New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e mu A of Xe-129(43+), 22 e mu A of Bi-209(41+), and 1.5 e mu A of Bi-209(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e mu A of Xe-129(27+) and 152 e mu A of Xe-129(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and Xe-129(27+), Kr-78(19+), Bi-209(31+), and Ni-58(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production. Finally the future development of SECRAL will be presented.

The Development of a Marine Natural Product-based Antifouling Paint

Problems with tin and copper antifouling compounds have highlighted the need to develop new environmentally friendly antifouling coatings. Bacteria isolated from living surfaces in the marine environment are a promising source of natural antifouling compounds. Four isolates were used to produce extracts that were formulated into ten waterbased paints. All but one of the paints showed activity against a test panel of fouling bacteria. Five of the paints were further tested for their ability to inhibit the settlement of barnacle larvae, Balanus amphitrite, and algal spores of Ulva lactuca, and for their ability to inhibit the growth of U. lactuca. Two paints caused a significant decrease in the number of settled barnacles. One paint containing extract of Pseudomonas sp. strain NUDMB50-11, showed excellent activity in all assays. The antifouling chemicals responsible for the activity of the extract were isolated, using bioassay guided fractionation, and their chemical structures determined.

New development of organolanthanide complexes containing chalcogenide ligands

This article is to present and outline new approaches to chalcogen coordination chemistry from the organolanthanides point of view.

Development of an efficient particle approach for micro-scale gas flow simulations

The micro-scale gas flows are usually low-speed flows and exhibit rarefied gas effects. It is challenging to simulate these flows because traditional CFD method is unable to capture the rarefied gas effects and the direct simulation Monte Carlo (DSMC) method is very inefficient for low-speed flows. In this study we combine two techniques to improve the efficiency of the DSMC method. The information preservation technique is used to reduce the statistical noise and the cell-size relaxed technique is employed to increase the effective cell size. The new cell-size relaxed IP method is found capable of simulating micro-scale gas flows as shown by the 2D lid-driven cavity flows.

Enhanced expression of antifreeze protein genes drives the development of freeze tolerance in an Antarctica isolate of Chlorella vulgaris

In adaptation to new environments, organisms may accumulate mutations within encoding sequences to modify protein characteristics or acquire mutations within regulatory sequences to alter gene expression levels. With the development of antifreeze capability as the example, this study presents the evidence that change in gene expression level is probably the most important mechanism for adaptive evolution in a green alga Chlorella vulgaris. C. vulgaris NJ-7, an isolate from Antarctica, possesses an 18S rRNA sequence identical to that of a temperate isolate, SAG211-11b/UTEX259, but shows much higher freeze tolerance than the later isolate. The chromosomal DNA/cDNA of four antifreeze genes, namely hiC6, hiC12, rpl10a and hsp70, from the two isolates of C. vulgaris were cloned and sequenced, and very few variations of deduced amino acid sequences were found. In contrast, the transcription of hiC6, hiC12 and rpl10a was greatly intensified in NJ-7 compared to that in UTEX259, which is correlated to the significantly enhanced freeze tolerance of the Antarctica isolate. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

Development of novel EST-SSR markers in common carp by data mining from public EST sequences

Expressed sequence tags (ESTs) are a source for microsatellite development. In the present study, EST-derived microsatelltes (EST-SSRs) were generated and characterized in the common carp (Cyprinus carpio) by data mining from updated public EST databases and by subsequent testing for polymorphism. About 5.5% (555) of 10,088 ESTs contain repeat motifs of various types and lengths with CA being the most abundant dinucleotide one. Out of the 60 EST-SSRs for which PCR primers were designed, 25 loci showed polymorphism in a common carp population with the alleles per locus ranging from 3 to 17 (mean 7). The observed (H-O) and expected (HE) heterozygosities of these EST-SSRs were 0.13-1.00 and 0.12-0.91, respectively. Six EST-SSR loci significantly deviated from the Hardy-Weinberg equilibrium (HWE) expectation, and the remaining 19 loci were in HWE. Of the 60 primer sets, the rates of polymorphic EST-SSRs were 42% in common carp, 17% in crucian carp (Carassius auratus), and 5% in silver carp (Hypophthalmichthys molitrix), respectively. These new EST-SSR markers would provide sufficient polymorphism for population genetic studies and genome mapping of the common carp and its closely related fishes. (c) 2007 Published by Elsevier B.V.

Development of a rapid, sensitive and specific diagnostic assay for fish Aquareovirus based on RT-PCR

A rapid, sensitive and highly specific detection method for Aquareovirus based on reverse-transcription polymerase chain reaction (RT-PCR) was developed. Based on multiple sequence alignment of the cloned sequences of a local isolates, the Threadfin reovirus (TFV) and Guppy reovirus (GPV) with Grass carp reovirus (GCRV), a pair of degenerate primers was selected carefully and synthesized. Using this primer combination, only one specific product, approximately 450 bp in length was obtained when RT-PCR was carried out using the genomic double-stranded RNA (dsRNA) of TFV, GPV and GCRV. Similar results were also obtained when Chum salmon reovirus (CSRV) and Striped bass reovirus (SBRV) dsRNA were used as templates. No products were observed when nucleic acids other than the dsRNA of the aquareoviruses described above were used as RT-PCR templates. This technique could detect not only TFV but also GPV and GCRV in low titer virus-infected cell cultured cells. Furthermore, this method has also been shown to be able to diagnose GPV-infected guppy (Poecilia reticulata) that exhibit clinical symptoms as well as GPV-carrier guppy. Collectively, these results showed that the RT-PCR amplification method using specific degenerate primers described below is very useful for rapid and accurate detection of a variety of aquareovirus strains isolated from different host species and origin. (C) 2004 Elsevier B.V. All rights reserved.