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81.
Fabrication of homogeneously dispersed graphene/Al composites by solution mixing and powder metallurgy
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Graphene-reinforced aluminum (Al) matrix composites were successfully prepared via solution mixing and powder metallurgy in this study. The mechanical properties of the composites were studied using microhardness and tensile tests. Compared to the pure Al alloy, the graphene/Al composites showed increased strength and hardness. A tensile strength of 255 MPa was achieved for the graphene/Al composite with only 0.3wt% graphene, which has a 25% increase over the tensile strength of the pure Al matrix. Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the morphologies, chemical compositions, and microstructures of the graphene and the graphene/Al composites. On the basis of fractographic evidence, a relevant fracture mechanism is proposed. 相似文献
82.
Selective functionalization of mesoporous silica nanospheres (MSNs) is crucial for nanoengineering of MSNs.
Herein, we have combined “surface-protected etching strategy” and “cationic surfactant assisted etching
strategy” to prepare functionalized MSNs with externally attached amino groups. The externally attached NH2
groups endow the catalysts with excellent catalytic performance for nitroaldol reaction between nitromethane
and benzaldehyde. In addition, those NH2-MSNs can also be used to support gold nanoparticles, which display
very good catalytic performance for reduction of 4-nitrophenol. It can be envisioned that the synthesis protocol
developed in this work could also be extended to nanoengineered MSNs, which provides opportunities for nanoreactors
design. 相似文献
83.
Inferentialists about scientific representation hold that an apparatus's representing a target system consists in the apparatus allowing “surrogative inferences” about the target. I argue that a serious problem for inferentialism arises from the fact that many scientific theories and models contain internal inconsistencies. Inferentialism, left unamended, implies that inconsistent scientific models have unlimited representational power, since an inconsistency permits any conclusion to be inferred. I consider a number of ways that inferentialists can respond to this challenge before suggesting my own solution. I develop an analogy to exploitable glitches in a game. Even though inconsistent representational apparatuses may in some sense allow for contradictions to be generated within them, doing so violates the intended function of the apparatus's parts and hence violates representational “gameplay”. 相似文献
84.
Electrorheological effect of Ti-bearing blast furnace slag with different TiC contents at 1500℃
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The electrorheological properties of CaO–SiO2–Al2O3–MgO–TiO2–TiC slags were investigated to enhance understanding of the effect of TiC addition on the viscosity, yield stress, and fluid pattern of Ti-bearing slags in a direct-current electric field. The viscosities and shear stresses of 4wt% and 8wt% TiC slags were found to increase substantially with increasing electric field intensity, whereas virtually no rheological changes were observed in the 0wt% TiC slag. The Herschel–Bulkley model was applied to demonstrate that the fluid pattern of the 4wt% TiC slag was converted from that of a Newtonian fluid to that of a Bingham fluid in response to the applied electric field; and the static yield stress increased linearly with the square of the electric field intensity. 相似文献
86.
With the development of the social media and Internet, discovering latent information from massive information is becoming particularly relevant to improving user experience. Research efforts based on preferences and relationships between users have attracted more and more attention. Predictive problems, such as inferring friend relationship and co-author relationship between users have been explored. However, many such methods are based on analyzing either node features or the network structures separately, few have tried to tackle both of them at the same time. In this paper, in order to discover latent co-interests’ relationship, we not only consider users’ attributes but network information as well. In addition, we propose an Interest-based Factor Graph Model (I-FGM) to incorporate these factors. Experiments on two data sets (bookmarking and music network) demonstrate that this predictive method can achieve better results than the other three methods (ANN, NB, and SVM). 相似文献
87.
88.
目的:比较腹腔镜胃癌根治术与传统胃癌根治术的临床效果。方法:回顾分析2010年10月至2013年10月大理大学附属医院行腹腔镜胃癌根治术及胃癌根治术共103例胃癌患者的临床资料,分析比较两组患者的临床效果。结果:应用腹腔镜组平均出血量为(153.05±11.71)m L,明显少于开腹手术的(278.45±12.65)m L(P<0.05)。腹腔镜组的平均术后恢复肛门排气时间(3.10±0.62)d,低于开腹手术组的(5.58±1.12)d(P<0.05)。腹腔镜组平均术后住院时间为(14.25±2.78)d,明显低于开腹手术的(22.07±3.59)d(P<0.05)。生存率:行腹腔镜手术者1年总生存率94.1%,开腹手术总生存率92.1%(P>0.05)。结论:腹腔镜胃癌根治术具有术中出血少、术后住院天数少、并发症少等优点,治疗效果与开腹手术相当。 相似文献
89.
90.
针对传统隔振方法对低频振动无法取得较好效果的问题,分析了波阻块( WIB)和蜂窝形波阻块( HWIB)对高速铁路引发的低频振动的隔振效果.首先建立了列车-路基的数值计算模型,将列车荷载简化为沿路基向前的移动荷载列,并采用基于拉格朗日算法的有限差分软件计算了埋设WIB和HWIB前后场地土的振动情况,最后与空沟的隔振效果进... 相似文献