分子蒸馏的原理及其应用进展

分子蒸馏又称短程蒸馏,是在高真空条件下进行的非平衡连续蒸馏过程,综述了分子蒸馏的发展过程、基本原理、特点及其设备,同时对分子蒸馏在植物、动物药用部分及其他方面的应用进行了介绍。     

分子蒸馏技术在中药提取中的应用

分子蒸馏技术是近年来应用较多的一种新的分离纯化技术,具有蒸馏温度低、受热时间短、分离程度高等优点,在食品和化工制药行业应用较多.总结了近年来分子蒸馏技术用于中药有效成分精制的研究进展与方法,围绕分子蒸馏技术的基本原理与实际应用,探讨了该技术用于中药有效成分分离纯化的基本规律,分析得出分子蒸馏技术是一种精制中药有效成分的良好途径,在中药有效成分提取分离阶段使用分子蒸馏技术,特别适用于传统中药中高沸点、热敏性及易氧化的有效成分分离和纯化,分子蒸馏技术有利于促进中药有效成分分离技术的现代化.     

分子蒸馏设备的发展及其在样品前处理中的应用

分子蒸馏是一种新型的高效液一液分离技术。本文对分子蒸馏的原理和设备组成以及国内外典型分子蒸馏设备的结构、特点和应用进行了简要归纳。对该技术在样品分析前处理工作中的应用探索进行了介绍,通过对分子蒸馏装置进行全新的设计,运用载体、携带物和综合蒸馏枝术完成了待测样品中微量成分的分离和富集,建立了一种新的样品前处理模式。     

OptiDist~(TM)全自动常压蒸馏仪常见故障和维护

介绍了OptiDist~(TM)全自动常压蒸馏仪常见故障,提出解决故障的具体方法,同时介绍了日常的维护措施。     

Eurodist全自动实沸点蒸馏仪在原油评价中应用研究

本文介绍了德国Eofa公司生产的全自动实沸点蒸馏仪的工作原理和操作方法,并利用该仪器在实验室对原油进行蒸馏,其蒸馏的数据与英国Intertek实验室进行了对比,我们对蒸馏的结果进行研究分析,研究结果表明,该仪器完全符合AST MD2892和ASTM D5256标准方法,已经应用于原油评价工作中,实现了测定原油沸点蒸馏的自动化。     

原油实沸点蒸馏仪期间核查方法的建立与应用

原油实沸点蒸馏仪作为常用的分析仪器,广泛应用于石油化工领域,仪器的准确性和可靠性直接影响原油评价数据结果和质量。然而,由于热电偶、真空计等与玻璃部件连接,拆卸困难,安全风险较大,送检周期长,这就给仪器的校验带来了不小的困难。为了提高原油实沸点蒸馏仪检测的准确性,本文依据实验室实践,建立了一套使用正十六烷和甲苯对原油实沸点蒸馏仪整体进行期间核查的方法,结果表明,原油实沸点蒸馏收率误差小,完全满足相关标准的要求,该方法能够在实验中应用。     

低温多效蒸馏法海水淡化技术

我国在20世纪80年代末开始研究低温多效蒸馏法海水淡化技术，初期主要是基础理论研究，到“九五”期间天津海水淡化研究所开展双效压汽蒸馏技术研究，在低温多效和压汽蒸馏方面取得了突破性进展，全面掌握了低温多效和压汽蒸馏淡化的关键技术，并且达到国际先进水平。在设备的效间联接、防蚀保护和材料选择等方面取得了成果。     

基于PLC控制的白酒蒸馏监控系统设计

白酒蒸馏是中国白酒酿造中的一项独特技术,针对中国白酒酿造工艺过程粗化、劳动强度大的问题,设计了基于组态王（KingView）的白酒蒸馏监控系统硬件结构、PLC控制配料过程、三蒸馏甑白酒的差压蒸馏节能生产和白酒蒸馏管理系统,实现了白酒装甑过程中蒸汽自动控制、成熟醪经成熟醪预热器预热后用三个蒸馏甑进行蒸馏、白酒装甑过程中蒸汽与冷凝水的自动控制和远程监控,达到能量耦合、降低能耗、提高白酒生产效率和降低成本的目标。     

基于色谱模拟蒸馏技术的石油馏分恩氏蒸馏馏程测定方法

以美国材料与试验协会（ASTM）方法为基础模型,提出一种基于色谱模拟蒸馏技术的恩氏蒸馏馏程测定方法。利用模型计算值与实验值之间的误差获得模型校正参数,对原始模型进行校正。校正模型已成功地应用于直馏汽油、煤油和柴油等馏分的恩氏蒸馏馏程预测。利用校正模型预测得到的馏程数据能够满足恩氏蒸馏测试重复性的要求。色谱模拟蒸馏是一种可以取代恩氏蒸馏的馏程测定方法。     

蒸馏法前处理联用离子色谱测定水体基质中氨氮

建立了一种用蒸馏法富集水体样品中氨氮并联用离子色谱技术检测的方法。该方法可以有效富集水体中的氨氮（以NH4＋形式）,并去除水体样品中的Na＋、K＋及其他基质离子的影响。以IonPac CS16色谱柱为分离柱,用甲磺酸等度洗脱方式使待测组分分离,流速为1mL/min,电导检测,外标法定量。在优化后的实验条件下,NH4＋的线性范围为0.01-50μg/mL,相关系数大于0.9991;将该方法应用于海水、湖水、苦咸水等水样的检测,实际样品加标回收率为86.8-106.8%,检测限为1.28ng/mL（信噪比S/N=3）。实验结果表明,该方法可以用于水体中氨氮的检测。     

Nonlinear control of a multicomponent distillation process coupled with a binary distillation model as an EKF predictor

The work is devoted to design the globally linearizing control (GLC) strategy for a multicomponent distillation process. The control system is comprised with a nonlinear transformer, a nonlinear closed-loop state estimator [extended Kalman filter (EKF)], and a linear external controller [conventional proportional integral (PI) controller]. The model of a binary distillation column has been used as a state predictor to avoid huge design complexity of the EKF estimator. The binary components are the light key and the heavy key of the multicomponent system. The proposed GLC-EKF (GLC in conjunction with EKF) control algorithm has been compared with the GLC-ROOLE [GLC coupled with reduced-order open-loop estimator (ROOLE)] and the dual-loop PI controller based on set point tracking and disturbance rejection performance. Despite huge process/predictor mismatch, the superiority of the GLC-EKF has been inspected over the GLC-ROOLE control structure.     

关于焦油蒸馏釜顶安全阀的讨论

针对焦油蒸馏釜顶安全阀在使用中遇到的一些实际问题，提出了改进建议。     

精馏塔温度模糊解耦控制系统的研究

精馏过程属于多变量、时变、强耦合和具有分布参数的非线性过程,为了实现精馏塔塔顶和塔底的产品均需达到一定纯度的要求,在分析精馏塔工作特性以及塔顶和塔底的温度耦合特征的基础上,提出了一种塔顶和塔底温度模糊解耦控制方案。通过对塔顶和塔底温度的PID控制、解耦控制、模糊解耦控制,进行了设定值扰动测试、过程扰动测试的仿真。结果表明,模糊解耦优于PID控制和解耦控制,验证了模糊解耦控制的可行性。     

Synthesis of nonlinear adaptive controller for a batch distillation

A nonlinear adaptive control strategy is proposed for a binary batch distillation column. The hybrid control algorithm comprises a generic model controller (GMC) and a nonlinear adaptive state estimator (ASE). The adaptive observation scheme mainly estimates the imprecisely known parameters based on the available tray temperature measurements. The sensitivity of the proposed estimator is investigated with respect to the effect of initialization error, unmeasured disturbance and uncertainty. Then, a comparative study is carried out between the derived nonlinear GMC-ASE controller and a traditional proportional integral law in terms of set point tracking and disturbance rejection performance. The study also includes the effect of measurement noise and parametric uncertainty on the closed-loop performance. The proposed adaptive control algorithm is shown to be quite promising due to the exponential error convergence capability of the ASE estimator in addition to the high-quality control action provided by the GMC controller.     

Side draw control design for a high purity multi-component distillation column

Industrial methanol production involves a multi component feed containing methanol, water and trace levels of ethanol being refined to produce AA grade methanol at high product recovery. Due to practical constraints, the bottoms discharge of the column is primarily water with only trace of methanol impurities. As a result of these constraints, ethanol, which is a non-key middle boiling component gets “trapped” near the side draw of the column forming an ethanol bulge, which in turn results in non-linear, inverse, time and state varying behaviour of the side draw ethanol composition. In this work, we established that the existence of the ethanol bulge creates the complex process behaviour of the side draw ethanol composition and that this bulge needs to be explicitly controlled. This type of explicit composition bulge analysis and subsequent control has not been attempted on methanol distillation columns before. For this purpose a novel, robust and practical side draw control scheme to detect and remedy the excess ethanol bulge movement using override control is presented. The side draw controller, together with other regulatory controllers is shown to maintain on-specification operations of the column. Disturbance rejection tests carried out illustrate that the side draw control scheme will keep the column operating within commercial specification. It is also shown that a traditional DV control structure is unable to achieve this objective.     

Neuro-estimator based GMC control of a batch reactive distillation

In this paper, an artificial neural network (ANN)-based nonlinear control algorithm is proposed for a simulated batch reactive distillation (RD) column. In the homogeneously catalyzed reactive process, an esterification reaction takes place for the production of ethyl acetate. The fundamental model has been derived incorporating the reaction term in the model structure of the nonreactive distillation process. The process operation is simulated at the startup phase under total reflux conditions. The open-loop process dynamics is also addressed running the batch process at the production phase under partial reflux conditions. In this study, a neuro-estimator based generic model controller (GMC), which consists of an ANN-based state predictor and the GMC law, has been synthesized. Finally, this proposed control law has been tested on the representative batch reactive distillation comparing with a gain-scheduled proportional integral (GSPI) controller and with its ideal performance (ideal GMC).     

分子影像学与蛋白质组学

分子影像学与蛋白质组学都是目前最前沿、最热门的医学研究领域。分子影像学通过先进的影像技术“在体”显示与疾病相关的分子改变,而蛋白质组学通过灵敏的体外检测技术分析与疾病相关的蛋白质组变化。将分子影像技术和蛋白质组学技术结合起来,很可能相互补充、相互促进,共同推动医学诊疗技术的突破。本文将在简要介绍分子影像学和蛋白质组学各自主要特点的基础上,分析二者相互结合的价值,并展望未来发展的方向。     

分子生物学的发展和相关科学仪器的进展

在基因工程,人类基因组计划,核酸测序,基因诊断,基因体外扩增技术和基因芯片等分子生物学领域中发展起来的一些科学仪器,文章描述了科学仪器与学科发展之间的关系。