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The timing of the Holocene summer monsoon maximum (HSMM) in northeastern China has been much debated and more quantitative precipitation records are needed to resolve the issue. In the present study, Holocene precipitation and temperature changes were quantitatively reconstructed from a pollen record from the sediments of Tianchi Crater Lake in northeastern China using a plant functional type-modern analogue technique (PFT-MAT). The reconstructed precipitation record indicates a gradual increase during the early to mid-Holocene and a HSMM at ~5500–3100 cal yr BP, while the temperature record exhibits a divergent pattern with a marked rise in the early Holocene and a decline thereafter. The trend of reconstructed precipitation is consistent with that from other pollen records in northeastern China, confirming the relatively late occurrence of the HSMM in the region. However, differences in the onset of the HSMM within northeastern China are also evident. No single factor appears to be responsible for the late occurrence of the HSMM in northeastern China, pointing to a potentially complex forcing mechanism of regional rainfall in the East Asian monsoon region. We suggest that further studies are needed to understand the spatiotemporal pattern of the HSMM in the region.
Our study profiles a varying process of the relationship between delay of gratification (DG) and job performance over time and examines the moderating role of perceived organisational justice in the DG-job performance relationship. Employees’ ability to delay gratification was measured during their job interviews (Time 1). When they had worked for 3 months (Time 2), their job performance was rated by their supervisors. When they had worked for 5 months (Time 3), their perception of perceived informational justice was measured. Their job performance was rated again by their supervisors at 6 months (Time 4). The results showed that DG could directly predict new employees’ short-term (3-month) job performance but not their longer-term (6-month) job performance. Moreover, perceived informational justice moderated the relationship between DG and 6-month job performance.
The dissimilar MIG welding of Mg alloy and ultra-high strength steel was investigated. The results indicated that the Mg-steel joints had characteristics of welding-brazing and included weld zone, bond zone, and interface zone. The weld zone with an equiaxed grain structure mainly consisted of α-Mg and α-Mg + β-Mg17Al12 phases when AZ31 and AZ61 filler metals were used respectively. The interface zone presents a double-layer structures: the AlFe3 layer at steel side and the Mg(Fe, Al)O4 + Mg3.1Al0.9 layer at Mg side, and their evolution process has been summarized. The joint strength was improved obviously at the heat input of 1987–2100 J/cm due to eliminating incomplete joining defects and cracks in the interface zone. With AZ61 filler metal, the weld Al content was 6.24%, the joint strength was elevated from 174 MPa for AZ31 filler metal to 201 MPa (83.8% of Mg alloy base metal), which is related to the increased Al promoting the interface reaction.
The effect of hydrostatic pressure treatment on the induction of mitogynogenesis in the eggs of Japanese flounder Paralichthys olivaceus (Temminck et Schlegel) by using heterospecific sperm were studied. Before treatment, the eggs were at metaphase of the first mitosis. The spindle was disassembled by the treatment and then resembled in its pretreatment position, and the chromosomes were rearranged, i.e., the first mitosis was not blocked. During the second mitotic cycle, only a monopolar spindle was assembled in each blastomere and the chromosomes doubled, but cell cleavage was blocked. In the third cycle, mitosis proceeded normally with a bipolar spindle in each blastomere. Flow cytometric analysis of ploidy demonstrated that mitogynogenetic larvae were all diploid. The ultraviolet light-irradiated sperm of the red sea bream (Pagrus major) was condensed, formed a dense chromatin body, and randomly entered one blastomere.
A solution-processed method is developed to fabricate fully transparent resistive random access memory (RRAM) devices with a configuration of FTO/ZrO2/ITO, where the zirconium dioxide (ZrO2) layer was firstly deposited on fluorine tin oxide (FTO) substrate by sol-gel and then indium tin oxide (ITO) films were deposited on ZrO2 layer by sol-gel as the top electrodes.The solution processed FTO/ZrO2/ITO based RRAM devices show the fully transparency and excellent bipolar resistance switching behaviors. The resistance ratio between high and low resistance states was more than 10, and more than 100 switching cycles and good data retention and multilevel resistive switching have been demonstrated.
In this work, we investigated the influence of N-polar wet etching on the properties of nitride-based hexagonal pyramids array (HPA) vertical-injection light emitting diodes (V-LEDs). The cathodeluminescence images showed the randomly distribution of hexagonal pyramids with isolated active regions. The transmission electron microscopy images demonstrated the reduced density of threading dislocations. The IQE was estimated by temperature dependence of photoluminescence, which showed 30% increase for HPA V-LEDs compared with broad area (BA) V-LEDs. The improved extraction efficiency was verified by finite difference time domain simulation, which was 20% higher than that of roughened BA V-LEDs. The electrical properties of HPA V-LEDs were measured by conductive atomic force microscopy (CAFM) measurements. HPA V-LEDs exhibited much lower leakage current due to the improved crystal quality.
Electrical conductivity and magnetic properties of core-shell silver-coated magnetite composite nanoparticles prepared by electroless deposition of silver on magnetite nanopowder are found to be affected mainly by the pressure used when preparing the nanoparticles sample cylinder and the Ag content in the nanoparticles. The electrical conductivity can be enhanced by increases of both the pressure and the Ag content. Direct current volume electrical resistivity of the nanoparticles with 40 wt% silver content is close to the order of 10−4 Ω cm when the pressure is larger than 1 × 106 Pa. The saturation magnetization of the nanoparticles almost reduces linearly with increasing the silver content. According to the rule of mixtures, the resistivity of the nanoparticles is calculated. But it shows that the calculated values have a large deviation with the corresponding measured ones. As a comparison, resistivity and saturation magnetization of the mixtures consisting of silver and magnetite nanopowder are also measured. It will be an effective method to adjust the electromagnetic properties of the nanoparticles by changing the silver content.
We propose a deterministic solver for the time-dependent multi-subband Boltzmann transport equation (MSBTE) for the two dimensional (2D) electron gas in double gate metal oxide semiconductor field effect transistors (MOSFETs) with flared out source/drain contacts. A realistic model with six-valleys of the conduction band of silicon and both intra-valley and inter-valley phonon-electron scattering is solved. We propose a second order finite volume method based on the positive and flux conservative (PFC) method to discretize the Boltzmann transport equations (BTEs). The transport part of the BTEs is split into two problems. One is a 1D transport problem in the position space, and the other is a 2D transport problem in the wavevector space. In order to reduce the splitting error, the 2D transport problem in the wavevector space is solved directly by using the PFC method instead of splitting into two 1D problems. The solver is applied to a nanoscale double gate MOSFET and the current-voltage characteristic is investigated. Comparison of the numerical results with ballistic solutions show that the scattering influence is not ignorable even when the size of a nanoscale semiconductor device goes to the scale of the electron mean free path.
A ring R is called a left APP-ring if the left annihilator lR(Ra) is pure as a left ideal of R for every a ∈ R; R is called (left principally) quasi-Baer if the left annihilator of every (principal) left ideal of R is generated by an idempotent. Let R be a ring and M an ordered monoid. Assume that there is a monoid homomorphism φ: M ⟶ Aut(R). We give a necessary and sufficient condition for the skew monoid ring (induced by φ) to be left APP (left principally quasi-Baer, quasi-Baer, respectively).
In basic homological algebra, projective, injective and flat modules play an important and fundamental role. In this paper, we discuss some properties of Gorenstein projective, injective and flat modules and study some connections between Gorenstein injective and Gorenstein flat modules. We also investigate some connections between Gorenstein projective, injective and flat modules under change of rings.
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