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Abstract: Cubic boron nitride (c-BN) crystals were synthesized in conditions of high temperature and high pressure (HTHP) when different kinds of bonded water were respectively added into the system of h-BN–Mg. All bonded water used in this work could reduce the temperature of growing c-BN compared to that in the system of h-BN–Mg. The c-BN color could change from black to yellow when certain amounts of bonded water, such as NiSO4·6H2O and CuSO4·5H2O, Mg(OH)2, were added. However, c-BN color remained black no matter how much bonded water, such as NiCl2·6H2O, CuCl2·2H2O, and SnCl2·2H2O, was added. The bonded water can be classified into Chlorine-containing bonded water (Cl-BW) and Chlorine-free bonded water (ClF-BW) according to their different characters and effects on the synthesized c-BN color. [Copyright &y& Elsevier]

Asserts the need for China to preserve its biodiversity. Factors affecting the country's biodiversity; Scientific basis of biodiversity research; Importance of conservation biology; Proposal for the establishment of a national centre for ecology and evolution.

ZnO/diamond hetero-junction diodes have been fabricated for the first time. The structure of the diode was n-type ZnO film/p-type diamond film on the {111} surface of a crystalline diamond. The contact between the n- and p-type semiconductors was found to be improved. The ratio of forward current to the reverse current exceeded 120 within the range of applied voltages of −4 to +4 V. The diode possessed an optical transmission of 50–70% in 500–700 nm wavelength regions. [Copyright &y& Elsevier]

Low-threshold heterojunctions have been formed from a boron-doped p-type diamond layer grown epitaxially on the {1 1 1} surface of a Si-treated single crystalline cubic boron nitride. The resistivity of the Si-treated cubic boron nitride was 0.1 Ω cm. With the resistivity of 0.1 Ω cm, which is lower than that of the sample prepared by conventional high-temperature and high-pressure method, the turn-on voltage and the highest current of the heterojunction are 0.5 V and 1 mA, respectively. [Copyright &y& Elsevier]

The growing behavior of cubic boron nitride (cBN) crystal in the system of hBN–Mg with bonded water (&z.dbnd6;(HO)2&z.dbnd6;) was investigated at 5.0 GPa and 1100–1500 °C. The results show that, with the existence of bonded water, the grown cBN crystals can appear different color and the growth temperature decreases approximately 300 °C with the pressure fixed at 5.0 GPa by contrast with that in the hBN–Mg system. In addition, the cBN synthesis process is quite different from that when bonded water is absent or that when magnesium is absent. [Copyright &y& Elsevier]

In the present work, the microstructure modifications and corrosion behaviors of a Mg-4Sm alloy treated by high current pulsed electron beam (HCPEB) with different number of pulses were investigated. The microstructure, composition and phase component in the treated surface layers were characterized by using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) and transmission electron microscope (TEM). The results showed the dissolution of large Mg 41 Sm 5 segregates, the formation of Mg 41 Sm 5 nano-precipitates and twins in the surface layers after treatments. Electrical impedance spectroscopy (EIS) and polarization tests in the 3.5 wt% NaCl solution showed that the 15 pulses treated Mg-4Sm alloy sample exhibited the lowest corrosion current density, highest corrosion potential and polarization resistance among all samples. This is attributed to the homogeneous microstructure and composition with fewer defects in the surface layer after sufficient number of HCPEB pulses. [ABSTRACT FROM AUTHOR]