Breathing Europium–Terbium Co-doped Luminescent MOF as a Broad-Range Ratiometric Thermometer with a Contrasting Temperature–Intensity Relationship

Solvothermal reactions of lanthanide salts and a semirigid tripodal H₃tatab (4,4′,4″-<i>s</i>-triazine-1,3,5-triyltri-<i>p</i>-aminobenzoic acid) ligand in mixed water and <i>N</i>-methyl pyrrolidone (NMP) generated novel breathing MOFs [Ln­(tatab)]·solvent (Ln = Eu in <b>1</b>-Eu, Tb in <b>1</b>-Tb, Eu_0.015Tb_0.985 in <b>1</b>-Eu_0.015Tb_0.985). The framework of <b>1</b> was contracted upon removal of guests to form partly desolvated [Ln (tatab)]·3.7H₂O·2.5NMP (<b>1′</b>). Single-crystal X-ray analyses demonstrated that <b>1</b> has the breathing ability to spontaneously release guests and maintain the same topology. In contrast to as-synthesized <b>1</b>, the cell volume of <b>1′</b> decreased markedly upon removal of the guests. Different from linear dicarboxylates, the semirigid tripodal tatab ligand is bridged to an inorganic Ln–O chain, limiting the rotation around the O–O-axis of carboxylate. The breathing mechanism is based on the flexible C–N–C angles of amide bonds in the tatab ligand, causing a change in the solvent-accessible volume in the framework. Interestingly, the luminescence color of breathing co-doped lanthanide MOF <b>1′</b>-Eu_0.015Tb_0.985 is blue-shifted and turned from orange to green with an increase in temperature, which can be attributed to a change in the relative intensity of Tb and Eu emissions, and is quite different from that observed for the reported related compounds. The breathing co-doped lanthanide MOF <b>1′</b>-Eu_0.015Tb_0.985 can be applied as a high-sensitivity ratiometric thermometer in a broad temperature from 90 to 300 K

Breathing Europium–Terbium Co-doped Luminescent MOF as a Broad-Range Ratiometric Thermometer with a Contrasting Temperature–Intensity Relationship

Solvothermal reactions of lanthanide salts and a semirigid tripodal H₃tatab (4,4′,4″-<i>s</i>-triazine-1,3,5-triyltri-<i>p</i>-aminobenzoic acid) ligand in mixed water and <i>N</i>-methyl pyrrolidone (NMP) generated novel breathing MOFs [Ln­(tatab)]·solvent (Ln = Eu in <b>1</b>-Eu, Tb in <b>1</b>-Tb, Eu_0.015Tb_0.985 in <b>1</b>-Eu_0.015Tb_0.985). The framework of <b>1</b> was contracted upon removal of guests to form partly desolvated [Ln (tatab)]·3.7H₂O·2.5NMP (<b>1′</b>). Single-crystal X-ray analyses demonstrated that <b>1</b> has the breathing ability to spontaneously release guests and maintain the same topology. In contrast to as-synthesized <b>1</b>, the cell volume of <b>1′</b> decreased markedly upon removal of the guests. Different from linear dicarboxylates, the semirigid tripodal tatab ligand is bridged to an inorganic Ln–O chain, limiting the rotation around the O–O-axis of carboxylate. The breathing mechanism is based on the flexible C–N–C angles of amide bonds in the tatab ligand, causing a change in the solvent-accessible volume in the framework. Interestingly, the luminescence color of breathing co-doped lanthanide MOF <b>1′</b>-Eu_0.015Tb_0.985 is blue-shifted and turned from orange to green with an increase in temperature, which can be attributed to a change in the relative intensity of Tb and Eu emissions, and is quite different from that observed for the reported related compounds. The breathing co-doped lanthanide MOF <b>1′</b>-Eu_0.015Tb_0.985 can be applied as a high-sensitivity ratiometric thermometer in a broad temperature from 90 to 300 K

Design of a curved surface constant force mechanism

<p>A new curved surface constant force mechanism which mainly consists of a roller and a curved surface has been proposed. The magnitude and the direction of normal force caused by squeezing between the roller and the curved surface satisfy a certain relationship, thus the decomposed force of the normal force keeps constant in a certain direction all the times. According to the envelope theorem, the trajectory of the roller center and the profile of the curved surface are obtained by ignoring friction. Then, the influence of the friction is discussed in detail. In addition, the simulation is performed to verify the theoretical calculation. The simulation results show that the output force is relatively constant and the friction has little effect on the output force.</p

Index Files

Index File

Appendix E. A table showing results of repeated measures analyses of variance (RMANOVAs) on woody stem density, species richness, and species turnover.

A table showing results of repeated measures analyses of variance (RMANOVAs) on woody stem density, species richness, and species turnover

Appendix C. A table showing results of repeated measures ANOVAs on life history group cover data.

A table showing results of repeated measures ANOVAs on life history group cover data

Cloning and analysis of reverse transcriptases from Ty1-<i>copia</i> retrotransposons in <i>Camellia sinensis</i>

<p>As mobile genetic elements, the diversity and activity of the Tyl-<i>copia</i> retrotransposons are key contributors to genome organisation and evolution, which have been investigated in many plants but little in the tea plant, <i>Camellia sinensis</i>. We selected a total of 12 varieties of tea plant distributed across a large geographical area and sequenced the reverse transcriptase (RT) sequences of Ty1-<i>copia</i> retrotransposons using degenerate primers. The sequences that were widespread among tea varieties, were approximately 260 bp in length and exhibited high heterogeneity among tea plants. The RT sequences from tea plants were similar to other known Ty1-<i>copia</i> retrotransposon RT sequences. Phylogenetic analysis showed that tea RT sequences were closely related to those from woody plants, such as pear, poplar and apple. In contrast, they were more distantly related to RT sequences from herbaceous plants, such as tomato and rice. Activity assay revealed that Ty1-<i>copia</i> retrotransposons are transcriptionally active during the normal development of tea plants. These results will support further research on Ty1-<i>copia</i> retrotransposons in <i>C. sinensis.</i></p

Appendix D. A figure showing scores of the first detrended correspondence axis (DC1) vs. year, derived from a detrended correspondence analysis of the yearly mean relative cover values.

A figure showing scores of the first detrended correspondence axis (DC1) vs. year, derived from a detrended correspondence analysis of the yearly mean relative cover values

Appendix F. A table showing -diversity for quadrat pairs within large and small patches in 1985, 1989, 1995, and 2000.

A table showing -diversity for quadrat pairs within large and small patches in 1985, 1989, 1995, and 2000

Appendix B. A table showing dominant plant species, by average percent cover per 1-m2 quadrat, for each of four intervals between 1984 and 2001.

A table showing dominant plant species, by average percent cover per 1-m2 quadrat, for each of four intervals between 1984 and 2001