Quantum walks are the quantum mechanical analog of classical random walks and an extremely powerful tool in quantum simulations, quantum search algorithms, and even for universal quantum computing. ...In our work, we have designed and fabricated an 8x8 two-dimensional square superconducting qubit array composed of 62 functional qubits. We used this device to demonstrate high fidelity single and two particle quantum walks. Furthermore, with the high programmability of the quantum processor, we implemented a Mach-Zehnder interferometer where the quantum walker coherently traverses in two paths before interfering and exiting. By tuning the disorders on the evolution paths, we observed interference fringes with single and double walkers. Our work is an essential milestone in the field, brings future larger scale quantum applications closer to realization on these noisy intermediate-scale quantum processors.
For metal matrix composites (MMCs), introduction of low-dimensional nano-carbon materials (NCMs) into three dimensional metallic matrix is commonly applied to enhance mechanical and physical ...properties of metals and thus significantly extend their wide range applications. However, the interfaces between the NCMs and metal matrix are always a major issue for achieving the best enhancement effects. In this paper, we investigated interfacial structures of graphene nanoplates (GNPs) reinforced Cu matrix composites fabricated using a simple and industrially scalable strategy, through integration of interface engineering design methodology and a spark plasma sintering (SPS) process. We then systematically evaluated their physico-mechanical properties, interfacial characteristics and strengthening mechanisms. The in-situ formed WxCy nano-layers and carbide nanoparticles on the surfaces of GNPs and near the interfaces of Cu grains promote strong interfacial bonding and improves the cohesive strength of Cu based nanocomposites. The GNPs-W/Cu composites show a good balance between strength and electrical conductivity. Their 0.2% yield strength and ultimate tensile strength have been improved up to 239.13% (112.73%) and 197.76% (72.51%), respectively, when compared with those of pure copper (or GNPs/Cu composites). Electrical conductivity of GNPs-W/Cu composites shows no apparent changes after the addition of the GNPs. The dislocation strengthening, refinement strengthening and load transfer strengthening were achieved simultaneously through the engineered interfaces in GNPs-W/Cu matrix composites. This work has provided a new strategy to fabricate high-performance NCMs enhanced MMCs by using the interface engineering methodology.
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For conventional titanium matrix composites (TiMCs), there is always a trade-off issue between enhanced strength and ductility of these materials. In this study, we explore a new design methodology ...by reinforcing titanium alloy matrix with carbonaceous nanomaterials and investigate the mechanisms for achieving a good balance of their strength and ductility. The TiMCs were synthesized through a low-cost powder metallurgy route using pre-mixed Ti-6Al-4V (TC4) powders and various carbon based nanofillers, including graphite powders (GPs), graphene oxide nanosheets (GONs) and graphene nanoplates (GNPs), and were further rolled at a temperature of 1173 K with a deformation of 66.7%. Among these three types of carbon reinforcing sources, the GNPs are more easily reacted with TC4 matrix and form more contents of TiC phases after sintering owing to their larger amounts of defects than those of the GPs and GONs. TiC products are identified to play a bridging role for not only connecting the TC4 matrix but also forming coherent interfaces with the TC4 matrix, thus facilitating a strong interfacial bonding of the composites. The as-rolled GNPs/TC4 composites exhibit a 0.2% yield strength of 1146.36 MPa (with an elongation of ∼8.1%), which is 24.6%, 9.22% and 5.62% higher than those of pure TC4, GPs/TC4 and GONs/TC4 composites. The GNPs/TC4 nanocomposites show a better balance of strength and ductility than those of the other two types of nanocomposites. The synergetic strengthening mechanisms are identified to be Orowan strengthening effect, effective load transfer capability of GNPs, and in-situ formation of interfacial TiC structures, which provide optimum interfacial microstructures to achieve good mechanical properties of the TiMCs.
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Multifunctional materials with more than two good properties are widely required in modern industries. However, some properties are often trade-off with each other by single microstructural ...designation. For example, nanostructured materials have high strength, but low ductility and thermal stability. Here by means of spark plasma sintering (SPS) of nitrided Ti particles, we synthesized bulk core-shell structured Ti alloys with isolated soft coarse-grained Ti cores and hard Ti-N solid solution shells. The core-shell Ti alloys exhibit a high yield strength (~1.4 GPa) comparable to that of nanostructured states and high thermal stability (over 1100 °C, 0.71 of melting temperature), contributed by the hard Ti-N shells, as well as a good plasticity (fracture plasticity of 12%) due to the soft Ti cores. Our results demonstrate that this core-shell structure offers a design pathway towards an advanced material with enhancing strength-plasticity-thermal stability synergy.
This study evaluated the effects of rumen-protected folic acid (RPFA) and betaine (BT) on growth performance, nutrient digestion and blood metabolites in bulls. Forty-eight Angus bulls were blocked ...by body weight and randomly assigned to four treatments in a 2 × 2 factorial design. BT of 0 or 0·6 g/kg DM was supplemented to diet without or with the addition of 6 mg/kg DM of folic acid from RPFA, respectively. Average daily gain increased by 25·2 and 6·29 % for addition of BT without RPFA and with RPFA, respectively. Digestibility and ruminal total volatile fatty acids of neutral-detergent fibre and acid-detergent fibre increased, feed conversion ratio and blood folate decreased with the addition of BT without RPFA, but these parameters were unchanged with BT addition in diet with RPFA. Digestibility of DM, organic matter and crude protein as well as acetate:propionate ratio increased with RPFA or BT addition. Ruminal ammonia-N decreased with RPFA addition. Activity of carboxymethyl cellulase, cellobiase, xylanase, pectinase and protease as well as population of total bacteria, protozoa, Fibrobacter succinogenes and Ruminobacter amylophilus increased with RPFA or BT addition. Laccase activity and total fungi, Ruminococcus flavefaciens and Prevotella ruminicola population increased with RPFA addition, whereas Ruminococcus albus population increased with BT addition. Blood glucose, total protein, albumin, growth hormone and insulin-like growth factor-1 increased with RPFA addition. Addition of RPFA or BT decreased blood homocysteine. The results indicated that addition of BT stimulated growth and nutrient digestion in bulls only when RPFA was not supplemented.
•The degree mismatch between Al (111) and Al4C3 (0001) interface was the lowest.•Al-C covalent bonds and Al-Al metallic bonds increased interfacial bonding strength.•α-Al nucleus tend to form on the ...C-termination-center-sited Al4C3 (0 0 0 1).
The graphene (Gr) reacted with Al, and the Al4C3 phase was precipitated during selective laser melting (SLM). The interfacial structure of Al/Al4C3 was calculated by the first principle. The degree mismatch between Al (1 1 1) and Al4C3 (0 0 0 1) interface was lowest. Al (1 1 1)/Al4C3 (0 0 0 1) interface models with different stacking sequences (top-site, center-site, and hollow-site) of different terminations (Al-termination and C-termination) were established. C-termination-center-sited interface has largest work of adhesion, and interfacial energy of this model is lower than that of α-Al/Al melt (0.15 J/m2), so that α-Al nucleus tend to form on the C-termination-center-sited Al4C3 (0 0 0 1). Al-C covalent bonds and Al-Al metallic bonds are formed across interface, which increased interfacial bonding strength.
Simultaneous improvement of the two disparate properties such as mechanical strength and corrosion resistance of Mg alloys is the object researchers have been pursuing all the time. In this study, by ...means of sliding friction treatment (SFT), a nanocrystalline surface layer (with an average grain size of 70 nm on the topmost surface) was successfully generated on coarse-grained (CG, mean grain size: 25 μm) Mg–3Al–1Zn (AZ31) alloy sheet. The SFTed AZ31 exhibited simultaneously enhanced mechanical strength and corrosion resistance as compared to the CG counterpart. Specifically, the yield strength (YS) of SFTed sample is 236 MPa, which is almost twice that of CG sample (123 MPa). Meanwhile, the hydrogen evolution rate during 80 h immersion in 3.5% NaCl is reduced from 0.44 ml/cm2/h to 0.17 ml/cm2/h after SFT treatment. Effective grain refinement was responsible for the notable strength increment. The improvement in corrosion resistance might be correlated with SFT-induced grain refinement, good surface quality, second-phase particles fragmentation and strong basal texture. These combined capabilities of SFT render it a commercially viable manufacturing process for comprehensive properties modification of Mg products.
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•A nano-grained layer on AZ31 was fabricated by sliding friction treatment (SFT).•The SFTed AZ31 exhibited superior strength-ductility combination.•The SFTed AZ31 exhibited both enhanced mechanical strength and corrosion resistance.
To evaluate the impacts of guanidinoacetic acid (GAA) and coated folic acid (CFA) on growth performance, nutrient digestion and hepatic gene expression, fifty-two Angus bulls were assigned to four ...groups in a 2 × 2 factor experimental design. The CFA of 0 or 6 mg/kg dietary DM folic acid was supplemented in diets with GAA of 0 (GAA-) or 0·6 g/kg DM (GAA+), respectively. Average daily gain (ADG), feed efficiency and hepatic creatine concentration increased with GAA or CFA addition, and the increased magnitude of these parameters was greater for addition of CFA in GAA- diets than in GAA+ diets. Blood creatine concentration increased with GAA or CFA addition, and greater increase was observed when CFA was supplemented in GAA+ diets than in GAA- diets. DM intake was unchanged, but rumen total SCFA concentration and digestibilities of DM, crude protein, neutral-detergent fibre and acid-detergent fibre increased with the addition of GAA or CFA. Acetate:propionate ratio was unaffected by GAA, but increased for CFA addition. Increase in blood concentrations of albumin, total protein and insulin-like growth factor-1 (IGF-1) was observed for GAA or CFA addition. Blood folate concentration was decreased by GAA, but increased with CFA addition. Hepatic expressions of IGF-1, phosphoinositide 3-kinase, protein kinase B, mammalian target of rapamycin and ribosomal protein S6 kinase increased with GAA or CFA addition. Results indicated that the combined supplementation of GAA and CFA could not cause ADG increase more when compared with GAA or CFA addition alone.
•Green and facile synthesis for rGO/Ag nanocomposites was synthesized.•Mechanism is attributed to the synergistic effect of two hydrolysis products of TD.•First principles prove defect is help for ...rGO/Ag formation and its conductivity.
Recently, graphene decorated with various inorganic nanoparticles, such as Pt, Au, Ag, TiO2 and Fe3O4, among which Ag nanocomposites are good candidates for electronics, optics, electrochemistry and catalysis. However, preparation techniques for Ag nanoparticles/carbon matrix hybrids require tedious multi-step processes often involving toxic reducing agents/high temperatures which is not viable for scalable production. Here, a facile, one step and eco-friendly chemical co-reduction route was utilized to synthesis of a new nanocomposites by Ag nanoparticle anchored on reduced graphene oxide (rGO) at ambient temperature and combined first principles theoretical analyze their interfacial adsorption behavior, is reported. In this way, graphene oxide (GO) and Ag+ simultaneously reduced by thiourea dioxide (TD) without using any additional reduced reactants. Results indicated that GO was successfully reduced to rGO and well-dispersed Ag nanoparticles with sizes of 6–7 nm, anchored on the surface of rGO sheets. Reduction mechanism was attributed to the synergistic effect of its hydrolysis products in aqueous media. The experiment and theoretical calculation results obtained demonstrate this method to be applicable to the synthesis of other metals on rGO sheets in order to improve wettability and interfacial bonding between rGO and metal and may possibly find various forthcoming medicinal, industrial and technological applications.
Guanidinoacetic acid (GAA) can improve the growth performance of bulls. This study investigated the influences of GAA addition on growth, nutrient digestion, ruminal fermentation and serum ...metabolites in bulls. Forty-eight Angus bulls were randomly allocated to experimental treatments, that is, control, low-GAA (LGAA), medium-GAA (MGAA) and high-GAA (HGAA), with GAA supplementation at 0, 0.3, 0.6 and 0.9 g/kg DM, respectively. Bulls were fed a basal diet containing 500 g/kg DM concentrate and 500 g/kg DM roughage. The experimental period was 104 days, with 14 days for adaptation and 90 days for data collection. Bulls in the MGAA and HGAA groups had higher DM intake and average daily gain than bulls in the LGAA and control groups. The feed conversion ratio was lowest in MGAA and highest in the control. Bulls receiving 0.9 g/kg DM GAA addition had higher digestibility of DM, organic matter, NDF and ADF than bulls in other groups. The digestibility of CP was higher for HGAA than for LGAA and control. The ruminal pH was lower for MGAA, and the total volatile fatty acid concentration was greater for MGAA and HGAA than for the control. The acetate proportion and acetate-to-propionate ratio were lower for MGAA than for LGAA and control. The propionate proportion was higher for MGAA than for control. Bulls receiving GAA addition showed decreased ruminal ammonia N. Bulls in MGAA and HGAA had higher cellobiase, pectinase and protease activities and Butyrivibrio fibrisolvens, Prevotella ruminicola and Ruminobacter amylophilus populations than bulls in LGAA and control. However, the total protozoan population was lower for MGAA and HGAA than for LGAA and control. The total bacterial and Ruminococcus flavefaciens populations increased with GAA addition. The blood level of creatine was higher for HGAA, and the activity of l-arginine glycine amidine transferase was lower for MGAA and HGAA, than for control. The blood activity of guanidine acetate N-methyltransferase and the level of folate decreased in the GAA addition groups. The results indicated that dietary addition of 0.6 or 0.9 g/kg DM GAA improved growth performance, nutrient digestion and ruminal fermentation in bulls.
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