Compressed stabilized earth blocks are the innovation of building materials replacing the earth blocks commonly called adobe. Common stabilizers (cement and lime) have been found to be expensive and harmful to the env...Compressed stabilized earth blocks are the innovation of building materials replacing the earth blocks commonly called adobe. Common stabilizers (cement and lime) have been found to be expensive and harmful to the environment. Finding a natural, available, environmentally friendly stabilizer is vital. The objective of this study was therefore to assess the effects of gum Arabic (GA) as binder on the durability properties of laterite blocks. Compressed laterite blocks were stabilized with 2% and 6% respectively as total percentage of binders in the blocks (cement and/or GA). The results showed that GA improved the abrasion and drop resistances of compressed blocks. It has been found that the abrasion resistance of compressed blocks increased with the increase of GA content and the decrease of cement content. For instance, the mass abraded away of blocks stabilized with cement only was reduced up to 95.18% when GA was used to partially replace cement. As for drop test, the higher the content of GA the higher the resistance of blocks to drop.展开更多
[Objective] The aim of this study was to manually isolate the microstructures such as ovule and embryo of Capsella bursa-pastoris (L.) Medic. by the non-enzymatic method. [Method] With the gum block and dissecting mic...[Objective] The aim of this study was to manually isolate the microstructures such as ovule and embryo of Capsella bursa-pastoris (L.) Medic. by the non-enzymatic method. [Method] With the gum block and dissecting microscope, its floral characteristics, ovule and embryo were manually isolated and observed by the non-enzymatic method. [Result] C. bursa-pastoris had four calyces, four petals, tetradynamous stamen and silicle, while its embryogenesis contained globular embryo, heart-shaped embryo and torpedo-shaped embryo. [Conclusion] The microstructures such as ovule and embryo of plants become easier to be isolated manually with the viscosity of gum block, which has small damage on embryo or disadvantages of keeping original shapes, and also can used in multi fields studies. This test can also be accomplished in labs with poor experiment facilities.展开更多
被子植物的胚珠微小,手工分离胚珠内的珠心比较困难（胡适宜,1994）。目前,人们多是借助于纤维素酶和果胶酶等的酶解技术,完成珠心、胚囊、卵细胞和合子等微小结构的人工分离（周嫦等,1982；Huang et al．，1990；Kovacs et al．，1994...被子植物的胚珠微小,手工分离胚珠内的珠心比较困难（胡适宜,1994）。目前,人们多是借助于纤维素酶和果胶酶等的酶解技术,完成珠心、胚囊、卵细胞和合子等微小结构的人工分离（周嫦等,1982；Huang et al．，1990；Kovacs et al．，1994；Tian et al．，1997；杨弘远等，1998；2001；Uchiumi et al．，2006）。由于胚囊和合子经酶处理后，展开更多
文摘Compressed stabilized earth blocks are the innovation of building materials replacing the earth blocks commonly called adobe. Common stabilizers (cement and lime) have been found to be expensive and harmful to the environment. Finding a natural, available, environmentally friendly stabilizer is vital. The objective of this study was therefore to assess the effects of gum Arabic (GA) as binder on the durability properties of laterite blocks. Compressed laterite blocks were stabilized with 2% and 6% respectively as total percentage of binders in the blocks (cement and/or GA). The results showed that GA improved the abrasion and drop resistances of compressed blocks. It has been found that the abrasion resistance of compressed blocks increased with the increase of GA content and the decrease of cement content. For instance, the mass abraded away of blocks stabilized with cement only was reduced up to 95.18% when GA was used to partially replace cement. As for drop test, the higher the content of GA the higher the resistance of blocks to drop.
基金Supported by Natural Science Foundation (No. 30770124)SRTP Fund from Henan University of Science and Technology~~
文摘[Objective] The aim of this study was to manually isolate the microstructures such as ovule and embryo of Capsella bursa-pastoris (L.) Medic. by the non-enzymatic method. [Method] With the gum block and dissecting microscope, its floral characteristics, ovule and embryo were manually isolated and observed by the non-enzymatic method. [Result] C. bursa-pastoris had four calyces, four petals, tetradynamous stamen and silicle, while its embryogenesis contained globular embryo, heart-shaped embryo and torpedo-shaped embryo. [Conclusion] The microstructures such as ovule and embryo of plants become easier to be isolated manually with the viscosity of gum block, which has small damage on embryo or disadvantages of keeping original shapes, and also can used in multi fields studies. This test can also be accomplished in labs with poor experiment facilities.
文摘被子植物的胚珠微小,手工分离胚珠内的珠心比较困难（胡适宜,1994）。目前,人们多是借助于纤维素酶和果胶酶等的酶解技术,完成珠心、胚囊、卵细胞和合子等微小结构的人工分离（周嫦等,1982；Huang et al．，1990；Kovacs et al．，1994；Tian et al．，1997；杨弘远等，1998；2001；Uchiumi et al．，2006）。由于胚囊和合子经酶处理后，
