣椒需求量的逐渐提高,为了满足人们的需要,通过大棚种植技术改良来提高辣椒在反季节的产量和质量有着重要的意义。就大棚温室辣椒栽培新技术以及病虫害防治等内容进行讨论,希望为广大农业工作者提供新的思路。     

HPLC测定黄柏石膏散中盐酸巴马丁和盐酸小檗碱含量

目的:建立测定黄柏石膏散中盐酸巴马丁和盐酸小檗碱含量的高效液相色谱法.方法:色谱柱:MZ C18柱(4.6mm ID&#215;250mm,5μm);流动相:水-乙腈(71:29),含0.5%三乙胺、磷酸调pH至3.0;检测波长343nm;流速:1ml/min.结果:盐酸巴马丁和盐酸小檗碱的理论板数分别为6500和7500.盐酸巴马丁回归方程为Y=-433601+93680500X,r=0.9999,线性范围0.1674μg-0.8372μg,平均回收率为98.7%(n=5,RSD 1.3%).盐酸小檗碱回归方程为Y=-887699+95231971X,r=0.9999,线性范围0.3789μg-1.894μg,平均回收率为99.2%(n=5,RSD 1.6%).结论:该法操作简便,结果准确,可用于黄柏石膏散中盐酸巴马丁和盐酸小檗碱含量测定.     

交通环境振动测试数据中暗振动去除的ANFIS法

轨道交通引起的环境振动测试数据中混杂着暗振动的成分。提出了一种去除暗振动的自适应神经模糊推理系统(adaptive neuro-fuzzy inference system,简称ANFIS)法,阐述了其基本原理,给出了该法的具体实现步骤。通过一条列车引起的地面振动加速度时程与一条暗振动加速度时程叠加得到现场实测振动加速度时程,采用提出的ANFIS法及其他几种已有方法对该算例进行了去除暗振动的计算,并进行了对比分析。几种方法计算的时程均方根误差分别为:谱幅值修正法0.414mm/s~2,自功率谱法0.363mm/s~2,自互功率谱法0.261mm/s~2,ANFIS法0.074mm/s~2,可见,ANFIS法均方根误差最小;几种方法计算的加权振级VLz分别为:振动级修正法63.842dB,谱幅值修正法62.894dB,自功率谱法63.859dB,自互功率谱法63.802dB,ANFIS法63.805dB,ANFIS法计算结果与真实交通振动值63.815dB最接近。结果表明,在时程、傅里叶谱、功率谱密度及振动级的计算上,ANFIS法计算结果都与真实交通振动值非常接近,产生的误差比其他已有方法更小。     

Rigid-plastic finite-element method for analysis of three-dimensional rolling that requires small memory capacity

At present, caliber rolling is analyzed using the three-dimensional rigid-plastic finite-element method. In this paper, a new method of analysis which requires less memory capacity than the conventional method is proposed. In the conventional method, the shape of the whole region is updated after the functional of the region is minimized, whereas in the proposed method, the shape of part of the region (large region) is updated after the functional of the large region is minimized. The load, torque, material shape, hydrostatic stress and equivalent strain rate obtained using the proposed method agree with those obtained using the conventional method within the allowable range of convergent error. Also, although the computation time for the proposed method is rather long compared with that for the conventional method, the memory capacity required for the proposed method is small compared with that for the conventional method. Finally, analysis of various types of caliber rolling in which the number of finite elements in the large region coincides with that in the whole region in analysis using the conventional method is carried out and reasonable stress and strain distributions are obtained.     

一种改进的增量谐波平衡法及其在非线性振动中的应用

对于一般的增量谐波平衡法而言,在求解分段线性系统周期响应时存在收敛速度慢的缺点。针对这一缺点,本文根据最小二乘法原理和增量过程提出了一种改进的增量谐波平衡算法,通过和原有算法进行对比发现二者之间存在着统一的算法形式,因此只要对原有算法作简单的改进即可方便地使用此方法。利用此方法成功计算了齿轮传动分段线性系统的周期解,通过对计算结果比较,发现迭代次数要比一般的增量谐波平衡法少30%左右。从而可以看出这种算法具有收敛速度快的优点。     

An adaptive moving total least squares method for curve fitting

The moving least squares (MLS) method and the moving total least squares (MTLS) method have been developed to deal with the measured data contaminated with random error. The local approximants of MLS method only take into account the error of dependent variable, whereas MTLS method considers the errors of all the variables, which determines the local approximants in the sense of the total least squares. MTLS method is more reasonable than MLS method for dealing with errors-in-variables (EIV) model. But because of the weight function with compact support, it is complicated to choose fitting method for the best performance. This paper presents an Adaptive Moving Total Least Squares (AMTLS) method for EIV model. In AMTLS method, a parameter λ associated with the direction of local approximants is introduced. MLS method and MTLS method can be considered as special cases of AMTLS method. Curve fitting examples are given to prove the better performance of AMTLS method than MLS method and MTLS method.     

基于扭矩法和超声法检测螺栓预紧力的误差分析

文中分析了螺栓预紧力测量中的扭矩法和超声法的检测精度。基于扭矩法和超声法的检测原理,设计出检测装置,采用这2种方法对同类型紧固螺栓的预紧力进行了测量分析,并根据测量结果,分析了采用扭矩法和超声法测量紧固螺栓预紧力的测量误差。结果表明,在实验室环境下,与扭矩法相比,采用超声法测量螺栓预紧力的误差更小。     

异常载荷剔除中幅值与梯度门限的联合应用

幅值门限法对于大误差及超数量级的异常数据具有良好的识别性,而梯度门限法对于小幅值的奇异点检测能力强。针对这一特点,分析比较了幅值门限法与梯度门限法在剔除异常载荷数据过程中的优劣特性,提出联合应用这两种方式来实现对奇异信号的处理,并以装载机传动系为例给出了异常载荷数据剔除的过程及结果,避免了基于假定样本数据服从某种典型概率分布,利用标准差剔除异常数据的方法存在的固有局限性,可以快速、准确地剔除不同概率分布下的样本异常数据。     

A non-convex regularization method combined with Landweber method for image reconstruction in electrical resistance tomography

Electrical resistance tomography (ERT) is a promising technique with which the conductivity distribution in the detected region can be visualized. Mathematically, the reconstruction of conductivity distribution is a seriously ill-posed inverse problem which poses a great challenge for the ERT sensing technique. The regularization method has been found to be an effective approach in coping with the inverse problem. In this work, a novel reconstruction strategy which combines the non-convex regularization method with Landweber method is proposed for the image reconstruction in ERT. At each iteration, the non-convex regularization is used to constrain the conductivity calculated with the Landweber method. A simple and efficient generalized iterated shrinkage algorithm is developed to solve the proposed method. To validate the performance of the proposed method, a series of numerical simulation is conducted and comparative analysis with other methods is performed. From the results, it can be observed that images with high quality are obtained when reconstructing with the proposed method. The impact of noise on the reconstruction is also investigated which shows that the images reconstructed by the proposed method are the least sensitive to the noise. The performance of the proposed method in the image reconstruction is also verified by experimental data. The results demonstrate that the inclusion is accurately reconstructed and the background is clear when the proposed method is adopted for the image reconstruction.     

淬火冷却过程三维反传热有限元分析中优化方法对计算效率的影响

研究了三维问题的温度场有限元模拟模型和组织场与相变潜热的计算方法,自主编写了三维有限元分析软件。在此基础上,以进退法确定初始搜索区间,分别采用黄金分割法、逐次二次插值法以及二者的混合法等优化方法确定换热系数的最优值,对淬火冷却过程三维反传热问题进行了研究和结果比较。计算结果显示,三种优化方法的结果与参考值均吻合良好,但对于解析性能较好的优化函数,黄金分割法计算效率最低,逐次二次插值法计算效率最高,混合法介于二者之间,略低于逐次二次插值法,但混合法对优化函数的适应性则好于逐次二次插值法,比较稳定。因此,在效率差别不大的情况下,应优先选用混合法。     

液固混合介质隔振系统的主共振分析

研究一类具有分段线性—非线性非光滑特性液固混合介质隔振器的主共振解析解。采用摄动法求解非线性段的瞬态响应,由常微分方程理论给出了线性段的瞬态响应。根据响应的连续性与周期性条件,联合接缝法与摄动法分析周期激励作用下系统的主共振响应。而后基于弹性恢复力的傅里叶展开,给出谐波平衡法求解非光滑隔振系统响应的一般步骤,并得到了一阶和二阶近似解。采用龙格—库塔算法对解析方法的有效性进行验证,结果表明:接缝法和数值计算的结果较为吻合,而谐波平衡法的二阶近似比一阶近似解更为精确。     

Sparse signal decomposition method based on multi-scale chirplet and its application to the fault diagnosis of gearboxes

Based on the chirplet path pursuit and the sparse signal decomposition method, a new sparse signal decomposition method based on multi-scale chirplet is proposed and applied to the decomposition of vibration signals from gearboxes in fault diagnosis. An over-complete dictionary with multi-scale chirplets as its atoms is constructed using the method. Because of the multi-scale character, this method is superior to the traditional sparse signal decomposition method wherein only a single scale is adopted, and is more applicable to the decomposition of non-stationary signals with multi-components whose frequencies are time-varying. When there are faults in a gearbox, the vibration signals collected are usually AM-FM signals with multiple components whose frequencies vary with the rotational speed of the shaft. The meshing frequency and modulating frequency, which vary with time, can be derived by the proposed method and can be used in gearbox fault diagnosis under time-varying shaft-rotation speed conditions, where the traditional signal processing methods are always blocked. Both simulations and experiments validate the effectiveness of the proposed method.