夏县玉米主导品种筛选及示范试验

通过不同玉米品种的田间设计,采取合理有效的技术措施,筛选出适合当地夏播种植的玉米品种,促进了玉米新品种的推广与应用。     

显微物镜光学传递函数测定

本文介绍了显微物镜光学传递函数测定仪的研制工作,包括仪器的基本工作原理,仪器电路设计、计算机接口设计、软件系统设计。并介绍了仪器的技术性能测试结果,仪器的使用效果。     

油砂含油量测定仪的研制

根据石油混合物液体的荧光特性,研制了油砂含油量测定仪。介绍了测量原理,光路系统和仪器总体结构,用光电倍增管将反映含油量的荧光强度转变成参量,利用单片机对数据进行分析处理,说明了油砂含油量单位和标准样品制作方法,给出了仪器实际测试结果。     

微波水分快速测定仪开创水分测试新纪元

介绍微波水分测定仪及其原理和技术要点、产品主要技术指标。微波水分测定是我国科研人员在"十二·五"期间独立完成一项原创测试技术,和传统的水分测试不同,具有省时、准确、可进行在线测量和快速检测的功能,为我国仪器行业发展做出贡献。     

国内机电市场动势

我国农村需要哪些仪器仪表一、育种选种仪器、农副产品质量检查分析仪器,如种子纯度测定仪、种子颗粒测定仪、粮食谷物品质分析仪、农药残留测定仪等。二、储运保鲜系统,如冷藏车、库温控制系统、充氮保鲜系统、环境试验设备。三、能在田间直接观察的土壤分析仪器,如氮、磷、钾快速测定仪、土壤水份测定仪等。四、仪器及轻工产品检查仪器,如电子天平、糖量计、水果品质检验仪。五、为畜牧业、饲料加工服务的超声波诊断仪、牲畜发情测定仪、饮     

油菜倒伏的原因及防倒措施

一、倒伏的原因 1.选用品种不当选用了茎秆细软、弹性不好、易感菌核病、不耐肥的品种. 2.氮肥施用过多油菜氮肥施用过量,前期易造成徒长、田间荫蔽、茎秆木质化程度低、茎秆细软而易倒伏.后期贪青晚熟,易遭病虫危害,也易倒伏.     

一种新型的屈服强度快速测定仪

一、仪器工作原理研制一种与普通拉力试验机配套使用的简易装置,以便迅速精确地测定屈服强度,是一项很有工程实用价值的课题。根据从试样总伸长量中检测出非比例伸长量而直读出屈服负荷值的原理〔1〕,研制成功的一种新型屈服强度快速测定仪,使用操作简便,测试效率高,测量精度符合国际标准的规定〔2〕。仪器的输入信号来源于     

基于电磁谐振技术的石油产品水分智能测定仪

以电容为敏感元件,利用电磁谐振技术研制了石油产品水分测定仪.阐述了仪器的测量原理,详细分析了仪器的影响因素,提出了用相变温控技术补偿温度影响误差.给出了仪器的硬件和远程测量软件系统,并在不同温度条件下,对不同的石油产品水分进行测定实验,实验表明:该仪器不需任何化学试剂,且重复性很好,最大重复性误差小于4%,完全满足实际需要.     

4种杀菌剂对不同玉米品种玉米大斑病田间试验评价

旨在明确4种药剂对不同玉米品种玉米大斑病的田间防效,为品种合理应用、玉米大斑病防控提供依据.结果表明,防效最好且增产效果最佳的2种药剂为43％戊唑醇和12.5％氟环唑悬浮剂(欧得).     

显微物镜光学传递函数测定

本文介绍了显微物镜光学传递函数测定仪的工作原理、电路设计、软件系统设计和该仪器的性能测试结果,使用效果。     

基于GMap.net雷电监测预警系统设计与实现

基于GMap.设计的雷电监测预警系统,以大气电场测量为基础,利用地面电场仪组网,实现自动、连续、实时监测强雷电活动中地面产生的电场强度变化,存储大气电场数据,回放历史数据,同时采用时序差分法设置三级电场阈值,使得预警更加准确,提高准确率,减少虚警率。通过对2011-05-11南京六合地区的雷暴作为个例进行分析演示发现：在测站范围内,当电场的快变抖动出现并且电场值达到一定阈值时,电场值会随着时间增加而达到事先设定的闪电出现的强度,很少会有电场快变而没有产生闪电的情况出现,预警效果相对理想。     

改进型的磁流变液剪切应力测试仪

针对圆盘缝隙磁场分布不均匀、磁场强度低和注液不方便等问题,对自行研制的旋转圆盘式磁流变液剪切屈服强度测试仪进行了改进.运用ANSYS磁路仿真软件对剪切圆盘机构的磁路进行了优化设计分析,对产生漏磁的部件和结构进行了改进,使测试圆盘所在区域的磁场强度的均匀性得到了加强;当电流为1.6 A时,圆盘间隙处的平均磁感应强度可达0.9 T;同时该测试仪的测试结果表明,Herschel-Bulkley模型可以较好地拟合MRF屈服后区的非线性特性.     

Use of the approximations in cell studies by total internal reflection fluorescence microscopy (TIRF)

In determining cell parameters by the use of total internal reflectance fluorescence microscopy it is necessary to evaluate the electric field strength in the neighbourhood of the cell. It has been suggested that the true field distribution be assumed to be of exponential form. In some circumstances, this approximation gives rise to errors and seriously incorrect results are obtained. The true field distribution is easily obtained numerically so the use of an exponential approximation is unnecessary and errors are avoided.     

一种实用视觉识别的仪表自动检定系统

介绍一种基于图像处理和神经网络识别技术的温控仪表自动检定系统。在系统中，计算机对被测仪表发出模拟热电偶测量信号，并获取被测仪表示显示值的视图，经过数字图像预处理后，采用神经网络感知器算法予以识别，得到仪表显示数。将被测仪表显示数与计算机内的测量值比较，其误差曲线即可确定该被测仪表的精度。     

Measurement of the gas flow stagnation temperature by the method of two identical thermocouples in the short-duration aerodynamic facilities

Investigations of the temperature and heat flux distributions over the external surface of flying vehicles are important for the development of hypersonic planes. For obtaining correct results, experiments are performed in short-duration high-enthalpy wind tunnels. Determination of the stagnation temperature of the flow in such facilities is a challenging task due to short start-up times and high flow temperature. In this paper a new method is proposed for determining the stagnation temperature of a gas flow in the short-duration aerodynamic wind tunnels with stepwise changes in its parameters. The method is based on using two identical thermocouples with different initial temperatures. It is shown that in the case of jump-like changes in flow parameters the instrument function of the difference of the thermocouple readings coincides with the instrument function of each thermocouple, and the instrument function itself is actually the normalized temperature difference. The instrument function obtained in the study allows temperature retrieval by the method of deconvolution. This approach is highly sensitive to random noise of experimental data; therefore, regularization methods are applied for high-frequency noise suppression. A procedure for choosing the regularization parameter for temperature reconstruction is proposed. The research novelty of the article is that the proposed method allows exact reproduction of the stepwise function and instrument function without any additional assumptions, while the measurements and dynamic calibration are performed in one experiment. Applicability of the method for obtaining the stagnation temperature in the short-duration high-enthrall wind tunnel IT-302 M ITAM SB RUS is demonstrated.     

The Acoustic Field of the Near Radiation Zone Formed upon EMAC in Metals

This paper analyzes the behavior of bulk types of waves generated by a circular bus with current by the magnetostriction mechanism in a normal polarizing field in a magnetic high-conductivity halfspace in relative proximity to a media boundary. Calculated dependences of the module of the amplitude and the angle characterizing the direction of radiation of bulk waves in the near zone are presented for radiators of different shapes. It has been shown that the acoustic field in the near radiation zone is a superimposition of waves that differ from purely longitudinal or shearing waves due to a considerable contribution of harmonics from the decaying part of the spectrum. The characteristic points of the field (the maximum amplitudes) decay abruptly and are shifted inward by curved trajectories; it is only in the far zone that they are transformed into straight lines directed at certain angles. Recommendations for determining the transition region between the zones are given.     

Editorial

The performance of many electron optical instruments is fundamentally limited by the dimensions of the focused probe. This is true of the scanning electron microscope and the scanning transmission electron microscope and, by inference, it may affect the transmission electron microscope. There has been very little improvement over the past few years and it seems reasonable to look for the explanation. It is possible to arrive at some simple expressions for the limiting performances of conventional instruments in a way that is independent of the design details and depends upon practical limits of field strength. Experiment and theory also appear to be in agreement with the fact that the limit for high-voltage instruments has been reached, although there is still room for improvement for low voltages.     

A highly sensitive field mill for registering weak and strong variations of the electric-field intensity of the Earth’s atmosphere

The design and the principle of operation of an electric-field intensity meter (field mill) are described. The instrument is intended for determining the energy, time, and spatial parameters of the atmospheric electric field near the Earth’s surface when monitoring a geophysical situation. The developed field mill allows registering both weak variations of the electric-field intensity in the atmosphere, such as global electromagnetic Schumann resonances, and strong variations that are caused by the passage of atmospheric fronts, heavy clouds, thunderstorms, etc. The instrument has a threshold sensitivity of ~10^–3 V/(m Hz^1/2) within a frequency range of 10^–3–25 Hz and a wide dynamic range of 120 dB.     

Quasi in situ scanning force microscope with an automatic operated reaction chamber

We describe the design and performance of a quasi in situ scanning force microscope with an automatic operated reaction chamber. The design provides a repetitive hermetically sealed sample environment for successive processing. The reaction chamber is based on a combination of a flexure-guided cover, a piezo-positioning system and a force applicator system. An axial force seals the cover against the reactor enabling flow-through applications at low pressure, ambient pressure, or elevated pressure. The position stability of the sample relative to the probe is characterized and a full automated operation of the instrument is explored by the alignment of an ABC terblock copolymer thin film undergoing solvent vapor annealing in the presence of a high electric field. Due to the high electric field strength and the sharp scanning force microscope tip it is impossible to perform in situ scanning in the presence of the electric field.     

Production of centrifugal fields greater than 100 million times gravity

A high-speed rotation instrument to produce centrifugal fields greater than 100 million times gravity has been constructed. Small, solid, spherical high-carbon chromium steel rotors are suspended magnetically in high vacuum and spun by a rotating magnetic field. It is found that the spinning rotor explodes when the calculated average value of stress in the meridian plane reaches about 1.2 times the tensile strength of the material. The maximum speed of rotation so far achieved for more than a few days without bursting was obtained with a rotor of 1.50 mm diameter. The speed of 2.11 x 10(5) rev/s corresponded to a centrifugal field of 1.34 x 10(8) times gravity. Our instrument will find application in the study of nuclear atomic phenomena.