The Ni/ZnO composites show two wide attractive absorption bands, which could broaden the effective absorption bandwidth.

Most intensive human activities occur in lowlands. However, sporadic reports indicate that human activities are expanding in some Asian highlands. Here we investigate the expansions of human activities in highlands and their effects over Asia from 2000 to 2020 by combining earth observation data and socioeconomic data. We find that ∼23% of human activity expansions occur in Asian highlands and ∼76% of these expansions in highlands comes from ecological lands, reaching 95% in Southeast Asia. The expansions of human activities in highlands intensify habitat fragmentation and result in large ecological costs in low and lower-middle income countries, and they also support Asian developments. We estimate that cultivated land net growth in the Asian highlands contributed approximately 54% in preventing the net loss of the total cultivated land. Moreover, the growth of highland artificial surfaces may provide living and working spaces for ∼40 million people. Our findings suggest that highland developments hold dual effects and provide new insight for regional sustainable developments.

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The mass spectrometric behaviour of eight ω-hydroxyalkyltriphenylphosphonium bromides was studied with the aid of mass-analysed ion kinetic energy spectrometry and high resolution data under fast-atom bombardment ionization. The fragmentation mechanism of a series of fragment ions at m/z 275, 289, 303, . Most insect sex pheromones consist of straight chain C 12 -C 16 alcohols, aldehydes, or acetates, with one or more double bonds.1 One important way to synthesize these pheromones is by the Wittig reaction.2 Recently, we aimed to synthesize ten conjugated tetradecadienyl alcohols and their acetates, having different double bond positions, so as to analyse the similarity of their mass spectra and hence distinguish double-bond positional isomers using fuzzy logic methods.3,4 Eight ω-hydroxyalkyltriphenylphosphonium bromides Ph 3 P + -(CH 2 ) n -OHBr -(n = 2-6, 8-10) were prepared. These are the intermediates which can react with aldehydes and generate the target products in which the double-bond locations are fixed. We carried out detailed research on the fragmentation mechanism of these eight compounds, using mass-analysed ion kinetic energy (MIKE) spectrometry, and found characteristic fragment ions. The mass spectra of these compounds are not reported in the literature. This paper is mainly concerned with the fragmentation mechanism of ions in the mass spectra of these compounds. MIKE spectrometry and high-resolution data provide necessary experimental evidence for the fragmentation mechanisms. EXPERIMENTALThe phosphonium salts, Ph 3 P + -(CH 2 ) n -OHBr -(n = 2-6, 8-10, Table 1) were synthesized by the reaction of ω-bromoalkanols with triphenylphosphine 5 in our laboratory. Each of the eight compounds is a white powder. Their structures have been proved by elemental analysis, mass spectrometry, IR and NMR. The fast-atom bombardment (FAB) mass spectra were obtained using a double-focusing mass spectrometer (ZAB-HS, Micromass, Manchester, UK) coupled with an 11-250 data system. FAB was used with glycerol or 1-thioglycerol as a matrix. The bombarding energy of the beam of primary argon atoms was 8 kV with a gun current of 1 mA. High-resolution data for some of the ions were obtained using a Bruker (Zurich, Switzerland) APEX 47e Fourier transform ion cyclotron resonance mass spectrometer, equipped with an external liquid secondary ion mass spectrometry (LSIMS) ion source.In order to record MIKE spectra, ions of interest (e.g. m/z 391, 373, 359, 345, 331 and 317 for compound 6) were located by scanning the magnetic field. Unimolecular decomposition of a selected precursor ion, in the second free-field region, produces fragment ions which can be registered by scanning the electrostatic analyser potential from 8000 V to 2000 V. Complete MIKE spectra were recorded with the help of an 11-250 data system. RESULTS AND DISCUSSIONCompound 6 is now taken as an example to describe *Correspondence to: M. He, Department of Chemistry, Peking University, Beijing 100871, P.R. China Table 1). a. Intensity of m/z 800-900 is enlarge...

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