棉袜也奢华?

300美元一双的棉袜？当你意识到袜子也可以是魅惑与亲密关系的代言品时，小心看好钱包。

Logical and Ontological Implications of Necessity in Aristotelian Teleology

Firstly, this paper is to illustrate through the analysis of Aristotelian texts that two kinds of necessity involved in the teleological account, the necessity απλωζand the necessity εξυποθεσεωζare related to an achievement of an endaccording to two thoroughly different ontological and logical grounds. Secondly, it is to bring the irreducibility of the teleological to non-teleological into organic development to unprecedented light so as to show how the ontological predominance of the finality over the material necessity may be adequately expressed by a logical implication, if it is appropriately stated and well distinct from other similar logical connectives such as the material implication and the biconditional if-and-only-if.

Assessment of the Potential Use of Hydroponic Effluents for Fodder Production

The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using farmers＇ fertiliser rate of 475 kg 17：8：25/ha applied at planting ＋ 235 kg Sulphate of Ammonia/ha applied as top dressing one month after and 150 kg 17：8：25/ha applied after each harvest. Yield response obtained in plots fertilised using undiluted hydroponic effluents was 16.7% lower than that recorded in plots fertilised using farmers＇ fertiliser rate. The study showed that there-is potential for using hydroponic effluents （undiluted or diluted in the ratio of 3 HE： 1 water） in fodder production as it can provide sustainable yield in the range of 39.5-41.7 t/ha per harvest. Moreover, dilution rate of hydroponic effluents has a direct impact on crop development and fresh biomass yield. Fodder crop yield responded negatively to the increase dilution of hydroponic effluents from 4HE： 0 water to 3HE： 1 water, 1HE： 1 water and 1HE： 3 water. Consequently, the use of hydroponic effluents can eventually help to save on mineral fertiliser use and reduce cost of production while at the same time address environmental hazards related to hydroponic effluents disposal.

丙烯酸-2,4,6-三硝基苯乙酯的合成及热分解

以TNT、甲醛为原料,在弱碱性条件下反应合成得到2,4,6-三硝基苯乙醇(PicCH2CH2OH);PicCH2CH2OH在浓硫酸催化下和丙烯酸在甲苯中回流反应24h,合成得到丙烯酸-2,4,6-三硝基苯乙酯,产率为62%。采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1HNMR)、红外光谱(FTIR)、质谱(MS)以及元素分析等对产物结构进行了表征。利用热重分析(TG)对产物热稳定性进行了研究,采用Kissinger方法和Ozawa方法计算其热分解活化能Ea分别为99.78,102.96kJ·mol-1。

Strengthening an in-service reinforcement concrete bridge with prestressed CFRP bars

Carbon fiber reinforced polymer (CFRP) bars were prestressed for the structural strengthening of 8 T-shaped rein-forced concrete (RC) beams of a 21-year-old bridge in China. The ultimate bearing capacity of the existing bridge after retrofit was discussed on the basis of concrete structures theory. The flexural strengths of RC beams strengthened with CFRP bars were controlled by the failure of concrete in compression and a prestressing method was applied in the retrofit. The field construction processes of strengthening with CFRP bars-including grouting cracks, cutting groove, grouting epoxy and embedding CFRP bars, surface treating, banding with the U-type CFRP sheets, releasing external prestressed steel tendons-were introduced in detail. In order to evaluate the effectiveness of this strengthening method, field tests using vehicles as live load were applied before and after the retrofit. The test results of deflection and concrete strain of the T-shaped beams with and without strengthening show that the capacity of the repaired bridge, including the bending strength and stiffness, is enhanced. The measurements of crack width also indicate that this strengthening method can enhance the durability of bridges. Therefore, the proposed strengthening technology is feasible and effective.

Environmental analysis of innovative sustainable composites with potential use in aviation sector -A life cycle assessment review

The forecast of growing air transport in the upcoming decades faces the challenge of an increasing environmental impact.Aviation industry is working on promising technologies to mitigate this environmental impact.Lightweight design is a strong lever to lower the fuel consumption and,consequently,with it the emissions of aviation.High performance composites are a key technology to help achieve these aims thanks to their favourable combination of mechanical properties and low weight in primary structures.However,mainly synthetic materials such as petrol based carbon fibres and epoxy resins are used nowadays to produce composite in aviation.Renewable materials like bio-based fibres and resin systems offer potential environmental advantages.However,they have not found their way into aviation,yet.The reasons are reduced mechanical properties and,especially for the use of natural fibres,their flammability.Improvements of these shortcomings are under investigation.Therefore the application of bio-based and recycled materials in certain areas of the aircraft could be possible in the future.Good examples for applications are furnishings and secondary structures.The motivation for this paper is to give an overview of potential environmental properties by using such eco-materials in aviation.Life cycle assessment(LCA) is a tool to calculate environmental impacts during all life stages of a product.The main focus is laid on the bio-fibres flax and ramie,recycled carbon fibres and bio-based thermoset resin systems.Furthermore an overview of environmental aspects of existing composite materials used in aviation is given.Generally,a lack of LCA results for the substitution of synthetic materials by bio-based/recycled composite materials in aviation applications has been identified.Therefore,available information from other transport areas,such as automotive,has been summarized.More detailed LCA data for eco-composite materials and technologies to improve their properties is important to understand potential environmental effects in aviation.

Highly structured metal-organic framework nanofibers for methane storage

Porous materials such as metal-organic frameworks(MOFs)with high theoretical volumetric gas uptake capacity are promising materials for gas storage and separation,but the structuring for practical applications is challenging.Herein,we report a general and feasible strategy to combine electrospinning with a phase conversion method to decorate polyacrylonitrile nanofibers(PAN NFs)with CuMOF(HKUST-1).The strategy is based on the combination of surface pretreatment of the NFs with Cu(OH)_(2) and a subsequent phase conversion into HKUST-1 crystals(PCHKUST-1).A significant higher loading of HKUST-1 in the PAN NF matrix was achieved by the phase conversion method compared with direct electrospinning of MOF slurries or insitu growth of MOF crystals on NFs.As a result,the hierarchical structured PC(phase conversion)-HKUST-1 NFs revealed the highest gravimetric storage capacity of 86 cm^(3) g^(-1)(STP)at 3500 kPa and 298 K for methane(CH_(4)),which is higher than other HKUST-1 NFs reported previously.The improved CH_(4) uptake can be explained by the high loading of HKUST-1 due to the high availability of Cu-ions localized on the surface of the NFs during the phase conversion process,resulting in high surface area and excellent gas access of the phase converted HKUST-1.Thus,the developed strategy of structuring MOFs could be of interest for the fabrication of tailor-made MOF NF architectures for other energy and environmental applications.