金属退火炉微机控制系统的设计

介绍了金属退火炉微机控制系统的功能、组成、控制方法及软件设计。该系统具有控制精度高、可靠性好等特点．适用于一般工业或实验室加热电炉的控制。     

A cytoprotective graphene oxide-polyelectrolytes nanoshell for single-cell encapsulation

Graphene oxide(GO)has been increasingly utilized in the fields of food,biomedicine,environment and other fields because of its benign biocompatible.We encapsulated two kinds of GO with different sizes on yeast cells with the assistance of polyelectrolytes poly(styrene sulfonic acid)sodium salt(PSS)and polyglutamic acid(PGA)(termed as Y@GO).The result does not show a significant difference between the properties of the two types of Y@GO(namely Y@GO1 and Y@GO2).The encapsulation layers are optimized as Yeast/PGA/PSS/PGA/GO/PGA/PSS based on the morphology,dispersity,colony-forming unit,and zeta potential.The encapsulation of GO increases the roughness of the yeast.It is proved that the Y@GO increases the survival time and enhance the activity of yeast cells.The GO shell improves the resistance of yeast cells against pH and salt stresses and extends the storage time of yeast cells.     

On developing a novel mixed-unit microparticle system for controlled release

In this study, uniform microparticles were prepared using the highly efficient microfluidic spray drying technology, and then a flexible controlled release mixed-unit microparticle system was developed to meet various needs. A mathematical drug release model of the mixed system was established and two mixed formulations were used to testify the predictive ability when initial parameters were given. Results have proved that the proposed model could precisely predict the release rate of tested samples. In conclusion, the novel system for controlled release may provide a new option for modified release drugs and may have a good prospect in the industrial application.     

New bilayer-coated microbead system for controlled release of 5-aminosalicylic acid

A new bilayer-coated microbeads for oral delivery of 5-aminosalicylic acid (5-ASA) were prepared from naturally occurring polysaccharides via emulsification method. 5-ASA was successfully encapsulated in chitosan–λ-carrageenan-coated alginate microbeads. The morphology and sizes of microparticles were studied using optical microscopy and dynamic light scattering. Drug release profiles were followed using high-performance liquid chromatography (HPLC) with spectrophotometric detection. The effect of chitosan thin layer and chitosan–λ-carrageenan bilayer on the drug release was studied at pH values simulating these characteristic for stomach (pH = 1.2) and intestine (pH = 7.4). Chitosan layer slightly increased 5-ASA release at pH = 1.2, whereas double-layer external coating decreased the release rates. Due to the bilayer properties, the micro-carriers were additionally protected against acidic conditions of the stomach and drug release in the intestine could be better controlled.     

A portable,four-wavelength,single-cell photoacoustic spectrometer for ambient aerosol absorption

Aerosols directly affect Earth's climate by scattering and absorbing solar radiation. Although they are ubiquitous in Earth's atmosphere, direct, in situ, wavelength-resolved measurements of aerosol optical properties remain challenging. As a result, the so-called aerosol direct effects are one of the largest uncertainties in predictions of Earth's future climate, and new instrumentation is needed to provide measurements of the absorption of sunlight by atmospheric particles. We have developed a portable, four-wavelength, single-cell photoacoustic spectrometer for simultaneous measurement of aerosol absorption at 406, 532, 662, and 785 nm, with an additional extinction measurement at 662 nm via a built-in cavity ringdown spectrometer. The instrument, dubbed MultiPAS-IV, is compact, robust, has low power requirements, and utilizes a multipass optical arrangement to achieve typical detection limits of 0.6–0.7 Mm^?1 for absorption (2σ, 2-min average). Tests with nigrosin aerosols show agreement with Mie theory calculations to within 2%, and comparison with a 7-wavelength aethalometer shows good correlation for ambient (Athens, GA, USA) aerosols. We demonstrate the utility of the broad spectral coverage and sensitivity of the MultiPAS-IV for calculating the absorption Ångström exponent of black carbon (AAE_BC, median value of 0.70) in ambient aerosols and use this value to derive the brown carbon contributions to absorption at 406 nm (43%) and 532 nm (13%) and its wavelength dependence (AAE_BrC = 6.3).

Copyright © 2018 American Association for Aerosol Research     

瓜胶及其衍生物在药物控制释放领域的研究进展

介绍了官能团衍生化、接枝共聚、交联等瓜胶衍生物的制备方法及影响因素、瓜胶及其衍生物在药物控制释放领域的应用现状,并指出改性瓜胶具有比原粉更好的药物控制释放效果,因此经过配方设计,瓜胶及其衍生物有望成为药物控制释放尤其是靶向结肠给药领域的理想载体。     

Bifurcations in a bang-bang controlled mixed culture system

A bang-bang controlled chemostat culture in which two microbial populations compete for the same nutrient was studied from the standpoint of bifurcation theory. The dilution rate was periodically switched between two fixed values. The bifurcations of periodic states due to changes in the control parameters, the period and the switching ratio were investigated and the region of co-existence in the control parameter plane was determined. The stability of each periodic state was determined by seeking the values of the corresponding characteristic multipliers. The bifurcations without any topological contradiction were determined by applying the index theory.     

可控硅整流系统的设计和运行

介绍了24相可控硅整流电路原理，分析了整流系统的设计和运行情况。     

一种新型汽车电子控制汽油喷射系统专用气雾型清洗剂

以大豆油甲酯、苯甲醇(BA)、二丙二醇丁醚(DPNB)、四氢萘(THN)等为主溶剂,以二甲醚(DME)与CO2为双推进剂,制备了一种气雾型汽车电子控制汽油喷射系统专用清洗剂。所制备的清洗剂具有溶解胶质、消除积炭、增强润滑、形成保护修复膜等特点。     

Plant-wide control system design: Primary controlled variable selection

This work is focused on the development of a rigorous, model-based approach for the selection of primary controlled variables as part of a plant-wide control system design methodology. Controlled variables should be selected for their self-optimizing control performance and controllability while ensuring satisfactory performance in terms of dead-time and closed loop interactions. This work has considered both self-optimizing and control performance as well as has addressed issues related to loop-interactions and superstructure constraints. The new three-stage approach developed in this work results in a large-scale, constrained, mixed-integer multi-objective optimization problem. For solving this problem, a parallelized, bi-directional branch and bound algorithm with dynamic search strategies has been developed to solve the problem on large computer clusters. The proposed approach is then applied to an acid gas removal unit as part of an integrated gasification combined cycle power plant with CO₂ capture.     

Kinetic degradation and controlled drug delivery system studies for sensitive hydrogels prepared by gamma irradiation

Ternary mixtures of N‐vinyl‐2‐pyrrolidone/itaconic acid and gelatin were irradiated by gamma rays at 30 kGy/s and at ambient temperature to prepared poly (NVP/IA and G) hydrogels. Poly (NVP/IA) hydrogels were prepared in different compositions (NVP/IA) mole ratio, (100/0), (98/1.5), (96.5/3.5), and (93/7.0) at 30 kGy. Then adding gelatin at different content (5, 10, 15, 20) mg to the best composition (NVP/IA/H₂O) (93/7)% for the characterization of network structure of these hydrogels, kinetic swelling drug release behavior and Scan Electron Microscope was studied. The equilibrium degree of swelling for P(NVP/IA) and P(NVP/IA/G) copolymer and the swelling‐degradation kinetics were also studies. According to dynamic swelling studies, both the diffusion exponent and the diffusion coefficient increase with increasing content of (IA), whereas, the addition of gelatin to (NVP/IA) composition by different content did not lead to any significant change in swelling percent. Also, the swelling behavior of copolymer hydrogels in response to pH value of the external media was studied, it is noted that the highest swelling values were at pH 4. The in vitro drug release behavior of these hydrogels was examined by quantification analysis with a UV/VIS spectrophotometers. Chlorpromazine hydrochloride was loaded into dried hydrogels to investigate the stimuli‐sensitive property at the specific pH and the drug release profile of these pH‐sensitive hydrogels in vitro. The release studies show that the highest value of release was at pH 4 which can be used for drug delivery system. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

全自动变频调速供水控制系统的改进

对全自动变频调速供水控制系统进行了分析，根据应用情况，对原控制系统中存在的不足之处进行改进，满足了生产的要求。     

计算机控制卡车调度若干决策因素的探讨

针对卡车调度决策中存在的若干问题，分别对设备故障的影响、调度点的优化设置。分区调度等问题进行了理论分析和实例模拟研究。比较了不同设置条件下的调度效果，对系统的产量、设备利用率等指标进行了对比分析，得出了优化的设置方式。     

A fed-batch design approach of struvite system in controlled supersaturation

This paper focuses on struvite (MgNH₄PO₄·6H₂O) crystallization in controlled supersaturation. Struvite can be used as a slow-release fertilizer. Crystallization experiments were conducted using supersaturated solutions. The secondary focus of this paper is the design of a struvite recovery system in fed-batch-controlled supersaturation mode. The design and commissioning of fed-batch struvite crystallization included the determination of operating supersaturation of struvite crystallization, suitable seed materials and the composition of feed solution. Determination of operating supersaturation of struvite crystallization was conducted by two steps including thermodynamic simulation using gPROMS² (process simulation software) along with a set of batch experiments. Investigation of suitable seed materials was also conducted using set of batch experiments. Two types of seed materials including quartz sand and struvite seeds were used in the investigation of seed materials. Composition of feed solution included the investigation of struvite solution chemistry using PHREEQC³ thermodynamic modeling package. Based on the previously investigated design approach, struvite crystallization in fed-batch system was conducted using a 44-L of reactor with 15-L of initial reactant volume.     

高压开关设备涂装工艺

介绍了国内和日本东芝公司成熟的高压开关设备涂装工艺，并对两种涂装设备进行对比，总结了涂装工艺特点。     

Stimuli‐responsive molecularly imprinted hybrid polymer gel as a potential system for controlled release

The purpose of this study is to develop a stimuli‐responsive hybrid polymer gel system with an improved mechanical stability as a controlled drug delivery carrier that can undergo phase transition by the stimulation of ethanol–water mixture. For this aim, trimethoxysilane terminated poly(propylene glycol) by coupling of 3‐isocyanatopropyl‐triethoxysilane with the hydroxyl end groups of poly(propylene glycol) through urethane bonds was synthesized. Hybrid polymer gels prepared in the presence of tryptophan (Trp), as a model of drug, were characterized and gelation time of polymer network was obtained by monitoring the fluorescence emission of Trp in pre‐gel solution. Swelling, solvent uptake and release kinetic of polymer gels were evaluated depending on time. The diffusional exponents (n) and diffusion constants (k) of each gel were calculated by using the swelling kinetic data. The effect of precursors as a monomer on Trp release profile was analyzed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42913.     

TVu5D低压继电器使用说明

1　概述TVu5 D是一种低继电器 ,主要用于同步性检查 ,继电器包括两个低压元件。2　技术规定下表为 TVu5 D继电器的额定值类型 TVu5 D形　　式 EG1元件数 ur× 2 (V1,V2 )额定电压 6 3 .5 V or 1 1 0 V额定频率 5 0 Hz or 6 0 HzDC电源 DC 1 1 0 V　　 +3 0 %- 2 0 %给定值 V1:1 0 - 1 5 - 2 0 - 2 5 - 3 0 (V)V2 :3 0 - 3 5 - 40 - 45 - 5 0 (V)额定负载CT 0 .5 VA/1 .5 VAPC 1 0 W触点能力 DC 2 2 0 V　 0 .1 A(L /R=40 ms)绝缘测试 2 KV　 5 0 Hz for 1 min耐脉动电压 5 0 KV　 1 .2 /5 0μS外部电阻 1 KΩ(2 W)容许…     

电池电压暂降保持电路的设计

针对大功率设备在上电瞬间存在的电池电压暂降问题,在比较4种现行方案后设计了一种电池电压暂降保持电路。仿真测试和现场实际使用结果表明:该电路能够动态、快速地补偿电压暂降问题,保证系统有足够的电能接续,使系统保持正常、稳定的工作状态。     

Development and hot-melt impregnation of a model controlled flow prepreg system

A controlled-flow epoxy-based model prepreg resin system was developed. The formulation of the model controlled-flow resin was designed from performance information obtained from a commercially available controlled-flow resin, presently used in the aircraft industry. Thermoanalytical techniques including rheometry were used to provide the necessary information to develop the model system along with a formulation methodology developed by Seferis and co-workers. The model resin formulation, which was a combination of tetraglycidyl ether of methylenedianiline (TGMDA), diglycidyl ether of bisphenol-A (DGEBA), carboxyl-modified butadiene/acrylonitrile rubber (CMBN), carboxyl-terminated butadiene/acrylonitrile rubber (CTBN), bisphenol-A (BPA), diaminodiphenyl sulfone (DDS), and dicyandiamide (DICY), was hot-melt impregnated into unidirectional carbon fibers on a laboratory scale hot-melt prepreg machine. A two-parameter, three-level design of experiments was performed on the prepreg processing parameters in which impregnation temperature and pressure were varied. Thus, a total of nine different experimental prepregs were produced and characterized by resin content, extent of impregnation, and tack. The results from the characterization of the nine experimental prepregs are compared with the effects of the prepreg processing conditions. These results are also compared with the results generated for the commercial controlled-flow resin. Collectively, this work provides a fundamental basis by which the analysis and rational utilization of controlled-flow matrix prepregs can be effected.     

An efficient method for the purification of arachidonic acid from fungal single-cell oil (ARASCO)

PUFA, such as arachidonic acid (AA), have several pharmaceutical applications. An efficient method was developed to obtain high-purity arachidonic acid (AA) from ARASCO, a single-cell oil from Martek (Columbia, MD). The method comprises three steps. In the first step, AA was enriched from saponified ARASCO oil by low-temperature solvent crystallization using a polar, aprotic solvent, which gave a FA fraction containing 75.7% AA with 97.3% yield. The second step involved enriching AA content via lipase-catalyzed selective esterification of FA with lauryl alcohol. When a mixture of 1 g FA/lauryl alcohol (2∶1 mol/mol), 50 mg Candida rugosa lipase, and 0.33 g water was incubated at 50°C for 24 h with stirring at 400 rpm, the AA content in the unesterified FA fraction was as much as 89.3%, with ca. 90% yield. Finally, a solvent extraction procedure, in which acetonitrile was the extracting solvent, was used to enrich AA from FA fraction dissolved in n-hexane. The best results were obtained when 2 g FA was dissolved in 80 mL hexane and extracted twice, each time with 20 mL acetonitrile at −20°C, by allowing 2 h storage. This step gave a FA fraction containing 95.3% AA with 81.2% yield. By using this three-step process the AA content in the saponified single-cell oil (ARASCO) was increased from 38.8 to 95.3% with a total yield of ca. 71%.