Experimental Investigation on Chip-break Influenced by Cryogenical Cold Air jet     

YANG Ying  TONG Ming-wei  YAN Xing-chun  SHEN Qiang 《保鲜与加工》2004,(5):74-77

In machine cutting, the replacement of traditionalKGcutting solution with cryogenical cold air jet not only possesses a good cooling and lubricating efficiency, but also can avoid the occurrenceof environmental pollution. In order to clarify the manner and performance of discharged cutting chip under cryogenical cold air jet condition, an experiment was carried out for steel grade 45 in the dry and cryogenical cold air jet cutting comparatively. The effects of cryogenical cold air jet on the breaking of cutting chip are discussed. Experimental results reveal that, in the valid ranges of pressure and temperature, the cryogenical cold air jet can widen the chip broken region effectively. Different insufflating angle of cold air behaves different influence on the chip-break. From the experiment, it has been gained that the optimized jet insufflatingangle, temperature effecting range and pressure working range of cold air, which provides the foundation of industrial manufacturing.  相似文献   

地下热水的来源与补给机制分析——以重庆北温泉为例     

肖琼  沈立成  杨雷 《保鲜与加工》2015,(4):91-103

地下热水的来源研究对地下热水资源量评价和可持续开发利用有重要意义。选取重庆市北温泉作为研究对象,采用水化学分析、D、O同位素以及实时在线监测对其热水来源进行了研究。研究认为：重庆市北温泉泉水为中-低温浅层中性地热水,水化学类型为SO4-Ca型,地下热水的δ 18O值为-8.48‰～-7.09‰,δD值为-55.46‰～-53.26‰,其补给来源为雨水,补给高程为海拔641～1 206 m的岩溶出露区。安装马歇尔槽和CDTP300高分辨率实时在线监测发现：1)地下热水水文地球化学特征在长时间内稳定,体现了稳定的水-岩作用过程;2)北温泉的流量与研究区降雨量呈现出以半年为单位的滞后,雨季偏低,旱季偏高;当场降雨后20 d左右,温泉水的水温和电导率微降,水量增加。地下热水的来源为大气降水,其补给除了长时间长距离的含水层稳定补给外,热水上升过程中受地表水和浅层地下水的补给。  相似文献   

Study of IP over WDM System Structure     

SHEN Ke  XU Guo  GAN Yu-yu 《保鲜与加工》2001,(3):103-106

WDM technology is the basis of optical network implementation. Due to eliminating SONET/SDH and ATM elements, and allowing direct connection with IP routers, IP over WDM can reduce network cost and simplify network expansion . In this thesis, the structure and protocol layers of IP over WDM are firstly explained. Then the procedures of this network are described briefly. At last, the problems and future of IP over WDM are analyzed  相似文献   

Lighting Design of Chinese Traditional Buildings and Application of New Type of Little Power LED     

LI Xu -ji  SHEN Tian- xing  MA Jian 《保鲜与加工》2006,(5):86-89

This paper is a part of the research on the lighting techniques of the traditional Chinese buildings in Summer Palace,Beijing,which is a sub-project of the Municipal Research Project on the Correlative Techniques for Beijing's Sustainable Development(Y0604017040391).The work,which the authors took part in,on the most representative Chinese traditional buildings in Summer Palace,is taken as a case study on lighting design and lab simulated experiments and checked by practical result,illustrating a working frame for other similar lighting design works.  相似文献   

Automatic Fingerprint Classification by GA-Based Neural Network     

HUANG Xi yue  MA Xiao xiao  SHEN Zhi xi  WANG Peng  ZHOU Xin 《保鲜与加工》2001,(1):74-77

Fingerprint classification can provide an important indexing mechanism in a fingerprint database. An accurate and consistent classification can greatly reduce fingerprint matching time for large database. In the paper, by combining genetic algorithm and neural network is presented a fingerprint classification algorithm which is able to achieve an accurate classification. By inputting the global feature represented by directional image to three layer neural network trained by genetic algorithm, the fingerprints were classified into six categories: whorl, right loop, left loop, arch, double loop and undiscerning type successfully.  相似文献   

Learning the BN Structure Based on the Sum of Mutual Information     

XING Yong kang  SHEN Yi dong 《保鲜与加工》2001,(1):78-83

The Crossing Entropy is defined to scale the similar level of two probability distribution. In many papers on learning BN structure,the Crossing Entropy was used as an indicator of measuring the learning accuracy of an algorithm.The known scoring metrics for learning BN structure is analyzed in this paper,then a new scoring metrics Sum of Mutual Information is proposed based on the information theory.At last,two algorithm for learning BN structure by SIM is represented.  相似文献   

铁矿粉烧结液相流动性能的特征数方程的建立     

吴铿  申威  杜瑞岭  闫广  门正朝  员晓 《保鲜与加工》2015,(5):26-31

为解决在研究铁矿粉烧结液相流动性能时通常只考虑面积增长率这一终点信息,而没有考虑过程信息的缺陷以及采用多个指标来表征流动性能在使用上的不便,对影响流动性的因素进行了分析,结合量纲分析和白金汉定理推导出了能定量表征流动性强弱的流动性特征数(LD),简化特征数方程后得到等效流动性特征数(Ld Θ)。试验采用了可视卧式高温炉,记录了铁矿粉烧结液相流动的整个过程信息,通过基础实验和对照实验确定液相流动的起点和终点之后,可以得到每一种矿粉相应的等效流动性特征数数值。测量5种铁矿粉在两种方法下的流动性指标,当只考虑面积增长率时的流动性强弱顺序为A>C≈D>B>E,新方法下为Ld ΘA>Ld ΘD>Ld ΘC≈Ld ΘE>Ld ΘB,两种方法下的指标相近,但是综合了各种重要信息的新指标能进一步区分出各个因素对流动性能的影响程度。  相似文献   

辽宁省玉米现状及其发展趋势     

申军 《种子世界》2007,(3):4-6

玉米起源于美洲，公元16世纪传入中国南部，17世纪中叶传入辽宁省，在辽宁省已有300多年的种植历史，和其他作物如水稻、小麦、高梁、谷子等作物数千年的种植历史相比，栽培时间很短，但其发展速度却很快，目前为辽宁省第一大作物。辽宁省具有玉米生产的自然优势，无霜期、有效积温、降雨量分布、日照时数等自然条件非常适合玉米栽培。[第一段]  相似文献   

棉铃虫对辛硫磷抗性的选育、交互抗性及增效剂增效作用研究   总被引：6，自引：0，他引：6  

杨亦桦  陈松  吴益东  沈晋良 《棉花学报》2002,14(1):13-16

1 991年采自河南偃师棉田的棉铃虫种群(简称 YS种群 )与敏感品系相比有 2 .7倍的抗性。该种群在室内经功夫菊酯 +辛硫磷 (1∶ 2 5 )筛选了 2 7代后 ,对辛硫磷的抗性达到 9.4倍 ,再单用辛硫磷对该种群筛选 2 1代 ,获得 6 3 .0倍的抗性。交互抗性测定结果表明 ,棉铃虫对辛硫磷产生高水平抗性后对灭多威具有比较明显的交互抗性 ,对久效磷具有一定程度交互抗性 ,对甲基对硫磷和丙溴磷只有较低水平的交互抗性。 3种增效剂 TPP、DEF和 PBO对辛硫磷的增效比分别为1 .4、2 4 .8和 1 .0 ,DEF的增效作用明显 ,使辛硫磷的抗性由 6 3倍降至 2 .5倍 ,初步证明酯酶是引起棉铃虫对辛硫磷产生抗性的重要原因。本文的研究结果对于在棉铃虫抗药性治理措施中选择辛硫磷的轮换或替代品种具有重要参考价值  相似文献   

燃料电池汽车智能仪表开发     

周逸峰  沈勇 《农业装备与车辆工程》2007,(5):30-32

通过对燃料电池汽车和现代汽车仪表的研究开发了一套智能仪表信息系统。该仪表以液晶显示屏为主背景．可数字化显示车速、里程、挡位信号、报警信号、环境温度，监测燃料电池的状态等，具有汽车故障诊断数据接口，读出保存的数据可以分析汽车的运行情况，有良好的多功能扩展性；软件设计基于国际流行的WindowsCE平台。  相似文献