No abstract

The information technology has led to the profound transformation of society, economy and education. Multimedia-assisted language teaching (MALT) is one of important applications of information technology to education. As a modern educational technology, MALT has been widely used and it is the main trend in English teaching at present. In this paper, the author will discuss MALT in English class of junior high school with the emphasis on formative assessments.

In this paper，we calculated the retarded modes of semi-infinite lateral ferromagnetic/ ferromagnetic superlattice with the effective medium theory. Take the Co/Ni system surface modes and bulk modes for the superlattice as the example and found some interesting properties which different from the lateral ferromagnetic/nonmagnetic superlattice. Lateral magnetism/magnetism superlattice have some complex retarded modes which are very common systems，changing the ratio of the superlattice ferromagnetism layer thickness so that two branches of surface modes frequency and bulk modes frequency band can be adjusted consequently. This tailoring effect is related to the two ferromagnetism layers saturation magnetization values. But the two saturation magnetization values are quite different than each other. If the difference between the tow values is large, the tailoring effect of f1 is more obvious. When the saturation magnetization value of the second ferromagnetic medium is approach to zero, this system will become magnetism/non-magnetism superlattice. If in Maxwell equation ε=0, the retarded modes will transite to ferromagnetic/ferromagnetic superlattice magnetostatic modes.

Effect of different amount sandy soil amendment on soil moisture and millet growth was studied in a rainfed field experiment in a semi-arid region in northern China in 2011-2013. Three-year results show: sandy soil amendment treatments all increased soil moisture, they are T3>T4>T5>T2>T1>CK, and with depth of soil layer increasing, differences of among treatments reduced; it can significantly (P<0.05) increased plant height of millet and dry matter accumulation above-ground by 1.77%-25.67% and 3.21%-104.79% respectively compared with CK; grain yield under sandy soil amendment is significantly (P<0.05) higher than CK, yield of 18000 kg·hm-2 and 24000 kg·hm-2 treatments is higher than others,being 5102.55 kg·hm-2 and 5035.85 kg·hm-2, biological yield, water and fertilizer use efficiency have the same effect as grain yield. Above all, using sandy soil amendment can improve the condition of soil moisture and fertilizer, sufficiently use limited rainfall, increase crop yield, increases water and fertilizer use efficiency, treatments with 18000 kg·hm-2,24000 kg·hm-2 sandy soil amendment show a better effect on resisting drought, retaining fertilizer and increasing yield under millet production in all the treatments.

The effect of different soil amendment (potassium polyacrylate; polyacrylamide;potassium humate; potassium polyacrylate+ potassium humate; polyacrylamide+ potassium humate) on soil physical and chemical properties in oat field was studied. The results showed that different soil amendments increase significantly the soil organic matter, available N, available P and available K content by 8.24%-30.22%, 7.60%-19.29%, 5.15%-29.45% and 27.86%-68.86% respectively. Soil water content at 0-60 cm depth is higher with soil amendment. But soil amendment has no effect on the soil water content at 60-100 cm soil depth. At the same time, soil amendments reduce the soil bulk density at 0-10 cm,10-20 cm, 20-40 cm and 40-60 cm depths, and they produce no obvious effect on soil bulk density at 60-100 cm depth. The proportion of > 0.25 mm soil aggregate at 0-10 cm,10-20 cm and 20-40 cm depth is increased significantly by applying soil amendment. Among five aggregate sizes (> 2 mm; 2-1 mm; 1-0.5 mm; 0.5-0.25 mm; 2 mm and 2-1 mm soil aggregates are the most. In conclusion, the mixing use of two kinds of soil amendments(potassium polyacrylate+ potassium humate and polyacrylamide+ potassium humate) is more effective for improving soil physical and chemical properties.