A convenient technique is reported in this note for measuring elastic modulus of extremely soft material for cellular adhesion. Specimens of bending cylinder under gravity are used to avoid contact problem between tes...A convenient technique is reported in this note for measuring elastic modulus of extremely soft material for cellular adhesion. Specimens of bending cylinder under gravity are used to avoid contact problem between testing device and sample, and a beam model is presented for evaluating the curvatures of gel beams with large elastic deformation. A self-adaptive algorithm is also proposed to search for the best estimation of gels＇ elastic moduli by comparing the experimental bending curvatures with those computed from the beam model with preestimated moduli. Application to the measurement of the property of polyacrylamide gels indi- cates that the material compliance varies with the concentrations of bis-acrylamide, and the gels become softer after being immersed in a culture medium for a period of time, no matter to what extent they are polymerized.展开更多
The principle, formula and determination of internal stresses of metal multilayer composite coatings by means of the bending strip method were studied. Using this method, internal stresses of ion-plated metal multilay...The principle, formula and determination of internal stresses of metal multilayer composite coatings by means of the bending strip method were studied. Using this method, internal stresses of ion-plated metal multilayer composite coatings and thick monolayer coating of aluminium bronze, stainless steel and nickel-iron alloy were determined. The reason of decrement in internal stresses of multilayer composite coatings was discussed.展开更多
It is meaningful to develop a high-performance optic bending sensor characterized by effective direction judgment, compact length, and high sensitivity. In this Letter, a compact Mach–Zehnder interferometer(MZI) fibe...It is meaningful to develop a high-performance optic bending sensor characterized by effective direction judgment, compact length, and high sensitivity. In this Letter, a compact Mach–Zehnder interferometer(MZI) fiber sensor for vector bending measurement is proposed and investigated. This sensor is prepared by off-axis splicing seven-core fibers(SCFs) and multi-mode fibers(MMFs) with different core diameters, which achieves a compact sensing length of 8 mm. The chirped core fiber structure excites the high-order cladding mode in the interference component, which enhances the sensing sensitivity. Experimental results indicate that the maximum bending sensitivity of the sensor is-230 nm/m^(-1). Moreover,the three bending directions of the sensor can be distinguished by judging the variations of the two interference dips during the measuring process. The proposed method and thought can provide some operating experience and principles for the allfiber curvature sensor design.展开更多
基金supported by the National Basic Research Program (2007CB935602)the National Natural Science Foundation of China (90607004, 10672005)
文摘A convenient technique is reported in this note for measuring elastic modulus of extremely soft material for cellular adhesion. Specimens of bending cylinder under gravity are used to avoid contact problem between testing device and sample, and a beam model is presented for evaluating the curvatures of gel beams with large elastic deformation. A self-adaptive algorithm is also proposed to search for the best estimation of gels＇ elastic moduli by comparing the experimental bending curvatures with those computed from the beam model with preestimated moduli. Application to the measurement of the property of polyacrylamide gels indi- cates that the material compliance varies with the concentrations of bis-acrylamide, and the gels become softer after being immersed in a culture medium for a period of time, no matter to what extent they are polymerized.
文摘The principle, formula and determination of internal stresses of metal multilayer composite coatings by means of the bending strip method were studied. Using this method, internal stresses of ion-plated metal multilayer composite coatings and thick monolayer coating of aluminium bronze, stainless steel and nickel-iron alloy were determined. The reason of decrement in internal stresses of multilayer composite coatings was discussed.
基金supported by the Joint Research Fund in Astronomy under a cooperative agreement between the National Natural Science Foundation of China (NSFC) and the Chinese Academy of Sciences (CAS) (No. U1831115)the Key Research and Development Plan of Heilongjiang Province (No. GA23A909)。
文摘It is meaningful to develop a high-performance optic bending sensor characterized by effective direction judgment, compact length, and high sensitivity. In this Letter, a compact Mach–Zehnder interferometer(MZI) fiber sensor for vector bending measurement is proposed and investigated. This sensor is prepared by off-axis splicing seven-core fibers(SCFs) and multi-mode fibers(MMFs) with different core diameters, which achieves a compact sensing length of 8 mm. The chirped core fiber structure excites the high-order cladding mode in the interference component, which enhances the sensing sensitivity. Experimental results indicate that the maximum bending sensitivity of the sensor is-230 nm/m^(-1). Moreover,the three bending directions of the sensor can be distinguished by judging the variations of the two interference dips during the measuring process. The proposed method and thought can provide some operating experience and principles for the allfiber curvature sensor design.
