共查询到20条相似文献,搜索用时 765 毫秒
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开包机在倒出纸箱烟包的过程中,容易出现卡料现象,通过对开包机的结构原理进行分析,设计一种以气缸驱动的纸箱推料装置,消除了卡料现象,保证了安全生产,提高了生产效率,减少了烟叶造碎损失. 相似文献
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对烟稻轮作区烟稻轮作与非烟稻轮作烤烟进行了对比试验,结果表明:两个处理的生育期无明显差异;田间长势长相烟稻轮作的烟株长势长相好于非烟稻轮作烟株;产量、产值、均价,上中等烟比例烟稻轮作烟叶分别比非烟稻轮作烟叶高5.2kg/亩、181.64元/亩、0.7元/kg、1.8%;烟稻轮作烟叶外观质量及抗逆性好于非烟稻轮作。 相似文献
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气相色谱-质谱联用测定大米中6种烟碱类农药残留 总被引:1,自引:0,他引:1
为了寻求烟碱类农药同时检测的新途径,建立了大米中烯啶虫胺、噻虫嗪、氯噻啉、吡蚜酮、吡虫啉、啶虫脒6种烟碱类农药气相色谱-质谱选择离子模式定性定量检测方法,并对比了提取溶剂、提取方法、固相萃取柱净化效果。结果表明,以乙腈超声提取、经Polymer Trap SPE净化,用气相色谱-质谱法对6种烟碱类农药进行定性定量检测,6种烟碱类农药在0.1~10 mg/kg质量浓度范围内呈良好的线性关系,相关系数为 0.991 8 ~ 0.998 9。在大米中添加0.05、0.2、1 mg/kg 3个浓度的平均回收率为83.1%~101.4%,相对标准偏差为1.3%~8.9%,最小检出量为0.002~0.012 ng,最低检测浓度为0.05 mg/kg。 相似文献
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《Wear》1986,113(3):331-352
It is shown that cylinders can wear against each other or against flats in only a very few ways, each of which can be defined geometrically. For each geometry the volume of any intersection varies with a few easily measured dimensions. When dealing with a wear scar on a tube it is relatively easy to relate the volume already lost as a fraction of the volume that must be removed before any particular depth is reached. The results are presented graphically so that calculations can be reduced to a minimum and the results made as widely applicable as possible.The methods developed here have already been employed to predict the lifetimes of irreplaceable tubes showing wear scars. Amongst other possible uses of these methods, one discussed in this paper is a better way of calculating specific wear rates in wear testing using crossed cylinder geometries. 相似文献
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研究了高低压腔气路闭环空气悬架系统充放气过程中的能耗问题。基于热力学和车辆动力学理论建立了气路闭环空气悬架充放气模型并在Simulink中仿真,通过1/2车对空气弹簧进行充放气实验,实验结果验证了所建立的充放气模型的正确性。为分析研究闭环系统能量损耗途径,采用压缩气体有效能(即压缩气体对外界大气所做的功)对系统充气、放气、升压三个过程的能量损耗进行量化计算。仿真结果表明:充气过程中能耗随高压腔压力升高而变大;放气与升压过程中的能耗都随低压腔压力升高而降低;在同等条件下,高低压腔气路闭环系统相对开环系统可以节约大量的能量。 相似文献
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Gopal B. Avinash 《Scanning》1995,17(3):156-160
To manage large volumes of image data generated routinely using real-time confocal microscopy, compressing image data using a lossy algorithm prior to sustained video rate transferring and/or storing is proposed. Test criteria for determining the acceptability of uncompressed data, both qualitatively and quantitatively, are described, and an empirical demonstration of the use of lossy compression in data management is provided. It is found that, if appropriately used, the lossy compression scheme could retain all the useful information in the data while providing better compression ratios (memory for the original/ memory for the compressed) when compared with a lossless scheme. 相似文献
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An oscillating cryo-knife reduces cutting-induced deformation of vitreous ultrathin sections 总被引:2,自引:0,他引:2
A new oscillating cryo‐knife for producing uncompressed vitreous sections is introduced. The knife is a modified cryo diamond knife that is driven by a piezo translator. Optimal setting for the oscillation was found to be in the inaudible frequency range of 20–25 kHz. Yeast cells and polystyrene spheres were used as model systems to describe compression in the vitreous sections. We found that compression could be reduced by a factor of about 2 when the knife was oscillating. When the oscillator was turned off, sections were compressed by 40–45%. However, only 15–25% compression was obtained when the knife was oscillating. In some cases completely uncompressed sections of yeast cells were produced. It was also found that the amount of compression depends on the specimen itself and on its embedding medium. With the results shown here, we demonstrate that the oscillating knife can produce high‐quality vitreous sections with minimum cutting artefacts. 相似文献
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为开拓间歇式能源应用新途径,本文提出了一种复合制冷系统,该系统带有抽水压缩气体储能装置。在储能阶段,该储能制冷系统通过水泵将电能转换为水气共容舱内带压气体的内能;释能阶段,在水气共容舱内高压气体的作用下,使其内部的水流经水轮机直接驱动制冷循环制冷,而制冷循环中冷凝器所释放的能量被水气共容舱内的高压气体全部吸收,最终完成了利用间歇式能源制冷之目的。文中建立了描述储能与制冷过程的热力学模型,并重点研究了储能和制冷过程中关键节点的热力学参数变化规律,与文献给出的储能制冷系统相比,该系统具有较高的制冷系数。为拓展间歇式能源实际应用途径提供了一种新思路。 相似文献
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提出了一种基于压缩体素模型的球头刀空间扫描体构造新方法,将球头刀分解为相应球体部分和圆柱体部分,分别给出了球体和圆柱体空间扫描体构造公式并构造出其表面模型,利用RayCasting方法分别将球体和圆柱体空间扫描体表面模型进行离散,将其分别转化为压缩体素模型,通过布尔并操作生成球头刀空间扫描体压缩体素模型。该方法由于采用三个方向的Dexel模型表示体素模型,其计算机内部存贮空间得到了很大地压缩,并简化了布尔操作和提高了布尔操作速度;通过MarchingCubes方法提取数控加工仿真工件表面模型并进行图形显示,提高了显示质量和显示速度。该方法在《基于压缩Voxel模型的五坐标数控加工仿真系统》中得到了应用并完成了某叶轮的五坐标数控加工仿真,仿真结果三维信息完备,NC编程人员可从任意方向观察、验证仿真结果,克服了现有五坐标数控加工仿真方法和商品化软件系统的不足,该方法是虚拟数控加工的关键技术。 相似文献
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为了实时、在线研究烟草原料烟丝的热裂解产物,本工作搭建了一套热裂解光电离质谱装置。利用真空紫外光电离飞行时间质谱装置研究烤烟烟丝不同部位(上-B2F、中-C3F和下-X2F)分别在300、400、500、600和700℃热裂解时的产物,在线获得3个部位烟丝一系列热解产物的光电离质谱图,比较不同裂解温度下热解产物的变化规律。实验进一步分析了500℃下热解产物,如乙烯胺(m/z 43)、异戊二烯(m/z 68)和二甲基呋喃(m/z 96)等信号强度随时间的动态变化曲线,掌握裂解反应的动态变化过程。通过主成分分析(PCA)法对裂解产物质谱图进行统计分析,得到不同部位烟丝化学成分的差异。其中,m/z 58、96、110组分为下部烟(X2F)热解的标志性产物,m/z 43、126组分为中部烟(C3F)的代表性产物,上部烟(B2F)的主要代表性产物为m/z 84组分。结果表明,光电离质谱技术是一种研究烟草热解产物动态变化的重要手段,可通过评估裂解产物中主要成分及相对含量快速区分不同部位烟草样品。 相似文献