Microstructure and mechanical performance of FSWed joint of T2 copper and AA 1061

Welding of copper and aluminium has been problematic with tradition fusion method. The friction stir welding (FSW) was employed to butt weld the T2 copper and 1061 aluminium alloy plates. The welding parameters were planned by the orthogonal experiment design method. The samples obtained in experiments were investigated in the aspects of microstructure, tensile strength, fatigue performance and micro-hardness. Sound weld with the best tensile strength and fatigue life was produced under the welding parameters of rotation speed, 1100 rpm and welding speed 50 mm min −1. The tensile strength was 193.16 MPa, 85% of the base aluminium material. Three intermetallic compounds of CuAl, Cu 3Al and Cu 9Al 4 were detected at the copper–aluminium interface in X-ray diffraction analysis

Highly frequent PIK3CA amplification is associated with poor prognosis in gastric cancer

<p>Abstract</p> <p>Background</p> <p>The phosphoinositide 3-kinase (PI3K)/Akt pathway plays a fundamental role in cell proliferation and survival in human tumorigenesis, including gastric cancer. <it>PIK3CA </it>mutations and amplification are two major causes of overactivation of this pathway in human cancers. However, until this work, there was no sound investigation on the association of <it>PIK3CA </it>mutations and amplification with clinical outcome in gastric cancer, particularly the latter.</p> <p>Methods</p> <p>Using direct sequencing and real-time quantitative PCR, we examined <it>PIK3CA </it>mutations and amplification, and their association with clinicopathological characteristics and clinical outcome of gastric cancer patients.</p> <p>Results</p> <p><it>PIK3CA </it>mutations and amplification were found in 8/113 (7.1%) and 88/131 (67%) gastric cancer patients, respectively. <it>PIK3CA </it>amplification was closely associated with increased phosphorylated Akt (p-Akt) level. No relationship was found between <it>PIK3CA </it>mutations and clinicopathological characteristics and clinical outcome in gastric cancer. <it>PIK3CA </it>amplification was significantly positively associated with cancer-related death. Importantly, Kaplan-Meier survival curves revealed that the patients with <it>PIK3CA </it>amplification had significantly shorter survival times than the patients without <it>PIK3CA </it>amplification.</p> <p>Conclusions</p> <p>Our data showed that <it>PIK3CA </it>mutations were not common, but its amplification was very common in gastric cancer and may be a major mechanism in activating the PI3K/Akt pathway in gastric cancer. Importantly, Kaplan-Meier survival curves revealed that <it>PIK3CA </it>amplification was significantly positively associated with poor survival of gastric cancer patients. Collectively, the PI3K/Akt signaling pathway may be an effective therapeutic target in gastric cancer.</p

Distribution pattern and main factors controlling hydrocarbon accumulation of global oil and gas-rich deepwater basins

It is observed from distribution of oil and gas-rich basins as well as summary and analysis of main control factor for hydrocarbon accumulation in global deepwater that oil and gas-rich basins in deepwater in the world shows “one horizontal and two vertical” in distribution pattern and that “one vertical” of deepwater basin group chiefly distributed in Atlantic Ocean from north to south of deepwater oil rich-basin group in the world is under the influence of fault basin group and that deepwater gas-rich basin group along Neo-tethyan tectonic domain and epicontinental basin group in East Africa shows “one horizontal and one vertical” in distribution, being under the influence of “fault basin group in transitional facies”; Comparative analysis and research of main factors for hydrocarbon accumulation in main deepwater oil and gas-rich basins in the world in a systemic way show that main control factors for hydrocarbon accumulation in deepwater oil and gas-rich basin in the world can be reduced to following five types: (1) Reservoir under common control of salt structure, passage system and large turbidite fan; (2) Reservoir under control of source control area and large reservoir body; (3) Reservoir under control of source rock and cap rock control area and large delta; (4) Reservoir under control of source and cover control zone and reef flat; (5) Reservoir under control of source heat control zone, passage system and trap. Keywords: Deepwater basin, Atlantic, Neotethys, East Africa, Main factors controlling hydrocarbon accumulatio

In situ fabrication of noble metal nanoparticles modified multiwalled carbon nanotubes and related electrocatalysis

Using multiwalled carbon nanotubes (MWNTs) as templates, noble metal (Au, Ag, Pt or Pd) nanoparticles (NPs) were fabricated in situ by electrochemistry with a diameter of 40-60 nm. Further, catalytic behaviors of these composite materials were investigated. Experiments showed that such carbon nanotubes decorated with Pd NPs modified glassy carbon electrodes exhibited higher electrocatalytic ability to some molecules such as evolution of hydrogen, reduction of oxygen and oxidation of ascorbic acid. Atomic force microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry were used to characterize the film formation and their properties

An Enriched Finite Element Method with Appropriate Interpolation Cover Functions for Transient Wave Propagation Dynamic Problems

A novel enriched finite element method (EFEM) was employed to analyze the transient wave propagation problems. In the present method, the traditional finite element approximation was enriched by employing the appropriate interpolation covers. We mathematically and numerically showed that the present EFEM possessed the important monotonic convergence property with the decrease of the used time steps for transient wave propagation problems when the unconditional stable Newmark time integration scheme was used for time integration. This attractive property markedly distinguishes the present EFEM from the traditional FEM for transient wave propagation problems. Two typical numerical examples were given to demonstrate the capabilities of the present method

Application of Sensor Networks to the Measurement of Subway-Induced Ground-Borne Vibration Near the Station

The subway-induced ground-borne vibration poses great challenge to the environment in the nearby districts. This problem is more prominent for near-station sections of subways since more buildings and human activities are influenced. And the train would be either accelerating or decelerating in this section; the vibration induced would be different from that induced by the train running on long straight subway sections. For the purpose of evaluating human comfort and designing vibration mitigation systems in the buildings, it is necessary to measure the ground-borne vibration induced by the subway. In the presented paper, a measurement system based on the CompactRIO system and LabVIEW platform is constructed. A network of acceleration sensors is placed to collect the vibration signals. This system is used to measure the ground vibration in terms of acceleration and the corresponding Fourier spectra at a near-station section of the Shanghai Metro Line 9. Some observations have been obtained towards the ground-borne vibration induced by a train running underground near the station as well as the vibration decay with the distance from the subway tunnel