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The boron nitride nanosheets (BNNSs)/aluminum nitride (AlN) composites were prepared by hot press sintering at 1600°C. The microstructure, mechanical properties, and thermal conductivity of the samples were measured, and the effect of adding BNNSs to AlN ceramics on the properties was studied. It is found that the addition of BNNSs can effectively improve the mechanical properties of AlN. When the additional amount is 1 wt%, the bending strength of the sample reaches the maximum value of 456.6 MPa, which is 23.1% higher than that of the AlN sample without BNNSs. The fracture toughness of the sample is 4.47 MPa m1/2, a 68.7% improvement over the sample without BNNSs. The composites obtained in the experiment have brilliant mechanical properties. [ABSTRACT FROM AUTHOR]

Uniformly dispersed boron nitride nanosheets (BNNSs) reinforced silicon nitride (Si 3 N 4) composites were prepared by surface modification assisted flocculation combined with SPS sintering. In order to improve the dispersibility of the BNNSs in the composites, the liquid phase stripped BNNSs are surface functionalized by a two-step covalently modification. The amino-modified BNNSs (NH 2 -BNNSs) and Si 3 N 4 powders have opposite surface potential, mixed evenly by electrostatic interaction during flocculation. The results showed that mechanical properties of Si 3 N 4 composites were obviously enhanced by adding NH 2 -BNNSs. The fracture toughness and bending strength of Si 3 N 4 composites added 0.75 wt% NH 2 -BNNSs were increased by 34% and 28%, respectively, compared with monolithic Si 3 N 4. Toughening mechanisms are synergistic action of the torn, pull-out or bridging of BNNSs and crack deflection mechanisms with microstructural analyzes. The dielectric properties of the Si 3 N 4 ceramics are also improved after the addition of NH 2 -BNNSs. [ABSTRACT FROM AUTHOR]

Transitional metal nitrides (TMNs) are regarded as comparatively promising electrode materials for supercapacitor due to the high electronic conductivity, good corrosion resistance and special electron structure. Herein, in this work a heterostructure Co 2 N-Ni 3 N nanosheets-nanowires arrays grown on Ni foam (NF) are designed and synthesized by a simple hydrothermal reaction and nitriding treatment. The prepared Co 2 N-Ni 3 N/NF nanoarrays has a high electrical conductivity, abundant surface active sites, charge transfer channels and the synergy effect between each component, which makes it exhibit outstanding electrochemical performance. Electrochemical test results revealed that the areal capacitance of Co 2 N-Ni 3 N/NF was 2.17 F cm−2 at 1 mA cm−2 using a three-electrode system in 1 M KOH. Meanwhile, when the current density increases to 20 mA cm−2, it can still retain 62.21% of the original capacitance, suggesting a good rate capability. In addition, in two-electrode test with Co 2 N-Ni 3 N/NF as the positive electrode and activated carbon as the negative electrode, a maximum energy density of 145.65 μWh cm−2 is shown when the power density is 0.75 mW cm−2. And it has 85.90% capacitance retention after 5000 cycles. [Display omitted] • Unique Co 2 N-Ni 3 N nanoarray heterostructure was successfully synthesized. • Co 2 N-Ni 3 N/NF achieves an areal capacitance 2.17 F cm-2 at current density of 1 mA cm-2. • The Co 2 N-Ni 3 N/NF // AC exhibits good electrochemical performance in two-electrode tests. [ABSTRACT FROM AUTHOR]

Early Permian fusulinids from both northern and southern parts of the Baoshan Block (western Yunnan, Southwest China) are illustrated and compared with coeval fusulinid faunas from other northern peri-Gondwana areas to disclose paleogeographic information. Systematic study of collected fusulinid materials and examination of published data from the Dingjiazhai area, northern Baoshan Block, show that fusulinids there include Eoparafusulina pseudosimplex and Pseudofusulina macilenta. Fusulinids from the Aluotian Section, southern Baoshan Block, consist of P. minituinidiscula n. sp., P. inacilenta, P. turnidiscula, E. pseudosimplex, E. aff. E. laudoni, and E. sp. Early Permian fusulinids from both northern and southern Baoshan Blocks are dominated by Pseudofusulina and Eoparafusulina species and they are similar to those from Central Pamir, South Afghanistan, East-Central Iran, Central Oman, East Hindu Kush and northern Karakorum, revealing a Sakmarian to Artinskian age. Moreover, detailed comparison shows that the Early Permian fusulinid assemblage from the Baoshan Block is more similar to those from East-Central Iran, Central Pamir and South Afghanistan. This implies that the Baoshan Block may have been near those areas during the Early Permian. [ABSTRACT FROM AUTHOR]

Two Permian fusulinid faunas, including nine species belonging to six genera, from the northern Tengchong Block, Southwest China, are studied and compared with the coeval fusulinid faunas from other blocks with Gondwana-affinity and South China. In the Kongshuhe section, the fauna is dominated by Eoparafusulina in the lower part of the Dadongchang Formation and possibly suggests an age of Sakmarian, while in the Shanmutang section, the fauna from the middle of the Dadongchang Formation mainly consists of Chusenella mingguangensis n. sp. and Monodiexodina gigas n. sp., indicating a Wordian to Capitanian age. Study has also demonstrated that fusulinid faunas from the Tengchong Block shared similar features with the contemporary faunas from the Baoshan Block and Sibumasu Block in the low generic and specific diversities and the absence of the taxa commonly found in Cathaysia Tethys areas, such as the Pseudoschwagerinidae, Verbeekinidae, and Neoschwagerinidae. However, visible differences in species composition still exist between the faunas of the Tengchong Block and those of the other two blocks, revealing an apparent regional feature in the faunas of the Tengchong Block. [ABSTRACT FROM AUTHOR]