葡萄贮藏中SO2伤害与活性氧代谢的关系

以耐SO2品种巨峰和不耐SO2品种红地球葡萄为材料,研究了葡萄贮藏中SO2伤害与活性氧代谢的关系,结果表明,SO2伤害葡萄体内活性氧水平,GSH含理和ASP活性增加,SOD和CAT活性降低,与红地球相比,巨峰具有较高的SOD活性和GSH水平,受SO2伤害后,巨峰的ASP活性上升幅度大于红地球,其SOD活性和CAT活性的下降幅度低于红地球。     

咪鲜胺等新型杀菌剂对葡萄病害的防治效果

本文选用5种低毒杀菌剂对葡萄灰霉病和黑豆病进行了田间防治试验,结果表明,25%使百克1000倍液对葡萄灰霉病和黑豆病防治效果都最好,80%大生-M800倍液对灰霉病防效好,40%福星6000倍液和5%安福1000倍液对黑豆病防效好,32.5%丰收纯800倍液次之,其它供试药剂防效不理想。     

The impact of office chair features on lumbar lordosis,intervertebral joint and sacral tilt angles: a radiographic assessment

Abstract

Background: The purpose of this study was to determine which office chair feature is better at improving spine posture in sitting. Method: Participants (n = 28) were radiographed in standing, maximum flexion and seated in four chair conditions: control, lumbar support, seat pan tilt and backrest with scapular relief. Measures of lumbar lordosis, intervertebral joint angles and sacral tilt were compared between conditions and sex. Results: Sitting consisted of approximately 70% of maximum range of spine flexion. No differences in lumbar flexion were found between the chair features or control. Significantly more anterior pelvic rotation was found with the lumbar support (p = 0.0028) and seat pan tilt (p < 0.0001). Males had significantly more anterior pelvic rotation and extended intervertebral joint angles through L1–L3 in all conditions (p < 0.0001). Conclusion: No one feature was statistically superior with respect to minimising spine flexion, however, seat pan tilt resulted in significantly improved pelvic posture.

Practitioner Summary: Seat pan tilt, and to some extent lumbar supports, appear to improve seated postures. However, sitting, regardless of chair features used, still involves near end range flexion of the spine. This will increase stresses to the spine and could be a potential injury generator during prolonged seated exposures.     

脱胶工艺对不同段棉秆皮纤维性能的影响

定量测定棉秆皮各段成分含量,并采用化学二煮法脱胶方法对棉秆皮进行分段脱胶.以棉秆皮纤维细度、残胶率、断裂强度为指标,研究脱胶处理对提取的不同段棉秆皮纤维性能的影响.结果表明,在同一脱胶工艺条件下,不同段棉杆皮纤维的细度、残胶率、断裂强度有较大差异,棉秆皮应采用分段脱胶处理.合理的棉秆皮脱胶分段方案为：第一段根部,地表以下部分;第二段中段,地表以上长度25cm;第三段稍部,地表以上长度大于25cm.     

Movements with Lateral Constraint

Abstract

The literature on terminal control tasks and continuous tracking tasks suggests a possible model for tasks where the subject must guide a vehicle at his own speed along a course defined by a tolerance band. The model predicts a linear relationship between the average velocity and the width of the tolerance band. Throe experiments are described which simulate vehicle guidance by pencil-and-paper experiments for courses consisting of straight lines and circles. The predictions of the model were confirmed, suggesting that a general measure for the ease of control of a vehicle (or other controlled system) is possible using this technique.     

Disturbance and recovery of trunk mechanical and neuromuscular behaviours following prolonged trunk flexion: influences of duration and external load on creep-induced effects

Trunk flexion results in adverse mechanical effects on the spine and is associated with a higher incidence of low back pain. To examine the effects of creep deformation on trunk behaviours, participants were exposed to full trunk flexion in several combinations of exposure duration and external load. Trunk mechanical and neuromuscular behaviours were obtained pre- and post-exposure and during recovery using sudden perturbations. Intrinsic trunk stiffness decreased with increasing flexion duration and in the presence of the external load. Recovery of intrinsic stiffness required more time than the exposure duration and was influenced by exposure duration. Reflexive trunk responses increased immediately following exposure but recovered quickly (～2.5 min). Alterations in reflexive trunk behaviour following creep deformation exposures may not provide adequate compensation to allow for complete recovery of concurrent reductions in intrinsic stiffness, which may increase the risk of injury due to spinal instability.

Statement of relevance: An increased risk of low back injury may result from flexion-induced disturbances to trunk behaviours. Such effects, however, appear to depend on the type of flexion exposure, and have implications for the design of work involving trunk flexion.     

Influences of denucleation on contact force of facet joints under whole body vibration

To investigate the influence of the injured disc, frequency, load and damping on the facet contact forces of the low lumbar spine on the condition of whole body vibration, a detailed 3-D nonlinear finite element model was created based on the actual geometrical data of embalmed vertebrae of lumbar spine. The denucleation and facetectomy, together with removal of the capsular ligaments was employed to mimic the injury conditions of lumbar spine after surgery. The compression cyclic force was assumed to mimic the dynamic loads of transport vehicles. The results show that the high frequency vibration might increase both of the value and the vibration amplitude of facet contact forces of the lumbar spine under whole body vibration. The nucleus removal may increase significantly the facet contact forces. Although damping can decrease the vibration amplitude of facet contact forces for intact models, it has less effect on the vibration amplitude of facet contact force for the denucleated models. The denucleation of intervertebral discs is more harmful to the facet articulation on the condition of whole body vibration.     

Primary Results of New Rare Earth Materials for Hongti Grape

New rare earth (RE) materials including RE phosphate as base fertilizer, bioactive RE micro-fertilizer and RE entire plant nutrition agent as topdressing fertilizer are treated on Hongti grope.The result showes that the plant leaves become thicker, the color is dark green, the plant disease index is lower, and the sugar content significantly increases.     

江永香柚柚皮中挥发性化学成分的GC-MS联用分析研究

采用水蒸气蒸馏法分别提取江永香柚外黄皮和内白皮中的挥发性成分,经GC-MS联用分析,分别鉴定出61种和22种化合物.江永香柚外黄皮中挥发性成分以柠烯碳氢化合物为主体成分,其中柠檬烯含量占粗精油的76.04%,江永香柚内白皮则以十八碳二烯酸、棕榈酸和七聚氧化乙烯为主体成分.     

金属型缸套涂料剝离的试验研究

本文就金属型离心铸造缸套涂料的剥离进行了研究。认为在以石英粉为主的涂料中加入低熔点耐火材料或助熔剂能使涂料在高温铁水的作用下烧结。利用铸件冷却过程中,被烧结的涂料层与铸件热膨胀系数不同的特性,可使涂料自铸件表面剥离,从而获得表面光洁的铸件,避免了涂料粘附在铁