Biochemical mechanisms conferring cross-resistance to fumigant toxicities of essential oils in a chlorpyrifos-methyl resistant strain of Oryzaephilus surinamensis L. (Coleoptera: Silvanidae)

The fumigant toxicities of lavender and ylang-ylang essential oils were tested against a chlorpyrifos-methyl resistant strain (QVOS102) and an insecticide-susceptible reference strain (VOS48) of the saw-toothed grain beetle, Oryzaephilus surinamensis L. (Coleoptera: Silvanidae). The resistant strain showed 1.3- and 1.6-fold higher tolerance against lavender and ylang-ylang fumigation toxicity, respectively, relative to the susceptible strain. LT₅₀ values calculated as the time to attain 50% mortality of tested insects during fumigation were determined at two different concentrations. At 15 μl/l of air, QVOS102 had 2.9- and 1.4-fold higher LT₅₀ values for lavender and ylang-ylang fumigation toxicity, respectively, than VOS48. At 200 μl/l air, QVOS102 had 6.4- and 2.9-fold higher LT₅₀ values for lavender and ylang-ylang fumigation toxicity, respectively, than VOS48. Piperonyl butoxide, a potential inhibitor of cytochrome P450-dependent monooxygenase, increased fumigant toxicities of the two essential oils against QVOS102. The enhanced tolerance for the essential oil may have resulted from the enhancement of detoxifying enzymes associated with insecticide resistance.     

老年人紧急呼救产品设计要素分析

中国已进入老龄化社会,老龄人口基数庞大,老年人问题已然成为社会的焦点。而我国目前社会基础设施、医疗配套设施、社会福利养老保障设施等都不完善,老年产品比较缺乏。尤其是随着经济的发展和人口的流动,空巢老人已成为社会不可忽视的一类群体,紧急呼救产品将会成为一种必需品。本课题通过对老年人紧急呼救产品设计要素进行详细的分析,从而对产品的开发起到一定的帮助和指导作用,为老年人的养老贡献一点力量。     

Concepts,processing, and recent developments in encapsulating essential oils

By the virtue of their olfactory, physicochemical, and biological characteristics, essential oils (EOs) have drawn wide attention as additives in daily chemicals like perfume or personal care products. Nevertheless, they are physicochemically unstable and susceptible to degradation or loss. Microencapsulation offers a feasible strategy to stabilize and prolong release of EO. This review summarizes the recognized benefits and functional properties of various preparation and characterization methods, wherein innovative fabrication strategies and their formation mechanisms are especially emphasized. Progress in combining detecting/measuring technologies with kinetic modelling are discussed, to give an integral approach of controlling the dynamic release of encapsulated EOs. Moreover, new development trends of EOs capsules are also highlighted.     

循环经济与知识经济的本质差异解读

目前循环经济和知识经济已成为现代社会经济发展的两种重要形态,为了深入地从理论上把握好知识经济和循环经济的实质,从而更好地指导经济发展实践,有必要全面准确认识和把握它们的本质差异,其本质差异主要表现在两者的含义、理念、特征和所属的分类标准三个方面。     

Plane stress fracture toughness of physically aged plasticized PETG as assessed by the essential work of fracture (EWF) method

The plane stress fracture toughness of amorphous copolyester (PETG) sheets plasticized by various amount of neopentylglycol dibenzoate (NPGDB in 0, 5, 10 and 20 wt%) was studied in as-received (AR) and rejuvenated (RJ) states by adopting the essential work of fracture (EWF) method. EWF tests were performed on deeply double-edge notched tensile loaded (DDEN-T) specimens at various deformation rates (2,10 and 100 mm/min) at room temperature. It was established that physical aging strongly affected the EWF terms. The specific yielding-related EWF increased with increasing deformation rate and decreased with increasing plasticizer content. The specific non-essential work and its necking-related constituent, which changed parallel to each other, remained constant up to 10 wt% NPGDB content and decreased afterwards. The plastic zone in the DDEN-T specimens was formed by cold drawing which is governed by the entanglement structure. This was demonstrated by the shape recovery of the plastic zone in the broken DDEN-T specimens after heating them above the T_g of the related PETG compound.     

冷轧轧制油特性的探讨

本文介绍了窄带钢冷轧机组在现场生产中,使用乳化状轧制油遇到的一些情况,同时讨论了冷轧轧制油的几个工艺特性及理化指标。     

Impacts of essential elements of management on IT application maturity — A perspective from firms in China

This paper explores the impacts of essential elements of management on IT application maturity (ITAM). A game theoretical model is established to show that a firm's IT application maturity should match with its essential elements of management. In order to further validate the analytical result, a data set with 137 firms was collected via a survey instrument. Using reliability and factor analysis on the dataset, a four-dimension measurement construct of IT application maturity is proposed together with a three-dimension measurement construct of essential elements of management. Empirical analysis is then conducted to address research questions on the impacts of essential elements of management on IT application maturity. It is found that while a firm's strategic cooperation capability has no significant effect on IT application maturity, its internal coordination capability positively influences all four dimensions of IT application maturity. For the firm's execution capability, although it shows no significant effect on the overall IT application maturity, it does positively affect the technology and man-machine synergy dimensions of IT application maturity. The findings of this study offer practical guidance for organizations to better align their IT application maturity with essential elements of management.     

论雷锋精神的本质内涵与时代价值

雷锋精神是中国共产党的精神坐标,它体现了社会主义精神文明的巨大感召力和文化穿透力,是时代精神的精华。在中国特色社会主义伟大实践中,大力弘扬雷锋精神不仅是人民和历史的选择,更是时代的呼唤。本文梳理了雷锋精神的历史资源和文化滋养,论述了雷锋精神的本质内涵和时代精神,并提出大力弘扬雷锋精神,积极推动社会主义核心价值体系建设,要切实做到：知与行的统一、广泛性与先进性的统一、长期性和有效性的统一。     

The use of lifetime functions in the optimization of interventions on existing bridges considering maintenance and failure costs

In the last decade, it became clear that life-cycle cost analysis of existing civil infrastructure must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating structures require the use of probabilistic methods to properly evaluate their lifetime performance. In this paper, the deterioration and the effect of maintenance actions are analyzed considering the performance of existing structures characterized by lifetime functions. These functions allow, in a simple manner, the consideration of the effect of aging on the decrease of the probability of survival of a structure, as well as the effect of maintenance actions. Models for the effects of proactive and reactive preventive maintenance, and essential maintenance actions are presented. Since the probability of failure is different from zero during the entire service life of a deteriorating structure and depends strongly on the maintenance strategy, the cost of failure is included in this analysis. The failure of one component in a structure does not usually lead to failure of the structure and, as a result, the safety of existing structures must be analyzed using a system reliability framework. The optimization consists of minimizing the sum of the cumulative maintenance and expected failure cost during the prescribed time horizon. Two examples of application of the proposed methodology are presented. In the first example, the sum of the maintenance and failure costs of a bridge in Colorado is minimized considering essential maintenance only and a fixed minimum acceptable probability of failure. In the second example, the expected lifetime cost, including maintenance and expected failure costs, of a multi-girder bridge is minimized considering reactive preventive maintenance actions.     

Physical Properties of Vegetable Oil and Chlorinated Ethene Mixtures

Laboratory experiments were conducted to investigate the abiotic interactions of soybean oil (SoyOil) and chlorinated ethene (CE) nonaqueous phase liquids (NAPLs). The mixed NAPL density and interfacial tension behaved ideally, as predicted by the volume ratio. The mixed NAPL viscosity increased exponentially from that of the pure CE to that of pure SoyOil as the volume fraction increased. The measured contact angle was highly variable and was unpredictable as a function of the volume composition of the mixed NAPL. The physical property effects indicate that the mobilization of residual CE NAPLs because of SoyOil injection is unlikely. Equilibrium dissolution of CEs from the NAPL mixtures behaved linearly as a function of the mole fraction. Dissolved SoyOil in simulated groundwater enhanced the dissolution of trichloroethene (TCE) during flow tests, increasing the effluent TCE concentration from 141?to?202?mg/L. The ready intermingling of the CE dense nonaqueous phase liquids (DNAPLs) and SoyOil indicate that such interactions may be significant at sites where vegetable oil is injected into DNAPL source areas to enhance in situ anaerobic bioremediation.