The nano-grained (NG) high-Mn austenitic steel with average grain size of 60 nm and the ultrafine-grained (UFG) steels with grain size below 500 nm are successfully produced by combination of the asymmetric rolling (ASR) and symmetric rolling (SR) method and the subsequent annealing treatment. The annealed NG steels exhibit relatively higher strain hardening and good balance of strength and ductility, which is attributed to the partial recrystallization of the nanostructures and the relatively lower stacking fault energy of the high-Mn TWIP steel.
Rudder is an important part for the glider aircraft.In order to satisfy the longtime high-velocity for the near-space vehicle in the atmosphere, the lightweight, high-stiffness and high-strength all-composites rudderpost is required urgently to be prepared.The all-composites rudderpost can keep high rudder efficiency in the high temperature environment.Based on the technique requirement of high-performance composites rudder, a 3D C/SiC rudderpost was manufactured by the CVI-CMC-SiC [1] processes.It was found during rudderpost testing that the high-temperature mechanical properties decreased and had large discretization.The analysis of the failure mechanisms was conducted by FTA method to recognize the failure modes and main reasons for rudderpost abnormal fracture and to reproduce the fracture phenomenon, which could guide production company to modify their preparation process control.Then the modified processes were proved to be validated.And the stability and reliability of the production performances were improved.
As many countries in the world pay great attention to marine science research and development, Sea Floor Observatory Network (SFON) technology has been more and more important. In this article, the definition and history of SFON are briefly introduced, the development and current status of SFON of various countries are compared, and key technologies for SFON are analyzed. In the end, the prospects of China's SFON are discussed and advices are given.
Due to the defects of modern radar simulator such as the outmoded single function operation interface and the progress is far behind the real equipment, we developing a novel radar simulator. The design of simulator is modularized. On the basis of the normal radar simulator we added some new practical function. With the aid of WPF and C# we finished the design and realization of the simulator. Our simulator not only can meet the requirement of normal radar simulator but also can do satisfy function innovation. It is in the leading level in such kind of simulator.
Abstract Polymer membrane type ion‐selective electrodes (ISEs) are now used routinely to measure clinically important ions (e.g., Na + , K + , Ca 2+ ) in undiluted blood. However, efforts to develop similar sensors suitable for the direct detection of larger biomolecules have been less successful owing to the difficulty in identifying appropriate membrane chemistries that yield a significant and selective response toward the desired macromolecular analytes. Recently, we have found that poorly plasticized polymer membranes (PVC) doped with lipophilic anion and cation exchangers exhibit unexpectedly large and reproducible potentiometric responses to low levels (< 1 μM) of certain biomedically important macromolecular polyionic species (heparin and protamine). This article provides data demonstrating how the specific membrane formulation and electrode geometry used influence the magnitude of the polyion EMF responses observed. The results suggest a non‐ equilibrium/steady‐state polyion extraction process is responsible for the potentiometric heparin and protamine responses exhibited by appropriately formulated membranes. The practical utility of these sensors for monitoring heparin levels in blood as well as heparin/ protamine binding to other biologically important macromolecules will be described. Further, the prospects of adapting the same polyion extraction chemistry to devise optically sensitive thin polymer films for monitoring heparin will also be addressed.
For the developing research and exploring of deep-sea mineral and biological resources, subsea observatory is quite an effective method for long-time automatic data or image collection of subsea environment and creatures. But building an observatory network underwater is complicated and the power/optical signal transmission between subsea nodes requires extension cables. In this paper, a new kind of passive cable laying system which is attached to 4500m Deep-Sea ROV (Remotely Operated Vehicle) is proposed for optical fiber laying operations for subsea cabled observatory. With full-mechanic cable tension management device, the tension of optical fiber could remain constant during laying operation, and the system requires no close-loop control for cable releasing speed. And because of long-distance operation, flotation adjustment is also an important issue for consideration. A buoyancy variation control system solves the problem by non-continuously adjustment for the weight of cable released from the bobbin.
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