ALBERT

Description: A series of short and steep unidirectionally migrating deep-water channels, which are typically without levees and migrate progressively northeastward, are identified in the Baiyun depression, Pearl River Mouth Basin. Using three-dimensional seismic and well data, the current study documents their morphology, internal architecture, and depositional history, and discusses the distribution and depositional controls on the bottom current–reworked sands within these channels. Unidirectionally migrating deep-water channels consist of different channel-complex sets (CCSs) that are, overall, short and steep, and their northeastern walls are, overall, steeper than their southwestern counterparts. Within each CCS, bottom current–reworked sands in the lower part grade upward into muddy slumps and debris-flow deposits and, finally, into shale drapes. Three stages of CCSs development are recognized: (1) the early lowstand incision stage, during which intense gravity and/or turbidity flows versus relatively weak along-slope bottom currents of the North Pacific intermediate water (NPIW-BCs) resulted in basal erosional bounding surfaces and limited bottom current–reworked sands; (2) the late lowstand lateral-migration and active-fill stage, with gradual CCS widening and progressively northeastward migration, characterized by reworking of gravity- and/or turbidity-flow deposits by vigorous NPIW-BCs and the CCSs being mainly filled by bottom current–reworked sands and limited slumps and debris-flow deposits; and (3) the transgression abandonment stage, characterized by the termination of the gravity and/or turbidity flows and the CCSs being widely draped by marine shales. These three stages repeated through time, leading to the generation of unidirectionally migrating deep-water channels. The distribution of the bottom current–reworked sands varies both spatially and temporally. Spatially, these sands mainly accumulate along the axis of the unidirectionally migrating deep-water channels and are preferentially deposited to the side toward which the channels migrated. Temporally, these sands mainly accumulated during the late lowstand lateral-migration and active-fill stage. The bottom current–reworked sands developed under the combined action of gravity and/or turbidity flows and along-slope bottom currents of NPIW-BCs. Other factors, including relative sea level fluctuations, sediment supply, and slope configurations, also affected the formation and distribution of these sands. The proposed distribution pattern of the bottom current–reworked sands has practical implications for predicting reservoir occurrence and distribution in bottom current–related channels.

Description: During the formation of the title salt, C7H10N+·C3H3O4−, an H atom of a carboxyl group was transferred to the amino group. All non-H atoms of the cation are essentially coplanar [r.m.s. deviation = 0.007 (4) Å]. The mean planes of the carboxylate and carboxyl groups of the anion form a dihedral of 69.67 (1)°. In the crystal, N—H...O and O—H...O hydrogen bonds connect the anions and cations, forming a two-dimensional network parallel to the bc plane.

Description: The asymmetric unit of the title compound, C6H5N2+·H2PO4−·C6H4N2·H3PO4, contains one 4-cyanopyridinium cation, one H2PO4− anion, one independent isonicotinonitrile molecule and one independent H3PO4 molecule. The dihedral angle between the mean planes of the separate protonated and unprotonated pyridine rings is 9.93 (8)°. In the crystal, N—H...O and O—H...N hydrogen bonds and weak C—H...O and C—H...N intermolecular interactions connect the organic molecules into a two-dimensional network parallel to the ac plane. O—H...O hydrogen-bonding interactions involving the H2PO4− anions and H3PO4 molecules provide additional support from the inorganic groups Weak π–π stacking interactions between the pyridine rings of neighbouring organic molecules [centroid–centroid distances = 3.711 (4) and 3.784 (2) Å] further link the layers into a three-dimensional network.

Description: In the centrosymmetric dimeric title compound, [Cu2Cl4(C16H20N2O)4]·0.5H2O, the CuII atom is in a distorted trigonal–bipyramidal environment defined by two bridging Cl atoms, one terminal Cl atom and two N atoms from two monodentate 4-(adamantan-1-ylcarbamoyl)pyridine ligands. The amine N atoms are involved in intramolecular N—H...O and intermolecular N—H...Cl hydrogen bonds. The latter hydrogen bonds link the complex molecules into a ribbon along [010]. The uncoordinated water molecule is 0.25-occupied.

Description: The asymmetric unit of the title complex, [Fe(C5H5)(C11H17N)]ClO4, contains two independent allyl(ferrocenylmethyl)dimethylammonium cations and two ClO4− anions. The anions are disordered each over two sets of sites, with an occupancy ratio of 0.617 (6):0.383 (6). The distances from the Fe atoms to the centroids of the unsubstituted and substituted cyclopentadienyl (Cp) rings are 1.645 (1)/1.657 (1) and 1.644 (1)/1.647 (1) Å. The dihedral angles between the two Cp rings are 2.49 (3) and 1.45 (4)° in the two ferrocenyl groups of the cations.

Description: The asymmetric unit of the title complex, {(C5H12NO)[BiCl4]}n, contains two bridging and two cis non-bridging chloride ligands coordinated to a central BiIII atom, and one 4-methylmorpholin-4-ium cation. The BiIII atoms are linked by the bridging chloride ligands into linear chains parallel to the c axis. The chloride ions create a pseudo-octahedral geometry about each BiIII atom. Bifurcated N—H...Cl hydrogen bonds link the cations to the anionic chains.

Description: The asymmetric unit of the title complex, [Fe(C5H5)(C9H15N)]ClO4, contains one discrete (ferrocenylmethyl)trimethylammonium cation and one perchlorate anion. The anion is disordered over two sets of sites, with refined occupancies of 0.776 (8) and 0.224 (8). The distances from the Fe atom to the centroids of the unsubstituted and substituted cyclopentadienyl (Cp) rings are 1.650 (1) and 1.640 (1) Å, respectively. The Cp rings form a dihedral angle of 2.66 (3)°.

Description: Lower Cretaceous pedogenic carbonates exposed in SE China have been dated by U–Pb isotope measurements on single zircons taken from intercalated volcanic rocks, and the ages integrated with existing stratigraphy. 13 C values of calcretes range from –7.0 to –3.0 and can be grouped into five episodes of increasing–decreasing values. The carbon isotope proxy derived from these palaeosol carbonates suggests p CO 2 mostly in the range 1000–2000 parts per million by volume (ppmV) at S ( z ) (CO 2 contributed by soil respiration) = 2500 ppmV and 25°C during the Hauterivian–Albian interval ( c . 30 Ma duration). Such atmospheric CO 2 levels are 4–8 times pre-industrial values, almost double those estimated by geochemical modelling and much higher than those established from stomatal indices in fossil plants. Rapid rises in p CO 2 are identified for early Hauterivian, middle Barremian, late Aptian, early Albian and middle Albian time, and rapid falls for intervening periods. These episodic cyclic changes in p CO 2 are not attributed to local tectonism and volcanism but rather to global changes. The relationship between reconstructed p CO 2 and the development of large igneous provinces (LIPs) remains unclear, although large-scale extrusion of basalt may well be responsible for relatively high atmospheric levels of this greenhouse gas. Suggested levels of relatively low p CO 2 correspond in timing to intervals of regional to global enrichment of marine carbon in sediments and negative carbon isotope ( 13 C) excursions characteristic of the oceanic anoxic events OAE1a (Selli Event), Kilian and Paquier events (constituting part of the OAE 1b cluster) and OAE1d. Short-term episodes of high p CO 2 coincide with negligible carbon isotope excursions associated with the Faraoni Event and the Jacob Event. Given that episodes of regional organic carbon burial would draw down CO 2 and negative 13 C excursions indicate the addition of isotopically light carbon to the ocean–atmosphere system, controls on the carbon cycle in controlling p CO 2 during Early Cretaceous time were clearly complex and made more so by atmospheric composition also being affected by changes in silicate weathering intensity.

Description: In this work, two kinds of partial least squares modelling methods are applied to predict a compressor map: one uses a power function polynomial as the basis function (PLSO), and the other uses a trigonometric function polynomial (PLSN). To demonstrate the potential capabilities of PLSO and PLSN for a typical interpolated prediction and an extrapolated prediction, they are compared with two other classical data-driven modelling methods, namely the look-up table and artificial neural network (ANN). PLSO and PLSN are also compared with each other. The results show that PLSO and PLSN have a better prediction performance than the look-up table and the ANN, especially for the extrapolated prediction. The computational time is also decreased sharply. Compared with PLSO, PLSN is characterized by a higher prediction accuracy and shorter computational time than PLSO. It is expected that PLSN could save computational time and also improve the accuracy of a thermodynamic model of a diesel engine.

Description: Aimed at the problem of exhaust gas recirculation (EGR) performance evaluation and optimal EGR rate determination of turbocharged diesel engines, an optimized decision-making method, based on grey theory and entropy weight, was proposed. The internal combustion pressure, fuel consumption rate, NO X , CO and smoke were selected as the decision-making targets and the initial decision-making model was established based on the traditional grey decision-making theory. According to the characteristics and optimization requirements of EGR, the optimal compromise between combustion and emission performance is proposed to transform into decision-making target weighting problem, then an optimized subjective weighting method based on expert scoring and grey relational analysis is proposed. Finally, the entropy weight method was used to solve the objective weight and the optimized multi-objective grey decision-making model was established, which can not only weaken the human error of subjective empowerment, but also fully explore the intrinsic relationship of the evaluation indexes. At last, an optimization simulation platform for EGR performance evaluation based on MATLB/GUIDE was designed and established. The results show that the optimization simulation platform can effectively improve the efficiency of simulation calculation, which is more convenient for practical engineering applications. The optimized method can successfully realize EGR performance evaluation and optimal EGR rate determination under different working conditions. The decision-making result was consistent with the present EGR control strategies, which provide a new research idea for EGR performance optimization.