Abstract: This present disclosure provides a method for preparing chondroitin sulfate from tilapia skull, including enzymatic hydrolyzing tilapia skull powder by Savinase 16L to obtain Savinase 16L enzymatic hydrolysate, re-enzymatic hydrolyzing the Savinase 16L enzymatic hydrolysate by 2709 alkaline protease, then separating and purificating the solution by ethanol and cetylpyridine chloride to obtain the chondroitin sulfate. The present disclosure adopts a compound enzymatic hydrolyzing method by Savinase 16L and 2709 alkaline protease to effectively achieve the efficient extraction of chondroitin sulfate of tilapia skull powder, and further achieve the purification of chondroitin sulfate by ethanol and cetylpyridine chloride, so that tilapia by-products can be utilized with high value.

Abstract: A device for separating and sequestrating carbon dioxide coupled with cold storage in mixed gas via hydrate method, which belongs to the technical field of application of natural gas hydrates includes a gas compression device, a refrigeration cycle device, a hydrate formation/decomposition device, a hydrate cold storage device, a water circulation device and a sensing and monitoring device; taking the separation and sequestration of biogas as an example, the refrigeration cycle device enables the cooling of biogas, decomposition of gas at all levels, hydrate, and circulating water to provide the low-temperature conditions required for hydrate formation; the hydrate cold energy storage device can fully use the latent heat of hydrate phase change to provide the required cooling capacity on the user side; the water circulation device can realize the recycling of decomposition water to ensure the continuous formation of hydrate.

Abstract: A vacuum chamber structure of an ultra-high gravity geotechnical centrifuge device, comprising: a cylindrical shell, a convex head, a bottom head, a lower bearing sealing cover, and a vacuum pressure-bearing chamber formed by sealing a top cylindrical cylinder and an upper sealing plate with sealing rings; wherein a high-speed rotor system is enclosed in the vacuum pressure-bearing chamber, and a cylindrical cooling device is installed between an internal side of the cylindrical shell and the high-speed rotor system. An annular cooling device is provided directly above the hanging baskets on both sides of the centrifuge arm. A vibration isolation expansion joint is arranged at the intersection of the high-speed rotor system and the cylindrical cylinder, which isolates the vibration of the main engine from the vacuum chamber and greatly reduces the vibration.

Abstract: The present invention provides a method of water flow erosion for marine gas hydrate exploitation. Based on the characteristics of higher permeability around gas hydrate exploitation well, controlling the seawater flow process by the pressure difference between hydrate reservoir and gas hydrate exploitation well. And the chemical potential difference between hydrate phase and water phase is the main driving factor for promoting the hydrate decomposition. Meanwhile, the salinity will increase and then the phase equilibrium temperature of hydrate will increase during seawater flow process. The water flow erosion accelerates the heat and mass transfer in hydrate reservoir to promote the efficient and complete decomposition and collection of hydrate. And the method of water flow erosion can decrease the risk of the geographical destruction caused by the large pressure drop. The present invention also provides the combination modes of water flow erosion with depressurization, thermal injection and other methods.

Abstract: The present invention relates to a leak detection method for GIS based on vibration signals and belongs to the technical field of apparatus for detecting or reacting mechanical or electrical troubles. The method is carried out by the following steps: 1) Installing a vibration sensor on each connecting flange of each gas-tight chamber of the GIS; 2) Starting the GIS; 3) Acquiring the vibration signals of sensors when the GIS operation is stable after starting; 4) Doing de-noise processing on the collected vibration signal; 5) Doing 4-layer wavelet packet decomposition of the vibration signal after noise reduction to obtain the energy proportion of the vibration signal in each frequency band; 6) Analyzing the energy proportion of the vibration signal in each frequency band in step 5), Then alarm to notify the relevant personnel. Return to step 3) until the fault has been solved.

Abstract: The noise suppression method of individual active noise reduction system comprises the steps that: (1) initial noise digital signals are received and converted to serve as input signals of a BP neural network; (2) the input signals are processed to generate secondary digital signals; (3) the secondary digital signals are output to a loudspeaker and secondary noise is generated; (4) remained noise digital signals obtained by overlapping the initial noise and the secondary noise are received; whether remained noise digital signals is continuously constant for the set times is judged; if yes, the secondary digital signals are kept outputting; (5) if not, BP neural network parameters are optimized and adjusted with the amplitude of the remained noise digital signals being minimum as the optimality principle; remained noise digital signals of previous step are served as new input signals and the step (2) is executed again.

Abstract: The present application discloses a hydraulic oil cylinder, of which a piston rod (3) is provided with at least two cushion collars (4, 11) which are axially slidable along the piston rod (3). Axial throttle oil channels (301a, 301b) are provided between the cushion collars (4, 11) and a piston (6). A first cushion collar (4) is provided with a sealing end face (401), and an end cover of a rod cavity (1) is provided with a sealing end face (101). The sealing end face (401) of the first cushion collar contacts with the sealing end face (101) of the end cover of the rod cavity to form a seal. Hydraulic oil within the rod cavity is discharged through one axial throttle oil channel (301a) to an oil passage B.

Abstract: The noise suppression method of individual active noise reduction system comprises the steps that: (1) initial noise digital signals are received and converted to serve as input signals of a BP neural network; (2) the input signals are processed to generate secondary digital signals; (3) the secondary digital signals are output to a loudspeaker and secondary noise is generated; (4) remained noise digital signals obtained by overlapping the initial noise and the secondary noise are received; whether remained noise digital signals is continuously constant for the set times is judged; if yes, the secondary digital signals are kept outputting; (5) if not, BP neural network parameters are optimized and adjusted with the amplitude of the remained noise digital signals being minimum as the optimality principle; remained noise digital signals of previous step are served as new input signals and the step (2) is executed again.

Abstract: The present invention relates to a leak detection method for GIS based on vibration signals and belongs to the technical field of apparatus for detecting or reacting mechanical or electrical troubles. The method is carried out by the following steps: 1) Installing a vibration sensor on each connecting flange of each gas-tight chamber of the GIS; 2) Starting the GIS; 3) Acquiring the vibration signals of sensors when the GIS operation is stable after starting; 4) Doing de-noise processing on the collected vibration signal; 5) Doing 4-layer wavelet packet decomposition of the vibration signal after noise reduction to obtain the energy proportion of the vibration signal in each frequency band; 6) Analyzing the energy proportion of the vibration signal in each frequency band in step 5), Then alarm to notify the relevant personnel. Return to step 3) until the fault has been solved.

Abstract: A hydraulic oil cylinder has a buffer sleeve (4), a rodless cavity sealing end face (1-2) and at least one throttle oil channel (3-1). The buffer sleeve (4) is sleeved on an additional section (3a) of a piston rod in the rodless cavity (2-2) and axially slidable along the additional section (3a) of the piston rod. The rodless cavity sealing end face (1-2) is provided in an oil cylinder cavity between a rodless cavity oil passing hole (1-1) and the termination of the rodless cavity end face of the piston for the retraction process of the piston rod (3), and enables to block the buffer sleeve (4) and attach to the first end surface (4-1) of the buffer sleeve thereby forming a sealing surface.

Abstract: The present application discloses a hydraulic oil cylinder, of which a piston rod (3) is provided with at least two cushion collars (4, 11) which are axially slidable along the piston rod (3). Axial throttle oil channels (301a, 301b) are provided between the cushion collars (4, 11) and a piston (6). A first cushion collar (4) is provided with a sealing end face (401), and an end cover of a rod cavity (1) is provided with a sealing end face (101). The sealing end face (401) of the first cushion collar contacts with the sealing end face (101) of the end cover of the rod cavity to form a seal. Hydraulic oil within the rod cavity is discharged through one axial throttle oil channel (301a) to an oil passage B. A second cushion collar (11) is provided with a sealing end face (111), and an end cover of a rodless cavity (12) is provided with a sealing end face (121). The sealing end face (111) of the second cushion collar contacts with the sealing end face (121) of the end cover of the rodless cavity to form a seal.

Abstract: A hydraulic oil cylinder has a cushion collar, which is sleeved in the cushion position of a piston rod and can axially slide along the piston rod. In the oil cylinder cavity between an oil hole of the rod cavity and the terminal position of the piston end surface of the rod cavity during the piston extending movement, a sealing end surface of the rod cavity is provided, which can block the cushion collar and contact with the first end surface of the cushion collar to form a sealing surface. At least a throttle oil channel is provided between the cushion collar and the piston rod.

Abstract: A hydraulic oil cylinder has a buffer sleeve (4), a rodless cavity sealing end face (1-2) and at least one throttle oil channel (3-1). The buffer sleeve (4) is sleeved on an additional section (3a) of a piston rod in the rodless cavity (2-2) and axially slidable along the additional section (3a) of the piston rod. The rodless cavity sealing end face (1-2) is provided in an oil cylinder cavity between a rodless cavity oil passing hole (1-1) and the termination of the rodless cavity end face of the piston for the retraction process of the piston rod (3), and enables to block the buffer sleeve (4) and attach to the first end surface (4-1) of the buffer sleeve thereby forming a sealing surface.