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基于CPFD(Computational particle fluid dynamics)方法,对实验室前期研究的催化裂化管式分配器内的颗粒分配特性及内部流动特性进行了数值模拟,系统研究了输送风、松动风及分配器倾斜角度对颗粒分配不均匀指数的影响,并进一步考察了输送风和松动风对分配器各出口气体流量分布及内部气 固流动特性的影响。结果表明,增大输送风量、松动风量以及分配器的倾斜角度均可以降低颗粒分配不均匀指数,但改变松动风量的效果不如改变输送风量和倾斜角度显著。分配器倾斜角存在一个最优值时,颗粒分配均匀性最佳。输送风的增大会使得颗粒出料量最高的排料口的位置逐渐向分配器的末端移动,中间排料口所流出的气体流量占比增大,末端排料口排风量占比减小。引入松动风后,各出口的颗粒排料量更加接近,同时靠近末端排料口的气体流量占比明显增大。  相似文献   
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王兴旭  孟坤  陈梦 《陕西煤炭》2020,39(1):27-31,17
地应力场主要由自重应力场和构造应力场组成,是影响井下采掘工程活动最重要和最根本的因素,掌握矿井的地应力场分布规律,对整体提高矿井的经济效益和社会效益具有重要的意义。本文在小庄煤矿区域采用套空应力解除法进行地应力场测量,并采用三维应力场反演验证测量结果,从而得出了小庄煤矿的应力分布规律,为矿井动力现象的预测预防奠定了基础。  相似文献   
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A new titanium (III) phosphite Ti2(HPO3)3, has been synthesized under hydrothermal conditions. The solid-state structure of this material was solved using single-crystal X-ray diffraction. The anionic inorganic skeleton has a three-dimensional structure, which is built up by TiO6 octahedral units linked together via bridging HPO3 pseudo pyramids, giving rise to tunnels along the three crystallographic axes. This new compound displays a high thermal stability limit of 625 °C. IR and Raman spectroscopies show the vibrational modes of the (HPO3)2−oxoanions. Electrochemical activity of this phase toward reversible insertion of Li ion was studied for the first time by galvanostatic charge-discharge measurements, an insertion host for reversible accommodation of Li+ was observed.  相似文献   
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为有效预防ZF2803工作面的冲击地压,本文采用多因素耦合分析法研究了初次来压、见方、煤柱、断层、邻近空区支承压力、煤层厚度变化及巷道底煤等7个因素的单独影响区域及叠加效果,确定了7个危险区:中等冲击危险区4个、强冲击危险区3个,给出了相应的煤层及底板大钻孔预卸压措施,工业性应用取得了良好的防治效果。  相似文献   
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Tumor progression is usually characterized by proliferation, migration, and angiogenesis, which is essential for supplying both nutrients and oxygen to the tumor cells. Therefore, targeting angiogenesis has been considered a promising therapeutic strategy for cancer prevention and treatment. In the present study, we demonstrated that in addition to suppressing lung cancer cell proliferation and migration in vitro, 10-hydroxycamptothecin (10-HCPT) is also capable of inhibiting angiogenesis in vivo with a miR-181a-dependent manner. Mechanistically, by upregulating miR-181a, which in turn downregulating FOXP1, 10-HCPT can inhibit the PI3K/Akt/ERK signaling pathwaymediated angiogenesis. Furthermore, reduced levels of miR-181a have been found in both lung cancer cell lines and xenograft with concurrently elevated levels of FOXP1, VEGF, bFGF, and HDGF. Consistent with the findings from the in vitro experiments, miR-181a impairs neovascularization in our xenograft model. In summary, our findings have not only established the anti-oncogenic role of miR-181a in lung cancer angiogenesis but also suggest that 10-HCPT could be a potential therapeutic reagent for lung cancer treatment.  相似文献   
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Fuel quality, especially biodiesel, is highly dependent on its water content, and the major sources of water in the fuel relate to the transportation, production, and storage processes. In this present contribution, the multilayer perceptron artificial neural network (MLP-ANN) was applied to predict the water content of biodiesel and diesel blend in terms of temperature and composition. The proposed algorithm was trained and tested by utilizing 400 experimental data points which were extracted from the literature. Based on the results, the MLP-ANN model has great ability to estimate the water content of biodiesel and diesel blend. The R-squared (R2), root mean square error, average absolute relative deviation, and a?bsolute deviation parameters for the total data set are obtained, respectively, as 0.99784, 123919.1172, 3.3632, and 1.17%, which indicate the effective performance suggested by ANN. As the computational study is cheaper and easier than the experimental study, the developed software could be considered as an alternative for laboratory study, and the environmental effect of biodiesel and produced undesired product after biodiesel combustion which is directly related to the water content of biodiesel is estimable with the information released in this study.  相似文献   
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In order to clarify the effect of grain size on the electrical performance of BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) solid electrolytes with addition of NiO, microcrystalline (~1.5?µm) and ultrafine-grained (~280?nm) BZCYYb electrolytes (with 1?wt% NiO) were fabricated by the conventional and two-step sintering method, respectively. The results show that compared with microcrystalline electrolytes, the ultrafine-grained electrolytes have similar grain-interior conductivities, but much lower grain-boundary conductivities, illustrating that the grain boundary is not conducive for ionic transport. As a result, the electrical conductivity of microcrystalline electrolytes (1.9?×?10?2 S?cm?1 at 600?°C in wet air) is higher than that of ultrafine-grained electrolytes (1.1?×?10?2 S?cm?1 at 600?°C in wet air). In addition, the OCV (open-circuit voltage) values of electrolyte-supported single cells show that the undesired electronic conduction exists in the electrolytes due to the BaY2NiO5 impurity formed by the reaction of NiO and BZCYYb. The ultrafine-grained electrolytes show lower OCV values than that of microcrystalline ones, due to the prolonged electronic transport paths. Therefore, large-grained or grain boundary-free microstructure are necessary for improving the electrical performance of BZCYYb electrolytes.  相似文献   
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Multimedia Tools and Applications - Semantic segmentation of ocean remote sensing images classifies each pixel in the image according to the ocean background and island type, and is an important...  相似文献   
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