钙钛锆石和榍石基人造岩石固化铀的研究

以天然锆英石(ZrSiO4)、CaCO3、TiO2和UO2(NO3)2·6H2O为原料,通过高温固相反应,制备了包容铀(质量分数4.5 %)的钙钛锆石和榍石基人造岩石固化体.借助X射线衍射(XRD)和扫描电子显微镜(SEM)研究了其矿相组成和微观结构.采用MMC-1静态浸泡法和γ射线辐照方法测定了其抗浸出性能和抗辐照性能.结果表明,制备钙钛锆石和榍石基固化体的最佳合成及烧结温度为1 290 ℃.所得固化体结构致密,有较好的抗浸出性和辐照稳定性.     

O3和UV-B共同作用对大豆干物质和产量的影响

为揭示O₃和UV-B共同作用对大豆干物质和产量的影响,以大豆“八月黄”为供试材料,利用OTC(开顶式气室)和紫外灯模拟O₃和UV-B共同作用环境,研究大豆干物质和产量的变化. 结果表明:与对照组相比,T1(UV-B辐射增强10%左右)、T2(100nL/L O₃与增强10%左右的UV-B复合)和T3(150nL/L O₃与增强10%左右的UV-B复合)处理下,成熟期大豆株高分别降低了12.73%、12.78%和14.15%;w〔Chl(a+b)〕分别减少了-1.16%(P>0.05)、34.20%(P<0.05)和57.38%(P<0.05);净光合速率(P_n)分别下降了11.50%、46.65%和48.58%;单株干物质质量显著降低(P<0.05),分别减少了31.02%、61.35%和67.53%;大豆产量分别减少了4.13%、54.09%和79.34%. O₃和UV-B对大豆的生长和干物质累积均有不利影响,并且存在一定的协同影响,2个因子共同作用对大豆生长和干物质累积更为不利;O₃和UV-B共同作用下大豆产量的降低主要是由粒数和粒质量降低所致.      

Effects of UV-B radiation on the gills of Catla catla during early development

Scanning electron microscopic (SEM) study of gills of Catla catla catla (17-day-old) exposed to UV-B radiation (145?µW?cm^?2 at the water surface) for three different exposure times: 5, 10 and 15?min was conducted. Fish without UV-B exposure served as control. UV-B radiation damaged both gill filaments and lamellae. The intensity of damage was minimal in 5?min exposed fish, followed by 10?min exposed fish and maximal in 15?min. The gill epithelium was severely damaged in 15?min irradiated fish compared to control. Pavement cells (PVCs) were damaged and the numbers of microridges within PVCs decreased. The deep boundary of PVC was not clear. In some area of gill epithelium, PVCs were destroyed and mitochondrion-rich cells (MRCs) were exposed. The 5?min exposure reduced the number of microridges in the PVCs, but the boundary of PVCs was still visible. MRCs in the gill epithelium were not exposed in 5?min exposed fish. The damage to PVCs and subsequent exposure of MRCs in UV-B irradiated fish may hamper respiratory functions and disturb osmoregulation in catla.     

Concentrations of uranium in drinking water and cumulative,age-dependent radiation doses in four districts of Uttar Pradesh,India

The present work deals with the determination of uranium concentrations in drinking and ground water samples by laser fluorimetry and calculation of cumulative, age-dependent radiation doses to humans. The concentrations were found to be between 0.20 ± 0.03 and 64.0 ± 3.6 μg L^?1, with an average of 11.1 ± 1.5 μg L^?1, well within the drinking water limit of regulatory bodies. The concentrations of uranium increase with depth of water samples collection. The estimated annual ingestion dose due to the intake of uranium through drinking water for all age groups varied between 0.2 and 137 μSv a^?1, with an average of 17.3 μSv a^?1. The mean annual ingestion dose is 5% of the global average ingestion dose, for infants, marginally higher than for other age group. Most effective dose values were less than 20 μSv a^?1.     

The role of the cloud optical thickness in the attenuation of the solar ultraviolet radiation reaching the ground: Implications to the human health impacts

Cloud optical depth, as it is derived from the King's method, is compared with that deduced from the simple two stream approximation for the greater Athens, Greece area. The results show that King's method overestimates the cloud optical thickness, in comparison to the two stream approximation. These estimations were also compared with satellite observations provided by the International Satellite Cloud Climatology Project. This comparison showed that there are large deviations between ground‐based and satellite observations. These deviations are probably due to the uncertainty introduced by the integration procedure of the satellite spatial analyzing resolution (distinctness). Furthermore, values of the simple scattering albedo were calculated by employing a recently proposed theoretical method and using the solar ultraviolet irradiance measurements performed at the Athens University on a routine basis. These results are of great importance for the densely populated areas like Athens, in a sense of health impacts, from enhanced incident solar ultraviolet radiation.     

现代生活要认识和防范电磁辐射——以一些新信息为例

社会在发展,生活水平和人们的追求也在不断地提高,绿色发展、和谐发展与科学发展,人的健康与提升生活品质都是第一要素.人们身边的电磁辐射内容是“百花齐放”,电磁辐射环境“丰富多彩”;电磁辐射无声地时刻伴随着人们.研究显示,过量、过度地电磁辐射会负影响人们的器官、肌体等.现代生活、工作中光生物安全是一很现实的问题,提升健康水平与生活幸福度,大家当增大对光安全的认知度,并增加、丰富电磁辐射及其防范之常识.参13.     

基于同步辐射的硬X射线荧光技术分析污染土壤中重金属分布

基于同步辐射技术的微束X射线荧光(μ-XRF)分析具备原位分析样品的元素组分,化学特性,物质结构及其二维分布等的能力,可更加直观地揭示目标元素在复杂体系中的分布状态.利用传统的化学消解与原位μ-XRF技术相结合的方法,探测锡矿山土壤中多种元素的含量和空间分布,采用线性回归方法分析各元素的相关性.结果表明,供试土壤Sb和As含量较高,分别为6 681和878 mg·kg-1,μ-XRF分析表明土壤中Fe、Mn分别与As的空间分布相关性较好,决定系数(R2)分别达0.225 8和0.181 1,更直观地揭示了As在土壤中以铁锰结合态为主.μ-XRF技术的应用原位直观地揭示了土壤中多种元素的分布关系,为综合评价和预测土壤中重金属的环境行为以及发展污染土壤修复技术等提供理论支持.     

某厂炼钢区域煤气超标原因分析

某钢铁厂一炼钢区域在3个月内多次发生煤气超标报警,但难以准确发现事故原因。事故调查组全面收集报警资料,深入一炼钢区域检查,查找分析煤气超标原因,排除了炉顶部位煤气泄漏、煤气设备密封不严泄漏、带煤气作业以及系统异常情况下紧急放散等可能因素,得出煤气报警与炼钢转炉煤气熄火放散存在较大关联的结论,并组织了柜前事故煤气管放散和转炉放散塔熄火放散或燃烧不充分模拟实验,实验结果与分析结论一致。最终给出了完善煤气放散点火系统、增加红外线火焰温度监测报警的技术对策和管理措施。     

树冠火对输油站热辐射影响的数值模拟研究

树冠火是森林火灾的一种,在森林的树冠层燃烧和蔓延,主要由地表火在强风作用下引起.树冠火很少发生,约占森林火灾的5％,但其燃烧温度高、热释放速率大、蔓延速度快,对周围物体的破坏性极大.处在森林地区的输油站面临着树冠火带来的潜在风险.火灾产生的热辐射极有可能导致输油站内人员伤亡,设备遭到破坏.通过确定树冠火热释放速率、火灾发生位置及环境参数来设计火灾场景,采用火灾动力学场模拟软件FDS,模拟分析树冠火对输油站的热辐射影响.结果表明,由于无法采用地面扑救,防火隔离带是应对树冠火威胁的有效措施;当防火隔离带达到一定间距时,有风条件下与无风条件相比目标物体不会接收到更多的热辐射;防火隔离带设置为坡面形式,可以增加其表面积,从而吸收更多的热辐射.     

Research progress on electromagnetic radiation in gas-containing coal and rock fracture and its applications

This paper reviews the status quo of the research on electromagnetic radiation in gas-containing coal and rock fracture. It focuses mainly on the electromagnetic radiation phenomena, the generation mechanism, characteristics, law of change and experimental applications in the field. Based on the authors’ research work in the past decade, detailed discussions are made with respect to the engineering applications of electromagnetic radiation spectrum, law of transmission and signal collection of gas-containing coal and rock. Furthermore, the paper gives the prospect of electromagnetic radiation effects in coal and rock fracture and its applications.