Preparation of novel nano-adsorbent based on organic-inorganic hybrid and their adsorption for heavy metals and organic pollutants presented in water environment

The nanocomposites based on organic-inorganic hybrid have been attracting much attention due to their potential applications used as new type of functional materials, such as colloidal stabilizers, electro-optical devices, and nanocomposites materials. The organic-inorganic hybrid of poly(acrylic acid-acrylonitrile)/attapulgite, P(A-N)/AT nanocomposites, were prepared by using in situ polymerization and composition of acrylic acid (AA) and acrylonitrile (AN) onto modified attapulgite (AT) nanoparticles. The resulting P(A-N)/AT nanocomposites were transformed into novel nano-adsorbent of poly(acrylic acid-acryloamidoxime)/attapulgite by further functionalization, i.e. P(A-O)/AT nano-adsorbent. The adsorption properties of P(A-O)/AT toward metal ions were determined, and the results indicated that the adsorbents with nanocomposite structure held a good of selectivity to Pb(2+) among numerous metal ions. The maximum removal capacity of Pb(2+) was up to 109.9 mg/g and it is notable to see that the adsorption removal of P(A-O)/AT nano-adsorbent for Pb(2+) could achieve more than 96.6% when the initial concentration of Pb(2+) was 120.0 mg/l. The kinetics, isotherm models, and conductivity were introduced to study the adsorption mechanism of P(A-O)/AT for Pb(2+) and it was concluded that it could be chemisorptions process and the best coordination form took place when AO:AA:Pb(2+) = 1:1:1. In addition, after simply treated with CTAB, P(A-O)/AT nano-adsorbent showed better adsorption properties for phenol than the same kinds of materials.     

Hydrogels for Engineering of Perfusable Vascular Networks

Hydrogels are commonly used biomaterials for tissue engineering. With their high-water content, good biocompatibility and biodegradability they resemble the natural extracellular environment and have been widely used as scaffolds for 3D cell culture and studies of cell biology. The possible size of such hydrogel constructs with embedded cells is limited by the cellular demand for oxygen and nutrients. For the fabrication of large and complex tissue constructs, vascular structures become necessary within the hydrogels to supply the encapsulated cells. In this review, we discuss the types of hydrogels that are currently used for the fabrication of constructs with embedded vascular networks, the key properties of hydrogels needed for this purpose and current techniques to engineer perfusable vascular structures into these hydrogels. We then discuss directions for future research aimed at engineering of vascularized tissue for implantation.     

电力系统暂态稳定性闭环控制（二）——多机电力系统暂态不稳定判别方法

定义了具有一定预测功能的复合功角,据此将多机系统实时划分为2组同调机群并等值为一个单机系统。将基于轨迹凹凸性的不稳定指标从单机系统拓展到多机系统中,针对非自治特性发展出角度-角加速度平面暂态不稳定辅助判据,提出基于响应的多机系统不稳定实时判别方案。IEEE 10机39节点系统和三华实际电网的仿真结果表明,该方案可以根据系统发生多次大扰动后的响应准确地判断系统的暂态稳定性,为后续闭环紧急控制奠定了基础。     

电力系统暂态稳定性闭环控制（三）——基于预测响应的暂态不稳定闭环控制启动判据

尽管基于实时响应的不稳定判据可以快速启动稳定控制,但为了提高控制投入后阻止不稳定的效果、减小控制的代价,最好在必要时尽可能早地启动闭环控制。提出基于电力系统发电机实测轨迹的滚动预测未来轨迹的方法,使用预测轨迹判别暂态不稳定,并启动后续的稳定性闭环控制。IEEE 10机39节点系统和三华电网实际系统的仿真验证了该预测暂态不稳定后启动控制的准确性和快速性。     

主流烟气中氨与部分羰基化合物的偏相关分析及应用

为提高离子色谱(IC)法测定卷烟主流烟气中氨的待测液的稳定性,分析了57种卷烟主流烟气中氨与部分挥发性羰基化合物(甲醛、乙醛、丙酮、丙烯醛、丙醛、巴豆醛和2-丁酮)的偏相关性;根据偏相关分析结果,以甲醛-HCl混合溶液(甲醛质量分数为15%,HCl物质的量浓度为100 mmol/L)作为萃取液对现行的检测方法(YC/T 377—2010)进行了改进,并考察了5种卷烟样品氨待测液的稳定性。结果表明:1主流烟气中的氨与甲醛呈极显著负相关,且二者在氨的待测溶液中会协同升高;2改进现有IC方法的萃取液后,5种卷烟样品的氨待测液经过24 h仍然比较稳定;3方法改进后,检出限为0.30μg/支,加标回收率为97.05%~102.40%,日间相对标准偏差(RSD)为1.28%。该方法较好地解决了待测液氨检测结果随时间不断升高的问题,适用于分析卷烟主流烟气中氨的释放量。     

新型稳定的TC35i短信模块电源设计

在TC35i短信模块开发中,电源的供给十分重要,电源设计不当可能会导致断线、发送短信失败等问题。本设计能提供4V稳定电压,杂波及干扰小稳定性好;还为TC35i模块提供了一路IGT使能信号,使得在上电后无需连接单片机就可自动登录网络。基于该设计的短信模块开发板能在单片机和电脑之间任意控制切换,且在实际项目中得以应用。     

POLYBASE系统中的查询处理技术*

POLYBASE系统是一个集成的多数据库系统．本文主要讨论了POLYBASE系统的体系结构、集成数据模型，提出了一个基于加权查询树的查询表示模型，设计并实现了基于加权查询树查询表示模型的一个有效的导航查询处理算法．     

电力系统暂态稳定性闭环控制（七）——实现方案与控制效果

给出基于广域测量系统的暂态稳定性闭环控制系统实现方案,该闭环控制系统应用实时测量信息,依据系统相轨迹几何特征,实测、预测暂态不稳定并实时计算、分配切除超前机组,实现电力系统暂态稳定性的闭环控制。讨论了闭环控制系统的系统结构框架和物理实施条件,包括系统控制主站、发电厂子站的功能和软件流程图,以及子站与主站间的配合。IEEE 39节点系统和三华电网系统仿真表明,在单一重大扰动、连续重大扰动及前期控制作用下,所提方案都能对暂态稳定性作出准确预测,并对将要失稳的系统施加有效、经济的切机控制。     

Study on the tribological properties of porous sweating PEEK composites under ionic liquid lubricated condition

The tribological behaviors of novel porous Polyetheretherketone (PEEK) composites under 1‐hexyl‐3‐methylimidazolium tetrafluoroborate ionic liquid lubricated condition were investigated. The effect of sliding velocity and applied load on the sweating tribological properties and the stability of lubricating oil film was also studied. Results indicated that when the sliding velocity was 0.69 m/s and the applied load was 250 N, the friction coefficient and wear rate of the ionic liquid lubricated porous sweating activated carbon fiber/polytetrafluoroethene/PEEK composites showed the minimum values, were 0.0197 and 4.145 × 10^?15 m³/Nm, respectively. The friction coefficients fluctuated in a narrow range of 0.0162–0.0215. It was found that the porous sweating PEEK composites under ionic liquid lubricated condition showed good low‐friction and antiwear performance, especially under the condition of high sliding velocity and applied load. The formed transfer film due to the tribo‐chemical reaction as well as boundary lubricating film is effective in improving the carrying capacity and antiwear properties of the porous sweating PEEK composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40989.     

核设施退役土壤中氚允许残留量限值推定的一种方法

本文应用美国能源部的程序ＲＥＳＲＡＤ５．０对我国某氚实验设施场址给出了土壤中残留氚容许限值与年有效剂量目标的关系。介绍了所用方法，主要计算公式和最后结果。