An exotic invasive pest of pines, the red turpentine beetle, Dendroctonus valens LeConte (Scolytidae) (RTB), was first detected in Shanxi Province, northern China, in 1998 and started causing widespread tree mortality there in 1999. This outbreak continues and has spread to three adjacent provinces, causing unprecedented tree mortality. Although it is considered a minor pest of pines in North America, RTB has proven to be an aggressive and destructive pest of Pinus tabuliformis, China's most widely planted pine species. The bionomics and occurrence, distribution, response to host volatiles, and host preference of this pine beetle in China are compared with what is known of the beetle in its native range in North America. Factors likely contributing to D. valens success in China and control of the beetle outbreak are discussed. (À)-b-pinene was shown to be the most attractive host volatile for D. valens from the Sierra Nevada of California, whereas 3-(+)-carene is the most attractive host volatile for beetles in China. Monocultures of Pinus tabuliformis, several consecutive years of drought conditions and warm winters have apparently factored D. valens invasion and establishment in China.

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The "Sharpless-type click chemistry" 1 has attracted considerable attention during the past decade 2 since it provides an easy way to obtain complex macromolecular architectures such as linear, 3 star, 4,5 cyclic, 6 graft polymers, 7 and copolymers as dendrimers. 8-10 However, the polymers with azide group used in "Sharpless-type click chemistry" are difficult to be preserved due to their photosensitivity and thermal instability, which means special care should be taken. Another type of click chemistry, the Diels-Alder reaction 11 (DA) [4 + 2] system, provides a coupling strategy using a diene and dienophile by intra-or intermolecular reaction. This shows great potential based on the macromolecular chemistry particularly providing new materials. [12][13][14][15][16] However, the maleimide or anthracene end-functionalized polymers generally require multistep synthesis and purification. Monteiro 17 also reports a radical coupling method to make highmolecular-weight multiblock copolymers from a difunctional PS, by an outer-sphere electron transfer mechanism. Recently, our group found macroradicals, generated in the presence of metal catalyst and conjugates, could be instantly captured by the 2,2,6, 6-tetramethylpiperidinyl-1-oxy (TEMPO) group in another polymer chain by formation of alkoxyamine linkage with high effiency. 18,19 This kind of reaction is named as "atom transfer nitroxide radical coupling" (ATNRC) reaction.Generally, CuBr and N,N,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDETA) were used as the catalyst to generate macroradicals in ATNRC under a relatively high temperature, which could cause side reactions such as cross-link and chain transfer. Some polymers obtained from active monomers, such as methacrylic esters, cannot be conducted in ATNRC due to the significant β-hydrogen transfer from the macroradicals. 20,21 To overcome these disadvantages, the condition of ATNRC should be optimized. Percec 22 reported that an ultrafast synthesis of ultrahigh-molecular-weight polymers from various functional monomers prepared by single-electron-transfer living radical polymerization (SET-LRP) at ambient temperature and Cu 0 was used to substitute the Cu I to generate the radicals, which provides us a new strategy to generate macroradicals in our ATNRC system.In this paper, the reaction conditions for SET are applied in the nitroxide radical coupling reaction and the macroradicals generated by SET mechanism at ambient temperature are trapped by nitroxide radicals, named as single-electron-transfer nitroxideradical-coupling (SET-NRC) reaction (Scheme 1). A living macroradical (P n • ) is generated from P n -X 23 (halogen-containing polymers) by SET mechanism by the oxidation of Cu 0 to Cu I , which is efficiently trapped by TEMPO-P m (TEMPO-containing

In this article, ZnO nanorods (NRs) were grafted on Ti-based vertically aligned TiO 2 nanotubes (NTs) by a feasible seed-induced hydrothermal reaction. Through such a simple but interesting structure combination of the two semiconductors, a novel composite photocatalytic anode of ZnO NRs/TiO 2 NTs with high efficiency was accordingly obtained. In this coupling, ZnO NRs could grow to flowerlike clusters directly grafted on the tops of TiO 2 NTs, acting just like a large number of lead wires, outstretched from the trunk TiO 2 NTs. Thus, the grafted ZnO NRs could serve conveniently as favorable hole channels and receptors for the efficient separation of photoelectrons and holes, which resulted in a slight shift of the band gap absorption edges and consequently changed the band gap energy (Eg). Moreover, the graft amount would further make a certain impact on the Eg. With an appropriate graft amount, ZnO NRs/TiO 2 NTs exhibited broader optical absorption range and higher photocatalytic activity than pure TiO 2 NTs or ZnO NRs did. Under the illumination of 365 nm UV light, the photoelectric conversion efficiency was enhanced from 7.0% of pure TiO 2 NTs to 23.6% of ZnO NRs/TiO 2 NTs. In the photoelectrocatalytic oxidation application, ZnO NRs/TiO 2 NTs exhibited higher removal ability for bisphenol A (BPA). The kinetic constant was 21.4 × 10 -5 s -1 , almost 2.3 times faster than that on pure TiO 2 NTs. Also, the stability of ZnO NRs was promoted on TiO 2 NTs with a stable BPA cyclic removal percentage because the receipted holes on ZnO NRs could prevent ZnO from photocorrosion efficiently.