硝酸介质中亚硝酰钌配合物的光分解反应动力学研究

研究了硝酸介质中亚硝酰钌配合物的光分解反应，测定了亚硝酰钌配合物的紫外吸收光谱。实验结果表明：在低压汞灯２５４ｎｍ的紫外光照射下，硝酸介质中亚硝酰钌配合物的光分解反应属表观准一级反应；在ｃＨＮＯ３＜２ｍｏｌ／Ｌ时，反应速率常数随硝酸浓度的增加而增大，在ｃＨＮＯ３＞２ｍｏｌ／Ｌ时，反应速率常数随硝酸浓度增大而减小。温度在１０—４０℃时，速率常数随着温度的上升而减小。     

177Lu-DOTA/DTPA-Bz-Cys-RGDdimer的制备及正常鼠体内生物分布

制备177Lu-DOTA-Bz-Cys-RGD dimer和177Lu-DTPA-Bz-Cys-RGD dimer,并对其体内外性质进行比较.TLC和HPLC分析结果表明,在pH=5.0和100 ℃条件下反应15～20 min,2种标记物的标记率均大于95%,并且在室温条件下2种标记物均保持良好的体外稳定性.HPLC分析结果和脂水分配系数lg P测定结果证实,177Lu-DOTA-Bz-Cys-RGD dimer的脂溶性高于177Lu-DTPA-Bz-Cys-RGD dimer.生物分布实验数据显示,注射后4 h,除了血液和脾,177Lu-DTPA-Bz-Cys-RGD dimer在其它组织中的摄取明显高于177Lu-DOTA-Bz-Cys-RGD dimer,177Lu-DOTA-Bz-Cys-RGD dimer的体内稳定性远好于177Lu-DTPA-Bz-Cys-RGD dimer.Bz-DOTA更适于作为双功能螯合剂用于RGD dimer的177Lu标记.     

[188Re(CO)3L]n新型配合物的小鼠体内生物分布

选择了3种三齿配体(二(2-吡啶甲基)-胺基)-乙胺(L1NH2)、(二(2-吡啶甲基)-氨基)-乙酸(L2H)和((6-胺基-N-叔丁氧基羰基-己基)-吡啶-2-甲基氨基)-乙酸(L3NH2),用于设计合成新的以 fac-[188Re(CO)3] 为核心的放射性药物.3种配体在低浓度(10-5 mol/L)的条件下,反应时间小于60 min,标记率可达90%以上,放射化学纯度大于92%;3种标记物的体外稳定性均很高,标记后24 h内基本不分解.生物分布结果表明,配合物均能较快地从血液和多数的组织器官中清除,主要通过排泄系统代谢,并初步探讨了这3个配合物在小鼠体内的生物分布行为可能与它们的脂水分配系数lg P有关.lg P值(-0.36)高的配合物[188Re(CO)3L3NH2], 24 h时在各个器官中放射性保留均高于其它2个配合物,但可能不是唯一的影响因素.总的来说,3个配基是用fac-[188Re(H2O)3(CO)3] 标记的比较理想的双功能螯合剂.     

[99TcmN(PNP)]2+标记葡萄糖硫酮类衍生物混配配合物的研究

为研究新的99TcmN核心标记的心肌和肿瘤显像药物,选用自行合成的二硫化碳-葡萄糖(硫酮类)衍生物Ln(L1～L5)制备一系列带有葡萄糖衍生物基团的新型[99Tcm (DTC)(PNP)]+类配合物,经TLC和HPLC检测,配合物的放射化学纯度均大于90%.小鼠生物分布实验表明,99TcmN(PNP)Ln(L1～L5)系列配合物在正常小鼠体内初始的放射性摄取主要分布于心肌、肝、肺、肾等脏器,并且30 min内各脏器均可迅速清除.初步的荷EMT-6鼠生物分布实验显示,99TcmN(PNP)L2在肿瘤中放射性摄取不高,30 min时为(0.39±0.03)%ID/g,其它组织的放射性摄取与正常小鼠类似.     

90Y/177Lu标记DOTA-Bz-RGDtetramer 和DOTA-RGDtetramer的比较

分别选用90Y和177Lu标记DOTA-Bz-RGD tetramer和DOTA-RGD tetramer,比较不同形式的双功能螯合剂对标记条件以及标记物的体外稳定性的影响.考察了反应pH值、反应温度和反应时间对标记率的影响.ITLC和HPLC分析结果表明,pH=6.0, 100 ℃下反应15～20 min, 4种标记物的标记率均大于95%;在生理盐水和牛血清体系中,4种标记物均保持良好的稳定性.苄基(Bz)的引入并不影响标记条件和标记物的体外稳定性,但对整个分子的极性带来了影响.HPLC分析结果和lg P测定结果显示,引入苄基(Bz)使标记物分子的脂溶性略微增加.     

电动势法研究HAN与Fe3+氧化还原反应动力学

采用电动势法研究了硝酸体系中硝酸羟胺(HAN)还原Fe3+离子的反应动力学,得到了动力学表观速率方程-dc(Fe3+)/dt=kc0.62(HAN)c-2.80(H+)c(Fe3+)c-0.85(Fe2+);当温度为50℃、离子强度I=1.0mol/L时,表观速率常数k=(2.9±0.1)×10-6(mol/L)3.02/s,反应表观活化能Ea=(125±3)kJ/mol。硝酸根的存在对反应起到抑制作用,离子强度的增大对反应有促进作用。     

99Tcm标记HYNIC-Anx13用于细胞凋亡显像的研究

为探讨⁹⁹Tc^m标记的HYNIC-Anx13用于细胞凋亡显像的可能性，分别以N-［三（羟甲基）甲基］甘氨酸（Tricine）, 乙二胺-N,N'-二乙酸（EDDA）和EDDA/Tricine为协同配体，对经6-肼基烟酰基（HYNIC）修饰的膜联蛋白V（Annexin V）片段（HYNIC-Anx13）的⁹⁹Tc^m 标记条件和主要影响因素进行了研究，并完成了HYNIC-Anx13的⁹⁹Tc^m标记物在正常小鼠体内的生物分布和大鼠细胞凋亡模型的显像实验。实验结果表明，标记物在反应溶液和小牛血清中较稳定，但在与半胱氨酸的竞争反应中及在生物体内的稳定性较差。生物分布实验及体内显像结果表明，⁹⁹Tc^m标记HYNIC-Anx13的血液清除较快，在体内主要经肾脏排泄；在模型组的靶器官中的放射性摄取明显高于对照组（p<0.05），但靶与非靶组织的放射性比值较低，细胞凋亡组织的显像图像不够理想。     

99Tcm(CO)+3核心标记的邻二氮杂菲类化合物的理化性质和生物分布

确定化合物可以通过血脑屏障进入脑中并迅速从脑中清除,是判断药物能否作为阿尔茨海默病显像剂的首要条件.为发展99Tcm标记的阿尔茨海默病早期显像诊断药物,在前期研究与DNA分子结合的荧光探针钌金属配合物的基础上,设计合成了2个邻二氮杂菲类配体2-(9-蒽基)-1氢-咪唑[4, 5-f][1, 10]邻菲咯啉(2-(9-anthryl)-1H-imidazo[4, 5-f][1, 10]phenanthroline, aip)和2-(9-蒽基)-1乙基-咪唑[4, 5-f][1, 10]邻菲咯啉(2-(9-anthryl)-1ethyl-imidazo[4, 5-f][1, 10]phenanthroline, aeip),并与99Tcm (CO)+3进行标记.采用R-HPLC、纸电泳等方法研究标记产物的理化性质.正常小鼠体内生物分布研究表明,2种化合物99Tcm (CO)3+-aip和99Tcm (CO)3+-aeip均有一定的脑初始摄取,注射后2 min,前者为(1.028±0.096)%ID/g;后者为(1.191±0 197)%ID/g,因此标记物具有进一步研究的价值.     

99Tcm标记糖肽及其在荷瘤小鼠体内的分布与代谢动力学

Glucose and galactose are conjugated to the N- mercaptoacetyl-Val-Gly-Gly (MAVGG). The glycopeptides and MAVGG are labeled with 99Tcm. The partition coefficients between octanol and water (Pow) are measured. Glycopeptides or MAVGG labeled with 99Tcm areinjected into the mice bearing S180 tumor. 10μL blood samples are withdrawn at different time points and the radioactivities are counted to calculate the effective halflife (T1/2) using a bi-exponential fit. Biodistribution is measured at 3 h postinjection and the percentage of injected dose per gram ( ID%/g ) and tumor to normal tissue ratio (T/NT) were calculated. The assigned structures were confirmed on the basis of IR, NMR and MS. The 99Tcm labeling yield 巨radiochemical purity is greater than 90%. The lgPow of 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG are –1.974, –2.128 and –1.378, respectively. The T1/2αof the three labeled peptides are 24.3, 37.1, 46.3 min and T1/2β are 221.5, 158.4 and 198.4 min, respectively. The tumor uptakes at 3 h postinjection are 1.46, 1.55 and 0.67 for 99Tcm-Glu-MAVGG, 99Tcm-Gal-MAVGG and 99Tcm-MAVGG, respectively. Their T/NT for tumor over muscle are 3.74、7.38 and 3.53, respectively. The results demonstrated that after carbohydrate conjugate of peptides, the lipophilicity is decreased , the blood clearance is increased and the tumor uptake is enhanced. Of the two glucopeptides, 99Tcm-Gal-MAVGG shows faster blood clearance, higher tumor uptake and T/NT, which suggests the potential utility of 99Tcm-Gal-MAVGG as a suitable tumor imaging agent.     

含生物素的双功能螯合剂合成及[99Tcm(CO)3(H2O)3]+标记

设计合成了一种新的用于生物素偶联的双功能螯合剂N-α-(2-皮考基)-N-ε-D-生物素基-L- 赖氨酸甲酯( PLB )，并完成其Re(CO)3 PLB配合物的合成及化学结构的表征。[99Tc m(CO)3(H2O)3]+ 的标记条件研究表明，PLB配体浓度在10μmol/L以上，pH在正常生理值7.4左右，于95℃加热30min，标记物的放化纯度大于95％，比活度达37～55.5TBq/mmol。     

LiCl-KCl-LaCl_(3)熔盐体系中La^(3+)的反应动力学机理北大核心CSCD

在LiCl-KCl共晶盐中,研究了在不同温度下La^(3+)的反应动力学机理。首先,在723~873 K范围内,利用循环伏安法(CV)测得La^(3+)的扩散系数D为3.06×10^(-5)~6.08×10^(-5)cm^(2)/s,并根据Arrhenius方程计算了La^(3+)在电解质中的扩散活化能E_(D)=34.51 kJ/mol。随后,利用电化学阻抗谱技术(EIS)研究了La^(3+)在电极上的动力学参数并测得交换电流密度i_(0)为0.48~1.39 A/cm^(2)、反应速率常数k_(0)=2.04×10^(-4)~5.90×10^(-4)cm/s及反应活化能E_(a)=35.04 kJ/mol。通过Nyquist图和拟合的等效电路图研究La^(3+)在W电极上的反应动力学机理,发现在LiCl-KCl共晶盐中La^(3+)的电化学反应速率不仅受扩散控制还受电荷转移控制,且与温度成正相关。     

一元线性回归处理逆动态法实验数据

阐述了一元线性回归处理逆动态法实验数据的原理。采用该方法除能获得反应性外还,可得到外中子有效源强。根据逆动态法实验原理和一元线性回归方法编写了计算程序,对俄罗斯动力研究院零功率装置BFS-1的实验数据进行处理,并与俄罗斯的计算结果进行了比较。计算结果表明：利用一元线性回归方法处理逆动态法实验数据可准确获得反应性和有效源强,提高了测量结果的精度,利用计算出的反应性可方便获得中心元件的效率;在反应堆功率较低、外源较强的情况下,应考虑外源对反应性测量的影响。     

Simple Method for Evaluation of [lbar] Used for Kinetic Calculations of One Point Reactor Model

Graphite Material has been widely used as first wall material in present large tokamak devices. However, overall evaluation with respect to vacuum engineering properties, interactions with plasmas, and thermal and mechanical properties has not been systematically performed so far, though these properties much depend on the kind of the graphite material. For the overall evaluation of the graphite as fusion first wall material, the “Graphite Project” was organized in 1986 under the support of the Ministry of Education, Science and Culture. More than 20 institutions participated in this project and 27 graphite material (isotropic graphite, pyrolytic carbon, C/C composite) supplied from 8 graphite manufactureres of Japan were characterized as “common samples”.

It was found that the vacuum engineering properties such as outgassing, effective surface area and hydrogen permeation significantly depended on the pore structure of the graphite. Both the outgassing quantity and the surface area were observed to be small for the graphite with low density. The mechanism of hydrogen permeability was explained by the molecular flow through the pore structure. The chemical sputtering yield of metal deposited graphite was significantly lower than that of the graphite with clean surface. The hydrogen retention was considerably reduced by the iron or titanium deposition onto the graphite surface. The yield of the radiation enhanced sublimation for the isotropic graphite was measured and the result showed that the yield of the isotropic graphite was quite similar to that of the pyrolytic carbon. The heat load experiments showed that most of the isotropic graphite failed at roughly the same heat load and the fracture toughness was also approximately the same. The C/C composite materials, however, had the thermal shock resistance and the fracture toughness, which were several times larger than that of the isotropic graphite.     

快中子临界装置逆动态法反应性测量系统研制与应用

逆动态法可实时、准确地测量反应性,在反应性部件刻度、扰动反应性效应测量、动力堆的瞬态分析等领域具有独特的优点。本文基于逆动态法研制了快中子临界装置反应性测量系统,并对其进行了算法验证与指标分析。实验结果表明,该系统具有测量精度高、响应快、分辨率高、使用方便等优点,满足实验需求。     

杯[8]芳烃羧酸衍生物对铁、镧的萃取研究

合成了对叔丁基杯 [8]芳烃乙酸衍生物。在 (30± 1 )℃ ,I =0 1mol/kg条件下 ,研究了它对Fe3 、La3 的萃取性能 ;用斜率法研究了萃取反应机理 ,得到了萃取反应平衡常数 ,并发现该萃取剂对Fe3 、La3 存在着两种不同的萃取机理。     

可逆比热容法测量反应堆中子注量率的可行性及应用前景

热分析仪器和测量技术的迅速发展为通过测量受辐照材料热性质的变化测量中子注量提供了可能。本文提出采用调制差示扫描量热（MDSC）法测量反应堆辐照的含硼材料可逆比热容的变化,进而得到反应堆的中子注量率。从理论和实验两方面讨论了利用该方法测量反应堆中子注量率的可行性。介绍了可逆比热容法测量反应堆中子注量率的原理和实验方法。展望了这种测量方法在测量高注量反应堆中子注量率的应用前景。     

等离子体气相凝聚技术制备铜纳米团簇薄膜的沉积速率研究

采用等离子体气相凝聚技术并结合差分抽气技术产生铜纳米团簇束流,然后在衬底上沉积铜纳米团簇薄膜,研究了溅射电流、氩气流量和结露区长度对其沉积速率的影响。利用X射线衍射仪和透射电子显微镜对薄膜微结构进行了表征。结果表明：保持其他参数不变的情况下,增加溅射电流和氩气流量,铜纳米团簇薄膜的沉积速率均呈现先增大后减小的趋势,而结露区长度对沉积速率的影响无明显规律,这主要归因于铜纳米团簇粒子的平均自由程变化。铜纳米团簇薄膜主要由粒径约为几纳米的团簇颗粒组成,其结晶程度较低。     

基于MELCOR与MCNP程序的安全壳剂量率计算方法

严重事故条件下,评估安全壳内的放射性剂量率水平对核电厂严重事故管理、应急响应等环节具有重要指导意义。本工作利用MELCOR程序模拟严重事故序列,计算不同核素组释放进入安全壳内的质量;利用ORIGEN2程序计算不同核素组的堆芯积存量及核素的γ源强;利用MCNP程序计算每组核素100%释放进入安全壳所产生的剂量率水平;最后根据拟合公式求解安全壳剂量率。中核核电运行管理有限公司30万千瓦机组安全壳剂量率的计算结果说明该方法切实可行。     

Overall Reaction Rate Analysis of Ion-Exchange Resins Incineration by Fluidized Bed

A kinetic study on the incineration of ion-exchange resins was conducted using fluidized bed. In the experiment, cation or anion exchange resins with known quantities were fed into the fluidized bed maintained at a constant temperature from 550 to 750°C. The apparent reaction rate constants k _ap could be evaluated by the time for completion of combustion derived from the continuous measurement of CO₂ concentration in the off-gas.

It was confirmed that the reaction of the ion-exchange resins proceeded with the shrinking particle model forming no solid product layer and the rate of disappearance of the resins could be expressed by the surface chemical reaction.

Most preferable conditions for incinerating the ion-exchange resins were found to be about 650°C for temperature and more than 4.91 x 10^?2 m-s^?1 for the air velocities at fluidized bed u _B . Also, k _ap for cation and anion exchange resins were found to be 1.25x10^?2 and 1.51x10^?2 s^?1, respectively, at 650°C and u _B of 5.45x10^?2m.s^?1.     

[G-~3H]-雷公藤甲素的制备

采用催化气-液同位素交换法制备了氚化雷公藤甲素，探讨了反应时间和反应介质对反应产额的影响。用纸色层法分离与纯化产品，最终获得产品的放射性比活度和放化纯度分别为0.61TBq/g和98%。