基于电容式湿度传感器的植物粉料含水率测量

提出了一种基于电容式湿度传感器的植物粉料含水率测量方法。由电容式湿度传感器和数据采集卡组成的测量系统获取植物粉料含水率数据,应用一阶差分法剔除奇异值后,通过惯性滤波法处理数据。由菊花粉含水率的13个测量值与烘干法测得的真值对比试验结果可知,测量值与真值之间的最大相对误差为1.61%,平均相对误差为0.76%,均小于5%(测量样品数为5时置信区间为95%),表明该方法能够用于测量低水分植物粉料的含水率。     

智能制造和大数据挖掘在农业机械设计中的应用

随着制造信息的爆炸性增长及处理信息工作量的猛增,要求制造系统表现出更大的智能化,除了需要专业人才和专门知识外,还需要智能制造系统具有大数据挖掘和分析处理能力,从而使系统具有感知分析、推理、决策、控制等功能。为此,在农机数字化设计平台上引入了智能制造系统,并利用大数据挖掘技术对系统进行了优化,建立了经验数据库,在加工类似零部件时可以直接生成加工指令和工艺方案。实际应用表明:智能制造系统地引入有效缩短了加工工艺的设计周期,提高了设计效率,降低了设计制造成本。     

温室墙体复合相变材料的制备与有限元分析

采用共混法制备了一种适合温室生产要求的复合相变材料,用差示扫描量热仪(DSC)测量了相变温度和相变潜热,并验证了复合相变材料的储能能力及材料的热稳定性.另外,借助有限元软件来模拟复合材料在吸热过程中温度及热梯度场的分布情况,对实际生产有一定的参考价值.     

Classification of Peruvian highland maize races using plant traits

The maize of Latin America, with its enormous diversity, has played an important role in the development of modern maize cultivars of the American continent. Peruvian highland maize shows a high degree of variation stemming from its history of cultivation by Andean farmers. Multivariate statistical methods for classifying accessions have become powerful tools for classifying genetic resources conservation and the formation of core subsets. This study has two objectives: (1) to use a numerical classification strategy for classifying eight Peruvian highland races of maize based on six vegetative traits evaluated in two years and (2) to compare this classification with the existing racial classification. The numerical classification maintained the main structure of the eight races, but reclassified parts of the races into new groups (Gi). The new groups are more separated and well defined with a decreasing accession within group × environment interaction. Most of the accessions from G1 are from Cusco Gigante, all of the accessions from G3 (except one) are from Confite Morocho, and all of the accessions from G7 are from Chullpi. Group G2 has four accessions from Huayleño and four accessions from Paro, whereas G4 has four accessions from Huayleño and five accessions from San Geronimo. Group G5 has accessions from four races, and G6 and G8 formed small groups with two and one accession each, respectively. These groups can be used for forming core subsets for the purpose of germplasm enhancement and assembling gene pools for further breeding.     

笼养肉仔鸡生产性能及其胴体品质影响因素的研究

该本文采用三因素三水平正交试验设计，就笼底材料、饲养密度、不同性别组群下3～6周龄AA肉仔鸡的生产性能及其胴体品质进行研究。结果表明：竹竿和塑料笼底下肉仔鸡的胴体品质以及笼养密度11 ～14只／m²下的生产性能较高，以塑料笼底、低密度和公鸡单饲组的肉仔鸡总增重最高，达1.82kg。笼底材料对增重、饲料转化率、屠宰率、腹脂率以及胸肌纤维直径没有影响，但铁丝笼底会导致胸囊肿发病率升高。高饲养密度下能显著降低肉鸡增重和饲料转化率，但肉仔鸡的屠宰率有所增加；而低饲养密度有利于胸肌纤维直径的增加。单饲母鸡的腹脂率显著高于单饲公鸡和公母混群饲养鸡的腹脂率。     

Simplified culture method of detached ears and its application to vernalization in wheat

Summary The effects of the addition of sulfurous acid into culture solution and of cold treatment of the solution were examined to simplify the culture of detached wheat ears. In the simplified method, detached ears could be cultured at room temperature on the liquid medium containing 100 g/l sucrose and 0.075% sulfurous acid without any sterilization. The immature seeds in detached ears cultured by this method were treated with low temperature or with chemicals known to have vernalizing effect. The chemical treatment did not affect the chilling requirement of immature embryos, although photoperiodic response and narrow-sense earliness were reduced by kinetin and trypsin. The low temperature treatment drastically affected the chilling requirement, and fully vernalized mature seeds having normal germinability were obtained by treating the detached ears in culture with low temperature from 10 days after anthesis.     

履带式行走机构粘弹性悬挂机构的刚度-阻尼特性分析

针对传统履带式拖拉机行走系易受剧烈振动冲击的问题,开发出一种新型的粘弹性悬挂机构。用复刚度理论,建立起该机构的运动微分方程,对其刚度-阻尼特性进行了分析。依据能量转换的观点,分析了机构中粘弹性阻尼材料的静、动态对振动能转换率的影响。对开发后的应用在240kW履带式拖拉机粘弹性悬挂机构上进行了刚度曲线设计和性能分析,并在电液伺服试验机上对实际产品进行了性能试验     

库底土壤物质溶出对水库正常蓄水初期水质的影响

现场选取太湖流域老虎潭水库砂壤质竹林地、水田土壤和库区天然来水样本,进行水库正常蓄水初期模拟实验,分析研究了库水中pH值DO,CODcr,BOD,氮、磷及氟化物等组分在60 d内的动态变化及特征.实验结果表明,库底竹林地和水田地土壤在浸泡过程中会导致库水中pH值和DO的降低,CODcR,BOD5,氮,磷及氟化物等组分的含量则会增大.相对而言,竹林地土壤对水库水质的影响比水田地土壤要严重,建议对竹林地土壤采取相应处理措施.     

A reciprocal F1 monosomic analysis of the genetic control of time of ear emergence,number of leaves and number of spikelets in wheat (Triticum aestivum L.)

Summary A reciprocal F₁ monosomic analysis of chromosomal differences between Spica and Bersée was carried out under controlled environment conditions. Chromosomes associated with differences in days to ear emergence, number of leaves and number of spikelets were identified. The results indicated that chromosome 2B of Spica carries a photoperiod insensitivity allele at the Ppd ₂ locus. Both Spica and Bersée appear to have a vernalization insensitity allele at the Vrn ₂ locus on chromosome 5B. On chromosome 3A, 4B, 4D and 6B factors were found with major effects on earliness per se, diffeences in ear emergence and number of spikelets which were independent of photoperiod and vernalization. The possibility that these factors influence growth rate is discussed.     

Influence of the D genome in conferring resistance to fusarium head blight in spring wheat

Reciprocal crosses were made between resistant hexaploid spring wheat cultivars/lines Sumai 3, Ning8331, and 93FHB21, and susceptible tetraploids Stewart 63 and DT486 to generate 35 chromosome pentaploids. Four heads from each of five F₁ pentaploid plants from each cross were screened with Fusarium graminearum for fusarium head blight (FHB) reaction. No pentaploid was as resistant to FHB as the resistant parents. Pentaploids derived from several crosses were more resistant than the susceptible parents, a few were more susceptible, and all plants from crosses with 93FHB21 failed to survive. Most viable seeds were obtained from the cross Sumai 3 × DT486. From this cross four of the five F₁ pentaploid parents were fertile and 354F₂ seeds derived from these four pentaploids were sown and evaluated for their FHB reaction. The majority of F₂ plants from pentaploids 1 and 3had the visual appearance and level of resistance of Sumai 3, whereas progeny from pentaploids 4 and 5 were more varied morphologically and generally more susceptible. Forty-three of the screened F₂ plants were tested for the presence of specific D chromosomes by wheat microsatellite analysis. There was no relationship between presence/absence of D chromosomes and FHB reaction. Twenty-four lines had all D chromosomes present of which 10 were intermediate-susceptible and 14 were resistant to FHB. Three lines, one resistant and two intermediate, had no D chromosomes. The remainder had between 1 and 6 of the D chromosomes present and ranged from resistant to susceptible in FHB reaction. It appears that FHB resistance is not conferred by the D genome of Sumai 3. This revised version was published online in July 2006 with corrections to the Cover Date.