高压脉冲电场在桑果汁杀菌中的应用

研究了高压脉冲电场对不同桑果品种原汁的杀菌效果,以及高压脉冲电场对不同微生物的杀菌效果,比较了杀菌前后桑果原汁的一些指标变化。     

大气电场与大气污染物关系研究

为了研究大气电场与大气污染物关系,笔者利用太原地区2个气象站2012年6月—2015年5月的同步晴天大气电场、大气污染物、气象要素的观测资料,对太原地区晴天大气电场与大气污染物的相关性进行分析。结果表明：大气电场与大气颗粒物的相关性：PM₁₀>PM_2.5>PM_1.0,其中PM₁₀与大气电场的相关性比PM_2.5、PM_1.0显著大;大气电场与污染气体的相关性中NO_x较高,其次为O₃、CO,污染气体与大气基本带电粒子的相关性决定了它们与大气电场相关性的密切关系。通过对大气颗粒物的特征分析,给出了尖草坪大气电场高于桃园以及桃园大气电场在16:00左右出现1个小峰值的原因。     

Hybrid Electric Vehicle and Its Electrical Drive System

Hybrid electric vehicle (HEV) is a mixture of electric vehicle and conventional vehicle, which has the merits of reducing exhaust gas and the consumption of gasoline HEV is the new development way of automobile industry. This paper introduces HEV, and discusses the essential framework of HEV drive system,the basic types of the electrical drive and their features and the present state of the development at home and abroad.Some key technologies are also proposed which determine the drive and control performance of HEV.     

Analysis of Unified Power Flow Controller in Damping Low Frequency Oscillation of Power System

With the development and complication of power system, the problem of low frequency oscillation in electric network becomes obvious. Unified Power Flow Controller is one of the most powerful facilities in Flexible AC Transmission Systems, which can improve the transient stability and damp the low oscillation in power system with suitable control. Considering the characteristics of inverter's output voltage magnitude, adjustment of phase and process of charge and discharge of dc capacitance, the dynamic model of UPFC is proposed by a series of nonlinear differential coefficient equations. Based on UPFC's dynamic model, the linear optimal controller of UPFC with state feedback is proposed. In this way, the low frequency oscillation is damped effectively. A simulation is processed basing the theory.     

Model and Numerical Analysis of Radiation Field Created by Lightning Overvoltage Wave on Transmission Lines

The radiation field created by the transmission line stroked by lightning far from the lightning channel has been analyzed by the FDTD method.The authors we establish the calculation model and FDTD calculation method of transmission line,and discusses the import of lightning excitation source.The simulation of lightning stroked on a single transmission line in free space or stroked on three-phase high voltage transmission lines in actual environments has been done,and gives the distribution of transient radiation field around the transmission lines when lightning overvoltage wave transmits along the transmission line.The simulation result shows that: the effect of the transient radiation field caused by lightning over voltage wave done with environment is obvious,and the high frequency component of transient radiation field may disturb or do harm to the electronic facility or communication facility around the transmission lines.     

工频电场对辣根过氧化物酶紫外-可见光谱及其活性的影响

辣根过氧化物酶经工频电场处理,测试电场处理前后的紫外-可见光谱和酶的活性.结果表明:辣根过氧化物酶紫外-可见光谱发生了明显变化,说明电场可以改变酶的构象;电场处理使辣根过氧化物酶活性普遍增加,酶活性增加可能是由酶构象的改变引起.研究结果对解释静电宏观生物效应具有重要意义.     

Surface Charge Distribution and Tip Electric Field about Carbon Nanotubes

Carbon nanotubes(CNTs) have some special physic properties which may own important technical values. We studied the electric characteristics of metallic carbon nanotubes including potential distribution, surface charge distribution and tip electric field based on electromagnetic theory. Our results show that the relative values of tip charge densities of short CNTs are bigger and so are the absolute values for long CNTs. We also find the electric field at the tips of metallic nanotubes is much bigger than external electric field. This is helpful for exploring theoretical problems about CNTs' field emission.     

Power Lines Icing Characteristics of the Three Gorges District and a Model of the Accumulation of Ice on Electric on Electric Power Lines

Based on the study of accidents investigation of the electrical power lines because of icing in the district of Three Gorges,this paper analyzes the icing conditions and characteristics of various ice accreted and develops a model of the accumution of hard rime on electrical lines.     

田间肥效试验数据的频率分析和施肥决策

为解决农业试验统计分析软件、扬州分析器(2.2)、Excel进行回归分析建立的部分非典型性肥料效应方程推荐的施肥量出现异常偏大、偏低甚至负值,脱离当地生产实际的问题。本文应用概率理论的基本知识和频数的原理和方法,对油菜田间肥效试验数据应用频率分析法进行统计分析,得到的油菜优化施肥量产量为1732.4 kg/hm²,氮、磷、钾优化组合范围分别为210.36~149.64 kg/hm²、81.89~58.11 kg/hm²、81.89~58.11 kg/hm²,与试验地（田）和当地生产实际相吻合。本研究是在频率分析的基础上,用加权平均方法,确定各种不同产量目标的生产因素组合,将其中产量高,出现频率大（稳产）,用肥节省的组合作为优化生产措施,具有增加施肥决策信息量,减少或避免小概率事件的风险的优点。可解决肥效试验数据分析统计汇总,应用扬州分析器(2.2)、Excel、DPS等统计分析软件进行回归分析建立的部分非典型肥料效应函数推荐的施肥量和目标产量出现异常值,与当地生产实际不相符的问题。肥料效应函数方程经方差分析不显著的试验,能否应用该研究方法进行施肥决策,推荐氮、磷、钾肥料优化组合和优化施肥量产量,还需在以后的工作实践中进一步探讨。     

通辽市固日班花风电场风能储量分析

为了开发科尔沁沙地的风能资源,为其治理提供便捷、安全的能源,利用科尔沁沙地最典型地区奈曼旗固日班花风电场测风塔和奈曼气象站的风向、风速资料,对固日班花风电场的风能储量进行分析。结果表明,固日班花风电场塔高10、60、65、70、80 m处的年平均风速订正后分别为4.9、6.8、7.0、7.2、7.3 m/s;相应风功率密度分别为136.5、315.4、341.3、365.6、382.1 W/m2。逐月风速与逐月风功率密度年内变化规律基本一致。风电场风能资源较为丰富,达到了建设大型风电厂的要求。     

The Simulating and Actual Measuring Calculation of the Inverse Problem of Circular Low Frequency Electric Current Field

The inverse problem of circular low frequence electric current field is calculated using simulated and actually measured data by modified iterative equipotential line algorithm.     

沙尘天气下大气电场与颗粒物关系研究

大气电场对各种气象要素的变化有着敏锐的反应,对一个地区大气电场特征的研究,有助于分析各种相关的天气过程,对该地区气候特征的研究也有重要意义。本文给出了太原地区3次沙尘天气下2个气象站内大气电场与大气颗粒物以及风速、湿度等气象要素相关性进行分析。结果表明,沙尘与晴天天气的大气电场有较大的差别,当沙尘到来后,大气电场值迅速下降,并且始终保持为较大的负值;沙尘天气下大气电场、PM10、PM2.5都发生剧烈的变化,PM1.0变化相对较小,其中沙尘天气下大气电场的绝对值、PM10、PM2.5分别比晴天天气下的值高3.94~5.74、2.07.94~5.89、1.28~5.91倍,沙尘天气下的PM1.0比晴天降低0.25~0.75倍）。不同粒径颗粒物的起电机理以及颗粒物来源不同导致颗粒物与大气电场的相关性不同,其中PM10、PM2.5呈较高的正相关,PM1.0呈负相关,且相关性较低。由于郊区站与城市站的下垫面不同,较大的风速将郊区站地表较大粗粒子吹起,使得郊区站沙尘大气电场在一些时段内会出现正值。     

高压矩形脉冲电场果蔬预处理微观结构变形机理的研究

基于电磁力学理论,结合苹果单细胞模型,研究其性状的变化,获得了HPEF作用果蔬的微观机理。研究显示,HPEF处理果蔬的效果与物料性质有关,不同物料预处理显著程度不同,主要是由于不同物料的细胞参数以及其结构引起力学性质的改变不同;HPEF处理作用强度越大,细胞膜受到的应力也越大。     

Effect of humidity and temperature on power electric field intensity

We measure power electric field intensity at a substation in southwestern P. R. China at various humidity levels and temperatures. Measurement data and a back propagation neural network are used to construct a model of electrical field intensity responses to fluctuations in humidity and ambient temperatures. The maximum error is 0.047 5. The results show that the power electric field intensity increases as humidity rises when the temperature is constant; when humidity is a constant, temperature changes do not affect the regularity of the electric field intensity in a consistent manner regularly.     

Reliability Evaluation for Bulk Power System Including Dependent Outage of Transmission Line

In order to calculate and analyze the effect of two transmission lines in parallel on the reliability evaluation of bulk power system, a model including independent outage, common mode outage and dependent outage of these lines is deduced and a new algorithm corresponding to the model is presented. Two transmission lines in parallel including common mode outages and dependent outages can be really simulated as a multi-state component. While reliability indices are calculated, the probability and frequency of independent outage, common mode outage and dependent outage of a system failure state can be calculated at the same time, and computation complexity is reduced. The proposed model and algorithm are applied to the RBTS system, IEEE One Area RTS96 system and a real power system for reliability computation and analysis. Results show that the new algorithm is credible and validity.     

超高效液相色谱-串联质谱法测定稻田中肟菌酯及其代谢物的残留

为评价肟菌酯在水稻和环境中的安全性,笔者开展肟菌酯在水稻和稻田环境中的残留量及消解动态研究。笔者进行2年3地田间试验。植株消解动态试验按84.37 g a.i./hm2,土壤、田水消解按562.5 g a.i./hm2各施药1次;最终残留试验按84.37 g a.i./hm2(高剂量)和56.25 g a.i./hm2(低剂量)分别施药3次和4次,水稻收获期采样。结果表明,肟菌酯在田水、土壤和植株中的消解半衰期分别为1.8~7.3天、2.4~9.7天、1.4~12.4天。肟菌酯在土壤、植株、谷壳和糙米中的最高残留量分别为0.293、4.435、8.569、0.901 mg/kg。糙米最终残留量低于CAC规定的最大残留限量(MRL)5.0 mg/kg。