We propose to build a large water-Cherenkov-type muon-detector array (Tibet MD array) around the 37,000 m 2 Tibet air shower array (Tibet AS array) already constructed at 4,300 m above sea level in Tibet, China. Each muon detector is a waterproof concrete pool, 6 m wide × 6 m long × 1.5 m deep in size, equipped with a 20 inch-in-diameter PMT. The Tibet MD array consists of 240 muon detectors set up 2.5 m underground. Its total effective area will be 8,640 m 2 for muon detection. The Tibet MD array will significantly improve gamma-ray sensitivity of the Tibet AS array in the 100 TeV region (10-1000 TeV) by means of gamma/hadron separation based on counting the number of muons accompanying an air shower. The Tibet AS+MD array will have the sensitivity to gamma rays in the 100 TeV region by an order of magnitude better than any other previous existing detectors in the world. Keywords Gamma ray · Cosmic ray · Muon · SNR PACS 95.55.Ka · 98.70.Sa · 95.85.Ry

Petroporphyrins were enriched and purified from atmospheric residues of two typical heavy oils, Canadian oil sand bitumen (OSAR, Ni: 80 ppm, V: 190 ppm, S: 3.97 wt%) and Chinese Liaohe heavy oil (LHAR, Ni: 68.7 ppm, V: 1.81 ppm, S: 0.36 wt%) by silica gel chromatography. The separation and purification were confirmed by atomic absorption spectroscopy (AAS) combined with UV-vis spectroscopy, and the petroporphyrins were characterized by positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Vanadyl and nickel porphyrins in OSAR are simultaneously identified by mass measurement and isotopic fine structure. Vanadyl porphyrins with structures of N 4 VO, N 4 VO 2 and N 4 VOS are all detected as protonated analyte ([M+H] + ). Both molecular ion (M +• ) and analyte ([M+H] + ) as well as their corresponding isotopes are observed for N 4 Ni porphyrins in OSAR and LHAR with an average mass resolving power of over 400 000 (m/∆m 50% ). This is rarely detected by FT-ICR MS using ESI technique previously. Formation of molecular ion can be attributed to the low oxidation potential of nickel porphyrins, effect of oil matrix on the solution conductivity and the relatively low flow rate of solution into the capillary. Three more highly unsaturated types of N 4 VO porphyrins were identified in addition to the six well-documented structures. Compared to N 4 VO porphyrins, N 4 VOS porphyrins present higher DBE ranging from 21 to 27 while N 4 VO 2 porphyrins show lower DBE ranging from 18 to 20 and narrower carbon number distribution, suggesting possible different origins of sulfur (pyrolysis of kerogen) and oxygen (diagenesis of chlorophyills). Ni/V and ratio of relative abundance of ETIO porphyrins to DPEP porphyrins (∑ETIO/∑DPEP) for nickel porphyrins indicate that Liaohe oil and Canadian oil sand bitumen are continental and marine sediment, respectively, and Liaohe oil has a higher maturity.Enrichment by the simple chromatographic method facilitates the mass spectral identification of nickel porphyrins even for heavy residue with low content of nickel and high content of sulfur.

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In the search for new marine derived antibiotics, 43 epi- and endophytic fungal strains were isolated from the surface or the inner tissue of different marine plants and invertebrates. Through preliminary and secondary screening, 10 of them were found to be able to produce broad-spectrum antimicrobial metabolites. By morphological and molecular biological methods, three active strains were characterized to be Penicillium glabrum, Fusarium oxysporum, and Alternaria alternata.

Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads (2.3 Gb) of P. cuspidatum root transcriptome were obtained via Illumina HiSeq 2000 sequencing. A total of 86418 unigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid (MVA), methyl-D-erythritol 4-phosphate (MEP), shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthraquinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.