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With the generalization of the use of gas and natural gas, the design and research of the timing shut-off device for gas has become an indispensable factor to avoid gas poisoning incidents. In order to solve such problems, this paper proposes a mechanical gas timing shut-off device design, expounds the operation principle of the device, draws the device schematic diagram and assembly drawing, and introduces the key technological breakthroughs in the research of mechanical gas timing shut-off device. Clarified the innovation and promotion significance of the device.

In this paper, we present an alternate iterative Gauss-Seidel method for linear systems. The spectral radius of the iteration matrix and the convergence of the proposed method are discussed. Finally, the numerical examples are provided to confirm our theoretical analysis and demonstrate the efficiency of the new method.

We report a drastic reduction of hardness of about 61% from WB3 to WB4. The three-dimensional covalent network consisting of boron honeycomb planes interconnected with strong zigzag W-B bonds underlies the high hardness of WB3. Despite the strong intralayer and interstitial B-B bonds, the interlayer B-B nonbonding and the considerably weak zigzag W-B bonding allow the layers of WB4 to cleave readily, which results in the anomalous softening of WB4. The results provide robust evidence that the highest boride of tungsten, which is characterized experimentally by an inexpensive superhard material, should be stoichiometric WB3, not WB4.

The magnetic properties of the partially filled skutterudite Eu(0.5)Co(4)Sb(12) are investigated by a model Hamiltonian, with special emphasis on the effect of ordering and disordering occupancy of the filler atoms Eu on the magnetic properties. The magnetization, magnetic specific heat and entropy are calculated within the mean-field approximation. By introducing the position disorder of the filler atoms, the critical temperature T(C) above which the magnetization disappears is changed. The magnetization curve near T(C) also becomes concave compared to the convex magnetization of the ordered system. The filler disordering also leads to a kink in the isothermal magnetization curve and a valley in the magnetic specific heat near T(C). The effective magnetic field acting on the localized spin of the filler atoms has a competitive effect with the disorder and therefore makes the valley disappear.