A phenetic analysis and lateral key of the genus Lolium (Gramineae)

88 herbarium specimens of the genus Lolium were scored for 22 characters, comprising 7 vegetative, 8 inflorescence and 7 seed characters. The aim was to review the species relationship and to produce a lateral key to the genus. The data were analysed using principal components analysis, discriminant function analysis and cluster analysis. All analyses separated L. perenne, L. multiflorum and L. temulentum from each other. The 2 varieties of L. rigidum showed varying degrees of separation from each other and from L. multiflorum. Their distinction as a species and as 2 varieties is discussed. L. perenne and L. rigidum were shown to contain the greatest similarity between species and L. temulentum was found to be the most distinct. A lateral key is proposed that separates the species on the basis of 11 morphological characters that are easily scored in the field.     

罗田垂枝杉不同年龄侧枝光合生理及形态特征

以15年生普通杉木为对照,分析罗田垂枝杉不同年龄侧枝叶片的光合生理特征变化规律。结果表明,罗田垂枝杉的冠高比和冠幅面积仅是杉木的45．33％和15．29％,两者差异极显著（p＜0．01）;罗田垂枝杉净光合速率（Pn）日变化呈单峰曲线,其4－5年生枝叶片光合能力明显低于杉木同年生侧枝叶片;罗田垂枝杉最大净光合速率（ Pnmax ）与光饱和点（ LSP, r＝0．956）、表观光合量子效率（AQY, r＝0．897）呈极显著正相关（p＜0．01）,与光补偿点（LCP, r＝0．416）、暗呼吸速率（Rd, r＝0．455）呈显著正相关（p＜0．05）,而与叶片含水率及叶绿素含量相关性不明显。罗田垂枝杉一年生到多年生侧枝的光合能力变化趋势与其侧枝逐渐自然脱落的过程具有一致性。     

EFFECT OF DEPENDENCY VERSUS NONDEPENDENCY ON LUNG LESION VISUALIZATION

Paraffin blocks and mineral oil were used as a model to determine the effect of dependency versus nondependency on radiographic visualization of lung lesions in lateral thoracic radiographs. It was concluded that the increased opacity of the material surrounding the lesion, not contact between the heart and the lesion, was responsible for the inability to detect lung disease in the dependent lung. The results were tested in dogs with pneumonia in the right middle lung lobe. When the dog was in right lateral recumbency, the dependent right lung was increased in opacity and decreased in volume and the pulmonary lesion was difficult to detect. When the dog was in left lateral recumbency, the nondependent right lung was increased in volume and decreased in opacity and the pulmonary disease was clearly visible. A single recumbent lateral radiograph must not be used to assess a dog with suspected lung disease because lesions in the dependent lung lobes may not be detected.     

Thoracolumbar lateral corpectomy for treatment of chronic disk herniation: technique description and use in 15 dogs

OBJECTIVE: To describe a technique for thoracolumbar lateral corpectomy and to evaluate its use for treatment of chronic thoracolumbar disk disease in dogs. STUDY DESIGN: Retrospective study. ANIMALS: Fifteen dogs with signs of chronic thoracolumbar disk herniation. METHODS: After a dorsal or lateral approach to the spine, a lateral slot was created in 2 adjacent vertebral bodies on either side of the herniated disk and extruded/protruded material was removed. Data collected included history, duration of clinical signs, presurgical assessment of neurologic status, postsurgical neurologic status, complications, and outcome. RESULTS: Ambulatory capacity was maintained or regained, and neurologic status improved by 1 grade (3 dogs), 2 grades (8), 3 grades (2), or 4 grades (2). Eleven dogs were considered free of disease. A seroma in 1 dog was the sole complication observed. CONCLUSIONS: Lateral corpectomy permits relatively easy removal of protruded-extruded disk material from within the vertebral canal in chronic disk disease without further iatrogenic injury to the spinal cord. CLINICAL RELEVANCE: Lateral corpectomy is an alternative to dorsal decompression for treatment of ventral and lateroventral thoracolumbar chronic disk disease in dogs.     

头枕高度对侧卧睡眠舒适性的影响

通过人体侧卧时头部及颈肩部压力分布测试、舒适感主观评价及相关性分析,以及人体胸颈部脊柱定位点分析和肩颧距测量等方法,研究承重后头枕高度变化对人体睡眠舒适性变化的影响。结果发现:侧卧人群宜选择承重后高度7～8cm的睡枕;枕高5cm时,脊柱上部呈"凸"字形状,枕高14cm时,脊柱上部呈"\"字形状;肩颧距与舒适枕高值存在较高的正相关性,最佳枕高值小于肩颧距。该结果可为侧卧枕高的个性化设计提供依据。     

短侧枝挂果核桃优良品种选择

针对云南核桃产业发展中存在的品种混杂,良莠不齐,丰产性能差等问题,开展了核桃(Juglans sig-illata)优良品种的选育工作。经过对核桃各品种的挂果情况的调查研究和品质分析,选出龙佳核桃、宁香核桃2个良种。     

黧蒴栲芽苗截根移栽育苗及造林成效研究

为了提高黧蒴栲苗木质量和造林成活率,利用随机区组设计开展了黧蒴栲芽苗截根移栽、截根苗造林对比试验.结果表明：黧蒴栲芽苗截根处理对苗高、主根长、一级侧根数、叶干重、茎枝干重、根器官干重有极显著影响,对苗木地径、一级侧根长度有显著影响.芽苗截根处理后苗木高度增加17.51％、地径增加13.72％.不同剪叶处理方式对黧蒴栲苗木造林成活率有极显著影响,芽苗截根苗造林以剪叶75％效果最好,造林成活率达95.86％,而未剪叶苗造林成活率为57.69％;应用芽苗截根苗造林可提高造林成活率17.0％～24.0％,增加当年树高、地径生长量分别为18.22％、15.44％.     

液罐车稳定性最优控制仿真

针对重型液罐车在紧急避障或转弯时液体和车体相互耦合作用引发的侧翻危险,用势流理论建立液体晃动控制方程并求解液体晃动力和力矩,结合半挂车刚体模型,将液体晃动模型统一到液罐车整车模型中。在鱼钩工况下,对比分析装载等质量液体和固体在激励作用下对罐车稳定性的影响。在非稳态因素影响下,设计了最优控制策略,并进行TruckSim/Simulink 联合仿真分析。结果表明:最优控制策略提高了车辆的鲁棒性,对增强液罐车的稳定性具有指导意义。     

丁香酸对不同品种烟草苗期根系生长的影响

为探究最新发现的植物源生物硝化抑制剂丁香酸对烟草品种K326和云烟85苗期根系生长的影响,通过基质培养试验,设置0、10、25、50、100、200 μmol/L 6个丁香酸浓度,研究了不同浓度丁香酸在不同时间(3 d和5 d)对K326和云烟85主根伸长量和一级侧根发育的影响。结果表明:与对照(0 μmol/L)相比,25～100 μmol/L丁香酸能促进K326主根伸长,在3 d时促进率为13.33%～30.67%,在5 d时促进率降为8.54%～22.55%,最适浓度为50 μmol/L;10～50 μmol/L丁香酸促进云烟85主根伸长,在3 d时促进率为7.81%～18.75%,在5 d时促进率维持在4.10%～10.66%,最佳促进浓度25 μmol/L;丁香酸对两个烟草品种主根伸长的促进效果均为3 d优于5 d。在侧根发育方面,低浓度丁香酸能显著促进K326和云烟85一级侧根数,两个品种促进侧根发育的最适浓度均为25 μmol/L。相关性分析表明,丁香酸处理下两个烟草品种苗期的主根伸长变化率与侧根数变化率呈显著正相关。可见,适宜浓度的丁香酸对两个典型烟草品种苗期主根增长和...