聚丙烯酰胺-咪唑类聚离子液体凝胶的辐射合成及其对铀和碘的吸附

采用γ射线辐射引发技术制备了一类聚丙烯酰胺-咪唑类聚离子液体凝胶(PAm-C_nvim_2Br_2)。当吸收剂量为5kGy时,得到了凝胶分数超过95%的聚离子液体凝胶,其溶胀度可由吸收剂量控制。合成的PAmC_nvim_2Br_2可以从碳酸盐溶液中吸附铀最大吸附量约130mg/g,或从碘化钠溶液中吸附碘离子最大吸附量约160mg/g,吸附过程符合Langmuir模型。红外与XPS分析表明,吸附过程遵循离子交换的反应机理。PAmC_nvim_2Br_2凝胶对铀及碘有很好的吸附、解吸性能,有望用于含有铀和碘的放射性废水处理。     

反硝化细菌生物反应器去除地浸采铀矿山退役采区地下水中NO3——N的试验研究

地浸采铀矿山退役采区地下水的NO₃^--N污染是一备受关注的问题。本文通过对取自某地浸采铀矿山退役采区的污泥进行驯化,得到了能去除地浸采铀矿山退役采区污染地下水中NO₃^--N的反硝化细菌,自行设计了上流式固定床反硝化细菌生物反应器,研究了pH值、C/N比和水力停留时间（HRT）对反硝化细菌生物反应器去除地浸采铀矿山退役采区污染地下水中NO₃^--N的影响。研究结果表明：当进液pH值为6.50、NO₃^--N浓度为1 000 mg/L、HRT为2 3 h时,NO₃^--N的去除率和去除速率分别达97%和388 mg/(h•L),生物反应器处理废水的能力达0.35 m³/(h•m³);当进液NO₃^--N浓度为550 mg/L、HRT为1.4 h时,NO₃^--N的去除率和去除速率分别达96%和368 mg/(h•L),生物反应器处理废水的能力达0.62 m³/(h•m³);反硝化细菌生物反应器适宜的运行条件是pH值为5.00～8.00,C/N比为0.6～0.8。     

Comparison of Reynolds average Navier-Stokes turbulence models in numerical simulations of the DC arc plasma torch

Five turbulence models of Reynolds average Navier-Stokes(RANS),including the standard k-ω model,the RNG k-e model taking into account the low Reynolds number effect,the realizable k-ω model,the SST k-ω model,and the Reynolds stress model(RSM),are employed in the numerical simulations of direct current(DC)arc plasma torches in the range of arc current from 80 A to 240 A and air gas flow rate from 10 m^3 h^-1 to 50 m^3 h^-1.The calculated voltage,electric field intensity,and the heat loss in the arc chamber are compared with the experiments.The results indicate that the arc voltage,the electric field,and the heat loss in the arc chamber calculated by using the standard k-ω model,the RNG k-ωmodel taking into account the low Reynolds number effect,and the realizable k-ω model are much larger than those in the experiments.The RSM predicts relatively close results to the experiments,but fails in the trend of heat loss varying with the gas flow rate.The calculated results of the SST k-ω model are in the best agreement with the experiments,which may be attributed to the reasonable predictions of the turbulence as well as its distribution.     

Microchannel cooling technique for dissipating high heat flux on W/Cu flat-type mock-up for EAST divertor

As an important component of tokamaks, the divertor is mainly responsible for extracting heat and helium ash, and the targets of the divertor need to withstand high heat flux of 10 MW m⁻² for steady-state operation. In this study, we proposed a new strategy, using microchannel cooling technology to remove high heat load on the targets of the divertor. The results demonstrated that the microchannel-based W/Cu flat-type mock-up successfully withstood the thermal fatigue test of 1000 cycles at 10 MW m⁻² with cooling water of 26 l min⁻¹, 30 °C (inlet), 0.8 MPa (inlet), 15 s power on and 15 s dwell time; the maximum temperature on the heat-loaded surface (W surface) of the mock-up was 493 °C, which is much lower than the recrystallization temperature of W (1200 °C). Moreover, no occurrence of macrocrack and 'hot spot' at the W surface, as well as no detachment of W/Cu tiles were observed during the thermal fatigue testing. These results indicate that microchannel cooling technology is an efficient method for removing the heat load of the divertor at a low flow rate. The present study offers a promising solution to replace the monoblock design for the EAST divertor     

聚丙烯腈基钛酸钾球形复合吸附剂的制备及其对Sr2+的吸附性能研究

以钛酸钾（KTiO）为有效成分、聚丙烯腈（PAN）为基体,制备了聚丙烯腈基钛酸钾球形复合吸附剂（PAN-KTiO）。采用扫描电镜（SEM）、X射线衍射仪（XRD）等对PAN-KTiO进行了表征,并通过静态吸附实验,研究了接触时间、pH值、竞争离子、Sr²⁺初始浓度等对PAN-KTiO吸附Sr²⁺效果的影响,分析了吸附过程的反应动力学和吸附等温线。结果表明,PAN-KTiO对Sr²⁺的吸附平衡时间约为24 h,PAN-KTiO吸附Sr²⁺时,溶液最佳pH值约为6.55;Ca²⁺、Mg²⁺对Sr²⁺在PAN-KTiO上的吸附存在较强的抑制作用;准二级动力学方程能更好地描述PAN-KTiO对Sr²⁺的吸附动力学过程,而Langmuir模型能更好地描述PAN-KTiO对Sr²⁺的吸附等温线;PAN-KTiO对Sr²⁺的吸附过程是以化学吸附为主的单分子层吸附,PAN-KTiO对Sr²⁺的饱和吸附容量可达53.850 mg/g。     

壳聚糖修饰碳纳米管对含铁放射性废水的处理

采用稳定性同位素⁵⁶Fe的硫酸亚铁溶液模拟核医学放射性废水中的⁵⁵Fe、⁵⁹Fe、⁵²Fe,研究经壳聚糖修饰的多壁碳纳米管CS-MWNTs对亚铁离子的吸附效果。并研究不同pH值、温度、时间、平衡离子浓度对吸附量的影响。结果表明,在相同条件下,CS-MWNTs相比原始多壁碳纳米管MWNTs吸附量有较大提升。CS-MWNTs与MWNTs在中性条件下的吸附效果均较酸性条件下的好,而在偏碱性条件下,溶液会发生沉淀,吸附不再是主要作用。CS-MWNTs与MWNTs对亚铁离子的吸附作用约在3 h达到平衡,且均为吸热反应。在室温25 ℃、pH＝5条件下,CS-MWNTs和MWNTs对亚铁离子的饱和吸附量分别为51 mg/g和27 mg/g。两种吸附材料的吸附过程均符合Freundlich方程。     

高效过滤器钠焰效率试验中NaCl浓度对测量精度的影响

在核级高效过滤器钠焰效率试验中,使用自制的稀释装置和研制的钠焰光度计,试验测量了NaCl浓度在4 ng/m³～13 mg/m³范围内,气溶胶燃烧光强与浓度之间的关系,然后用最小二乘法对测量值进行曲线拟合。研究结果表明：低浓度区,光电流与NaCl浓度间为线性关系,光谱的自吸收系数为1;中、高浓度区,光电流与NaCl浓度间不再符合线性关系,光谱的自吸收系数随浓度的增加而减小。研究结果要求：在高效过滤器效率测量时,如果使用国标的效率计算公式,须保证NaCl的原始浓度低于0.05 mg/m³;如果原始浓度高于0.05 mg/m³,则需使用实际标定的光电流与NaCl浓度间的关系曲线来代替国标的效率计算公式。     

二硫代氨基甲酸盐树脂的合成及其对废水中Fe3+、Co2+、Mn2+的吸附性能研究

以D309树脂为原料,采用甲醇 水溶液法合成二硫代氨基甲酸盐（DTCR）树脂,利用红外光谱和扫描电镜对其结构进行了表征,测试了合成树脂对废水中Fe³⁺、Co²⁺、Mn²⁺的吸附性能,并通过等温吸附实验和动力学实验考察了合成树脂对金属离子的吸附去除能力随接触时间的变化情况和吸附机理。研究表明,该树脂对Fe³⁺、Co²⁺、Mn²⁺的吸附符合Langmuir等温线,在25 ℃下最大吸附量可分别达25.07、20.58、41.87 mg/g,吸附速率较快,吸附4 h均可达到吸附平衡;在二元金属离子混合体系中,树脂对3种金属离子的吸附关系遵守Mn²⁺＞Co²⁺＞Fe³⁺的基本关系;Ca²⁺、Mg²⁺干扰离子存在情况下,树脂对Co²⁺的去除率基本不变,维持在97%左右,树脂对Fe³⁺的去除率得到提高,由50%上升到98%,而树脂对Mn²⁺的去除率反而下降,由92%下降到80%。     

多孔石墨相氮化碳的制备及对U(Ⅵ)的吸附机理研究

以三聚氰胺为原料、碳酸钙为辅助模板,采用热聚合法对石墨相氮化碳（g-C₃N₄）进行改性,制备了多孔石墨相氮化碳（PCN）材料,研究了g-C₃N₄改性前后对U(Ⅵ)的吸附效果,并利用SEM、BET、FT-IR、XPS等表征手段对PCN吸附U(Ⅵ)的机理进行了分析。结果表明：PCN比表面积显著增大（58.5 m²/g）,约为g-C₃N₄的4倍;在初始pH=5、吸附时间2 h、U(Ⅵ)初始浓度10 mg/L、PCN用量0.2 g/L、温度303 K条件下,PCN对U(Ⅵ)的最大吸附量为92 mg/g;整个吸附过程符合准二级动力学方程以及Langmuir等温吸附模型;此外,升高温度有利于PCN对U(Ⅵ)的吸附。FT-IR、XPS表征结果表明,PCN中的含氮基团参与了PCN对U(Ⅵ)的吸附去除。     

1,2,4-trichlorobenzene decomposition using non-thermal plasma technology

Non-thermal plasma(NTP)is regarded as a potential application for environmental pollution control due to its ability to remove pollutants.As a major precursor of dioxins,the influence of the parameters of 1,2,4-trichlorobenzene(TCB)decomposition using NTP technology was investigated through a series of experiments,including voltage,frequency,water content,initial concentration,flow rate,and oxygen content.The experimental results show that the energy injected into the NTP system has a positive correlation to voltage and frequency.Oxygen has the greatest influence on TCB decomposition.The optimal reaction condition was at 15 kV,1000 Hz,an initial concentration of 20 mg m^?3,a flow rate of 2 l min^?1,H2O at 4%,and O2 at 0%.Under this condition,the TCB removal efficiency could reach 92%.According to the generated product backstepping,the hydroxyl radical(·OH)plays an important role in TCB decomposition due to its strong oxidation,which participates in the dechlorination and oxidation reactions as free radicals,and the possible decomposition pathway of TCB by NTP is inferred from the identified byproducts.It is of great significance to investigate the influence of the parameters of TCB decomposition using NTP technology in order to provide references for industrial application.     

Investigation of electron cyclotron current drive efficiency on the J-TEXT tokamak

Electron cyclotron current drive (ECCD) efficiency research is of great importance for the neoclassical tearing mode (NTM) stabilization. Improving ECCD efficiency is beneficial for the NTM stabilization and the ECCD power threshold reduction. ECCD efficiency has been investigated on the J-TEXT tokamak. The electron cyclotron wave (ECW) power scan was performed to obtain the current drive efficiency. The current drive efficiency is derived to be approximately η₀ = (0.06–0.16) × 10¹⁹ A m⁻² W⁻¹ on the J-TEXT tokamak. The effect of the residual toroidal electric field has been included in the determination of the current drive efficiency, which will enhance the ECCD efficiency. At the plasma current of I_p = 100 kA and electron density of n_e = 1.5 × 10¹⁹ m⁻³, the ratio of Spitzer conductivity between omhic (OH) and ECCD phases is considered and the experimental data have been corrected. The correction results show that the current drive efficiency η1 caused by the fast electron hot conductivity decreases by approximately 79%. It can be estimated that the driven current is approximately 24 kA at 300 kW ECW power.     

粉煤灰衍生介孔硅钙材料吸附去除Co(Ⅱ)及放射性过渡金属离子性能研究

针对含低水平放射性过渡金属离子废水的处理需求,本工作以Co(Ⅱ)为代表,研究了粉煤灰衍生介孔硅钙材料对Co(Ⅱ)的吸附去除性能。研究结果表明,高铝粉煤灰“预脱硅-碱石灰烧结提铝”工艺在预脱硅阶段产生的硅钙材料副产品,以水化硅酸钙（C-S-H(Ⅰ)）（钙硅原子摩尔比n(Ca)/n(Si)=0.98～1.00）为主要矿相,属于具有高比表面积（733 m²/g）且孔隙发达的介孔材料,同时,其具有良好的酸碱缓冲性能（pH=2～10）以及一定的阳离子交换性能（Ca²⁺/H⁺）。介孔硅钙材料在35～60℃对Co(Ⅱ)吸附容量最高可达209~296 mg/g,整个过程符合Langmuir单分子层化学吸附,为吸热反应,吸附可在3 h内快速达到平衡,吸附机理主要为离子交换（占84.5%）。而对实际核电站大修废水的吸附试验结果表明,对其中的放射性Co(Ⅱ)去除率大于98.6%,并且其他放射性过渡金属离子也得到去除。在当前放射性核素的水泥固化处置中,介孔硅钙材料不仅与水泥有较高的相容性从而实现放射性核素的高效稳定化,同时还可替代部分水泥从而实现固化产物的减量化,具有较好的环境和经济效益,因此,该介孔硅钙材料在放射性废水核素去除方面具有较大的资源化应用潜力。     

土壤中球孢枝孢对铀（Ⅵ）的吸附

从拟作为低放射性废物处置填埋场土壤中分离出一种霉菌,经过鉴定为链孢霉目黑霉科球孢枝孢,并考察该菌对UO₂²⁺的吸附行为。实验结果表明：铀初始质量浓度为10mg/L,加入5g/L的新鲜湿菌体,其吸附平衡时间约为24h,最终吸附率约94.1%,吸附符合准二级动力学模型;吸附最适宜pH=5～9,当pH≤2时,菌体几乎不吸附UO₂²⁺;铀初始质量浓度为2~10mg/L时,吸附率均在90%左右;吸附近似符合Langmuir吸附经验公式;菌体累积吸附6次吸附量可达6.6mg/g;Ca²⁺会降低微生物对铀的吸附;柠檬酸、硝酸和EDTA对吸附的铀均具有一定的解吸能力,其中柠檬酸最高为67%。采用红外吸收光谱分析,显示吸附后出现UO₂²⁺的吸收峰,表明铀主要以UO₂²⁺的形式被菌体吸附。     

层状金属硫化物硫化锡钾的制备及其对Sr2+的吸附性能研究

本文用水热法合成了硫化锡钾（KSnS）,利用扫描电镜（SEM）、X射线衍射（XRD）仪等对KSnS的形貌和组成进行了表征分析,并通过静态吸附实验分别研究了pH值、接触时间、共存离子和Sr²⁺初始浓度对KSnS吸附Sr²⁺的影响。结果表明,在40 ℃、pH=7.25、Sr²⁺初始浓度为5.5 mg/L的条件下,KSnS对Sr²⁺的吸附平衡时间约为35 min,Sr²⁺去除率为99.62%。吸附反应可操作pH值范围较宽,52+去除率保持在80%以上。溶液中含有K⁺、Na⁺、Ca²⁺和Mg²⁺等共存离子时,二价离子的干扰大于一价离子。KSnS对Sr²⁺的吸附动力学行为可用准二级动力学方程描述,吸附过程属于化学吸附。通过Weber-Morris模型和Boyd模型分析可知,液膜扩散是主导吸附速率的步骤。     

Bright γ-ray source with large orbital angular momentum from the laser near-critical-plasma interaction

We propose a new laser-plasma-based method to generate bright γ-rays carrying large orbital angular momentum by interacting a circularly polarized Laguerre–Gaussian laser pulse with a near-critical hydrogen plasma confined in an over-dense solid tube. In the first stage of the interaction, it is found via fully relativistic three-dimensional particle-in-cell simulations that high-energy helical electron beams with large orbital angular momentum are generated. In the second stage, this electron beam interacts with the laser pulse reflected from the plasma disc behind the solid tube, and helical γ beams are generated with the same topological structure as the electron beams. The results show that the electrons receive angular momentum from the drive laser, which can be further transferred to the γ photons during the interaction. The γ beam orbital angular momentum is strongly dependent on the laser topological charge l and laser intensity a0, which scales as ${L}_{\gamma }\propto {a}_{0}^{4}$. A short (duration of 5 fs) isolated helical γ beam with an angular momentum of −3.3 × 10⁻¹⁴ kg m² s⁻¹ is generated using the Laguerre–Gaussian laser pulse with l = 2. The peak brightness of the helical γ beam reaches 1.22 × 10²⁴ photons s⁻¹ mm⁻² mrad⁻² per 0.1% BW (at 10 MeV), and the laser-to-γ-ray angular momentum conversion rate is approximately 2.1%.     

Pulse-burst laser-based 10kHz Thomson scattering measurements

Thomson scattering(TS),as a popular and reliable diagnostic technique,has successfully measured electron temperatures and electron number densities of plasmas for many years.However,conventional TS techniques using Nd:YAG lasers operate only at tens of hertz.Here,we present the development of a high-repetition-rate TS instrument based on a high-speed,pulse-burst laser system to greatly increase the temporal resolution of measurements.Successful instrument prototype testing was carried out by collecting TS light from laboratory helium and argon plasmas at 10 kHz.Calibration of the instrument detection sensitivity using nitrogen/oxygen rotational Raman scattering signal is also presented.Quantitative electron number densities and electron temperatures of the plasma were acquired at 10 kHz,for stable plasma discharges as,respectively,～0.9 eV and ～5.37×10~(21)m~(-3) for the argon plasma,and ～1eV and ～6.5×1021 m~(-3) for the helium plasma.     

Activated persulfate by DBD plasma and activated carbon for the degradation of acid orange Ⅱ

In this study, the effect of activated peroxydisulfate(PDS) by dielectric barrier discharge(DBD) plasma and activated carbon(HGAC) on the removal of acid orange Ⅱ(AOⅡ) was investigated. The effects of applied voltage, PDS dosage, HGAC dosage, initial pH value, and inorganic anions on the removal rate of AOⅡ were discussed. The main free radicals degrading azo dyes during the experiment were also studied. Experimental results show that the removal rate of AOⅡ in DBD/HGAC/PDS synergistic system is much higher than that in the single system. With the applied voltage of 16 kV, HGAC dosage of 1 g l-1, PDS and AOⅡ molar ratio of 200:1, initial pH value of 5.4 and concentration of AOⅡ solution of 20 mg l-1, the removal rate of AOⅡ reached 97.6% in DBD/HGAC/PDS process after 28 min of reaction.Acidic and neutral conditions are beneficial for AOⅡ removal. Sulfate and hydroxyl radicals play an important role in the removal of AOⅡ. Inorganic anions are not conducive to the removal of AOⅡ.     

磁性富羧基碳复合材料的制备及对Pb(Ⅱ)、Ni(Ⅱ)、Hg(Ⅱ)和U(Ⅵ)的吸附

采用溶剂热法制备了富羧基碳,随后通过化学共沉淀法合成了磁性富羧基碳复合材料。利用透射电子显微镜(TEM)、红外光谱分析(FTIR)、X射线衍射(XRD)、振动样品磁强计(VSM)、热重差热分析(TGA)、zeta电位分析及比表面积(BET)等手段对磁性富羧基碳的形貌、组成、结构、磁性以及表面电荷特性等进行了表征,并考察了富羧基碳和磁性富羧基碳对Pb(Ⅱ)、Ni(Ⅱ)、Hg(Ⅱ)和U(Ⅵ)的吸附性能。结果表明:富羧基碳经磁性改性后表面负载了铁氧化物纳米颗粒,比表面积由29.2m2/g提高到45.4m2/g,热稳定性提高,由磁滞回线可知,磁性富羧基碳的饱和磁化强度为30.68A.m2/kg。Pb(Ⅱ)、Ni(Ⅱ)、Hg(Ⅱ)和U(Ⅵ)在磁性富羧基碳上的平衡吸附容量分别为477.50、23.50、260.20、54.86mg/g,低于富羧基碳,吸附等温线符合Langmuir等温模型。从磁性富羧基碳对Pb(Ⅱ)、Ni(Ⅱ)、Hg(Ⅱ)和U(Ⅵ)均具有较高的吸附容量和不同吸附剂对U(Ⅵ)吸附容量的比较可以看出,该吸附剂是重金属污水和放射性废液处理领域中极具发展前景的吸附材料。     

真菌曲霉F77对水中Cs~+的吸附

微生物在环境放射性污染修复中具有广泛的应用前景。从放射性污染土壤中筛选出一株耐辐射真菌曲霉F77,研究了它对水中Cs+的吸附及其影响因素。结果表明:酸对Cs+在曲霉F77上的吸附存在竞争作用,pH=2.0~3.5溶液中的Cs+几乎不被曲霉F77吸附;曲霉F77生长过程中代谢产生大量的酸性物质;Cs+的吸附随着曲霉F77培养时间的增长而增大,在曲霉F77逐渐衰亡时吸附降低;K+质量浓度小于500mg/L时对Cs+在曲霉F77上的吸附没有影响,当K+质量浓度大于500mg/L时Cs+的吸附随K+浓度增大而减少;溶液中Cs+质量浓度为0~500mg/L范围内,曲霉F77对Cs+均有较高的吸附,Cs+质量浓度为500mg/L时,Cs+的吸附量为27.6mg/g。温度影响曲霉F77对Cs+吸附的快慢,不影响最后的吸附量;曲霉F77对Cs+具有较好的吸附性能,表明曲霉F77具有吸附剂的潜质。     

Discharge and post-explosion behaviors of electrical explosion of conductors from a single wire to planar wire array

This work deals with an experimental study of a Cu planar wire array (PWA) in air and water under the stored energy 300–1200 J. A single Cu wire is adopted as a controlled trial. Four configurations of PWA and a wire with the same mass (cross-section area) but the different specific surface areas (15–223 cm² g⁻¹) are exploded. The transient process is analyzed using high-speed photography in combination with the results of optical emission and discharge. Discharge characteristics revealed that PWA always has a higher electric power peak, early but higher voltage peak, as well as faster vaporization and ionization process than the single-wire case. Two to three times stronger optical emission could be obtained when replacing the single-wire with PWA, indicating a higher energy-density state is reached. Phenomenologically, in both air and water, single-wire load tends to develop a transverse stratified structure, while PWA is dominated by the uneven energy deposition among wires. Finally, the synchronism and uniformity of the PWA explosion are discussed.