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In our screening program for insecticidal activity of the essential oils/extracts derived from some Chinese medicinal herbs and spices, garlic (Allium sativum L.) essential oil was found to possess strong insecticidal activity against overwintering adults of Cacopsylla chinensis Yang et Li (Hemiptera: Psyllidae). The commercial essential oil of A. sativum was analyzed by gas chromatog-raphy-mass spectrometry. Sixteen compounds, accounting for 97.44% of the total oil, were identified, and the main components of the essential oil of A. sativum were diallyl trisulfide (50.43%), diallyl disulfide (25.30%), diallyl sulfide (6.25%), diallyl tetrasulfide (4.03%), 1,2-dithiolane (3.12%), allyl methyl disulfide (3.07%), 1,3-dithiane (2.12%), and allyl methyl trisulfide (2.08%). The essential oil of A. sativum possessed contact toxicity against overwintering C. chinensis, with an LC50 value of 1.42 fig per adult. The two main constituent compounds, diallyl trisulfide and diallyl disulfide, exhibited strong acute toxicity against the overwintering C. chinensis, with LC50 values of 0.64 and 11.04 μg per adult, respectively. [ABSTRACT FROM AUTHOR]

There are a lot of holes in a progressive die for mounting inserts, assembles, and standards. This paper gives the classification of plate holes of progressive die design according to their structural types and relationships between the correlating parts and the plate holes and describes an automated hole design system for progressive dies. Taking advantage of prebuilt design knowledge and standard parts database, this system is able to generate the correlated holes on the main plates of progressive dies, such as upper die shoes, lower die shoes, stripper plates, punch plates, die plates, punch backing plates, and die backing plates according to the inserted parts or functional assembles. A descriptive model is set up. The feature library technology is adopted to develop the function for the design of plate holes, which can improve the efficiency and shorten the design cycle. The hole design system is built on the top of SolidWorks, taking advantage of its built-in modules, including part, assembly, and drawing. We use progressive die for motor core as concrete examples to demonstrate the power of our system. Experimental results show that our system cannot only improve the design quality but also reduce the design time and cost. [ABSTRACT FROM AUTHOR]