Influence of ^(60)Co gamma radiation on fluorine plasma treated enhancement-mode high-electron-mobility transistor

A1GaN/GaN depletion-mode high-electron-mobility transistor （D-HEMT） and fluorine （F） plasma treated enhancement-mode high-electron-mobility transistor （E-HEMT） are exposed to 60Co gamma radiation with a dose of 1.6 Mrad （Si）. No degradation is observed in the performance of D-HEMT. However, the maximum transeonductance of E-HEMT is increased after radiation. The 2DEG density and the mobility are calculated from the results of capacitance-voltage measurement. The electron mobility decreases after fluorine plasma treatment and recovers after radiation. Conductance measurements in a frequency range from 10 kHz to 1 MHz are used to characterize the trapping effects in the devices. A new type of trap is observed in the F plasma treated E-HEMT compared with the D-HEMT, but the density of the trap decreases by radiation. Fitting of Gp/w data yields the trap densities DT = （1-3）Х1012 cm^-2.eV^-1 and DT = （0,2-0.8）Х10^12 cm^2-eV^-1 before and after radiation, respectively. The time constant is 0.5 ms-6 ms. With F plasma treatment, the trap is introduced by etch damage and degrades the electronic mobility. After 60Co gamma radiation, the etch damage decreases and the electron mobility is improved. The gamma radiation can recover the etch damage caused by F plasma treatment.

Preparation and characterization of iron-ore-imbedded silicone rubber materials for radiation protection

Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle size of iron ore resulted in better gamma radiation protection owing to more homogenous distribution. In addition, the materials had flexible properties up to the addition of 60 wt% iron ore content. Further, 0.5 mm Pb E gamma protection was provided by using 2.06-mm-thick SDT-60 as the Co-60 source. Iron ore–silicone rubber composites are candidate materials for lead-free flexible radiation protection systems owing to their relatively inexpensive and easy production.

Preliminary Research on Radiation Breeding of Pteroceltis tatarinowii Maxim.

In order to explore the effect of radiation breeding on new germplasm innovation of Pteroceltis tatarinowii,the dry seeds of P.tatarinowii from Lingyan Temple were used as test materials in this study,which were irradiated by ^(60)Co-γ rays with different radiation doses.The results showed that the emergence rate decreased with the increase of radiation dose,the emergence rate of low dose below 200 Gy decreased slowly,and the emergence rate of high dose above 200 Gy decreased sharply;when the radiation dose ranged from 100 to 200 Gy,the mutagenic effect of P.tatarinowii seeds was the best;and radiation obviously affected the leaf color and leaf shape of seedlings.This study provides original materials for the cultivation of new P.tatarinowii varieties and the study of color-changing mechanism.

Investigation on the Appropriate Dose of ^(60)Co-γ Irradiation for Tubers of Purple Sweet Potato

[Objective] This study aimed to investigate the appropriate dose of 60^Co-γ irradiation for tubers of purple sweet potato.[Methods] The tubers of two purple sweet potato varieties Xuzi L-7 and Yuenanzi were used as experimental materials,and treated with 60^Co-γ irradiation at different doses（0,25,50,75,100,125 and 150 Gy） to determine the emergence rate,number of emerged seedlings per tuber and fresh weight per seedling.[Results] After the 60^Co-γ irradiation at different doses,the emergence period of tubers was postponed while the emergence rate,number of emerged seedlings per tuber and fresh weight per plant were decreased,and the differences between different varieties and different irradiation doses reached significance level.Compared with the control,the emergence period of tubers at irradiation doses above 25 Gy were postponed by 2,3,5,6 and 12 d,respectively.[Conclusion] The half lethal dose（LD50） of Xuzi L-7 was 66.73 Gy,and that of Yuenanzi was 74.96 Gy.

^(60)Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices

The testing techniques and experimental methods of the 60Co gamma irradiation effect on A1GaN/A1N/ GaN high electron mobility transistors （HEMTs） are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on A1GaN/A1N/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the A1GaN/A1N/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

Real-time ultra-wideband video streaming in long-reach passive optical networks with wireless radiation in the 10 and 60 GHz bands

Real-time video streaming using ultra-wideband(UWB) technology is experimentally demonstrated along long-reach passive optical networks(LR-PONs) with different wired and wireless reaches. Experimental tests using external and direct modulation with UWB wireless radiation in the 10- and 60-GHz bands are performed. An ultra-bendable fiber is also considered for a last-mile distribution. The video quality at the output of the optical fiber infrastructure of the LR-PON is assessed using the error vector magnitude(EVM), and the link quality indicator(LQI) is used as a figure of merit after wireless radiation. An EVM below –17 dB is achieved for both externally and directly modulated LR-PONs comprising up to 125 km of optical fiber. EVM improvement is observed for longer LR-PONs when directly modulated lasers(DMLs) are used because of the amplitude gain provided by the combined effect of dispersion and DML's chirp. Compared with optical back-to-back operation, the LQI level degrades to the maximum around 20% for LR-PONs ranging between 75 and 125 km of fiber reach and with a wireless coverage of 2 m in the 10-GHz UWB band. The same level of LQI degradation is observed using the 60-GHz UWB band with a LR-PON integrating 101 km of access network, a last-mile distribution using ultra-bendable fiber, and a 5.2-m wireless link.

60^Co-γ辐照诱变处理下白三叶草种子萌发期抗旱性研究

为了解白三叶草种子萌发期的抗旱性能,以聚乙二醇(PEG-4000)为渗透介质模拟干旱水分胁迫条件,对6份白三叶品种60Co-γ辐照诱变种子萌发期的发芽率、发芽势、胚根长、叶绿素和胚根水势等指标进行测定,运用标准差系数赋予权重法对胡衣阿品种的各PEG质量浓度胁迫的各测定指标值进行综合评价,筛选出最佳PEG胁迫质量浓度,并以筛选出的PEG质量浓度为依据,利用主成分分析法对6份白三叶品种的各测定指标予以鉴定筛选,然后再以筛选后的指标和最佳PEG胁迫质量浓度为根据,对各品种的抗旱性进行综合评价。结果表明:PEG120g/L为白三叶诱变种子萌发期的最佳干旱胁迫质量浓度,发芽率、发芽势、发芽指数和活力指数为主要抗旱性鉴定指标,胡衣阿、瑞文德、铺地、库拉、海法和克尔利卡诺瓦品种的最佳辐照剂量分别为800、1 000、60、30、60和400Gy。

Apoptotic Sensitivity to Irradiation Increased after Transfection of chk1 Antisense Chain to HL-60 Cell Line

Summary： The HL-60 cells were transfected with chkl antisense and sense chain, and 24 h later subjected to irradiation. Twenty-four h after irradiation, the changes in the chk1 protein expression was assayed by Western blot, and the cell cycles and apoptosis rate detected by FCM. The irradiated apoptosis sensitivity was increased by antisense blocking of chk1 gene in HL-60 cell line with the apoptosis rate being 26.31 %, significantly higher than that by the sense blocking （10.34 %, 0. 025〈P〈0.05）. In HL-60 cells transfected with chkl antisense chain, the G2/M phase arrest was attenua：ted and the cells in G2/M phase were accounted for 38.42 %, significantly lower than those of the cells transfected with chkl sense chain （54.64 %, 0. 005〈P〈0.01）. It was concluded that antisense blocking of chk1 gene could increase the apoptosis sensitivity to irradiation.

Total ionizing dose effects on a radiation-induced BiMOS analog-to-digital converter

The total dose effect of an AD678 with a BiMOS process is studied.We investigate the performance degradation of the device in different bias states and at several dose rates.The results show that an AD678 can endure 3 krad（Si） at low dose rate and 5 krad（Si） at a high dose rate for static bias.The sensitive parameters to the bias states also differ distinctly.We find that the degradation is more serious on static bias.The underlying mechanisms are discussed in detail.

^(60)Co-γ辐射对2种锦带幼苗生长及生理指标的影响

为了探究辐射诱变对“白花锦带花”和“锦带花”形态及生理特性的影响,采用不同剂量(0~300 Gy)的^(60)Co-γ射线辐射“白花锦带花”与“锦带花”休眠期种子,观测辐射对锦带花生长的影响,测定其生长量及幼苗叶片的叶绿素含量、叶绿素荧光指标、光合作用参数、SOD、POD、MDA和可溶性蛋白含量。研究结果显示,由于辐射剂量的增大,苗高、叶长、叶宽、节间距、叶绿素荧光、光合作用参数、SOD活性、POD活性出现了明显的先升高后降低的趋势,在50 Gy时到达了峰值。同时,随着辐射剂量的增加,叶绿素含量和可溶性蛋白含量呈现出下降的趋势,MDA含量明显升高。综上所述,在(2 Gy/min)剂量率的辐射条件下“白花锦带花”种子较适宜的诱变剂量为50 Gy,而“锦带花”以50~100 Gy最合适。

(60)^Co-γ辐照模式下玉米中赤霉烯酮和品质的变化及对绵羊定时人工授精的影响

为研究经赤霉烯酮(ZEN)自然污染与(60)^Co-γ辐照处理后的玉米对绵羊定时人工授精中澳洲白种公羊、湖羊母羊的生殖性能的影响,本试验选取含ZEN玉米样本,分别用0、3、5、8、10 kGy剂量的(60)^Co-γ辐照,并测定辐照后玉米主要营养成分变化。然后分别将未污染玉米(Ⅰ对照组)、经10 kGy(60)^Co-γ辐照的污染玉米(试验Ⅱ组)、污染玉米(试验Ⅲ组)饲喂定时人工授精的绵羊,检测澳洲白种公羊的精液质量,测定湖羊母羊的繁殖性能指标。结果表明,未经(60)^Co-γ辐照的玉米含ZEN 2153μg·kg^(-1),在10 kGy(60)^Co-γ辐照剂量下,玉米中ZEN降解率为83.7%;当(60)^Co-γ辐照剂量低于10 kGy时,玉米淀粉表面结构无变化,主要营养成分无显著变化。试验Ⅱ组澳洲白种公羊的采精量、精子活力、精子密度与试验Ⅲ组相比显著升高(P<0.05),与Ⅰ对照组相比无显著差异(P>0.05);试验Ⅲ组澳洲白种公羊第30天精子畸形率与试验Ⅱ组、Ⅰ对照组相比均显著升高(P<0.05),显微镜下观察可见双尾精子、双头精子、无尾精子等现象,其中双尾精子头部、尾部不完整;试验Ⅱ组湖羊母羊同期发情率、受胎率、产羔率和羔羊始重等指标与试验Ⅲ组相比显著升高(P<0.05),与Ⅰ对照组无显著差异(P>0.05)。综上,使用经10 kGy(60)^Co-γ辐照后ZEN含量低于2153μg·kg^(-1)的玉米饲喂繁育绵羊,对绵羊定时人工授精无不利影响。本研究结果为(60)^Co-γ辐照模式下玉米中赤霉烯酮和品质的变化对绵羊定时人工授精的影响研究提供了理论依据。

Effect of irradiation on temperature performance of dispersioncompensation no-core cascade optical-fiber sensor coated with polydimethylsiloxane film

A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.

不同^(60)Co-γ辐射剂量对月季仙境、北京红、金凤凰生长和开花的影响

为研究物理辐射对3个月季品种扦插苗的影响,利用0、10、20、40、60、80 Gy剂量的^(60)Co-γ对仙境、北京红、金凤凰月季扦插苗进行辐射处理,测定和分析处理后月季苗的形态指标、突变率、死亡率和半致死率等。结果表明,随着辐射剂量增加,3个月季品种的扦插苗的株高、冠幅、侧枝数、侧枝长度、复叶长、复叶宽随之降低,其中仙境和北京红在10 Gy辐射剂量下生长势最好,而金凤凰在20 Gy生长势最好。供试植株的死亡率随着辐射剂量增加而增加,仙境在10和20 Gy处理下死亡率较低且花色变异较多。仙境、北京红、金凤凰的半致死剂量分别为53、132、19.87 Gy。仙境在10 Gy辐射剂量下突变率最高达31.67%,产生了白色、水粉色、嫩粉色、粉白相间等多种花色突变;金凤凰在10 Gy剂量下花瓣边缘有缺裂,在20 Gy辐射剂量下花瓣边缘深裂、反卷;北京红在10 Gy剂量下有花瓣数量明显增加,花型为千重瓣。综上所述,^(60)Co-γ辐射剂量10和20 Gy有利于促进供试植株的生长,同时产生新的变异花色和新花型。本研究结果为月季的良种选育和新品系培育提供了参考。

^(60)Co-γ辐射对非洲菊组培苗苗期生长的影响

研究结果表明,非洲菊组培苗经60Co-γ辐射处理后,株高、生根率、黄化率、死亡率与辐射剂量呈负相关,且生根组培苗与无根组培苗对辐射的敏感性不同。其中,低剂量辐射处理对生根苗根系的损伤较小,随着辐射剂量的增加,抑制效应越明显、生根苗的死亡率有升高的趋势;而经辐射处理的无根组培苗叶片黄化现象严重,未经辐射处理的无根苗均能生根,30 Gy处理无根苗部分生根,50、70 Gy处理无根苗则毫无生根迹象,同时指出要提高非洲菊组培苗后期变异的总成活株数,以生根组培苗为佳。

^(60)Co-γ辐射对嘎拉苹果枝条诱变效应的研究

采用不同剂量^(60)Co-γ射线对嘎拉苹果休眠枝条进行辐照处理,研究其对苹果枝条嫁接成活率及诱变效应的影响。结果表明,随^(60)Co-γ辐照剂量的增加,嫁接成活率呈下降趋势;60 Gy剂量处理的枝条嫁接60 d的成活率为47.50%,确定为本研究的半致死剂量(LD50);^(60)Co-γ处理使枝条生长量减少,叶面积降低,叶片出现畸形,二叉枝和多叉枝数量增加。

^(60)Co-γ射线辐照对日日春种子发芽率及幼苗生长的影响

用不同剂量的60Co-γ射线辐射日日春种子,观测其对种子发芽率和幼苗生长的影响。结果表明:发芽率、根长、芽长与辐射剂量都呈负相关。在辐射剂量为10、30Gy处有利于提高种子的发芽率及其幼苗的生长,其中辐射剂量为10Gy的更为突出,而其它剂量的辐照对日日春种子的生长有抑制作用。

^(60)Co-γ辐射诱变在木本植物育种中的研究进展

^(60)Co-γ辐射育种是当前诱变育种研究中应用最广泛的诱变技术,为我国农业的发展作出了巨大的贡献,但是在木本植物育种方面应用相对较少,并且受限于木本植物漫长的生长周期,许多研究难以形成突破性的研究成果,急需系统性、全面性的理论指导。本文对近二十年来木本植物的^(60)Co-γ辐射诱变育种研究进行了总结,详细介绍了辐射诱变原理与方法、辐射材料与辐射强度的选择、突变体鉴定等技术,对^(60)Co-γ辐射诱变效应与分子机理进行了探讨,并提出后续研究的重点方向,为将来木本植物的^(60)Co-γ辐射诱变育种提供理论指导。

^(60)Co-γ射线辐照对菜用枸杞VM_2生长势及品质的影响

用10～14Gy^(60)Co-γ射线辐照菜用枸杞农枸1号枝条,研究低剂量辐照对无性繁殖二代(VM2)生长与品质的影响。结果表明:10、11Gy辐照促进菜用枸杞VM2的生长,其中经10Gy辐照的促进效果最好,其株高、叶长和叶宽显著高于对照V2,13、14Gy辐照对VM2生长有一定抑制作用;辐照对菜用枸杞VM2嫩茎叶的VC、可溶性糖和氨基酸含量均有较大影响,其中10、11Gy辐照显著增加了VC、可溶性糖和氨基酸含量;经模糊数学隶属函数法综合分析评价,10Gy辐照处理的VM综合品质最优。

^(60)Co-γ辐射对朝天椒种子超微结构、叶表显微结构及分子鉴定的影响

由于朝天椒种质资源多态性低、遗传基础狭窄,加强人工培育朝天椒种质资源尤为重要。为研究^(60)Co-γ辐射对朝天椒的影响,以朝天椒常规品种中农千斤红为试材,对朝天椒干种子进行不同^(60)Co-γ辐射剂量处理(0、25、50、100、200、300、400、500、600 Gy),以无辐射种子为对照,对各处理种子发芽率、成苗率、畸形率、种胚超微结构、叶片显微结构进行测定,并采用SSR分子标记对辐射后长成的幼苗进行分子鉴定。结果表明:辐射剂量小于200 Gy时种子的发芽率、出苗率和成苗率均大于70%;辐射剂量为0、25、50 Gy时辣椒幼苗畸形率均为0%,辐射剂量达100 Gy后畸形率随辐射剂量的增加而增加。对照种子在种胚萌动过程中种胚细胞内线粒体及细胞核等主要细胞器的结构形态均表现正常,^(60)Co-γ辐射剂量为25、200 Gy时种胚内主要细胞器结构和形态仍较为正常,但是随着辐射剂量的增长和辐射时间的增加,种胚细胞的超微结构被损伤的程度愈发严重,线粒体由椭球形膨大成圆球形,脂体变透明,胞质膜、核膜破裂加重,细胞核变形严重,种胚细胞行为异常,直至丧失分裂、代谢功能。经过辐射处理的辣椒种子,长成的幼苗叶片上、下表皮的气孔数与辐射剂量成正相关,表皮细胞的形状也因辐射剂量的增长变得扭曲。经辐射诱变后的长成材料经SSR分子鉴定,较对照发生DNA水平上的变异,扩增谱带突变类型主要为“条带新增型”“混合型”和“条带缺失型”。本试验筛选出了适宜的^(60)Co-γ辐射剂量为200 Gy,以及适宜的引物用于诱变材料SSR分子鉴定,为朝天椒辐射育种提供一定的有益参考。

当归补血汤对^(60)Co-γ射线辐照小鼠造血功能损伤的防护作用

目的:观察当归补血汤对^(60)Co-γ射线辐照小鼠造血功能损伤的防护作用。方法:将健康SPF级昆明种雄性小鼠随机分为5组(正常对照组、模型组、当归补血汤低、中、高剂量组),除正常对照组外,采用^(60)Co-γ射线辐射各组小鼠建立急性辐射损伤模型,测定各组小鼠外周血平均红细胞血红蛋白浓度(MCHC)、骨髓有核细胞数(BMC)、骨髓细胞DNA含量,并在光镜下观察小鼠骨髓组织形态学变化。结果:受^(60)Co-γ射线照射后,小鼠MCHC、BMC、骨髓细胞DNA含量均明显减少,骨髓组织形态变化明显。低、中、高剂量当归补血汤均可提高辐射损伤后小鼠MCHC、BMC及骨髓细胞DNA含量,促进辐照小鼠骨髓造血组织损伤的恢复,且高、中剂量当归补血汤对其造血系统的保护作用效果更明显。结论:当归补血汤对辐射小鼠造血系统的损伤有保护和促修复作用,且与剂量相关。