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1.
可张孔曝气器曝气能耗试验研究   总被引:1,自引:0,他引:1  
通过试验研究,总结出可张孔曝气阻力损失的影响因素,以优化产品的结构设计参数,降低产品在工程应用中的能耗,获取更好的经济效益。  相似文献   
2.
CuSO_4/TiO_2 catalysts with high catalytic activity and excellent resistant to SO_2 and H_2 O,were thought to be promising catalysts used in Selective catalytic reduction of nitrogen oxides by NH_3.The performance of catalysts is largely affected by calcination temperature.Here,effects of calcination temperature on physicochemical property and catalytic activity of CuSO_4/TiO_2 catalysts were investigated in depth.Catalyst samples calcined at different temperatures were prepared first and then physicochemical properties of the catalyst were characterized by N2 adsorption-desorption,X-ray diffraction,thermogravimetric analysis,Raman spectra,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,temperature-pro grammed desorption of NH_3,temperature-programmed reduction of H_2 and in situ diffuse reflectance infrared Fourier transform spectroscopy.Results revealed that high calcination temperature had three main effects on the catalyst.First,sintering and anatase transform into rutile with increase of calcination temperature,causing a decrement of specific surface area.Second,decomposition of CuSO_4 under higher calcination temperature,resulting in disappears of Br(?)nsted acid sites(S-OH),which had an adverse effect on surface acidity.Third,CuO from the decomposition of CuSO_4 changed surface reducibility of the catalyst and favored the process of NH_3 oxidation to nitrogen oxides(NO_x).Thus,catalytic activity of the catalyst calcined under high temperatures(≥600℃) decreased largely.  相似文献   
3.
通过温室盆栽试验,研究构树(Broussonetia papyrifera)生长对重金属污染土壤酶活性和微生物群落结构的影响.结果表明,构树修复污染土壤中酶活性和微生物多样性明显提高.经270d培养后,构树生长土壤中蔗糖酶和酸性磷酸酶活性与种植土壤相比分别显著(P<0.05)提高3.12倍和2.29倍;土壤脱氢酶与有效态As、Cd、Pb、Zn和Cu含量,蔗糖酶与有效态Cd含量,以及磷酸酶与有效态Cd和Cu含量之间呈显著负相关(P<0.05).根据16S和18S rDNA PCR-DGGE分析表明,构树修复可提高污染土壤中细菌和丛枝菌根真菌多样性.上述结果表明,构树修复可有效改善重金属污染土壤的环境质量.然而,污染土壤中重金属有效态含量下降不明显,必须辅助物理和化学措施来强化构树对重金属污染土壤的生态修复潜力.  相似文献   
4.
分析了铁的硫化物的危害特性,阐述了硫化物“自燃”产生的热量是造成油罐发生火灾事故的主要原因,并提出了相应的防护措施,提高油罐日常使用的安全可靠性。  相似文献   
5.
煤矿风井轴流风机气流速度大,扩散口噪声辐射强度高达113dB(A),降噪难度较大的低频成份突出。正确合理的低频噪声控制设计计算是噪声控制成功的关键。  相似文献   
6.
城市生活垃圾是指在城市日常生活中或者为城市日常生活提供服务的活动中产生的固体废物以及法律、行政规定视为城市生活垃圾的固体废弃物.随着中国城市化进程的加快和人民生活水平的提高,城市生活垃圾也在以每年8%~10%的速度增长,若垃圾问题得不到妥善解决,就会制约兰州市的发展.在对兰州市城市生活垃圾处理现状及存在问题分析的基础上,根据兰州市生活垃圾的特性,提出兰州市城市生活垃圾的处理办法:兰州市城市生活垃圾应当推行分类收集制度,由目前单一的卫生填埋处理走向资源化综合处理.  相似文献   
7.

Can Gio district is located in the coastal area of Ho Chi Minh City, southern Vietnam. Discharge of wastewater from Ho Chi Minh City and neighboring provinces to the rivers of Can Gio has led to concerns about the accumulation of trace metals (As, Cu, Cr, Ni, Pb, and Zn) in the coastal sediments. The main objective of this study was to assess the distribution of As, Cu, Cr, Ni, Pb, and Zn in surface and core sediments and to evaluate the contamination status in relation to local background values, as well as the potential release of these selected trace metals from sediments to the water environment. Sediment characteristization, including determination of fine fraction, pH, organic matter, and major elements (Al, Fe, Ca, K, Mg, and S), was carried out to investigate which parameters affect the trace metal enrichment. Fine fraction and Al contents were found to be the controlling proxies affecting the distribution of trace metals while other sediment characteristics did not show any clear influence on trace metals’ distribution. Although As concentrations in the sediments were much higher compared to its reference value in other areas, the enrichment factor based on local background values suggests minor contamination of this element as well as for Cr, Cu, and Pb. Risk assessment suggested a medium to very high risk of Mn, Zn, and Ni under acidification. Of importance is also that trace metals in sediments were not easily mobilized by organic complexation based on their low extractabilities by ammonium-EDTA extraction.

  相似文献   
8.
采用动态吸附法探讨了在活性碳纤维对模拟废气中丙烯酸和甲苯的吸附过程中,各因素对活性碳纤维穿透吸附量和饱和吸附量的影响。实验结果表明,在模拟废气中丙烯酸质量分数为0.2%、双柱塞泵流量为6.1mL/h、载气流量为1.60L/min的条件下,穿透时间为10min,活性碳纤维的穿透吸附量为227.5mg/g,饱和吸附时间为40min,活性碳纤维的饱和吸附量为460.0m g/g。  相似文献   
9.
Based on previous research, the sampling and analysis methods for phthalate esters (PAEs) were improved by increasing the sampling flow of indoor air from 1 to 4 L/min, shortening the sampling duration from 8 to 2 hr. Meanwhile, through the optimization of chromatographic conditions, the concentrations of 9 additional PAE pollutants in indoor air were measured. The optimized chromatographic conditions required a similar amount of time for analysis as before, but gave high responsivity, the capability of simultaneously distinguishing 15 kinds of PAEs, and a high level of discrimination between individual sample peaks, as well as stable peak generation. The recovery rate of all gas-phase and particle-phase samples of the 15 kinds of PAEs ranged from 91.26% to 109.42%, meeting the quantitative analysis requirements for indoor and outdoor air sampling and analysis. For the first time, investigation of the concentration levels as well as characteristics of 15 kinds of PAEs in the indoor air from four different traffic micro-environments (private vehicles, busses, taxis and subways) was carried out, along with validation of the optimized sampling and analytical method. The results show that all the 9 additional PAEs could be detected at relatively high pollution levels in the indoor air from the four traffic micro-environments. As none of the pollution levels of the 15 kinds of PAEs in the indoor air from the 4 traffic micro-environments should be neglected, it is of great significance to increase the types of PAEs able to be detected in indoor air.  相似文献   
10.
目的为了更好地解决高超声速飞行器舵、翼前缘及头锥等气动热环境恶劣区域的热防护问题。方法采用主动式热疏导技术,以高温液态合金为工质,设计并制作具有主动式热疏导功能的尖化前缘金属试验模型(R=5 mm)。根据模型外尺寸设计加工一套石英灯仿形加热器和热流测试模型,开展地面热环境模拟试验。结果试件在前缘中心温度530℃左右时具有瞬态启动特性。前缘中心和大面积中心最大辐射热流密度分别为1000 kw/m^2和580 kw/m^2,试件在该环境中长时间受热状态下仍具有较好的热疏导能力。试验后试件无工质泄漏和结构破坏,具有一定的可重复使用性。结论可以此热疏导方式结合现有成熟热防护技术进一步开展工程设计与应用。  相似文献   
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