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1.
Indoor surfaces may be adsorptive sinks with the potential to change Indoor Air Quality. To estimate this effect, the sorption parameters of formaldehyde and toluene were assessed on five floorings by an experimental method using solid-phase microextraction in an airtight emission cell. Adsorption rate constants ranged from 0.003 to 0.075 m·h−1, desorption rate constants from 0.019 to 0.51 h−1, and the partition coefficient from 0.005 to 3.9 m, and these parameters vary greatly from one volatile organic compound/material couple to another indicating contrasted sorption behaviors. A rubber was identified as a sink of formaldehyde characterized by a very low desorption constant close to 0. For these sorbent floorings identified, the adsorption rates of formaldehyde are from 2 to 4 times higher than those of toluene. Two models were used to evaluate the sink effects of floorings on indoor pollutant concentrations in one room from different realistic conditions. The scenarios tested came to the conclusion that the formaldehyde sorption on one rubber (identified as a sink) has a maximum contribution from 15% to 21% for the conditions of low air exchange rate. For other floorings, the sorption has a minor contribution less than or equal to 5%, regardless of the air exchange rate.  相似文献   
2.
The Medium Resolution Imaging Spectrometer (MERIS) was used to investigate the spatial and temporal dynamics of chlorophyll-a (chl-a) in Erhai Lake, the second largest freshwater lake in the Yunnan province of China. Six chl-a retrieval models, including four Basic ERS & Envisat (A)ATSR and Meris Toolbox (BEAM) software-incorporated algorithms and MERIS three-band and two-band models, were validated to find the best fit to extract chl-a concentration in Erhai Lake. With a chl-a range of 5–15 mg m–3, the Lakes/Eutrophic method showed the best performance. The algorithm was then applied to eight-year cloud-free MERIS images between 2003 and 2009, with seasonal and inter-annual variability analysed. Long-term chl-a distributions of Erhai Lake revealed significant seasonal and inter-annual variability. The mean chl-a of the south lake was higher in summer (14.3 mg m–3) than in spring (10.1 mg m–3), while generally lower chl-a was found in the north lake with a mean chl-a of 6.4 mg m–3 in spring and 9.0 mg m–3 in summer, respectively. An increasing trend was found between 2006 and 2009, and the increasing rate was 12.9% for annual chl-a of the entire lake. While chl-a seasonality was attributed to the seasonal changes of the local temperature, the inter-annual variation was possibly linked to the discharged wastewater from Dali City. This work could provide critical information for decision-makers to manage Erhai Lake’s aquatic ecosystems.  相似文献   
3.
4.
据工信部日前最新消息:今年上半年,我国西部地区水泥产量为2.3亿吨,同比增长25.9%,增速远高于东部和中部地区。但西部地区水泥出厂价格则呈持续下降态势。  相似文献   
5.
Caspase-1, as the main pro-inflammatory cysteine protease, was investigated mostly with respect to inflammation-related processes. Interestingly, caspase-1 was identified as being involved in lipid metabolism, which is extremely important for the proper differentiation of chondrocytes. Based on a screening investigation, general caspase inhibition impacts the expression of Cd36 in chondrocytes, the fatty acid translocase with a significant impact on lipid metabolism. However, the engagement of individual caspases in the effect has not yet been identified. Therefore, the hypothesis that caspase-1 might be a candidate here appears challenging. The primary aim of this study thus was to find out whether the inhibition of caspase-1 activity would affect Cd36 expression in a chondrogenic micromass model. The expression of Pparg, a regulator Cd36, was examined as well. In the caspase-1 inhibited samples, both molecules were significantly downregulated. Notably, in the treated group, the formation of the chondrogenic nodules was apparently disrupted, and the subcellular deposition of lipids and polysaccharides showed an abnormal pattern. To further investigate this observation, the samples were subjected to an osteogenic PCR array containing selected markers related to cartilage/bone cell differentiation. Among affected molecules, Bmp7 and Gdf10 showed a significantly increased expression, while Itgam, Mmp9, Vdr, and Rankl decreased. Notably, Rankl is a key marker in bone remodeling/homeostasis and thus is a target in several treatment strategies, including a variety of fatty acids, and is balanced by its decoy receptor Opg (osteoprotegerin). To evaluate the effect of Cd36 downregulation on Rankl and Opg, Cd36 silencing was performed using micromass cultures. After Cd36 silencing, the expression of Rankl was downregulated and Opg upregulated, which was an inverse effect to caspase-1 inhibition (and Cd36 upregulation). These results demonstrate new functions of caspase-1 in chondrocyte differentiation and lipid metabolism-related pathways. The effect on the Rankl/Opg ratio, critical for bone maintenance and pathology, including osteoarthritis, is particularly important here as well.  相似文献   
6.
This work reports adhesion behaviour of polyethylene on paper, and deals with the surface energy of the materials involved in the manufacture of these composites, and its influence on the adhesion strength, at constant roughness, for the paper substrates. The surface energy of different papers treated with various sizing agents was determined by measuring contact angles according to the Owens-Wendt method. The peeling energy was shown to follow a linear relationship versus the reversible energy of adhesion. This result is explained by the fact that rupture takes place at the interface and that the size of the defect at the interface depends on the spreading coefficient. Corona treatment, applied to strongly sized papers before making the composites, restored the adhesion strength to its original range of values, again demonstrating the thermodynamic character of adhesion in thermoplastic-paper composites.  相似文献   
7.
随着汽车部件电子化程度的不断提高,汽车工程师们正积极地寻求车辆系统中的先进控制和接口技术解决方案。目前,汽车系统中用来嵌入这些功能单元的空间和能源十分有限,汽车工程师们正借助于新颖的高压混合信号技术将复杂的——截至目前还不兼容的元件功能集成到一块芯片上。现在,应用与42V车载电压兼容的13T高电压技术已经可以将复杂的数字电路(如  相似文献   
8.
A new mathematical model, based on the observation of 13C-NMR spectra of two principal metabolites (glutamate and aspartate), was constructed to determine the citric acid cycle flux in the case of high aspartate transaminase activity leading to the formation of large amounts of labeled aspartate and glutamate. In this model, the labeling of glutamate and aspartate carbons by chemical and isotopic exchange with the citric acid cycle are considered to be interdependent. With [U-13C]Glc or [1,2-(13)C]acetate as a substrate, all glutamate and aspartate carbons can be labeled. The isotopic transformations of 32 glutamate isotopomers into 16 aspartate isotopomers or vice versa were studied using matrix operations; the results were compiled in two matrices. We showed how the flux constants of the citric acid cycle and the 13C-enrichment of acetyl-CoA can be deduced from 13C-NMR spectra of glutamate and/or aspartate. The citric acid cycle flux in beating Wistar rat hearts, aerobically perfused with [U-13C]glucose in the absence of insulin, was investigated by 13C-NMR spectroscopy. Surprisingly, aspartate instead of glutamate was found to be the most abundantly-labeled metabolite, indicating that aspartate transaminase (which catalyses the reversible reaction: (glutamate + oxaloacetate <--> 2-oxoglutarate + aspartate) is highly active in the absence of insulin. The amount of aspartate was about two times larger than glutamate. The quantities of glutamate (G0) or aspartate (A0) were approximately the same for all hearts and remained constant during perfusion: G0 = (0.74 +/- 0.03) micromol/g; A0 = (1.49 +/- 0.05) micromol/g. The flux constants, i.e., the fraction of glutamate and aspartate in exchange with the citric acid cycle, were about 1.45 min(-1) and 0.72 min(-1), respectively; the flux of this cycle is about (1.07 +/- 0.02) micromol min(-1) g(-1). Excellent agreement between the computed and experimental data was obtained, showing that: i) in the absence of insulin, only 41% of acetyl-CoA is formed from glucose while the rest is derived from endogenous substrates; and ii) the exchange between aspartate and oxaloacetate or between glutamate and 2-oxoglutarate is fast in comparison with the biological transformation of intermediate compounds by the citric acid cycle.  相似文献   
9.
This paper presents the physical design methodology of the VCI/SPIN wrappers. The challenge was the validation of the wrappers’ specification with Alliance CAD Tools.A wrapper is a standard gateway used by a subscriber to access an interconnect. Because there are as many wrappers as subscribers, it is relevant to have an estimation of the wrapper’s area, its frequency and then compare these results to the router’s.The interest to perform this study with academic tools is to show that commercial tools are not the unique way for experimentations.  相似文献   
10.
The extinction coefficient, used to express losses in optical fibres due to absorption and diffusion, fluctuates in time with a 1/f spectrum. The authors have measured fluctuations in the intensity of light propagating through optical fibres. Noise measurements as a function of fibre length show that the noise is not due to fluctuations in reflectivity at the ends. The relative noise in the intensity of the transmitted light is proportional to fibre length  相似文献   
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