国家农产品保鲜工程技术研究中心

<正>果蔬保鲜智能化臭氧精准测控装置臭氧作为一种强氧化剂,在食品加工、保鲜领域被广泛应用。采后果蔬是活体,仍进行着旺盛的生命代谢活动,使用臭氧化气体进行贮藏保鲜,不仅具有消除和降低果蔬菌源基数的作用,而且对部分水果的乙烯生成也有抑制作用。科学有效使用臭氧进行果蔬保鲜的核心技术是:在了解果蔬种类和品种对臭氧忍耐性的基础上,精准控制臭氧浓度,达到既有显著作用又不引起果蔬伤害的效果。为此,需要智能化精准控制臭氧浓度、处理时间和间隔。     

果蔬食品静电场保鲜机理研究

根据静电学和生物学的有关理论,探讨了果蔬食品静电场保鲜机理,提出了静电保鲜机理是固有电场和细胞膜的电位作用,电场击穿细菌"细胞电容器"的杀菌作用,臭氧强氧化杀菌作用和活性氧的杀菌作用。     

氧化还原电位法在线测定果蔬消毒用臭氧化水研究进展

采用臭氧化水对果蔬进行消毒保鲜是一种安全有效的方法,而适宜的臭氧浓度是保障消毒可靠性和使用经济性的基础。本文在简要介绍臭氧化水在果蔬消毒和去除农药残留的应用及其主要测定方法的基础上,重点综述了氧化还原电位(ORP)法在线测定果蔬消毒用臭氧化水的研究及应用情况,说明ORP法是一种经济实用的测定果蔬消毒用臭氧化水浓度的方法。     

果蔬保鲜新技术

对目前国内外果蔬保鲜的8种新技术的特点、机理进行了综述,并初步探讨了果蔬贮藏保鲜的发展方向。     

臭氧在果蔬保鲜储藏中的应用

臭氧是一种强氧化剂,具有广谱、高效的杀菌作用.同时臭氧对水果蔬菜的采后生命活动有着积极的调节作用.本文综述了臭氧在果蔬保鲜储藏中的应用机制,及对农药残留的降解作用,概括了臭氧在应用过程中的影响因素.     

臭氧在果蔬贮藏保鲜中的应用

臭氧是一种非常强的消毒剂，其氧化能力比氯强１．５倍，与氯及其他消毒剂相比，杀死病原菌范围更广，效率更高，速度更快，并且不会产生化学残留物。另外，臭氧可以分解果蔬成熟过程中释放的乙烯。在果蔬贮藏及运输过程中，使用臭氧进行消毒，结合包装、冷藏、气调等手段可以提高果蔬保鲜效果。１臭氧在果蔬贮藏保鲜中的应用步骤１．１空库消毒冷藏保鲜库的生物污染源主要是霉菌，霉菌可在低温低湿条件下存活，对一般消毒剂有较强的耐受力，试验表明，臭氧消毒对冷藏保鲜库效果很好，在２４mg／m３浓度下，３～４h可以杀死霉菌包括抵抗力极…     

果蔬保鲜膜与自发气调包装

在简述果蔬自发气调保鲜基本原理的基础上,介绍了常见保鲜膜及其各种性能与作用。重点分析了果蔬保鲜袋内的气体平衡规律,在此基础上提出果蔬自发气调包装设计的基本内容和方法,指出了自发气调保鲜的局限性,并分析了今后的发展趋势。     

GA Optimization for Variable Cross Section frame wind turbine

在对果蔬涂膜保鲜机理研究与分析的基础上,系统介绍了国内外不同种类涂膜剂的性能和特点,并综合分析了现阶段存在的问题和今后发展的方向,为果蔬涂膜保鲜技术的发展和应用提供了技术借鉴。     

船用多品种果蔬气调保鲜技术应用研究

通过介绍果蔬保鲜技术及船用果蔬保鲜应用现状,为满足远洋航行自持力45~60 d的需求,提出了船用多品种果蔬气调保鲜技术,将开环气体调制技术、PID精确温度控制技术、等焓加湿技术等融合创新,设计了保鲜专家系统以及库房安全保护装置,解决了多品种果蔬混贮保鲜周期短、保鲜品质差、自动化程度低及安全性差等问题。     

热带果蔬保鲜新技术研究进展及发展前景

综述了热带果蔬保鲜新技术原理和国内外研究现状,探讨了热带果蔬贮藏保鲜业目前存在的问题与发展对策,并展望了热带果蔬保鲜的未来发展前景。     

The power-supply of X-ray machine adopting PID control and high-frequency inverter technology

To solve the problem of low control accuracy and low stability of current X-ray machines, a kind of digital power supply for X-ray machine is introduced. In the digital power supply, some key technologies are used to improve the output stability of the high frequency inverter, including improved BUCK circuit for voltage regulating circuit, high frequency inverter and soft switching technology for the high-voltage generator. The PWM control technology is used to control the switch transistor of voltage regulating circuit and inverter circuit, which makes the drive waveform output stable and easy to control. In order to improve the control accuracy, reduce the volume and change high voltage consecutively, the software PID of the microcomputer is used to control the feedback circuit. The high-accuracy power chip is used for the filament power supply to make the filament electric current stable. Through the analysis of the circuit, the parameters of the circuit are calculated and the circuit is simulated by PSPICE software. The results show that the theoretical analysis is consistent with the practical simulation results. The design can meet the requirement of the technology indices of the power supply of the X-ray machines.     

Hybrid Power Supply Based on One Cycle Control

A hybrid power supply is composed by both a linear and a switching source connected in parallel and it can improve the dynamic response. But the hybrid power supply cant not effectively reject the perturbations in the power supply. A hybrid power supply based on one cycle control theory is proposed in order to improve the capability and the control precision. A switching source based on one cycle control is adopted in the hybrid power supply. The analysis results indicate that the hybrid power supply can effectively reject the perturbations in the power supply. And the analysis results also show that not only the control precision is improved, but also the control circuit is simple. The simulation resuits given verify the correctness and effectiveness of the proposed method.     

Hidden Dangers on Linkage Control of Electrical Devices and Design Installation and Debugging of Power Supply and Distribution Underground Space

Linkage control of fire-fighting electrical equipment effectively and reasonable design, installation and debugging of power supply and distribution are increasingly important to ensure the safety of underground space. As the linkage control systems associated with the fire control electrical equipment are very complicated, and the distribution of installation and debugging are very professional, there are many hidden troubles of safety in the whole life cycle process. On the basis of analysis of characteristics of underground space of fire, underground fire-fighting electrical equipment and the requirement of power supply system are expounded, hidden dangers on linkage control of electrical devices and design installation and debugging of power supply and distribution underground space are analyzed, and some suggestions and countermeasures are provided for relevant departments as decision-making reference.     

Analysis of the Power System''s Voltage Stabilization by Modeling and Simulink

The simulink of the power system can help people to analyze the actual power system's various state.As an important instrument,the Matlab software gains the recognition because of its all-sided and professional features.But when it is used in the field of dynamic process of the power system,there exist some disadvantages such as the difficulty of the modeling.The state-space module can be used to set up the three rank compact model of the generator and the electrical machine.It makes the modeling more convenient and more easily jointed to the system's primary parameter such as voltage and frequency.The typical model of the power system is built including the generator,electrical wire,load and SVC by using the function of the Simulink.In order to make the model's physical conception,some necessary predigestion is made to the typical model.At last,some conclusions about the voltage stabilization are gained by using the simulink of the system's malfunction,testifing the correctness and feasibility of this compact modeling.     

Development of a sub-nanosecond steep pulse generatorfor simulating weak PD UHF signal

In need of ultra-high frequency partial discharge location and correction of electrical equipment, we designed a sub-nanosecond steep pulse generator, and constructed the corresponding circuit model through the circuit simulation software Pspice. The influence of the storage capacitor and the supply voltage to the pulse waveform is analyzed. When the storage capacitor is 10 pF and 20pF respectively, the output pulse waveforms have been measured in the conditions of pulse rise time being 0.68 ns and 0.90 ns, pulse width being 0.98 ns and 1.18 ns, pulse peek being 8.72 V and 12.2 V respectively, and partical discharge capacity of charge being 320 pC and 600 pC. The picked multi-pulse singnals are steady with the developped sleeve monopole antenna, the error is less than 70 ps. It can be used for the experimental study of ultra-high frequency partial discharge location and correction of electrical equipment.     

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。     

Partition Algorithm of Power Network Based on the Optimum Clustering Principle

The paper construct the specimen of multi-dimensional space based on the definition of clustering, calculate the generator control sensitive to load and the Eulerian distance, partition the power system by the shortest distance method of clustering analysis. After the range of area num-ber is determined, the optimal area number and its validity is decided by Shannon function of entropy and Sugeno-Yasukaw rule. A case of IEEE 39-bus system is presented to verify the method.     

A fault data recording system design for hybrid electric vehicles

A data recording system for fault diagnosis of hybrid electric vehicles was studied by taking the integrated starter and generator (ISG) hybrid electric vehicle as the investigation object. The fault diagnosis communication net was established using a CAN bus and a K line. As designed, the system hardware structure included a CPU processing module, a communication module, and a USB recording module. With the system requirements and characteristics in mind, special circuit design and analysis of USB mass storage module were carried out based on the hardware scheme and software design. In the running test, the fault data recording system worked stably, and the data was recorded integrally and correctly. At the same time, the online display data accurately reflected the vehicle's running status.     

A Integrate-Reset-Controlled Single Phase Power Factor Correction with High Efficiency

A novel single phase boost type power factor correction circuit is introduced .The converter's efficiency is greatly improved by improving on the traditional boost type power factor correction circuit. Integrate Reset Control circuit is adopted to realize unity power factor. The Integrate Reset Control high efficiency single phase boost type power factor corrector has these characteristics as follows: It's constant frequency operation, which is of advantage of the design of filter. The control circuit is very simple and no need for multiplier. The result is quiet perfect, the input current follows the input voltage very well. The efficiency is very high. The result of simulation and experiment proves the correction of theory analysis.