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The wetting and interfacial reaction between the liquid Ag-Cu-Ti and SiO 2f /SiO 2 composites were studied at 860 °C for various holding durations. Typical interfacial microstructure of the AgCuTi-SiO 2f /SiO 2 system was firstly investigated. The formation sequence of the reaction layers was discussed. Then the relationship between contact angles and the types of reaction products were revealed. Results show that the formation of the Cu x Ti 6-x O (x = 2, 3) phase plays a key role on the wettability of the AgCuTi-SiO 2f /SiO 2 system. The microstructural evolution of the reaction products at the AgCuTi-SiO 2f /SiO 2 interface versus various holding durations was studied. Finally, the wetting mechanism of the AgCuTi-SiO 2f /SiO 2 system was proposed. This study can offer new insights into the reaction and joining nature of the AgCuTi-SiO 2f /SiO 2 system. • Ti 5 Si 3 + TiO 2 /Cu x Ti 6-x O (x = 2, 3) reaction layer formed for the AgCuTi-SiO 2f /SiO 2 wetting system. • Ti 5 Si 3 + TiO 2 proved to form first and Cu x Ti 6-x O(x = 2, 3) layer formed subsequently. • Cu x Ti 6-x O(x = 2, 3) layer became unstable with the extension of the holding duration. • Cu x Ti 6-x O(x = 2, 3) layer was the key that promoted the wetting of the SiO 2f /SiO 2 by AgCuTi. • 4 stages were divided for the wetting process of the AgCuTi-SiO 2f /SiO 2 system. [ABSTRACT FROM AUTHOR]

The wetting behavior and the interfacial reactions of molten Ti-40Ni-20Nb (at.%) filler alloy on the BN-SiO 2 ceramic were investigated by the a sessile drop method at 1453 K under a vacuum atmosphere. Results demonstrated that a good wettability with final contact angles of approximately 44°–15° was obtained. Interfacial microstructure examinations revealed that the Ti-40Ni-20Nb filler alloy reacted with the BN-SiO 2 ceramic, which resulted in the formation of TiN, TiB, Ti 5 Si 3 and Ti 3 O 5 at the interface. The wetting process of the Ti-40Ni-20Nb filler alloy on the BN-SiO 2 ceramic was identified into 3 stages: (i) rapid decreasing stage, (ii) sluggish spreading stage and (iii) final equilibrium stage. In order to reveal the essence of the reactive wetting, the wettability of the Ti-40Ni-20Nb (at.%) filler alloy on the BN-SiO 2 ceramic with three different BN contents were investigated. For the Ti-40Ni-20Nb/BN-SiO 2 system, the wettability mainly depended on the final interfacial chemistry of the system but the intensity of the interfacial reactions. The final contact angle of the Ti-40Ni-20Nb filler alloy on the BN-SiO 2 ceramic decreased as the BN content in the ceramic was increased from 20% to 80%. Unlabelled Image • Reaction layer mainly composed by TiN, TiB, Ti 5 Si 3 and Ti 3 O 5 is formed adjacent to the BN-SiO 2 ceramic. • The wetting of the TiNiNb filler alloy/BN-SiO 2 ceramic system can be explained by "Reaction Product Control" model. • With the improving of the BN content in the BN-SiO 2 ceramic, the ratio of (TiN+TiB):(Ti 5 Si 3 +Ti 3 O 5) in the reaction products increases, which can improve the wetting of the BN-SiO 2 ceramic. With BN content increases from 20% to 80%, the final contact angle decreases from 44° to 15°. [ABSTRACT FROM AUTHOR]

The Nb and Nb/Ni interlayers were designed for the diffusion bonding of the hydrogenated TC4 alloy and GH3128 superalloy joint. Typical microstructure of the TC4-0.3 H/Nb(Ni/Nb)/GH3128 joints were investigated. The effects of holding temperatures and durations on the microstructure evolution of the hydrogenated TC4/GH3128 joints were investigated. The addition of a Nb interlayer can successfully suppress the brittle Ti-Ni phase formation and the maximum joint strength reached 245 MPa bonded at 860 ℃/60 min under 10 MPa. The design of the Nb/Ni interlayer successfully eliminated the unbonded voids and the Ni-Cr layer formed when bonding with a single Nb interlayer. The maximum shear strength of ˜270 MPa was achieved when bonding at 860 ℃ for 80 min under 10 MPa. Fracture mechanism of the hydrogenated TC4/GH3128 joints bonded with two interlayers were analyzed finally. [ABSTRACT FROM AUTHOR]

Geothermal power has received a great deal of attention in China as the country strives to be less dependent on coal energy and to seek stable and base load renewable power. The country's 13th Five-Year Plan for geothermal energy calls for an additional 500 MW by 2020. To assess whether this ambitious target can be achieved, this paper provides an overview of the environmental and economic performance of geothermal power based on an emergy evaluation and economic analysis of the Yangbajain plant in Tibet, the largest working geothermal power plant in China. The results indicate that the full flow system that the plant currently uses has a much higher production efficiency than the dry steam geothermal power plant in Italy. In addition, the system exhibits a relatively good environmental sustainability compared to other renewable energy generation technologies. However, it is still not economically feasible without government subsidies. Labor is expensive due to the high demand for trained professionals and the harsh working conditions in Tibet. Since China's high-quality geothermal resources are mainly located in Tibet, it would be quite challenging to achieve the ambitious 500 MW target by 2020. However, considering its environmental competitiveness, attractive subsidy policies and support for scientific research to promote technological innovations are proposed in this study to encourage the growth of the geothermal power industry in China, which would provide the country with another valuable alternative to coal. • The development course of geothermal power in China was reviewed and analyzed. • The Yangbajain geothermal power plant was assessed via emergy and economic methods. • It obtains good environmental performance but has no economic competitiveness. • Future directions of the geothermal power industry in China were discussed. [ABSTRACT FROM AUTHOR]

Introduction: Hypertrophic scarring is commonly seen by plastic surgeons in China. Since the etiology of hypertrophic scarring is still unknown, the only reliable treatment is surgical excision. To understand if angiogenesis plays an important role in the formation of hypertrophic scars, we investigated the effect of angiostatin, a potent angiogenesis inhibitor, on hypertrophic scar formation. Our hypothesis is that angiogenesis is required for increased scar formation and angiogenesis inhibition may be one of the methods that can be used to prevent the formation of hypertrophic scars. Methods: We have developed a reliable model in rabbits that results in hypertrophic scarring by creating a 6mm x 6mm full thickness skin wound on both ears. The cDNA for angiostatin is cloned into the pcDNA 3.1 mammalian expression vector. After the wounds re-epithelialized but prior to excessive scarring, the angiostatin expression vector was injected with Lipofectin 2000 once every two days. The expression of angiostatin was confirmed by RT-PCR. The scar tissue was harvested 14 days after injection and processed for histology and total protein. Histology was examined with routine stains, the amount of collagen deposition in the scar tissue was detected by proline assay, and TGF-β1 and VEGF expression was detected by western blot. Results: Compared to the control injection scar, the injection of angiostatin led to a much more normal-looking of scar in the rabbit ear. The proline assay demonstrated that the injection of the angiostatin expression vector resulted in much less collagen in the scar tissue. Western blot analysis showed there was less TGF-β1 and VEGF protein expression in the treated ear compared to the control. Conclusion: The introduction of a vector over-expression angiostatin can result in the decreased formation of hypertrophic scars in a rabbit ear model. This is corroborated by evidence of decreased collagen deposition, the primary extracellular matrix component of scars. In addition, we demonstrate the decreased expression of τηϵ pro-fibrosis growth factor, TGF-1, and the potent angiogenic factor, VEGF. These data suggest that angiogenesis inhibitors may have a potential role in the treatment of hypertrophic scarring. [Copyright &y& Elsevier]

The microstructure and mechanical properties of Mg–6.63wt.%Zn–0.56wt.%Zr (ZK61) Mg alloy sheets processed by temperature–step–down multi–pass rolling were investigated. A uniform fine–grained structure with the average grain size of about 3.5 μm, which is enriched with rod–shaped β 1 ′ (MgZn 2 ) and blocky β 1 ′ (Mg 2 Zn 3 ) precipitates, is attained by multiple dynamical recrystallization. An intense {0002} basal texture with a–axis randomly rotated in the plane is developed. As a consequence, a yield strength of 219 MPa, an ultimate tensile strength of 313 MPa, and a fracture elongation larger than 32% can be obtained. This enhancement in strength during rolling is mainly due to grain refinement and basal texture strengthening in the early stage, and is further contributed by precipitation hardening, simultaneously. Ductility improvement is attributed to the enhanced uniform elongation correlated with twinning suppression, and the enhanced post–necking elongation controlled by grain refinement, especially at the fine grain sizes. This can provide an essential reference for designing high-performance wrought Mg alloy sheets suitable for industrial fabrication. [ABSTRACT FROM AUTHOR]

• Varied textures were feasibly controlled by combined-extrusion techniques. • Semianalytical Sachs model well predicted flow stress in tension/compression. • Asymmetry was improved by balancing slip/twinning contribution relying on texture. • Symmetric high-strength ZK61 achieved by texture dispersion via DUE technique. Three combined-extrusion techniques of second extrusion, die upsetting and extrusion, and cyclic extrusion and compression were used to fabricate three typical {0002} basal textures of fiber texture, dispersed texture and inclined texture, respectively, in the fine-grained ZK61 magnesium alloy. The tension-compression asymmetries were compared and the texture influence on asymmetry mechanical response was well evaluated using a Semianalytical Sachs model that followed Schmid law and highlighted the importance of slip/twining activity in tension-compression asymmetry. It was found that in strong fiber-textured materials, solely refining grains could not obviously improve the tension-compression asymmetry. However, basal texture dispersed/inclined was conducive to activation of basal slip in tension and impeding of twining in compression, leading to gentler strain hardening and low tension-compression asymmetry. The uniaxial symmetry managed to be kept in cyclic loading under low strain amplitude, with the cyclic maximum stresses in accordance with uniaxial yield values. Symmetric high-strength ZK61 magnesium alloys with tensile and compressive yield stresses (1.0 % offset) over 300 MPa were achieved by basal texture dispersion feasibly controlled by die upsetting extrusion technique. [ABSTRACT FROM AUTHOR]

It is clear that city must be part of the solution if an urbanizing world is to grapple successfully with ecological challenges such as energy depletion and climate change. A system dynamics model was developed in this study using STELLA platform to model the energy consumption and CO2 emission trends for the City of Beijing over 2005–2030. Results show that the total energy demand in Beijing is predicted to reach 114.30 million tonnes coal equivalent (Mtce) by 2030, while that value in 2005 is 55.99Mtce, which is 1.04 times higher than the level in 2005. Accordingly, the total CO2 emissions in 2030 will reach 169.67 million tonnes CO2 equivalent (Mt CO2-eq), 0.43 times higher than that of 2005. The change of energy structure from carbon rich fuel as coal to low-carbon fuel as natural gas will play a very essential role in carbon emission reduction activities of Beijing. The modeling results also shows that the service sector will gradually replace the industrial dominant status in energy consumption as the largest energy consuming sector, followed by industrial and transport sector. The sensitive analysis suggests that change of economic development mode and control of rational population growth will have a far-reaching influence on energy consumption and on carbon emissions. All these results will provide essential information for Beijing''s future energy and carbon emission profiles. [Copyright &y& Elsevier]

Abstract: An in vitro experiment was conducted to elucidate the role of polyamines and phospholipase D (PLD) in maize (Zea mays L.) response to drought stress simulated by PEG-6000. During the early stage of drought stress, an increase of PLD activity played a major role in stomatal closure as an adaptive response to drought stress and this process was independent of polyamine synthesis. Under prolonged drought stress, the total content of polyamines including putrescine (Put), spermidine (Spd) and spermine (Spm) increased at 120min after drought stress treatment while the ratio of Spd+Spm/Put decreased, which caused an increase in PLD activity, relative membrane permeability and malondialdehyde content (MDA). Exogenous polyamines enhanced PLD activity, and the greatest effect was induced by Put. Therefore, we concluded that PLD played an important role in mitigation of drought stress damage in the early stage of drought stress which was independent of polyamine accumulation. However, in the later stage of drought stress, the obvious elevation of PLD activity led to serious membrane damage regulated by the ratio of Spd+Spm/Put. [Copyright &y& Elsevier]

Abstract: This paper studies the small scale effect on the buckling behaviors of triple-walled carbon nanotubes (TWCNTs) with the initial axial stress under the temperature field. The TWCNTs are modeled as three elastic shells coupled together through vdW interaction between different layers. Buckling governing equations of CNTs are firstly formulated on the basis of nonlocal elastic theory and the small scale effect on CNTs buckling results with the change of temperature are then achieved. The results show that the critical buckling load is dependent on the temperature, scale parameter and wavenumber. Some conclusions are drawn that small scale effect will arise gradually with the increases of wavenumber, and the temperature can influence the ratio between the nonlocal buckling load and the corresponding local load. Furthermore, with or without effects of nonlocal considered, the same results is obtained that the axial buckling load increases as the value of temperature increases at low and room temperature condition, while at high temperature condition the axial buckling load decreases as the value of temperature increases. [Copyright &y& Elsevier]

Abstract: SiO2 glass ceramic has been successfully joined to Ti–6Al–4V alloy with AgCu/Ni composite interlayer. The brazing temperature varies from 950°C to 980°C, with the holding time ranging from 1min to 45min. AgCu eutectic foil melted first, followed by the Ti–Cu–Ni ternary eutectic reaction, then Ti reacted to SiO2 glass ceramic. All of Ti atoms came from Ti–6Al–4V alloy but not from braze alloy. The effects of brazing temperature and dwelling time on interface structure and joint strength were investigated in the present work. The largest shear strength of brazed joint could reach 110MPa when the brazing temperature was 970°C, holding time was 10min, and fracture occurred in the SiO2 glass ceramic part. While the thin reaction layer at SiO2 side is the weak part of the joint when the brazing parameter is not appropriate. [Copyright &y& Elsevier]

Abstract: This paper is concerned with the free vibration of the fluid-filled multi-walled carbon nanotubes (MWCNTs) with simply supported ends. Based on simplified Donnell’s cylindrical shell model and potential flow theory, the effect of internal fluid on the coupling vibration of the MWCNTs-fluid system is discussed in detail. The results show that the resonant frequencies are decreased due to the effect of the fluid, and the fluid has only a little influence on the associated amplitude ratio in MWCNTs corresponding to the natural resonant frequency (frequency of the innermost tube), while plays a significant role in the associated amplitude ratios corresponding to the intertube resonant frequency. For the natural resonant frequency, the vibration mode is coaxial. However, for the intertube resonant frequency, the system shows complex noncoaxial vibration, which plays a critical role in electronic and transport properties of carbon nanotubes (CNTs). [Copyright &y& Elsevier]

Abstract: Based on an elastic beam model and potential flow theory, and by adopting N-mode Galerkin discretization technique, the dynamical stability behaviors of fluid-conveyed multi-walled carbon nanotubes (MWCNTs) are studied. The influences of the flow inside the innermost tube and the van der Waals (vdW) interaction between any two walls on the instabilities of the CNTs-fluid system are discussed on the numerical simulations in detail. Also, the effects of the innermost tube radius, the length and the layer quantity of MWCNTs on the critical velocities of the destabilized system are intensively analyzed and compared. The results show that the critical velocities increase sharply as the radius becomes larger, the layer quantity increases, and the length decreases. The bifurcations happen in turn of divergence and Hopf types. [Copyright &y& Elsevier]

Abstract: In this study, the instability of triple-walled carbon nanotubes (TWCNTs) conveying fluid is studied based on an Euler–Bernoulli beam model. The van der Waals (vdW) interactions between different carbon nanotubes (CNTs) are taken into account in the analysis, and the Galerkin discretization approach is used to solve the coupled equations of the motions. Numerical simulations show that the interlayer vdW interactions play a significant role in the natural frequencies and the stability of TWCNTs. The critical flow velocities—associated with divergence, restabilization and flutter—are determined. The effects of different inner radius and the value of mode N used in Galerkin discretization on the dynamical behaviors of the fluid-conveyed TWCNTs are also examined in detail. Results reveal that the internal moving fluid plays an important role in the instability of TWCNTs. [Copyright &y& Elsevier]

Upsetting-extrusion (UE) process effectively prepared high-strength ZK61 magnesium alloy rods with tension/compression symmetry. The influence of upsetting-extrusion temperature and upsetting ratio on microstructure was studied. Microstructure evolution in the UE process included two stages: {10–12} tensile twinning significantly divided and refined the coarse grains in upsetting stage, forming a <0001>//ED (extrusion direction) texture component; grain refinement suppressed the inverse occurrence of {10–12} tensile twinning during extrusion stage, promoting multi-slip deformation and dynamic recrystallization (DRX) and leading to the diffused {0001}//ED texture. Lowering temperature and increasing upsetting ratio played positive roles in twinning division and DRX refinement. Both of them were beneficial to basal texture weakening which could effectively inhibit the activation of tensile twinning during compression, and promote basal slip contribution during tension, thus improving tension/compression asymmetry. The relationship between microstructure and tension/compression yield strengths was analyzed by texture-dependent Hall-Petch relationship composed of slip and twinning deformation mechanisms. Only slight weakening of the extruded fiber texture was required for tension/compression symmetry for fine-grained structure; but it was the opposite for coarse-grained structure. Correspondingly, only smaller critical upsetting ratio was needed at lower upsetting temperature. • Tension/compression symmetry achieved by upsetting-extrusion process. • Twinning division in upsetting aided grain refinement and basal texture weakening. • Dominant deformation mechanisms investigated from strain hardening and Schmidt factor. • Texture-dependent Hall-Petch relationship including slip and twinning was established. [ABSTRACT FROM AUTHOR]

Previously, we have reported that thalidomide (Thd) treatment can modulate the immune responses in female B6C3F1 mice. The present study was designed to evaluate whether or not these immunomodulatory responses were of sufficient magnitude to alter host resistances in a number of pathogen and tumor models. B6C3F1 mice were treated intraperitoneally with Thd (30–150 mg/kg) for 14 or 28 days, then inoculated with either Plasmodium yeolii, PYB6 fibrosarcoma tumor cells, B16F10 melanoma tumor cells, Listeria monocytogenes, or Streptococcus pneumoniae. Significant dose-dependent protection against B16F10 and L. monocytogenes was observed in mice that were treated with Thd. Furthermore, time course study using bacterial colony-forming units per spleen and liver as the endpoints indicated that the protective effect of Thd on host resistance to L. monocytogenes was time-dependent. In contrast, Thd treatment did not affect host resistance to P. yeolii, S. pneumoniae and PYB6 tumor. Additionally, the effect of Thd on the phagocytic function of the mononuclear phagocyte system (MPS) was evaluated following intravenous injection of 51Cr-labeled sRBCs. The overall phagocytic activity of MPS was not significantly altered by Thd treatment. In conclusion, these results demonstrate that Thd immunomodulation altered host resistance to B16F10 and L. monocytogenes; and selective modulation of Thd on the immune system may be responsible for the pathogen or tumor-specific effect of this compound. [Copyright &y& Elsevier]

CaO-Al 2 O 3 -SiO 2 (CAS) glass ceramics were designed and prepared using a melt-quench approach. The coefficient of the thermal expansion (CTE) of the synthesized CAS (4.12 × 10−6 K−1) matched perfectly with that of the SiC ceramic (4.01 × 10−6 K−1). Thermal analysis of the CAS was conducted. Then the joining of the SiC ceramics by the CAS glass ceramics under various process parameters were conducted. The bonding temperature affects the fluidity of the CAS glass and the oxidation of the SiC substrate. The holding duration decides the infiltration of the CAS glass into the SiC substrate. The optimal bonding parameter is 1400 ℃/10 min and the corresponding highest shear strength of the SiC/CAS/SiC bonded joints in average was 56 MPa. Fracture observation was also conducted to help analyze the relationship between the interfacial microstructure and the joint strength. Finally, the formation mechanism of the SiC/CAS/SiC bonded joints was proposed. [ABSTRACT FROM AUTHOR]

neoplasms

The cold drawing of magnesium wires has constantly been an obstacle in industrial manufacture due to the lack of sufficient independent slip system at ambient temperature and the frequent intermediate annealing gives rise to regrettably low production efficiency. Aiming at the technique challenge, a feasible and effective method of multi-pass cumulative cold drawing with small deformation per pass was utilized in this study and a wire of 0.625 mm in diameter was obtained out of primitive Φ2.0 mm material with the accomplishment of about 2.3 in cumulative strain (90% in area reduction), the efficiency of which was dramatically improved. The microstructure, texture and mechanical properties with the variation of cumulative area reduction were investigated. It can be apparently observed that continuous dynamic recrystallization had occurred during cold drawing. The outcomes are displayed as follows: the transition emerged from low angle grain boundary to high angle grain boundary; the increased fraction of undeformed/recrystallized structure first descended then ascended; the deformed structure initially appeared yet disappeared quickly. All of above owned an almost same critical point at around 23% cumulative area reduction. One of the most remarkable consequences of the deformation was the degeneration of the average grain size steadily from 11.8 to 3.1 µm. 〈10-10〉//DD fiber component was gradually transformed from the primitive {0002}//DD fiber texture and this deformation texture was continuously strengthened. The enhanced mechanical properties achieved uncommonly high strength of 214.5 MPa in yield strength and 256.9 MPa in ultimate tensile strength due to grain refinement arising from continuous dynamic recrystallization and intense fiber texture strengthening introduced during cold drawing. [ABSTRACT FROM AUTHOR]

ZrC-SiC ceramic and TC4 alloy were brazed using AgCuTi alloy. The microstructure and mechanical property of the joints obtained at different brazing parameters were investigated and the reaction mechanism was analyzed. The results indicated that the Ti from the AgCuTi and TC4 reacted with the ZrC in the ceramic to form different shaped TiC crystals adjacent to the ZrC-SiC ceramic. With the increase of brazing temperature or extending of holding time, the dissolution of TC4 became vigorous and much Ti dissolved into the braze alloy. As a result, Ti reacted with the Cu from AgCuTi alloy to form a series of Cu-Ti compounds in the brazing seam due to the strong affinity between Cu and Ti. The Cu-Ti compounds made the hardness and brittleness of brazing seam increase, which deteriorated the property of the brazed joint. The maximum shear strength was 39 MPa obtained at 810 °C for 5 min. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of the evaporation on wetting, reactive wetting of TiC-Ni cermet by molten Ag-Cu-Zn alloys with different Zn contents was studied at 810 °C using a sessile drop method in vacuum. The vapor recoil force induced by the strong evaporation of Zn in the Ag-Cu-25Zn alloy drove the spreading of the molten Ag-Cu-25Zn alloy. Furthermore, the sequential evaporation of Zn in the Ag-Cu-25Zn alloy caused the formation of a (Cu, Ni) solid-solution layer at the interface between the TiC-Ni cermet and the Ag-Cu-Zn alloy. Thus, the (Cu, Ni) solid-solution layer could serve as a metallization layer on the surface of the TiC-Ni cermet, which promoted the non-wetting to wetting transition of the TiC-Ni cermet by the Ag-Cu-25Zn alloy. The equilibrium contact angle of the Ag-Cu-25Zn alloy on the TiC-Ni cermet was 19.9°, approximately equal to that of a Ag-28Cu eutectic alloy on a Cu-Ni alloy surface. The final contact angle of the Ag-Cu-Zn liquid alloy on the TiC-Ni cermet first decreased and then increased as the Zn content in the liquid was increased from 0% to 30%. It reached a minimum value in the Ag-Cu-25Zn alloy. [ABSTRACT FROM AUTHOR]

In vacuum, the Gr/2024Al composite and TC4 alloy were brazed using AgCuTi filler alloy with the assist of Ni-Al interlayer as auxiliary heat source. Because of the thermal explosion synthesis reaction of Ni-Al interlayer, lots of heat can be produced and released, which promises that AgCuTi filler alloy melts and the Gr/2024Al composite and TC4 alloy brazes at low temperature. This method avoids the volatilization of Al in the Gr/2024Al composite at high brazing temperature, keeping the property of the Gr/2024Al composite. According to SEM analysis result, the Gr/2024Al composite reacts with the AgCuTi filler alloy to form a Ti 3 AlC 2 layer adjacent to the composite, which is the key factor to obtain a perfect joint. A series of Ni-Al compounds form after the thermal explosion synthesis reaction of the Ni-Al interlayer. The particle sizes of Ni and Al have important effects on the thermal explosion synthesis reaction, and then influence the interfacial reaction and the formation of the Ni-Al compounds. The maximum shear strength reaches 13 MPa when the diameter of the Ni and Al particles are 10 μm and 7 μm respectively. Cracks primarily happen in the Gr/2024Al composite and propagate in the composite away from the brazing seam. [ABSTRACT FROM AUTHOR]

The CaO B 2 O 3 Al 2 O 3 SiO 2 vitrified bonds are widely used in the manufacture of diamond abrasive tools. The effects of different amounts of WO 3 on the structure and properties of the SiO 2 B 2 O 3 Al 2 O 3 CaO system vitrified bonds were investigated by differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), bending strength, thermal expansion coefficients (CTE) and scanning electron microscope (SEM). FT-IR and XRD patterns suggested that the [BO 4 ] tetrahedron decreased, and [BO 3 ] triangle and CaWO 4 phase increased with increasing WO 3 . The bending strength and thermal expansion coefficients (CTE) analyses showed that bending strength of the vitrified bonds increased with increasing WO 3 , which reached its maximum of 114 MPa, and the CTEs of the varied vitrified bonds approximated to 6.8020 × 10 −6 °C −1 . The SEM analyses showed the vitrified bond completely wetted diamond grains, enhancing the properties of vitrified bond effectively. [ABSTRACT FROM AUTHOR]

Aflatoxins are toxic, mutagenic, and carcinogenic compounds that can contaminate various types of agro-products, among which peanuts are one of the most susceptible foodstuffs. In the current study, a total of 2494 peanut samples collected from four major peanut producing areas in China (Liaoning, Henan, Sichuan, and Guangdong provinces) from 2010 to 2013 were investigated for the occurrence of aflatoxins. A close relationship can be concluded between the result and the weather a month before harvest. According to the relationship, the highest aflatoxin contamination level occurred under the climatic conditions where precipitation was rare and the mean temperature was close to 23 °C, the minimum temperature was approximately 20 °C, and the maximum temperature was about 29 °C. This survey provided valuable information on aflatoxin contamination in pre-harvest peanuts under different agro-environmental conditions in China and laid a foundation for predicting aflatoxin contamination, which would be essential for taking preventive measures to alleviate pre-harvest aflatoxin contamination of peanuts. [ABSTRACT FROM AUTHOR]

In this study, Ag–Cu–Ti/Cu mesh/Ag–Cu–Ti composite foils were designed to braze ZrB 2 –SiC–C (ZSC) ceramic and GH99 superalloy, and sound brazed joints were obtained. The interfacial microstructure and mechanical properties of the brazed joints were investigated. By comparing joints brazed with Ag–Cu–Ti filler alloy and Ag–Cu–Ti/Cu foil/Ag–Cu–Ti composite foils, the mechanism by which Ag–Cu–Ti/Cu mesh/Ag–Cu–Ti composite foils improves the shear strength of the joint was assessed. Due to the application of a Cu mesh, a reticular braze seam with enhanced ductility was fabricated, which can inhibit the formation of Ti–Cu intermetallic compounds in the braze seam and decrease the thickness of the Ti 3 SiC 2 layer adjacent to ZSC. As a result, the residual stress concentration in a brazed joint can be reduced. Using Ag–Cu–Ti/Cu mesh/Ag–Cu–Ti composite foils, the maximum shear strength of the brazed joints increased to 121 MPa, which is 560% of the joints brazed with Ag–Cu–Ti filler alloy (21 MPa). [ABSTRACT FROM AUTHOR]

To address the excessive formation of brittle compounds when brazing TiAl alloys, a TiZrHfCoNiCu high-entropy brazed filler was developed to realize the brazing of TiAl/Ti 2 AlNb couples. The TiAl/Ti 2 AlNb brazed joints can be divided into 4 zones, i.e., 2 diffusion zones at the TiAl/braze filler, Ti 2 AlNb/braze filler interfaces and 2 zones divided inside the brazed seam. α 2 + γ-TiAl were the main reaction products formed at the TiAl/braze filler interface and α 2 + Ti 0.5 Al 0.12 Nb 0.38 were the main reaction products at the Ti 2 AlNb/braze filler interface. Effects of brazing temperatures on the interfacial microstructure and mechanical properties of the TiAl/Ti 2 AlNb brazed joints were investigated. When brazing at 1100°C/15 min, the highest shear strength can reach 157 MPa (room temperature), and 123 MPa (650°C) respectively. The relationship between the microstructure and the corresponding mechanical response were discussed in detail. This research can offer new insights on developing desirable brazing filler when joining TiAl and TiAl based alloys. • A TiZrHfCoNiCu high-entropy alloy braze filler was developed to realize the brazing of TiAl/Ti2AlNb couples. • Ti 0.5 Al 0.12 Nb 0.38 and α 2 + γ-TiAl formed at the braze filler/base metal interfaces were the key to realize the joining. • The α 2 + γ-TiAl at the TiAl/braze filler interface was preferential to crack for the strongest brazed joints. • Highest shear strength of 157 MPa (room temperature) and 123 MPa (650°C) were achieved at 1100°C/15 min. [ABSTRACT FROM AUTHOR]

Abstract: Seed dormancy is an important trait for the analysis and manipulation of pre-harvest sprouting resistance in rice. This study presents data on dissection of the genetic basis of the seed dormancy character in the indica cultivar N22, which exhibits levels of dormancy highly in excess of traditional rice cultivars. Three simple sequence repeat (SSR)-based linkage maps derived from two BC1-type populations of Nanjing35 (a japonica non-dormant breeding line)/N22//Nanjing35 and USSR5 (non-dormant japonica cultivar)/N22//USSR5, and one F2 population of USSR5/N22, were constructed to detect genes controlling seed dormancy. Five quantitative trait loci (QTLs) for seed dormancy, i.e., qSdn-1, qSdnj-3, qSdn-5, qSdn-7 and qSdn-11, were identified on chromosomes 1, 3, 5, 7 and 11, respectively. The N22-derived alleles were observed to increase the seed dormancy at all the loci except qSdnj-3. Genes conferring seed dormancy in N22 showed incomplete dominance effect. Two QTLs, qSdn-5 and qSdn-11 were detected in the two BC1 populations, while qSdnj-3 and qSdn-7 were only identified in the one BC1 population (Nanjing35/N22//Nanjing35), whereas the QTL qSdn-1 was common in all the three populations. The dormancy trait was expressed whenever any of the dormancy genes presents and can be further improved by pyramiding these genes. Of all QTLs, qSdn-1 provided the most obvious target for marker-assisted selection (MAS) due to its stability for improving rice pre-harvest sprouting tolerance. [Copyright &y& Elsevier]

Plasma membrane (PM) vesicles were purified from two wheat (Tritium aestivum yiujian24 (Y-J24) and longchun20 (L-Ch20)) roots by discontinuous sucrose gradient centrifugation to study the regulatory mechanism of the H+-ATPase activities in response to NaCl treatment. Salt-stress reduced the PM H+-ATPase activity in Y-J24 roots, but increased in L-Ch20 roots. Analysis of lipid peroxidation in the wheat root PM vesicles indicated that NaCl treatment induced a higher degree of oxidative damage on Y-J24 root PM, but did not affect lipid peroxidation of L-Ch20 root PM. Further studies showed that the PM protein thiol (P-SH) contents correlated with the changes of H+-ATPase activity in Y-J24 and L-Ch20 root PM. Western blot analysis revealed a decrease in the amount of the PM H+-ATPase in Y-J24 roots exposed for 72 h to 100 mM NaCl, and an increase in L-Ch20 roots, respectively. Therefore, thiol oxidation and a decrease in the enzyme content might be responsible for the inhibition of the PM H+-ATPase activity in Y-J24 roots in response to salt-stress; the increased H+-ATPase activities in L-Ch20 root PM might be due to up-regulation of the expression of the PM H+-ATPase. [Copyright &y& Elsevier]

The isolation technique is widely studied and applied in structural engineering due to its excellent seismic performance. However, the existing research mostly focuses on the conventional structure under the action of regular ground motions. In this paper, a story-adding seismic structure, a base-isolated structure, and a story-adding isolated structure were simulated by using numerical simulation methods. The dynamic response characteristics of the three structures under near-fault pulse-like ground motions are analysed and compared with the far-fault ground motions. The results showed that using the base isolation can significantly extend the period of the main structure and reduce the seismic response on the upper structure. The inter-story drift ratio, inter-story shear force, and the story acceleration of all three structures under near-field pulse-like ground motions were all larger than that of far-field earthquakes. Both base-isolated structure and story-adding isolated structure showed excellent damping performance. Besides, the damping properties of the base-isolated structure are better than the story-adding isolated structure. • The dynamic response of structures under near-fault pulse-like ground motions and far-fault ground motions are studied. • Isolation technique is applied in story-adding structures. • The seismic performances of different story-adding schemes are studied and compared. • Seismic response of the adding-story structure is amplified due to the higher altitude installation position of bearings. [ABSTRACT FROM AUTHOR]

Thermally induced residual stresses across the TSV-Cu/TiW/SiO 2 /Si interface in through‑silicon vias (TSVs) have raised serious concerns about mechanical and electrical reliability in 3D ICs. The lack of a nanometer-precision measurement technique for the TSV interfacial stress gradient makes the interface failure mechanism unclear. In this work, we propose an ion beam layer removal (ILR) method for determining the residual stress in the as-fabricated TSV-Cu/TiW/SiO 2 /Si interface on a nanoscale to facilitate identification of the failure mechanism of the TSV-Cu/TiW/SiO 2 /Si interface in as-fabricated TSVs. The measurement results showed that the residual stress fluctuates across the TSV-Cu/TiW/SiO 2 /Si interface and that both compressive stress and tensile stress existed within the interface system. Compressive stress occurred at all three interfaces, the TSV-Cu/TiW, TiW/SiO 2 , and SiO 2 /Si interfaces, but transitioned to tensile stress at a distance of 25–45 nm from these interfaces. The highest level of shear stress concentration appeared inside the TSV-Cu at a distance of approximately 45 nm from the TSV-Cu/TiW interface. This shear stress concentration explains the experimentally observed TSV interfacial cracking phenomenon. Graphic abstract Unlabelled Image • ILR method was used for determining the residual stress in the TSV-Cu/TiW/SiO 2 /Si interface. • The residual stress fluctuated across the TSV-Cu/TiW/SiO 2 /Si interface. • The highest level of shear stress appears inside Cu at a distance of 45 nm from the TSV-Cu/TiW interface. • The shear stress concentration explains the TSV interfacial cracking phenomenon. [ABSTRACT FROM AUTHOR]