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利用高速摄影研究二甲基醚的喷雾特性   总被引:2,自引:1,他引:2  
李君  佐藤由雄  野田明 《汽车工程》2002,24(2):112-114,156
本文利用高速摄影技术在定容压力室中,通过6孔电磁喷射器,研究了二甲基醚(DME)的喷雾特性。结果表明,二甲基醚的喷雾射程随着定容压力室内气体压力的增加而减少;喷雾锥角则随和的升高而增大,在相同的条件下,二甲基 喷射锥角大于 喷射锥角;喷雾射程则低于柴油的喷雾射程。Hiroyasu喷雾射程的计算模型,通过适当的系数修正可以用于DME喷雾射程预测,由于DME喷雾射程和着火延迟期都比柴油短,在屐机缸内着火时刻,柴油的喷雾射程约为DME的2倍,从高速摄影的喷雾影像中可以清楚的看到,DME的蒸发速度明显比柴油快。  相似文献   
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In moving-ship type CO2 ocean sequestration, liquid CO2 is discharged into a domain in a water column. Since the maximum CO2 concentration that is reached depends on the horizontal shape of the water column and the depths of release, it is very important to optimize these parameters for each injection site in order to minimize the biological impact. We conducted numerical experiments using an offline Oceanic General Circulation Model with a horizontal resolution of 0.1 degree × 0.1 degree. Experiments using a different horizontal site shape show that a site elongated in the meridional direction is effective to reduce the CO2 concentration. This is because CO2 has a tendency to be transported in a zonal direction. Optimization of the vertical distribution of CO2 injections is inherently determined by the balance of the following two factors; (1) dilution effect by eddy activity which decreases with depth, and the (2) predicted no effect concentration (PNEC), a criterion concentration causing no effect on biota, which increases with depth. Based on superposition of simulated CO2 concentration, we determined the optimized vertical distribution of CO2 injection which keeps the ratio of a simulated maximum CO2 concentration to PNEC constant.  相似文献   
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为研究磷酸盐皮膜结晶结构与其各种物性之间的关系,对磷酸锌皮膜主要成分(磷酸锌和磷酸铁锌)的结晶结构进行了分析。结果表明:两者晶体结构基本相似;结晶水是与6配位的锌结合在一起,如果此部位的锌被其他金属置换后,结晶水的结合状态将发生变化,从而引起结晶水脱离温度以及耐碱性也发生变化;皮膜从4水盐脱水变成2水盐时,在厚度方向上将产生收缩等。  相似文献   
4.
Apparent phytoplankton bloom due to island mass effect   总被引:1,自引:0,他引:1  
A continuous monitoring of temperature and chlorophyll-a (Chl-a) concentration from a surface water monitoring system and a towed free fall instrument (MVP) around a small island in the Kuroshio showed low sea surface temperature (SST) and high surface Chl-a concentration (SCC) distribution in the lee of the island that indicates typical “island mass effect” phenomena. When the observed Chl-a profiles (0 to 250 m) were integrated, the total amounts in the lee side data were slightly smaller than those of the upstream side of the island. The difference was statistically significant at the 95% confidence level. The cross section diagram of Chl-a indicated the diffusion of subsurface Chl-a maximum (SCM) from the upstream to the downstream flanks of the island. The diffusivity of SCM and the change of potential energy require the same level of strong turbulent dissipation rate at the flanks of the island. That is consistent with our previous direct measurement in a similar hydrodynamic condition. Therefore, the observed high SCC is due to turbulent diffusion of SCM, and clearly showed that high SCC does not require any new production. Although a high fluorescence field behind an isolated island in a strong flow is often visible from satellite images, the images do not necessarily indicate an enhanced primary production at that moment.  相似文献   
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随着信息使用费用的急剧下降 ,我们可以使用的信息量不仅比以前大大增加 ,而且使用信息的人数也越来越多。现在社会学家已不再谈及技术时代、计算机时代或电子时代了 ,因为我们这一代正在建立的社会是信息社会 ,它将给人类生活的各个方面带来重大改变。为使全球各地能真正公平合理地享受信息社会带来的益处 ,信息社会必须覆盖全球。数字电子设备包括的计算机网络、数字电视、3G电话以及相关硬件、软件和服务是信息社会的关键构件 ,也可以把它们统称为信息通讯技术 (ICTs)。ICTs对信息和知识的电子化传播是必不可少的 ,没有ICTs就没有全…  相似文献   
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