可控串补在天平500kV交流输变电工程中的应用

通过对天平500kV线路可控串补系统控制及保护模块的介绍,剖析了该可控串补系统固定式常规串补(FSC)和动态式可控串补(TCSC)的控制和触发过程及保护原理,强调随着可控硅、氧化锌非线性电阻等先进技术的研发和应用,串补技术在电网系统尤其是超高压远距离输电系统中的应用前景广阔。     

我国纸包装制品的现状与发展前景分析

随着纸包装制品产量的增加和品种的多样化，纸包装制品的作用和地位已大大提高。“绿色包装”的兴起和食品纸包装化，将使纸包装制品的发展前景更为广阔。     

直接还原铁在我厂电弧炉炼钢中的应用及效果分析

概述了直接还原铁的特性及在我厂电弧炉炼钢中的使用情况，并将其效果作了进一步分析。     

Silk Fibroin as an Efficient Biomaterial for Drug Delivery,Gene Therapy,and Wound Healing

Silk fibroin (SF), an organic material obtained from the cocoons of a silkworm Bombyx mori, is used in several applications and has a proven track record in biomedicine owing to its superior compatibility with the human body, superb mechanical characteristics, and its controllable propensity to decay. Due to its robust biocompatibility, less immunogenic, non-toxic, non-carcinogenic, and biodegradable properties, it has been widely used in biological and biomedical fields, including wound healing. The key strategies for building diverse SF-based drug delivery systems are discussed in this review, as well as the most recent ways for developing functionalized SF for controlled or redirected medicines, gene therapy, and wound healing. Understanding the features of SF and the various ways to manipulate its physicochemical and mechanical properties enables the development of more effective drug delivery devices. Drugs are encapsulated in SF-based drug delivery systems to extend their shelf life and control their release, allowing them to travel further across the bloodstream and thus extend their range of operation. Furthermore, due to their tunable properties, SF-based drug delivery systems open up new possibilities for drug delivery, gene therapy, and wound healing.     

Corrosion inhibition by naturally occurringsubstances—I. The effect of Hibiscus subdariffa (karkade) extract on the dissolution of Al and Zn

The thermometric, the weight-loss and the galvanostatic polarization techniques wereused to establish the inhibition of the dissolution of Al and Zn in HCl and NaOH by different concentrations of aqueous extract of Hibiscus subdariffa (Karkade). The extent of corrosion inhibition as measured by the three techniques is comparable. The results indicated that the additive acts by way of adsorption on both cathodic and anodic corrosion areas. Curves representing the variation of the reaction number (R.N.), in thermometric experiments, and the decrease in weight as a function of the concentration of the additive, are invariably sigmoid in nature. When present in enough amounts, the additive decreases the dissolution rate by as much as 85 per cent of the value recorded in its absence.     

A new expert system for learning management systems evaluation based on neutrosophic sets

There has been a sudden increase in the usage of Learning Management Systems applications to support learner's learning process in higher education. Many studies in learning management system evaluation are implemented under complete information, while the real environment has uncertainty aspects. As these systems were described by development organizations with uncertainty terms such as vague, imprecise, ambiguity and inconsistent, that is why traditional evaluation methods may not be effective. This paper suggests neutrosophic logic as a better option to simulate human thinking than fuzzy logic because unlike fuzzy logic, it is able to handle indeterminacy of information which expresses the percentage of unknown parameters. As previous studies suggested neutrosophic decision maker and neutrosophic expert systems as future work in ecommerce and e‐learning applications, this paper presents neutrosphic expert system for learning management systems evaluation. Information for building and validating the neutrosophic expert system is collected from five experts using surveys, and then analysis is done by using Fuzzytech 5.54d software. Finally, the comparison between fuzzy expert system and neutrosophic expert system results show that the neutrosophic logic is capable of representing uncertainty in human thinking for evaluating Learning Management Systems.     

Technological,Regulatory, and Ethical Aspects of In Vitro Meat: A Future Slaughter‐Free Harvest

Defined as meat cultured in a laboratory within a bioreactor under controlled artificial conditions, in vitro meat is a relatively recent area that has opened a whole universe of possibilities and opportunities for the meat sector. With improved chemical and microbial safety and varied options, in vitro meat has been proposed as a green, healthy, environmentally friendly, and nutritionally better product that is free from animal suffering and death. Cell culture and tissue culture are the most probable technologies for the development of this futuristic muscle product. However, there are many challenges in the production of a suitable product at an industrial scale under a sustainable production system and a great body of research is required to fill the gaps in our knowledge. Many materials used in the product development are novel and untested within the food industry and demand urgent regulatory and safety assessment systems capable of managing any risks associated with the development of cultured meat. The future of this product will depend on the actions of governments and regulatory agencies. This article highlights emerging biotechnological options for the development of cultured meat and suggests ways to integrate these emerging technologies into meat research. It considers the problems and possibilities of developing cultured meat, opportunities, ethical issues as well as emerging safety and regulatory issues in this area.     

规则度量值序列的信息扩散估计研究

对若干连续期间的数据挖掘将形成规则的度量值序列。对度量值序列的参数估计，可获得度量值的基本特征参数，用作评价规则的兴趣度，掌握规则的演化规律。基于信息扩散原理，提出了适用于小样本的度量值扩散估计方法。以度量值序列作为非完备知识样本，讨论在波动和上升(下降)趋势下的序列参数计算。实验表明，该方法准确简便、抗干扰性好。     

Synthesis,Thermal Properties and Electrical Conductivity of Na-Sialate Geopolymer

This work aims to study the thermal behavior of basic-geopolymers derived from metakaolin (clay). The geopolymers were characterized by different techniques: thermal analysis (DTA, TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and impedance spectroscopy. Some physicochemical properties of the products were also determined: the phases obtained after geopolymer heat treatment and their electrical properties. The results obtained after drying and heat treatment showed that the products kept their initial shapes, but revealed variable colors depending on the temperatures at which they were treated. The products obtained are amorphous between 300 up to 600 °C with peaks relating to the presence of nanocrystallites of muscovites and zeolite, thus at 900 °C it is quite amorphous but only contains nanocrystallites of muscovites. From the temperature of 950 °C, we notice that the geopolymer has been transformed into a crystalline compound predominated by the Nepheline (NaAlSiO₄) with the presence of a crystalline phase by minor peaks of Muscovite, this crystalline character has been increased at 1100 °C to obtain a whole phase crystalline of a Nepheline. The treatment of this geopolymer for one hour at 1200 °C shows an amorphous phase again corresponding to corundum (α-Al₂O₃). This indicates that the dissolution of the grains by the liquid phase induces the conversion of the material structure from sialate [–Si–O–Al–O] to sialate siloxo [–Si–O–Al–O–Si–O–] and the formation of a new crystalline phase (α-Al₂O₃). This development of sialate to sialate-siloxo was confirmed by IR spectroscopy. As mentioned above, from 300 to 900 °C, Na-sialate geopolymer exhibits the same disorder structure of nepheline. The crystal structure of nepheline is characterized by layers of six-membered tetrahedral rings of exclusively oval conformation. The rings are built by Regularly alternating tetrahedral AlO₄ and SiO₄. Stacking the layer’s parallel to the c axis gives a three-dimensional network containing channels occupied by Na cations. This topology favors easy movement of Na⁺ ions throughout the structure. For this reason, ionic migration in nepheline is widely reported. The refinement of Na-Sialate geopolymer at room temperature gives bulk high ionic conductivity of about 5 × 10^?5 S cm^?1 and this is due to the probable joint contribution of H⁺ and Na⁺ ions. Above 200 °C, Na⁺ seems to remain the only charge carrier with a low activation energy of about Ea?=?0.26 eV. At higher temperatures, the characteristic frequencies become so close that it is impossible to distinguish the contributions. A total resistance comprising both grain and grain boundaries contribution is then determined.