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In order to improve the competitiveness, optimizing the fuel economy and competitiveness of civil turbofan engines is becoming the research highlights recently. The comparison analysis of cycle parameters is carried out for different configurations such as advanced turbofan(ATF), geared turbofan(GTF) and intercooled recuperated aero-engine(IRA). The technical advantage of different configurations is determined. The research results show that the specific fuel consumption at the cruise uninstall condition of GTF configuration is decreased by 2.5% compared to that of ATF configuration. The specific fuel consumption at the cruise uninstall condition of IRA configuration is decreased by 11.97% compared to that of ATF configuration, and which is decreased by 9.7% compared to that of GTF configuration. Comparing to ATF and GTF configurations, the stage number of high pressure compressor and high pressure turbine in IRA configuration can be reduced to shorten the core engine length, and this also diminish the design difficulties of high pressure compressor.

A coarse-grained mapping scheme of polyimide (PI) and carbon nanotube (CNT) was designed, and the coarse-grained field parameters of CNT/PI-based composites were obtained by the constant strain method based on the conservation of the total strain energy. The accuracy of coarse-grained field parameters is verified by comparing the matching degree between the simulation results of all-atom and coarse-grain. The tensile stiffness of CNT and PI molecular chains, the interface interaction between CNT and PI matrix, and the Young's modulus of CNT/PI composite were simulated by field parameters. The results showed that the coarse-grained field parameters obtained by the constant strain method could accurately reflect the mechanical properties of nanocomposites. The effects of the equilibrium distance (r0) and well parameters (D0) of Van Der Waals potential function on the density of the model, the interface interaction between CNT and PI matrix, and the Young's modulus of the nanocomposite were discussed. The results showed that the increase of r0 reduce the density of the model. The interfacial interaction between CNT and PI matrix and the Young's modulus of nanocomposites could improve when D0 increased. [ABSTRACT FROM AUTHOR]

TRIM13, a member of the TRIM family, is a RING domain containing E3 ubiquitin ligase which plays critical roles in diverse cellular processes including cell death, cancer and antiviral immunity. However, its expression and molecular mechanism on renal cell carcinoma (RCC) have not been characterized. This study explored the clinical significance and biological function of TRIM13 in human RCC. Western blot analyses and Immunohistochemical were performed in RCC tissues. The clinical relevance of TRIM13 in RCC was evaluated by immunohistochemical staining using tissue microarray. The role of TRIM13 in migration was studied in renal cell carcinoma cell lines of 786-O through knocking down TRIM13 with siRNA and over-expression of TRIM13. The regulation of TRIM13 on migration and invasion were determined by wound-healing and transwell assays. Western blot analyses showed that TRIM13 expression was dramatically decreased in RCC tissues compared with adjacent non-tumorous tissues. Up-regulation of TRIM13 in 786-O cells resulted in decreased NF-kB, MMP-9 and p-AKT levels and the capability for migration and invasion. In contrast, the ectopic expression of TRIM13 decreased the migration and invasion ability of 786-O cells. These findings indicate that TRIM13 decreases RCC metastasis and invasion may serve as a candidate RCC prognostic marker and a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Featured Application: This paper developed a kind of insulator electrified dry-ice cleaning mechanical arm, which can be used for electrified cleaning of insulator or other similar equipment in substation. Polluted flashover of insulators has always been a crucial hidden peril to the reliability of substation for supplying electricity. At present, the insulator of the substation is mainly cleaned manually in the case of power-cut, which greatly affects the reliability of power supply and operation safety. In this paper, an insulator dry-ice mechanical arm capable of electrified working is proposed. Under the regular operation of the power grid, the operator can remotely control the mechanical arm to clean the insulators of the substation with high-pressure gas mixed with dry-ice particles. This will not only ensure the regular operation of the power grid, but also greatly protects the safety of personnel. Considering the operation environment and high-voltage working conditions of the substation, the mechanism and control system of the dry-ice cleaning mechanical arm are designed, and the motion analysis, simulation, and strength analysis of the mechanical arm are carried out. Finally, the high-voltage-insulation test of the mechanical arm and the actual operation of the substation insulator cleaning working test are carried out, which proves that this mechanical arm can adapt to the operation environment of the substation, and the working is stable, safe, and reliable, which has an important application value to solve the problem in the cleaning of the substation insulator and other electrified equipment. [ABSTRACT FROM AUTHOR]

The matching problem becomes much more difficult between a regulated two-stage turbocharging system and a diesel engine when they are required to work at different altitudes. This is mainly because there are three or even four main variables to be determined for a regulated two-stage turbocharging system, and the change in the operating altitude also extends the matching problem from a two-dimensional problem of the speed and the load to a three-dimensional problem of the speed, the load and the operating altitude. An optimal scheme for a regulated two-stage turbocharging system should be determined to optimize the plateau adaptability based on the relationship between the matching point, the desirable pressure ratio distribution and the operating altitude. Therefore, a theoretical study on matching a regulated two-stage turbocharging system to a diesel engine at different altitudes is conducted in this paper. The turbine equivalent area of a regulated two-stage turbocharging system is derived on the basis of the turbine flow characteristic model with the thermodynamics equations and the mass and energy conservation of the turbocharging system. The speed and altitude ranges are discussed with the results calculated by the proposed matching model in MATLAB software. Then the simulations with GT-Power software are carried out to validate the application of the equivalent matching model. The calculated results show that the problem of the speed range of the regulated two-stage turbocharging system at different altitudes can be converted to the speed range of a matching scheme based on different pressure ratio distributions at a constant altitude. The altitude range of the regulated two-stage turbocharging system is mainly affected by the matching speed and the bypass flow rate ratio. The validation results of the GT-Power model show that the plateau adaptability of the matched regulated two-stage turbocharging system can be investigated effectively using the equivalent matching model. Therefore, the equivalent matching model can be utilized to achieve a reasonable selection of the matching speed and it can simplify the matching problem of the regulated two-stage turbocharging system at different altitudes. [ABSTRACT FROM AUTHOR]

A theoretical study on matching a parallel sequential turbocharging system and a diesel engine is conducted. The relationship between the turbocharging system and the engine is represented through expressions for the geometry-equivalent areas of the turbine nozzle and the engine parameters, which are derived on the basis of the thermodynamics equations, and the mass and energy conservation of the turbocharging engine system. The feasible range of the geometry-equivalent areas of the turbine nozzle for a given engine operation condition is determined by the limits of the engine and the turbochargers. The number of sequential turbocharging system phases is determined by the feasible range of geometry-equivalent areas of the turbine nozzle, and the switching boundaries are calculated for the engine’s best performance. The matching method is applied to design the sequential turbocharging system for a six-cylinder diesel engine. The results prove that the number of phases and the switching boundary are accurately estimated by this model. The relative error in the pressure ratio between the results obtained by this matching method and those determined by the validated GT-Power model is less than 6.4%. It is helpful for sequential turbocharging preliminary selection and for providing a foundation for a further matching method. [ABSTRACT FROM PUBLISHER]

The drilling part of the full term underbalanced drilling and completion technology is easy to achieve underbalanced operations, but the completion part is difficult. To solve the difficulties of high cost when using casing valves and limited application scope when using open-hole completion, smart pack completion technique was proposed. It uses some gel system to separate the upper killing fluid from the formation, so as to protect the formation. By a large number of experiments, optimal choice of smart pack recipe was selected, and the smart pack recipe was studied in view of pressure tolerance performance, strength, sealing performance, stability, gelation time, gel breaking time, operation technique, and flow-back technique. Field tests on ten wells, including Well Niudong89-912 and Well Ya940, showed the technology not only solves the passive situation of relatively simple underbalanced completion method, but also achieved the objectives of high effeciency and low cost. [ABSTRACT FROM AUTHOR]