[en] The composition and structure of pour point depressant/viscosity reducer for pipeline transportation and its application effect in long-distance pipeline transportation in China as well as the application effect of oil-soluble viscosity reducer and water-soluble viscosity reducer for wellbore lift in low-viscosity and high-viscosity heavy oil wells in China are introduced. The main technical problems existing in the study of viscosity reducer for heavy oil formations drive are presented. (paper)

[en] Effects of air vessel on water hammer process in a pumping station with high-head were analyzed by using the characteristics method. The results show that the air vessel volume is the key parameter that determines the protective effect on water hammer pressure. The maximum pressure in the system declines with increasing air vessel volume. For a fixed volume of air vessel, the shape of air vessel and mounting style, such as horizontal or vertical mounting, have little effect on the water hammer. In order to obtain good protection effects, the position of air vessel should be close to the outlet of the pump. Generally, once the volume of air vessel is guaranteed, the water hammer of a entire pipeline is effectively controlled

[en] Compared with water flooding, the produced wastewater quality of polymer flooding and ASP flooding has changed significantly. The effect of chemical flooding agent on the stability and purification process of oil droplets and suspended solids in wastewater was analyzed. The two-stage sedimentation-pressure filtration process and the continuous batch sedimentation-two-stage filtration process used in the treatment of chemical flooding wastewater are introduced. The application of organic flocculants, inorganic flocculants, reverse demulsifiers, chemical desiliconizing agents and other purifying agents in the treatment of chemical flooding wastewater is summarized. The key research directions of wastewater treatment from chemical flooding in the future are put forward. (paper)

[en] Chinese water flooding heavy oil reserves are abundant and the output is increasing year by year, but the heavy oil water flooding recovery rate is low. It is of great significance to improve the heavy oil water flooding recovery rate to improve the development level of heavy oil reservoirs. This paper reviews heavy oil emulsified viscosity reduction technology, emulsified viscosity reduction theory, viscosity reducer flooding microscopic mechanism and structural characteristics of surfactants for heavy oil emulsified viscosity reduction. Meanwhile, the research focus of emulsified viscosity reducer in the future is put forward. (paper)

[en] We experimentally demonstrated a simple and effective method to write long period fiber gratings (LPFGs) with low fiber grating birefringence using high frequency CO₂ laser pulses. Such LPFGs were fabricated by introducing twist strains to the fiber and then exposing the fiber to the laser. We theoretically analyzed the influence of the twist strains on the spectra of the LPFGs, and examined bend characteristics of twisted long period fiber gratings (T-LPFGs). Experimental results showed that T-LPFGs exhibited clear spectra, low insertion loss, and low polarization-dependent loss (PDL) compared with conventional LPFGs exposed to a single-side CO₂ laser beam. The slope of the linear equation of the distance between the two split resonance peaks in the bending experiment is 20.55 nm/m⁻¹, which makes T-LPFGs sensitive bending sensors. (paper)

[en] Electric transport coefficients such as carrier type, density, and mobility are the important physical parameters in designing functional devices. In this work, we report the study on the electric transport coefficients of the highly epitaxial LaBaCo_2O_5_ _+_ _δ (LBCO) films, which were discussed as a function of electric conductivity for the first time and compared with the results calculated by the theory for mixed conduction. The mobility in the LBCO films was determined to be ∼0.85 and ∼40 cm"2/V s for holes and electrons, respectively, and the density of p-type carriers strongly depends on the oxygen deficiency. Solid evidence is presented to demonstrate that the oxygen deficiency cannot make LBCO materials changed from p- to n-type. The n-type conduction observed in experiment is a counterfeit phenomenon caused by the deficiency in Hall measurement, rather than a realistic transition induced by oxygen deficiency. In addition, the temperature-dependent conductivity was discussed using the differential coefficients, which might be useful in the study of the samples with magnetic transition.

[en] Interfacial structures and electrical resistivities of a carbon-doped Cu film at different annealing temperatures and times were investigated. The film was prepared by magnetron sputtering on barrierless silicon. After annealing, grain growth was distinctly hindered and a carbon-containing nanometer thick passive amorphous layer was formed at the film/substrate interface. The film had a resistivity of about 2.7 μΩ cm after annealing at 400 deg. C for 1 h and maintained a low resistivity of 3.8 μΩ cm even after 9 h annealing at 400 deg. C. The low electrical resistivity in combination with the high thermal stability makes carbon doping a promising technique for future Cu interconnects on barrierless Si.

[en] Highlights: • Technology for removal of Y-shaped airway stents under fluoroscopy was developed. • The technique was applied to 33 patients to remove airway stents. • All the stents were removed successfully, without serious complications. • The technique for fluoroscopic removal of the airway stent is feasible and safe. To review the removal of Y-shaped airway self-expanding covered metallic stents using the interventional technique under fluoroscopy.

[en] This paper describes in detail the acrylic vessels used to encapsulate the target and gamma catcher regions in the Daya Bay experiment's first pair of antineutrino detectors. We give an overview of the design, fabrication, shipping, and installation of the acrylic vessels and their liquid overflow tanks. The acrylic quality assurance program and vessel characterization, which measures all geometric, optical, and material properties relevant to ν-bar _e detection at Daya Bay are summarized. This paper is the technical reference for the Daya Bay acrylic vessels and can provide guidance in the design and use of acrylic components in future neutrino or dark matter experiments.