微波辐照激发粉煤灰活性的试验研究

粉煤灰经过微波辐照,其活性得到提高。调节微波功率和时间,确定最佳的微波辐照参数。结果表明,采用450 W微波功率辐照10 min,粉煤灰活性提高效果最明显。将微波辐照的粉煤灰与水泥熟料混合,制备大掺量粉煤灰水泥。砂浆强度试验显示,当II级粉煤灰掺量达40%时,3、28 d强度满足32.5级粉煤灰水泥国家标准的强度要求。对微波辐照的粉煤灰进行红外光谱分析,发现在1 100 cm-1附近强吸收区Si-O伸缩振动频率与粉煤灰活性存在对应关系,即Si-O伸缩振动频率越低,其活性越高。     

两种微波—活性炭法对苯酚的去除效果及其效能比较

以活性炭为吸附剂和吸波栽体,对微波再生法和直接微波法去除水中的苯酚进行了对比试验研究.结果表明,在两种微波辐射方式下,活性炭都能有效去除水中的苯酚,其中微波再生法对活性炭的一次再生率可达96%,多次再生率为50%～70%;活性炭直接微波法对苯酚的去除率较单独活性炭吸附提高了7%～20%,在苯酚浓度较低(462 mg/L)时对其去除率最高达93%.试验结果还表明,微波再生法的除污效能指标(P)值普遍高于直接微波法,且活性炭可重复利用,是一种更为经济有效的微波方法.     

混凝土的微波辐射和红外辐射随应力变化的实验研究

对混凝土的微波辐射和红外辐射在实验室进行了加载实验，发现混凝土的微波辐射能量和红外辐射能量随混凝土应力状态变化而显著变化，且混凝土试件临破裂前，微波辐射和红外辐射出现多种破裂前兆异常。这表明微波遥感和红外遥感可用于混凝土工程应力和应力场分布测量，并可用于混凝土工程因应力集中造成工程可能发生危险或遭到破坏时的监测和预报。     

微波辅助机械破岩试验和理论研究进展

微波辅助机械破岩是微波加热技术和机械破岩技术相结合的一种混合型破岩方法。岩石内不同矿物成分对微波能具有不同的吸收特性,各矿物不同的热膨胀产生的内应力使岩石内发生沿晶断裂和穿晶断裂,使试样产生损伤和微裂纹,这会引起岩石强度的降低。辐射功率和辐射时间是影响岩石力学特性的重要参数,一定功率的微波辐射处理后,试样的点荷载强度、单轴抗压强度和抗拉强度发生显著降低,微波功率越高,辐射时间越长,对试样强度的折减效果越明显。数值研究结果与试验研究结果基本一致,增加功率的同时降低辐射时间对试样强度折减具有更好的效果。岩石点荷载强度、单轴抗压强度和抗拉强度的降低能够显著提高机械破岩设备刀具的侵入率和刀具寿命,解决机械刀具的磨损问题。微波辅助机械破岩对钻孔、TBM掘进和实现金属矿矿岩连续开采都具有重要影响作用。     

微波法制备污泥吸附剂的性能优化研究

通过向污泥中添加吸收微波能的物质实现了微波热解法制备污泥吸附剂,并考察了不同制备条件对污泥吸附剂性能的影响.结果表明,当污泥用量为35 g时,微波法制备污泥吸附剂的最佳务件:微波功率为1.2 kW、辐照时间为10 min、微波能吸收物质的用量为10 g,制得的污泥吸附剂的碘吸附值达585.95 mg/g.采用扫描电镜分析污泥吸附剂的表观结构可知,适宜的微波辐射通过有效热解污泥中的有机质可形成以炭骨架为主体的污泥吸附剂,该吸附剂可有效吸附酸、碱染料,但吸附量与商业活性炭仍存在一定差距.     

微波固化环氧树脂混凝土路面抢修材料的力学性能

研究了环氧树脂混凝土试件在自制微波辐射装置下的固化时间,发现其在该条件下10 min即可实现基本固化,并达到较高强度;进一步研究了微波固化环氧树脂混凝土的力学性能,结果表明:该混凝土抗压强度近50 MPa,抗折强度可达10 MPa以上,且与原结构黏结强度高,同时具有良好的低温性能.研究用微波固化环氧树脂混凝土具有高强、快硬、施工方便及固化易于控制等优点,可应用于路面抢修抢建工程.     

浅谈微波技术应用于火灾探测

论述了微波技术应用于火灾探测的可行性，阐述了火场微波辐射强度和天线接收微波辐射强度的计算方法，讨论了系统工作中心频率、带宽以及天线自身特性等因素对微波火灾探测系统工作灵敏度和可靠性的影响。     

水对微波辐射下硬岩劣化效果的影响试验研究

在微波辅助破岩中,水是影响岩石劣化的重要因素。为了研究在微波辐射下,水对岩石劣化的影响规律,以湖北花岗岩为研究对象,岩石孔隙率、超声波波速、抗拉强度作为参考指标,通过试验法测得水在微波辐射下对岩石劣化的影响规律。结果表明:水是造成岩石劣化的关键因素,微波辐射后浸水冷却能够对岩石产生更大的破坏效果;岩石的损伤程度受试件初始含水率影响显著,饱和试件较干燥试件而言在微波辐射后破坏效果更明显;采用初始含水率为饱和状态、冷却方式为浸水冷却的条件时,微波辐射对岩石强度的折减效果达到峰值。因此,在微波辐射前后充分利用水分这一影响因素能够更好地造成岩石的劣化,降低岩石破碎时能量的消耗,对微波辅助破岩技术的发展具有重要意义。     

微波辐射危害的控制措施

在广泛应用微波技术的同时,还应重视其对周围人体健康产生不同程度辐射污染的影响.本文通过监测、统计和定量分析某微波辐射源的功率密度及危害,提出可行的安装屏蔽帘的建议.实践证明,此法可以有效地减弱微波辐射.     

Indoor and outdoor natural radiation survey programmes aspects of instrumentation and organisation,results

In the last two decades many countries started national or regional surveys to assess the average exposure to natural radiation of the general public. Survey programmes for external radiation as well as for radon and decay products have been performed are still in progress or will be started in the near future. The paper discusses briefly technical and organisational aspects of survey measurements as well as practical experiences and results available from national or regional survey programmes.     

甘肃五市伴生放射性矿污染源调查成果及处理意见

伴生放射性矿普查是重要的国情调查,是近两年在全国范围内开展的重要环保工作之一。对甘肃省天水市、平凉市、临夏回族自治州、张掖市、酒泉市5个地市81家涉及伴生放射性污染的企业进行初测,调查结果显示这5个地市的辐射环境本底水平在54~114 nGy/h之间,与甘肃省近几年辐射环境本底相当;伴生放射性污染源主要分布在敦煌市,涉及的矿种主要为钒矿,污染源类型为钒矿废渣,测量值一般是本底水平的3~5倍,对辐射环境影响较大,其他矿种测量值均较小。分析研究之后,笔者建议在加强敦煌市钒矿生产企业环境辐射监测、加强对钒矿原矿和固体废物中铀、磷等有用资源综合利用的同时,还应开展伴生放射性矿污染物防治技术研究。通过调查研究,了解了五市的辐射环境本底水平及主要伴生放射性污染源,健全了伴生放射性矿污染源信息数据库,可为伴生放射性矿环境辐射监管提供科学依据。     

Possibility of improving technological effectiveness of dairy wastewater treatment through application of active fillings and microwave radiation

The aim of the study was to determine the technological effectiveness of treatment process of model dairy wastewater in anaerobic reactors with active filling (AF), heated with electromagnetic microwave radiation (EMR). Experiments were conducted on a laboratory scale. The AF were produced using micro-pore extrusion technology. The study demonstrated that AF introduction to the technological system and application of EMR significantly improved the effectiveness of organic compounds, phosphorus removal and biogas production. Initial organic loading rate also affected the final results of wastewater treatment.     

铁层柱蒙脱石处理垃圾渗滤液

采用铁盐水解聚合物为柱化剂改性钠基蒙脱石,制备了铁层柱蒙脱石催化剂,将其用于微波诱导催化处理经常规生化处理的垃圾渗滤液,进行深度处理。实验结果表明：初始COD浓度为1 100 mg/L～1 300 mg/L的垃圾渗滤液,以铁层柱蒙脱石作为催化剂,在微波功率600 W,辐照时间30 s条件下,经微波诱导催化处理后,COD去除率达到39%,并对微波作用机理进行了初步探讨。     

Disintegration as a key-step in pre-treatment of surplus activated sludge

This study has been carried out to investigate the effect of microwave, alkalization and freezing on surplus activated sludge disintegration (release of organic/inorganic substances into the supernatant) and mesophilic fermentation. After applying pre-treatments, chemical oxygen demand increased by 7–35 times, disintegration degree was 35–47%, proteins by 5–25, carbohydrates by 2–3, phosphates 7–22 and ammonium by 3–16 times. Disintegration by microwave, alkalization and freezing has a positive effect on the rate of sludge anaerobic digestion. Biogas production increased by: 62; 49 and 58%, for microwave radiation, alkalization and freezing, respectively. The conducted research shows that the application of disintegration as a pre-treatment of surplus activated sludge is an effective method, allowing for practical using sewage sludge.     

Gamma dose profile and risk to scavengers and occupants near waste dumpsites in coastal Nigeria

Radioactive waste handling and disposal are a major topic in radiation protection. The comparative survey of gamma radiation exposure in the vicinity of some ordinary, general waste dumpsites in this study indicates that they could also pose radiation health hazards. The mean Absorbed Dose Rate (ADR) from all the dumpsites was 309 ± 2.12 nGy h^?1. The ADR near the landfills was higher than those of e-waste, metal scraps and municipal solid waste dumpsites. The results also show that the waste dumps contribute to the gamma ADR in their vicinity. ANOVA revealed that ADR at different distances from each of the dumpsites had a statistical variation at the 0.05 significance level. The scavengers and occupants of shanties near the dumpsites receive annual effective doses above the value accepted worldwide average of 0.07 mSv.     

Influence of microwave treatment on mechanical behaviour of compact basalts under different confining pressures

The realisation of microwave-induced fracturing of hard rocks has potential signiflcance for microwave-assisted mechanical rock fracturing and stress release in deep rock masses.In this context,compact basalts were treated by microwave heating in a multi-mode cavity at a frequency of 2450 MHz,and then,we investigated the mechanical behaviour of basalt samples after microwave treatment under uniaxial compression and conventional triaxial compression(CTC)tests.After microwave exposure,cracks appeared on the surface and inside of the rock sample,and the temperature of the sample's surface was unevenly distributed.The results show that the conventional triaxial compressive strength(CTCS)of basalt samples decreased linearly with microwave exposure time,and the higher the confining pressure,the smaller the reduction in the strength of basalt samples after microwave treatment.Under uniaxial compression,microwave exposure greatly affected the axial deformation,suggesting that deformation resistance of the samples gradually decreases with increasing microwave exposure time.Under triaxial compression,some microcracks induced by microwave exposure closed due to the effect of confining pressure,resulting in the confining pressure inhibiting any rightward shift of the axial deformation curve.Furthermore,under uniaxial compression,the elastic modulus and Poisson's ratio of basalts also decreased in a quasi-linear manner with elapsed microwave exposure time.Under triaxial compression,microwave exposure has slight influence on elastic modulus and Poisson's ratio.After microwave treatment,the changes in rock strength and deformation mainly result from changes in between the mineral structures.Confining pressure results in the closure of microcracks produced by microwave exposure,so that effects of microwave treatment on strength and deformation decrease,thus reducing the influence on elastic constants.The cohesion decreases with increasing microwave exposure time and shows an approximately linear decrease over time.In the basalt samples,new microcracks in various directions generated by microwave exposure can increase the discreteness of test results,while the discreteness of test results caused by microcracks gradually reduces with increasing confining pressure.     

Fresh metamaterials ideas for metallic lenses

In this work we provide further advances in the applications of Metamaterial concepts to the classical field of metallic lenses. Some of the limitations that metallic lenses have, such as imperfect matching with free space, can be overcome by Metamaterials, which makes them powerful tools not only in lens field but also in many others. Specifically, our work is devoted to the Extraordinary Transmission Metamaterial because of its low-losses and its potential scaling to any range of the spectrum. Firstly, we explore at the microwave regime the modification of the radiation pattern of a commercial horn antenna when 1 and 4 stacked subwavelength hole arrays are placed as a superstrate. Afterwards, the design of plano- and bi-concave ETM lenses operating at millimetre waves are analysed. Numerical analyses are confirmed by experimental results.     

微波炉法快速测定红粘土含水量的试验研究

对含水量的测定方法进行了分析比较,指出微波法具有广泛的应用前景,探讨了微波加热法的基本原理及试验过程,比较了微波加热法与标准烘干法试验数据,对微波炉法快速测定红粘土含水量的试验结果进行了回归分析,结果表明微波炉法测定红粘土含水量具有精度高、效率高的优点。     

改性膨润土吸附剂的制备及其吸附性能的研究

本文以钠基膨润土为主要原料,选用壳聚糖作为改性剂,通过微波辐射进行改性,制备出壳聚糖改性膨润土吸附剂,并研究了其对Cr（VI）的吸附陛能和吸附工艺条件。结果表明,吸附剂对Cr（VI）具有较好的吸附性能,吸附的适宜工艺条件是：pH值为5-6,吸附时间为30min,吸附剂用量为12．0g／L。与单一的膨润土或壳聚糖相比,该吸附剂对Cr（VI）离子的吸附速度快、吸附能力强,并且具有成本低、应用范围广的优点,Cr（VI）的去除率可达N85％。