112 results about "Volume deformation" patented technology

The invention discloses silicon-carbon composite granules and a preparation method and an application therefor. The silicon-carbon composite granules mainly comprise nanometer silicon, carbon nanotubes and organic cracked carbon; the carbon nanotubes wind mutually to form a porous granular structure; the carbon nanotubes alternately penetrate nanometer silicon gaps to form a porous structure to be used as a nanometer silicon carrier, and a conductive network is provided; by virtue of the porous structure, volume expansion of the nanometer silicon in a charging-discharging process can be effectively relieved; the space between the nanometer silicon and the carbon nanotubes is filled with the organic cracked carbon, so that attachment of the nanometer silicon on the carbon nanotubes can be improved, detachment of the nanometer silicon after volume deformation can be prevented, and direct contact between the nanometer silicon and an electrolyte is reduced at the same time; the silicon-carbon composite granules have excellent cycling performance, specific capacity, rate capability and low volume expansion effect, and can be used as an ideal negative electrode material of a lithium ion battery; and meanwhile, the production process is simple and easy to control, the product dimension is uniform, the appearance is regular and tidy, and large-scale industrial production can be achieved favorably.

The invention discloses an ultrasonic technology-based method for detecting and evaluating damage of subgrade soil materials in seasonal frozen regions. The method comprises the following steps: an initial state sample and a test sample are prepared according to an evaluation scheme on the basis of a formed sample meeting requirements of subgrade soil; the initial state sample is not subjected tofreeze-thaw cycles and has humidity being the evaluation standard moisture content; the test sample is a soil sample which is subjected to freezing and thawing cycling and has humidity at the requiredmoisture content for testing; the initial state sample and the test sample are both subjected to geometric parameter measurement and ultrasonic wave velocity test, the volume deformation rate of thetest sample and the longitudinal wave velocity of the test sample and the initial state sample are obtained, the longitudinal wave velocity, the moisture content and the volume deformation rate of thetest sample are measured according to the longitudinal wave velocity and moisture content of the initial state sample, and the damage variable of the test sample is calculated. Therefore, with the method, the damage degree of soil can be evaluated accurately, comprehensively and non-destructively and the damage mechanism can be reflected without destructive tests.

The invention provides a real-time testing device and a real-time testing method of size deformation after cement based composite materials hardening. The real-time testing device and the real-time testing method of the size deformation after the cement based composite materials hardening comprise a measurement component, a detachable component and a fixing component, wherein the fixing component comprises a base and an outer die. The outer die is arranged at an edge of the base and is perpendicular to the base. The detachable component comprises a round inner die which is perpendicular to the base, and the diameter of the round inner die is 0.5-0.8 times as long as the width of the outer die. The measurement component comprises a dial indicator and a test probe, and the dial indicator penetrates through holes formed in the outer die and the round inner die. The test probe is pre-embedded in a test piece, and the position of the test probe corresponds to the dial indicator. Through a round inner forming test piece, wherein the diameter of the round inner forming test piece is far larger than the height of the round inner forming test piece, the test piece is enabled to freely set, harden and deform in the outer die with the diameter larger than that of the inner die, radial deformation quantity of the test piece after preheating is continuously tested by the adoption of the dial indicator, and under the premise that the test piece is not moved, and the deformation of the test piece cannot be restrained by containers around, the testing device can effectively, continuously and accurately test shrinkage and deformation of the cement based composite material after hardening.