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机械分割的小鼠桑椹胚和囊胚的发育能力
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作者 王周吉 Alan Trounson 《东北农学院学报》 CSCD 1992年第3期293-299,共7页
利用机械方法二等份分割小鼠的桑椹胚、早期囊胚和晚期囊胚,并在体外培养分割的半胚到晚期囊胚。将这些囊胚移植到假孕受体鼠子宫内以评价他们附植后发育的能力。在体外培养中发现,囊胚期分割的胚胎比桑椹胚期分割的胚胎有较高的成活率... 利用机械方法二等份分割小鼠的桑椹胚、早期囊胚和晚期囊胚,并在体外培养分割的半胚到晚期囊胚。将这些囊胚移植到假孕受体鼠子宫内以评价他们附植后发育的能力。在体外培养中发现,囊胚期分割的胚胎比桑椹胚期分割的胚胎有较高的成活率。通过附植前胚胎细胞数量分析得知,囊胚期半胚的细胞数量大约是对照组的一半,但内细胞团细胞与整个胚胎细胞的数量比不变。虽然从半胚发育到囊胚期的胚胎附植率仅略低于对照组,但半胚形成胎儿的能力却显著低于全胚。组织学分析表明,附植后的这种低成活率现象是由于缺乏卵柱发育造成的,而此卵柱则与半胚中的内细胞团的细胞数量减少有关。移植到第3天假孕受体鼠中的半胚,附植后的发育情况明显地比移植到第4天受体中的好。 展开更多
关键词 小鼠 桑椹胚 囊胚 机械分割 发育
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原子论认识模式之启示 被引量:2
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作者 于秀彬 《吉林师范大学学报(人文社会科学版)》 2005年第4期14-16,共3页
原子论的思维模式古已有之,这种认识模式里有“基本组成部分”和“分割”这样的思维方式和观念。科学发展使人类思维深入到“基本粒子”的层次,在研究微观世界的组成时,我们有必要对原子论思维模式中某些机械的观念进行修正。
关键词 原子论 思维模式 微观世界 机械分割
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Image Analysis of Fabric Pilling Based on Light Projection 被引量:3
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作者 陈霞 黄秀宝 《Journal of Donghua University(English Edition)》 EI CAS 2003年第4期1-4,共4页
The objective assessment of fabric pilling based on light projection and image analysis has been exploited recently.The device for capturing the cross-sectional images of the pilled fabrics with light projection is el... The objective assessment of fabric pilling based on light projection and image analysis has been exploited recently.The device for capturing the cross-sectional images of the pilled fabrics with light projection is elaborated.The detection of the profile line and integration of the sequential cross-sectional pilled image are discussed.The threshold based on Gaussian model is recommended for pill segmentation.The results show that the installed system is capable of eliminating the interference with pill information from the fabric color and pattern. 展开更多
关键词 fabric pilling image analysis of fabric pilling light projection image edge detection of projected profile pill segmentation
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Soil Disturbance from Different Mechanised Harvesting in Hill Tropical Forest, Peninsular Malaysia
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作者 Mohd Hasmadi Ismail Norizah Kamarudin 《Journal of Environmental Science and Engineering》 2010年第1期34-41,共8页
The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing ... The impacts of mechanised forest harvesting to soil physical properties are the major concern by forest managers, which have the potential to impact soil sustainability and forest productivity. Malaysia is practicing reduce impact logging (RIL) and applying code of forest harvest practice in forest harvesting and operations for sustainable forest resources management. In 2001, a machinery called Rimbaka Timber Harvester R2020-A was introduced for timber extraction for peat swamp forest and later on the machine was introduced to the hill tropical forest as an alternative to other machines. The study aimed to evaluate soil compaction (soil cone index, soil bulk density, soil moisture content and soil pore space) by Rimbaka Timber Harvester R2020-A and crawler tractor KOMATSU D60-A. A total of five samples were randomly taken using core sampler of 50 mm height and 50 mm diameter at the beneath a lug imprint for passes 1, 4 and 8. Altogether samples were 45. The locations of sample were to the fight and left of each rut centre for both machines. Treatment effects were evaluated using analysis of variance (ANOVA). Result showed that compaction by Rimbaka machine was increased bulk density from 1.14 to 1.43 g/cc, cone index from 1.94 to 3.45 g/cm3 decreased total pore space by 43% and decreased soil moisture content by 19%. Meanwhile compaction by KOMATSU D60-A was increased bulk density from 1.2 to 1.43 g/co, cone index from 1.24 to 1.94 g/cm3 decreased soil moisture content by 11% and total pore space by 6%, respectively. The value increased rapidly as more passes increase on the track surface. The higher soil disturbance by Rimbaka machine was due to physical design and specification of the machine. This study also observed that there was significant difference in the total passes of machinery used in harvesting operation. Although Rimbaka machine is showing more effected to soil compaction, the machine is a practical alternative to avoid skid trail and reduce road density in forest area. 展开更多
关键词 Soil disturbance bulk density cone index pore space harvesting operation Rimbaka harvester system crawler tractor.
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