Water use efficiency of China\u27s terrestrial ecosystems and responses to drought

Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China’s terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg−1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. “Turning-points” were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity

N-(1-Acetyl-5-benzoyl-1,4,5,6-tetra­hydro­pyrrolo­[3,4-c]pyrazol-3-yl)benzamide

In the mol­ecule of the title compound, C21H18N4O3, the fused pyrrolo­[3,4-c]pyrazole ring system is approximately planar [maximum deviation = 0.0486 (16) Å] and forms dihedral angles of 87.21 (8) and 35.46 (7)° with the phenyl rings. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds and weak C—H⋯π inter­actions link the mol­ecules into chains parallel to [201]

Reinforcement Learning Ramp Metering without Complete Information

This paper develops a model of reinforcement learning ramp metering (RLRM) without complete information, which is applied to alleviate traffic congestions on ramps. RLRM consists of prediction tools depending on traffic flow simulation and optimal choice model based on reinforcement learning theories. Moreover, it is also a dynamic process with abilities of automaticity, memory and performance feedback. Numerical cases are given in this study to demonstrate RLRM such as calculating outflow rate, density, average speed, and travel time compared to no control and fixed-time control. Results indicate that the greater is the inflow, the more is the effect. In addition, the stability of RLRM is better than fixed-time control

3-(5-Chloro­naphthalene-1-sulfonamido)-2-(2-hy­droxy­eth­yl)-4,5,6,7-tetra­hydro-2H-pyrazolo­[4,3-c]pyridin-5-ium chloride

In the cation of the title compound, C18H20ClN4O3S+·Cl−, the tetra­hydro­pyridinium ring assumes a half-chair conformation. The dihedral angle between the pyrazole ring and the naphthalene ring system is 75.19 (6)°. In the crystal, ions are linked into a three-dimensional network by N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds and weak π–π stacking inter­actions with centroid–centroid distances of 3.608 (2) Å

A triclinic polymorph with Z = 3 of N,N′-bis­(2-pyrid­yl)oxamide

The asymmetric unit of the title compound, C12H10N4O2, contains three half-mol­ecules. Each half-mol­ecule is completed by crystallographic inversion symmetry. The title compound, (I), is a polymorph of the structure, (II), reported by Hsu & Chen [Eur. J. Inorg. Chem. (2004), 1488–1493]. In the original report, the compound crystallized in the tetra­gonal space group P 21c (Z = 8), whereas the structure reported here is triclinic (P , Z = 3). In both forms, each oxamide mol­ecule is almost planar (with maximum deviations are 0.266 and 0.166 Å) and the O atoms are trans oriented. The principal difference between the two forms lies in the different hydrogen-bonding patterns. In (I), two N—H⋯O and one N—H⋯N hydrogen bonds link the mol­ecules, forming a two-dimensional network, whereas in (II) there are no classical hydrogen bonds to O atoms and only weak C—H⋯O inter­actions are found along with rings of N—H⋯N bonds