Abstract: The present invention discloses a deformation controllable compression ring-based mechanical test system for rocks with variable stiffness and a test method thereof, which comprises a loading device, a variable stiffness regulating device, a data monitoring system and a controlling system; the energy storing spring in the loading device allows the rebounding direction of the loading device to be contrary to the strain direction of the test-piece, which eliminates the energy supplement of the loading device to the test-piece and realizes the loading of an oversized stiffness on the test system; the variable stiffness regulating device precisely regulates the loaded stiffness by regulating the loaded stiffness of the test system according to test requirements, which realizes the test of loading different stiffness on the same test system and avoids the influences of differences to loading parameters between different test systems on the test results.

Abstract: The present invention discloses a deformation controllable compression ring-based mechanical test system for rocks with variable stiffness and a test method thereof, which comprises a loading device, a variable stiffness regulating device, a data monitoring system and a controlling system; the energy storing spring in the loading device allows the rebounding direction of the loading device to be contrary to the strain direction of the test-piece, which eliminates the energy supplement of the loading device to the test-piece and realizes the loading of an oversized stiffness on the test system; the variable stiffness regulating device precisely regulates the loaded stiffness by regulating the loaded stiffness of the test system according to test requirements, which realizes the test of loading different stiffness on the same test system and avoids the influences of differences to loading parameters between different test systems on the test results.

Abstract: A laser system may include a seed laser formed from a Ti:Sapphire laser providing pulsed light and an optical parametric amplifier to generate pulsed light within a Holmium emission spectrum as seed pulses in response to the pulsed light from the Ti:Sapphire laser. A laser system may further include an amplifier to generate amplified pulses of light in response to the seed pulses from the seed laser, where the amplified pulses include at least some of the seed pulses amplified by the one or more Holmium-doped gain media pumped by the one or more pump lasers. The amplifier may include one or more Holmium-doped gain media and one or more pump lasers providing continuous-wave pump light within an absorption spectrum of the one or more Holmium-doped gain media.

Abstract: The present disclosure provides a true triaxial tester with adjustable loading stiffness and a test method, relating to the technical field of rock mechanics. The tester includes a first principal stress variable stiffness loading apparatus, a second principal stress variable stiffness loading apparatus, a third principal stress loading apparatus, a monitoring system, and a control system. The monitoring system includes a stiffness sensor, a pressure sensor, and a displacement sensor. Loading stiffness in a first principal stress direction and a second principal stress direction is adjustable. The tester has the following advantages: it has fixed loading stiffness, can complete stiffness loading of one side being free and five sides being variable, and is easy to operate.

Abstract: The present disclosure provides an inner and outer framework combined variable stiffness rock mechanics tester and a testing method, relating to the technical field of rock mechanics. The tester includes a stiffness adjusting apparatus, a test loading apparatus, a monitoring system, and a control system. During a test, according to monitoring data, the load of the stiffness adjusting cylinder is controlled through the control system, and the displacement of the inner top beam is adjusted in real time, to ensure that the loading stiffness reaches a design value and remains constant, which solves the technical problem that the loading stiffness of the rock mechanics tester cannot be quantitatively adjusted, and is easy to operate.

Abstract: The present disclosure provides a true triaxial tester with adjustable loading stiffness and a test method, relating to the technical field of rock mechanics. The tester includes a first principal stress variable stiffness loading apparatus, a second principal stress variable stiffness loading apparatus, a third principal stress loading apparatus, a monitoring system, and a control system. The monitoring system includes a stiffness sensor, a pressure sensor, and a displacement sensor. Loading stiffness in a first principal stress direction and a second principal stress direction is adjustable. The tester has the following advantages: it has fixed loading stiffness, can complete stiffness loading of one side being free and five sides being variable, and is easy to operate.

Abstract: The present disclosure provides an inner and outer framework combined variable stiffness rock mechanics tester and a testing method, relating to the technical field of rock mechanics. The tester includes a stiffness adjusting apparatus, a test loading apparatus, a monitoring system, and a control system. During a test, according to monitoring data, the load of the stiffness adjusting cylinder is controlled through the control system, and the displacement of the inner top beam is adjusted in real time, to ensure that the loading stiffness reaches a design value and remains constant, which solves the technical problem that the loading stiffness of the rock mechanics tester cannot be quantitatively adjusted, and is easy to operate.

Abstract: The present invention demonstrates a technique for achieving milli-joule level and higher energy, broad bandwidth laser pulses centered around 2.4 micrometer with a kilohertz and other repetition rate. The key to such technique is to start with a broadband micro-joule level seed laser at around 2.4 micrometer, which could be generated through difference frequency generation, four-wave mixing process and other methods. This micro-joule level seed laser could then be amplified to above one milli-joule through chirped pulse amplification in a Cr2+:ZnSe or Cr2+:ZnS crystal pumped by a commercially available Ho:YAG or other appropriate suitable lasers. Due to the high seed energy, fewer gain passes are needed to achieve a milli-joule level output thus significantly simplifies laser architectures. Furthermore, gain narrowing effect in a typical chirped pulse amplifier is also mitigated and thus enable a broadband output.

Abstract: The present invention demonstrates a technique for achieving milli-joule level and higher energy, broad bandwidth laser pulses centered around 2.4 micrometer with a kilohertz and other repetition rate. The key to such technique is to start with a broadband micro-joule level seed laser at around 2.4 micrometer, which could be generated through difference frequency generation, four-wave mixing process and other methods. This micro-joule level seed laser could then be amplified to above one milli-joule through chirped pulse amplification in a Cr2+:ZnSe or Cr2+:ZnS crystal pumped by a commercially available Ho:YAG or other appropriate suitable lasers. Due to the high seed energy, fewer gain passes are needed to achieve a milli-joule level output thus significantly simplifies laser architectures. Furthermore, gain narrowing effect in a typical chirped pulse amplifier is also mitigated and thus enable a broadband output.