拟南芥与烟草细胞低温胁迫下的粘弹性变化规律与耐冷性比较

研究旨在通过实时监测与比较拟南芥与烟草BY-2细胞在降温过程的粘弹性变化规律以建立衡量植物耐冷性的一种新指标。采用修饰带正电荷的聚二烯丙基二甲基氯化铵石英晶体微天平实时跟踪测定拟南芥悬浮细胞和烟草BY-2细胞在降温过程的粘弹性变化规律。随着温度的降低,拟南芥和烟草细胞的粘弹性指数绝对值均下降,细胞硬度增加。温度降得越低,粘弹性指数绝对值下降越大,细胞越硬。当温度从25℃降到5℃时,拟南芥细胞比BY-2细胞的粘弹性指数变化值要小,这与拟南芥比烟草耐受低温相符。植物细胞在低温下的粘弹性变化规律可以用来研究植物寒冷胁迫和作为衡量植物耐冷性的一种新指标。     

基于WSN的果蔬冷链物流实时监测系统研究

为降低果蔬运输过程的损耗,提高果蔬冷链物流信息化程度,提出以ZigBee协议为基础的无线传感网络(WSN)的果蔬冷链物流实时监测系统。该系统采用CC2530F256片上系统构建ZigBee网络,实现对冷链物流运输及仓储的温湿度实时监测。冷链环境下测试结果表明,传感器节点在恒温0℃环境下工作可靠,能准确地监测环境温度及相对湿度等参数的变化,协调器将汇总的温湿度数据通过GPRS模块上传到远程监控软件,并由监控软件实时向数据库存储数据,监测过程中未发生丢包现象。     

人类首次让光停止传播60秒

正光速是目前宇宙真空环境中的"极限速度",为了使宇宙速度最快的光"停止"下来,德国科学家使用了一种被称为电磁感应透明效应(EIT)技术,通过量子相干效应使得光原子共振吸收频率上变得透明,在EIT形成的频谱上,只有一定频率范围内存在透明和不吸收的通道,德国科学家将受控光速指向含有镨元素的硅酸钇晶体,通过控制激光束调节晶体的透明态和不透明态,使入射光束无法折射,最终在原子自旋的介入下控制光子携带的信息。该实验对量子通讯有着很大的意义。     

农业物料细观力学研究进展及农产品加工中的应用

农业物料细观力学性质的研究为宏观力学在农业工程中的应用奠定了基础，为设计农产品加工机械、农业生产系统装备、检测系统设计等方面的应用提供了理论支持。通过对有限元法、解析细胞模型和图像处理技术等方法解决农业物料细观力学问题的研究进展进行分析，较为全面地综述了农业物料细观力学的研究现状、发展趋势和解决农产品加工实际问题的应用概况，旨在为研究运用农业物料细观力学提供参考。     

影响白三叶草高频率植株再生因素的研究

以白三叶草子叶和下胚轴为外植体,进行直接再生系统中不同基本培养基成分和激素浓度的研究发现：白三叶草下胚轴顶端细胞的分化能力最强,分化率在65％以上,子叶次之,下胚轴其他部位几乎不分化。高维生素和微量元素可有效提高子叶的再生频率15％,而对下胚轴顶端细胞的分化影响不大。在6-BA 3mg／L NAA0．08ms／L的浓度下,下胚轴上段的再生频率最高,达80％以上。     

农业资源遥感监测系统的计算环境设计与应用

计算环境是包括农情遥感监测系统在内的农业资源遥感监测系统的重要支撑。该文在对农业资源遥感监测系统硬件环境组成、逻辑结构、核心功能分析等内容阐述基础上,以中国农业科学院农业资源与农业区划研究所运行的“国家农情遥感监测业务运行系统”硬件环境为例,进行了具体说明。研究结果表明,农业资源遥感监测系统是以基础硬件层为支撑,以计算层为核心,以存储层作为辅助,在网络层、软件层支持下,开展农情遥感监测应用。核心功能包括括登录节点、管理节点、计算节点、存储服务器(包括磁盘)等5个部分。“国家农情遥感监测业务运行系统”的计算环境的硬件是以42台基于Intel 64位至强处理器的IBM Flex X240刀片服务器为核心,4台S5700 10G以太网交换机为中转设备,连接华为1套N8500 NAS集群、1台基于Intel 64位至强处理器的IBM X3650M4管理服务器；56G计算IB网络是通过1台Mellanox 36口FDR交换机实现,并包括KVM交换机、机架键盘、液晶显示器,以及机柜、电源插座、连接线缆等附件。系统理论运行效率可以达到13.312万亿次,实际运行效率可以达到理论值的85%以上。     

玉米细胞抽提物在寡核苷酸指导的基因修复中的作用

寡核苷酸指导的基因修复是近几年发展起来的改造生物体遗传物质的技术。为了深入研究玉米细胞抽提物在寡核苷酸指导基因修复的体外系统中的作用,本研究分别将玉米细胞抽提物介导修复的质粒分子和无细胞抽提物条件下通过变性-复性的方法形成的寡核苷酸、靶质粒的结合态分子,转入3种不同基因型的大肠杆菌菌株,研究基因修复的频率,探讨基因修复的机制。结果表明,玉米细胞抽提物可能公促进了靶质粒分子和寡核苷酸分子的配对,其后的DNA修复过程由大肠杆菌的修复系统完成。     

基于双模定位的冷链物流实时监测系统

为加强冷链物流监管，实现冷链物流的全程温度和定位监测，设计了基于双模定位的冷链物流实时监测系统。本系统除了集成嵌入式技术、卫星定位技术和GPRS无线通信技术等以实现温度采集、数据远程传输和定位等功能，还使用融合数据的双模定位取代单GPS定位以提高复杂环境下的定位精度，并提出使用改进的扩展卡尔曼滤波算法进行定位解算以实现双系统下定位数据融合，在静态时对水平精度和三维精度分别提高了37.5%和28.6%。测试结果表明，本系统提高了冷链物流监测能力，为未来研究冷链无人配送的定位问题提供基础。     

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。     

离体培养植物细胞的表面与农杆菌介导基因转化频率的研究

以玉米、黑麦、烟草为材料 ,对细胞表面进行了扫描电镜观察 ,研究了离体培养植物细胞的细胞壁外表面的结构及其变化与农杆菌介导转化频率之间的关系。正常继代培养的烟草细胞 ,其细胞壁外表面光滑 ,大部分细胞在扫描电镜下坍陷或皱折 ;经处理用于农杆菌介导转化的烟草细胞 ,其表面有很多颗粒状突起和纤丝状物或纤丝状网 ;光滑的表面很少见到菌 ,而粗糙表面则有很多菌。玉米和黑麦愈伤组织中 ,浅黄色、疏松易散的胚性细胞团 ,其表面细胞有很多未坍陷 ,相当一部分未坍陷细胞的细胞壁外表面与烟草细胞一样 ,具有很多较小的颗粒状突起和纤丝状物或纤丝状网 ;白色松软的愈伤组织 ,其外层细胞大多坍陷或呈柱状 ,未坍陷细胞的表面光滑 ,有些似有一层膜状物。对植物细胞壁上的农杆菌结合位点和基因转化频率进行了讨论     

Application on Plasm Viscosity Detection With Piezoelectric Sensors

A piezoelectric biosensors for detection of plasm viscosity is developed, which is based on liquid damping effect of quartz crystal resonator. The measuring principal is given. Simultaneously, the detector of sensor and oscillator circuit is developed. The test results show that the maximal frequency shift of sensor are linearly dependent on square root of viscosity. The proposed sensor is much more simpler, more sensitive than the traditional methods. Furthermore, The sensor can be used to on-line detection.     

Development of Virtual Sweep Signal Source

A new kind of virtual sweep signal source which can be used to output specific sweep signal according to(users') configuration and can be widely applied to frequency characteristics measurement in the field of mechanics,electrics and electronics,is developed by using Dot Net software engineering technique,C/S architecture and general data acquisition platform.The virtual instruments not only make up the intrinsic defect of traditional instruments based on hardware components in high performance,remote control and data processing,but also indicate the powerful life and nice future of virtual instrument technologies.     

Fast modeling of the motor broadband equivalent circuit model

This paper proposes a modeling method of the motor broadband equivalent circuit model. The impedance amplitude-frequency characteristics of the motor terminal through measuring are obtained. The impedance amplitude-frequency characteristics are devided into several regions based on its first resonant point information,and the motor broadband circuit topology is developed with each region equaling a resonance unit. The RLC parameters of resonance unit are extracted through frequency and corresponding impedance of the any non-resonant and resonant point in each unit. This proposed method is used to build DC and AC motor broadband equivalent circuit model. Their impedance amplitude-frequency characteristics are simulated by the Saber software. The measurement results and the simulation result of references are compared. The DC motor simulation results coincide with the measurement results in 0.1~50 MHz,and the AC motor is in 0.1~40 MHz. The results show that the motor broadband circuit model is reliable and feasible.     

Product for the CAI of the Digital-Circuit-Curriculum Based on Simple-MPC

Combined with the characteristics of the digital circuit curriculum,this paper shows a full performance of the product for the CAI system of the digital circuit curriculum(CSDCC) based on simple MPC. CSDCC includes four parts:system design, classroom teaching, ICAI system, experiment teaching. From construction to details, the system design module is designed to complete the design of he system is bottom database.Providing three kinds of teaching style : commonness, practice, hyperText , the classroom teaching module completes teaching for the whole contents of and the ICAI system module gives the product, which is the ICAI system of the K map Simplification of Logical Function.     

Design of Virtual Instrument for Automobile Based on PC/104

The design of virtual instrument for automobile based on PC/104 has been presented by comparing with the traditional auto meter. The paper focuses on the development environment, system construction and operation principle. The data of the virtual instrument is transported by CAN bus, and this system can monitor in real-time, display in digit and fire the alarm to the super-speed, save the record.     

Analysis and experiment for reliability of power module driving circuit in renewable energy conversion system

Reducing the driving resistance for the present push-pull driving circuit for power module will make the time shorter,but this process will result in the increase of current and voltage thermal stress. Therefore,a novel driving method based on dSPACE is introduced and validated on the basis of analyzing the failure mechanism and thermal model of power module. The ascending theory of case-temperature is investigated and then an exponential curve is achieved for power module. Experiments prove that the method has a good driving and protective performance,and it effectively reduces harmonics of output current and voltage in the new energy conversion system,and enhances the voltage utilization rate and waveforms quality. Thus the reliability of power module is greatly improved.     

LCL型CPT系统的参数设计方法及频率特性分析

以金鲳鱼为原料,固定小麦粉与水的质量比为2∶1,食盐添加量2%,微波真空度0.095 MPa,在单因素试验的基础上,通过正交试验对微波真空技术膨化鱼糜饼工艺条件进行优化。结果表明,鱼糜饼制作的最佳工艺条件为:鱼糜含量35%,膨化温度100℃,膨化时间20 min,鱼糜饼厚度2 mm,在该工艺条件下,制得的膨化鱼糜饼色泽金黄、质地酥脆、风味清香,成品膨化率可达到540%。     

Theory Model of Viscoelasticity of Hepatocellullar Carcinoma Cells by Micropipette Aspiration Method

The mechanical properties of cells are relation to their structure and function. Viscoelasticity is a kind of essence properties of cells and an important researching contents in the field of cellular mechanics. Micropipette aspiration technology is an advanced artifice on the level of single cell to study the mechanics of cells. In order to investigate the theory and method in researching mechanical properties of hepatocellullar carcinoma cells with micropipette aspiration, hepatocellullar carcinoma cells was regarded as an even linear solid and the standard linear solid viscoelastic model was chosen to describe viscoelasticity of hepatocellullar carcinoma cells, theory model of viscoelasticity of hepatocellullar carcinoma cells by micropipette aspiration was established according to the related papers, it will provide methodology reference for studies in this fields.     

矿用高压开关电器短路开断与关合试验电源

针对国内冲击发电机性能参数不足,以国外冲击发电机作为试验电源,建立基于直接试验法的矿用高压开关电器短路开断与关合试验系统,提出了一种新的技术解决方案。仿真试验结果表明,该方案满足综合性煤矿高压电气实验室建设项目技术指标和试验标准要求,为大容量开断与关合试验系统设计和建造提供一种技术思路。