During 1961–2012, the regional average annual potential evapotranspiration (PET) of Southwest China (SWC) and the four subregions (named as SR1, SR2, SR3, and SR4) showed different decreases (excluding SR3); while the breakpoint analysis suggested that PET changes (i.e., sign and magnitude) have shifted. Based on a group of sensitivity experiments with Penman‐Monteith equation and a new separating method, the contributions of each climate factor alone (i.e., net radiation, Rn; mean temperature, Tave; wind speed, Wnd; and vapor pressure deficit, Vpd) to PET changes were calculated. Results showed that declined Wnd in SR1, reduced Rn in SR2, SR4, and SWC, and increased Vpd in SR3 were responsible for the PET changes during 1961–2012. However, the determinant factor for each subregion and SWC varied in different segmented periods, which were identified using the breakpoint analysis. The impacts of PET shifts on SWC dryness/wetness (reflected by the 3 month Standardized Precipitation‐Evapotranspiration index, SPEI‐3) during 1961–2012 were then quantified. Briefly, SPEI‐3 changes in SR3, SR4, and SWC had the determinant factor of PET in the first one or two period(s), and precipitation in the last period; while they were attributed to PET (precipitation) in SR1 (SR2) for each segmented period. It is found that PET and precipitation had comparable contributions to the variations in SWC dryness/wetness. Our findings have suggested that more attentions should be paid to the impacts of PET changes and shifts in future studies of dryness/wetness or drought.

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It has been demonstrated for the first time that α-phosphonovinyl tosylates could efficiently couple with a range of arylboronic acids to access α-arylethenylphosphonates. The unprecedented procedure exhibits excellent functional group tolerance, giving the terminal vinylphosphonates in good to excellent isolated yields (60-99%) under mild reaction conditions.

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Throughout the 50–1050 cm−1 range, in addition to the first order Raman peak of optical phonon, a weak structure in the vicinity of 147 cm−1 and two intense peaks (bands) in the vicinities of 632 and 956 cm−1 have been observed. The structure at 147 cm−1 is believed to be mainly due to scattering by the transverse acoustic single phonon mode; the intense peak at 632 cm−1 is thought to be mainly due to the transverse acoustic and optical combination phonon modes and the intense peak at 956 cm−1 to the transverse optical overtone double phonon mode of the p− type porous silicon (PS) layer. A comparison of spectral features indicates that, in PS Raman spectra, there is no substantial contribution due to the a-Si component and for PS the crystalline characteristic still remains to a great extent. Contrary to what would be expected using the conventional and simplified microcrystal model, Raman frequency downshifts of the aforementioned structures near 632 and 956 cm−1 were clearly observed, which indicates that, unlike the case of the first order Raman spectrum of optical phonon, the microcrystal model is too simple to give an interpretation of PS second order Raman spectra.

Aerosol mass spectrometry was used to characterize submicron aerosols before and after aging in a Gothenburg Potential Aerosol Mass (Go:PAM) reactor at two suburban sites in China, one in northern China at Changping (CP), Beijing, and a second in southern China at Hong Kong (HK). Organic aerosol (OA) dominated in the ambient nonrefractory particulate matter <1 μm (NR‐PM1) for both CP (42–71%) and HK (43–61%), with a large contribution from secondary OA factors that were semivolatile oxygenated (SVOOA) and low‐volatility oxygenated (LVOOA). Under constant OH exposure, OA enhancement (78–98%) dominated the NR‐PM1 mass increment at both sites, while nitrate was enhanced the most among the inorganic species (7–9%). Overall, the CP site exhibited higher OA oxidation potential and more enhancement of SVOOA than LVOOA (7.5 vs. 2.7 μg/m3), but the reverse was observed in HK (0.8 vs. 2.6 μg/m3). In CP, more enhancement of the less oxygenated SVOOA suggests that aerosol aging was more sensitive to the abundant locally emitted primary OA and volatile organic compound precursors. On the contrary, the more formation of the highly oxidized LVOOA in HK indicates that aerosol aging mainly escalated the degree of oxygenation of OA as ambient aerosol was already quite aged and there was a lack of volatile organic compound precursors. The comparative measurements using the same oxidation system reveal distinct key factors and mechanisms that influence secondary aerosol formation in two suburban locations in China, providing scientific insights to assist formulation of location‐specific mitigation measures of secondary pollution.

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