基于模糊数学法优化巴沙鱼糜脆片微波膨化工艺研究

以冷冻巴沙鱼加工制成的鱼糜为主要原料,采用微波膨化技术研发鱼糜脆片。通过建立模糊数学感官评价体系,考察微波时间、微波功率以及辅料盐、糖、小苏打的添加量对鱼糜脆片感官品质的影响。在单因素试验的基础上,结合响应面法优化鱼糜脆片的加工工艺。结果表明,巴沙鱼糜脆片微波膨化的最佳制作工艺为:微波功率440 W,微波时间70 s,小苏打用量0.5%,各因素对感官品质的影响大小依次为:微波功率>微波时间>小苏打用量。按上述工艺条件制得的鱼糜脆片模糊数学感官评分最高(97分),且脆片组织完整无破损,色泽明亮均匀,香味浓郁,膨化效果最优。     

微波膨化银杏饼工艺研究

以银杏为原料,采用微波技术开发膨化银杏饼。研究了淀粉种类和干燥水分含量对银杏饼感官品质和膨化率的影响。结果表明,淀粉种类和干燥水分含量对银杏饼的感官品质和膨化率都有一定的影响;与其他淀粉相比,添加糯米淀粉制备的银杏饼感官品质好、膨化率高;水分含量过大过小都降低了银杏饼的膨化率。通过单因素和正交试验确定膨化银杏饼的最佳工艺为微波功率用中火,银杏饼厚度3 mm,微波时间80 s,水分含量12%。     

怀山药微波膨化脆片的工艺优化

以怀山药为原料,在单因素试验的基础上,以水分含量、膨化时间、切片厚度为主要影响因素,以综合得分为考察指标,通过响应面法优化了怀山药微波膨化脆片的工艺参数。结果表明,怀山药微波膨化的最佳工艺参数为:原料水分含量10%,膨化时间45 s,切片厚度8 mm,微波膨化综合评分为4.95分。在此工艺条件下制得的怀山药微波膨化脆片白色略带微黄,质地酥脆,口感良好,具有很好的膨化度,并保留了怀山药特有的清香。     

全含油膨化对油菜籽预榨饼残油的研究

针对油菜籽传统加工工艺存在的不足,提出了油菜籽全含油膨化预榨制油新技术,并研究了膨化操作参数对预榨饼残油的影响规律。在单因素试验的基础上,以油菜籽为原料,通过正交实验,研究了原料水分含量、膨化温度、模孔直径,以及喂料速度对预榨饼残油含量的影响,并得到最优工艺组合。结果表明,原料水分含量和喂料速度对预榨饼残油含量影响显著;在原料水分含量8%,喂料量33t/h,膨化温度95℃,模孔直径8mm的条件下,预榨饼的残油最低。此参数下的验证试验也与以上结论一致。与传统工艺相比,该技术显著降低了预榨饼残油(由18%以上降到15%以下),同时毛油质量得到改善,含磷量显著下降(由800×10-6降到150×10-6以下),有利于浸出过程的进行。     

恰玛古脆片不同干燥方式工艺初探

旨在确定恰玛古最佳干燥工艺条件。以新疆柯坪县恰玛古为试验材料,开展了不同切分尺寸、不同前处理方式（热烫、冷冻、冷藏）试验,以及热风干燥、微波真空干燥和联合干燥试验;通过对比恰玛古在不同条件干燥过程中水分含量、水分活度、色差、膨化率、感官评定等指标的变化情况,确定最佳干燥工艺条件。结果表明,最优切分方式为片,热烫处理为6 min;冷藏处理较冷冻处理好;联合干燥方式失水速率较其他2 种方式快,水分含量、水分活度值都较低,色泽也较好,膨化率也较高。最终确定恰玛古最佳干燥工艺为：热风干燥温度45℃ 微波真空干燥1 kW 10 min,此时水分含量为7.74%、水分活度为0.19、色差L*69.4,a*4.2,b*21.0、膨化率14.80%、感官评分85。产品酥脆,色泽金黄,口感微甜。本研究具有一定的生产指导意义。     

高粱挤压膨化工艺条件的研究

在单因素试验基础上,采用响应面分析法研究挤压工艺条件对高粱仁膨化特性的影响。结果表明,回归方程能较好地预测高粱膨化度随挤压工艺参数变化的规律,高粱挤压膨化的最佳工艺条件是:物料含水量25.5%,物料粒度60目,转速300 r/min,膨化温度164℃,膨化度3.22。     

菊花微波杀青及干燥工艺的研究

为提高微波杀青及干燥后菊花的药效与品质,确立一种保质高效的菊花干燥工艺,本文以干制菊花色差值为考察指标,在单因素试验的基础上,通过正交试验优化了菊花微波杀青及干燥的最佳工艺参数,同时运用高效液相色谱法(HPLC)对33%、55%、77%微波频段(100%微波频段为2 450 Hz,菊花层厚1 cm,杀青时间3 min)干制菊花的氨基酸含量进行了测定。结果表明,对菊花色差影响的主次顺序为:杀青时间微波频段菊花层厚;微波杀青及干燥菊花的最佳工艺条件为:55%微波频段,菊花层厚1 cm,杀青时间3 min。同时结合测定的氨基酸含量指标显示,最佳工艺条件制得的菊花色泽最好、氨基酸总量最大。     

响应面试验优化挤压膨化法制备速食糙米粥工艺

为拓宽糙米开发利用领域,以糙米粉为原料,采用挤压膨化法制备速食糙米粥。在单因素试验的基础上,建立响应面二次多项式回归模型,研究挤压膨化处理对糙米粉复水率、糊化度及感官品质的影响。分析得到挤压膨化法制备速食糙米粥的最佳工艺参数为：机筒温度110℃、糙米粉含水量21.60%、糙米粉浆pH 7.11,以此工艺条件进行验证试验,速食糙米粥的糊化度平均值为87.93%。糙米粉经挤压膨化处理后,脂肪含量相比于原糙米粉降低了28.8%,膳食纤维含量比原糙米粉增加了9.3%。快速黏度测定结果表明,糙米粉经挤压膨化处理后峰值黏度、谷值黏度、衰减值、最终黏度及回生值均下降。本研究可为糙米精深加工提供一定的参考。     

挤压膨化甘薯无蒸煮无糖化酒精发酵的研究

为了挤压膨化甘薯酒精发酵应用于工业生产提供理论依据。利用挤压膨化甘薯粉为原料,研究料水比、糖化酶添加量、酵母接种量等基本因素对挤压膨化甘薯酒精发酵的影响。得出最佳工艺：料水比1:2、糖化酶用量130 U/g、酵母接种量为0.1%。在此条件下,30℃发酵72 h,发酵醪酒精度为14.43%,与传统发酵工艺相比,发酵醪酒精度提高了21.7%。     

鲅鱼鱼糜制品凝胶弹性及品质的研究

以冷冻鲅鱼为材料制作鱼糜制品,运用正交试验法研究不同擂溃时间、不同用盐量、不同蛋清量对鲅鱼鱼糜制品凝胶弹性和品质的影响。结果表明,在擂溃时间为45 min,用盐质量为鱼糜质量的2%,蛋清质量为鱼糜质量的15%时,制成的鱼糜制品凝胶弹性和品质最好。     

Structural Strength Study of Switching Cam Profile VVT Mechanism

The switching cam profile variable valve timing(VVT) mechanism is able to control valve lifting and timing system through higher and lower intake rockers at different engine speed.In this paper,multi-body dynamics and the(finite) element method(FEM) analysis method were combined to study the VVT mechanism.The analysis results indicate that intake rockers satisfy for design requirements and the dimensional discrepancy of the switching piston little(affects) on the VVT mechanism performance.     

Hybrid Lumped Parameter Transformer Winding Model for Very Fast Tansient

The very fast Transient over-voltage generated due to the switchgear in GIS switching off or on is very harmful to transformer insulation. The model presented is a winding hybrid lumped parameter model which combines the branch model based on parallel cables in one turn with grouped-turns model of two discs to efficiently simulate the very fast transient in the coil. Under quasi-stationary electromagnetic field, network topology and element size are derived from the geometry and properties of the transformer, whose inductance and capacitance are assumed to be passive and to have linear characteristics, however which have an inherent feature of a medium, which propagates waves. The formula of parameters are obtained. Based on the built winding model, the voltage gradients between discs and turns are found out, according to the simulation results, the reasonable winding insulation design can be made.     

Improvement and simulation on direct torque control system of permanent magnet synchronous motor

To solve the problems of large flux, torque ripple and inconstant inverter switching frequency in conventional direct torque control (DTC), a space vector modulation (SVM) technique is introduced to the conventional PMSM-DTC system and analyzed thoroughly based on the mathematical model. This novel control method which enjoys the advantages of VC and DTC has only one easy adjustable PI regulator and is easy to realize. The simulation verifies that this control system is capable of effectively improving the steady state performance and keeping the excellent dynamic performance of the PMSM-DTC system simultaneously and remain the switching frequency constant.     

Single-end Flyback High-frequency High-voltage Switching Power Supplies

Based on the research of a practical project of high frequency high voltage switching power supplies,the system design and experimental investigation of a single end flyback high frequency high voltage switching power supply are presented. In order to solve the problem of durable voltage of power MOSFETs that are used in the single end flyback high voltage switching power supply,an effective approach that adopts dual MOSFETs in series connected is proposed.The procedure of the designing and the parameter of each device is given in detail.A prototype of 220 Volt input and 2000V/3mA output is developed, and the validity of the scheme is demonstrated by the experiment.     

Robust H control for vehicle seat suspension systems with stochastic disturbance

The paper proposes the design method of robust H controller of vehicle seat suspension system. The dynamic model of seat suspension is developed,and the parameters uncertainties (mass, stiffness, damping) and stochastic vibration are introduced into the model system. Based on stochastic differential theory and Lyapunov functional, a semi controller is designed, and the controller parameters are solved by linear matrix inequality (LMI) which guarantees H performance index. The simulation results in time domain and frequency domain show that the controller designed for parameter uncertainties and stochastic vibration can attenuate the vertical acceleration of suspension system and improve riding comfort of human.     

食品介电特性参数试验机理分析

分析了食品介电特性参数的理论基础,结合试验研究的现状,探讨了介电特性参数的物理意义和使用条件。指出以测量食品等效电容对应食品其他性质的方法而得出结论的重复性和可验证性较差;食品介电特性研究需同时指出测量的频率,甚至需要通过介电常数频谱测量,找出测量该物料复介电常数的最佳频率;复介电常数测量受到夹持物料应力大小的影响。     

Research on a Novel Inverter of VSC

In order to improve waveform performance of light HVDC system, a lot of switches which operate in high frequency are used, which causes large switching losses and results high cost. A new Buck type voltage source converter(BVSC) is proposed. The new BVSC comprises a dual-buck converter and a three-phase inverter operating in grid frequency. Only two high frequency switches are used, which results good output waveform performance. In order to reduce the high frequency switching losses, a novel improved double-frequency Buck type voltage source converter(DBVSC) is also proposed. An additional dual-Buck converter is added to the BVSC, the added dual-Buck converter deals with the fundamental power that operates in low frequency, and BVSC only deals with harmonic power that operates in high frequency. The output waveform is enhanced and the switching losses are reduced in DBVSC, and the power rating is also increased. The DBVSC is very suitable for large power rating application. The one cycle control theory is adopted to control the proposed DBVSC with analog circuit, which is very simple. The proposed DBVSC and control method are verified by simulation.     

Soft-switching Analysis Phase-Shifted-FB-ZVS-PWM DC-DC Converter With Saturable Inductor

Compared with the traditional full-bridge(FB)zero-voltage-switched(ZVS) pulsewidth-modulated(PWM) converter, the FB-ZVS-PWM converter with a saturable inductor has a wider load range with ZVS and smaller circulating energy as well as smaller duty cycle loss. By analyzing the operation principle of the converter, this paper studies design considerations of the parameter bringing about ZVS and dead time of the switch, and gives out the design method, finally simulation testing has been carried out.     

DIGITAL POWER SYSTEM STABILIZER ( DPSS )

A digital power system stabilizer ( DPSS ) and its design method are presented in this paper. The mathematical model of a single machine infinite bus power system is obtained using off-line parameter identifications, and on the base of the identified model the control system is synthesized by generalized minimum variance control principles. Through feedback combination of several signals this control system has double functions of damping low frequency oscillation and automatic voltage regulating. In order to avoid static errors the very effective way is to combine discrete generalized minimum variance control with continuous integral control. Besides the proposed control strategy is very simple in structures and very easy to realize. Simulation results under several cases have shown the correctness and effectiveness of the proposed control strategy.     

Desiqn Parameter Related to the Sensibility of Torsion Vibration Natural Frequency on 2300 Rolling Mill Main Transmission System

Based on the study of effec t of torsion vibration natrual frequency on rollingmill main transmission system , the sensibility formula of natural frequency related to design parameter is given,By the means of programming, analysis and calculation have been carried out on 2300rolling mill main transmission system,It provides theoretical asis for dynamic optimizing transmis sion svstems.