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991.
992.
The case for the imposition of carbon (emission) taxes or tradable carbon permits in important tax jurisdictions is arguably strong, based upon the polluter pays principle first proposed by Pigou almost a century ago. This paper briefly reviews the arguments for and against these market-based instruments, and discusses their relative advantages and disadvantages in a practical context. In the case of Australia, the revenue effect of the proposed tradable carbon permits scheme is estimated to be A$11.5 billion in 2010–11. For comparison, this is roughly equivalent to a quarter of the revenue from the Goods and Services Tax. The paper focuses on three neglected aspects of climate change taxation discussion to date: how much tax revenue is likely to be raised, and the administrative and compliance costs of an emissions trading scheme, with particular reference to Australia. In discussing these issues, the paper draws upon selected and relevant international experience, particularly the European Union emissions trading scheme. The challenges of an emissions trading scheme, including integration with the existing tax system, particularly in an Australian context, are also discussed. The paper concludes by emphasising the key challenges and issues facing this ‘ultimate externality’ debate, particularly from a taxation policy perspective.  相似文献   
993.
The relationship of capillary pressure to liquid saturation for the water-air fluid pair in two different types of gas diffusion media (GDM) used in polymer electrolyte membrane fuel cell (PEMFC) electrodes is elucidated. It is experimentally demonstrated that GDM samples with and without treatment with poly(tetrafluoroethylene) (PTFE) ubiquitously display permanent capillary pressure hysteresis. Water does not imbibe spontaneously into a dry GDM, neither is it ejected spontaneously from a water-saturated GDM. Rather, positive displacement pressure is required to force both water and air into GDMs, whereas the main effect of adding PTFE is to increase the amount of work required for forcing water into the GDM, and to decrease the work required for water removal. Irrespective of PTFE content, the GDM samples tested are generally shown to behave as materials of intermediate (neutral) wettability. The US Bureau of Mines (USBM) wettability index nevertheless shows that water is the preferentially non-wetting phase in PTFE-treated GDMs and the preferentially wetting phase in untreated GDMs. Water-air capillary pressure curves are found to depend on sample thickness, clearly demonstrating that finite size effects are important. Finally, compression of the GDM is found to increase the capillary pressures for water injection and decrease the capillary pressures required for water withdrawal. These results should aid the design of GDMs with improved water management properties and the modeling of PEMFC electrodes in general.  相似文献   
994.
We recently proposed that the biological markers improved by carbohydrate restriction were precisely those that define the metabolic syndrome (MetS), and that the common thread was regulation of insulin as a control element. We specifically tested the idea with a 12-week study comparing two hypocaloric diets (~1,500 kcal): a carbohydrate-restricted diet (CRD) (%carbohydrate:fat:protein = 12:59:28) and a low-fat diet (LFD) (56:24:20) in 40 subjects with atherogenic dyslipidemia. Both interventions led to improvements in several metabolic markers, but subjects following the CRD had consistently reduced glucose (−12%) and insulin (−50%) concentrations, insulin sensitivity (−55%), weight loss (−10%), decreased adiposity (−14%), and more favorable triacylglycerol (TAG) (−51%), HDL-C (13%) and total cholesterol/HDL-C ratio (−14%) responses. In addition to these markers for MetS, the CRD subjects showed more favorable responses to alternative indicators of cardiovascular risk: postprandial lipemia (−47%), the Apo B/Apo A-1 ratio (−16%), and LDL particle distribution. Despite a threefold higher intake of dietary saturated fat during the CRD, saturated fatty acids in TAG and cholesteryl ester were significantly decreased, as was palmitoleic acid (16:1n-7), an endogenous marker of lipogenesis, compared to subjects consuming the LFD. Serum retinol binding protein 4 has been linked to insulin-resistant states, and only the CRD decreased this marker (−20%). The findings provide support for unifying the disparate markers of MetS and for the proposed intimate connection with dietary carbohydrate. The results support the use of dietary carbohydrate restriction as an effective approach to improve features of MetS and cardiovascular risk. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
995.
随着汽车、航空航天等行业激光焊接应用的发展,含有非平行直线或曲线焊缝的剪裁激光拼焊板件快速增长,柔性的机器人激光焊应用也随之增加.但目前的大多数关节式工业机器人尚难以有效地追踪重复性不足的焊缝.集成了激光视觉传感的DIGI-LAS激光焊接头系统特别适合这些机器人或专机的激光焊应用.DIGI-LAS系统配置了2个激光传感器,一个用于焊前搜索、定位焊缝及焊缝跟踪,另一个用于实时检测焊缝,包括焊缝的成形尺寸和探测表面缺陷.此外,DIGI-LAS的激光传感器能够记录机器人追踪焊缝的误差,在焊接时给予补偿,保证了机器人系统可以满足激光焊的精度要求.经过补偿后,在超过6 m/min的焊接速度下,系统追踪曲率半径为50 mm的曲线焊缝的对中误差小于100 μm.检测结果通过数字IO输出到机器人、PLC或外部的质量管理系统.自动的焊接质量检测有助于用户实现6σ的质量控制与管理.  相似文献   
996.
The current study tested spatial memory recall in 1 male and 1 female giant panda (Ailuropoda melanoleuca). The task required subjects to make a delayed response to a previously lighted location, with varying lengths of delay between the observation phase and the test phase. The male subject reached criterion at 2-, 3-, 4-, 5-, 6-, and 10-s delays. The female subject reached criterion at 2-, 3-, 4-, 5-, 6-, 10-, and 15-s delays. The results support the hypothesis that giant pandas demonstrate significant working memory for spatial location in the absence of external cues, which may be an important mechanism for survival in the wild. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
997.
Signal integrity constraints of high-speed electronics have made multidrop electrical buses infeasible. This high-speed alternative uses hollow metal waveguides and pellicle beam splitters that interconnect modules attached to the bus. With 1 mW of laser power, the bus can interconnect eight modules at 10 Gbps per channel and achieves an aggregate bandwidth of more than 25 Gbytes per second with 10-bit-wide signaling paths.  相似文献   
998.
Terry Bollinger and Clement McGowan provide differing viewpoints on the CMM's progress since their 1991 article, A Critical Look at Software Capability Evaluations.  相似文献   
999.
1000.
Laser-induced delamination (LID) is a technique aimed at measuring the work of adhesion of thin polymer coatings on metal substrates. A laser pulse is used to create a blister that initiates delamination of the film under pressure. The stress fields in the blister wall and the work of adhesion of the interface are determined using a linear elastic model.In this paper we discuss validity of the LID results addressing permeation of gas through the blister wall and the initial high temperature of the substrate. A procedure to account for the effect of gas permeation in the calculations of the work of adhesion is proposed. Permeation of gas is also considered under compressive and tensile in-plane stresses. Modeling of the permeation process demonstrates a good agreement with the experiment.At early stage of the blister formation the metal substrate and the blister gas experience high temperatures. The time scales of the cooling processes are estimated. Possible effects of the high temperatures on the permeation of gas and on the process of delamination are discussed.  相似文献   
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