油菜不同产量类型品种氮素吸收与利用特性研究

探讨甘蓝型油菜不同产量类型品种氮素吸收与利用特性.在不同土壤肥力条件下以甘蓝型油菜品种(2006-2007年度73个、2007-2008年度98个)为材料,成熟期测定各器官干物重、氮素含量,采用组内最小平方和动态聚类方法对供试品种产量进行聚类.研究不同产量类型品种氮素积累与分配差异.结果表明:供试品种间产量差异很大,类型间差异显著.随着产量增加,氮素吸收总量、氮素籽粒生产效率增加,籽粒氮素积累量增加,茎枝、果壳氮素分配比例下降,籽粒氮素比例增加.土壤肥力高,植株吸氮总量增加,氮素籽粒生产效率降低.增加氮素吸收总量,促进氮素向籽粒中输送,使得高产和高氮素利用效率统一.     

Discovery of and Preliminary studies on a Rapid-Leafing Rice Genotype at the Vegetative G rowth Stage

The leafing rates of fourteen rice varieties were measured in a sowing-time experiment.and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559.The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont,and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar grovvth durations from sowing to heading.Furthermore,the difference of the leafing rate was significant at the vegetative growth stage,but not distinctive at the panicle initiation stage.Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character.Based on results of investigation for some plants with similar growth durations in the backcrossing populations,the rapid leafing genotypes exhibited earlier tiltering and more tiller numbers per plant,and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes.Further research and application feasibility of the rapid leafing genotype in breeding were discussed.     

煤层气发动机稳态空燃比前馈控制脉谱生成

基于煤层气发动机进气系统的物理特性,采用平均值、多项式和模糊神经网络建模方法,建立了用于稳态空燃比前馈控制的递阶模型,并通过该模型生成了三维初始控制脉谱图.借助于辨识的过量空气系数自适应神经网络模糊推理系统(ANFIS)模型,进行了静态空燃比前馈控制仿真.利用前馈控制模型生成的数据,检验了实际控制效果.结果表明,前馈控制模型具有良好的预测能力,模型最大和平均预测误差分别小于8%和5%.     

上游泵送机械密封润滑膜固液两相流动特性

为了研究上游泵送机械密封润滑膜内部微小颗粒的分布规律及其对密封性能的影响,建立密封动、静环间液膜三维几何模型和数值模拟计算模型.基于两相流体的连续介质理论,利用Mixture模型对液膜内的两相流动进行数值模拟,分析了微尺度液膜内颗粒相的分布特点、进口颗粒体积分数对颗粒分布的影响以及由此引起的密封性能变化.研究表明:微小颗粒相主要存在于螺旋槽的槽根半径处及靠近螺旋槽的密封坝处,分布特征随着颗粒进口体积分数的增大而逐渐明显,这可能是上游泵送机械密封易出现螺旋槽堵塞的原因;在所研究的参数范围内,颗粒相的存在使液膜开启力增大且开启力和端面摩擦扭矩随着颗粒进口体积分数的增大而增大.     

基尼系数视野下的安徽省水土资源匹配分析

为科学地规划区域农业的发展,通过构建区域基尼曲线和计算区域基尼系数,同时选用单位面积耕地所拥有的水资源总量法,对安徽省2000—2012年的水资源和耕地资源进行匹配分析。结果显示：安徽省多年平均水土资源空间匹配的区域基尼系数G=0.4449,水土资源空间匹配状况优于中国(0.5664)、世界(0.5864)平均水平。安徽省水土资源匹配在地市尺度上具有明显空间分异,呈现皖南地区水土资源匹配状况优于江淮之间,而江淮之间又优于皖北地区的水土资源匹配格局。     

Disentangling the factors that contribute to variation in forest biomass increments in the mid-subtropical forests of China

Mid-subtropical forests are the main vegetation type of global terrestrial biomes, and are critical for maintaining the global carbon balance. However, estimates of forest biomass increment in mid-subtropical forests remain highly uncertain. It is critically important to determine the relative importance of different biotic and abiotic factors between plants and soil, particularly with respect to their influence on plant regrowth. Consequently,it is necessary to quantitatively characterize the dynamicspatiotemporal distribution of forest carbon sinks at a regional scale. This study used a large, long-term dataset in a boosted regression tree(BRT) model to determine the major components that quantitatively control forest biomass increments in a mid-subtropical forested region(Wuyishan National Nature Reserve, China). Long-term,stand-level data were used to derive the forest biomass increment, with the BRT model being applied to quantify the relative contributions of various biotic and abiotic variables to forest biomass increment. Our data show that total biomass(t) increased from 4.62 9 106 to 5.30 9 106 t between 1988 and 2010, and that the mean biomass increased from 80.19 ± 0.39 t ha-1(mean ± standard error) to 94.33 ± 0.41 t ha-1in the study region. The major factors that controlled biomass(in decreasing order of importance) were the stand, topography, and soil. Stand density was initially the most important stand factor, while elevation was the most important topographic factor. Soil factors were important for forest biomass increment but have a much weaker influence compared to the other two controlling factors. These results provide baseline information about the practical utility of spatial interpolationmethods for mapping forest biomass increments at regional scales.     

超声功率对超声振动辅助制粒质量的影响

以苜蓿草为原料并利用超声振动辅助制粒。通过单因素实验研究超声功率对颗粒质量(密度、抗碎性、吸水性)的影响。实验结果表明,成型颗粒的密度、抗跌碎率随超声功率的升高而升高,成型颗粒的吸水性随超声功率的升高而降低。当使用70%超声功率(超声振幅为0.031 mm)制成的苜蓿草颗粒颗粒质量最优,颗粒密度达到最高值为575.84 kg/m3,抗跌碎率达到最高值为80%,吸水率降低为最低值45.6%。     

基于FPGA的鸡舍环境监控系统

为解决鸡舍环境参数较难控制问题,设计一种以FPGA、传感器、无线模块、GPRS模块和执行机构为硬件核心,以Kingview6.55软件为开发平台的实时环境参数监控系统。该系统通过无线模块将FPGA采集到的鸡舍参数值传到上位机,并对其采集数据进行分析和处理,实现数据采集、处理、显示、存储及执行机构控制等功能。同时,管理人员也可以通过手机终端以短信方式实现数据查询和设备控制等功能。试验结果表明,该系统既可以为蛋鸡提供更佳的产蛋环境,又可以提高产蛋量,节约饲料、电能和人力成本,在农业和牧业领域有良好的推广和应用价值。     

Characteristics of P accumulation and distribution at the maturity stage of Brassica Napus varieties with different phosphorus use efficiency for grain production

Phosphorus (P) is one of nutrients essential for plant growth. The differences in P content, accumulation, and distribution among 98 rapeseed (Brassica napus) varieties with different P use efficiency for grain production (PUEg) were studied. The results showed that there were highly significant differences in P contents of the whole plant and various organs among different rapeseed varieties. Furthermore, PUEg had significantly negative correlations with P accumulations in whole plant, stems, shells, and seeds. The correlation analysis showed that the correlation coefficient of PUEg and P distribution ratio in stems was smaller, and it was significantly negatively correlated in shells, while it showed highly positive correlations in seeds. It indicated that P content in rapeseed plant stems and shells appeared to be transported into seeds to increase P distribution in seedpods at the late maturity stage, which could help improve PUEg.     

落地式救生器支架的力学性能分析和加强措施验证

为了提高落地式救生器支架的安全性和可靠性,利用DH-3816静态应变采集系统采集救生器支架静力加载447 kg时各构件的最大应力值,分析救生器支架的结构安全性,提出对薄弱构件的优化设计方案。结果表明,加载到447 kg时挡杆的最大应力达到所用材料极限抗拉强度的75%,已屈服失效,挡杆为薄弱构件。应用商用有限元,模拟了静力加载过程,所得结论与实验结果十分吻合。提出了将挡杆直径由10 mm增大到20 mm的结构优化方案,仿真模拟计算结果表明,该方案可有效提高救生器支架的安全性和可靠性。