A method of manufacturing a magnetic recording medium forms an unfinished product including a magnetic recording layer and a protection layer that are successively formed on a substrate, and forms a lubricant layer on the protection layer of the unfinished product. The lubricant layer is formed by coating a first organic fluorine compound on the protection layer of the unfinished product, and supplying a gas, including a second organic fluorine compound, onto the protection layer of the unfinished product, and decomposing the second organic fluorine compound by Townsend discharge and ultraviolet ray irradiation. The protection layer includes carbon, and the first organic fluorine compound includes a functional group at a terminal thereof.

An alkali-free glass substrate contains, as represented by mass % based on oxides: 54% to 68% of SiO.sub.2; 10% to 25% of Al.sub.2O.sub.3; 0.1% to 5.5% of B.sub.2O.sub.3; and 8% to 26% of MgO+CaO+SrO+BaO. The alkali-free glass substrate has β-OH of 0.15 mm.sup.−1 to 0.35 mm.sup.−1, and a Cl content of 0.15 to 0.3 mass %. A bubble growth index I of the alkali-free glass substrate given by the following formula is 320 or more: I=590.5×[β-OH]+874.1×[Cl]−5.7×[B.sub.2O.sub.3]−33.3. In the formula, [β-OH] is β-OH of the alkali-free glass substrate in mm.sup.−1, [Cl] is the Cl content of the alkali-free glass substrate in mass %, and [B.sub.2O.sub.3] is a B.sub.2O.sub.3 content of the alkali-free glass substrate in mass %.

Letting a particle diameter be Dx (μm) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 μm or less, and a difference between D95 and D5 is 3 μm or more.

In an amorphous glass, an SiO.sub.2 content is in a range of 56 mol% or more. An MgO content is in a range of 15 mol% or more and 28 mol% or less. An Li.sub.2O content is in a range of 0.2 mol% or more. An Na.sub.2O content is in a range of 5 mol% or less. A total content of Al.sub.2O.sub.3, MgO, and CaO (Al.sub.2O.sub.3 + MgO + CaO) is 36.50 mol% or less. The total content of SiO.sub.2, MgO, Li20, Al.sub.2O.sub.3, and CaO (SiO.sub.2 + MgO + Li20 + Al.sub.2O.sub.3 + CaO) is 97.5 mol% or more. A mole ratio of the total content of SiO.sub.2 and MgO relative to the Li.sub.2O content [(SiO.sub.2 + MgO) / Li.sub.2O] is 13 or more. A mole ratio of a CaO content relative to a total content of Al.sub.2O.sub.3 and MgO [CaO / (Al.sub.2O.sub.3 + MgO)] is 0.10 or less.

A magnetic recording medium includes a substrate, an underlayer provided above the substrate, and a magnetic layer provided on and in contact with the underlayer. The underlayer includes a compound represented by a general formula MgO.sub.(1-x), where x falls within a range of 0.07 to 0.25. The magnetic layer includes an alloy having a L1.sub.0 structure, and the alloy having the L1.sub.0 structure includes one or more elements selected from a group consisting of Al, Si, Ga, and Ge.

A magnetic recording medium includes a substrate, an underlayer disposed above the substrate, and a first magnetic layer disposed above the underlayer. The first magnetic layer has a granular structure including magnetic grains having a L1.sub.0 structure, and grain boundaries. A content of the grain boundaries is in a range of 25 volume percent to 50 volume percent, and the grain boundaries include a chalcogenide-based layered material.

Embodiments of chair systems incorporating trekking poles include a low-back design employing fixed-length trekking poles, and a high-back design employing adjustable-length trekking poles that allow for adjusting the recline angle of the chair. The chair system generally includes a tubular frame that releasably engages a flexible seat. The tubular frame includes a front hub and a rear hub spaced one from the other by a cross bar, plus front and rear footings which stabilize the chair system on the ground or undersurface. A V-shaped upper support extending from the front hub supports and holds open the leg portion of the flexible seat, while the trekking poles are releasably engaged with and extend upwardly from the rear hub to support, and hold open and upright the back portion of the flexible seat.

Letting a particle diameter be Dx (μm) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 μm or less, and a difference between D95 and D5 is 3 μm or more.

Embodiments of chair systems incorporating trekking poles include a low-back design employing fixed-length trekking poles, and a high-back design employing adjustable-length trekking poles that allow for adjusting the recline angle of the chair. The chair system generally includes a tubular frame that releasably engages a flexible seat. The tubular frame includes a front hub and a rear hub spaced one from the other by a cross bar, plus front and rear footings which stabilize the chair system on the ground or undersurface. A V-shaped upper support extending from the front hub supports and holds open the leg portion of the flexible seat, while the trekking poles are releasably engaged with and extend upwardly from the rear hub to support, and hold open and upright the back portion of the flexible seat.

Letting a particle diameter be Dx (μm) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 μm or less, D100 is 3 μm or more, D50 is 0.8 to 2.4 μm, and Dpeak−D5 is less than D95−Dpeak.