基于用户需求的产品形态设计研究

目的研究产品设计中直观外在体现的产品形态设计,使产品满足用户的物质功能需求和审美文化需求,避免设计中的伪设计和过设计问题。方法从用户需求的角度出发,综合分析产品形态设计中本能、行为和反思3个维度的要求,通过探讨用户需求理论、用户需求与产品形态设计的相互影响因素,从正反两方面分析和比较优秀与劣质的产品形态设计的内在原因,形成综合使用需求、加工工艺、结构限定、绿色、环保等多角度综合考量的产品形态设计思路。结论产品设计是多因素共同作用下的综合设计,深入研究用户需求是产品形态设计多因素约束的前提和基础,只有真正理解用户需求的深刻内涵,才能实现满足物质功能和精神功能的优秀设计。     

亚麻织物绳状煮练纵向条纹产生的原因及解决

本文对亚麻织物绳状煮练纵向条纹产生的原因进行了分析,并提出了解决纵向条纹的方法,即煮练时加入高效煮练助剂,丝光对减轻纵向条纹也是有效的。     

自由曲面薄壳结构数值逆吊找形方法研究

数值逆吊找形法是一种生成零弯矩型自由曲面薄壳结构的高效方法。为了解决基于非线性有限元数值逆吊找形法在求解弱刚度结构时收敛性不佳的问题,通过引入向量式有限元法,提出了一种改进的数值逆吊找形方法。该方法采用向量式有限元法求解逆吊结构的平衡构形,并通过局部线性化方法调整柔性索单元的弹性模量,实现对逆吊结构形状的控制。在此基础上,进一步提出了可实现多点精确控制的分步刚化法,解决了复杂形状逆吊结构的找形问题。应用所提方法对Isler设计的某逆吊石膏模型进行数值找形,并将数值找形结果与实际模型扫描结果进行对比,验证了所提方法的正确性和有效性。     

利用聚酯废料开发高收缩有色短纤维

对聚酯废料生产高收缩有色短纤维过程中影响收缩率的主要因素；初生纤维结构形态及后纺工艺参数等进行探讨。     

富硒萝卜叶中的硒的赋存形态及分布研究

实验研究了营养元素硒在萝卜叶中赋存形态、分布及含硒大分子的提取分离技术;采用pH值分别为8．5和6．0的KH2PO4-Na2HPO4缓冲溶液、蒸馏水、稀盐、乙醇、稀碱分别依次提取不同种类的蛋白质,热水浸提法提取多糖,原子吸收分光光度法测定不同种类蛋白质、多糖、干样品中硒的含量。结果表明：萝卜叶中的含硒组分主要有蛋白硒和多糖硒,分别占样品含硒量的54．48％和17．31％,在硒蛋白组分中又以水溶性蛋白结合硒含量最高,占样品含硒量的26．78％。     

按时间抽取的FFT矩阵形式的研究

借助于奇、偶行（列）矩阵,前、后行（列）矩阵,奇偶行（列）分块矩阵及分块矩阵的准数乘运算等概念,分析了按时间抽取（DIT）的基-2 FFT算法分量形式的特点．将以自然数次序输出的按时间抽取（DIT）的基-2 FFT算法用较简单的矩阵形式来表示．     

果蔬三维切丁机改进仿真模型及试验

针对已有果蔬三维切丁断面易出现大弧形、倾斜等问题,采用虚拟样机技术,建立切丁机三维模型,并将其导入机械系统动力学分析软件ADAMS中,仿真分析推进滚筒与横切刀转速比在0.11~0.22、推进滚筒中心与横切刀中心水平间距在260~305 mm时切得的不同丁断面形状。仿真结果表明,引起切丁断面倾斜的主要因素是推进滚筒转速和横切刀转速的不匹配,当推进滚筒与横切刀之间的中心水平间距为280~300 mm、转速比n_1/n_2为0.11~0.22时,可取得较理想的切丁断面,其断面形状比较平直。为验证所得结论,在推进滚筒中心与横切刀中心水平间距290 mm、转速比为0.17条件下,分别进行10,15,20 mm 3种规格的切削性能试验,试验结果表明切出的3种规格丁断面形状规整,断面偏差小,其断面相对偏差百分数最大为12.7%,达到了国外同类先进产品质量标准。     

Body condition scores and dairy form evaluations as indicators of days open in US Holsteins

The objectives of this study were to estimate genetic correlations among body condition score (BCS), dairy form, milk yield, and days open in US Holsteins and investigate the potential of using BCS or dairy form evaluations as early indicators of days open. Dairy form and BCS obtained from the Holstein Association USA, Inc., were merged with mature equivalents (ME) for milk yields and days open data from AIPL-USDA. Cows were required to be classified between 24 and 60 mo of age, before 335 d in milk (DIM) and have ME milk of at least 4537 kg. A minimum of 20 daughters per sire and 10 cows per herd-classification visit (HV) or herd-year-season of calving (HYS) were required. The final data set included 159,700 records. Heritabilities and correlations among dairy form, BCS, milk yield, and days open were estimated with multiple trait sire models. Fixed effects included age at classification for dairy form and BCS, age at calving for milk yield, HV for dairy form and BCS, HYS for milk yield and days open, DIM within lactation group for dairy form and BCS and lactation group for milk yield and days open. Correlations among dairy form, BCS, and days open were generated with and without a ME milk covariable. Correlations between ME milk and days open were generated with and without covariables for dairy form or BCS. Random effects included sire and error. The genetic correlation estimates of days open with dairy form, BCS, and ME milk were 0.48, -0.30, and 0.38, respectively. The genetic correlation estimate between days open and dairy form was 0.38 after adjustment for ME milk, whereas the genetic correlation between days open and BCS was -0.24 after adjustment for ME milk. Combining dairy form evaluations with days open evaluations for 19 recently proven bulls resulted in an average increase of 0.06 for reliability of days open evaluations. The addition of BCS evaluations did not increase reliability when dairy form observations were available.     

Correlations among body condition scores from various sources, dairy form, and cow health from the United States and Denmark

The objectives of this study were to estimate genetic correlations among body condition scores (BCS) from various sources, dairy form, and measures of cow health. Body condition score and dairy form evaluated during routine type appraisal was obtained from the Holstein Association USA, Inc. A second set of BCS was obtained from Dairy Records Managements Systems (DRMS) and was recorded by producers that use PCDART dairy management software. Disease observations were obtained from recorded veterinarian treatments in several dairy herds in the United States. Estimated breeding values for diseases in Denmark were also obtained. Genetic correlations among BCS, dairy form, and cow health traits in the United States were generated with sire models. Models included fixed effects for age, DIM, and contemporary group. Random effects included sire, permanent environment, herd-year season for health traits, and error. Predicted transmitting abilities (PTA) for BCS and dairy form were correlated with estimated breeding values for disease in Denmark. The genetic correlation estimate between BCS from DRMS and BCS from the Holstein Association USA, Inc., was 0.85. The genetic correlation estimate between BCS and a composite of all diseases in the United States was -0.79, and PTA for BCS was favorably correlated with an index of resistance to disease other than mastitis in Denmark (0.27). Dairy form was positively correlated with a composite of all diseases in the United States (0.85) and was unfavorably correlated with an index for resistance to disease other than mastitis in Denmark (-0.29). Adjustment for protein yield PTA had a minimal affect on correlations between PTA for BCS or dairy form and disease in Denmark. Selection for higher body condition or lower dairy form with continued selection for yield may slow deterioration in cow health as a correlated response to selection for increased yield.