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11.
Anna Wieclaw-Midor Pawel Falkowski Mikolaj Szafran 《International Journal of Applied Ceramic Technology》2020,17(1):248-254
The heterogeneous nucleation-and-growth processing was used to obtain core-shell particles based on alpha alumina core with silica layer. Presence of silica shell was confirmed by transmission electron microscopy (TEM) and zeta potential measurement. The coverage of aluminum oxide surface by SiO2 improved a cure of the depth of photopolymerizable ceramic dispersion around 20%. The proposed surface modification enables the production of thicker cured layer which is favorable for additive manufacturing methods such as stereolithography. Thus, the number of layers that have to be printed to form the 3D object might significantly decrease, thereby reducing time and costs of fabrication. 相似文献
12.
Xianghui Wang Pengda Zhao Jianwei Chen Huizhong Zhao Kai He 《Ceramics International》2018,44(11):12162-12168
Al–Cr slag is the solid waste generated by the smelting of Cr metal. It presents a range of environmental hazards. This study addressed the corrosion resistance of Al–Cr slag containing chromium–corundum refractories to slags with different basicity. Herein, we provide suggestions for the use of Cr–corundum of different basicity in kilns. Al–Cr slag, brown fused Al2O3, and chrome green were used as the raw materials, with pure calcium aluminate cement being used as a binder. The brick samples, prepared using different blends of chrome green and corundum, were fired at 1600?°C, and subsequently subjected to a slag corrosion test. After corrosion by slag of different basicity, the phase composition and microstructure of the sample were analyzed by X-ray diffraction, energy dispersive spectrometer and scanning electron microscopy. There were two major findings. First, Cr–corundum brick made from Al–Cr slag has a better slag corrosion resistance than that made from Cr2O3 and brown fused Al2O3. Second, Cr–corundum brick made from Al–Cr slag has superior corrosion resistance to slag with a CaO:SiO2 ratio of 2:1. 相似文献
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随着矿山开采深度的不断增加,“三高一扰动”恶劣开采环境问题日益突出,给矿井通风降温工作带来极大困难。对于深井矿山,仅采用通风降温难以满足深部开采的需要,系统研究高温深井矿山通风降温技术的适用性问题,对矿山深部开采具有重要的理论意义和工程适用价值。首先从热力学角度,揭示风流在通风线路中的热交换规律;其次利用差分法原理计算深井筒风流温度,并依此推导出巷道和回采工作面风流温度变化趋势;然后结合采场安全生产允许温度进行反推,最终获取通风降温条件下的可采极限深度计算公式,并选取广西铜坑矿锌多金属矿体作为工程应用试验区进行论证分析。结果表明:基于风流的热交换模型可以推导出风流在井筒、巷道及工作面的温度计算公式,该公式与低温梯度、风流流经路径长度有关;假定工作面温度达到安全开采允许最高温度,可反推出该条件下矿山可采极限深度和巷道通风极限长度(仅采用通风降温措施时);基于铜坑矿区锌多金属矿的实际条件,代入相关数据,验证计算所得极限开采深度符合实际,即所推导公式是可行的。 相似文献
15.
针对互联网中恶意域名攻击事件频发,现有域名检测方法实时性不强的问题,提出一种基于词法特征的恶意域名快速检测算法。该算法根据恶意域名的特点,首先将所有待测域名按照长度进行正则化处理后赋予权值;然后利用聚类算法将待测域名划分成多个小组,并利用改进的堆排序算法按照组内权值总和计算各域名小组优先级,根据优先级降序依次计算各域名小组中每一域名与黑名单上域名之间的编辑距离;最后依据编辑距离值快速判定恶意域名。算法运行结果表明,基于词法特征的恶意域名快速检测算法与单一使用域名语义和单一使用域名词法的恶意域名检测算法相比,准确率分别提高1.7%与2.5%,检测速率分别提高13.9%与6.8%,具有更高的准确率和实时性。 相似文献
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17.
Wonsiri Punurai Md Samdani Azad Nantiwat Pholdee Sujin Bureerat Chana Sinsabvarodom 《Computational Intelligence》2020,36(1):132-150
Offshore jacket platforms are widely used for oil and gas extraction as well as transportation in shallow to moderate water depth. Tubular cross-sectional elements are used to construct offshore platforms. Tubular cross sections impart higher resistance against hydrodynamic forces and have high torsional rigidity. During operation, the members can be partially or fully damaged due to lateral impacts. The lateral impacts can be due to ship collisions or through the impact of falling objects. The impact forces can weaken some members that influence the overall performance of the platform. This demonstrates an urgent need to develop a framework that can accurately forecast dent depth as well as dent angle of the affected members. This study investigates the use of an adaptive metaheuristics algorithm to provide automatic detection of denting damage in an offshore structure. The damage information includes dent depth and the dent angle. A model is developed in combination with the percentage of the dent depth of the damaged member and is used to assess the performance of the method. It demonstrates that small changes in stiffness of individual damaged bracing members are detectable from measurements of global structural motion. 相似文献
18.
Effects of food container depth on the quality and yield of superchilled and iced Atlantic salmon 总被引:1,自引:0,他引:1
Rúnar Ingi Tryggvason Björn Margeirsson Magnea Karlsdóttir Adalheidur Ólafsdóttir María Gudjónsdóttir Sigurjón Arason 《Packaging Technology and Science》2020,33(8):289-302
Insulated food containers of different sizes are commonly used to preserve the quality of perishable fresh fish products during transport and storage. The aim of the study was to explore the effects of packaging solutions with various depths on the quality of iced and superchilled farmed Atlantic salmon (Salmo salar). Insulated containers of different depths (32, 42, and 60 cm) and 17-cm deep expanded polystyrene (EPS) boxes were used to simulate transport and storage of the fish. The fish quality was evaluated after 4, 10, and 14 days of storage, where measurements on drip loss, texture, cooking yield, sensory evaluation, water and lipid distribution, and characteristics analysis in the fish muscle by nuclear magnetic resonance (NMR) spectroscopy were performed. Increased container depth from 32 to 42 cm increased the drip loss of superchilled salmon from 2.4% to 3.1% after 10 days of storage at −1°C. Iced storage of salmon for 10 days in EPS boxes resulted in less drip loss (0.5%) compared with superchilled salmon (1.5%) stored in EPS. The NMR analysis, sensory evaluation, texture analysis, and cooking yield did not reveal any major differences between salmon stored in containers of different depths. Iced storage increased pressure marks as compared with non-iced, superchilled storage in insulated containers. The results indicate that transport of whole salmon in reusable insulated plastic containers with a depth of 60 cm is possible without major quality changes observed for up to 10 days. 相似文献
19.
《International Journal of Hydrogen Energy》2020,45(1):605-618
In this work, the synthesis of cheap BiVO4 photoanodes for the photoelectrochemical water splitting reaction was optimized via the scalable thin film electrodeposition method. Factors affecting the photoelectrochemical activity, such as the electrodeposition time, the ratio of the Bi-KI to benzoquinone-EtOH in the deposition bath, and the calcination temperature, have been investigated by using the Central Composite Design of Experiments. Pristine monoclinic scheelite BiVO4 photoanodes having a photocurrent density of 0.45 ± 0.05 mA/cm2 at 1.23 V vs RHE have been obtained. It was shown that a high photocurrent density is generally dictated by the following physico-chemical properties: a higher crystallite size, optimal thickness and a porous morphology, which give rise to a low charge transfer resistance, low onset potential and a high donor density. Moreover, to the best of our knowledge, this is the first report on the depth profile XPS analysis performed in BiVO4 photoanodes made by electrodeposition technique, from which it was concluded that the surface V species exist as V4+ while the bulk V species are V5+. The V4+ induces a higher amount of surface oxygen vacancies, which was found to be beneficial for the photoactivity. 相似文献
20.
针对利用深度学习方法对街道图像进行深度估计,提出采用语义分割的方法解决深度图出现边界模糊等问题;估计深度通过左右视角图生成视差图进行无监督的训练。在网络模型中添加语义分割层,采取多个空洞卷积并行的结构增加感受野,同时减少了图像下采样的次数,降低了由于下采样带来的信息损失,使得的结果更加准确。这也是在深度估计中首次与空洞卷积相结合增加准确率。通过对KITTI街道数据集进行训练,与现有结果相比,除了增加检测准确性,降低错误率之外,使得效果图中的物体更加清晰,并且在效果图中还保留了一些原模型中被忽视掉的细节信息,将原始图像更加完整的表现出来。 相似文献