胶棒滚筒式采棉机棉箱的建模与仿真

为了研究胶棒滚筒式采棉机棉箱翻转机构的工作性能,利用ADAMS软件对采棉机关键部件（棉箱）进行建模,并对棉箱关键构件（翻转机构）进行了仿真及参数优化,通过对棉箱在翻转过程中质心的位移、加速度的分析,得到了棉箱关键部件的优化参数,为进一步研究胶棒滚筒采棉机棉箱的设计提供指导。     

壳聚糖在农作物产品保鲜及抗逆性方面的研究进展

综述了壳聚糖在果实、蔬菜和花卉中的保鲜作用及提高作物抗逆性等方面的研究进展,旨在为实现壳聚糖在农业上的生产化应用提供理论依据。     

Effect of acupuncture on CD4+ CD25+ Foxp3+ regulatory T-cells in rats of embryo implantation failure

AIM：To observe the effect of acupuncture on CD4+ CD25+ Foxp3(forkhead box P3)+ regulatory T-cells(Treg cells) in rats with embryo implantation failure. METHODS：One hundred and forty-four pregnant rats were randomly divided into control group(N), mifepristone treatment group(M), mifepristone+acupuncture treatment group(A) and mifepristone+progestin treatment group(W). The rats in groups M, A and W were treated with mifepristone-sesame oil solution on day 1, while the rats in group N were injected with the same amount of sesame oil. The Housanli(ST36) and Sanyinjiao(SP6) points were selected for acupuncture. From day 1 to the time of death, the rats in group A were fasten up and then the acupuncture was performed. Accordingly, the rats in group N and group M were only fixed, and the rats in group W were given progestin. Implanted embryos in each group were counted. The proportions of CD4+ CD25+ Foxp3+ Treg cells in peripheral blood and CD4+ Foxp3+ Treg cells in the endometrium were detected by flow cytometry. The mRNA and protein levels of Foxp3 were determined by real-time PCR and Western blotting, respectively. RESULTS：Compared with group N, the number of implanted embryos, the percentages of CD4+ CD25+ Foxp3+ Treg cells in peripheral blood and CD4+ Foxp3+ Treg cells in the endometrium, and the expression of Foxp3 protein and mRNA in the endometrium were significantly decreased in group M(P<005). Compared with group M, the above indexes in group A and group W were significantly increased. CONCLUSION: The effect of acupuncture in rats with embryo implantation failure may be closely correlated with the modulation of CD4+ CD25+ Foxp3+ Treg cells.     

凸多边形的最小面积凸四边形包围盒生成算法

基于遗传算法的思想,研究并提出了凸多边形面积最小的凸四边形包围盒生成算法。该算法简单,速度快,效果显著。实际应用表明了该算法的有效性与实用性。     

草莓采后热处理保鲜效应研究

草莓采后热处理保鲜效应研究张子德，马俊莲（河北农业大学食品系，保定０７１００１）关键词草萄，热处理，保鲜分类号Ｓ６６８．４Ｓ６０９．３近年来，热处理做为无公害保鲜水果的一种方法已引起人们的普遍关注。据报道，热处理后果实的呼吸作用下降”‘，延迟跃变型果...     

几种保鲜方法对秦美猕猴桃常温贮藏效果的研究

采用7种保鲜方法对秦美猕猴桃进行了常温贮藏研究,结果表明,固体保鲜剂和赤霉素浸果均可有效延缓呼吸,降低腐果率和失重率,延长贮藏期,在试验所涉及的范围3内,以采用40μg/g和50μg/g的GA3处理效果好,与对照相比,可使呼吸高峰推迟14d到来,贮藏45d总损耗率分别较对照降低73．9％和72．6％,并且保持了良好的果肉硬度和品质。     

斜拉桥钢箱梁在车辆荷载作用下的局部应力分析

从钢箱梁结构应力分析的角度,采用ANSYS有限元软件,对斜拉桥钢箱梁在车辆荷载作用下的 局部应力进行了分析。给出了在车辆荷载作用下钢箱粱的局部(包括桥面板、U型肋、横隔板、中腹板 和底板)应力分布状况,为斜拉桥的整体分析及优化设计提供了依据。     

冬枣贮藏保鲜的影响因素及保鲜技术研究进展

总结了影响冬枣贮藏保鲜的主要因素,介绍了冬枣贮藏保鲜的主要技术及研究进展,为冬枣贮藏保鲜研究及应用提供思路。     

葫芦茶提取液对草莓保鲜效果的研究

[目的]开发安全的水果保鲜剂,研究葫芦茶提取液对草莓的保鲜效果。[方法]按葫芦茶∶水1∶20的比例制备葫芦茶提取液原溶液和稀释5倍的稀释液,对草莓进行保鲜试验。[结果]葫芦茶稀释液对草莓的呼吸作用具有抑制作用,处理3 d后呼吸强度显著低于对照(P<0.05)。葫芦茶提取液处理可以明显延缓草莓可滴定酸下降的速度,葫芦茶提取液处理后6 d草莓可滴定酸下降20%左右,而对照下降30.6%。[结论]葫芦茶提取液能明显改善草莓感观品质,具有保鲜效果。     

富贵竹茎段保鲜研究

[目的]更好地解决富贵竹采后出现的黄化、软腐等问题。[方法]以株龄13个月的富贵竹为材料,采用不同的保鲜剂配方配制保鲜液,筛选出适合富贵竹茎段保鲜及贮运的保鲜液。[结果]用保鲜液200 mg/L Al2(SO4)3+100 mg/L Vc+200 mg/L CaCl2+1%Sug+250mg/L 8-HQC+0.02%CCC+1/1 000 70%甲基托布津冬季处理的富贵竹茎段上端切口状态最佳,收口细密,颜色均匀无黄化。200 mg/LAl2(SO4)3+0.05 mg/L 2,4-D+10 mg/L VB5+10 mg/L VB保鲜液在富贵竹茎段鲜重、叶绿素含量、CAT活性方面与其他配方保鲜液存在极显著差异(P<0.01),保鲜效果最好,防治下端切口(脚部)黄化的效果最佳。[结论]该研究筛选出的2个保鲜液配方能很好地解决富贵竹茎段上端切口开裂、失水皱缩和黄化问题以及茎段脚部黄化、植株腐烂、死亡等问题。