用多施主求解策略集成智能制造中的车间层控制问题

本文与传统的集中全局控制方案不同，这里采用一系列可完成各自子任务的“智能团体”，相互协作完成整个控制过程。该框架使用一个竞争驱动模型组合各“智能团体”的利益与任务，通过零件与资源的多步谈判解决车间层控制问题。     

Methodology for the simultaneous optimization of location and parameters of friction dampers in the frequency domain

It is well known that the use of passive energy dissipation devices such as friction dampers reduces the dynamic response of structures subjected to earthquakes. However, the parameters of each damper as well as the best position of these devices in the structure remain difficult to determine. Although articles on optimum design of tuned mass dampers and viscous dampers have been published, there is a lack of studies on the optimization of friction dampers. In previous contributions, the authors proposed a method for optimum design of this kind of damper. The proposed method is very useful; however, the computational time required is high. Thus, in this article, a new methodology for the simultaneous optimization of placement and forces of friction dampers is proposed. As this new method is developed in the frequency domain, the computational time is considerably reduced. For this purpose, the search group algorithm, recently developed by the authors, is employed, which is able to deal with optimization problems involving mixed discrete and continuous variables. For illustrative purposes, a six-storey shear building is analysed. Forces and positions of friction dampers are the design variables, while the objective function is to minimize the root mean square displacement at the top of the building. The results showed the excellent performance of the proposed method, reducing the root mean square displacement by more than 82%, with only three friction dampers and in a relatively short computational time.     

Preliminary study on the development of nanoemulsions for carbamazepine intravenous delivery: an investigation of drug polymorphic transition

Carbamazepine (CBZ) is available on the pharmaceutical market as tablets, capsules, and oral suspensions, but not as a parenteral formulation for clinical use. Parenteral emulsions are a good alternative to poorly water-soluble drugs such as CBZ. In this way, four different emulsions containing 3 mg/mL of CBZ were developed, but during a period of storage, drug crystal precipitates appeared. To investigate this phenomenon, differential scanning calorimetry, infrared spectroscopy, and light microscopy were employed. The results suggested a polymorphic transition from β form to dehydrate form, resulting in drug precipitation, although the emulsions themselves remained stable for at least three months.     

Study of mechanical degradation of UHMWPE acetabular components due to clinical X-ray procedures

The use of multi-component femoral implants to replace the femur head and re-establish bone motion has been widespread since the 70s. Frequently these implants have spherical metallic heads made of, for example, 316-L stainless steel or Cr–Co alloys, which allow rotational motion towards a polymeric component (UHMWPE). One of the major causes of implant rejection is the generation of UHMWPE debris on the surface between the implant head and the polymeric component. The gamma ray sterilization of implants and the periodical X-ray medical control could contribute to premature degradation of the polymeric surface, resulting in increased wear and shortened lifetime of the implant. In this work we study the degradation degree of the polymeric UHMWPE component as function of the X-ray dose. The elasto-plastic deformation and recovery were carried out by means of a nanohardness tester equipment and the polymer degradation was measured using a fast Fourier transform infra-red (FT-IR) equipment. The results show the compromise among the irradiation doses, the surface oxidation and the mechanical properties of the samples.     

知识经济需要宽带网

信息和知识已成为社会和经济发展的战略资源和基本要素,而它们的传播和共享需要高速实时的知识化网络,并使网络不断升级。对未来宽带网的发展以及北美地区宽带网的发展计划和做法进行了介绍和分析。     

Crystallisation kinetics of palm stearin,palm kernel olein and their blends

The kinetics of isothermal crystallisation of palm stearin, palm kernel olein and their blends (20–80 g/100 g palm stearin with 20 g/100 g increment) were determined using differential scanning calorimetry (DSC). The mechanism of crystallisation (n) was calculated by applying the Avrami equation using the crystallisation curves obtained at 10, 15 and 20 °C. The DSC isothermal crystallisation data at 10, 15 and 20 °C fitted well into the Avrami equation over the entire fractional crystallisation with correlation coefficient always greater than 0.98. Based on the Avrami exponent obtained, the palm stearin and palm kernel olein have different nucleation and growth mechanisms. The suggested mechanism for palm kernel olein was high nucleation rate at the beginning of crystallisation, which decreased with time, and plate-like growth (n = 2). On the other hand, the mechanism for palm stearin was instantaneous heterogeneous nucleation followed by spherulitic growth (n = 3). For blends of palm stearin and palm kernel olein, the mechanisms of crystallisation were 2 and 3 depending on the composition of the blends and crystallisation temperatures.     

A New Simplified and Stability Indicating Liquid Chromatography Method for Routine Analysis of Isoflavones Aglycones in Different Complex Matrices

In this work, a stability indicating method for routine analysis of isoflavones in different matrices was developed and validated. In order to simplify the analytical method, the glycosides were previously hydrolyzed to the corresponding aglycone forms. The separation of all isoflavone aglycones was achieved in 23 min, with a total time of analysis of 30 min, using trifluoroacetic acid 0.1 % (v/v) and acetonitrile:trifluoroacetic acid (100:0.01, v/v) as mobile phase. The LC method specificity was evaluated by the analysis of isoflavone standards submitted to acidic, alkali, neutral, oxidative, and photolytic stress conditions. The isoflavones degraded in alkali at 60 °C or in alkali under ulraviolet C (UVC) radiation, forming, in both conditions, three degradation products D1, D2, and D3 which were analyzed by liquid chromatography mass spectroscopy (LC-MS/MS). The method showed linearity higher than 0.999 with the concentration ranged from 0.1 to 10 μg ml^-1 for all isoflavone aglycones. The limits of quantitation obtained using calibration curves were from 0.28 to 0.37 μg ml^-1 and the intermediary precision at three levels (2, 6, and 10 μg ml^-1) showed RSD values between 0.03 and 0.25 %. After the performed validation, the LC method was applied to compare the isoflavone aglycones content in three different matrices: Glycine max beans, Glycine max dry extract, and isoflavone aglycone loaded nanoemulsion. The repeatability data showed RSD values between 0.02 and 1.41 % and the intermediary precision at three levels showed RSD values between 0.05 and 1.99 %. The recovery data of the isoflavone aglycones standards in the matrices at three levels were between 90.74 and 106.43 %.     

水平井在草古1潜山裂缝性稠油油藏开发中的应用

方法：采用油藏地质研究,数值模拟研究和现场试验分析等技术,对胜利油区草古1潜山裂缝性稠油油藏利用水平井开发的可行性进行了研究,目的：在分析水平井开发潜山油藏可行性的基础上,利用水平井开发潜山稠油油藏,提高开发效果,结果：利用水平井开发草古1潜山裂缝性稠油油藏的生产实践证明,水平井日产油一般为20－30t,而相邻直井一般为7－10t,水平井产油量是其邻近直井相同生产时间产油量的2－3倍,结论：水平井开发潜山裂缝性稠油油藏取得了较好的开发效果。     

Clotrimazole-loaded Eudragit® RS100 nanocapsules: Preparation,characterization and in vitro evaluation of antifungal activity against Candida species

Clotrimazole is a common choice for the treatment of vulvovaginal infections, but its low solubility and some side effects pose a challenge to its application. This work evaluated the feasibility to formulate clotrimazole-loaded cationic nanocapsules using Eudragit® RS100 and medium chain triglycerides as polymer and oily core, respectively, by the method of interfacial deposition of a preformed polymer. The physicochemical characteristics of nanocapsule formulations were evaluated at 0 day and 60 days after preparation. Particle size, zeta potential, polydispersity index, pH and drug content were stable during this period. In addition, nanocapsules were able to protect clotrimazole from photodegradation under UV radiation. By the dialysis bag diffusion technique, the nanosized formulations showed prolonged release of clotrimazole by anomalous transport and first order kinetics. A microbiological study was carried out by the microdilution method and showed that nanocapsules (mean size: 144 nm; zeta potential: + 12 mV) maintained the antifungal activity of clotrimazole against Candida albicans and Candida glabrata strains susceptible and resistant to fluconazole.     

重油加氢装置动态仿真系统的集成

以微机多用户系统作为重油加氢反应系统动态仿真器的硬件基础，与常用的网络结构相比，硬件只增加一块多用户卡；操作系统适用于基于ＤＯＳ、ＷＩＮＤＯＷＳ及自行开发的各类软件；系统安装及使用方便。仿真器以实时仿真动态数据库为核心，对各种功能模块进行一体化集成。采用统一时钟，通过消息机制实现前台、数据库和数学模型之间的信息传递，实现结构化与模块化设计。所构造的软件系统层次清晰，可作为通用的ＤＣＳ仿真框架结构。