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31.
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。  相似文献   
32.
咪鲜胺等新型杀菌剂对葡萄病害的防治效果   总被引:3,自引:0,他引:3  
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。  相似文献   
33.
采用粉质仪和拉伸仪研究了不同添加量玉米种皮膳食纤维面团的粉质拉伸特性和质构特性,采用物性测试仪(TPA)研究了不同添加量玉米种皮膳食纤维对制作的生饺子皮和熟饺子皮质构的影响.结果表明:玉米种皮膳食纤维的添加,使面团的吸水率增大、形成时间与稳定时间显著延长、弱化度下降;使面团的拉伸曲线面积、抗拉伸阻力和拉伸比例增大,面团延伸性变小;使生饺子皮硬度和黏附性减小,其弹性、内聚性、胶凝性、咀嚼性和回复性增大,熟饺子皮黏附性减小,硬度、弹性、胶凝性、咀嚼性和回复性增大,内聚性基本不变.  相似文献   
34.
《Ergonomics》2012,55(10):1393-1404
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.  相似文献   
35.
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.  相似文献   
36.
《Ergonomics》2012,55(2):293-305
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.  相似文献   
37.
《Ergonomics》2012,55(11):1043-1052
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.  相似文献   
38.
《Ergonomics》2012,55(7):967-978
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.  相似文献   
39.
柚皮提取物不同级分的抗氧化活性研究   总被引:8,自引:1,他引:8  
为柚皮资源的精细化利用提供参考依据,采用弱极性的DM130大孔吸附树脂为吸附剂、以不同浓度的乙醇溶液对柚皮提取物进行梯度洗脱,得到5种洗脱级分。采用二苯代苦肼自由基法和硫氰酸铁盐比色法对该5种级分的抗氧化活性进行了测定。结果显示:5种洗脱级分表现出不同程度的清除DPPH自由基和抗亚油酸过氧化活性,其作用大小依次为:水级分、20%乙醇级分、40%乙醇级分、60%乙醇级分和80%乙醇级分,5种洗脱级分的抗氢化活性均高干柚皮苷,但均低于二丁基羟基甲苯。柚皮提取物不同洗脱级分具有不同的抗氧化活性。  相似文献   
40.
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.  相似文献   
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