This tin or tin alloy plating solution includes a soluble salt including at least a stannous salt (A), an acid selected from an organic acid and an inorganic acid or a salt thereof (B), a surfactant (C), benzalacetone (D), and a solvent (E), wherein the plating solution is used to form a pattern in which bump diameters are different from each other on a base material, an amount of the benzalacetone (D) is 0.05 g/L to 0.2 g/L, a mass ratio (C/D) of the surfactant (C) to the benzalacetone (D) is 10 to 200, and a mass ratio (E/D) of the solvent (E) to the benzalacetone (D) is 10 or more.

This tin or tin alloy plating solution includes a soluble salt including at least a stannous salt (A), an acid selected from an organic acid and an inorganic acid or a salt thereof (B), a surfactant (C), benzalacetone (D), and a solvent (E), wherein the plating solution is used to form a pattern in which bump diameters are different from each other on a base material, an amount of the benzalacetone (D) is 0.05 g/L to 0.2 g/L, a mass ratio (C/D) of the surfactant (C) to the benzalacetone (D) is 10 to 200, and a mass ratio (E/D) of the solvent (E) to the benzalacetone (D) is 10 or more.

To provide a Sn-based plated steel sheet excellent in yellowing resistance, coating film adhesiveness, and sulfurization blackening resistance without performing the conventional chromate treatment. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein: the Sn-based plating layer contains 0.10 to 15.00 g/m.sup.2 of Sn per side in terms of metal Sn; the coating layer contains a Zr oxide and a Mn oxide; a content of the Zr oxide is 0.20 to 50.00 mg/m.sup.2 per side in terms of metal Zr; a content of the Mn oxide in terms of metal Mn is 0.01 to 0.50 times on a mass basis relative to the content of the Zr oxide in terms of metal Zr; and a depth position A where an element concentration of Mn is maximum is located on a side closer to a surface of the coating layer than a depth position B where an element concentration of Zr is maximum, and a distance in a depth direction between the depth position A and the depth position B is 2 nm or more in an element analysis in the depth direction by XPS.

To provide a Sn-based plated steel sheet excellent in yellowing resistance, coating film adhesiveness, and sulfurization blackening resistance without performing the conventional chromate treatment. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein: the Sn-based plating layer contains 0.10 to 15.00 g/m.sup.2 of Sn per side in terms of metal Sn; the coating layer contains a Zr oxide and a Mn oxide; a content of the Zr oxide is 0.20 to 50.00 mg/m.sup.2 per side in terms of metal Zr; a content of the Mn oxide in terms of metal Mn is 0.01 to 0.50 times on a mass basis relative to the content of the Zr oxide in terms of metal Zr; and a depth position A where an element concentration of Mn is maximum is located on a side closer to a surface of the coating layer than a depth position B where an element concentration of Zr is maximum, and a distance in a depth direction between the depth position A and the depth position B is 2 nm or more in an element analysis in the depth direction by XPS.

An aqueous composition comprising (a) metal ions comprising tin ions and silver ions and (b) at least one complexing agent of formula (C1) R.sup.1X.sup.1SX.sup.21[D.sup.1-X.sup.22].sub.nSX.sup.3R.sup.2, (C2) R.sup.1X.sup.1SX.sup.31-D.sup.2-[X.sup.32S].sub.nX.sup.3R.sup.2, (C3) R.sup.3X.sup.1SX.sup.41-[D.sup.3X.sup.42].sub.nSX.sup.3R.sup.4 wherein X.sup.1, X.sup.3 are independently selected from a linear or branched C.sub.1-C.sub.12 alkanediyl, which may be unsubstituted or substituted by OH; X.sup.21, X.sup.22 are independently selected from X.sup.1, which may be further substituted by X.sup.5COOR.sup.12, X.sup.5SO.sub.2OR.sup.12, a C.sub.2 to C.sub.6 polyoxyalkylene group of formula (OCH.sub.2CHR.sup.11).sub.zOH, or a combination thereof, and X.sup.1NHCOX.sup.6CONHX.sup.1; X.sup.31, X.sup.32 are independently selected from a chemical bond and X.sup.1; X.sup.41, X.sup.42 are independently selected from X.sup.1; X.sup.5 is a linear or branched Ci to C10 alkyl; X.sup.6 is selected from X.sup.1 and a divalent 5 or 6 membered aromatic group; R.sup.1, R.sup.2 are independently selected from a monovalent 5 or 6 membered aromatic N-heterocyclic group comprising one N atom or two N atoms which are separated by at least one C atom, and its derivatives received by N-alkylation with a C.sub.1-C.sub.6-alkyl group, which may be substituted by COOR.sup.12 or SO.sub.2OR.sup.12, and which aromatic N-heterocyclic group may optionally further comprise, under the proviso that X21 is substituted by at least one OH, one S atom; R.sup.3, R.sup.4 are independently selected from a monovalent 5 or 6 membered aliphatic N-heterocyclic group comprising one N atom and one O atom; D.sup.1 is independently selected from S, O and NR.sup.10; D.sup.2 is (a) a divalent 5 or 6 membered aliphatic heterocyclic ring system comprising 1 or 2 S atoms, or (b) a 5 or 6 membered aromatic heterocyclic ring system comprising at least two N atoms and optionally one or two S atoms; D.sup.3 is independently selected from S and NR.sup.10; n is an integer of from 0 to 5; z is an integer from 1 to 50; R.sup.10 is selected from H and a linear or branched C.sub.1-C.sub.12 alkyl; R.sup.11 is selected from H and a linear or branched C.sub.1 to C.sub.6 alkyl; and R.sup.12 is selected from R10 and a cation.

An aqueous composition comprising (a) metal ions comprising tin ions and silver ions and (b) at least one complexing agent of formula (C1) R.sup.1X.sup.1SX.sup.21[D.sup.1-X.sup.22].sub.nSX.sup.3R.sup.2, (C2) R.sup.1X.sup.1SX.sup.31-D.sup.2-[X.sup.32S].sub.nX.sup.3R.sup.2, (C3) R.sup.3X.sup.1SX.sup.41-[D.sup.3X.sup.42].sub.nSX.sup.3R.sup.4 wherein X.sup.1, X.sup.3 are independently selected from a linear or branched C.sub.1-C.sub.12 alkanediyl, which may be unsubstituted or substituted by OH; X.sup.21, X.sup.22 are independently selected from X.sup.1, which may be further substituted by X.sup.5COOR.sup.12, X.sup.5SO.sub.2OR.sup.12, a C.sub.2 to C.sub.6 polyoxyalkylene group of formula (OCH.sub.2CHR.sup.11).sub.zOH, or a combination thereof, and X.sup.1NHCOX.sup.6CONHX.sup.1; X.sup.31, X.sup.32 are independently selected from a chemical bond and X.sup.1; X.sup.41, X.sup.42 are independently selected from X.sup.1; X.sup.5 is a linear or branched Ci to C10 alkyl; X.sup.6 is selected from X.sup.1 and a divalent 5 or 6 membered aromatic group; R.sup.1, R.sup.2 are independently selected from a monovalent 5 or 6 membered aromatic N-heterocyclic group comprising one N atom or two N atoms which are separated by at least one C atom, and its derivatives received by N-alkylation with a C.sub.1-C.sub.6-alkyl group, which may be substituted by COOR.sup.12 or SO.sub.2OR.sup.12, and which aromatic N-heterocyclic group may optionally further comprise, under the proviso that X21 is substituted by at least one OH, one S atom; R.sup.3, R.sup.4 are independently selected from a monovalent 5 or 6 membered aliphatic N-heterocyclic group comprising one N atom and one O atom; D.sup.1 is independently selected from S, O and NR.sup.10; D.sup.2 is (a) a divalent 5 or 6 membered aliphatic heterocyclic ring system comprising 1 or 2 S atoms, or (b) a 5 or 6 membered aromatic heterocyclic ring system comprising at least two N atoms and optionally one or two S atoms; D.sup.3 is independently selected from S and NR.sup.10; n is an integer of from 0 to 5; z is an integer from 1 to 50; R.sup.10 is selected from H and a linear or branched C.sub.1-C.sub.12 alkyl; R.sup.11 is selected from H and a linear or branched C.sub.1 to C.sub.6 alkyl; and R.sup.12 is selected from R10 and a cation.

A metal material having thermodynamic anisotropy has an X-axis hardness of 160-180 HV, an X-axis hardness thermal expansion coefficient of 510-6-10010-6 K.sup.1; a Y-axis hardness of 160-180 HV, a Y-axis hardness thermal expansion coefficient of 510-6-10010-6 K.sup.1; and a Z-axis hardness of 180-250 HV, a Z-axis hardness thermal expansion coefficient of 5010-6-100010-6 K.sup.1. A method for preparing a metal material having thermodynamic anisotropy is also disclosed.

A method of providing spatial diversity for critical data delivery in a beamformed mmWave small cell is proposed. The proposed spatial diversity scheme offers duplicate or incremental data/signal transmission and reception by using multiple different beams for the same source and destination. The proposed spatial diversity scheme can be combined with other diversity schemes in time, frequency, and code, etc. for the same purpose. In addition, the proposed spatial diversity scheme combines the physical-layer resources associated with the beams with other resources of the same or different protocol layers. By spatial signaling repetition to avoid Radio Link Failure (RLF) and Handover Failure (HOF), mobility robustness can be enhanced. Mission-critical and/or time-critical data delivery can also be achieved without relying on retransmission.

A method of providing spatial diversity for critical data delivery in a beamformed mmWave small cell is proposed. The proposed spatial diversity scheme offers duplicate or incremental data/signal transmission and reception by using multiple different beams for the same source and destination. The proposed spatial diversity scheme can be combined with other diversity schemes in time, frequency, and code, etc. for the same purpose. In addition, the proposed spatial diversity scheme combines the physical-layer resources associated with the beams with other resources of the same or different protocol layers. By spatial signaling repetition to avoid Radio Link Failure (RLF) and Handover Failure (HOF), mobility robustness can be enhanced. Mission-critical and/or time-critical data delivery can also be achieved without relying on retransmission.

The Sn-based alloy plated steel sheet of this disclosure includes: a steel sheet; a composite plating layer formed on at least one side of the steel sheet and including an FeNiSn alloy layer and an island-shaped Sn layer located on the FeNiSn alloy layer; and a coating layer formed on the surface of the composite plating layer and containing zirconium oxide and tin oxide, and the composite plating layer contains a predetermined amount of Ni and a predetermined amount of Sn, a content of the zirconium oxide in the coating layer is from 0.2 mg/m.sup.2 to 50 mg/m.sup.2 in terms of metal Zr amount, and a peak position of binding energy of Sn3d.sub.5/2 according to X-ray photoelectron spectroscopy of the tin oxide in the coating layer is 1.6 eV or higher than a peak position of binding energy of the metal Sn.