153 research outputs found
This special issue honors the distinguished economic geologist, Professor Yuchuan Chen on the occasion of his 80th birthday (2014)
No full text[Extract] Professor Yuchuan Chen, born in December 7, 1934, in Pinghu city of Zhejiang province, China, is an economic geologist well known not only in China but all over the world. He graduated from the Donetsk National University in 1959. From that time he has devoted himself to the fields of economic geology, geochemistry, regional metallogeny, mineral prospecting and exploration for 60 years
Preparation of Stannum and Titanium Precipitation Particles and its High Electrorheological Properties
No full textA type of stannum and titanium precipitation (STP) particle was synthesized by means of co-precipitation method. Suspensions made by dispersing the STP particles in silicone oil exhibit excellent electrorheological (ER) effect with high yield stress, high shear stress at higher shear rate. The static yield stress of the STP ER can be up to 84 kPa at an electric field of 5 kV/mm. The high yield stress and its near-linear dependence on the electric field indicate that the rheological behaviors of our STP ER fluid can be explained by the model of the polar molecule dominated ER (PMER) effect, which arises from the alignment of polar molecules in the gap between neighboring particles
Application of 1D attapulgite as reservoir with benzotriazole for corrosion protection of carbon steel
No full textThe development of active systems to protect metal substrates against corrosion by using inhibitor loaded nanocontainers is a promising approach for many industrial applications. This study introduces attapulgite as a reservoir for loading a corrosion inhibitor (benzotriazole). As a key component, inhibitor loaded attapulgite was dispersed in a water-based epoxy coating to protect carbon steel. The release behavior of the encapsulated inhibitor from the attapulgite nanocontainers in response to pH variation was investigated using UV-visible spectroscopy. The corrosion properties of the composite coatings were explored by electrochemical impedance spectroscopy. The coating with inhibitor-loaded attapulgite demonstrated enhanced film barrier properties compared with blank coating. The scratched coating with inhibitor-loaded attapulgite showed increased corrosion resistance relative to that of the blank coating after immersion and hence exhibited an active corrosion protection. The coating's self-healing mechanism can be attributed to the passive film formation on the metal surface promoted by the inhibitor release from the nanocontainers. (C) 2017 Elsevier B.V. All rights reserved
PREPARATION AND ELECTRORHEOLOGICAL EFFECT OF ACETAMIDE-MODIFIED TITANATE NANOTUBE SUSPENSIONS INSTRUCTIONS
No full textTitanate nanotube (TN) synthesized by hydrothermal reaction of titania nanoparticles in alkali solution, then the TNs were modified by acetamide. X-ray diffraction analyses, scanning electron microscopy and Fourier transform infrared spectrometry are used to determine the structure of the TNs. Under DC electric field, the yield stress of these acetamide-modified TN suspensions shows large yield stress. It is also found that the ER effect is sensitive to the wettability of the TNs
ELECTRORHEOLOGICAL PROPERTIES OF AMORPHOUS TITANIUM OXIDE PARTICLES WITH DIFFERENT SIZES
No full textA kind of amorphous titanium oxide particles with different sizes (30nm, 80nm, 240nm and 640nm) was prepared using a hydrolysis method. The microstructure, dielectric properties and ER performance were investigated. The results show that the suspensions composed of smaller particles have higher yield stress at DC electric field, but also possess higher zero field viscosity. The maximal ER efficiency of the ER fluids with the larger particle size is higher than that for the smaller particles. The particles with the sizes of 30nm, 80nm, 240nm possess an excellent antisedimentation stability, while the particle with the size of 640nm shows a poor antisedimentation stability. The particle with size of 240nm has the best comprehensive performance
Reconstructive memory and the impact of technology in Ted Chiang’s The Truth of Fact and Anxiety is The Dizziness / Yuchuan Zheng
No full textFallible and reconstructive memory has been frequently interpreted in science fiction stories and examined in studies as a major drawback that is inferior to digitalized memory and vulnerable to capitalist manipulation. There are still insufficient studies about technology’s non-capitalist and humanistic impacts on human reconstructive memory. American author Ted Chiang’s novellas The Truth of Fact, the Truth of Feeling and Anxiety is the Dizziness of Freedom reveal reconstructive memory’s unobtrusive nature and delve into the humanistic impacts of technology on people’s cognition and relationships. This research examines how Chiang embeds his postulation about technology’s humanistic impacts in his narrative thought experiments in the form of fiction, in which he creates an intense and dynamic interaction between science fiction devices and multiple characters. Applying Frederic Bartlett’s theory of Reconstructive Memory and the theory of Reading Fiction as Thought Experiments, this dissertation focuses on two main characters the father and Dana’s cognitive transformations having interacted with science fiction devices Remem and Prism, elucidating the complicated mutual influences between technology and human reconstructive memory. Chapters two and three discover that these science fiction devices represent sharp-end technology with rich symbolic meanings and are essential tools of Chiang’s narrative thought experiments. This dissertation also found that these science fiction devices engender schematic changes in characters, allowing them to reappraise their attitude toward a guilty relationship. This study contributes to a humanistic and nuanced approach to technology in science fiction stories which is addressed as techno-realism, and stimulates rumination over technology’s humanistic impacts on human reconstructive memory and a possible direction for the development of memory-modulating technology
Electrorheological Properties of TiO2/ZnC2O4 Nanocomposites
No full textTiO2/ZnC2O4 nanocomposites were synthesized by means of co-precipitation method. The XRD, SEM, FTIR and DTA/TG were used to determine the structure of the nanocomposites. The electrorheological (ER) activity of the suspension of TiO2/ZnC2O4 dispersed in silicone oil was investigated under a dc electric field. An excellent ER effect was found. Under 5 kV/mm external electric field, the yield stress of the TiO2/ZnC2O4 suspension can reach up to 90 kPa, and the leaking electric current density is lower than 20 mu A/cm(2). The yield stresses exhibit a near linear dependence on applied electric field unlike the conventional fluids. The results demonstrate that the polar molecules such as hydroxyl groups and oxalate groups adsorbed on the particles play a decisive role in determining the characteristics of the ER fluids
synthesis and electrorheological properties of polar molecule-dominated tio (2) particles with high yield stress
No full textA novel silica nanowire-silica composite aerogels dried at ambient pressure
No full textA novel silica nanowire-silica composite aerogels with excellent thermal insulation and mechanical properties was prepared by adding SiO2 nanowires as a secondary phase into the silica matrix and drying at ambient pressure. The SiO2 nanowires and silica aerogel matrix have outstanding compatibility and dispersibility because the components of nanowire and aerogel matrix all are silica, which contributes to the improvement of the mechanical property of the silica composite aerogels. The physical, mechanical and thermal properties of the SiO2 nanowires based composite silica aerogel are investigated and discussed in detail. The results indicate that the monolithic aerogels with high specific surface area, porosity and large pore volume. The thermal conductivity of the composite silica aerogels only increases gently (0.006 W.m(-1) K-1) as the addition of SiO2 nanowires rises from 0 wt% to 14 wt%, while their mechanical properties have been improved greatly. The SiO2 nanowires based composite silica aerogel would be widely used in the thermal insulation application because of its outstanding thermal insulation property. (C) 2016 Elsevier Ltd. All rights reserved
Properties of oriented carbon fiber/polyamide 12 composite parts fabricated by fused deposition modeling
No full textThis paper reports the thermal and mechanical properties of carbon fiber (CF) reinforced polyamide 12 (PA12) composites for fused deposition modeling (FDM) process. The printable filaments of carbon fiber/PA12 composites with different mass fraction were fabricated and applied in FDM. The results indicate that the tensile strength and flexural strength of 10 wt% CF/PA12 composites are enhanced by 102.2% and 251.1% respectively. The laser-flash diffusivity analysis measurements exhibit remarkable improvements on thermal conductivity (lambda) of carbon fiber/PA12 composites. Moreover, the carbon fiber/PA12 composites mechanical properties are greatly improved. Our work presents a kind of anisotropic high performance composite for FDM. (C) 2017 Elsevier Ltd. All rights reserved
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