微波沥青路面除冰斜角辐射喇叭天线设计

 为拓展微波加热的应用领域，对微波路面除冰进行了研究。为使辐射天线与沥青负载近距离达到较好匹配，改善加热区域，减少波导阵列的加热盲区，设计了矩形口径喇叭。在此基础上，还设计了带有不同倾斜角的斜角喇叭，测试了斜角喇叭天线在沥青混合料为加热负载时的驻波比，做了实际的加热对比实验。对实验结果进行了分析，得到不同斜角喇叭在沥青料加热中的性能和使用高度,发现15°斜角喇叭符合微波除冰等近距离加热要求。     

微波加热原理及其应用

从微波加热的热效应和非热效应阐述微波加热工作原理和特点，并结合实例介绍了微波加热在农业和食品加工业中的应用。     

随机相位和随机频率微波加热效应的数值模拟

 利用时域有限差分法（FDTD）并结合蛙跳技术，通过联合求解Maxwell方程组和热传导方程，模拟了水的微波加热过程，计算了烧杯中的水的温度分布；研究了随机相位和随机频率微波功率源合成时水的加热情况，对比了随机相位和随机频率非相干微波功率源与相干微波功率源作用下水的吸热和温升。计算结果表明，随机相位功率源进行合成时，烧杯中的水温分布更均匀，水所吸收的热量也较相干功率源合成加热时有较大增加；而随机频率功率源进行合成时，加热效果没有明显的变化。     

微波磁学及其应用的新进展

美国、苏联等国家对毫米波技术，隐形技术等研究非常重视，并认为是发展通讯和先进武器系统的重要手段，本文对这些技术和先进武器所需要的微波铁氧体材料及器件进行讨论．根据国际上的发展动态。指出我国要努力加强对毫米波铁氧体材料和器件，微波吸收材料，静磁波材料和器件，移相器和双模器件等技术的研究．     

微波辐照对胶原蛋白三股螺旋结构的影响

胶原蛋白的三股螺旋结构是其不同于其他蛋白质的特殊结构，也是其具有特殊功能的基础，然而，胶原的三股螺旋结构易在外界条件的影响下被破坏。目前微波已被越来越多的应用于胶原蛋白的提取和改性过程，但是关于微波辐照对胶原蛋白结构影响的研究还相对较少。首先从牛跟腱中提取胶原蛋白，然后采用0.5 mg·mL-1的胶原蛋白溶液在30 ℃下以微波辐照保温为实验样，水浴加热和未经加热处理为对比样，最后采用紫外-可见光谱、傅里叶变换红外光谱、圆二色谱以及荧光发射光谱等方法，对不同加热方法中胶原蛋白的三股螺旋结构和超分子结构进行表征，研究了微波辐照对胶原蛋白结构的影响。实验结果表明，在低于胶原变性温度的条件下，无论是微波辐照还是水浴加热都不会破坏胶原蛋白的三股螺旋结构，也不会使胶原蛋白变性。但是，与水浴加热相比，微波辐照会对胶原蛋白的聚集行为产生抑制作用。微波辐照对胶原蛋白的作用既有与常规加热相同的热效应，又有常规加热过程中不存在的非热效应，非热效应表现为抑制胶原蛋白的聚集行为。研究结果可为微波场中胶原蛋白结构和性质的变化提供科学依据。     

国家“八六三”计划强辐射重点实验室简介

强辐射科学技术研究是２０世纪后期随着激光、光电子学和微波科学技术发展而迅速兴起的，是一项跨世纪的高技术．我国强辐射科学技术的研究，是在国家“八六三”高技术研究计划推动下发展起来的，已在强激光技术、高功率微波技术研究方面取得了许多进展．为更进一步促进我...     

液化残渣的微波热解与常规热解对比分析

采用微波加热和常规电加热两种条件进行液化残渣(DCLR)的热解实验，考察了热解产物固体焦、焦油及煤气的组成及结构的变化规律，采用红外分析(FTIR)与气相色谱-质谱(GC-MS)联用技术对热解产品进行了分析表征。研究表明，在微波场中，DCLR的升温速率很快，20 min左右物料温度就可达到900 ℃，最大升温速率可达到329 ℃·min-1，而常规加热的升温速率基本保持恒定。与常规热解相比，微波热解后固体焦的产率降低2.85%，而焦油和煤气产率分别增加了0.66%和2.19%。DCLR热解后固体焦的索氏萃取组分重油(HS)、沥青烯(A)及前沥青烯(PA)含量均大幅降低，而四氢呋喃不溶物(THFIS)则有所增加，但是两种热解条件下得到的固体焦的四种索氏组成差异不是很大，说明DCLR的热解过程是以HS，A与PA的转化为主的。微波热解后固体焦红外谱上3 437.6，1 632.0 cm-1以及1 079.99 cm-1处吸收峰的强度与常规热解相比明显降低，说明微波场中DCLR的热解更为彻底。热解后焦油和煤气产率均有所增加，煤气中H₂含量均达到60%以上。GC-MS分析表明，经由石油醚萃取后的热解焦油中脂肪类、芳香类与醇类物质组成以及C_1~5，C_11~20与C₂₀以上组分的含量均没有发生明显变化，而微波热解焦油中沥青质的含量则下降了7.7%，说明微波作用可有效促进DCLR中沥青质的热分解，有利于热解焦油的轻质化。     

微波混合加热技术及应用前景

报道了氧化锆和氧化硅陶瓷材料的微波烧结实验结果,并详细讨论了微波混合加热技术在陶瓷材料微波烧结中的应用。     

微波激励源方案设计

在托卡马克实验装置上进行等离子体低杂波电流驱动和加热实验，需要输入兆瓦量级的微波功率。这是由多只大功率速调管并联运行而实现的，而这些速调管需要前级微波激励源进行驱动。我们目前使用的微波激励源经过十几年的使用，元器件老化和磨损严重，导致了整个设备工作性能的明显下降，不能满足低杂波电流驱动和加热实验的多管并联运行的实验要求。因此有必要设计一个新的微波激励源，工作部件全部采用固态微波器件，稳幅控制。模块化设计采用多路输出，新增加微波相位多路控制，以满足以后实验中低杂波电流驱动和加热两种不同工作方式的需求。     

微波场对Co／La2O3上的甲烷部分氧化制合成气的影响

考察了微波场对Ｃｏ／Ｌａ２Ｏ３上的甲烷部分氧化制合成气的催化活性及产物选择性的影响，为揭示微波场与物质之间的相互作用规律进行了有意义的探索，结果表明，微波辐照下的反应有如下特点；在达到相同的ＣＨ４转化率时，微波活化方式下催化剂床层温度远比常规加热低得多，且产物中Ｈ２和ＣＯ选择性明显高于后者，微波活化方式的优越性还表现为：当微波加热的温度等于或高于１０７３Ｋ时，甲烷的转化率高达９９．３％以上，Ｈ２Ｏ     

Microwave-induced low-temperature crystallization of amorphous Si thin films

Microwave heating was utilized for low-temperature crystallization of amorphous Si (a-Si) films. Microwave heating lowered the annealing temperature and reduced the annealing time. By microwave heating the hydrogen in the amorphous films was diffused out long before the nucleation of polycrystalline Si (poly-Si). The combination of NiCl₂ coating on a-Si and microwave heating greatly reduced crystallization temperature. The combination of metal-induced crystallization and microwave-induced crystallization might be a useful technique to develop high-quality poly-Si films at low temperature.     

On the study of pH effects in the microwave enhanced rapid synthesis of nano-ZnO

The rapid synthesis of ZnO nanostructures by microwave treatment of aqueous solutions of different pH values is reported for the first time. Microwave in various wattages was used as the source of heating or energy feeding the aqueous precursors. The pH of the zinc metal source was altered by a suitable amount of mineralisers. The considered pH values are 8, 10, 12 and 13.5. Microwave dielectric heating is dependent on the ability of the material to absorb microwave. This is responsible for molecular friction and dielectric loss, which as a result produce internal heating of the dielectric medium, in this case the solution. In typical microwave assisted synthesis, the total exposure to the microwave treatment was near about 25 to 35 minutes. The ZnO nanostructures obtained were studied by XRD, SEM and TEM characterisations. From the XRD pattern and the full width half maximum of the dominant reflections, microstructural parameters of the nanostructures are calculated and compared for the different pH values. Flower petal like flakes and hexagonal nanorods are formed for the lower and higher pH solutions, respectively. From the SEM images, the size distributions for the pH 12 and 13.5 cases are compared by drawing a histogram.     

微波溶样的机理,设备和应用

本文简要阐述了微波溶样的机理,介绍了MDS-81D型微波炉的性能特点,对微波溶样的应用作了概述。     

Parallel microwave chemistry in silicon carbide reactor platforms: an in-depth investigation into heating characteristics

The heating behavior of silicon carbide reaction platforms under 2.45 GHz microwave irradiation was investigated with the aid of online thermoimaging cameras and multiple-channel fiber-optic probe temperature sensors placed inside the wells/vials of the silicon carbide microtiter plates. Microwave irradiation leads to a rapid and homogeneous heating of the entire plate, with minimal deviations in the temperature recorded at different positions of the plate or inside the wells. In temperature-controlled experiments using dedicated multimode reactors, solvents with different microwave absorption characteristics can be heated in parallel in individual wells/vials of the silicon carbide plate reaching the same set temperature. Due to the large heat capacity and high thermal conductivity of silicon carbide, the plates are able to moderate any field inhomogeneities inside a microwave cavity. Although the heating of the plates can be performed extremely efficiently inside a microwave reactor, heating and synthetic applications can alternatively be carried out by applying conventional conductive heating of the silicon carbide plates on a standard hotplate. Due to the slower heating of the silicon carbide material under these conditions, somewhat longer reaction times will be required.     

Preparation of a Novel Oriented Structure in Carbon Black Filled Isotactic Polypropylene Composites by Microwave Selective Heating

Microwave heating technology has numerous advantages compared with the traditional heating methods and has been widely used to process materials. However, most thermoplastics do not possess a sufficiently high dielectric property to be heated by microwaves. In this study, carbon black (CB) was utilized as the microwave absorber to improve the microwave heatability of isotactic polypropylene (iPP). Effects of CB contents on the microwave heatability of iPP/CB composites were studied. The temperature of iPP/CB composites with relatively low CB content (5% and 10%) increased slowly and tended to remain unchanged after 120 s of microwave exposure. In contrast, iPP/CB composites with relatively high CB content (15% and 20%) presented a much faster heating rate and the temperature of the sample kept increasing with the prolongation of exposure time. On the basis of the fact that iPP/CB composites with different CB contents have different microwave heatability, a novel oriented structure, in which the core layer has relatively high orientation and the surface layer has relatively low orientation, was prepared by selective microwave heating. Two-dimensional wide angle X-ray diffraction (2D-WAXD) analysis indicates that the orientation parameter calculated by the (040) plane of the surface layer (0.45) was lower than that of the core layer (0.83). The novel oriented structure is different from the common skin-core structure formed in the samples of semicrystalline polymers by traditional polymer processing methods, in which orientation of the skin layer is higher than that of the core layer. The novel oriented structure has not been reported before to our knowledge and its formation mechanism is also discussed in this paper.     

多功能微波等离子体教学研究装置的研制

针对目前国内等离子体技术的教学和研究远远落后于工程应用的实际情况,开发了多功能微波等离子体教学研究装置.该装置利用频率2.45 GHz的微波激励稀薄气体放电,形成轴对称的等离子体球,产生的等离子体无内部电极,可避免放电污染.同时通过微波技术、真空技术、冷却技术的集成,使该装置结构紧凑、性能稳定、性价比较高.利用该装置进行了金刚石薄膜沉积与离子体诊断实验,效果良好.     

L波段微波脉冲对微型计算机的辐照效应实验

 在L波段使用1.3 GHz载波频率的微波脉冲辐照微型计算机主板，通过改变脉冲宽度、重复频率和脉冲串长度等参数，实验研究了微波脉冲辐照导致微型计算机失去响应的功率阈值的变化规律，讨论了L波段微波脉冲辐射的积累效应。实验结果表明：当微波脉冲宽度增加时，微波功率阈值下降；当微波脉冲重复频率升高时，微波功率阈值呈下降趋势；在固定重复频率的条件下，微波脉冲数目的增加也会导致微波功率阈值的下降；微波脉冲功率阈值始终小于连续波微波的功率阈值。当微波脉冲间隔时间较长或者脉冲宽度较宽时，微波功率阈值由单个微波脉冲的参数确定，与脉冲重复频率没有明显关系。利用假设的微波脉冲辐射积累效应，可以定性解释和分析微波脉冲辐照微型计算机实验中功率阈值变化的趋势。     

Integrated microwave photonics

Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A particular aspect that recently gains significant interests is the use of photonic integrated circuit (PIC) technology in the MWP field for enhanced functionalities and robustness as well as the reduction of size, weight, cost and power consumption. This article reviews the recent advances in this emerging field which is dubbed as integrated microwave photonics. Key integrated MWP technologies are reviewed and the prospective of the field is discussed.     

Phenomenological models of microwave heating of a flat coal mass with release of absorbed heat by the convection law

Phenomenological models of electrodynamics and heat transfer in application to microwave heating are constructed. Analytically rigorous solutions to problems of heating a flat coal mass under microwave radiation are obtained. The boundary conditions correspond to convection mechanism of absorbed heat release to the ambient medium. Mathematical models of dielectric heating for homogeneous boundary conditions are solved by a method of dual integral Laplace and Fourier transform. In the presence of inhomogeneities in the boundary conditions, a quite universal method of Green functions is used. The obtained formulas have a constraint associated with constancy of electro- and thermophysical characteristics of coal fuel, or when their piecewise constant approximation is admissible. The obtained dependences form the basis for scientific support of the microwave heating technology.     

Susceptor-Assisted Enhanced Microwave Processing of Ceramics - A Review

Susceptor-assisted microwave processing is a rapidly growing technology due to its superiority over the conventional processing. In contrast to the conventional heating from the surface, the microwave heating occurs volumetrically via direct interaction with the material. Correspondingly, the microwave heating rates are in general much faster than the heating rates in the conventional furnaces, where heat has to be transferred from the heat sources to the material via conduction, convection and radiation. The need for the susceptor stems from the fact that the majority of the ceramics are low lossy materials and they cannot couple well with the microwave at room temperatures. The susceptor provides an easy and non-invasive technique to exploit the rapid microwave processing even for the highly microwave transparent ceramics, such as alumina, silicon nitride, quartz, etc. This article critically evaluates the susceptor-assisted microwave sintering and solid state synthesis of ceramics which have been reported over the last two decades. A wide range of ceramics has been considered and each case has been analyzed in terms of the enhancement of the processing rates and product qualities (grain structure, material properties, etc.) compared to the conventional processing. It has been shown that the susceptor-assisted microwave processing can greatly reduce the processing time while providing an easy pathway to achieve the desired product qualities. The use of the appropriate susceptor is the key to achieve the fast, smooth, and reliable microwave processing of ceramics and this article provides the required database for the appropriate design of the susceptor based on the process requirement.