自行车轴皮电镀

自行车轴皮,俗称花鼓筒.其质量好坏对自行车骑行的轻快与否有很大影响.轴皮电镀有一些较特殊的要求,所以有一定的难度.一、轴皮电镀要求轴皮电镀属防护、装饰性电镀,有较高的要求.而且一般厂家均先电镀单件,然后总装.如果整只轴皮电镀则它的电镀质量与机械性能都会受到一定影响.轴皮电镀有下列几点要求:

“大康”牌轴皮 开拓新市场

上海大康轴皮厂是一家具有10多年历史生产优质儿童自行车轴皮的专业厂。该厂为了进一步满足国内童车厂对轴皮的需要,对轴皮的生产工艺进行了全面的改革,采用了新一代冲压组合式新工艺生产轴皮。使用新工艺生产后,产品的加工工序减少33％,设备容量大量减少(原来最大为560吨冲床。

半开轴的加工

０引言我厂为外单位制造了三台自行车行业加工轴皮的专用机床。该机床结构新颖、生产效率高、零件的材料利用率极高，是自行车行业的升级换代产品。其主轴是该设备的主要零件（见图１），材质为４５钢，整体调质，局部外圆高频淬火。此主轴为半开结构，在自然状态下分离，...

Highly Sensitive Flexible Pressure Sensors based on Graphene/Graphene Scrolls Multilayer Hybrid Films

In recent years,flexible pressure sensors have attracted much attention owing to their potential applications in motion detection and wearable electronics.As a result,important innovations have been reported in both conductive materials and the underlying substrates,which are the two crucial components of a pressure sensor.1D materials like nanowires are being widely used as the conductive materials in flexible pressure sensors,but such sensors usually exhibit low performances mainly due to the lack of strong interfacial interactions between the substrates and 1D materials.In this paper,we report the use of graphene/graphene scrolls hybrid multilayers films as the conductive material and a microstructured polydimethylsiloxane substrate using Epipremnum aureum leaf as the template to fabricate highly sensitive pressure sensors.The 2D structure of graphene allows to strongly anchor the scrolls to ensure the improved adhesion between the highly conductive hybrid films and the patterned substrate.We attribute the increased sensitivity(3.5 k Pa^-1),fast response time(<50 ms),and the good reproducibility during 1000 loading-unloading cycles of the pressure sensor to the synergistic effect between the 1D scrolls and 2D graphene films.Test results demonstrate that these sensors are promising for electronic skins and motion detection applications.

Process design for multi-stage stretch forming of aluminium alloy aircraft skin

A process design approach for multi-stage stretch forming was proposed by combining the strain distribution method and finite element method(FEM)to determine the minimum stage number and deformation amount of each stage.The strain distribution method was used to calculate the deformation amount of each stage and evaluate the formability through a safety criterion.FE simulation was taken as an analysis tool to reveal the deformation behaviour,to predict the strain contour and to determine the process parameters at each stage.To evaluate the effect of heat treatment after pre-strain on occurrence of deformation defects during the subsequent deformation,a multi-stage uniaxial tension test for 2B06 aluminium alloy sheet was carried out.A case study demonstrates that the approach has high reliability and good practicability.

Increased expression level of corticotropin-releasing hormone in the amygdala and in the hypothalamus in rats exposed to chronic unpredictable mild stress

Objective Corticotropin-releasing hormone（CRH）plays an important role in neuroendocrine,autonomic and behavioral responses to stressors.In the present study,the effect of chronic unpredictable mild stress（CUMS）on CRH neurons was investigated in rat brain.Methods The rats were exposed to one of the stressors each day for 21 d.Immunostaining was performed to detect the CRH-positive neurons in the paraventricular nucleus（PVN）of the hypothalamus and in amygdala.Results After the stress protocol,the animals showed a reduction in body weight gain as well as reduced sucrose preference and locomotor activity.Interestingly,the CRH neurons in both PVN and central nucleus of the amygdala（CeA）were stimulated by CUMS.The densities of CRH-containing neurons in both PVN and CeA were significantly higher than those in control group.Conclusion The CRH systems in PVN and CeA may both contribute to depression-like behaviors during CUMS.

Influence of Acupuncture on HPA Axis in a Rat Model of Chronic Stress-induced Depression

Objective： To investigate the neurobiological mechanism of depression pathogenesis and reveal the mechanism of acupuncture treatment of depression. Methods： Wistar rats were selected for subjects. A rat model of depression was made by individually housing with unpredicted chronic moderate stimuli. Changes in behavior and hypothalamus-pituitaryadrenocortical axis were examined in rat models of stress-induced depression. Meanwhile, the intervening effect of acupuncture was evaluated and the curative effects of different acupuncture methods compared. Results： CORT and ACTH contents of serum were significantly higher in the model and normal saline groups than in the control group （P〈0.05）, significantly lower in the hand acupuncture and electroacupuncture groups than in the model group （P〈0.05） and significantly lower in the medication group than in the normal saline group （P〈0.05）. There were no significant differences between the hand acupuncture, electroacupuncture and medication groups. Conclusion： Acupuncture of Baihui（GV 20） and Taichong （LR 3） has a marked antidepressant effect. Its mechanism may be related to the regulation of HPA axis by acupuncture.

Effects of neuro-immuno-modulation on healing of wound combined with local radiation injury in rats

Purpose： To investigate effects of neuro-immuno-modulation on wound healing by observing changes of cytokines and hypothalamic-pituitary-adrenal （HPA） axis hormones in acute stress reaction in rats with wound and combined local radiation injury. Methods： Sixty female Wistar rats （weighting 200 ± 20 g） were randomly divided into normal control group, wound group and combined wound-local radiation （CWR） group （25 Gy local radiation post wound）, 20 rats in each group. Contents of IL-1β, IL-6 and IFN-γ and IL-4 in serum were measured and changes of adrenocorticotropic hormone （ACTH） and glucocorticoid （GC） in serum were analyzed by using enzyme-linked immunosorbent assay and radioimmunologic assay, respectively at different time points post wound and radiation. Results： （1） The level of IFN-γ, one of the Thl cell cytokines increased significantly at 14 d post CWIL which was markedly higher than that in control group and wound group. However, the level of IL-4, IL-1β and IL-6, one of the Th2 cell cytokines, did not show obvious change. （2） Ratio of Thl/Th2 （IFN-γ/IL-4） in wound group and CWR group increased significantly at 7 d after wound and radiation, which suggested that Thl/Th2 balance drifted to Thl immune response. The ratio of Thl/Th2 in wound group returned to the normal level up to 14 d after the wound and radiation, while the Thl/Th2 ratio in CWR group increased persistently and was much higher than that in control and wound groups. （3） Level of serous ACTH and CC in CWR group increased at 3 d post wound and radiation, and among them, level of CC showed statistically significant increase, which was much higher than that in control and wound groups. Conclusion： Level of serous neurohormone CC in rats increased significantly immediately after wound and radiation; while the level of IFN-γ showed significant increase only up to 14 d after wound and radiation, and the Th1/Th2 imbalance sustained till 28 d post wound and radiation. In order to reduce acute damage caused by CWR, organic immune system and nerve system showed up a marked regulate effects simultaneously and mutually. Nonetheless, the excessive stress induced by CWR causes distur- bance of immunoregulation, which is one of the key reasons for delayed wound healing in CWR.