Abstract: A biomass-based long-chain alcohol ether oxygenated additive and a preparation method and application thereof are disclosed. The additive used agricultural and forestry wastes as raw materials, and has a general chemical formula of R—(O—C1-3)n—R—OH. The preparation method includes the following steps: step 1, performing drying pretreatment on biomass raw materials, performing rapid pyrolysis under an inert atmosphere to obtain a pyrolysis product containing water, gases, water-phase bio-oil and oil-phase bio-oil, separating out the water-phase bio-oil and performing catalytic hydrogenation on the water-phase bio-oil to obtain polyols; step 2, performing catalytic dehydration on the polyols obtained in step 1 under a basic catalyst system to obtain epoxyalkane; and step 3, making the epoxyalkane obtained in step 2 and methanol undergo a reaction under a molecular sieve catalyst and removing the solid catalyst by separation to obtain the long-chain alcohol ether oxygenated additive.

Abstract: A sealing assembly for electronic components including a sealing seat and a sealing shell for mounting the electronic component. The sealing shell is received through an opening in the top of the sealing seat and into complementary mounting chamber. A left end of the sealing shell includes a first connection channel; a left end of the mounting chamber includes a second connection channel and a sealing gasket surrounding the second connection channel. A right end of the mounting chamber includes an elastic latch. After installing the sealing shell in the mounting chamber, the elastic latch laterally abuts the sealing shell's right end and is in a lateral compression position, and the first connection channel and the second connection channel are aligned and in sealing communication through the sealing gasket. The elastic latch includes a right backstop to prevent the sealing shell from being vertically detached from the mounting chamber.

Abstract: A biomass-based long-chain alcohol ether oxygenated additive and a preparation method and application thereof are disclosed. The additive used agricultural and forestry wastes as raw materials, and has a general chemical formula of R—(O—C1-3)n—R—OH. The preparation method includes the following steps: step 1, performing drying pretreatment on biomass raw materials, performing rapid pyrolysis under an inert atmosphere to obtain a pyrolysis product containing water, gases, water-phase bio-oil and oil-phase bio-oil, separating out the water-phase bio-oil and performing catalytic hydrogenation on the water-phase bio-oil to obtain polyols; step 2, performing catalytic dehydration on the polyols obtained in step 1 under a basic catalyst system to obtain epoxyalkane; and step 3, making the epoxyalkane obtained in step 2 and methanol undergo a reaction under a molecular sieve catalyst and removing the solid catalyst by separation to obtain the long-chain alcohol ether oxygenated additive.

Abstract: A sealing assembly for electronic components including a sealing seat and a sealing shell for mounting the electronic component. The sealing shell is received through an opening in the top of the sealing seat and into complementary mounting chamber. A left end of the sealing shell includes a first connection channel; a left end of the mounting chamber includes a second connection channel and a sealing gasket surrounding the second connection channel. A right end of the mounting chamber includes an elastic latch. After installing the sealing shell in the mounting chamber, the elastic latch laterally abuts the sealing shell's right end and is in a lateral compression position, and the first connection channel and the second connection channel are aligned and in sealing communication through the sealing gasket. The elastic latch includes a right backstop to prevent the sealing shell from being vertically detached from the mounting chamber.

Abstract: A liquid nitrogen cyclic freeze-thaw permeability-improvement gas drainage method based on horizontal directional boreholes comprises: first constructing a main borehole at an intake roadway or a return roadway, a low-level roadway and a high-level roadway, after a drill bit reaches a pre-set target position of a coal bed, uniformly and directionally constructing a plurality of branch boreholes along a horizontal direction of the coal bed, injecting water to the coal bed, opening a valve, filling the main boreholes with liquid nitrogen, rapidly freezing the water injected into the branch boreholes and the periphery of the coal bed, and stopping injecting the nitrogen when an average temperature of a pre-permeability-improvement area monitored by a temperature measuring hole is lowered to ?2° C. or lower.

Abstract: A liquid nitrogen cyclic freeze-thaw permeability-improvement gas drainage method based on horizontal directional boreholes comprises: first constructing a main borehole at an intake roadway or a return roadway, a low-level roadway and a high-level roadway, after a drill bit reaches a pre-set target position of a coal bed, uniformly and directionally constructing a plurality of branch boreholes along a horizontal direction of the coal bed, injecting water to the coal bed, opening a valve, filling the main boreholes with liquid nitrogen, rapidly freezing the water injected into the branch boreholes and the periphery of the coal bed, and stopping injecting the nitrogen when an average temperature of a pre-permeability-improvement area monitored by a temperature measuring hole is lowered to ?2° C. or lower.