Previous reports indicated that AtMYB103 has an important role in tapetum development, callose dissolution, and exine formation in A. thaliana anthers. Here, we further characterized its function in ...anther development by expression pattern analysis, transmission electron microscopy observation of the knockout mutant, and microarray analysis of downstream genes. A total of 818 genes differentially expressed between ms188 and the wild-type were identified by global expression profiling analysis. Functional classification showed that loss-of-function of AtMYB103 impairs cell wall modification, lipid metabolic pathways, and signal transduction throughout anther development. RNA in situ hybridization confirmed that transcription factors acting downstream of AtMYB103 (At1g06280 and At1g02040) were expressed in the tapetum and microspores at later stages, suggesting that they might have important roles in microsporogenesis. These results indicated that AtMYB103 is a crucial regulator of Arabidopsis anther development.
Herein, we designed a new NO
x
storage and reduction CuO/K
2
CO
3
/MgAl
2
O
4
catalyst operating within the high temperature region of 350-550 °C. Compared with the Al
2
O
3
supported catalyst with ...the same Cu and K loading, it exhibits superior NO
x
storage and reduction performance. The NO
x
reduction percentage (NRP) of the CuO/K
2
CO
3
/MgAl
2
O
4
catalyst remains above 90% over a wide temperature range (400-550 °C), and reaches the highest NRP of 99.9% at 450 °C with the N
2
selectivity of 99.7%. Uncovered CuO particles with better reducibility exist on the CuO/K
2
CO
3
/MgAl
2
O
4
catalyst, with the high NO
x
oxidation and reduction ability above 400 °C. Potassium carbonates on the CuO/K
2
CO
3
/MgAl
2
O
4
catalyst mainly exist in three forms, including free ionic carbonate, bridging bidentate carbonate and chelating bidentate carbonate. Under lean-burn conditions, most of carbonates on the CuO/K
2
CO
3
/MgAl
2
O
4
catalyst can store NO
x
to form nitrates, but only parts of them participate in NO
x
storage on the CuO/K
2
CO
3
/Al
2
O
3
catalyst. The MgAl
2
O
4
support offers additional sites for NO
x
adsorption, while the formed nitrate on it shows low thermal stability. So, NO
x
is mainly stored on K
2
CO
3
at high temperatures, because MgAl
2
O
4
can enhance the thermal stability of the supported K
2
CO
3
on it. Our results show that the thermal stability of K
2
CO
3
directly determines the thermal stability of the formed nitrates. Accordingly, the CuO/K
2
CO
3
/MgAl
2
O
4
catalyst shows the high NSR activity because of the efficient redox ability of CuO and high thermal stability of K
2
CO
3
at high operating temperatures.
The CuO/K
2
CO
3
/MgAl
2
O
4
catalyst can store and reduce NO
x
efficiently in alternative lean/rich atmospheres at high operating temperatures.
A semi-active suspension design based on the traditional method of skyhook control is not capable of effectively controlling the attitude of the vehicle. However, an innovative approach called ...decoupling skyhook control allows the attitude of the vehicle body and its vibration characteristics to be effectively controlled. In this paper, a new decoupling skyhook controller for semi-active suspension is presented. Vehicle body motions in the three directions of vertical, pitch, and roll have been adopted to develop three skyhook controllers and directly control the vehicle body attitude. Furthermore, three orientation skyhook control forces are converted into actual damping forces of four adjustable dampers through the input decoupling transformation. The simulation results show that the developed controller is more effective than the traditional skyhook control in improving ride comfort.
Herein, we investigate the De-NO x activity of Pt/Ba/Sn x Ce1–x O2 catalysts at high temperatures. Our results show that at high temperatures, their NO x storage capacity (NSC), linked to the ...quantity of highly dispersed BaCO3 species on the catalysts, determines the De-NO x activity instead of the NO x oxidation and reduction ability. Moreover, we identify that monodentate nitrate species are more stable than free ion nitrate species on the Ce-containing catalysts. Thus, the presence of monodentate nitrate species is beneficial to improve the H2O and CO2 tolerance by inhibiting the latter ones’ competitive adsorption on NO x storage sites. Compared with other catalysts, Pt/Ba/Sn0.8Ce0.2O2 possesses the larger amount of highly dispersed BaCO3 species, and especially, more monodentate nitrate species are formed on it during the NO x storage period. Thus, it exhibits the superior De-NO x performance with NO x removal percentage over 86% in the presence of H2O and CO2 at 350∼500 °C.
Herein, we report the function of Pd species in the Pd-added La0.7Sr0.3CoO3 perovskite for removal of NO x (NO+NO2) in the lean-burn NO x traps (LNT) process. The addition of Pd significantly ...improves the De-NO x activity of the perovskite-based catalysts. The Pd-supported catalyst has an excellent NO x removal efficiency of 90.4%, which is higher than the Pd-doped catalyst (74.4%) and pure La0.7Sr0.3CoO3 (51.6%). Our results show that the addition of Pd species enhances both the NO x desorption behaviors to regenerate the NO x storage sites and NO x reduction ability of the catalysts in the fuel-rich period, which induces the improved NO x trapping performance in the followed lean-burn period. These achievements result in the enhanced De-NO x activity of the Pd-added catalyst in the alternative NO x storage and reduction operations. Compared with the Pd-doped catalyst, the Pd-supported catalyst possesses the higher utilization efficiency of the Pd, thus exhibiting a higher catalytic activity.
The crosstalk and flexibility are two problems in three-dimensional force sensor with sandwich structure. In this paper, a piezoresistive flexible three-dimensional force sensor is presented. It ...consists of three parts: the bump layer, the pressure sensitive layer and the flexible electrode layer. The threedimensional force sensor has several independent pressure units isolated by PDMS and single-layer electrode structure. This kind of structure not only can suppress the crosstalk, but also has better flexibility. The three-dimensional force is measured by each layer cooperated. The measuring principle and preparation method of the three-dimensional force are studied here. It shows that the anti-crosstalk piezoresistive three-dimensional force sensor is realizable in the field of intelligent perception such as dexterous robot hand.
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