Assessing Human Exposure to Organic Pollutants in the Indoor Environment

There is an ongoing probing of the role of chemicals in the indoor environment. The majority of potential target substances are so‐called very volatile, volatile, and semi‐volatile organic compounds (VVOCs, VOCs, and SVOCs). Depending on their physical properties and the mass transfer conditions, they are distributed in or between the gas phase, particle phase, settled house dust, surface films, clothing, and other fabrics as well as the exposed skin and hair of the occupants themselves. Therefore, inhalation, ingestion, and dermal uptake all must be considered as relevant pathways for exposure assessment in human habitats. Exposure to VVOCs, VOCs, and SVOCs can be estimated by measuring their concentrations in relevant indoor compartments or by determining the amounts of the target compounds and/or their metabolites in urine and blood. Assessing the various routes of exposure often requires a combination of sophisticated and interdisciplinary theoretical background and experimental techniques. Consequently, close communication and collaboration between chemical and exposure scientists are needed to achieve a better understanding of human exposure to chemical substances in various indoor environments. Embedded in the toxicological context, this is the basis for assessing the corresponding health risks and for determining control strategies or approaches to limit such risks.     

Chaotic synchronization and anti-synchronization based on suitable separation

Based on a suitable separation of systems, Lyapunov stability theory and matrix measure, the complete synchronization and anti-synchronization for chaotic systems is investigated. Some simple but generic criteria for the chaotic synchronization and anti-synchronization for chaotic systems are derived, along with a simple configuration by the corresponding suitable separation. Then, to apply the conditions to typical chaotic system—the original Chua's circuit chaotic system such that synchronization and anti-synchronization are achieved.     

扁化效应对弯曲段套管抗挤强度的影响对比分析

针对弯曲段套管抗挤强度随井眼曲率变化规律问题，利用材料力学理论将弯曲段套管等价为均布载荷作用下的弯曲梁模型，根据拉梅厚壁筒理论和强度理论得到套管抗挤强度公式．借鉴扁化变形在圆管类结构中的研究思路，将其拓展到套管抗挤强度分析，对比分析是否考虑扁化效应下四种规格套管不同井眼曲率下的抗外挤强度．研究表明，套管轴向应力随井眼曲率基本呈线性变化；套管抗挤强度随井眼曲率的增加非线性下降．井眼曲率为2o/30 m时，是否考虑套管扁化变形得到的5 1/2"×10.54 mm P110套管抗挤强度误差为12.8 %；井眼曲率为12o/30 m时，误差46.9 %．井眼曲率为2o/30 m时，4 1/2"×9.65 mm TP140V套管抗挤强度误差11.9 %；井眼曲率为12o/30 m时，误差44.7 %．可见，考虑扁化变形后套管抗挤强度小于未考虑扁化变形情况；井眼曲率不大时，两种算法的差距较小，随着井眼曲率的增加，套管扁化变形对套管抗挤强度的影响不能忽略．     

粘结固体润滑膜及其应用

粘结固体润滑膜是固体润滑材料的主要类型之一，因其性能优异而获得了从民用机械到空间技术等各个方面的广泛应用，几乎可以用到工程实际中所有的摩擦部件上．近年来，我国粘结固体润滑膜的应用除在航空航天等尖端技术方面继续保持原有的优势外，其在民用机械中的应用也在逐年增多．但是，由于大多数工程技术人员目前对粘结固体润滑膜还不够了解，实际使用中尚有一定的困难．针对这种情况，并且为了推动国内粘结固体润滑膜之研究与应用的更快发展，系统地对这类固体膜的分类、性能特点、制备工艺和典型应用等进行了综合介绍与评述，指出要充分发挥粘结固体润滑膜的优势，利用其创造更大的社会效益和经济效益，就应当重视开展对这种固体润滑材料与技术的工业应用研究．     

Symbolic computation of exact solutions for a nonlinear evolution equation

In this paper, by means of the Jacobi elliptic function method, exact double periodic wave solutions and solitary wave solutions of a nonlinear evolution equation are presented. It can be shown that not only the obtained solitary wave solutions have the property of loop-shaped, cusp-shaped and hump-shaped for different values of parameters, but also different types of double periodic wave solutions are possible, namely periodic loop-shaped wave solutions, periodic hump-shaped wave solutions or periodic cusp-shaped wave solutions. Furthermore, periodic loop-shaped wave solutions will be degenerated to loop-shaped solitary wave solutions for the same values of parameters. So do cusp-shaped solutions and hump-shaped solutions. All these solutions are new and first reported here.     

襄樊市区1235名孕妇尿碘含量监测分析

对襄樊市区孕妇尿碘含量进行了监测。监测结果：尿碘低于１００μｇ／Ｌ者，３０岁以上年龄组为高，达４８．３９％，９－１１月季节组为高，达４４．３５％；７个月以上的孕期组为高，达３０．６４％，农民缺磺情况远远高于工人（２６．０７％）、干部（２２．３％）、商人（１５．９８％），其尿碘平均含量低于１００μｇ／Ｌ者，高达４０．４５％，为各职业之冠，可见孕妇尿碘含量监测的重点应是病区农民。     

Analysis and design of set-stability for impulsive control systems

This Letter studies analysis and design of set-stability for impulsive control systems. A new comparison theorem of asymptotic set-stability for impulsive differential system is presented. Based on the new result, we derive some less conservative conditions for asymptotic set-stability of impulsive control systems with impulse at fixed times, and the results are used to design impulsive control laws of nonlinear systems for set-stability. A numerical example is used to verify the theoretical result.     

Cr/Cr2O3多层薄膜的制备、力学及摩擦学性能研究

为了提高Cr2O3陶瓷薄膜的韧性及摩擦学性能,设计制备了Cr/Cr2O3软硬交替的多层薄膜,通过复配韧性层提高Cr2O3陶瓷薄膜的韧性及摩擦学性能,同时研究了调制周期对Cr/Cr2O3薄膜力学性能及摩擦学性能的影响.研究结果表明多层薄膜的韧性和第一临界载荷随调制周期的减小而增大,而其硬度随调制周期的减小而降低.调制周期为1 075 nm的薄膜表现出了最好的综合性能,即薄膜具有较好的膜基结合强度、较高的韧性和硬度,同时薄膜具有最好的抗磨损性能.     

Control of formaldehyde emission from wood-based panels by doping adsorbents: optimization and application

This paper puts forward an approach to determine the optimal mode of doping adsorbents into the wood-based panels for control of their formaldehyde emission. Based on the optimization conclusion, a novel design method for low-emitting wood-based panels by daubing adsorbent layer on the panel’s surface is proposed. The formaldehyde emission results from the prepared laboratory specimens indicate the feasibility of the proposed method. This study provides a meaningful guidance on designing low-emitting wood-based panels.