Although Li‐oxygen batteries offer extremely high theoretical specific energy, their practical application still faces critical challenges. One of the main obstacles is the high charge overpotential caused by sluggish kinetics of charge transfer that is closely related to the morphology of discharge products and their distribution on the cathode. Here, a series of noble metal nanoparticles (Pd, Pt, Ru and Au) are encapsulated inside end‐opened carbon nanotubes (CNTs) by wet impregnation followed by thermal annealing. The resultant cathode materials exhibit a dramatic reduction of charge overpotentials compared to their counterparts with nanoparticles supported on CNT surface. Notably, the charge overpotential can be as low as 0.3 V when CNT‐encapsulated Pd nanoparticles are used on the cathode. The cathode also shows good stability during discharge–charge cycling. Density functional theory (DFT) calculations reveal that encapsulation of “guest” noble metal nanoparticles in “host” CNTs is able to strengthen the electron density on CNT surfaces, and to avoid the regional enrichment of electron density caused by the direct exposure of nanoparticles on CNT surface. These unique properties ensure the uniform coverage of Li2O2 nanocrystals on CNT surfaces instead of localized distribution of Li2O2 aggregation, thus providing efficient charge transfer for the decomposition of Li2O2.

Using tetrathienoacene (TT) and diketopyrrolopyrrole (DPP) units as donor and acceptor blocks, three new low band gap (LBG) conjugated copolymers (PTTDPO, PTTDPS and PTTDPSe) with different heterocycle bridges (furan, thiophene and selenophene) were designed and synthesized by Stille coupling polymerization reactions. Their structures were verified by 1 HNMR spectroscopy and elemental analysis.All these copolymers exhibit broad absorption bands with small band gaps. UV-vis absorption spectra and cyclic voltammetry (CV) measurements indicated that the selenophene inclusion resulted in a reduction in the band gap, which could be attributed to a reduction of oxidation potentials and an increase of the electron affinities of the related copolymer. The density functional theory (DFT) calculations showed that PTTDPSe with selenophene bridges favoured a much more planar conformation than PTTDPO and PTTDPS, which afforded a higher hole mobility of 7.9 Â 10 À4 cm 2 V À1 s À1 . Photovoltaic properties of the copolymers blended with [6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM) as an electron acceptor were investigated. The polymer solar cell (PSC) based on the structure of ITO/PEDOT:PSS/PTTDPSe:PC 71 BM (1 : 1.5, w/w)/Ca/Al exhibited a high power conversion efficiency (PCE) of 5.68% with an improved short circuit current density (J sc ) of 15.62 mA cm À2 . The primary resultsshow that changing heterocycle bridges with different electron-donating ability can easily and finely tune the optical absorptions, band gaps and energy levels of DPP-containing copolymers. The results also demonstrate that the TT unit is a new and promising electron-donating donor block for constructing highly efficient LBG photovoltaic materials.

Aim  Small mammal species richness and relative abundance vary along elevational gradients, but there are different patterns that exist. This study reports the patterns of distribution and abundance of small mammals along the broader elevational gradient of Mt. Qilian range. Location  The study was conducted in the Mt. Qilian range, north‐western China, from June to August 2001. Methods  Removal trapping was conducted using a standardized technique at 7 sites ranging between 1600 and 3900 m elevation within three transects. Correlation, regression and graphical analyses were used to evaluate the diversity patterns along this elevational gradient. Results   In total, 586 individuals representing 18 nonvolant small mammal species were collected during 20 160 trap nights. Species composition was different among the three transects with 6 (33%) of the species found only within one transect. Elevational distribution and relative abundance of small rodents showed substantial spatial variation, with only 2 species showing nonsignificant capture frequencies across elevations. Despite these variations, some general patterns of elevational distribution emerged: humped‐shape relationships between species diversity and elevation were noted in all three transects with diversity peaks at middle elevations. In addition, relative abundance was negatively correlated with elevation. Conclusions  Results indicate that maximum richness and diversity of nonvolant small mammals occurred at mid‐elevations where several types of plants reached their maximum diversity and primary productivity, and where rainfall and humidity reached a maximum. It is demonstrated that the mid‐elevation bulge is a general feature of at least a large portion of the biota on the Mt. Qilian range.

We studied seasonal movements of golden takin (Budorcas taxicolor bedfordi), a large, social, forest‐dwelling ungulate, by radiotracking and field surveys during 1995–1996 and 2002–2005 at Foping National Nature Reserve on the southern slope of the Qinling Mountains, China. Takins inhabited forests and subalpine meadows at an altitudinal range from 1,360 m to 2,890 m. Our results showed that golden takins had a complicated seasonal movement pattern and underwent altitudinal migration 4 times each year. Takins occupied a high‐altitude range during summer, stayed at low‐altitude ranges for short periods during spring and autumn, and resided at an intermediate‐altitude range during winter. Changes in plant phenology may have caused seasonal movements. Reserves for takin conservation should incorporate lower altitude habitats than those takins use in spring and autumn, and seasonal movements by takins should be protected from disturbance by human activities. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):611–617; 2008)