Cerbera manghas is a mangrove plant which possesses comprehensive biological activities. A great deal of research has been undertaken on the chemical constituents and medical functions of C. manghas; insecticidal and antifungal activities have also been reported, but the acaricidal activity has not been studied. In our study, the acaricidal activity and active substances of C. manghas were investigated using a spray method, which showed that the methanol extracts of the fruit, twigs and leaves exhibited contact activity against female adults of Panonychus citri, with LC50 values at 24 h of 3.39 g L−1, 4.09 g L−1 and 4.11 g L−1, respectively. An acaricidal compound was isolated from C. manghas by an activity-guided isolation method, and identified as (-)-17β-neriifolin, which is a cardiac glycoside. (-)-17β-Neriifolin revealed high contact activity against female adults, nymphae, larvae and eggs of P. citri, with LC50 values at 24 h of 0.28 g L−1, 0.29 g L−1, 0.28 g L−1 and 1.45 g L−1, respectively.
Bionic design is a new method in engineering design. The mouthpart of the larva long
horned beetle and its tunnel in wood are discussed in this article. To improve the cutting properties
and tool life are always the main aim of cutting tool design. The foreground of cutting tool design
using the larva long horned beetle is discussed on the bases of the mouthpart maxillae of
Aphrodisium sauteri (Matsushita) and the tunnel in Quercus myrsinaefolia. The research can also
make direction at new tool material and tool geometry parameter design.
Bionic design is a new method in engineering design. The mouthparts especially for the chewing ones of the insects are discussed in this article. To improve the tool life and cutting properties are always the critical for the cutting tool design aim. The foreground of cutting tool design is discussed using the mouthpart of insect as bionic design object. The basic structure of the chewing mouthpart, type of mandibles, geometry, hardness, and element contained, moving mechanism and so on will be described. The research can also make direction at new tool material and tool geometry parameter design.
This paper deals with the High-speed Hard and Dry Cutting mechanism of hardened alloy-steel with PCBN tool: the cutting speed and workpieces temperature and tool wear are being discussed in different cutting speeds when cutting alloy-steel 42CrMo. After the workpiece temperature measured by ThermaVision, it is proved that the workpiece temperature was not high and changed little. Through the SEM and EDS analyses for chip and tool wear, it is proved that PCBN tool is suitable for High-speed Hard and Dry Cutting. It is suitable for PCBN tool to cut hardened alloy-steel 42CrMo instead of grinding.
Tool material has been one of the focuses in tool research. Diamond and cubic boron nitride (c-BN) are materials of exceptional and very similar properties that make them extremely valuable not only for the aesthetics of diamond. C-BN is a material synthesized rather recently that has rapidly spurred technological and scientific interest. Presently, both materials have found commercial applications. There is still a long way for the practical application of cBN film. The main problems are such as adhesion, thickness, purity, nucleating, and growth mechanism. We will develop a new way of DC plasma jet CVD way to synthesis the cBN film. The deposition of cBN films can be performed in a DC jet plasma CVD reactor by using an Ar-N2-BF3-H2 gas mixture, on the basis of deposition of diamond has been achieved.
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