X-ray diffraction traces for the density fractions from each soil.

<p>A. 5 year old forest; b. 12 year old forest; c. 25 year old forest. Al: albite; Am: amphibole; Cl: clinochlore; Mi: microcline; Mu: muscovite; Q: quartz. For a specific density fraction, soil samples from the Crop lands showed the same X-ray diffraction traces with that of adjacent forest soil. Therefore, only the results for forest soils were presented.</p

Forest C input (a) and decay rate (b) of old C (mean ± standard error) for bulk soil and density fractions of 5, 12 and 25 years forest.

<p>Forest C input (a) and decay rate (b) of old C (mean ± standard error) for bulk soil and density fractions of 5, 12 and 25 years forest.</p

Distribution of mass, SOC and N across the density fractions from the crop and forest land (F5, 5 yr forest; C5, F5 adjacent crop soil; F12, 12 yr forest; C12, F12 adjacent crop soil; F25, 25 yr forest; C25, F25 adjacent crop soil.

<p>Error bars are standard error of the means; ns: P > 0.05. The density axis in this graph reflects the midpoint of each density range except for the two extremes which are plotted as the lowest and highest minus or plus 0.1 g cm^-3.</p

δ¹³C for the 5 density fractions from 5, 12 and 25 yr forest and adjacent crop sites.

<p>Error bars are standard error of the means. The δ¹³C data for arable crop litter and forest litter were-12.8‰ and-29.0‰, respectively.</p

SOC concentration for the 5 density fractions from 5, 12 and 25 yr forest and the adjacent crop soil.

<p>Error bars are standard error of the means; Within a group, different letters indicate a significant difference between land uses (P < 0.05).</p

Sample code, depth, land use, specific location and soil type.

<p>Sample code, depth, land use, specific location and soil type.</p

Characteristics of bulk soils.

<p>^a,: mean of five sites ± standard error.</p><p>*: the difference between forest soil and adjacent crop soil was significant at P < 0.05.</p><p>**: the difference between forest soil and adjacent crop soil was significant at P < 0.01.</p><p>Characteristics of bulk soils.</p

Total N concentration for the 5 density fractions from 5, 12 and 25 yr forest and its adjacent crop soil.

<p>Error bars are standard error of the means. Within a group, different letters indicate a significant difference between land uses (P < 0.05).</p

Forest site and adjacent cropland site locations (Jilin province, China).

<p>Forest site and adjacent cropland site locations (Jilin province, China).</p

CuBr-Promoted Formal Hydroacylation of 1‑Alkynes with Glyoxal Derivatives: An Unexpected Synthesis of 1,2-Dicarbonyl-3-enes

An efficient and concise protocol has been developed for the highly regio- and stereoselective synthesis of <i>E</i>-1,2-dicarbonyl-3-ene derivatives by a copper-promoted reaction of 1-alkynes with α-carbonyl aldehydes in the presence of morpholine. The products obtained are believed as the formal hydroacylation of the triple bond