Use of dielectric spectroscopy to assess adhesively bonded composite structures,Part III: Investigation of mechanical strength

This paper explores the way in which the data obtained from the dielectric study (reported in Part II of this 3-part series of articles), can be related to the mechanical strength of the bonded structure. Exposure of the adhesive bonded joints to a hot and wet environment leads to a loss of strength. Changes are observed in the dielectric properties on exposure to the humid environment, and an attempt is made to relate these observations to the mechanisms leading to loss in the mechanical strength ofthe bond. The observation of a correlation between the changes in these physical properties indicates the possibility ofusingdielectricspectroscopyas a powerful nondestructive evaluation (NDE) technique for bonded composite structures.     

Molecular Modeling Studies of Candidate Chromophores

Two 2-dimensional tableaus of heterocyclic molecular systems are shown to have molecular graphs that are pairwise strongly subspectral (having a preponderance of common eigenvalues). Based on this result, the electronic similarity of candidate chromophores are proposed.     

A Unified Structure Theory for Polycyclic Conjugated Hydrocarbons--A Review of What Every Chemist Should Know!

The important concepts of a formula periodic table set, aufbau principle, elementary substructures, excised internal structure/circumscribing algorithm, leapfrog algorithm, and hexagonal-to-pentagonal ring contraction algorithm will be reviewed. These concepts have been instrumental in organizing polyhex/polypent systems from benzenoid hydrocarbons to fullerene carbons. Some recent experimental verification of our prior predictions in this work will be noted.     

Fixation of Chromium in Wood from Dichromate and Chromate Salt Solutions

It has been reported that treatment of wood surfaces with aqueous solutions of chromium trioxide imparts some beneficial properties like weather resistance and some degree of water repellency. The work presented here aims at finding alternative ways of fixing chromium in wood with the avoidance of the very acidic and strong oxidant conditions of chromic acid solutions. This is because these solutions may affect the strength of wood, and are known to have a very high human toxicity. In this study, chromium has been fixed into wood from hexavalent chromium solutions at pH's of ～1.5 (CrO₃ aq.), ～3.8–3.9 (K₂Cr₂O₇ aq.) and ～9.5–10.3 (K₂CrO₄ aq.). For the CrO₃-solutions the effects of temperature and reaction time on the fixation of chromium were investigated. For the dichromate and chromate solutions, fixation experiments were carried out with Cr-concentration and reaction times as variables. It is shown that a 3%-fixation level of chromium in small wood specimens can be attained from dichromate and chromate solutions without significant mechanical damage to wood. On the other hand, even diluted CrO₃-solutions (0.01 M) impart serious strength reductions in wood at temperatures of 90° C and higher when reacted for 8 hours, and the chromium content of wood resulting from such treatment is of the order of only 1%.     

便携式应用设备电源设计的新趋势(一)

<正>如今,随着集成功能的不断增加,移动电话还可作为便携式媒体播放器(PMP)、数码相机、掌上电脑(PDA)、甚至全球定位系统(GPS)使用。如何获得更加逼真的显示、突破热瓶颈、高效智能地管理电源是系统设计人员当前面临的挑战。     

Do males and females think in the same way? An empirical investigation on the gender differences in Web advertising evaluation

Informativeness and entertainment are regarded as two types of advertising value that can influence consumers’ attitudes toward Web advertising. Despite of many studies on these two factors, there are two research gaps in extant literature. First, the effects of informativeness and entertainment on attitude are considered separately, yet their interaction effect is neglected. Second, the role of individual characteristics (e.g., gender) in the advertising evaluation process is far from clear. To address these two issues, a laboratory experiment was conducted to investigate the interaction effect between informativeness and entertainment, and also the moderating role of gender. The results indicate that informativeness can help form a more positive attitude for males than for females, and entertainment can lead to a more positive attitude for females than for males. It is also found that there is a three-way interaction among informativeness, entertainment, and gender. More specifically, the interaction effect between informativeness and entertainment is significant for females, but insignificant for males. Results, research contributions, and limitations are discussed, and implications for future studies are suggested.     

Pheromone-Based Pest Management in China: <Emphasis Type="Italic">Past,Present, and Future Prospects</Emphasis>

Semiochemical-based pest management technology has been widely used to monitor and control insect pests in agricultural, forestry, and public health sectors in the western world. It became a popular tool in the early 1970s with tremendous efforts in developing environment-friendly control technologies for the integrated pest management. However, in China, similar research lagged 15 to 20 years and was not initiated until the late 1980s. In this review, we present the early history of pheromone research that has led to the current practical applications in China, particularly in the development of pheromone-based pest management products. We also provide information regarding the current status of pheromone-based product manufacturing, marketing, and regulatory issues related to local semiochemical industries, which may be useful to other international companies interested in pursuing business in China. In addition, we share some research topics that represent new directions of the present pheromone research to explore novel tools for advancing semiochemical-based pest management in China.