排序方式： 共有40条查询结果，搜索用时 15 毫秒
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穴播穴灌坐水播种机水路系统的结构优化 总被引：4，自引：0，他引：4
针对当前坐水播种机具存在的结构复杂、种液播施难同位等问题,提出了“开沟-种、液同时播施-覆土-镇压”的机械作业新工艺,在此基础上设计了新型穴播穴灌坐水播种机水路系统.以该水路系统关键部件水阀为例,建立了其设计参数的数学模型,利用惩罚函数法和Matlab提供的优化函数对模型参数进行求解.优化结果为：水阀出口内径为2.5 cm,阀芯头部厚度为0.7 cm,阀芯上下运动行程为1.9 cm,阀芯头部上下端面直径分别为3.0和6.1 cm;室内样机试验测得的水阀局部水头损失系数为2.08.该方法适用于水路系统其他部件参数的优化设计. 相似文献
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Zhang Jianhui Deng Anfu 《保鲜与加工》1999,(2):84
The application of the element-free method in the bending problems of plates has not been found since it was proposed.In this paper,the element-free method is applied to compute the deflection and the moment of the elastic foundation plate with free boundary,and the corresponding formulas as well as the computer program are developed.Numerical examples show that the accuracy of the method used in the foundation plate problem is satisfactory.Therefore,it is reasonable and feasible for using the element-free method in the plate bending problems. 相似文献
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瓜尔豆[Cyamopsis tetragonoloba (L.) Taub.]为一年生抗旱耐热豆类植物,是Cyamopsis属中经济性最为重要的一个种。有关商业品种的遗传关系的信息对于瓜尔豆育种至关重要。本文依据6个瓜尔豆,1个C. senegalensis 种和1个 C. serrata种的引种系的RAPD和植物学性状数据采用UPGMA方法 进行了聚类分析。供试的三个种共扩增出29条带,其中26条具有多态性。每个引物扩增出的多态性片段为2至6条,平均3.3条。基于这26条多态性RAPD片段的Jaccard相似系数,聚类分析将这3个种分为2组：第一组包括C. serrata 和 C. senegalensis 2个野生种,第二组包括Cyamopsis tetragonoloba种的6个品种。在第二组中,‘Kinman’与其他5个品种的关系较远。用这8个材料形态性状非相似系数进行的聚类分析获得了类似的结果,但用形态性状比之RAPD检测到组内更多的变异。 相似文献
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Bo Zhang Pengyin Chen Sandra L. Florez-Palacios Ainong Shi Anfu Hou Tetsuaki Ishibashi 《Euphytica》2010,173(3):387-396
Diversity of food-grade soybeans is critical for utilization of genetic resources in cultivar development, germplasm enhancement,
and end-product commercialization. The objective of this study was to assess seed quality attributes and phenotypic variability
among 54 U.S. and 51 Asian food-grade cultivars and breeding lines. The results showed greater genetic diversity of protein
content, calcium content, seed hardness, and seed size uniformity than other quality traits in both small- and large-seeded
genotypes evaluated in this study. Among the small-seeded soybeans, the U.S. genotypes were more diverse and exhibited higher
swell ratio and oil content but lower stone seed ratio and protein content than Asian accessions. Among the large-seeded accessions,
U.S. genotypes had higher stone seed ratio and oil content but lower swell ratio and protein content, and were less diverse
than Asian genotypes. The characterization of diverse food-grade soybeans will facilitate parent selection in specialty soybean
breeding. 相似文献
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苦马豆素对小白鼠移植性肿瘤S180,ARS的抑制试验 总被引：11，自引：0，他引：11
民豆素饮水或配合皮下注射对小白鼠移植性肿瘤Ｓ１８０的抑制率为３０．５７％－４０．７６％，若马豆素饮水兼皮下注射并配合干扰素或聚肌胞对Ｓ１８０的抑制率为５９．２４％－６９．４３％。 相似文献
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He Shuiyuan Deng Anfu 《保鲜与加工》1997,(2):36-41
On the basis of the achivements of home and abroad,a study and fabrication of multi- module and multi- function intelligent design soft ware SBSDES has been completed successfully.The ES has been expounded systematically in the paper,such as knowledge- base, data- base,reasoning mechanism,graph function and user interface ,and so on.Finally,the SBSDES is used for design two roadways.The industrial tests show that SBSDES is scientific and practical. 相似文献
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He Shuiyuan Deng Anfu Wang Cheng 《保鲜与加工》1999,(2):23
On the basis of discussing the damage mechanism of cushion cap, a method of optimum design for pile group foundation is put forward in this paper.The piles are decorated on the cushion cap which makes the area of cushion cap minimum.The object function of optimum design for cushion cap is its volume and the binding functions are the requirements of shear, column die cutting, corner-pile die cutting and settlement for cushion cap.The optimum design has been done by a computer program. This method is used to design a factory building. The final result suggests that this method is highly effective and practical. A fair-scale economic efficiency can be obtained in ifs practical use. 相似文献