We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in ${\mathrm{La}}_{1.675}{\mathrm{Eu}}_{0.2}{\mathrm{Sr}}_{0.125}{\mathrm{CuO}}_4$. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as $T^{-2}$ towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (${\mathrm{La}}_{1.875}{\mathrm{Ba}}_{0.125}{\mathrm{CuO}}_4$, ${\mathrm{La}}_{1.475}{\mathrm{Nd}}_{0.4}{\mathrm{Sr}}_{0.125}{\mathrm{CuO}}_4$, and ${\mathrm{La}}_{1.875}{\mathrm{Sr}}_{0.125}{\mathrm{CuO}}_4$) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in ${\mathrm{La}}_{1.675}{\mathrm{Eu}}_{0.2}{\mathrm{Sr}}_{0.125}{\mathrm{CuO}}_4$ extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

ディスク固相抽出とハンドヘルド蛍光X線分析を組み合わせて飲料水中のMn，Fe，Cu，Zn，Cd，Hg，Pbを試料採取現場で定量する方法を開発した．酢酸緩衝溶液でpH 5に調整した試料水50 mLを直径13 mmのイミノ二酢酸キレートディスクに通液し，水中の重金属を濃縮した．ディスクの両面をセロハンテープでコーティングし，100℃ で60 s加熱乾燥した．これをハンドヘルド蛍光X線分析に供すことで水中の重金属を定量した．Cdを定量する際はディスクの下にW板を敷き，散乱線を抑制した．各重金属の検出限界はMn: 6.6 μg L⁻¹，Fe: 9.4 μg L⁻¹，Cu: 4.0 μg L⁻¹，Zn: 3.6 μg L⁻¹，Cd: 7.6 μg L⁻¹，Hg: 4.4 μg L⁻¹，Pb: 3.2 μg L⁻¹であった．ミネラルウォーターと井戸水で添加回収試験を行ったところ，各元素の回収率は89.0～110％ であった．この方法は環境や人体に影響を与える試薬や電源を用いないことから，水中重金属のオンサイトスクリーニングに使用することができる．