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[en] Acquiring information about creep strain directly from small punch creep tests is difficult because the deformation behaviour of the small punch specimen is complicated. A routine is suggested in the present paper to treat this problem indirectly. Based on a finite element analysis, it is proposed that the relationship of central deflection δ to central creep strain εc of a specimen subjected to creep can be represented approximately by the relationship of central deflection δ to central (elastic-plastic) strain ε of a specimen not subjected to creep. With this hypothesis, the δ∼εc relation of the small punch creep specimen is obtained by resorting to a rigid-plastic membrane stretch forming model. Finally, small punch creep test results are used to evaluate creep strain and creep strain rate by taking advantage of this δ∼εc relation
[en] Highlights: • Flotation of powellite from fluorapatite at pH 2–7 using 50–80 mg/L sodium oleate can be achieved. • Oleate chemisorbs on powellite by interaction of carboxylate group with lattice Ca atoms. • Calcium dioleate precipitates can also adsorb on powellite surface. - Abstract: Flotation and adsorption performance of sodium oleate(NaOl)on powellite and fluorapatite were investigated in this work through micro-flotation tests, work of adhesion calculations, molecular dynamics simulation, micro-topography studies and FTIR measurements. The micro-flotation results show a similar flotation behaviors of powellite and fluorapatite under alkaline conditions, but a considerable difference in mineral recoveries in the pH range 2–7, which demonstrates the possibilities for separating powillite from fluorapatite under acidic conditions. The great difference in mineral recovery displays a good accordance with the obvious difference in the work of adhesion of powellite and fluorapatite at NaOl dosage range of 40–80 mg/L, obtained from flotation and contact angle measurements, respectively. The more negative interaction energy (ΔE) between NaOl and powellite/water interface from molecular dynamics simulation reveals a more easily adsorption of NaOl onto powellite than onto fluorapatite, which excellently matches with the results of flotation and work of adhesion. The results of micro-topography study shows that the adsorption of NaOl on powellite is mainly ascribed to the chemisorption of oleate ions with Ca"2"+ on powellite lattice or the precipitation of calcium dioleate agglomerates on powellite surface when it was in the solution without or with Ca"2"+, respectively. The FTIR measurements further confirm the chemisorption of oleate ions with Ca"2"+ active sites on powellite surface.
[en] It presents from the collection of particle-ray counting, infrared data communication, real-time monitoring and alarming, GPRS and other issues start to realize the digital management of radioactive sources, complete the real-time monitoring of all aspects, include the storing of radioactive sources, transporting and using, framing intelligent radioactive sources transporter, as a result, achieving reliable security supervision of radioactive sources. (authors)
[en] Atomic-layer-deposited Al2O3 and HfO2 films on GaSb substrates were treated by in-situ ozone post deposition treatment (PDT). The effects of ozone PDT on the interfacial and electrical properties of Al2O3 and HfO2 gate dielectric films on GaSb substrates were investigated carefully. It is found that the dielectric quality and the interfacial properties of the Al2O3 and HfO2 films are improved by ozone PDT. After in-situ ozone PDT for 5 min, the Al2O3 and HfO2 films on GaSb substrates exhibit improved electrical and interfacial properties, such as reduced frequency dispersion, gate leakage current, border traps and interface traps. Interface trap density is reduced by ∼24% for the Al2O3/GaSb stacks and ∼27% for the HfO2/GaSb stacks. In-situ ozone PDT is proved to be a promising technique in improving the quality of high-k gate stacks on GaSb substrates.
[en] In this paper we describe a new method for the realization of two-color femtosecond radiation pulses in a seeded free-electron laser (FEL). The two-color pulses are obtained from two electron bunches and a chirped seeding laser. Compared to the previous methods based on seeded FELs, our method has the advantages of producing two-color FEL pulses with more flexible tunability both in the pulse durations and separations. Numerical simulations for the Dalian Coherent Light Source confirm that femtosecond XUV pulses with variable pulse durations and time delay can be directly generated from a chirped seed laser at 250 nm by using this technique. We also show the possibility of performing a proof-of-principle experiment of this technique based on the Shanghai Deep-Ultraviolet FEL facility.
[en] A bibliometric analysis based on the Science Citation Index Expanded from the Web of Science was carried out to provide insights into research activities and tendencies of the global drinking water from 1992 to 2011. Study emphases included performance of publication covering annual outputs, mainstream journals, Web of Science categories, leading countries, institutions, research tendencies and hotspots. The results indicated that annual output of the related scientific articles increased steadily. Water Research, Environmental Science and Technology, and Journal American Water Works Association were the three most common journals in drinking water research. The USA took a leading position out of 168 countries/territories, followed by Japan and Germany. A summary of the most frequently used keywords obtained from words in paper title analysis, author keyword analysis and KeyWords Plus analysis provided the clues to discover the current research emphases. The mainstream research related to drinking water was water treatment methods and the related contaminants. Disinfection process and consequent disinfection by-products attracted much attention. Ozonation and chlorination in disinfection, and adsorption were common techniques and are getting popular. Commonly researched drinking water contaminants concerned arsenic, nitrate, fluoride, lead, and cadmium, and pharmaceuticals emerged as the frequently studied contaminants in recent years. Disease caused by contaminants strongly promoted the development of related research. - Highlights: ► Drinking water research was characterized based on SCI-Expanded during 1992–2011. ► Research emphases were obtained from title, author keywords and KeyWords Plus. ► Ozonation, chlorination and adsorption were common techniques and are getting popular. ► Emerging contaminants concerned arsenic, nitrate, fluoride, lead, and cadmium
[en] Duplex Ni-P-TiO2 /Ni-P coatings were electrodeposited onto brass substrates. High phosphorus Ni-P coatings were plated as the inner layer to improve the corrosion resistance, while low phosphorus sol-enhanced Ni-P-TiO2 coatings were deposited on the top to strengthen the mechanical property. The microstructure, morphology, mechanical property and corrosion resistance of coatings were investigated systematically. The results show that duplex coatings exhibit both excellent mechanical property and good corrosion resistance. The hardness was further improved from ~545 HV50 of duplex Ni-P/Ni-P coating to ~622 HV50 of duplex Ni-P-12.5mL/L TiO2 /Ni-P coating, while the hardness of single Ni-P coating was only ~387 HV50. The corrosion resistance of duplex coatings improved significantly by adding a suitable amount of TiO2 sol. Duplex Ni-P-12.5mL/L TiO2 /Ni-P coating presented the highest corrosion resistance. However, adding excessive quantities of sol (more than 12.5mL/L) caused nanoparticle agglomeration and created a porous structure in the outer layer, deteriorating the properties of coatings. (author)
[en] In the containment analysis of nuclear power plant, containment scaling analysis could be used to confirm the important phenomena of containment cooling system and demonstrate the sufficiency of test data. Based on the design basis accident (DBA) of passive nuclear power plant, the scaling analysis method was used to quantify the effect of heat and mass transfer characteristic of liquid drop to mass, energy and RPC. The effect of containment cooling system phenomena to containment pressure response can be confirmed by this scaling analysis. (authors)
[en] For the nuclear safety-related valve, structural mechanical analysis is obligatory during its safety evaluation. This paper introduces the procedure of structural analysis of a nuclear safety class 2 electric ball valve in seismic condition using three-dimensional FEA software, and the result is assessed according to ASME Section Ⅲ. (authors)