稻谷颗粒内部水分迁移过程的有限元分析

研究稻谷颗粒内部水分的迁移规律,以求达到较好的烘干效果,是一个重要的问题。该文研制了可用于空间轴对称湿扩散问题的有限元计算软件,并用其对描述圆粒、长粒稻谷的３层圆球和椭球两种模型进行计算,得到了两种模型在干燥、缓苏状态下的湿度及其梯度场随时间变化规律。经分析发现,烘干温度较低时,椭球脱湿速度低于圆球,烘干温度较高时,两者差异变小。两模型的含水率（干基）及其梯度分布有明显差别。     

干燥和储藏过程中稻谷颗粒内部应力的有限元法分析

以粘弹性材料的积分松弛型本构关系为基础,建立了粘弹性体的有限元分析模型,编制了热一湿应力计算的轴对称有限元程序。应用该程序研究了长粒稻谷在干燥和储藏过程中内部应力分布及其变化规律,并与实验结果进行了比较,分析了谷粒在储藏阶段出现裂纹的直接原因。     

云南大围山自然保护区的丝孢菌

 报道云南大围山自然保护区的2种丝孢菌:矮生长囊头孢霉Doratomyces nanum ( Ehrenb. ex Link)Morton et Smith,展开角状孢Ceratosporium productum Petch,为国内新记录属和种,新记录提供形态描述及形态图。标本收藏于云南农业大学真菌标本室（MHYAU）。     

多刺裸腹溞的精子发生

应用组织学方法和电镜技术,研究了多刺裸腹溞(Moina macrocopa)的精子发生、成熟精子的形态以及雄性生殖系统的结构特征。多刺裸腹溞雄性生殖系统包括1对精巢、1对输精管和1个生殖孔。精巢壁薄,由电子密度不同的2层结缔组织膜组成。生殖孔位于尾爪底部,其周围无类似交媾器等其他附属结构。多刺裸腹溞的精子发生经历精原细胞、精母细胞、精子细胞和成熟精子4个主要时期。精原细胞呈椭圆形,核染色质较分散,细胞质中分布着大量的粗面内质网和游离的核糖体。精母细胞由于挤压呈多角形,细胞核为椭圆形,核基质和染色质分别位于细胞核的一侧,细胞质中存在少量的线粒体,内质网呈片层状。精子细胞向精子分化,形态上纵向拉长,细胞核也纵向伸长;细胞质中线粒体数量增多,个体增大,且部分线粒体内嵴溶解,形成空泡状的衍生物;内质网大量发生。成熟精子弯曲成棒形,细胞核变小,呈圆形,位于精子的中央。扫描电镜观察显示,精子外表面光滑无附属结构。在整个精子发生过程中,细胞核双层核膜结构完整且清晰。此外在精巢中还存在巨大细胞。     

Effects of dietary proline on growth,physiology, biochemistry and TOR pathway-related gene expression in juvenile spotted drum Nibea diacanthus

Fisheries Science - Amino acids can act as signaling molecules in protein synthesis and animal growth by regulating several genes in the target of rapamycin (TOR) pathway. An 8-week feeding trial...     

Effect of hydroxyproline supplementation on growth performance,body composition,amino acid profiles,blood‐biochemistry and collagen synthesis of juvenile chu's croaker (Nibea coibor)

Hydroxyproline (Hyp) may play an important role in collagen metabolism, as it is almost exclusively found in collagen. To examine this possibility, a 56‐day feeding trial was conducted to evaluate the effect of graded supplementaries of Hyp (0, 2.5, 5, 7.5, 10 and 12.5 g/kg dry diet weight) on growth performance, feed utilization, biochemical composition and collagen synthesis of chu's croaker, Nibea coibor (13.6 ± 0.28 g). The growth performance and feed utilization were improved with increased levels of dietary Hyp, reaching a maximum at 5 g/kg (diet H2) followed by a slight decrease. Polynomial regression analysis showed that the maximum specific growth rate (SGR) was attained at 7.177 g/kg dietary Hyp. Increasing levels of Hyp did not affect body composition of juvenile Nibea coibor. However, dietary Hyp supplementation significantly affected the levels of Leu, Ile, Met, Lys, Ser, Glu and Pro in muscle and the levels of Met, Lys, Glu, Pro and Gly in swim bladder. The serum calcium (SC) level decreased significantly with increasing levels of dietary Hyp. However, the triglycerides (TG) and total cholesterol (T‐CH) levels in serum and liver were relatively stable. Importantly, the acid‐soluble collagen (ASC) and total collagen (TC) levels in swim bladder increased significantly initially and then decreased after reaching a maximum. Polynomial regression analysis revealed that the maximum TC level in swim bladder was attained at 9.736 g/kg of dietary Hyp. Collectively, these results suggest that the appropriate provision of hydroxyproline is essential for maximal collagen synthesis and growth.     

3种植物免疫诱抗剂对番茄灰霉病菌的抑制作用

为明确植物免疫诱抗剂对番茄灰霉菌的抑菌效果,选用3%氨基寡糖素水剂、0.5%几丁聚糖水剂和1%香菇多糖水剂3种常规植物免疫诱抗剂,分别配制高、中、低3个浓度,采用含药培养基的方法开展室内抑菌试验,明确3种植物免疫诱抗剂相应最佳抑菌浓度后,在番茄生育期开展田间诱导抗灰霉病试验。室内抑菌试验结果表明：3种植物免疫诱抗剂均可抑制番茄灰霉菌的生长,其中,1%香菇多糖水剂对番茄灰霉病菌具有较好的速效性和持效性,1%香菇多糖水剂20倍液接菌1d后的抑菌率为36.1%,4d后抑菌率为67.43%;3%氨基寡糖素水剂抑菌效果次之,3%氨基寡糖素水剂100倍液接菌1d后抑菌率为22.1%;0.5%几丁聚糖水剂抑菌效果相对较低,抑菌率维持在0.0%～14.3%。田间诱导抗病试验结果表明：0.5%几丁聚糖水剂200倍液对番茄灰霉病具有较好的诱抗效果,连续施用4次后,番茄灰霉病防效达61.83%。     

基于模型的四足机器人步态转换控制研究

为了解决基于模型的控制方法在四足机器人步态转换过程中稳定控制问题,本文在仿生学和机构学基础上设计了一款四足机器人样机平台,并推导了机器人单腿运动学模型。在足端可达工作空间内规划了机器人抬腿高度和迈步步长,利用理想的复合摆线轨迹,通过合理控制步态周期,提出了一种过渡段变周期控制方法,实现了步态转换前后定速度控制和变步长控制,保证了步态转换前后速度不变或可变。为了验证所提算法的正确性和稳定性,分别开展了单腿足端轨迹实验和整机步态转换实验。在完成整机运动控制的基础上,对比了基于模型的控制方式和基于中枢模式发生器的控制方式在四足机器人步态转换过程的应用。仿真和实验结果表明,在基于模型的控制算法下,四足机器人可以实现步态的平滑转换,且速度能伴随步长和周期的变化实现调节,满足了不同速度下的行走要求,为四足机器的运动控制提供了参考。     

冬青新品种‘大别山冬青1号’

‘大别山冬青1号’是从大别山冬青（Ilex dabieshanensis）实生苗中选育出的新品种。树皮灰白色,平滑;叶片亮绿色具光泽,卵状长圆形或椭圆形,具4 ~ 8对刺齿;花黄绿色,花期在3—4月;果球形,成熟时呈鲜红色,挂果期10月至次年2月。抗寒性强,耐盐碱性好,生长旺盛,扦插易成活。     

Effects of water and nitrogen addition on vegetation carbon pools in a semi-arid temperate steppe

Global change will lead to increases in regional precipitation and nitrogen(N) deposition in the semi-arid grasslands of northern China. We investigated the responses of vegetation carbon(C) pools to simulated precipitation and N deposition increases through field experiments in a typical steppe in Inner Mongolia. The treatments included NH_4NO_3 addition at concentrations of 0(CK), 5(LN, low nitrogen), 10(middle nitrogen, MN), and 20(HN,high nitrogen)(g m~(-2)a~(-1)) with and without water. After three consecutive years of treatment, from 2010 to 2012,water addition did not significantly change the size of the total vegetation C pools, but it significantly decreased the ratio of root:shoot(R:S)(P = 0.05) relative to controls. By contrast, N addition significantly increased the total vegetation C pools. The C pools in the LN, MN and HN treatments increased by 22, 39 and 44 %, respectively. MN produced the largest effect among the N concentrations,although differences between N-added treatments were not significant(P [ 0.05). N addition significantly reduced the ratio of root:shoot(R:S)(P = 0.03). However, there were no significant interactive effects of water and N addition on the vegetation C pools.