在Na2CO3溶液中季铵盐萃取Zr机理的研究

用红外光谱分析和季铵盐萃取研究了Zr—DBP界面物在碳酸钠溶液中的溶解机理。结果表明,Zr—DBP界面物在碳酸钠溶液中生成了能溶于水的配合阴离子Zr(CO3)4^4-或ZrO(CO3)3^4-,Zr—DBP界面物溶解前后与纯HDBP的红外谱图相比,溶解液中DBP的P—O键的特征峰与纯HDBP的更为接近。说明界面物在溶解Na2CO3过程中,破坏了原有界面物的配合,DBP不再与Zr配合,而以自由离子形式存在。     

2-甲基1，4-萘醌激发三重态与核酸反应的电子自旋共振自旋消减法研究

应用电子自旋共振（Electron spin resonance，ESR）自旋消减法，研究了内源性光敏剂2-甲基-1，4萘醌（VK3）的激发三重态（^3VK3^＊）与核酸及其组分的反应性顺序，得到。VK3^＊与四个核苷及四个单核苷酸的反应性顺序为Gua〉Ade〉Cyt〉Thy，dGMP〉dAMP〉dCMP〉TMP。结果与早前采用激光光解瞬态吸收光谱研究^3VK3^＊氧化DNA，测得的DNA及其组分阳离子自由基生成速率常数、核苷及核苷酸的氧化还原电位排序相一致。对^3VK3^＊与几种富含鸟嘌呤（G）的寡聚核苷酸：端粒DNA重复序列、端粒酶RNA亚基模版及其L6-P6发夹序列反应的ESR自旋消减法研究结果表明，其反应性大小与寡聚物中鸟嘌呤含量正相关，其中与端粒DNA的反应性最强。     

氚标记胆红素的研制及应用

由胆绿素经钠硼氚还原生成氚标记胆红素，而胆绿素是由胆红素经ＤＤＱ脱氢氧化形成，钠硼氚是在镍催化及高温下由钠硼氢与氚气交换得到，氚标记胆红素比活率为３０６ＴＢｑ／ｍｏｌ，放化纯度经高效液相色谱及纸层析鉴定均大于９５％，用氚标记胆红素进行开放血脑屏障的动物实验获得了满意的结果。     

酶促磷酸化法合成氚标记核苷三磷酸

以5 BrUMP、5 BrCMP、8 BrAMP及8 BrGMP为原料,使用催化氚卤置换法制备了[5-~3H]UMP、[5-~3H]CMP、[8-~3H]AMP及[8-~3H]GMP。再用从啤酒鲜酵母中提取的粗酶,经酶促磷酸化,将[5-~3H]UMP、[5-~3H]CMP、[8-~3H]AMP及[8-~3H]GMP进一步合成了[5-~3H]UTP、[5-~3H]CTP、[8-~3H]ATP及[8-~3H]GTP,并用纸层析方法进行纯化。作为副产品,还得到了氚标记核苷一磷酸和氚标记核苷二磷酸。产品的比活度为14—19 Ci/mmol,放化纯度大于98%。     

DRDECMP-TBP/煤油萃取性能的研究Ⅱ.对锕系-镧系元素的萃取

研究并测定了DRDECMP TBP/煤油对Am3 、Gd3 、UO2 2 的萃取分配比。研究结果表明 ,分配比随DRDECMP浓度或水相中HNO3浓度的增大而增大 ,随水相中Gd3 浓度的增大或温度的升高而降低 ;当有机相中TBP浓度增大时 ,Am3 、Gd3 的分配比略有下降 ,UO2 2 的分配比略有升高 ;酸度低时 ,Am3 和Gd3 的分配比低 ,可实现低酸反萃取 ;而低酸下UO2 2 的分配比较高 ,采用H2 C2 O4 等配位剂可有效降低其分配比 ,实现配合反萃取。     

Calculation and characteristic analysis on synergistic effect of CF3I gas mixtures

CF_3I is a potential SF_6 alternative gas.In order to study the insulation properties and synergistic effects of CF_3I/N_2 and CF_3I/CO_2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionization coefficient α,attachment coefficient η and the critical equivalent electrical field strength(E/N)_(cr).The results show that the(E/N)_(cr)of CF_3I gas at 300 K is 1.2 times that of SF_6 gas,and CF_3I/N_2 and CF_3I/CO_2 gas mixtures both have synergistic effect occurred.The synergistic effect coefficient of CF_3I/CO_2 gas mixture was higher than that of CF_3I/N_2 gas mixture.But the(E/N)_(cr)of CF_3I/N_2 is higher than that of CF_3I/CO_2 under the same conditions.When the content of CF_3I exceeds 20%,the (E/N)_(cr) of CF_3I/N_2 and CF_3I/CO_2 gas mixture increase linearly with the increasing of CF_3I gas content.The breakdown voltage of CF_3I/N_2 gas mixture is also higher than that of CF_3I/CO_2 gas mixture in slightly non-uniform electrical field under power frequency voltage,but the synergistic effect coefficients of the two gas mixtures are basically the same.     

99Tcm-MAG3-RRL肿瘤靶向肽的标记和性质鉴定

将具有肿瘤靶向性的精氨酸-精氨酸-亮氨酸（RRL）多肽与双功能螯合剂MAG₃相连,摸索其螯合⁹⁹Tc^m的适宜标记条件并评价探针的体外稳定性。标记利用SnCl₂还原法进行⁹⁹Tc^m标记,对影响标记的主要变量因素分别进行探究以获得适宜标记条件,采用纸层析法测定标记率和放射化学纯度。实验所得MAG₃-RRL纯度为98.94%,适宜标记条件下,标记率为93.67%±1.10%,纯化后放射化学纯度为94.32%±0.19%（n=3）。⁹⁹Tc^m-MAG₃-RRL在生理盐水和50%牛血清白蛋白（BSA）中放置,6 h内放射化学纯度均大于90%（n=3）,在半胱氨酸溶液中的最高置换率为0.57%±0.21%,生理盐水对照为0.41%±0.04%（n=3,P＞0.05）。⁹⁹Tc^m-MAG₃-RRL的脂水分配系数为lg P=-0.15±0.01（n=3）。结果表明：MAG3可成功连接RRL多肽,并能进一步提高标记率;探针制备方法简单快速,体外稳定性好,为进一步的生物学实验提供了良好的基础。     

硫酸亚铁剂量计摩尔线性吸收系数的测定

介绍了采用分光光度法测定Fe3+离子摩尔线性吸收系数的原理、方法及Fe3+离子标准溶液的制备过程;在一定的Fe3+离子浓度范围内,测定了Fe3+离子摩尔线性吸收系数,给出了测量结果,并对测量结果的不确定度进行了评定。     

Ru3+和［RuNO］3+的速差动力学分析方法

建立了用速差动力学分光光度法分析同一体系中Ru³⁺和［RuNO］³⁺的方法。在盐酸羟胺存在下，测定了Ru³⁺和［RuNO］³⁺与bipy的反应表观速率常数、浓度级次及反应平衡常数。通过测量反应产物Ru(bipy)²⁺₃的起始反应速率和平衡时的浓度，由建立的相关线性方程组计算出Ru³⁺和［RuNO］³⁺的浓度。Ru³⁺和［RuNO］³⁺的回收率分别为96%~105%和95%~106%。加入EDTA能较好地掩蔽常见金属离子的干扰。     

Influence of Deposition Temperature on the Structure Of Si3N4 Thin Film Prepared By MWECR-PECVD

The Si3N4 thin film is prepared by MWECR-PECVD at different deposition temperature and the structure of the Si3N4 thin film is investigated. The results indicate that the structure of the Si3N4 thin film prepared at low deposition temperature is in the amorphous phase. However, when the deposition temperature increases to 280℃, the Si3N4 thin film changes to crystalline a-Si3N4. With a further increase of the deposition temperature, the grain of the Si3N4 thin film becomes more fine, uniform and flat. XRD analysis shows that the structure of the Si3N4 thin film prepared at 280℃ is of a crystalline structure.     

UD3的表面钝化和氧化特性研究

本文研究了UD₃的表面钝化和氧化特性。利用XRD、激光拉曼技术观察到钝化的UD₃表面致密保护层的主要成分为UO₂。利用量热法研究了钝化的UD₃在空气中的氧化自燃特性,结果显示：当反应温度低于110 ℃时,钝化的UD₃在空气中反应缓慢;当反应温度高于130 ℃时,钝化的UD₃表面保护层被破坏,UD₃在空气中剧烈氧化,钝化的UD₃的自燃温度约为140 ℃。     

三羰基铼[188Re]的放射化学合成

合成了化合物[N(Et)4]2ERe(CO)3Br3],并用IR,ICP—MS,元素分析等方法对化合物进行了表征。分析了此化合物溶于水后,阴离子部分的3个Br^-可定量地被3个H2O分子取代,得到前体化合物fac-[Re(CO)3(H2O)3]^ 。同时合成了放射性前体化合物fac-[^188Re(CO)3(H2O)3]^ ,放化产率约为80％,Sep-Pak分离后,放化纯度大于95％。通过HPLC分析比较了这两个前体,确定了放化前体fac-[^188Re(CO)3(H2O)3]^ 的结构。     

Status of developing HPGe γ-ray spectrum analysis code HYPERGAM

HYPERGAM, a new MS-Windows version of HPGe γ-ray spectrum analysis code HYPERMET, is being developed. Graphic user interface is provided and the control parameters of analysis are minimized. The semi-automatic algorithm for γ-ray peak analysis is adopted from the original HYPERMET routines whose performance is well known. The details of fitting result are graphically displayed so the analyst can determine reliability. Simpler methods for peak analysis and system non-linearity calibration are newly added. The present code is widely applicable to γ-ray spectroscopy including neutron activation analysis, but it is specifically designed to become a tool for automatic spectrum–isotopic analysis in environmental radiation monitoring.     

Improvement of β-phase crystal formation in a BaTiO_3-modified PVDF membrane

In this paper,low temperature plasma is used to modify the surface of barium titanate(BaTiO_3)nanoparticles in order to enhance the interfacial compatibility between ferroelectric poly(vinylidene fluoride)(PVDF) and BaTiO_3 nanoparticles.The results demonstrate that oxygenic groups are successfully attached to the BaTiO_3 surface,and the quantity of the functional groups increases with the treatment voltage.Furthermore,the effect of modified BaTiO_3 nanoparticles on the morphology and crystal structure of the PVDF/BaTiO_3 membrane is investigated.The results reveal that the dispersion of BaTiO_3 nanoparticles in the PVDF matrix was greatly improved due to the modification of the BaTiO_3 nanoparticles by air plasma.It is worth noting that the formation of a β-phase in a PVDF/modified BaTiO_3 membrane is observably promoted,which results from the strong interaction between PVDF chains and oxygenic groups fixed on the BaTiO_3 surface and the better dispersion of BaTiO_3 nanoparticles in the PVDF matrix.Besides,the PVDF/modified BaTiO_3 membrane at the treatment voltage of 24 k V exhibits a lower water contact angle(≈68.4°) compared with the unmodified one(≈86.7°).Meanwhile,the dielectric constant of PVDF/BaTiO_3 nanocomposites increases with the increase of working voltage.     

Analysis of irreversible circulation in reactor noise

A new parameter is proposed as a statistical variable of multi-dimensional reactor noise analysis. It indicates circulation in a space of state variables, while the well-known variance σ represents the spread of distribution of fluctuations. The pair of quantities σ and are minimum necessary integral indices to characterize any power spectral density and are convenient for data retrieval. The is less sensitive to the effect of low-cut filter than σ. The analysis of experimental data by using is demonstrated and compared with the results of theoretical treatment.     

C+W+C离子注入H13钢复合钝化层的抗腐蚀特性

用多次扫描电位法研究了C＋W＋C离子注入H13钢的结构和相变及其对抗腐蚀特性的影响,研究了抗腐蚀相生成的条件以及这些相对抗腐蚀特性的作用,并对其改性机理进行了讨论。实验结果表明,W离子和C离子多重离子注入H13钢可在注入层中形成超饱和浓度的W和C原子分布,分布形状为类高斯分布;并可在注入层中形成钨的碳化物WC和W2C相、合金相Fe2W和Fe6W6C等,这些弥散相不但可以使注入层强化,而且也可使表面钝化,从而增强了表面抗腐蚀特性;W和C双重离子注入具有W和C单离子注入的特性,可进一步提高H13钢的抗腐蚀特性,随着W重离子和C重离子注入剂量的增加,抗腐蚀特性进一步增强。样品C3W3C3的Jp经50个周期腐蚀后,其值比H13钢的Jp下降了60％,而C3W3的Jp比H13钢的Jp下降了47％。C3W3C3的Jp比C3W3的Jp小34％。扫描电子显微镜观察表明,腐蚀后抗腐蚀的钝化层依然存在。     

Bromate removal by gamma irradiation in aqueous solutions

Bromate(BrO_3) is a disinfection by-product in drinking water, and its removal is very difficult especially at low levels.60 Co gamma rays were used to remove BrO_3in aqueous solution in this study. The effects of absorbed doses, BrO_3initial concentration, gas saturation, p H value and coexisting anions(Cl, NO 3, SO2 4and HCO 3=CO_3~(2 -))on BrO_3reduction were evaluated. After 4.0-k Gy irradiation of air-equilibrated solution of 30.7 lg/L BrO_3, the residual BrO_3was 8.3 lg/L, which is below the maximum contaminant level of drinking water. The BrO_3reduction rate increased with the dose, in the order of N2[ air [ O_2[ N_2O atmosphere under similar conditions. The results also show that high p H favored the BrO_3removal. According to the experimental results, it can be concluded that the efficiency of decomposing BrO_3by reactive species followed the order of e aq[ H [ HO_2 [ O_2. Coexisting Cl, HCO 3=CO_3~(2 -)and SO2 4ions have little effect on BrO_3removal, whereas NO_3can inhibit its removal as a result of competition with BrO_3for e aq.     

甲醇-硝酸-阴离子交换树脂体系中用高压离子交换色层法分离镅和锔

在以硝酸作为络合剂的水-醇混合溶液中分离超钚元素,其效果优于纯水溶液。作者在前一工作中介绍了使用甲醇-硝酸-阴离子交换树脂从辐照靶中分离镅和锔的工艺流程,本文采用高压色层技术进行镅、锔分离,并且对此体系的动力学性能进行探讨。 在文献上未见到阴离子树脂分离元素时采用高压技术,直到实验结束后才看到使用类似