Partitions for all the indexed tree-ring widths occurring in relatively a) cold and b) warm winter years computed by the FCM clustering.

Partitions for all the indexed tree-ring widths occurring in relatively a) cold and b) warm winter years computed by the FCM clustering.</p

Correlations performed between the regional chronology PC1 and monthly a) mean temperature and b) total precipitation from previous May to current September during the period 1951–2005.

<p>The 95% and 99% significance levels are indicated by dash and bold lines, respectively.</p

Artificial neural network (ANN) simulates tree-ring indices from January average temperature increasing from -11°C to -65°C associated with previous November-December average temperature increasing from -68°C to -4°C during the period 1951–2005.

<p>Artificial neural network (ANN) simulates tree-ring indices from January average temperature increasing from -11°C to -65°C associated with previous November-December average temperature increasing from -68°C to -4°C during the period 1951–2005.</p

Climate-Driven Synchronized Growth of Alpine Trees in the Southeast Tibetan Plateau

<div><p>Knowledge about the spatiotemporal tree growth variability and its associations with climate provides key insights into forest dynamics under future scenarios of climate change. We synthesized 17 tree-ring width chronologies from four tree species at the high-elevation sites in the southeast Tibetan Plateau (SETP) to study the regional tree growth variability and climate-growth relationships. Despite of diverse habitats and different physiological characteristics of these species, these tree-ring chronologies shared a significant common variance in SETP. An unprecedented increase in the shared variance is found along the latter half of the 20th century, coinciding with the enhancement of the frequency of extreme rings among chronologies. It is found that minimum winter temperature tends to be the dominant climate for trees in this region. The site-specific responses in cold (1965–1980) and warm (1990–2005) intervals by means of Fuzzy Cmeans (FCM) clustering reveal that the remarkable enhancement of growth synchrony among trees mainly occur in warm conditions. This is different from previous findings indicating that increased consistence among temperature sensitive tree rings in cold periods. This may be related to the reduced temperature sensitivity of regional tree growth as winter minimum temperature is lower than a certain threshold, which is in agreement with the “principle of ecological amplitude”. In addition, it is worth noting that precipitation in June have started to restrain the tree growth since the beginning of the 1980s, which is possibly an important contributor for synchronized growth among trees in SETP.</p></div

Mode-locked fiber laser with offset splicing between two multimode fibers as a saturable absorber

A novel mode-locked fiber laser based on offset splicing technology between two kinds of graded index multimode fibers is proposed and experimentally demonstrated. The offset splice spot structure acts as a saturable absorber via nonlinear multimodal interference mechanism. The absorption modulation depth of the device is 2.8%, with a saturation intensity of 2.5 MW/cm2. The fiber laser operates at a stable mode-locked state when the pump power reaches 114 mW. The laser oscillates at 1039 nm with a pulsewidth of 17.6 ps, a repetition rate of 32.619 MHz, and a high signal noise ratio of 65 dB. The fiber laser is superior in terms of low cost, high damage threshold, and easy fabrication, thus providing many potential applications in ultrafast photonics and industrial processing

Descriptions of the geographic features and characteristics of the 17 tree-ring chronologies across SETP.

<p>Descriptions of the geographic features and characteristics of the 17 tree-ring chronologies across SETP.</p

Temporal changes of the growth-climate relationships as shown by moving correlations between tree growth and a) November-January average temperature and b) June precipitation totals using a sliding window of 30 years assigned to the center year of the window.

<p>The shaded areas are the 95% confidence limits.</p

The instrumental record (black line) and EEMD-based nonlinear trend (red line) of a) November-January temperature, b) June temperature, c) June precipitation and d) March-May temperature over SETP during the period from 1951–2005.

<p>The instrumental record (black line) and EEMD-based nonlinear trend (red line) of a) November-January temperature, b) June temperature, c) June precipitation and d) March-May temperature over SETP during the period from 1951–2005.</p

Map showing the sites of selected tree-ring chronologies, gridded climate records and major cities over SETP <i>Picea likiangensis (Franchet) Pritzel</i> chronologies are represented by green stars, <i>Abies forestii Rogers</i> chronologies by blue squares, <i>Juniperus tibetica Kom</i> chronologies by purple circles and <i>Tsuga dumosa Eichler</i> chronologies by red triangles.

<p>Map showing the sites of selected tree-ring chronologies, gridded climate records and major cities over SETP <i>Picea likiangensis (Franchet) Pritzel</i> chronologies are represented by green stars, <i>Abies forestii Rogers</i> chronologies by blue squares, <i>Juniperus tibetica Kom</i> chronologies by purple circles and <i>Tsuga dumosa Eichler</i> chronologies by red triangles.</p

Vertical Organic Field-Effect Transistors for Integrated Optoelectronic Applications

Direct integration of a vertical organic field-effect transistor (VOFET) and an optoelectronic device offers a single stacked, low power optoelectronic VOFET with high aperture ratios. However, a functional optoelectronic VOFET could not be realized because of the difficulty in fabricating transparent source and gate electrodes. Here, we report a VOFET with an on/off ratio up to 10⁵ as well as output current saturation by fabricating a transparent gate capacitor consisting of a perforated indium tin oxide (ITO) source electrode, HfO₂ gate dielectric, and ITO gate electrode. Effects of the pore size and the pore depth within the porous ITO electrodes on the on/off characteristic of a VOFET are systematically explained in this work. By combining a phosphorescent organic light-emitting diode with an optimized VOFET structure, a vertical organic light-emitting transistor with a luminance on/off ratio of 10⁴ can be fabricated