植物生长延缓剂~(14)C-PP333的合成

用相转移催化方法,标记合成了1-对氯苯基-2-[(5-~(14)C)-1,2,4-王唑-1-基]-4,4-二甲戊-3-醇(~(14)-PP333)。其步骤包括:在相转移催化剂(PEG800)的存在下,(5-~(14)C)-1,2,4-三唑与一氯片呐酮在乙酸乙酯溶液中反应,生成(5-~(14)C)-α-三唑基片呐酮(2);后者在苯溶液中再与对氯氯苄反应,生成~(14)C-三唑酮(3);最后在甲醇溶液中~(14)C-三唑酮用硼氢化钠还原得到~(14)C-PP333,其总放化收率为20.9％(以~(14)C-三唑计),放化纯度大于99％。     

高比活度碳-14标记吡虫啉的合成与分析

以[14 C]碳酸钡为原料,通过格氏、还原、溴化和亲核取代等五步反应制备了碳-14标记吡虫啉的粗品,经制备型HPLC纯化获得了目标物14 C-吡虫啉(1-(6-氯-3-吡啶[14 C]甲基)-N-硝基咪唑-2-亚胺,1 354.2 MBq)纯品,反应总放化收率为51%。目标物化学结构经质谱(ESI-MS)和核磁共振氢谱(1 H NMR)确认,其放化纯度和化学纯度分别以放射性薄层层析-同位素成像分析法(TLC-IIA)、离线放射性高效液相色谱法(HPLCLSC)、在线放射性高效液相色谱法(HPLC-FSA)和多波长高效液相色谱法(HPLC-PDA)测定。结果表明,目标物14 C-吡虫啉的放化纯度和化学纯度均大于98%,比活度为1 871.46GBq/mol。目标物14 C-吡虫啉可作为放射性示踪剂,用于吡虫啉在不同植物中的定向积累与代谢特征研究。     

~3H和~(14)C标记常咯啉的合成

本文用合成方法制备了抗心律不齐新药常咯啉的三种不同位置~3H和~(14)C的标记化合物。以5-溴邻氨基苯甲酸按Scheme 1经5步反应得6-溴代常咯啉(Ⅵ),Ⅵ用氚经催化脱卤得[6-~3H]常咯啉(Ⅰ)用[~(14)]甲酸制成[~(14)C]甲酰胺,按Scheme 1经二步反应得[2~(14)C]5-氯代喹唑啉(V,R=H)再按Sc-heme2即得[2-~(14)C]常咯啉(Ⅱ)。以[~(14)C]甲醛为原料按Schemel的最后一步可直接制得(甲撑-~(14)C)常咯啉(Ⅲ)     

简便快速自动化合成报告基因表达PET显像剂18F-FHBG

用一锅法和TRACERlab FXF-N合成仪自动化合成9-(4-18F-3-羟甲基丁基)鸟嘌呤(188F-FHBG).以N2-(对甲氧苯基二苯基甲基)-9-[(4-甲苯磺酰基)-3-对甲氧苯基二苯基甲氧基-甲基丁基]鸟嘌呤为前体,在同一反应瓶中经亲核氟化、水解两步反应及SEP-PAK小柱分离纯化制备18 F-FHBG注射液,总合成时间<40 min,未校正放化产率为7%-12%(n>10),放化纯度>95%.用SEP-PAK分离纯化的一锅法,操作简便,很容易实现18F-FHBG的自动化合成.     

PET示踪剂~(11)C-氟马西尼的合成及质量控制

为制备满足临床应用需要的~(11)C-氟马西尼,以~(11)C-CH3I为甲基化试剂,使用国产PET-CM-3H-IT-I型模块对~(11)C-氟马西尼的制备及纯化方法进行改进。用液相法合成~(11)C-CH3I,研究反应溶剂、碱性强度、碱量、反应温度对合成效率的影响,优化~(11)C-氟马西尼的合成条件。优化后的条件为:先将~(11)C-CH3I在室温下通入含1mg去甲基氟马西尼前体和1mg氢化钠的200μL DMF溶液中,加热至55℃恒温反应2min。反应物经半制备HPLC分离收集粗产品,再经SEP-PAK C-18柱固相萃取,对产品质量进行分析。结果表明,以捕获~(11)C-CO2计算,~(11)C-氟马西尼合成时间为(26±2)min,经衰减校正后放化产率为(45±4)%(n=10),产品放化纯度大于99%,放射性浓度为370~550 MBq/mL,比活度为4.7TBq/mmol,产品细菌和热源检测结果符合规定。通过优化反应条件,大幅度提高了标记率,用国产合成模块能够制备高质量、高比活度的~(11)C-氟马西尼,满足临床应用需求。     

醋酸棉酚-~(14)C_2的合成

醋酸棉酚能抑制生精过程,是有希望的男性抗生育药物。本文合成了醋酸棉酚-~(14)C_2(Ⅰ)。先由甲酸-~(14)C与苯胺缩合成NN′-二苯基甲脒-1*~(14)C(Ⅱ)。Ⅱ与去甲酰棉酚(Ⅲ)反应成二苯胺基衍生物(Ⅳ),Ⅳ在硫酸水溶液中水解成(Ⅰ)。 反应式如下:     

5-HT_(1A)受体拮抗剂~(11)C-WAY-100635的自动化合成

为自动化合成用于5-羟色胺(5-HT_(1A))受体显像~(11)C标记的N-[2-[4-(2-甲氧基苯基)-1-哌嗪基]乙基]-N-2-吡啶基环己烷甲酰胺(~(11)C-WAY-100635),采用自动化合成模块,以去甲基WAY-100635为前体,经甲基化,HPLC纯化和Sep-Pak Plus C18柱去除有机溶剂制得~(11)C-WAY-100635注射液。结果显示,合成方法共耗时约40 min,~(11)C-WAY-100635注射液的未校正放化产率10%~20%,放化纯度97%;静脉注射日本大耳白兔~(11)C-WAY-100635(约111 MBq)后,脑组织放射性摄取显著,且明显高于头颅等其他组织。自动化合成5-HT_(1A)受体显像剂~(11)C-WAY-100635方法简单,反应时间较短,放化纯度高,产率稳定可靠,可在临床中推广应用。     

~(14)C-甲基托布津的制备

甲基托布津(C_(12)H_(14)N_4O_4S_2)为高效、低毒、广谱的内吸杀菌剂。其纯品为无色结晶。主要用于防治水稻纹枯病、稻瘟病、油菜菌核病等。我们采用1-氨基2(3-甲氧甲酰2′-硫脲基)苯胺为中间体来合成~(14)C-甲基托布津,合成线路如下:     

[2′,6′-~3H]除草醚和[2′,6′-~3H]草枯醚的合成

用合成法制备了[2’,6’-~3H]除草醚和[2’,6’-~3H]草枯醚。以间溴氯苯(Ⅰ)为起始原料,经催化卤-氚取代反应制得[3,5-~3H]氯苯(Ⅱ);然后用硝酸-浓硫酸的混合物硝化(Ⅱ)得[3,5-~3H]对氯硝基苯(Ⅲ);最后使(Ⅲ)分别与2,4-二氯苯酚或2,4,6-三氯苯酚起缩合反应生成[2’,6’-~3H]除草醚(Ⅳ)和[2’,6’-~3H]草枯醚(Ⅴ),比活度分别为1.16TBq/mol和1.89TBq/mol,放化纯度均大于95％。     

心肌显像剂锝-99m-胺苯缩硫脲的合成及其初步动物实验

3-(对三甲氨乙基)-苯丙烷-2,3-二酮-双(N-甲基缩氨基硫脲)-碘化物(p-TPA-DTS)是由氨乙基苯为原料,通过甲基化、丙酰化、亚硝基化和与甲缩氨基硫脲缩合及季铵化合成的。该化合物在pH3的水溶液中,由氯化亚锡还原高锝酸钠制备而得狸-99m-胺苯缩硫脲,本品用兔实验显示清晰的心肌显像,并能迅速经肝脏细胞运行。     

Hydrodynamic characteristics of lead and lead-bismuth coolants

The results of an analysis of the effect of the physical properties of lead and lead-bismuth coolants on the hydrodynamic characteristics and the results of experimental investigations of the particulars of the hydrodynamic flows of these coolants in application to loops with fast reactors are presented. It is shown that cavitation, in the conventional meaning of this word, cannot arise in flow part of vane pumps pumping lead and lead-bismuth coolants in a reactor loop. It is confirmed that a gas gap can form between the surface of a heavy liquid-metal coolant flow and the channel walls not wetted by it. The results of experimental studies of the rupture of a column of heavy liquid-metal coolant and detachment of a centrifugal pump flow, probably because of the appearance of gas cavitation, are presented.     

基于CFD数值模拟的复合叶轮核主泵压力脉动特性研究

为了降低核主泵在不同工况下运行时的压力脉动,采用数值模拟对核主泵3种不同进口直径的短叶片进行对比。结果表明：短叶片进口直径的改变并未改变叶轮的主频,但随着短叶片进口直径的增加,背面高频值逐渐减小,而工作面高频值却逐渐增大。在小流量工况下不同进口直径的短叶片的压力脉动幅值均较大;在设计工况下叶片背面各监测点在低频区与高频区域的波动能量明显大于叶片工作面各监测点在低频区和高频区的波动能量;大流量工况下叶片背面附近各监测点的低频区带宽及高频区的脉动能量明显增加,叶片工作面附近各监测点的脉动幅值出现较大的增加,短叶片背面附近各监测点的脉动幅值明显高于长叶片背面的脉动幅值。分析结果表明：短叶片进口直径为0.72D₂时,压力脉动在各种工况下运行最小。     

金的找矿标志——黄铁矿的穆斯堡尔谱

火成岩中浸染状及网脉状金银矿床中,自然金常产在黄铁矿中。破碎带经历多次构造活动,经应力作用改造而成,从而也引起多次热液活动的发生。从玲珑和新城两矿区大量的岩矿鉴定资料来看,其中低温脉旁交代黄铁绢英岩化作用与金的矿化有关。按热液活动的产物,不同的共生组合分为三个阶段:第Ⅰ成矿阶段。银金矿——绢云母——石英菱铁矿——黄铁矿阶段。第Ⅱ成矿阶段。银金矿——绢云母——石英——多金属硫化物阶段。第Ⅲ成矿阶段。     

A new method for studying the process of sublimation of metals

A new method is proposed for determining the heats of sublimation of metals by means of radioactive isotopes, which makes it possible to obtain continuous measurement of the speed of flow of the saturated vapor through a small opening. The radioactive isotope is introduced into the metal by melting; the uniformity of Its distribution is checked by means of autoradiography. The speed of flow of the saturated vapor out of a small opening into a vacuum is found from the increase of the radioactivity of a target, which is measured with a counter located near the target. The method makes it possible to observe continuously both the process of evaporation and the course of the process of condensation in time, and can also be used for the study of processes of diffusion in metals and alloys.     

Economic efficiency of radionuclide neutron sources

Conclusion The method considered here enables us to make comparative economic estimates at the stages of development and application of RNS in the solution of the following problems: determining the limits of competitiveness of RNS based on different radionuclides, and also of RNS and other types of NS, determining the efficiency of utilization of specific RNS in comparison with conventional methods of performing the work, justifying the nomenclature of RNS manufacture with specific radionuclides, justifying the unit power and the number of simultaneously used RNS, estimating the efficiency of utilization of different combinations of RNS that have been used for a specified time and of new RNS, determining the efficiency of the successive use of RNS in different regions as their power is depleted, justifying the desirability of chemical reprocessing of the RNS used, etc.Today the method is used in practice for different purposes. In particular, an estimate has been prepared for the economic efficiency of the chemical reprocessing of californium RNS that have been taken out of service. The method has also been used for determining the limit of RNS power above which chemical reprocessing is effective. It has been shown that the chemical reprocessing makes it possible to increase the output of californium and reduce the cost of its manufacture. Researchers have also determined the economically advantageous interval of reprocessing with due regard for the decay of californium and the desirability of increasing the batches reprocessed.Translated from Atomnaya Énergiya, Vol. 58, No. 5, pp. 355–359, May, 1985.     

不可压缩流中非对称板状结构模态局部化分析的摄动法

本文研究了一个两跨板状简单模型在不可压缩流中振动时的固有动特特。应用假设模态法建立系统的运动微分方程，应用摄动法看考虑了结构的长非对称及扭转刚度非对称对系统模态局部化程度的影响。结果表明，二阶摄动理论能很好地用于计算该系统的动态特性，水的耦合作用对上、下板模态局部化现象的影响有差异。长度非对称参数是导致结构模态产生局部化现象的主要原因，扭簧刚度扰动也对结构模态局部化现象有较大影响。     

Creep of high temperature steam piping: EDF experience with fossil-fired power plants from 1955 to 1987

Since 1955, EDF has maintained a constant policy of the systematic inspection of its high temperature piping. As these pipes are made of the same material, the measures taken in many plants are comparable.EDF can now, after 30 years of operation, analyse the availability of its means of measurement, the choice of the materials and of the calculation rules, the accuracy of the measurements, and finally the good behaviour of most of our pipes. Some particular cases of abnormal creep rate have been the subject of a particular study.     

钠冷快堆丧失蒸汽发生器模块后的最佳工况研究

钠冷快堆通过采用模块式蒸汽发生器的设计方案以提高核电厂的负荷因子。核电厂运行中若发生丧失蒸汽发生器模块事件,核电厂工况将发生变化,应进行适当的调节,调节的目标工况可通过设计与研究给出。本工作对某典型池式钠冷快堆丧失1个蒸汽发生器模块后的最佳工况进行研究,主要研究内容包括对其主热传输系统进行建模,开展主热参数匹配计算,根据相关运行限值来筛选方案并分析关键参数,最终给出较为合适的运行工况。本工作为钠冷快堆在丧失蒸汽发生器模块后的工况设计提供了重要依据。